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Sample records for metal sources identification

  1. Spatial assessment and source identification of heavy metals pollution in surface water using several chemometric techniques.

    Science.gov (United States)

    Ismail, Azimah; Toriman, Mohd Ekhwan; Juahir, Hafizan; Zain, Sharifuddin Md; Habir, Nur Liyana Abdul; Retnam, Ananthy; Kamaruddin, Mohd Khairul Amri; Umar, Roslan; Azid, Azman

    2016-05-15

    This study presents the determination of the spatial variation and source identification of heavy metal pollution in surface water along the Straits of Malacca using several chemometric techniques. Clustering and discrimination of heavy metal compounds in surface water into two groups (northern and southern regions) are observed according to level of concentrations via the application of chemometric techniques. Principal component analysis (PCA) demonstrates that Cu and Cr dominate the source apportionment in northern region with a total variance of 57.62% and is identified with mining and shipping activities. These are the major contamination contributors in the Straits. Land-based pollution originating from vehicular emission with a total variance of 59.43% is attributed to the high level of Pb concentration in the southern region. The results revealed that one state representing each cluster (northern and southern regions) is significant as the main location for investigating heavy metal concentration in the Straits of Malacca which would save monitoring cost and time. The monitoring of spatial variation and source of heavy metals pollution at the northern and southern regions of the Straits of Malacca, Malaysia, using chemometric analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Quantitative identification and source apportionment of anthropogenic heavy metals in marine sediment of Hong Kong

    Science.gov (United States)

    Zhou, Feng; Guo, Huaicheng; Liu, Lei

    2007-10-01

    Based on ten heavy metals collected twice annually at 59 sites from 1998 to 2004, enrichment factors (EFs), principal component analysis (PCA) and multivariate linear regression of absolute principal component scores (MLR-APCS) were used in identification and source apportionment of the anthropogenic heavy metals in marine sediment. EFs with Fe as a normalizer and local background as reference values was properly tested and suitable in Hong Kong, and Zn, Ni, Pb, Cu, Cd, Hg and Cr mainly originated from anthropogenic sources, while Al, Mn and Fe were derived from rocks weathering. Rotated PCA and GIS mapping further identified two types of anthropogenic sources and their impacted regions: (1) electronic industrial pollution, riparian runoff and vehicle exhaust impacted the entire Victoria Harbour, inner Tolo Harbour, Eastern Buffer, inner Deep Bay and Cheung Chau; and (2) discharges from textile factories and paint, influenced Tsuen Wan Bay and Kwun Tong typhoon shelter and Rambler Channel. In addition, MLR-APCS was successfully introduced to quantitatively determine the source contributions with uncertainties almost less than 8%: the first anthropogenic sources were responsible for 50.0, 45.1, 86.6, 78.9 and 87.5% of the Zn, Pb, Cu, Cd and Hg, respectively, whereas 49.9% of the Ni and 58.4% of the Cr came from the second anthropogenic sources.

  3. Source identification of heavy metal contamination using metal association and Pb isotopes in Ulsan Bay sediments, East Sea, Korea

    International Nuclear Information System (INIS)

    Chae, Jung Sun; Choi, Man Sik; Song, Yun Ho; Um, In Kwon; Kim, Jae Gon

    2014-01-01

    Highlights: • The levels of Cu, Zn, and Pb in sediments were higher than the Korean TEL at one-third of all sites. • The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor. • Three different anthropogenic sources and background sediments could be identified as endmembers using Pb isotopes. • The major anthropogenic Pb sources were identified as imported ores from Australia and Peru. • Isotope ratios in anthropogenic Pb discharged from Ulsan Bay to offshore could be identified. - Abstract: To determine the characteristics of metal pollution sources in Ulsan Bay, East Sea, 39 surface and nine core sediments were collected within the bay and offshore area, and analyzed for metals and stable lead (Pb) isotopes. Most surface sediments (>95% from 48 sites) had high copper (Cu), zinc (Zn), cadmium (Cd), and Pb concentrations that were as much as 1.3 times higher than background values. The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor, and the next largest source was from shipbuilding companies located at the mouth of the Taehwa River. Three different anthropogenic sources and background sediments could be identified as end-members using Pb isotopes. Isotopic ratios for the anthropogenic Pb revealed that the sources were imported ores from Australia, Peru, and the United States. In addition, Pb isotopes of anthropogenic Pb discharged from Ulsan Bay toward offshore could be determined

  4. Source identification of heavy metals in atmospheric dust using Platanus orientalis L. leaves as bioindicator

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    Samira Norouzi

    2015-07-01

    Full Text Available Studies on atmospheric dust have been limited by the high cost of instrumental monitoring methods and also sampling difficulties. The use of organisms acting as bioaccumulators has recently been proposed. In this study, the leaves of Platanus orientalis L., as a possible biomonitor of heavy metals in atmospheric dust, were evaluated to understand the likely source(s of pollution in Isfahan, Iran. Concentration of Zn, Cu, Ni and Mn and Magnetic susceptibility (χlf were determined in washed (WL and unwashed leaves (UL, monthly sampled from May to Nov., 2012. By subtracting the amount of metal concentrations and χlf in UL and WL, the amount of these parameters in dust deposited on the leaves (UL-WL were calculated. Enrichment factor analysis (EF, correlation coeficient, principal component analysis (PCA and cluster analysis (CA on the UL-WL data were employed to trace the heavy metals sources. Results showed that the metal concentration in UL and WL in primary sampling times was not statistically different. As time passed, this difference became more noticeable. Seasonal accumulation trends of elements concentration in UL-WL, referred to as accumulative biomonitors showing the accumulation of dust on the leaves are considerable and the contamination of plants by metal occurs mainly by retention of particulate matter. All the heavy metals are well correlated with χlf, indicating the potential of magnetic measurement as an inexpensive and less laborious method to estimate heavy metals. Cu and Zn exhibited a very strong correlation with each other and the highest correlation with χlf, suggesting an anthropogenic nature of these two metals. High EF of Cu and Zn showed that anthropogenic sources contribute a substantial amount of these metals to dust deposited on leaves. Whereas, less EF for Mn and Ni shows that natural source and local polluted soils might be the main origins of these metals. PCA results showed 2 principal components. Factor 1 with

  5. Characterization, source identification and apportionment of selected metals in TSP in an urban atmosphere.

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    Shah, Munir H; Shaheen, N; Jaffar, M

    2006-03-01

    To understand the metal distribution characteristics in the atmosphere of urban Islamabad, total suspended particulate (TSP) samples were collected on daily 12 h basis, at Quaid-i-Azam University campus, using high volume sampler. The TSP samples were treated with HNO(3)/HClO(4) based wet digestion method for the quantification of eight selected metals; Fe, Zn, Pb, Mn, Cr, Co, Ni and Cd by FAAS method. The monitoring period ran from June 2001 to January 2002, with a total of 194 samples collected on cellulose filters. Effects of different meteorological conditions such as temperature, relative humidity, wind speed and wind direction on selected metal levels were interpreted by means of multivariate statistical approach. Enhanced metal levels for Fe (930 ng/m(3)), Zn (542 ng/m(3)) and Pb (210 ng/m(3)) were found on the mean scale while Mn, Cr, Co and Ni emerged as minor contributors. Statistical correlation study was also conducted and a strong correlation was observed between Pb-Cr (r=0.611). The relative humidity showed some significant influence on atmospheric metal distribution while other meteorological parameters showed weak relationship with TSP metal levels. Regarding the origin of sources of heavy metals in TSP, the statistical procedure identified three source profiles; automobile emissions, industrial/metallurgical units, and natural soil dust. The metal levels were also compared with those reported for other parts of the world which showed that the metal levels in urban atmosphere of Islamabad are in exceedence than those of European industrial and urban sites while comparable with some Asian sites.

  6. Source Identification of Heavy Metals in Soils Surrounding the Zanjan Zinc Town by Multivariate Statistical Techniques

    Directory of Open Access Journals (Sweden)

    M.A. Delavar

    2016-02-01

    Full Text Available Introduction: The accumulation of heavy metals (HMs in the soil is of increasing concern due to food safety issues, potential health risks, and the detrimental effects on soil ecosystems. HMs may be considered as the most important soil pollutants, because they are not biodegradable and their physical movement through the soil profile is relatively limited. Therefore, root uptake process may provide a big chance for these pollutants to transfer from the surface soil to natural and cultivated plants, which may eventually steer them to human bodies. The general behavior of HMs in the environment, especially their bioavailability in the soil, is influenced by their origin. Hence, source apportionment of HMs may provide some essential information for better management of polluted soils to restrict the HMs entrance to the human food chain. This paper explores the applicability of multivariate statistical techniques in the identification of probable sources that can control the concentration and distribution of selected HMs in the soils surrounding the Zanjan Zinc Specialized Industrial Town (briefly Zinc Town. Materials and Methods: The area under investigation has a size of approximately 4000 ha.It is located around the Zinc Town, Zanjan province. A regular grid sampling pattern with an interval of 500 meters was applied to identify the sample location, and 184 topsoil samples (0-10 cm were collected. The soil samples were air-dried and sieved through a 2 mm polyethylene sieve and then, were digested using HNO3. The total concentrations of zinc (Zn, lead (Pb, cadmium (Cd, Nickel (Ni and copper (Cu in the soil solutions were determined via Atomic Absorption Spectroscopy (AAS. Data were statistically analyzed using the SPSS software version 17.0 for Windows. Correlation Matrix (CM, Principal Component Analyses (PCA and Factor Analyses (FA techniques were performed in order to identify the probable sources of HMs in the studied soils. Results and

  7. Identification of sources of heavy metals in the Dutch atmosphere using air filter and lichen analysis

    International Nuclear Information System (INIS)

    de Bruin, M.; Wolterbeek, H.T.

    1984-01-01

    Aerosol samples collected in an industrialized region were analyzed by instrumental neutron activation analysis. Correlation with wind direction and factor analysis were applied to the concentration data to obtain information on the nature and position of the sources. Epiphytic lichens were sampled over the country and analyzed for heavy metals (As, Cd, Sc, Zn, Sb). The data were interpreted by geographically plotting element concentrations and enrichment factors, and by factor analysis. Some pitfalls are discussed which are associated with the use of aerosol and lichen data in studies of heavy metal air pollution. 14 references, 8 figures, 3 tables

  8. Deposition behavior, risk assessment and source identification of heavy metals in reservoir sediments of Northeast China.

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    Zhu, Lin; Liu, Jianwei; Xu, Shiguo; Xie, Zaigang

    2017-08-01

    Sediment cores from five reservoirs, located in the Liaoning and Jilin Provinces in Northeast China, were collected to investigate the accumulation and potential toxicity of heavy metals (Fe, Mn, Cu, Cd, Pb, Zn, and Cr) during a sampling campaign in February, 2015. The results showed that all the detected metals accumulated significantly, especially Cd, compared to their respective background values. Among these reservoirs, Biliuhe Reservoir had markedly increasing trends for organic matter and all the metals, among which Mn was elevated by 280% to 3411mg/kg in a core of only 18cm in depth. Xinlicheng Reservoir was characterized by heavy siltation and varying metal distribution due to its regular geometric features and pulsed flood events. The Enrichment factor (EF) and geo-accumulation index (I geo ) indicated Cd was strongly enriched by anthropogenic inputs, with the values of EF and I geo greater than 8 and 3, respectively. The toxicity assessment calculated using consensus-based sediment quality guidelines (SQGs) implied the whole cores of Tanghe and Dahuofang and the upper cores of Biliuhe, Xinlicheng and Fengman exhibited toxicity to sediment-dwelling organisms. Cr contributed more to Q m-PEC than the other heavy metals, because only Cr exceeded the probable effect concentration (PEC) despite its low enrichment. According to the results of correlation analysis (CA) and principal components analysis (PCA), mining industries and agricultural activities within the basin were the main anthropogenic pollution sources for these heavy metals. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Source identification and apportionment of heavy metals in urban soil profiles.

    Science.gov (United States)

    Luo, Xiao-San; Xue, Yan; Wang, Yan-Ling; Cang, Long; Xu, Bo; Ding, Jing

    2015-05-01

    Because heavy metals (HMs) occurring naturally in soils accumulate continuously due to human activities, identifying and apportioning their sources becomes a challenging task for pollution prevention in urban environments. Besides the enrichment factors (EFs) and principal component analysis (PCA) for source classification, the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) and Pb isotopic mixing model were also developed to quantify the source contribution for typical HMs (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in urban park soils of Xiamen, a representative megacity in southeast China. Furthermore, distribution patterns of their concentrations and sources in 13 soil profiles (top 20 cm) were investigated by different depths (0-5, 5-10, 10-20 cm). Currently the principal anthropogenic source for HMs in urban soil of China is atmospheric deposition from coal combustion rather than vehicle exhaust. Specifically for Pb source by isotopic model ((206)Pb/(207)Pb and (208)Pb/(207)Pb), the average contributions were natural (49%)>coal combustion (45%)≫traffic emissions (6%). Although the urban surface soils are usually more contaminated owing to recent and current human sources, leaching effects and historic vehicle emissions can also make deep soil layer contaminated by HMs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Source identification, geochemical normalization and influence factors of heavy metals in Yangtze River Estuary sediment.

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    Sun, Xueshi; Fan, Dejiang; Liu, Ming; Tian, Yuan; Pang, Yue; Liao, Huijie

    2018-06-18

    Sediment samples, including 40 surface samples and 12 sediment cores, were collected from 52 stations of the Yangtze River Estuary (YRE) in 2015 and 2016. The 95% linear prediction intervals (LPI) and principal components analysis (PCA), were conducted to evaluate the metal sources and grain-size effect (GSE). The in situ physico-chemical properties of pH, Eh, DO, salinity, temperature and turbidity were combined to elucidate the relationships between environmental factors and the fate of heavy metals in the river-estuary-shelf system. This study indicates a decreasing trend of metals in sediments from the estuary towards the adjacent shelf and the river channel and that Zn, Cu and Cr are mainly derived from natural processes throughout the catchment, whereas Pb appears to have anthropogenic inputs via atmospheric deposition. Furthermore, considering the best fit regression lines between the concentrations of Al and heavy metals as well as the deficiencies of the conventional C elements /C Al method, we introduce an approach (Al-SN: Al-scope normalization) that can eliminate the GSE on heavy metals and be applied to other estuaries. After Al-scope normalization, the relatively constant levels of Zn, Cu and Cr that remain in sediments from the river channel to the estuary and shelf confirmed that the variation of grain size in sediments almost entirely explained the distribution patterns of sediment toxicity in the YRE, while the enrichment of Pb in estuarine sediments could be attributed to its chemical species and physico-chemical properties. The results further suggest that the relationship between grain size and spatial behavior of sediment pollutants should be given priority over the contamination assessment and provenance discrimination in estuarine or similar environments with complex sediment compositions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Assessment and source identification of trace metals in the soils of greenhouse vegetable production in eastern China.

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    Yang, Lanqin; Huang, Biao; Hu, Wenyou; Chen, Yong; Mao, Mingcui

    2013-11-01

    Worldwide concern about the occurrence of trace metals in greenhouse vegetable production soils (GVPS) is growing. In this study, a total of 385 surface GVPS samples were collected in Shouguang and four vegetable production bases in Nanjing, Eastern China, for the determination of As and Hg using atomic fluorescence spectrometry and Pb, Cu, Cd, and Zn using inductively coupled plasma-mass spectrometry. Geo-accumulation indices and factor analysis were used to investigate the accumulation and sources of the trace metals in soils in Eastern China. The results revealed that greenhouse production practices increased accumulation of the trace metals, particularly Cd, Zn, and Cu in soils and their accumulation became significant with increasing years of cultivation. Accumulation of Cd and Zn was also found in soils from organic greenhouses. The GVPS was generally less polluted or moderately polluted by As, Cu, Zn, and Pb but heavily polluted by Cd and Hg in some locations. Overall, accumulation of Cd, Zn, and Cu in GVPS was primarily associated with anthropogenic activities, particularly, application of manure. The high level of Hg found in some sites was related to historical heavy application of Hg containing pesticides. However, further identification of Hg sources is needed. To reduce accumulation of the trace metals in GVPS, organic fertilizer application should be suggested through development and implementation of reasonable and sustainable strategies. © 2013 Elsevier Inc. All rights reserved.

  12. Pollution characteristics and source identification of trace metals in riparian soils of Miyun Reservoir, China.

    Science.gov (United States)

    Han, Lanfang; Gao, Bo; Lu, Jin; Zhou, Yang; Xu, Dongyu; Gao, Li; Sun, Ke

    2017-10-01

    The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline soils into Miyun Reservoir (MYR). Here, riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206 Pb/ 207 Pb and 208 Pb/ 207 Pb values of soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Heavy metal pollution assessment, source identification, and health risk evaluation in Aibi Lake of northwest China.

    Science.gov (United States)

    Zhaoyong, Zhang; Xiaodong, Yang; Shengtian, Yang

    2018-01-08

    This study sought to analyze heavy metal (Pb, Zn, Cu, Ni, Mn, and Fe) pollution status in the waters of Aibi Lake in northwest China through the use of an applied comprehensive pollution index, health risk model, and multivariate statistical analyses in combination with the lake's land use types. Results showed that (1) the maximum (average) values of the heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 0.0644 (0.0123), 0.0006 (0.0002), 0.0009 (0.0032), 0.1235 (0.0242), 0.0061 (0.0025), and 0.0222 (0.0080) μg/L, respectively. Among these, in all the samples, Pb and Ni exceeded the standard and acceptable values put forth by the World Health Organization by 21.13 and 25.67%, respectively. Ni also exceeded (30.16%) the third grade of the Environmental Quality Standards for Surface Water of China. The levels of the six heavy metals were all within the fishery and irrigation water quality standard ranges in China. (2) The average values for single pollution index of heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 1.000, 0.0006, 0.0009, 3.000, 0.060, and 0.070, respectively, among which Ni levels indicated moderate to significant pollution, while others indicated healthy levels. (3) Health risk evaluation showed that the R n values for Pb, Zn, Cu, Mn, and Fe were 1.8 × 10 -4 , 5.33 × 10 -9 , 4.80 × 10 -7 , 1.08 × 10 -6 , and 2.51 × 10 -7  a -1 , respectively, of which, in all samples, Pb and Ni contents all exceeded the maximum acceptable risk levels according to the International Commission on Radiological Protection (ICRP) as well as the U.S. Environment Protection Agency. (4) Combining with multivariate statistical analyses along with the land use distribution within the lake basin, Pb, Zn, Cu, Ni, and Mn were mainly influenced by the agriculture production and emission from urban lives and traffics, and Fe mainly originated from the natural environment. The results of this research can provide reference values for heavy metal pollution

  14. Distribution and Identification of Sources of Heavy Metals in the Voghji River Basin Impacted by Mining Activities (Armenia

    Directory of Open Access Journals (Sweden)

    A. V. Gabrielyan

    2018-01-01

    Full Text Available The objective of this research is to assess the distribution of heavy metals in the waters and sediments of the Voghji River and its tributaries impacted by mining activity and to reveal the real source of each of the heavy metals in the environment for assessing the pollution level of heavy metals. Voghji River with two main tributaries (Geghi and Norashenik drain two mining regions. To identify distribution and pollution sources of heavy metals, the water and sediment samples were collected from eight sampling sites. The results of statistical analysis based on data sets of the period 2014–2016 showed that, after the influence of drainage water and wastewater of mining regions, heavy metal contents in the Voghji River basin dramatically increased. The waters of the Voghji River were highly polluted by Mn, Co, Cu, Zn, Mo, Cd, and Pb. The relation of metals content was highly changed due to anthropogenic impact disturbing the geochemical balance of the Voghji River. The water quality based on only heavy metal contents in the source of the Voghji River belongs to “good” chemical status, and in the sources of Geghi and Norashenik Rivers it is “moderate.” The water quality of Voghji and Norashenik Rivers is sharply worsening after the influence of mining activity, becoming “bad” chemical status. The research revealed the pollution sources of each metal.

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

    Science.gov (United States)

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

    2015-09-01

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

  16. Spatial distribution and source identification of heavy metals in surface soils in a typical coal mine city, Lianyuan, China.

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    Liang, Jie; Feng, Chunting; Zeng, Guangming; Gao, Xiang; Zhong, Minzhou; Li, Xiaodong; Li, Xin; He, Xinyue; Fang, Yilong

    2017-06-01

    In this study, we investigated the pollution degree and spatial distribution of heavy metals and determined their sources in topsoil in a typical coal mine city, Lianyuan, Hunan Province, China. We collected 6078 soil surface samples in different land use types. And the concentrations of Zn, Cd, Cu, Hg, Pb, Sb, As, Mo, V, Mn, Fe and Cr were measured. The average contents of all heavy metals were lower than their corresponding Grade II values of Chinese Soil Quality Standard with the exception of Hg. However, average contents of twelve heavy metals, except for Mn, exceeded their background level in soils in Hunan Province. Based on one-way analysis of variance (ANOVA), the contents of Cu, Zn, Cd, Pb, Hg, Mo and V were related to the anthropogenic source and there were statistically significant differences in their concentrations among different land use patterns. The spatial variation of heavy metal was visualized by GIS. The PMF model was used to ascertain contamination sources of twelve heavy metals and apportion their source contributions in Lianyuan soils. The results showed that the source contributions of the natural source, atmospheric deposition, industrial activities and agricultural activities accounted for 33.6%, 26.05%, 23.44% and 16.91%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Transfer characteristic and source identification of soil heavy metals from water-level-fluctuating zone along Xiangxi River, three-Gorges Reservoir area].

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    Xu, Tao; Wang, Fei; Guo, Qiang; Nie, Xiao-Qian; Huang, Ying-Ping; Chen, Jun

    2014-04-01

    Transfer characteristics of heavy metals and their evaluation of potential risk were studied based on determining concentration of heavy metal in soils from water-level-fluctuating zone (altitude:145-175 m) and bank (altitude: 175-185 m) along Xiangxi River, Three Gorges Reservoir area. Factor analysis-multiple linear regression (FA-MLR) was employed for heavy metal source identification and source apportionment. Results demonstrate that, during exposing season, the concentration of soil heavy metals in water-level-fluctuation zone and bank showed the variation, and the concentration of soil heavy metals reduced in shallow soil, but increased in deep soil at water-level-fluctuation zone. However, the concentration of soil heavy metals reduced in both shallow and deep soil at bank during the same period. According to the geoaccumulation index,the pollution extent of heavy metals followed the order: Cd > Pb > Cu > Cr, Cd is the primary pollutant. FA and FA-MLR reveal that in soils from water-level-fluctuation zone, 75.60% of Pb originates from traffic, 62.03% of Cd is from agriculture, 64.71% of Cu and 75.36% of Cr are from natural rock. In soils from bank, 82.26% of Pb originates from traffic, 68.63% of Cd is from agriculture, 65.72% of Cu and 69.33% of Cr are from natural rock. In conclusion, FA-MLR can successfully identify source of heavy metal and compute source apportionment of heavy metals, meanwhile the transfer characteristic is revealed. All these information can be a reference for heavy metal pollution control.

  18. Pollution Assessment and Sources Identification of Heavy Metals in Surface Sediments from the Nantaizi Lake, Middle China

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    Ma, Jinlong; Li, Fei; Jia, Xiaolin; Zhang, Jingdong

    2018-01-01

    The total contents of heavy metal elements including Cr, Cd, Cu, Zn, Pb and As were investigated in sediments from the Nantaizi Lake in Hanyang district of Wuhan. The heavy metal pollution level of Nantaizi Lake was calculated by potential ecological risk index and the main sources of pollutants were researched by correlation analysis and principal component analysis. The results show that heavy metal concentration of Nantaizi Lake sediments is within the Chinese Environmental Quality Standard for Soils (GB 15618-1995) level-II standard limitation. According to the result of potential ecological risk index, ecological hazard rank of heavy metal element of Nantaizi Lake sediments is: Cd>Cu>As>Pb>Zn>Cr, and whole water environment of lake is slightly polluted. Through correlation analysis and principal component analysis, it is found that industrial sewage and domestic wastewater in human activities are the main contributors to heavy metal sources of Nantaizi Lake, and chemical processes, such as endogenous microbial activities of lake etc., also affect heavy metal sources in sediments simultaneously.

  19. Source identification of heavy metals in peri-urban agricultural soils of southeast China: An integrated approach.

    Science.gov (United States)

    Hu, Wenyou; Wang, Huifeng; Dong, Lurui; Huang, Biao; Borggaard, Ole K; Bruun Hansen, Hans Christian; He, Yue; Holm, Peter E

    2018-06-01

    Intensive human activities, in particular agricultural and industrial production have led to heavy metal accumulation in the peri-urban agricultural soils of China threatening soil environmental quality and agricultural product security. A combination of spatial analysis (SA), Pb isotope ratio analysis (IRA), input fluxes analysis (IFA), and positive matrix factorization (PMF) model was successfully used to assess the status and sources of heavy metals in typical peri-urban agricultural soils from a rapidly developing region of China. Mean concentrations of Cd, As, Hg, Pb, Cu, Zn and Cr in surface soils (0-20 cm) were 0.31, 11.2, 0.08, 35.6, 44.8, 119.0 and 97.0 mg kg -1 , respectively, exceeding the local background levels except for Hg. Spatial distribution of heavy metals revealed that agricultural activities have significant influence on heavy metal accumulation in the surface soils. Isotope ratio analysis suggested that fertilization along with atmospheric deposition were the major sources of heavy metal accumulation in the soils. Based on the PMF model, the relative contribution rates of the heavy metals due to fertilizer application, atmospheric deposition, industrial emission, and soil parent materials were 30.8%, 33.0%, 25.4% and 10.8%, respectively, demonstrating that anthropogenic activities had significantly higher contribution than natural sources. This study provides a reliable and robust approach for heavy metals source apportionment in this particular peri-urban area with a clear potential for future application in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Application of stochastic models in identification and apportionment of heavy metal pollution sources in the surface soils of a large-scale region.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2013-04-16

    As heavy metals occur naturally in soils at measurable concentrations and their natural background contents have significant spatial variations, identification and apportionment of heavy metal pollution sources across large-scale regions is a challenging task. Stochastic models, including the recently developed conditional inference tree (CIT) and the finite mixture distribution model (FMDM), were applied to identify the sources of heavy metals found in the surface soils of the Pearl River Delta, China, and to apportion the contributions from natural background and human activities. Regression trees were successfully developed for the concentrations of Cd, Cu, Zn, Pb, Cr, Ni, As, and Hg in 227 soil samples from a region of over 7.2 × 10(4) km(2) based on seven specific predictors relevant to the source and behavior of heavy metals: land use, soil type, soil organic carbon content, population density, gross domestic product per capita, and the lengths and classes of the roads surrounding the sampling sites. The CIT and FMDM results consistently indicate that Cd, Zn, Cu, Pb, and Cr in the surface soils of the PRD were contributed largely by anthropogenic sources, whereas As, Ni, and Hg in the surface soils mostly originated from the soil parent materials.

  1. Ecological risk assessment and source identification for heavy metals in surface sediment from the Liaohe River protected area, China.

    Science.gov (United States)

    Ke, Xin; Gui, Shaofeng; Huang, Hao; Zhang, Haijun; Wang, Chunyong; Guo, Wei

    2017-05-01

    Surface sediment samples collected from 19 sites in the Liaohe River protected area were analysed for heavy metals to evaluate their potential ecological risk. The results demonstrated that the degree of pollution from seven heavy metals decreases in the following sequence: cadmium(Cd)>arsenic(As)>copper(Cu)>nickel(Ni)>lead(Pb)>chromium(Cr)>zinc(Zn). The metal speciation analysis indicated that Cd, Pb and Zn were dominated by non-residual fractions and have high mobility and bioavailability, indicating significant anthropogenic sources. Based on the potential ecological risk index (PERI), geo-accumulation index (I geo ) and risk assessment code (RAC), Cd made the most dominant contribution, with a high to very high potential ecological risk being determined in this studied area. Moreover, in reference to the results of multivariate statistical analyses, we deduced that Cd and Zn originated from agriculture sources within the Liaohe River protected area, whereas Cu, Cr and Ni primarily originated from natural sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Source identification and exchangeability of heavy metals accumulated in vegetable soils in the coastal plain of eastern Zhejiang province, China.

    Science.gov (United States)

    Qiutong, Xu; Mingkui, Zhang

    2017-08-01

    Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL -1 CaCl 2 ). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the

  3. Distribution, source identification and health risk assessment of soil heavy metals in urban areas of Isfahan province, Iran

    Science.gov (United States)

    Rastegari Mehr, Meisam; Keshavarzi, Behnam; Moore, Farid; Sharifi, Reza; Lahijanzadeh, Ahmadreza; Kermani, Maryam

    2017-08-01

    The present study examines some heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) contents in urban soils of 23 cities in Isfahan province, central Iran. For this purpose, 83 topsoil samples were collected and analyzed by ICP-MS. Results showed that the concentrations of As, Cd, Cu, Pb and Zn are higher than background values, while Co, Cr and Ni concentrations are close to the background. Compared with heavy metal concentrations in selected cities around the world, As, Cd, Cu, Pb and Zn concentrations in urban soils of Isfahan are relatively enriched. Moreover, natural background concentrations of Co, Cr and Ni in Isfahan province soil are high and the apparent enrichment relative to other major cities of the world is due to this high background contents. Calculated contamination factor (CF) confirmed that As, Cd, Cu, Pb and Zn are extremely enriched in the urban soils. Furthermore, pollution load index (PLI) and Geoaccumulation index (Igeo) highlighted that highly contaminated cities are mostly affected by pollution from traffic, industries and Shahkuh Pb-Zn mine. Based on hazard quotients (HQ), hazard index (HI) and cancer risk (CR) calculated in this study, human health risk (particularly for Pb and Cd) have reached alarming scales. Results from principle component analysis (PCA) and positive matrix factorization (PMF) introduces three sources for soils heavy metals including mine and industries (mainly for Pb, Zn, Cd and As); urban activities (particularly for Cu, Pb and Zn); and geogenic source (Ni, Co and Cr).

  4. Distribution, source identification, and ecological risk assessment of heavy metals in wetland soils of a river-reservoir system.

    Science.gov (United States)

    Jiang, Xiaoliang; Xiong, Ziqian; Liu, Hui; Liu, Guihua; Liu, Wenzhi

    2017-01-01

    The majority of rivers in the world have been dammed, and over 45,000 large reservoirs have been constructed for multiple purposes. Riparian and reservoir shorelines are the two most important wetland types in a dammed river. To date, few studies have concerned the heavy metal pollution in wetland soils of these river-reservoir systems. In this study, we measured the concentrations of ten heavy metals (Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, and Zn) in surface soils collected from riparian and reservoir shorelines along the Han River in different seasons. Our results found that the Co, Cu, and Ni concentrations in riparian wetlands were significantly lower than those in reservoir shorelines. In riparian wetlands, only soil Sr concentration significantly increased after summer and autumn submergence. Multivariate statistical analyses demonstrated that Ba and Cd might originate from industrial and mining sources, whereas Sr and Mn predominantly originated from natural rock weathering. The ecological risk assessment analysis indicated that both riparian and reservoir shorelines along the Han River in China exhibited a moderate ecological risk in soil heavy metals. The upper Han River basin is the water resource area of China's Middle Route of the South-to-North Water Transfer Project. Therefore, to control the contamination of heavy metals in wetland soils, more efforts should be focused on reducing the discharge of mining and industrial pollutants into the riparian and reservoir shorelines.

  5. Metal extent in blood of livestock from Dandora dumping site, Kenya: Source identification of Pb exposure by stable isotope analysis

    International Nuclear Information System (INIS)

    Nakata, Hokuto; Nakayama, Shouta M.M.; Ikenaka, Yoshinori; Mizukawa, Hazuki; Ishii, Chihiro; Yohannes, Yared B.; Konnai, Satoru; Darwish, Wageh Sobhy; Ishizuka, Mayumi

    2015-01-01

    Nairobi city in Kenya produces 2000 tons/day of garbage, and most of it is dumped onto the Dandora dumping site, home to a quarter-million residents. This study was conducted (1) to assess the contamination levels of nine metals and a metalloid (arsenic) in the blood of pigs, goats, sheep and cattle from Dandora, and (2) to identify a possible source of lead (Pb) pollution. Cadmium (Cd, 0.17–4.35 μg/kg, dry-wt) and Pb (90–2710 μg/kg) levels in blood were generally high, suggesting human exposure to Cd through livestock consumption and Pb poisoning among pigs (2600 μg/kg) and cattle (354 μg/kg). Results of Pb isotope ratios indicated that the major exposure route might differ among species. Our results also suggested a possibility that the residents in Dandora have been exposed to the metals through livestock consumption. - Highlights: • Metals extent in blood of livestock were examined. • Dandora dumping site, Kenya is study site. • Concentrations of Cd and Pb were high in the blood of livestock. • Pb isotope ratios indicated that major exposure route might differ among species. - Metal extent and stable Pb isotope ratio in livestock from Dandora, Kenya were examined

  6. Selective structural source identification

    Science.gov (United States)

    Totaro, Nicolas

    2018-04-01

    In the field of acoustic source reconstruction, the inverse Patch Transfer Function (iPTF) has been recently proposed and has shown satisfactory results whatever the shape of the vibrating surface and whatever the acoustic environment. These two interesting features are due to the virtual acoustic volume concept underlying the iPTF methods. The aim of the present article is to show how this concept of virtual subsystem can be used in structures to reconstruct the applied force distribution. Some virtual boundary conditions can be applied on a part of the structure, called virtual testing structure, to identify the force distribution applied in that zone regardless of the presence of other sources outside the zone under consideration. In the present article, the applicability of the method is only demonstrated on planar structures. However, the final example show how the method can be applied to a complex shape planar structure with point welded stiffeners even in the tested zone. In that case, if the virtual testing structure includes the stiffeners the identified force distribution only exhibits the positions of external applied forces. If the virtual testing structure does not include the stiffeners, the identified force distribution permits to localize the forces due to the coupling between the structure and the stiffeners through the welded points as well as the ones due to the external forces. This is why this approach is considered here as a selective structural source identification method. It is demonstrated that this approach clearly falls in the same framework as the Force Analysis Technique, the Virtual Fields Method or the 2D spatial Fourier transform. Even if this approach has a lot in common with these latters, it has some interesting particularities like its low sensitivity to measurement noise.

  7. Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

    Science.gov (United States)

    Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

    2017-10-06

    Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

  8. Size distribution and source identification of total suspended particulate matter and associated heavy metals in the urban atmosphere of Delhi.

    Science.gov (United States)

    Srivastava, Arun; Jain, V K

    2007-06-01

    A study of the atmospheric particulate size distribution of total suspended particulate matter (TSPM) and associated heavy metal concentrations has been carried out for the city of Delhi. Urban particles were collected using a five-stage impactor at six sites in three different seasons, viz. winter, summer and monsoon in the year 2001. Five samples from each site in each season were collected. Each sample (filter paper) was extracted with a mixture of nitric acid, hydrochloric acid and hydrofluoric acid. The acid solutions of the samples were analysed in five-particle fractions by atomic absorption spectrometry (AAS). The impactor stage fractionation of particles shows that a major portion of TSPM concentration is in the form of PM0.7 (i.e. metal mass viz. Mn, Cr, Cd, Pb, Ni, and Fe are also concentrated in the PM0.7 mode. The only exceptions are size distributions pertaining to Cu and Ca. Though, Cu is more in PM0.7 mode, its presence in size intervals 5.4-1.6microm and 1.6-0.7microm is also significant, whilst in case of Ca there is no definite pattern in its distribution with size of particles. The average PM10.9 (i.e. Source apportionment reveals that there are two sources of TSPM and PM10.9, while three and four sources were observed for PM1.6 (i.e. <1.6microm) and PM0.7, respectively. Results of regression analyses show definite correlations between PM10.9 and other fine size fractions, suggesting PM10.9 may adequately act as a surrogate for both PM1.6 and PM0.7, while PM1.6 may adequately act as a surrogate for PM0.7.

  9. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1977-01-01

    Identifications are suggested for 53 radio sources from the southern zones of the Parkes 2700-MHz survey, 32 with galaxies, 11 with suggested QSOs and 10 with confirmed QSOs. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar Sky Survey prints. Accurate optical positions have been measured for four of the new identifications and for two previously suggested identifications. A further nine previously suggested QSO identifications have also been confirmed by two-colour photography or spectroscopy. (author)

  10. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1976-01-01

    Identifications are suggested for 36 radio sources from the southern zones of the Parkes 2700 MHz survey, 28 with galaxies, six with confirmed and two with suggested quasi-stellar objects. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for nine of the objects and for five previously suggested identifications. (author)

  11. Source Identification and Sequential Leaching of Heavy Metals in Soil Samples Collected from Selected Dump Sites in Ekiti State, Nigeria

    OpenAIRE

    , E.E. Awokunmi; , S.S. Asaolu; , O.O Ajayi; , A.O. Adebayo

    2011-01-01

    Ten heavy metals (Fe, Cu, Mn, Zn, Pb, Ni, Co, Cd, Cr and Sn) in fractioned and bulk soil samples collected from four dump sites located in AdoEkiti and Ikere -Ekiti, South western Nigeria were analysed using a modified Tessier’s procedure and acid digestion to obtain the distribution pattern of metal in this region. The metals were found to have been distributed in all phases with Fe, Cr, and Sn dominating the residual fraction (90.12 - 94.88%), Co, Ni, Cu, and Zn were found in all the extrac...

  12. Sources identification and pollution evaluation of heavy metals in the surface sediments of Bortala River, Northwest China.

    Science.gov (United States)

    Zhang, Zhaoyong; Juying, Li; Mamat, Zulpiya; QingFu, Ye

    2016-04-01

    The current study focused on the Bortala River - a typical inland river located in an oasis of arid area in northwestern China. The sediment and soil samples were collected from the river and drainage basin. Results showed that: (1) the particle size of the sand fraction of the sediments was 78-697 µm, accounting for 78.82% of the total samples; the average concentrations of eight heavy metals fell within the concentration ranges recommended by the Secondary National Standard of China, while the maximum concentrations of Pb, Cd, and Hg exceeded these standards; (2) results from multivariate statistical analysis indicated that Cu, Ni, As, and Zn originated primarily from natural geological background, while Cd, Pb, Hg and Cr in the sediments originated from human activities; (3) results of the enrichment factor analysis and the geo-accumulation index evaluation showed that Cd, Hg, and Pb were present in the surface sediments of the river at low or partial serious pollution levels, while Zn, Cr, As, Ni, and Cu existed at zero or low pollution levels; (4) calculation of the potential ecological hazards index showed that among the eight tested heavy metals, Cd, Pb, Hg, and Cr were the main potential ecological risk factors, with relative contributions of 25.43%, 22.23%, 21.16%, and 14.87%, respectively; (5) the spatial distribution of the enrichment factors (EF(S)), the Geo-accumulation index (I(geo)), and the potential ecological risk coefficient (E(r)(i)) for eight heavy metals showed that there was a greater accumulation of heavy metals Pb, Cd, and Hg in the sediments of the central and eastern parts of the river. Results of this research can be a reference for the heavy metals pollution prevention, the harmony development of the ecology protection and the economy development of the oases of inland river basin of arid regions of China, Central Asia and also other parts of the world. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.

    1976-01-01

    Identifications are suggested for 32 radio sources from the southern zones of the Parkes 2700 MHz survey, 18 with galaxies, one with a confirmed and 12 with possible quasistellar objects, and one with a supernova remnant in the Large Magellanic Cloud. The identifications were made from the ESO IIa-O quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for 10 of the objects and for five previously suggested QSOs. (author)

  14. Identification of the sources of metal (lead) contamination in drinking waters in north-eastern Tasmania using lead isotopic compositions.

    Science.gov (United States)

    Harvey, P J; Handley, H K; Taylor, M P

    2015-08-01

    This study utilises a range of scientific approaches, including lead isotopic compositions, to differentiate unknown sources of ongoing lead contamination of a drinking water supply in north-eastern Tasmania, Australia. Drinking water lead concentrations are elevated above the Australian Drinking Water Guideline (10 μg/L), reaching 540 μg/L in the supply network. Water lead isotopic compositions from the town of Pioneer ((208)Pb/(207)Pb 2.406, (206)Pb/(207)Pb 1.144 to (208)Pb/(207)Pb 2.360, (206)Pb/(207)Pb 1.094) and Ringarooma ((208)Pb/(207)Pb 2.398, (206)Pb/(207)Pb 1.117) are markedly different from the local bedrock ((208)Pb/(207)Pb 2.496, (206)Pb/(207)Pb 1.237). The data show that the lead in the local waters is sourced from a combination of dilapidated drinking water infrastructure, including lead jointed pipelines, end-of-life polyvinyl chloride pipes and household plumbing. Drinking water is being inadvertently contaminated by aging infrastructure, and it is an issue that warrants investigation to limit the burden of disease from lead exposure.

  15. Identification of petroleum pollution sources

    International Nuclear Information System (INIS)

    Begak, O.Yu.; Syroezhko, A.M.

    2001-01-01

    A possibility of preliminary identification of petroleum pollution sources was investigated on specimens of the Khanty-Mansi autonomous district six deposits and specimens of soil and water polluted by these petroleums. Investigations were conducted using IR Fourier spectroscopy and gamma spectrometry, as well as methods of chromato-mass spectrometry and capillary gas liquid chromatography. Every of studied samples of petroleum from different deposits have an individual radiation impression. Insignificant total content of radionuclides in samples is specific to the Khanty-Mansi petroleum region. Gamma spectrometry admits to identify potential source of petroleum pollution using radionuclides of uranium and thorium series [ru

  16. The ecological risk, source identification, and pollution assessment of heavy metals in road dust: a case study in Rafsanjan, SE Iran.

    Science.gov (United States)

    Mirzaei Aminiyan, Milad; Baalousha, Mohammed; Mousavi, Rouhollah; Mirzaei Aminiyan, Farzad; Hosseini, Hamideh; Heydariyan, Amin

    2018-05-01

    Heavy metal (HM) contamination in road dust is a potential environmental and human health threat. The sources, concentrations, spatial distribution, and ecological risk of As, Cd, Cu, Cr, Ni, Pb, and Zn in road dust in Rafsanjan City, Iran, were investigated. Pollution was assessed using the enrichment factor (EF). The potentially harmful effects of HMs were evaluated by calculating the potential ecological risk factor of individual metals (E r ) and of multiple metals (RI) using the Hakanson method. Correlation and principal component analyses (PCA) were applied to identify HM pollution sources. The concentrations of HMs in road dust were higher (ca. 5-10 folds) than their natural background values. The EF and E r increased according to the following order Cu > Pb > As > Zn > Cd > Cr > Ni and Cu > Cd > Pb > As > Ni > Zn > Cr, respectively. Thus, Cu is regarded as the pollutant of highest concern. Based on potential ecological risk index (RI) spatial distribution, all parts of Rafsanjan are characterized by significantly high potential ecological risk. HM concentration heat maps, PCA, and correlation analysis suggest that Cu, Pb, As, Cd, and Zn may have originated from the same source and follow the same spatial distribution pattern. These metals originated mainly from anthropogenic sources like copper mining and smelting plants, industrial and chemical activities, inordinate application of chemical fertilizers and pesticides in farmlands, and heavy traffic. Ni and Cr are likely to origniate from the industrial activities and traffic load in Rafsanjan City.

  17. Metals and metalloids in precipitation collected during CHINARE campaign from Shanghai, China, to Zhongshan Station, Antarctica: Spatial variability and source identification

    Science.gov (United States)

    Shi, G.; Teng, J.; Ma, H.; Li, Y.; Sun, B.

    2015-06-01

    Metals and metalloids in continental precipitation have been widely observed, but the data over open oceans are still very limited. Investigation of metals and metalloids in marine precipitation is of great significance to understand global transport of these elements in the atmosphere and their input fluxes to the oceans. So shipboard sampling of precipitation was conducted during a Chinese National Antarctic Research Expedition campaign from Shanghai, China, to Zhongshan Station, East Antarctica, and 22 samples (including 17 rainfall and 5 snowfall events) were collected and analyzed for concentrations of Pb, Ni, Cr, Cu, Co, Hg, As, Cd, Sb, Se, Zn, Mn, and Ti. Results show that concentrations of both metals and metalloids vary considerably along the cruise, with higher concentrations at coastal sites and lower values on the south Indian Ocean. Although only soluble fractions were determined for elements, concentrations in this study are generally comparable to the reported values of marine rain. Enrichment factor analysis shows that most of metals and metalloids are enriched versus crustal sources, even in the samples collected from remote south Indian Ocean. In addition, metals and metalloids in precipitation are also very enriched above sea-salt abundance, indicating that impacts of sea-salt aerosols on their concentrations are negligible. Main sources of metals and metalloids were explored with the aid of multivariate statistical analyses. The results show that human emissions have far-reaching distribution, which may exert an important influence on the solubility of elements in precipitation. This investigation provides valuable information on spatial variation and possible sources of trace elements in precipitation over the open oceans corresponding to understudied region.

  18. [Source identification and potential ecological hazards assessment of trace metalloid/heavy metals in the soil of Tianshan Mountains, Xinjiang, China].

    Science.gov (United States)

    Zhang, Zhao-Yong; Jilili, Abuduwailil; Jiang, Feng-Qing

    2014-11-01

    In this study, the contents of ten metalloid/heavy metals (As, Pb, Ni, Cd, Co, Hg, Cu, Mn, Zn and Cr) in soil samples collected from three sections including the central Urumqi-Akesu, eastern Blikun-Yiwu and western Zhaosu-Tekesi in Tianshan Mountains were determined, and their sources were identified by using typical statistical and multivariate statistical methods. The potential ecological risks of these heavy metals were assessed by employing pollution index method, potential ecological risk index and the background values of Tianshan Mountains, and Xinjiang, and also the Second National Standard of the Soil Qualities of China. The results showed that the contents of the heavy metals (Pb, Ni, Cd, Co, Hg, Cu, Mn Zn and Cr) and metalloid As were all higher than the soil background values of the Tianshan Mountain or Xinjiang, and their variation co- efficients belonged to the medium variation. In general, the contents of the ten metalloid/heavy metals in the soil of Tianshan Mountains were low. Principal component analysis showed that the ten metalloid/heavy metals could be identified as two principal components, among which PC1 (Cd, Pb, Hg, Mn and Zn) could be seen as 'human influence sources factor', PC2 (Cu, Ni, Cr, Co and As) as 'natural sources factor'. Mn and As had larger loads both in PC1 and PC2, and they could be co-influenced by human and natural sources. The pollution assessment showed that Hg and Cd in central Urumuqi-Akesu section and As in western Zhaosu-Tekesi section were all at alert level, while the other heavy metals in other sections were all at security level. From the comprehensive pollution indices (P(z)) of heavy metals, it was found that the ten metalloid/heavy metals in the soils of central Urumqi-Akesu section were at low pollution level, but those in the other two sections were at clean level. The potential ecological risk assessment showed that the potential ecological risk coefficient (E(i)r) and the ecological damage index (RI) of Hg

  19. Risk Assessment and Source Identification of 17 Metals and Metalloids on Soils from the Half-Century Old Tungsten Mining Areas in Lianhuashan, Southern China

    OpenAIRE

    Guo, Li; Zhao, Weituo; Gu, Xiaowen; Zhao, Xinyun; Chen, Juan; Cheng, Shenggao

    2017-01-01

    Background: Mining activities always emit metal(loid)s into the surrounding environment, where their accumulation in the soil may pose risks and hazards to humans and ecosystems. Objective: This paper aims to determine of the type, source, chemical form, fate and transport, and accurate risk assessment of 17 metal(loid) contaminants including As, Cd, Cu, Ni, Pb, Zn, Cr, Ag, B, Bi, Co, Mo, Sb, Ti, V, W and Sn in the soils collected from an abandoned tungsten mining area, and to guide the imple...

  20. Multi-element characterization and source identification of trace metal in road dust from an industrial city in semi-humid area of Northwest China

    International Nuclear Information System (INIS)

    Mengmeng Zhang; Xinwei Lu; Hao Chen; Panpan Gao; Yi Fu

    2015-01-01

    Concentrations and sources of multi-elements in road dusts from an industrial city of northwest China were determined. Dust samples have elevated concentrations of Co, Cr, Cu, Pb, Zn, Sr and Ba. The dusts were mainly moderate enrichment by Co and Pb, minimal enrichment to moderate enrichment by Sr and Zn, and deficiency to minimal enrichment by other trace metals. Mn, V, Y, La, Hf, Th and U originated from soil. Cu, Pb, Cr, Ba and Sr mainly derived from traffic. Co, Zr, Ni, Ga, As and Zn have mixed sources of nature, industry and traffic. (author)

  1. Distribution, speciation, environmental risk, and source identification of heavy metals in surface sediments from the karst aquatic environment of the Lijiang River, Southwest China.

    Science.gov (United States)

    Xu, Daoquan; Wang, Yinghui; Zhang, Ruijie; Guo, Jing; Zhang, Wei; Yu, Kefu

    2016-05-01

    The distribution and speciation of several heavy metals, i.e., As, Cd, Cr, Cu, Hg, Pb, and Zn, in surface sediments from the karst aquatic environment of the Lijiang River, Southwest China, were studied comparatively. The mean contents of Cd, Cu, Hg, Pb, and Zn were 1.72, 38.07, 0.18, 51.54, and 142.16 mg/kg, respectively, which were about 1.5-6 times higher than their corresponding regional sediment background values. Metal speciation obtained by the optimized BCR protocol highlighted the bioavailable threats of Cd, Cu, and Zn, which were highly associated with the exchangeable fraction (the labile phase). Hierarchical cluster analysis indicated that in sediments, As and Cr were mainly derived from natural and industrial sources, whereas fertilizer application might lead to the elevated level of Cd. Besides, Cu, Hg, Pb, and Zn were related to traffic activities. The effects-based sediment quality guidelines (SQGs) showed that Hg, Pb, and Zn could pose occasional adverse effects on sediment-dwelling organisms. However, based on the potential ecological risk assessment (PER) and risk assessment code (RAC), Cd was the most outstanding pollutant and posed the highest ecological hazard and bioavailable risk among the selected metals. Moreover, the metal partitioning between water and sediments was quantified through the calculation of the pseudo-partitioning coefficient (K P), and result implied that the sediments in this karst aquatic environment cannot be used as stable repositories for the metal pollutants.

  2. 40 CFR 62.5103 - Identification of sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Identification of sources. 62.5103 Section 62.5103 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., Frederick, Maryland. [50 FR 9628, Mar. 11, 1985] Metals, Acid Gases, Organic Compounds and Nitrogen Oxide...

  3. 40 CFR 62.9140 - Identification of source.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Identification of source. 62.9140 Section 62.9140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...] Metals, Acid Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste...

  4. Assessment and source identification of pollution risk for touristic ports: Heavy metals and polycyclic aromatic hydrocarbons in sediments of 4 marinas of the Apulia region (Italy).

    Science.gov (United States)

    Mali, Matilda; Dell'Anna, Maria Michela; Mastrorilli, Piero; Damiani, Leonardo; Piccinni, Alberto Ferruccio

    2017-01-30

    The Apulia region in Italy has the longest Adriatic coastline; thus, maritime tourism is the driving force for its economic development. Pollution risk for four representative touristic ports of the region was assessed by determining the concentrations of 10 metals, 16 polycyclic aromatic hydrocarbons (PAHs) congeners, and the main nutrients. The cumulative mean Effects Range-Median quotient (mERMq) was used to assess the hazard degree, while the distribution patterns and content ratios of different PAH sediment concentrations were investigated to identify the pollution sources. Principal component analyses indicated an anomalous pollution trend for one of the small touristic ports assessed; this trend emerged from contamination by heavy metals and PAHs to a larger extent than expected, considering the main activity in this port, especially in its inner basin. The reason of this anomaly is thought to be the hydrodynamic and/or other stress factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Identification of heavy metals sources in the Mexico city atmosphere, using the proton induced x-ray analytical technique and multifactorial statistics techniques

    International Nuclear Information System (INIS)

    Hernandez M, B.

    1997-01-01

    The objectives of this work are: to identify the heavy metals present in the air, and its concentrations. To know the behavior from the polluting chemical elements to the long of an annual cycle corresponding to 1990, based on the concentrations of the same ones, obtained through the PIXE technique. To identify the suitable statistical methods to use to the data of metals concentration in form of total suspended particle (PST), found in this investigation. To relate the concentrations and the meteorological parameters considered to be able to suggest the possible pollution sources. In function of the obtained results, to serve as base to the decisions making and measures control that are planned by diverse institutions focused to the problem of the atmospheric pollution in the Metropolitan area of Mexico City (ZMCM). (Author)

  6. Risk Assessment and Source Identification of 17 Metals and Metalloids on Soils from the Half-Century Old Tungsten Mining Areas in Lianhuashan, Southern China.

    Science.gov (United States)

    Guo, Li; Zhao, Weituo; Gu, Xiaowen; Zhao, Xinyun; Chen, Juan; Cheng, Shenggao

    2017-11-29

    Background: Mining activities always emit metal(loid)s into the surrounding environment, where their accumulation in the soil may pose risks and hazards to humans and ecosystems. Objective : This paper aims to determine of the type, source, chemical form, fate and transport, and accurate risk assessment of 17 metal(loid) contaminants including As, Cd, Cu, Ni, Pb, Zn, Cr, Ag, B, Bi, Co, Mo, Sb, Ti, V, W and Sn in the soils collected from an abandoned tungsten mining area, and to guide the implementing of appropriate remediation strategies. Methods : Contamination factors ( CFs ) and integrated pollution indexes ( IPIs ) and enrichment factors ( EFs ) were used to assess their ecological risk and the sources were identified by using multivariate statistics analysis, spatial distribution investigation and correlation matrix. Results : The IPI and EF values indicated the soils in the mine site and the closest downstream one were extremely disturbed by metal(loid)s such as As, Bi, W, B, Cu, Pb and Sn, which were emitted from the mining wastes and acid drainages and delivered by the runoff and human activities. Arsenic contamination was detected in nine sites with the highest CF values at 24.70 next to the mining site. The Cd contamination scattered in the paddy soils around the resident areas with higher fraction of bioavailable forms, primarily associated with intense application of phosphorus fertilizer. The lithogenic elements V, Ti, Ag, Ni, Sb, Mo exhibit low contamination in all sampling points and their distribution were depended on the soil texture and pedogenesis process. Conclusions : The long term historical mining activities have caused severe As contamination and higher enrichment of the other elements of orebody in the local soils. The appropriate remediation treatment approach should be proposed to reduce the bioavailability of Cd in the paddy soils and to immobilize As to reclaim the soils around the mining site. Furthermore, alternative fertilizing way

  7. Multi-element sewer slime impact pattern--a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems.

    Science.gov (United States)

    Kintrup, J; Wünsch, G

    2001-11-01

    The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution. Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling. Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods. A new dimensionless characteristic "sewer slime impact" is proposed, which is zero for unloaded samples. Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto.

  8. Assessment of pollution and identification of sources of heavy metals in the sediments of Changshou Lake in a branch of the Three Gorges Reservoir.

    Science.gov (United States)

    Liang, Ao; Wang, Yechun; Guo, Hongtao; Bo, Lei; Zhang, Sheng; Bai, Yili

    2015-10-01

    To assess the heavy metal pollution in Changshou Lake, sediments were collected from nine sites at three periods (dry, normal, and wet) in 2013. The Hg, As, Cr, Cd, Pb, Cu, and Zn levels were then determined. The index of geoaccumulation (I geo) and the sediment pollution index (SPI) were applied to the sediment assessment, and Pearson's correlation analysis and factor analysis (FA) were performed to identify common pollution sources in the basin. The results showed that heavy metals presented significant spatial variations with Cr, Cd, Pb, Cu, Zn, Hg, and As concentrations of 29.66~42.58, 0.62~0.91, 24.91~37.96, 21.18~74.91, 41.65~86.86, 0.079~0.152, and 20.17~36.88 mg kg(-1), respectively, and no obvious variations were found among the different periods. The average contents of the metals followed the order Zn > Cu > Cr > Pb > As > Cd > Hg, which showed a high pollution in the sediments collected from open water and at the river mouth. The assessment results indicated that toxic heavy metals presented obvious pollution with I Hg of 0.64~1.36 (moderately polluted), I Cd of 1.66~2.22 (moderately to heavily polluted), and I As of 1.21~2.07 (moderately to heavily polluted). The heavy metal pollution states followed the order Cd > As > Hg > Cu > Pb > Zn > Cr, and the SPI showed that the sediment collected from open water area was more polluted than those obtained from the tributaries and the river mouth. Cr, Cd, Hg, Pb, Cu, As, and Zn were mainly attributed to sediment weathering with Hg, Pb, and Cu and partially due to domestic sewage from the upper reaches. These results indicate that the more attention should be paid to the inner loads of sediment in order to achieve improvements in reservoir water quality after the control of external pollution.

  9. Risk Assessment and Source Identification of 17 Metals and Metalloids on Soils from the Half-Century Old Tungsten Mining Areas in Lianhuashan, Southern China

    Directory of Open Access Journals (Sweden)

    Li Guo

    2017-11-01

    Full Text Available Background: Mining activities always emit metal(loids into the surrounding environment, where their accumulation in the soil may pose risks and hazards to humans and ecosystems. Objective: This paper aims to determine of the type, source, chemical form, fate and transport, and accurate risk assessment of 17 metal(loid contaminants including As, Cd, Cu, Ni, Pb, Zn, Cr, Ag, B, Bi, Co, Mo, Sb, Ti, V, W and Sn in the soils collected from an abandoned tungsten mining area, and to guide the implementing of appropriate remediation strategies. Methods: Contamination factors (CFs and integrated pollution indexes (IPIs and enrichment factors (EFs were used to assess their ecological risk and the sources were identified by using multivariate statistics analysis, spatial distribution investigation and correlation matrix. Results: The IPI and EF values indicated the soils in the mine site and the closest downstream one were extremely disturbed by metal(loids such as As, Bi, W, B, Cu, Pb and Sn, which were emitted from the mining wastes and acid drainages and delivered by the runoff and human activities. Arsenic contamination was detected in nine sites with the highest CF values at 24.70 next to the mining site. The Cd contamination scattered in the paddy soils around the resident areas with higher fraction of bioavailable forms, primarily associated with intense application of phosphorus fertilizer. The lithogenic elements V, Ti, Ag, Ni, Sb, Mo exhibit low contamination in all sampling points and their distribution were depended on the soil texture and pedogenesis process. Conclusions: The long term historical mining activities have caused severe As contamination and higher enrichment of the other elements of orebody in the local soils. The appropriate remediation treatment approach should be proposed to reduce the bioavailability of Cd in the paddy soils and to immobilize As to reclaim the soils around the mining site. Furthermore, alternative fertilizing

  10. Multi-element sewer slime impact pattern - a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems

    Energy Technology Data Exchange (ETDEWEB)

    Kintrup, J. [Chemistry Lab., Wessling GmbH, Hannover (Germany); Wuensch, G. [Lehrgebiet Analytische Chemie, Univ. Hannover (Germany)

    2001-11-01

    The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution. Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling. Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods. A new dimensionless characteristic ''sewer slime impact'' is proposed, which is zero for unloaded samples. Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto. (orig.)

  11. Identification of oil spill's sources

    International Nuclear Information System (INIS)

    Boniforti, R.

    1992-10-01

    Identifying the source of a marine oil spill is complicated because of the rapid modifications (weathering) undergone by oil as soon as it reaches the sea. Deciding if differences occurring between an oil sample collected after the spill and the original oil can be attributed to weathering involves not only adoption of sophisticated analytical methods but also correct sampling techniques and strict adherence to a chain-of-custody procedure. The method described in this paper, largely based on those adopted by some northern European countries, establishes the identity or non-identity of two samples by exploiting differences rather than similarities between them. It increases the efficiency of the method because it is sufficient to establish that there exists only one difference for deciding that two samples are different

  12. Identifications of Einstein Slew Survey sources

    Science.gov (United States)

    Schachter, Jonathan F.; Elvis, Martin S.; Plummer, David; Fabbiano, G.

    1992-01-01

    The status of identifications of the Einstien Slew Survey, a bright soft x-ray catalog with 550 new x-ray sources, is discussed. Possible counterparts were found for greater than 95 percent of the Slew Survey based on positional coincidences and color-color diagnostics. The survey will be fully identified via upcoming radio and optical observations.

  13. Metal vapor vacuum arc ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

    1990-06-01

    We have developed a family of metal vapor vacuum are (MEVVA) high current metal ion sources. The sources were initially developed for the production of high current beams of metal ions for heavy ion synchrotron injection for basic nuclear physics research; more recently they have also been used for metal ion implantation. A number of different embodiments of the source have been developed for these specific applications. Presently the sources operate in a pulsed mode, with pulse width of order 1 ms and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV, and since the ions produced in the vacuum arc plasma are in general multiply ionized the ion energy is up to several hundred keV. Beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Nearly all of the solid metals of the Periodic Table have been use to produce beam. A number of novel features have been incorporated into the sources, including multiple cathodes and the ability to switch between up to 18 separate cathode materials simply and quickly, and a broad beam source version as well as miniature versions. here we review the source designs and their performance. 45 refs., 7 figs

  14. A Source Identification Algorithm for INTEGRAL

    Science.gov (United States)

    Scaringi, Simone; Bird, Antony J.; Clark, David J.; Dean, Anthony J.; Hill, Adam B.; McBride, Vanessa A.; Shaw, Simon E.

    2008-12-01

    We give an overview of ISINA: INTEGRAL Source Identification Network Algorithm. This machine learning algorithm, using Random Forests, is applied to the IBIS/ISGRI dataset in order to ease the production of unbiased future soft gamma-ray source catalogues. The key steps of candidate searching, filtering and feature extraction are described. Three training and testing sets are created in order to deal with the diverse timescales and diverse objects encountered when dealing with the gamma-ray sky. Three independent Random Forest are built: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the Transient Matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples.

  15. Language identification using excitation source features

    CERN Document Server

    Rao, K Sreenivasa

    2015-01-01

    This book discusses the contribution of excitation source information in discriminating language. The authors focus on the excitation source component of speech for enhancement of language identification (LID) performance. Language specific features are extracted using two different modes: (i) Implicit processing of linear prediction (LP) residual and (ii) Explicit parameterization of linear prediction residual. The book discusses how in implicit processing approach, excitation source features are derived from LP residual, Hilbert envelope (magnitude) of LP residual and Phase of LP residual; and in explicit parameterization approach, LP residual signal is processed in spectral domain to extract the relevant language specific features. The authors further extract source features from these modes, which are combined for enhancing the performance of LID systems. The proposed excitation source features are also investigated for LID in background noisy environments. Each chapter of this book provides the motivatio...

  16. Gas and metal ion sources

    International Nuclear Information System (INIS)

    Oaks, E.; Yushkov, G.

    1996-01-01

    The positive ion sources are now of interest owing to both their conventional use, e.g., as injectors in charged-particle accelerators and the promising capabilities of intense ion beams in the processes related to the action of ions on various solid surfaces. For industrial use, the sources of intense ion beams and their power supplies should meet the specific requirements as follows: They should be simple, technologically effective, reliable, and relatively low-cost. Since the scanning of an intense ion beam is a complicated problem, broad ion beams hold the greatest promise. For the best use of such beams it is desirable that the ion current density be uniformly distributed over the beam cross section. The ion beam current density should be high enough for the treatment process be accomplished for an acceptable time. Thus, the ion sources used for high-current, high-dose metallurgical implantation should provide for gaining an exposure dose of ∼ 10 17 cm -2 in some tens of minutes. So the average ion current density at the surface under treatment should be over 10 -5 A/cm 2 . The upper limit of the current density depends on the admissible heating of the surface under treatment. The accelerating voltage of an ion source is dictated by its specific use; it seems to lie in the range from ∼1 kV (for the ion source used for surface sputtering) to ∼100 kV and over (for the ion sources used for high-current, high-dose metallurgical implantation)

  17. ISINA: INTEGRAL Source Identification Network Algorithm

    Science.gov (United States)

    Scaringi, S.; Bird, A. J.; Clark, D. J.; Dean, A. J.; Hill, A. B.; McBride, V. A.; Shaw, S. E.

    2008-11-01

    We give an overview of ISINA: INTEGRAL Source Identification Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. First, we introduce the data set and the problems encountered when dealing with images obtained using the coded mask technique. The initial step of source candidate searching is introduced and an initial candidate list is created. A description of the feature extraction on the initial candidate list is then performed together with feature merging for these candidates. Three training and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky. Three independent random forests are built: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain), Czech Republic and Poland, and the participation of Russia and the USA. E-mail: simo@astro.soton.ac.uk

  18. Applicability of concentration factors for the heavy metals hazard identification

    International Nuclear Information System (INIS)

    Guzzi, Luigi

    2006-01-01

    The bioconcentration factor (BCF) and bioaccumulation factor (BAF) used as criteria for heavy metals hazards identification are inadequate. These considerations is based on the argument that the BCF-BAF model was developed and validated for xenobiotic synthetic organic substances and that does not recognize the complex internal metal dynamic of uptake, the internal sequestration, and the essentially of some heavy metals [it

  19. Pseudo ribbon metal ion beam source

    International Nuclear Information System (INIS)

    Stepanov, Igor B.; Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A.

    2014-01-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface

  20. Pseudo ribbon metal ion beam source.

    Science.gov (United States)

    Stepanov, Igor B; Ryabchikov, Alexander I; Sivin, Denis O; Verigin, Dan A

    2014-02-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  1. 40 CFR 62.10860 - Identification of sources.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Texas Sulfuric Acid Mist from Existing Sulfuric Acid Plants § 62.10860 Identification of sources. (a) Identification of sources. The plan includes the following sulfuric acid production plants: (1) Diamond-Shamrock...

  2. Source Region Identification Using Kernel Smoothing

    Science.gov (United States)

    As described in this paper, Nonparametric Wind Regression is a source-to-receptor source apportionment model that can be used to identify and quantify the impact of possible source regions of pollutants as defined by wind direction sectors. It is described in detail with an exam...

  3. Heavy Metals Pollution on Surface Water Sources in Kaduna ...

    African Journals Online (AJOL)

    This study examine the effects of heavy metal pollutants to aquatic ecosystems and the environment by considering the role of urban, municipal, agricultural, industrial and other anthropogenic processes as sources of heavy metal pollution in surface water sources of Kaduna metropolis. Samples of the polluted water were ...

  4. [Regional atmospheric environment risk source identification and assessment].

    Science.gov (United States)

    Zhang, Xiao-Chun; Chen, Wei-Ping; Ma, Chun; Zhan, Shui-Fen; Jiao, Wen-Tao

    2012-12-01

    Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.

  5. Principal sources of EMI identification and fixes

    International Nuclear Information System (INIS)

    Nason, W.D.

    1993-01-01

    The sources of disruptive energy involved in an EMI episode all fall in one or the other of two types: intentional emitters or incidental emitters. Intentional emitters, such as communications transmitters, radars, walkie talkies etc., depend on emitting energy to satisfy the functional role assigned to the. Incidental emitters are those devices that emit energy unintentionally and are not dependent on those emissions to fulfill the assigned function. Power line conducted emissions typically fall in this latter category. The corrective action to be taken in controlling a problem that is present in a system is quite different if an incidental emitter is involved from that which is proper if an intentional emitter is present. Some of the methods that can be used to identify the emission sources which are contributing to a problem are presented in this paper along with some of the possible corrective actions that can be applied. 7 figs

  6. Noise source identification for ducted fan systems

    OpenAIRE

    BENNETT, GARETH; FITZPATRICK, JOHN AIDAN

    2008-01-01

    PUBLISHED Coherence based source analysis techniques can be used to identify the contribution of combustion noise in the exhaust of a jet engine and hence enable the design of noise reduction devices. However, when the combustion noise propagates in a non-linear fashion the identified contribution using ordinary coherence methods will be inaccurate. In this paper, an analysis technique to enable the contribution of linear and non-linear mechanisms to the propagated sound ...

  7. Data sources avalaibility to dangers identification

    International Nuclear Information System (INIS)

    Carrillo, M.

    2013-01-01

    The power point presentation is about epidemiological studies, animals in vivo studies, in vitro studies, activity and structure, key data to consider for risk characterization, stimation and dose, exposicition limits,NOEL, data sources more important to exposition evaluation, consumption Data, concentration data, population data studies, chemical concentration in food, maximum levels(LMs) maximum limits of wastes LMRs, monitoring data and sanitary surveillance, diet studies, (EDTs), data base GEMS/Food, data report and use, consumption data base, risk determination strategy in health produced by food contaminant intake

  8. Point source identification in nonlinear advection–diffusion–reaction systems

    International Nuclear Information System (INIS)

    Mamonov, A V; Tsai, Y-H R

    2013-01-01

    We consider a problem of identification of point sources in time-dependent advection–diffusion systems with a nonlinear reaction term. The linear counterpart of the problem in question can be reduced to solving a system of nonlinear algebraic equations via the use of adjoint equations. We extend this approach by constructing an algorithm that solves the problem iteratively to account for the nonlinearity of the reaction term. We study the question of improving the quality of source identification by adding more measurements adaptively using the solution obtained previously with a smaller number of measurements. (paper)

  9. Microstructured liquid metal electron and ion sources (MILMES/MILMIS)

    Energy Technology Data Exchange (ETDEWEB)

    Mitterauer, J [Technische Universitaet Wien (Austria). Institut fuer Allgemeine Elektrotechnik und Elektronik

    1997-12-31

    Ion or electron beams can be emitted from liquid metal wetted needles, or from capillaries or slits into which the liquid metal is allowed to flow. Large-area liquid metal field emission sources have been proposed recently, using either two-dimensional, regular arrays of cones or capillaries, or even a substrate with an intrinsically microstructured surface covered by a liquid metal film. This latter concept has been realized in a pilot experiment by in situ wicking and wetting of a porous sintered metal disc. Microstructured liquid metal ion or electron sources are capable of operating in a pulsed mode at a current level which is orders of magnitude above that for steady-state operation. (author). 3 figs., 10 refs.

  10. Source identification of hydrocarbons following environmental releases

    Energy Technology Data Exchange (ETDEWEB)

    Birkholz, D.A. [ALS Environmental, Edmonton, AB (Canada)

    2010-07-01

    Methods of identifying the sources of hydrocarbon contaminations were discussed in this PowerPoint presentation. Laboratories analyze for total petroleum hydrocarbons (TPH) by obtaining chromatograms of observed products. However, many petroleum products provide similar chromatograms. Several independent lines of evidence are needed for the purposes of accurate determination in legal applications. A case study of a lube oil plant spill was used to demonstrate the inconclusiveness of chromatograms and the need to determine petroleum biomarkers. Terpane, sterane, triaromatic sterane, isoprenoid, and alkylcyclohexane analyses were conducted to differentiate between the hydrocarbon samples. The analysis methods are being used with various soil, water, and crab species samples from the BP oil spill. Oil found at the different sites must be directly related to the spill. However, there are 3858 oil and gas platforms currently operating in the Gulf of Mexico. Ratios of biomarkers and polycyclic aromatic hydrocarbons (PAHs) are being developed to generate weight of evidence. A critical difference analysis was also presented. tabs., figs.

  11. 40 CFR 62.1101 - Identification of sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Identification of sources. 62.1101 Section 62.1101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Company in San Joaquin County. (b) Simplot Company in Kings County. (c) Valley Nitrogen Products, Inc., in...

  12. Identifiability and Identification of Trace Continuous Pollutant Source

    Directory of Open Access Journals (Sweden)

    Hongquan Qu

    2014-01-01

    Full Text Available Accidental pollution events often threaten people’s health and lives, and a pollutant source is very necessary so that prompt remedial actions can be taken. In this paper, a trace continuous pollutant source identification method is developed to identify a sudden continuous emission pollutant source in an enclosed space. The location probability model is set up firstly, and then the identification method is realized by searching a global optimal objective value of the location probability. In order to discuss the identifiability performance of the presented method, a conception of a synergy degree of velocity fields is presented in order to quantitatively analyze the impact of velocity field on the identification performance. Based on this conception, some simulation cases were conducted. The application conditions of this method are obtained according to the simulation studies. In order to verify the presented method, we designed an experiment and identified an unknown source appearing in the experimental space. The result showed that the method can identify a sudden trace continuous source when the studied situation satisfies the application conditions.

  13. Identification of Cu’s sources in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Li, Haixia; Ding, Jun; Zhang, Longlei; Li, Jiangmin

    2017-12-01

    Many marine bays have been polluted by Cu along with the rapid development of industry, economy and population size, and identification the sources of Cu is essential to environmental protection. This paper identified the sources of Cu in according to the horizontal distribution in Jiaozhou Bay during 1982-1986. Results showed that there were five Cu sources during study years including marine current, stream flow, island top, overland runoff and marine traffic, respectively. These findings were helpful information in decision-making of pollution control and environmental remediation practice.

  14. Failed fuel identification techniques for liquid-metal cooled reactors

    International Nuclear Information System (INIS)

    Lambert, J.D.B.; Gross, K.C.; Mikaili, R.; Frank, S.M.; Cutforth, D.C.; Angelo, P.L.

    1995-01-01

    The Experimental Breeder Reactor II (EBR-II), located in Idaho and operated for the US Department of Energy by Argonne National Laboratory, has been used as an irradiation testbed for LMR fuels and components for thirty years. During this time many endurance tests have been carried out with experimental LMR metal, oxide, carbide and nitride fuel elements, in which cladding failures were intentionally allowed to occur. This paper describes methods that have been developed for the detection, identification and verification of fuel failures

  15. Identification of emission sources of umbral flashes using phase congruency

    International Nuclear Information System (INIS)

    Feng Song; Yang Yun-Fei; Ji Kai-Fan; Yu Lan

    2014-01-01

    The emission sources of umbral flashes (UFs) are believed to be closely related to running umbral and penumbral waves, and are concluded to be associated with umbral dots in the solar photosphere. Accurate identification of emission sources of UFs is crucial for investigating these physical phenomena and their inherent relationships. A relatively novel model of shape perception, namely phase congruency (PC), uses phase information in the Fourier domain to identify the geometrical shape of the region of interest in different intensity levels, rather than intensity or gradient. Previous studies indicate that the model is suitable for identifying features with low contrast and low luminance. In the present paper, we applied the PC model to identify the emission sources of UFs and to locate their positions. For illustrating the high performance of our proposed method, two time sequences of Ca II H images derived from the Hinode/SOT on 2010 August 10 and 2013 August 20 were used. Furthermore, we also compared these results with the analysis results that are identified by the traditional/classical identification methods, including the gray-scale adjusted technique and the running difference technique. The result of our analysis demonstrates that our proposed method is more accurate and effective than the traditional identification methods when applied to identifying the emission sources of UFs and to locating their positions. (research papers)

  16. Trends and sources for heavy metals in urban atmosphere

    International Nuclear Information System (INIS)

    Kemp, Kaare

    2002-01-01

    The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing

  17. Trends and sources for heavy metals in urban atmosphere

    Science.gov (United States)

    Kemp, Kåre

    2002-04-01

    The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing.

  18. Upgraded vacuum arc ion source for metal ion implantation

    International Nuclear Information System (INIS)

    Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu.; Brown, I. G.

    2012-01-01

    Vacuum arc ion sources have been made and used by a large number of research groups around the world over the past twenty years. The first generation of vacuum arc ion sources (dubbed ''Mevva,'' for metal vapor vacuum arc) was developed at Lawrence Berkeley National Laboratory in the 1980s. This paper considers the design, performance parameters, and some applications of a new modified version of this kind of source which we have called Mevva-V.Ru. The source produces broad beams of metal ions at an extraction voltage of up to 60 kV and a time-averaged ion beam current in the milliampere range. Here, we describe the Mevva-V.Ru vacuum arc ion source that we have developed at Tomsk and summarize its beam characteristics along with some of the applications to which we have put it. We also describe the source performance using compound cathodes.

  19. Chromatographic fingerprint similarity analysis for pollutant source identification

    International Nuclear Information System (INIS)

    Xie, Juan-Ping; Ni, Hong-Gang

    2015-01-01

    In the present study, a similarity analysis method was proposed to evaluate the source-sink relationships among environmental media for polybrominated diphenyl ethers (PBDEs), which were taken as the representative contaminants. Chromatographic fingerprint analysis has been widely used in the fields of natural products chemistry and forensic chemistry, but its application to environmental science has been limited. We established a library of various sources of media containing contaminants (e.g., plastics), recognizing that the establishment of a more comprehensive library allows for a better understanding of the sources of contamination. We then compared an environmental complex mixture (e.g., sediment, soil) with the profiles in the library. These comparisons could be used as the first step in source tracking. The cosine similarities between plastic and soil or sediment ranged from 0.53 to 0.68, suggesting that plastic in electronic waste is an important source of PBDEs in the environment, but it is not the only source. A similarity analysis between soil and sediment indicated that they have a source-sink relationship. Generally, the similarity analysis method can encompass more relevant information of complex mixtures in the environment than a profile-based approach that only focuses on target pollutants. There is an inherent advantage to creating a data matrix containing all peaks and their relative levels after matching the peaks based on retention times and peak areas. This data matrix can be used for source identification via a similarity analysis without quantitative or qualitative analysis of all chemicals in a sample. - Highlights: • Chromatographic fingerprint analysis can be used as the first step in source tracking. • Similarity analysis method can encompass more relevant information of pollution. • The fingerprints strongly depend on the chromatographic conditions. • A more effective and robust method for identifying similarities is required

  20. Groundwater Pollution Source Identification using Linked ANN-Optimization Model

    Science.gov (United States)

    Ayaz, Md; Srivastava, Rajesh; Jain, Ashu

    2014-05-01

    Groundwater is the principal source of drinking water in several parts of the world. Contamination of groundwater has become a serious health and environmental problem today. Human activities including industrial and agricultural activities are generally responsible for this contamination. Identification of groundwater pollution source is a major step in groundwater pollution remediation. Complete knowledge of pollution source in terms of its source characteristics is essential to adopt an effective remediation strategy. Groundwater pollution source is said to be identified completely when the source characteristics - location, strength and release period - are known. Identification of unknown groundwater pollution source is an ill-posed inverse problem. It becomes more difficult for real field conditions, when the lag time between the first reading at observation well and the time at which the source becomes active is not known. We developed a linked ANN-Optimization model for complete identification of an unknown groundwater pollution source. The model comprises two parts- an optimization model and an ANN model. Decision variables of linked ANN-Optimization model contain source location and release period of pollution source. An objective function is formulated using the spatial and temporal data of observed and simulated concentrations, and then minimized to identify the pollution source parameters. In the formulation of the objective function, we require the lag time which is not known. An ANN model with one hidden layer is trained using Levenberg-Marquardt algorithm to find the lag time. Different combinations of source locations and release periods are used as inputs and lag time is obtained as the output. Performance of the proposed model is evaluated for two and three dimensional case with error-free and erroneous data. Erroneous data was generated by adding uniformly distributed random error (error level 0-10%) to the analytically computed concentration

  1. Case studies using the United States Coast Guard's Oil Identification System for petroleum spill source identification

    International Nuclear Information System (INIS)

    Grosser, P.W.; Castellano, F.P.

    1993-01-01

    The Oil Identification System (OIS) was developed in the 1970's at the Coast Guard Research and Development Center, to determine the unique, intrinsic properties which would allow the matching of a spilled oil with its correct source. The Central Oil Identification Laboratory (COIL) was established in 1978 as the operating facility to implement the OIS. The OIS encompasses four analytical methods; thin layer chromatography, fluorescence spectroscopy, infrared spectroscopy and gas chromatography. A sample can be studied according to each individual method or multi-methods approach can be chosen if no single technique gives unequivocal results. Combined these methods are greater than 99% effective. The authors recently utilized the OIS and the COIL for three petroleum spill investigations in New York. As part of the investigation to determine the source(s) of several different petroleum product spills, OIS was conducted along with a review of groundwater sample chromatograms

  2. High-current pulsed ion source for metallic ions

    International Nuclear Information System (INIS)

    Gavin, B.; Abbott, S.; MacGill, R.; Sorensen, R.; Staples, J.; Thatcher, R.

    1981-03-01

    A new sputter-ion PIG source and magnet system, optimized for intermediate charge states, q/A of 0.02 to 0.03, is described. This source will be used with the new Wideroe-based injector for the SuperHILAC. Pulsed electrical currents of several emA of heavy metal ions have been produced in a normalized emittance area of .05π cm-mr. The source system is comprised of two electrically separate anode chambers, one in operation and one spare, which can be selected by remote control. The entire source head is small and quickly removable

  3. Contaminant source identification using semi-supervised machine learning

    International Nuclear Information System (INIS)

    Vesselinov, Velimir Valentinov; Alexandrov, Boian S.; O’Malley, Dan

    2017-01-01

    Identification of the original groundwater types present in geochemical mixtures observed in an aquifer is a challenging but very important task. Frequently, some of the groundwater types are related to different infiltration and/or contamination sources associated with various geochemical signatures and origins. The characterization of groundwater mixing processes typically requires solving complex inverse models representing groundwater flow and geochemical transport in the aquifer, where the inverse analysis accounts for available site data. Usually, the model is calibrated against the available data characterizing the spatial and temporal distribution of the observed geochemical types. Numerous different geochemical constituents and processes may need to be simulated in these models which further complicates the analyses. In this paper, we propose a new contaminant source identification approach that performs decomposition of the observation mixtures based on Non-negative Matrix Factorization (NMF) method for Blind Source Separation (BSS), coupled with a custom semi-supervised clustering algorithm. Our methodology, called NMFk, is capable of identifying (a) the unknown number of groundwater types and (b) the original geochemical concentration of the contaminant sources from measured geochemical mixtures with unknown mixing ratios without any additional site information. NMFk is tested on synthetic and real-world site data. Finally, the NMFk algorithm works with geochemical data represented in the form of concentrations, ratios (of two constituents; for example, isotope ratios), and delta notations (standard normalized stable isotope ratios).

  4. An open source toolkit for medical imaging de-identification

    International Nuclear Information System (INIS)

    Rodriguez Gonzalez, David; Carpenter, Trevor; Wardlaw, Joanna; Hemert, Jano I. van

    2010-01-01

    Medical imaging acquired for clinical purposes can have several legitimate secondary uses in research projects and teaching libraries. No commonly accepted solution for anonymising these images exists because the amount of personal data that should be preserved varies case by case. Our objective is to provide a flexible mechanism for anonymising Digital Imaging and Communications in Medicine (DICOM) data that meets the requirements for deployment in multicentre trials. We reviewed our current de-identification practices and defined the relevant use cases to extract the requirements for the de-identification process. We then used these requirements in the design and implementation of the toolkit. Finally, we tested the toolkit taking as a reference those requirements, including a multicentre deployment. The toolkit successfully anonymised DICOM data from various sources. Furthermore, it was shown that it could forward anonymous data to remote destinations, remove burned-in annotations, and add tracking information to the header. The toolkit also implements the DICOM standard confidentiality mechanism. A DICOM de-identification toolkit that facilitates the enforcement of privacy policies was developed. It is highly extensible, provides the necessary flexibility to account for different de-identification requirements and has a low adoption barrier for new users. (orig.)

  5. Distribution and source apportionment studies of heavy metals in soil of cotton/wheat fields.

    Science.gov (United States)

    Rafique, Nazia; Tariq, Saadia R

    2016-05-01

    Heavy metals enriched agricultural soils have been the subject of great concern because these metals have potential to be transferred to the soil solution and afterward accumulated in food chain. To study the trace metal persistence in crop soil, 90 representative soil samples were collected and analyzed for heavy metal (As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn) and anions (chloride, nitrates, phosphates and sulfates). Cluster and factor analysis techniques were used for the source identification of these excessive heavy metal levels and ecological risk was determined with potential ecological risk assessment. The degree of enrichment of eight studied heavy metals in comparison with the corresponding background levels decreased in order: Cd > Pb > Fe > Ni > Mn > As > Cu ~ Zn. Arsenic and cadmium exhibited 1.30- and 1.64-fold exceeded levels than threshold limits set by National environment quality standards, respectively. Cd in cotton field's soil may lead to higher potential risk than other heavy metals. On overall basis, the cumulative mean potential ecological risk for the district (207.75) corresponded to moderate risk level with higher contributions from As and Pb especially from Cd. Cadmium formed strong positive correlation with phosphate content of soil at p < 0.01. Cluster analysis indicated that Cluster 1 (extremely polluted) probably originated from anthropogenic inputs of phosphate fertilizer and past usage of arsenical pesticides.

  6. Identification of heavy metals sources in the Mexico city atmosphere, using the proton induced x-ray analytical technique and multifactorial statistics techniques; Identificacion de fuentes de metales pesados en la atmosfera de la Ciudad de Mexico, usando la tecnica de analisis por induccion de rayos X con proton y tecnicas estadisticas multifactoriales

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, B [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    1997-07-01

    The objectives of this work are: to identify the heavy metals present in the air, and its concentrations. To know the behavior from the polluting chemical elements to the long of an annual cycle corresponding to 1990, based on the concentrations of the same ones, obtained through the PIXE technique. To identify the suitable statistical methods to use to the data of metals concentration in form of total suspended particle (PST), found in this investigation. To relate the concentrations and the meteorological parameters considered to be able to suggest the possible pollution sources. In function of the obtained results, to serve as base to the decisions making and measures control that are planned by diverse institutions focused to the problem of the atmospheric pollution in the Metropolitan area of Mexico City (ZMCM). (Author)

  7. Adaptation of metal arc plasma source to plasma source ion implantation

    International Nuclear Information System (INIS)

    Shamim, M.M.; Fetherston, R.P.; Conrad, J.R.

    1995-01-01

    In Plasma Source Ion Implantation (PSII) a target is immersed in a plasma and a train of high negative voltage pulses is applied to accelerate ions into the target and to modify the properties in the near surface region. In PSII, until now the authors have been using gaseous species to generate plasmas. However metal ion plasma may be used to modify the surface properties of material for industrial applications. Conventionally the ion implantation of metal ions is performed using beam line accelerators which have complex engineering and high cost. The employment of a metal arc source to PSII has tremendous potential due to its ability to process the conformal surfaces, simple engineering and cost effectiveness. They have installed metal arc source for generation of titanium plasma. Currently, they are investigating the properties of titanium plasma and material behavior of titanium implanted aluminum and 52100 steel. The recent results of this investigation are presented

  8. Inverse mathematical modelling and identification in metal powder compaction process

    International Nuclear Information System (INIS)

    Gakwaya, A.; Hrairi, M.; Guillot, M.

    2000-01-01

    An online assessment of the quality of advanced integrated computer aided manufacturing systems require the knowledge of accurate and reliable non-linear constitutive material behavior. This paper is concerned with material parameter identification based on experimental data for which non uniform distribution of stresses and deformation within the volume of the specimen is considered. Both geometric and material non linearities as well interfacial frictional contact are taken into account during the simulation. Within the framework of finite deformation theory, a multisurface multiplicative plasticity model for metal powder compaction process is presented. The model is seen to involve several parameters which are not always activated by a single state variable even though it may be technologically important in assessing the final product quality and manufacturing performance. The resulting expressions are presented in spatial setting and gradient based descent method utilizing the modified Levenberg-Marquardt scheme is used for the minimization of least square functional so as to obtain the best agreement between relevant experimental data and simulated data in a specified energy norm. The identification of a subset of material parameters of the cap model for stainless steel powder compaction is performed. The obtained parameters are validated through a simulation of an industrial part manufacturing case. A very good agreement between simulated final density and measured density is obtained thus demonstrating the practical usefulness of the proposed approach. (author)

  9. Source of atmospheric heavy metals in winter in Foshan, China.

    Science.gov (United States)

    Tan, Ji-Hua; Duan, Jing-Chun; Ma, Yong-Liang; Yang, Fu-Mo; Cheng, Yuan; He, Ke-Bin; Yu, Yong-Chang; Wang, Jie-Wen

    2014-09-15

    Foshan is a ceramics manufacturing center in the world and the most polluted city in the Pearl River Delta (PRD) in southern China measured by the levels of atmospheric heavy metals. PM2.5 samples were collected in Foshan in winter 2008. Among the 22 elements and ions analyzed, 7 heavy metals (Zn, V, Mn, Cu, As, Cd and Pb) were studied in depth for their levels, spatiotemporal variations and sources. The ambient concentrations of the heavy metals were much higher than the reported average concentrations in China. The levels of Pb (675.7 ± 378.5 ng/m(3)), As (76.6 ± 49.1 ng/m(3)) and Cd (42.6 ± 45.2 ng/m(3)) exceeded the reference values of NAAQS (GB3095-2012) and the health guidelines of the World Health Organization. Generally, the levels of atmospheric heavy metals showed spatial distribution as: downtown site (CC, Chancheng District)>urban sites (NH and SD, Nanhai and Shunde Districts)>rural site (SS, Shanshui District). Two sources of heavy metals, the ceramic and aluminum industries, were identified during the sampling period. The large number of ceramic manufactures was responsible for the high levels of atmospheric Zn, Pb and As in Chancheng District. Transport from an aluminum industry park under light north-west winds contributed high levels of Cd to the SS site (Shanshui District). The average concentration of Cd under north-west wind was 220 ng/m(3), 20.5 times higher than those under other wind directions. The high daily maximum enrichment factors (EFs) of Cd, Pb, Zn, As and Cu at all four sites indicated extremely high contamination by local emissions. Back trajectory analysis showed that the heavy metals were also closely associated with the pathway of air mass. A positive matrix factorization (PMF) method was applied to determine the source apportionment of these heavy metals. Five factors (industry including the ceramic industry and coal combustion, vehicle emissions, dust, transportation and sea salt) were identified and industry was the most

  10. Ion beam exposure apparatus using a liquid metal source

    International Nuclear Information System (INIS)

    Komuro, M.

    1982-01-01

    A field effect liquid metal ion source is described. The current-voltage characteristics, the angular intensity distribution and the total energy distribution were measured for gallium, gold and lead sources. The results are presented and the effect of space charge on the emission current is discussed. Optimum working conditions for the use of the ion sources in probe formation are derived. On the basis of the experimental results, an apparatus operating at 50 kV or less was designed. Details of the design, which includes a triode ion gun and an einzel lens, are given together with preliminary results of pattern delineation with the apparatus. (Auth.)

  11. Cd isotopes as a potential source tracer of metal pollution in river sediments

    International Nuclear Information System (INIS)

    Gao, Bo; Zhou, Haidong; Liang, Xirong; Tu, Xianglin

    2013-01-01

    Tracing the sources of heavy metals in water environment is key important for our understanding of their pollution behavior. In this present study, Cd concentrations and Cd isotopic compositions in sediments were determined to effectively identify possible Cd sources. Results showed that elevated concentrations and high enrichment factor for Cd were found in all sediments, suggesting anthropogenic Cd origin. Cd isotopic compositions in sediments yielded relative variations ranged from −0.35‰ to 0.07‰ in term of δ 114/110 Cd (the mean: −0.08‰). Large fractionated Cd was found in sediments collected from a smelter and an E-waste town. Cd isotopic compositions and Cd concentrations measured in sediments allowed the identification of three main origins (dust from metal refining (δ 114/110 Cd 114/110 Cd > 0), and those δ 114/110 Cd = 0, such as background and mining activity). According to the actual precision obtained, Cd isotopes could be a potential tool for tracing metal pollution sources in water environment. -- The information and application of Cd isotopic compositions will provide a new direction in tracing metal pollution in water environment

  12. Efficient Bayesian experimental design for contaminant source identification

    Science.gov (United States)

    Zhang, Jiangjiang; Zeng, Lingzao; Chen, Cheng; Chen, Dingjiang; Wu, Laosheng

    2015-01-01

    In this study, an efficient full Bayesian approach is developed for the optimal sampling well location design and source parameters identification of groundwater contaminants. An information measure, i.e., the relative entropy, is employed to quantify the information gain from concentration measurements in identifying unknown parameters. In this approach, the sampling locations that give the maximum expected relative entropy are selected as the optimal design. After the sampling locations are determined, a Bayesian approach based on Markov Chain Monte Carlo (MCMC) is used to estimate unknown parameters. In both the design and estimation, the contaminant transport equation is required to be solved many times to evaluate the likelihood. To reduce the computational burden, an interpolation method based on the adaptive sparse grid is utilized to construct a surrogate for the contaminant transport equation. The approximated likelihood can be evaluated directly from the surrogate, which greatly accelerates the design and estimation process. The accuracy and efficiency of our approach are demonstrated through numerical case studies. It is shown that the methods can be used to assist in both single sampling location and monitoring network design for contaminant source identifications in groundwater.

  13. Calibration experiments of neutron source identification and detection in soil

    International Nuclear Information System (INIS)

    Gorin, N. V.; Lipilina, E. N.; Rukavishnikov, G. V.; Shmakov, D. V.; Ulyanov, A. I.

    2007-01-01

    In the course of detection of fissile materials in soil, series of calibration experiments were carried out on in laboratory conditions on an experimental installation, presenting a mock-up of an endless soil with various heterogeneous bodies in it, fissile material, measuring boreholes. A design of detecting device, methods of neutrons detection are described. Conditions of neutron background measuring are given. Soil density, humidity, chemical composition of soil was measured. Sensitivity of methods of fissile materials detection and identification in soil was estimated in the calibration experiments. Minimal detectable activity and the distance at which it can be detected were defined. Characteristics of neutron radiation in a borehole mock-up were measured; dependences of method sensitivities from water content in soil, source-detector distance and presence of heterogeneous bodies were examined. Possibility of direction detection to a fissile material as neutron source from a borehole using a collimator is shown. Identification of fissile material was carried out by measuring the gamma-spectrum. Mathematical modeling was carried out using the PRIZMA code (Developed in RFNC-VNIITF) and MCNP code (Developed in LANL). Good correlation of calculational and experimental values was shown. The methodic were shown to be applicable in the field conditions

  14. Spectroscopy for identification of plasma sources for lithography and water window imaging

    International Nuclear Information System (INIS)

    O'Sullivan, Gerry; Dunne, Padraig; Liu, Luning; Lokasani, Ragava; Long, Elaine; O'Reilly, Fergal; Sheridan, Paul; Sokell, Emma; Wu, Tao; Higashiguchi, Takeshi; Li, Bowen; Ohashi, Hayato; Suzuki, Chihiro

    2015-01-01

    The identification of sources for applications that include nanolithography, surface patterning and high resolution imaging is the focus of a considerable activity in the extreme ultraviolet (EUV) or soft x-ray (SXR) spectral regions. We report on the result of a study of the spectra from laser produced plasmas of a number of medium and high Z metals undertaken in order to identify potential sources for use with available multilayer mirrors. The main focus was the study of unresolved transition arrays emitted from ions with 3d, 4d and 4f valence subshells that emit strongly in the water window (2.34-4.38 nm).and that could be used for biological imaging or cell tomography. (paper)

  15. Distribution and Source Identification of Pb Contamination in industrial soil

    Science.gov (United States)

    Ko, M. S.

    2017-12-01

    INTRODUCTION Lead (Pb) is toxic element that induce neurotoxic effect to human, because competition of Pb and Ca in nerve system. Lead is classified as a chalophile element and galena (PbS) is the major mineral. Although the Pb is not an abundant element in nature, various anthropogenic source has been enhanced Pb enrichment in the environment after the Industrial Revolution. The representative anthropogenic sources are batteries, paint, mining, smelting, and combustion of fossil fuel. Isotope analysis widely used to identify the Pb contamination source. The Pb has four stable isotopes that are 208Pb, 207Pb, 206Pb, and 204Pb in natural. The Pb is stable isotope and the ratios maintain during physical and chemical fractionation. Therefore, variations of Pb isotope abundance and relative ratios could imply the certain Pb contamination source. In this study, distributions and isotope ratios of Pb in industrial soil were used to identify the Pb contamination source and dispersion pathways. MATERIALS AND METHODS Soil samples were collected at depth 0­-6 m from an industrial area in Korea. The collected soil samples were dried and sieved under 2 mm. Soil pH, aqua-regia digestion and TCLP carried out using sieved soil sample. The isotope analysis was carried out to determine the abundance of Pb isotope. RESULTS AND DISCUSSION The study area was developed land for promotion of industrial facilities. The study area was forest in 1980, and the satellite image show the alterations of land use with time. The variations of land use imply the possibilities of bringing in external contaminated soil. The Pb concentrations in core samples revealed higher in lower soil compare with top soil. Especially, 4 m soil sample show highest Pb concentrations that are approximately 1500 mg/kg. This result indicated that certain Pb source existed at 4 m depth. CONCLUSIONS This study investigated the distribution and source identification of Pb in industrial soil. The land use and Pb

  16. Radioactivity measurements of metallic 192Ir sources by calorimetric methods

    International Nuclear Information System (INIS)

    Genka, Tsuguo; Iwamoto, Seikichi; Takeuchi, Norio

    1992-01-01

    The necessity of establishing the traceability of dose measurement in brachytherapy 192 Ir sources is realized by physicians and researchers in the medical field. Standard sources of various shapes such as open-quotes hairpin,close quotes open-quotes single pin,close quotes open-quotes thin wire,close quotes and open-quotes seedclose quotes for calibrating ionization chambers in hospitals are being demanded. Nominal activities of not only these source products but also the standard sources have been so far specified by open-quotes apparentclose quotes values. Determination of open-quotes absoluteclose quotes activity by an established means such as 4pi-beta-gamma coincidence counting is not practical because quantitative dissolution of metallic iridium is very difficult. We tried to determine the open-quotes absoluteclose quotes activity by a calorimetric method in a fully nondestructive way

  17. Decentralized modal identification using sparse blind source separation

    International Nuclear Information System (INIS)

    Sadhu, A; Hazra, B; Narasimhan, S; Pandey, M D

    2011-01-01

    Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time–frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure

  18. Decentralized modal identification using sparse blind source separation

    Science.gov (United States)

    Sadhu, A.; Hazra, B.; Narasimhan, S.; Pandey, M. D.

    2011-12-01

    Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time-frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure.

  19. Variation in Microbial Identification System Accuracy for Yeast Identification Depending on Commercial Source of Sabouraud Dextrose Agar

    OpenAIRE

    Kellogg, James A.; Bankert, David A.; Chaturvedi, Vishnu

    1999-01-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc.) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system’s accuracy.

  20. Variation in Microbial Identification System accuracy for yeast identification depending on commercial source of Sabouraud dextrose agar.

    Science.gov (United States)

    Kellogg, J A; Bankert, D A; Chaturvedi, V

    1999-06-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc. ) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system's accuracy.

  1. Activities and Issues in Monitoring Scrap Metal Against Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.Y., E-mail: sychen@anl.gov [Argonne National Laboratory, Argonne, IL (United States)

    2011-07-15

    Over the past few decades, the global scrap metal industry has grown increasingly vigilant regarding radioactive contamination. Accidental melts of radioactive sources in some smelting facilities, in particular, have caused considerable damage and required recovery efforts costing tens of millions of dollars. In response, the industry has developed and deployed countermeasures. Increasingly expensive and sophisticated radiation monitoring devices have been implemented at key scrap entry points - ports and scrapyards. Recognition of the importance of such endeavors has led to a series of activities aimed at establishing organized and coordinated efforts among the interested parties. Recent concerns over the potential use of radioactive sources for radiological devices in terrorist acts have substantially heightened the need for national and international authorities to further control, intercept, and secure the sources that have escaped the regulatory domain. Enhanced collaboration by the government and industry could substantially improve the effectiveness of efforts at control; the 'Spanish Protocol' as developed by the Spanish metal industry and government regulators is a good example of such collaboration. (author)

  2. Long range implantation by MEVVA metal ion source

    International Nuclear Information System (INIS)

    Zhang Tonghe; Wu Yuguang; Ma Furong; Liang Hong

    2001-01-01

    Metal vapor vacuum arc (MEVVA) source ion implantation is a new technology used for achieving long range ion implantation. It is very important for research and application of the ion beam modification of materials. The results show that the implanted atom diffusion coefficient increases in Mo implanted Al with high ion flux and high dose. The implanted depth is 311.6 times greater than that of the corresponding ion range. The ion species, doses and ion fluxes play an important part in the long-range implantation. Especially, thermal atom chemistry have specific effect on the long-range implantation during high ion flux implantation at transient high target temperature

  3. IDENTIFICATIONS OF FIVE INTEGRAL SOURCES VIA OPTICAL SPECTROSCOPY

    International Nuclear Information System (INIS)

    Butler, Suzanne C.; Tomsick, John A.; Chaty, Sylvain; Heras, Juan A. Zurita; Rodriguez, Jerome; Walter, Roland; Kaaret, Philip; Kalemci, Emrah; Oezbey, Mehtap

    2009-01-01

    The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is discovering hundreds of new hard X-ray sources, many of which remain unidentified. We report on optical spectroscopy of five such sources for which X-ray observations at lower energies (∼0.5-10 keV) and higher angular resolutions than INTEGRAL have allowed for unique optical counterparts to be located. We find that INTEGRAL Gamma-Ray (IGR) J16426+6536 and IGR J22292+6647 are Type 1 Seyfert active galactic nuclei (with IGR J16426+6536 further classified as a Seyfert 1.5) which have redshifts of z = 0.323 and z = 0.113, respectively. IGR J18308-1232 is identified as a cataclysmic variable (CV), and we confirm a previous identification of IGR J19267+1325 as a magnetic CV. IGR J18214-1318 is identified as an obscured high-mass X-ray binary (HMXB), which are systems thought to have a compact object embedded in the stellar wind of a massive star. We combine Chandra fluxes with distances based on the optical observations to calculate X-ray luminosities of the HMXB and CVs, finding L 0.3-10keV = 5 x 10 36 erg s -1 for IGR J18214-1318, L 0.3-10keV = 1.3 x 10 32 erg s -1 for IGR J18308-1232, and L 0.3-10keV = 6.7 x 10 32 erg s -1 for IGR J19267+1325.

  4. Quantitative Real-Time PCR Fecal Source Identification in the ...

    Science.gov (United States)

    Rivers in the Tillamook Basin play a vital role in supporting a thriving dairy and cheese-making industry, as well as providing a safe water resource for local human and wildlife populations. Historical concentrations of fecal bacteria in these waters are at times too high to allow for safe use leading to economic loss, endangerment of local wildlife, and poor conditions for recreational use. In this study, we employ host-associated qPCR methods for human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), cattle (CowM2 and CowM3), canine (DG3 and DG37), and avian (GFD) fecal pollution combined with high-resolution geographic information system (GIS) land use data and general indicator bacteria measurements to elucidatewater quality spatial and temporal trends. Water samples (n=584) were collected over a 1-year period at 29 sites along the Trask, Kilchis, and Tillamook rivers and tributaries (Tillamook Basin, OR). A total of 16.6% of samples (n=97) yielded E. coli levels considered impaired based on Oregon Department of Environmental Quality bacteria criteria (406 MPN/100mL). Hostassociated genetic indicators were detected at frequencies of 39.2% (HF183/BacR287), 16.3% (HumM2), 74.6% (Rum2Bac), 13.0% (CowM2), 26.7% (CowM3), 19.8% (DG3), 3.2% (DG37), and 53.4% (GFD) across all water samples (n=584). Seasonal trends in avian, cattle, and human fecal pollution sources were evident over the study area. On a sample site basis, quantitative fecal source identification and

  5. CADDIS Volume 2. Sources, Stressors and Responses: Metals - Point Sources from Industry

    Science.gov (United States)

    Introduction to the metals module, when to list metals as a candidate cause, ways to measure metals, simple and detailed conceptual diagrams for metals, metals module references and literature reviews.

  6. MetalS(3), a database-mining tool for the identification of structurally similar metal sites.

    Science.gov (United States)

    Valasatava, Yana; Rosato, Antonio; Cavallaro, Gabriele; Andreini, Claudia

    2014-08-01

    We have developed a database search tool to identify metal sites having structural similarity to a query metal site structure within the MetalPDB database of minimal functional sites (MFSs) contained in metal-binding biological macromolecules. MFSs describe the local environment around the metal(s) independently of the larger context of the macromolecular structure. Such a local environment has a determinant role in tuning the chemical reactivity of the metal, ultimately contributing to the functional properties of the whole system. The database search tool, which we called MetalS(3) (Metal Sites Similarity Search), can be accessed through a Web interface at http://metalweb.cerm.unifi.it/tools/metals3/ . MetalS(3) uses a suitably adapted version of an algorithm that we previously developed to systematically compare the structure of the query metal site with each MFS in MetalPDB. For each MFS, the best superposition is kept. All these superpositions are then ranked according to the MetalS(3) scoring function and are presented to the user in tabular form. The user can interact with the output Web page to visualize the structural alignment or the sequence alignment derived from it. Options to filter the results are available. Test calculations show that the MetalS(3) output correlates well with expectations from protein homology considerations. Furthermore, we describe some usage scenarios that highlight the usefulness of MetalS(3) to obtain mechanistic and functional hints regardless of homology.

  7. A theoretical model of a liquid metal ion source

    International Nuclear Information System (INIS)

    Kingham, D.R.; Swanson, L.W.

    1984-01-01

    A model of liquid metal ion source (LMIS) operation has been developed which gives a consistent picture of three different aspects of LMI sources: (i) the shape and size of the ion emitting region; (ii) the mechanism of ion formation; (iii) properties of the ion beam such as angular intensity and energy spread. It was found that the emitting region takes the shape of a jet-like protrusion on the end of a Taylor cone with ion emission from an area only a few tens of A across, in agreement with recent TEM pictures by Sudraud. This is consistent with ion formation predominantly by field evaporation. Calculated angular intensities and current-voltage characteristics based on our fluid dynamic jet-like protrusion model agree well with experiment. The formation of doubly charged ions is attributed to post-ionization of field evaporated singly charged ions and an apex field strength of about 2.0 V A -1 was calculated for a Ga source. The ion energy spread is mainly due to space charge effects, it is known to be reduced for doubly charged ions in agreement with this post-ionization mechanism. (author)

  8. Heating effects in a liquid metal ion source

    International Nuclear Information System (INIS)

    Mair, G.L.R.; Aitken, K.L.

    1984-01-01

    A reassessment is made of the heating occurring at the anode of a liquid metal ion source, in the light of new microscopic observations. The apex region of the cones is in the form of a cusp, or jet, even at very low currents. The calculation for ohmic heating is conclusive for low currents; no heating occurs at the anode; for high currents (approx. 50-100 μA), substantial heating is conceivable, if a long, very thin, cylindrical jet exists at the apex of the anode. The answer to the problem of external heating, in the form of electrons bombarding the anode, is not quite conclusive; this is because of the impossibility of correctly assessing the electron flux entering the anode. However, it would appear to be a definite conclusion that for reasons of self-consistency field-ionisation of thermally released atoms cannot be a significant ion emission mechanism. (author)

  9. Water cooled metal optics for the Advanced Light Source

    International Nuclear Information System (INIS)

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-01-01

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously

  10. Pyrometallurgical slags as a potential source of selected metals recovery

    Directory of Open Access Journals (Sweden)

    K. Nowińska

    2014-10-01

    Full Text Available Complex analysis of concentration and form of occurrence such metals as Zn, Pb, Fe and Cu in slags formed during a current zinc production in the Imperial Smelting Process (ISP is a possible basis for development of optimal recovery technology. For this purpose studies of slags from the current production of the Shaft Furnace Unit and of the Lead Refining of the “Miasteczko Śląskie” Zinc Smelting Plant were carried out. The studies results show that slags includes high concentrations of: Zn from 0,064 % to 1,680 %, Pb from 10,56 % to 50,71 %, Fe from 0,015 % to 2,576 %, Cu from 7,48 % to 64,95 %, and change in a broad range. This slags show significant heterogeneity, caused by intermetallic phases (Zn - Pb, Cu - Zn, Cu - Pb formed on the surface thereof. It is so possible that slag can be a potential source of this metals recovery.

  11. New developments in metal ion implantation by vacuum arc ion sources and metal plasma immersion

    International Nuclear Information System (INIS)

    Brown, I.G.; Anders, A.; Anders, S.

    1996-01-01

    Ion implantation by intense beams of metal ions can be accomplished using the dense metal plasma formed in a vacuum arc discharge embodied either in a vacuum arc ion source or in a metal plasma immersion configuration. In the former case high energy metal ion beams are formed and implantation is done in a more-or-less conventional way, and in the latter case the substrate is immersed in the plasma and repetitively pulse-biased so as to accelerate the ions at the high voltage plasma sheath formed at the substrate. A number of advances have been made in the last few years, both in plasma technology and in the surface modification procedures, that enhance the effectiveness and versatility of the methods, including for example: controlled increase of the in charge states produced; operation in a dual metal-gaseous ion species mode; very large area beam formation; macroparticle filtering; and the development of processing regimes for optimizing adhesion, morphology and structure. These complementary ion processing techniques provide the plasma tools for doing ion surface modification over a very wide parameter regime, from pure ion implantation at energies approaching the MeV level, through ion mixing at energies in the ∼1 to ∼100 keV range, to IBAD-like processing at energies from a few tens of eV to a few keV. Here the authors review the methods, describe a number of recent developments, and outline some of the surface modification applications to which the methods have been put. 54 refs., 9 figs

  12. Source term identification in atmospheric modelling via sparse optimization

    Science.gov (United States)

    Adam, Lukas; Branda, Martin; Hamburger, Thomas

    2015-04-01

    Inverse modelling plays an important role in identifying the amount of harmful substances released into atmosphere during major incidents such as power plant accidents or volcano eruptions. Another possible application of inverse modelling lies in the monitoring the CO2 emission limits where only observations at certain places are available and the task is to estimate the total releases at given locations. This gives rise to minimizing the discrepancy between the observations and the model predictions. There are two standard ways of solving such problems. In the first one, this discrepancy is regularized by adding additional terms. Such terms may include Tikhonov regularization, distance from a priori information or a smoothing term. The resulting, usually quadratic, problem is then solved via standard optimization solvers. The second approach assumes that the error term has a (normal) distribution and makes use of Bayesian modelling to identify the source term. Instead of following the above-mentioned approaches, we utilize techniques from the field of compressive sensing. Such techniques look for a sparsest solution (solution with the smallest number of nonzeros) of a linear system, where a maximal allowed error term may be added to this system. Even though this field is a developed one with many possible solution techniques, most of them do not consider even the simplest constraints which are naturally present in atmospheric modelling. One of such examples is the nonnegativity of release amounts. We believe that the concept of a sparse solution is natural in both problems of identification of the source location and of the time process of the source release. In the first case, it is usually assumed that there are only few release points and the task is to find them. In the second case, the time window is usually much longer than the duration of the actual release. In both cases, the optimal solution should contain a large amount of zeros, giving rise to the

  13. Radio identifications of IRAS point sources with b greater than 30 deg

    International Nuclear Information System (INIS)

    Condon, J.J.; Broderick, J.J.; Virginia Polytechnic Institute and State Univ., Blacksburg)

    1986-01-01

    The present radio identifications of IRAS point sources on the basis of Green Bank 1400 MHz survey maps notes that 365 hot IR sources are not detectable radio sources, and that nearly all cool high latitude IRAS sources are extragalactic. The fainter IR-source identifications encompass optically bright quasars, BL Lac objects, Seyfert galaxies, and elliptical galaxies. No IRAS sources could be identified with distant elliptical radio galaxies, so that although the radio and IR fluxes of most IRAS extragalactic sources are tightly correlated, complete samples of strong radio and IR sources are almost completely disjoint; no more than 1 percent of the IR sources are radio sources and less than 1 percent of the radio sources are IR ones. 35 references

  14. Study of highly charged ion production by electron cyclotron resonance ion source. Interactions of Argon 17+ ions with metallic surface at grazing incidence

    International Nuclear Information System (INIS)

    Ban, G.

    1992-04-01

    In this thesis divided in 2 parts, the author first presents the operating of MiniMafios 16/18 GHz ECR ion sources and methods of extracted multicharged ion identification and then, studies the highly charged ion interactions with a metallic surface and the formation of 'hollow atoms'. 556 figs., 17 tabs

  15. A Parameter Identification Method for Helicopter Noise Source Identification and Physics-Based Semi-Empirical Modeling

    Science.gov (United States)

    Greenwood, Eric, II; Schmitz, Fredric H.

    2010-01-01

    A new physics-based parameter identification method for rotor harmonic noise sources is developed using an acoustic inverse simulation technique. This new method allows for the identification of individual rotor harmonic noise sources and allows them to be characterized in terms of their individual non-dimensional governing parameters. This new method is applied to both wind tunnel measurements and ground noise measurements of two-bladed rotors. The method is shown to match the parametric trends of main rotor Blade-Vortex Interaction (BVI) noise, allowing accurate estimates of BVI noise to be made for operating conditions based on a small number of measurements taken at different operating conditions.

  16. Pollutant source identification model for water pollution incidents in small straight rivers based on genetic algorithm

    Science.gov (United States)

    Zhang, Shou-ping; Xin, Xiao-kang

    2017-07-01

    Identification of pollutant sources for river pollution incidents is an important and difficult task in the emergency rescue, and an intelligent optimization method can effectively compensate for the weakness of traditional methods. An intelligent model for pollutant source identification has been established using the basic genetic algorithm (BGA) as an optimization search tool and applying an analytic solution formula of one-dimensional unsteady water quality equation to construct the objective function. Experimental tests show that the identification model is effective and efficient: the model can accurately figure out the pollutant amounts or positions no matter single pollution source or multiple sources. Especially when the population size of BGA is set as 10, the computing results are sound agree with analytic results for a single source amount and position identification, the relative errors are no more than 5 %. For cases of multi-point sources and multi-variable, there are some errors in computing results for the reasons that there exist many possible combinations of the pollution sources. But, with the help of previous experience to narrow the search scope, the relative errors of the identification results are less than 5 %, which proves the established source identification model can be used to direct emergency responses.

  17. Use of dc Ar microdischarge with nonlocal plasma for identification of metal samples

    Energy Technology Data Exchange (ETDEWEB)

    Kudryavtsev, A. A., E-mail: akud@ak2138.spb.edu [St. Petersburg State University, 7-9 Universitetskaya nab., 199034 St. Petersburg (Russian Federation); Stefanova, M. S.; Pramatarov, P. M. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria)

    2015-04-07

    The possibility of using the collisional electron spectroscopy (CES) method for the detection of atoms from metal samples is experimentally verified. The detection and identification of metal atoms from a Pt sample in the nonlocal plasma of short (without positive column) dc Ar microdischarge at intermediate pressures (5–30 Torr) is realized in this work. Cathode sputtering is used for atomization of the metal under analysis. The identification of the analyzed metal is made from the energy spectra of groups of fast nonlocal electrons—characteristic electrons released in the Penning ionization of the Pt atoms by Ar metastable atoms and molecules. The acquisition of the electron energy spectra is performed using an additional electrode—a sensor located at the boundary of the discharge volume. The Pt characteristic Penning electrons form the maxima in the electron energy spectra at the energies of their appearance, which are 2.6 eV and 1.4 eV. From the measured energy of the maxima, identification of the metal atoms is accomplished. The characteristic Ar maxima due to pair collisions between Ar metastable atoms and molecules and super-elastic collisions are also recorded. This study demonstrates the possibility of creating a novel microplasma analyzer for atoms from metal samples.

  18. Identification of metal-tolerant organisms isolated from the ...

    African Journals Online (AJOL)

    2011-01-28

    Jan 28, 2011 ... To whom all correspondence should be addressed. ☎ +27 21 460-9095; ... mostly as biofilm communities attached to surfaces; microbial biofilms exhibit high ... 1) in a 10 ℓ plastic container and transported at 4°C. Metal concentrations .... using Blastn from the National Centre for Biotechnology. Information ...

  19. Characterization and source identification of pollutants in runoff from a mixed land use watershed using ordination analyses.

    Science.gov (United States)

    Lee, Dong Hoon; Kim, Jin Hwi; Mendoza, Joseph A; Lee, Chang Hee; Kang, Joo-Hyon

    2016-05-01

    While identification of critical pollutant sources is the key initial step for cost-effective runoff management, it is challenging due to the highly uncertain nature of runoff pollution, especially during a storm event. To identify critical sources and their quantitative contributions to runoff pollution (especially focusing on phosphorous), two ordination methods were used in this study: principal component analysis (PCA) and positive matrix factorization (PMF). For the ordination analyses, we used runoff quality data for 14 storm events, including data for phosphorus, 11 heavy metal species, and eight ionic species measured at the outlets of subcatchments with different land use compositions in a mixed land use watershed. Five factors as sources of runoff pollutants were identified by PCA: agrochemicals, groundwater, native soils, domestic sewage, and urban sources (building materials and automotive activities). PMF identified similar factors to those identified by PCA, with more detailed source mechanisms for groundwater (i.e., nitrate leaching and cation exchange) and urban sources (vehicle components/motor oils/building materials and vehicle exhausts), confirming the sources identified by PCA. PMF was further used to quantify contributions of the identified sources to the water quality. Based on the results, agrochemicals and automotive activities were the two dominant and ubiquitous phosphorus sources (39-61 and 16-47 %, respectively) in the study area, regardless of land use types.

  20. Identification and Quantification of Heavy Metals Concentrations in Pistacia

    Directory of Open Access Journals (Sweden)

    Gholamhossein DAVARYNEJAD

    2013-12-01

    Full Text Available The levels of heavy metals are very important in pistachio nuts, because the edible nuts have an important and increasing role in human nutrition. Pistachio is one of the native nuts of Iran which contains high genetic resources, but there is insufficient information regarding nutritional properties and other elements like heavy metals. The objective of the present study was to investigate and compare heavy metals contents in the kernels of various pistachio samples including; ‘Daneshmandi’, ‘Sephid’, ‘Garmeh’, ‘Momtaz’, ‘Ahmad Aghaei’, ‘Badami Zarand’, Pistacia atlantica Desf. (‘Baneh’, Pistacia vera ‘Sarakhs’ and chance seedling as ‘Non-grafted 1’, ‘Non-grafted 2’ and ‘Non-grafted 3’. Inductively coupled plasma emission spectrophotometer (ICP was used for the determination of aluminium, chromium, nickel, copper, strontium, arsenic, cadmium and cobalt concentrations in pistachio kernels. This study showed that there were significant differences among the samples in all measured heavy metals except the arsenic, cadmium and cobalt. The content of aluminium varied from 3.22 to 9.59 (mg kg-1 of dry matter and chromium concentration from 0.60 to 1.86 (mg kg-1 of dry matter. The nickel content of examined pistachio samples was found between 0.43 and 3.63 (mg kg-1 of dry matter and copper ranged from 3.20 to 12.33 (mg kg-1 of dry matter. The strontium content was observed between 4.96 and 24.93 (mg kg-1 of dry matter. The contents of arsenic, cadmium and cobalt not reported, because their amounts were lower than the detection limit of the applied measuring method (ICP. These data demonstrated that the concentrations of heavy metals in pistachios varied by cultivar.

  1. Application of Metamodels to Identification of Metallic Materials Models

    OpenAIRE

    Pietrzyk, Maciej; Kusiak, Jan; Szeliga, Danuta; Rauch, Łukasz; Sztangret, Łukasz; Górecki, Grzegorz

    2016-01-01

    Improvement of the efficiency of the inverse analysis (IA) for various material tests was the objective of the paper. Flow stress models and microstructure evolution models of various complexity of mathematical formulation were considered. Different types of experiments were performed and the results were used for the identification of models. Sensitivity analysis was performed for all the models and the importance of parameters in these models was evaluated. Metamodels based on artificial ne...

  2. Application of Metamodels to Identification of Metallic Materials Models

    Directory of Open Access Journals (Sweden)

    Maciej Pietrzyk

    2016-01-01

    Full Text Available Improvement of the efficiency of the inverse analysis (IA for various material tests was the objective of the paper. Flow stress models and microstructure evolution models of various complexity of mathematical formulation were considered. Different types of experiments were performed and the results were used for the identification of models. Sensitivity analysis was performed for all the models and the importance of parameters in these models was evaluated. Metamodels based on artificial neural network were proposed to simulate experiments in the inverse solution. Performed analysis has shown that significant decrease of the computing times could be achieved when metamodels substitute finite element model in the inverse analysis, which is the case in the identification of flow stress models. Application of metamodels gave good results for flow stress models based on closed form equations accounting for an influence of temperature, strain, and strain rate (4 coefficients and additionally for softening due to recrystallization (5 coefficients and for softening and saturation (7 coefficients. Good accuracy and high efficiency of the IA were confirmed. On the contrary, identification of microstructure evolution models, including phase transformation models, did not give noticeable reduction of the computing time.

  3. Identification of Potential Sources of Mercury (Hg) in Farmland Soil Using a Decision Tree Method in China.

    Science.gov (United States)

    Zhong, Taiyang; Chen, Dongmei; Zhang, Xiuying

    2016-11-09

    Identification of the sources of soil mercury (Hg) on the provincial scale is helpful for enacting effective policies to prevent further contamination and take reclamation measurements. The natural and anthropogenic sources and their contributions of Hg in Chinese farmland soil were identified based on a decision tree method. The results showed that the concentrations of Hg in parent materials were most strongly associated with the general spatial distribution pattern of Hg concentration on a provincial scale. The decision tree analysis gained an 89.70% total accuracy in simulating the influence of human activities on the additions of Hg in farmland soil. Human activities-for example, the production of coke, application of fertilizers, discharge of wastewater, discharge of solid waste, and the production of non-ferrous metals-were the main external sources of a large amount of Hg in the farmland soil.

  4. Identification of radioactive sources and devices. Reference manual

    International Nuclear Information System (INIS)

    2007-01-01

    This publication is intended to be a basic guide and not a comprehensive tool kit to identify and provide detailed emergency handling instructions for radioactive sources, devices and transport containers. In addition, this publication helps to identify sources and highlight the risks they present, and provides information on appropriate action. It is a small but significant step in the international community's continuing efforts to strengthen control of radioactive sources and nuclear material, increase safety and security, and thereby make the benefits of radioactive sources ever more broadly accessible. This publication was partly funded through the Nuclear Security Fund established under the Nuclear Security Plan

  5. Development of unauthorized airborne emission source identification procedure

    Science.gov (United States)

    Shtripling, L. O.; Bazhenov, V. V.; Varakina, N. S.; Kupriyanova, N. P.

    2018-01-01

    The paper presents the procedure for searching sources of unauthorized airborne emissions. To make reasonable regulation decisions on airborne pollutant emissions and to ensure the environmental safety of population, the procedure provides for the determination of a pollutant mass emission value from the source being the cause of high pollution level and the search of a previously unrecognized contamination source in a specified area. To determine the true value of mass emission from the source, the minimum of the mean-root-square mismatch criterion between the computed and measured pollutant concentration in the given location is used.

  6. Identification of Turbomachinery Noise Sources Using Acoustical Holography, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Evaluation and enhancement of the acoustical performance of turbomachinery requires knowledge of the acoustic sources. However, the noise generation mechanisms...

  7. Weak acid extractable metals in Bramble Bay, Queensland, Australia: temporal behaviour, enrichment and source apportionment.

    Science.gov (United States)

    Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

    2015-02-15

    Sediment samples were taken from six sampling sites in Bramble Bay, Queensland, Australia between February and November in 2012. They were analysed for a range of heavy metals including Al, Fe, Mn, Ti, Ce, Th, U, V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Te, Hg, Tl and Pb. Fraction analysis, Enrichment Factors and Principal Component Analysis-Absolute Principal Component Scores (PCA-APCS) were carried out in order to assess metal pollution, potential bioavailability and source apportionment. Cr and Ni exceeded the Australian Interim Sediment Quality Guidelines at some sampling sites, while Hg was found to be the most enriched metal. Fraction analysis identified increased weak acid soluble Hg and Cd during the sampling period. Source apportionment via PCA-APCS found four sources of metals pollution, namely, marine sediments, shipping, antifouling coatings and a mixed source. These sources need to be considered in any metal pollution control measure within Bramble Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Future radiation sources and identification of irradiated foods

    International Nuclear Information System (INIS)

    Brynjolfsson, A.

    1989-01-01

    Two major questions regarding irradiation that are raised today are: (1) Which sources should be used for irradiating food? and (2) How can irradiated foods be identified? This article considers both questions. After briefly mentioning a few of the historical stepping stones in the development of radiation sources, present and future radiation sources are discussed. Next the changes in foods caused by irradiation are considered. These changes are extremely small-so minor in fact that it is difficult to detect if the food has been irradiated. Still, these are several detection methods available, and this article describes them

  9. Application of spectrometric analysis to the identification of pollution sources causing cultural heritage damage.

    Science.gov (United States)

    Belfiore, C M; Barca, D; Bonazza, A; Comite, V; La Russa, M F; Pezzino, A; Ruffolo, S A; Sabbioni, C

    2013-12-01

    Black crusts are recognized to have been, up to now, one of the major deterioration forms affecting the built heritage in urban areas. Their formation is demonstrated to occur mainly on carbonate building materials, whose interaction with an SO2-loaded atmosphere leads to the transformation of calcium carbonate (calcite) into calcium sulfate dihydrate (gypsum) which, together with embedded carbonaceous particles, consequently forms the black crusts on the stone surface. An analytical study was carried out on black crust samples collected from limestone monumental buildings and churches belonging to the European built Heritage, i.e., the Corner Palace in Venice (Italy), the Cathedral of St. Rombouts in Mechelen (Belgium), and the Church of St. Eustache in Paris (France). For a complete characterization of the black crusts, an approach integrating different and complementary techniques was used, including laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), Fourier transform infrared spectroscopy, optical and scanning electron microscopy. In particular, the application of LA-ICP-MS permitted to obtain a complete geochemical characterization in terms of trace elements of the black crusts from the inner parts to the external layers contributing to the identification of the major combustion sources responsible for the deterioration over time of the monuments under study. In addition, the obtained results revealed a relation between the height of sampling and the concentration of heavy metals and proved that the crust composition can be a marker to evaluate the variation of the fuels used over time.

  10. Source identification of a tar residue from Mumbai Beach

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A; Rokade, M.A

    A tar residue from Mumbai Beach, Maharashtra, India was matched with the suspected source sample from a tanker using UV, IR and GLC techniques. Negligible differences in several ratios of UV absorbances and ratios of infrared transmittances...

  11. Optical identifications of flat-spectrum radio sources

    International Nuclear Information System (INIS)

    Condon, J.J.; Condon, M.A.; Broderick, J.J.; Davis, M.M.

    1983-01-01

    A complete sample of radio sources with S> or =0.3 Jy at 1400 MHz, +24 0 0 , and low-frequency spectral indices α(408, 1400) or =+0.5 are usually in empty fields. The lower limits that can be assigned to the radio-optical spectral indices α/sub RO/ of these sources are significantly higher than the median α/sub RO/ of the sources with flat high-frequency spectra, so the optical characteristics of the two classes of radio source are intrinsically different. The radio and optical fluxes of flat-spectrum QSO's appear to be correlated, at least when averaged over 10 2 --10 3 yr

  12. High Fidelity Tool for Noise Source Identification, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorough understanding of airframe and propulsion aerodynamic noise sources and the subsequent acoustic propagation to the farfield is necessary to the design and...

  13. Demonstration of an ethane spectrometer for methane source identification.

    Science.gov (United States)

    Yacovitch, Tara I; Herndon, Scott C; Roscioli, Joseph R; Floerchinger, Cody; McGovern, Ryan M; Agnese, Michael; Pétron, Gabrielle; Kofler, Jonathan; Sweeney, Colm; Karion, Anna; Conley, Stephen A; Kort, Eric A; Nähle, Lars; Fischer, Marc; Hildebrandt, Lars; Koeth, Johannes; McManus, J Barry; Nelson, David D; Zahniser, Mark S; Kolb, Charles E

    2014-07-15

    Methane is an important greenhouse gas and tropospheric ozone precursor. Simultaneous observation of ethane with methane can help identify specific methane source types. Aerodyne Ethane-Mini spectrometers, employing recently available mid-infrared distributed feedback tunable diode lasers (DFB-TDL), provide 1 s ethane measurements with sub-ppb precision. In this work, an Ethane-Mini spectrometer has been integrated into two mobile sampling platforms, a ground vehicle and a small airplane, and used to measure ethane/methane enhancement ratios downwind of methane sources. Methane emissions with precisely known sources are shown to have ethane/methane enhancement ratios that differ greatly depending on the source type. Large differences between biogenic and thermogenic sources are observed. Variation within thermogenic sources are detected and tabulated. Methane emitters are classified by their expected ethane content. Categories include the following: biogenic (6%), pipeline grade natural gas (30%). Regional scale observations in the Dallas/Fort Worth area of Texas show two distinct ethane/methane enhancement ratios bridged by a transitional region. These results demonstrate the usefulness of continuous and fast ethane measurements in experimental studies of methane emissions, particularly in the oil and natural gas sector.

  14. Source-Type Identification Analysis Using Regional Seismic Moment Tensors

    Science.gov (United States)

    Chiang, A.; Dreger, D. S.; Ford, S. R.; Walter, W. R.

    2012-12-01

    Waveform inversion to determine the seismic moment tensor is a standard approach in determining the source mechanism of natural and manmade seismicity, and may be used to identify, or discriminate different types of seismic sources. The successful applications of the regional moment tensor method at the Nevada Test Site (NTS) and the 2006 and 2009 North Korean nuclear tests (Ford et al., 2009a, 2009b, 2010) show that the method is robust and capable for source-type discrimination at regional distances. The well-separated populations of explosions, earthquakes and collapses on a Hudson et al., (1989) source-type diagram enables source-type discrimination; however the question remains whether or not the separation of events is universal in other regions, where we have limited station coverage and knowledge of Earth structure. Ford et al., (2012) have shown that combining regional waveform data and P-wave first motions removes the CLVD-isotropic tradeoff and uniquely discriminating the 2009 North Korean test as an explosion. Therefore, including additional constraints from regional and teleseismic P-wave first motions enables source-type discrimination at regions with limited station coverage. We present moment tensor analysis of earthquakes and explosions (M6) from Lop Nor and Semipalatinsk test sites for station paths crossing Kazakhstan and Western China. We also present analyses of smaller events from industrial sites. In these sparse coverage situations we combine regional long-period waveforms, and high-frequency P-wave polarity from the same stations, as well as from teleseismic arrays to constrain the source type. Discrimination capability with respect to velocity model and station coverage is examined, and additionally we investigate the velocity model dependence of vanishing free-surface traction effects on seismic moment tensor inversion of shallow sources and recovery of explosive scalar moment. Our synthetic data tests indicate that biases in scalar

  15. Stable Isotope Identification of Nitrogen Sources for United ...

    Science.gov (United States)

    We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected δ15N of macroalgae data and supplemented this with available data from the literature for estuaries from Mexico to Alaska. Stable isotope ratios of green macroalgae were compared to δ15N of dissolved inorganic nitrogen of oceanic and watershed end members. There was a latitudinal gradient in δ15N of macroalgae with southern estuaries being 7 per mil heavier than northern estuaries. Gradients in isotope data were compared to nitrogen sources estimated by the USGS using the SPARROW model. In California estuaries, the elevation of isotope data appeared to be related to anthropogenic nitrogen sources. In Oregon systems, the nitrogen levels of streams flowing into the estuaries are related to forest cover, rather than to developed land classes. In addition, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources. There was also a strong gradient in δ15N of macroalgae with heavier sites located near the estuary mouth. In some Oregon estuaries, there was an elevation an elevation of δ15N above marine end members in the vicinity of wastewater treatment facility discharge locations, suggesting isotopes may be useful for distinguishing inputs along an estuarine gradient. Nutrients are the leading cause of water quality impairments in the United States, and as a result too

  16. incidence of heavy metals in kano metropolis drinking water sources

    African Journals Online (AJOL)

    userpc

    corrosion of brass fittings of certain submersible pumps and pipes used in borehole and taps specifically. The contamination of well with heavy metals might be due to seepage of sewage ... Chloride determination (Agumetric method):.

  17. Assessment of Heavy Metals in Waterleaf from Various Sources in ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Standard method was followed for sample treatment, digestion, and analysis of selected heavy metals: lead .... research laboratory, University of Ibadan. Each ... Survey of consumption of waterleaf in Ota: Over 500 ..... In Encyclopedia of.

  18. Identification of resistant sources in chickpea against fusarium wilt

    International Nuclear Information System (INIS)

    Ahmad, M.A.; Ayub, N.; Akram, A.

    2010-01-01

    Wilt caused by Fusarium oxysporum Schlechtend.Fr. f. sp. ciceris is a devastating disease of chickpea in Pakistan. In the present study 321 genotypes from different sources were evaluated under controlled condition to identify genetic sources of resistance against this disease at seedling and reproductive stage. Disease reaction at two stages revealed considerable variation among the genotypes. At seedling stage disease incidence varied from 0 to 29.3% whereas at reproductive stage ranged from 0 to 57%. At seedling stage 173 genotypes were resistant, 54 were tolerant and 94 were susceptible, whereas at reproductive stage, 102 genotypes were resistant, 36 were tolerant and 183 were susceptible. Eighty two genotypes showed steady resistance at both stages. These genotypes may be exploited for the development of resistant cultivars against wilt. (author

  19. Response of dissolved trace metals to land use/land cover and their source apportionment using a receptor model in a subtropic river, China.

    Science.gov (United States)

    Li, Siyue; Zhang, Quanfa

    2011-06-15

    Water samples were collected for determination of dissolved trace metals in 56 sampling sites throughout the upper Han River, China. Multivariate statistical analyses including correlation analysis, stepwise multiple linear regression models, and principal component and factor analysis (PCA/FA) were employed to examine the land use influences on trace metals, and a receptor model of factor analysis-multiple linear regression (FA-MLR) was used for source identification/apportionment of anthropogenic heavy metals in the surface water of the River. Our results revealed that land use was an important factor in water metals in the snow melt flow period and land use in the riparian zone was not a better predictor of metals than land use away from the river. Urbanization in a watershed and vegetation along river networks could better explain metals, and agriculture, regardless of its relative location, however slightly explained metal variables in the upper Han River. FA-MLR analysis identified five source types of metals, and mining, fossil fuel combustion, and vehicle exhaust were the dominant pollutions in the surface waters. The results demonstrated great impacts of human activities on metal concentrations in the subtropical river of China. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Preliminary investigation of processes that affect source term identification

    International Nuclear Information System (INIS)

    Wickliff, D.S.; Solomon, D.K.; Farrow, N.D.

    1991-09-01

    Solid Waste Storage Area (SWSA) 5 is known to be a significant source of contaminants, especially tritium ( 3 H), to the White Oak Creek (WOC) watershed. For example, Solomon et al. (1991) estimated the total 3 H discharge in Melton Branch (most of which originates in SWSA 5) for the 1988 water year to be 1210 Ci. A critical issue for making decisions concerning remedial actions at SWSA 5 is knowing whether the annual contaminant discharge is increasing or decreasing. Because (1) the magnitude of the annual contaminant discharge is highly correlated to the amount of annual precipitation (Solomon et al., 1991) and (2) a significant lag may exist between the time of peak contaminant release from primary sources (i.e., waste trenches) and the time of peak discharge into streams, short-term stream monitoring by itself is not sufficient for predicting future contaminant discharges. In this study we use 3 H to examine the link between contaminant release from primary waste sources and contaminant discharge into streams. By understanding and quantifying subsurface transport processes, realistic predictions of future contaminant discharge, along with an evaluation of the effectiveness of remedial action alternatives, will be possible. The objectives of this study are (1) to characterize the subsurface movement of contaminants (primarily 3 H) with an emphasis on the effects of matrix diffusion; (2) to determine the relative strength of primary vs secondary sources; and (3) to establish a methodology capable of determining whether the 3 H discharge from SWSA 5 to streams is increasing or decreasing

  1. Identification of Radiation Sources in a Peacetime Environment

    Science.gov (United States)

    1998-04-01

    Radionuclides in Medicine, Research, and Industry (continued) Isotope Symbol Polonium - 210 Po- 210 Promethium-147 Pr-147 Radium-226 Ra-226 Selenium-75 Se...equip- ment seen in a nuclear medicine department or nuclear pharmacy, radia- tion therapy sources, industrial food irradiation facilities, and small... Food Irradiator 28 Commercial Irradiator Facility 28 Appendix 1. Commonly Used Radionuclides in Medicine, Research, and Industry 29 General

  2. Vertical characteristics and source identification of PM10 in Tianjin

    Institute of Scientific and Technical Information of China (English)

    Zhimei Xiao; Jianhui Wu; Suqin Han; Yufen Zhang; Hong Xu; Xiaoyong Zhang; Guoliang Shi; Yinchang Feng

    2012-01-01

    Ambient PM10 (particulate matter with a diameter less than 10 μm) concentrations were measured on a 255 meter tower in Tianjin,China.The samples were collected at four vertical levels (10,40,120 and 220 m).Vertical characteristics for PM10 samples were studied.The results showed that the concentrations of PM10 and constituent species had a negative correlation with the sampling height.The highest concentrations of PM10 and species were obtained at the 10 m level,and the lowest concentrations were measured at the 220 m level.For the fractions of species to total mass,SO42- and NO3- had higher values (fraction) at greater height; while Ca had a higher fraction at lower height.Possible source categories for the PM10 ambient dataset were identified by the principal component analysis method.The possible source categories included crustal dust,vehicles,cement dust,and incineration as well as secondary sulfate and nitrate sources.Analysis of meteorological factors on PM10 concentrations indicated that wind speed and inversion may be the main factors contributing to different concentrations of PM10 at different heights.

  3. Applications of Open Source GMAW-Based Metal 3-D Printing

    OpenAIRE

    Yuenyong Nilsiam; Paul G. Sanders; Joshua M. Pearce

    2018-01-01

    The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequ...

  4. Metallic vapor supplying by the electron bombardment for a metallic ion production with an ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kitagawa, Atsushi; Sasaki, Makoto; Muramatsu, Masayuki [National Inst. of Radiological Sciences, Chiba (Japan); Jincho, Kaoru; Sasaki, Noriyuki; Sakuma, Tetsuya; Takasugi, Wataru; Yamamoto, Mitsugu [Accelerator Engineering Corporation, Chiba (Japan)

    2001-11-19

    To produce the metallic ion beam for the injection into the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS), a new gas supply method has been developed for an 18 GHz ECR ion source (NIRS-HEC). A metallic target rod at a high positive potential is melted by the electron bombardment technique. The evaporated gas with a maximum flow rate of 50A/sec is supplied into the ECR plasma in case of Fe metal. (author)

  5. Metallic vapor supplying by the electron bombardment for a metallic ion production with an ECR ion source

    International Nuclear Information System (INIS)

    Kitagawa, Atsushi; Sasaki, Makoto; Muramatsu, Masayuki; Jincho, Kaoru; Sasaki, Noriyuki; Sakuma, Tetsuya; Takasugi, Wataru; Yamamoto, Mitsugu

    2001-01-01

    To produce the metallic ion beam for the injection into the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS), a new gas supply method has been developed for an 18 GHz ECR ion source (NIRS-HEC). A metallic target rod at a high positive potential is melted by the electron bombardment technique. The evaporated gas with a maximum flow rate of 50A/sec is supplied into the ECR plasma in case of Fe metal. (author)

  6. Identification of lead sources in residential environments: Sydney Australia

    International Nuclear Information System (INIS)

    Laidlaw, M.A.S.; Zahran, S.; Pingitore, N.; Clague, J.; Devlin, G.; Taylor, M.P.

    2014-01-01

    Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure. Exterior dust gauge Pb loading rates (μg/m 2 /28 days), interior vacuum dust Pb concentrations (mg/kg) and interior petri-dish Pb loading rates (μg/m 2 /28 days), were correlated positively with soil Pb concentrations. Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peaked in the summer. Lead isotope and Pb speciation (XAS) were analysed in soil and vacuum dust samples from three of the five houses that had elevated Pb concentrations. Results show that the source of interior dust lead was primarily from soil in two of the three houses and from soil and Pb paint in the third home. IEUBK child blood Pb modelling predicts that children's blood Pb levels could exceed 5 μg/dL in two of the five houses. -- Highlights: • Exterior Pb loading and interior Pb dust loading and concentrations correlate with soil Pb. • Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peak in the summer. • Interior dust lead came from soil in two of the three houses and from soil and Pb paint in the third home. • Modelling predicts that children's blood Pb levels could exceed 5 μg/dL in two of the five houses. -- Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure

  7. Development of a novel methodology for indoor emission source identification

    DEFF Research Database (Denmark)

    Han, K.H.; Zhang, J.S.; Knudsen, H.N.

    2011-01-01

    The objective of this study was to develop and evaluate a methodology to identify individual sources of emissions based on the measurements of mixed air samples and the emission signatures of individual materials previously determined by Proton Transfer Reaction-Mass Spectrometry (PTR-MS), an on......-line analytical device. The methodology based on signal processing principles was developed by employing the method of multiple regression least squares (MRLS) and a normalization technique. Samples of nine typical building materials were tested individually and in combination, including carpet, ceiling material...... experiments and investigation are needed for cases where the relative emission rates among different compounds may change over a long-term period....

  8. [Source identification of toxic wastewaters in a petrochemical industrial park].

    Science.gov (United States)

    Yang, Qian; Yu, Yin; Zhou, Yue-Xi; Chen, Xue-Min; Fu, Xiao-Yong; Wang, Miao

    2014-12-01

    Petrochemical wastewaters have toxic impacts on the microorganisms in biotreatment processes, which are prone to cause deterioration of effluent quality of the wastewater treatment plants. In this study, the inhibition effects of activated sludge's oxygen consumption were tested to evaluate the toxicity of production wastewaters in a petrochemical industrial park. The evaluation covered the wastewaters from not only different production units in the park, but also different production nodes in each unit. No direct correlation was observed between the toxicity effects and the organic contents, suggesting that the toxic properties of the effluents could not be predicted by the organic contents. In view of the variation of activated sludge sensitivity among different tests, the toxicity data were standardized according to the concentration-effect relationships of the standard toxic substance 3, 5-dichlorophenol on each day, in order to improve the comparability among the toxicity data. Furthermore, the Quality Emission Load (QEL) of corresponding standard toxic substance was calculated by multiplying the corresponding 3, 5-dichlorophenol concentration and the wastewater flow quantity, to indicate the toxicity emission contribution of each wastewater to the wastewater treatment plant. According to the rank list of the toxicity contribution of wastewater from different units and nodes, the sources of toxic wastewater in the petrochemical industrial park were clearly identified. This study provides effective guidance for source control of wastewater toxicity in the large industrial park.

  9. Blind source identification from the multichannel surface electromyogram

    International Nuclear Information System (INIS)

    Holobar, A; Farina, D

    2014-01-01

    The spinal circuitries combine the information flow from the supraspinal centers with the afferent input to generate the neural codes that drive the human skeletal muscles. The muscles transform the neural drive they receive from alpha motor neurons into motor unit action potentials (electrical activity) and force. Thus, the output of the spinal cord circuitries can be examined noninvasively by measuring the electrical activity of skeletal muscles at the surface of the skin i.e. the surface electromyogram (EMG). The recorded multi-muscle EMG activity pattern is generated by mixing processes of neural sources that need to be identified from the recorded signals themselves, with minimal or no a priori information available. Recently, multichannel source separation techniques that rely minimally on a priori knowledge of the mixing process have been developed and successfully applied to surface EMG. They act at different scales of information extraction to identify: (a) the activation signals shared by synergistic skeletal muscles, (b) the specific neural activation of individual muscles, separating it from that of nearby muscles i.e. from crosstalk, and (c) the spike trains of the active motor neurons. This review discusses the assumptions made by these methods, the challenges and limitations, as well as examples of their current applications. (topical review)

  10. Isotopic abundances relevant to the identification of magma sources

    International Nuclear Information System (INIS)

    O'Nions, R.K.

    1984-01-01

    The behaviour of natural radiogenic isotope tracers in the Earth that have lithophile and atmophile geochemical affinity is reviewed. The isotope tracer signature of oceanic and continental crust may in favourable circumstances by sufficiently distinct from that of the mantle to render a contribution from these sources resolvable within the isotopic composition of the magma. Components derived from the sedimentary and altered basaltic portion of oceanic crust are recognized in some island arc magmas from their Sr, Nd and Pb isotopic signatures. The rare-gas isotope tracers (He, Ar, Xe in particular) are not readily recycled into the mantle and thus provide the basis of an approach that is complementary to that based on the lithophile tracers. In particular, a small mantle-derived helium component may be readily recognized in the presence of a predominant radiogenic component generated in the continents. The importance of assessing the mass balance of these interactions rather than merely a qualitative recognition is emphasized. The question of the relative, contribution of continental-oceanic crust and mantle to magma sources is an essential part of the problem of generation and evolution of continental crust. An approach to this problem through consideration of the isotopic composition of sediments is briefly discussed. (author)

  11. Radon in houses - identification of sources and pathways of transfer

    International Nuclear Information System (INIS)

    Robe, M.C.; Rannou, A.; Le Bronec, J.

    1992-01-01

    The Institut de Protection et de Surete Nucleaire (IPSN) is studying the remedial actions to reduce high concentration of radon in houses. The first step to know how to modify houses is to identify radon sources and pathways of transfer to upper floors. A pilot study in Brittany was designed to develop a simple method of diagnosis. This investigation was based on indoor and outdoor measurements of 222 Rn activity concentration in the air and 222 Rn area exhalation rate from the soils and walls, measurements of the potential alpha energy concentration of 222 Rn daughters and the ventilation rate. The structural characteristics of houses and the influence of the life style of the inhabitants were examined. Analysis of the results showed that a limited number of parameters can be selected for use in a rapid radon diagnosis. (author)

  12. Ecotoxicology of Metals - Sources, Transport, and Effects on the Ecosystem

    DEFF Research Database (Denmark)

    Bjerregaard, Poul; Andersen, Christian B. I.; Andersen, Ole

    2014-01-01

    . In the environment, the most adverse impacts of metals (on populations) have been caused by organic tin compounds used in antifouling paints and aluminum mobilized by acid rain. High concentrations of organic mercury and cadmium in certain organisms may cause concerns for the health of human populations that rely...

  13. Malbranchea cinnamomea: A thermophilic fungal source of catalytically efficient lignocellulolytic glycosyl hydrolases and metal dependent enzymes.

    Science.gov (United States)

    Mahajan, Chhavi; Basotra, Neha; Singh, Surender; Di Falco, Marcos; Tsang, Adrian; Chadha, B S

    2016-01-01

    This study reports thermophilic fungus Malbranchea cinnamomea as an important source of lignocellulolytic enzymes. The secretome analysis using LC-MS/MS orbitrap showed that fungus produced a spectrum of glycosyl hydrolases (cellulase/hemicellulase), polysaccharide lyases (PL) and carbohydrate esterases (CE) in addition to cellobiose dehydrogenase (CDH) indicating the presence of functional classical and oxidative cellulolytic mechanisms. The protein fractions in the secretome resolved by ion exchange chromatography were analyzed for ability to hydrolyze alkali treated carrot grass (ATCG) in the presence of Mn(2+)/Cu(2+). This strategy in tandem with peptide mass fingerprinting led to identification of metal dependent protein hydrolases with no apparent hydrolytic activity, however, showed 5.7 folds higher saccharification in presence of Mn(2+). Furthermore, adding different protein fractions to commercial cellulase (Novozymes: Cellic CTec2) resulted in enhanced hydrolysis of ATCG ranging between 1.57 and 3.43 folds indicating the enzymes from M. cinnamomea as catalytically efficient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Source identification of individual soot agglomerates in Arctic air by transmission electron microscopy

    Science.gov (United States)

    Weinbruch, S.; Benker, N.; Kandler, K.; Schütze, K.; Kling, K.; Berlinger, B.; Thomassen, Y.; Drotikova, T.; Kallenborn, R.

    2018-01-01

    Individual soot agglomerates collected at four different locations on the Arctic archipelago Svalbard (Norway) were characterised by transmission electron microscopy and energy-dispersive X-ray microanalysis. For source identification of the ambient soot agglomerates, samples from different local sources (coal burning power plants in Longyearbyen and Barentsburg, diesel and oil burning for power generation in Sveagruva and Ny Ålesund, cruise ship) as well as from other sources which may contribute to Arctic soot concentrations (biomass burning, aircraft emissions, diesel engines) were investigated. Diameter and graphene sheet separation distance of soot primary particles were found to be highly variable within each source and are not suited for source identification. In contrast, concentrations of the minor elements Si, P, K, Ca and Fe showed significant differences which can be used for source attribution. The presence/absence of externally mixed particle groups (fly ashes, tar balls, mercury particles) gives additional hints about the soot sources. Biomass/wood burning, ship emissions and coal burning in Barentsburg can be excluded as major source for ambient soot at Svalbard. The coal power plant in Longyearbyen is most likely a major source of soot in the settlement of Longyearbyen but does not contribute significantly to soot collected at the Global Atmosphere Watch station Zeppelin Mountain near Ny Ålesund. The most probable soot sources at Svalbard are aircraft emissions and diesel exhaust as well as long range transport of coal burning emissions.

  15. On-chip fabrication of alkali-metal vapor cells utilizing an alkali-metal source tablet

    International Nuclear Information System (INIS)

    Tsujimoto, K; Hirai, Y; Sugano, K; Tsuchiya, T; Tabata, O; Ban, K; Mizutani, N

    2013-01-01

    We describe a novel on-chip microfabrication technique for the alkali-metal vapor cell of an optically pumped atomic magnetometer (OPAM), utilizing an alkali-metal source tablet (AMST). The newly proposed AMST is a millimeter-sized piece of porous alumina whose considerable surface area holds deposited alkali-metal chloride (KCl) and barium azide (BaN 6 ), source materials that effectively produce alkali-metal vapor at less than 400 °C. Our experiments indicated that the most effective pore size of the AMST is between 60 and 170 µm. The thickness of an insulating glass spacer holding the AMST was designed to confine generated alkali metal to the interior of the vapor cell during its production, and an integrated silicon heater was designed to seal the device using a glass frit, melted at an optimum temperature range of 460–490 °C that was determined by finite element method thermal simulation. The proposed design and AMST were used to successfully fabricate a K cell that was then operated as an OPAM with a measured sensitivity of 50 pT. These results demonstrate that the proposed concept for on-chip microfabrication of alkali-metal vapor cells may lead to effective replacement of conventional glassworking approaches. (paper)

  16. Application of the positive matrix factorization approach to identify heavy metal sources in sediments. A case study on the Mexican Pacific Coast.

    Science.gov (United States)

    González-Macías, C; Sánchez-Reyna, G; Salazar-Coria, L; Schifter, I

    2014-01-01

    During the last two decades, sediments collected in different sources of water bodies of the Tehuantepec Basin, located in the southeast of the Mexican Pacific Coast, showed that concentrations of heavy metals may pose a risk to the environment and human health. The extractable organic matter, geoaccumulation index, and enrichment factors were quantified for arsenic, cadmium, copper, chromium, nickel, lead, vanadium, zinc, and the fine-grained sediment fraction. The non-parametric SiZer method was applied to assess the statistical significance of the reconstructed metal variation along time. This inference method appears to be particularly natural and well suited to temperature and other environmental reconstructions. In this approach, a collection of smooth of the reconstructed metal concentrations is considered simultaneously, and inferences about the significance of the metal trends can be made with respect to time. Hence, the database represents a consolidated set of available and validated water and sediment data of an urban industrialized area, which is very useful as case study site. The positive matrix factorization approach was used in identification and source apportionment of the anthropogenic heavy metals in the sediments. Regionally, metals and organic matter are depleted relative to crustal abundance in a range of 45-55 %, while there is an inorganic enrichment from lithogenous/anthropogenic sources of around 40 %. Only extractable organic matter, Pb, As, and Cd can be related with non-crustal sources, suggesting that additional input cannot be explained by local runoff or erosion processes.

  17. PAH diagnostic ratios for the identification of pollution emission sources

    International Nuclear Information System (INIS)

    Tobiszewski, Marek; Namieśnik, Jacek

    2012-01-01

    Polycyclic aromatic hydrocarbon (PAH) diagnostic ratios have recently come into common use as a tool for identifying and assessing pollution emission sources. Some diagnostic ratios are based on parent PAHs, others on the proportions of alkyl-substituted to non-substituted molecules. The ratios are applicable to PAHs determined in different environmental media: air (gas + particle phase), water, sediment, soil, as well as biomonitor organisms such as leaves or coniferous needles, and mussels. These ratios distinguish PAH pollution originating from petroleum products, petroleum combustion and biomass or coal burning. The compounds involved in each ratio have the same molar mass, so it is assumed they have similar physicochemical properties. Numerous studies show that diagnostic ratios change in value to different extents during phase transfers and environmental degradation. The paper reviews applications of diagnostic ratios, comments on their use and specifies their limitations. - Highlights: ► PAH diagnostic ratios may identify pollution coming from petroleum spills, fuel combustion and coal or biomass burning. ► They are sensitive to changes during PAHs environmental fate processes. ► Some diagnostic ratios are of limited value due to fast photodegradation of one of the compounds. - The paper reviews PAH diagnostic ratios that are applied to identify pollution emission originating from petroleum products, fuel combustion or coal and biomass burning.

  18. Source identification of soil mercury in the Spanish islands.

    Science.gov (United States)

    Rodríguez Martín, José Antonio; Carbonell, Gregoria; Nanos, Nikos; Gutiérrez, Carmen

    2013-02-01

    This study spatially analysed the relation between mercury (Hg) content in soil and Hg in rock fragment for the purpose of assessing natural soil Hg contribution compared with Hg from human inputs. We present the Hg content of 318 soil and rock fragment samples from 11 islands distributed into two Spanish archipelagos (the volcanic Canary Islands [Canaries] and the Mediterranean Balearic [Balearic] islands). Assumedly both are located far enough away from continental Hg sources to be able to minimise the effects of diffuse pollution. Physical and chemical soil properties were also specified for the samples. Hg contents were significantly greater in the Balearic limestone soils (61 μg kg(-1)) than in the volcanic soils of the Canaries (33 μg kg(-1)). Hg levels were also greater in topsoil than in rocky fragments, especially on the Balearics. The soil-to-rock ratios varied between 1 and 30. Interestingly, the highest topsoil-to-rock Hg ratio (>16 ×) was found in the vicinity of a coal-fired power plant in Majorca, whereas no similar areas in the Canary archipelago were identified.

  19. Identification of neutron noise sources in a boiling water reactor

    International Nuclear Information System (INIS)

    Sides, W.H. Jr.; Mathis, M.V.; Smith, C.M.

    1977-01-01

    Measurements were made at units 2 and 3 of the Browns Ferry Nuclear Power Plant in order to characterize the noise signatures of the neutron and process signals and to determine the usefulness of such signatures for anomaly detection in BWR-4s. Previous measurements and theoretical analyses of BWR noise by others were concerned with the determination of steam velocity and void fraction (using the local component of neutron noise) and with the sources of global noise. The work described is under a five-part program to develop a complete and systematic analysis and representation of BWR neutron and process noise through complementary measurements and stochastic model developments. The parts are: (1) recording as many neutron detector and process noise signals as are available in a BWR-4; (2) reducing these data to noise signatures in order to perform an empirical analysis of these signatures, and documenting the relationships between the signals from spatially separated neutron detectors and between neutron and process variables; (3) developing spatially dependent neutronic models coupled with thermal-hydraulic models to aid in interpreting the observed relationships among the measured noise signatures, (4) comparing measured noise signatures with model predictions to obtain additional insight into BWR-4 dynamic behavior and to validate the models; and (5) using these models to predict the sensitivity of noise monitoring for detection, surveillance, and diagnosis of postulated in-core anomalies in BWRs. The paper describes the procedures used to obtain the noise recordings and presents initial empirical analysis and observations pertaining to the noise signatures and the relationships between several noise variables in the 0.01- to 1-Hz range. The mathematical models have not been developed sufficiently to report theoretical results or to compare measured spectra with model predictions at this time

  20. Space-time quantitative source apportionment of soil heavy metal concentration increments.

    Science.gov (United States)

    Yang, Yong; Christakos, George; Guo, Mingwu; Xiao, Lu; Huang, Wei

    2017-04-01

    Assessing the space-time trends and detecting the sources of heavy metal accumulation in soils have important consequences in the prevention and treatment of soil heavy metal pollution. In this study, we collected soil samples in the eastern part of the Qingshan district, Wuhan city, Hubei Province, China, during the period 2010-2014. The Cd, Cu, Pb and Zn concentrations in soils exhibited a significant accumulation during 2010-2014. The spatiotemporal Kriging technique, based on a quantitative characterization of soil heavy metal concentration variations in terms of non-separable variogram models, was employed to estimate the spatiotemporal soil heavy metal distribution in the study region. Our findings showed that the Cd, Cu, and Zn concentrations have an obvious incremental tendency from the southwestern to the central part of the study region. However, the Pb concentrations exhibited an obvious tendency from the northern part to the central part of the region. Then, spatial overlay analysis was used to obtain absolute and relative concentration increments of adjacent 1- or 5-year periods during 2010-2014. The spatial distribution of soil heavy metal concentration increments showed that the larger increments occurred in the center of the study region. Lastly, the principal component analysis combined with the multiple linear regression method were employed to quantify the source apportionment of the soil heavy metal concentration increments in the region. Our results led to the conclusion that the sources of soil heavy metal concentration increments should be ascribed to industry, agriculture and traffic. In particular, 82.5% of soil heavy metal concentration increment during 2010-2014 was ascribed to industrial/agricultural activities sources. Using STK and SOA to obtain the spatial distribution of heavy metal concentration increments in soils. Using PCA-MLR to quantify the source apportionment of soil heavy metal concentration increments. Copyright © 2017

  1. Optical identifications of IRAS point sources: the Fornax, Hydra I and Coma clusters

    International Nuclear Information System (INIS)

    Wang, G.; Leggett, S.K.; Savage, A.

    1991-01-01

    We present optical identifications for 66 IRAS point sources in the region of the Fornax cluster of galaxies, 106 IRAS point sources in the region of the Hydra I cluster of galaxies (Abell 1060) and 59 IRAS point sources in the region of the Coma cluster of galaxies (Abell 1656). Eight other sources in Hydra I do not have optical counterparts and are very probably due to infrared cirrus. Twenty-three (35 per cent) of the Fornax sources are associated with stars and 43 (65 per cent) with galaxies; 48 (42 per cent) of the Hydra I sources are associated with stars and 58 (51 per cent) with galaxies; 18 (31 per cent) of the Coma sources are associated with stars and 41 (69 per cent) with galaxies. The stellar and infrared cirrus surface density is consistent with the galactic latitude of each field. (author)

  2. Recognition of the importance of geogenic sources in the content of metals in PM2.5 collected in the Mexico City Metropolitan Area.

    Science.gov (United States)

    Morton-Bermea, Ofelia; Garza-Galindo, Rodrigo; Hernández-Álvarez, Elizabeth; Amador-Muñoz, Omar; Garcia-Arreola, Maria Elena; Ordoñez-Godínez, Sara L; Beramendi-Orosco, Laura; Santos-Medina, Graciela L; Miranda, Javier; Rosas-Pérez, Irma

    2018-01-17

    The study of airborne metals in urban areas is relevant due to their toxic effects on human health and organisms. In this study, we analyzed metals including rare earth elements (REE) in particles smaller than 2.5 μm (PM 2.5 ), collected at five sites around the Mexico City Metropolitan Area (MCMA), during three periods in 2011: April (dry-warm season, DW), August (rainy season, R), and November (dry-cold season, DC). Principal component analysis allowed identifying factors related to geogenic sources and factors related to anthropogenic sources. The recognition of the high impact of geogenic sources in PM 2.5 is in agreement with the REE distribution patterns, which show similar behavior as those shown by igneous rocks, confirming the influence of the regional geogenic material. Metals associated to geogenic sources showed higher concentration (p  0.05) and no similar seasonal pattern among them. These unexpected results exposed outstanding information regarding the identification of different geogenic sources as the main contributors of metals in the atmospheric environment in the MCMA and highlighted the importance of meteorology in the spatial and seasonal metal patterns.

  3. The occurrence and source identification of bisphenol compounds in wastewaters.

    Science.gov (United States)

    Česen, Marjeta; Lenarčič, Kaja; Mislej, Vesna; Levstek, Meta; Kovačič, Ana; Cimrmančič, Bernardka; Uranjek, Nataša; Kosjek, Tina; Heath, David; Dolenc, Marija Sollner; Heath, Ester

    2018-03-01

    This study reports the occurrence of eight bisphenols (BPs): bisphenol AF (BPAF), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bisphenol F (BPF), bisphenol S (BPS) and bisphenol Z (BPZ) in wastewaters (WWs). Sample preparation involved pre-concentration with SPE cartridges (Oasis HLB), followed by derivatization using N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide with 1% tert-butyldimethylchlorosilane. Chemical analysis was based on gas chromatography-mass spectrometry. A validated method with limits of detection (LODs) at ngL -1 range was applied to WWs collected at five Slovene wastewater treatment plants (WWTPs) and WW inflows from industrial, commercial and residential sources entering the sewerage systems of two catchments (Domžale-Kamnik (DK) and Ljubljana (LJ)). The presence of all BPs was confirmed in three inflows in DK and two inflows in the LJ catchments. High cumulative concentrations of all BPs were determined in WW from food processing facilities (LJ: 3030ngL -1 and DK: 599ngL -1 ). A high detection frequency was observed in the WW from two textile cleaning companies (6 BPs for LJ and 8 BPs for DK). The analysis of WW from WWTPs revealed that only BPF (36.7ngL -1 ) and BPS (40.6ngL -1 ) were >LODs in the influents, whereas other BPs were detected also in the effluents. BPZ was found in the highest concentration (403ngL -1 at WWTP-DK). WW collected at this WWTP also contained the highest amount of BPE (238ngL -1 ). Although BPs removal could not be directly compared between the WWTPs, with the exception of BPAP and BPB in the case of two smaller WWTPs (6.39%-43.2%) bisphenols were in general highly removed (≥96.2%). Finally, levels of BPC>LOD are reported for first time (WWTP in the DK catchment: 1.01ngL -1 -11.8ngL -1 ; LJ inflow from food processing plant up to 2560ngL -1 ). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Angular and mass resolved energy distribution measurements with a gallium liquid metal ion source

    International Nuclear Information System (INIS)

    Marriott, Philip

    1987-06-01

    Ionisation and energy broadening mechanisms relevant to liquid metal ion sources are discussed. A review of experimental results giving a picture of source operation and a discussion of the emission mechanisms thought to occur for the ionic species and droplets emitted is presented. Further work is suggested by this review and an analysis system for angular and mass resolved energy distribution measurements of liquid metal ion source beams has been constructed. The energy analyser has been calibrated and a series of measurements, both on and off the beam axis, of 69 Ga + , Ga ++ and Ga 2 + ions emitted at various currents from a gallium source has been performed. A comparison is made between these results and published work where possible, and the results are discussed with the aim of determining the emission and energy spread mechanisms operating in the gallium liquid metal ion source. (author)

  5. Numerical method of identification of an unknown source term in a heat equation

    Directory of Open Access Journals (Sweden)

    Fatullayev Afet Golayo?lu

    2002-01-01

    Full Text Available A numerical procedure for an inverse problem of identification of an unknown source in a heat equation is presented. Approach of proposed method is to approximate unknown function by polygons linear pieces which are determined consecutively from the solution of minimization problem based on the overspecified data. Numerical examples are presented.

  6. Source Identification in Structural Acoustics with an Inverse Frequency Response Function Technique

    NARCIS (Netherlands)

    Visser, Rene

    2002-01-01

    Inverse source identification based on acoustic measurements is essential for the investigation and understanding of sound fields generated by structural vibrations of various devices and machinery. Acoustic pressure measurements performed on a grid in the nearfield of a surface can be used to

  7. Identification of metal ion binding sites based on amino acid sequences.

    Science.gov (United States)

    Cao, Xiaoyong; Hu, Xiuzhen; Zhang, Xiaojin; Gao, Sujuan; Ding, Changjiang; Feng, Yonge; Bao, Weihua

    2017-01-01

    The identification of metal ion binding sites is important for protein function annotation and the design of new drug molecules. This study presents an effective method of analyzing and identifying the binding residues of metal ions based solely on sequence information. Ten metal ions were extracted from the BioLip database: Zn2+, Cu2+, Fe2+, Fe3+, Ca2+, Mg2+, Mn2+, Na+, K+ and Co2+. The analysis showed that Zn2+, Cu2+, Fe2+, Fe3+, and Co2+ were sensitive to the conservation of amino acids at binding sites, and promising results can be achieved using the Position Weight Scoring Matrix algorithm, with an accuracy of over 79.9% and a Matthews correlation coefficient of over 0.6. The binding sites of other metals can also be accurately identified using the Support Vector Machine algorithm with multifeature parameters as input. In addition, we found that Ca2+ was insensitive to hydrophobicity and hydrophilicity information and Mn2+ was insensitive to polarization charge information. An online server was constructed based on the framework of the proposed method and is freely available at http://60.31.198.140:8081/metal/HomePage/HomePage.html.

  8. Extraction, identification and quantification of heavy metals in Venice lagoon sediments using toxicity tests with microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Passarini, F.; Rampazzo, G.; Volpi Ghirardini, A.; Sperni, L.; Salizzato, M.; Pavoni, B. [Venice Univ., Venice (Italy). Dipt. di Scienze Ambientali

    2000-02-01

    Sediments are the major sink for metal pollutants in the aquatic ecosystem but also an important source for the release of them in the water. In order to assess the contribution of heavy metals to the total sediment toxicity, a methodology that permits to integrate the chemical approach with a direct toxicological approach has been ste up. Toxicological results using Microtox test are compared with analytical results. [Italian] I sedimenti sono il principale deposito per contaminanti metalli nel''ecosistema acquatico, ma anche una fonte importnate di rilascio nell'acqua. Al fine di valutare il contributo dei metalli pesanti alla tossicita' totale del sedimento, e' stata messa a punto una metodologia che permette di integrare l'appoccio chimico con un approccio tossicologico diretto. I risultati dei test di tossicita' Microtox vengono confrontati con i risultati analitici.

  9. Study of non-metallic inclusion sources in steel

    International Nuclear Information System (INIS)

    Khons, Ya.; Mrazek, L.

    1976-01-01

    A study of potential inclusion sources was carried out at the Tvinec steel plant using an unified labelling procedure for different sources. A lanthanum oxide labelling method has been used for refractories with the subsequent La determination in steel by the neutron activation analysis. Samarium and cerium oxides and the 141 Ce radionuclide have been used in conjunction with the testing. The following sources of exogenous inclusions have been studied: 1)Refractory material comprising fireclay and corundum for steel-teeming trough in open-heart furnaces; 2) Fireclay bottom-pouring refractories; 3) Steel-teeming laddle lining; 4) Heat-insulating and exothermic compounds for steel ingots; 5) Vacuum treatment plant lining; 6) Open-hearth and electric arc furnace slag. The major oxide inclusion source in steel was found to be represented by the furnace slag, since it forms about 40 p.c. of all oxide inclusions. The contributions of the remaining sources did not exceede 5 p.c. each

  10. Positive matrix factorization and trajectory modelling for source identification: A new look at Indian Ocean Experiment ship observations

    Science.gov (United States)

    Bhanuprasad, S. G.; Venkataraman, Chandra; Bhushan, Mani

    The sources of aerosols on a regional scale over India have only recently received attention in studies using back trajectory analysis and chemical transport modelling. Receptor modelling approaches such as positive matrix factorization (PMF) and the potential source contribution function (PSCF) are effective tools in source identification of urban and regional-scale pollution. In this work, PMF and PSCF analysis is applied to identify categories and locations of sources that influenced surface concentrations of aerosols in the Indian Ocean Experiment (INDOEX) domain measured on-board the research vessel Ron Brown [Quinn, P.K., Coffman, D.J., Bates, T.S., Miller, T.L., Johnson, J.E., Welton, E.J., et al., 2002. Aerosol optical properties during INDOEX 1999: means, variability, and controlling factors. Journal of Geophysical Research 107, 8020, doi:10.1029/2000JD000037]. Emissions inventory information is used to identify sources co-located with probable source regions from PSCF. PMF analysis identified six factors influencing PM concentrations during the INDOEX cruise of the Ron Brown including a biomass combustion factor (35-40%), three industrial emissions factors (35-40%), primarily secondary sulphate-nitrate, balance trace elements and Zn, and two dust factors (20-30%) of Si- and Ca-dust. The identified factors effectively predict the measured submicron PM concentrations (slope of regression line=0.90±0.20; R2=0.76). Probable source regions shifted based on changes in surface and elevated flows during different times in the ship cruise. They were in India in the early part of the cruise, but in west Asia, south-east Asia and Africa, during later parts of the cruise. Co-located sources include coal-fired electric utilities, cement, metals and petroleum production in India and west Asia, biofuel combustion for energy and crop residue burning in India, woodland/forest burning in north sub-Saharan Africa and forest burning in south-east Asia. Significant findings

  11. Source discrimination of atmospheric metal deposition by multi-metal isotopes in the Three Gorges Reservoir region, China.

    Science.gov (United States)

    Liu, Jinling; Bi, Xiangyang; Li, Fanglin; Wang, Pengcong; Wu, Jin

    2018-05-12

    Concentrations of heavy metals, as well as isotopic compositions of mercury (Hg) and lead (Pb), in mosses (Bryum argenteum) from the Three Gorges Reservoir (TGR) region were investigated to decipher the sources of atmospheric metals in this region. Higher contents of metals (0.90 ± 0.65 mg/kg of Cd, 24.6 ± 27.4 mg/kg of Cu, and 36.1 ± 51.1 mg/kg of Pb) in the mosses from TGR were found compared with those from pollution-free regions. Principal component analysis (PCA) grouped the moss metals into four main components which were associated with both anthropogenic and natural sources. The ratios of Pb isotopes of the mosses (1.153-1.173 for 206 Pb/ 207 Pb and 2.094-2.129 for 208 Pb/ 206 Pb) fell between those of the traffic emissions and coals. Similarly, the compositions of δ 202 Hg (-4.29∼-2.33‰) and Δ 199 Hg (within ±0.2‰) were comparable to those of the coals and coal combustion emissions from China and India. These joined results of Pb and Hg isotope data give solid evidences that the coal combustion and traffic emissions are the main causes of metal accumulation in the TGR region. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Tamil Chola Bronzes and Swamimalai Legacy: Metal Sources and Archaeotechnology

    Science.gov (United States)

    Srinivasan, Sharada

    2016-08-01

    This review explores the great copper alloy image casting traditions of southern India from archaeometallurgical and ethnometallurgical perspectives. The usefulness of lead isotope ratio and compositional analysis in the finger-printing and art historical study of more than 130 early historic, Pallava, Chola, later Chola, and Vijayanagara sculptures (fifth-eighteenth centuries) is highlighted, including Nataraja, Buddha, Parvati, and Rama images made of copper, leaded bronze, brass, and gilt copper. Image casting traditions at Swamimalai in Tamil Nadu are compared with artistic treatises and with the technical examination of medieval bronzes, throwing light on continuities and changes in foundry practices. Western Indian sources could be pinpointed for a couple of medieval images from lead isotope analysis. Slag and archaeometallurgical investigations suggest the exploitation of some copper and lead-silver sources in the Andhra and Karnataka regions in the early historic Satavahana period and point to probable copper sources for the medieval images in Karnataka, Tamil Nadu, and Andhra Pradesh. The general lower iron content in southern Indian bronzes perhaps renders the proximal copper-magnetite reserves of Seruvila in Sri Lanka as a less likely source. Given the lack of lead deposits in Sri Lanka, however, the match of the lead isotope signatures of a well-known Ceylonese Buddhist Tara in British Museum with a Buddha image from Nagapattinam in Tamil Nadu may underscore ties between the island nation and the southern Indian Tamil regions.

  13. Multi-cathode metal vapor arc ion source

    International Nuclear Information System (INIS)

    Brown, I.G.; MacGill, R.A.

    1988-01-01

    This patent describes an apparatus for generating an ion beam. It comprises: a vacuum enclosure; a support member; cathodes; an anode; means for transporting; a source of electrical power; means for producing an electric arc; means for guiding; and means for extracting ions

  14. Radio Galaxy Zoo: Machine learning for radio source host galaxy cross-identification

    Science.gov (United States)

    Alger, M. J.; Banfield, J. K.; Ong, C. S.; Rudnick, L.; Wong, O. I.; Wolf, C.; Andernach, H.; Norris, R. P.; Shabala, S. S.

    2018-05-01

    We consider the problem of determining the host galaxies of radio sources by cross-identification. This has traditionally been done manually, which will be intractable for wide-area radio surveys like the Evolutionary Map of the Universe (EMU). Automated cross-identification will be critical for these future surveys, and machine learning may provide the tools to develop such methods. We apply a standard approach from computer vision to cross-identification, introducing one possible way of automating this problem, and explore the pros and cons of this approach. We apply our method to the 1.4 GHz Australian Telescope Large Area Survey (ATLAS) observations of the Chandra Deep Field South (CDFS) and the ESO Large Area ISO Survey South 1 (ELAIS-S1) fields by cross-identifying them with the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. We train our method with two sets of data: expert cross-identifications of CDFS from the initial ATLAS data release and crowdsourced cross-identifications of CDFS from Radio Galaxy Zoo. We found that a simple strategy of cross-identifying a radio component with the nearest galaxy performs comparably to our more complex methods, though our estimated best-case performance is near 100 per cent. ATLAS contains 87 complex radio sources that have been cross-identified by experts, so there are not enough complex examples to learn how to cross-identify them accurately. Much larger datasets are therefore required for training methods like ours. We also show that training our method on Radio Galaxy Zoo cross-identifications gives comparable results to training on expert cross-identifications, demonstrating the value of crowdsourced training data.

  15. Radar Emission Sources Identification Based on Hierarchical Agglomerative Clustering for Large Data Sets

    Directory of Open Access Journals (Sweden)

    Janusz Dudczyk

    2016-01-01

    Full Text Available More advanced recognition methods, which may recognize particular copies of radars of the same type, are called identification. The identification process of radar devices is a more specialized task which requires methods based on the analysis of distinctive features. These features are distinguished from the signals coming from the identified devices. Such a process is called Specific Emitter Identification (SEI. The identification of radar emission sources with the use of classic techniques based on the statistical analysis of basic measurable parameters of a signal such as Radio Frequency, Amplitude, Pulse Width, or Pulse Repetition Interval is not sufficient for SEI problems. This paper presents the method of hierarchical data clustering which is used in the process of radar identification. The Hierarchical Agglomerative Clustering Algorithm (HACA based on Generalized Agglomerative Scheme (GAS implemented and used in the research method is parameterized; therefore, it is possible to compare the results. The results of clustering are presented in dendrograms in this paper. The received results of grouping and identification based on HACA are compared with other SEI methods in order to assess the degree of their usefulness and effectiveness for systems of ESM/ELINT class.

  16. Heavy metal in sediments of Ziya River in northern China: distribution, potential risks, and source apportionment.

    Science.gov (United States)

    Zhu, Xiaolei; Shan, Baoqing; Tang, Wenzhong

    2016-12-01

    The concentration partitioning between the sediment particle and the interstitial water phase plays an important role in controlling the toxicity of heavy metals in aquatic systems. The aim of this study was to assess the sediment quality in a polluted area of the Ziya River, Northern China. The contamination potential and bioavailability of six metals were determined from the concentrations of total metals and the bioavailable fractions. The results showed that the concentrations of Cr, Cu, Ni, Zn, and Pb exceeded the probable effect concentration at several sites. The high geoaccumulation indices showed that the sediments were seriously contaminated by Cd. The ratio of acid-volatile sulfide (AVS) to simultaneously extracted metal (SEM) was higher than 1, which indicated that the availability of metals in sediments was low. The risk assessment of interstitial waters confirmed that there was little chance of release of metals associated with acid-volatile sulfide into the water column. Values of the interstitial water criteria toxicity unit indicated that none of the concentrations of the studied metals exceeded the corresponding water quality thresholds of the US Environmental Protection Agency. Positive matrix factorization showed that the major sources of metals were related to anthropogenic activities. Further, if assessments are based on total heavy metal concentrations, the toxicity of heavy metals in sediment may be overestimated.

  17. Accumulation status, sources and phytoavailability of metals in greenhouse vegetable production systems in Beijing, China.

    Science.gov (United States)

    Xu, Li; Lu, Anxiang; Wang, Jihua; Ma, Zhihong; Pan, Ligang; Feng, Xiaoyuan; Luan, Yunxia

    2015-12-01

    The accumulation status, sources and phytoavailability of selected metals in greenhouse vegetable production systems in peri-urban areas of Beijing were investigated. The mean concentrations of As, Cd, Cr, Hg and Pb in greenhouse soils were 8.44, 0.25, 69.0, 0.09 and 22.0 mg kg(-1), dw, respectively. According to principal component analysis, As, Cd, Cr and Hg are mainly from anthropogenic source, but Pb is likely from natural source. Metal concentrations in all vegetable samples were decreased in the order of Cr>As>Pb>Cd>Hg. Compared with root and fruit vegetables, leaf vegetables had relatively high concentrations and transfer factors of heavy metals, except for Cd. By including soil pH, OM and greenhouse soil metals, 10 empirical models were derived using stepwise multiple linear regression analysis to predict heavy metal concentrations in the edible parts of different vegetables. Among the different vegetable groups, the highest intakes of metals occurred through consumption of leaf vegetables for the two age groups, except for Cd. The HI value of the studied metals were all below 1, indicating that consumption of vegetables grown in greenhouse soils was of low risk to consumers in our study area. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Suggestibility and state anxiety: how the two concepts relate in a source identification paradigm.

    Science.gov (United States)

    Ridley, Anne M; Clifford, Brian R

    2006-01-01

    Source identification tests provide a stringent method for testing the suggestibility of memory because they reduce response bias and experimental demand characteristics. Using the techniques and materials of Maria Zaragoza and her colleagues, we investigated how state anxiety affects the ability of undergraduates to identify correctly the source of misleading post-event information. The results showed that individuals high in state anxiety were less likely to make source misattributions of misleading information, indicating lower levels of suggestibility. This effect was strengthened when forgotten or non-recognised misleading items (for which a source identification task is not possible) were excluded from the analysis. Confidence in the correct attribution of misleading post-event information to its source was significantly less than confidence in source misattributions. Participants who were high in state anxiety tended to be less confident than those lower in state anxiety when they correctly identified the source of both misleading post-event information and non-misled items. The implications of these findings are discussed, drawing on the literature on anxiety and cognition as well as suggestibility.

  19. Status of metal levels and their potential sources of contamination in Southeast Asian rivers.

    Science.gov (United States)

    Chanpiwat, Penradee; Sthiannopkao, Suthipong

    2014-01-01

    To assess the concentration and status of metal contaminants in four major Southeast Asian river systems, water were collected from the Tonle Sap-Bassac Rivers (Cambodia), Citarum River (Indonesia), lower Chao Phraya River (Thailand), and Saigon River (Vietnam) in both dry and wet seasons. The target elements were Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Ba, Tl, and Pb and the concentrations exceeded the background metal concentrations by 1- to 88-fold. This distinctly indicates enrichment by human urban area activities. The results of a normalization technique used to distinguish natural from enriched metal concentrations confirmed contamination by Al, Cd, Co, Mn, Ni, Pb, and Zn. Cluster analysis revealed the probable source of metals contamination in most sampling sites on all rivers studied to be anthropogenic, including industrial, commercial, and residential activities. Stable lead isotopes analyses applied to track the sources and pathways of anthropogenic lead furthermore confirmed that anthropogenic sources of metal contaminated these rivers. Discharges of wastewater from both industrial and household activities were major contributors of Pb into the rivers. Non-point sources, especially road runoff and street dust, also contributed contamination from Pb and other metals.

  20. Applications of lead isotope rations for identification and apportionment on pollution sources in food

    International Nuclear Information System (INIS)

    Zhao Duoyong; Wei Yimin; Guo Boli; Wei Shuai

    2011-01-01

    Lead is one of the toxic heavy metals which can accumulate to an adverse effect level in human bodies through ingestion, inhalation or other pathways. Because of the persistent lead contamination in farmland environment, large risk exists in the primary stage of 'from farm to table' chain. Environmental media such as soils, atmospheric aerosols were the possible lead sources of agro-food. To pinpoint the pollution sources exactly, cut off the contamination pathways in time, and reduce the risk of hazard, pollution sources tracing was very important. Lead isotope ratio combined with certain models is an effective method to discriminate correctly pollution sources and calculate the individual source contributions. In this review, to provide theoretical and technical reference for controlling lead pollution in environment and food, lead pollution sources in food, tracing principle and methods of lead isotope ratios, and its applications on vegetable, tea, wine, cereal and other food products were concerned. (authors)

  1. Using portable X-ray fluorescence spectrometry and GIS to assess environmental risk and identify sources of trace metals in soils of peri-urban areas in the Yangtze Delta region, China.

    Science.gov (United States)

    Ran, Jing; Wang, Dejian; Wang, Can; Zhang, Gang; Yao, Lipeng

    2014-08-01

    Portable X-ray fluorescence (PXRF) spectrometry may be very suitable for a fast and effective environmental assessment and source identification of trace metals in soils. In this study, topsoils (0-10 cm) at 139 sites were in situ scanned for total trace metals (Cr, Cu, Ni, Pb and Zn) and arsenic concentrations by PXRF in a typical town in Yangtze Delta region of Jiangsu province, China. To validate the utility of PXRF, 53 samples were collected from the scanning sites for the determination of selected trace metals using conventional methods. Based on trace metal concentrations detected by in situ PXRF, the contamination extent and sources of trace metals were studied via geo-accumulation index, multivariate analysis and geostatistics. The trace metal concentrations determined by PXRF were similar to those obtained via conventional chemical analysis. The median concentration of As, Cr, Cu, Ni, Pb and Zn in soils were 10.8, 56.4, 41.5, 43.5, 33.5, and 77.7 mg kg(-1), respectively. The distribution patterns of Cr, Cu, Ni, Pb, and Zn were mostly affected by anthropogenic sources, while As was mainly derived from lithogenic sources. Overall, PXRF has been successfully applied to contamination assessment and source identification of trace metals in soils.

  2. Sources and speciation of heavy metals in municipal solid waste (MSW) and its effect on the separation technique

    Energy Technology Data Exchange (ETDEWEB)

    Biollaz, S; Ludwig, Ch; Stucki, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A literature search was carried out to determine sources and speciation of heavy metals in MSW. A combination of thermal and mechanical separation techniques is necessary to achieve the required high degrees of metal separation. Metallic goods should be separated mechanically, chemically bound heavy metals by a thermal process. (author) 1 fig., 1 tab., 6 refs.

  3. STATE OF THE ART TECHNIQUES USED FOR NOISE SOURCE IDENTIFICATION ON COMPLEX BODIES

    Directory of Open Access Journals (Sweden)

    Corneliu STOICA

    2010-03-01

    Full Text Available Over the last few decades, many approaches have been undertaken in order to asses detailed noise source identification on complex bodies, i.e. aircrafts, cars, machinery. Noise source identification implies to accurately obtain the position and frequency of the dominant noise sources. There are cases where traditional testing methods can not be applied at all or their use involves some limitations. Optical systems used for near field analysis require a line of sight that may not be available. The state-of-the-art technology for this purpose is the use of a large number of microphones whose signals are acquired simultaneously, i.e. microphone phased array. Due to the excessive cost of the instruments and the data acquisition system required, the implementation of this technology was restricted to governmental agencies (NASA, DLR and big companies such as Boeing and Airbus. During the past years, this technique was developed in wind tunnels and some universities to perform noise source identification on scale airframes, main landing gear models, and aerodynamic profiles (used on airplanes, helicopter rotors and wind mills.

  4. Simultaneous identification of unknown groundwater pollution sources and estimation of aquifer parameters

    Science.gov (United States)

    Datta, Bithin; Chakrabarty, Dibakar; Dhar, Anirban

    2009-09-01

    Pollution source identification is a common problem encountered frequently. In absence of prior information about flow and transport parameters, the performance of source identification models depends on the accuracy in estimation of these parameters. A methodology is developed for simultaneous pollution source identification and parameter estimation in groundwater systems. The groundwater flow and transport simulator is linked to the nonlinear optimization model as an external module. The simulator defines the flow and transport processes, and serves as a binding equality constraint. The Jacobian matrix which determines the search direction in the nonlinear optimization model links the groundwater flow-transport simulator and the optimization method. Performance of the proposed methodology using spatiotemporal hydraulic head values and pollutant concentration measurements is evaluated by solving illustrative problems. Two different decision model formulations are developed. The computational efficiency of these models is compared using two nonlinear optimization algorithms. The proposed methodology addresses some of the computational limitations of using the embedded optimization technique which embeds the discretized flow and transport equations as equality constraints for optimization. Solution results obtained are also found to be better than those obtained using the embedded optimization technique. The performance evaluations reported here demonstrate the potential applicability of the developed methodology for a fairly large aquifer study area with multiple unknown pollution sources.

  5. Evaluation of the Possible Sources and Controlling Factors of Toxic Metals/Metalloids in the Florida Everglades and Their Potential Risk of Exposure.

    Science.gov (United States)

    Li, Yanbin; Duan, Zhiwei; Liu, Guangliang; Kalla, Peter; Scheidt, Daniel; Cai, Yong

    2015-08-18

    The Florida Everglades is an environmentally sensitive wetland ecosystem with a number of threatened and endangered fauna species susceptible to the deterioration of water quality. Several potential toxic metal sources exist in the Everglades, including farming, atmospheric deposition, and human activities in urban areas, causing concerns of potential metal exposure risks. However, little is known about the pollution status of toxic metals/metalloids of potential concern, except for Hg. In this study, eight toxic metals/metalloids (Cd, Cr, Pb, Ni, Cu, Zn, As, and Hg) in Everglades soils were investigated in both dry and wet seasons. Pb, Cr, As, Cu, Cd, and Ni were identified to be above Florida SQGs (sediment quality guidelines) at a number of sampling sites, particularly Pb, which had a level of potential risk to organisms similar to that of Hg. In addition, a method was developed for quantitative source identification and controlling factor elucidation of toxic metals/metalloids by introducing an index, enrichment factor (EF), in the conventional multiple regression analysis. EFs represent the effects of anthropogenic sources on metals/metalloids in soils. Multiple regression analysis showed that Cr and Ni were mainly controlled by anthropogenic loading, whereas soil characteristics, in particular natural organic matter (NOM), played a more important role for Hg, As, Cd, and Zn. NOM may control the distribution of these toxic metals/metalloids by affecting their mobility in soils. For Cu and Pb, the effects of EFs and environmental factors are comparable, suggesting combined effects of loading and soil characteristics. This study is the first comprehensive research with a vast amount of sampling sites on the distribution and potential risks of toxic metals/metalloids in the Everglades. The finding suggests that in addition to Hg other metals/metalloids could also potentially be an environmental problem in this wetland ecosystem.

  6. A review of output-only structural mode identification literature employing blind source separation methods

    Science.gov (United States)

    Sadhu, A.; Narasimhan, S.; Antoni, J.

    2017-09-01

    Output-only modal identification has seen significant activity in recent years, especially in large-scale structures where controlled input force generation is often difficult to achieve. This has led to the development of new system identification methods which do not require controlled input. They often work satisfactorily if they satisfy some general assumptions - not overly restrictive - regarding the stochasticity of the input. Hundreds of papers covering a wide range of applications appear every year related to the extraction of modal properties from output measurement data in more than two dozen mechanical, aerospace and civil engineering journals. In little more than a decade, concepts of blind source separation (BSS) from the field of acoustic signal processing have been adopted by several researchers and shown that they can be attractive tools to undertake output-only modal identification. Originally intended to separate distinct audio sources from a mixture of recordings, mathematical equivalence to problems in linear structural dynamics have since been firmly established. This has enabled many of the developments in the field of BSS to be modified and applied to output-only modal identification problems. This paper reviews over hundred articles related to the application of BSS and their variants to output-only modal identification. The main contribution of the paper is to present a literature review of the papers which have appeared on the subject. While a brief treatment of the basic ideas are presented where relevant, a comprehensive and critical explanation of their contents is not attempted. Specific issues related to output-only modal identification and the relative advantages and limitations of BSS methods both from theoretical and application standpoints are discussed. Gap areas requiring additional work are also summarized and the paper concludes with possible future trends in this area.

  7. Source Identification of Human Biological Materials and Its Prospect in Forensic Science.

    Science.gov (United States)

    Zou, K N; Gui, C; Gao, Y; Yang, F; Zhou, H G

    2016-06-01

    Source identification of human biological materials in crime scene plays an important role in reconstructing the crime process. Searching specific genetic markers to identify the source of different human biological materials is the emphasis and difficulty of the research work of legal medical experts in recent years. This paper reviews the genetic markers which are used for identifying the source of human biological materials and studied widely, such as DNA methylation, mRNA, microRNA, microflora and protein, etc. By comparing the principles and methods of source identification of human biological materials using different kinds of genetic markers, different source of human biological material owns suitable marker types and can be identified by detecting single genetic marker or combined multiple genetic markers. Though there is no uniform standard and method for identifying the source of human biological materials in forensic laboratories at present, the research and development of a series of mature and reliable methods for distinguishing different human biological materials play the role as forensic evidence which will be the future development direction. Copyright© by the Editorial Department of Journal of Forensic Medicine.

  8. Sources of hydrocarbons in urban road dust: Identification, quantification and prediction.

    Science.gov (United States)

    Mummullage, Sandya; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

    2016-09-01

    Among urban stormwater pollutants, hydrocarbons are a significant environmental concern due to their toxicity and relatively stable chemical structure. This study focused on the identification of hydrocarbon contributing sources to urban road dust and approaches for the quantification of pollutant loads to enhance the design of source control measures. The study confirmed the validity of the use of mathematical techniques of principal component analysis (PCA) and hierarchical cluster analysis (HCA) for source identification and principal component analysis/absolute principal component scores (PCA/APCS) receptor model for pollutant load quantification. Study outcomes identified non-combusted lubrication oils, non-combusted diesel fuels and tyre and asphalt wear as the three most critical urban hydrocarbon sources. The site specific variabilities of contributions from sources were replicated using three mathematical models. The models employed predictor variables of daily traffic volume (DTV), road surface texture depth (TD), slope of the road section (SLP), effective population (EPOP) and effective impervious fraction (EIF), which can be considered as the five governing parameters of pollutant generation, deposition and redistribution. Models were developed such that they can be applicable in determining hydrocarbon contributions from urban sites enabling effective design of source control measures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); He, Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Japenga, Jan; Deng, Meihua [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaoe, E-mail: xeyang@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2015-12-15

    Highlights: • Heavy metal source apportionment was conducted in peri-urban agricultural areas. • Precise and quantified results were obtained by using isotope ratio analysis. • The integration of IRA, GIS, PCA, and CA was proved to be more reliable. • Hg pollution was from the use of organic fertilizers in this area. - Abstract: Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74–100% and 0–24% of the total Hg input, while road dusts and solid wastes contributed for 0–80% and 19–100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  10. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils

    International Nuclear Information System (INIS)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-01-01

    Highlights: • Heavy metal source apportionment was conducted in peri-urban agricultural areas. • Precise and quantified results were obtained by using isotope ratio analysis. • The integration of IRA, GIS, PCA, and CA was proved to be more reliable. • Hg pollution was from the use of organic fertilizers in this area. - Abstract: Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74–100% and 0–24% of the total Hg input, while road dusts and solid wastes contributed for 0–80% and 19–100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  11. Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques.

    Directory of Open Access Journals (Sweden)

    Nsikak U Benson

    Full Text Available Trace metals (Cd, Cr, Cu, Ni and Pb concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria. The degree of contamination was assessed using the individual contamination factors (ICF and global contamination factor (GCF. Multivariate statistical approaches including principal component analysis (PCA, cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources.

  12. Identification of radioisotopes in bulks with disused sealed sources using a high performance portable spectrometer

    International Nuclear Information System (INIS)

    Zapata, Luis; Mallaupoma, Mario

    2013-01-01

    Sealed radioactive sources are widely used in many industrial applications, and after completing its useful life must be managed as radioactive wastes. One of the most common problems of disused sealed radioactive sources is that many times they lack proper identification and their certificates of manufacture. In that context, it is necessary to identify them, prior to any other management step. There are a number of techniques which can be used; however they are sometimes complex. This technical paper shows a simple way for its identification using the InSpector 1000 monitor which allows to know their energy spectra. These modern instruments and detectors have been obtained thanks to the Project Global Threat Reduction Initiative (Programa de Reduccion de Amenazas) between IPEN and the US DOE. (authors).

  13. Computational Acoustic Beamforming for Noise Source Identification for Small Wind Turbines.

    Science.gov (United States)

    Ma, Ping; Lien, Fue-Sang; Yee, Eugene

    2017-01-01

    This paper develops a computational acoustic beamforming (CAB) methodology for identification of sources of small wind turbine noise. This methodology is validated using the case of the NACA 0012 airfoil trailing edge noise. For this validation case, the predicted acoustic maps were in excellent conformance with the results of the measurements obtained from the acoustic beamforming experiment. Following this validation study, the CAB methodology was applied to the identification of noise sources generated by a commercial small wind turbine. The simulated acoustic maps revealed that the blade tower interaction and the wind turbine nacelle were the two primary mechanisms for sound generation for this small wind turbine at frequencies between 100 and 630 Hz.

  14. Methods of the Detection and Identification of Structural Defects in Saturated Metallic Composite Castings

    Directory of Open Access Journals (Sweden)

    Gawdzińska K.

    2017-09-01

    Full Text Available Diagnostics of composite castings, due to their complex structure, requires that their characteristics are tested by an appropriate description method. Any deviation from the specific characteristic will be regarded as a material defect. The detection of defects in composite castings sometimes is not sufficient and the defects have to be identified. This study classifies defects found in the structures of saturated metallic composite castings and indicates those stages of the process where such defects are likely to be formed. Not only does the author determine the causes of structural defects, describe methods of their detection and identification, but also proposes a schematic procedure to be followed during detection and identification of structural defects of castings made from saturated reinforcement metallic composites. Alloys examination was conducted after technological process, while using destructive (macroscopic tests, light and scanning electron microscopy and non-destructive (ultrasonic and X-ray defectoscopy, tomography, gravimetric method methods. Research presented in this article are part of author’s work on castings quality.

  15. Atmospheric heavy metals and Arsenic in China: Situation, sources and control policies

    Science.gov (United States)

    Duan, Jingchun; Tan, Jihua

    2013-08-01

    In recent years, heavy metal pollution accidents were reported frequently in China. The atmospheric heavy metal pollution is drawing all aspects of attention. This paper summarizes the recent research results from our studies and previous studies in recent years in China. The level, temporal variation, seasonal variation and size distribution of the heavy metals of atmospheric Lead(Pb), Vanadium(V), Manganese(Mn), Nickel(Ni), Chromium(Cr), Cadmium(Cd), Copper(Cu), Zinc(Zn) and Arsenic(As) were characterized in China. The emission characteristics and sources of atmospheric heavy metals and As in China were reviewed. Coal burning, iron and steel industry and vehicle emission are important sources in China. Control policies and effects in China were reviewed including emission standards, ambient air quality standards, phase out of leaded gasoline and so on, and further works for atmospheric heavy metals control were suggested. The comprehensive heavy metals pollution control measures and suggestions were put forward based on the summarization of the development and experience of the atmospheric heavy metal pollution control abroad.

  16. Magnetic properties, microstructure and mineralogical phases of technogenic magnetic particles (TMPs) in urban soils: Their source identification and environmental implications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shenggao, E-mail: lusg@zju.edu.cn [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yu, Xiuling [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Chen, Yuyin [Institute of Biological Resources, Zhejiang University, Hangzhou 310058 (China)

    2016-02-01

    Magnetic measurement is an effective method to determine spatial distribution and the degree of heavy metal pollution and to identify various anthropogenic sources of heavy metals. The objectives of this investigation are to characterize the magnetic properties, microstructure and mineralogical phases of technogenic magnetic particles (TMPs) in urban soils and to discuss their potential environmental implications. The TMPs are separated from the urban topsoils of Luoyang city, China. The magnetic properties, morphology, and mineral phase of TMPs are studied using mineral magnetic measurement, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction, and synchrotron–radiation-based microprobe. The content of TMPs in urban topsoils ranges from 0.05 to 1.95% (on average 0.32%). The magnetic susceptibility of TMPs ranges from 4559 × 10{sup −8} to 23,661 × 10{sup −8} m{sup 3} kg{sup −1} (on average 13,637 × 10{sup −8} m{sup 3} kg{sup −1}). Thermomagnetic and bulk X-ray diffraction analyses indicate that main magnetic minerals of TMPs are magnetite (Fe{sub 3}O{sub 4}) and hematite (α-Fe{sub 2}O{sub 3}). The morphology of TMPs observed by SEM includes three shape types: spherule, irregular-shaped, and aggregate particles. The size of spherical TMPs ranges from 30 to about 200 μm, with the largest percentage of 30–50 μm. Synchrotron–radiation-based microprobe (μ-XRF and μ-XRD) indicates that TMPs are enriched with heavy metals Pb, Cd, Zn, Cu, and Cr, which are incorporated into lattice or adsorbed on the surface of magnetite/hematite. The content of TMPs significantly relates with the Tomlinson Pollution Load Index (PLI) (R{sup 2} = 0.467), suggesting that it can be used as proxy indicator of degree of heavy metal contamination in urban soils. The magnetic properties, microstructure and mineralogical phases of TMPs can serve as the identification of pollution sources in urban soils. - Graphical

  17. Atmospheric toxic metals emission inventory and spatial characteristics from anthropogenic sources of Guangdong province, China

    Science.gov (United States)

    Cher, S.; Menghua, L.; Xiao, X.; Yuqi, W.; Zhuangmin, Z.; Zhijiong, H.; Cheng, L.; Guanglin, J.; Zibing, Y.; Junyu, Z.

    2017-12-01

    Atmospheric toxic metals (TMs) are part of particulate matters, and may create adverse effects on the environment and human health depending upon their bioavailability and toxicity. Localized emission inventory is fundamental for parsing of toxic metals to identify key sources in order to formulate efficient toxic metals control strategies. With the use of the latest municipal level environment statistical data, this study developed a bottom-up emission inventory of five toxic metals (Hg, As, Pb, Cd, Cr) from anthropogenic activities in Guangdong province for the year of 2014. Major atmospheric toxic metals sources including combustion sources (coal, oil, biomass, municipal solid waste) and industrial process sources (cement production, nonferrous metal smelting, iron and steel industry, battery and fluorescent lamp production) were investigated. Results showed that: (1) The total emissions of Hg, As, Pb, Cd, Cr in Guangdong province were 18.14, 32.59, 411.34, 13.13, 84.16 t, respectively. (2) Different pollutants have obvious characteristics of emission sources. For total Hg emission, 46% comes from combustion sources, of which 32% from coal combustion and 8% from MSW combustion. Other 54% comes from industrial processes, which dominated by the cement (19%), fluorescent lamp (18%) and battery production (13%). Of the total Hg emission, 69% is released as Hg0 , 29% as Hg2+ , and only 2% as Hgp due to strict particulate matters controls policies. For As emissions, coal combustion, nonferrous metal smelting and iron and steel industry contributed approximate 48%, 25% and 24%, respectively. Pb emissions primarily come from battery production (42%), iron and steel industry (21%) and on-road mobile gasoline combustion (17%). Cd and Cr emissions were dominated by nonferrous metal smelting (71%) and iron and steel industry (82%), respectively. (3) In term of the spatial distribution, emissions of atmospheric toxic metals are mainly concentrated in the central region of

  18. DNA evolutionary algorithm (DNAEA) for source term identification in convection-diffusion equation

    International Nuclear Information System (INIS)

    Yang, X-H; Hu, X-X; Shen, Z-Y

    2008-01-01

    The source identification problem is changed into an optimization problem in this paper. This is a complicated nonlinear optimization problem. It is very intractable with traditional optimization methods. So DNA evolutionary algorithm (DNAEA) is presented to solve the discussed problem. In this algorithm, an initial population is generated by a chaos algorithm. With the shrinking of searching range, DNAEA gradually directs to an optimal result with excellent individuals obtained by DNAEA. The position and intensity of pollution source are well found with DNAEA. Compared with Gray-coded genetic algorithm and pure random search algorithm, DNAEA has rapider convergent speed and higher calculation precision

  19. Revisiting source identification, weathering models, and phase discrimination for Exxon Valdez oil

    International Nuclear Information System (INIS)

    Driskell, W.B.; Payne, J.R.; Shigenaka, G.

    2005-01-01

    A large chemistry data set for polycyclic aromatic hydrocarbon (PAH) and saturated hydrocarbon (SHC) contamination in sediment, water and tissue samples has emerged in the aftermath of the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska. When the oil was fresh, source identification was a primary objective and fairly reliable. However, source identification became problematic as the oil weathered and its signatures changed. In response to concerns regarding when the impacted area will be clean again, this study focused on developing appropriate tools to confirm hydrocarbon source identifications and assess weathering in various matrices. Previous efforts that focused only on the whole or particulate-phase oil are not adequate to track dissolved-phase signal with low total PAH values. For that reason, a particulate signature index (PSI) and dissolved signature index (DSI) screening tool was developed in this study to discriminate between these 2 phases. The screening tool was used to measure the dissolved or water-soluble fraction of crude oil which occurs at much lower levels than the particulate phase, but which is more widely circulated and equally as important as the particulate oil phase. The discrimination methods can also identify normally-discarded, low total PAH samples which can increase the amount of usable data needed to model other effects of oil spills. 37 refs., 3 tabs., 10 figs

  20. Legionellosis: a Walk-through to Identification of the Source of Infection.

    Science.gov (United States)

    Chochlakis, Dimosthenis; Sandalakis, Vassilios; Keramarou, Maria; Tselentis, Yannis; Psaroulaki, Anna

    2017-09-01

    Although a number of human Legionnaires' disease in tourists are recorded annually in Europe, there are few cases where a direct link can be made between the infected person and the source of infection (hotel or other accommodation). We present a scheme followed in order to track down and identify the source of infection in a tourist suffering from L. pneumophila sg 5 infection, who was accommodated in seven different hotels during his holidays in the island of Crete, and we comment on various difficulties and draw-backs of the process. Water samples were collected from the seven hotels where the patient had resided and analyzed at the regional public health laboratory using cultivation and molecular tests. Of 103 water samples analyzed, 19 (18.4%) were positive for Legionella non-pneumophila and 8 (7.8%) were positive for L. pneumophila. A successful L. pneumophila sg 5 match was found between the clinical and environmental sample, which led us to the final identification of the liable hotel. Timely notification of the case, within the the European Legionnaires' Disease Surveillance Network (ELDSNet) of the partners involved, is crucial during a course of travel associated with Legionella case investigation. Moreover, the urinary antigen test alone cannot provide sufficient information for the source identification. However, acquiring clinical as well as environmental isolates for serogroup and SBT identification is highly important for the successful matching. Copyright© by the National Institute of Public Health, Prague 2017

  1. Source apportionment of trace metals in river sediments: A comparison of three methods

    International Nuclear Information System (INIS)

    Chen, Haiyang; Teng, Yanguo; Li, Jiao; Wu, Jin; Wang, Jinsheng

    2016-01-01

    Increasing trace metal pollution in river sediment poses a significant threat to watershed ecosystem health. Identifying potential sources of sediment metals and apportioning their contributions are of key importance for proposing prevention and control strategies of river pollution. In this study, three advanced multivariate receptor models, factor analysis with nonnegative constraints (FA-NNC), positive matrix factorization (PMF), and multivariate curve resolution weighted-alternating least-squares (MCR-WALS), were comparatively employed for source apportionment of trace metals in river sediments and applied to the Le'an River, a main tributary of Poyang Lake which is the largest freshwater lake in China. The pollution assessment with contamination factor and geoaccumulation index suggested that the river sediments in Le'an River were contaminated severely by trace metals due to human activities. With the three apportionment tools, similar source profiles of trace metals in sediments were extracted. Especially, the MCR-WALS and PMF models produced essentially the same results. Comparatively speaking, the weighted schemes might give better solutions than the unweighted FA-NNC because the uncertainty information of environmental data was considered by PMF and MCR-WALS. Anthropogenic sources were apportioned as the most important pollution sources influencing the sediment metals in Le'an River with contributions of about 90%. Among them, copper tailings occupied the largest contribution (38.4–42.2%), followed by mining wastewater (29.0–33.5%), and agricultural activities (18.2–18.7%). To protect the ecosystem of Le'an River and Poyang Lake, special attention should be paid to the discharges of mining wastewater and the leachates of copper tailing ponds in that region. - Highlights: • Three advanced receptor models were comparatively employed for source apportionment. • The MCR-WALS and PMF models produce essentially same source profiles. • Copper

  2. Identification of source of a marine oil-spill using geochemical and chemometric techniques

    International Nuclear Information System (INIS)

    Lobao, Marcio M.; Cardoso, Jari N.; Mello, Marcio R.; Brooks, Paul W.; Lopes, Claudio C.; Lopes, Rosangela S.C.

    2010-01-01

    Research highlights: → San Marcos bay (Maranhao, Brazil) contains small levels of petroleum hydrocarbons. → Oil pollution in San Marcos bay is low-level but chronic. → Aliphatic biomarkers were more useful for spill-oil source correlation in the area. - Abstract: The current work aimed to identify the source of an oil spill off the coast of Maranhao, Brazil, in September 2005 and effect a preliminary geochemical survey of this environment. A combination of bulk analytical parameters, such as carbon isotope (δ 13 C) and Ni/V ratios, and conventional fingerprinting methods (High Resolution Gas Chromatography and Mass Spectrometry) were used. The use of bulk methods greatly speeded source identification for this relatively unaltered spill: identification of the likely source was possible at this stage. Subsequent fingerprinting of biomarker distributions supported source assignment, pointing to a non-Brazilian oil. Steranes proved the most useful biomarkers for sample correlation in this work. Distribution patterns of environmentally more resilient compound types, such as certain aromatic structures, proved inconclusive for correlation, probably in view of their presence in the background.

  3. Source apportionment of soil heavy metals using robust absolute principal component scores-robust geographically weighted regression (RAPCS-RGWR) receptor model.

    Science.gov (United States)

    Qu, Mingkai; Wang, Yan; Huang, Biao; Zhao, Yongcun

    2018-06-01

    The traditional source apportionment models, such as absolute principal component scores-multiple linear regression (APCS-MLR), are usually susceptible to outliers, which may be widely present in the regional geochemical dataset. Furthermore, the models are merely built on variable space instead of geographical space and thus cannot effectively capture the local spatial characteristics of each source contributions. To overcome the limitations, a new receptor model, robust absolute principal component scores-robust geographically weighted regression (RAPCS-RGWR), was proposed based on the traditional APCS-MLR model. Then, the new method was applied to the source apportionment of soil metal elements in a region of Wuhan City, China as a case study. Evaluations revealed that: (i) RAPCS-RGWR model had better performance than APCS-MLR model in the identification of the major sources of soil metal elements, and (ii) source contributions estimated by RAPCS-RGWR model were more close to the true soil metal concentrations than that estimated by APCS-MLR model. It is shown that the proposed RAPCS-RGWR model is a more effective source apportionment method than APCS-MLR (i.e., non-robust and global model) in dealing with the regional geochemical dataset. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. The metal-organic framework MIL-53(Al) constructed from multiple metal sources: alumina, aluminum hydroxide, and boehmite.

    Science.gov (United States)

    Li, Zehua; Wu, Yi-nan; Li, Jie; Zhang, Yiming; Zou, Xin; Li, Fengting

    2015-04-27

    Three aluminum compounds, namely alumina, aluminum hydroxide, and boehmite, are probed as the metal sources for the hydrothermal synthesis of a typical metal-organic framework MIL-53(Al). The process exhibits enhanced synthetic efficiency without the generation of strongly acidic byproducts. The time-course monitoring of conversion from different aluminum sources into MIL-53(Al) is achieved by multiple characterization that reveals a similar but differentiated crystallinity, porosity, and morphology relative to typical MIL-53(Al) prepared from water-soluble aluminum salts. Moreover, the prepared MIL-53(Al) constructed with the three insoluble aluminum sources exhibit an improved thermal stability of up to nearly 600 °C and enhanced yields. Alumina and boehmite are more preferable than aluminum hydroxide in terms of product porosity, yield, and reaction time. The adsorption performances of a typical environmental endocrine disruptor, dimethyl phthalate, on the prepared MIL-53(Al) samples are also investigated. The improved structural stability of MIL-53(Al) prepared from these alternative aluminum sources enables double-enhanced adsorption performance (up to 206 mg g(-1)) relative to the conventionally obtained MIL-53(Al). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Mercury-impacted scrap metal: Source and nature of the mercury.

    Science.gov (United States)

    Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

    2015-09-15

    The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

  6. Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques

    International Nuclear Information System (INIS)

    Suneel, V.; Vethamony, P.; Zakaria, M.P.; Naik, B.G.; Prasad, K.V.S.R.

    2013-01-01

    Highlights: ► This is first fingerprinting study in India on identification of source of tar balls. ► Tar balls were formed from tanker-wash spills and they resemble floating tar ball. ► δ 13 C values of Bombay High crude oil and the present tar balls do not match. ► Compound specific stable carbon isotope analysis confirmed the source of tar balls. ► Source is confirmed as the South East Asian Crude Oil and not the Bombay High crude. -- Abstract: Deposition of tar balls along the coast of Goa, India is a common phenomenon during the southwest monsoon. Representative tar ball samples collected from various beaches of Goa and one Bombay High (BH) crude oil sample were subjected to fingerprint analysis based on diagnostic ratios of n-alkane, biomarkers of pentacyclic tri-terpanes and compound specific stable carbon isotope (δ 13 C) analysis to confirm the source. The results were compared with the published data of Middle East Crude Oil (MECO) and South East Asian Crude Oil (SEACO). The results revealed that the tar balls were from tanker-wash derived spills. The study also confirmed that the source is not the BH, but SEACO. The present study suggests that the biomarkers of alkanes and hopanes coupled with stable carbon isotope analysis act as a powerful tool for tracing the source of tar balls, particularly when the source specific biomarkers fail to distinguish the source

  7. Applications of Open Source GMAW-Based Metal 3-D Printing

    Directory of Open Access Journals (Sweden)

    Yuenyong Nilsiam

    2018-03-01

    Full Text Available The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width control, mechanical properties, and support for overhangs. These previous works showed that GMAW-based metal 3-D printing has a good adhesion between layers and is not porous inside the printed parts, but they did not proceed far enough to demonstrate applications. In this study, the utility of the GMAW approach to 3-D printing is investigated using a low-cost open-source metal 3-D printer and a converted Computer Numerical Control router machine to make useful parts over a range of applications including: fixing an existing part by adding a 3-D metal feature, creating a product using the substrate as part of the component, 3-D printing in high resolution of useful objects, near net objects, and making an integrated product using a combination of steel and polymer 3-D printing. The results show that GMAW-based 3-D printing is capable of distributed manufacturing of useful products for a wide variety of applications for sustainable development.

  8. High charge state metal ion production in vacuum arc ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.; Anders, A.; Anders, S.

    1994-01-01

    The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle or order 1% and operation of a dc embodiment has been demonstrated also. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with peak (pulsed) beam current up to several amperes. The ion charge state distribution has been extensively studied. Ion spectra have been measured for a wide range of metallic cathode materials, including Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U, as well as compound and alloy cathode materials such as TiC, SiC, UC, PbS, brass, and stainless steel. The ions generated are in general multiply-stripped with a mean charge state of from 1 to 3, depending on the particular metal species, and the charge state distribution can have components from Q = 1+ to 6+. Here the authors review the characteristics of vacuum arc ion sources from the perspective of their high charge state metal ion production

  9. Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems.

    Science.gov (United States)

    Munier, B; Bendell, L I

    2018-01-01

    Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the "inherent" load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

  10. Application of hydrogen isotopes and metal hydrides in future energy source

    Energy Technology Data Exchange (ETDEWEB)

    Guoqiang, Jiang [Sichuan Inst. of Materials and Technology, Chengdu, SC (China)

    1994-12-01

    The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China`s energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed.

  11. Application of hydrogen isotopes and metal hydrides in future energy source

    International Nuclear Information System (INIS)

    Jiang Guoqiang

    1994-12-01

    The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China's energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed

  12. Environmental impact of ongoing sources of metal contamination on remediated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Knox, Anna Sophia, E-mail: anna.knox@srn.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Paller, Michael H., E-mail: michael.paller@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Milliken, Charles E., E-mail: charles.milliken@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Redder, Todd M., E-mail: tredder@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Wolfe, John R., E-mail: jwolfe@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Seaman, John, E-mail: seaman@srel.uga.edu [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

    2016-09-01

    A challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixed amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 h experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p < 0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. These findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination. - Graphical abstract: Conventional methods of remediating contaminated sediments may be inadequate for the protection of benthic organisms when ongoing sources of contamination are present. However, sediment caps with chemically active sequestering agents have the ability to reduce the bioavailable pool of metals in ongoing sources of contamination (red dots), reduce toxicity to

  13. Environmental impact of ongoing sources of metal contamination on remediated sediments

    International Nuclear Information System (INIS)

    Knox, Anna Sophia; Paller, Michael H.; Milliken, Charles E.; Redder, Todd M.; Wolfe, John R.; Seaman, John

    2016-01-01

    A challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixed amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 h experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p < 0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. These findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination. - Graphical abstract: Conventional methods of remediating contaminated sediments may be inadequate for the protection of benthic organisms when ongoing sources of contamination are present. However, sediment caps with chemically active sequestering agents have the ability to reduce the bioavailable pool of metals in ongoing sources of contamination (red dots), reduce toxicity to

  14. Pollution assessment and source apportionment of heavy metals in contaminated site soils

    Science.gov (United States)

    Zheng, Hongbo; Ma, Yan

    2018-03-01

    Pollution characteristics of heavy metals in soil were analyzed with a typical contaminated site as the case area. The pollution degree of the element was evaluated by indexes of geoaccumulation (Igeo). The potential ecological risk of heavy metals was assessed with potential ecological risk index model. Principal component analysis (PCA) model was simultaneously carried out to identify the main sources of heavy metals in topsoils. The results indicated that: 1. Mean values of 11 kinds of metals in topsoils were greater than respective soil background values, following the order: Zn>Pb>V>Cr>Cu>Ni>Co>As>Sb>Cd>Hg. Heavy metals with a certain accumulation in the research area were significantly affected by external factors. 2. Igeo results showed that Cd and Zn reached strongly polluted degree, while Pb with moderately to strongly polluted, Sb and Hg with moderately polluted, Cu, Co, Ni and Cr with unpolluted to moderately polluted, V and As with un-polluted. 3. Potential ecological risk assessment showed the degree of ecological risk with Cd at very high risk, Hg at high risk, Pb at moderate risk and others at low risk. The comprehensive risk of all the metals was very high. 4. PCA got three main sources with contributions, including industrial activities (44.18%), traffic and burning dust (26.68%) and soil parent materials (12.20%).

  15. Heavy metal contamination status and source apportionment in sediments of Songhua River Harbin region, Northeast China.

    Science.gov (United States)

    Li, Ning; Tian, Yu; Zhang, Jun; Zuo, Wei; Zhan, Wei; Zhang, Jian

    2017-02-01

    The Songhua River represents one of the seven major river systems in China. It flows through Harbin city with 66 km long, locating in the northern China with a longer winter time. This paper aimed to study concentration distributions, stability, risk assessment, and source apportionment of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), and nickel (Ni) in 11 selected sections of the Songhua River Harbin region. Results showed that Cr, Cd, Pb, Hg, and As exceeded their respective geochemical background values in sediments of most monitoring sections. Compared with other important rivers and lakes in China, Cr, Hg, Cd, and As pollutions in surface sediments were above medium level. Further analysis of chemical speciation indicated that Cr and As in surface sediments were relatively stable while Pb and Cd were easily bioavailable. Correlation analysis revealed sources of these metals except As might be identical. Pollution levels and ecological risks of heavy metals in surface sediments presented higher in the mainstream region (45° 47.0' N ~ 45° 53.3' N, 126° 37.0' E ~ 126° 42.1' E). Source apportionment found Hejiagou and Ashi River were the main contributors to metal pollution of this region. Thus, anthropogenic activities along the Hejiagou and Ashi River should be restricted in order to protect the Songhua River Harbin region from metal contamination.

  16. Assessing heavy metal sources in sugarcane Brazilian soils: an approach using multivariate analysis.

    Science.gov (United States)

    da Silva, Fernando Bruno Vieira; do Nascimento, Clístenes Williams Araújo; Araújo, Paula Renata Muniz; da Silva, Luiz Henrique Vieira; da Silva, Roberto Felipe

    2016-08-01

    Brazil is the world's largest sugarcane producer and soils in the northeastern part of the country have been cultivated with the crop for over 450 years. However, so far, there has been no study on the status of heavy metal accumulation in these long-history cultivated soils. To fill the gap, we collect soil samples from 60 sugarcane fields in order to determine the contents of Cd, Cr, Cu, Ni, Pb, and Zn. We used multivariate analysis to distinguish between natural and anthropogenic sources of these metals in soils. Analytical determinations were performed in ICP-OES after microwave acid solution digestion. Mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 1.9, 18.8, 6.4, 4.9, 11.2, and 16.2 mg kg(-1), respectively. The principal component one was associated with lithogenic origin and comprised the metals Cr, Cu, Ni, and Zn. Cluster analysis confirmed that 68 % of the evaluated sites have soil heavy metal concentrations close to the natural background. The Cd concentration (principal component two) was clearly associated with anthropogenic sources with P fertilization being the most likely source of Cd to soils. On the other hand, the third component (Pb concentration) indicates a mixed origin for this metal (natural and anthropogenic); hence, Pb concentrations are probably related not only to the soil parent material but also to industrial emissions and urbanization in the vicinity of the agricultural areas.

  17. Optical identifications of celestial high energy sources with the Telescopio Nazionale Galileo

    International Nuclear Information System (INIS)

    Turriziani, Sara

    2012-01-01

    To ascertain the nature of celestial high energy sources, it is crucial to identify their optical counterparts. However, the currently available astronomical public optical databases do not provide an adequate support for a systematic high energy sources identification work. In particular, the optical limiting magnitude represents a severe limitation since the deepest flux limits reached by X-ray surveys require of course similarly deeper optical catalogs to homogeneously sample the available parameter space. Nonetheless, dedicated spectroscopic campaigns are being carried out successfully with the Telescopio Nazionale Galileo (TNG), a 4-m class telescope. To set up a winning observational campaign, the first and most important step is to define a strong science case, as it will allow for selections of good targets for observations: the key is to increase the identification efficiency while keeping down the required telescope time. In this context, as the Principal Investigator, I will give an overview of the first spectroscopic campaign carried out at the TNG to identify Swift X-ray serendipitous sources, and I will show the valuable results achieved with only one night of observations. As a second example, I will review the strategy for the northern-sky classification of candidate blazars associated to unidentified Fermi γ-ray sources, and I will show the results coming from the related observational campaign at TNG I have been involved during the last two years.

  18. Identifications and Photometric Redshifts of the 2 Ms Chandra Deep Field-South Sources

    Science.gov (United States)

    Luo, B.; Brandt, W. N.; Xue, Y. Q.; Brusa, M.; Alexander, D. M.; Bauer, F. E.; Comastri, A.; Koekemoer, A.; Lehmer, B. D.; Mainieri, V.; Rafferty, D. A.; Schneider, D. P.; Silverman, J. D.; Vignali, C.

    2010-04-01

    We present reliable multiwavelength identifications and high-quality photometric redshifts for the 462 X-ray sources in the ≈2 Ms Chandra Deep Field-South (CDF-S) survey. Source identifications are carried out using deep optical-to-radio multiwavelength catalogs, and are then combined to create lists of primary and secondary counterparts for the X-ray sources. We identified reliable counterparts for 442 (95.7%) of the X-ray sources, with an expected false-match probability of ≈ 6.2%; we also selected four additional likely counterparts. The majority of the other 16 X-ray sources appear to be off-nuclear sources, sources associated with galaxy groups and clusters, high-redshift active galactic nuclei (AGNs), or spurious X-ray sources. A likelihood-ratio method is used for source matching, which effectively reduces the false-match probability at faint magnitudes compared to a simple error-circle matching method. We construct a master photometric catalog for the identified X-ray sources including up to 42 bands of UV-to-infrared data, and then calculate their photometric redshifts (photo-z's). High accuracy in the derived photo-z's is accomplished owing to (1) the up-to-date photometric data covering the full spectral energy distributions (SEDs) of the X-ray sources, (2) more accurate photometric data as a result of source deblending for ≈10% of the sources in the infrared bands and a few percent in the optical and near-infrared bands, (3) a set of 265 galaxy, AGN, and galaxy/AGN hybrid templates carefully constructed to best represent all possible SEDs, (4) the Zurich Extragalactic Bayesian Redshift Analyzer used to derive the photo-z's, which corrects the SED templates to best represent the SEDs of real sources at different redshifts and thus improves the photo-z quality. The reliability of the photo-z's is evaluated using the subsample of 220 sources with secure spectroscopic redshifts. We achieve an accuracy of |Δz|/(1 + z) ≈ 1% and an outlier [with |

  19. Influence of reactive gas admixture on transition metal cluster nucleation in a gas aggregation cluster source

    Science.gov (United States)

    Peter, Tilo; Polonskyi, Oleksandr; Gojdka, Björn; Mohammad Ahadi, Amir; Strunskus, Thomas; Zaporojtchenko, Vladimir; Biederman, Hynek; Faupel, Franz

    2012-12-01

    We quantitatively assessed the influence of reactive gases on the formation processes of transition metal clusters in a gas aggregation cluster source. A cluster source based on a 2 in. magnetron is used to study the production rate of titanium and cobalt clusters. Argon served as working gas for the DC magnetron discharge, and a small amount of reactive gas (oxygen and nitrogen) is added to promote reactive cluster formation. We found that the cluster production rate depends strongly on the reactive gas concentration for very small amounts of reactive gas (less than 0.1% of total working gas), and no cluster formation takes place in the absence of reactive species. The influence of discharge power, reactive gas concentration, and working gas pressure are investigated using a quartz micro balance in a time resolved manner. The strong influence of reactive gas is explained by a more efficient formation of nucleation seeds for metal-oxide or nitride than for pure metal.

  20. Identification of dust storm source areas in West Asia using multiple environmental datasets.

    Science.gov (United States)

    Cao, Hui; Amiraslani, Farshad; Liu, Jian; Zhou, Na

    2015-01-01

    Sand and Dust storms are common phenomena in arid and semi-arid areas. West Asia Region, especially Tigris-Euphrates alluvial plain, has been recognized as one of the most important dust source areas in the world. In this paper, a method is applied to extract SDS (Sand and Dust Storms) sources in West Asia region using thematic maps, climate and geography, HYSPLIT model and satellite images. Out of 50 dust storms happened during 2000-2013 and collected in form of MODIS images, 27 events were incorporated as demonstrations of the simulated trajectories by HYSPLIT model. Besides, a dataset of the newly released Landsat images was used as base-map for the interpretation of SDS source regions. As a result, six main clusters were recognized as dust source areas. Of which, 3 clusters situated in Tigris-Euphrates plain were identified as severe SDS sources (including 70% dust storms in this research). Another cluster in Sistan plain is also a potential source area. This approach also confirmed six main paths causing dust storms. These paths are driven by the climate system including Siberian and Polar anticyclones, monsoon from Indian Subcontinent and depression from north of Africa. The identification of SDS source areas and paths will improve our understandings on the mechanisms and impacts of dust storms on socio-economy and environment of the region. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Seamount mineral deposits: A source of rare metals for high technology industries

    Science.gov (United States)

    Hein, James R.; Conrad, Tracey A.; Staudigel, Hubert

    2010-01-01

    The near exponential growth in Earth’s population and the global economy puts increasing constraints on our planet’s finite supply of natural metal resources, and, consequently, there is an increasing need for new sources to supply high-tech industries. To date, effectively all of our raw-metal resources are produced at land-based sites. Except for nearshore placer deposits, the marine environment has been largely excluded from metal mining due to technological difficulties, even though it covers more than 70% of the planet. The case can be made that deep-water seabed mining is inevitable in the future, owing to the critical and strategic metal needs for human society. In this paper, we evaluate the case that seamounts offer significant potential for mining.

  2. [Metallic content of water sources and drinkable water in industrial cities of Murmansk region].

    Science.gov (United States)

    Doushkina, E V; Dudarev, A A; Sladkova, Yu N; Zachinskaya, I Yu; Chupakhin, V S; Goushchin, I V; Talykova, L V; Nikanov, A N

    2015-01-01

    Performed in 2013, sampling of centralized and noncentralized water-supply and analysis of engineering technology materials on household water use in 6 cities of Murmansk region (Nikel, Zapolyarny, Olenegorsk, Montchegorsk, Apatity, Kirovsk), subjected to industrial emissions, enabled to evaluate and compare levels of 15 metals in water sources (lakes and springs) and the cities' drinkable waters. Findings are that some cities lack sanitary protection zones for water sources, most cities require preliminary water processing, water desinfection involves only chlorination. Concentrations of most metals in water samples from all the cities at the points of water intake, water preparation and water supply are within the hygienic norms. But values significantly (2-5 times) exceeding MACs (both in water sources and in drinkable waters of the cities) were seen for aluminium in Kirovsk city and for nickel in Zapolarny and Nikel cities. To decrease effects of aluminium, nickel and their compounds in the three cities' residents (and preserve health of the population and offsprings), the authors necessitate specification and adaptation of measures to purify the drinkable waters from the pollutants. In all the cities studied, significantly increased concentrations of iron and other metals were seen during water transportation from the source to the city supply--that necessitates replacement of depreciated water supply systems by modern ones. Water taken from Petchenga region springs demonstrated relatively low levels of metals, except from strontium and barium.

  3. Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

    Science.gov (United States)

    Lampkin, Gregory; Thomas, Edward, Jr.; Watson, Michael; Wallace, Kent; Chen, Henry; Burger, Arnold

    1998-01-01

    The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

  4. Rapid identification and source-tracking of Listeria monocytogenes using MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Jadhav, Snehal; Gulati, Vandana; Fox, Edward M; Karpe, Avinash; Beale, David J; Sevior, Danielle; Bhave, Mrinal; Palombo, Enzo A

    2015-06-02

    Listeria monocytogenes is an important foodborne pathogen responsible for the sometimes fatal disease listeriosis. Public health concerns and stringent regulations associated with the presence of this pathogen in food and food processing environments underline the need for rapid and reliable detection and subtyping techniques. In the current study, the application of matrix assisted laser desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS) as a single identification and source-tracking tool for a collection of L. monocytogenes isolates, obtained predominantly from dairy sources within Australia, was explored. The isolates were cultured on different growth media and analysed using MALDI-TOF MS at two incubation times (24 and 48 h). Whilst reliable genus-level identification was achieved from most media, identification at the species level was found to be dependent on culture conditions. Successful speciation was highest for isolates cultured on the chromogenic Agar Listeria Ottaviani Agosti agar (ALOA, 91% of isolates) and non-selective horse blood agar (HBA, 89%) for 24h. Chemometric statistical analysis of the MALDI-TOF MS data enabled source-tracking of L. monocytogenes isolates obtained from four different dairy sources. Strain-level discrimination was also observed to be influenced by culture conditions. In addition, t-test/analysis of variance (ANOVA) was used to identify potential biomarker peaks that differentiated the isolates according to their source of isolation. Source-tracking using MALDI-TOF MS was compared and correlated with the gold standard pulsed-field gel electrophoresis (PFGE) technique. The discriminatory index and the congruence between both techniques were compared using the Simpsons Diversity Index and adjusted Rand and Wallace coefficients. Overall, MALDI-TOF MS based source-tracking (using data obtained by culturing the isolates on HBA) and PFGE demonstrated good congruence with a Wallace coefficient of 0.71 and

  5. Biotechnological recovery of heavy metals from secondary sources-An overview

    International Nuclear Information System (INIS)

    Hoque, Md E.; Philip, Obbard J.

    2011-01-01

    The demand for heavy metals is ever increasing with the advance of the industrialized world, whereas worldwide reserves of high-grade ores are diminishing. However, there exist large stockpiles of low and lean grade ores that are yet to be exploited. In addition, heavy metals that are present in a spectrum of waste streams including mine drainage, industrial effluents, river sediments, electronic scraps and ashes are also available for recovery and utilization. Heavy metal recovery from low and lean grade ores using conventional techniques such as pyrometallurgy, etc. chemical metallurgy encompass several inherent constraints like, high energy and capital inputs, and high risk of secondary environmental pollution. As environmental regulations become ever more stringent, particularly regarding the disposal of toxic wastes, the costs for ensuring environmental protection will continue to rise. Therefore, there is a need to utilize more efficient technologies to recover heavy metals from secondary sources in order to minimize capital outlay, environmental impact and to respond to increased demand. Biohydrometallurgy, which exploits microbiological processes to recover heavy metal ions, is regarded as one of the most promising and revolutionary biotechnologies. The products of such processes are deposited in aqueous solution thereby rendering them to be more amenable to containment, treatment and recovery. On top of this, biohydrometallurgy can be conducted under mild conditions, usually without the use of any toxic chemicals. Consequently, the application of biohydrometallurgy in recovery of heavy metals from lean grade ores, and wastes, has made it an eco-friendly biotechnology for enhanced heavy metal production.

  6. Size distribution, characteristics and sources of heavy metals in haze episode in Beijing.

    Science.gov (United States)

    Duan, Jingchun; Tan, Jihua; Hao, Jiming; Chai, Fahe

    2014-01-01

    Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard (GB3095-2012) and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are: Pb (62.1%) > As (58.1%) > Cd (57.9%) > Zn (57.7%) > Cu (55.8%) > Ni (53.5%) > Cr (52.2%) > Mn (49.2%) > V (43.5%). Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO4(2-) etc., and four factors (dust, vehicle, aged and transportation, unknown) are identified and the size distribution contribution of them to atmospheric heavy metals are discussed.

  7. Biotechnological recovery of heavy metals from secondary sources-An overview

    Energy Technology Data Exchange (ETDEWEB)

    Hoque, Md E., E-mail: enamul.hoque@nottingham.edu.my [Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan (Malaysia); Philip, Obbard J., E-mail: esejpo@nus.edu.sg [Division of Environmental Science and Engineering, National University of Singapore, 119260 (Singapore)

    2011-03-12

    The demand for heavy metals is ever increasing with the advance of the industrialized world, whereas worldwide reserves of high-grade ores are diminishing. However, there exist large stockpiles of low and lean grade ores that are yet to be exploited. In addition, heavy metals that are present in a spectrum of waste streams including mine drainage, industrial effluents, river sediments, electronic scraps and ashes are also available for recovery and utilization. Heavy metal recovery from low and lean grade ores using conventional techniques such as pyrometallurgy, etc. chemical metallurgy encompass several inherent constraints like, high energy and capital inputs, and high risk of secondary environmental pollution. As environmental regulations become ever more stringent, particularly regarding the disposal of toxic wastes, the costs for ensuring environmental protection will continue to rise. Therefore, there is a need to utilize more efficient technologies to recover heavy metals from secondary sources in order to minimize capital outlay, environmental impact and to respond to increased demand. Biohydrometallurgy, which exploits microbiological processes to recover heavy metal ions, is regarded as one of the most promising and revolutionary biotechnologies. The products of such processes are deposited in aqueous solution thereby rendering them to be more amenable to containment, treatment and recovery. On top of this, biohydrometallurgy can be conducted under mild conditions, usually without the use of any toxic chemicals. Consequently, the application of biohydrometallurgy in recovery of heavy metals from lean grade ores, and wastes, has made it an eco-friendly biotechnology for enhanced heavy metal production.

  8. IDENTIFICATIONS AND PHOTOMETRIC REDSHIFTS OF THE 2 Ms CHANDRA DEEP FIELD-SOUTH SOURCES

    International Nuclear Information System (INIS)

    Luo, B.; Brandt, W. N.; Xue, Y. Q.; Rafferty, D. A.; Schneider, D. P.; Brusa, M.; Alexander, D. M.; Lehmer, B. D.; Bauer, F. E.; Comastri, A.; Koekemoer, A.; Mainieri, V.; Silverman, J. D.; Vignali, C.

    2010-01-01

    We present reliable multiwavelength identifications and high-quality photometric redshifts for the 462 X-ray sources in the ∼2 Ms Chandra Deep Field-South (CDF-S) survey. Source identifications are carried out using deep optical-to-radio multiwavelength catalogs, and are then combined to create lists of primary and secondary counterparts for the X-ray sources. We identified reliable counterparts for 442 (95.7%) of the X-ray sources, with an expected false-match probability of ∼ 6.2%; we also selected four additional likely counterparts. The majority of the other 16 X-ray sources appear to be off-nuclear sources, sources associated with galaxy groups and clusters, high-redshift active galactic nuclei (AGNs), or spurious X-ray sources. A likelihood-ratio method is used for source matching, which effectively reduces the false-match probability at faint magnitudes compared to a simple error-circle matching method. We construct a master photometric catalog for the identified X-ray sources including up to 42 bands of UV-to-infrared data, and then calculate their photometric redshifts (photo-z's). High accuracy in the derived photo-z's is accomplished owing to (1) the up-to-date photometric data covering the full spectral energy distributions (SEDs) of the X-ray sources, (2) more accurate photometric data as a result of source deblending for ∼10% of the sources in the infrared bands and a few percent in the optical and near-infrared bands, (3) a set of 265 galaxy, AGN, and galaxy/AGN hybrid templates carefully constructed to best represent all possible SEDs, (4) the Zurich Extragalactic Bayesian Redshift Analyzer used to derive the photo-z's, which corrects the SED templates to best represent the SEDs of real sources at different redshifts and thus improves the photo-z quality. The reliability of the photo-z's is evaluated using the subsample of 220 sources with secure spectroscopic redshifts. We achieve an accuracy of |Δz|/(1 + z) ∼ 1% and an outlier [with |

  9. [Source apportionment of soil heavy metals in Jiapigou goldmine based on the UNMIX model].

    Science.gov (United States)

    Ai, Jian-chao; Wang, Ning; Yang, Jing

    2014-09-01

    The paper determines 16 kinds of metal elements' concentration in soil samples which collected in Jipigou goldmine upper the Songhua River. The UNMIX Model which was recommended by US EPA to get the source apportionment results was applied in this study, Cd, Hg, Pb and Ag concentration contour maps were generated by using Kriging interpolation method to verify the results. The main conclusions of this study are: (1)the concentrations of Cd, Hg, Pb and Ag exceeded Jilin Province soil background values and enriched obviously in soil samples; (2)using the UNMIX Model resolved four pollution sources: source 1 represents human activities of transportation, ore mining and garbage, and the source 1's contribution is 39. 1% ; Source 2 represents the contribution of the weathering of rocks and biological effects, and the source 2's contribution is 13. 87% ; Source 3 is a comprehensive source of soil parent material and chemical fertilizer, and the source 3's contribution is 23. 93% ; Source 4 represents iron ore mining and transportation sources, and the source 4's contribution is 22. 89%. (3)the UNMIX Model results are in accordance with the survey of local land-use types, human activities and Cd, Hg and Pb content distributions.

  10. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    International Nuclear Information System (INIS)

    Bhowmik, Avit Kumar; Alamdar, Ambreen; Katsoyiannis, Ioannis; Shen, Heqing; Ali, Nadeem; Ali, Syeda Maria; Bokhari, Habib; Schäfer, Ralf B.; Eqani, Syed Ali Musstjab Akber Shah

    2015-01-01

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  11. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, Avit Kumar [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Alamdar, Ambreen [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Katsoyiannis, Ioannis [Aristotle University of Thessaloniki, Department of Chemistry, Division of Chemical Technology, Box 116, Thessaloniki 54124 (Greece); Shen, Heqing [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Ali, Nadeem [Department of Environmental Sciences, FBAS, International Islamic University, Islamabad (Pakistan); Ali, Syeda Maria [Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah (Saudi Arabia); Bokhari, Habib [Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan); Schäfer, Ralf B. [Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau in der Pfalz (Germany); Eqani, Syed Ali Musstjab Akber Shah, E-mail: ali_ebl2@yahoo.com [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2015-12-15

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150–200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. - Highlights: • Predictions of trace metal concentration use geographically weighted regression • Human health risk

  12. Source identification in acoustics and structural mechanics using Sierra/SD.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Aquino, Wilkins [Duke University Durham, NC; Ross, Michael

    2013-03-01

    In this report we derive both time and frequency-domain methods for inverse identification of sources in elastodynamics and acoustics. The inverse/design problem is cast in a PDE-constrained optimization framework with efficient computation of gradients using the adjoint method. The implementation of source inversion in Sierra/SD is described, and results from both time and frequency domain source inversion are compared to actual experimental data for a weapon store used in captive carry on a military aircraft. The inverse methodology is advantageous in that it provides a method for creating ground based acoustic and vibration tests that can reduce the actual number of flight tests, and thus, saving costs and time for the program.

  13. The identification of metallic elements in airborne particulate matter derived from fossil fuels at Puertollano, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Teresa; Alastuey, Andres; Querol, Xavier; Font, Oriol [Institute of Earth Sciences ' ' Jaume Almera' ' , CSIC, C/Lluis Sole i Sabaris s/n, Barcelona 08028 (Spain); Gibbons, Wes [AP 23075, Barcelona 08080 (Spain)

    2007-07-02

    Puertollano is the largest industrial centre in central Spain, and includes fossil fuel burning power plants as well as petrochemical and fertilizer complexes. The coal-fired power plants use locally mined coal from extensive coal deposits which continue to be exploited and used locally. The coal deposits have a distinctive geochemistry, being particularly enriched in Sb and Pb, as well as several other metals/metalloids that include Zn and As. ICP-AES and ICP-MS chemical analysis of particulate matter samples (both PM{sub 10} and PM{sub 2.5}) collected at Puertollano over a 57-week period in 2004-2005 reveals enhanced levels of several metallic trace elements, especially in the finer (PM{sub 2.5}) aerosol fraction. Factor analysis applied to the data indicates that at least some of these metallic elements are likely to originate from hydrocarbon combustion: Sb and Pb are markers linked to the local coals, whereas V and Ni are, at least in the finer (PM{sub 2.5}) fraction, likely associated with other anthropogenic sources. Other factors measured are related to natural sources such as crustal/mineral and sea spray particles. Our study provides an example of how chemical analysis of large numbers of ambient PM samples, combined with statistical factor analysis and coal geochemistry, can reveal airborne emissions from the combustion of specifically identifiable fuels. (author)

  14. Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

    Science.gov (United States)

    Yang, Pingguo; Ge, Jing; Yang, Miao

    2017-06-01

    The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg -1 ), Zn (99.72 mg kg -1 ), Pb (90.99 mg kg -1 ), Cu (36.14 mg kg -1 ). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

  15. An efficient laser vaporization source for chemically modified metal clusters characterized by thermodynamics and kinetics

    Science.gov (United States)

    Masubuchi, Tsugunosuke; Eckhard, Jan F.; Lange, Kathrin; Visser, Bradley; Tschurl, Martin; Heiz, Ulrich

    2018-02-01

    A laser vaporization cluster source that has a room for cluster aggregation and a reactor volume, each equipped with a pulsed valve, is presented for the efficient gas-phase production of chemically modified metal clusters. The performance of the cluster source is evaluated through the production of Ta and Ta oxide cluster cations, TaxOy+ (y ≥ 0). It is demonstrated that the cluster source produces TaxOy+ over a wide mass range, the metal-to-oxygen ratio of which can easily be controlled by changing the pulse duration that influences the amount of reactant O2 introduced into the cluster source. Reaction kinetic modeling shows that the generation of the oxides takes place under thermalized conditions at less than 300 K, whereas metal cluster cores are presumably created with excess heat. These characteristics are also advantageous to yield "reaction intermediates" of interest via reactions between clusters and reactive molecules in the cluster source, which may subsequently be mass selected for their reactivity measurements.

  16. Identification of some heavy metals and natural radionuclides levels in Mzerib lake environment

    International Nuclear Information System (INIS)

    Al-Nimeh, M.; Al-Rayyes, A.; Al-Masri, M. S.

    2002-01-01

    Some trace metals (Cd, Pb, Cu, and Zn) and natural radionuclides ( 238 U, 210 Po, 210 Pb) were measured in environmental samples from Mzerib lake during 1998. This will help in evaluating the water quality and the effects of agricultural and humanitarian activities on the lake environment. Results showed that the lake water is of a good quality. Trace metals levels in water, sediments, freshwater clam (Unio terminals), and fish (cyprinus Cario) fall within the accepted range, although they were higher in some sites due to the presence of a potential source for pollution (e.g. the restaurant). The clam soft tissue samples showed the highest levels of Cd. Carp fish gonads and gills also showed high levels of cadmium, while Carp fish samples showed the highest levels of zinc. radionuclides levels were low and in agreement with levels reported in previous local and international studies. (authors)

  17. Means for obtaining a metal ion beam from a heavy-ion cyclotron source

    Science.gov (United States)

    Hudson, E.D.; Mallory, M.L.

    1975-08-01

    A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

  18. Identification of the sources of primary organic aerosols at urban schools: A molecular marker approach

    International Nuclear Information System (INIS)

    Crilley, Leigh R.; Qadir, Raeed M.; Ayoko, Godwin A.; Schnelle-Kreis, Jürgen; Abbaszade, Gülcin; Orasche, Jürgen; Zimmermann, Ralf; Morawska, Lidia

    2014-01-01

    Children are particularly susceptible to air pollution and schools are examples of urban microenvironments that can account for a large portion of children's exposure to airborne particles. Thus this paper aimed to determine the sources of primary airborne particles that children are exposed to at school by analyzing selected organic molecular markers at 11 urban schools in Brisbane, Australia. Positive matrix factorization analysis identified four sources at the schools: vehicle emissions, biomass burning, meat cooking and plant wax emissions accounting for 45%, 29%, 16% and 7%, of the organic carbon respectively. Biomass burning peaked in winter due to prescribed burning of bushland around Brisbane. Overall, the results indicated that both local (traffic) and regional (biomass burning) sources of primary organic aerosols influence the levels of ambient particles that children are exposed at the schools. These results have implications for potential control strategies for mitigating exposure at schools. - Highlights: • Selected organic molecular markers at 11 urban schools were analyzed. • Four sources of primary organic aerosols were identified by PMF at the schools. • Both local and regional sources were found to influence exposure at the schools. • The results have implications for mitigation of children's exposure at schools. - The identification of the most important sources of primary organic aerosols at urban schools has implications for control strategies for mitigating children's exposure at schools

  19. A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

    Directory of Open Access Journals (Sweden)

    Dong-Sup Lee

    2015-01-01

    Full Text Available Independent Component Analysis (ICA, one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: insta- bility and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to vali- date the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.

  20. Identification of metal elements by time-resolved LIBS technique in sediments lake the “Cisne”

    Science.gov (United States)

    Pacheco, P.; Arregui, E.; Álvarez, J.; Rangel, N.; Sarmiento, R.

    2017-01-01

    Laser induced breakdown spectroscopy (LIBS), is a kind of spectral method of atomic emission that uses pulses of radiation high energy laser as excitation source. One of the advantages of technical LIBS lies in the possibility of analyse the substances in any State of aggregation, already is solid, liquid or gaseous, even in colloids as aerosols, gels and others. Another advantage over other conventional techniques is the simultaneous analysis of elements present in a sample of multielement. This work is made in the use of this technique for the identification of metal pollutants in the Swan Lake sediment samples, collected by drilling cores. Plasmas were generated by focusing the radiation of Nd: YAG laser with an energy per pulse 13mJ and 4ns duration, wavelength of 532nm. The spectra of radiation from the plasmas of sediment were recorded with an Echelle spectrograph type coupled to an ICCD camera. The delay times were between 0.5μs and 7μs, while the gate width was of 2μs. To ensure the homogeneity of the plasmas, the sediment sample was placed in a positioning system of linear and rotary adjustment of smooth step synchronized with the trigger of the laser pulse. The registration of the spectra of the sediment to different times of delay, allowed to identify the lines prominent of the different elements present in the sample. The analysis of the Spectra allowed the identification of some elements in the sample as if, Ca, Na, Mg, and Al through the measurement of wavelengths of the prominent peaks.

  1. Identification of metal elements by time-resolved LIBS technique in sediments lake the “Cisne”

    International Nuclear Information System (INIS)

    Pacheco, P; Arregui, E; Álvarez, J; Rangel, N; Sarmiento, R

    2017-01-01

    Laser induced breakdown spectroscopy (LIBS), is a kind of spectral method of atomic emission that uses pulses of radiation high energy laser as excitation source. One of the advantages of technical LIBS lies in the possibility of analyse the substances in any State of aggregation, already is solid, liquid or gaseous, even in colloids as aerosols, gels and others. Another advantage over other conventional techniques is the simultaneous analysis of elements present in a sample of multielement. This work is made in the use of this technique for the identification of metal pollutants in the Swan Lake sediment samples, collected by drilling cores. Plasmas were generated by focusing the radiation of Nd: YAG laser with an energy per pulse 13mJ and 4ns duration, wavelength of 532nm. The spectra of radiation from the plasmas of sediment were recorded with an Echelle spectrograph type coupled to an ICCD camera. The delay times were between 0.5μs and 7μs, while the gate width was of 2μs. To ensure the homogeneity of the plasmas, the sediment sample was placed in a positioning system of linear and rotary adjustment of smooth step synchronized with the trigger of the laser pulse. The registration of the spectra of the sediment to different times of delay, allowed to identify the lines prominent of the different elements present in the sample. The analysis of the Spectra allowed the identification of some elements in the sample as if, Ca, Na, Mg, and Al through the measurement of wavelengths of the prominent peaks. (paper)

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  4. Sources of heavy metals in sediments of the Hudson River Estuary

    International Nuclear Information System (INIS)

    Williams, S.C.; Simpson, H.J.; Olsen, C.R.; Bopp, R.F.

    1978-01-01

    Sediments in the Hudson Estuary contain zinc, copper and lead from metal pollutants discharged to the harbor in the New York City area, from dispersed sources of contamination introduced upstream, and from natural weathering processes. The magnitude of the contribution from each of these three sources to particular sites can be estimated on the basis of total metal abundances, relative proportions of several metals, and other sediment properties. The pattern of recent heavy-metal contamination in Hudson sediments closely follows the distribution in sediments of 137 Cs which was derived over the past two decades from global fallout and local releases from a commercial nuclear reactor. Several simple empirical corrections related to grain size and mineralogy variations are suggested for comparing heavy-metal contamination levels of sandy continental shelf sediments with fine-grained estuarine and coastal sediments. Iron has little variation in Hudson sediments while manganese is greater in surface sediment of some low-salinity and fresh-water areas than deeper in the sediments, and generally less in the high-salinity area of rapid sediment deposition in New York harbor. Much of the pollutant Cu added to the harbor appears to be rapidly deposited in the sediments. (Auth.)

  5. In-situ hydrogen in metal determination using a minimum neutron source strength and exposure time.

    Science.gov (United States)

    Hatem, M; Agamy, S; Khalil, M Y

    2013-08-01

    Water is frequently present in the environment and is a source of hydrogen that can interact with many materials. Because of its small atomic size, a hydrogen atom can easily diffuse into a host metal, and though the metal may appear unchanged for a time, the metal will eventually abruptly lose its strength and ductility. Thus, measuring the hydrogen content in metals is important in many fields, such as in the nuclear industry, in automotive and aircraft fabrication, and particularly, in offshore oil and gas fields. It has been demonstrated that the use of nuclear methods to measure the hydrogen content in metals can achieve sensitivity levels on the order of parts per million. However, the use of nuclear methods in the field has not been conducted for two reasons. The first reason is due to exposure limitations. The second reason is due to the hi-tech instruments required for better accuracy. In this work, a new method using a low-strength portable neutron source is explored in conjunction with detectors based on plastic nuclear detection films. The following are the in-situ requirements: simplicity in setup, high reliability, minimal exposure dose, and acceptable accuracy at an acceptable cost. A computer model of the experimental setup is used to reproduce the results of a proof-of-concept experiment and to predict the sensitivity levels under optimised experimental conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    Science.gov (United States)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Use of Portal Monitors for Detection of Technogenic Radioactive Sources in Scrap Metal

    Science.gov (United States)

    Solovev, D. B.; Merkusheva, A. E.

    2017-11-01

    The article considers the features of organization of scrap-metal primary radiation control on the specialized enterprises engaging in its deep processing and storage at using by primary technical equipment - radiation portal monitors. The issue of this direction relevance, validity of radiation control implementation with the use of radiation portal monitors, physical and organizational bases of radiation control are considered in detail. The emphasis is put on the considerable increase in the number of technogenic radioactive sources detected in scrap-metal that results in the entering into exploitation of radioactive metallic structures as different building wares. One of reasons of such increase of the number of technogenic radioactive sources getting for processing with scrap-metal is the absence of any recommendations on the radiation portal monitors exploitation. The practical division of the article offers to recommendation on tuning of the modes of work of radiation portal monitors depending on influence the weather factor thus allowing to considerably increase the percent of technogenic radioactive sources detection.

  8. Sources and levels of concentration of metal pollutants in Kubanni dam, Zaria, Nigeria

    Directory of Open Access Journals (Sweden)

    Butu, A.W.

    2013-06-01

    Full Text Available The paper looked at the sources and levels of concentration of metal pollutants in Kubanni dam, Zaria, Nigeria. The main sources of data for the study were sediment from four different sections of the long profile of the dam. The samples were prepared in the laboratory according to standard methods and the instrumental Neutron Activation Analysis (INAA technique was adopted in the analysis using Nigeria Research Reactor – 1 (NIRR – 1. The results of the analysis showed that 29 metal pollutants; Mg, Al, Ca, Ti, V, Mn, Dy, Na, K, As, La, Sm, Yb, U, Br, Sc, Cr, Fe, Co, Rb, Zn,Cs, Ba, Eu, Lu, Hf, Ta, Sb and Th currently exist in Kubanni dam in various levels of concentrations. The results showed that most of the metal pollutants in the dam are routed to anthropogenic activities within the dam catchment area while few are routed to geologic formation. The results further revealed that metal pollutants that their sources are traceable to refuse dumps, farmlands, public drains and effluents showed higher levels of concentration in the dam than the ones that are gradually released from the soil regolith system.

  9. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    International Nuclear Information System (INIS)

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2016-01-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  10. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  11. Sythesis of metal sulfide nanomaerials via thermal decomposition of single-source percursors

    Energy Technology Data Exchange (ETDEWEB)

    Jen-La Plante, Ilan; Zeid, Tahani W.; Yang, Peidong; Mokari, Taleb

    2010-06-03

    In this report, we present a synthetic method for the formation of cuprous sulfide (Cu2S) and lead sulfide (PbS) nanomaterials directly on substrates from the thermolysis of single-source precursors. We find that the final morphology and arrangement of the nanomaterials may be controlled through the concentration of the dissolved precursors and choice of solvent. One-dimensional (1-D) morphologies may also be grown onto substrates with the addition of a metal catalyst layer through solution-liquid-solid (SLS) growth. These synthetic techniques may be expanded to other metal sulfide materials.

  12. Assessment of toxic metals in wheat crops grown on selected soils, irrigated by different water sources

    Directory of Open Access Journals (Sweden)

    Zeid A. Al-Othman

    2016-11-01

    Full Text Available We describe a comparative study of the concentration of different metals (e.g., Cd, Pb, As, Ni, Cu, Zn, Mn, and Cr in various parts of wheat plants (e.g., roots, stem, leaves and seeds collected at several locations in Khyber Pukhtoon Khaw, Pakistan. The wheat crop in these areas was irrigated using different irrigation sources, including rain, tube well, river, and canal. In wheat samples, the concentration of metals was analyzed using an atomic absorption spectrophotometer. Among the various parts of the plant, the roots had the highest levels of heavy metals, followed by the vegetative parts. By comparison, the seeds and grains had the lowest levels of heavy metals. The levels of heavy metals in all of the studied areas were not significantly localized to any particular area. The general order for the accumulation of studied metals in wheat was found to be Mn > Zn > Cu > Ni > Cr > As > Pb > Cd.

  13. Diffusion induced nuclear reactions in metals: a possible source of heat in the core

    International Nuclear Information System (INIS)

    Hamza, V.M.; Iyer, S.S.S.

    1989-01-01

    It has recently been proposed that diffusion of light nuclei in metals can give rise to unusual electrical charge distributions in their lattice structures, inducing thereby certain nuclear reactions that are otherwise uncommon. In the light of these results we advance the hypothesis that such nuclear reactions take place in the metal rich core of the earth, based on following observations: 1 - The solubility of hydrogen in metals is relatively high compared to that in silicates. 2 - Studies of rare gas samples in intraplate volcanos and diamonds show that 3 He/ He ratio increases with depth in the mantle. 3 - There are indications that He is positively correlated with enrichment of metals in lavas. We propose that hydrogen incorporated into metallic phases at the time of planetary accretion was carried to the core by downward migration of metal rich melts during the early states of proto-earth. Preliminary estimates suggest that cold fusion reactions can give rise to an average rate of heat generation of 8.2x10 12 W and may thus serve as a supplementary source of energy for the geomagnetic dynamo. (author)

  14. Liquid-metal-jet anode electron-impact x-ray source

    International Nuclear Information System (INIS)

    Hemberg, O.; Otendal, M.; Hertz, H.M.

    2003-01-01

    We demonstrate an anode concept, based on a liquid-metal jet, for improved brightness in compact electron-impact x-ray sources. The source is demonstrated in a proof-of-principle experiment where a 50 keV, ∼100 W electron beam is focused on a 75 μm liquid-solder jet. The generated x-ray flux and brightness is quantitatively measured in the 7-50 keV spectral region and found to agree with theory. Compared to rotating-anode sources, whose brightness is limited by intrinsic thermal properties, the liquid-jet anode could potentially be scaled to achieve a brightness >100x higher than current state-of-the-art sources. Applications such as mammography, angiography, and diffraction would benefit from such a compact high-brightness source

  15. The K giant stars from the LAMOST survey data. I. Identification, metallicity, and distance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chao; Deng, Li-Cai; Li, Jing; Gao, Shuang; Yang, Fan; Xu, Yan; Zhang, Yue-Yang; Xin, Yu; Wu, Yue [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Datun Road 20A, Beijing 100012 (China); Carlin, Jeffrey L.; Newberg, Heidi Jo [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Smith, Martin C. [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Xue, Xiang-Xiang [Max Planck Institute for Astronomy, Königstuhl 17, Heidelberg D-69117 (Germany); Jin, Ge, E-mail: liuchao@nao.cas.cn [University of Science and Technology of China, Hefei 230026 (China)

    2014-08-01

    We present a support vector machine classifier to identify the K giant stars from the LAMOST survey directly using their spectral line features. The completeness of the identification is about 75% for tests based on LAMOST stellar parameters. The contamination in the identified K giant sample is lower than 2.5%. Applying the classification method to about two million LAMOST spectra observed during the pilot survey and the first year survey, we select 298,036 K giant candidates. The metallicities of the sample are also estimated with an uncertainty of 0.13 ∼ 0.29 dex based on the equivalent widths of Mg{sub b} and iron lines. A Bayesian method is then developed to estimate the posterior probability of the distance for the K giant stars, based on the estimated metallicity and 2MASS photometry. The synthetic isochrone-based distance estimates have been calibrated using 7 globular clusters with a wide range of metallicities. The uncertainty of the estimated distance modulus at K = 11 mag, which is the median brightness of the K giant sample, is about 0.6 mag, corresponding to ∼30% in distance. As a scientific verification case, the trailing arm of the Sagittarius stream is clearly identified with the selected K giant sample. Moreover, at about 80 kpc from the Sun, we use our K giant stars to confirm a detection of stream members near the apo-center of the trailing tail. These rediscoveries of the features of the Sagittarius stream illustrate the potential of the LAMOST survey for detecting substructures in the halo of the Milky Way.

  16. Transition radiation in metal-metal multilayer nanostructures as a medical source of hard x-ray radiation

    International Nuclear Information System (INIS)

    Pokrovsky, A. L.; Kaplan, A. E.; Shkolnikov, P. L.

    2006-01-01

    We show that a periodic metal-metal multilayer nanostructure can serve as an efficient source of hard x-ray transition radiation. Our research effort is aimed at developing an x-ray source for medical applications, which is based on using low-energy relativistic electrons. The approach toward choosing radiator-spacer couples for the generation of hard x-ray resonant transition radiation by few-MeV electrons traversing solid multilayer structures for the energies of interest to medicine (30-50 keV) changes dramatically compared with that for soft x-ray radiation. We show that one of the main factors in achieving the required resonant line is the absence of the contrast of the refractive indices between the spacer and the radiator at the far wings of the radiation line; for that purpose, the optimal spacer, as a rule, should have a higher atomic number than the radiator. Having experimental goals in mind, we have considered also the unwanted effects due to bremsstrahlung radiation, absorption and scattering of radiated photons, detector-related issues, and inhibited coherence of transition radiation due to random deviation of spacing between the layers. Choosing as a model example a Mo-Ag radiator-spacer pair of materials, we demonstrate that the x-ray transition radiation line can be well resolved with the use of spatial and frequency filtering

  17. Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems.

    Directory of Open Access Journals (Sweden)

    B Munier

    . Plastic debris will affect metals within coastal ecosystems by; 1 providing a sorption site (copper and lead, notably for PVC 2 desorption from the plastic i.e., the "inherent" load (cadmium and zinc and 3 serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

  18. Identification of non-linear kinematic hardening with bending and unbending tests in anisotropic sheet-metals

    International Nuclear Information System (INIS)

    Brunet, M.; Morestin, F.; Godereaux, S.

    2000-01-01

    An inverse identification technique is proposed based on bending-unbending experiments on anisotropic sheet-metal strips. The initial anisotropy theory of plasticity is extended to include the concept of combined isotropic and non-linear kinematic hardening. This theory is adopted to characterise the anisotropic hardening due to loading-unloading which occurs in sheet-metal forming processes. To this end, a specific bending-unbending apparatus has been built to provide experimental moment-curvature curves. The constant bending moment applied over the length of the specimen to determine numerically the strain-stress behaviour but without Finite Element Analysis. Four constitutive parameters have to be identified by an inverse approach. Our identification results show that bending-unbending tests are suitable to model quite accurately the constitutive behaviour of sheet metals under complex loading paths. (author)

  19. A modified receptor model for source apportionment of heavy metal pollution in soil.

    Science.gov (United States)

    Huang, Ying; Deng, Meihua; Wu, Shaofu; Japenga, Jan; Li, Tingqiang; Yang, Xiaoe; He, Zhenli

    2018-07-15

    Source apportionment is a crucial step toward reduction of heavy metal pollution in soil. Existing methods are generally based on receptor models. However, overestimation or underestimation occurs when they are applied to heavy metal source apportionment in soil. Therefore, a modified model (PCA-MLRD) was developed, which is based on principal component analysis (PCA) and multiple linear regression with distance (MLRD). This model was applied to a case study conducted in a peri-urban area in southeast China where soils were contaminated by arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb). Compared with existing models, PCA-MLRD is able to identify specific sources and quantify the extent of influence for each emission. The zinc (Zn)-Pb mine was identified as the most important anthropogenic emission, which affected approximately half area for Pb and As accumulation, and approximately one third for Cd. Overall, the influence extent of the anthropogenic emissions decreased in the order of mine (3 km) > dyeing mill (2 km) ≈ industrial hub (2 km) > fluorescent factory (1.5 km) > road (0.5 km). Although algorithm still needs to improved, the PCA-MLRD model has the potential to become a useful tool for heavy metal source apportionment in soil. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Spatial clustering of metal and metalloid mixtures in unregulated water sources on the Navajo Nation - Arizona, New Mexico, and Utah, USA.

    Science.gov (United States)

    Hoover, Joseph H; Coker, Eric; Barney, Yolanda; Shuey, Chris; Lewis, Johnnye

    2018-08-15

    Contaminant mixtures are identified regularly in public and private drinking water supplies throughout the United States; however, the complex and often correlated nature of mixtures makes identification of relevant combinations challenging. This study employed a Bayesian clustering method to identify subgroups of water sources with similar metal and metalloid profiles. Additionally, a spatial scan statistic assessed spatial clustering of these subgroups and a human health metric was applied to investigate potential for human toxicity. These methods were applied to a dataset comprised of metal and metalloid measurements from unregulated water sources located on the Navajo Nation, in the southwest United States. Results indicated distinct subgroups of water sources with similar contaminant profiles and that some of these subgroups were spatially clustered. Several profiles had metal and metalloid concentrations that may have potential for human toxicity including arsenic, uranium, lead, manganese, and selenium. This approach may be useful for identifying mixtures in water sources, spatially evaluating the clusters, and help inform toxicological research investigating mixtures. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Source identification of particulate matter in a semi-urban area of Malaysia using multivariate techniques.

    Science.gov (United States)

    Wahid, N B A; Latif, M T; Suan, L S; Dominick, D; Sahani, M; Jaafar, S A; Mohd Tahir, N

    2014-03-01

    This study aims to determine the composition and sources of particulate matter with an aerodynamic diameter of 10 μm or less (PM10) in a semi-urban area. PM10 samples were collected using a high volume sampler. Heavy metals (Fe, Zn, Pb, Mn, Cu, Cd and Ni) and cations (Na(+), K(+), Ca(2+) and Mg(2+)) were detected using inductively coupled plasma mass spectrometry, while anions (SO4 (2-), NO3 (-), Cl(-) and F(-)) were analysed using Ion Chromatography. Principle component analysis and multiple linear regressions were used to identify the source apportionment of PM10. Results showed the average concentration of PM10 was 29.5 ± 5.1 μg/m(3). The heavy metals found were dominated by Fe, followed by Zn, Pb, Cu, Mn, Cd and Ni. Na(+) was the dominant cation, followed by Ca(2+), K(+) and Mg(2+), whereas SO4 (2-) was the dominant anion, followed by NO3 (-), Cl(-) and F(-). The main sources of PM10 were the Earth's crust/road dust, followed by vehicle emissions, industrial emissions/road activity, and construction/biomass burning.

  2. Modal parameter identification based on combining transmissibility functions and blind source separation techniques

    Science.gov (United States)

    Araújo, Iván Gómez; Sánchez, Jesús Antonio García; Andersen, Palle

    2018-05-01

    Transmissibility-based operational modal analysis is a recent and alternative approach used to identify the modal parameters of structures under operational conditions. This approach is advantageous compared with traditional operational modal analysis because it does not make any assumptions about the excitation spectrum (i.e., white noise with a flat spectrum). However, common methodologies do not include a procedure to extract closely spaced modes with low signal-to-noise ratios. This issue is relevant when considering that engineering structures generally have closely spaced modes and that their measured responses present high levels of noise. Therefore, to overcome these problems, a new combined method for modal parameter identification is proposed in this work. The proposed method combines blind source separation (BSS) techniques and transmissibility-based methods. Here, BSS techniques were used to recover source signals, and transmissibility-based methods were applied to estimate modal information from the recovered source signals. To achieve this combination, a new method to define a transmissibility function was proposed. The suggested transmissibility function is based on the relationship between the power spectral density (PSD) of mixed signals and the PSD of signals from a single source. The numerical responses of a truss structure with high levels of added noise and very closely spaced modes were processed using the proposed combined method to evaluate its ability to identify modal parameters in these conditions. Colored and white noise excitations were used for the numerical example. The proposed combined method was also used to evaluate the modal parameters of an experimental test on a structure containing closely spaced modes. The results showed that the proposed combined method is capable of identifying very closely spaced modes in the presence of noise and, thus, may be potentially applied to improve the identification of damping ratios.

  3. Seasonal and Spatial Variations of Heavy Metals in Two Typical Chinese Rivers: Concentrations, Environmental Risks, and Possible Sources

    Science.gov (United States)

    Yao, Hong; Qian, Xin; Gao, Hailong; Wang, Yulei; Xia, Bisheng

    2014-01-01

    Ten metals were analyzed in samples collected in three seasons (the dry season, the early rainy season, and the late rainy season) from two rivers in China. No observed toxic effect concentrations were used to estimate the risks. The possible sources of the metals in each season, and the dominant source(s) at each site, were assessed using principal components analysis. The metal concentrations in the area studied were found, using t-tests, to vary both seasonally and spatially (P = 0.05). The potential risks in different seasons decreased in the order: early rainy season > dry season > late rainy season, and Cd was the dominant contributor to the total risks associated with heavy metal pollution in the two rivers. The high population and industrial site densities in the Taihu basin have had negative influences on the two rivers. The river that is used as a source of drinking water (the Taipu River) had a low average level of risks caused by the metals. Metals accumulated in environmental media were the main possible sources in the dry season, and emissions from mechanical manufacturing enterprises were the main possible sources in the rainy season. The river in the industrial area (the Wusong River) had a moderate level of risk caused by the metals, and the main sources were industrial emissions. The seasonal and spatial distributions of the heavy metals mean that risk prevention and mitigation measures should be targeted taking these variations into account. PMID:25407421

  4. Seasonal and Spatial Variations of Heavy Metals in Two Typical Chinese Rivers: Concentrations, Environmental Risks, and Possible Sources

    Directory of Open Access Journals (Sweden)

    Hong Yao

    2014-11-01

    Full Text Available Ten metals were analyzed in samples collected in three seasons (the dry season, the early rainy season, and the late rainy season from two rivers in China. No observed toxic effect concentrations were used to estimate the risks. The possible sources of the metals in each season, and the dominant source(s at each site, were assessed using principal components analysis. The metal concentrations in the area studied were found, using t-tests, to vary both seasonally and spatially (P = 0.05. The potential risks in different seasons decreased in the order: early rainy season > dry season > late rainy season, and Cd was the dominant contributor to the total risks associated with heavy metal pollution in the two rivers. The high population and industrial site densities in the Taihu basin have had negative influences on the two rivers. The river that is used as a source of drinking water (the Taipu River had a low average level of risks caused by the metals. Metals accumulated in environmental media were the main possible sources in the dry season, and emissions from mechanical manufacturing enterprises were the main possible sources in the rainy season. The river in the industrial area (the Wusong River had a moderate level of risk caused by the metals, and the main sources were industrial emissions. The seasonal and spatial distributions of the heavy metals mean that risk prevention and mitigation measures should be targeted taking these variations into account.

  5. New Advanced Source Identification Algorithm (ASIA-NEW) for radiation monitors with plastic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stavrov, Andrei; Yamamoto, Eugene [Rapiscan Systems, Inc., 14000 Mead Street, Longmont, CO, 80504 (United States)

    2015-07-01

    Radiation Portal Monitors (RPM) with plastic detectors represent the main instruments used for primary border (customs) radiation control. RPM are widely used because they are simple, reliable, relatively inexpensive and have a high sensitivity. However, experience using the RPM in various countries has revealed the systems have some grave shortcomings. There is a dramatic decrease of the probability of detection of radioactive sources under high suppression of the natural gamma background (radiation control of heavy cargoes, containers and, especially, trains). NORM (Naturally Occurring Radioactive Material) existing in objects under control trigger the so-called 'nuisance alarms', requiring a secondary inspection for source verification. At a number of sites, the rate of such alarms is so high it significantly complicates the work of customs and border officers. This paper presents a brief description of new variant of algorithm ASIA-New (New Advanced Source Identification Algorithm), which was developed by the authors and based on some experimental test results. It also demonstrates results of different tests and the capability of a new system to overcome the shortcomings stated above. New electronics and ASIA-New enables RPM to detect radioactive sources under a high background suppression (tested at 15-30%) and to verify the detected NORM (KCl) and the artificial isotopes (Co-57, Ba-133 and other). New variant of ASIA is based on physical principles and does not require a lot of special tests to attain statistical data for its parameters. That is why this system can be easily installed into any RPM with plastic detectors. This algorithm was tested for 1,395 passages of different transports (cars, trucks and trailers) without radioactive sources. It also was tested for 4,015 passages of these transports with radioactive sources of different activity (Co-57, Ba-133, Cs-137, Co-60, Ra-226, Th-232) and these sources masked by NORM (K-40) as well

  6. Laser Scanning Systems and Techniques in Rockfall Source Identification and Risk Assessment: A Critical Review

    Science.gov (United States)

    Fanos, Ali Mutar; Pradhan, Biswajeet

    2018-04-01

    Rockfall poses risk to people, their properties and to transportation ways in mountainous and hilly regions. This catastrophe shows various characteristics such as vast distribution, sudden occurrence, variable magnitude, strong fatalness and randomicity. Therefore, prediction of rockfall phenomenon both spatially and temporally is a challenging task. Digital Terrain model (DTM) is one of the most significant elements in rockfall source identification and risk assessment. Light detection and ranging (LiDAR) is the most advanced effective technique to derive high-resolution and accurate DTM. This paper presents a critical overview of rockfall phenomenon (definition, triggering factors, motion modes and modeling) and LiDAR technique in terms of data pre-processing, DTM generation and the factors that can be obtained from this technique for rockfall source identification and risk assessment. It also reviews the existing methods that are utilized for the evaluation of the rockfall trajectories and their characteristics (frequency, velocity, bouncing height and kinetic energy), probability, susceptibility, hazard and risk. Detail consideration is given on quantitative methodologies in addition to the qualitative ones. Various methods are demonstrated with respect to their application scales (local and regional). Additionally, attention is given to the latest improvement, particularly including the consideration of the intensity of the phenomena and the magnitude of the events at chosen sites.

  7. Technical note: Efficient online source identification algorithm for integration within a contamination event management system

    Science.gov (United States)

    Deuerlein, Jochen; Meyer-Harries, Lea; Guth, Nicolai

    2017-07-01

    Drinking water distribution networks are part of critical infrastructures and are exposed to a number of different risks. One of them is the risk of unintended or deliberate contamination of the drinking water within the pipe network. Over the past decade research has focused on the development of new sensors that are able to detect malicious substances in the network and early warning systems for contamination. In addition to the optimal placement of sensors, the automatic identification of the source of a contamination is an important component of an early warning and event management system for security enhancement of water supply networks. Many publications deal with the algorithmic development; however, only little information exists about the integration within a comprehensive real-time event detection and management system. In the following the analytical solution and the software implementation of a real-time source identification module and its integration within a web-based event management system are described. The development was part of the SAFEWATER project, which was funded under FP 7 of the European Commission.

  8. A Soft Computing Approach to Crack Detection and Impact Source Identification with Field-Programmable Gate Array Implementation

    Directory of Open Access Journals (Sweden)

    Arati M. Dixit

    2013-01-01

    Full Text Available The real-time nondestructive testing (NDT for crack detection and impact source identification (CDISI has attracted the researchers from diverse areas. This is apparent from the current work in the literature. CDISI has usually been performed by visual assessment of waveforms generated by a standard data acquisition system. In this paper we suggest an automation of CDISI for metal armor plates using a soft computing approach by developing a fuzzy inference system to effectively deal with this problem. It is also advantageous to develop a chip that can contribute towards real time CDISI. The objective of this paper is to report on efforts to develop an automated CDISI procedure and to formulate a technique such that the proposed method can be easily implemented on a chip. The CDISI fuzzy inference system is developed using MATLAB’s fuzzy logic toolbox. A VLSI circuit for CDISI is developed on basis of fuzzy logic model using Verilog, a hardware description language (HDL. The Xilinx ISE WebPACK9.1i is used for design, synthesis, implementation, and verification. The CDISI field-programmable gate array (FPGA implementation is done using Xilinx’s Spartan 3 FPGA. SynaptiCAD’s Verilog Simulators—VeriLogger PRO and ModelSim—are used as the software simulation and debug environment.

  9. Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant

    Directory of Open Access Journals (Sweden)

    Zamani Abbas Ali

    2012-12-01

    Full Text Available Abstract The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP. Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs. Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area.

  10. Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant.

    Science.gov (United States)

    Zamani, Abbas Ali; Yaftian, Mohammad Reza; Parizanganeh, Abdolhossein

    2012-12-17

    The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran) for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP). Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs). Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area.

  11. Identification and chemical characterization of industrial particulate matter sources in southwest Spain.

    Science.gov (United States)

    Alastuey, Andrés; Querol, Xavier; Plana, Feliciano; Viana, Mar; Ruiz, Carmen R; Sánchez de la Campa, Ana; de la Rosa, Jesús; Mantilla, Enrique; García dos Santos, Saul

    2006-07-01

    A detailed physical and chemical characterization of coarse particulate matter (PM10) and fine particulate matter (PM2.5) in the city of Huelva (in Southwestern Spain) was carried out during 2001 and 2002. To identify the major emission sources with a significant influence on PM10 and PM2.5, a methodology was developed based on the combination of: (1) real-time measurements of levels of PM10, PM2.5, and very fine particulate matter (PM1); (2) chemical characterization and source apportionment analysis of PM10 and PM2.5; and (3) intensive measurements in field campaigns to characterize the emission plumes of several point sources. Annual means of 37, 19, and 16 microg/m3 were obtained for the study period for PM10, PM2.5, and PM1, respectively. High PM episodes, characterized by a very fine grain size distribution, are frequently detected in Huelva mainly in the winter as the result of the impact of the industrial emission plumes on the city. Chemical analysis showed that PM at Huelva is characterized by high PO4(3-) and As levels, as expected from the industrial activities. Source apportionment analyses identified a crustal source (36% of PM10 and 31% of PM2.5); a traffic-related source (33% of PM10 and 29% of PM2.5), and a marine aerosol contribution (only in PM10, 4%). In addition, two industrial emission sources were identified in PM10 and PM2.5: (1) a petrochemical source, 13% in PM10 and 8% in PM2.5; and (2) a mixed metallurgical-phosphate source, which accounts for 11-12% of PM10 and PM2.5. In PM2.5 a secondary source has been also identified, which contributed to 17% of the mass. A complete characterization of industrial emission plumes during their impact on the ground allowed for the identification of tracer species for specific point sources, such as petrochemical, metallurgic, and fertilizer and phosphate production industries.

  12. Identifying sources of metal exposure in organic and conventional dairy farming.

    Science.gov (United States)

    López-Alonso, M; Rey-Crespo, F; Herrero-Latorre, C; Miranda, M

    2017-10-01

    In humans the main route of exposure to toxic metals is through the diet, and there is therefore a clear need for this source of contamination to be minimized, particularly in food of animal origin. For this purpose, the various sources of toxic metals in livestock farming (which vary depending on the production system) must be taken into account. The objectives of the present study were to establish the profile of metal exposure in dairy cattle in Spain and to determine, by chemometric (multivariate statistical) analysis, any differences between organic and conventional systems. Blood samples from 522 cows (341 from organic farms and 181 from conventional farms) were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of 14 elements: As, Cd, Co, Cr, Cu, Fe, Hg, I, Mn, Mo, Ni, Pb, Se and Zn. In conventional systems the generally high and balanced trace element concentrations in the mineral-supplemented concentrate feed strongly determined the metal status of the cattle. However, in organic systems, soil ingestion was an important contributing factor. Our results demonstrate that general information about the effects of mineral supplementation in conventional farming cannot be directly extrapolated to organic farming and special attention should be given to the contribution of ingestion of soil during grazing and/or ingestion of soil contaminated forage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Sources of heavy metal contamination in Swedish wood waste used for combustion

    International Nuclear Information System (INIS)

    Krook, J.; Martensson, A.; Eklund, M.

    2006-01-01

    In this paper, wood waste (RWW) recovered for heat production in Sweden was studied. Previous research has concluded that RWW contains elevated amounts of heavy metals, causing environmental problems during waste management. This study extends previous work on RWW by analysing which pollution sources cause this contamination. Using existing data on the metal contents in various materials, and the amounts of these materials in RWW, the share of the elevated amounts of metals in RWW that these materials explain was quantified. Six different materials occurring in RWW were studied and the results show that they explain from 70% to 100% of the amounts of arsenic, chromium, lead, copper and zinc in RWW. The most important materials contributing to contamination of RWW are surface-treated wood, industrial preservative-treated wood, plastic and galvanised fastening systems. These findings enable the development and evaluation of strategies aiming to decrease pollution and resource loss from handling RWW. It is argued that source separation and measures taken further downstream from the generation site, such as treatment, need to be combined to substantially decrease the amount of heavy metals in RWW

  14. Assessment of heavy metals in agricultural soils and their source apportionment: a Turkish district survey.

    Science.gov (United States)

    Dartan, Güler; Taşpınar, Fatih; Toröz, İsmail

    2015-03-01

    This study aimed at investigating the impact of industrialization on the quality of agricultural soils in the district of Bandırma, Turkey, in terms of soil heavy metal contamination. Many soil and phosphogypsum samples were analyzed, and enrichment factors (EFs) were calculated. The average concentration gradient of metals in the soil (mg/kg) was As metal enrichments in the soil were found to be moderately high and significant. In the majority of soil samples, Ni, Cu, Co, Zn, Se, Pb, and Cr were moderately enriched whereas Sb and Cd were extremely highly enriched. A factor analysis (FA) was applied to the cross-correlations of the elements to identify their sources. Six significant factors were extracted with the help of FA, explaining 77.22 % of the total variance, and the elements loaded on these factors were interpreted. The evaluations of the factors showed that the study area has been exposed to heavy metal pollution from anthropogenic sources considering the high levels of Cr, Cd, Cu, P, V, Zn, Ni, Sb, and Pb in the soil and the higher EFs falling in the range of 2.54-372.87. Moreover, the soil concentrations of Mn, Mg, Co, Al, K, and Ca were also high, but they were of lithogenic in origin according to the FA.

  15. Thickness measurement for the different metals by using Cs-137 gamma source with gamma transmission technique

    International Nuclear Information System (INIS)

    Bueyuek, B.; Tugrul, B.

    2009-01-01

    The purpose of this study is an experimental analysis of thickness measurement for various metals with the gamma transmission technique using Cs-137 as the radioisotope source. Lead, steel, brass, and aluminum, which are frequently used metals in industry, were chosen for the experiments. As the radioisotope source Cs-137 was preferred for the study since it has long half-life, it is mono energetic, and it penetrates the metals that were studied. Experiments were observed in the constant experimental geometry. Calibration curves for the four metal samples were plotted using the obtained results. To test the plotted calibration curves, counts for determining thickness measurement were collected for each sample and the obtained relative count values were used in conjunction with the plotted calibration curves for each sample to determine its thickness. The thicknesses of the samples have been measured with a micrometer and the results were comparatively analyzed with the measurement results obtained by the gamma transmission technique. The results of the analyses revealed that the thickness measurement values obtained with the gamma transmission technique and the thickness measurement values obtained with the conventional technique significantly converge to each other and the difference between the two values is at an acceptable level. Therefore the reliability of thickness measurements with the gamma transmission technique and the resulting calibration curves have been demonstrated.

  16. Source apportionment and heavy metal health risk (HMHR) quantification from sources in a southern city in China, using an ME2-HMHR model.

    Science.gov (United States)

    Peng, Xing; Shi, GuoLiang; Liu, GuiRong; Xu, Jiao; Tian, YingZe; Zhang, YuFen; Feng, YinChang; Russell, Armistead G

    2017-02-01

    Heavy metals (Cr, Co, Ni, As, Cd, and Pb) can be bound to PM adversely affecting human health. Quantifying the source impacts on heavy metals can provide source-specific estimates of the heavy metal health risk (HMHR) to guide effective development of strategies to reduce such risks from exposure to heavy metals in PM 2.5 (particulate matter (PM) with aerodynamic diameter less than or equal to 2.5 μm). In this study, a method combining Multilinear Engine 2 (ME2) and a risk assessment model is developed to more effectively quantify source contributions to HMHR, including heavy metal non-cancer risk (non-HMCR) and cancer risk (HMCR). The combined model (called ME2-HMHR) has two steps: step1, source contributions to heavy metals are estimated by employing the ME2 model; step2, the source contributions in step 1 are introduced into the risk assessment model to calculate the source contributions to HMHR. The approach was applied to Huzou, China and five significant sources were identified. Soil dust is the largest source of non-HMCR. For HMCR, the source contributions of soil dust, coal combustion, cement dust, vehicle, and secondary sources are 1.0 × 10 -4 , 3.7 × 10 -5 , 2.7 × 10 -6 , 1.6 × 10 -6 and 1.9 × 10 -9 , respectively. The soil dust is the largest contributor to HMCR, being driven by the high impact of soil dust on PM 2.5 and the abundance of heavy metals in soil dust. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Glovebox enclosed dc plasma source for the determination of metals in plutonium

    International Nuclear Information System (INIS)

    Morris, W.F.

    1986-01-01

    The direct current plasma source of a Beckman Spectraspan IIIB emission spectrometer was enclosed in a glovebox at Lawrence Livermore National Laboratory in December 1982. Since that time, the system has been used for the routine determination of alloy and impurity metals in plutonium. This paper presents the systematic steps involved in developing the glovebox and gives information regarding performance of the plasma in the glovebox and the effectiveness of containment of plutonium. 8 refs., 9 figs., 3 tabs

  18. Sources, transport and deposition of heavy metals and persistent organic pollutants (POPs)

    Energy Technology Data Exchange (ETDEWEB)

    Pacyna, J M

    1996-01-01

    The conference paper deals with a study on the behaviour of heavy metals (HMs) and persistent organic pollutants (POPs) in the environment. The conclusion is that many of these compounds create serious problems due their toxicity and bioaccumulation in various environmental compartments. Several scientific questions have been posed for improved understanding of the nature and the extent of these problems. The present paper addresses questions related to sources, fluxes, and atmospheric pathways of HMs and POPs in Europe

  19. Heavy metals in marine coastal sediments: assessing sources, fluxes, history and trends.

    Science.gov (United States)

    Frignani, Mauro; Bellucci, Luca Giorgio

    2004-01-01

    Examples are presented from the Adriatic Sea, the Ligurian Sea and the Venice Lagoon to illustrate different approaches to the study of anthropogenic metals in marine coastal sediments. These examples refer to studies of areal distribution and transport mechanisms, individuation of the sources, sediment dating, chronology of the fluxes, present and past trends. In particular, some of the findings achieved in studying the Venice Lagoon are discussed from the point of view of anthropogenic changes both in sediment composition and contaminant fluxes.

  20. Measurement of thermal conductivity of uranium metal using transient plane source technique

    International Nuclear Information System (INIS)

    Subramanian, G.G.S.; Bapuji, T.; Panneerselvam, G.; Antony, M.P.; Nagarajan, K.

    2012-01-01

    Thermo physical properties of fuel, cladding and structural materials play a significant role in the reactor operation. Thermal conductivity is one of the most important physical properties of the fuel which determines the maximum linear heat rating of the fuel in a reactor. As part of this study, the thermal conductivity of uranium metal was measured using a transient plane source (TPS) by Hot-disc method

  1. A high current metal vapour vacuum arc ion source for ion implantation studies

    International Nuclear Information System (INIS)

    Evans, P.J.; Noorman, J.T.; Watt, G.C.; Cohen, D.D.; Bailey, G.M.

    1989-01-01

    The main features of the metal vapour vacuum arc(MEVA) as an ion source are presented. The technology utilizes the plasma production capabilities of a vacuum arc cathode. Some of the ions produced in this discharge flow through the anode and the 3 extraction grids to form an extracted ion beam. The high beam current and the potential for generating broad beams, make this technology suitable for implantation of large surface areas. The composition of the vacuum arc cathode determines the particular ions obtained from the MEVA source. 3 refs., 1 tab., 2 figs

  2. Impact source identification in finite isotropic plates using a time-reversal method: theoretical study

    International Nuclear Information System (INIS)

    Chen, Chunlin; Yuan, Fuh-Gwo

    2010-01-01

    This paper aims to identify impact sources on plate-like structures based on the synthetic time-reversal (T-R) concept using an array of sensors. The impact source characteristics, namely, impact location and impact loading time history, are reconstructed using the invariance of time-reversal concept, reciprocal theory, and signal processing algorithms. Numerical verification for two finite isotropic plates under low and high velocity impacts is performed to demonstrate the versatility of the synthetic T-R method for impact source identification. The results show that the impact location and time history of the impact force with various shapes and frequency bands can be readily obtained with only four sensors distributed around the impact location. The effects of time duration and the inaccuracy in the estimated impact location on the accuracy of the time history of the impact force using the T-R method are investigated. Since the T-R technique retraces all the multi-paths of reflected waves from the geometrical boundaries back to the impact location, it is well suited for quantifying the impact characteristics for complex structures. In addition, this method is robust against noise and it is suggested that a small number of sensors is sufficient to quantify the impact source characteristics through simple computation; thus it holds promise for the development of passive structural health monitoring (SHM) systems for impact monitoring in near real-time

  3. Profiling oil sands mixtures from industrial developments and natural groundwaters for source identification.

    Science.gov (United States)

    Frank, Richard A; Roy, James W; Bickerton, Greg; Rowland, Steve J; Headley, John V; Scarlett, Alan G; West, Charles E; Peru, Kerry M; Parrott, Joanne L; Conly, F Malcolm; Hewitt, L Mark

    2014-01-01

    The objective of this study was to identify chemical components that could distinguish chemical mixtures in oil sands process-affected water (OSPW) that had potentially migrated to groundwater in the oil sands development area of northern Alberta, Canada. In the first part of the study, OSPW samples from two different tailings ponds and a broad range of natural groundwater samples were assessed with historically employed techniques as Level-1 analyses, including geochemistry, total concentrations of naphthenic acids (NAs) and synchronous fluorescence spectroscopy (SFS). While these analyses did not allow for reliable source differentiation, they did identify samples containing significant concentrations of oil sands acid-extractable organics (AEOs). In applying Level-2 profiling analyses using electrospray ionization high resolution mass spectrometry (ESI-HRMS) and comprehensive multidimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF/MS) to samples containing appreciable AEO concentrations, differentiation of natural from OSPW sources was apparent through measurements of O2:O4 ion class ratios (ESI-HRMS) and diagnostic ions for two families of suspected monoaromatic acids (GC × GC-TOF/MS). The resemblance between the AEO profiles from OSPW and from 6 groundwater samples adjacent to two tailings ponds implies a common source, supporting the use of these complimentary analyses for source identification. These samples included two of upward flowing groundwater collected <1 m beneath the Athabasca River, suggesting OSPW-affected groundwater is reaching the river system.

  4. Polyatomic ions from a high current ion implanter driven by a liquid metal ion source

    Science.gov (United States)

    Pilz, W.; Laufer, P.; Tajmar, M.; Böttger, R.; Bischoff, L.

    2017-12-01

    High current liquid metal ion sources are well known and found their first application as field emission electric propulsion thrusters in space technology. The aim of this work is the adaption of such kind of sources in broad ion beam technology. Surface patterning based on self-organized nano-structures on, e.g., semiconductor materials formed by heavy mono- or polyatomic ion irradiation from liquid metal (alloy) ion sources (LMAISs) is a very promising technique. LMAISs are nearly the only type of sources delivering polyatomic ions from about half of the periodic table elements. To overcome the lack of only very small treated areas by applying a focused ion beam equipped with such sources, the technology taken from space propulsion systems was transferred into a large single-end ion implanter. The main component is an ion beam injector based on high current LMAISs combined with suited ion optics allocating ion currents in the μA range in a nearly parallel beam of a few mm in diameter. Different types of LMAIS (needle, porous emitter, and capillary) are presented and characterized. The ion beam injector design is specified as well as the implementation of this module into a 200 kV high current ion implanter operating at the HZDR Ion Beam Center. Finally, the obtained results of large area surface modification of Ge using polyatomic Bi2+ ions at room temperature from a GaBi capillary LMAIS will be presented and discussed.

  5. Spatial Distribution, Sources Apportionment and Health Risk of Metals in Topsoil in Beijing, China

    Directory of Open Access Journals (Sweden)

    Chunyuan Sun

    2016-07-01

    Full Text Available In order to acquire the pollution feature and regularities of distribution of metals in the topsoil within the sixth ring road in Beijing, a total of 46 soil samples were collected, and the concentrations of twelve elements (Nickel, Ni, Lithium, Li, Vanadium, V, Cobalt, Co, Barium, Ba, Strontium, Sr, Chrome, Cr, Molybdenum, Mo, Copper, Cu, Cadmium, Cd, Zinc, Zn, Lead, Pb were analyzed. Geostatistics and multivariate statistics were conducted to identify spatial distribution characteristics and sources. In addition, the health risk of the analyzed heavy metals to humans (adult was evaluated by an U.S. Environmental Protection Agency health risk assessment model. The results indicate that these metals have notable variation in spatial scale. The concentration of Cr was high in the west and low in the east, while that of Mo was high in the north and low in the south. High concentrations of Cu, Cd, Zn, and Pb were found in the central part of the city. The average enrichment degree of Cd is 5.94, reaching the standard of significant enrichment. The accumulation of Cr, Mo, Cu, Cd, Zn, and Pb is influenced by anthropogenic activity, including vehicle exhaustion, coal burning, and industrial processes. Health risk assessment shows that both non-carcinogenic and carcinogenic risks of selected heavy metals are within the safety standard and the rank of the carcinogenic risk of the four heavy metals is Cr > Co > Ni > Cd.

  6. Spatial Distribution, Sources Apportionment and Health Risk of Metals in Topsoil in Beijing, China.

    Science.gov (United States)

    Sun, Chunyuan; Zhao, Wenji; Zhang, Qianzhong; Yu, Xue; Zheng, Xiaoxia; Zhao, Jiayin; Lv, Ming

    2016-07-20

    In order to acquire the pollution feature and regularities of distribution of metals in the topsoil within the sixth ring road in Beijing, a total of 46 soil samples were collected, and the concentrations of twelve elements (Nickel, Ni, Lithium, Li, Vanadium, V, Cobalt, Co, Barium, Ba, Strontium, Sr, Chrome, Cr, Molybdenum, Mo, Copper, Cu, Cadmium, Cd, Zinc, Zn, Lead, Pb) were analyzed. Geostatistics and multivariate statistics were conducted to identify spatial distribution characteristics and sources. In addition, the health risk of the analyzed heavy metals to humans (adult) was evaluated by an U.S. Environmental Protection Agency health risk assessment model. The results indicate that these metals have notable variation in spatial scale. The concentration of Cr was high in the west and low in the east, while that of Mo was high in the north and low in the south. High concentrations of Cu, Cd, Zn, and Pb were found in the central part of the city. The average enrichment degree of Cd is 5.94, reaching the standard of significant enrichment. The accumulation of Cr, Mo, Cu, Cd, Zn, and Pb is influenced by anthropogenic activity, including vehicle exhaustion, coal burning, and industrial processes. Health risk assessment shows that both non-carcinogenic and carcinogenic risks of selected heavy metals are within the safety standard and the rank of the carcinogenic risk of the four heavy metals is Cr > Co > Ni > Cd.

  7. Application of phased array technology for identification of low frequency noise sources

    Energy Technology Data Exchange (ETDEWEB)

    Hugo E. Camargo; Patricio A. Ravetta; Ricardo A. Burdisso; Adam K. Smith [NIOSH (United States)

    2009-12-15

    A study conducted by the National Institute for Occupational Safety and Health (NIOSH) revealed that 90% of coal miners have hearing impairment by age 50, compared to only 10% of those not exposed to occupational noise. According to the Mine Safety and Health Administration (MSHA), Continuous Mining Machine (CM) operators account for 30% of workers exposed to noise doses exceeding the Permissible Exposure Level (PEL). In this context, NIOSH is conducting research to identify and control dominant noise sources in CMs. Previous noise source identification was performed using a Bruel & Kjaer (B&K) 1.92-m diameter, 42-microphone phased array. These measurements revealed that the impacts from the conveyor chain onto the tail roller, and the impacts from the conveyor chain onto the upper deck are the dominant noise sources at the tail-section of the CM. The objectives of the work presented in this paper were: (1) To rank the noise radiated by the different sections of the conveyor, and (2) to determine the effect of a urethane-coated tail roller on the noise radiated by the tail-section. This test was conducted using an Acoustical and Vibrations Engineering Consultants (AVEC) 3.5-m diameter, 121-microphone phased array. The results from this new test show that a urethane-coated tail roller yields reductions in the tail-section of 2 to 8 dB in Sound Pressure Level in the frequency range of 1 kHz to 5 kHz. However, integration of the acoustic maps shows that the front-section and mid-section of the conveyor also contain dominant noise sources. Therefore, a urethane-coated tail roller in combination with a chain with urethane-coated flights that reduces the noise sources in the front and mid sections of the conveyor is required to yield a significant noise reduction on the CM operator's overall exposure. These results show the applicability of phased array technology for low frequency noise source identification.

  8. Multivariate analysis for source identification of pollution in sediment of Linggi River, Malaysia.

    Science.gov (United States)

    Elias, Md Suhaimi; Ibrahim, Shariff; Samuding, Kamarudin; Rahman, Shamsiah Ab; Wo, Yii Mei; Daung, Jeremy Andy Dominic

    2018-03-29

    Rapid socioeconomic development in the Linggi River Basin has contributed to the significant increase of pollution discharge into the Linggi River and its adjacent coastal areas. The toxic element contents and distributions in the sediment samples collected along the Linggi River were determined using neutron activation analysis (NAA) and inductively coupled plasma-mass spectrometry (ICP-MS) techniques. The measured mean concentration of As, Cd, Pb, Sb, U, Th and Zn is relatively higher compared to the continental crust value of the respective element. Most of the elements (As, Cr, Fe, Pb, Sb and Zn) exceeded the freshwater sediment quality guideline-threshold effect concentration (FSQG-TEC) value. Downstream stations of the Linggi River showed that As concentrations in sediment exceeded the freshwater sediment quality guideline-probable effect concentration (FSQG-PEC) value. This indicates that the concentration of As will give an adverse effect to the growth of sediment-dwelling organisms. Generally, the Linggi River sediment can be categorised as unpolluted to strongly polluted and unpolluted to strongly to extremely polluted. The correlation matrix of metal-metal relationship, principle component analysis (PCA) and cluster analysis (CA) indicates that the pollution sources of Cu, Ni, Zn, Cd and Pb in sediments of the Linggi River originated from the industry of electronics and electroplating. Elements of As, Cr, Sb and Fe mainly originated from motor-vehicle workshops and metal work, whilst U and Th originated from natural processes such as terrestrial runoff and land erosion.

  9. Very broad beam metal ion source for large area ion implantation application

    International Nuclear Information System (INIS)

    Brown, I.; Anders, S.; Dickinson, M.R.; MacGill, R.A.; Yao, X.

    1993-01-01

    The authors have made and operated a very broad beam version of vacuum arc ion source and used it to carry out high energy metal ion implantation of a particularly large substrate. A multiple-cathode vacuum arc plasma source was coupled to a 50 cm diameter beam extractor (multiple aperture, accel-decel configuration) operated at a net extraction voltage of up to 50 kV. The metal ion species chosen were Ni and Ta. The mean ion charge state for Ni and Ta vacuum arc plasmas is 1.8 and 2.9, respectively, and so the mean ion energies were up to about 90 and 145 keV, respectively. The ion source was operated in a repetitively pulsed mode with pulse length 250 μs and repetition rate several pulses per second. The extracted beam had a gaussian profile with FWHM about 35 cm, giving a nominal beam area of about 1,000 cm 2 . The current of Ni or Ta metal ions in the beam was up to several amperes. The targets for the ion implantation were a number of 24-inch long, highly polished Cu rails from an electromagnetic rail gun. The rails were located about 80 cm away from the ion source extractor grids, and were moved across a diameter of the vessel in such a way as to maximize the uniformity of the implant along the rail. The saturation retained dose for Ta was limited to about 4 x 10 16 cm -2 because of the rather severe sputtering, in accordance with the theoretical expectations for these implantation conditions. Here they describe the ion source, the implantation procedure, and the kinds of implants that can be produced in this way

  10. CADDIS Volume 2. Sources, Stressors and Responses: Metals - Detailed Conceptual Model Diagram

    Science.gov (United States)

    Introduction to the metals module, when to list metals as a candidate cause, ways to measure metals, simple and detailed conceptual diagrams for metals, metals module references and literature reviews.

  11. CADDIS Volume 2. Sources, Stressors and Responses: Metals - Simple Conceptual Model Diagram

    Science.gov (United States)

    Introduction to the metals module, when to list metals as a candidate cause, ways to measure metals, simple and detailed conceptual diagrams for metals, metals module references and literature reviews.

  12. Model-based evaluation of the use of polycyclic aromatic hydrocarbons molecular diagnostic ratios as a source identification tool

    International Nuclear Information System (INIS)

    Katsoyiannis, Athanasios; Breivik, Knut

    2014-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool. -- Highlights: • Model-based evaluation of the PAHs molecular diagnostic ratios efficiency. • Individual PAHs are characterized by different characteristic travel distances. • MDRs are proven to be a limited tool for source identification. • Use of MDRs for other environmental media is likely unfeasible. -- PAHs molecular diagnostic ratios which change greatly as a function of distance from the emitting source are improper for source identification purposes

  13. Goods in the Anthroposphere as a Metal Emission Source A Case Study of Stockholm, Sweden

    International Nuclear Information System (INIS)

    Soerme, L.; Bergbaeck, B.; Lohm, U.

    2001-01-01

    The aim of this study was to quantify the diffuse emissions during use of metal containing goods in the capital of Sweden,Stockholm. The following metals were studied: Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni) and Zinc (Zn).A major part of the metals are found in a protected environment where degrading processes like corrosion are most limited. However, during the lifetime of some goods the metal release to the environment is significant. The quantitatively most dominant emissions were found for Cu and Zn. The tap water system and roofs/fronts (Cu) represent goods with large exposed areas but with relatively small release rates per unit. In contrast, brake linings, aerial lines and electrical grounding (Cu) and tyres, brake linings and chemicals (Zn) are all goods with high release rates but mostly limited exposed stocks.High yearly emissions are also found for Pb, ammunition and sinkers dominate the calculated emissions totally. For Cr and Ni, stainless steel represent the major part of the stocks, but corrosion was estimated to give only a minor contribution to the emissions. Potential emission sources, i.e. stabilisers,pigments and plated goods dominate the exposed Cd stock. These emissions were not quantified due to lack of data. Hg is currently phased out, but one major source of emission, i.e. the use of amalgam, will be continuously significant for several decades. The importance of the traffic sector is obvious. The emissions from brake linings (Cu, Zn and Pb), tyres (Zn, Pb, Cr and Ni)and asphalt wear (Cu, Zn, Cr, Ni and Pb) are all of large importance for the total emission from respectively metal

  14. Some novel design features of the LBL metal vapor vacuum arc ion sources

    International Nuclear Information System (INIS)

    MacGill, R.A.; Brown, I.G.; Galvin, J.E.

    1990-01-01

    The family of MEVVA (metal vapor vacuum arc) high current metal ion sources developed at LBL over the past several years has grown to include a number of different source versions with a wide range of some of the design and operational parameters. The MicroMEVVA source is a particularly compact version, about 2 cm diam and 10 cm long, while the MEVVA IV weighs some 30 kG. MEVVAs IV and V incorporate multiple cathode assemblies (16 and 18 separate cathodes, respectively), and the operating cathode can be switched rapidly and without downtime. The new MEVVA V embodiment is quite compact considering its broad beam (10 cm), high voltage (100 kV), and multiple cathode features. The large-area extractor grids used in MEVVA V were fabricated using a particularly simple technique, and they are clamped into position and can thus be changed simply and quickly. The electrical system used to drive the arc is particularly simple and incorporates several attractive features. In this article we review and describe a number of the mechanical and electrical design features that have been developed for these sources

  15. Metal negative ion beam extraction from a radio frequency ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, S.; Yamada, N.; Kasuya, T.; Romero, C. F. P.; Wada, M.

    2015-04-08

    A metal ion source of magnetron magnetic field geometry has been designed and operated with a Cu hollow target. Radio frequency power at 13.56 MHz is directly supplied to the hollow target to maintain plasma discharge and induce self-bias to the target for sputtering. The extraction of positive and negative Cu ion beams have been tested. The ion beam current ratio of Cu{sup +} to Ar{sup +} has reached up to 140% when Ar was used as the discharge support gas. Cu{sup −} ion beam was observed at 50 W RF discharge power and at a higher Ar gas pressure in the ion source. Improvement of poor RF power matching and suppression of electron current is indispensable for a stable Cu{sup −} ion beam production from the source.

  16. Modeling the source contribution of heavy metals in surficial sediment and analysis of their historical changes in the vertical sediments of a drinking water reservoir

    Science.gov (United States)

    Wang, Guoqiang; A, Yinglan; Jiang, Hong; Fu, Qing; Zheng, Binghui

    2015-01-01

    Increasing water pollution in developing countries poses a significant threat to environmental health and human welfare. Understanding the spatial distribution and apportioning the sources of pollution are important for the efficient management of water resources. In this study, ten types of heavy metals were detected during 2010-2013 for all ambient samples and point sources samples. A pollution assessment based on the surficial sediment dataset by Enrichment Factor (EF) showed the surficial sediment was moderately contaminated. A comparison of the multivariate approach (principle components analysis/absolute principle component score, PCA/APCS) and the chemical mass balance model (CMB) shows that the identification of sources and calculation of source contribution based on the CMB were more objective and acceptable when source profiles were known and source composition was complex. The results of source apportionment for surficial heavy metals, both from PCA/APCS and CMB model, showed that the natural background (30%) was the most dominant contributor to the surficial heavy metals, followed by mining activities (29%). The contribution percentage of the natural background was negatively related to the degree of contamination. The peak concentrations of many heavy metals (Cu, Ba, Fe, As and Hg) were found in the middle layer of sediment, which is most likely due to the result of development of industry beginning in the 1970s. However, the highest concentration of Pb appeared in the surficial sediment layer, which was most likely due to the sharp increase in the traffic volume. The historical analysis of the sources based on the CMB showed that mining and the chemical industry are stable sources for all of the sections. The comparing of change rates of source contribution versus years indicated that the composition of the materials in estuary site (HF1) is sensitive to the input from the land, whereas center site (HF4) has a buffering effect on the materials from

  17. Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs.

    Science.gov (United States)

    Hogsden, Kristy L; Harding, Jon S

    2012-03-01

    We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-04-01

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

  19. System identification through nonstationary data using Time-Frequency Blind Source Separation

    Science.gov (United States)

    Guo, Yanlin; Kareem, Ahsan

    2016-06-01

    Classical output-only system identification (SI) methods are based on the assumption of stationarity of the system response. However, measured response of buildings and bridges is usually non-stationary due to strong winds (e.g. typhoon, and thunder storm etc.), earthquakes and time-varying vehicle motions. Accordingly, the response data may have time-varying frequency contents and/or overlapping of modal frequencies due to non-stationary colored excitation. This renders traditional methods problematic for modal separation and identification. To address these challenges, a new SI technique based on Time-Frequency Blind Source Separation (TFBSS) is proposed. By selectively utilizing "effective" information in local regions of the time-frequency plane, where only one mode contributes to energy, the proposed technique can successfully identify mode shapes and recover modal responses from the non-stationary response where the traditional SI methods often encounter difficulties. This technique can also handle response with closely spaced modes which is a well-known challenge for the identification of large-scale structures. Based on the separated modal responses, frequency and damping can be easily identified using SI methods based on a single degree of freedom (SDOF) system. In addition to the exclusive advantage of handling non-stationary data and closely spaced modes, the proposed technique also benefits from the absence of the end effects and low sensitivity to noise in modal separation. The efficacy of the proposed technique is demonstrated using several simulation based studies, and compared to the popular Second-Order Blind Identification (SOBI) scheme. It is also noted that even some non-stationary response data can be analyzed by the stationary method SOBI. This paper also delineates non-stationary cases where SOBI and the proposed scheme perform comparably and highlights cases where the proposed approach is more advantageous. Finally, the performance of the

  20. An novel identification method of the environmental risk sources for surface water pollution accidents in chemical industrial parks.

    Science.gov (United States)

    Peng, Jianfeng; Song, Yonghui; Yuan, Peng; Xiao, Shuhu; Han, Lu

    2013-07-01

    The chemical industry is a major source of various pollution accidents. Improving the management level of risk sources for pollution accidents has become an urgent demand for most industrialized countries. In pollution accidents, the released chemicals harm the receptors to some extent depending on their sensitivity or susceptibility. Therefore, identifying the potential risk sources from such a large number of chemical enterprises has become pressingly urgent. Based on the simulation of the whole accident process, a novel and expandable identification method for risk sources causing water pollution accidents is presented. The newly developed approach, by analyzing and stimulating the whole process of a pollution accident between sources and receptors, can be applied to identify risk sources, especially on the nationwide scale. Three major types of losses, such as social, economic and ecological losses, were normalized, analyzed and used for overall consequence modeling. A specific case study area, located in a chemical industry park (CIP) along the Yangtze River in Jiangsu Province, China, was selected to test the potential of the identification method. The results showed that there were four risk sources for pollution accidents in this CIP. Aniline leakage in the HS Chemical Plant would lead to the most serious impact on the surrounding water environment. This potential accident would severely damage the ecosystem up to 3.8 km downstream of Yangtze River, and lead to pollution over a distance stretching to 73.7 km downstream. The proposed method is easily extended to the nationwide identification of potential risk sources.

  1. Review on recent progress in observations, source identifications and countermeasures of PM2.5.

    Science.gov (United States)

    Liang, Chun-Sheng; Duan, Feng-Kui; He, Ke-Bin; Ma, Yong-Liang

    2016-01-01

    Recently, PM2.5 (atmospheric fine particulate matter with aerodynamic diameter ≤ 2.5 μm) have received so much attention that the observations, source appointment and countermeasures of it have been widely studied due to its harmful impacts on visibility, mood (mental health), physical health, traffic safety, construction, economy and nature, as well as its complex interaction with climate. A review on the PM2.5 related research is necessary. We start with summary of chemical composition and characteristics of PM2.5 that contains both macro and micro observation results and analysis, wherein the temporal variability of concentrations of PM2.5 and major components in many recent reports is embraced. This is closely followed by an overview of source appointment, including the composition and sources of PM2.5 in different countries in the six inhabitable continents based on the best available results. Besides summarizing PM2.5 pollution countermeasures by policy, planning, technology and ideology, the World Air Day is proposed to be established to inspire and promote the crucial social action in energy-saving and emission-reduction. Some updated knowledge of the important topics (such as formation and evolution mechanisms of hazes, secondary aerosols, aerosol mass spectrometer, organic tracers, radiocarbon, emissions, solutions for air pollution problems, etc.) is also included in the present review by logically synthesizing the studies. In addition, the key research challenges and future directions are put forward. Despite our efforts, our understanding of the recent reported observations, source identifications and countermeasures of PM2.5 is limited, and subsequent efforts both of the authors and readers are needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Identification and assessment of the need to improve the operation of production systems in the metal sector enterprises

    Directory of Open Access Journals (Sweden)

    M. Górska

    2017-01-01

    Full Text Available In this paper an attempt was made to identify the areas of metal products manufacturing processes that require improvement. Determination of such areas may become a source of a lot of valuable information for the enterprise, enabling the development of its improvement directions. The results of survey allowed also to define a model of implementation importance for tasks contributing to the metal sector enterprises improvement.

  3. Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan.

    Science.gov (United States)

    Bhowmik, Avit Kumar; Alamdar, Ambreen; Katsoyiannis, Ioannis; Shen, Heqing; Ali, Nadeem; Ali, Syeda Maria; Bokhari, Habib; Schäfer, Ralf B; Eqani, Syed Ali Musstjab Akber Shah

    2015-12-15

    The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150-200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Source and Assessment of Metal Pollution at Khetri Copper Mine Tailings and Neighboring Soils, Rajasthan, India.

    Science.gov (United States)

    Punia, Anita; Siddaiah, N Siva; Singh, Saurabh K

    2017-11-01

    We present here the results of the study on metal pollution by identifying source, abundance and distribution in soil and tailings of Khetri copper complex (KCC) mines, Rajasthan India. The region is highly contaminated by copper (Cu) with higher values in the soil near overburden material (1224 mg/kg) and tailings (111 mg/kg). The average Cu (231 mg/kg) concentration of soil is ~9, 5 and 32 times higher than upper crust, world average shale (WAS) and local background soil (LS), respectively. However this reaches to ~82, 46 and 280 times higher in case of tailing when compared. The correlation and principal component analysis for soil reveals that the source of Cu, Zn, Co, Ni, Mn and Fe is mining and Pb and Cd could be result of weathering of parent rocks and other anthropogenic activities. The source for Cr in soil is both mining activities and weathering of parent rocks. The values of index of geo-accumulation (I geo ) and pollution load index for soil using LS as background are higher compared to values calculated using WAS. The metal rich sulphide bearing overburden material as well as tailings present in the open environment at KCC mines region warrants a proper management to minimize their impact on the environment.

  5. Nanocomposite metal/plasma polymer films prepared by means of gas aggregation cluster source

    Energy Technology Data Exchange (ETDEWEB)

    Polonskyi, O.; Solar, P.; Kylian, O.; Drabik, M.; Artemenko, A.; Kousal, J.; Hanus, J.; Pesicka, J.; Matolinova, I. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Kolibalova, E. [Tescan, Libusina trida 21, 632 00 Brno (Czech Republic); Slavinska, D. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Biederman, H., E-mail: bieder@kmf.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic)

    2012-04-02

    Nanocomposite metal/plasma polymer films have been prepared by simultaneous plasma polymerization using a mixture of Ar/n-hexane and metal cluster beams. A simple compact cluster gas aggregation source is described and characterized with emphasis on the determination of the amount of charged clusters and their size distribution. It is shown that the fraction of neutral, positively and negatively charged nanoclusters leaving the gas aggregation source is largely influenced by used operational conditions. In addition, it is demonstrated that a large portion of Ag clusters is positively charged, especially when higher currents are used for their production. Deposition of nanocomposite Ag/C:H plasma polymer films is described in detail by means of cluster gas aggregation source. Basic characterization of the films is performed using transmission electron microscopy, ultraviolet-visible and Fourier-transform infrared spectroscopies. It is shown that the morphology, structure and optical properties of such prepared nanocomposites differ significantly from the ones fabricated by means of magnetron sputtering of Ag target in Ar/n-hexane mixture.

  6. An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Silze, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

    2014-05-15

    An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10{sup 10} cm{sup −3} to 1 × 10{sup 11} cm{sup −3}, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10{sup 18} atoms/s for aluminum, which meets the demand for the production of a milliampere Al{sup +} ion beam.

  7. Final Air Toxics Standards for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources Fact Sheet

    Science.gov (United States)

    This page contains a December 2007 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources

  8. A comparison of PCA and PMF models for source identification of fugitive methane emissions

    Science.gov (United States)

    Assan, Sabina; Baudic, Alexia; Bsaibes, Sandy; Gros, Valerie; Ciais, Philippe; Staufer, Johannes; Robinson, Rod; Vogel, Felix

    2017-04-01

    different sources from the variability of atmospheric observations are compared with an independent source identification method using stable methane isotopic analysis and simple CH_4/VOC ratios. Allen, D. T. (2014). Methane emissions from natural gas production and use: reconciling bottom-up and top-down measurements. Current Opinion in Chemical Engineering, 5, 78-83. Assan, S., Baudic, A., Guemri, A., Ciais, P., Gros, V., and Vogel, F. R.: Characterisation of interferences to in-situ observations of δ13CH4 and C2H6 when using a Cavity Ring Down Spectrometer at industrial sites, Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2016-261, in review, 2016. Etminan, M., G. Myhre, E. J. Highwood and K. P. Shine (2016), Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing, Geophys. Res.Lett,43. Kirschke, S., Bousquet, P., Ciais, P., Saunois, M., Canadell, J. G., Dlugokencky, E. et al. (2013). Three decades of global methane sources and sinks. Nature Geoscience, 6(10), 813-823. U.S. Environmental Protection Agency's (U.S. EPA's). (2011) Global Anthropogenic Emissions of Non-CO2 Greenhouse Gases: 1990-2030. EPA 430-D-11-003

  9. Village-Level Identification of Nitrate Sources: Collaboration of Experts and Local Population in Benin, Africa

    Science.gov (United States)

    Crane, P.; Silliman, S. E.; Boukari, M.; Atoro, I.; Azonsi, F.

    2005-12-01

    Deteriorating groundwater quality, as represented by high nitrates, in the Colline province of Benin, West Africa was identified by the Benin national water agency, Direction Hydraulique. For unknown reasons the Colline province had consistently higher nitrate levels than any other region of the country. In an effort to address this water quality issue, a collaborative team was created that incorporated professionals from the Universite d'Abomey-Calavi (Benin), the University of Notre Dame (USA), Direction l'Hydraulique (a government water agency in Benin), Centre Afrika Obota (an educational NGO in Benin), and the local population of the village of Adourekoman. The goals of the project were to: (i) identify the source of nitrates, (ii) test field techniques for long term, local monitoring, and (iii) identify possible solutions to the high levels of groundwater nitrates. In order to accomplish these goals, the following methods were utilized: regional sampling of groundwater quality, field methods that allowed the local population to regularly monitor village groundwater quality, isotopic analysis, and sociological methods of surveys, focus groups, and observations. It is through the combination of these multi-disciplinary methods that all three goals were successfully addressed leading to preliminary identification of the sources of nitrates in the village of Adourekoman, confirmation of utility of field techniques, and initial assessment of possible solutions to the contamination problem.

  10. Identification of 'Point A' as the prevalent source of error in cephalometric analysis of lateral radiographs.

    Science.gov (United States)

    Grogger, P; Sacher, C; Weber, S; Millesi, G; Seemann, R

    2018-04-10

    Deviations in measuring dentofacial components in a lateral X-ray represent a major hurdle in the subsequent treatment of dysgnathic patients. In a retrospective study, we investigated the most prevalent source of error in the following commonly used cephalometric measurements: the angles Sella-Nasion-Point A (SNA), Sella-Nasion-Point B (SNB) and Point A-Nasion-Point B (ANB); the Wits appraisal; the anteroposterior dysplasia indicator (APDI); and the overbite depth indicator (ODI). Preoperative lateral radiographic images of patients with dentofacial deformities were collected and the landmarks digitally traced by three independent raters. Cephalometric analysis was automatically performed based on 1116 tracings. Error analysis identified the x-coordinate of Point A as the prevalent source of error in all investigated measurements, except SNB, in which it is not incorporated. In SNB, the y-coordinate of Nasion predominated error variance. SNB showed lowest inter-rater variation. In addition, our observations confirmed previous studies showing that landmark identification variance follows characteristic error envelopes in the highest number of tracings analysed up to now. Variance orthogonal to defining planes was of relevance, while variance parallel to planes was not. Taking these findings into account, orthognathic surgeons as well as orthodontists would be able to perform cephalometry more accurately and accomplish better therapeutic results. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. Identification of recharge sources of groundwater in the Joganjigawa Fan, Toyama, using isotopic and chemical data

    International Nuclear Information System (INIS)

    Mizutani, Yoshihiko; Sakurai, Kazuhiro

    1988-01-01

    The Joganjigawa Fan, an area of rice farming of 50 km 2 lies to the southeast of Toyama city and was formed in the Late Quarternary by terrestrial gravel deposition by the Joganji River. To identify sources of water in shallow aquifers (maximum depth 100 m) beneath the fan, studies of hydrogen and oxygen isotopes in the ground and surface waters of the fan have been made. Major rivers flowing onto the fan are from higher-altitude catchments (maximum altitude 3000 m) and have lower δ 18 D and δO values than rainfall on the fan. The isotopic measurements indicate that the aquifers are mainly recharged by infiltration of the irrigation water, which is derived from the Joganji River, and local precipitations from the surface. In narrow areas along the Jinzu and its tributary the Kumano Rivers, the aquifers are locally recharged from the Jinzu and Kumano Rivers, respectively. Chemical data support this identification of sources of water in the aquifers. (author)

  12. The use of polynuclear aromatic hydrocarbon (PAH) alkyl homologues in determining petroleum source identification and weathering

    International Nuclear Information System (INIS)

    Brown, J.S.; Boehm, P.D.; Sauer, T.C.; Wong, W.M.C.

    1993-01-01

    Techniques utilizing double ratio plots of selected polynuclear aromatic hydrocarbon (PAH) alkyl homologues were used to identify and distinguish crude oils and refined petroleum products from each other and to distinguish petroleum sources in complex pollutant regimes. Petroleum samples were fractionated by high performance liquid chromatography (HPLC) into saturated and aromatic (PAH) hydrocarbon fractions. The saturated hydrocarbon fractions were then analyzed by gas chromatography/flame ionization detection (GC/FID) to obtain a resolved/unresolved alkane fingerprint of each oil. The aromatic fractions of the oils were analyzed by gas chromatography/mass spectrometry (GC/MS) for PAH and selected alkyl homologues. Comparisons of the saturated hydrocarbon fingerprints indicated that some oils were indistinguishable based on the alkane fingerprint alone. Another double ratio plot of the alkyl chrysenes and alkyl dibenzothiophenes was effective in establishing the weathering of oil in environmental samples which were processed using the same analytical techniques, since the dibenzothiophenes are degraded more rapidly than the chrysenes. The application of selected ratios in oil spill source identification in complex environmental samples from Suisin Bay California and Boston Harbor are discussed. The use of ratios to measure the extent of weathering in oil spill samples from Prince William Sound and the Gulf of Alaska is examined

  13. Comparative study of surrogate models for groundwater contamination source identification at DNAPL-contaminated sites

    Science.gov (United States)

    Hou, Zeyu; Lu, Wenxi

    2018-05-01

    Knowledge of groundwater contamination sources is critical for effectively protecting groundwater resources, estimating risks, mitigating disaster, and designing remediation strategies. Many methods for groundwater contamination source identification (GCSI) have been developed in recent years, including the simulation-optimization technique. This study proposes utilizing a support vector regression (SVR) model and a kernel extreme learning machine (KELM) model to enrich the content of the surrogate model. The surrogate model was itself key in replacing the simulation model, reducing the huge computational burden of iterations in the simulation-optimization technique to solve GCSI problems, especially in GCSI problems of aquifers contaminated by dense nonaqueous phase liquids (DNAPLs). A comparative study between the Kriging, SVR, and KELM models is reported. Additionally, there is analysis of the influence of parameter optimization and the structure of the training sample dataset on the approximation accuracy of the surrogate model. It was found that the KELM model was the most accurate surrogate model, and its performance was significantly improved after parameter optimization. The approximation accuracy of the surrogate model to the simulation model did not always improve with increasing numbers of training samples. Using the appropriate number of training samples was critical for improving the performance of the surrogate model and avoiding unnecessary computational workload. It was concluded that the KELM model developed in this work could reasonably predict system responses in given operation conditions. Replacing the simulation model with a KELM model considerably reduced the computational burden of the simulation-optimization process and also maintained high computation accuracy.

  14. Using ensemble models to identify and apportion heavy metal pollution sources in agricultural soils on a local scale

    International Nuclear Information System (INIS)

    Wang, Qi; Xie, Zhiyi; Li, Fangbai

    2015-01-01

    This study aims to identify and apportion multi-source and multi-phase heavy metal pollution from natural and anthropogenic inputs using ensemble models that include stochastic gradient boosting (SGB) and random forest (RF) in agricultural soils on the local scale. The heavy metal pollution sources were quantitatively assessed, and the results illustrated the suitability of the ensemble models for the assessment of multi-source and multi-phase heavy metal pollution in agricultural soils on the local scale. The results of SGB and RF consistently demonstrated that anthropogenic sources contributed the most to the concentrations of Pb and Cd in agricultural soils in the study region and that SGB performed better than RF. - Highlights: • Ensemble models including stochastic gradient boosting and random forest are used. • The models were verified by cross-validation and SGB performed better than RF. • Heavy metal pollution sources on a local scale are identified and apportioned. • Models illustrate good suitability in assessing sources in local-scale agricultural soils. • Anthropogenic sources contributed most to soil Pb and Cd pollution in our case. - Multi-source and multi-phase pollution by heavy metals in agricultural soils on a local scale were identified and apportioned.

  15. Source term analysis for a criticality accident in metal production line glove boxes

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1991-06-01

    A recent development in criticality accident analysis is the deterministic calculations of the transport of fission products and actinides through the barriers of the physical facility. The knowledge of the redistribution of the materials inside the facility will help determine the reentry and clean-up procedures. The amount of radioactive materials released to the environment is the source term for dispersion calculations. We have used an integrated computer model to determine the release of fission products to the environment from a hypothetical criticality event in a glove box of the metal production line (MPL) at the Lawrence Livermore National Laboratory (LLNL)

  16. Development and pilot production of three ingot-source beryllium sheet metal parts

    International Nuclear Information System (INIS)

    Floyd, D.R.

    1975-01-01

    Results of an extensive development program aimed at making three, separate, structural components from beryllium, using sheet-metal fabrication methods, are presented. Ingot-source beryllium sheet at thicknesses of 0.100, 0.125, and 0.170 inch is formed in a fully-recrystallized and in a partially-recrystallized condition. The tensile yield strength is 26,000 psi after full recrystallization. After partial recrystallization, tensile yield strength is between 35,000 and 45,000 psi, depending upon sheet thickness, heat treat temperature, and time at temperature. The high yield strength is retained in the parts after forming. (U.S.)

  17. Exploding metal film active anode source experiments on the LION extractor ion diode

    International Nuclear Information System (INIS)

    Rondeau, G.D.; Bordonaro, G.J.; Greenly, J.B.; Hammer, D.A.

    1989-01-01

    In this paper the authors report results using an extractor geometry magnetically insulated ion diode on the 0.5 TW LION accelerator. Experiments with an exploding metal film active anode plasma source (EMFAAPS) have shown that intense beams with significantly improved turn-on time compared to epoxy-filled-groove anodes can be produced. A new geometry, in which a plasma switch is used to provide the current path that explodes the thin film anode, has improved the ion efficiency (to typically 70%) compared with the previous scheme in which an electron collector on the anode provided this current. Leakage electron current is reduced when no collector is used

  18. Source-specific speciation profiles of PM2.5 for heavy metals and their anthropogenic emissions in China.

    Science.gov (United States)

    Liu, Yayong; Xing, Jia; Wang, Shuxiao; Fu, Xiao; Zheng, Haotian

    2018-08-01

    Heavy metals are concerned for its adverse effect on human health and long term burden on biogeochemical cycling in the ecosystem. In this study, a provincial-level emission inventory of 13 kinds of heavy metals including V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, Sb, Ba and Pb from 10 anthropogenic sources was developed for China, based on the 2015 national emission inventory of primary particulate matters and source category-specific speciation profiles collected from 50 previous studies measured in China. Uncertainties associated with the speciation profiles were also evaluated. Our results suggested that total emissions of the 13 types of heavy metals in China are estimated at about 58000 ton for the year 2015. The iron production is the dominant source of heavy metal, contributing 42% of total emissions of heavy metals. The emissions of heavy metals vary significantly at regional scale, with largest amount of emissions concentrated in northern and eastern China. Particular, high emissions of Cr, Co, Ni, As and Sb (contributing 8%-18% of the national emissions) are found in Shandong where has large capacity of industrial production. Uncertainty analysis suggested that the implementation of province-specific source profiles in this study significantly reduced the emission uncertainties from (-89%, 289%) to (-99%, 91%), particularly for coal combustion. However, source profiles for industry sectors such as non-metallic mineral manufacturing are quite limited, resulting in a relative high uncertainty. The high-resolution emission inventories of heavy metals are essential not only for their distribution, deposition and transport studies, but for the design of policies to redress critical atmospheric environmental hazards at local and regional scales. Detailed investigation on source-specific profile in China are still needed to achieve more accurate estimations of heavy metals in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Identification of dominant flow structures in rapidly rotating convection of liquid metals using Dynamic Mode Decomposition

    Science.gov (United States)

    Horn, S.; Schmid, P. J.; Aurnou, J. M.

    2016-12-01

    The Earth's metal core acts as a dynamo whose efficiency in generating and maintaining the magnetic field is essentially determined by the rotation rate and the convective motions occurring in its outer liquid part. For the description of the primary physics in the outer core the idealized system of rotating Rayleigh-Bénard convection is often invoked, with the majority of studies considering only working fluids with Prandtl numbers of Pr ≳ 1. However, liquid metals are characterized by distinctly smaller Prandtl numbers which in turn result in an inherently different type of convection. Here, we will present results from direct numerical simulations of rapidly rotating convection in a fluid with Pr ≈ 0.025 in cylindrical containers and Ekman numbers as low as 5 × 10-6. In this system, the Coriolis force is the source of two types of inertial modes, the so-called wall modes, that also exist at moderate Prandtl numbers, and cylinder-filling oscillatory modes, that are a unique feature of small Prandtl number convection. The obtained flow fields were analyzed using the Dynamic Mode Decomposition (DMD). This technique allows to extract and identify the structures that govern the dynamics of the system as well as their corresponding frequencies. We have investigated both the regime where the flow is purely oscillatory and the regime where wall modes and oscillatory modes co-exist. In the purely oscillatory regime, high and low frequency oscillatory modes characterize the flow. When both types of modes are present, the DMD reveals that the wall-attached modes dominate the flow dynamics. They precess with a relatively low frequency in retrograde direction. Nonetheless, also in this case, high frequency oscillations have a significant contribution.

  20. Optical identifications of radio sources in the 5C 7 survey

    International Nuclear Information System (INIS)

    Perryman, M.A.C.

    1979-01-01

    An identification procedure developed for the deep radio survey 5C 6 has been refined and applied to the 5C 7 survey. Positions and finding charts are presented for candidate identifications from deep plates taken with the Palomar 48-inch Schmidt telescope. The identification statistics are in good agreement with the 5C 6 results, the accurate radio positions obtained at 1407 MHz defining a reasonably reliable and complete sample of associations with an identification rate of about 40 per cent. At 408 MHz the positional uncertainties are larger and the identifications are thus of lower reliability; the identification rate is about 20 per cent. The results are in good agreement with the assumptions that the optical identifications are coincident with the radio centroids, and that the identifications are not preferentially associated with faint clusters. (author)

  1. The impact of seasonal varied human activity on characteristics and sources of heavy metals in metropolitan road dusts.

    Science.gov (United States)

    Men, Cong; Liu, Ruimin; Wang, Qingrui; Guo, Lijia; Shen, Zhenyao

    2018-10-01

    Due to significant human activity, road dust is becoming contaminated by heavy metals in many cities. To comprehensively investigate the variation of contamination level and sources of heavy metals in road dust, 10 heavy metals in road dust samples from Beijing, China, in both summer and winter, were evaluated by spatial analysis using geographic information system (GIS) mapping technology and the positive matrix factorization (PMF) Model. Although the concentrations of some heavy metals between summer and winter had similarities, the differences of others and spatial distributions of heavy metals between summer and winter were considerable. The mean concentrations of As, Cd, Cr, Cu, and Fe were lower in winter, while those of Hg, Mn, Ni, Pb, and Zn were higher. According to the values of the Pollution Index (PI) and Nemerow Integrated Pollution Index (NIPI), there were no obvious differences between summer and winter, but the range between different sites in winter was nearly twice that of summer. Based on the PMF model, four sources of heavy metals in the dust samples were identified. Although the types of sources were consistent, the relative contributions of each source differed between summer and winter. Non-exhaust vehicle emissions was the most important source in summer (34.47 wt%), while fuel combustion contributed the largest proportion to the total heavy metals in winter (32.40 wt%). The impact of each source also showed spatial variation different trends in summer and winter. With the alteration of seasons, intensity of human activities also changed, such as the number of tourists, energy needs for building temperature regulation, construction, and the amount of pesticides and fertilizer. That might be the reason for the variation of heavy metal concentrations and relative contribution of their sources between summer and winter. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Source apportionment of heavy metals and their ecological risk in a tropical river basin system.

    Science.gov (United States)

    Kumar, Balwant; Singh, Umesh Kumar

    2018-06-27

    Surface water and sediment samples were collected from Ajay River basin to appraise the behavior of heavy metals with surrounding environments and their inter-elemental relationships. Parameters like pH and organic carbon are having a minimal role in heavy metal distribution while some elements like Fe and Cu showed great affinity for organic matter based on linear regression analysis (LRA). Ficklin diagram justified that river basin is not contaminated through acidic pollutants. The river basin is highly enriched with Cu, Cd, Pb, and Ni which were much higher than world average values, average shale standard, effect range low (ERL), and threshold effect level (TEL). PCA and LRA verified that Cu, Cd, Pb, and Ni were mainly derived from anthropogenic inputs, and others like Fe, Mn, Zn, and Co came from geogenic sources. Pollution indices revealed that river basin is moderately to highly contaminated by Cu, Cd, and Ni. Furthermore, Ajay River basin is under strong potential ecological risk based on the obtained value of risk index and probable effect level/effect range median quotient index. However, river basin is strongly influenced by lithological properties, diversified hydrogeological settings, mineralization and mobilization of subsurface materials, and urban and industrial effluents which are controlling the heavy metals.

  3. Epitaxial Oxide Thin Films Grown by Solid Source Metal-Organic Chemical Vapor Deposition.

    Science.gov (United States)

    Lu, Zihong

    1995-01-01

    The conventional liquid source metal-organic chemical vapor deposition (MOCVD) technique is capable of producing large area, high quality, single crystal semiconductor films. However, the growth of complex oxide films by this method has been hampered by a lack of suitable source materials. While chemists have been actively searching for new source materials, the research work reported here has demonstrated the successful application of solid metal-organic sources (based on tetramethylheptanedionate) to the growth of high quality thin films of binary compound cerium dioxide (CeO_2), and two more complex materials, the ternary compound lithium niobate (LiNbO_3), with two cations, and the quaternary compound strontium barium niobate (SBN), with three cations. The growth of CeO_2 thin films on (1012)Al_2O_3 substrates has been used as a model to study the general growth behavior of oxides. Factors affecting deposition rate, surface morphology, out-of-plane mosaic structure, and film orientation have been carefully investigated. A kinetic model based on gas phase prereaction is proposed to account for the substrate temperature dependence of film orientation found in this system. Atomically smooth, single crystal quality cerium dioxide thin films have been obtained. Superconducting YBCO films sputtered on top of solid source MOCVD grown thin cerium dioxide buffer layers on sapphire have been shown to have physical properties as good as those of YBCO films grown on single crystal MgO substrates. The thin film growth of LiNbO_3 and Sr_{1-x}Ba _{x}Nb_2 O_6 (SBN) was more complex and challenging. Phase purity, transparency, in-plane orientation, and the ferroelectric polarity of LiNbO _3 films grown on sapphire substrates was investigated. The first optical quality, MOCVD grown LiNbO _3 films, having waveguiding losses of less than 2 dB/cm, were prepared. An important aspect of the SBN film growth studies involved finding a suitable single crystal substrate material. Mg

  4. Consideration of the Change of Material Emission Signatures due to Longterm Emissions for Enhancing VOC Source Identification

    DEFF Research Database (Denmark)

    Han, K. H.; Zhang, J. S.; Knudsen, Henrik Nellemose

    2011-01-01

    The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of in...

  5. Ecological risk of heavy metals in sediments of the luan river source water

    Science.gov (United States)

    Liu, J.; Li, Y.; Zhang, B.; Cao, J.; Cao, Z.; Domagalski, Joseph L.

    2009-01-01

    Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in animal bodies, Hg at the sampling site of Wuliehexia was 1.39 mg/kg, Cr at Sandaohezi was 152.37 mg/kg and Cu at Hanjiaying was 178.61 mg/kg exceeding the severe effect screening level. There were 90% of sampling sites of Cr and Pb and 50% sites of Cu exceeded the lowest effect screening level. At Boluonuo and Wuliehexia, the exchangeable and carbonate fractions for above 50% of sites were at high risk levels and that for above 30% of sites at Xiahenan and Wulieheshang were also at high risk levels. Other sites were at medium risk level. Compared to soil background values of China, Hg and Cd showed very strong ecological risk, and the seven heavy metals of Hg, Cd, Cu, As, Pb, Cr, Zn at ecological risk levels were in the descending order. The results could give insight into risk assessment of environmental pollution and decision-making for water source security. ?? 2009 Springer Science+Business Media, LLC.

  6. High intensity metallic ion beams from an ecr ion source at GANIL

    International Nuclear Information System (INIS)

    Leherissier, P.; Barue, C.; Canet, C.; Dupuis, M.; Flambard, J.L.; Gaubert, G.; Gibouin, S.; Huguet, Y.; Jardin, P.; Lecesne, N.; Lemagnen, F.; Leroy, R.; Pacquet, J.Y.; Pellemoine-Landre, F.; Rataud, J.P.; Jaffres, P.A.

    2001-01-01

    In the recent years, progress concerning the production of high intensity of metallic ions beams ( 58 Ni, 48 Ca, 76 Ge) at Ganil have been performed. The MIV0C method has been successfully used to produce a high intensity nickel beam with the ECR4 ion source: 20 eμA of 58 Ni 11+ at 24 kV extraction voltage. This beam has been maintained for 8 days and accelerated up to 74.5 MeV/u by our cyclotrons with a mean intensity of 0.13 pμA on target. This high intensity, required for experiment, led to the discovery of the doubly magic 48 Ni isotope. The oven method has been first tested with natural metallic calcium on the ECR4 ion source, then used to produce a high power beam (740 W on target i.e. 0.13 pμA accelerated up to 60 MeV/u) of 48 Ca still keeping a low consumption (0.09 mg/h). A germanium beam is now under development, using the oven method with germanium oxide. The ionization efficiencies have been measured and compared. (authors)

  7. Ion spectra of the metal vapor vacuum arc ion source with compound and alloy cathodes

    Science.gov (United States)

    Sasaki, Jun; Brown, Ian G.

    1990-01-01

    In metal vapor vacuum arc (MEVVA) ion sources, vacuum arc plasma with cathodes of single, pure elements has been utilized for the production of metal ions. In this study, we have investigated the charge state distributions of ions produced in vacuum arc plasmas in a MEVVA ion source for the case when the cathode is an alloy or a compound material. The ion charge state spectra were analyzed by means of a time-of-flight apparatus. We have compared the ion spectra for a cathode of an alloy or a compound material with its constituent elements: TiC/TiN/TiO2/Ti/C, SiC/Si/C, WC/W/C U/UN/(UN-ZrC)/Zr/C, and brass/Zn/Cu. We find that the MEVVA produces ions of all constituent elements in the compound and the alloy cathodes. The charge state distribution of each element differs, however, from the charge state distribution obtained in the vacuum arc with a cathode made of the pure, single constituent element. Fractional values of the total ion numbers of each constituent element in the extracted beam depart from the stoichiometry of the elements in the cathode material. In an operation with a TiC cathode, we irradiated a 304 stainless-steel plate with the extracted beam. Results from glow-discharge spectroscopy (GDS) of the surface show that both titanium and carbon are implanted in the substrate after the irradiation.

  8. Emissions of perfluorinated alkylated substances (PFAS) from point sources--identification of relevant branches.

    Science.gov (United States)

    Clara, M; Scheffknecht, C; Scharf, S; Weiss, S; Gans, O

    2008-01-01

    Effluents of wastewater treatment plants are relevant point sources for the emission of hazardous xenobiotic substances to the aquatic environment. One group of substances, which recently entered scientific and political discussions, is the group of the perfluorinated alkylated substances (PFAS). The most studied compounds from this group are perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS), which are the most important degradation products of PFAS. These two substances are known to be persistent, bioaccumulative and toxic (PBT). In the present study, eleven PFAS were investigated in effluents of municipal wastewater treatment plants (WWTP) and in industrial wastewaters. PFOS and PFOA proved to be the dominant compounds in all sampled wastewaters. Concentrations of up to 340 ng/L of PFOS and up to 220 ng/L of PFOA were observed. Besides these two compounds, perfluorohexanoic acid (PFHxA) was also present in nearly all effluents and maximum concentrations of up to 280 ng/L were measured. Only N-ethylperfluorooctane sulphonamide (N-EtPFOSA) and its degradation/metabolisation product perfluorooctane sulphonamide (PFOSA) were either detected below the limit of quantification or were not even detected at all. Beside the effluents of the municipal WWTPs, nine industrial wastewaters from six different industrial branches were also investigated. Significantly, the highest emissions or PFOS were observed from metal industry whereas paper industry showed the highest PFOA emission. Several PFAS, especially perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA) and PFOS are predominantly emitted from industrial sources, with concentrations being a factor of 10 higher than those observed in the municipal WWTP effluents. Perfluorodecane sulphonate (PFDS), N-Et-PFOSA and PFOSA were not detected in any of the sampled industrial point sources. (c) IWA Publishing 2008.

  9. Source identification and long-term monitoring of airborne particulate matter (PM2.5/PM10) in an urban region of Korea

    International Nuclear Information System (INIS)

    Yong-Sam Chung; Sun-Ha Kim; Jong-Hwa Moon; Young-Jin Kim; Jong-Myoung Lim; Jin-Hong Lee

    2006-01-01

    For the identification of air pollution sources, about 500 airborne particulate matter (PM 2.5 and PM 10 ) samples were collected by using a Gent air sampler and a polycarbonate filter in an urban region in the middle of Korea from 2000 to 2003. The concentrations of 25 elements in the samples were measured by using instrumental neutron activation analysis (INAA). Receptor modeling was performed on the air monitoring data by using the positive matrix factorization (PMF2) method. According to this analysis, the existence of 6 to 10 PMF factors, such as metal-alloy, oil combustion, diesel exhaust, coal combustion, gasoline exhaust, incinerator, Cu-smelter, biomass burning, sea-salt, and soil dust were identified. (author)

  10. A simple alkali-metal and noble gas ion source for SIMS equipments with mass separation of the primary ions

    International Nuclear Information System (INIS)

    Duesterhoeft, H.; Pippig, R.

    1986-01-01

    An alkali-metal ion source working without a store of alkali-metals is described. The alkali-metal ions are produced by evaporation of alkali salts and ionization in a low-voltage arc discharge stabilized with a noble gas plasma or in the case of small alkali-metal ion currents on the base of the well known thermic ionization at a hot tungsten wire. The source is very simple in construction and produces a stable ion current of 0.3 μA for more than 100 h. It is possible to change the ion species in a short time. This source is applicable to all SIMS equipments using mass separation for primary ions. (author)

  11. Influence of source parameters on the growth of metal nanoparticles by sputter-gas-aggregation

    Science.gov (United States)

    Khojasteh, Malak; Kresin, Vitaly V.

    2017-11-01

    We describe the production of size-selected manganese nanoclusters using a magnetron sputtering/aggregation source. Since nanoparticle production is sensitive to a range of overlapping operating parameters (in particular, the sputtering discharge power, the inert gas flow rates, and the aggregation length), we focus on a detailed map of the influence of each parameter on the average nanocluster size. In this way, it is possible to identify the main contribution of each parameter to the physical processes taking place within the source. The discharge power and argon flow supply the metal vapor, and argon also plays a crucial role in the formation of condensation nuclei via three-body collisions. However, the argon flow and the discharge power have a relatively weak effect on the average nanocluster size in the exiting beam. Here the defining role is played by the source residence time, governed by the helium supply (which raises the pressure and density of the gas column inside the source, resulting in more efficient transport of nanoparticles to the exit) and by the aggregation path length.

  12. 10 GHz multicharged-heavy-ion source CAPRICE for all metallic and gaseous elements

    International Nuclear Information System (INIS)

    Bourg, F.; Geller, R.; Jacquot, B.

    1987-01-01

    A new compact multiply charged E.C.R. ion source completely enclosed by an iron return yoke is described. A new coaxial 10 GHz microwave accessibility is operating. This allows a very compact two stages source in an entirely removable vacuum chamber and a very easy increasing possibility of the axial magnetic field value. Then two different working modes are possible. A classical mode (ω ce =ω rf , 100% cw, rf power 300 W, coils supply 20 kW) gives same performance than all the other reliable larger 10 GHz sources. A second mode (100% cw, rf power 600 W, coils supply 33 kW) operates with an additional resonant surface ω ce =2ω rf and increases by a factor 3 or 4 all currents on high charge states. Total extraction current is multiplied by a factor of 4 just as it would do by using a classical 20 GHz source by increase in density. This new resonant surface is unfortunately stopped in its radial part by the wall of the vacuum chamber due to a too low 10 GHz sextupole (0,4 T). Presently a better sextupole (0,8 T) is being built in order to work with both whole resonant surfaces inside the plasma chamber and perhaps so to improve charge states distribution by rising the plasma life time. On the other hand both the removable vacuum chamber and the coaxial rf feeder are well fitted to produce all metallic ions in long run and high intensity by working without any insulator inside the plasma chamber and by a good cleaning possibility. One shows cw spectra of 10 metallic elements from Al to Au and one can observe an exponential decrease for Ca, Ag and Au. This remark indicates a possible easy way to yield high charge states of all metals. One can expect to regulate all the lightest elements like Al, Si, Fe, Ni, Mo, Ta and W for 100 h. For example a good (within 1%) regulation of a 15 μA 56 Fe 7+ for 10 h is partly shown. (orig.)

  13. Assessment of Heavy Metal Contamination in Marine Sediments of East Coast of Tamil Nadu Affected by Different Pollution Sources.

    Science.gov (United States)

    Harikrishnan, N; Ravisankar, R; Chandrasekaran, A; Suresh Gandhi, M; Kanagasabapathy, K V; Prasad, M V R; Satapathy, K K

    2017-08-15

    The aim of this study was to determine the concentration of heavy metals in the sediments of Periyakalapet to Parangipettai coast, east coast of Tamil Nadu, by using energy-dispersive X-ray fluorescence (EDXRF) technique. The average heavy metal concentrations in the sediment samples were found in the order Al>Fe>Ca>Ti>K>Mg>Mn>Ba>V>Cr>Zn>La>Ni>Pb>Co>Cd>Cu. The average heavy metal concentrations were below the world crustal average. The degree of contamination by heavy metals was evaluated using pollution indices. The results of pollution indices revealed that titanium (Ti) and cadmium (Cd) were significantly enriched in sediments. Pearson correlation analysis was performed among heavy metal concentrations to know the existing relationship between them. Multivariate statistical technique was employed to identify the heavy metal pollution sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Identification of metallic items that caused nickel dermatitis in Danish patients.

    Science.gov (United States)

    Thyssen, Jacob P; Menné, Torkil; Johansen, Jeanne D

    2010-09-01

    Nickel allergy is prevalent as assessed by epidemiological studies. In an attempt to further identify and characterize sources that may result in nickel allergy and dermatitis, we analysed items identified by nickel-allergic dermatitis patients as causative of nickel dermatitis by using the dimethylglyoxime (DMG) test. Dermatitis patients with nickel allergy of current relevance were identified over a 2-year period in a tertiary referral patch test centre. When possible, their work tools and personal items were examined with the DMG test. Among 95 nickel-allergic dermatitis patients, 70 (73.7%) had metallic items investigated for nickel release. A total of 151 items were investigated, and 66 (43.7%) gave positive DMG test reactions. Objects were nearly all purchased or acquired after the introduction of the EU Nickel Directive. Only one object had been inherited, and only two objects had been purchased outside of Denmark. DMG testing is valuable as a screening test for nickel release and should be used to identify relevant exposures in nickel-allergic patients. Mainly consumer items, but also work tools used in an occupational setting, released nickel in dermatitis patients. This study confirmed 'risk items' from previous studies, including mobile phones.

  15. Identification of the source of PFOS and PFOA contamination at a military air base site.

    Science.gov (United States)

    Arias E, Victor A; Mallavarapu, Megharaj; Naidu, Ravi

    2015-01-01

    Although the use of perfluorooctane sulfonic acid (PFOS)/perfluorooctanoic acid (PFOA)-based aqueous fire-fighting foams (AFFF) has been banned due to their persistence, bioaccumulation and toxicity to biota, PFOS and PFOA are still present at significant levels in the environment due to their past usage. This study investigated the reasons for detection of PFOS and PFOA in an evaporation pond used to collect the wastewater arising from fire-fighting exercises at a military air base despite the replacement of PFOS/PFOA-based foam with no PFOS/PFOA-foam about 6 years ago. Concentrations in the wastewater stored in this pond ranged from 3.6 to 9.7 mg/L for PFOS and between 0.6 and 1.7 mg/L for PFOA. The hypothesis tested in a laboratory study was that PFOS and PFOA have accumulated in the sediments of the pond and can be released into the main body of the water. Concentrations detected in the sediments were 38 and 0.3 mg/g for PFOS and PFOA, respectively. These values exceed the recently reported average global values for sediments (0.2-3.8 ng/g for PFOS and from 0.1 to 0.6 ng/g for PFOA) by a factor of several thousands. PFOS and PFOA distribution coefficients were derived for the organic content of the pond sediment (1.6%). Identification of the source of contamination and knowledge of the partition between soil and aqueous phases are vital first steps in developing a sustainable remediation technology to remove the source from the site. This study clearly suggests that unless the sediment is cleaned of PFOS/PFOA, these chemicals will continue to be detected for a long period in the pond water, with potential adverse impacts on the ecosystem.

  16. Characterization of atmospheric emission sources in lichen from metal and organic contaminant patterns.

    Science.gov (United States)

    Ratier, Aude; Dron, Julien; Revenko, Gautier; Austruy, Annabelle; Dauphin, Charles-Enzo; Chaspoul, Florence; Wafo, Emmanuel

    2018-03-01

    Lichen samples from contrasted environments, influenced by various anthropic activities, were investigated focusing on the contaminant signatures according to the atmospheric exposure typologies. Most of the contaminant concentrations measured in the 27 lichen samples, collected around the industrial harbor of Fos-sur-Mer (France), were moderate in rural and urban environments, and reached extreme levels in industrial areas and neighboring cities (Al up to 6567 mg kg -1 , Fe 42,398 mg kg -1 , or ΣPAH 1417 μg kg -1 for example). At the same time, a strong heterogeneity was noticed in industrial samples while urban and rural ones were relatively homogeneous. Several metals could be associated to steel industry (Fe, Mn, Cd), road traffic, and agriculture (Sb, Cu, Sn), or to a distinct chemical installation (Mo). As well, PCDFs dominated in industrial samples while PCDDs prevailed in urban areas. The particularities observed supported the purpose of this work and discriminated the contributions of various atmospheric pollution emission sources in lichen samples. A statistical approach based on principal component analysis (PCA) was applied and resolved these potential singularities into specific component factors. Even if a certain degree of mixing of the factors is pointed out, relevant relationships were observed with several atmospheric emission sources. By this methodology, the contribution of industrial emissions to the atmospheric metal, PAH, PCB, and PCDD/F levels was roughly estimated to be 60.2%, before biomass burning (10.2%) and road traffic (3.8%). These results demonstrate that lichen biomonitoring offers an encouraging perspective of spatially resolved source apportionment studies.

  17. Implementation of an Imaging Spectrometer for Localization and Identification of Radioactive Sources

    International Nuclear Information System (INIS)

    Hermine, Lemaire; Carrel, Frederick; Gmar, Mehdi; Menesguen Yves; Normand, Stephane; Schoepff, Vincent; Abou-Khalil, Roger; Amgarou, Khalil; Menaa, Nabil; Tebug, Timi; Angelique, Jean-Claude; Bonnet, Florent; De-Toro, Daniel; Giarmana, Olivier; Patoz, Audrey; Talent, Philippe

    2013-06-01

    Spatial localization of radioactive sources is currently a main issue interesting nuclear industry as well as homeland security applications, and can be achieved using gamma cameras. For several years, CEA LIST has been designing a new system, called GAMPIX, with improved sensitivity, portability and ease of use. The main remaining limitation is the lack of spectrometric information, preventing radioactive materials identification. This article describes the development of an imaging spectrometer based on the GAMPIX technology. Experimental tests have been carried out according to both spectrometric methods enabled by the pixelated Timepix readout chip used in the GAMPIX gamma camera. The first method is based on the size of the impacts produced by a gamma-ray energy deposition in the detection matrix. The second one uses the Time over Threshold (ToT) mode of the Timepix chip and deals with time spent by pulses generated by charge preamplifiers over a user-specified threshold. Both energy resolution and sensitivity studies proved the superiority of the ToT approach that will consequently be further explored. Energy calibration, tests of several pixel sizes and use of the Medipix3 readout chip are tracks to improve performances of the newly implemented imaging spectrometer. (authors)

  18. Source identification of uranium-containing materials at mine legacy sites in Portugal.

    Science.gov (United States)

    Keatley, A C; Martin, P G; Hallam, K R; Payton, O D; Awbery, R; Carvalho, F P; Oliveira, J M; Silva, L; Malta, M; Scott, T B

    2018-03-01

    Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  19. Identification of Non-Stationary Magnetic Field Sources Using the Matching Pursuit Method

    Directory of Open Access Journals (Sweden)

    Beata Palczynska

    2017-05-01

    Full Text Available The measurements of electromagnetic field emissions, performed on board a vessel have showed that, in this specific environment, a high level of non-stationary magnetic fields (MFs is observed. The adaptive time-frequency method can be used successfully to analyze this type of measured signal. It allows one to specify the time interval in which the individual frequency components of the signal occur. In this paper, the method of identification of non-stationary MF sources based on the matching pursuit (MP algorithm is presented. It consists of the decomposition of an examined time-waveform into the linear expansion of chirplet atoms and the analysis of the matrix of their parameters. The main feature of the proposed method is the modification of the chirplet’s matrix in a way that atoms, whose normalized energies are lower than a certain threshold, will be rejected. On the time-frequency planes of the spectrograms, obtained separately for each remaining chirlpet, it can clearly identify the time-frequency structures appearing in the examined signal. The choice of a threshold defines the computing speed and precision of the performed analysis. The method was implemented in the virtual application and used for processing real data, obtained from measurements of time-vary MF emissions onboard a ship.

  20. Image features dependant correlation-weighting function for efficient PRNU based source camera identification.

    Science.gov (United States)

    Tiwari, Mayank; Gupta, Bhupendra

    2018-04-01

    For source camera identification (SCI), photo response non-uniformity (PRNU) has been widely used as the fingerprint of the camera. The PRNU is extracted from the image by applying a de-noising filter then taking the difference between the original image and the de-noised image. However, it is observed that intensity-based features and high-frequency details (edges and texture) of the image, effect quality of the extracted PRNU. This effects correlation calculation and creates problems in SCI. For solving this problem, we propose a weighting function based on image features. We have experimentally identified image features (intensity and high-frequency contents) effect on the estimated PRNU, and then develop a weighting function which gives higher weights to image regions which give reliable PRNU and at the same point it gives comparatively less weights to the image regions which do not give reliable PRNU. Experimental results show that the proposed weighting function is able to improve the accuracy of SCI up to a great extent. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Using ensemble models to identify and apportion heavy metal pollution sources in agricultural soils on a local scale.

    Science.gov (United States)

    Wang, Qi; Xie, Zhiyi; Li, Fangbai

    2015-11-01

    This study aims to identify and apportion multi-source and multi-phase heavy metal pollution from natural and anthropogenic inputs using ensemble models that include stochastic gradient boosting (SGB) and random forest (RF) in agricultural soils on the local scale. The heavy metal pollution sources were quantitatively assessed, and the results illustrated the suitability of the ensemble models for the assessment of multi-source and multi-phase heavy metal pollution in agricultural soils on the local scale. The results of SGB and RF consistently demonstrated that anthropogenic sources contributed the most to the concentrations of Pb and Cd in agricultural soils in the study region and that SGB performed better than RF. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Analysis and assessment on heavy metal sources in the coastal soils developed from alluvial deposits using multivariate statistical methods.

    Science.gov (United States)

    Li, Jinling; He, Ming; Han, Wei; Gu, Yifan

    2009-05-30

    An investigation on heavy metal sources, i.e., Cu, Zn, Ni, Pb, Cr, and Cd in the coastal soils of Shanghai, China, was conducted using multivariate statistical methods (principal component analysis, clustering analysis, and correlation analysis). All the results of the multivariate analysis showed that: (i) Cu, Ni, Pb, and Cd had anthropogenic sources (e.g., overuse of chemical fertilizers and pesticides, industrial and municipal discharges, animal wastes, sewage irrigation, etc.); (ii) Zn and Cr were associated with parent materials and therefore had natural sources (e.g., the weathering process of parent materials and subsequent pedo-genesis due to the alluvial deposits). The effect of heavy metals in the soils was greatly affected by soil formation, atmospheric deposition, and human activities. These findings provided essential information on the possible sources of heavy metals, which would contribute to the monitoring and assessment process of agricultural soils in worldwide regions.

  3. The effects of similarity, parasocial identification, and source credibility in obesity public service announcements on diet and exercise self-efficacy.

    Science.gov (United States)

    Phua, Joe

    2016-05-01

    This study examined the effect of the audience's similarity to, and parasocial identification with, spokespersons in obesity public service announcements, on perceived source credibility, and diet and exercise self-efficacy. The results (N = 200) indicated that perceived similarity to the spokesperson was significantly associated with three dimensions of source credibility (competence, trustworthiness, and goodwill), each of which in turn influenced parasocial identification with the spokesperson. Parasocial identification also exerted a positive impact on the audiences' diet and exercise self-efficacy. Additionally, significant differences were found between overweight viewers and non-overweight viewers on perceived similarity, parasocial identification with the spokesperson, and source credibility. © The Author(s) 2014.

  4. Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China.

    Science.gov (United States)

    Yang, Jie; Teng, Yanguo; Song, Liuting; Zuo, Rui

    2016-01-01

    Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area.

  5. Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China.

    Directory of Open Access Journals (Sweden)

    Jie Yang

    Full Text Available Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn. The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment > Zn, Ni, Cr, Fe, and Mn (moderate enrichment > Cd and Ni (minimal enrichment. Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area.

  6. Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs

    International Nuclear Information System (INIS)

    Hogsden, Kristy L.; Harding, Jon S.

    2012-01-01

    We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. - Highlights: ► Food webs in acid mine drainage impacted streams are small and extremely simplified. ► Conductivity explained differences in food web properties between streams. ► Number of links and web size accounted for much dissimilarity between food webs. ► Food web structure was comparable in naturally acidic and circumneutral streams. - Food web structure differs in streams with anthropogenic and natural sources of acidity and metals.

  7. Heavy metal contamination of surface soil in electronic waste dismantling area: site investigation and source-apportionment analysis.

    Science.gov (United States)

    Jinhui Li; Huabo Duan; Pixing Shi

    2011-07-01

    The dismantling and disposal of electronic waste (e-waste) in developing countries is causing increasing concern because of its impacts on the environment and risks to human health. Heavy-metal concentrations in the surface soils of Guiyu (Guangdong Province, China) were monitored to determine the status of heavy-metal contamination on e-waste dismantling area with a more than 20 years history. Two metalloids and nine metals were selected for investigation. This paper also attempts to compare the data among a variety of e-waste dismantling areas, after reviewing a number of heavy-metal contamination-related studies in such areas in China over the past decade. In addition, source apportionment of heavy metal in the surface soil of these areas has been analysed. Both the MSW open-burning sites probably contained invaluable e-waste and abandoned sites formerly involved in informal recycling activities are the new sources of soil-based environmental pollution in Guiyu. Although printed circuit board waste is thought to be the main source of heavy-metal emissions during e-waste processing, requirement is necessary to soundly manage the plastic separated from e-waste, which mostly contains heavy metals and other toxic substances.

  8. Distribution and source analysis of heavy metal pollutants in sediments of a rapid developing urban river system.

    Science.gov (United States)

    Xia, Fang; Qu, Liyin; Wang, Ting; Luo, Lili; Chen, Han; Dahlgren, Randy A; Zhang, Minghua; Mei, Kun; Huang, Hong

    2018-09-01

    Heavy metal pollution of aquatic environments in rapidly developing industrial regions is of considerable global concern due to its potential to cause serious harm to aquatic ecosystems and human health. This study assessed heavy metal contamination of sediments in a highly industrialized urban watershed of eastern China containing several historically unregulated manufacturing enterprises. Total concentrations and solid-phase fractionation of Cu, Zn, Pb, Cr and Cd were investigated for 39 river sediments using multivariate statistical analysis and geographically weighted regression (GWR) methods to quantitatively examine the relationship between land use and heavy metal pollution at the watershed scale. Results showed distinct spatial patterns of heavy metal contamination within the watershed, such as higher concentrations of Zn, Pb and Cd in the southwest and higher Cu concentration in the east, indicating links to specific pollution sources within the watershed. Correlation and PCA analyses revealed that Zn, Pb and Cd were dominantly contributed by anthropogenic activities; Cu originated from both industrial and agricultural sources; and Cr has been altered by recent pollution control strategies. The GWR model indicated that several heavy metal fractions were strongly correlated with industrial land proportion and this correlation varied with the level of industrialization as demonstrated by variations in local GWR R 2 values. This study provides important information for assessing heavy metal contaminated areas, identifying heavy metal pollutant sources, and developing regional-scale remediation strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Thallium dispersal and contamination in surface sediments from South China and its source identification.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Shen, Chuan-Chou; Jiang, Xiuyang; Xie, Xiaofan; Chen, Diyun; Lippold, Holger; Wang, Chunlin

    2016-06-01

    Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3 mg/kg) measured 4 km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Field-emission liquid-metal ion source and triode ion gun

    International Nuclear Information System (INIS)

    Komuro, M.; Kawakatsu, H.

    1981-01-01

    A pointed-filament-type field-emission liquid-metal ion source is designed and employed as a gold ion source. By adding a crossbar across a hairpin bend, the amount of the gold adhering on the filament is increased. The lifetime is estimated to be over 200 h at 10-mA emission current. The emission current increases with increasing extraction voltage up to a saturation value which is ascribed to a limitation of the supply of liquid gold to the needle apex. The value of current density per unit solid angle is 30 mA/sr at a total current of 30 mA, which is of the same order as that obtained from a gallium ion source previously reported. Emission current fluctuations of a few tens of percent of the dc component are observed. In order to regulate the emission current and suppress current fluctuations, a bias electrode in addition to a counterelectrode is placed close to the needle apex. With such a triode structure, the emission current is regulated by a bias voltage of several hundred volts and stabilized to within 1% by means of feedback to the bias voltage of a current monitor output

  11. A Mechanistic Source Term Calculation for a Metal Fuel Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2017-06-26

    A mechanistic source term (MST) calculation attempts to realistically assess the transport and release of radionuclides from a reactor system to the environment during a specific accident sequence. The U.S. Nuclear Regulatory Commission (NRC) has repeatedly stated its expectation that advanced reactor vendors will utilize an MST during the U.S. reactor licensing process. As part of a project to examine possible impediments to sodium fast reactor (SFR) licensing in the U.S., an analysis was conducted regarding the current capabilities to perform an MST for a metal fuel SFR. The purpose of the project was to identify and prioritize any gaps in current computational tools, and the associated database, for the accurate assessment of an MST. The results of the study demonstrate that an SFR MST is possible with current tools and data, but several gaps exist that may lead to possibly unacceptable levels of uncertainty, depending on the goals of the MST analysis.

  12. Optimum source/drain overlap design for 16 nm high-k/metal gate MOSFETs

    International Nuclear Information System (INIS)

    Jang, Junyong; Lim, Towoo; Kim, Youngmin

    2009-01-01

    We explore a source/drain (S/D) design for a 16 nm MOSFET utilizing a replacement process for a high-k gate dielectric and metal gate electrode integration. Using TCAD simulation, a trade-off study between series resistance and overlap capacitance is carried out for a high-k dielectric surrounding gate structure, which results from the replacement process. An optimum S/D overlap to gate for the high-k surrounding gate structure is found to be different from the conventional gate structure, i.e. 0∼1 nm underlap is preferred for the surround high-k gate structure while 1∼2 nm overlap for the conventional gate one

  13. High performance Ω-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts.

    Science.gov (United States)

    Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E

    2010-10-29

    Ge nanowires (NWs) about 2 µm long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH(4) as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu(3)Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga(+) implantation leading to a high performance Ω-gated Ge-NW MOSFET with saturation currents of a few microamperes.

  14. Optical emission spectra of a copper plasma produced by a metal vapour vacuum arc plasma source

    International Nuclear Information System (INIS)

    Yotsombat, B.; Poolcharuansin, P.; Vilaithong, T.; Davydov, S.; Brown, I.G.

    2001-01-01

    Optical emission spectroscopy in the range 200-800 nm was applied for investigation of the copper plasma produced by a metal vapour vacuum arc plasma source. The experiments were conducted for the cases when the plasma was guided by straight and Ω-shaped curved solenoids as well as without solenoids, and also for different vacuum conditions. It was found that, besides singly- and doubly-charged ions, a relatively high concentration of excited neutral copper atoms was present in the plasma. The relative fraction of excited atoms was much higher in the region close to the cathode surface than in the plasma column inside the solenoid. The concentration of excited neutral, singly- and doubly-ionized atoms increased proportionally when the arc current was increased to 400 A. Some weak lines were attributed to more highly ionized copper species and impurities in the cathode material. (author)

  15. Photoemission studies of clean and adsorbate covered metal surfaces using synchrotron and uv radiation sources

    International Nuclear Information System (INIS)

    Apai, G.R. II.

    1977-09-01

    Photoemission energy distribution experiments on clean metal and adsorbate-covered surfaces were performed under ultrahigh vacuum conditions by using x-ray and ultraviolet photon sources in the laboratory as well as continuously-tunable, highly polarized synchrotron radiation obtainable at the Stanford Synchrotron Radiation Laboratory (SSRL). Studies focused on two general areas: cross-section modulation in the photoemission process was studied as a function of photon energy and orbital composition. Sharp decreases in intensity of the valence bands of several transition metals (i.e., Ag, Au, and Pt) are attributed to the radial nodes in the respective wave functions. Adsorbate photoemission studies of CO adsorbed on platinum single crystals have demonstrated a very high spectral sensitivity to the 4sigma and (1π + 5sigma) peaks of CO at photon energies of 150 eV. Angle-resolved photoemission allowed determination of the orientation of CO chemisorbed on a Pt (111) or Ni(111) surface. Prelinimary results at high photon energies (approximately 150 eV) indicated scattering from the substrate which could yield chemisorption site geometries

  16. Tracing sediment sources in the Williams River catchment using caesium-137 and heavy metals: towards an assessment of the relative importance of surface erosion and gully erosion

    International Nuclear Information System (INIS)

    Krause, A.K.; Kalma, J.D.; Loughran, R.J.

    1999-01-01

    Recent sediment sourcing in the 1175km 2 Williams River catchment near Newcastle, NSW, has involved the use of caesium-137 ( 137 Cs) and heavy metals to identify zones of erosion and estimate erosion rates. Sediment sources to the Williams River include sheet erosion from forested and grazed lands, stream channels (especially banks), gullies and roads. The fallout environmental radioisotope 137 Cs was used to assess the erosion status of five vegetated slopes using soil sampling along transects. The net loss or gain of 137 Cs at each sampling point was compared with the 137 Cs level at a reference site at the slope crest. Net soil loss at each point was calculated from an Australian regression model relating net soil loss from runoff-erosion plots to 137 Cs deficit in soils (n=34; r=0.84). Net soil gain was calculated using the regression model in reverse mode. A weighted net soil loss (or gain) was then calculated for each slope transect. Results showed low net soil loss, ranging from zero to 0.64 t ha -1 yr 1 , suggesting that slopes were not major contributors of sediment to the Williams River. A small sub-catchment south of Wirragulla Hill, typical of the lower Williams region, was selected for more detailed tracing of sediment sources. The catchment contains gullies, sheet-erosion exposed sub-soil, grassland and one unsealed road. Heavy metals and 137 Cs have been used to fingerprint the sources, and these measurements will be compared with suspended sediment collected from drainage water in the creek. Only preliminary results have been obtained for this component of the study. The paper will assess these two approaches for the identification of sediment sources and discuss practical applications in water resources management

  17. Pollution characteristics, source apportionment, and health risk of heavy metals in street dust of Suzhou, China.

    Science.gov (United States)

    Lin, Manli; Gui, Herong; Wang, Yao; Peng, Weihua

    2017-01-01

    To analyze the pollution characteristics, source apportionment, and health risk of heavy metals (HMs) in street dust of Suzhou, China, 23 sampling sites were selected and periodically sampled for 12 months. A total of 276 samples were collected, and the concentrations of selected HMs (e.g., Cr, Cu, Fe, Mn, Pb, V, and Zn) were examined with an X-ray fluorescence spectrum analyzer. Results showed that the mean concentrations of Cr, Cu, Fe, Mn, Pb, V, and Zn in the street dust of Suzhou were 112.9, 27.5, 19941.3, 410.3, 45.2, 75.6, and 225.3 mg kg -1 , respectively. Cr, Cu, Pb, and Zn exceeded their background values in local natural soils by 1.3-3.6-fold, whereas Fe, Mn, and V were all within their background values. However, enrichment factor analysis revealed that Cr, Cu, Mn, Pb, V, and Zn, especially Cr, Cu, Pb, and Zn, were enriched in Suzhou street dust. The HMs showed no significant seasonal changes overall, but spatial distribution analysis implied that the high values of Cr, Cu, Mn, Pb, V, and Zn were mainly distributed in areas with frequent human activities. Results of multivariate techniques (e.g., Pearson correlation, hierarchical cluster, and principal components analyses) suggested that Pb and Zn had complicated sources; Cu and V mainly originated from traffic sources; Fe and Mn mainly came from natural sources; and Cr was dominantly related to industrial district. Health risk assessment revealed that a single heavy metal might not cause both non-cancer and carcinogenic risks to local residents. Nevertheless, the sum of the hazard index of all selected HMs for children slightly exceeded the safety value, thereby implying that the HMs from Suzhou street dust can possibly produce significant risk to children. Cr was the priority pollutant in the study area because of its high concentration, high enrichment, and high contribution to non-cancer risk values.

  18. Investigation of firing temperature variation in ovens for ceramic-fused-to-metal dental prostheses using swept source optical coherence tomography

    Science.gov (United States)

    Todor, Raluca; Negrutiu, Meda-Lavinia; Sinescu, Cosmin; Topala, Florin Ionel; Bradu, Adrian; Duma, Virgil-Florin; Romînu, Mihai; Podoleanu, Adrian G.

    2018-03-01

    One of the most common fabrication techniques for dental ceramics is sintering, a process of heating of the ceramic to ensure densification. This occurs by viscous flow when the firing temperature is reached. Acceptable restorations require the alloy and ceramic to be chemically, thermally, mechanically, and aesthetically compatible. Thermal and mechanical compatibility include a fusing temperature of ceramic that does not cause distortion of the metal substructure. Decalibration of ovens used for firing of the ceramic layers for metal ceramic dental prostheses leads to stress and cracks in the veneering material, and ultimately to the failure of the restoration. 25 metal ceramic prostheses were made for this study. They were divided in five groups, each sintered at a different temperature: a group at the temperature prescribed by the producer, two groups at lower and two groups at higher temperatures set in the ceramic oven. An established noninvasive biomedical imaging method, swept source (SS) optical coherence tomography (OCT) was employed, in order to evaluate the modifications induced when using temperatures different from those prescribed for firing the samples. A quantitative assessment of the probes is performed by en-face OCT images, taken at constant depths inside the samples. The differences in granulation, thus in reflectivity allow for extracting rules-of-thumb to evaluate fast, by using only the prostheses currently produced the current calibration of the ceramic oven. OCT imaging can allow quick identification of the oven decalibration, to avoid producing dental prostheses with defects.

  19. Simultaneous identification of a contaminant source and hydraulic conductivity via the restart normal-score ensemble Kalman filter

    Science.gov (United States)

    Xu, Teng; Gómez-Hernández, J. Jaime

    2018-02-01

    Detecting where and when a contaminant entered an aquifer from observations downgradient of the source is a difficult task; this identification becomes more challenging when the uncertainty about the spatial distribution of hydraulic conductivity is accounted for. In this paper, we have implemented an application of the restart normal-score ensemble Kalman filter (NS-EnKF) for the simultaneous identification of a contaminant source and the spatially variable hydraulic conductivity in an aquifer. The method is capable of providing estimates of the spatial location, initial release time, the duration of the release and the mass load of a point-contamination event, plus the spatial distribution of hydraulic conductivity together with an assessment of the estimation uncertainty of all the parameters. The method has been applied in synthetic aquifers exhibiting both Gaussian and non-Gaussian patterns. The identification is made possible by assimilating in time both piezometric head and concentration observations from an array of observation wells. The method is demonstrated in three different synthetic scenarios that combine hydraulic conductivities with unimodal and bimodal histograms, and releases in high and low conductivity zones. The results prove that the specific implementation of the EnKF is capable of recovering the source parameters with some uncertainty and of recovering the main patterns of heterogeneity of the hydraulic conductivity fields by assimilating a sufficient number of state variable observations. The proposed approach is an important step towards contaminant source identification in real aquifers, which may have logconductivity spatial distributions with either Gaussian or non-Gaussian features, yet, it is still far from practical applications since the transport parameters, the external sinks and sources and the initial and boundary conditions are assumed known.

  20. The identification of 'hotspots' of heavy metal pollution in soil-rice systems at a regional scale in eastern China.

    Science.gov (United States)

    Li, Wanlu; Xu, Binbin; Song, Qiujin; Liu, Xingmei; Xu, Jianming; Brookes, Philip C

    2014-02-15

    Chinese agricultural soils and crops are suffering from increasing damage from heavy metals, which are introduced from various pollution sources including agriculture, traffic, mining and especially the flourishing private metal recycling industry. In this study, 219 pairs of rice grain and corresponding soil samples were collected from Wenling in Zhejiang Province to identify the spatial relationship and pollution hotspots of Cd, Cu, Ni and Zn in the soil-rice system. The mean soil concentrations of heavy metals were 0.316 mg kg(-1) for Cd, 47.3 mg kg(-1) for Cu, 31.7 mg kg(-1) for Ni and 131 mg kg(-1) for Zn, and the metal concentrations in rice grain were 0.132 mg kg(-1) for Cd, 2.46 mg kg(-1) for Cu, 0.223 mg kg(-1) for Ni and 17.4 mg kg(-1) for Zn. The coefficient of variability (CV) of soil Cd, Cu and rice Cd were 147%, 146% and 180%, respectively, indicating an extensive variability. While the CVs of other metals ranged from 23.4% to 84.3% with a moderate variability. Kriging interpolation procedure and the Local Moran's I index detected the locations of pollution hotspots of these four metals. Cd and Cu had a very similar spatial pattern, with contamination hotspots located simultaneously in the northwestern part of the study area, and there were obvious hotspots for soil Zn in the north area, while in the northeast for soil Ni. The existence of hotspots may be due to industrialization and other anthropogenic activities. An Enrichment Index (EI) was employed to measure the uptake of heavy metals by rice. The results indicated that the accumulation and availability of heavy metals in the soil-rice system may be influenced by both soil heavy metal concentrations and soil physico-chemical properties. Cross-correlograms quantitatively illustrated that EIs were significantly correlated with soil properties. Soil pH and organic matter were the most important factors controlling the uptake of heavy metals by rice. As results, positive measures should be taken into

  1. Content and the forms of heavy metals in bottom sediments in the zone of industrial pollution sources ,

    Directory of Open Access Journals (Sweden)

    Voytyuk Y.Y.

    2014-12-01

    Full Text Available Regularities in the distribution of heavy metals in sediments in the zone of influence of the steel industry in Mariupol are installed. The study results of the forms of occurrence of Zn, Pb, Cu, Cr, Ni are represented. Ecological and geochemical assessment of sediment contamination by heavy metals is performed. The main sources of pollution of bottom sediments are air borne emissions from industrial plants, hydrogenous pollution in industrial sewage entering the water, sewage sludge, ash dumps, slag, ore, sludge, oil spills and salt solutions. Pollution hydrogenous sediments may be significant, contaminated sediments are a source of long-term contamination of water, even after cessation of discharges into rivers untreated wastewater. The environmental condition of bottom sediments in gross content of heavy metals is little information because they do not reflect the transformation and further migration to adjacent environment. The study forms of giving objective information for ecological and geochemical evaluation. The study forms of heavy metals in the sediments carried by successive extracts. Concentrations of heavy metals in the extracts determined by atomic absorption spectrometer analysis CAS-115. It was established that a number of elements typical of exceeding their content in bottom sediments of the background values, due likely to their technogenic origin. Man-made pollution of bottom sediments. Mariupol has disrupted the natural form of the ratio of heavy metals. In the studied sediments form ion exchange increased content of heavy metals, which contributes to their migration in the aquatic environment.

  2. Source apportionment of heavy metals in agricultural soil based on PMF: A case study in Hexi Corridor, northwest China.

    Science.gov (United States)

    Guan, Qingyu; Wang, Feifei; Xu, Chuanqi; Pan, Ninghui; Lin, Jinkuo; Zhao, Rui; Yang, Yanyan; Luo, Haiping

    2018-02-01

    Hexi Corridor is the most important base of commodity grain and producing area for cash crops. However, the rapid development of agriculture and industry has inevitably led to heavy metal contamination in the soils. Multivariate statistical analysis, GIS-based geostatistical methods and Positive Matrix Factorization (PMF) receptor modeling techniques were used to understand the levels of heavy metals and their source apportionment for agricultural soil in Hexi Corridor. The results showed that the average concentrations of Cr, Cu, Ni, Pb and Zn were lower than the secondary standard of soil environmental quality; however, the concentrations of eight metals (Cr, Cu, Mn, Ni, Pb, Ti, V and Zn) were higher than background values, and their corresponding enrichment factor values were significantly greater than 1. Different degrees of heavy metal pollution occurred in the agricultural soils; specifically, Ni had the most potential for impacting human health. The results from the multivariate statistical analysis and GIS-based geostatistical methods indicated both natural sources (Co and W) and anthropogenic sources (Cr, Cu, Mn, Ni, Pb, Ti, V and Zn). To better identify pollution sources of heavy metals in the agricultural soils, the PMF model was applied. Further source apportionment revealed that enrichments of Pb and Zn were attributed to traffic sources; Cr and Ni were closely related to industrial activities, including mining, smelting, coal combustion, iron and steel production and metal processing; Zn and Cu originated from agricultural activities; and V, Ti and Mn were derived from oil- and coal-related activities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Geo-Parcel Based Crop Identification by Integrating High Spatial-Temporal Resolution Imagery from Multi-Source Satellite Data

    Directory of Open Access Journals (Sweden)

    Yingpin Yang

    2017-12-01

    Full Text Available Geo-parcel based crop identification plays an important role in precision agriculture. It meets the needs of refined farmland management. This study presents an improved identification procedure for geo-parcel based crop identification by combining fine-resolution images and multi-source medium-resolution images. GF-2 images with fine spatial resolution of 0.8 m provided agricultural farming plot boundaries, and GF-1 (16 m and Landsat 8 OLI data were used to transform the geo-parcel based enhanced vegetation index (EVI time-series. In this study, we propose a piecewise EVI time-series smoothing method to fit irregular time profiles, especially for crop rotation situations. Global EVI time-series were divided into several temporal segments, from which phenological metrics could be derived. This method was applied to Lixian, where crop rotation was the common practice of growing different types of crops, in the same plot, in sequenced seasons. After collection of phenological features and multi-temporal spectral information, Random Forest (RF was performed to classify crop types, and the overall accuracy was 93.27%. Moreover, an analysis of feature significance showed that phenological features were of greater importance for distinguishing agricultural land cover compared to temporal spectral information. The identification results indicated that the integration of high spatial-temporal resolution imagery is promising for geo-parcel based crop identification and that the newly proposed smoothing method is effective.

  4. Management of radiation sources and personal dosimeters based on the optical identification using two-dimensional barcode

    International Nuclear Information System (INIS)

    Takao, Hideaki; Yoshida, Masahiro; Kaneko, Mamoru; Miura, Miwa; Hayashida, Rika; Okumura, Yutaka; Matsuda, Naoki

    2006-01-01

    For accurate and efficient radiation safety management in facilities using radioisotopes, two-dimensional barcode (2-DC) was applied to the optical identification of radiation sources and personal dosimeters. The mobile personal computer (PC) equipped with a barcode reader, which has imported inventory records from the pre-existing radiation management system, enabled us to finish inventory procedures for 170 2-DC-labelled radiation sources in as short as 20min by one person. Identification of 270 personal dosimeters in their monthly replacement procedures also successfully completed within 20 min by incorporating pre-labeled 2-DC to PC installed with inventory records of dosimeters and radiation workers. As equipments and software required for 2-DC are affordable, easy to operate, and potentially expandable, the introduction of 2-DC system may help to establish practically higher level of radiation management. (author)

  5. Development and Characterization of a Metal Injection Molding Bio Sourced Inconel 718 Feedstock Based on Polyhydroxyalkanoates

    Directory of Open Access Journals (Sweden)

    Alexandre Royer

    2016-04-01

    Full Text Available The binder plays the most important role in the metal injection molding (MIM process. It provides fluidity of the feedstock mixture and adhesion of the powder to keep the molded shape during injection molding. The binder must provide strength and cohesion for the molded part and must be easy to remove from the molded part. Moreover, it must be recyclable, environmentally friendly and economical. Also, the miscibility between polymers affects the homogeneity of the injected parts. The goal of this study is to develop a feedstock of superalloy Inconel 718 that is environmentally friendly. For these different binders, formulations based on polyethylene glycol (PEG, because of his water solubility property, and bio sourced polymers were studied. Polyhydroxyalkanoates (PHA were investigated as a bio sourced polymer due to its miscibility with the PEG. The result is compared to a standard formulation using polypropylene (PP. The chemical and rheological behavior of the binder formulation during mixing, injection and debinding process were investigated. The feedstock was characterized in the same way as the binders and the interactions between the powder and the binders were also studied. The results show the well adapted formulation of polymer binder to produce a superalloy Inconel 718 feedstock.

  6. Preparation of value-added metal-organic frameworks (MOFs) using waste PET bottles as source of acid linker

    CSIR Research Space (South Africa)

    Dyosiba, Xoliswa

    2016-12-01

    Full Text Available of Value-added Metal-organic Frameworks (MOFs) Using Waste PET Bottles as Source of Acid Linker Xoliswa Dyosiba, Jianwei Ren, Nicholas M. Musyoka, Henrietta W. Langmi, Mkhulu Mathe, Maurice S. Onyango PII: S2214-9937(16)30053-7 DOI: doi:10.1016/j..., Hen- rietta W. Langmi, Mkhulu Mathe, Maurice S. Onyango, Preparation of Value-added Metal-organic Frameworks (MOFs) Using Waste PET Bottles as Source of Acid Linker, Sustainable Materials and Technologies (2016), doi:10.1016/j.susmat.2016...

  7. Contamination characteristics and source apportionment of heavy metals in topsoil from an area in Xi'an city, China.

    Science.gov (United States)

    Chen, Xiuduan; Lu, Xinwei

    2018-04-30

    As soil-extractable elements potentially pose ecological and health risks, identifying their contamination characteristics and sources is crucial. Therefore, to understand topsoil trace elements in the urban ring zone from the Second Ring Road to the Third Ring of Xi'an city in China, we determined the concentrations of Zn, Co, V, As, Cu, Mn, Ba, Ni and Pb, and analyzed the sources of the contamination. The results showed that the individual pollution indices of Pb, Co, Cu, Zn, Ba, Ni, Mn, As, and V were 1.79, 1.48, 1.41, 1.33, 1.20, 1.07, 1.04, 0.99, and 0.99, respectively. Evaluation with the aid of the pollution load index (PLI) indicated slight soil contamination by these elements in the study area. Using the positive matrix factorization (PMF) method, we identified four sources of contamination, namely (1) a natural source, (2) traffic emission source, (3) industrial emission source, and (4) mixed source. PMF is an effective tool for source apportionment of heavy metals in topsoil. The contribution rates of the natural source, traffic source, mixed source, and industrial source to the heavy metal contamination were specified as 25.04%, 24.71%, 24.99%, and 25.26%, respectively. Considering the above, any attempt to reduce the soil environmental cost of urban development, has to take into account the heavy metal contamination of the topsoil from industries, traffic, and other activities. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis) Ciferri

    OpenAIRE

    Satyabrata Nanda; Subodh Kumar Chand; Purander Mandal; Pradyumna Tripathy; Raj Kumar Joshi

    2016-01-01

    Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ?CBT-Ac77? and cultivar ?Arka Kalyan? were observed to be highly resistant. In vitro inoculation...

  9. Pollutant Source Tracking (PST) Technical Guidance

    Science.gov (United States)

    2011-12-01

    in the context of heavy metals (lead, copper), is considered to be a minor process contribution to the source fingerprint. 3.7 RAPID SCREENING...limits (summarized in Table 2) support the use of ICP-AES (ICP-OES) for heavy metal determination in soils , sediments, wastewater and other matrices...are included here. Isotopic ratios of stable isotopes of the metal of interest can be used for source identification and apportionment in complex

  10. Spatial distribution and sources of heavy metals in natural pasture soil around copper-molybdenum mine in Northeast China.

    Science.gov (United States)

    Wang, Zhiqiang; Hong, Chen; Xing, Yi; Wang, Kang; Li, Yifei; Feng, Lihui; Ma, Silu

    2018-06-15

    The characterization of the content and source of heavy metals are essential to assess the potential threat of metals to human health. The present study collected 140 topsoil samples around a Cu-Mo mine (Wunugetushan, China) and investigated the concentrations and spatial distribution pattern of Cr, Ni, Zn, Cu, Mo and Cd in soil using multivariate and geostatistical analytical methods. Results indicated that the average concentrations of six heavy metals, especially Cu and Mo, were obviously higher than the local background values. Correlation analysis and principal component analysis divided these metals into three groups, including Cr and Ni, Cu and Mo, Zn and Cd. Meanwhile, the spatial distribution maps of heavy metals indicated that Cr and Ni in soil were no notable anthropogenic inputs and mainly controlled by natural factors because their spatial maps exhibited non-point source contamination. The concentrations of Cu and Mo gradually decreased with distance away from the mine area, suggesting that human mining activities may be crucial in the spreading of contaminants. Soil contamination of Zn were associated with livestock manure produced from grazing. In addition, the environmental risk of heavy metal pollution was assessed by geo-accumulation index. All the results revealed that the spatial distribution of heavy metals in soil were in agreement with the local human activities. Investigating and identifying the origin of heavy metals in pasture soil will lay the foundation for taking effective measures to preserve soil from the long-term accumulation of heavy metals. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Source apportionment and health risk assessment of heavy metals in soil for a township in Jiangsu Province, China.

    Science.gov (United States)

    Jiang, Yanxue; Chao, Sihong; Liu, Jianwei; Yang, Yue; Chen, Yanjiao; Zhang, Aichen; Cao, Hongbin

    2017-02-01

    Human activities contribute greatly to heavy metal pollution in soils. Concentrations of 15 metal elements were detected in 105 soil samples collected from a typical rural-industrial town in southern Jiangsu, China. Among them, 7 heavy metals-lead, copper, zinc, arsenic, chromium, cadmium, and nickel-were considered in the health risk assessment for residents via soil inhalation, dermal contact, and/or direct/indirect ingestion. Their potential sources were quantitatively apportioned by positive matrix factorization using the data set of all metal elements, in combination with geostatistical analysis, land use investigation, and industrial composition analysis. Furthermore, the health risks imposed by sources of heavy metal in soil were estimated for the first time. The results indicated that Cr, Cu, Cd, Pb, Ni, and Co accumulated in the soil, attaining a mild pollution level. The total hazard index values were 3.62 and 6.11, and the total cancer risks were 9.78 × 10 -4 and 4.03 × 10 -4 for adults and children, respectively. That is, both non-carcinogenic and carcinogenic risks posed by soil metals were above acceptable levels. Cr and As require special attention because the health risks of Cr and As individually exceeded the acceptable levels. The ingestion of homegrown produce was predominantly responsible for the high risks. The potential sources were apportioned as: a) waste incineration and textile/dyeing industries (28.3%), b) natural sources (45.4%), c) traffic emissions (5.3%), and d) electroplating industries and livestock/poultry breeding (21.0%). Health risks of four sources accounted for 23.5%, 32.7%, 7.4%, and 36.4% of the total risk, respectively. Copyright © 2016. Published by Elsevier Ltd.

  12. Study of radioactive sources accumulation with application of thermoluminescence dosemeters on the base of alkaline earth metals sulfates

    International Nuclear Information System (INIS)

    Tokbergenov, I.; Sadykov, T.

    2001-01-01

    Methodic for study of accumulation and distribution of radioactive sources in a nature objects is developed. An essence of the method consists of in that quantity of accumulated radioactive sources in a nature objects is defining by absorption dose measured with help of thermoluminescent dosemeters on the base of alkaline earth metals sulfates such as CaSO 4 :Dy and SrSO 4 :Eu

  13. Sources of metals in the Porgera gold deposit, Papua New Guinea: Evidence from alteration, isotope, and noble metal geochemistry

    Science.gov (United States)

    Richards, Jeremy P.; McCulloch, Malcolm T.; Chappell, Bruce W.; Kerrich, Robert

    1991-02-01

    The Porgera gold deposit is spatially and temporally associated with the Late Miocene, mafic, alkalic, epizonal Porgera Intrusive Complex (PIC), located in the highlands of Papua New Guinea (PNG). The highlands region marks the site of a Tertiary age continent-island-arc collision zone, located on the northeastern edge of the Australasian craton. The PIC was emplaced within continental crust near the Lagaip Fault Zone, which represents an Oligocene suture between the craton and volcano-sedimentary rocks of the Sepik terrane. Magmatism at Porgera probably occurred in response to the Late Miocene elimination of an oceanic microplate, and subsequent Early Pliocene collision between the craton margin and an arc system located on the Bismarck Sea plate. Gold mineralization occurred within 1 Ma of the time of magmatism. Metasomatism accompanying early disseminated Au mineralization in igneous host rocks resulted in additions of K, Rb, Mn, S, and CO 2, and depletions of Fe, Mg, Ca, Na, Ba, and Sr; rare-earth and high-field-strength elements remained largely immobile. Pervasive development of illite-K-feldspar-quartz-carbonate alteration assemblages suggests alteration by mildly acidic, 200 to 350°C fluids, at high water/ rock ratios. Strontium and lead isotopic compositions of minerals from early base-metal sulphide veins associated with K-metasomatism, and later quartz-roscoelite veins carrying abundant free gold and tellurides, are remarkably uniform (e.g., 87Sr /86Sr = 0.70745 ± 0.00044 [n = 10] , 207Pb /204Pb = 15.603 ± 0.004 [n = 15] ). These compositions fall between those of unaltered igneous and sedimentary host rocks, and specifically sedimentary rocks from the Jurassic Om Formation which underlies the deposit (igneous rocks: 87Sr /86Sr ≈ 0.7035 , 207Pb /204Pb ≈ 15.560 ; Om Formation: 87Sr /86Sr |t~ 0.7153 , 207Pb /204Pb ≈ 15.636 ). It is therefore suggested that the hydrothermal fluids acquired their Sr and Pb isotopic signatures by interaction with, or

  14. The mineralogy and petrology of I-type cosmic spherules: Implications for their sources, origins and identification in sedimentary rocks

    Science.gov (United States)

    Genge, Matthew J.; Davies, Bridie; Suttle, Martin D.; van Ginneken, Matthias; Tomkins, Andrew G.

    2017-12-01

    I-type cosmic spherules are micrometeorites that formed by melting during atmospheric entry and consist mainly of iron oxides and FeNi metal. I-types are important because they can readily be recovered from sedimentary rocks allowing study of solar system events over geological time. We report the results of a study of the mineralogy and petrology of 88 I-type cosmic spherules recovered from Antarctica in order to evaluate how they formed and evolved during atmospheric entry, to constrain the nature of their precursors and to establish rigorous criteria by which they may be conclusively identified within sediments and sedimentary rocks. Two textural types of I-type cosmic spherule are recognised: (1) metal bead-bearing (MET) spherules dominated by Ni-poor (100 and suggest that metal from H-group ordinary, CM, CR and iron meteorites may form the majority of particles. Oxidation during entry heating increases in the series MET 80 wt% Ni comprising a particle mass fraction of exchange of Ni between wüstite and metal, and magnetite and wüstite are suggested as proxies for the rate of oxidation and cooling rate respectively. Variations in magnetite and wüstite crystal sizes are also suggested to relate to cooling rate allowing relative entry angle of particles to be evaluated. The formation of secondary metal in the form of sub-micron Ni-rich or Pt-group nuggets and as symplectite with magnetite was also identified and suggested to occur largely due to the exsolution of metallic alloys during decomposition of non-stoichiometric wüstite. Weathering is restricted to replacement of metal by iron hydroxides. The following criteria are recommended for the conclusive identification of I-type spherules within sediments and sedimentary rocks: (i) spherical particle morphologies, (ii) dendritic crystal morphologies, (iii) the presence of wüstite and magnetite, (iv) Ni-bearing wüstite and magnetite, and (v) the presence of relict FeNi metal.

  15. Time-response characteristic and potential biomarker identification of heavy metal induced toxicity in zebrafish.

    Science.gov (United States)

    Yin, Jian; Wang, Ai-Ping; Li, Wan-Fang; Shi, Rui; Jin, Hong-Tao; Wei, Jin-Feng

    2018-01-01

    The present work aims to explore the time-response (from 24 h to 96 h) characteristic and identify early potential sensitive biomarkers of copper (Cu) (as copper chloride dihydrate), cadmium (Cd) (as cadmium acetate), lead (Pb) (as lead nitrate) and chromium (Cr) (as potassium dichromate) exposure in adult zebrafish, focusing on reactive oxygen species (ROS), SOD activity, lipid peroxidation and gene expression related to oxidative stress and inflammatory response. Furthermore, the survival rate decreased apparently by a concentration-dependent manner after Cu, Cr, Cd and Pb exposure, and we selected non-lethal concentrations 0.05 mg/L for Cu, 15 mg/L for Cr, 3 mg/L for Cd and 93.75μg/L for Pb to test the effect on the following biological indicators. Under non-lethal concentration, the four heavy metals have no apparent histological change in adult zebrafish gills. Similar trends in ROS production, MDA level and SOD activity were up-regulated by the four heavy metals, while MDA level responded more sensitive to Pb by time-dependent manner than the other three heavy metals. In addition, mRNA levels related to antioxidant system (SOD1, SOD2 and Nrf2) were up-regulated by non-lethal concentration Cu, Cr, Cd and Pb exposure. MDA level and SOD1 gene have a more delayed response to heavy metals. Genes related to immunotoxicity were increased significantly after heavy metals exposure at non-lethal concentrations. TNF-α and IL-1β gene have similar sensibility to the four heavy metals, while IL-8 gene was more responsive to Cr, Cd and Pb exposure at 48 h groups and IFN-γ gene showed more sensitivity to Cu at 48 h groups than the other heavy metals. In conclusion, the present works have suggested that the IFN-γ gene may applied as early sensitive biomarker to identify Cu-induced toxicity, while MDA content and IL-8 gene may use as early sensitive biomarkers for evaluating the risk of Pb exposure. Moreover, IL-8 and IFN-γ gene were more responsive to heavy

  16. Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Arabic Edition)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-09-01

    Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives.

  17. Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide

    International Nuclear Information System (INIS)

    2014-01-01

    Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as … well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

  18. Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Arabic Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

  19. Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide

    International Nuclear Information System (INIS)

    2012-01-01

    Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives.

  20. Control of Orphan Sources and Other Radioactive Material in the Metal Recycling and Production Industries. Specific Safety Guide (Spanish Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    Accidents involving orphan sources and other radioactive material in the metal recycling and production industries have resulted in serious radiological accidents as well as in harmful environmental, social and economic impacts. This Safety Guide provides recommendations, the implementation of which should prevent such accidents and provide confidence that scrap metal and recycled products are safe. Contents: 1. Introduction; 2. Protection of people and the environment; 3. Responsibilities; 4. Monitoring for radioactive material; 5. Response to the discovery of radioactive material; 6. Remediation of contaminated areas; 7. Management of recovered radioactive material; Annex I: Review of events involving radioactive material in the metal recycling and production industries; Annex II: Categorization of radioactive sources; Annex III: Some examples of national and international initiatives

  1. Identification of an exposure risk to heavy metals from pharmaceutical-grade rubber stoppers.

    Science.gov (United States)

    Li, Xianghui; Qian, Pingping

    2017-07-01

    Exposure to low concentrations of heavy metals and metalloids represents a well-documented risk to animal and human health. However, current standards (European Pharmacopeia [EP], United States Pharmacopoeia [USP], International Organization for Standardization [ISO], YBB concerned with rubber closures) only require testing for Zn in pharmaceutical-grade rubber stoppers and then using only pure water as a solvent. We extracted and quantified heavy metals and trace elements from pharmaceutical-grade rubber stoppers under conditions that might occur during the preparation of drugs. Pure water, saline, 10% glucose, 3% acetic acid (w/v), 0.1 mol/L hydrochloric acid, and diethylenetriaminepentaacetic acid (4 mg/mL, 0.4 mg/mL, and 0.04 mg/mL) were used as extraction agents. We quantified the extracted arsenic, lead, antimony, iron, magnesium, aluminum, and zinc using inductively coupled plasma mass spectrometry. The concentration of extracted metals varied depending on the different extraction solutions used and between the different rubber stopper manufacturers. Rubber stoppers are ubiquitously used in the pharmaceutical industry for the storage and preparation of drugs. Extraction of heavy metals during the manufacturing and preparation of drugs represents a significant risk, suggesting a need for industry standards to focus on heavy metal migration from rubber stoppers. Copyright © 2016. Published by Elsevier B.V.

  2. Potential bioavailability assessment, source apportionment and ecological risk of heavy metals in the sediment of Brisbane River estuary, Australia.

    Science.gov (United States)

    Duodu, Godfred Odame; Goonetilleke, Ashantha; Ayoko, Godwin A

    2017-04-15

    A weak acid extraction was used to mobilize the loosely bound metals in estuary sediment samples. More than 30% of Ag, As, Ca, Cd, Co, Cu, Hg, Mn Ni, Pb and Zn were leached from the sediment showing that these metals are significantly present in the bioavailable form. PCA/APCS identified three sources of the metals, namely: lithogenic accounting for 72%, shipping related contributing 15% and traffic related representing 13% of the total load. Application of pollution index (PI) and modified pollution index (MPI) revealed that the sediment range from unpolluted to heavily polluted while ecological risk index (RI) classifies the sediment as posing low ecological risk modified ecological risk index (MRI) suggests considerable to very high ecological risk. To provide holistic insights into the ecological risks posed by metals, enrichment factor, MPI and MRI are recommended for the assessment of sediment in complex environments such as estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Analysis on the distribution characteristics and sources of soil heavy metals in suburban farmland in Xiangtan City

    Science.gov (United States)

    Zhang, Yong; Sun, Xinxin

    2018-01-01

    The rapid development of the economy will inevitably have an impact on the farmland soil environment. The content of heavy metal is increasing day by day, and the heavy metal can enter people's body through different channels and endanger people's health. Based on agricultural land and crop types in accordance with the regional land use classification, using the method of the Single Factor Index and Comprehensive Pollution Index, the pollution status of heavy metals in farmland soil in the suburbs of Xiangtan city was studied and evaluated. At the same time, we use SPSS software to analyze the four heavy metal elements (Cu, Zn, As and Pb) and analyze their possible sources. The results showed that the farmland soils in Erhuan Road and Zhubu Port were polluted, and the farmland soil in Shuangma (an old industrial district) was not polluted; for different crop lands, orchards and vegetable lands were not contaminated, but rape and rice lands were contaminated. Pearson correlation analysis showed that Cu, As and Pb might come from the same pollution source, while Zn might come from other sources. Waste water from a chemical plant, crop types, automobile exhaust and other human factors may be important sources of soil pollution in agricultural fields.

  4. [Sources, pollution statue and potential ecological risk of heavy metals in surface sediments of Aibi Lake, Northwest China].

    Science.gov (United States)

    Zhang, Zhao-Yong; Abuduwaili, Jilili; Jiang, Feng-Qing

    2015-02-01

    In this paper, the surface sediment samples were harvested from Aibi Lake, and total contents of 8 heavy metals ( Cu, Pb, Zn, As, Hg, Cr, Ni and Cd) were determined. Then the sources, pollution statue, and potential ecological risk were analyzed by using multiple analysis methods. The results show that: (1) The order of the skewness for these 8 heavy metals is: Hg > Cd > Pb > Zn > As > Cu > Cr > Ni. (2) Multivariate statistical analysis shows that 8 heavy metals can be classified to 2 principle components, among which PC1 ( Cd, Pb, Hg and Zn) is man-made source factor and mainly came from all kinds of waste of agriculture; PC2 ( Cu, Ni, Cr and As) is natural source and was mainly controlled by the background of the natural geography of this area. (3) Accumulation of index evaluation results show that the order of pollution degree values of 8 heavy metals in surface sediments of Aibi Lake is: Cd > Hg > Pb > Zn > As > Cu > Ni > Cr. In all samples, heavy metals Hg, Cd and Pb all belong to low and partial moderate pollution statue, while Zn, As, Cr, Ni and Cu belong to no pollution statue in majority samples. (4) Potential ecological risk assessment results show that the potential ecological risk of heavy metals in surface sediments of Aibi Lake mainly caused by Cd, Hg and Pb, and they accounting for 42.6%, 28.6% and 24.0% of the total amount, respectively, among which Cd is the main ecological risk factor, followed by Hg and Pb. In all samples, the potential ecological risk index values (RI) of 8 heavy metals are all lower than 150, and they are all at low ecological risk levels. However, this research also shows that there have high content of Cd and Pb in the sediment. Therefore, we should make long-term monitoring of the lake environment.

  5. A Study on Mono-energetic Beam Source Using Characteristic X-ray for Substance Identification System

    International Nuclear Information System (INIS)

    Lee, Hwan Soo

    2009-02-01

    A new mono-energetic beam source was developed by using characteristic X-ray for improving performance of the substance identification system. Most of inspection systems use X-ray tubes for their source modules. However, the broad energy spectrum of X-ray tube causes an increase of uncertainty. In this study, it was found that mono-energetic beam sources can be generated by using X-ray tube and the designed target filter assembly. In order to investigate the monoenergetic beam source, the sensitivity study was conducted with a series of different X-ray tube potentials, radiator and filter materials using Monte Carlo simulation. The developed beam sources have a mono-energy peak at 69 keV, 78 keV and 99 keV, and they are named as characteristic X-ray beam BEAM69, BEAM78 and BEAM99, respectively. The characteristic X-ray beam intensity was over thirty three times more than that of hardening beam used previous work at Hanyang University. And BEAM69 and BEAM99 were applied to the substance identification system as a source. The relative error between results of characteristic X-ray beams and 69 keV and 99 keV photons was about 2% on the average for five unknown materials. In comparison with experiment results by using hardening beam, characteristic X-ray beam achieves better accuracy which is about 6.46 % on the average. Hence, it is expected that the developed characteristic X-ray beam source helps lower uncertainty of the inspection system, and the inspection time will be reduced considerably due to its high beam intensity

  6. European Legislation to Prevent Loss of Control of Sources and to Recover Orphan Sources, and Other Requirements Relevant to the Scrap Metal Industry

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, A.; Tanner, V.; Mundigl, S., E-mail: augustin.janssens@ec.europa.eu [European Commission (Luxembourg)

    2011-07-15

    European legislation (Council Directive 2003/122/EURATOM) has been adopted with regard to the control of high-activity sealed radioactive sources (HASS). This Directive is now part of an overall recast of current radiation protection legislation. At the same time the main Directive, 96/29/EURATOM, laying down Basic Safety Standards (BSS) for the health protection of the general public and workers against the dangers of ionizing radiation, is being revised in the light of the new recommendations of the International Commission on Radiological Protection (ICRP). The provisions for exemption and clearance are a further relevant feature of the new BSS. The current issues emerging from the revision and recast of the BSS are discussed, in the framework of the need to protect the scrap metal industry from orphan sources and to manage contaminated metal products. (author)

  7. Streptomyces sp. MUM212 as a Source of Antioxidants with Radical Scavenging and Metal Chelating Properties

    Directory of Open Access Journals (Sweden)

    Loh Teng-Hern Tan

    2017-05-01

    Full Text Available Reactive oxygen species and other radicals potentially cause oxidative damage to proteins, lipids, and DNA which may ultimately lead to various complications including mutations, carcinogenesis, neurodegeneration, cardiovascular disease, aging, and inflammatory disease. Recent reports demonstrate that Streptomyces bacteria produce metabolites with potent antioxidant activity that may be developed into therapeutic drugs to combat oxidative stress. This study shows that Streptomyces sp. MUM212 which was isolated from mangrove soil in Kuala Selangor, Malaysia, could be a potential source of antioxidants. Strain MUM212 was characterized and determined as belonging to the genus Streptomyces using 16S rRNA gene phylogenetic analysis. The MUM212 extract demonstrated significant antioxidant activity through DPPH, ABTS and superoxide radical scavenging assays and also metal-chelating activity of 22.03 ± 3.01%, 61.52 ± 3.13%, 37.47 ± 1.79%, and 41.98 ± 0.73% at 4 mg/mL, respectively. Moreover, MUM212 extract was demonstrated to inhibit lipid peroxidation up to 16.72 ± 2.64% at 4 mg/mL and restore survival of Vero cells from H2O2-induced oxidative damages. The antioxidant activities from the MUM212 extract correlated well with its total phenolic contents; and this in turn was in keeping with the gas chromatography–mass spectrometry analysis which revealed the presence of phenolic compounds that could be responsible for the antioxidant properties of the extract. Other chemical constituents detected included hydrocarbons, alcohols and cyclic dipeptides which may have contributed to the overall antioxidant capacity of MUM212 extract. As a whole, strain MUM212 seems to have potential as a promising source of novel molecules for future development of antioxidative therapeutic agents against oxidative stress-related diseases.

  8. Identification of passive shutdown system parameters in a metal fueled LMR

    International Nuclear Information System (INIS)

    Vilim, R.B.

    1992-01-01

    This document discusses periodic testing of the passive shutdown system in a metal fueled liquid metal reactor which has been proposed as a Technical Specification requirement. In the approach to testing considered in this paper, perturbation experiments performed at normal operation are used to predict an envelope that bounds reactor response to flowrate, inlet temperature and external reactivity forcing functions. When the envelope for specific upsets lies within safety limits, one concludes that the passive shutdown system is operation properly for those upsets. Simulation results for the EBR-II reactor show that the response envelope for loss of flow and rod reactivity insertion events does indeed bound these events

  9. Urban farming as a possible source of trace metals in human diets

    Directory of Open Access Journals (Sweden)

    Joshua O. Olowoyo

    2016-02-01

    Full Text Available Rapid industrialisation and urbanisation have greatly increased the concentrations of trace metals as pollutants in the urban environment. These pollutants (trace metals are more likely to have an adverse effect on peri-urban agriculture which is now becoming a permanent feature of the landscape of many urban cities in the world. This review reports on the concentrations of trace metals in crops, including leafy vegetables harvested from different urban areas, thus highlighting the presence of trace metals in leafy vegetables. Various pathways of uptake of trace metals by leafy vegetables, such as the foliar and roots, and possible health risks associated with urban faming are discussed and various morphological and physiological impacts of trace metals in leafy vegetables are described. Defensive mechanisms and positive aspects of trace metals in plants are also highlighted.

  10. Online Identification of Photovoltaic Source Parameters by Using a Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Giovanni Petrone

    2017-12-01

    Full Text Available In this paper, an efficient method for the online identification of the photovoltaic single-diode model parameters is proposed. The combination of a genetic algorithm with explicit equations allows obtaining precise results without the direct measurement of short circuit current and open circuit voltage that is typically used in offline identification methods. Since the proposed method requires only voltage and current values close to the maximum power point, it can be easily integrated into any photovoltaic system, and it operates online without compromising the power production. The proposed approach has been implemented and tested on an embedded system, and it exhibits a good performance for monitoring/diagnosis applications.

  11. Development of a technical guide for the identification of radiological sources of potential exposure and/or contamination

    International Nuclear Information System (INIS)

    Reyes, R.; Scott, A.; Falo, G.; Collins, J.; Szrom, F.; Collins, D.

    1999-01-01

    Radiological assessment of sites with radioactive residues starts with the identification of potential sources. The US Army Center for Health Promotion and Preventive Medicine (USACHPPM) has developed a technical guide that summarizes sources of potential radiological exposures of both civilian and military origin. These sources include those found in the natural environment, in the nuclear fuel cycle, in medical and industrial settings, in the transportation of radioactive materials, in US Army commodities and foreign materiel, and in the use and storage of nuclear weapons. This technical guide is intended to foster awareness of radiological hazards and to provide the reader with the knowledge necessary to take the first step in radiological health risk assessment: recognition of the hazard. Furthermore, this guide can be used in conjunction with other technical guides for performing radiological surveys and field dose assessments in war or peacetime operations. (author)

  12. Seasonal and spatial variation of diffuse (non-point) source zinc pollution in a historically metal mined river catchment, UK

    Energy Technology Data Exchange (ETDEWEB)

    Gozzard, E., E-mail: emgo@ceh.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Mayes, W.M., E-mail: W.Mayes@hull.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Potter, H.A.B., E-mail: hugh.potter@environment-agency.gov.uk [Environment Agency England and Wales, c/o Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Jarvis, A.P., E-mail: a.p.jarvis@ncl.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2011-10-15

    Quantifying diffuse sources of pollution is becoming increasingly important when characterising river catchments in entirety - a prerequisite for environmental management. This study examines both low and high flow events, as well as spatial variability, in order to assess point and diffuse components of zinc pollution within the River West Allen catchment, which lies within the northern England lead-zinc Orefield. Zinc levels in the river are elevated under all flow regimes, and are of environmental concern. Diffuse components are of little importance at low flow, with point source mine water discharges dominating instream zinc concentration and load. During higher river flows 90% of the instream zinc load is attributed to diffuse sources, where inputs from resuspension of metal-rich sediments, and groundwater influx are likely to be more dominant. Remediating point mine water discharges should significantly improve water quality at lower flows, but contribution from diffuse sources will continue to elevate zinc flux at higher flows. - Highlights: > Zinc concentrations breach EU quality thresholds under all river flow conditions. > Contributions from point sources dominate instream zinc dynamics in low flow. > Contributions from diffuse sources dominate instream zinc dynamics in high flow. > Important diffuse sources include river-bed sediment resuspension and groundwater influx. > Diffuse sources would still create significant instream pollution, even with point source treatment. - Diffuse zinc sources are an important source of instream contamination to mine-impacted rivers under varying flow conditions.

  13. Diurnal and seasonal trends and source apportionment of redox-active metals in Los Angeles using a novel online metal monitor and Positive Matrix Factorization (PMF)

    Science.gov (United States)

    Mousavi, Amirhosein; Sowlat, Mohammad H.; Sioutas, Constantinos

    2018-02-01

    In the present study, we identified the sources of four redox-active metals, including Iron (Fe), Chromium (Cr), Cupper (Cu), and Manganese (Mn) and quantified the contribution of these sources to PM2.5 concentrations in central Los Angeles, California, by employing time-resolved measurements (i.e., a time resolution of 2 h) with a recently developed online metal monitor and Positive Matrix Factorization (PMF). Size distribution of ambient PM (14 nm-10 μm) was measured using the Scanning Mobility Particle Sizer (SMPS) and Optical Particle Sizer (OPS). Auxiliary variables were also collected, including elemental (EC) and organic carbon (OC), gaseous pollutants (NO2 and O3), meteorological parameters (including relative humidity (RH) and temperature), and traffic data (for heavy- (HDVs) and light-duty vehicles (LDVs)). A 4-factor solution was found to be optimum for the chemically-speciated dataset, whereas a 5-factor solution appeared to be most plausible for the size distribution data. The factors included fresh traffic, soil/road dust, urban background aerosol, secondary aerosol, and nucleation (only resolved for the size distribution data). Fresh traffic was the major contributor to Fe and Cu concentrations, whereas Cr was mostly found in the urban background aerosol (reflecting a mixture of small local sources as well as aged traffic emissions), and Mn mostly came from both soil/road dust and was to a lesser degree found in urban background aerosol. Secondary aerosol did not contribute to the concentrations of any of these metals, but was associated with very high loading of OC, as expected. Even though the urban background aerosol and secondary aerosol appeared to be characterized by "aged" particles and have a rather homogeneous spatial distribution, the reactions and processes involved in their formation are entirely different. Our results provide insights into the sources of redox-active metals in central Los Angeles. They also underscore the benefits of

  14. Investigation and Identification of Types and Amounts of Heavy Metals in Soil of an Industrial Area

    Directory of Open Access Journals (Sweden)

    Majid Mohammadhosseini

    2014-12-01

    Full Text Available This study was mainly designed to investigate and identify the amounts and types of heavy metals in the soils of National Iranian Oil Refining & Distribution Company in Shahrood region and tried to establish a logical relation between the presence of heavy metals and their damage on vegetation. In addition, considering the power of drained soil and due to the proximity of ground water in Shahrood region, conducting this study provides a better insight into recognition of the possible contamination centers of drinking waters. The gridding and selective method was used for sampling step. Accordingly, five sub-samples were taken from each grid and finally after mixing all of the sub-samples, the final samples were obtained with an average weight of 400 grams prior to sending to the laboratory. To determine the total concentration of heavy metals in soil, extraction was done using concentrated solutions of HCl and HNO3. The total concentration of the heavy metals of chromium, cobalt and nickel were measured using an ICP-MS instrument, and the rest of the elements using an XRF device. The results explicitly indicated that the quantities of nickel, lead, zinc and strontium in patient samples exceeded the standard, and the other elements were lower than their standard limits. More specifically, the contents of lead and strontium in both normal and patient samples were higher than their standard contents. Moreover, the majority of the vegetation loss across the affected areas was caused by heavy metal accumulation, particularly nickel, lead, zinc, and strontium.

  15. Separation of zeros for source signature identification under reverberant path conditions.

    Science.gov (United States)

    Hasegawa, Tomomi; Tohyama, Mikio

    2011-10-01

    This paper presents an approach to distinguishing the zeros representing a sound source from those representing the transfer function on the basis of Lyon's residue-sign model. In machinery noise diagnostics, the source signature must be separated from observation records under reverberant path conditions. In numerical examples and an experimental piano-string vibration analysis, the modal responses could be synthesized by using clustered line-spectrum modeling. The modeling error represented the source signature subject to the source characteristics being given by a finite impulse response. The modeling error can be interpreted as a remainder function necessary for the zeros representing the source signature. © 2011 Acoustical Society of America

  16. Controlling the Outcome of Melting Radioactive Sources in Scrap Metal: from Exclusion, Exemption and Clearance towards a 'Codex Metallarius'

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A.J., E-mail: agonzale@sede.arn.gov.ar [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2011-07-15

    Orphan radiation sources have been inadvertently incorporated into scrap metal and traces of radioactive residues have appeared in finished metal products causing public anxiety, despair in industry and governmental concern. The international principles of exclusion, exemption and clearance can be used to tackle this problem. They are described in detail, as they are becoming universally established for defining the scope of radiation protection regulations. However, notwithstanding the relevance of these principles, the paper suggests a straightforward professional consensus for discontinuing radiological control of commodities with minute traces of radioactive residues. The consensus should unambiguously specify a generic activity concentration in inedible commodities, including metals, below which radiological control may be effectively relinquished. A subsequent legally binding intergovernmental undertaking could resolve the current regulatory ambiguity, facilitate commercial exchange and ensure adequate public protection. For metals, it might take the form of a 'Codex Metallarius' (similar to the existing Codex Alimentarius for edible commodities) establishing a generic level of radiological acceptability for finished metal products. Furthermore, it is proposed that there should be an international convention to prevent radioactive sources becoming orphaned from regulatory control and then inadvertently appearing in trash and scrap. (author)

  17. Risk assessment and source analysis of soil heavy metal pollution from lower reaches of Yellow River irrigation in China.

    Science.gov (United States)

    Zhang, Pengyan; Qin, Chengzhe; Hong, Xin; Kang, Guohua; Qin, Mingzhou; Yang, Dan; Pang, Bo; Li, Yanyan; He, Jianjian; Dick, Richard P

    2018-08-15

    The level of concentration of heavy metal in soil is detrimental to soil quality. The Heigangkou-Liuyuankou irrigation area in the lower-reach of Yellow River irrigation, as home to a large population and a major site to agricultural production, is vulnerable to heavy metal pollution. This study examined soil quality in Heigangkou-Liuyuankou irrigation areas of Kaifeng, China. Pollution in soil and potential risks introduced by heavy metal accumulation were assessed using Nemerow, Geoaccumulation, and Hakanson's ecological risk indices. Statistics and Geographic Information Systems (GIS) were used to model and present the spatiotemporal changes of the pollution sources and factors affecting the levels of pollution. The heavy metals found in the sampled soil are Cr, Ni, Cu, Zn, Cd, Pb, As, and Hg. Among them, Cd is more concentrated than the others. The southwestern region of the studied area confronts the most serious heavy metal pollution. There exist spatial disparities of low concentrations of different heavy metals in the study area. Hg and Cd are found to pose the highest potential ecological risks. However, their risk levels are not the same across the study area. Levels concentration of Ni, Cu, Zn, Cd, Pb, As, and Hg in soil are highly correlated. In combination, they post an additional threat to the ecological environment. Transportation, rural settlements, and water bodies are found to be the major sources of Cr, Ni, Cu, Zn, Cd, Pb, and Hg pollution in the soil; among the major sources, transportation is the most significant factor. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. On a second order of accuracy stable difference scheme for the solution of a source identification problem for hyperbolic-parabolic equations

    Science.gov (United States)

    Ashyralyyeva, Maral; Ashyraliyev, Maksat

    2016-08-01

    In the present paper, a second order of accuracy difference scheme for the approximate solution of a source identification problem for hyperbolic-parabolic equations is constructed. Theorem on stability estimates for the solution of this difference scheme and their first and second order difference derivatives is presented. In applications, this abstract result permits us to obtain the stability estimates for the solutions of difference schemes for approximate solutions of two source identification problems for hyperbolic-parabolic equations.

  19. Identification of the Parameters of the Instantaneous Point Pollution Source in the Azov Sea Based on the Adjoint Method

    Directory of Open Access Journals (Sweden)

    V.S. Kochergin

    2017-02-01

    Full Text Available The passive admixture transport model in the Azov Sea is considered. The problem of cartelistic impulse local source identification at the sea surface based on adjoint method is solving by integration of independent series of adjoint tasks. Simultaneous solution of this problem at the parallel mode is realized by the aforementioned approach. The efficiency of the algorithm optimal value power of source search agreed with the data measurements is shown in the test example. The measurement data assimilation algorithm in the passive admixture transfer model is implemented applying variational methods of filtration for optimal estimate retrieval. The retrieval is carried out by means of the method of adjoint equations and solving of linear systems. On the basis of the variational filtration method of data assimilation, the optimal estimate retrieval algorithm for pollution source power identification is constructed. In application of the algorithm, the integration of the main, linked and adjoint problems is implemented. Integration problems are solved using TVD approximations. For the application of the procedure, the Azov current fields and turbulent diffusion coefficients are obtained using the sigma coordinate ocean model (POM under the eastern wind stress conditions being dominant at the observed time period. Furthermore, the results can be used to perform numerical data assimilation on loads of suspended matter.

  20. The identification of Volatile Organic Compound's emission sources in indoor air of living spaces, offices and laboratories

    Science.gov (United States)

    Kultys, Beata

    2018-01-01

    Indoor air quality is important because people spend most of their time in closed rooms. If volatile organic compounds (VOCs) are present at elevated concentrations, they may cause a deterioration in human well-being or health. The identification of indoor emission sources is carried out by comparison indoor and outdoor air composition. The aim of the study was to determinate the concentration of VOCs in indoor air, where there was a risk of elevated levels due to the kind of work type carried out or the users complained about the symptoms of a sick building followed by an appropriate interpretation of the results to determine whether the source of the emission in the tested room occurs. The air from residential, office and laboratory was tested in this study. The identification of emission sources was based on comparison of indoor and outdoor VOCs concentration and their correlation coefficients. The concentration of VOCs in all the rooms were higher or at a similar level to that of the air sampled at the same time outside the building. Human activity, in particular repair works and experiments with organic solvents, has the greatest impact on deterioration of air quality.

  1. Parameter identification for continuous point emission source based on Tikhonov regularization method coupled with particle swarm optimization algorithm.

    Science.gov (United States)

    Ma, Denglong; Tan, Wei; Zhang, Zaoxiao; Hu, Jun

    2017-03-05

    source parameters identification. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Environmental risk of heavy metal pollution and contamination sources using multivariate analysis in the soils of Varanasi environs, India.

    Science.gov (United States)

    Singh, Shubhra; Raju, N Janardhana; Nazneen, Sadaf

    2015-06-01

    This study assessed soil pollution in the Varanasi environs of Uttar Pradesh in India. Assessing the concentration of potentially harmful heavy metals in the soils is imperative in order to evaluate the potential risks to human. To identify the concentration and sources of heavy metals and assess the soil environmental quality, 23 samples were collected from different locations covering dumping, road and agricultural area. The average concentrations of the heavy metals were all below the permissible limits according to soil quality guidelines except Cu (copper) and Pb (lead) in dumping and road soils. Soil heavy metal contamination was assessed on the basis of geoaccumulation index (Igeo), pollution index (PI) and integrated pollution index (IPI). The IPI of the metals ranged from 0.59 to 9.94, with the highest IPI observed in the dumping and road soils. A very significant correlation was found between Pb and Cu. The result of principal component analysis suggested that PC1 was mainly affected by the use of agrochemicals, PC2 was affected by vehicular emission and PC3 was affected by dumping waste. Meanwhile, PC4 was mainly controlled by parent material along with anthropogenic activities. Appropriate measures should be taken to minimize the heavy metal levels in soils and thus protect human health.

  3. Method of making a self-aligned schottky metal semi-conductor field effect transistor with buried source and drain

    International Nuclear Information System (INIS)

    Bol, I.

    1984-01-01

    A semi-conductor structure and particularly a high speed VLSI Self-Aligned Schottky Metal Semi-Conductor Field Effect Transistor with buried source and drain, fabricated by the ion implantation of source and drain areas at a predetermined range of depths followed by very localized laser annealing to electrically reactivate the amorphous buried source and drain areas thereby providing effective vertical separation of the channel from the buried source and drain respectively. Accordingly, spatial separations between the self-aligned gate-to-drain, and gate-to-source can be relatively very closely controlled by varying the doping intensity and duration of the implantation thereby reducing the series resistance and increasing the operating speed

  4. Fluid fractionation of tungsten during granite-pegmatite differentiation and the metal source of peribatholitic W quartz veins: Evidence from the Karagwe-Ankole Belt (Rwanda)

    Science.gov (United States)

    Hulsbosch, Niels; Boiron, Marie-Christine; Dewaele, Stijn; Muchez, Philippe

    2016-02-01

    The identification of a magmatic source for granite-associated rare metal (W, Nb, Ta and Sn) mineralisation in metasediment-hosted quartz veins is often obscured by intense fluid-rock interactions which metamorphically overprinted most source signatures in the vein system. In order to address this recurrent metal sourcing problem, we have studied the metasediment-hosted tungsten-bearing quartz veins of the Nyakabingo deposit of the Karagwe-Ankole belt in Central Rwanda. The vein system (992 ± 2 Ma) is spatiotemporal related to the well-characterised B-rich, F-poor G4 leucogranite-pegmatite suite (986 ± 10 Ma to 975 ± 8 Ma) of the Gatumba-Gitarama area which culminated in Nb-Ta-Sn mineralisation. Muscovite in the Nyakabingo veins is significantly enriched in granitophile elements (Rb, Cs, W and Sn) and show alkali metal signatures equivalent to muscovite of less-differentiated pegmatite zones of the Gatumba-Gitarama area. Pegmatitic muscovite records a decrease in W content with increasing differentiation proxies (Rb and Cs), in contrast to the continuous enrichment of other high field strength elements (Nb and Ta) and Sn. This is an indication of a selective redistribution for W by fluid exsolution and fluid fractionation. Primary fluid inclusions in tourmaline of these less-differentiated pegmatites demonstrate the presence of medium to low saline, H2O-NaCl-KCl-MgCl2-complex salt (e.g. Rb, Cs) fluids which started to exsolve at the G4 granite-pegmatite transition stage. Laser ablation inductively coupled plasma mass-spectrometry shows significant tungsten enrichment in these fluid phases (∼5-500 ppm). Fractional crystallisation has been identified previously as the driving mechanism for the transition from G4 granites, less-differentiated biotite, biotite-muscovite towards muscovite pegmatites and eventually columbite-tantalite mineralised pegmatites. The general absence of tungsten mineralisation in this magmatic suite, including the most differentiated

  5. Classification Identification of Acoustic Emission Signals from Underground Metal Mine Rock by ICIMF Classifier

    Directory of Open Access Journals (Sweden)

    Hongyan Zuo

    2014-01-01

    Full Text Available To overcome the drawback that fuzzy classifier was sensitive to noises and outliers, Mamdani fuzzy classifier based on improved chaos immune algorithm was developed, in which bilateral Gaussian membership function parameters were set as constraint conditions and the indexes of fuzzy classification effectiveness and number of correct samples of fuzzy classification as the subgoal of fitness function. Moreover, Iris database was used for simulation experiment, classification, and recognition of acoustic emission signals and interference signals from stope wall rock of underground metal mines. The results showed that Mamdani fuzzy classifier based on improved chaos immune algorithm could effectively improve the prediction accuracy of classification of data sets with noises and outliers and the classification accuracy of acoustic emission signal and interference signal from stope wall rock of underground metal mines was 90.00%. It was obvious that the improved chaos immune Mamdani fuzzy (ICIMF classifier was useful for accurate diagnosis of acoustic emission signal and interference signal from stope wall rock of underground metal mines.

  6. Spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a century-old nonferrous metal mining and smelting area in China.

    Science.gov (United States)

    Gong, Xing; Chen, Zhihua; Luo, Zhaohui

    2014-12-01

    This study first presents the spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a nonferrous metal mine area in China. Unconfined groundwater was polluted by Pb, Zn, As, and Cu, in order, while confined karst water in the mines showed pollution in the following sequence: Zn, Cd, Cu, Pb, and As. Pollution by Pb was widespread, while Zn, As, Cu, and Cd were found to be high in the north-central industrial region and to decrease gradually with distance from smelters and tailings. Vertically, more Pb, Zn, Cu, and Cd have accumulated in shallow Quaternary groundwater, while more As have migrated into the deeper fracture groundwater in the local discharge area. Zn, Cd, and Cu concentrations in groundwater along the riverside diminished owing to reduced wastewater drainage since 1977, while samples in the confluence area were found to have increasing contents of Pb, Zn, As, Cu, and Cd since industrialization began in the 1990s. Sources of heavy metals in groundwater were of anthropogenic origin except for Cr. Pb originated primarily from airborne volatile particulates, wastewater, and waste residues and deposited continuously, while Zn, Cd, and Cu were derived from the wastewater of smelters and leakage of tailings, which corresponded to the related soil and surface residue researches. Elevated As values around factories might be the result of chemical reactions. Flow patterns in different hydrogeological units and adsorption capability of from Quaternary sediments restricted their cross-border diffusion.

  7. Historical evolution of sources identification by means of Receptor Modeling in the Metropolitan Area of São Paulo, Brazil.

    Science.gov (United States)

    Miranda, R. M.; Andrade, M. D. F.; Marien, Y., Sr.

    2017-12-01

    The atmospheric aerosols sources have been identified in Sao Paulo since the 80´s with the use of receptor models. The Metropolitan Area of São Paulo (MASP) is a megacity with a population of 21 million, corresponding to more than 11% of the total population of Brazil. The first results for the identification of sources of particles were obtained with the application of Absolute Principal Component Analysis, Factor Analysis and Chemical Mass Balance. More recently the Positive Matrix Factorization has been used in combination with the other receptor models. With the improvement of the aerosol composition analytical determination (more elements and better resolution) the source identification has became more accurate. But, in spite of that, the main sources are the same for fine particles: vehicular emission, secondary formation and biomass burning. The large amount of biofuels used in the MASP makes this region an important example of the atmospheric chemistry of fossil fuel and biofuel emissions. The 7 million vehicles can run on gasohol, ethanol (95% ethanol + 5% gasoline) and biodiesel (mostly for trucks and buses). We have considered the Black Carbon as the tracer for diesel engines and biomass burning, being this last source associated not only with burning of sugar cane plantation and forest fires, but also with wood and charcoal used in restaurant and domestic cooking and residues burning. The responsibility of the vehicular emission to the fine particles has been maintained in approximately 50% of the mass. The soil resuspension was associated with 8% of the fine particles origin. We are presenting the data obtained from experiments performed from 1983 to 2014, not continuously and mainly performed in the winter time. It is a long period of data that is going to be considered. The previous results obtained with the application of PCA were compared to that obtained with PMF applied to the historical data collected at MASP, showing the evolution of the

  8. [Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

    Science.gov (United States)

    Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

    2013-04-01

    The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.

  9. Combining emission inventory and isotope ratio analyses for quantitative source apportionment of heavy metals in agricultural soil.

    Science.gov (United States)

    Chen, Lian; Zhou, Shenglu; Wu, Shaohua; Wang, Chunhui; Li, Baojie; Li, Yan; Wang, Junxiao

    2018-08-01

    Two quantitative methods (emission inventory and isotope ratio analysis) were combined to apportion source contributions of heavy metals entering agricultural soils in the Lihe River watershed (Taihu region, east China). Source apportionment based on the emission inventory method indicated that for Cd, Cr, Cu, Pb, and Zn, the mean percentage input from atmospheric deposition was highest (62-85%), followed by irrigation (12-27%) and fertilization (1-14%). Thus, the heavy metals were derived mainly from industrial activities and traffic emissions. For Ni the combined percentage input from irrigation and fertilization was approximately 20% higher than that from atmospheric deposition, indicating that Ni was mainly derived from agricultural activities. Based on isotope ratio analysis, atmospheric deposition accounted for 57-93% of Pb entering soil, with the mean value of 69.3%, which indicates that this was the major source of Pb entering soil in the study area. The mean contributions of irrigation and fertilization to Pb pollution of soil ranged from 0% to 10%, indicating that they played only a marginally important role. Overall, the results obtained using the two methods were similar. This study provides a reliable approach for source apportionment of heavy metals entering agricultural soils in the study area, and clearly have potential application for future studies in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Simple Methods for Production of Nanoscale Metal Oxide Films from Household Sources

    Science.gov (United States)

    Campbell, Dean J.; Baliss, Michelle S.; Hinman, Jordan J.; Ziegenhorn, John W.; Andrews, Mark J.; Stevenson, Keith J.

    2013-01-01

    Production of thin metal oxide films was recently explored as part of an outreach program with a goal of producing nanoscale structures with household items. Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses. As part of a materials chemistry laboratory experiment…

  11. Methods and compositions for identification of source of microbial contamination in a sample

    Science.gov (United States)

    Andersen, Gary L.; Dubinsky, Eric A.

    2017-08-08

    Herein are described 1058 different bacterial taxa that were unique to either human, grazing mammal, or bird fecal wastes. These identified taxa can serve as specific identifier taxa for these sources in environmental waters. Two field tests in marine waters demonstrate the capacity of phylogenetic microarray analysis to track multiple sources with one test.

  12. 40 CFR 144.7 - Identification of underground sources of drinking water and exempted aquifers.

    Science.gov (United States)

    2010-07-01

    ..., all aquifers or parts of aquifers which meet the definition of an “underground source of drinking... underground source of drinking water if it meets the definition in § 144.3. (b)(1) The Director may identify... mineral or hydrocarbon producing. Information contained in the mining plan for the proposed project, such...

  13. Methane source identification in Boston, Massachusetts using isotopic and ethane measurements

    Science.gov (United States)

    Down, A.; Jackson, R. B.; Plata, D.; McKain, K.; Wofsy, S. C.; Rella, C.; Crosson, E.; Phillips, N. G.

    2012-12-01

    Methane has substantial greenhouse warming potential and is the principle component of natural gas. Fugitive natural gas emissions could be a significant source of methane to the atmosphere. However, the cumulative magnitude of natural gas leaks is not yet well constrained. We used a combination of point source measurements and ambient monitoring to characterize the methane sources in the Boston urban area. We developed distinct fingerprints for natural gas and multiple biogenic methane sources based on hydrocarbon concentration and isotopic composition. We combine these data with periodic measurements of atmospheric methane and ethane concentration to estimate the fractional contribution of natural gas and biogenic methane sources to the cumulative urban methane flux in Boston. These results are used to inform an inverse model of urban methane concentration and emissions.

  14. Ceramic to metal joining by using 1064 nm pulsed and CW laser energy source

    International Nuclear Information System (INIS)

    Lee, Young Min; Kim, Soo Won; Choi, Hae Woon; Kim, Joo Han

    2013-01-01

    A novel joining method for ceramic and metallic layers is proposed using laser drilling and surface tension driven liquid metal filling. A high intensity laser beam irradiated a 500 µm thick ceramic filter, and the irradiated laser drilled the ceramic layer. The pulsed or CW laser transmitted through the ceramic layer irradiated the bottom metallic layer; the molten metallic layer then filled the drilled ceramic holes by the capillary force between the liquid metal and ceramic layer. As process variables, average laser power, pulse duration, and the number of pulses were used. The scattering optical properties were also studied for both green and red lasers. There was no significant difference between the colors and the estimated extinction coefficients were -26.94 1/mm and -28.42 1/mm for the green and red lasers, respectively.

  15. On the Feasibility of Very-Low-Density Pure Metal Foams as Bright High-Energy X-ray Sources

    Science.gov (United States)

    Colvin, Jeffrey; Felter, Thomas

    2003-10-01

    We have used the Busquet approximation (M. Busquet, Phys. Fluids B 5(11), 4191 (1993)) to explore calculationally what the possible x-ray conversion efficiencies into the K-band would be from irradiating very-low-density pure metal foams with tens of kilojoules of 1/3-micron laser light. We will discuss the advantages of pure metal foams as bright high-energy x-ray sources, and some results of this calculational study. We will also present our ideas for how to fabricate pure metal foams with densities of a few milligrams per cubic centimeter. This work was performed under the auspices of the US Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

  16. Speciation of heavy metals in different grain sizes of Jiaozhou Bay sediments: Bioavailability, ecological risk assessment and source analysis on a centennial timescale.

    Science.gov (United States)

    Kang, Xuming; Song, Jinming; Yuan, Huamao; Duan, Liqin; Li, Xuegang; Li, Ning; Liang, Xianmeng; Qu, Baoxiao

    2017-09-01

    Heavy metal contamination is an essential indicator of environmental health. In this work, one sediment core was used for the analysis of the speciation of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in Jiaozhou Bay sediments with different grain sizes. The bioavailability, sources and ecological risk of heavy metals were also assessed on a centennial timescale. Heavy metals were enriched in grain sizes of Pb > Cd > Zn > Cu >Ni > Cr > As. Enrichment factors (EF) indicated that heavy metals in Jiaozhou Bay presented from no enrichment to minor enrichment. The potential ecological risk index (RI) indicated that Jiaozhou Bay had been suffering from a low ecological risk and presented an increasing trend since 1940s owing to the increase of anthropogenic activities. The source analysis indicated that natural sources were primary sources of heavy metals in Jiaozhou Bay and anthropogenic sources of heavy metals presented an increasing trend since 1940s. The principal component analysis (PCA) indicated that Cr, Mn, Ni, Cu and Pb were primarily derived from natural sources and that Zn and Cd were influenced by shipbuilding industry. Mn, Cu, Zn and Pb may originate from both natural and anthropogenic sources. As may be influenced by agricultural activities. Moreover, heavy metals in sediments of Jiaozhou Bay were clearly influenced by atmospheric deposition and river input. Copyright © 2017. Published by Elsevier Inc.

  17. Irradiation of Liquid Fungi Isolated Media from Contaminated Sources with Heavy Metals Additive

    International Nuclear Information System (INIS)

    Tawfiq, E.; Mohamed, A.A.; El-Kabbany, H.M.

    2012-01-01

    Occupational lead exposure is an important health issue in Egyptian workers, employees of paint factories, workers of copying centres, drivers, and tile making factories are in higher risk of lead toxicity. Wastewater, particularly from electroplating, paint, leather, metal and tanning industries, contain enormous amount of heavy metals. Microorganisms including fungi have been reported to exclude heavy metals from wastewater through bioaccumulation and bio sorption at low cost and in eco-friendly way. Low level lead exposure can significantly induce motor dis functions and cognitive impairment in children. Seventy six fungal isolates tolerant to heavy metals like Pb, Cd, Cr and Ni were isolated from sewage, sludge and industrial effluents containing heavy metals. Four fungi (Phanerochaete chrysosporium, Aspergillus awamori, Aspergillus flavus, Trichoderma viride) were included in this study. The majority of the fungal isolates were able to tolerate up to 400 ppm concentration of Pb, Cd, Cr and Ni. The most heavy metal tolerant fungi were studied for removal of heavy metals from liquid media at 50 ppm concentration. Results indicated removal of substantial amount of heavy metals by some of the fungi with respect to Pb, Cd, Cr and Ni with maximum uptake of 59.67, 16.25, 0.55 and 0.55 mg/g by fungi Pb 3 (Aspergillus terreus), Trichoderma viride, C r 8 (Trichoderma longibrachiatum), and isolate Ni 27 (A. niger), respectively. This indicated the potential of these fungi as bio sorbent for removal of heavy metals from wastewater and industrial effluents containing higher concentration of heavy metals. The F-ratio was 0.55 and gives non-significant as irradiated

  18. Antibiotics and heavy metals resistance patterns of Enterococcus faecalis and faecium bacteria isolated from the human and the livestock sources

    Directory of Open Access Journals (Sweden)

    Yaser Sharifi

    2015-12-01

    Full Text Available Background: Enterococci have emerged as a major cause of nosocomial infections and within this group, Enterococcus faecalis and Enterococcus faecium cause the majority of human and livestock enterococcal infections. In this article, we tried to determine antibiotics and metals resistance patterns of E. faecalis and E. faecium strains. Methods: One hundred sixty different strains of E. faecalis and E. faecium were collected from livestock sewage and the human fecal waste during 15 months. Then bacterial antibiotics sensitivity tests were carried out using the Agar disc diffusion method. Results: Generally, 100% of E. faecalis strains separated from human and livestock sources (i.e. sheep showed penicillin (P/ kanamycin (K/ nitrofurantoin (N/ loracarbef (L/ Ciprofloxacin (Cc/ ampicillin (AN/ nalidixic acid (NA/ sulfamethoxazole (S antibiotics resistance patterns. In addition, 55% of isolated E. faecium showed P/S/AN/NA antibiotics resistance patterns. Each strain showed a resistance to at least two aminoglycoside antibiotics. However, E. faecalis strains from human and the livestock sources showed 94% and 100% of resistance to nitrofurantoin, respectively. The effects of different metal concentrations was evaluated in both strains. The agar dilution method was applied in this stage. Hg at 0.05 mmol/L of minimum inhibitory concentration (MIC showed toxicity to both the human and livestock Enterococcus strains. Cadmium at 1 mmol/L and 0.5 mmol/L concentrations had the most toxicity to E. faecalis and E. faecium strains, respectively. Obviously, toxicity to bacteria is less than other metals. As a result, Zn/Ni/Cu/Co resistance pattern is suggested for both strains. Finally, antibiotics and heavy metals resistance patterns were monitored simultaneously. Conclusion: Almost all E. faecalis strains isolated from humans and livestock showed antibiotics and heavy metals resistance patterns of P/K/L/Cc/S/AN/NA/Zn/Cu/Co simultaneously. Moreover, 55% of E

  19. Enrichment and geochemical mobility of heavy metals in bottom sediment of the Hoedong reservoir, Korea and their source apportionment.

    Science.gov (United States)

    Lee, Pyeong-Koo; Kang, Min-Ju; Yu, Soonyoung; Ko, Kyung-Seok; Ha, Kyoochul; Shin, Seong-Cheon; Park, Jung Han

    2017-10-01

    Physicochemical characteristics of bottom sediment in the Hoedong reservoir were studied to evaluate the effectiveness of the reservoir as traps for trace metals. Roadside soil, stream sediment and background soil were also studied for comparison. Sequential extractions were carried out, and lead isotopic compositions of each extraction were determined to apportion Pb sources. Besides, particle size distribution of roadside soil, and metal concentrations and Pb isotopes of each size group were determined to characterize metal contamination. In result, Zn and Cu were enriched in sediment through roadside soil. The data on metal partitioning implied that Zn posed potential hazards for water quality. Meanwhile, the noticeable reduction of the 206 Pb/ 207 Pb isotopic ratio in the acid-soluble fraction in the size group 200 μm - 2 mm of national roadside soil indicated that this size group was highly contaminated by automotive emission with precipitation of acid-soluble secondary minerals during evaporation. Based on the Pb isotopic ratios, the dry deposition of Asian dust (AD) and non-Asian dust (NAD) affected roadside soil, while the effects of AD and NAD on bottom sediment appeared to be low given the low metal concentrations in sediment. Metal concentrations and Pb isotopic compositions indicated that sediments were a mixture of background and roadside soil. Source apportionment calculations showed that the average proportion of traffic Pb in bottom and stream sediments was respectively 34 and 31% in non-residual fractions, and 26 and 28% in residual fraction. The residual fraction of sediments appeared to be as contaminated as the non-residual fractions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Heavy metals in the surface sediments of the northern portion of the South China Sea shelf: distribution, contamination, and sources.

    Science.gov (United States)

    Xu, Fangjian; Tian, Xu; Yin, Feng; Zhao, Yongfang; Yin, Xuebo

    2016-05-01

    The concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) in the surface sediments of the northern portion of the South China Sea (SCS) shelf collected between 2012 and 2014 were measured to assess the potential contamination levels and determine the environmental risks that are associated with heavy metals in the area. The measured concentrations in the sediments were 12.4-72.5 mg kg(-1) for Cr, 4.4-29.2 mg kg(-1) for Ni, 7.1-38.1 mg kg(-1) for Cu, 19.3-92.5 mg kg(-1) for Zn, 1.3-12.1 mg kg(-1) for As, 0.03-0.24 mg kg(-1) for Cd, and 8.5-24.4 mg kg(-1) for Pb. These results indicate that the heavy metal concentrations in the sediments generally meet the China Marine Sediment Quality criteria and suggest that the overall sediment quality of the northern portion of the SCS shelf has not been significantly impacted by heavy metal pollution. However, the enrichment factor (EF) and geoaccumulation index (I geo) clearly show that elevated concentrations of Cd occur in the region. A Pearson's correlation analysis was performed, and the results suggest that Cr, Ni, Cu, and Zn have a natural origin; Cd is primarily sourced from anthropogenic activities, with partial lithogenic components, and As and Pb may be affected by factors such as varying input sources or pathways (i.e., coal burning activities and aerosol precipitation). Heavy metal contamination mostly occurred to the east of Hainan Island, mainly because of the rapid economic and social developments in the Hainan Island. The results of this study will be useful for marine environment managers for the remediation of pollution sources.

  1. Real breakthrough in detection of radioactive sources by portal monitors with plastic detectors and New Advanced Source Identification Algorithm (ASIA-New)

    Energy Technology Data Exchange (ETDEWEB)

    Stavrov, Andrei; Yamamoto, Eugene [Rapiscan Systems, Inc., 14000 Mead Street, Longmont, CO, 80504 (United States)

    2015-07-01

    Radiation Portal Monitors (RPM) with plastic detectors represent the main instruments used for primary border (customs) radiation control. RPM are widely used because they are simple, reliable, relatively inexpensive and have a high sensitivity. However, experience using the RPM in various countries has revealed the systems have some grave shortcomings. There is a dramatic decrease of the probability of detection of radioactive sources under high suppression of the natural gamma background (radiation control of heavy cargoes, containers and, especially, trains). NORM (Naturally Occurring Radioactive Material) existing in objects under control trigger the so-called 'nuisance alarms', requiring a secondary inspection for source verification. At a number of sites, the rate of such alarms is so high it significantly complicates the work of customs and border officers. This paper presents a brief description of new variant of algorithm ASIA-New (New Advanced Source Identification Algorithm), which was developed by the Rapiscan company. It also demonstrates results of different tests and the capability of a new system to overcome the shortcomings stated above. New electronics and ASIA-New enables RPM to detect radioactive sources under a high background suppression (tested at 15-30%) and to verify the detected NORM (KCl) and the artificial isotopes (Co- 57, Ba-133 and other). New variant of ASIA is based on physical principles, a phenomenological approach and analysis of some important parameter changes during the vehicle passage through the monitor control area. Thanks to this capability main advantage of new system is that this system can be easily installed into any RPM with plastic detectors. Taking into account that more than 4000 RPM has been installed worldwide their upgrading by ASIA-New may significantly increase probability of detection and verification of radioactive sources even masked by NORM. This algorithm was tested for 1,395 passages of

  2. Spatio-Temporal Patterns and Source Identification of Water Pollution in Lake Taihu (China

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-03-01

    Full Text Available Various multivariate methods were used to analyze datasets of river water quality for 11 variables measured at 20 different sites surrounding Lake Taihu from 2006 to 2010 (13,200 observations, to determine temporal and spatial variations in river water quality and to identify potential pollution sources. Hierarchical cluster analysis (CA grouped the 12 months into two periods (May to November, December to the next April and the 20 sampling sites into two groups (A and B based on similarities in river water quality characteristics. Discriminant analysis (DA was important in data reduction because it used only three variables (water temperature, dissolved oxygen (DO and five-day biochemical oxygen demand (BOD5 to correctly assign about 94% of the cases and five variables (petroleum, volatile phenol, dissolved oxygen, ammonium nitrogen and total phosphorus to correctly assign >88.6% of the cases. In addition, principal component analysis (PCA identified four potential pollution sources for Clusters A and B: industrial source (chemical-related, petroleum-related or N-related, domestic source, combination of point and non-point sources and natural source. The Cluster A area received more industrial and domestic pollution-related agricultural runoff, whereas Cluster B was mainly influenced by the combination of point and non-point sources. The results imply that comprehensive analysis by using multiple methods could be more effective for facilitating effective management for the Lake Taihu Watershed in the future.

  3. Uncertainty quantification and experimental design based on unsupervised machine learning identification of contaminant sources and groundwater types using hydrogeochemical data

    Science.gov (United States)

    Vesselinov, V. V.

    2017-12-01

    Identification of the original groundwater types present in geochemical mixtures observed in an aquifer is a challenging but very important task. Frequently, some of the groundwater types are related to different infiltration and/or contamination sources associated with various geochemical signatures and origins. The characterization of groundwater mixing processes typically requires solving complex inverse models representing groundwater flow and geochemical transport in the aquifer, where the inverse analysis accounts for available site data. Usually, the model is calibrated against the available data characterizing the spatial and temporal distribution of the observed geochemical species. Numerous geochemical constituents and processes may need to be simulated in these models which further complicates the analyses. As a result, these types of model analyses are typically extremely challenging. Here, we demonstrate a new contaminant source identification approach that performs decomposition of the observation mixtures based on Nonnegative Matrix Factorization (NMF) method for Blind Source Separation (BSS), coupled with a custom semi-supervised clustering algorithm. Our methodology, called NMFk, is capable of identifying (a) the number of groundwater types and (b) the original geochemical concentration of the contaminant sources from measured geochemical mixtures with unknown mixing ratios without any additional site information. We also demonstrate how NMFk can be extended to perform uncertainty quantification and experimental design related to real-world site characterization. The NMFk algorithm works with geochemical data represented in the form of concentrations, ratios (of two constituents; for example, isotope ratios), and delta notations (standard normalized stable isotope ratios). The NMFk algorithm has been extensively tested on synthetic datasets; NMFk analyses have been actively performed on real-world data collected at the Los Alamos National

  4. Spatial and temporal variation of heavy metal risk and source in sediments of Dongting Lake wetland, mid-south China.

    Science.gov (United States)

    Liang, Jie; Liu, Jiayu; Yuan, Xingzhong; Zeng, Guangming; Lai, Xu; Li, Xiaodong; Wu, Haipeng; Yuan, Yujie; Li, Fei

    2015-01-01

    Surface sediments of Dongting Lake wetland were collected from ten sites to investigate variation trend, risk and sources of heavy metal distribution in dry seasons of 2011∼2013. The three-year mean concentrations (mg/kg) of Cr, Cu, Pb, Cd, Hg and As were 91.33, 36.27, 54.82, 4.39, 0.19 and 25.67, respectively, which were all higher than the corresponding background values. Sediment quality guidelines (SQGs) and Geo-accumulation index (Igeo) were used for the assessment of pollution level of heavy metals. The pollution risk of Cd, Hg and As were great and that of Cr needed urgent attention because of its obvious increase. Pollution load index (PLI) and geographic information system (GIS) methods were conducted to assess spatial and temporal variation of heavy metal contamination. Results confirmed an increased contamination contribution inflow from Xiang River. Multivariate statistical analyses were applied to identify contribution sources of heavy metal, which showed anthropogenic origin mainly from mining, smelting, chemical industry and agricultural activity.

  5. Identification and quantification of phthalates, PAHs, amines, phenols, and metals in tattoo

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Sang; Lim, Hyun Hee [Kongju National University, Kongju (Korea, Republic of)

    2015-08-15

    The determination methods of polycyclic aromatic hydrocarbons (PAHs), phthalates, primary amines, phenols, and metals in tattoo dyes have been optimized and validated using gas chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, and inductively coupled plasma-mass spectrometry. Twelve PAHs, 3 phthalates, 4 amines, and 15 metals were identified and quantified in 16 different tattoo dyes purchased from shops in the Republic of Korea. Phenols were not detected in any sample. The total PAHs in six inks and benzo(a)pyrene in one tattoo ink exceeded the legal limit set by the Council of Europe, and their maximum detected concentrations were about 10 and 5 times the limits of the compounds, respectively. 3,3′-Dichlorobenzidine and o-anisidine, which should not be present in tattoo inks by Resolution ResAP (2008) of the Council of Europe, were detected in tattoo inks. Also, Cd, Pb, Cu, Ba, Ni, Sb, Zn, and As exceeded the limits. These hazardous compounds should be controlled to the lowest possible concentrations in the raw materials and the production procedure of tattoo ink.

  6. Heavy metal content and molecular species identification in canned tuna: Insights into human food safety.

    Science.gov (United States)

    Pappalardo, Anna Maria; Copat, Chiara; Ferrito, Venera; Grasso, Alfina; Ferrante, Margherita

    2017-05-01

    Canned tuna in olive oil and in brine of the most popular brands sold in Italian markets were analyzed to verify the authentication of transformed products, with the aim to unveil commercial frauds due to the substitutions of high value species with species of low commercial value, and to assess the health risk of consumers related to cadmium (Cd), lead (Pb) and mercury (Hg) contents. Species authentication was evaluated with amplification of COI DNA barcode and confirmed the declared species. Among tested metals, Hg had the highest concentrations, followed by Cd and Pb. None of the tested samples surpassed the European regulatory limits no. 1881/2006 fixed for Hg and Pb, whereas one batch of canned tuna in olive oil exceeded standard for Cd. Risk for human health was evaluated by the metals daily intake and target hazard quotient (THQ). As a result, Cd and Pb did not exceed the toxicological reference values established by World Health Organization (WHO) and the Environmental Protection Agency (EPA). Conversely, Hg content suggests a consumption no more than once a week and a continuous surveillance of this fishery products for consumer protection.

  7. Study and identification of retention process of heavy metals by adsorption on agricultural byproducts

    Energy Technology Data Exchange (ETDEWEB)

    Bencheikh-Lehocine, M.; Arris, S.; Meniai, A.H. [Laboratoire de l' Ingenierie des Procedes d' Environnement, Universite Mentouri Constantine (Algeria); Morcellet, M.; Bacquet, M.; Martel, B. [Laboratoire de Chimie Macromoleculaire, UPRESA CNRS 8009 de l' Universite des Sciences et Technologies de Lille (USTL) (France); Mansri, A. [Laboratoire de Recherche sur les Macromolecules, Universite Abou Bakr Belkaid, Tlemcen (Algeria)

    2003-09-01

    This present study considers the adsorption of cations of heavy metals (zinc, cadmium, copper) which are frequently encountered in industrial wastewaters. The solid material used as adsorbent is nonactivated carbon obtained from a local cereal byproduct. In order to assess this material, adsorbents obtained from other agricultural byproducts, such as almond and peanuts shells, have also been tested. Adsorption isotherms have been determined and the influence of various parameters, such as the particle size, the solid-liquid contacting time, the pH of the solution, the initial concentration, the mixing velocity, the temperature and the ratio solid mass over solution volume, have been considered. The case of simultaneous presence of metallic cations in the solution has also been considered in order to examine their affinity towards the adsorbent. An attempt to determine whether the retention of the cations is a pure adsorption or an ion exchange has also been carried out. Retention yield values exceeding 90 % have been reached with an initial concentration of 10 mg/L, a temperature of 20 C, a particle size smaller than 0.1 mm, a mixing velocity of 600 rev/min, a ratio of 0.5 g adsorbent over 50 ml of solution and a pH varying between 3 and 6. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  8. Identification and quantification of phthalates, PAHs, amines, phenols, and metals in tattoo

    International Nuclear Information System (INIS)

    Shin, Ho Sang; Lim, Hyun Hee

    2015-01-01

    The determination methods of polycyclic aromatic hydrocarbons (PAHs), phthalates, primary amines, phenols, and metals in tattoo dyes have been optimized and validated using gas chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, and inductively coupled plasma-mass spectrometry. Twelve PAHs, 3 phthalates, 4 amines, and 15 metals were identified and quantified in 16 different tattoo dyes purchased from shops in the Republic of Korea. Phenols were not detected in any sample. The total PAHs in six inks and benzo(a)pyrene in one tattoo ink exceeded the legal limit set by the Council of Europe, and their maximum detected concentrations were about 10 and 5 times the limits of the compounds, respectively. 3,3′-Dichlorobenzidine and o-anisidine, which should not be present in tattoo inks by Resolution ResAP (2008) of the Council of Europe, were detected in tattoo inks. Also, Cd, Pb, Cu, Ba, Ni, Sb, Zn, and As exceeded the limits. These hazardous compounds should be controlled to the lowest possible concentrations in the raw materials and the production procedure of tattoo ink

  9. Process development study on production of uranium metal from monazite sourced crude uranium tetra-fluoride

    International Nuclear Information System (INIS)

    Chowdhury, S; Satpati, S.K.; Hareendran, K.N.; Roy, S.B.

    2014-01-01

    Development of an economic process for recovery, process flow sheet development, purification and further conversion to nuclear grade uranium metal from the crude UF 4 has been a technological challenge and the present paper, discusses the same.The developed flow-sheet is a combination of hydrometallurgical and pyrometallurgical processes. Crude UF 4 is converted to uranium di-oxide (UO 2 ) by chemical conversion route and UO 2 produced is made fluoride-free by repeated repulping, followed by solid liquid separation. Uranium di-oxide is then purified by two stages of dissolution and suitable solvent extraction methods to get uranium nitrate pure solution (UNPS). UNPS is then precipitated with air diluted ammonia in a leak tight stirred vessel under controlled operational conditions to obtain ammonium di-uranate (ADU). The ADU is then calcined and reduced to produce metal grade UO 2 followed by hydro-fluorination using anhydrous hydrofluoric acid to obtain metal grade UF 4 with ammonium oxalate insoluble (AOI) content of 4 is essential for critical upstream conversion process. Nuclear grade uranium metal ingot is finally produced by metallothermic reduction process at 650℃ in a closed vessel, called bomb reactor. In the process, metal-slag separation plays an important role for attaining metal purity as well as process yield. Technological as well economic feasibility of indigenously developed process for large scale production of uranium metal from the crude UF 4 has been established in Bhabha Atomic Research Centre (BARC), India

  10. Carrageenans as a new source of drugs with metal binding properties.

    Science.gov (United States)

    Khotimchenko, Yuri S; Khozhaenko, Elena V; Khotimchenko, Maxim Y; Kolenchenko, Elena A; Kovalev, Valeri V

    2010-04-01

    Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y(3+) or Pb(2+) ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that kappa-, iota-, and lambda-carrageenans are favorable sorbents. The largest amount of Y(3+) and Pb(2+) ions are bound by iota-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties.

  11. Carrageenans as a New Source of Drugs with Metal Binding Properties

    Directory of Open Access Journals (Sweden)

    Yuri S. Khotimchenko

    2010-04-01

    Full Text Available Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y3+ or Pb2+ ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that κ-, ι-, and λ-carrageenans are favorable sorbents. The largest amount of Y3+ and Pb2+ ions are bound by i-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties.

  12. Statistical forensic methodology for oil spill source identification using two-tailed student's t approach. Volume 1

    International Nuclear Information System (INIS)

    Yang, C.; Wang, Z.; Hollebone, B.; Brown, C.E.; Landriault, M.

    2007-01-01

    A thorough chemical characterization of oil must be conducted following an oil spill in order to determine the source of the oil, to distinguish the spilled oil from background hydrocarbons and to quantitatively evaluate the extent of impact of the spill. Gas chromatography, flame ionization and mass spectrometry analysis was used in conjunction with statistical data analysis to determine the source of a spill that occurred in 2004 in a harbor in the Netherlands. Three oil samples were collected from the harbor spill, where a thick layer of oil was found between a bunker boat and the quay next to the bunker centre. The 3 samples were sent to different laboratories for a round robin test to defensively correlate the spilled oil to the suspected source candidates. The source characterization and identification was validated by quantitative evaluation of 5 petroleum-characteristic alkylated PAH homologous series (naphthalene, phenanthrene, dibenzothiophene, fluorene and chrysene), pentacyclic biomarkers, bicyclic sesquiterpanes and diamondoid compounds. The use of biomarkers for identifying the source of spilled oils has also increased in recent years due to their specificity and high resistance to biodegradation. There was no strong difference among the 3 oil samples according to radar plots of diagnostic ratios of PAHs, isoprenoids, biomarkers, bicyclic sesquiterpanes and diamondoids. The two-tailed unpaired student's t-tests provided strong evidence for which ship was responsible for the oil spill incident. However, it was cautioned that although two-tailed unpaired student's t-tests along with oil fingerprinting successfully identified the spill source, the method has limitations. Experimental results showed that the spilled oil and two source candidates were quite similar in both chemical fingerprints and concentration profiles for determined target hydrocarbons. 17 refs., 4 tabs., 3 figs

  13. Winter-time size distribution and source apportionment of total suspended particulate matter and associated metals in Delhi

    Science.gov (United States)

    Srivastava, Arun; Gupta, Sandeep; Jain, V. K.

    2009-03-01

    A study of the winter time size distribution and source apportionment of total suspended particulate matter (TSPM) and associated heavy metal concentrations have been carried out for the city of Delhi. This study is important from the point of view of implementation of compressed natural gas (CNG) as alternate of diesel fuel in the public transport system in 2001 to reduce the pollution level. TSPM were collected using a five-stage cascade impactor at six sites in the winters of 2005-06. The results of size distribution indicate that a major portion (~ 40%) of TSPM concentration is in the form of PM0.7 (heavy metals associated with various size fractions of TSPM. A very good correlation between coarse and fine size fraction of TSPM was observed. It was also observed that the metals associated with coarse particles have more chances of correlation with other metals; rather they are associated with fine particles. Source apportionment was carried out separately in coarse and fine size modes of TSPM by Chemical Mass Balance Receptor Model (CMB8) as well as by Principle Component Analysis (PCA) of SPSS. Source apportionment by PCA reveals that there are two major sources (possibly vehicular and crustal re-suspension) in both coarse and fine size fractions. Results obtained by CMB8 show the dominance of vehicular pollutants and crustal dust in fine and coarse size mode respectively. Noticeably the dominance of vehicular pollutants are now confined to fine size only whilst during pre CNG era it dominated both coarse and fine size mode. An increase of 42.5, 44.4, 48.2, 38.6 and 38.9% in the concentrations of TSPM, PM10.9, coarse particles, fine particles and lead respectively was observed during pre (2001) to post CNG (2005-06) period.

  14. Heavy Metals in Contaminated Soils: A Review of Sources, Chemistry, Risks and Best Available Strategies for Remediation

    OpenAIRE

    Wuana, Raymond A.; Okieimen, Felix E.

    2011-01-01

    Scattered literature is harnessed to critically review the possible sources, chemistry, potential biohazards and best available remedial strategies for a number of heavy metals (lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel) commonly found in contaminated soils. The principles, advantages and disadvantages of immobilization, soil washing and phytoremediation techniques which are frequently listed among the best demonstrated available technologies for cleaning up heavy met...

  15. Low-Cost Open-Source Voltage and Current Monitor for Gas Metal Arc Weld 3D Printing

    OpenAIRE

    Pinar, A.; Wijnen, B.; Anzalone, G. C.; Havens, T. C.; Sanders, P. G.; Pearce, J. M.

    2015-01-01

    Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW) RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder cu...

  16. Mineralogic sources of metals in leachates from the weathering of sedex, massive sulfide, and vein deposit mining wastes

    Science.gov (United States)

    Diehl, S.F.; Hageman, P.L.; Seal, R.R.; Piatak, N.M.; Lowers, H.

    2011-01-01

    Weathered mine waste consists of oxidized primary minerals and chemically unstable secondary phases that can be sources of readily soluble metals and acid rock drainage. Elevated concentrations of metals such as Cd, Cu, Fe, Mn, Ni, Pb, and Zn are observed in deionized water-based leachate solutions derived from complex sedex and Cu-Pb-Zn mine wastes. Leachate (USGS FLT) from the Elizabeth mine, a massive sulfide deposit, has a pH of 3.4 and high concentrations of Al (16700 ug/L), Cu (440 ug/L), and Zn (8620 ug/L). Leachate from the sedex Faro mine has a pH of 3.5 and high concentrations of Al (2040 ug/L), Cu (1930 ug/L), Pb (2080 ug/L), and Zn (52900 ug/L). In contrast, higher-pH leachates produced from tailings of polymetallic vein deposits have order of magnitude lower metal concentrations. These data indicate that highly soluble secondary mineral phases exist at the surface of waste material where the samples were collected. Sulfide minerals from all sites exhibit differential degrees of weathering, from dissolution etched grain rims, to rinds of secondary minerals, to skeletal remnants. These microscale mineral-dissolution textures enhance weathering and metal teachability of waste material. Besides the formation of secondary minerals, sulfide grains from dried tailings samples may be coated by amorphous Fe-Al-Si minerals that also adsorb metals such as Cu, Ni, and Zn.

  17. Possible source and pattern distribution of heavy metals content in urban soil at Kuala Terengganu town center

    International Nuclear Information System (INIS)

    Foo, Toon Fong; Poh, Seng Chee; Asrul Azani Mahmood; Norhayati Mohd Tahir

    2008-01-01

    Total concentration of five trace metals (Cu, Mn, Cd, Pb and Zn) and two major elements (Al and Fe) as well as soil parameters (soil organic matter, pH and cation exchange capacity) were measured in soils of Kuala Terengganu town center. 40 surface soils (0-20 cm) were collected during the month of August, 2005. The soil samples (< 600 μm) were subjected to acid digestion and the concentration of total metal was measured using Atomic Absorption Spectrometer. Results show that the range of metals observed were 4.16-40.90 mg/ kg, 83.70 - 380.80 mg/ kg, 2940.00 - 28600.00 mg/ kg below detection limit (BDL) - 4.88 mg/ kg, 20.00 - 219.00 mg/ kg, 7.47 - 171.00 mg/ kg and 8840.00 - 62500.00 mg/ kg for Cu, Mn, Fe, Cd, Pb, Zn and Al, respectively. Factor and Pearsons correlation analyses suggest that the Fe, Mn and Al originates from the parent materials, whereas the possible sources of Cu, Cd, Pb and Zn are due to anthropogenic input such as vehicular traffic and metal corrosion since there are no major industrial activities in Kuala Terengganu. In addition, calculation of enrichment factors (Efs) for trace metals showed that Pb, Cd and Zn were significantly enriched, providing additional support to the contention that Pb, Cd and Zn level in Kuala Terengganu town center soils are due to human related activities. (author)

  18. Dataset for Testing Contamination Source Identification Methods for Water Distribution Networks

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the results of a simulation study using the source inversion techniques available in the Water Security Toolkit. The data was created to test...

  19. The difference between the metal ion extracted from the R.F. ion source by applying plasma chemistry reaction and by non-plasma range chemistry reaction

    International Nuclear Information System (INIS)

    Bai Gui Bin

    1987-01-01

    The paper introduced the difference between using plasma chemistry reaction draw metal ion and non-plasma range chemistry reaction in the R.F. ion source. By using of the plasma chemistry reaction draw metal ion higher percentage than non-plasma range chemistry reaction in the R.F. ion source. The authors plasma chemistry reaction to R.F. ion source and implanter successfully. The effect is very well, it has its own characteristic

  20. Heavy metals

    OpenAIRE

    Adriano, Domy; VANGRONSVELD, Jaco; Bolan, N.S.; Wenzel, W.W.

    2005-01-01

    - Sources of Metals in the Environment - Environmental Contamination - Retention and Dynamics of Metals in Soils - Adsorption - Complexation - Precipitation - Bioavailability–Natural Attenuation Interactions - Biological Response to Metals - Soil Remediation

  1. Source discrimination of heavy metals in sediment and water of To Lich River in Hanoi City using multivariate statistical approaches.

    Science.gov (United States)

    Thuong, Nguyen Thi; Yoneda, Minoru; Ikegami, Maiko; Takakura, Masato

    2013-10-01

    The concentrations of Mn, Fe, Ni, Cr, Cu, Pb, Zn, As, and Cd were determined to evaluate the level of contamination of To Lich River in Hanoi City. All metal concentrations in 0-10-cm water samples, except Mn, were lower than the maximum permitted concentration for irrigation water standard. Meanwhile, concentrations of As, Cd, and Zn in 0-30-cm sediments were likely to have adverse effects on agriculture and aquatic life. Sediment pollution assessment was undertaken using enrichment factor and geoaccumulation index (I geo). The I geo results indicated that the sediment was not polluted with Cr, Mn, Fe, and Ni, and the pollution level increased in the order of Cu < Pb < Zn < As < Cd. Meanwhile, significant enrichment was shown for Cd, As, Zn, and Pb. Cluster and principal component analyses suggest that As and Mn in sediment were derived from both lithogenic and anthropogenic sources, while Cu, Pb, Zn, Cr, Cd, and Ni originated from anthropogenic sources such as vehicular fumes for Pb and metallic discharge from industrial sources and fertilizer application for other metals.

  2. Identification of specific sources of airborne particles emitted from within a complex industrial (steelworks) site

    Science.gov (United States)

    Beddows, D. C. S.; Harrison, Roy M.

    2018-06-01

    A case study is provided of the development and application of methods to identify and quantify specific sources of emissions from within a large complex industrial site. Methods include directional analysis of concentrations, chemical source tracers and correlations with gaseous emissions. Extensive measurements of PM10, PM2.5, trace gases, particulate elements and single particle mass spectra were made at sites around the Port Talbot steelworks in 2012. By using wind direction data in conjunction with real-time or hourly-average pollutant concentration measurements, it has been possible to locate areas within the steelworks associated with enhanced pollutant emissions. Directional analysis highlights the Slag Handling area of the works as the most substantial source of elevated PM10 concentrations during the measurement period. Chemical analyses of air sampled from relevant wind directions is consistent with the anticipated composition of slags, as are single particle mass spectra. Elevated concentrations of PM10 are related to inverse distance from the Slag Handling area, and concentrations increase with increased wind speed, consistent with a wind-driven resuspension source. There also appears to be a lesser source associated with Sinter Plant emissions affecting PM10 concentrations at the Fire Station monitoring site. The results are compared with a ME2 study using some of the same data, and shown to give a clearer view of the location and characteristics of emission sources, including fugitive dusts.

  3. Identification of Hard X-ray Sources in Galactic Globular Clusters: Simbol-X Simulations

    Science.gov (United States)

    Servillat, M.

    2009-05-01

    Globular clusters harbour an excess of X-ray sources compared to the number of X-ray sources in the Galactic plane. It has been proposed that many of these X-ray sources are cataclysmic variables that have an intermediate magnetic field, i.e. intermediate polars, which remains to be confirmed and understood. We present here several methods to identify intermediate polars in globular clusters from multiwavelength analysis. First, we report on XMM-Newton, Chandra and HST observations of the very dense Galactic globular cluster NGC 2808. By comparing UV and X-ray properties of the cataclysmic variable candidates, the fraction of intermediate polars in this cluster can be estimated. We also present the optical spectra of two cataclysmic variables in the globular cluster M 22. The HeII (4868 Å) emission line in these spectra could be related to the presence of a magnetic field in these objects. Simulations of Simbol-X observations indicate that the angular resolution is sufficient to study X-ray sources in the core of close, less dense globular clusters, such as M 22. The sensitivity of Simbol-X in an extended energy band up to 80 keV will allow us to discriminate between hard X-ray sources (such as magnetic cataclysmic variables) and soft X-ray sources (such as chromospherically active binaries).

  4. Tsunami Source Identification on the 1867 Tsunami Event Based on the Impact Intensity

    Science.gov (United States)

    Wu, T. R.

    2014-12-01

    The 1867 Keelung tsunami event has drawn significant attention from people in Taiwan. Not only because the location was very close to the 3 nuclear power plants which are only about 20km away from the Taipei city but also because of the ambiguous on the tsunami sources. This event is unique in terms of many aspects. First, it was documented on many literatures with many languages and with similar descriptions. Second, the tsunami deposit was discovered recently. Based on the literatures, earthquake, 7-meter tsunami height, volcanic smoke, and oceanic smoke were observed. Previous studies concluded that this tsunami was generated by an earthquake with a magnitude around Mw7.0 along the Shanchiao Fault. However, numerical results showed that even a Mw 8.0 earthquake was not able to generate a 7-meter tsunami. Considering the steep bathymetry and intense volcanic activities along the Keelung coast, one reasonable hypothesis is that different types of tsunami sources were existed, such as the submarine landslide or volcanic eruption. In order to confirm this scenario, last year we proposed the Tsunami Reverse Tracing Method (TRTM) to find the possible locations of the tsunami sources. This method helped us ruling out the impossible far-field tsunami sources. However, the near-field sources are still remain unclear. This year, we further developed a new method named 'Impact Intensity Analysis' (IIA). In the IIA method, the study area is divided into a sequence of tsunami sources, and the numerical simulations of each source is conducted by COMCOT (Cornell Multi-grid Coupled Tsunami Model) tsunami model. After that, the resulting wave height from each source to the study site is collected and plotted. This method successfully helped us to identify the impact factor from the near-field potential sources. The IIA result (Fig. 1) shows that the 1867 tsunami event was a multi-source event. A mild tsunami was trigged by a Mw7.0 earthquake, and then followed by the submarine

  5. Development of high current electron source using photoemission from metals with ultrashort laser pulses

    International Nuclear Information System (INIS)

    Tsang, T.; Srinivasan-Rao, T.; Fischer, J.

    1990-10-01

    We summarize the studies of photoemission from metal photocathodes using picosecond pulses in the UV (4.66 eV) wavelength and femtosecond laser pulses in the visible (2 eV) wavelengths. To achieve high current density yield from metal photocathodes, multiphoton photoemission using femtosecond laser pulses are suggested. Electron yield improvement incorporating surface photoemission and surface plasmon resonance in metals and metal films are demonstrated. We examine the possibility of the nonlinear photoemission process overtaking the linear process, and identity some possible complexity. To extract the large amount of electrons free of space charge, a pulsed high voltage is designed; the results of the preliminary test are presented. Finally, for the first time, the width of the electron temporal profiles are measured, utilizing the nonlinear photoelectric effect, to below 100 fsec time regime. The results indicated that the electron pulse duration follows the laser pulses and are not limited by the material. 8 refs., 15 figs

  6. Inverse identification of unknown finite-duration air pollutant release from a point source in urban environment

    Science.gov (United States)

    Kovalets, Ivan V.; Efthimiou, George C.; Andronopoulos, Spyros; Venetsanos, Alexander G.; Argyropoulos, Christos D.; Kakosimos, Konstantinos E.

    2018-05-01

    In this work, we present an inverse computational method for the identification of the location, start time, duration and quantity of emitted substance of an unknown air pollution source of finite time duration in an urban environment. We considered a problem of transient pollutant dispersion under stationary meteorological fields, which is a reasonable assumption for the assimilation of available concentration measurements within 1 h from the start of an incident. We optimized the calculation of the source-receptor function by developing a method which requires integrating as many backward adjoint equations as the available measurement stations. This resulted in high numerical efficiency of the method. The source parameters are computed by maximizing the correlation function of the simulated and observed concentrations. The method has been integrated into the CFD code ADREA-HF and it has been tested successfully by performing a series of source inversion runs using the data of 200 individual realizations of puff releases, previously generated in a wind tunnel experiment.

  7. Identification of Glucosinolates in Seeds of Three Brassicaceae Species Known to Hyperaccumulate Heavy Metals.

    Science.gov (United States)

    Montaut, Sabine; Guido, Benjamin S; Grison, Claude; Rollin, Patrick

    2017-03-01

    Plants from the Brassicaceae family are known to contain secondary metabolites called glucosinolates. Our goal was to establish by LC/MS the glucosinolate profile of seeds of three Brassicaceae species known to hyperaccumulate heavy metals. We investigated Alyssum fallacinum auct. non Hausskn., Iberis intermedia Guers., and Noccaea caerulescens (J. Presl & C. Presl) F. K. Mey. Our results indicate that A. fallacinum seeds contain glucoiberin and glucoibervirin, which had not been previously identified in this plant. Furthermore, we report for the first time the presence of glucoiberin, glucoibervirin, glucotropaeolin, and sinigrin in I. intermedia. We have detected for the first time glucoconringiin in N. caerulescens. In addition, glucosinalbin, 4-hydroxyglucobrassicin, and glucomoringin were also detected. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  8. Identification, Attribution, and Quantification of Highly Heterogeneous Methane Sources Using a Mobile Stable Isotope Analyzer

    Science.gov (United States)

    Crosson, E.; Rella, C.; Cunningham, K.

    2012-04-01

    Despite methane's importance as a potent greenhouse gas second only to carbon dioxide in the magnitude of its contribution to global warming, natural contributions to the overall methane budget are only poorly understood. A big contributor to this gap in knowledge is the highly spatially and temporally heterogeneous nature of most natural (and for that matter anthropogenic) methane sources. This high degree of heterogeneity, where the methane emission rates can vary over many orders of magnitude on a spatial scale of meters or even centimeters, and over a temporal scale of minutes or even seconds, means that traditional methods of emissions flux estimation, such as flux chambers or eddy-covariance, are difficult or impossible to apply. In this paper we present new measurement methods that are capable of detecting, attributing, and quantifying emissions from highly heterogeneous sources. These methods take full advantage of the new class of methane concentration and stable isotope analyzers that are capable of laboratory-quality analysis from a mobile field platform in real time. In this paper we present field measurements demonstrating the real-time detection of methane 'hot spots,' attribution of the methane to a source process via real-time stable isotope analysis, and quantification of the emissions flux using mobile concentration measurements of the horizontal and vertical atmospheric dispersion, combined with atmospheric transport calculations. Although these techniques are applicable to both anthropogenic and natural methane sources, in this initial work we focus primarily on landfills and fugitive emissions from natural gas distribution, as these sources are better characterized, and because they provide a more reliable and stable source of methane for quantifying the measurement uncertainty inherent in the different methods. Implications of these new technologies and techniques are explored for the quantification of natural methane sources in a variety of

  9. Source identification of ambient PM2.5 during summer inhalation exposure studies in Detroit, MI

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, M.; Keeler, G.J.; Wagner, J.G.; Harkema, J.R. [University of Michigan, Ann Arbor, MI (United States). Air Quality Laboratory

    2006-07-15

    Particulate air pollution is associated with cardiopulmonary morbidity and mortality in heavily populated urban centers of the United States. Because ambient fine particulate matter (aerodynamic diameter {<=} 2.5 {mu}m; PM2.5) is a complex mixture resulting from multiple sources and variable atmospheric conditions, it is difficult to identify specific components of PM2.5 that are responsible for adverse health effects. During four consecutive summers from 2000 to 2003 we characterized the ambient gaseous and PM2.5 air quality in an urban southwest Detroit community where childhood asthma hospitalization rates are more than twice the statewide average. Both integrated and continuous PM measurements together with gaseous air pollution measurements were performed using a mobile air research facility, AirCARE1, in which concurrent toxicological studies were being conducted. Chemical and physical characterizations of PM2.5 as well as receptor modeling using positive matrix factorization (PMF) were completed. Results from PMF indicated that six major sources contributed to the observed ambient PM2.5 mass during the summer months. Primary sources included (1) coal combustion/secondary sulfate aerosol, (2) motor vehicle/urban road dust, (3) municipal waste incinerators, (4) oil combustion/refineries, (5) sewage sludge incinerators, and (6) iron/steel manufacturing. Although the contribution of the coal/secondary sulfate aerosol source was greater than other factors, increased levels of urban PM2.5 from local combustion sources were also observed. In addition to characterization of ambient PM2.5 and their sources in southwest Detroit, this paper discusses possible associations of ambient PM2.5 from local combustion sources, specifically incinerator and refinery emissions and the observed adverse health effects during the inhalation exposure campaigns.

  10. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    International Nuclear Information System (INIS)

    Vargas-García, María del Carmen; López, María José; Suárez-Estrella, Francisca; Moreno, Joaquín

    2012-01-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: ► Composting is a good reservoir for the isolation of HM-resistant microorganisms. ► Pb was the most removed heavy metal in multi-polluted aqueous systems. ► Intracellular accumulation was the predominant mechanism for heavy metal removal. ► Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  11. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Garcia, Maria del Carmen, E-mail: mcvargas@ual.es; Lopez, Maria Jose, E-mail: mllopez@ual.es; Suarez-Estrella, Francisca, E-mail: fsuarez@ual.es; Moreno, Joaquin, E-mail: jcasco@ual.es

    2012-08-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: Black-Right-Pointing-Pointer Composting is a good reservoir for the isolation of HM-resistant microorganisms. Black-Right-Pointing-Pointer Pb was the most removed heavy metal in multi-polluted aqueous systems. Black-Right-Pointing-Pointer Intracellular accumulation was the predominant mechanism for heavy metal removal. Black-Right-Pointing-Pointer Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  12. Study of Selected Metals Distribution, Source Apportionment, and Risk Assessment in Suburban Soil, Pakistan

    OpenAIRE

    Iqbal, Javed; Shah, Munir H.

    2015-01-01

    Composite soil samples collected from suburban areas were analyzed for Cd, Co, Cr, Cu, Fe, Mn, Pb, Sr, and Zn by atomic absorption spectrophotometry. Based on pseudototal metal analysis, Fe, Mn, Sr, and Zn were the prevailing metals while Cd, Co, Cr, and Pb were the least participants. However, based on bioavailability, Cd, Co, Pb, and Sr were easily leachable and might pose adverse effects to soil biota. In ecological risk assessment, contamination factor demonstrated moderate contamination ...

  13. Assessment of soil contamination with Cd, Pb and Zn and source identification in the area around the Huludao Zinc Plant

    International Nuclear Information System (INIS)

    Lu, C.A.; Zhang, J.F.; Jiang, H.M.; Yang, J.C.; Zhang, J.T.; Wang, J.Z.; Shan, H.X.

    2010-01-01

    The distribution characteristics of heavy metals (cadmium (Cd), lead (Pb) and zinc (Zn)) in the natural soil profiles around the Huludao Zinc Plant (HZP), an old industrial base in Northeast China, were analyzed. The pollutant source was identified using 210 Pb isotope technique to evaluate the geochemical characteristics of Pb and the historical production records of HZP. The results indicated: dust precipitation from HZP was the primary source of the pollutants. The average deposition rates of Cd, Pb and Zn were 0.33, 1.75, and 30.97 g/m 2 year, respectively at 1 km away after HZP, and 0.0048, 0.035, and 0.20 g/m 2 year, respectively at 10 km away after HZP. There is a risk of secondary pollution to the environment as well as the food chain in seriously polluted areas used for cultivation.

  14. Assessment of soil contamination with Cd, Pb and Zn and source identification in the area around the Huludao Zinc Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lu, C.A.; Zhang, J.F.; Jiang, H.M. [Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences,100081 Beijing (China); Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, 100081 Beijing (China); Yang, J.C., E-mail: yangjch@263.net [Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences,100081 Beijing (China) and Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, 100081 Beijing (China); Zhang, J.T.; Wang, J.Z.; Shan, H.X. [Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 100081 Beijing (China); Graduate School of Chinese Academy of Agricultural Sciences,100081 Beijing (China)

    2010-10-15

    The distribution characteristics of heavy metals (cadmium (Cd), lead (Pb) and zinc (Zn)) in the natural soil profiles around the Huludao Zinc Plant (HZP), an old industrial base in Northeast China, were analyzed. The pollutant source was identified using {sup 210}Pb isotope technique to evaluate the geochemical characteristics of Pb and the historical production records of HZP. The results indicated: dust precipitation from HZP was the primary source of the pollutants. The average deposition rates of Cd, Pb and Zn were 0.33, 1.75, and 30.97 g/m{sup 2} year, respectively at 1 km away after HZP, and 0.0048, 0.035, and 0.20 g/m{sup 2} year, respectively at 10 km away after HZP. There is a risk of secondary pollution to the environment as well as the food chain in seriously polluted areas used for cultivation.

  15. Final report of the IAEA advisory group meeting on accelerator-based nuclear analytical techniques for characterization and source identification of aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The field of aerosol characterization and source identification covers a wide range of scientific and technical activities in many institutions, in both developed and developing countries. This field includes research and applications on urban air pollution, source apportionment of suspended particulate matter, radioactive aerosol particles, organic compounds carried on particulate matter, elemental characterization of particles, and other areas. The subject of this AGM focused on the use of accelerator-based nuclear analytical techniques for determination of elemental composition of particles (by either bulk or single particle analysis) and the use of accumulated knowledge for source identification.

  16. Final report of the IAEA advisory group meeting on accelerator-based nuclear analytical techniques for characterization and source identification of aerosol particles

    International Nuclear Information System (INIS)

    1995-01-01

    The field of aerosol characterization and source identification covers a wide range of scientific and technical activities in many institutions, in both developed and developing countries. This field includes research and applications on urban air pollution, source apportionment of suspended particulate matter, radioactive aerosol particles, organic compounds carried on particulate matter, elemental characterization of particles, and other areas. The subject of this AGM focused on the use of accelerator-based nuclear analytical techniques for determination of elemental composition of particles (by either bulk or single particle analysis) and the use of accumulated knowledge for source identification

  17. Minor metals and renewable energy—Diversifying America’s energy sources

    Science.gov (United States)

    Singerling, Sheryl A.; Nassar, Nedal T.

    2017-08-16

    Solar photovoltaic (PV) and wind turbine technologies are projected to make up an increasing proportion of electricity generation capacity in the United States in the coming decades. By 2050, they will account for 36 percent (or 566 gigawatts) of capacity compared with about 11 percent (or 118 gigawatts) in 2016 (fig. 1; EIA, 2017). There are several different types of commercial solar PV and wind turbine technologies, and each type makes use of different minor metals. “Minor metal” is the term used for metals for which world production is small compared with the more widely produced base metals, and they are often produced as byproducts of the mining or processing of base metals. Minor metals used in renewable energy technologies often have complex supply chains, are often produced primarily outside of the United States, and are also used in many other applications. A larger amount of minor metals will be needed in the future to support the projected increases in solar PV and wind energy production capacity (Nassar and others, 2016).

  18. Lead isotopes and trace metal ratios of aerosols as tracers of Pb pollution sources in Kanpur, India

    Science.gov (United States)

    Sen, Indra; Bizimis, Michael; Tripathi, Sachchida; Paul, Debajyoti; Tyagi, Swati; Sengupta, Deep

    2015-04-01

    The anthropogenic flux of Pb in the Earth's surface is almost an order of magnitude higher than its corresponding natural flux [1]. Identifying the sources and pathways of anthropogenic Pb in environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb- isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, an industrial city in northern India. The Pb concentration in the airborne particulate matter varies between 14-216 ng/m3, while the other heavy metals vary by factor of 10 or less, e.g. Cd=0.3-3 ng/m3, As=0.4-3.5 ng/m3, Zn=36-161 ng/m3, and Cu=3-22 ng/m3. The 206Pb/207Pb, 208Pb/206Pb, and 208Pb/207Pb vary between 1.112 - 1.129, 2.123-2.141, and 2.409-2.424 respectively, and are highly correlated with each other (R2>0.9). Pb isotopes and trace metal data reveals that coal combustion is the major source of anthropogenic Pb in the atmosphere, with limited contribution from mining and smelting processes. We further conclude that combination of Pb isotope ratios and V/Pb ratios are powerful tracers for Pb source apportionment studies, which is otherwise difficult to differentiate based only on Pb systematics [1] Sen and Peucker-Ehrenbrink (2012), Environ. Sci. Technol.(46), 8601-8609

  19. An Analysis of Air Pollution in Makkah - a View Point of Source Identification

    Directory of Open Access Journals (Sweden)

    Turki M. Habeebullah

    2013-07-01

    Full Text Available Makkah is one of the busiest cities in Saudi Arabia and remains busy all year around, especially during the season of Hajj and the month of Ramadan when millions of people visit this city. This emphasizes the importance of clean air and of understanding the sources of various air pollutants, which is vital for the management and advanced modeling of air pollution. This study intends to identify the major sources of air pollutants in Makkah, near the Holy Mosque (Al-Haram using a graphical approach. Air pollutants considered in this study are nitrogen oxides (NOx, nitrogen dioxide (NO2, nitric oxide (NO, carbon monoxide (CO, sulphur dioxide (SO2, ozone (O3 and particulate matter with aero-dynamic diameter of 10 um or less (PM10. Polar plots, time variation plots and correlation analysis are used to analyse the data and identify the major sources of emissions. Most of the pollutants demonstrate high concentrations during the morning traffic peak hours, suggesting road traffic as the main source of emission. The main sources of pollutant emissions identified in Makkahwere road traffic, re-suspended and windblown dust and sand particles. Further investigation on detailedsource apportionment is required, which is part of the ongoing project.

  20. Identification of Pollution Patterns and Sources in a Semi-Arid Urban Stream

    Directory of Open Access Journals (Sweden)

    Vassiliki Markogianni

    2018-03-01

    Full Text Available The impact and occurrence of human-induced pollution sources have been investigated in one of the few remaining urban streams located in Attica, Greece. Baseline information is provided on the presence and concentration of physicochemical parameters, nutrients, total coliforms, hydrocarbons and phenols in 12 key points along the Pikrodafni stream. The aim was to evaluate the relative importance of key water quality variables and their sources. Indicator substances (i.e. concentrations of nitrate, ammonium, phosphate and total coliforms in certain stations indicating wastewater exposure; PAHs indicating petroleum sources successfully related the water quality variables to pollution sources. Furthermore, a pollution pressure map has been developed with the activities identified from in-situ visits and Google Earth surveys, while the statistical analysis (CA and PCA has contributed to the further exploration of the relative magnitude of pollution sources effects. Our results underline initially the importance of diffuse pollution management accompanied by the necessity for continuous environmental monitoring and the application of legal and environmental restoration actions if water quality is to be improved according to WFD 2000/60/EC.

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

    Science.gov (United States)

    Chimidza, S.; Moloi, K.

    2000-07-01

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

  2. Source Identification and Apportionment of Trace Elements in Soils in the Yangtze River Delta, China.

    Science.gov (United States)

    Shao, Shuai; Hu, Bifeng; Fu, Zhiyi; Wang, Jiayu; Lou, Ge; Zhou, Yue; Jin, Bin; Li, Yan; Shi, Zhou

    2018-06-12

    Trace elements pollution has attracted a lot of attention worldwide. However, it is difficult to identify and apportion the sources of multiple element pollutants over large areas because of the considerable spatial complexity and variability in the distribution of trace elements in soil. In this study, we collected total of 2051 topsoil (0⁻20 cm) samples, and analyzed the general pollution status of soils from the Yangtze River Delta, Southeast China. We applied principal component analysis (PCA), a finite mixture distribution model (FMDM), and geostatistical tools to identify and quantitatively apportion the sources of seven kinds of trace elements (chromium (Cr), cadmium (Cd), mercury (Hg), copper (Cu), zinc (Zn), nickel (Ni), and arsenic (As)) in soil. The PCA results indicated that the trace elements in soil in the study area were mainly from natural, multi-pollutant and industrial sources. The FMDM also fitted three sub log-normal distributions. The results from the two models were quite similar: Cr, As, and Ni were mainly from natural sources caused by parent material weathering; Cd, Cu, and Zu were mainly from mixed sources, with a considerable portion from anthropogenic activities such as traffic pollutants, domestic garbage, and agricultural inputs, and Hg was mainly from industrial wastes and pollutants.

  3. Dust Storm over the Middle East: Retrieval Approach, Source Identification, and Trend Analysis

    Science.gov (United States)

    Moridnejad, A.; Karimi, N.; Ariya, P. A.

    2014-12-01

    The Middle East region has been considered to be responsible for approximately 25% of the Earth's global emissions of dust particles. By developing Middle East Dust Index (MEDI) and applying to 70 dust storms characterized on MODIS images and occurred during the period between 2001 and 2012, we herein present a new high resolution mapping of major atmospheric dust source points participating in this region. To assist environmental managers and decision maker in taking proper and prioritized measures, we then categorize identified sources in terms of intensity based on extracted indices for Deep Blue algorithm and also utilize frequency of occurrence approach to find the sensitive sources. In next step, by implementing the spectral mixture analysis on the Landsat TM images (1984 and 2012), a novel desertification map will be presented. The aim is to understand how human perturbations and land-use change have influenced the dust storm points in the region. Preliminary results of this study indicate for the first time that c.a., 39 % of all detected source points are located in this newly anthropogenically desertified area. A large number of low frequency sources are located within or close to the newly desertified areas. These severely desertified regions require immediate concern at a global scale. During next 6 months, further research will be performed to confirm these preliminary results.

  4. Identification of tropospheric emissions sources from satellite observations: Synergistic use of HCHO, NO2, and SO2 trace gas measurements

    Science.gov (United States)

    Marbach, T.; Beirle, S.; Khokhar, F.; Platt, U.

    2005-12-01

    We present case studies for combined HCHO, NO2, and SO2 satellite observations, derived from GOME measurements. Launched on the ERS-2 satellite in April 1995, GOME has already performed continuous operations over 8 years providing global observations of the different trace gases. In this way, satellite observations provide unique opportunities for the identifications of trace gas sources. The satellite HCHO observations provide information concerning the localization of biomass burning (intense source of HCHO). The principal biomass burning areas can be observed in the Amazon basin region and in central Africa Weaker HCHO sources (south east of the United States, northern part of the Amazon basin, and over the African tropical forest), not correlated with biomass burning, could be due to biogenic isoprene emissions. The HCHO data can be compared with NO2 and SO2 results to identify more precisely the tropospheric sources (biomass burning events, human activities, additional sources like volcanic emissions). Biomass burning are important tropospheric sources for both HCHO and NO2. Nevertheless HCHO reflects more precisely the biomass burning as it appears in all biomass burning events. NO2 correlate with HCHO over Africa (grassland fires) but not over Indonesia (forest fires). In south America, an augmentation of the NO2 concentrations can be observed with the fire shift from the forest to grassland vegetation. So there seems to be a dependence between the NO2 emissions during biomass burning and the vegetation type. Other high HCHO, SO2, and NO2 emissions can be correlated with climatic events like the El Nino in 1997, which induced dry conditions in Indonesia causing many forest fires.

  5. Impact of the diagnostic process on the accuracy of source identification and time to antibiotics in septic emergency department patients.

    Science.gov (United States)

    Uittenbogaard, Annemieke J M; de Deckere, Ernie R J T; Sandel, Maro H; Vis, Alice; Houser, Christine M; de Groot, Bas

    2014-06-01

    Timely administration of effective antibiotics is important in sepsis management. Source-targeted antibiotics are believed to be most effective, but source identification could cause time delays. First, to describe the accuracy/time delays of a diagnostic work-up and the association with time to antibiotics in septic emergency department (ED) patients. Second, to assess the fraction in which source-targeted antibiotics could have been administered solely on the basis of patient history and physical examination. Secondary analysis of the prospective observational study on septic ED patients was carried out. The time to test result availability was associated with time to antibiotics. The accuracy of the suspected source of infection in the ED was assessed. For patients with pneumosepsis, urosepsis, and abdominal sepsis, combinations of signs and symptoms were assessed to achieve a maximal positive predictive value for the sepsis source, identifying a subset of patients in whom source-targeted antibiotics could be administered without waiting for diagnostic test results. The time to antibiotics increased by 18 (95% confidence interval: 12-24) min/h delay in test result availability (n=323). In 38-79% of patients, antibiotics were administered after additional tests, whereas the ED diagnosis was correct in 68-85% of patients. The maximal positive predictive value of signs and symptoms was 0.87 for patients with pneumosepsis and urosepsis and 0.75 for those with abdominal sepsis. Use of signs and symptoms would have led to correct ED diagnosis in 33% of patients. Diagnostic tests are associated with delayed administration of antibiotics to septic ED patients while increasing the diagnostic accuracy to only 68-85%. In one-third of septic ED patients, the choice of antibiotics could have been accurately determined solely on the basis of patient history and physical examination.

  6. Combined sensors for the detection, identification and monitoring of radiation sources

    International Nuclear Information System (INIS)

    Yaar, I.

    2006-01-01

    Radiation sources widely used in industry, medicine, agriculture. Research and education are the most dangerous from the viewpoint of their widespread and easy access.The probability that these sources will be stolen and used to assemble a radiological dispersive (RDD) is nor negligible. Such a device can be used by terrorist groups for the purpose of contamination of industrial centers, airports, seaports and residential areas, which can affect a large sector of the economy of a country. Detonation of a RDD can lead to death and exposure of the population to radiation, but, as a whole, the use of the bomb is aimed at creating panic among population, causing economic damage and social shock to the society. In this work, ways to reduce the threat of radiation sources obtained outside and within a country will be discussed

  7. Source identification of hydrocarbon contaminants and their transportation over the Zonguldak shelf, Turkish Black Sea

    Science.gov (United States)

    Unlu, S.; Alpar, B.

    2009-04-01

    Under great anthropogenic pressure due to the substantial freshwater input from the surrounding industrial and agricultural areas, especially central and middle-Eastern Europe, the Black Sea basin is ranked among the most ecologically threatened water bodies of the world. Oil levels are unacceptable in many coastal areas perilously close to polluted harbors and many river mouths; the places presenting the highest levels of bio-diversity and having a high socio-economic importance due to human use of coastal resources. There are about sixty sources of pollution which resulted in "hot spots" having disastrous impacts on sensitive marine and coastal areas and needing immediate priorities for action. Beyond such land-based sources, trans-boundary pollution sources from Black Sea riparian countries, heavy maritime traffic, particularly involving petroleum transports and fishing boats, and the improper disposal of ballast and bilge waters and solid waste are also important marine sources of pollution. Found in fossil fuels such as Polycyclic Aromatic Hydrocarbons are generated by incomplete combustion of organic matter. In order to estimate their distribution in sediment and their sources, they were monitored from the bottom samples offshore the Zonguldak industry region, one of the most polluted spots in the Turkish Black Sea. There the budget of pollutants via rivers is not precisely known due to an evident lack of data on chemical and granulometric composition of the river runoff and their fluxes. Therefore the marine sediments, essential components of marine ecosystems, are very important in our estimating the degree of the damage given to the ecosystem by such inputs. Realization of the sources and transport of these contaminants will be a critical tool for future management of the Zonguldak industry region and its watershed. The sea bottom in study area is composed of mainly sand and silt mixtures with small amount of clay. Geochemical analyses have shown that oil

  8. Glyphosate Utilization as the Source of Carbon: Isolation and Identification of new Bacteria

    Directory of Open Access Journals (Sweden)

    M. Mohsen Nourouzi

    2011-01-01

    Full Text Available Mixed bacteria from oil palm plantation soil (OPS were isolated to investigate their ability to utilize glyphosate as carbon source. Results showed that approximately all of the glyphosate was converted to aminomethyl-phosphonic acid (AMPA (99.5%. It is worthy to note that mixed bacteria were able to degrade only 2% of AMPA to further metabolites. Two bacterial strains i.e. Stenotrophomonas maltophilia and Providencia alcalifaciens were obtained from enrichment culture. Bacterial isolates were cultured individually on glyphosate as a sole carbon source. It was observed that both isolates were able to convert glyphosate to AMPA.

  9. Bio aerosol Generation at wastewater treatment plants: Identification of main bio aerosols sources

    International Nuclear Information System (INIS)

    Sanchez Monedero, M. A.; Aguilar, M. I.; Fenoll, R.; Roig, A.

    2009-01-01

    Typical operations taking place at wastewater treatment plants, especially those involving aeration and mechanical agitation of raw wastewater, represent one of the main sources of bio aerosols that, if inhaled, could pose a biologic hazard to site workers and local residents. Six different wastewater treatment plants from southeast Spain were monitories in order to identify the main bio aerosol sources and to evaluate the airborne microorganisms levels to which workers may be exposed to. Air samples were taken from selected locations by using a single stage impactor. (Author)

  10. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China.

    Science.gov (United States)

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-12-11

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index I(geo) and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. I(geo) classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes.

  11. Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina

    International Nuclear Information System (INIS)

    Wannaz, Eduardo D.; Carreras, Hebe A.; Perez, Carlos A.; Pignata, Maria L.

    2006-01-01

    The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n = 38) were chosen in the province of Cordoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies

  12. Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Wannaz, Eduardo D. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina); Carreras, Hebe A. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina); Perez, Carlos A. [Laboratorio Nacional de Luz Sincrotron - LNLS/CNPq, Caixa Postal 6192, 13038-970 Campinas (Brazil); Pignata, Maria L. [Departamento de Quimica, Instituto Multidisciplinario de Biologia Vegetal - IMBIV/CONICET-UNC, Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, Ciudad Universitaria (X5016GCA) Cordoba (Argentina)]. E-mail: pignata@com.uncor.edu

    2006-05-15

    The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n = 38) were chosen in the province of Cordoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies.

  13. Identification of a time-varying point source in a system of two coupled linear diffusion-advection- reaction equations: application to surface water pollution

    International Nuclear Information System (INIS)

    Hamdi, Adel

    2009-01-01

    This paper deals with the identification of a point source (localization of its position and recovering the history of its time-varying intensity function) that constitutes the right-hand side of the first equation in a system of two coupled 1D linear transport equations. Assuming that the source intensity function vanishes before reaching the final control time, we prove the identifiability of the sought point source from recording the state relative to the second coupled transport equation at two observation points framing the source region. Note that at least one of the two observation points should be strategic. We establish an identification method that uses these records to identify the source position as the root of a continuous and strictly monotonic function. Whereas the source intensity function is recovered using a recursive formula without any need of an iterative process. Some numerical experiments on a variant of the surface water pollution BOD–OD coupled model are presented

  14. Identification and quantification of point sources of surface water contamination in fruit culture in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Beltman, W.H.J.; Werd, de H.A.E.; Zande, van de J.C.

    2008-01-01

    Measurements of pesticide concentrations in surface water by the water boards show that they have decreased less than was expected from model calculations. Possibly, the implementation of spray drift reducing techniques is overestimated in the model calculation. The impact of point sources is

  15. Identification of Watershed-scale Critical Source Areas Using Bayesian Maximum Entropy Spatiotemporal Analysis

    Science.gov (United States)

    Roostaee, M.; Deng, Z.

    2017-12-01

    The states' environmental agencies are required by The Clean Water Act to assess all waterbodies and evaluate potential sources of impairments. Spat