WorldWideScience

Sample records for sample source in-state

  1. Geochemical evidence for diversity of dust sources in the southwestern United States

    Science.gov (United States)

    Reheis, M.C.; Budahn, J.R.; Lamothe, P.J.

    2002-01-01

    Several potential dust sources, including generic sources of sparsely vegetated alluvium, playa deposits, and anthropogenic emissions, as well as the area around Owens Lake, California, affect the composition of modern dust in the southwestern United States. A comparison of geochemical analyses of modern and old (a few thousand years) dust with samples of potential local sources suggests that dusts reflect four primary sources: (1) alluvial sediments (represented by Hf, K, Rb, Zr, and rare-earth elements, (2) playas, most of which produce calcareous dust (Sr, associated with Ca), (3) the area of Owens (dry) Lake, a human-induced playa (As, Ba, Li, Pb, Sb, and Sr), and (4) anthropogenic and/or volcanic emissions (As, Cr, Ni, and Sb). A comparison of dust and source samples with previous analyses shows that Owens (dry) Lake and mining wastes from the adjacent Cerro Gordo mining district are the primary sources of As, Ba, Li, and Pb in dusts from Owens Valley. Decreases in dust contents of As, Ba, and Sb with distance from Owens Valley suggest that dust from southern Owens Valley is being transported at least 400 km to the east. Samples of old dust that accumulated before European settlement are distinctly lower in As, Ba, and Sb abundances relative to modern dust, likely due to modern transport of dust from Owens Valley. Thus, southern Owens Valley appears to be an important, geochemically distinct, point source for regional dust in the southwestern United States. Copyright ?? 2002 Elsevier Science Ltd.

  2. Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  3. Spatial Variability of Sources and Mixing State of Atmospheric Particles in a Metropolitan Area.

    Science.gov (United States)

    Ye, Qing; Gu, Peishi; Li, Hugh Z; Robinson, Ellis S; Lipsky, Eric; Kaltsonoudis, Christos; Lee, Alex K Y; Apte, Joshua S; Robinson, Allen L; Sullivan, Ryan C; Presto, Albert A; Donahue, Neil M

    2018-05-30

    Characterizing intracity variations of atmospheric particulate matter has mostly relied on fixed-site monitoring and quantifying variability in terms of different bulk aerosol species. In this study, we performed ground-based mobile measurements using a single-particle mass spectrometer to study spatial patterns of source-specific particles and the evolution of particle mixing state in 21 areas in the metropolitan area of Pittsburgh, PA. We selected sampling areas based on traffic density and restaurant density with each area ranging from 0.2 to 2 km 2 . Organics dominate particle composition in all of the areas we sampled while the sources of organics differ. The contribution of particles from traffic and restaurant cooking varies greatly on the neighborhood scale. We also investigate how primary and aged components in particles mix across the urban scale. Lastly we quantify and map the particle mixing state for all areas we sampled and discuss the overall pattern of mixing state evolution and its implications. We find that in the upwind and downwind of the urban areas, particles are more internally mixed while in the city center, particle mixing state shows large spatial heterogeneity that is mostly driven by emissions. This study is to our knowledge, the first study to perform fine spatial scale mapping of particle mixing state using ground-based mobile measurement and single-particle mass spectrometry.

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  5. Source-dependent and source-independent controls on plutonium oxidation state and colloid associations in groundwater.

    Science.gov (United States)

    Buesseler, Ken O; Kaplan, Daniel I; Dai, Minhan; Pike, Steven

    2009-03-01

    Plutonium (Pu) was characterized for its isotopic composition, oxidation states, and association with colloids in groundwater samples near disposal basins in F-Area of the Savannah River Site and compared to similar samples collected six years earlier. Two sources of Pu were identified, the disposal basins, which contained a 24Pu/l39Pu isotopic signature consistent with weapons grade Pu, and 244Cm, a cocontaminant that is a progenitor radionuclide of 24Pu. 24Pu that originated primarily from 244Cm tended to be appreciably more oxidized (Pu(V/VI)), less associated with colloids (approximately 1 kDa - 0.2 microm), and more mobile than 239Pu, as suggested by our prior studies at this site. This is not evidence of isotope fractionation but rather "source-dependent" controls on 240Pu speciation which are processes that are not at equilibrium, i.e., processes that appear kinetically hindered. There were also "source-independent" controls on 239Pu speciation, which are those processes that follow thermodynamic equilibrium with their surroundings. For example, a groundwater pH increase in one well from 4.1 in 1998 to 6.1 in 2004 resulted in an order of magnitude decrease in groundwater 239Pu concentrations. Similarly, the fraction of 239Pu in the reduced Pu(III/IV) and colloidal forms increased systematically with decreases in redox condition in 2004 vs 1998. This research demonstrates the importance of source-dependent and source-independent controls on Pu speciation which would impact Pu mobility during changes in hydrological, chemical, or biological conditions on both seasonal and decadal time scales, and over short spatial scales. This implies more dynamic shifts in Pu speciation, colloids association, and transport in groundwater than commonly believed.

  6. Stratified source-sampling techniques for Monte Carlo eigenvalue analysis

    International Nuclear Information System (INIS)

    Mohamed, A.

    1998-01-01

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

  7. Quality of Source Water from Public-Supply Wells in the United States, 1993-2007

    Science.gov (United States)

    Toccalino, Patricia L.; Norman, Julia E.; Hitt, Kerie J.

    2010-01-01

    More than one-third of the Nation's population receives their drinking water from public water systems that use groundwater as their source. The U.S. Geological Survey (USGS) sampled untreated source water from 932 public-supply wells, hereafter referred to as public wells, as part of multiple groundwater assessments conducted across the Nation during 1993-2007. The objectives of this study were to evaluate (1) contaminant occurrence in source water from public wells and the potential significance of contaminant concentrations to human health, (2) national and regional distributions of groundwater quality, and (3) the occurrence and characteristics of contaminant mixtures. Treated finished water was not sampled. The 932 public wells are widely distributed nationally and include wells in selected parts of 41 states and withdraw water from parts of 30 regionally extensive aquifers used for public water supply. These wells are distributed among 629 unique public water systems-less than 1 percent of all groundwater-supplied public water systems in the United States-but the wells were randomly selected within the sampled hydrogeologic settings to represent typical aquifer conditions. Samples from the 629 systems represent source water used by one-quarter of the U.S. population served by groundwater-supplied public water systems, or about 9 percent of the entire U.S. population in 2008. One groundwater sample was collected prior to treatment or blending from each of the 932 public wells and analyzed for as many as six water-quality properties and 215 contaminants. Consistent with the terminology used in the Safe Drinking Water Act (SDWA), all constituents analyzed in water samples in this study are referred to as 'contaminants'. More contaminant groups were assessed in this study than in any previous national study of public wells and included major ions, nutrients, radionuclides, trace elements, pesticide compounds, volatile organic compounds (VOCs), and fecal

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

    Science.gov (United States)

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

    2017-06-01

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

  9. Sources of Malaria Information among Pregnant Women in Ebonyi State and Implications for Malaria Health Education

    Science.gov (United States)

    Amari-Omaka, Lois Nnenna; Obande-Ogbuinya, Nkiru Edith

    2016-01-01

    The purpose of this study was to determine sources of malaria information among pregnant women in Ebonyi state and implications for malaria education. The cross sectional research design was adopted and stratified sampling technique was used to select a total of five hundred and four (504) pregnant women from 12 hospitals in the state. A self…

  10. Trimethylsilyl derivatives of organic compounds in source samples and in atmospheric fine particulate matter.

    Science.gov (United States)

    Nolte, Christopher G; Schauer, James J; Cass, Glen R; Simoneit, Bernd R T

    2002-10-15

    Source sample extracts of vegetative detritus, motor vehicle exhaust, tire dust paved road dust, and cigarette smoke have been silylated and analyzed by GC-MS to identify polar organic compounds that may serve as tracers for those specific emission sources of atmospheric fine particulate matter. Candidate molecular tracers were also identified in atmospheric fine particle samples collected in the San Joaquin Valley of California. A series of normal primary alkanols, dominated by even carbon-numbered homologues from C26 to C32, the secondary alcohol 10-nonacosanol, and some phytosterols are prominent polar compounds in the vegetative detritus source sample. No new polar organic compounds are found in the motor vehicle exhaust samples. Several hydrogenated resin acids are present in the tire dust sample, which might serve as useful tracers for those sources in areas that are heavily impacted by motor vehicle traffic. Finally, the alcohol and sterol emission profiles developed for all the source samples examined in this project are scaled according to the ambient fine particle mass concentrations attributed to those sources by a chemical mass balance receptor model that was previously applied to the San Joaquin Valley to compute the predicted atmospheric concentrations of individual alcohols and sterols. The resulting underprediction of alkanol concentrations at the urban sites suggests that alkanols may be more sensitive tracers for natural background from vegetative emissions (i.e., waxes) than the high molecular weight alkanes, which have been the best previously available tracers for that source.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    2004-06-17

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

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

    Directory of Open Access Journals (Sweden)

    Fernández-Esquer Maria E

    2004-06-01

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

  14. A Multi-Sample Cs-Sputter Negative Ion Source

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  15. A Multi-Sample Cs-Sputter Negative Ion Source

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-10-05

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

  16. Open source laboratory sample rotator mixer and shaker

    Directory of Open Access Journals (Sweden)

    Karankumar C. Dhankani

    2017-04-01

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

  17. Monte Carlo stratified source-sampling

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  18. Small-angle scattering at a pulsed neutron source: comparison with a steady-state reactor

    Energy Technology Data Exchange (ETDEWEB)

    Borso, C S; Carpenter, J M; Williamson, F S; Holmblad, G L; Mueller, M H; Faber, J Jr; Epperson, J E; Danyluk, S S [Argonne National Lab., IL (USA)

    1982-08-01

    A time-of-flight small-angle diffractometer employing seven tapered collimator elements and a two-dimensional gas proportional counter was successfully utilized to collect small-angle scattering data from a solution sample of the lipid salt cetylpyridinium chloride, C/sub 21/H/sub 38/N/sup +/.Cl/sup -/, at the Argonne National Laboratory prototype pulsed spallation neutron source, ZING-P'. Comparison of the small-angle scattering observed from the same compound at the University of Missouri Research Reactor corroborated the ZING-P' results. The results are used to compare the neutron flux available from the ZING-P' source relative to the well characterized University of Missouri source. Calculations based on experimentally determined parameters indicated the time-averaged rate of detected neutrons at the ZING-P' pulsed spallation source to have been at least 33% higher than the steady-state count rate from the same sample. Differences between time-of-flight techniques and conventional steady-state techniques are discussed.

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

    Science.gov (United States)

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

    2014-05-01

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

  20. 45 CFR 265.5 - May States use sampling?

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false May States use sampling? 265.5 Section 265.5... REQUIREMENTS § 265.5 May States use sampling? (a) Each State may report the disaggregated data in the TANF Data... the use of a scientifically acceptable sampling method that we have approved. States may use sampling...

  1. Elemental contents in soil samples in Wad Hamid, River Nile State

    International Nuclear Information System (INIS)

    Mohammed, Khansaa Elawad Elhag

    2016-03-01

    In the present study a total of 30 samples were collected from Wad Hamid River Nile State. Sampling area of (two feddan) of agricultural soil. The sampling area was divided in two locations (fertile and non fertile soil). The samples were analyzed for their content of 13 elements (K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, Y, Zr, and Np). 10 samples from location 1 (non-fertile soil) and 20 samples from location 2 (fertile soil). X-ray fluorescence (X RF) Spectrometer (system used based on 1"0"9"Cd excitation 1"0"9"Cd source which has an average energy of 22.6 kev and able to excite the elements from Z = 13 to 92 using K and L lines) used to identify the elemental concentration in soil samples. The reliability of X RF technique as multi elements detecting method for measuring elements concentration in soil sample , (IAEA-SOIL-7) standard reference material was used. Measured values found in agreement with the certified values. The average elemental concentration of K,Ca, Ti, Fe, Cu, Zn, Pb, Sr, Y, Zr, and Np in location 1 were 878, 29690, 13400, 983, 70380, 10.07, 19.07, 40.92,261.4, 23.59,294.8, 47.82, while the average elemental concentration in location 2 were 9848, 27780, 13076,13076,989, 68135, 9.6, 96.3 19.86, 43.7, 225.5, 22.49, 284.75, 46.15, respectively. comparison between the average elemental concentration in fertile soil and non-fertile was done correlations between element were performed Cluster analyses of element in soil samples were obtained comparison between this study and data from literature were done. The elemental concentration in location 1 (non- fertile soil) are higher than location 2 ( fertile soil) because the plant absorbed fertilizer of soil and transfer most elements in soil to plant. (Author)

  2. Other Sources of Animal Protein in Ogun State, Nigeria | Taiwo ...

    African Journals Online (AJOL)

    Inadequate animal protein intake is widely orchestrated among Nigerians especially Ogun State indigenes. This led to investigating other sources of animal protein in the rural and suburban areas of the state that could bridge inadequate supply from the conventional sources of animal protein. Structured questionnaires ...

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

    Science.gov (United States)

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

    2009-10-01

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

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

    Directory of Open Access Journals (Sweden)

    David P. Griesheimer

    2017-09-01

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

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

    Science.gov (United States)

    Harper, S L; Gutknecht, W F

    2001-06-01

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

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

    International Nuclear Information System (INIS)

    Soltan, A.

    1978-01-01

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

  7. ANALYSIS OF A STATE CHANGING SUPERSOFT X-RAY SOURCE IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Patel, B. [Department of Physics and Astronomy Rutgers, State University of New Jersey, Piscataway, NJ 08854-8019 (United States); Di Stefano, R.; Primini, F. A.; Liu, J.; Scoles, S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Nelson, T. [Department of Physics, 1000 Hilltop Circle, University of Maryland at Baltimore, Baltimore, MD 21250 (United States)

    2013-07-01

    We report on observations of a luminous supersoft X-ray source (SSS) in M31, r1-25, that has exhibited spectral changes to harder X-ray states. We document these spectral changes. In addition, we show that they have important implications for modeling the source. Quasisoft states in a source that has been observed as an SSS represent a newly discovered phenomenon. We show how such state changers could prove to be examples of unusual black hole or neutron star accretors. Future observations of this and other state changers can provide the information needed to determine the nature(s) of these intriguing new sources.

  8. Investigation of Pseudo-Active State in Z-Source Inverter

    DEFF Research Database (Denmark)

    Schaltz, Erik; Oprea, Octavian; Larsen, Lasse

    2005-01-01

    This paper introduces a new operating state of the Z-source inverter denoted the pseudo-active state. The pseudoactive state is a state that may boost the output voltage of the Zsource inverter to a level higher than expected. The influence of the pseudo-active state is investigated and an equation...

  9. Preparation of in-house calibration source for the use in radioactivity analysis of the environmental samples. Consideration of homogeneity

    International Nuclear Information System (INIS)

    Aba, A.; Ismaeel, A.

    2013-01-01

    An in-house reference material has been prepared in Kuwait Institute for Scientific Research radioecology laboratory, for quality control purposes of gamma spectrometer systems. The material contains a known amount of uranium ore reference material (prepared by the International Atomic Energy Agency and coded as IAEA-RGU-1) which is mixed with marine sediment collected from Kuwait bay. The IAEA-RGU-1 has been certified that it is in equilibrium state with the decay daughters, and stable to be used for quality control purposes. Nevertheless, the homogeneous distribution of the doped material with the prepared source should be verified. This has been examined using gamma spectrometry measurements in conjunction with analysis of variance statistical tools, Dixon, box plots and Grubbs tests. The calculated total uncertainty has been utilized to establish the recommended specific activity ranges of 226 Ra, 224 Th, 214 Pb, 214 Bi and 210 Pb radioisotopes in the prepared source. The obtained results showed that the estimated uncertainty arising from the sample inhomogeneity has a significant contribution in the total uncertainty. The stability control charts of the ultra-low background gamma spectrometry system demonstrated the suitability of the prepared material for the purpose of quality control. However, the emitted gamma-rays from the prepared source covers the required energy range for determination of natural and artificial radionuclides in different species of environmental samples such as marine sediment, soil samples, and samples contaminated by naturally occurring radioactive material produced by oil industry. In addition, the material might be used for system calibration in case its traceability is proven. The experimental data revealed the significance of the homogeneity in preparing environmental samples for radioactivity measurements; in particular when small sample quantities of environmental samples are required to be analyzed. (author)

  10. Factors associated with sources, transport, and fate of volatile organic compounds and their mixtures in aquifers of the United States

    Science.gov (United States)

    Squillace, P.J.; Moran, M.J.

    2007-01-01

    Factors associated with sources, transport, and fate of volatile organic compounds (VOCs) in groundwater from aquifers throughout the United States were evaluated using statistical methods. Samples were collected from 1631 wells throughout the conterminous United States between 1996 and 2002 as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. Water samples from wells completed in aquifers used to supply drinking water were analyzed for more than 50 VOCs. Wells were primarily rural domestic water supplies (1184), followed by public water supplies (216); the remaining wells (231) supplied a variety of uses. The median well depth was 50 meters. Age-date information shows that about 60% of the samples had a fraction of water recharged after 1953. Chloroform, toluene, 1,2,4-trimethylbenzene, and perchloroethene were some of the frequently detected VOCs. Concentrations generally were less than 1 ??g/L. Source factors include, in order of importance, general land-use activity, septic/sewer density, and sites where large concentrations of VOCs are potentially released, such as leaking underground storage tanks. About 10% of all samples had VOC mixtures that were associated with concentrated sources; 20% were associated with dispersed sources. Important transport factors included well/screen depth, precipitation/groundwater recharge, air temperature, and various soil characteristics. Dissolved oxygen was strongly associated with VOCs and represents the fate of many VOCs in groundwater. Well type (domestic or public water supply) was also an important explanatory factor. Results of multiple analyses show the importance of (1) accounting for both dispersed and concentrated sources of VOCs, (2) measuring dissolved oxygen when sampling wells to help explain the fate of VOCs, and (3) limiting the type of wells sampled in monitoring networks to avoid unnecessary variance in the data, or controlling for this variance during data analysis.

  11. Urban Water Services in Fragile States: An Analysis of Drinking Water Sources and Quality in Port Harcourt, Nigeria, and Monrovia, Liberia

    Science.gov (United States)

    Kumpel, Emily; Albert, Jeff; Peletz, Rachel; de Waal, Dominick; Hirn, Maximilian; Danilenko, Alexander; Uhl, Vincent; Daw, Ashish; Khush, Ranjiv

    2016-01-01

    Establishing and maintaining public water services in fragile states is a significant development challenge. In anticipation of water infrastructure investments, this study compares drinking water sources and quality between Port Harcourt, Nigeria, and Monrovia, Liberia, two cities recovering from political and economic instability. In both cities, access to piped water is low, and residents rely on a range of other private and public water sources. In Port Harcourt, geographic points for sampling were randomly selected and stratified by population density, whereas in Monrovia, locations for sampling were selected from a current inventory of public water sources. In Port Harcourt, the sampling frame demonstrated extensive reliance on private boreholes and a preference, in both planned and unplanned settlements, for drinking bottled and sachet water. In Monrovia, sample collection focused on public sources (predominantly shallow dug wells). In Port Harcourt, fecal indicator bacteria (FIB) were detected in 25% of sources (N = 566), though concentrations were low. In Monrovia, 57% of sources contained FIB and 22% of sources had nitrate levels that exceeded standards (N = 204). In Monrovia, the convenience of piped water may promote acceptance of the associated water tariffs. However, in Port Harcourt, the high prevalence of self-supply and bottled and sachet drinking water suggests that the consumer's willingness to pay for ongoing municipal water supply improvements may be determined by service reliability and perceptions of water quality. PMID:27114291

  12. Challenges with secondary use of multi-source water-quality data in the United States

    Science.gov (United States)

    Sprague, Lori A.; Oelsner, Gretchen P.; Argue, Denise M.

    2017-01-01

    Combining water-quality data from multiple sources can help counterbalance diminishing resources for stream monitoring in the United States and lead to important regional and national insights that would not otherwise be possible. Individual monitoring organizations understand their own data very well, but issues can arise when their data are combined with data from other organizations that have used different methods for reporting the same common metadata elements. Such use of multi-source data is termed “secondary use”—the use of data beyond the original intent determined by the organization that collected the data. In this study, we surveyed more than 25 million nutrient records collected by 488 organizations in the United States since 1899 to identify major inconsistencies in metadata elements that limit the secondary use of multi-source data. Nearly 14.5 million of these records had missing or ambiguous information for one or more key metadata elements, including (in decreasing order of records affected) sample fraction, chemical form, parameter name, units of measurement, precise numerical value, and remark codes. As a result, metadata harmonization to make secondary use of these multi-source data will be time consuming, expensive, and inexact. Different data users may make different assumptions about the same ambiguous data, potentially resulting in different conclusions about important environmental issues. The value of these ambiguous data is estimated at \\$US12 billion, a substantial collective investment by water-resource organizations in the United States. By comparison, the value of unambiguous data is estimated at \\$US8.2 billion. The ambiguous data could be preserved for uses beyond the original intent by developing and implementing standardized metadata practices for future and legacy water-quality data throughout the United States.

  13. Reference volumetric samples of gamma-spectroscopic sources

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  14. The United States initiative for international radioactive source management (ISRM)

    International Nuclear Information System (INIS)

    Naraine, N.; Karhnak, J.

    1999-01-01

    The United States takes seriously the potential problems from uncontrolled radioactive sources. To address these problems, the United States Department of State is leading the development of an initiative for International Radioactive Source Management (ISRM). The Department of State, through a number of Federal and state agencies, regulatory bodies and private industry, will endeavor to provide coordinated support to the international community, particularly through IAEA, to assist in the development and implementation of risk-based clearance levels to support import/export of radioactive contaminated metals and the tracking, management, identification, remediation, and disposition of 'lost sources' entering nation states and targeted industries. The United States believes that the international control of radioactive sources is critical in avoiding wide-spread contamination of the world metal supply. Thus the initiative has four objectives: (1) Protect sources from becoming lost (Tracking management); (2) Identify primary locations where sources have been lost (Stop future losses); (3) Locate lost sources (monitor and retrieve); and (4) Educate and train (deploy knowledge and technology). A number of efforts already underway in the United States support the overall initiative. The EPA has provided a grant to the Conference of Radiation Program Control Directors (CRCPD) to develop a nation-wide program for the disposition of orphaned radioactive sources. This program now has internet visibility and a toll-free telephone number to call for assistance in the disposal of sources. The Nuclear Regulatory Commission (NRC), the Department of Energy (DOE), and other government agencies as well as private companies are assisting CRCPD in this program. The NRC has begun a program to improve control of radioactive sources in the United States, and also intends to promulgate a regulation defining conditions for the release of materials from licensed facilities. The DOE is

  15. A new sample of faint Gigahertz Peaked Spectrum radio sources

    NARCIS (Netherlands)

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

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

  16. Development of a compact powdery sample negative ion source

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-02-01

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

  17. Understanding the Impacts of Land Uses on the Source Apportionment of Atmospheric Contamination By Polycyclic Aromatic Hydrocarbons throughout a Small State in the Northeast United States

    Science.gov (United States)

    Schifman, L. A.; Boving, T. B.

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous contaminants that enter the environment through combustion processes and are often found in higher concentration of urban areas. However, once released, these compounds can travel long distances via transport through the atmosphere and can be deposited on the landscape far away from their original source. This PAH deposition pattern can slowly lead to the diffuse contamination of whole landscapes. Since most of the air masses entering the northeastern United States originate from the Midwest where coal burning power plants are plentiful, several atmospheric pollutants are introduced to the region in addition to local sources. Here, atmospheric deposition of PAHs in six different locations throughout Rhode Island was measured using passive bulk-deposition samplers for 3 years. The data were analyzed statistically by principal component analysis and factor analysis to identify the source of contamination and respective apportionment. The data clearly show that an urban-to- rural gradient exists where deposition rates are significantly higher in urban areas (up to 12325 ng/d m2 ∑PAH) compared to rural areas (as low as 11 ng/d m2 ∑PAH) and also follow seasonal trends that show higher deposition rates in the fall and winter compared to the summer and spring time. Further, based on PAH source apportionment ratios, contamination origins differ spatially. For example, fossil fuel, coal, and vehicle combustion is present in all samples; however fossil fuel combustion is dominant in urban samples. In Rural areas biomass combustion is much more prevalent and is not as greatly represented in urban or suburban areas. Therefore, even in a small state such as Rhode Island airborne PAH contamination can be fingerprinted readily for different sampling areas, indicating that distant emission sources have a widespread impact on regional air quality.

  18. Microbial pathogens in source and treated waters from drinking water treatment plants in the United States and implications for human health

    Science.gov (United States)

    An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Aspe...

  19. Grandfather regulations, new source bias, and state air toxics regulations

    International Nuclear Information System (INIS)

    Levinson, Arik

    1999-01-01

    This paper uses plant-level data from the Census of Manufactures and the variation in toxic air pollution regulations across states to measure the effects of laws that are more stringent for new sources of pollution than for existing sources (so-called 'grandfather' regulations). Of particular interest is the resulting 'new source bias' and its effects on capital vintage and investment. Two industries are examined: commercial printing, which has a local product market; and paint manufacturing, which has a more national market. In general, there seem to be no statistically significant differences in capital vintage or investment between plants in states that grandfather new sources of pollution, plants in states that have no air toxics regulations, and plants in states that regulate both new and existing sources

  20. Nuclear thermal source transfer unit, post-blast soil sample drying system

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, Ralph S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Valencia, Matthew J [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-03

    Los Alamos National Laboratory states that its mission is “To solve national security challenges through scientific excellence.” The Science Undergraduate Laboratory Internship (SULI) programs exists to engage undergraduate students in STEM work by providing opportunity to work at DOE facilities. As an undergraduate mechanical engineering intern under the SULI program at Los Alamos during the fall semester of 2016, I had the opportunity to contribute to the mission of the Laboratory while developing skills in a STEM discipline. I worked with Technology Applications, an engineering group that supports non-proliferation, counter terrorism, and emergency response missions. This group specializes in tool design, weapons engineering, rapid prototyping, and mission training. I assisted with two major projects during my appointment Los Alamos. The first was a thermal source transportation unit, intended to safely contain a nuclear thermal source during transit. The second was a soil drying unit for use in nuclear postblast field sample collection. These projects have given me invaluable experience working alongside a team of professional engineers. Skills developed include modeling, simulation, group design, product and system design, and product testing.

  1. Nuclear thermal source transfer unit, post-blast soil sample drying system

    International Nuclear Information System (INIS)

    Wiser, Ralph S.; Valencia, Matthew J

    2017-01-01

    Los Alamos National Laboratory states that its mission is ''To solve national security challenges through scientific excellence.'' The Science Undergraduate Laboratory Internship (SULI) programs exists to engage undergraduate students in STEM work by providing opportunity to work at DOE facilities. As an undergraduate mechanical engineering intern under the SULI program at Los Alamos during the fall semester of 2016, I had the opportunity to contribute to the mission of the Laboratory while developing skills in a STEM discipline. I worked with Technology Applications, an engineering group that supports non-proliferation, counter terrorism, and emergency response missions. This group specializes in tool design, weapons engineering, rapid prototyping, and mission training. I assisted with two major projects during my appointment Los Alamos. The first was a thermal source transportation unit, intended to safely contain a nuclear thermal source during transit. The second was a soil drying unit for use in nuclear postblast field sample collection. These projects have given me invaluable experience working alongside a team of professional engineers. Skills developed include modeling, simulation, group design, product and system design, and product testing.

  2. An accelerator based steady state neutron source

    International Nuclear Information System (INIS)

    Burke, R.J.; Johnson, D.L.

    1985-01-01

    Using high current, c.w. linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the Accelerator Based Neutron Research Facility (ABNR) would initially achieve the 10 16 n/cm 2 .s thermal flux goal of the advanced steady state neutron source, and upgrading could provide higher steady state fluxes. The relatively low ion energy compared to other spallation sources has an important impact on R and D requirements as well as capital cost, for which a range of $300-450M is estimated by comparison to other accelerator-based neutron source facilities. The source is similar to a reactor source in most respects. It has some higher energy neutrons but fewer gamma rays, and the moderator region is free of many of the design constraints of a reactor, which helps to implement sources for various neutron energy spectra, many beam tubes, etc. With the development of multi-beam concept and the basis for currents greater than 100 mA that is assumed in the R and D plan, the ABNR would serve many additional uses, such as fusion materials development, production of proton-rich isotopes, and other energy and defense program needs

  3. Sample preparations for spark source mass spectrography

    International Nuclear Information System (INIS)

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

    1977-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  5. Accounting for Diversity in Suicide Research: Sampling and Sample Reporting Practices in the United States.

    Science.gov (United States)

    Cha, Christine B; Tezanos, Katherine M; Peros, Olivia M; Ng, Mei Yi; Ribeiro, Jessica D; Nock, Matthew K; Franklin, Joseph C

    2018-04-01

    Research on suicidal thoughts and behaviors (STB) has identified many risk factors, but whether these findings generalize to diverse populations remains unclear. We review longitudinal studies on STB risk factors over the past 50 years in the United States and evaluate the methodological practices of sampling and reporting sample characteristics. We found that articles frequently reported participant age and sex, less frequently reported participant race and ethnicity, and rarely reported participant veteran status or lesbian, gay, bisexual, and transgender status. Sample reporting practices modestly and inconsistently improved over time. Finally, articles predominantly featured White, non-Hispanic, young adult samples. © 2017 The American Association of Suicidology.

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

    International Nuclear Information System (INIS)

    HASSAN, A.M.

    2009-01-01

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

  7. 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.

  8. A high charge state heavy ion beam source for HIF

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.

    1995-04-01

    A high current low emittance high charge state heavy ion beam source is being developed. This is designed to deliver HIF (heavy ion fusion) driver accelerator scale beam. Using high-charge-state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system which consists of the gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 2D beam envelope simulations and experimental feasibility studies' results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector

  9. A preliminary assessment of the spatial sources of contemporary suspended sediment in the Ohio River basin, United States, using water quality data from the NASQAN programme in a source tracing procedure

    Science.gov (United States)

    Zhang, Y.-S.; Collins, A.L.; Horowitz, A.J.

    2012-01-01

    Reliable information on catchment scale suspended sediment sources is required to inform the design of management strategies for helping abate the numerous environmental issues associated with enhanced sediment mobilization and off-site loadings. Since sediment fingerprinting techniques avoid many of the logistical constraints associated with using more traditional indirect measurement methods at catchment scale, such approaches have been increasingly reported in the international literature and typically use data sets collected specifically for sediment source apportionment purposes. There remains scope for investigating the potential for using geochemical data sets assembled by routine monitoring programmes to fingerprint sediment provenance. In the United States, routine water quality samples are collected as part of the US Geological Survey's revised National Stream Quality Accounting Network programme. Accordingly, the geochemistry data generated from these samples over a 10-year period (1996-2006) were used as the basis for a fingerprinting exercise to assess the key tributary sub-catchment spatial sources of contemporary suspended sediment transported by the Ohio River. Uncertainty associated with the spatial source estimates was quantified using a Monte Carlo approach in conjunction with mass balance modelling. Relative frequency weighted means were used as an alternative way of summarizing the spatial source contributions, thereby avoiding the need to use confidence limits. The results should be interpreted in the context of the routine, but infrequent nature, of the suspended sediment samples used to assemble geochemistry as a basis for the sourcing exercise. Nonetheless, the study demonstrates how routine monitoring samples can be used to provide some preliminary information on sediment provenance in large drainage basins. ?? 2011 John Wiley & Sons, Ltd.

  10. Importance sampling large deviations in nonequilibrium steady states. I

    Science.gov (United States)

    Ray, Ushnish; Chan, Garnet Kin-Lic; Limmer, David T.

    2018-03-01

    Large deviation functions contain information on the stability and response of systems driven into nonequilibrium steady states and in such a way are similar to free energies for systems at equilibrium. As with equilibrium free energies, evaluating large deviation functions numerically for all but the simplest systems is difficult because by construction they depend on exponentially rare events. In this first paper of a series, we evaluate different trajectory-based sampling methods capable of computing large deviation functions of time integrated observables within nonequilibrium steady states. We illustrate some convergence criteria and best practices using a number of different models, including a biased Brownian walker, a driven lattice gas, and a model of self-assembly. We show how two popular methods for sampling trajectory ensembles, transition path sampling and diffusion Monte Carlo, suffer from exponentially diverging correlations in trajectory space as a function of the bias parameter when estimating large deviation functions. Improving the efficiencies of these algorithms requires introducing guiding functions for the trajectories.

  11. Importance sampling large deviations in nonequilibrium steady states. I.

    Science.gov (United States)

    Ray, Ushnish; Chan, Garnet Kin-Lic; Limmer, David T

    2018-03-28

    Large deviation functions contain information on the stability and response of systems driven into nonequilibrium steady states and in such a way are similar to free energies for systems at equilibrium. As with equilibrium free energies, evaluating large deviation functions numerically for all but the simplest systems is difficult because by construction they depend on exponentially rare events. In this first paper of a series, we evaluate different trajectory-based sampling methods capable of computing large deviation functions of time integrated observables within nonequilibrium steady states. We illustrate some convergence criteria and best practices using a number of different models, including a biased Brownian walker, a driven lattice gas, and a model of self-assembly. We show how two popular methods for sampling trajectory ensembles, transition path sampling and diffusion Monte Carlo, suffer from exponentially diverging correlations in trajectory space as a function of the bias parameter when estimating large deviation functions. Improving the efficiencies of these algorithms requires introducing guiding functions for the trajectories.

  12. Deriving consumer-facing disease concepts for family health histories using multi-source sampling.

    Science.gov (United States)

    Hulse, Nathan C; Wood, Grant M; Haug, Peter J; Williams, Marc S

    2010-10-01

    The family health history has long been recognized as an effective way of understanding individuals' susceptibility to familial disease; yet electronic tools to support the capture and use of these data have been characterized as inadequate. As part of an ongoing effort to build patient-facing tools for entering detailed family health histories, we have compiled a set of concepts specific to familial disease using multi-source sampling. These concepts were abstracted by analyzing family health history data patterns in our enterprise data warehouse, collection patterns of consumer personal health records, analyses from the local state health department, a healthcare data dictionary, and concepts derived from genetic-oriented consumer education materials. Collectively, these sources yielded a set of more than 500 unique disease concepts, represented by more than 2500 synonyms for supporting patients in entering coded family health histories. We expect that these concepts will be useful in providing meaningful data and education resources for patients and providers alike.

  13. Determination of the provenance of obsidian samples collected in the archaeological site of San Miguel Ixtapan, Mexico State, Mexico by means of neutron activation analysis

    International Nuclear Information System (INIS)

    Almazan-Torres, M.G.; Aguirre-Martinez, P.I.

    2004-01-01

    Obsidian samples from San Miguel Ixtapan Mexico State, Mexico were analyzed by means of neutron activation. Statistical treatments such as bivariate, cluster and principal-components analyses were applied to the data set. Obsidians were identified as coming from three important sources: Sierra of Pachuca in the state of Hidalgo, Zinap uaro and Zin aro-Varal in the state of Michoacan. (author)

  14. Parameter optimization in biased decoy-state quantum key distribution with both source errors and statistical fluctuations

    Science.gov (United States)

    Zhu, Jian-Rong; Li, Jian; Zhang, Chun-Mei; Wang, Qin

    2017-10-01

    The decoy-state method has been widely used in commercial quantum key distribution (QKD) systems. In view of the practical decoy-state QKD with both source errors and statistical fluctuations, we propose a universal model of full parameter optimization in biased decoy-state QKD with phase-randomized sources. Besides, we adopt this model to carry out simulations of two widely used sources: weak coherent source (WCS) and heralded single-photon source (HSPS). Results show that full parameter optimization can significantly improve not only the secure transmission distance but also the final key generation rate. And when taking source errors and statistical fluctuations into account, the performance of decoy-state QKD using HSPS suffered less than that of decoy-state QKD using WCS.

  15. 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

  16. Anthropogenic organic compounds in source water of select community water systems in the United States, 2002-10

    Science.gov (United States)

    Valder, Joshua F.; Delzer, Gregory C.; Kingsbury, James A.; Hopple, Jessica A.; Price, Curtis V.; Bender, David A.

    2014-01-01

    Drinking water delivered by community water systems (CWSs) comes from one or both of two sources: surface water and groundwater. Source water is raw, untreated water used by CWSs and is usually treated before distribution to consumers. Beginning in 2002, the U.S. Geological Survey’s (USGS) National Water-Quality Assessment Program initiated Source Water-Quality Assessments (SWQAs) at select CWSs across the United States, primarily to characterize the occurrence of a large number of anthropogenic organic compounds that are predominantly unregulated by the U.S. Environmental Protection Agency. Source-water samples from CWSs were collected during 2002–10 from 20 surface-water sites (river intakes) and during 2002–09 from 448 groundwater sites (supply wells). River intakes were sampled approximately 16 times during a 1-year sampling period, and supply wells were sampled once. Samples were monitored for 265 anthropogenic organic compounds. An additional 3 herbicides and 16 herbicide degradates were monitored in samples collected from 8 river intakes and 118 supply wells in areas where these compounds likely have been used. Thirty-seven compounds have an established U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) for drinking water, 123 have USGS Health-Based Screening Levels (HBSLs), and 29 are included on the EPA Contaminant Candidate List 3. All compounds detected in source water were evaluated both with and without an assessment level and were grouped into 13 categories (hereafter termed as “use groups”) based on their primary use or source. The CWS sites were characterized in a national context using an extract of the EPA Safe Drinking Water Information System to develop spatially derived and system-specific ancillary data. Community water system information is contained in the EPA Public Supply Database, which includes 2,016 active river intakes and 112,099 active supply wells. Ancillary variables including population served

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  18. The new orphaned radioactive sources program in the United States

    International Nuclear Information System (INIS)

    Naraine, N.; Karhnak, J.M.

    1998-01-01

    Exposure of the public to uncontrolled radioactive sources has become an significant concern to the United States (US) Government because of the continuous increase in the number of sources that are being found, sometimes without proper radiation markings. This problem is primarily due to inadequate control, insufficient accountability, and improper disposal of radioactive materials. The US Environmental Protection Agency (EPA) has funded a cooperative 'orphaned' source initiative with the Conference of Radiation Control Program Directors (CRCPD) to bring under control unwanted sources and thus reduce the potential for unnecessary exposure to the public, workers and the environment. The program is being developed through the cooperative efforts of government agencies and industry, and will provide a quick and efficient method to bring orphaned sources under control and out of potentially dangerous situations. (author)

  19. Miniaturized radioisotope solid state power sources

    Science.gov (United States)

    Fleurial, J.-P.; Snyder, G. J.; Patel, J.; Herman, J. A.; Caillat, T.; Nesmith, B.; Kolawa, E. A.

    2000-01-01

    Electrical power requirements for the next generation of deep space missions cover a wide range from the kilowatt to the milliwatt. Several of these missions call for the development of compact, low weight, long life, rugged power sources capable of delivering a few milliwatts up to a couple of watts while operating in harsh environments. Advanced solid state thermoelectric microdevices combined with radioisotope heat sources and energy storage devices such as capacitors are ideally suited for these applications. By making use of macroscopic film technology, microgenrators operating across relatively small temperature differences can be conceptualized for a variety of high heat flux or low heat flux heat source configurations. Moreover, by shrinking the size of the thermoelements and increasing their number to several thousands in a single structure, these devices can generate high voltages even at low power outputs that are more compatible with electronic components. Because the miniaturization of state-of-the-art thermoelectric module technology based on Bi2Te3 alloys is limited due to mechanical and manufacturing constraints, we are developing novel microdevices using integrated-circuit type fabrication processes, electrochemical deposition techniques and high thermal conductivity substrate materials. One power source concept is based on several thermoelectric microgenerator modules that are tightly integrated with a 1.1W Radioisotope Heater Unit. Such a system could deliver up to 50mW of electrical power in a small lightweight package of approximately 50 to 60g and 30cm3. An even higher degree of miniaturization and high specific power values (mW/mm3) can be obtained when considering the potential use of radioisotope materials for an alpha-voltaic or a hybrid thermoelectric/alpha-voltaic power source. Some of the technical challenges associated with these concepts are discussed in this paper. .

  20. Heroin-related overdose: The unexplored influences of markets, marketing and source-types in the United States

    Science.gov (United States)

    Mars, Sarah G.; Fessel, Jason N.; Bourgois, Philippe; Montero, Fernando; Karandinos, George; Ciccarone, Daniel

    2015-01-01

    Heroin overdose, more accurately termed ‘heroin-related overdose’ due to the frequent involvement of other drugs, is the leading cause of mortality among regular heroin users. (Degenhardt et al., 2010) Heroin injectors are at greater risk of hospital admission for heroin-related overdose (HOD) in the eastern United States where Colombian-sourced powder heroin is sold than in the western US where black ‘tar’ heroin predominates. (Unick et al., 2014) This paper examines under-researched influences on HOD, both fatal and non-fatal, using data from a qualitative study of injecting drug users of black tar heroin in San Francisco and powder heroin in Philadelphia Data were collected through in-depth, semi-structured interviews carried out in 2012 that were conducted against a background of longer-term participant-observation, ethnographic studies of drug users and dealers in Philadelphia (2007–12) and of users in San Francisco (1994–2007, 2012). Our findings suggest three types of previously unconsidered influences on overdose risk that arise both from structural socio-economic factors and from the physical properties of the heroin source-types: 1) retail market structure including information flow between users; 2) marketing techniques such as branding, free samples and pricing and 3) differences in the physical characteristics of the two major heroin source forms and how they affect injecting techniques and vascular health. Although chosen for their contrasting source-forms, we found that the two cities have contrasting dominant models of drug retailing: San Francisco respondents tended to buy through private dealers and Philadelphia respondents frequented an open-air street market where heroin is branded and free samples are distributed, although each city included both types of drug sales. These market structures and marketing techniques shape the availability of information regarding heroin potency and its dissemination among users who tend to seek out

  1. Heroin-related overdose: The unexplored influences of markets, marketing and source-types in the United States.

    Science.gov (United States)

    Mars, Sarah G; Fessel, Jason N; Bourgois, Philippe; Montero, Fernando; Karandinos, George; Ciccarone, Daniel

    2015-09-01

    Heroin overdose, more accurately termed 'heroin-related overdose' due to the frequent involvement of other drugs, is the leading cause of mortality among regular heroin users. (Degenhardt et al., 2010) Heroin injectors are at greater risk of hospital admission for heroin-related overdose (HOD) in the eastern United States where Colombian-sourced powder heroin is sold than in the western US where black 'tar' heroin predominates. (Unick et al., 2014) This paper examines under-researched influences on HOD, both fatal and non-fatal, using data from a qualitative study of injecting drug users of black tar heroin in San Francisco and powder heroin in Philadelphia Data were collected through in-depth, semi-structured interviews carried out in 2012 that were conducted against a background of longer-term participant-observation, ethnographic studies of drug users and dealers in Philadelphia (2007-12) and of users in San Francisco (1994-2007, 2012). Our findings suggest three types of previously unconsidered influences on overdose risk that arise both from structural socio-economic factors and from the physical properties of the heroin source-types: 1) retail market structure including information flow between users; 2) marketing techniques such as branding, free samples and pricing and 3) differences in the physical characteristics of the two major heroin source forms and how they affect injecting techniques and vascular health. Although chosen for their contrasting source-forms, we found that the two cities have contrasting dominant models of drug retailing: San Francisco respondents tended to buy through private dealers and Philadelphia respondents frequented an open-air street market where heroin is branded and free samples are distributed, although each city included both types of drug sales. These market structures and marketing techniques shape the availability of information regarding heroin potency and its dissemination among users who tend to seek out the

  2. Scientific and technical information as a source for IAEA safeguards state evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, M.; Feldman, Y.; Ferguson, M. [International Atomic Energy Agency, Vienna (Austria)

    2014-07-01

    The IAEA Department of Safeguards is continually working to refine its methodologies and procedures for the analysis of information relevant to the evaluation of the nuclear fuel cycle in States that have safeguards agreements with the IAEA. This analysis is required to achieve an understanding of States' nuclear-related activities against which a State's declarations are evaluated for correctness as well as completeness, and to provide credible assurances on the peaceful uses of nuclear material in the State. To achieve this end, diversification of sources and comparison for consistency among available information is essential to ensure an accurate assessment of a State's nuclear activities. Open sources of information on scientific and technical (S&T) developments and research provide the Department of Safeguards with an enhanced basis to evaluate the technical capabilities of States. These information sources are regularly and systematically assessed to provide information about industrial capabilities, patenting activities and research and development activities in States as reflected through published scientific and technical literature. Using such sources, in addition to other, long-established safeguards information sources, helps the IAEA to draw soundly-based safeguards conclusions. The utility of this category of information in terms of the State evaluation process lies primarily in the comparison with other sources of information, especially State-declared information, and in the assessment of consistency of all safeguards-relevant information regarding nuclear fuel cycle technologies and activities in a State. The current paper aims to describe the use of S&T literature, how information from different sources is consolidated, how it is analysed and how it contributes in the overall process of State evaluation in the IAEA Department of Safeguards. (author)

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

    Science.gov (United States)

    Andersson, August

    2011-12-15

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

  4. Monitoring alert and drowsy states by modeling EEG source nonstationarity

    Science.gov (United States)

    Hsu, Sheng-Hsiou; Jung, Tzyy-Ping

    2017-10-01

    Objective. As a human brain performs various cognitive functions within ever-changing environments, states of the brain characterized by recorded brain activities such as electroencephalogram (EEG) are inevitably nonstationary. The challenges of analyzing the nonstationary EEG signals include finding neurocognitive sources that underlie different brain states and using EEG data to quantitatively assess the state changes. Approach. This study hypothesizes that brain activities under different states, e.g. levels of alertness, can be modeled as distinct compositions of statistically independent sources using independent component analysis (ICA). This study presents a framework to quantitatively assess the EEG source nonstationarity and estimate levels of alertness. The framework was tested against EEG data collected from 10 subjects performing a sustained-attention task in a driving simulator. Main results. Empirical results illustrate that EEG signals under alert versus drowsy states, indexed by reaction speeds to driving challenges, can be characterized by distinct ICA models. By quantifying the goodness-of-fit of each ICA model to the EEG data using the model deviation index (MDI), we found that MDIs were significantly correlated with the reaction speeds (r  =  -0.390 with alertness models and r  =  0.449 with drowsiness models) and the opposite correlations indicated that the two models accounted for sources in the alert and drowsy states, respectively. Based on the observed source nonstationarity, this study also proposes an online framework using a subject-specific ICA model trained with an initial (alert) state to track the level of alertness. For classification of alert against drowsy states, the proposed online framework achieved an averaged area-under-curve of 0.745 and compared favorably with a classic power-based approach. Significance. This ICA-based framework provides a new way to study changes of brain states and can be applied to

  5. The Oxidation State of Fe in Glasses from the Galapagos Archipelago: Variable Oxygen Fugacity as a Function of Mantle Source

    Science.gov (United States)

    Peterson, M. E.; Kelley, K. A.; Cottrell, E.; Saal, A. E.; Kurz, M. D.

    2015-12-01

    The oxidation state of the mantle plays an intrinsic role in the magmatic evolution of the Earth. Here we present new μ-XANES measurements of Fe3+/ΣFe ratios (a proxy for ƒO2) in a suite of submarine glasses from the Galapagos Archipelago. Using previously presented major, trace, and volatile elements and isotopic data for 4 groups of glass that come from distinct mantle sources (depleted upper mantle, 2 recycled, and a primitive mantle source) we show that Fe3+/ΣFe ratios vary both with the influence of shallow level processes and with variations in mantle source. Fe3+/ΣFe ratios increase with differentiation (i.e. decreasing MgO), but show a large variation at a given MgO. Progressive degassing of sulfur accompanies decreasing Fe3+/ΣFe ratios, while assimilation of hydrothermally altered crust (as indicated by increasing Sr/Sr*) is shown to increase Fe3+/ΣFe ratios. After taking these processes into account, there is still variability in the Fe3+/ΣFe ratios of the isotopically distinct sample suites studied, yielding a magmatic ƒO2 that ranges from ΔQFM = +0.16 to +0.74 (error ITE = enriched Sr and Pb isotopes) shows evidence of mixing between oxidized and reduced sources (ITE oxidized end-member = 0.177). This suggests that mantle sources in the Galapagos that are thought to contain recycled components (i.e., WD and ITE groups) have distinct oxidation states. The high 3He/4He Fernandina samples (HHe group) are shown to be the most oxidized (ave. 0.175 ± 0.006). With C/3He ratios an order of magnitude greater than MORB this suggests that the primitive mantle is a more carbonated and oxidized source than the depleted upper mantle.

  6. Distribution and Sources of Nitrate-Nitrogen in Kansas Groundwater

    Directory of Open Access Journals (Sweden)

    Margaret A. Townsend

    2001-01-01

    Full Text Available Kansas is primarily an agricultural state. Irrigation water and fertilizer use data show long- term increasing trends. Similarly, nitrate-N concentrations in groundwater show long-term increases and exceed the drinking-water standard of 10 mg/l in many areas. A statistical analysis of nitrate-N data collected for local and regional studies in Kansas from 1990 to 1998 (747 samples found significant relationships between nitrate-N concentration with depth, age, and geographic location of wells. Sources of nitrate-N have been identified for 297 water samples by using nitrogen stable isotopes. Of these samples, 48% showed fertilizer sources (+2 to +8 and 34% showed either animal waste sources (+10 to +15 with nitrate-N greater than 10 mg/l or indication that enrichment processes had occurred (+10 or above with variable nitrate-N or both. Ultimate sources for nitrate include nonpoint sources associated with past farming and fertilization practices, and point sources such as animal feed lots, septic systems, and commercial fertilizer storage units. Detection of nitrate from various sources in aquifers of different depths in geographically varied areas of the state indicates that nonpoint and point sources currently impact and will continue to impact groundwater under current land uses.

  7. Occurrence of cocaine and benzoylecgonine in drinking and source water in the São Paulo State region, Brazil.

    Science.gov (United States)

    Campestrini, Iolana; Jardim, Wilson F

    2017-01-15

    The occurrence of illicit drugs in natural waters (surface, source and drinking water) is of interest due to the poor sanitation coverage and the high consumption of drugs of abuse in Brazil. In addition, little is known about the effects of these compounds on aquatic organisms and human health. This work investigates the occurrence of cocaine (COC) and its major metabolite, benzoylecgonine (BE), in surface and drinking water collected in rivers from a populated geographic area in Brazil. Surface water samples were collected in 22 locations from 16 different rivers and one dam from São Paulo State, whereas drinking water samples were collected in 5 locations. Samples were collected during the dry and wet season. Among the 34 surface water samples analyzed, BE was detected above the LOD in 94%, while COC in 85%. BE concentrations ranged from 10ngL -1 to 1019ngL -1 and COC concentrations from 6ngL -1 to 62ngL -1 . In the drinking water samples analyzed, BE and COC were found in 100% of the samples analyzed. For BE, concentrations were found in the range from 10ngL -1 to 652ngL -1 , and COC was quantified in concentrations between 6 and 22ngL -1 . These concentrations are one of the highest found in urban surface waters and may pose some risk to aquatic species. However, no human health risk was identified using the Hazard Quotient. BE is proposed as a reliable indicator of sewage contamination in both source and drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Radiation traces in exportation food samples of Parana State, Brazil

    International Nuclear Information System (INIS)

    Scheibel, Viviane

    2002-02-01

    This work deals with radioactive traces measurements in foodstuffs produced at the State of Parana, with large export rate and also of nutritious products of some regional trading companies. The measured foods were: sulfite treated sugar, tea, mint candy, soy in grain, soy crumb, gross soy oil, gum free oil and commercial refined soy oil. Six samples of each lot of the analyzed material were prepared, which represent a sampling with 90% of confidence. The samples were sealed in Marinelli beaker of 2.1 L completely filled and kept during 40 days until secular equilibrium was achieved. The counting time for each measure was of 48 hours. Measurements were carried out by gamma-ray spectrometry employing a HPGe detector with 10% of relative efficiency, coupled to standard nuclear electronics and a 8 l multichannel card. The acquisition of the data was accomplished with the software Maestro TM , version 3.2. The energy resolution of the 137 Cs 661.62 keV gamma line was 1.75 keV. The larger intensity gamma lines observed in the spectra were from the following radionuclides: 228 Ac, 208 Tl, 212 Pb of the 232 Th series, 214 Bi and 214 Pb from the 238 U series, 227 Ac from the 235 U series and 40 K. Activities and lower level of detection limits were calculated according to the International Agency of Atomic Energy norms.The detector efficiency was measured using a 152 Eu certified source and IAEA-375 and IAEA-326 certified reference materials. For most of the radionuclides it was possible only the measurement of the minimum activity detectable in the foodstuffs. Self-attenuation corrections were accomplished with support literature results. The most important activity observed was that of 40 K, whose value measured for soy in natura was 745.0 + - 9 .1 Bq/kg and for the crumb soy 1473 ± 15 Bq/kg.. he measured activities of the several analyzed foods were compatible with the values expected for non contaminated normal environmental samples, except for soy crumb, whose 40 K

  9. Sources of variation on the mini-mental state examination in a population-based sample of centenarians.

    Science.gov (United States)

    Dai, Ting; Davey, Adam; Woodard, John L; Miller, Lloyd Stephen; Gondo, Yasuyuki; Kim, Seock-Ho; Poon, Leonard W

    2013-08-01

    Centenarians represent a rare but rapidly growing segment of the oldest-old. This study presents item-level data from the Mini-Mental State Examination (MMSE) in a cross-sectional, population-based sample of 244 centenarians and near-centenarians (aged 98-108, 16% men, 21% African-American, 38% community dwelling) from the Georgia Centenarian Study (2001-2008) according to age, education, sex, race, and residential status. Multiple-Indicator Multiple-Cause (MIMIC) models were used to identify systematic domain-level differences in MMSE scores according to demographic characteristics in this age group. Indirect effects of age, educational attainment, race, and residential status were found on MMSE scores. Direct effects were limited to concentration for education and race and orientation for residential status. Mean levels of cognitive functioning in centenarians were low, with mean values below most commonly-used cutoffs. Overall scores on the MMSE differed as a function of age, education, race, and residential status, with differences in scale performance limited primarily to concentration and orientation and no evidence of interactions between centenarian characteristics. Adjusting for education was not sufficient to account for differences according to race, and adjusting for residential status was not sufficient to account for differences according to age. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

  10. A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States - II) Untreated drinking water sources

    Science.gov (United States)

    Focazio, M.J.; Kolpin, D.W.; Barnes, K.K.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Barber, L.B.; Thurman, M.E.

    2008-01-01

    Numerous studies have shown that a variety of manufactured and natural organic compounds such as pharmaceuticals, steroids, surfactants, flame retardants, fragrances, plasticizers and other chemicals often associated with wastewaters have been detected in the vicinity of municipal wastewater discharges and livestock agricultural facilities. To provide new data and insights about the environmental presence of some of these chemicals in untreated sources of drinking water in the United States targeted sites were sampled and analyzed for 100 analytes with sub-parts per billion detection capabilities. The sites included 25 ground- and 49 surface-water sources of drinking water serving populations ranging from one family to over 8 million people.

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

    Science.gov (United States)

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

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

  12. Polychromatic solid-state lamps versus tungsten radiator: hue changes of Munsell samples

    International Nuclear Information System (INIS)

    Stanikunas, R; Vaitkevicius, H; Svegzda, A; Viliunas, V; Bliznikas, Z; Breive, K; Vaicekauskas, R; Novickovas, A; Kurilcik, G; Zukauskas, A; Gaska, R; Shur, M S

    2005-01-01

    Colour-perception differences under illumination by two quadrichromatic solid-state sources of light have been studied with respect to a tungsten radiator with the same correlated colour temperature (2600 K). A virtual RYgCB source (illuminant), which contains red, yellow-green, cyan and blue components with the line width typical of AlGaInP and AlInGaN light-emitting diodes (LEDs), was fully optimized for the highest value of the general colour-rendering index (CRI) (R a = 98.3). An implemented RAGB source (lamp) contained commercially available red, amber, green and blue LEDs (R a 79.4). Colorimetric calculations in the Commission Internationale de l'Eclairage 1976 (u',v') colour plane for 40 Munsell colour samples (value 6, chroma/6, hue increment 2.5) revealed the differences in hue discrimination and distortion for both sources in the yellow-green and blue-cyan ranges. These differences were not revealed by the standard analysis of the special CRIs and were lower for the RYgCB illuminant, which contained primary LEDs in the sensitive ranges. A psychophysical experiment on seven subjects was performed using the RAGB lamp stabilized against thermal and ageing drifts. Despite different colour-perception abilities of the subjects under investigation, the experiment confirmed the calculation results. Methods of obtaining composite white light with high subjective ratings are discussed, based on the obtained data

  13. Future prospects for ECR ion sources with improved charge state distributions

    International Nuclear Information System (INIS)

    Alton, G.D.

    1995-01-01

    Despite the steady advance in the technology of the ECR ion source, present art forms have not yet reached their full potential in terms of charge state and intensity within a particular charge state, in part, because of the narrow band width. single-frequency microwave radiation used to heat the plasma electrons. This article identifies fundamentally important methods which may enhance the performances of ECR ion sources through the use of: (1) a tailored magnetic field configuration (spatial domain) in combination with single-frequency microwave radiation to create a large uniformly distributed ECR ''volume'' or (2) the use of broadband frequency domain techniques (variable-frequency, broad-band frequency, or multiple-discrete-frequency microwave radiation), derived from standard TWT technology, to transform the resonant plasma ''surfaces'' of traditional ECR ion sources into resonant plasma ''volume''. The creation of a large ECR plasma ''volume'' permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, thereby producing higher charge state ions and much higher intensities within a particular charge state than possible in present forms of' the source. The ECR ion source concepts described in this article offer exciting opportunities to significantly advance the-state-of-the-art of ECR technology and as a consequence, open new opportunities in fundamental and applied research and for a variety of industrial applications

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

    Science.gov (United States)

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

    2014-10-01

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

  15. Analysis of Some Clay Samples from Yauri (Kebbi State), Goronyo ...

    African Journals Online (AJOL)

    Analysis of some clay samples presumed to be kaolin obtained from different deposits in Yauri (kebbi state), Goronyo, Munwadata, Atokonyo (Sokoto state), Nigeria was carried out. The samples were subjected to quantitative analysis to determine major and trace constituents using gravimetric, colorimetric, titrimetric and ...

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

    Directory of Open Access Journals (Sweden)

    Kar-Weng Chan

    2014-06-01

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

  17. 318-MHz variability of complete samples of extragalactic radio sources. II

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  18. Norm in soil and sludge samples in Dukhan oil Field, Qatar state

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kinani, A.T.; Hushari, M.; Al-Sulaiti, Huda; Alsadig, I.A., E-mail: mmhushari@moe.gov.qa [Radiation and Chemical Protection Department, Ministry of Environment, Doha (Qatar)

    2015-07-01

    The main objective of this work is to measure the activity concentrations of Naturally Occurring radioactive Materials (NORM) produced as a buy products in oil production. The analyses of NORM give available information for guidelines concerning radiation protection. Recently NORM subjected to restricted regulation issued by high legal authority at Qatar state. Twenty five samples of soil from Dukhan onshore oil field and 10 sludge samples collected from 2 offshore fields at Qatar state. High resolution low-level gamma-ray spectrometry used to measure gamma emitters of NORM. The activity concentrations of natural radionuclide in 22 samples from Dukhan oil field, were with average worldwide values . Only three soil samples have high activity concentration of Ra-226 which is more than 185 Bq/kg the exempted level for NORM in the Quatrain regulation. The natural radionuclide activity concentrations of 10 sludge samples from offshore oil fields was greater than 1100Bq/kg the exempted values of NORM set by Quatrain regulation so the sludge need special treatments. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for the 22 samples were below the word permissible values .This means that the human exposure to such material not impose any radiation risk. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for 3 soil samples and sludge samples are higher than the published maximal permissible. Thus human exposure to such material impose radiation risk. (author)

  19. Norm in soil and sludge samples in Dukhan oil Field, Qatar state

    International Nuclear Information System (INIS)

    Al-Kinani, A.T.; Hushari, M.; Al-Sulaiti, Huda; Alsadig, I.A.

    2015-01-01

    The main objective of this work is to measure the activity concentrations of Naturally Occurring radioactive Materials (NORM) produced as a buy products in oil production. The analyses of NORM give available information for guidelines concerning radiation protection. Recently NORM subjected to restricted regulation issued by high legal authority at Qatar state. Twenty five samples of soil from Dukhan onshore oil field and 10 sludge samples collected from 2 offshore fields at Qatar state. High resolution low-level gamma-ray spectrometry used to measure gamma emitters of NORM. The activity concentrations of natural radionuclide in 22 samples from Dukhan oil field, were with average worldwide values . Only three soil samples have high activity concentration of Ra-226 which is more than 185 Bq/kg the exempted level for NORM in the Quatrain regulation. The natural radionuclide activity concentrations of 10 sludge samples from offshore oil fields was greater than 1100Bq/kg the exempted values of NORM set by Quatrain regulation so the sludge need special treatments. The average hazards indices (H ex , D , and Ra eq ), for the 22 samples were below the word permissible values .This means that the human exposure to such material not impose any radiation risk. The average hazards indices (H ex , D , and Ra eq ), for 3 soil samples and sludge samples are higher than the published maximal permissible. Thus human exposure to such material impose radiation risk. (author)

  20. Broadband spectrally dynamic solid state illumination source

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, David B; Asghar, Ali; Gupta, Shalini; Kang, Hun; Pan, Ming [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Strassburg, Martin [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Georgia State University, Department of Physics and Astronomy, Atlanta, GA 30302-4106 (United States); Summers, Chris; Ferguson, Ian T [Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA 30332 (United States)

    2006-06-15

    Solid state lighting has done well recently in niche markets such as signage and displays, however, no available SSL technologies incorporate all the necessary attributes for general illumination. Development of a novel solid state general illumination source is discussed here. Two LEDs emitting at two distinct wavelengths can be monolithically grown and used to excite two or more phosphors with varied excitation spectra. The combined phosphorescence spectrum can then be controlled by adjusting the relative intensities of the two LED emissions. Preliminary phosphor analysis shows such a scheme to be viable for use in a spectrally dynamic broadband general illumination source. A tunnel junction is envisioned as a means of current spreading in a buried layer for three terminal operation. However, tunnel junction properties in GaN based materials are not well understood, and require further optimization to be practical devices. Preliminary results on GaN tunnel junctions are presented here as well. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. A high charge state heavy ion beam source for heavy ion fusion

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.

    1996-01-01

    A high current, low emittance, high charge state heavy ion beam source is being developed. This is designed to deliver a heavy ion fusion (HIF) driver accelerator scale beam. Using a high charge state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system, which consists of a gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 3D beam simulations and experimental feasibility study results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector. (orig.)

  2. Performance on the low charge state laser ion source in BNL

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.

    2015-09-07

    On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).

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

    Directory of Open Access Journals (Sweden)

    Sharyn J Goldstien

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  5. Accelerated Enveloping Distribution Sampling: Enabling Sampling of Multiple End States while Preserving Local Energy Minima.

    Science.gov (United States)

    Perthold, Jan Walther; Oostenbrink, Chris

    2018-05-17

    Enveloping distribution sampling (EDS) is an efficient approach to calculate multiple free-energy differences from a single molecular dynamics (MD) simulation. However, the construction of an appropriate reference-state Hamiltonian that samples all states efficiently is not straightforward. We propose a novel approach for the construction of the EDS reference-state Hamiltonian, related to a previously described procedure to smoothen energy landscapes. In contrast to previously suggested EDS approaches, our reference-state Hamiltonian preserves local energy minima of the combined end-states. Moreover, we propose an intuitive, robust and efficient parameter optimization scheme to tune EDS Hamiltonian parameters. We demonstrate the proposed method with established and novel test systems and conclude that our approach allows for the automated calculation of multiple free-energy differences from a single simulation. Accelerated EDS promises to be a robust and user-friendly method to compute free-energy differences based on solid statistical mechanics.

  6. Mobile source pollution control in the United States and China

    International Nuclear Information System (INIS)

    Menz, Fredric C

    2002-01-01

    This paper reviews policies for the control of mobile source pollution and their potential application in China. The first section of the paper reviews the U.S. experience with mobile source pollution control since regulations were first established in the Clean Air Act of 1970. Highlights in the policy and trends in vehicle emissions over the 1970 to 2000 time period are discussed. The second section of the paper discusses the range of policy instruments that could be used to control vehicle pollution, ranging from traditional direct regulations to market-based instruments. Experiences with the use of economic incentives in the United States and elsewhere are also discussed. The third section of the paper discusses possible implications of the U.S. experience for controlling vehicle pollution in China. While market-based instruments might be particularly appropriate for use in several aspects of China's pollution control policies, important differences between the institutional structures in China and the United States suggest that they should be phased in gradually. The paper closes with concluding remarks. (author)

  7. Mobile source pollution control in the United States and China

    Energy Technology Data Exchange (ETDEWEB)

    Menz, Fredric C

    2002-07-01

    This paper reviews policies for the control of mobile source pollution and their potential application in China. The first section of the paper reviews the U.S. experience with mobile source pollution control since regulations were first established in the Clean Air Act of 1970. Highlights in the policy and trends in vehicle emissions over the 1970 to 2000 time period are discussed. The second section of the paper discusses the range of policy instruments that could be used to control vehicle pollution, ranging from traditional direct regulations to market-based instruments. Experiences with the use of economic incentives in the United States and elsewhere are also discussed. The third section of the paper discusses possible implications of the U.S. experience for controlling vehicle pollution in China. While market-based instruments might be particularly appropriate for use in several aspects of China's pollution control policies, important differences between the institutional structures in China and the United States suggest that they should be phased in gradually. The paper closes with concluding remarks. (author)

  8. Measuring radon source magnitude in residential buildings

    International Nuclear Information System (INIS)

    Nazaroff, W.W.; Boegel, M.L.; Nero, A.V.

    1981-08-01

    A description is given of procedures used in residences for rapid grab-sample and time-dependent measurements of the air-exchange rate and radon concentration. The radon source magnitude is calculated from the results of simultaneous measurements of these parameters. Grab-sample measurements in three survey groups comprising 101 US houses showed the radon source magnitude to vary approximately log-normally with a geometric mean of 0.37 and a range of 0.01 to 6.0 pCi 1 -1 h -1 . Successive measurements in six houses in the northeastern United States showed considerable variability in source magnitude within a given house. In two of these houses the source magnitude showed a strong correlation with the air-exchange rate, suggesting that soil gas influx can be an important transport process for indoor radon

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  10. Experiments with radioactive samples at the Advanced Photon Source

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  11. Nonpoint and Point Sources of Nitrogen in Major Watersheds of the United States

    Science.gov (United States)

    Puckett, Larry J.

    1994-01-01

    Estimates of nonpoint and point sources of nitrogen were made for 107 watersheds located in the U.S. Geological Survey's National Water-Quality Assessment Program study units throughout the conterminous United States. The proportions of nitrogen originating from fertilizer, manure, atmospheric deposition, sewage, and industrial sources were found to vary with climate, hydrologic conditions, land use, population, and physiography. Fertilizer sources of nitrogen are proportionally greater in agricultural areas of the West and the Midwest than in other parts of the Nation. Animal manure contributes large proportions of nitrogen in the South and parts of the Northeast. Atmospheric deposition of nitrogen is generally greatest in areas of greatest precipitation, such as the Northeast. Point sources (sewage and industrial) generally are predominant in watersheds near cities, where they may account for large proportions of the nitrogen in streams. The transport of nitrogen in streams increases as amounts of precipitation and runoff increase and is greatest in the Northeastern United States. Because no single nonpoint nitrogen source is dominant everywhere, approaches to control nitrogen must vary throughout the Nation. Watershed-based approaches to understanding nonpoint and point sources of contamination, as used by the National Water-Quality Assessment Program, will aid water-quality and environmental managers to devise methods to reduce nitrogen pollution.

  12. Pollen analysis in honey samples from the two main producing regions in the Brazilian northeast.

    Science.gov (United States)

    Sodré, Geni da S; Marchini, Luís C; Carvalho, Carlos A L de; Moreti, Augusta C de C C

    2007-09-01

    Knowledge about the botanical source of honey is very important for the beekeeper while it indicates adequate and abundant supply sources of nectar and pollen for the bees, thus contributing toward improved yield. The present study means to identify the pollen types occurring in 58 samples of honey produced in two states of the northeastern region of Brazil, Piauí (38 samples) and Ceará (20 samples), and to verify the potential of the honey plants during the months of February to August. The samples were obtained directly from beekeepers in each state and analyzed at the Apiculture Laboratory of the Entomology Section of Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, State of São Paulo, Brazil. The pollen analysis was performed using the acetolysis method. The samples were submitted to both a qualitative and a quantitative analysis. The dominant pollen in the State of Ceará is from Mimosa caesalpiniaefolia, M. verrucosa, Borreria verticillata, Serjania sp., and a Fabaceae pollen type, while in the State of Piauí it is from Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana and Tibouchina sp.

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

    Science.gov (United States)

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

    2012-01-01

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

  14. Ionizing radiation sources management in the Commonwealth of Independent States - CIS

    International Nuclear Information System (INIS)

    Iskra, A.; Bufetova, M.

    2006-01-01

    Ionizing radiation sources cover a broad band of power: from powerful NPP reactors and research reactors to portable radioisotope ionizing radiation sources applied in medicine, agriculture, industry and in the energy supply systems of remote facilities. At present, scales and use field of radionuclide sources in the CIS have the tendency to increase. In this connection, the issues of ionizing radiation sources management safety at all stages of their life cycle, from production to treatment, have been of a great importance. The materials on ionizing radiation sources inventory and treatment in the CIS (Russia, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan and Ukraine) are presented in the report. It is shown that in some republics, there is difficulty in ionizing radiation sources accounting and control system; the national regulatory and legal framework bases regulating activity on radioactive sources use, localization and treatment require update. Many problems are connected with the sources beyond state accounting. The problem of ionizing radiation sources use safety is complicated by the growing activity of various terrorist groups. The opportunity to use ionizing radiation sources with terrorism goals requires the application of defined systems of security and physical protection at all stages of their management. For this purpose a collective, with all CIS countries, organization of radioactive sources accounting and control as well as countermeasures on their illegal transportation and use are necessary. In this connection, the information collection regarding situation with providing of ionizing radiation sources safety, conditions of equipment and storage facilities, radioactive materials accounting and control system in the CIS countries is vitally needed

  15. Exogenous sample contamination. Sources and interference.

    Science.gov (United States)

    Cornes, Michael P

    2016-12-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  17. High-power, solid-state rf source for accelerator cavities

    International Nuclear Information System (INIS)

    Vaughan, D.R.; Mols, G.E.; Reid, D.W.; Potter, J.M.

    1985-01-01

    During the past few years the Defense and Electronics Center of Westinghouse Electric Corporation has developed a solid-state, 250-kW peak, rf amplifier for use with the SPS-40 radar system. This system has a pulse length of 60 μs and operates across the frequency band from 400 to 450 MHz. Because of the potential use of such a system as an rf source for accelerator applications, a collaborative experiment was initiated between Los Alamos National Laboratory and Westinghouse to simulate the resonant load conditions of an accelerator cavity. This paper describes the positive results of that experiment as well as the solid-state amplifier architecture. It also explores the future of high-power, solid-state amplifiers as rf sources for accelerator structures

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Survey of elemental concentrations in lichen samples collected from Sao Paulo State

    International Nuclear Information System (INIS)

    Saiki, M.; Horimoto, L.K.; Vasconcellos, M.B.A.; Coccaro, D.M.B.; Marcelli, M.P.

    2001-01-01

    Samples of the lichen Canoparmelia texana collected in seven different sites of Sao Paulo State and one site of the Parana State were analysed by neutron activation analysis in order to obtain information on the air quality in these regions and also to select a region of interest for the evaluation of baseline level of elements in lichen species. Concentrations of the elements Al, As, Br, Ca, Cd, Cl, Co, Cs, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ti, Th, U, V, Zn and lanthanides were determined and a preliminary comparisons was made between the results obtained for samples collected in different sites. (author)

  20. Monte Carlo importance sampling for the MCNP trademark general source

    International Nuclear Information System (INIS)

    Lichtenstein, H.

    1996-01-01

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

  1. Pollen spectrum of propolis samples from São Paulo State, Brazil - doi: 10.4025/actascianimsci.v35i3.18389

    Directory of Open Access Journals (Sweden)

    Ricardo Oliveira Orsi

    2013-07-01

    Full Text Available The pollen spectrum of propolis is a good indicative of the phytogeographical origin of the bee product and the local flora available for bee visiting. The present study aimed to perform pollen analysis of propolis produced by Apis mellifera L., in the São Paulo State, Brazil. Propolis samples were directly obtained from beekeepers and slides were prepared for qualitative and quantitative analysis of pollen after propolis extraction. According to the results twenty-eight types of pollen were found and distributed in fifteen botanical families. Pollens from Mimosoideae and Myrtaceae types were found in all samples. In São Paulo State, there is a wide variety of vegetal sources which are components of the final propolis composition.   

  2. Sources of individual differences in depressive symptoms: analysis of two samples of twins and their families.

    Science.gov (United States)

    Kendler, K S; Walters, E E; Truett, K R; Heath, A C; Neale, M C; Martin, N G; Eaves, L J

    1994-11-01

    Self-reported symptoms of depression are commonly used in mental health research to assess current psychiatric state, yet wide variation in these symptoms among individuals has been found in both clinical and epidemiologic populations. The authors sought to understand, from a genetic-epidemiologic perspective, the sources of individual differences in depressive symptoms. Self-reported symptoms of depression were assessed in two samples of twins and their spouses, parents, siblings, and offspring: one sample contained volunteer twins recruited through the American Association of Retired Persons and their relatives (N = 19,203 individuals) and the other contained twins from a population-based twin registry in Virginia and their relatives (N = 11,242 individuals). Model fitting by an iterative, diagonal, weighted least squares method was applied to the 80 different family relationships in the extended twin-family design. Independent analyses of the two samples revealed that the level of depressive symptoms was modestly familial, and familial resemblance could be explained solely by genetic factors and spousal resemblance. The estimated heritability of depressive symptoms was between 30% and 37%. There was no evidence that the liability to depressive symptoms was environmentally transmitted from parents to offspring or was influenced by environmental factors shared either generally among siblings or specifically between twins. With correction for unreliability of measurement, genetic factors accounted for half of the stable variance in depressive symptoms. Depressive symptoms in adulthood partly reflect enduring characteristics of temperament that are substantially influenced by hereditary factors but little, or not at all, by shared environmental experiences in the family of origin.

  3. The Potential of Online Respondent Data for Choice Modeling in Transportation Research: Evidence from Stated Preference Experiments using Web-based Samples: Evidence from Stated Preference Experiments using Web-based Samples

    OpenAIRE

    Hoffer, Brice

    2015-01-01

    The aim of this thesis is to analyze the potential of online survey services for conducting stated preference experiments in the field of transportation planning. Several web-products for hosting questionnaires are evaluated considering important features required when conducting a stated preference survey. Based on this evaluation, the open-source platform LimeSurvey is the most appropriated for this kind of research. A stated preference questionnaire about pedestrians’ route choice in a Sin...

  4. Sources and effects of work-related stress among employees in foreign-owned manufacturing companies in Ogun state, Nigeria

    Directory of Open Access Journals (Sweden)

    Ajibade David

    2016-12-01

    Full Text Available This study investigates the sources and effects of work-related stress among employees in foreign owned manufacturing companies in Ogun State, Nigeria. The study used cross sectional descriptive design and a total of three hundred and two (302 respondents were selected using stratified random sampling technique from five randomly selected foreign-owned manufacturing companies. Data were collected using questionnaire and statistically analysed using frequencies, percentages and weighted means. The study reveals factors such as unfavourable physical working conditions, job insecurity, poor career development, and long working hours fostering stress on employees in the sampled companies. The study further reveals that respondents suffered consequences such as restlessness, anxiety and nervous indigestion, headache, neck ache, and inability to concentrate. This study however has implication for management of foreign-owned manufacturing organization. Based on this, appropriate recommendations were made application of which will help to ensure enabling workplace environment and thus reduce the effects of stress on employees.

  5. State of the Art ECR Ion Sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.

    1997-01-01

    Electron Cyclotron Resonance (ECR) ion source which produces highly-charged ions is used in heavy ion accelerators worldwide. Applications also found in atomic physics research and industry ion implantation. ECR ion source performance continues to improve, especially in the last few years with new techniques, such as multiple-frequency plasma heating and better methods to provide extra cold electrons, combined with higher magnetic mirror fields. So far more than 1 emA of multiply-charged ions such as He 2+ and O 6+ , and 30 eμA of Au 32+ , 1.1 eμA of 238 U 48+ , and epA currents of very high charge states such as 86 Kr 35+ and 238 U 60+ have been produced

  6. Atmospheric Nitrogen Deposition in the Western United States: Sources, Sinks and Changes over Time

    Science.gov (United States)

    Anderson, Sarah Marie

    Anthropogenic activities have greatly modified the way nitrogen moves through the atmosphere and terrestrial and aquatic environments. Excess reactive nitrogen generated through fossil fuel combustion, industrial fixation, and intensification of agriculture is not confined to anthropogenic systems but leaks into natural ecosystems with consequences including acidification, eutrophication, and biodiversity loss. A better understanding of where excess nitrogen originates and how that changes over time is crucial to identifying when, where, and to what degree environmental impacts occur. A major route into ecosystems for excess nitrogen is through atmospheric deposition. Excess nitrogen is emitted to the atmosphere where it can be transported great distances before being deposited back to the Earth's surface. Analyzing the composition of atmospheric nitrogen deposition and biological indicators that reflect deposition can provide insight into the emission sources as well as processes and atmospheric chemistry that occur during transport and what drives variation in these sources and processes. Chapter 1 provides a review and proof of concept of lichens to act as biological indicators and how their elemental and stable isotope composition can elucidate variation in amounts and emission sources of nitrogen over space and time. Information on amounts and emission sources of nitrogen deposition helps inform natural resources and land management decisions by helping to identify potentially impacted areas and causes of those impacts. Chapter 2 demonstrates that herbaria lichen specimens and field lichen samples reflect historical changes in atmospheric nitrogen deposition from urban and agricultural sources across the western United States. Nitrogen deposition increases throughout most of the 20 th century because of multiple types of emission sources until the implementation of the Clean Air Act Amendments of 1990 eventually decrease nitrogen deposition around the turn of

  7. High Intensity High Charge State ECR Ion Sources

    CERN Document Server

    Leitner, Daniela

    2005-01-01

    The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...

  8. Anti-correlated Soft Lags in the Intermediate State of Black Hole Source GX 339-4

    OpenAIRE

    Sriram, K.; Rao, A. R.; Choi, C. S.

    2010-01-01

    We report the few hundred second anti-correlated soft lags between soft and hard energy bands in the source GX 339-4 using RXTE observations. In one observation, anti-correlated soft lags were observed using the ISGRI/INTEGRAL hard energy band and the PCA/RXTE soft energy band light curves. The lags were observed when the source was in hard and soft intermediate states, i.e., in a steep power-law state.We found that the temporal and spectral properties were changed during the lag timescale. T...

  9. 34 CFR 364.29 - What are the requirements for coordinating Federal and State sources of funding?

    Science.gov (United States)

    2010-07-01

    ... State sources of funding? 364.29 Section 364.29 Education Regulations of the Offices of the Department... and State sources of funding? (a) The State plan must describe efforts to coordinate Federal and State funding for centers and IL services. (b) The State plan must identify the amounts, sources, and purposes...

  10. Surface-water nutrient conditions and sources in the United States Pacific Northwest

    Science.gov (United States)

    Wise, D.R.; Johnson, H.M.

    2011-01-01

    The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well as landscape characteristics that affect nutrient delivery to streams. Annual nutrient yields were higher in watersheds on the wetter, west side of the Cascade Range compared to watersheds on the drier, east side. High nutrient enrichment (relative to the U.S. Environmental Protection Agency's recommended nutrient criteria) was estimated in watersheds throughout the region. Forest land was generally the largest source of total nitrogen stream load and geologic material was generally the largest source of total phosphorus stream load generated within the 12,039 modeled watersheds. These results reflected the prevalence of these two natural sources and the low input from other nutrient sources across the region. However, the combined input from agriculture, point sources, and developed land, rather than natural nutrient sources, was responsible for most of the nutrient load discharged from many of the largest watersheds. Our results provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to environmental managers in future water-quality planning efforts.

  11. Solid state characterization of commercial crystalline and amorphous atorvastatin calcium samples.

    Science.gov (United States)

    Shete, Ganesh; Puri, Vibha; Kumar, Lokesh; Bansal, Arvind K

    2010-06-01

    Atorvastatin calcium (ATC), an anti-lipid BCS class II drug, is marketed in crystalline and amorphous solid forms. The objective of this study was to perform solid state characterization of commercial crystalline and amorphous ATC drug samples available in the Indian market. Six samples each of crystalline and amorphous ATC were characterized using X-ray powder diffractometry (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis, Karl Fisher titrimetry, microscopy (hot stage microscopy, scanning electron microscopy), contact angle, and intrinsic dissolution rate (IDR). All crystalline ATC samples were found to be stable form I, however one sample possessed polymorphic impurity, evidenced in XRPD and DSC analysis. Amongst the amorphous ATC samples, XRPD demonstrated five samples to be amorphous 'form 27', while, one matched amorphous 'form 23'. Thermal behavior of amorphous ATC samples was compared to amorphous ATC generated by melt quenching in DSC. ATC was found to be an excellent glass former with T(g)/T(m) of 0.95. Residual crystallinity was detected in two of the amorphous samples by complementary use of conventional and modulated DSC techniques. The wettability and IDR of all amorphous samples was found to be higher than the crystalline samples. In conclusion, commercial ATC samples exhibited diverse solid state behavior that can impact the performance and stability of the dosage forms.

  12. Directional dependency of air sampling

    International Nuclear Information System (INIS)

    1994-01-01

    A field study was performed by Idaho State University-Environmental Monitoring Laboratory (EML) to examine the directional dependency of low-volume air samplers. A typical continuous low volume air sampler contains a sample head that is mounted on the sampler housing either horizontally through one of four walls or vertically on an exterior wall 'looking down or up.' In 1992, a field study was undertaken to estimate sampling error and to detect the directional effect of sampler head orientation. Approximately 1/2 mile downwind from a phosphate plant (continuous source of alpha activity), four samplers were positioned in identical orientation alongside one sampler configured with the sample head 'looking down'. At least five consecutive weekly samples were collected. The alpha activity, beta activity, and the Be-7 activity collected on the particulate filter were analyzed to determine sampling error. Four sample heads were than oriented to the four different horizontal directions. Samples were collected for at least five weeks. Analysis of the alpha data can show the effect of sampler orientation to a know near source term. Analysis of the beta and Be-7 activity shows the effect of sampler orientation to a ubiquitous source term

  13. Point sources of emerging contaminants along the Colorado River Basin: Source water for the arid Southwestern United States

    Science.gov (United States)

    Jones-Lepp, Tammy L.; Sanchez, Charles; Alvarez, David A.; Wilson, Doyle C.; Taniguchi-Fu, Randi-Laurant

    2012-01-01

    Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into empty SPEs and eluted with methanol. All extracts were prepared for, and analyzed by, liquid chromatography–electrospray-ion trap mass spectrometry (LC–ESI-ITMS). Log DOW values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the yeast estrogen screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicity response. In the grab samples, azithromycin (an antibiotic) was detected in all but one urban waste stream, with concentrations ranging from 30 ng/L to 2800 ng/L. Concentration levels of azithromycin, methamphetamine and pseudoephedrine showed temporal variation from the Tucson WWTP. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10 ng/L), but most were below detection limits.

  14. Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

    Science.gov (United States)

    This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practica...

  15. Sample size of the reference sample in a case-augmented study.

    Science.gov (United States)

    Ghosh, Palash; Dewanji, Anup

    2017-05-01

    The case-augmented study, in which a case sample is augmented with a reference (random) sample from the source population with only covariates information known, is becoming popular in different areas of applied science such as pharmacovigilance, ecology, and econometrics. In general, the case sample is available from some source (for example, hospital database, case registry, etc.); however, the reference sample is required to be drawn from the corresponding source population. The required minimum size of the reference sample is an important issue in this regard. In this work, we address the minimum sample size calculation and discuss related issues. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  17. Tri-State Current Source Inverter With Improved Dynamic Performance

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chiang; Wong, Chow Pang

    2008-01-01

    Traditional dc-ac current source inverter (CSI) has a right-half-plane (RHP) zero in its control-to-output transfer function. This RHP zero causes the inverter output to fall before rising when a step increase in command reference is required (commonly known as non-minimum-phase effect). To achieve...... a better dynamic response, this paper proposes the design of a tri-state CSI using only an additional semiconductor switch for introducing unique freewheeling states to the traditional six active and three null states of a CSI. With the freewheeling states inserted appropriately within the inverter state...... sequence, the inductive boosting and discharging intervals can be decoupled, allowing the RHP zero to be eliminated with only minor circuit modifications (high level control schemes like predictive and multiloop voltage/current control remain unchanged). The designed inverter can be controlled using...

  18. Coupling meteorology, metal concentrations, and Pb isotopes for source attribution in archived precipitation samples.

    Science.gov (United States)

    Graney, Joseph R; Landis, Matthew S

    2013-03-15

    A technique that couples lead (Pb) isotopes and multi-element concentrations with meteorological analysis was used to assess source contributions to precipitation samples at the Bondville, Illinois USA National Trends Network (NTN) site. Precipitation samples collected over a 16month period (July 1994-October 1995) at Bondville were parsed into six unique meteorological flow regimes using a minimum variance clustering technique on back trajectory endpoints. Pb isotope ratios and multi-element concentrations were measured using high resolution inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) on the archived precipitation samples. Bondville is located in central Illinois, ~250km downwind from smelters in southeast Missouri. The Mississippi Valley Type ore deposits in Missouri provided a unique multi-element and Pb isotope fingerprint for smelter emissions which could be contrasted to industrial emissions from the Chicago and Indianapolis urban areas (~125km north and east, of Bondville respectively) and regional emissions from electric utility facilities. Differences in Pb isotopes and element concentrations in precipitation corresponded to flow regime. Industrial sources from urban areas, and thorogenic Pb from coal use, could be differentiated from smelter emissions from Missouri by coupling Pb isotopes with variations in element ratios and relative mass factors. Using a three endmember mixing model based on Pb isotope ratio differences, industrial processes in urban airsheds contributed 56±19%, smelters in southeast Missouri 26±13%, and coal combustion 18±7%, of the Pb in precipitation collected in Bondville in the mid-1990s. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2018-01-01

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

  20. Sub-sampling-based 2D localization of an impulsive acoustic source in reverberant environments

    KAUST Repository

    Omer, Muhammad

    2014-07-01

    This paper presents a robust method for two-dimensional (2D) impulsive acoustic source localization in a room environment using low sampling rates. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. We consider the RIR as a sparse phenomenon and apply a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) for its estimation from the sub-sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR, and their difference yields the desired time delay estimate (TDE). Low sampling rates reduces the hardware and computational complexity and decreases the communication between the microphones and the centralized location. Simulation and experimental results of an actual hardware setup are presented to demonstrate the performance of the proposed technique.

  1. Sub-sampling-based 2D localization of an impulsive acoustic source in reverberant environments

    KAUST Repository

    Omer, Muhammad; Quadeer, Ahmed A; Sharawi, Mohammad S; Al-Naffouri, Tareq Y.

    2014-01-01

    This paper presents a robust method for two-dimensional (2D) impulsive acoustic source localization in a room environment using low sampling rates. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. We consider the RIR as a sparse phenomenon and apply a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) for its estimation from the sub-sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR, and their difference yields the desired time delay estimate (TDE). Low sampling rates reduces the hardware and computational complexity and decreases the communication between the microphones and the centralized location. Simulation and experimental results of an actual hardware setup are presented to demonstrate the performance of the proposed technique.

  2. Financing state newborn screening programs: sources and uses of funds.

    Science.gov (United States)

    Johnson, Kay; Lloyd-Puryear, Michele A; Mann, Marie Y; Ramos, Lauren Raskin; Therrell, Bradford L

    2006-05-01

    Financing for newborn screening is different from virtually all other public health programs. All except 5 screening programs collect fees as the primary source of program funding. A fee-based approach to financing newborn screening has been adopted by most states, to ensure consistent funding for this critical public health activity. Two types of data are reported here, ie, primary data from a survey of 37 state public health agencies and findings from exploratory case studies from 7 states. Most of the programs that participated in this survey (73%) reported that their newborn screening funding increased between 2002 and 2005, typically through increased fees and to a lesser extent through Medicaid, Title V Maternal and Child Health Services Block Grant, and state general revenue funding. All of the responding states that collect fees (n = 31) use such funds to support laboratory expenses, and most (70%) finance short-term follow-up services and program management. Nearly one half (47%) finance longer-term follow-up services, case management, or family support beyond diagnosis. Other states (43%) finance genetic or nutritional counseling and formula foods or treatment. Regardless of the source of funds, the available evidence indicates that states are committed to maintaining their programs and securing the necessary financing for the initial screening through diagnosis. Use of federal funding is currently limited; however, pressure to provide dedicated federal funding would likely increase if national recommendations for a uniform newborn screening panel were issued.

  3. Importance sampling of rare events in chaotic systems

    DEFF Research Database (Denmark)

    Leitão, Jorge C.; Parente Lopes, João M.Viana; Altmann, Eduardo G.

    2017-01-01

    space of chaotic systems. As examples of our general framework we compute the distribution of finite-time Lyapunov exponents (in different chaotic maps) and the distribution of escape times (in transient-chaos problems). Our methods sample exponentially rare states in polynomial number of samples (in......Finding and sampling rare trajectories in dynamical systems is a difficult computational task underlying numerous problems and applications. In this paper we show how to construct Metropolis-Hastings Monte-Carlo methods that can efficiently sample rare trajectories in the (extremely rough) phase...... both low- and high-dimensional systems). An open-source software that implements our algorithms and reproduces our results can be found in reference [J. Leitao, A library to sample chaotic systems, 2017, https://github.com/jorgecarleitao/chaospp]....

  4. Extent of Head Teachers' Utilization of Innovative Sources of Funding Primary Schools in Enugu State of Nigeria

    Science.gov (United States)

    Amogechukwu, Eze Thecla; Unoma, Chidobi Roseline

    2017-01-01

    The purpose of this study was to examine the extent Head teachers utilize innovative sources of funding primary schools in Enugu State of Nigeria. Descriptive survey design was employed to examine the extent head teachers utilize innovative sources of funding primary schools in Enugu State. Data were collected through a 14-item questionnaire…

  5. Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples

    International Nuclear Information System (INIS)

    Hoetzl, H.; Rosner, G.; Winkler, R.; Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg

    1992-01-01

    The sources of Chernobyl-derived caesium concentrations in air and deposition samples collected from mid-1986 to end-1990 at Munich- Neuherberg, Germany, were investigated. Local resuspension has been found to be the main source. By comparison with deposition data from other locations it is estimated that within a range from 20 Bq m -2 to 60 kBq m -2 of initially deposited 137 Cs activity ∼2% is re-deposited by the process of local resuspension in Austria, Germany, Japan and United Kingdom, while significantly higher total resuspension is to be expected for Denmark and Finland. Stratospheric contribution to present concentrations is shown to be negligible. This is confirmed by cross correlation analysis between the time series of 137 Cs in air and precipitation before and after the Chernobyl accident and the respective time series of cosmogenic 7 Be, which is an indicator of stratospheric input. Seasonal variations of caesium concentrations with maxima in winter were observed. (author). 32 refs.; 5 figs.; 1 tab

  6. Adaptive importance sampling of random walks on continuous state spaces

    International Nuclear Information System (INIS)

    Baggerly, K.; Cox, D.; Picard, R.

    1998-01-01

    The authors consider adaptive importance sampling for a random walk with scoring in a general state space. Conditions under which exponential convergence occurs to the zero-variance solution are reviewed. These results generalize previous work for finite, discrete state spaces in Kollman (1993) and in Kollman, Baggerly, Cox, and Picard (1996). This paper is intended for nonstatisticians and includes considerable explanatory material

  7. [PHAHs levels in soil samples from the E-waste disassembly sites and their sources allocation].

    Science.gov (United States)

    Zhao, Gao-Feng; Wang, Zi-Jian

    2009-06-15

    Soil samples (each with 3 replicates of - 1 kg, at the top 0-5 cm layer) were collected from each of the e-waste disassembly sites and the control site. Also obtained from each disassembly site were samples (each weighing - 0.2 kg) of cable coating,stuffing powder, and circuit boards chipping. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in soil and in their potential sources, including e-waste residues, were measured using the GC-MS5975B technique. The highest level of PBBs was found in the cable coating among the three e-waste residues, with a concentration of 35.25 ng x g(-1). The contents of low-brominated PBBs (including monobromobiphenyls and dibromobiphenyls) accounted for 38% of the total PBBs concentration observed in cable coating sample. The highest levels of PBDEs and PBDE209 were found in the stuffing powder for electronic component among the collected e-waste residues, with a concentration of 29.71 and 4.19 x 10(3) ng x g(-1). PBDE153 and PBDE183 were the most predominant PBDE congeners, with their concentration accounting for 43% and 24% of the total PBDEs concentration observed in the stuffing powder sample, respectively. Levels of PCBs in cable coating were the highest in these e-waste residues, with a concentration of 680.02 ngx g(-1). The observed values of the three PHAHs in soils from the disassembly site were considerably higher than their corresponding values observed in the control site (p < 0.05), which indicates that these PHAHs from e-waste is the pollution source of local environment.

  8. Resource cost results for one-way entanglement distillation and state merging of compound and arbitrarily varying quantum sources

    International Nuclear Information System (INIS)

    Boche, H.; Janßen, G.

    2014-01-01

    We consider one-way quantum state merging and entanglement distillation under compound and arbitrarily varying source models. Regarding quantum compound sources, where the source is memoryless, but the source state an unknown member of a certain set of density matrices, we continue investigations begun in the work of Bjelaković et al. [“Universal quantum state merging,” J. Math. Phys. 54, 032204 (2013)] and determine the classical as well as entanglement cost of state merging. We further investigate quantum state merging and entanglement distillation protocols for arbitrarily varying quantum sources (AVQS). In the AVQS model, the source state is assumed to vary in an arbitrary manner for each source output due to environmental fluctuations or adversarial manipulation. We determine the one-way entanglement distillation capacity for AVQS, where we invoke the famous robustification and elimination techniques introduced by Ahlswede. Regarding quantum state merging for AVQS we show by example that the robustification and elimination based approach generally leads to suboptimal entanglement as well as classical communication rates

  9. Sources of information influencing the state-of-the-science gap in hormone replacement therapy usage.

    Directory of Open Access Journals (Sweden)

    Fiona Chew

    Full Text Available Medical reviews and research comprise a key information source for news media stories on medical therapies and innovations as well as for physicians in updating their practice. The present study examined medical review journal articles, physician surveys and news media coverage of hormone replacement therapy (HT to assess the relationship between the three information sources and whether/if they contributed to a state-of-the-science gap (a condition when the evaluation of a medical condition or therapy ascertained by the highest standards of investigation is incongruent with the science-in-practice such as physician recommendations and patient actions.We content-analyzed 177 randomly sampled HT medical reviews between 2002 and 2014, and HT news valence in three major TV networks, newspapers and magazines/internet sites in 2002-2003, 2008-2009 and 2012-14. The focus in both analyses was whether HT benefits outweighed risks, risks outweighed benefits or both risks and benefits were presented. We also qualitatively content-analyzed all 19 surveys of US physicians' HT recommendations from 2002 to 2009, and 2012 to 2014.Medical reviews yielded a mixed picture about HT (40.1% benefits, 26.0% risks, and 33.9% both benefits and risks. While a majority of physician surveys were pro-HT 10/19, eight showed varied attitudes and one was negative. Newspaper and television coverage reflected a pro and con balance while magazine stories were more positive in the later reporting period.Medical journal review articles, physicians, and media reports all provide varying view points towards hormone therapy use thus leading to limited knowledge about the actual risks and benefits of HT among peri- and menopausal women and a state-of-the-science gap.

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

    Directory of Open Access Journals (Sweden)

    Yue Kan

    2015-06-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  13. Open source Matrix Product States: Opening ways to simulate entangled many-body quantum systems in one dimension

    Science.gov (United States)

    Jaschke, Daniel; Wall, Michael L.; Carr, Lincoln D.

    2018-04-01

    Numerical simulations are a powerful tool to study quantum systems beyond exactly solvable systems lacking an analytic expression. For one-dimensional entangled quantum systems, tensor network methods, amongst them Matrix Product States (MPSs), have attracted interest from different fields of quantum physics ranging from solid state systems to quantum simulators and quantum computing. Our open source MPS code provides the community with a toolset to analyze the statics and dynamics of one-dimensional quantum systems. Here, we present our open source library, Open Source Matrix Product States (OSMPS), of MPS methods implemented in Python and Fortran2003. The library includes tools for ground state calculation and excited states via the variational ansatz. We also support ground states for infinite systems with translational invariance. Dynamics are simulated with different algorithms, including three algorithms with support for long-range interactions. Convenient features include built-in support for fermionic systems and number conservation with rotational U(1) and discrete Z2 symmetries for finite systems, as well as data parallelism with MPI. We explain the principles and techniques used in this library along with examples of how to efficiently use the general interfaces to analyze the Ising and Bose-Hubbard models. This description includes the preparation of simulations as well as dispatching and post-processing of them.

  14. Simulation of a Jackson tandem network using state-dependent importance sampling

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2008-01-01

    This paper considers importance sampling as a tool for rare-event simulation. The focus is on estimating the probability of overflow in the downstream queue of a Jackson two-node tandem queue. It is known that in this setting 'traditional' state-independent importance-sampling distributions perform

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

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

    Science.gov (United States)

    Kwon, Hyeokjun; Kang, Yoojin; Jang, Junwoo

    2017-09-01

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

  17. Racialized risk environments in a large sample of people who inject drugs in the United States.

    Science.gov (United States)

    Cooper, Hannah L F; Linton, Sabriya; Kelley, Mary E; Ross, Zev; Wolfe, Mary E; Chen, Yen-Tyng; Zlotorzynska, Maria; Hunter-Jones, Josalin; Friedman, Samuel R; Des Jarlais, Don; Semaan, Salaam; Tempalski, Barbara; DiNenno, Elizabeth; Broz, Dita; Wejnert, Cyprian; Paz-Bailey, Gabriela

    2016-01-01

    Substantial racial/ethnic disparities exist in HIV infection among people who inject drugs (PWID) in many countries. To strengthen efforts to understand the causes of disparities in HIV-related outcomes and eliminate them, we expand the "Risk Environment Model" to encompass the construct "racialized risk environments," and investigate whether PWID risk environments in the United States are racialized. Specifically, we investigate whether black and Latino PWID are more likely than white PWID to live in places that create vulnerability to adverse HIV-related outcomes. As part of the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance, 9170 PWID were sampled from 19 metropolitan statistical areas (MSAs) in 2009. Self-reported data were used to ascertain PWID race/ethnicity. Using Census data and other administrative sources, we characterized features of PWID risk environments at four geographic scales (i.e., ZIP codes, counties, MSAs, and states). Means for each feature of the risk environment were computed for each racial/ethnic group of PWID, and were compared across racial/ethnic groups. Almost universally across measures, black PWID were more likely than white PWID to live in environments associated with vulnerability to adverse HIV-related outcomes. Compared to white PWID, black PWID lived in ZIP codes with higher poverty rates and worse spatial access to substance abuse treatment and in counties with higher violent crime rates. Black PWID were less likely to live in states with laws facilitating sterile syringe access (e.g., laws permitting over-the-counter syringe sales). Latino/white differences in risk environments emerged at the MSA level (e.g., Latino PWID lived in MSAs with higher drug-related arrest rates). PWID risk environments in the US are racialized. Future research should explore the implications of this racialization for racial/ethnic disparities in HIV-related outcomes, using appropriate methods. Copyright © 2015

  18. The study towards high intensity high charge state laser ion sources.

    Science.gov (United States)

    Zhao, H Y; Jin, Q Y; Sha, S; Zhang, J J; Li, Z M; Liu, W; Sun, L T; Zhang, X Z; Zhao, H W

    2014-02-01

    As one of the candidate ion sources for a planned project, the High Intensity heavy-ion Accelerator Facility, a laser ion source has been being intensively studied at the Institute of Modern Physics in the past two years. The charge state distributions of ions produced by irradiating a pulsed 3 J/8 ns Nd:YAG laser on solid targets of a wide range of elements (C, Al, Ti, Ni, Ag, Ta, and Pb) were measured with an electrostatic ion analyzer spectrometer, which indicates that highly charged ions could be generated from low-to-medium mass elements with the present laser system, while the charge state distributions for high mass elements were relatively low. The shot-to-shot stability of ion pulses was monitored with a Faraday cup for carbon target. The fluctuations within ±2.5% for the peak current and total charge and ±6% for pulse duration were demonstrated with the present setup of the laser ion source, the suppression of which is still possible.

  19. Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Rosner, G.; Winkler, R. (Gesellschaft fuer Strahlen-und Umweltforschung Munich, Neuherberg (Germany). Forschungszentrum fuer Umwelt und Gesundheit Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany). Inst. fuer Strahlenschutz)

    1992-06-01

    The sources of Chernobyl-derived caesium concentrations in air and deposition samples collected from mid-1986 to end-1990 at Munich- Neuherberg, Germany, were investigated. Local resuspension has been found to be the main source. By comparison with deposition data from other locations it is estimated that within a range from 20 Bq m[sup -2] to 60 kBq m[sup -2] of initially deposited [sup 137]Cs activity [approx]2% is re-deposited by the process of local resuspension in Austria, Germany, Japan and United Kingdom, while significantly higher total resuspension is to be expected for Denmark and Finland. Stratospheric contribution to present concentrations is shown to be negligible. This is confirmed by cross correlation analysis between the time series of [sup 137]Cs in air and precipitation before and after the Chernobyl accident and the respective time series of cosmogenic [sup 7]Be, which is an indicator of stratospheric input. Seasonal variations of caesium concentrations with maxima in winter were observed. (author). 32 refs.; 5 figs.; 1 tab.

  20. Evaluation of PCB sources and releases for identifying priorities to reduce PCBs in Washington State (USA).

    Science.gov (United States)

    Davies, Holly; Delistraty, Damon

    2016-02-01

    Polychlorinated biphenyls (PCBs) are ubiquitously distributed in the environment and produce multiple adverse effects in humans and wildlife. As a result, the purpose of our study was to characterize PCB sources in anthropogenic materials and releases to the environment in Washington State (USA) in order to formulate recommendations to reduce PCB exposures. Methods included review of relevant publications (e.g., open literature, industry studies and reports, federal and state government databases), scaling of PCB sources from national or county estimates to state estimates, and communication with industry associations and private and public utilities. Recognizing high associated uncertainty due to incomplete data, we strived to provide central tendency estimates for PCB sources. In terms of mass (high to low), PCB sources include lamp ballasts, caulk, small capacitors, large capacitors, and transformers. For perspective, these sources (200,000-500,000 kg) overwhelm PCBs estimated to reside in the Puget Sound ecosystem (1500 kg). Annual releases of PCBs to the environment (high to low) are attributed to lamp ballasts (400-1500 kg), inadvertent generation by industrial processes (900 kg), caulk (160 kg), small capacitors (3-150 kg), large capacitors (10-80 kg), pigments and dyes (0.02-31 kg), and transformers (PCB distribution and decrease exposures include assessment of PCBs in buildings (e.g., schools) and replacement of these materials, development of Best Management Practices (BMPs) to contain PCBs, reduction of inadvertent generation of PCBs in consumer products, expansion of environmental monitoring and public education, and research to identify specific PCB congener profiles in human tissues.

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

    Science.gov (United States)

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

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

  2. Relation between Nitrates in Water Wells and Potential Sources in the Lower Yakima Valley, Washington State

    Science.gov (United States)

    Results of a study EPA conducted to investigate the contribution of various sources to the high nitrate levels in groundwater and residential drinking water wells in the Lower Yakima Valley of Washington State.

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

    Science.gov (United States)

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

    2017-07-27

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

  4. Design of a scanning probe microscope with advanced sample treatment capabilities: An atomic force microscope combined with a miniaturized inductively coupled plasma source

    International Nuclear Information System (INIS)

    Hund, Markus; Herold, Hans

    2007-01-01

    We describe the design and performance of an atomic force microscope (AFM) combined with a miniaturized inductively coupled plasma source working at a radio frequency of 27.12 MHz. State-of-the-art scanning probe microscopes (SPMs) have limited in situ sample treatment capabilities. Aggressive treatments such as plasma etching or harsh treatments such as etching in aggressive liquids typically require the removal of the sample from the microscope. Consequently, time consuming procedures are required if the same sample spot has to be imaged after successive processing steps. We have developed a first prototype of a SPM which features a quasi in situ sample treatment using a modified commercial atomic force microscope. A sample holder is positioned in a special reactor chamber; the AFM tip can be retracted by several millimeters so that the chamber can be closed for a treatment procedure. Most importantly, after the treatment, the tip is moved back to the sample with a lateral drift per process step in the 20 nm regime. The performance of the prototype is characterized by consecutive plasma etching of a nanostructured polymer film

  5. An empirical assessment of near-source strong ground motion for a 6.6 mb (7.5 MS) earthquake in the Eastern United States

    International Nuclear Information System (INIS)

    Campbell, Kenneth W.

    1984-06-01

    To help assess the impact of the current U.S. Geological Survey position on the seismic safety of nuclear power plants in the Eastern United States (EUS), several techniques for estimating near-source strong ground motion for a Charleston size earthquake were evaluated. The techniques for estimating the near-source strong ground motion for a 6.6 m b (7.5 M S ) in the Eastern United States which were assessed are methods based on site specific analyses, semi-theoretical scaling techniques, and intensity-based estimates. The first involves the statistical analysis of ground motion records from earthquakes and recording stations having the same general characteristics (earthquakes with magnitudes of 7.5 M S or larger, epicentral distances of 25 km or less, and sites of either soil or rock). Some recommendations for source and characterization scaling of the bias resulting primarily from an inadequate sample of near-source recordings from earthquakes of large magnitude are discussed. The second technique evaluated requires that semi-theoretical estimates of peak ground motion parameters for a 6.6 m b (7.5 M S ) earthquake be obtained from scaling relations. Each relation uses a theoretical expression between peak acceleration magnitude and distance together with available strong motion data (majority coming from California) to develop a scaling relation appropriate for the Eastern United States. None of the existing ground motion models for the EUS include the potential effects of source or site characteristics. Adjustments to account for fault mechanisms, site topography, site geology, and the size and embedment of buildings are discussed. The final approach used relations between strong ground motion parameters and Modified Mercalli Intensity in conjunction with two methods to estimate peak parameters for a 6.6 m s (7.5 M S ) earthquake. As with other techniques, adjustment of peak acceleration estimates are discussed. Each method differently approaches the problem

  6. Time delay estimation in a reverberant environment by low rate sampling of impulsive acoustic sources

    KAUST Repository

    Omer, Muhammad

    2012-07-01

    This paper presents a new method of time delay estimation (TDE) using low sample rates of an impulsive acoustic source in a room environment. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. The RIR is considered a sparse phenomenon and a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) is utilized for its estimation from the low rate sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR and their difference yields the desired time delay. Low sampling rates reduce the hardware and computational complexity and decrease the communication between the microphones and the centralized location. The performance of the proposed technique is demonstrated by numerical simulations and experimental results. © 2012 IEEE.

  7. Media Use and Source Trust among Muslims in Seven Countries: Results of a Large Random Sample Survey

    Directory of Open Access Journals (Sweden)

    Steven R. Corman

    2013-12-01

    Full Text Available Despite the perceived importance of media in the spread of and resistance against Islamist extremism, little is known about how Muslims use different kinds of media to get information about religious issues, and what sources they trust when doing so. This paper reports the results of a large, random sample survey among Muslims in seven countries Southeast Asia, West Africa and Western Europe, which helps fill this gap. Results show a diverse set of profiles of media use and source trust that differ by country, with overall low trust in mediated sources of information. Based on these findings, we conclude that mass media is still the most common source of religious information for Muslims, but that trust in mediated information is low overall. This suggests that media are probably best used to persuade opinion leaders, who will then carry anti-extremist messages through more personal means.

  8. Use of CITATION code for flux calculation in neutron activation analysis with voluminous sample using an Am-Be source

    International Nuclear Information System (INIS)

    Khelifi, R.; Idiri, Z.; Bode, P.

    2002-01-01

    The CITATION code based on neutron diffusion theory was used for flux calculations inside voluminous samples in prompt gamma activation analysis with an isotopic neutron source (Am-Be). The code uses specific parameters related to the energy spectrum source and irradiation system materials (shielding, reflector). The flux distribution (thermal and fast) was calculated in the three-dimensional geometry for the system: air, polyethylene and water cuboidal sample (50x50x50 cm). Thermal flux was calculated in a series of points inside the sample. The results agreed reasonably well with observed values. The maximum thermal flux was observed at a distance of 3.2 cm while CITATION gave 3.7 cm. Beyond a depth of 7.2 cm, the thermal flux to fast flux ratio increases up to twice and allows us to optimise the detection system position in the scope of in-situ PGAA

  9. Prevalence of antimicrobial residues in eggs, tissue and feed samples in the State of Kuwait

    International Nuclear Information System (INIS)

    Alomirah, H.; Al-Mazeedi, H.; Al-Zenki, S.; Al-Faili, B.; Al-Foudary, M.; Abuzid, A.; Al-Sayed, I.; Sidhu, J.

    2007-01-01

    A total of 238 locally produced and imported eggs, tissue (meat, poultry and aquacultured fish) and feed and feedstuffs samples were collected at different seasonal periods from different farms and retail outlets in Kuwait and screened for presence of beta-lactams, tetracyclines, sulfonamides, streptomycin, macrolides and chloramphenicol (799 tests) using Charm II system. The results indicated that all of the 222 tests performed on table egg samples were negative for the analyzed antimicrobial residues indicating adherence to the guidelines for microbial use and withdrawal. Similarly, all of the 268 tests performed on tissue samples were negative for the analyzed antimicrobial residues except for chloramphenicol. These chloramphenicol positive samples, all of the 66 tests performed were negative for beta-lactams residues. Out of the 79 feed and feedstuff samples analyzed for teracyclines residues, broiler diet and concentrate samples (5%) were above the tetracyclines MRL (100 ppb.). On the other hands, results have revealed a widespread of sulfonamide residues and to a less extent chloramphenicol in tested feed and feedstuff samples. The Charm II system was reliable for rapid screening of antimicrobial residues. In general, results obtained in our study necessitate more effective and well planned national antimicrobial residues surveillance programs focusing particularly on samples imported from highly risk sources. (author)

  10. Sources and mixing state of summertime background aerosol in the north-western Mediterranean basin

    Science.gov (United States)

    Arndt, Jovanna; Sciare, Jean; Mallet, Marc; Roberts, Greg C.; Marchand, Nicolas; Sartelet, Karine; Sellegri, Karine; Dulac, François; Healy, Robert M.; Wenger, John C.

    2017-06-01

    An aerosol time-of-flight mass spectrometer (ATOFMS) was employed to provide real-time single particle mixing state and thereby source information for aerosols impacting the western Mediterranean basin during the ChArMEx-ADRIMED and SAF-MED campaigns in summer 2013. The ATOFMS measurements were made at a ground-based remote site on the northern tip of Corsica. Twenty-seven distinct ATOFMS particle classes were identified and subsequently grouped into eight general categories: EC-rich (elemental carbon), K-rich, Na-rich, amines, OC-rich (organic carbon), V-rich, Fe-rich and Ca-rich particles. Mass concentrations were reconstructed for the ATOFMS particle classes and found to be in good agreement with other co-located quantitative measurements (PM1, black carbon (BC), organic carbon, sulfate mass and ammonium mass). Total ATOFMS reconstructed mass (PM2. 5) accounted for 70-90 % of measured PM10 mass and was comprised of regionally transported fossil fuel (EC-rich) and biomass burning (K-rich) particles. The accumulation of these transported particles was favoured by repeated and extended periods of air mass stagnation over the western Mediterranean during the sampling campaigns. The single particle mass spectra proved to be valuable source markers, allowing the identification of fossil fuel and biomass burning combustion sources, and was therefore highly complementary to quantitative measurements made by Particle into Liquid Sampler ion chromatography (PILS-IC) and an aerosol chemical speciation monitor (ACSM), which have demonstrated that PM1 and PM10 were comprised predominantly of sulfate, ammonium and OC. Good temporal agreement was observed between ATOFMS EC-rich and K-rich particle mass concentrations and combined mass concentrations of BC, sulfate, ammonium and low volatility oxygenated organic aerosol (LV-OOA). This combined information suggests that combustion of fossil fuels and biomass produced primary EC- and OC-containing particles, which then

  11. Sources and mixing state of summertime background aerosol in the north-western Mediterranean basin

    Directory of Open Access Journals (Sweden)

    J. Arndt

    2017-06-01

    Full Text Available An aerosol time-of-flight mass spectrometer (ATOFMS was employed to provide real-time single particle mixing state and thereby source information for aerosols impacting the western Mediterranean basin during the ChArMEx-ADRIMED and SAF-MED campaigns in summer 2013. The ATOFMS measurements were made at a ground-based remote site on the northern tip of Corsica. Twenty-seven distinct ATOFMS particle classes were identified and subsequently grouped into eight general categories: EC-rich (elemental carbon, K-rich, Na-rich, amines, OC-rich (organic carbon, V-rich, Fe-rich and Ca-rich particles. Mass concentrations were reconstructed for the ATOFMS particle classes and found to be in good agreement with other co-located quantitative measurements (PM1, black carbon (BC, organic carbon, sulfate mass and ammonium mass. Total ATOFMS reconstructed mass (PM2. 5 accounted for 70–90 % of measured PM10 mass and was comprised of regionally transported fossil fuel (EC-rich and biomass burning (K-rich particles. The accumulation of these transported particles was favoured by repeated and extended periods of air mass stagnation over the western Mediterranean during the sampling campaigns. The single particle mass spectra proved to be valuable source markers, allowing the identification of fossil fuel and biomass burning combustion sources, and was therefore highly complementary to quantitative measurements made by Particle into Liquid Sampler ion chromatography (PILS-IC and an aerosol chemical speciation monitor (ACSM, which have demonstrated that PM1 and PM10 were comprised predominantly of sulfate, ammonium and OC. Good temporal agreement was observed between ATOFMS EC-rich and K-rich particle mass concentrations and combined mass concentrations of BC, sulfate, ammonium and low volatility oxygenated organic aerosol (LV-OOA. This combined information suggests that combustion of fossil fuels and biomass produced primary EC- and OC-containing particles, which

  12. Laser solid sampling for a solid-state-detector ICP emission spectrometer

    International Nuclear Information System (INIS)

    Noelte, J.; Moenke-Blankenburg, L.; Schumann, T.

    1994-01-01

    Solid sampling with laser vaporization has been coupled to an ICP emission spectrometer with an Echelle optical system and a solid-state-detector for the analysis of steel and soil samples. Pulsation of the vaporized material flow was compensated by real-time background correction and internal standardization, resulting in good accuracy and precision. (orig.)

  13. A compact time-of-flight SANS instrument optimised for measurements of small sample volumes at the European Spallation Source

    Energy Technology Data Exchange (ETDEWEB)

    Kynde, Søren, E-mail: kynde@nbi.ku.dk [Niels Bohr Institute, University of Copenhagen (Denmark); Hewitt Klenø, Kaspar [Niels Bohr Institute, University of Copenhagen (Denmark); Nagy, Gergely [SINQ, Paul Scherrer Institute (Switzerland); Mortensen, Kell; Lefmann, Kim [Niels Bohr Institute, University of Copenhagen (Denmark); Kohlbrecher, Joachim, E-mail: Joachim.kohlbrecher@psi.ch [SINQ, Paul Scherrer Institute (Switzerland); Arleth, Lise, E-mail: arleth@nbi.ku.dk [Niels Bohr Institute, University of Copenhagen (Denmark)

    2014-11-11

    The high flux at European Spallation Source (ESS) will allow for performing experiments with relatively small beam-sizes while maintaining a high intensity of the incoming beam. The pulsed nature of the source makes the facility optimal for time-of-flight small-angle neutron scattering (ToF-SANS). We find that a relatively compact SANS instrument becomes the optimal choice in order to obtain the widest possible q-range in a single setting and the best possible exploitation of the neutrons in each pulse and hence obtaining the highest possible flux at the sample position. The instrument proposed in the present article is optimised for performing fast measurements of small scattering volumes, typically down to 2×2×2 mm{sup 3}, while covering a broad q-range from about 0.005 1/Å to 0.5 1/Å in a single instrument setting. This q-range corresponds to that available at a typical good BioSAXS instrument and is relevant for a wide set of biomacromolecular samples. A central advantage of covering the whole q-range in a single setting is that each sample has to be loaded only once. This makes it convenient to use the fully automated high-throughput flow-through sample changers commonly applied at modern synchrotron BioSAXS-facilities. The central drawback of choosing a very compact instrument is that the resolution in terms of δλ/λ obtained with the short wavelength neutrons becomes worse than what is usually the standard at state-of-the-art SANS instruments. Our McStas based simulations of the instrument performance for a set of characteristic biomacromolecular samples show that the resulting smearing effects still have relatively minor effects on the obtained data and can be compensated for in the data analysis. However, in cases where a better resolution is required in combination with the large simultaneous q-range characteristic of the instrument, we show that this can be obtained by inserting a set of choppers.

  14. The development of an automatic sample-changer and control instrumentation for isotope-source neutron-activation analysis

    International Nuclear Information System (INIS)

    Andeweg, A.H.; Watterson, J.I.W.

    1983-01-01

    An automatic sample-changer was developed at the Council for Mineral Technology for use in isotope-source neutron-activation analysis. Tests show that the sample-changer can transfer a sample of up to 3 kg in mass over a distance of 3 m within 5 s. In addition, instrumentation in the form of a three-stage sequential timer was developed to control the sequence of irradiation transfer and analysis

  15. Signal Sampling for Efficient Sparse Representation of Resting State FMRI Data

    Science.gov (United States)

    Ge, Bao; Makkie, Milad; Wang, Jin; Zhao, Shijie; Jiang, Xi; Li, Xiang; Lv, Jinglei; Zhang, Shu; Zhang, Wei; Han, Junwei; Guo, Lei; Liu, Tianming

    2015-01-01

    As the size of brain imaging data such as fMRI grows explosively, it provides us with unprecedented and abundant information about the brain. How to reduce the size of fMRI data but not lose much information becomes a more and more pressing issue. Recent literature studies tried to deal with it by dictionary learning and sparse representation methods, however, their computation complexities are still high, which hampers the wider application of sparse representation method to large scale fMRI datasets. To effectively address this problem, this work proposes to represent resting state fMRI (rs-fMRI) signals of a whole brain via a statistical sampling based sparse representation. First we sampled the whole brain’s signals via different sampling methods, then the sampled signals were aggregate into an input data matrix to learn a dictionary, finally this dictionary was used to sparsely represent the whole brain’s signals and identify the resting state networks. Comparative experiments demonstrate that the proposed signal sampling framework can speed-up by ten times in reconstructing concurrent brain networks without losing much information. The experiments on the 1000 Functional Connectomes Project further demonstrate its effectiveness and superiority. PMID:26646924

  16. Triplet Excited States as a Source of Relevant (Bio)Chemical Information

    OpenAIRE

    Jiménez Molero, María Consuelo; Miranda Alonso, Miguel Ángel

    2014-01-01

    The properties of triplet excited states are markedly medium-dependent, which turns this species into valuable tools for investigating the microenvironments existing in protein binding pockets. Monitoring of the triplet excited state behavior of drugs within transport proteins (serum albumins and alpha(1)-acid glycoproteins) by laser flash photolysis constitutes a valuable source of information on the strength of interaction, conformational freedom and protection from oxygen or other external...

  17. Herbicides and their transformation products in source-water aquifers tapped by public-supply wells in Illinois, 2001-02

    Science.gov (United States)

    Mills, Patrick C.; McMillan, William D.

    2004-01-01

    During 2001-02, ground-water samples were collected from 117 public-supply wells distributed throughout Illinois to evaluate the occurrence of herbicides and their transformation products in the State?s source-water aquifers. Wells were selected using a stratified-random method to ensure representation of the major types of source-water aquifers in the State. Samples were analyzed for 18 herbicides and 18 transformation products, including 3 triazine and 14 chloroacetanilide products. Herbicide compounds (field-applied parent herbicides and their transformation products) were detected in 34 percent of samples. A subset of samples was collected unfiltered to determine if analytical results for herbicides in unfiltered samples are similar to those in paired filtered samples and, thus, can be considered equally representative of herbicide concentrations in ground water supplied to the public. The study by the U.S. Geological Survey was done in cooperation with the Illinois Environmental Protection Agency. Parent herbicides were detected in only 4 percent of all samples. The six most frequently detected herbicide compounds (from 5 to 28 percent of samples) were chloroacetanilide transformation products. The frequent occurrence of transformation products and their higher concentrations relative to those of most parent herbicides confirm the importance of obtaining information on transformation products to understand the mobility and fate of herbicides in ground-water systems. No sample concentrations determined during this study exceeded current (2003) Federal or State drinking-water standards; however, standards are established for only seven parent herbicides. Factors related to the occurrence of herbicide compounds in the State?s source-water aquifers include unconsolidated and unconfined conditions, various hydrogeologic characteristics and well-construction aspects at shallow depths, and proximity to streams. Generally, the closer an aquifer (or well location) is

  18. Detection of silver nanoparticles in parsley by solid sampling high-resolution-continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Feichtmeier, Nadine S; Leopold, Kerstin

    2014-06-01

    In this work, we present a fast and simple approach for detection of silver nanoparticles (AgNPs) in biological material (parsley) by solid sampling high-resolution-continuum source atomic absorption spectrometry (HR-CS AAS). A novel evaluation strategy was developed in order to distinguish AgNPs from ionic silver and for sizing of AgNPs. For this purpose, atomisation delay was introduced as significant indication of AgNPs, whereas atomisation rates allow distinction of 20-, 60-, and 80-nm AgNPs. Atomisation delays were found to be higher for samples containing silver ions than for samples containing silver nanoparticles. A maximum difference in atomisation delay normalised by the sample weight of 6.27 ± 0.96 s mg(-1) was obtained after optimisation of the furnace program of the AAS. For this purpose, a multivariate experimental design was used varying atomisation temperature, atomisation heating rate and pyrolysis temperature. Atomisation rates were calculated as the slope of the first inflection point of the absorbance signals and correlated with the size of the AgNPs in the biological sample. Hence, solid sampling HR-CS AAS was proved to be a promising tool for identifying and distinguishing silver nanoparticles from ionic silver directly in solid biological samples.

  19. Research on pathogens at Great Lakes beaches: sampling, influential factors, and potential sources

    Science.gov (United States)

    ,

    2013-01-01

    The overall mission of this work is to provide science-based information and methods that will allow beach managers to more accurately make beach closure and advisory decisions, understand the sources and physical processes affecting beach contaminants, and understand how science-based information can be used to mitigate and restore beaches and protect the public. The U.S. Geological Survey (USGS), in collaboration with many Federal, State, and local agencies and universities, has conducted research on beach health issues in the Great Lakes Region for more than a decade. The work consists of four science elements that align with the USGS Beach Health Initiative Mission: real-time assessments of water quality; coastal processes; pathogens and source tracking; and data analysis, interpretation, and communication. The ongoing or completed research for the pathogens and source tracking topic is described in this fact sheet.

  20. Application of HDF5 in long-pulse quasi-steady state data acquisition at high sampling rate

    International Nuclear Information System (INIS)

    Chen, Y.; Wang, F.; Li, S.; Xiao, B.J.; Yang, F.

    2014-01-01

    Highlights: • The new data-acquisition system supports long-pulse EAST data acquisition. • The new data-acquisition system is capable for most of the high frequency signals of EAST experiments. • The system's total throughput is about 500 MB/s. • The system uses HDF5 to store data. - Abstract: A new high sampling rate quasi-steady state data-acquisition system has been designed for the microwave reflectometry diagnostic of EAST experiments. In order to meet the requirements of long-pulse discharge and high sampling rate, it is designed based on PXI Express technology. A high-performance digitizer National Instruments PXIe-5122 with two synchronous analog input channels in which the maximum sampling rate is 100 MHz has been adopted. Two PXIe-5122 boards at 60 MSPS and one PXIe-6368 board at 2 MSPS are used in the system and the total throughput is about 500 MB/s. To guarantee the large amounts of data being saved continuously in the long-pulse discharge, an external hard-disk data stream enclosure NI HDD-8265 in which the capacity of sustained speed of reading and writing is 700 MB/s. And in RAID-5 mode its storage capacity is 80% of the total. The obtained raw data firstly stream continuously into NI HDD-8265 during the discharge. Then it will be transferred to the data server automatically and converted into HDF5 file format. HDF5 is an open source file format for data storage and management which has been widely used in various fields, and suitable for long term case. The details of the system are described in the paper

  1. Comparison between correlated sampling and the perturbation technique of MCNP5 for fixed-source problems

    International Nuclear Information System (INIS)

    He Tao; Su Bingjing

    2011-01-01

    Highlights: → The performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. → In terms of precision, the MCNP perturbation technique outperforms correlated sampling for one type of problem but performs comparably with or even under-performs correlated sampling for the other two types of problems. → In terms of accuracy, the MCNP perturbation calculations may predict inaccurate results for some of the test problems. However, the accuracy can be improved if the midpoint correction technique is used. - Abstract: Correlated sampling and the differential operator perturbation technique are two methods that enable MCNP (Monte Carlo N-Particle) to simulate small response change between an original system and a perturbed system. In this work the performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. In terms of precision of predicted response changes, the MCNP perturbation technique outperforms correlated sampling for the problem involving variation of nuclide concentrations in the same direction but performs comparably with or even underperforms correlated sampling for the other two types of problems that involve void or variation of nuclide concentrations in opposite directions. In terms of accuracy, the MCNP differential operator perturbation calculations may predict inaccurate results that deviate from the benchmarks well beyond their uncertainty ranges for some of the test problems. However, the accuracy of the MCNP differential operator perturbation can be improved if the midpoint correction technique is used.

  2. Determination of 2-alkylcyclobutanones in ultraviolet light-irradiated fatty acids, triglycerides, corn oil, and pork samples: Identifying a new source of 2-alkylcyclobutanones.

    Science.gov (United States)

    Meng, Xiangpeng; Chan, Wan

    2017-02-15

    Previous studies have established that 2-alkylcyclobutanones (2-ACBs) are unique radiolytic products in lipid-containing foods that could only be formed through exposure to ionizing radiation, but not by any other means of physical/heat treatment methods. Therefore, 2-ACBs are currently the marker molecules required by the European Committee for Standardization to be used to identify foods irradiated with ionizing irradiation. Using a spectrum of state-of-the-art analytical instruments, we present in this study for the first time that the generation of 2-ACBs was also possible when fatty acids and triglycerides are exposed to a non-ionizing, short-wavelength ultraviolet (UV-C) light source. An irradiation dosage-dependent formation of 2-ACBs was also observed in UV-C irradiated fatty acids, triglycerides, corn oil, and pork samples. With UV-C irradiation becoming an increasingly common food treatment procedure, it is anticipated that the results from this study will alert food scientists and regulatory officials to a potential new source for 2-ACBs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Molecular beam sampling of a hollow cathode arc

    International Nuclear Information System (INIS)

    Theuws, P.

    1981-01-01

    This thesis deals with the description of the process of molecular beam sampling of a Hollow Cathode Arc. The aim of the study is twofold, i.e. investigation of the applicability of molecular beam sampling as a plasma diagnostic and the use of a Hollow Cathode Arc as a high intensity beam source for ground state atoms and metastable state atoms in the superthermal energy range. Suitable models are introduced, describing the process of molecular beam sampling of both ground state atoms and metastable state atoms. Fast ground state atoms produced by ion-atom collisions. The experimental facilities, i.e. the Hollow Cathode Arc, the time-of-flight machine and the dye laser system are described. And an alternative detection scheme for ground state atoms is presented and experimental results on the molecular beam sampling of a low density plasma (densities 10 19 -10 20 m -3 ) in the long arc configuration are reported. The results on the short arc configuration (densities 10 21 -10 22 m -3 ) are discussed. (Auth.)

  4. State of art and perspectives of using renewable energy sources

    International Nuclear Information System (INIS)

    Berkovskij, B.M.; Mikhalevich, A.A.

    1996-01-01

    State of art of renewable energy sources for the beginning of the nineties and perspectives up to 2020 are considered by the forecast of the European Commission. The program of the World Sun Summit up to 1996-2005 is presented

  5. Efficient all solid-state continuous-wave yellow-orange light source

    DEFF Research Database (Denmark)

    Janousek, Jiri; Johansson, Sandra; Tidemand-Lichtenberg, Peter

    2005-01-01

    We present highly efficient sum-frequency generation between two CW IR lasers using periodically poled KTP. The system is based on the 1064 and 1342 nm laser-lines of two Nd:YVO4 lasers. This is an all solid-state light source in the yellow-orange spectral range. The system is optimized in terms ...

  6. Decoy-state quantum key distribution with both source errors and statistical fluctuations

    International Nuclear Information System (INIS)

    Wang Xiangbin; Yang Lin; Peng Chengzhi; Pan Jianwei

    2009-01-01

    We show how to calculate the fraction of single-photon counts of the 3-intensity decoy-state quantum cryptography faithfully with both statistical fluctuations and source errors. Our results rely only on the bound values of a few parameters of the states of pulses.

  7. An all-solid state laser system for the laser ion sources RILIS and in-source laser spectroscopy of astatine at ISOLDE/CERN

    International Nuclear Information System (INIS)

    Rothe, Sebastian

    2012-01-01

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at CERN/ISOLDE by the addition of an all-solid state tunable titanium:sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE/CERN and at ISAC/TRIUMF radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  8. An all-solid state laser system for the laser ion source RILIS and in-source laser spectroscopy of astatine at ISOLDE, CERN

    CERN Document Server

    Rothe, Sebastian; Nörtershäuser, W

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at ISOLDE, CERN, by the addition of an all-solid state tuneable titanium: sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE, CERN, and at ISAC, TRIUMF, radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  9. An all-solid state laser system for the laser ion sources RILIS and in-source laser spectroscopy of astatine at ISOLDE/CERN

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, Sebastian

    2012-09-24

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at CERN/ISOLDE by the addition of an all-solid state tunable titanium:sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE/CERN and at ISAC/TRIUMF radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  10. Single blood-Hg samples can result in exposure misclassification: temporal monitoring within the Japanese community (United States

    Directory of Open Access Journals (Sweden)

    Tsuchiya Ami

    2012-06-01

    Full Text Available Abstract Background The most prominent non-occupational source of exposure to methylmercury is the consumption of fish. In this study we examine a fish consuming population to determine the extent of temporal exposure and investigate the extent to which single time estimates of methylmercury exposure based on blood-Hg concentration can provide reliable estimates of longer-term average exposure. Methods Blood-mercury levels were obtained from a portion of the Arsenic Mercury Intake Biometric Study (AMIBS cohort. Specifically, 56 Japanese women residing in the Puget Sound area of Washington State, US were sampled on three occasions across a one-year period. Results An average of 135 days separated samples, with mean blood-mercury levels for the visits being 5.1, 6.6 and 5.0 μg/l and geometric means being 2.7, 4.5 and 3.1 μg/l. The blood-mercury levels in this group exceed national averages with geometric means for two of the visits being between the 90th and 95th percentiles of nationally observed levels and the lowest geometric mean being between the 75th and 90th percentile. Group means were not significantly different across sampling periods suggesting that exposure of combined subjects remained relatively constant. Comparing intra-individual results over time did not reveal a strong correlation among visits (r = 0.19, 0.50, 0.63 between 1st and 2nd, 2nd and 3rd, and 1st and 3rd sample results, respectively. In comparing blood-mercury levels across two sampling interval combinations (1st and 2nd, 2nd and 3rd, and 1st and 3rd visits, respectively, 58% (n = 34, 53% (n = 31 and 29% (n = 17 of the individuals had at least a 100% difference in blood-Hg levels. Conclusions Point estimates of blood-mercury, when compared with three sample averages, may not reflect temporal variability and individual exposures estimated on the basis of single blood samples should be treated with caution as indicators of long-term exposure

  11. MEG source imaging method using fast L1 minimum-norm and its applications to signals with brain noise and human resting-state source amplitude images.

    Science.gov (United States)

    Huang, Ming-Xiong; Huang, Charles W; Robb, Ashley; Angeles, AnneMarie; Nichols, Sharon L; Baker, Dewleen G; Song, Tao; Harrington, Deborah L; Theilmann, Rebecca J; Srinivasan, Ramesh; Heister, David; Diwakar, Mithun; Canive, Jose M; Edgar, J Christopher; Chen, Yu-Han; Ji, Zhengwei; Shen, Max; El-Gabalawy, Fady; Levy, Michael; McLay, Robert; Webb-Murphy, Jennifer; Liu, Thomas T; Drake, Angela; Lee, Roland R

    2014-01-01

    The present study developed a fast MEG source imaging technique based on Fast Vector-based Spatio-Temporal Analysis using a L1-minimum-norm (Fast-VESTAL) and then used the method to obtain the source amplitude images of resting-state magnetoencephalography (MEG) signals for different frequency bands. The Fast-VESTAL technique consists of two steps. First, L1-minimum-norm MEG source images were obtained for the dominant spatial modes of sensor-waveform covariance matrix. Next, accurate source time-courses with millisecond temporal resolution were obtained using an inverse operator constructed from the spatial source images of Step 1. Using simulations, Fast-VESTAL's performance was assessed for its 1) ability to localize multiple correlated sources; 2) ability to faithfully recover source time-courses; 3) robustness to different SNR conditions including SNR with negative dB levels; 4) capability to handle correlated brain noise; and 5) statistical maps of MEG source images. An objective pre-whitening method was also developed and integrated with Fast-VESTAL to remove correlated brain noise. Fast-VESTAL's performance was then examined in the analysis of human median-nerve MEG responses. The results demonstrated that this method easily distinguished sources in the entire somatosensory network. Next, Fast-VESTAL was applied to obtain the first whole-head MEG source-amplitude images from resting-state signals in 41 healthy control subjects, for all standard frequency bands. Comparisons between resting-state MEG sources images and known neurophysiology were provided. Additionally, in simulations and cases with MEG human responses, the results obtained from using conventional beamformer technique were compared with those from Fast-VESTAL, which highlighted the beamformer's problems of signal leaking and distorted source time-courses. © 2013.

  12. Solid state light source driver establishing buck or boost operation

    Science.gov (United States)

    Palmer, Fred

    2017-08-29

    A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

  13. Application of a compact diode pumped solid-state laser source for quantitative laser-induced breakdown spectroscopy analysis of steel

    Science.gov (United States)

    Tortschanoff, Andreas; Baumgart, Marcus; Kroupa, Gerhard

    2017-12-01

    Laser-induced breakdown spectroscopy (LIBS) technology holds the potential for onsite real-time measurements of steel products. However, for a mobile and robust LIBS measurement system, an adequate small and ruggedized laser source is a key requirement. In this contribution, we present tests with our compact high-power laser source, which, initially, was developed for ignition applications. The CTR HiPoLas® laser is a robust diode pumped solid-state laser with a passive Q-switch with dimensions of less than 10 cm3. The laser generates 2.5-ns pulses with 30 mJ at a maximum continuous repetition rate of about 30 Hz. Feasibility of LIBS experiments with the laser source was experimentally verified with steel samples. The results show that the laser with its current optical output parameters is very well-suited for LIBS measurements. We believe that the miniaturized laser presented here will enable very compact and robust portable high-performance LIBS systems.

  14. Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

    Science.gov (United States)

    Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

    2017-12-01

    Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

  15. Solid State Characterization of Commercial Crystalline and Amorphous Atorvastatin Calcium Samples

    OpenAIRE

    Shete, Ganesh; Puri, Vibha; Kumar, Lokesh; Bansal, Arvind K.

    2010-01-01

    Atorvastatin calcium (ATC), an anti-lipid BCS class II drug, is marketed in crystalline and amorphous solid forms. The objective of this study was to perform solid state characterization of commercial crystalline and amorphous ATC drug samples available in the Indian market. Six samples each of crystalline and amorphous ATC were characterized using X-ray powder diffractometry (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis, Karl Fisher titrimetry, microscopy (hot s...

  16. Analysis of environment state in technogenic region and its threat to public health

    Directory of Open Access Journals (Sweden)

    Grishenko S.V.

    2014-03-01

    Full Text Available The purpose of the research is to give a complex hygienic evaluation of environment state in Donetsk region and to determine the degree of their potential danger to population health. It includes air pollution, water contamination, state of soil. Nearly 43000 samples of air, 32000 drinking water samples and 4500 soil samples were analyzed. Regions with the highest rate of environmental pollution were defined. It was found that the main sources of environment pollution in Donetsk region are ferrous and nonferrous metallurgy enterprises, power, coal, building industry and transport. All other sources ac¬count for only 5-10% of total emissions. Level of harmful technogenic pressing on population’s health was determined.

  17. Modeled Sources, Transport, and Accumulation of Dissolved Solids in Water Resources of the Southwestern United States.

    Science.gov (United States)

    Anning, David W

    2011-10-01

    Information on important source areas for dissolved solids in streams of the southwestern United States, the relative share of deliveries of dissolved solids to streams from natural and human sources, and the potential for salt accumulation in soil or groundwater was developed using a SPAtially Referenced Regressions On Watershed attributes model. Predicted area-normalized reach-catchment delivery rates of dissolved solids to streams ranged from Salton Sea accounting unit.

  18. ANTI-CORRELATED SOFT LAGS IN THE INTERMEDIATE STATE OF BLACK HOLE SOURCE GX 339-4

    International Nuclear Information System (INIS)

    Sriram, K.; Choi, C. S.; Rao, A. R.

    2010-01-01

    We report the few hundred second anti-correlated soft lags between soft and hard energy bands in the source GX 339-4 using RXTE observations. In one observation, anti-correlated soft lags were observed using the ISGRI/INTEGRAL hard energy band and the PCA/RXTE soft energy band light curves. The lags were observed when the source was in hard and soft intermediate states, i.e., in a steep power-law state. We found that the temporal and spectral properties were changed during the lag timescale. The anti-correlated soft lags are associated with spectral variability during which the geometry of the accretion disk is changed. The observed temporal and spectral variations are explained using the framework of truncated disk geometry. We found that during the lag timescale, the centroid frequency of quasi-periodic oscillation is decreased, the soft flux is decreased along with an increase in the hard flux, and the power-law index steepens together with a decrease in the disk normalization parameter. We argue that these changes could be explained if we assume that the hot corona condenses and forms a disk in the inner region of the accretion disk. The overall spectral and temporal changes support the truncated geometry of the accretion disk in the steep power-law state or in the intermediate state.

  19. The state and profile of open source software projects in health and medical informatics.

    Science.gov (United States)

    Janamanchi, Balaji; Katsamakas, Evangelos; Raghupathi, Wullianallur; Gao, Wei

    2009-07-01

    Little has been published about the application profiles and development patterns of open source software (OSS) in health and medical informatics. This study explores these issues with an analysis of health and medical informatics related OSS projects on SourceForge, a large repository of open source projects. A search was conducted on the SourceForge website during the period from May 1 to 15, 2007, to identify health and medical informatics OSS projects. This search resulted in a sample of 174 projects. A Java-based parser was written to extract data for several of the key variables of each project. Several visually descriptive statistics were generated to analyze the profiles of the OSS projects. Many of the projects have sponsors, implying a growing interest in OSS among organizations. Sponsorship, we discovered, has a significant impact on project success metrics. Nearly two-thirds of the projects have a restrictive license type. Restrictive licensing may indicate tighter control over the development process. Our sample includes a wide range of projects that are at various stages of development (status). Projects targeted towards the advanced end user are primarily focused on bio-informatics, data formats, database and medical science applications. We conclude that there exists an active and thriving OSS development community that is focusing on health and medical informatics. A wide range of OSS applications are in development, from bio-informatics to hospital information systems. A profile of OSS in health and medical informatics emerges that is distinct and unique to the health care field. Future research can focus on OSS acceptance and diffusion and impact on cost, efficiency and quality of health care.

  20. Radiation source states on-line supervision system design and implementation based on RFID technology

    International Nuclear Information System (INIS)

    Yang Binhua; Ling Qiu; Yin Guoli; Yang Kun; Wan Xueping; Wang Kan

    2011-01-01

    It puts forward radiation source states on-line monitoring resolution based on RFID technology. Firstly, the system uses RFID in real-time transmission of the radiation dose rate, and monitors the radiation source states and dose rate of the surrounding environment on-line. Then it adopts regional wireless networking mode to construct enterprise level monitoring network, which resolves long-distance wiring problems. And then it uses GPRS wireless to transport the real-time data to the monitoring center and the government supervision department, By adopting randomly dynamic cording in display update every day, it strengthens the supervision of the radiation source. At last this system has been successful applied to a thickness gauge project, which verifies the feasibility and practicality is good. (authors)

  1. Sources of pre-analytical variations in yield of DNA extracted from blood samples: analysis of 50,000 DNA samples in EPIC.

    Directory of Open Access Journals (Sweden)

    Elodie Caboux

    Full Text Available The European Prospective Investigation into Cancer and nutrition (EPIC is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88% performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies.

  2. Very high flux steady state reactor and accelerator based sources

    International Nuclear Information System (INIS)

    Ludewig, H.; Todosow, M.; Simos, N.; Shapiro, S.; Hastings, J.

    2004-01-01

    With the number of steady state neutron sources in the US declining (including the demise of the Bnl HFBR) the remaining intense sources are now in Europe (i.e. reactors - ILL and FMR, accelerator - PSI). The intensity of the undisturbed thermal flux for sources currently in operation ranges from 10 14 n/cm 2 *s to 10 15 n/cm 2 *s. The proposed Advanced Neutron Source (ANS) was to be a high power reactor (about 350 MW) with a projected undisturbed thermal flux of 7*10 15 n/cm 2 *s but never materialized. The objective of the current study is to explore the requirements and implications of two source concepts with an undisturbed flux of 10 16 n/cm 2 *s. The first is a reactor based concept operating at high power density (10 MW/l - 15 MW/l) and a total power of 100 MW - 250 MW, depending on fissile enrichment. The second is an accelerator based concept relying on a 1 GeV - 1.5 GeV proton Linac with a total beam power of 40 MW and a liquid lead-bismuth eutectic target. In the reactor source study, the effects of fissile material enrichment, coolant temperature and pressure drop, and estimates of pressure vessel stress levels will be investigated. The fuel form for the reactor will be different from all other operating source reactors in that it is proposed to use an infiltrated graphitic structure, which has been developed for nuclear thermal propulsion reactor applications. In the accelerator based source the generation of spallation products and their activation levels, and the material damage sustained by the beam window will be investigated. (authors)

  3. A formal method for identifying distinct states of variability in time-varying sources: SGR A* as an example

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, L.; Witzel, G.; Ghez, A. M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Longstaff, F. A. [UCLA Anderson School of Management, University of California, Los Angeles, CA 90095-1481 (United States)

    2014-08-10

    Continuously time variable sources are often characterized by their power spectral density and flux distribution. These quantities can undergo dramatic changes over time if the underlying physical processes change. However, some changes can be subtle and not distinguishable using standard statistical approaches. Here, we report a methodology that aims to identify distinct but similar states of time variability. We apply this method to the Galactic supermassive black hole, where 2.2 μm flux is observed from a source associated with Sgr A* and where two distinct states have recently been suggested. Our approach is taken from mathematical finance and works with conditional flux density distributions that depend on the previous flux value. The discrete, unobserved (hidden) state variable is modeled as a stochastic process and the transition probabilities are inferred from the flux density time series. Using the most comprehensive data set to date, in which all Keck and a majority of the publicly available Very Large Telescope data have been merged, we show that Sgr A* is sufficiently described by a single intrinsic state. However, the observed flux densities exhibit two states: noise dominated and source dominated. Our methodology reported here will prove extremely useful to assess the effects of the putative gas cloud G2 that is on its way toward the black hole and might create a new state of variability.

  4. Disambiguate: An open-source application for disambiguating two species in next generation sequencing data from grafted samples [version 2; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Miika J. Ahdesmäki

    2017-01-01

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

  5. Disambiguate: An open-source application for disambiguating two species in next generation sequencing data from grafted samples [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Miika J. Ahdesmäki

    2016-11-01

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

  6. Pesticide Information Sources in the United States.

    Science.gov (United States)

    Alston, Patricia Gayle

    1992-01-01

    Presents an overview of electronic and published sources on pesticides. Includes sources such as databases, CD-ROMs, books, journals, brochures, pamphlets, fact sheets, hotlines, courses, electronic mail, and electronic bulletin boards. (MCO)

  7. In-situ X-ray diffraction system using sources and detectors at fixed angular positions

    Science.gov (United States)

    Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

    2007-06-26

    An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

  8. Perceived Sources of Occupational Stress among Primary School Teachers in Delta State of Nigeria

    Science.gov (United States)

    Akpochafo, G. O.

    2012-01-01

    This study investigated the most prevalent sources of occupational stress and also the demographic variables of gender, age and length of service among primary school teachers in Delta State. Two research questions and three hypotheses guided the study. The study used a descriptive survey design. The population was the primary school teachers in…

  9. NEXAFS spectroscopy with a laser plasma x-ray source on soil samples

    International Nuclear Information System (INIS)

    Sedlmair, J; Geber, S-C; Thieme, J; Peth, C; Mann, K

    2009-01-01

    Humic substances are post-mortal organic substances without an exact chemical structure. Their large specific surface is important for transport processes, especially in soils. We analyzed the NEXAFS spectra of humic substances, from which the amount of certain chemical compounds such as aromatic and aliphatic groups can be verified by the resonances of their binding energy. For the experiments, a compact table-top setup working with a laser plasma source was used. NEXAFS makes it possible to distinguish between samples, even if they contain the same composits, because information about the specific functional groups in the sample is supplied. The evaluation was carried out using the program SpecFit. It was developed on IDL within our group and allows to fit the NEXAFS-data with a combination of arctangent, Gaussian and Lorentzian curves.

  10. NEXAFS spectroscopy with a laser plasma x-ray source on soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Sedlmair, J; Geber, S-C; Thieme, J [Institute for X-Ray Physics, Georg-August-University Goettingen, Friedrich-Hund-Platz 1, D-37077 (Germany); Peth, C; Mann, K, E-mail: jsedlma@gwdg.d [Laser-Laboratorium Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 (Germany)

    2009-09-01

    Humic substances are post-mortal organic substances without an exact chemical structure. Their large specific surface is important for transport processes, especially in soils. We analyzed the NEXAFS spectra of humic substances, from which the amount of certain chemical compounds such as aromatic and aliphatic groups can be verified by the resonances of their binding energy. For the experiments, a compact table-top setup working with a laser plasma source was used. NEXAFS makes it possible to distinguish between samples, even if they contain the same composits, because information about the specific functional groups in the sample is supplied. The evaluation was carried out using the program SpecFit. It was developed on IDL within our group and allows to fit the NEXAFS-data with a combination of arctangent, Gaussian and Lorentzian curves.

  11. Clostridium difficile from food and surface samples in a Belgian nursing home: an unlikely source of contamination.

    Science.gov (United States)

    Rodriguez, C; Korsak, N; Taminiau, B; Avesani, V; Van Broeck, J; Brach, P; Delmée, M; Daube, G

    2015-04-01

    This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. High Incidence and Levels of Ochratoxin A in Wines Sourced from the United States.

    Science.gov (United States)

    De Jesus, Christopher Lawrence; Bartley, Amanda; Welch, Aaron Z; Berry, John P

    2017-12-21

    Ochratoxin A (OTA) is one of the most prevalent mycotoxin contaminants of food crops. Among the agricultural products consequently contaminated by OTA is wine. In the present study, a sample of wines sourced from the United States was assessed for OTA. Wines were primarily analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FD) coupled to a liquid-liquid extraction (LLE) technique which was developed and validated as a simplified sample preparation approach. More than 85% of the wines evaluated were found to contain OTA, at levels above the limit-of-detection (LOD = 0.1 µg L -1 ), and 76% were above the limit-of-quantitation (LOQ = 0.3 µg L -1 ) for the LLE/HPLC-FD method. More than two-thirds of the wines above the LOQ were found to exceed 1 µg L -1 . Complementary analysis by HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) confirmed OTA in 74% of the OTA-positive wines (i.e., >LOQ by HPLC-FD). Overall, both the occurrence and measured levels of OTA were generally high, specifically relative to previous assessments of OTA in wine, and two of the wines were above the only current (European Union) regulatory limit of two parts-per-billion (ppb, ~2 µg L -1 ). Possible trends with respect to geographical region and/or growing climate are noted. As the first assessment of U.S. wines in more than a decade, the overall high occurrence and levels of OTA in wine, and possible geographic and climatic trends, point to a need for regular surveillance of wines, as well as investigation of the relevant contributors to OTA occurrence toward mitigating contamination and exposure risks.

  13. Simultaneous determination of Cd and Fe in beans and soil of different regions of Brazil using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling.

    Science.gov (United States)

    dos Santos, Lisia M G; Welz, Bernhard; Araujo, Rennan G O; Jacob, Silvana do C; Vale, Maria Goreti R; Martens, Andreas; Gonzaga Martens, Irland B; Becker-Ross, Helmut

    2009-11-11

    A fast routine screening method for the simultaneous determination of cadmium and iron in bean and soil samples is proposed, using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling. The primary absorption line at 228.802 nm has been used for the determination of cadmium, and an adjacent secondary line, at 228.726 nm, for iron. Fourteen bean samples and 10 soil samples from nine states all over Brazil have been analyzed. The limits of detection (3 sigma, n = 10) were 2.0 microg kg(-1) for Cd and 4.5 mg kg(-1) for Fe. The relative standard deviation ranged from 4 to 7% for Cd and from 5 to 28% for Fe, which is usually acceptable for a screening method. The accuracy of the method has been confirmed by the analysis of two certified reference materials; the results were in agreement with the certified values at a 95% confidence interval.

  14. Characteristics of prepared gamma-ray calibration sources for radioactivity measurement of environmental and radiation control samples

    International Nuclear Information System (INIS)

    Samat, S.B.; Oi, Yoshihiro; Taki, Mitsumasa; Manabe, Iwao; Yoshida, Makoto; Minami, Kentaro

    1995-03-01

    Several types of calibration source having different density were prepared using one or combinations of those materials, namely foam cement, liquid, glass beads, polystyrene foam bead and hard plastic bead for gamma-ray spectrometry of the samples with different densities and shapes(variable height with constant base area). For each type of the source, a few sources were prepared to examine characteristics in such cases as (a) different heights but constant density, and (b) constant height and constant density. For the foam cement source, several sources with different densities and a constant height were prepared. All the sources were measured with a gamma-ray spectrometry system and the results were discussed. This report also presents the results obtained from the experiments for the evaluation of (1) the variation of detector efficiency-energy with gamma-ray energy, and (2) the variation of detector efficiency with density of the sources. (author)

  15. Sources of ultrafine particles in the Eastern United States

    Science.gov (United States)

    Posner, Laura N.; Pandis, Spyros N.

    2015-06-01

    Source contributions to ultrafine particle number concentrations for a summertime period in the Eastern U.S. are investigated using the chemical transport model PMCAMx-UF. New source-resolved number emissions inventories are developed for biomass burning, dust, gasoline automobiles, industrial sources, non-road and on-road diesel. According to the inventory for this summertime period in the Eastern U.S., gasoline automobiles are responsible for 40% of the ultrafine particle number emissions, followed by industrial sources (33%), non-road diesel (16%), on-road diesel (10%), and 1% from biomass burning and dust. With these emissions as input, the chemical transport model PMCAMx-UF reproduces observed ultrafine particle number concentrations (N3-100) in Pittsburgh with an error of 12%. For this summertime period in the Eastern U.S., nucleation is predicted to be the source of more than 90% of the total particle number concentrations. The source contributions to primary particle number concentrations are on average similar to those of their source emissions contributions: gasoline is predicted to contribute 36% of the total particle number concentrations, followed by industrial sources (31%), non-road diesel (18%), on-road diesel (10%), biomass burning (1%), and long-range transport (4%). For this summertime period in Pittsburgh, number source apportionment predictions for particles larger than 3 nm in diameter (traffic 65%, other combustion sources 35%) are consistent with measurement-based source apportionment (traffic 60%, combustion sources 40%).

  16. Radiocarbon Analysis to Calculate New End-Member Values for Biomass Burning Source Samples Specific to the Bay Area

    Science.gov (United States)

    Yoon, S.; Kirchstetter, T.; Fairley, D.; Sheesley, R. J.; Tang, X.

    2017-12-01

    Elemental carbon (EC), also known as black carbon or soot, is an important particulate air pollutant that contributes to climate forcing through absorption of solar radiation and to adverse human health impacts through inhalation. Both fossil fuel combustion and biomass burning, via residential firewood burning, agricultural burning, wild fires, and controlled burns, are significant sources of EC. Our ability to successfully control ambient EC concentrations requires understanding the contribution of these different emission sources. Radiocarbon (14C) analysis has been increasingly used as an apportionment tool to distinguish between EC from fossil fuel and biomass combustion sources. However, there are uncertainties associated with this method including: 1) uncertainty associated with the isolation of EC to be used for radiocarbon analysis (e.g., inclusion of organic carbon, blank contamination, recovery of EC, etc.) 2) uncertainty associated with the radiocarbon signature of the end member. The objective of this research project is to utilize laboratory experiments to evaluate some of these uncertainties, particularly for EC sources that significantly impact the San Francisco Bay Area. Source samples of EC only and a mix of EC and organic carbon (OC) were produced for this study to represent known emission sources and to approximate the mixing of EC and OC that would be present in the atmosphere. These samples include a combination of methane flame soot, various wood smoke samples (i.e. cedar, oak, sugar pine, pine at various ages, etc.), meat cooking, and smoldering cellulose smoke. EC fractions were isolated using a Sunset Laboratory's thermal optical transmittance carbon analyzer. For 14C analysis, samples were sent to Woods Hole Oceanographic Institution for isotope analysis using an accelerated mass spectrometry. End member values and uncertainties for the EC isolation utilizing this method will be reported.

  17. Examination Of The Physicochemical Characteristics Of Domestic Water Sources In Ebonyi Local Government Area Of Ebonyi State Nigeria.

    Directory of Open Access Journals (Sweden)

    Nwidembia

    2015-08-01

    Full Text Available Lack of good drinking water due to contamination by chemicals has been a global menace. It is one of the most serious environmental problems that have greatly impacted human health. Basic quality parameters of domestic water sources in Ebonyi Local Government Area were studied in the months of September 2014 and October 2014. Samples were randomly collected from common water sources well stream borehole and pond across four communities in the Local Government Area. The physicochemical characteristics of the collected water samples were investigated using standard procedures. The results showed mean pH values of 7.3 7.8 6.8 and 7.0 for well stream borehole and pond water samples respectively. The colour examination showed 13 HU 11 HU 13 HU and 16 HU for well stream borehole and pond water samples respectively. The turbidity were recorded as 103 NTU well 90 NTU stream 0.8 NTU borehole and 92 NTU pond. Total dissolved solids TDS showed a record of 595 mgL 386mgL 76 mgL and 563 mgL for well stream borehole and pond respectively. Well water recorded 78 mgL stream 112 mgL borehole 42 mgL and pond 795 mgL for Total Suspended Solids respectively. Also the total hardness showed 525 mgL 779 mgL 44 mgL and 837 mgL for well stream borehole and pond water samples respectively. The results show that most of the common sources of water in the studied areas are not good for drinking since the physicochemical variables evaluated mostly exceeded WHO permissible limits. We therefore recommend that water treatment should be paramount as alternative sources of drinking water in the communities should be considered.

  18. Monte Carlo Sampling of Negative-temperature Plasma States

    International Nuclear Information System (INIS)

    John A. Krommes; Sharadini Rath

    2002-01-01

    A Monte Carlo procedure is used to generate N-particle configurations compatible with two-temperature canonical equilibria in two dimensions, with particular attention to nonlinear plasma gyrokinetics. An unusual feature of the problem is the importance of a nontrivial probability density function R0(PHI), the probability of realizing a set Φ of Fourier amplitudes associated with an ensemble of uniformly distributed, independent particles. This quantity arises because the equilibrium distribution is specified in terms of Φ, whereas the sampling procedure naturally produces particles states gamma; Φ and gamma are related via a gyrokinetic Poisson equation, highly nonlinear in its dependence on gamma. Expansion and asymptotic methods are used to calculate R0(PHI) analytically; excellent agreement is found between the large-N asymptotic result and a direct numerical calculation. The algorithm is tested by successfully generating a variety of states of both positive and negative temperature, including ones in which either the longest- or shortest-wavelength modes are excited to relatively very large amplitudes

  19. Design of interferometer system for Keda Torus eXperiment using terahertz solid-state diode sources

    International Nuclear Information System (INIS)

    Xie, Jinlin; Wang, Haibo; Li, Hong; Lan, Tao; Liu, Adi; Liu, Wandong; Yu, Changxuan; Ding, Weixing

    2014-01-01

    A solid-state source based terahertz (THz) interferometer diagnostic system has been designed and characterized for the Keda Torus eXperiment (KTX). The THz interferometer utilizes the planar diodes based frequency multiplier (X48) to provide the probing beam at fixed frequency 0.650 THz, and local oscillator is provided by an independent solid-state diode source with tunable frequency (0.650 THz +/− 10 MHz). Both solid-state sources have approximately 1 mW power. The planar-diode mixers optimized for high sensitivity, ∼750 mV/mW, are used in the heterodyne detection system, which permits multichannel interferometer on KTX with a low phase noise. A sensitivity of e l> min = 4.5 × 10 16 m −2 and a temporal resolution of 0.2 μs have been achieved during the initial bench test

  20. Sediment source fingerprinting as an aid to catchment management: A review of the current state of knowledge and a methodological decision-tree for end-users

    Science.gov (United States)

    Collins, A.L; Pulley, S.; Foster, I.D.L; Gellis, Allen; Porto, P.; Horowitz, A.J.

    2017-01-01

    The growing awareness of the environmental significance of fine-grained sediment fluxes through catchment systems continues to underscore the need for reliable information on the principal sources of this material. Source estimates are difficult to obtain using traditional monitoring techniques, but sediment source fingerprinting or tracing procedures, have emerged as a potentially valuable alternative. Despite the rapidly increasing numbers of studies reporting the use of sediment source fingerprinting, several key challenges and uncertainties continue to hamper consensus among the international scientific community on key components of the existing methodological procedures. Accordingly, this contribution reviews and presents recent developments for several key aspects of fingerprinting, namely: sediment source classification, catchment source and target sediment sampling, tracer selection, grain size issues, tracer conservatism, source apportionment modelling, and assessment of source predictions using artificial mixtures. Finally, a decision-tree representing the current state of knowledge is presented, to guide end-users in applying the fingerprinting approach.

  1. Composition and oxidation state of sulfur in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    A. F. Longo

    2016-10-01

    Full Text Available The chemical and physical speciation of atmospheric sulfur was investigated in ambient aerosol samples using a combination of sulfur near-edge x-ray fluorescence spectroscopy (S-NEXFS and X-ray fluorescence (XRF microscopy. These techniques were used to determine the composition and oxidation state of sulfur in common primary emission sources and ambient particulate matter collected from the greater Atlanta area. Ambient particulate matter samples contained two oxidation states: S0 and S+VI. Ninety-five percent of the individual aerosol particles (> 1 µm analyzed contain S0. Linear combination fitting revealed that S+VI in ambient aerosol was dominated by ammonium sulfate as well as metal sulfates. The finding of metal sulfates provides further evidence for acidic reactions that solubilize metals, such as iron, during atmospheric transport. Emission sources, including biomass burning, coal fly ash, gasoline, diesel, volcanic ash, and aerosolized Atlanta soil, and the commercially available bacterium Bacillus subtilis, contained only S+VI. A commercially available Azotobacter vinelandii sample contained approximately equal proportions of S0 and S+VI. S0 in individual aerosol particles most likely originates from primary emission sources, such as aerosolized bacteria or incomplete combustion.

  2. Nonequilibrium Gyrokinetic Fluctuation Theory and Sampling Noise in Gyrokinetic Particle-in-cell Simulations

    International Nuclear Information System (INIS)

    Krommes, John A.

    2007-01-01

    The present state of the theory of fluctuations in gyrokinetic (GK) plasmas and especially its application to sampling noise in GK particle-in-cell (PIC) simulations is reviewed. Topics addressed include the Δf method, the fluctuation-dissipation theorem for both classical and GK many-body plasmas, the Klimontovich formalism, sampling noise in PIC simulations, statistical closure for partial differential equations, the theoretical foundations of spectral balance in the presence of arbitrary noise sources, and the derivation of Kadomtsev-type equations from the general formalism

  3. Nonequilibrium Gyrokinetic Fluctuation Theory and Sampling Noise in Gyrokinetic Particle-in-cell Simulations

    Energy Technology Data Exchange (ETDEWEB)

    John A. Krommes

    2007-10-09

    The present state of the theory of fluctuations in gyrokinetic GK plasmas and especially its application to sampling noise in GK particle-in-cell PIC simulations is reviewed. Topics addressed include the Δf method, the fluctuation-dissipation theorem for both classical and GK many-body plasmas, the Klimontovich formalism, sampling noise in PIC simulations, statistical closure for partial differential equations, the theoretical foundations of spectral balance in the presence of arbitrary noise sources, and the derivation of Kadomtsev-type equations from the general formalism.

  4. Comprehensive trends assessment of nitrogen sources and loads to estuaries of the coterminous United States

    Science.gov (United States)

    Sources of nitrogen and phosphorus to estuaries and estuarine watersheds of the coterminous United States have been compiled from a variety of publically available data sources (1985 – 2015). Atmospheric loading was obtained from two sources. Modelled and interpolated meas...

  5. PCDD/PCDF and dl-PCB in the ambient air of a tropical Andean city: passive and active sampling measurements near industrial and vehicular pollution sources.

    Science.gov (United States)

    Cortés, J; González, C M; Morales, L; Abalos, M; Abad, E; Aristizábal, B H

    2014-09-01

    Concentration gradients were observed in gas and particulate phases of PCDD/F originating from industrial and vehicular sources in the densely populated tropical Andean city of Manizales, using passive and active air samplers. Preliminary results suggest greater concentrations of dl-PCB in the mostly gaseous fraction (using quarterly passive samplers) and greater concentrations of PCDD/F in the mostly particle fraction (using daily active samplers). Dioxin-like PCB predominance was associated with the semi-volatility property, which depends on ambient temperature. Slight variations of ambient temperature in Manizales during the sampling period (15°C-27°C) may have triggered higher concentrations in all passive samples. This was the first passive air sampling monitoring of PCDD/F conducted in an urban area of Colombia. Passive sampling revealed that PCDD/F in combination with dioxin-like PCB ranged from 16 WHO-TEQ2005/m(3) near industrial sources to 7 WHO-TEQ2005/m(3) in an intermediate zone-a reduction of 56% over 2.8 km. Active sampling of particulate phase PCDD/F and dl-PCB were analyzed in PM10 samples. PCDD/F combined with dl-PCB ranged from 46 WHO-TEQ2005/m(3) near vehicular sources to 8 WHO-TEQ2005/m(3) in the same intermediate zone, a reduction of 83% over 2.6 km. Toxic equivalent quantities in both PCDD/F and dl-PCB decreased toward an intermediate zone of the city. Variations in congener profiles were consistent with variations expected from nearby sources, such as a secondary metallurgy plant, areas of concentrated vehicular emissions and a municipal solid waste incinerator (MSWI). These variations in congener profile measurements of dioxins and dl-PCBs in passive and active samples can be partly explained by congener variations expected from the various sources. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Factors for Microbial Carbon Sources in Organic and Mineral Soils from Eastern United States Deciduous Forests

    Energy Technology Data Exchange (ETDEWEB)

    Stitt, Caroline R. [Mills College, Oakland, CA (United States)

    2013-09-16

    Forest soils represent a large portion of global terrestrial carbon; however, which soil carbon sources are used by soil microbes and respired as carbon dioxide (CO2) is not well known. This study will focus on characterizing microbial carbon sources from organic and mineral soils from four eastern United States deciduous forests using a unique radiocarbon (14C) tracer. Results from the dark incubation of organic and mineral soils are heavily influenced by site characteristics when incubated at optimal microbial activity temperature. Sites with considerable differences in temperature, texture, and location differ in carbon source attribution, indicating that site characteristics play a role in soil respiration.

  7. Trends in the chemical state of polonium-210 in the atmosphere

    International Nuclear Information System (INIS)

    Abe, M.; Abe, S.

    1980-01-01

    Trends of the chemial state of 210 Po in airborne dusts at Chiba, Japan, between 1963 and 1976 are discussed. A sublimination method is used to determine the chemical state of the 210 Po. The results show that the fraction of the component volatilizing at low temperature varies yearly in the range between 0 and 50%. If we assume the component comes from an artificial source, it may be suggested that a large fraction of 210 Po in airborne dusts comes from artificial sources. Additional reference data that show local properties of our sampling site are presented

  8. Analysis of environment state in technogenic region and its threat to public health

    OpenAIRE

    Grishenko S.V.; Grishenko I.I.; Ohotnikova M.V.; Mustafina A.O.; Kudimov P.V.; Mustafin T.A.

    2014-01-01

    The purpose of the research is to give a complex hygienic evaluation of environment state in Donetsk region and to determine the degree of their potential danger to population health. It includes air pollution, water contamination, state of soil. Nearly 43000 samples of air, 32000 drinking water samples and 4500 soil samples were analyzed. Regions with the highest rate of environmental pollution were defined. It was found that the main sources of environment pollution in Donetsk region are fe...

  9. POLLUTION SOURCES AND WATER QUALITY STATE OF THE SUPRAŚL RIVER

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2016-04-01

    Full Text Available The main purpose of the study was to evaluate water quality of the Supraśl river and identify its main pollution sources. On the river and its tributaries, 8 control points were selected, located near Krynica, Gródek, Nowosiółki, Zasady (mouth of the tributary Sokołda, Supraśl, Nowodworce, Dobrzyniewo (mouth of the tributary Biała and Dzikie. The control points were selected in such a way as to take into account the impact of major point sources of analyzed components located along the river and its main tributaries on water quality in the main stream catchment. Water samples were collected once a month during the period from May to November in 2014. In water samples the concentration of dissolved oxygen, Cl-, SO42-, N-NH4+, P-PO43- and the values of pH, BOD5 and electrolytic conductivity were indicated. Based on the obtained results, loads of the individual components in river waters were calculated as a product of concentration and Supraśl waters flow rate in a particular month. Supraśl waters, due to values of most analyzed parameters, should be classified as first quality class. The source of Cl-, SO42-, N-NH4+ in Supraśl waters were treated wastewater and other anthropogenic sources associated with the basin development. Reduced Supraśl water quality is caused by the inflow of organic substances expressed by BZT5 from natural and anthropogenic origin and concentration of PO43-, which were mainly delivered with treated wastewater.

  10. Alpha-particle autoradiography by solid state track detectors to spatial distribution of radioactivity in alpha-counting source

    International Nuclear Information System (INIS)

    Ishigure, Nobuhito; Nakano, Takashi; Enomoto, Hiroko; Koizumi, Akira; Miyamoto, Katsuhiro

    1989-01-01

    A technique of autoradiography using solid state track detectors is described by which spatial distribution of radioactivity in an alpha-counting source can easily be visualized. As solid state track detectors, polymer of allyl diglycol carbonate was used. The advantage of the present technique was proved that alpha-emitters can be handled in the light place alone through the whole course of autoradiography, otherwise in the conventional autoradiography the alpha-emitters, which requires special carefulness from the point of radiation protection, must be handled in the dark place with difficulty. This technique was applied to rough examination of self-absorption of the plutonium source prepared by the following different methods; the source (A) was prepared by drying at room temperature, (B) by drying under an infrared lamp, (C) by drying in ammonia atmosphere after redissolving by the addition of a drop of distilled water which followed complete evaporation under an infrared lamp and (D) by drying under an infrared lamp after adding a drop of diluted neutral detergent. The difference in the spatial distributions of radioactivity could clearly be observed on the autoradiographs. For example, the source (C) showed the most diffuse distribution, which suggested that the self-absorption of this source was the smallest. The present autoradiographic observation was in accordance with the result of the alpha-spectrometry with a silicon surface-barrier detector. (author)

  11. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians.

    Science.gov (United States)

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G

    2017-02-17

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)NJOPFM1367-263010.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  12. Monitoring well utility in a heterogeneous DNAPL source zone area: Insights from proximal multilevel sampler wells and sampling capture-zone modelling.

    Science.gov (United States)

    McMillan, Lindsay A; Rivett, Michael O; Wealthall, Gary P; Zeeb, Peter; Dumble, Peter

    2018-03-01

    Groundwater-quality assessment at contaminated sites often involves the use of short-screen (1.5 to 3 m) monitoring wells. However, even over these intervals considerable variation may occur in contaminant concentrations in groundwater adjacent to the well screen. This is especially true in heterogeneous dense non-aqueous phase liquid (DNAPL) source zones, where cm-scale contamination variability may call into question the effectiveness of monitoring wells to deliver representative data. The utility of monitoring wells in such settings is evaluated by reference to high-resolution multilevel sampler (MLS) wells located proximally to short-screen wells, together with sampling capture-zone modelling to explore controls upon well sample provenance and sensitivity to monitoring protocols. Field data are analysed from the highly instrumented SABRE research site that contained an old trichloroethene source zone within a shallow alluvial aquifer at a UK industrial facility. With increased purging, monitoring-well samples tend to a flow-weighted average concentration but may exhibit sensitivity to the implemented protocol and degree of purging. Formation heterogeneity adjacent to the well-screen particularly, alongside pump-intake position and water level, influence this sensitivity. Purging of low volumes is vulnerable to poor reproducibility arising from concentration variability predicted over the initial 1 to 2 screen volumes purged. Marked heterogeneity may also result in limited long-term sample concentration stabilization. Development of bespoke monitoring protocols, that consider screen volumes purged, alongside water-quality indicator parameter stabilization, is recommended to validate and reduce uncertainty when interpreting monitoring-well data within source zone areas. Generalised recommendations on monitoring well based protocols are also developed. A key monitoring well utility is their proportionately greater sample draw from permeable horizons constituting

  13. Monitoring well utility in a heterogeneous DNAPL source zone area: Insights from proximal multilevel sampler wells and sampling capture-zone modelling

    Science.gov (United States)

    McMillan, Lindsay A.; Rivett, Michael O.; Wealthall, Gary P.; Zeeb, Peter; Dumble, Peter

    2018-03-01

    Groundwater-quality assessment at contaminated sites often involves the use of short-screen (1.5 to 3 m) monitoring wells. However, even over these intervals considerable variation may occur in contaminant concentrations in groundwater adjacent to the well screen. This is especially true in heterogeneous dense non-aqueous phase liquid (DNAPL) source zones, where cm-scale contamination variability may call into question the effectiveness of monitoring wells to deliver representative data. The utility of monitoring wells in such settings is evaluated by reference to high-resolution multilevel sampler (MLS) wells located proximally to short-screen wells, together with sampling capture-zone modelling to explore controls upon well sample provenance and sensitivity to monitoring protocols. Field data are analysed from the highly instrumented SABRE research site that contained an old trichloroethene source zone within a shallow alluvial aquifer at a UK industrial facility. With increased purging, monitoring-well samples tend to a flow-weighted average concentration but may exhibit sensitivity to the implemented protocol and degree of purging. Formation heterogeneity adjacent to the well-screen particularly, alongside pump-intake position and water level, influence this sensitivity. Purging of low volumes is vulnerable to poor reproducibility arising from concentration variability predicted over the initial 1 to 2 screen volumes purged. Marked heterogeneity may also result in limited long-term sample concentration stabilization. Development of bespoke monitoring protocols, that consider screen volumes purged, alongside water-quality indicator parameter stabilization, is recommended to validate and reduce uncertainty when interpreting monitoring-well data within source zone areas. Generalised recommendations on monitoring well based protocols are also developed. A key monitoring well utility is their proportionately greater sample draw from permeable horizons constituting a

  14. How Fred Hoyle Reconciled Radio Source Counts and the Steady State Cosmology

    Science.gov (United States)

    Ekers, Ron

    2012-09-01

    In 1969 Fred Hoyle invited me to his Institute of Theoretical Astronomy (IOTA) in Cambridge to work with him on the interpretation of the radio source counts. This was a period of extreme tension with Ryle just across the road using the steep slope of the radio source counts to argue that the radio source population was evolving and Hoyle maintaining that the counts were consistent with the steady state cosmology. Both of these great men had made some correct deductions but they had also both made mistakes. The universe was evolving, but the source counts alone could tell us very little about cosmology. I will try to give some indication of the atmosphere and the issues at the time and look at what we can learn from this saga. I will conclude by briefly summarising the exponential growth of the size of the radio source counts since the early days and ask whether our understanding has grown at the same rate.

  15. Diurnal Variation and Spatial Distribution Effects on Sulfur Speciation in Aerosol Samples as Assessed by X-Ray Absorption Near-Edge Structure (XANES

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2012-01-01

    Full Text Available This paper focuses on providing new results relating to the impacts of Diurnal variation, Vertical distribution, and Emission source on sulfur K-edge XANES spectrum of aerosol samples. All aerosol samples used in the diurnal variation experiment were preserved using anoxic preservation stainless cylinders (APSCs and pressure-controlled glove boxes (PCGBs, which were specially designed to prevent oxidation of the sulfur states in PM10. Further investigation of sulfur K-edge XANES spectra revealed that PM10 samples were dominated by S(VI, even when preserved in anoxic conditions. The “Emission source effect” on the sulfur oxidation state of PM10 was examined by comparing sulfur K-edge XANES spectra collected from various emission sources in southern Thailand, while “Vertical distribution effects” on the sulfur oxidation state of PM10 were made with samples collected from three different altitudes from rooftops of the highest buildings in three major cities in Thailand. The analytical results have demonstrated that neither “Emission source” nor “Vertical distribution” appreciably contribute to the characteristic fingerprint of sulfur K-edge XANES spectrum in PM10.

  16. Microbial pathogens in source and treated waters from drinking water treatment plants in the US

    Science.gov (United States)

    An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Asp...

  17. X RF measurement for sediment sample collected from the niles in Khartoum State

    International Nuclear Information System (INIS)

    Mohammed, Aisha Abdelgader Ahmed

    2015-04-01

    The goal of this study to determine the concentration of element (K, Ca Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, Y and Zr) in sediment sample collected from thirty different sites from the three rivers in Khartoum state. X-ray fluorescence (X RF) was used to identify the element concentration. Validation of the equipment was done by measuring reference samples provided by IAEA. Iron was found to be the dominant element with concentration ranged between (13000 ppm) in the white nile to (101000 ppm) in the blue nile, Pb was found to be the lowest among the twelve elements measured with concentration ranged between (11.7 ppm) in the white nile to (28 ppm) in the river nile for all samples. In general there was no variation of the concentration of elements between the blue nile sediments and the river nile sediments and was found variation of concentration of elements between the white nile sediments and other two niles. (Author).

  18. Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

    2014-09-01

    In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Are biogenic emissions a significant source of summertime atmospheric toluene in the rural Northeastern United States?

    Directory of Open Access Journals (Sweden)

    M. L. White

    2009-01-01

    Full Text Available Summertime atmospheric toluene enhancements at Thompson Farm in the rural northeastern United States were unexpected and resulted in a toluene/benzene seasonal pattern that was distinctly different from that of other anthropogenic volatile organic compounds. Consequently, three hydrocarbon sources were investigated for potential contributions to the enhancements during 2004–2006. These included: (1 increased warm season fuel evaporation coupled with changes in reformulated gasoline (RFG content to meet US EPA summertime volatility standards, (2 local industrial emissions and (3 local vegetative emissions. The contribution of fuel evaporation emission to summer toluene mixing ratios was estimated to range from 16 to 30 pptv d−1, and did not fully account for the observed enhancements (20–50 pptv in 2004–2006. Static chamber measurements of alfalfa, a crop at Thompson Farm, and dynamic branch enclosure measurements of loblolly pine trees in North Carolina suggested vegetative emissions of 5 and 12 pptv d−1 for crops and coniferous trees, respectively. Toluene emission rates from alfalfa are potentially much larger as these plants were only sampled at the end of the growing season. Measured biogenic fluxes were on the same order of magnitude as the influence from gasoline evaporation and industrial sources (regional industrial emissions estimated at 7 pptv d−1 and indicated that local vegetative emissions make a significant contribution to summertime toluene enhancements. Additional studies are needed to characterize the variability and factors controlling toluene emissions from alfalfa and other vegetation types throughout the growing season.

  20. The State of Open Source Electronic Health Record Projects: A Software Anthropology Study.

    Science.gov (United States)

    Alsaffar, Mona; Yellowlees, Peter; Odor, Alberto; Hogarth, Michael

    2017-02-24

    Electronic health records (EHR) are a key tool in managing and storing patients' information. Currently, there are over 50 open source EHR systems available. Functionality and usability are important factors for determining the success of any system. These factors are often a direct reflection of the domain knowledge and developers' motivations. However, few published studies have focused on the characteristics of free and open source software (F/OSS) EHR systems and none to date have discussed the motivation, knowledge background, and demographic characteristics of the developers involved in open source EHR projects. This study analyzed the characteristics of prevailing F/OSS EHR systems and aimed to provide an understanding of the motivation, knowledge background, and characteristics of the developers. This study identified F/OSS EHR projects on SourceForge and other websites from May to July 2014. Projects were classified and characterized by license type, downloads, programming languages, spoken languages, project age, development status, supporting materials, top downloads by country, and whether they were "certified" EHRs. Health care F/OSS developers were also surveyed using an online survey. At the time of the assessment, we uncovered 54 open source EHR projects, but only four of them had been successfully certified under the Office of the National Coordinator for Health Information Technology (ONC Health IT) Certification Program. In the majority of cases, the open source EHR software was downloaded by users in the United States (64.07%, 148,666/232,034), underscoring that there is a significant interest in EHR open source applications in the United States. A survey of EHR open source developers was conducted and a total of 103 developers responded to the online questionnaire. The majority of EHR F/OSS developers (65.3%, 66/101) are participating in F/OSS projects as part of a paid activity and only 25.7% (26/101) of EHR F/OSS developers are, or have been

  1. Sample size and number of outcome measures of veterinary randomised controlled trials of pharmaceutical interventions funded by different sources, a cross-sectional study.

    Science.gov (United States)

    Wareham, K J; Hyde, R M; Grindlay, D; Brennan, M L; Dean, R S

    2017-10-04

    Randomised controlled trials (RCTs) are a key component of the veterinary evidence base. Sample sizes and defined outcome measures are crucial components of RCTs. To describe the sample size and number of outcome measures of veterinary RCTs either funded by the pharmaceutical industry or not, published in 2011. A structured search of PubMed identified RCTs examining the efficacy of pharmaceutical interventions. Number of outcome measures, number of animals enrolled per trial, whether a primary outcome was identified, and the presence of a sample size calculation were extracted from the RCTs. The source of funding was identified for each trial and groups compared on the above parameters. Literature searches returned 972 papers; 86 papers comprising 126 individual trials were analysed. The median number of outcomes per trial was 5.0; there were no significant differences across funding groups (p = 0.133). The median number of animals enrolled per trial was 30.0; this was similar across funding groups (p = 0.302). A primary outcome was identified in 40.5% of trials and was significantly more likely to be stated in trials funded by a pharmaceutical company. A very low percentage of trials reported a sample size calculation (14.3%). Failure to report primary outcomes, justify sample sizes and the reporting of multiple outcome measures was a common feature in all of the clinical trials examined in this study. It is possible some of these factors may be affected by the source of funding of the studies, but the influence of funding needs to be explored with a larger number of trials. Some veterinary RCTs provide a weak evidence base and targeted strategies are required to improve the quality of veterinary RCTs to ensure there is reliable evidence on which to base clinical decisions.

  2. Insights into the processes behind the contamination of degraded human teeth and bone samples with exogenous sources of DNA

    DEFF Research Database (Denmark)

    Gilbert, M. T. P.; Hansen, Anders J.; Willerslev, E.

    2006-01-01

    A principal problem facing human DNA studies that use old and degraded remains is contamination from other sources of human DNA. In this study we have attempted to contaminate deliberately bones and teeth sampled from a medieval collection excavated in Trondheim, Norway, in order to investigate......, prior to assaying for the residual presence of the handler's DNA. Surprisingly, although our results suggest that a large proportion of the teeth were contaminated with multiple sources of human DNA prior to our investigation, we were unable to contaminate the samples with further human DNA. One...

  3. A Systematic Review of Surgical Randomized Controlled Trials: Part 2. Funding Source, Conflict of Interest, and Sample Size in Plastic Surgery.

    Science.gov (United States)

    Voineskos, Sophocles H; Coroneos, Christopher J; Ziolkowski, Natalia I; Kaur, Manraj N; Banfield, Laura; Meade, Maureen O; Chung, Kevin C; Thoma, Achilleas; Bhandari, Mohit

    2016-02-01

    The authors examined industry support, conflict of interest, and sample size in plastic surgery randomized controlled trials that compared surgical interventions. They hypothesized that industry-funded trials demonstrate statistically significant outcomes more often, and randomized controlled trials with small sample sizes report statistically significant results more frequently. An electronic search identified randomized controlled trials published between 2000 and 2013. Independent reviewers assessed manuscripts and performed data extraction. Funding source, conflict of interest, primary outcome direction, and sample size were examined. Chi-squared and independent-samples t tests were used in the analysis. The search identified 173 randomized controlled trials, of which 100 (58 percent) did not acknowledge funding status. A relationship between funding source and trial outcome direction was not observed. Both funding status and conflict of interest reporting improved over time. Only 24 percent (six of 25) of industry-funded randomized controlled trials reported authors to have independent control of data and manuscript contents. The mean number of patients randomized was 73 per trial (median, 43, minimum, 3, maximum, 936). Small trials were not found to be positive more often than large trials (p = 0.87). Randomized controlled trials with small sample size were common; however, this provides great opportunity for the field to engage in further collaboration and produce larger, more definitive trials. Reporting of trial funding and conflict of interest is historically poor, but it greatly improved over the study period. Underreporting at author and journal levels remains a limitation when assessing the relationship between funding source and trial outcomes. Improved reporting and manuscript control should be goals that both authors and journals can actively achieve.

  4. Chemical profiling of six samples of Brazilian propolis

    Directory of Open Access Journals (Sweden)

    Caroline C. Fernandes-Silva

    2013-01-01

    Full Text Available Six samples of Brazilian propolis from Minas Gerais and Paraná states were analyzed to identify the constituents (GC/MS and HPLC/MS and to determine their contents (HPLC and external standardization. All samples contained characteristic constituents of green propolis, but the samples from Minas Gerais had higher contents of prenylated phenylpropanoids and caffeoylquinic acids. Kaempferide and two other flavonoids were among the major constituents of the samples from Minas Gerais. Luteolin 5-O-methyl ether was detected only in samples from Paraná. Baccharis dracunculifolia was a source of resins for all samples analyzed, but the samples from Paraná had more complex plant origin.

  5. Efficient all solid-state UV source for satellite-based lidar applications.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Darrell Jewell; Smith, Arlee Virgil

    2003-07-01

    A satellite-based UV-DIAL measurement system would allow continuous global monitoring of ozone concentration in the upper atmosphere. However such systems remain difficult to implement because aerosol-scattering return signals for satellite-based lidars are very weak. A suitable system must produce high-energy UV pulses at multiple wavelengths with very high efficiency. For example, a nanosecond system operating at 10 Hz must generate approximately 1 J per pulse at 308-320 nm. An efficient space-qualified wavelength-agile system based on a single UV source that can meet this requirement is probably not available using current laser technology. As an alternative, we're pursuing a multi-source approach employing all-solid-state modules that individually generate 300-320 nm light with pulse energies in the range of 50-200 mJ, with transform-limited bandwidths and good beam quality. Pulses from the individual sources can be incoherently summed to obtain the required single-pulse energy. These sources use sum-frequency mixing of the 532 nm second harmonic of an Nd:YAG pump laser with 731-803 nm light derived from a recently-developed, state-of-the-art, nanosecond optical parametric oscillator. Two source configurations are under development, one using extra-cavity sum-frequency mixing, and the other intra-cavity sum-frequency mixing. In either configuration, we hope to obtain sum-frequency mixing efficiency approaching 60% by carefully matching the spatial and temporal properties of the laser and OPO pulses. This ideal balance of green and near-IR photons requires an injection-seeded Nd:YAG pump-laser with very high beam quality, and an OPO exhibiting unusually high conversion efficiency and exceptional signal beam quality. The OPO employs a singly-resonant high-Fresnel-number image-rotating self-injection-seeded nonplanar-ring cavity that achieves pump depletion > 65% and produces signal beams with M{sup 2} {approx} 3 at pulse energies exceeding 50 mJ. Pump beam

  6. Current State and Prospects of Studying Sources on the History of Crimean Khanate in Turkish Archives »

    Directory of Open Access Journals (Sweden)

    Sh.E. Seit-Mametov

    2016-09-01

    Full Text Available Research objectives: to consider the current state of the study of sources on the history of the Crimean Khanate in Turkish archives and determine the prospects for the study of this issue. Research materials: works of domestic and foreign Orientalists in the study of the Crimean sources in Turkish archives. Results and novelty of the research: the author analyzed the current state of the study of sources on the history of the Crimean Khanate in Turkish archives. The works of such prominent scholars as A. Bennigsen, Ö. Gokbilgin, A.N. Kurat, Ch. Lemercier-Quelquejay, V.D. Smirnov and others deserve the most attention. Sophisticated paleography (age and conditions of documents of the Ottoman sources and difficulties with their translation were the main reason for their insufficient use. In their studies, Orientalists presents facsimiles of the originals of letters and their translations, give the transcript values of complex or controversial words, solve problems with the translation of dates into the modern chronology and also produce a detailed external criticism of documents: they describe their length, quality of the paper, handwriting and also decode the khans’ seals. This enables modern researchers to get acquainted with some of the earliest sources on the history of the Crimean Khanate. The author has revealed a number of new challenges that need to be addressed in the further study of sources on the history of the Crimean Khanate: translation of foreign Orientalists’ works into Russian as well as synthesis and integration of predecessors’ works, since each individual work does not cover all the documents of interest to modern scholars. The study of sources on the history of the Crimean Khanate remains a promising challenge for modern researchers, since in Turkish archives are stored unpublished documents waiting for their turn to enter into scholarly circulation.

  7. Efficient Sampling of the Structure of Crypto Generators' State Transition Graphs

    Science.gov (United States)

    Keller, Jörg

    Cryptographic generators, e.g. stream cipher generators like the A5/1 used in GSM networks or pseudo-random number generators, are widely used in cryptographic network protocols. Basically, they are finite state machines with deterministic transition functions. Their state transition graphs typically cannot be analyzed analytically, nor can they be explored completely because of their size which typically is at least n = 264. Yet, their structure, i.e. number and sizes of weakly connected components, is of interest because a structure deviating significantly from expected values for random graphs may form a distinguishing attack that indicates a weakness or backdoor. By sampling, one randomly chooses k nodes, derives their distribution onto connected components by graph exploration, and extrapolates these results to the complete graph. In known algorithms, the computational cost to determine the component for one randomly chosen node is up to O(√n), which severely restricts the sample size k. We present an algorithm where the computational cost to find the connected component for one randomly chosen node is O(1), so that a much larger sample size k can be analyzed in a given time. We report on the performance of a prototype implementation, and about preliminary analysis for several generators.

  8. A Comparison between Predicted and Observed Atmospheric States and their Effects on Infrasonic Source Time Function Inversion at Source Physics Experiment 6

    Science.gov (United States)

    Aur, K. A.; Poppeliers, C.; Preston, L. A.

    2017-12-01

    The Source Physics Experiment (SPE) consists of a series of underground chemical explosions at the Nevada National Security Site (NNSS) designed to gain an improved understanding of the generation and propagation of physical signals in the near and far field. Characterizing the acoustic and infrasound source mechanism from underground explosions is of great importance to underground explosion monitoring. To this end we perform full waveform source inversion of infrasound data collected from the SPE-6 experiment at distances from 300 m to 6 km and frequencies up to 20 Hz. Our method requires estimating the state of the atmosphere at the time of each experiment, computing Green's functions through these atmospheric models, and subsequently inverting the observed data in the frequency domain to obtain a source time function. To estimate the state of the atmosphere at the time of the experiment, we utilize the Weather Research and Forecasting - Data Assimilation (WRF-DA) modeling system to derive a unified atmospheric state model by combining Global Energy and Water Cycle Experiment (GEWEX) Continental-scale International Project (GCIP) data and locally obtained sonde and surface weather observations collected at the time of the experiment. We synthesize Green's functions through these atmospheric models using Sandia's moving media acoustic propagation simulation suite (TDAAPS). These models include 3-D variations in topography, temperature, pressure, and wind. We compare inversion results using the atmospheric models derived from the unified weather models versus previous modeling results and discuss how these differences affect computed source waveforms with respect to observed waveforms at various distances. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear

  9. Iron solubility related to particle sulfur content in source emission and ambient fine particles.

    Science.gov (United States)

    Oakes, M; Ingall, E D; Lai, B; Shafer, M M; Hays, M D; Liu, Z G; Russell, A G; Weber, R J

    2012-06-19

    The chemical factors influencing iron solubility (soluble iron/total iron) were investigated in source emission (e.g., biomass burning, coal fly ash, mineral dust, and mobile exhaust) and ambient (Atlanta, GA) fine particles (PM2.5). Chemical properties (speciation and mixing state) of iron-containing particles were characterized using X-ray absorption near edge structure (XANES) spectroscopy and micro-X-ray fluorescence measurements. Bulk iron solubility (soluble iron/total iron) of the samples was quantified by leaching experiments. Major differences were observed in iron solubility in source emission samples, ranging from low solubility (iron solubility did not correspond to silicon content or Fe(II) content. However, source emission and ambient samples with high iron solubility corresponded to the sulfur content observed in single particles. A similar correspondence between bulk iron solubility and bulk sulfate content in a series of Atlanta PM2.5 fine particle samples (N = 358) further supported this trend. In addition, results of linear combination fitting experiments show the presence of iron sulfates in several high iron solubility source emission and ambient PM2.5 samples. These results suggest that the sulfate content (related to the presence of iron sulfates and/or acid-processing mechanisms by H(2)SO(4)) of iron-containing particles is an important proxy for iron solubility.

  10. An empirical assessment of near-source strong ground motion for a 6.6 m{sub b} (7.5 M{sub S}) earthquake in the Eastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Kenneth W

    1984-06-01

    To help assess the impact of the current U.S. Geological Survey position on the seismic safety of nuclear power plants in the Eastern United States (EUS), several techniques for estimating near-source strong ground motion for a Charleston size earthquake were evaluated. The techniques for estimating the near-source strong ground motion for a 6.6 m{sub b} (7.5 M{sub S}) in the Eastern United States which were assessed are methods based on site specific analyses, semi-theoretical scaling techniques, and intensity-based estimates. The first involves the statistical analysis of ground motion records from earthquakes and recording stations having the same general characteristics (earthquakes with magnitudes of 7.5 M{sub S} or larger, epicentral distances of 25 km or less, and sites of either soil or rock). Some recommendations for source and characterization scaling of the bias resulting primarily from an inadequate sample of near-source recordings from earthquakes of large magnitude are discussed. The second technique evaluated requires that semi-theoretical estimates of peak ground motion parameters for a 6.6 m{sub b} (7.5 M{sub S}) earthquake be obtained from scaling relations. Each relation uses a theoretical expression between peak acceleration magnitude and distance together with available strong motion data (majority coming from California) to develop a scaling relation appropriate for the Eastern United States. None of the existing ground motion models for the EUS include the potential effects of source or site characteristics. Adjustments to account for fault mechanisms, site topography, site geology, and the size and embedment of buildings are discussed. The final approach used relations between strong ground motion parameters and Modified Mercalli Intensity in conjunction with two methods to estimate peak parameters for a 6.6 m{sub s} (7.5 M{sub S}) earthquake. As with other techniques, adjustment of peak acceleration estimates are discussed. Each method

  11. Investigation of Biogenic and Non-biogenic Methane Sources in Texas

    Science.gov (United States)

    Yang, S.; Talbot, R. W.; Liu, L.; Lan, X.

    2016-12-01

    Methane (CH4) is a potent greenhouse gas with its mixing ratio increasing in the global atmosphere. Texas is one of the significant areas where underestimation of CH4 emissions by the U.S. inventories are pronounced. This study focused on two areas of Texas: Houston, the energy capital of the world, and the Barnett Shale area which is one of the largest onshore natural gas fields in the United States. The investigation of background CH4 and the fingerprints of CH4 emissions are critical to understanding potential impacts of extensive nature gas operations in these two areas. One-year of stationary CH4 measurements were studied to deduce the regional background CH4 characteristics and to identify the principle CH4 sources in Houston. Key information concerning CH4 sources can be obtained through the stable carbon isotope δ13CH4 during two field campaigns using a state-of-the-art mobile laboratory. CH4 mixing ratio and δ13C in CH4 were sampled by two cavity ring-down spectrometers (CRDS), one of which is coupled to a custom air core 13C sampling device which can supply more than 600 measurements for each plume analysis. Here, we report results of the overall δ13CH4 values and CH4 emission signatures derived from thirty-three sources in the two studied areas, ranging from oil production and processing, waste managements and landfills, to livestock. δ13CH4 signatures of these sources vary from -76‰ to -23‰. Several repeated measurements were sampled to investigate the variability of source signatures. We investigated a case of unexpected massive CH4 leaking detected near the San Jacinto River Fleet site. At the regional scale, the comparison of background δ13CH4 signatures were conducted to obtain the difference of dominate CH4 sources in two study areas. At the local scale, the combination of tower and mobile lab measurements were used to estimate and characterize CH4 emissions in Houston. The results and findings can supply valuable references for the local

  12. Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison.

    Science.gov (United States)

    Jonker, Michiel T O; van der Heijden, Stephan A; Adelman, Dave; Apell, Jennifer N; Burgess, Robert M; Choi, Yongju; Fernandez, Loretta A; Flavetta, Geanna M; Ghosh, Upal; Gschwend, Philip M; Hale, Sarah E; Jalalizadeh, Mehregan; Khairy, Mohammed; Lampi, Mark A; Lao, Wenjian; Lohmann, Rainer; Lydy, Michael J; Maruya, Keith A; Nutile, Samuel A; Oen, Amy M P; Rakowska, Magdalena I; Reible, Danny; Rusina, Tatsiana P; Smedes, Foppe; Wu, Yanwen

    2018-03-20

    This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical guidance for standardized passive sampling, and advance the use of passive sampling in regulatory decision making by increasing confidence in the use of the technique. The study was performed by a consortium of 11 laboratories and included experiments with 14 passive sampling formats on 3 sediments for 25 target chemicals (PAHs and PCBs). The resulting overall interlaboratory variability was large (a factor of ∼10), but standardization of methods halved this variability. The remaining variability was primarily due to factors not related to passive sampling itself, i.e., sediment heterogeneity and analytical chemistry. Excluding the latter source of variability, by performing all analyses in one laboratory, showed that passive sampling results can have a high precision and a very low intermethod variability (sampling, irrespective of the specific method used, is fit for implementation in risk assessment and management of contaminated sediments, provided that method setup and performance, as well as chemical analyses are quality-controlled.

  13. An open source framework for tracking and state estimation ('Stone Soup')

    Science.gov (United States)

    Thomas, Paul A.; Barr, Jordi; Balaji, Bhashyam; White, Kruger

    2017-05-01

    The ability to detect and unambiguously follow all moving entities in a state-space is important in multiple domains both in defence (e.g. air surveillance, maritime situational awareness, ground moving target indication) and the civil sphere (e.g. astronomy, biology, epidemiology, dispersion modelling). However, tracking and state estimation researchers and practitioners have difficulties recreating state-of-the-art algorithms in order to benchmark their own work. Furthermore, system developers need to assess which algorithms meet operational requirements objectively and exhaustively rather than intuitively or driven by personal favourites. We have therefore commenced the development of a collaborative initiative to create an open source framework for production, demonstration and evaluation of Tracking and State Estimation algorithms. The initiative will develop a (MIT-licensed) software platform for researchers and practitioners to test, verify and benchmark a variety of multi-sensor and multi-object state estimation algorithms. The initiative is supported by four defence laboratories, who will contribute to the development effort for the framework. The tracking and state estimation community will derive significant benefits from this work, including: access to repositories of verified and validated tracking and state estimation algorithms, a framework for the evaluation of multiple algorithms, standardisation of interfaces and access to challenging data sets. Keywords: Tracking,

  14. Dosimetric calibration of solid state detectors with low energy β sources

    International Nuclear Information System (INIS)

    Fidanzio, Andrea; Pia Toni, Maria; Capote, Roberto; Pena, Juan; Pasciuti, Katia; Bovi, Maurizio; Perrone, Franco; Azario, Luigi; Lazzeri, Mauro; Gaudino, Diego; Piermattei, Angelo

    2008-01-01

    A PTW Optidos plastic scintillation and a PTW natural diamond detectors were calibrated in terms of absorbed dose to water with β fields produced by 90 Sr + 90 Y and 85 Kr reference sources. Each source was characterized at the Italian National Metrological Institute - the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti of ENEA (ENEA-INMRI) - for two different series, 1 and 2, of ISO reference β-particle radiation fields. Beam flattening filters were used for the series 1 β fields to give uniform absorbed dose rates over a large area at a source-to-reference plane distance of 30 cm. The series 2 β fields were produced at source-to-reference plane distance of 10 cm, without the beam flattening filters, in order to obtain higher absorbed dose rates. The reference absorbed dose rate values were directly determined by the Italian national standard for β-particle dosimetry (a PTW extrapolation ionization chamber) for the series 1 β fields and by a calibrated transfer standard chamber, (a Capintec thin fixed-volume parallel plate ionization chamber) for the series 2 β fields. Finally the two solid state detectors were calibrated in terms of absorbed dose to water with the series 2 β field. The expanded uncertainties of the calibration coefficients obtained for the plastic scintillation dosimeter were 10% and 12% (2SD) for the 90 Sr + 90 Y and the 85 Kr sources, respectively. The expanded uncertainties obtained for the diamond dosimeter were 10% (2SD) and 16% (2SD) for the 90 Sr + 90 Y and the 85 Kr sources, respectively. The good results obtained with the 90 Sr + 90 Y and the 85 Kr β sources encourage to implement this procedure to calibrate this type of detectors at shorter distances and with other β sources of interest in brachytherapy, for example the 106 Ru source

  15. A United States forensic sample for the Gudjonsson Suggestibility Scales.

    Science.gov (United States)

    Frumkin, I Bruce; Lally, Stephen J; Sexton, James E

    2012-01-01

    The Gudjonsson Suggestibility Scales (GSS) is a valuable test to use as part of a comprehensive assessment of psychological and interrogative factors relevant to a defendant's vulnerability to giving a false or involuntary confession. One limitation of the test is that the manual only provides information for samples from Iceland and Great Britain. This report describes the results of 334 individuals in the United States, who were administered the tests as part of an evaluation to assess confession-related issues in a forensic context (i.e., capacity to waive Miranda rights or vulnerability in providing a false or involuntary confession). This forensic sample includes both juveniles and adults. Results are consistent with Gudjonsson's British and Icelandic samples, in which the Yield 1 score is more affected by intellectual and cognitive variables, but Shift and, to a lesser extent, Yield 2 scores are more related to emotional and personality characteristics. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Determination of the hydrogen content of oil samples from Nigeria using an Am-Be neutron source

    International Nuclear Information System (INIS)

    Jonah, S.A.; Elegba, S.B.; Zakari, I.I.

    1998-01-01

    A 5 Ci Am-Be neutron source-based facility, which utilises the principles of thermal neutron reflection technique in combination with foil activation method, has been used to determine the total hydrogen content of commercial oil samples from Nigeria. With an established detection limit of 0.25 H w% for oil matrix of volume 600-ml, the total hydrogen contents of the samples were found to be in the range of 11.11-14.22 H w%. The facility is economical and suitable for the determination of moisture in solid samples. A brief description of the ongoing projects and future plans concerning the CRP are enumerated. (author)

  17. An application of sample entropy to precipitation in Paraíba State, Brazil

    Science.gov (United States)

    Xavier, Sílvio Fernando Alves; da Silva Jale, Jader; Stosic, Tatijana; dos Santos, Carlos Antonio Costa; Singh, Vijay P.

    2018-05-01

    A climate system is characterized to be a complex non-linear system. In order to describe the complex characteristics of precipitation series in Paraíba State, Brazil, we aim the use of sample entropy, a kind of entropy-based algorithm, to evaluate the complexity of precipitation series. Sixty-nine meteorological stations are distributed over four macroregions: Zona da Mata, Agreste, Borborema, and Sertão. The results of the analysis show that intricacies of monthly average precipitation have differences in the macroregions. Sample entropy is able to reflect the dynamic change of precipitation series providing a new way to investigate complexity of hydrological series. The complexity exhibits areal variation of local water resource systems which can influence the basis for utilizing and developing resources in dry areas.

  18. Dissolved-solids sources, loads, yields, and concentrations in streams of the conterminous United States

    Science.gov (United States)

    Anning, David W.; Flynn, Marilyn E.

    2014-01-01

    Recent studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, domestic, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey’s National Water Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model that has improved the understanding of sources, loads, yields, and concentrations of dissolved solids in streams of the conterminous United States.

  19. State of the art in polarized proton sources

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1987-01-01

    Present day polarized H/sup +/ and H/sup -/ ion sources are reviewed by describing the performance of sources representative of each of the techniques being used. New ideas for producing higher intensities are then mentioned. Presently, pulsed H/sup +/ currents in the milliampere range, and H/sup -/ currents of hundreds of μA's, can be obtained

  20. Quality Assessment of Honey Sourced from Natural and Artificial Apiaries in Ekiti State, Nigeria.

    Directory of Open Access Journals (Sweden)

    Oyeyemi Sunday Dele

    2017-10-01

    Full Text Available Honey samples were obtained from wild and domesticated sources and analyzed for some physicochemical properties such as color, pH, moisture content, ash content, refractive index, specific gravity, total solid, viscosity, glucose and fructose content following Standard Association of Official Analytical Chemistry. The following range of values for pH (3.55-4.20, moisture content (18.50-25.60%, soluble solids (74.10-81.20%, ash content (0.08-0.14%, specific gravity (1.38-1.47, refractive index (81.3-83.4%, fructose content (40.5-63.04% and glucose content (19.35-32.34%. The mineral composition analyzed revealed potassium to be the dominant mineral in the honey samples followed by Calcium. However, Cadmium and lead where not detected in the honey samples. The results indicated that parameters such as pH, moisture content, ash content, specific gravity, sugar (majorly fructose and glucose content, fructose/glucose ratio, glucose/water ratio conform within the limit of the international standard for honey. However, moisture contents of the wild honey samples (22.05% and 25.60% were a little higher than the Codex Standards of ≤ 21%. In conclusion, the honey samples investigated have the needed quality criteria and are good for human consumption. The results also revealed excellent organoleptic acceptability of the honey samples, hence are suitable for human uses.

  1. Direct Power Control for Three-Phase Two-Level Voltage-Source Rectifiers Based on Extended-State Observation

    DEFF Research Database (Denmark)

    Song, Zhanfeng; Tian, Yanjun; Yan, Zhuo

    2016-01-01

    This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent characte......This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent...

  2. The needs for brachytherapy source calibrations in the United States

    International Nuclear Information System (INIS)

    Coursey, B.M.; Goodman, L.J.; Hoppes, D.D.; Loevinger, R.; McLaughlin, W.L.; Soares, C.G.; Weaver, J.T.

    1992-01-01

    Brachytherapy sources of beta and gamma radiation ('brachy' is from the Greek, meaning 'near') have a long history of use in interstitial, intracavitary, intraluminal, and ocular radiation therapy. In the past the US national standards for these sources were often specified in activity or milligram radium equivalent. With the introduction of new radionuclide sources to replace radium, source strength calibrations are now expressed as air kerma rate at a meter. In this paper, we review the NIST standards for brachytherapy sources, list some of the common radionuclides and source encapsulations in use in the US radiology community, and describe the latest NIST work, in collaboration with several US medical institutions, on a method of two- and three-dimensional dose mapping of brachytherapy sources using radiochromic films. (orig.)

  3. A general assignment method for oriented sample (OS) solid-state NMR of proteins based on the correlation of resonances through heteronuclear dipolar couplings in samples aligned parallel and perpendicular to the magnetic field.

    Science.gov (United States)

    Lu, George J; Son, Woo Sung; Opella, Stanley J

    2011-04-01

    A general method for assigning oriented sample (OS) solid-state NMR spectra of proteins is demonstrated. In principle, this method requires only a single sample of a uniformly ¹⁵N-labeled membrane protein in magnetically aligned bilayers, and a previously assigned isotropic chemical shift spectrum obtained either from solution NMR on micelle or isotropic bicelle samples or from magic angle spinning (MAS) solid-state NMR on unoriented proteoliposomes. The sequential isotropic resonance assignments are transferred to the OS solid-state NMR spectra of aligned samples by correlating signals from the same residue observed in protein-containing bilayers aligned with their normals parallel and perpendicular to the magnetic field. The underlying principle is that the resonances from the same residue have heteronuclear dipolar couplings that differ by exactly a factor of two between parallel and perpendicular alignments. The method is demonstrated on the membrane-bound form of Pf1 coat protein in phospholipid bilayers, whose assignments have been previously made using an earlier generation of methods that relied on the preparation of many selectively labeled (by residue type) samples. The new method provides the correct resonance assignments using only a single uniformly ¹⁵N-labeled sample, two solid-state NMR spectra, and a previously assigned isotropic spectrum. Significantly, this approach is equally applicable to residues in alpha helices, beta sheets, loops, and any other elements of tertiary structure. Moreover, the strategy bridges between OS solid-state NMR of aligned samples and solution NMR or MAS solid-state NMR of unoriented samples. In combination with the development of complementary experimental methods, it provides a step towards unifying these apparently different NMR approaches. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Modelling of the influence of the vacancy source and sink activity and the stress state on diffusion in crystalline solids

    International Nuclear Information System (INIS)

    Svoboda, J.; Fischer, F.D.

    2011-01-01

    Diffusion in solids is a well-known phenomenon that has many consequences in technology and material science. Modelling of diffusion-controlled processes requires both a reliable theory of diffusion and reliable kinetic coefficients, as well as other thermodynamic data. Often the classical Darken theory, valid for stress-free systems with ideal vacancy source and sink activity, is generalized to multicomponent systems with ideal vacancy source and sink activity. Nazarov and Gurov presented a theory for stress-free systems with no vacancy source and sink activity. Recently we published a general theory of diffusion that accounted for the role of non-ideal vacancy source and sink activity, as well as the stress state. Since diffusion theories are tested and diffusion coefficients measured usually on diffusion couples, this paper presents evolution equations based on that general theory for a diffusion couple. In the limit, the equations of the Darken theory and the Nazarov and Gurov theory are valid for ideal vacancy source and sink activity and no vacancy source and sink activity, respectively. Simulations for binary and ternary diffusion couples demonstrate the influence of the vacancy source and sink activity and the stress state on evolution of site fraction profiles of components and vacancies, and on the Kirkendall effect.

  5. Fluctuations of Attentional Networks and Default Mode Network during the Resting State Reflect Variations in Cognitive States: Evidence from a Novel Resting-state Experience Sampling Method.

    Science.gov (United States)

    Van Calster, Laurens; D'Argembeau, Arnaud; Salmon, Eric; Peters, Frédéric; Majerus, Steve

    2017-01-01

    Neuroimaging studies have revealed the recruitment of a range of neural networks during the resting state, which might reflect a variety of cognitive experiences and processes occurring in an individual's mind. In this study, we focused on the default mode network (DMN) and attentional networks and investigated their association with distinct mental states when participants are not performing an explicit task. To investigate the range of possible cognitive experiences more directly, this study proposes a novel method of resting-state fMRI experience sampling, informed by a phenomenological investigation of the fluctuation of mental states during the resting state. We hypothesized that DMN activity would increase as a function of internal mentation and that the activity of dorsal and ventral networks would indicate states of top-down versus bottom-up attention at rest. Results showed that dorsal attention network activity fluctuated as a function of subjective reports of attentional control, providing evidence that activity of this network reflects the perceived recruitment of controlled attentional processes during spontaneous cognition. Activity of the DMN increased when participants reported to be in a subjective state of internal mentation, but not when they reported to be in a state of perception. This study provides direct evidence for a link between fluctuations of resting-state neural activity and fluctuations in specific cognitive processes.

  6. Detection of fission fragments using thick samples in contact with solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Lima, D.A. de; Martins, J.B.; Tavares, O.A.P.

    1987-01-01

    Whenever use is made of thick samples in contact with solid state nuclear track detectors for determining fission yields, one of the fundamental problems is the evaluation of the effective number of target nuclei which contributes to the fraction of the number of fission events that will be recorded. The evaluation of the effective number of target nuclei which contributes to recorded events is based on the effective thickness of the sample. A method for evaluating effective thickness of thick samples for binary fission modes, is presented. A cross section equation which takes into account all the necessary corrections due to fragment attenuation effects by a thick target for calculation induced fission yields, was obtained. (Author) [pt

  7. Urban PM in Eastern Germany: Source apportionment and contributions from different spatial scales

    Science.gov (United States)

    van Pinxteren, D.; Fomba, K. W.; Mothes, F.; Spindler, G.; Herrmann, H.

    2017-12-01

    Understanding the contributions of particulate matter (PM) sources and the source areas impacting total PM levels in a city are important requirements for further developing clean air policies and efficient abatement strategies. This presentation reports on two studies in Eastern Germany providing a detailed picture of present-day urban PM sources and discriminating contributions of local, regional and long-range sources. The "Leipzig Aerosol 2013-15" study yielded contributions of 12 sources to coarse, fine, and ultrafine particles, resolved by Positive Matrix Factorization (PMF) from comprehensive chemical speciation of 5-stage Berner impactor samples at 4 different sites in the Leipzig area. Dominant winter-time sources were traffic exhaust and non-exhaust emissions, secondary aerosol formation, and combustion emissions from both biomass and coal burning with different relative importance in different particle size ranges. Local sources dominated PM levels in ultrafine and coarse particles (60% - 80%) while high mass concentrations in accumulation mode particles mainly resulted from regional import into the city (70%). The "PM-East" study compiled PM10 mass and constituents' concentrations at 10 urban and rural sites in Eastern Germany during winter 2016/17, which included a 3-week episode of frequent exceedances of the PM10 limit value. PMF source apportionment is performed for a subset of the sites, including the city of Berlin. Contributions from short-, mid-, and long-range sources, including trans-boundary pollution import from neighbouring countries, are quantitatively assessed by advanced back trajectory statistical methods. Data analysis in PM-East is ongoing and final results will be available by November. Funding is acknowledged from 4 federal states of Germany: Berlin Senate Department for Environment, Transport and Climate Protection; Saxon State Office for Environment, Agriculture and Geology; State Agency for Environment, Nature Conservation and

  8. Chemical and Microbiological Analysis of Certain Water Sources and Industrial Wastewater Samples in Dakahlia Governorate

    International Nuclear Information System (INIS)

    El-Fadaly, H.; El-Defrawy, M.M.; El-Zawawy, F.; Makia, D.

    1999-01-01

    The chemical analysis included quantitative measurement of electrical conductivity, alkalinity , hardness sulphate, ph, total dissolved solids, chloride, as well as dissolved oxygen was carried out. The microbiological examination for different water sources and industrial wastewater samples was also conducted. some of heavy metals, Co 2+ Cu 2+ Fe 3+ and Mn 2+ were determined in fresh water, while other metals, such as Cr 6+ , Co 2+ , Zn 2+ and Ni 2+ were measured in industrial wastewater. Results of the chemical analysis showed that all measured parameters were found within the limitation either national or international law, except some samples which showed higher values than the permissible limits for some measured parameters. The microbiological analysis exhibited presence of yeasts, fungi and bacteria. Most bacterial isolates were short rod, spore formers as well as coccoid shaped bacteria. The efficiency of water treatment process on the reduction of microbial load was also calculated. Regarding the pathogenic bacteria, data showed that neither water samples nor industrial wastewater contain pathogens when using specific cultivation media for the examination. Furthermore, data proved the possibility of recycling of the tested industrial wastewater on which some microorganisms can grow. Data showed that the percent of heavy metals removal can reach to more than 70% in some cases as a result to bacterial treatment of industrial wastewater

  9. The relationship between the FFM personality traits, state psychopathology, and sexual compulsivity in a sample of male college students.

    Science.gov (United States)

    Pinto, Joana; Carvalho, Joana; Nobre, Pedro J

    2013-07-01

    Several studies have advocated a relationship between psychopathological features and sexual compulsivity. Such relationship is often found among individuals seeking help for out of control sexual behavior, suggesting that the association between psychological adjustment and sexual compulsivity may have a significant clinical value. However, a more complete approach to the topic of sexual compulsivity would also include the analysis of nonclinical samples as healthy individuals may be at risk of developing some features of hypersexuality in the future. The aim of this study was to explore the relationship between stable traits of personality, state psychopathology, and sexual compulsivity in a sample of male college students. Furthermore, the potential mediating role of state psychopathology in the relationship between personality traits and sexual compulsivity was tested. Participants completed the following measures: the NEO Five-Factor Inventory, the Brief Symptom Inventory, and the Compulsive Sexual Behavior Inventory-22. The sample included 152 male college students recruited in a Portuguese university using nonrandom methods. The measures were completed individually and anonymously. Findings on state psychopathology suggested that psychoticism may be one of the key dimensions associated with sexual compulsivity in male students. The personality traits of Neuroticism and Agreeableness were also significant predictors of sexual compulsivity. Findings on the mediating effects suggested that state psychopathology mediated the relationship between Neuroticism and sexual compulsivity but not between Agreeableness and sexual compulsivity. A psychopathological path (encompassing Neuroticism and state psychopathology) and a behavioral path (encompassing Agreeableness features) may be involved in sexual compulsivity as reported by a nonclinical sample of male students. © 2013 International Society for Sexual Medicine.

  10. Food Sources of Energy and Nutrients among Children in the United States: National Health and Nutrition Examination Survey 2003–2006

    Science.gov (United States)

    Keast, Debra R.; Fulgoni III, Victor L.; Nicklas, Theresa A.; O’Neil, Carol E.

    2013-01-01

    Background: Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Methods: Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332) in the 2003–2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. Results: The two top ranked food/food group sources of energy and nutrients were: energy—milk (7% of energy) and cake/cookies/quick bread/pastry/pie (7%); protein—milk (13.2%) and poultry (12.8%); total carbohydrate—soft drinks/soda (10.5%) and yeast bread/rolls (9.1%); total sugars—soft drinks/soda (19.2%) and yeast breads and rolls (12.7%); added sugars—soft drinks/soda (29.7%) and candy/sugar/sugary foods (18.6%); dietary fiber—fruit (10.4%) and yeast bread/rolls (10.3%); total fat—cheese (9.3%) and crackers/popcorn/pretzels/chips (8.4%); saturated fatty acids—cheese (16.3%) and milk (13.3%); cholesterol—eggs (24.2%) and poultry (13.2%); vitamin D—milk (60.4%) and milk drinks (8.3%); calcium—milk (33.2%) and cheese (19.4%); potassium—milk (18.8%) and fruit juice (8.0%); and sodium—salt (18.5%) and yeast bread and rolls (8.4%). Conclusions: Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient density of

  11. Food sources of energy and nutrients among children in the United States: National Health and Nutrition Examination Survey 2003–2006.

    Science.gov (United States)

    Keast, Debra R; Fulgoni, Victor L; Nicklas, Theresa A; O'Neil, Carol E

    2013-01-22

    Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332) in the 2003-2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. The two top ranked food/food group sources of energy and nutrients were: energy - milk (7% of energy) and cake/cookies/quick bread/pastry/pie (7%); protein - milk (13.2%) and poultry (12.8%); total carbohydrate - soft drinks/soda (10.5%) and yeast bread/rolls (9.1%); total sugars - soft drinks/soda (19.2%) and yeast breads and rolls (12.7%); added sugars - soft drinks/soda (29.7%) and candy/sugar/sugary foods (18.6%); dietary fiber - fruit (10.4%) and yeast bread/rolls (10.3%); total fat - cheese (9.3%) and crackers/popcorn/pretzels/chips (8.4%); saturated fatty acids - cheese (16.3%) and milk (13.3%); cholesterol - eggs (24.2%) and poultry (13.2%); vitamin D - milk (60.4%) and milk drinks (8.3%); calcium - milk (33.2%) and cheese (19.4%); potassium - milk (18.8%) and fruit juice (8.0%); and sodium - salt (18.5%) and yeast bread and rolls (8.4%). Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient density of children's diets.

  12. Determination of total sulfur in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry.

    Science.gov (United States)

    Virgilio, Alex; Raposo, Jorge L; Cardoso, Arnaldo A; Nóbrega, Joaquim A; Gomes Neto, José A

    2011-03-23

    The usefulness of molecular absorption was investigated for the determination of total sulfur (S) in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry. The lines for CS at 257.595, 257.958, and 258.056 nm and for SH at 323.658, 324.064, and 327.990 nm were evaluated. Figures of merit, such as linear dynamic range, sensitivity, linear correlation, characteristic concentration, limit of detection, and precision, were established. For selected CS lines, wavelength-integrated absorbance equivalent to 3 pixels, analytical curves in the 100-2500 mg L(-1) (257.595 nm), 250-2000 mg L(-1) (257.958 nm), and 250-5000 mg L(-1) (258.056 nm) ranges with a linear correlation coefficient better than 0.9980 were obtained. Results were in agreement at a 95% confidence level (paired t test) with those obtained by gravimetry. Recoveries of S in fungicide and fertilizer samples were within the 84-109% range, and the relative standard deviation (n=12) was typically <5%.

  13. Numerically Accelerated Importance Sampling for Nonlinear Non-Gaussian State Space Models

    NARCIS (Netherlands)

    Koopman, S.J.; Lucas, A.; Scharth, M.

    2015-01-01

    We propose a general likelihood evaluation method for nonlinear non-Gaussian state-space models using the simulation-based method of efficient importance sampling. We minimize the simulation effort by replacing some key steps of the likelihood estimation procedure by numerical integration. We refer

  14. Imaging of fast-neutron sources using solid-state track-recorder pinhole radiography

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Gold, R.; Roberts, J.H.; Kaiser, B.J.; Preston, C.C.

    1983-08-01

    Pinhole imaging methods are being developed and tested for potential future use in imaging the intense neutron source of the Fusion Materials Irradiation Test (FMIT) Facility. Previously reported, extensive calibration measurements of the proton, neutron, and alpha particle response characteristics of CR-39 polymer solid state track recorders (SSTRs) are being used to interpret the results of imaging experiments using both charged particle and neutron pinhole collimators. High resolution, neutron pinhole images of a 252 Cf source have been obtained in the form of neutron induced proton recoil tracks in CR-39 polymer SSTR. These imaging experiments are described as well as their potential future applications to FMIT

  15. Psychometric Properties of the Penn State Worry Questionnaire for Children in a Large Clinical Sample

    Science.gov (United States)

    Pestle, Sarah L.; Chorpita, Bruce F.; Schiffman, Jason

    2008-01-01

    The Penn State Worry Questionnaire for Children (PSWQ-C; Chorpita, Tracey, Brown, Collica, & Barlow, 1997) is a 14-item self-report measure of worry in children and adolescents. Although the PSWQ-C has demonstrated favorable psychometric properties in small clinical and large community samples, this study represents the first psychometric…

  16. What Are “X-shaped” Radio Sources Telling Us? II. Properties of a Sample of 87

    Science.gov (United States)

    Saripalli, Lakshmi; Roberts, David H.

    2018-01-01

    In an earlier paper, we presented Jansky Very Large Array multi-frequency, multi-array continuum imaging of a unique sample of low-axial ratio radio galaxies. In this paper, the second in the series, we examine the images to learn the phenomenology of how the off-axis emission relates to the main radio source. Inversion-symmetric offset emission appears to be bimodal and to originate from one of two strategic locations: outer ends of radio lobes (outer-deviation) or from inner ends (inner-deviation). The latter sources are almost always associated with edge-brightened sources. With S- and Z-shaped sources being a subset of outer-deviation sources, this class lends itself naturally to explanations involving black hole axis precession. Our data allow us to present a plausible model for the more enigmatic inner-deviation sources with impressive wings; as for outer-deviation sources these too require black hole axis shifts, although they also require plasma backflows into relic channels. Evolution in morphology over time relates the variety in structures in inner-deviation sources including XRGs. With features such as non-collinearities, central inner-S “spine,” corresponding lobe emission peaks, double and protruding hotspots not uncommon, black hole axis precession, drifts, or flips could be active in a significant fraction of radio sources with prominent off-axis emission. At least 4% of radio galaxies appear to undergo black hole axis rotation. Quasars offer a key signature for recognizing rotating axes. With a rich haul of sources that have likely undergone axis rotation, our work shows the usefulness of low-axial ratio sources in pursuing searches for binary supermassive black holes.

  17. Iron influence in self-attenuation of gamma radiation in sand samples

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Reginaldo R.; Cavalcante, Fernanda; Pecequilo, Brigitte R.S, E-mail: raquino@ipen.br, E-mail: fcavalcante@ipen.br, E-mail: brigitte@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Self-attenuation of gamma rays are usually observed in sand samples, due to the presence of iron particles of natural or anthropogenic causes, which may lead to misleading activities concentrations results. As iron atoms are often present in sand samples, the self-attenuation contribution from this mineral requires special attention when assessing sand samples radioactivity. This contributions in verified in the in the present study, using several silica (sand-like) samples doped with different concentrations of iron. The samples were arranged with pure SiO{sub 4} (98,9%) mineral from the region of Setiba, (Espirito Santo state, Brazil) and Itabirito mineral, from Itabira (Minas Gerais state, Brazil), using standard 100 mL high density polyethylene (HDPE) flat-botton cylindrical flasks, each sealed using a 52.5 mm plan screw cap and bubble spigot. Three samples were arranged in different concentrations - Fe 25% and SiO{sub 4} 75%; Fe 50% and SiO{sub 4} 50%; Fe 75% and SiO{sub 4} 25% and two other samples were assembled in the same geometry, using 100% SiO{sub 4} and 100% Fe. These samples were exposed to a large spectrum of gamma radiation (121 keV to 1408 keV) emitted by sources of {sup 60}Co, {sup 137}Cs and {sup 152}Eu. These gamma radiations were collimated and directed over the doped samples in a high resolution gamma ray spectrometer, whose spectra were analyzed with the Winner Gamma software. The matrix effect intensity is inferred by the percentage differences observed in varying the iron concentration that proved to be more intense for lower energy radiation. (author)

  18. 135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

    International Nuclear Information System (INIS)

    Snow, Mathew S.; Snyder, Darin C.

    2016-01-01

    135 Cs/ 137 Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135 Cs/ 137 Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135 Cs/ 137 Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135 Cs/ 137 Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135 Cs/ 137 Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in 135 Cs/ 137 Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135 Cs/ 137 Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. - Highlights: • 135 Cs/ 137 Cs useful for tracking anthropogenic environmental radiocesium releases. • European surface soils/vegetation have uniform ratio consistent with Chernobyl. • 135 Cs/ 137 Cs in Irish sea represents thermal fission ratio distinct from Chernobyl. • Can distinguish between major source terms in Europe based on 135 Cs/ 137 Cs.

  19. The Potential of Open Source Information in Supporting Acquisition Pathway Analysis to Design IAEA State Level Approaches

    International Nuclear Information System (INIS)

    Renda, G.; Kim, L.; Jungwirth, R.; Pabian, F.; Wolfart, E.; Cojazzi, G.G.M.; )

    2015-01-01

    International Atomic Energy Agency (IAEA) safeguards designed to deter nuclear proliferation are constantly evolving to respond to new challenges. Within its State Level Concept, the IAEA envisions an objective-based and information-driven approach for designing and implementing State Level Approaches (SLAs), using all available measures to improve the effectiveness and efficiency of safeguards. The main Objectives of a SLA are a) to detect undeclared nuclear material or activities in the State, b) to detect undeclared production or processing of nuclear materials in declared facilities or locations outside facilities (LOFs), c) to detect diversion of declared nuclear material in declared facilities or LOFs. Under the SLA, States will be differentiated based upon objective State-Specific Factors that influence the design, planning, conduct and evaluation of safeguards activities. Proposed categories of factors include both technical and legal aspects, spanning from the deployed fuel cycle and the related state's technical capability to the type of safeguards agreements in force and the IAEA experience in implementing safeguards in that state. To design a SLA, the IAEA foresees the use of Acquisition Path Analysis (APA) to identify the plausible routes for acquiring weapons-usable material and to assess their safeguards significance. In order to achieve this goal, APA will have to identify possible acquisition paths, characterize them and eventually prioritize them. This paper will provide an overview of how the use of open source information (here loosely defined as any type of non-classified or proprietary information and including, but not limited to, media sources, government and non-governmental reports and analyzes, commercial data, satellite imagery, scientific/ technical literature, trade data) can support this activity in the various aspects of a typical APA approach. (author)

  20. Design and Development of a Robot-Based Automation System for Cryogenic Crystal Sample Mounting at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Shu, D.; Preissner, C.; Nocher, D.; Han, Y.; Barraza, J.; Lee, P.; Lee, W.-K.; Cai, Z.; Ginell, S.; Alkire, R.; Lazarski, K.; Schuessler, R.; Joachimiak, A.

    2004-01-01

    X-ray crystallography is the primary method to determine the 3D structures of complex macromolecules at high resolution. In the years to come, the Advanced Photon Source (APS) and similar 3rd-generation synchrotron sources elsewhere will become the most powerful tools for studying atomic structures of biological molecules. One of the major bottlenecks in the x-ray data collection process is the constant need to change and realign the crystal sample. This is a very time- and manpower-consuming task. An automated sample mounting system will help to solve this bottleneck problem. We have developed a novel robot-based automation system for cryogenic crystal sample mounting at the APS. Design of the robot-based automation system, as well as its on-line test results at the Argonne Structural Biology Center (SBC) 19-BM experimental station, are presented in this paper

  1. Micro-PIXE on thin plant tissue samples in frozen hydrated state: A novel addition to JSI nuclear microprobe

    International Nuclear Information System (INIS)

    Vavpetič, P.; Pelicon, P.; Vogel-Mikuš, K.; Grlj, N.; Pongrac, P.; Jeromel, L.; Ogrinc, N.; Regvar, M.

    2013-01-01

    Recently we completed a construction of a cryostat at Jožef Stefan Institute (JSI) nuclear microprobe enabling us to analyze various types of biological samples in frozen hydrated state using micro-PIXE/STIM/RBS. Sample load-lock system was added to our existing setup to enable us to quickly insert a sample holder with frozen hydrated tissue samples onto a cold goniometer head cooled with liquid nitrogen inside the measuring chamber. Cryotome-cut slices of frozen hydrated plant samples were mounted between two thin silicon nitride foils and then attached to the sample holder. Sufficient thermal contact between silicon nitride foils and sample holder must be achieved, as well as between the sample holder and the cold goniometer head inside the measuring chamber to prevent melting of the samples. Matrix composition of frozen hydrated tissue is consisted mostly of ice. Thinning of the sample as well as water evaporation during high vacuum and proton beam exposure was inspected by the measurements with RBS and STIM method simultaneously with micro-PIXE. For first measuring attempts a standard micro-PIXE configuration for tissue mapping was used with proton beam cross section of 1.2 × 1.2 μm 2 and a beam current of 100 pA. The temperature of the cold goniometer head was kept below 130 K throughout the entire proton beam exposure. First measurements of thin plant tissue samples in frozen hydrated state show minute sample degradation during the 10 h period of micro-PIXE measurements

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

    Science.gov (United States)

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

    2007-10-01

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

  3. Parametric source of two-photon states with a tunable degree of entanglement and mixing: Experimental preparation of Werner states and maximally entangled mixed states

    International Nuclear Information System (INIS)

    Cinelli, C.; Di Nepi, G.; De Martini, F.; Barbieri, M.; Mataloni, P.

    2004-01-01

    A parametric source of polarization-entangled photon pairs with striking spatial characteristics is reported. The distribution of the output electromagnetic k modes excited by spontaneous parametric down-conversion and coupled to the output detectors can be very broad. Using these states realized over a full entanglement ring output distribution, the nonlocal properties of the generated entanglement have been tested by standard Bell measurements and by Ou-Mandel interferometry. A 'mode-patchwork' technique based on the quantum superposition principle is adopted to synthesize in a straightforward and reliable way any kind of mixed state, of large conceptual and technological interest in modern quantum information. Tunable Werner states and maximally entangled mixed states have indeed been created by this technique and investigated by quantum tomography. A study of the entropic and nonlocal properties of these states has been undertaken experimentally and theoretically, by a unifying variational approach

  4. Improving the Efficiency of Solid State Light Sources

    International Nuclear Information System (INIS)

    Joanna McKittrick

    2003-01-01

    This proposal addresses the national need to develop a high efficiency light source for general illumination applications. The goal is to perform research that would lead to the fabrication of a unique solid state, white-emitting light source. This source is based on an InGaN/GaN UV-emitting chip that activates a luminescent material (phosphor) to produce white light. White-light LEDs are commercially available which use UV from a GaN chip to excite a phosphor suspended in epoxy around the chip. Currently, these devices are relatively inefficient. This research will target one technical barrier that presently limits the efficiency of GaN based devices. Improvements in efficiencies will be achieved by improving the internal conversion efficiency of the LED die, by improving the coupling between the die and phosphor(s) to reduce losses at the surfaces, and by selecting phosphors to maximize the emissions from the LEDs in conversion to white light. The UCSD research team proposes for this project to develop new phosphors that have high quantum efficiencies that can be activated by the UV-blue (360-410 nm) light emitted by the GaN device. The main goal for the UCSD team was to develop new phosphor materials with a very specific property: phosphors that could be excited at long UV-wavelengths (λ=350-410 nm). The photoluminescence of these new phosphors must be activated with photons emitted from GaN based dies. The GaN diodes can be designed to emit UV-light in the same range (λ=350-410 nm). A second objective, which is also very important, is to search for alternate methods to fabricate these phosphors with special emphasis in saving energy and time and reduce pollution

  5. Oxidation state inherited from the magma source and implications for mineralization: Late Jurassic to Early Cretaceous granitoids, Central Lhasa subterrane, Tibet

    Science.gov (United States)

    Cao, MingJian; Qin, KeZhang; Li, GuangMing; Evans, Noreen J.; McInnes, Brent I. A.; Li, JinXiang; Zhao, JunXing

    2018-03-01

    Arc magmas are more oxidized than mid-ocean ridge basalts; however, there is continuing debate as to whether this higher oxidation state is inherited from the source magma or developed during late-stage magmatic differentiation processes. Well-constrained Late Jurassic to Early Cretaceous arc-related intermediate to felsic rocks derived from distinct magma sources provide us with a good opportunity to resolve this enigma. A series of granitoids from the western Central Lhasa subterrane were analyzed for whole-rock magnetic susceptibility, Fe2O3/FeO ratios, and trace elements in zircon. Compared to Late Jurassic samples (1.8 ± 2.0 × 10-4 emu g-1 oe-1, Fe3+/Fetotal = 0.32 ± 0.07, zircon Ce4+/Ce3+* = 15.0 ± 13.4), Early Cretaceous rocks show higher whole-rock magnetic susceptibility (5.8 ± 2.5 × 10-4 emu g-1 oe-1), Fe3+/Fetotal ratios (0.43 ± 0.04), and zircon Ce4+/Ce3+* values (23.9 ± 22.3). In addition, positive correlations among whole-rock magnetic susceptibility, Fe3+/Fetotal ratios, and zircon Ce4+/Ce3+* reveal a slight increase in oxidation state from fO2 = QFM to NNO in the Late Jurassic to fO2 = ˜NNO in the Early Cretaceous. Obvious linear correlation between oxidation indices (whole-rock magnetic susceptibility, zircon Ce4+/Ce3+*) and source signatures (zircon ɛHf(t), TDM C ages) indicates that the oxidation state was predominantly inherited from the source with only a minor contribution from magmatic differentiation. Thus, the sources for both the Late Jurassic and Early Cretaceous rocks were probably influenced by mantle wedge-derived magma, contributing to the increased fO2. Compared to ore-forming rocks at giant porphyry Cu deposits, the relatively low oxidation state (QFM to NNO) and negative ɛHf(t) (-16 to 0) of the studied granitoids implies relative infertility. However, this study demonstrates two potential fast and effective indices ( fO2 and ɛHf(t)) to evaluate the fertility of granitoids for porphyry-style mineralization. In an

  6. A preliminary nationwide survey of the presence of emerging contaminants in drinking and source waters in Brazil.

    Science.gov (United States)

    Machado, Kelly C; Grassi, Marco Tadeu; Vidal, Cristiane; Pescara, Igor C; Jardim, Wilson F; Fernandes, Andreia N; Sodré, Fernando F; Almeida, Fernanda V; Santana, Joyce S; Canela, Maria Cristina; Nunes, Camila R O; Bichinho, Kátia M; Severo, Flaviana J R

    2016-12-01

    This is the first nationwide survey of emerging contaminants in Brazilian waters. One hundred drinking water samples were investigated in 22 Brazilian state capitals. In addition, seven source water samples from two of the most populous regions of the country were evaluated. Samples were collected from June to September of 2011 and again during the same period in 2012. The study covered emerging contaminants of different classes, including hormones, plasticizers, herbicides, triclosan and caffeine. The analytical method for the determination of the compounds was based on solid-phase extraction followed by analysis via liquid chromatography electrospray triple-quadrupole mass spectrometry (LC-MS/MS). Caffeine, triclosan, atrazine, phenolphthalein and bisphenol A were found in at least one of the samples collected in the two sampling campaigns. Caffeine and atrazine were the most frequently detected substances in both drinking and source water. Caffeine concentrations in drinking water ranged from 1.8ngL -1 to values above 2.0μgL -1 while source-water concentrations varied from 40ngL -1 to about 19μgL -1 . For atrazine, concentrations were found in the range from 2.0 to 6.0ngL -1 in drinking water and at concentrations of up to 15ngL -1 in source water. The widespread presence of caffeine in samples of treated water is an indication of the presence of domestic sewage in the source water, considering that caffeine is a compound of anthropogenic origin. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Design of long pulse/steady state negative hydrogen ion sources for fusion applications

    International Nuclear Information System (INIS)

    Prelec, K.

    1980-01-01

    By using parameters of ion sources when operating in a pulsed mode and without cooling (pulse length 2 . For the range of cathode power densities between 0.2 kW/cm 2 and 1 Kw/cm 2 , nucleated boiling has to be used for heat removal; below 0.2 kW/cm 2 water flow cooling suffices. Although this source should deliver 0.3 to 0.5 A of H - ions in a steady state operation and at full power, the other source, which has a magnetron geometry, is more promising. The latter incorporates two new features compared to first designs, geometrical focusing of fast, primary negative hydrogen ions from the cathode into the extraction slit, and a wider discharge gap in the back of the source. These two changes have resulted in an improvement of the power and gas efficiencies by a factor of 3 to 4 and in a reduction of the cathode power density by an order of magnitude. The source has water cooling for all the electrodes, because maximum power densities will not be higher than 0.2 kW/cm 2 . Very recently a modification of this magnetron source is being considered; it consists of plasma injection into the source from a hollow cathode discharge

  8. Efficiency of resource-use in Cassava production in Edo state, Nigeria

    African Journals Online (AJOL)

    This study employed the use of the Maximum Likelihood Estimation Technique in estimating the efficiency of resource-use in cassava production in Edo State. Data used for the study were sourced through the cost-route method of data collection, based on a stratified random sampling technique. The average farm size of ...

  9. RECOMMENDED OPERATING PROCEDURE NO. 56: COLLECTION OF GASEOUS GRAB SAMPLES FROM COMBUSTION SOURCES FOR NITROUS OXIDE MEASUREMENT

    Science.gov (United States)

    The document is a recommended operating procedure, prepare or use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). The procedure applies to the collection of gaseous grab samples from fossil fuel combustion sources for subsequent a...

  10. Electro-optic sampling of THz pulses at the CTR source at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, Steffen

    2012-06-15

    Several applications in material science, non-linear optics and solid-state physics require short pulses with a high pulse energy of radiation in the far-infrared and in the terahertz (THz) regime in particular. As described in the following, coherent transition radiation generated by high-relativistic electron bunches at FLASH provides broadband single-cycle pulses of sub-picosecond length. The pulses are characterized using the quantitative and time-resolved technique of electro-optic sampling showing peak field strengths in the order of 1 MV/cm.

  11. Electro-optic sampling of THz pulses at the CTR source at FLASH

    International Nuclear Information System (INIS)

    Wunderlich, Steffen

    2012-06-01

    Several applications in material science, non-linear optics and solid-state physics require short pulses with a high pulse energy of radiation in the far-infrared and in the terahertz (THz) regime in particular. As described in the following, coherent transition radiation generated by high-relativistic electron bunches at FLASH provides broadband single-cycle pulses of sub-picosecond length. The pulses are characterized using the quantitative and time-resolved technique of electro-optic sampling showing peak field strengths in the order of 1 MV/cm.

  12. Solid-phase extraction and separation procedure for trace aluminum in water samples and its determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

    Science.gov (United States)

    Ciftci, Harun; Er, Cigdem

    2013-03-01

    In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L(-1) HNO(3) and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L(-1) and 3.91 μg L(-1), respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples.

  13. 200 Area TEDF effluent sampling and analysis plan

    International Nuclear Information System (INIS)

    Alaconis, W.C.; Ballantyne, N.A.; Boom, R.J.

    1995-06-01

    This sampling analysis sets forth the effluent sampling requirements, analytical methods, statistical analyses, and reporting requirements to satisfy the State Waste Discharge Permit No. ST4502 for the Treated Effluent Disposal Facility. These requirements are listed below: Determine the variability in the effluent of all constituents for which enforcement limits, early warning values and monitoring requirements; demonstrate compliance with the permit; and verify that BAT/AKART (Best Available Technology/All know and Reasonable Treatment) source, treatment, and technology controls are being met

  14. Salmonellosis outbreaks in the United States due to fresh produce: sources and potential intervention measures.

    Science.gov (United States)

    Hanning, Irene B; Nutt, J D; Ricke, Steven C

    2009-01-01

    Foodborne Salmonella spp. is a leading cause of foodborne illness in the United States each year. Traditionally, most cases of salmonellosis were thought to originate from meat and poultry products. However, an increasing number of salmonellosis outbreaks are occurring as a result of contaminated produce. Several produce items specifically have been identified in outbreaks, and the ability of Salmonella to attach or internalize into vegetables and fruits may be factors that make these produce items more likely to be sources of Salmonella. In addition, environmental factors including contaminated water sources used to irrigate and wash produce crops have been implicated in a large number of outbreaks. Salmonella is carried by both domesticated and wild animals and can contaminate freshwater by direct or indirect contact. In some cases, direct contact of produce or seeds with contaminated manure or animal wastes can lead to contaminated crops. This review examines outbreaks of Salmonella due to contaminated produce, the potential sources of Salmonella, and possible control measures to prevent contamination of produce.

  15. All solid state high voltage power supply for neutral beam sources

    International Nuclear Information System (INIS)

    Praeg, W.F.

    1984-01-01

    The conceptual design of a high frequency solid state, high power, high voltage, power system that reacts fast enough to be compatible with the requirements of a neutral beam source is presented. The system offers the potential of significant advantages over conventional power line frequency systems; such as high reliability, long life, relatively little maintenance requirements, compact size and modular design

  16. Identifying sources of methane sampled in the Arctic using δ13C in CH4 and Lagrangian particle dispersion modelling.

    Science.gov (United States)

    Cain, Michelle; France, James; Pyle, John; Warwick, Nicola; Fisher, Rebecca; Lowry, Dave; Allen, Grant; O'Shea, Sebastian; Illingworth, Samuel; Jones, Ben; Gallagher, Martin; Welpott, Axel; Muller, Jennifer; Bauguitte, Stephane; George, Charles; Hayman, Garry; Manning, Alistair; Myhre, Catherine Lund; Lanoisellé, Mathias; Nisbet, Euan

    2016-04-01

    An airmass of enhanced methane was sampled during a research flight at ~600 m to ~2000 m altitude between the North coast of Norway and Svalbard on 21 July 2012. The largest source of methane in the summertime Arctic is wetland emissions. Did this enhancement in methane come from wetland emissions? The airmass was identified through continuous methane measurements using a Los Gatos fast greenhouse gas analyser on board the UK's BAe-146 Atmospheric Research Aircraft (ARA) as part of the MAMM (Methane in the Arctic: Measurements and Modelling) campaign. A Lagrangian particle dispersion model (the UK Met Office's NAME model) was run backwards to identify potential methane source regions. This was combined with a methane emission inventory to create "pseudo observations" to compare with the aircraft observations. This modelling was used to constrain the δ13C CH4 wetland source signature (where δ13C CH4 is the ratio of 13C to 12C in methane), resulting in a most likely signature of -73‰ (±4‰7‰). The NAME back trajectories suggest a methane source region of north-western Russian wetlands, and -73‰ is consistent with in situ measurements of wetland methane at similar latitudes in Scandinavia. This analysis has allowed us to study emissions from remote regions for which we do not have in situ observations, giving us an extra tool in the determination of the isotopic source variation of global methane emissions.

  17. Current State and Future Perspectives of Energy Sources for Totally Implantable Cardiac Devices.

    Science.gov (United States)

    Bleszynski, Peter A; Luc, Jessica G Y; Schade, Peter; PhilLips, Steven J; Tchantchaleishvili, Vakhtang

    There is a large population of patients with end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. Implantable cardiac devices, many designated as destination therapy, have revolutionized patient care and outcomes, although infection and complications related to external power sources or routine battery exchange remain a substantial risk. Complications from repeat battery replacement, power failure, and infections ultimately endanger the original objectives of implantable biomedical device therapy - eliminating the intended patient autonomy, affecting patient quality of life and survival. We sought to review the limitations of current cardiac biomedical device energy sources and discuss the current state and trends of future potential energy sources in pursuit of a lifelong fully implantable biomedical device.

  18. Groundwater sampling in uranium reconnaissance

    International Nuclear Information System (INIS)

    Butz, T.R.

    1977-03-01

    The groundwater sampling program is based on the premise that ground water geochemistry reflects the chemical composition of, and geochemical processes active in the strata from which the sample is obtained. Pilot surveys have shown that wells are the best source of groundwater, although springs are sampled on occasion. The procedures followed in selecting a sampling site, the sampling itself, and the field measurements, as well as the site records made, are described

  19. Environmental research at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Kemner, K.M.; Boyanov, M.I.; Eng, P.; Fenter, P.; Heald, S.; Lai, B.; Lee, S.S.; Scheckel, K.G.; Skanthakumar, S.; Sutton, S.R.; Wilson, R.E.

    2010-01-01

    Because of the importance of probing molecular-scale chemical and physical structure of environmental samples in their natural and often hydrated state, synchrotron radiation has been a powerful tool for environmental scientists for decades. Thus, the crucial role that a highly coherent and high-brightness hard X-ray source such as the Advance Photon Source (APS) can play in addressing many of the outstanding questions in molecular environmental science (MES) was recognized even before 'first light' at the facility. No single synchrotron-based technique or experimental approach can adequately address the tremendous temporal and spatial heterogeneities of the chemistry, physics, and biology of natural environmental samples. Thus, it is common at the APS that multiple X-ray techniques and experimental systems are employed to investigate environmental samples, often chosen for their ability to focus on solute species, plants, microbes, organics, interfacial species, or solids.

  20. White HDPE bottles as source of serious contamination of water samples with Ba and Zn.

    Science.gov (United States)

    Reimann, Clemens; Grimstvedt, Andreas; Frengstad, Bjørn; Finne, Tor Erik

    2007-03-15

    During a recent study of surface water quality factory new white high-density polyethylene (HDPE) bottles were used for collecting the water samples. According to the established field protocol of the Geological Survey of Norway the bottles were twice carefully rinsed with water in the field prior to sampling. Several blank samples using milli-Q (ELGA) water (>18.2 MOmega) were also prepared. On checking the analytical results the blanks returned values of Ag, Ba, Sr, V, Zn and Zr. For Ba and Zn the values (c. 300 microg/l and 95 microg/l) were about 10 times above the concentrations that can be expected in natural waters. A laboratory test of the bottles demonstrated that the bottles contaminate the samples with significant amounts of Ba and Zn and some Sr. Simple acid washing of the bottles prior to use did not solve the contamination problem for Ba and Zn. The results suggest that there may exist "clean" and "dirty" HDPE bottles depending on manufacturer/production process. When collecting water samples it is mandatory to check bottles regularly as a possible source of contamination.

  1. Health risk assessment of drinking arsenic-containing groundwater in Hasilpur, Pakistan: effect of sampling area, depth, and source.

    Science.gov (United States)

    Tabassum, Riaz Ahmad; Shahid, Muhammad; Dumat, Camille; Niazi, Nabeel Khan; Khalid, Sana; Shah, Noor Samad; Imran, Muhammad; Khalid, Samina

    2018-02-10

    Currently, several news channels and research publications have highlighted the dilemma of arsenic (As)-contaminated groundwater in Pakistan. However, there is lack of data regarding groundwater As content of various areas in Pakistan. The present study evaluated As contamination and associated health risks in previously unexplored groundwater of Hasilpur-Pakistan. Total of 61 groundwater samples were collected from different areas (rural and urban), sources (electric pump, hand pump, and tubewell) and depths (35-430 ft or 11-131 m). The water samples were analyzed for As level and other parameters such as pH, electrical conductivity, total dissolved solids, cations, and anions. It was found that 41% (25 out of 61) water samples contained As (≥ 5 μg/L). Out of 25 As-contaminated water samples, 13 water samples exceeded the permissible level of WHO (10 μg/L). High As contents have been found in tubewell samples and at high sampling depths (> 300 ft). The major As-contaminated groundwater in Hasilpur is found in urban areas. Furthermore, health risk and cancer risk due to As contamination were also assessed with respect to average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk (CR). The values of HQ and CR of As in Hasilpur were up to 58 and 0.00231, respectively. Multivariate analysis revealed a positive correlation between groundwater As contents, pH, and depth in Hasilpur. The current study proposed the proper monitoring and management of well water in Hasilpur to minimize the As-associated health hazards.

  2. Sources of Legal Regulation of Mergers, Acquisitions, Consolidations, Joint Stock Companies in Russia and Corporations in the United States

    Directory of Open Access Journals (Sweden)

    Stanislav E. Kuzmin

    2015-01-01

    Full Text Available The article outlines general characteristics of the sources of law, regulating relations associated with mergers, consolidations, acquisitions of joint stock companies in Russia and corporations in the United States respectively in the Russian legislation and the legislation of the United States and individual States. Both in Russia and in the USA there is a constitutional separation of powers between the Federal authorities and the Subjects of the Federation/States respectively. In both countries legal regulation of mergers and acquisitions of corporations is carried out first of all by a number of laws. These laws fall into three main groups: securities laws, antitrust (competition laws and civil and joint-stock legislation in Russia and corporate laws in the US. All the three groups are federal laws in Russia, while in the US the first two are federal too, but the last one is state laws. It is necessary to highlight the important role of judicial decisions in the United States on legal regulation of mergers, acquisitions, takeovers in comparison with Russia, which is due to the differences in the legal systems of the states in question. However, although Russia is not a state of case law, such legal acts as the resolution of the Plenum of the Supreme Commercial Court will undoubtedly have an impact on law enforcement practice and, consequently, on the regulation of relevant relations. Of particular importance are the findings of the Constitutional Court, whose decisions may cancel acts or their separate provisions provided they are recognized as unconstitutional. Such acts are repealed. Decisions of courts and other bodies based on acts or their separate provisions, recognized by the Constitutional Court of the Russian Federation unconstitutional, are not subject to execution and shall be revised in accordance with the Federal law. The US case law implies existence of a hierarchy of precedents according to which decisions adopted by the

  3. Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid microvolume samples.

    Science.gov (United States)

    Schaper, J Niklas; Pfeuffer, Kevin P; Shelley, Jacob T; Bings, Nicolas H; Hieftje, Gary M

    2012-11-06

    One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads can quench the afterglow and, thus, the formation of reagent ions. As a result, the analysis of liquid samples is preferably carried out by analyzing dried residues or by desorbing small amounts of liquid samples directly from the liquid surface. In the former case, reproducibility of sample introduction is crucial if quantitative results are desired. In the present study, introduction of liquid samples as very small droplets helps overcome the issues of sample positioning and reduced levels of solvent intake. A recently developed "drop-on-demand" (DOD) aerosol generator is capable of reproducibly producing very small volumes of liquid (∼17 pL). In this paper, the coupling of FAPA-MS and DOD is reported and applications are suggested. Analytes representing different classes of substances were tested and limits of detections were determined. Matrix tolerance was investigated for drugs of abuse and their metabolites by analyzing raw urine samples and quantification without the use of internal standards. Limits of detection below 2 μg/mL, without sample pretreatment, were obtained.

  4. Generalized molybdenum oxide surface chemical state XPS determination via informed amorphous sample model

    Energy Technology Data Exchange (ETDEWEB)

    Baltrusaitis, Jonas, E-mail: job314@lehigh.edu [Department of Chemical Engineering, Lehigh University, B336 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 (United States); PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Mendoza-Sanchez, Beatriz [CRANN, Chemistry School, Trinity College Dublin, Dublin (Ireland); Fernandez, Vincent [Institut des Matériaux Jean Rouxel, 2 rue de la Houssinière, BP 32229, F-44322 Nantes Cedex 3 (France); Veenstra, Rick [PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Dukstiene, Nijole [Department of Physical and Inorganic Chemistry, Kaunas University of Technology, Radvilenu pl. 19, LT-50254 Kaunas (Lithuania); Roberts, Adam [Kratos Analytical Ltd, Trafford Wharf Road, Wharfside, Manchester, M17 1GP (United Kingdom); Fairley, Neal [Casa Software Ltd, Bay House, 5 Grosvenor Terrace, Teignmouth, Devon TQ14 8NE (United Kingdom)

    2015-01-30

    Highlights: • We analyzed and modeled spectral envelopes of complex molybdenum oxides. • Molybdenum oxide films of varying valence and crystallinity were synthesized. • MoO{sub 3} and MoO{sub 2} line shapes from experimental data were created. • Informed amorphous sample model (IASM) developed. • Amorphous molybdenum oxide XPS envelopes were interpreted. - Abstract: Accurate elemental oxidation state determination for the outer surface of a complex material is of crucial importance in many science and engineering disciplines, including chemistry, fundamental and applied surface science, catalysis, semiconductors and many others. X-ray photoelectron spectroscopy (XPS) is the primary tool used for this purpose. The spectral data obtained, however, is often very complex and can be subject to incorrect interpretation. Unlike traditional XPS spectra fitting procedures using purely synthetic spectral components, here we develop and present an XPS data processing method based on vector analysis that allows creating XPS spectral components by incorporating key information, obtained experimentally. XPS spectral data, obtained from series of molybdenum oxide samples with varying oxidation states and degree of crystallinity, were processed using this method and the corresponding oxidation states present, as well as their relative distribution was elucidated. It was shown that monitoring the evolution of the chemistry and crystal structure of a molybdenum oxide sample due to an invasive X-ray probe could be used to infer solutions to complex spectral envelopes.

  5. Source identification of an unknown spill (2002) from Canal Ste-Anne-de-Bellevue, Quebec by the multi-criterion analytical approach and lab simulation of the spill sample

    International Nuclear Information System (INIS)

    Wang, Z.; Hollebone, B.; Yang, C.; Fingas, M.F.; Landriault, M.; Environment Canada, Ottawa, ON

    2004-01-01

    This study characterized the chemical composition of a variety of laboratory oil samples in order to determine the type, nature and sources of 3 unknown oil samples from an oil spill that occurred in Canal Ste-Anne-de-Bellevue, Quebec in 2002. An integrated multi-criterion approach using gas chromatography/mass spectrometry and gas chromatography/flame ionization detection was applied to characterize the laboratory samples. Results of chemical fingerprinting were presented. The distribution patterns of hydrocarbons in the spill and suspected source samples were recognized and compared. The study also involved an analysis of oil characteristic biomarkers and the extended suite of parent and alkylated polycyclic aromatic hydrocarbons. Several diagnostic ratios of source-specific marker compounds for fingerprint interpretation were determined. The major components in the suspected source samples were then identified. 40 refs., 5 tabs., 10 figs

  6. Solid-state high voltage modulator and its application to rf source high voltage power supplies

    International Nuclear Information System (INIS)

    Tooker, J.F.; Huynh, P.; Street, R.W.

    2009-01-01

    A solid-state high voltage modulator is described in which series-connected insulated-gate bipolar transistors (IGBTs) are switched at a fixed frequency by a pulse width modulation (PWM) regulator, that adjusts the pulse width to control the voltage out of an inductor-capacitor filter network. General Atomics proposed the HV power supply (HVPS) topology of multiple IGBT modulators connected to a common HVdc source for the large number of 1 MW klystrons in the linear accelerator of the Accelerator Production of Tritium project. The switching of 24 IGBTs to obtain 20 kVdc at 20 A for short pulses was successfully demonstrated. This effort was incorporated into the design of a -70 kV, 80 A, IGBT modulator, and in a short-pulse test 12 IGBTs regulated -5 kV at 50 A under PWM control. These two tests confirm the practicality of solid-state IGBT modulators to regulate high voltage at reasonable currents. Tokamaks such as ITER require large rf heating and current drive systems with multiple rf sources. A HVPS topology is presented that readily adapts to the three rf heating systems on ITER. To take advantage of the known economy of scale for power conversion equipment, a single HVdc source feeds multiple rf sources. The large power conversion equipment, which is located outside, converts the incoming utility line voltage directly to the HVdc needed for the class of rf sources connected to it, to further reduce cost. The HVdc feeds a set of IGBT modulators, one for each rf source, to independently control the voltage applied to each source, maximizing operational flexibility. Only the modulators are indoors, close to the rf sources, minimizing the use of costly near-tokamak floor space.

  7. 77 FR 24148 - Revision to the Hawaii State Implementation Plan, Minor New Source Review Program

    Science.gov (United States)

    2012-04-23

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2012-0213; FRL-9661-6] Revision to the Hawaii State Implementation Plan, Minor New Source Review Program AGENCY: Environmental Protection Agency... final action to approve revisions to the Hawaii State Implementation Plan (SIP). These revisions would...

  8. Autonomous Energy Sources in the North of the Far East: Current State and Directions of Diversification

    Directory of Open Access Journals (Sweden)

    Boris Grigorievich Saneev

    2018-03-01

    Full Text Available The paper presents the current state of autonomous energy sources in the north of the Far East. Consideration is given to the capacity structures with a focus on industrial and residential autonomous energy sources. One of the main problems facing power supply to residential consumers in the north of the Far East is the insufficiently developed transport infrastructure, which causes complicated fuel delivery patterns, fuel price rise, and hence high electricity generation cost. The changes in the installed capacity of renewable energy sources (RES in the north of the Far East are demonstrated for the period between 2011 and 2015. The research shows the main directions of power production diversification in the north of the Far East. The directions include the use of local fuel types, the development of cogeneration, the involvement of renewable energy sources and small-scale nuclear power plants. The paper presents a forecast for the renewable energy development in the north of the Far East up to 2035, made by the authors. The priority RES projects in the off-grid power supply in the north of the Far East are wind and solar power plants

  9. Interplanetary scintillation observations of an unbiased sample of 90 Ooty occultation radio sources at 326.5 MHz

    International Nuclear Information System (INIS)

    Banhatti, D.G.; Ananthakrishnan, S.

    1989-01-01

    We present 327-MHz interplanetary scintillation (IPS) observations of an unbiased sample of 90 extragalactic radio sources selected from the ninth Ooty lunar occultation list. The sources are brighter than 0.75 Jy at 327 MHz and lie outside the galactic plane. We derive values, the fraction of scintillating flux density, and the equivalent Gaussian diameter for the scintillating structure. Various correlations are found between the observed parameters. In particular, the scintillating component weakens and broadens with increasing largest angular size, and stronger scintillators have more compact scintillating components. (author)

  10. 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

  11. Mercury in fish and macroinvertebrates from New York's streams and rivers: A compendium of data sources

    Science.gov (United States)

    Riva-Murray, Karen; Burns, Douglas A.

    2016-01-01

    The U.S. Geological Survey has compiled a list of existing data sets, from selected sources, containing mercury (Hg) concentration data in fish and macroinvertebrate samples that were collected from flowing waters of New York State from 1970 through 2014. Data sets selected for inclusion in this report were limited to those that contain fish and (or) macroinvertebrate data that were collected across broad areas, cover relatively long time periods, and (or) were collected as part of a broader-scale (e.g. national) study or program. In addition, all data sets listed were collected, processed, and analyzed with documented methods, and contain critical sample information (e.g. fish species, fish size, Hg species) that is needed to analyze and interpret the reported Hg concentration data. Fourteen data sets, all from state or federal agencies, are listed in this report, along with selected descriptive information regarding each data source and data set contents. Together, these 14 data sets contain Hg and related data for more than 7,000 biological samples collected from more than 700 unique stream and river locations between 1970 and 2014.

  12. An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC

    Energy Technology Data Exchange (ETDEWEB)

    Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory

    2012-08-02

    Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.

  13. Present state of tandem accelerator analysis facility of the National Institute for Environmental Studies. 2. Sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Kumamoto, Yuichiro; Shibata, Yasuyuki; Kume, Hiroshi; Tanaka, Atsushi; Yoneda, Minoru; Uehiro, Takashi; Morita, Masatoshi [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)

    1996-12-01

    An AMS exclusive apparatus constituted for a center of 5 MV of tandem accelerator (15SDH-2) was introduced to the National Institute for Environmental Studies on September, 1995. The incidental part of the apparatus is constituted by combining negative ion source for solid sample (MC-SNICS) with successive incidental system and combining negative ion source for gas sample (MGF-SNICS) with simultaneous incidental system. In this study, preparation of graphite target for testing of {sup 14}C at a temporary aim of supplying solid sample for MC-SNICS necessary to modulate the apparatus has been conducted. As a result, it was found that most of isotope fractionation on graphite formation from oxalic acid could be neglected. However, as it was said that efficiency of the graphite formation was largely changed with mixing with traced volume of gas such as sulfur dioxide and so on, future presumption is laid at investigation of such isotope fractionation effect on some samples except oxalic acid. In order to conduct contamination evaluation of 14-C at sample preparation, graphite preparation from organic matters and carbon dioxide obtained the fossil fuels without containing 14-C are exchanged in present research. (G.K.)

  14. Issues of assessment of doses from natural sources in working conditions: implications for the unified state system of individual dose monitoring

    Directory of Open Access Journals (Sweden)

    T. A. Kormanovskaya

    2017-01-01

    Full Text Available The aims of the work are: 1 an analysis of information on radiation doses from natural sources of ionizing radiation of employees of enterprises in some industries of the Russian Federation and 2 an assessment of the state of registration of doses from natural sources in working conditions in the Unified System of Individual Dose Control. Materials and methods. The analysis was performed on the results of the operation of the Federal database of radiation doses of the population due to natural and artificial radiation background in 2013–2015 on the basis of the forms of the Federal statistical observation No. 4-DOZ in terms of collecting information on the radiation doses of workers in some non-nuclear industries due to natural sources of ionizing radiation. Results. Analysis of enterprises in 17 industries in 23 regions of Russia connected with the specificity of production processes showed cases of natural exposure of workers at the dose level exceeding 5 mSv/year. We have identified those branches of industry, for which the doses were close to 5 mSv/year.Examples of reducing the radiation doses by reducing the time spent by workers in workplaces with high levels of radiation are given. The problems of insufficient representativeness of the sample data are due to the lack of interaction of the management of industrial enterprises with the bodies of the Rospotrebnadzor. The obtained data allow speaking about the problem of assessing the quality of radiation control in the organizations where additional exposure of workers from natural radiation sources is expected. It is necessary to create a system of regulatory and procedural documents to solve the problem at the national level.

  15. Characterization of selenium in ambient aerosols and primary emission sources.

    Science.gov (United States)

    De Santiago, Arlette; Longo, Amelia F; Ingall, Ellery D; Diaz, Julia M; King, Laura E; Lai, Barry; Weber, Rodney J; Russell, Armistead G; Oakes, Michelle

    2014-08-19

    Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ∼16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (∼20000 ng/m(3)).

  16. Lower Bounds on the Capacity of the Relay Channel with States at the Source

    Directory of Open Access Journals (Sweden)

    Abdellatif Zaidi

    2009-01-01

    Full Text Available We consider a state-dependent three-terminal full-duplex relay channel with the channel states noncausally available at only the source, that is, neither at the relay nor at the destination. This model has application to cooperation over certain wireless channels with asymmetric cognition capabilities and cognitive interference relay channels. We establish lower bounds on the channel capacity for both discrete memoryless (DM and Gaussian cases. For the DM case, the coding scheme for the lower bound uses techniques of rate-splitting at the source, decode-and-forward (DF relaying, and a Gel'fand-Pinsker-like binning scheme. In this coding scheme, the relay decodes only partially the information sent by the source. Due to the rate-splitting, this lower bound is better than the one obtained by assuming that the relay decodes all the information from the source, that is, full-DF. For the Gaussian case, we consider channel models in which each of the relay node and the destination node experiences on its link an additive Gaussian outside interference. We first focus on the case in which the links to the relay and to the destination are corrupted by the same interference; and then we focus on the case of independent interferences. We also discuss a model with correlated interferences. For each of the first two models, we establish a lower bound on the channel capacity. The coding schemes for the lower bounds use techniques of dirty paper coding or carbon copying onto dirty paper, interference reduction at the source and decode-and-forward relaying. The results reveal that, by opposition to carbon copying onto dirty paper and its root Costa's initial dirty paper coding (DPC, it may be beneficial in our setup that the informed source uses a part of its power to partially cancel the effect of the interference so that the uninformed relay benefits from this cancellation, and so the source benefits in turn.

  17. A new method for determining the uranium and thorium distribution in volcanic rock samples using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Bakhchi, A.; Ktata, A.; Koutit, A.; Lamine, J.; Ait nouh, F.; Oufni, L.

    2000-01-01

    A method based on using solid state nuclear track detectors (SSNTD) CR- 39 and LR-115 type II and calculating the probabilities for the alpha particles emitted by the uranium and thorium series to reach and be registered on these films was utilized for uranium and thorium contents determination in various geological samples. The distribution of uranium and thorium in different volcanic rocks has been investigated using the track fission method. In this work, the uranium and thorium contents have been determined in different volcanic rock samples by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD). The mean critical angles of etching of the solid state nuclear track detectors utilized have been calculated. A petrographical study of the volcanic rock thin layers studied has been conducted. The uranium and thorium distribution inside different rock thin layers has been studied. The mechanism of inclusion of the uranium and thorium nuclei inside the volcanic rock samples studied has been investigated. (author)

  18. Effects of state and trait anxiety on selective attention to threatening stimuli in a non-clinical sample of school children

    Directory of Open Access Journals (Sweden)

    Jeniffer Ortega Marín

    2015-01-01

    Full Text Available Attentional biases, consisting of a preferential processing of threatening stimuli, have been found in anxious adults as predicted by several cognitive models. However, studies with non-clinical samples of children have provided mixed results. therefore, the aim of this research was to determine the effects of state and trait anxiety on the selective attention towards threatening stimuli in a non-clinical sample of school children (age: 8 to 13, n = 110 using the dot-probe task. This study did not reveal an effect of trait anxiety on selective attention towards threatening stimuli. However, a significant difference was found between participants with low state anxiety and high state anxiety. Nevertheless, the effect size was small. Specifically, participants with low state anxiety showed a bias towards threatening stimuli. Overall, the findings of this research with a non-clinical sample of school children suggest that attentional biases towards threatening information, which has been repeatedly found in anxious adults, are not necessarily inherent to non-clinical anxiety in children and on the other hand, the relationship between attentional biases and anxiety in this population might be moderated by other cognitive processes.

  19. Are biogenic emissions a significant source of summertime atmospheric toluene in the rural Northeastern United States?

    OpenAIRE

    M. L. White; R. S. Russo; Y. Zhou; J. L. Ambrose; K. Haase; E. K. Frinak; R. K. Varner; O. W. Wingenter; H. Mao; R. Talbot; B. C. Sive

    2009-01-01

    Summertime atmospheric toluene enhancements at Thompson Farm in the rural northeastern United States were unexpected and resulted in a toluene/benzene seasonal pattern that was distinctly different from that of other anthropogenic volatile organic compounds. Consequently, three hydrocarbon sources were investigated for potential contributions to the enhancements during 2004–2006. These included: (1) increased warm season fuel evaporation coupled with changes in reformulated gasoline (RFG) con...

  20. All fiber optics circular-state swept source polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Lin, Hermann; Kao, Meng-Chun; Lai, Chih-Ming; Huang, Jyun-Cin; Kuo, Wen-Chuan

    2014-02-01

    A swept source (SS)-based circular-state (CS) polarization-sensitive optical coherence tomography (PS-OCT) constructed entirely with polarization-maintaining fiber optics components is proposed with the experimental verification. By means of the proposed calibration scheme, bulk quarter-wave plates can be replaced by fiber optics polarization controllers to, therefore, realize an all-fiber optics CS SSPS-OCT. We also present a numerical dispersion compensation method, which can not only enhance the axial resolution, but also improve the signal-to-noise ratio of the images. We demonstrate that this compact and portable CS SSPS-OCT system with an accuracy comparable to bulk optics systems requires less stringent lens alignment and can possibly serve as a technology to realize PS-OCT instrument for clinical applications (e.g., endoscopy). The largest deviations in the phase retardation (PR) and fast-axis (FA) angle due to sample probe in the linear scanning and a rotation angle smaller than 65 deg were of the same order as those in stationary probe setups. The influence of fiber bending on the measured PR and FA is also investigated. The largest deviations of the PR were 3.5 deg and the measured FA change by ~12 to 21 deg. Finally, in vivo imaging of the human fingertip and nail was successfully demonstrated with a linear scanning probe.

  1. Cortical sources of resting state EEG rhythms are related to brain hypometabolism in subjects with Alzheimer's disease: an EEG-PET study.

    Science.gov (United States)

    Babiloni, Claudio; Del Percio, Claudio; Caroli, Anna; Salvatore, Elena; Nicolai, Emanuele; Marzano, Nicola; Lizio, Roberta; Cavedo, Enrica; Landau, Susan; Chen, Kewei; Jagust, William; Reiman, Eric; Tedeschi, Gioacchino; Montella, Patrizia; De Stefano, Manuela; Gesualdo, Loreto; Frisoni, Giovanni B; Soricelli, Andrea

    2016-12-01

    Cortical sources of resting state electroencephalographic (EEG) delta (2-4 Hz) and low-frequency alpha (8-10.5 Hz) rhythms show abnormal activity (i.e., current density) in patients with dementia due to Alzheimer's disease (AD). Here, we hypothesized that abnormality of this activity is related to relevant disease processes as revealed by cortical hypometabolism typically observed in AD patients by fluorodeoxyglucose positron emission tomography. Resting state eyes-closed EEG data were recorded in 19 AD patients with dementia and 40 healthy elderly (Nold) subjects. EEG frequency bands of interest were delta and low-frequency alpha. EEG sources were estimated in these bands by low-resolution brain electromagnetic tomography (LORETA). Fluorodeoxyglucose positron emission tomography images were recorded only in the AD patients, and cortical hypometabolism was indexed by the so-called Alzheimer's discrimination analysis tool (PALZ) in the frontal association, ventromedial frontal, temporoparietal association, posterior cingulate, and precuneus areas. Results showed that compared with the Nold group, the AD group pointed to higher activity of delta sources and lower activity of low-frequency alpha sources in a cortical region of interest formed by all cortical areas of the PALZ score. In the AD patients, there was a positive correlation between the PALZ score and the activity of delta sources in the cortical region of interest (p < 0.05). These results suggest a relationship between resting state cortical hypometabolism and synchronization of cortical neurons at delta rhythms in AD patients with dementia. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Local source impacts on primary and secondary aerosols in the Midwestern United States

    Science.gov (United States)

    Jayarathne, Thilina; Rathnayake, Chathurika M.; Stone, Elizabeth A.

    2016-04-01

    Atmospheric particulate matter (PM) exhibits heterogeneity in composition across urban areas, leading to poor representation of outdoor air pollutants in human exposure assessments. To examine heterogeneity in PM composition and sources across an urban area, fine particulate matter samples (PM2.5) were chemically profiled in Iowa City, IA from 25 August to 10 November 2011 at two monitoring stations. The urban site is the federal reference monitoring (FRM) station in the city center and the peri-urban site is located 8.0 km to the west on the city edge. Measurements of PM2.5 carbonaceous aerosol, inorganic ions, molecular markers for primary sources, and secondary organic aerosol (SOA) tracers were used to assess statistical differences in composition and sources across the two sites. PM2.5 mass ranged from 3 to 26 μg m-3 during this period, averaging 11.2 ± 4.9 μg m-3 (n = 71). Major components of PM2.5 at the urban site included organic carbon (OC; 22%), ammonium (14%), sulfate (13%), nitrate (7%), calcium (2.9%), and elemental carbon (EC; 2.2%). Periods of elevated PM were driven by increases in ammonium, sulfate, and SOA tracers that coincided with hot and dry conditions and southerly winds. Chemical mass balance (CMB) modeling was used to apportion OC to primary sources; biomass burning, vegetative detritus, diesel engines, and gasoline engines accounted for 28% of OC at the urban site and 24% of OC at the peri-urban site. Secondary organic carbon from isoprene and monoterpene SOA accounted for an additional 13% and 6% of OC at the urban and peri-urban sites, respectively. Differences in biogenic SOA across the two sites were associated with enhanced combustion activities in the urban area and higher aerosol acidity at the urban site. Major PM constituents (e.g., OC, ammonium, sulfate) were generally well-represented by a single monitoring station, indicating a regional source influence. Meanwhile, nitrate, biomass burning, food cooking, suspended dust, and

  3. Food Sources of Energy and Nutrients among Children in the United States: National Health and Nutrition Examination Survey 2003–2006

    Directory of Open Access Journals (Sweden)

    Victor L. Fulgoni

    2013-01-01

    Full Text Available Background: Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Methods: Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332 in the 2003–2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. Results: The two top ranked food/food group sources of energy and nutrients were: energy — milk (7% of energy and cake/cookies/quick bread/pastry/pie (7%; protein — milk (13.2% and poultry (12.8%; total carbohydrate — soft drinks/soda (10.5% and yeast bread/rolls (9.1%; total sugars — soft drinks/soda (19.2% and yeast breads and rolls (12.7%; added sugars — soft drinks/soda (29.7% and candy/sugar/sugary foods (18.6%; dietary fiber — fruit (10.4% and yeast bread/rolls (10.3%; total fat — cheese (9.3% and crackers/popcorn/pretzels/chips (8.4%; saturated fatty acids — cheese (16.3% and milk (13.3%; cholesterol — eggs (24.2% and poultry (13.2%; vitamin D — milk (60.4% and milk drinks (8.3%; calcium — milk (33.2% and cheese (19.4%; potassium — milk (18.8% and fruit juice (8.0%; and sodium — salt (18.5% and yeast bread and rolls (8.4%. Conclusions: Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient

  4. Extended radio sources in the cluster environment

    International Nuclear Information System (INIS)

    Burns, J.O. Jr.

    1979-01-01

    Extended radio galaxies that lie in rich and poor clusters were studied. A sample of 3CR and 4C radio sources that spatially coincide with poor Zwicky clusters of galaxies was observed to obtain accurate positions and flux densities. Then interferometer observations at a resolution of approx. = 10 arcsec were performed on the sample. The resulting maps were used to determine the nature of the extended source structure, to make secure optical identifications, and to eliminate possible background sources. The results suggest that the environments around both classical double and head-tail radio sources are similar in rich and poor clusters. The majority of the poor cluster sources exhibit some signs of morphological distortion (i.e., head-tails) indicative of dynamic interaction with a relatively dense intracluster medium. A large fraction (60 to 100%) of all radio sources appear to be members of clusters of galaxies if one includes both poor and rich cluster sources. Detailed total intensity and polarization observations for a more restricted sample of two classical double sources and nine head-tail galaxies were also performed. The purpose was to examine the spatial distributions of spectral index and polarization. Thin streams of radio emission appear to connect the nuclear radio-point components to the more extended structures in the head-tail galaxies. It is suggested that a non-relativistic plasma beam can explain both the appearance of the thin streams and larger-scale structure as well as the energy needed to generate the observed radio emission. The rich and poor radio cluster samples are combined to investigate the relationship between source morphology and the scale sizes of clustering. There is some indication that a large fraction of radio sources, including those in these samples, are in superclusters of galaxies

  5. Pollen analysis in honey samples from the two main producing regions in the Brazilian northeast

    Directory of Open Access Journals (Sweden)

    Geni da S. Sodré

    2007-09-01

    Full Text Available Knowledge about the botanical source of honey is very important for the beekeeper while it indicates adequate and abundant supply sources of nectar and pollen for the bees, thus contributing toward improved yield. The present study means to identify the pollen types occurring in 58 samples of honey produced in two states of the northeastern region of Brazil, Piauí (38 samples and Ceará (20 samples, and to verify the potential of the honey plants during the months of February to August. The samples were obtained directly from beekeepers in each state and analyzed at the Apiculture Laboratory of the Entomology Section of Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, State of São Paulo, Brazil. The pollen analysis was performed using the acetolysis method. The samples were submitted to both a qualitative and a quantitative analysis. The dominant pollen in the State of Ceará is from Mimosa caesalpiniaefolia, M. verrucosa, Borreria verticillata, Serjania sp., and a Fabaceae pollen type, while in the State of Piauí it is from Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana and Tibouchina sp.O conhecimento da origem botânica do mel é de grande importância para o apicultor por indicar fontes adequadas e de abundante suprimento de néctar e pólen para as abelhas, contribuindo, desta forma, para uma melhor produção. O presente estudo teve como objetivo identificar os tipos polínicos em 58 amostras de méis produzidos em dois estados da região nordeste do Brasil, Piauí (38 amostras e Ceará (20 amostras, verificando o potencial das plantas apícolas durante os meses de fevereiro a agosto. As amostras foram obtidas diretamente de apicultores de cada Estado e analisadas no Laboratório de Apicultura do Setor de Entomologia da Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, Estado de São Paulo. A análise polínica foi realizada utilizando-se o método da acetólise. As amostras foram

  6. Analysis of particle sources by interferometry in a three-body final state

    International Nuclear Information System (INIS)

    Humbert, P.

    1984-01-01

    This work presents the set-up of an original interferometrical method the aim of which is to access the intrinsic parameters (lifetime or natural width) of intermediate resonances created during nuclear collisions. The technic is based on the overlap of two events in the same detection, and shows some analogies with the interferometrical measurements based on the HANBURY-BROWN, TWISS effect. It applies to reactions leading to a three particle final state for which at least two particles are identical. The considered reactions are 11 B(α, 7 Li)αα; 12 C( 16 0,α) 12 C 12 C, 11 B(p,α)αα in which the intermediate source is respectively a level of 11 B*, 16 0*, 8 Be*. The results are in qualitative agreement with such an analysis [fr

  7. SANSPOL at a pulsed source

    Energy Technology Data Exchange (ETDEWEB)

    Bleuel, Markus [Intense Pulsed Neutron Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Lang, Ed [Intense Pulsed Neutron Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Krist, Thomas [BENSC, Hahn-Meitner Institut, D 14109 Berlin (Germany); Wagner, Werner [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Lal, Jyotsana [Intense Pulsed Neutron Source, Argonne National Laboratory, Argonne, IL 60439 (United States)]. E-mail: jlal@anl.gov

    2007-07-15

    Neutron polarization has not been implemented successfully on a time-of-flight small angle neutron scattering (TOF-SANS) machine to this date anywhere in the world. Designing a suitable one for the small angle scattering instrument (SASI) at IPNS, and implementing it, is an important first on a pulsed source. To achieve this, the installation of a solid-state supermirror-based polarizer, a gradient field adiabatic spin flipper, and a new collimator package were required. A polarizing solid-state bender without adsorbing layers, designed to transmit one polarized spin state and reflect the other has been purchased from Neutron Optics Berlin (NOB). By placing this package upstream of the collimation only the transmitted spin-state passes through to the sample. The polarization achieved with this technique up to now is 80% for neutrons in a wavelength range of 3-8 A and 67% for larger wavelengths. The polarizer is placed on a linear translator so it can be easily removed from the beam, when regular SANS measurements are desired. The first experimental results from a two-phase CuNiFe alloy sample are reported here.

  8. Chapter 27: Deja vu All Over Again: Using NVO Tools to Re-Investigate a Complete Sample of Texas Radio Survey Sources

    Science.gov (United States)

    Lucas, Ray A.; Rohde, David; Tamura, Takayuki; van Dyne, Jeffrey

    At the first NVO Summer School in September 2004, a complete sample of Texas Radio Survey sources, first derived in 1989 and subsequently observed with the VLA in A-array snapshot mode in 1990, was revisited. The original investigators had never had the occasion to reduce the A-array 5-minute snapshot data, nor to do any other significant follow-up, though the sample still seemed a possibly useful but relatively small study of radio galaxies, AGN, quasars, extragalactic sources, and galaxy clusters, etc. At the time of the original sample definition in late 1989, the best optical material available for the region was the SRC-J plate from the UK Schmidt Telescope in Australia. In much more recent times, the Sloan Digital Sky Survey has included the region in its DR2 data release, so good multicolor optical imaging in a number of standard bandpasses has finally become available. These data, along with other material in the radio, infrared, and (where available) were used to get a better preliminary idea of the nature of the objects in the 1989 sample. We also investigated one of the original questions: whether these radio sources with steeper (or at least non-flat) radio spectra were associated with galaxy clusters, and in some cases higher-redshift galaxy clusters and AGN. A rudimentary web service was created which allowed the user to perform simple cone searches and SIAP image extractions of specified field sizes for multiwavelength data across the electromagnetic spectrum, and a prototype web page was set up which would display the resulting images in wavelength order across the page for sources in the sample. Finally, as an additional investigation, using radio and X-ray IDs as a proxy for AGN which might be associated with large, central cluster galaxies, positional matches of radio and X-ray sources from two much larger catalogs were done using the tool TOPCAT in order to search for the degree of correlation between ID positions, radio luminosity, and cluster

  9. The Mediating Effect of Organizational Justice Between Power Sources and Organizational Commitment

    OpenAIRE

    Pahrudin; Noor; Kasmir

    2017-01-01

    This study examines the role of organizational justice in the relationship between energy sources and organizational commitment. This study uses structural equation modeling (SEM) to test the hypothesis on a sample of 160 Indonesian workers in a state enterprise. The results show that energy sources are positively associated with organizational commitment and that organizational fairness is positively related to organizational commitment. The power source, in turn, has a positive effect on or...

  10. An International Look at Women in Open Source

    Directory of Open Access Journals (Sweden)

    Cathy Malmrose

    2009-05-01

    Full Text Available When attending conferences, working with various open source teams, and generally interacting with people in the open source world, we see women as a small representative minority. The disparity leaves us wondering: "How to activate the other 50% of the population?". The question, "How do we include more women?" has been asked many times and answered in many ways. Cathy Malmrose, CEO of ZaReason, a Linux hardware company, stated, "possibly the most immediately effective solution is to showcase women internationally and their contributions. By simply talking about what women are doing all over the world, it creates an atmosphere of acceptance, encouraging more women to try contributing, no matter where they are located or what their situation is. Our goal is to normalize the experience of having women on open source projects". This issue of OSBR is a powerful effort to do just that. This article provides a glance at women in open source internationally. It is by no means comprehensive and is based solely on a random sampling of women who are currently contributing. The goal of this article is to give you a sense of the breadth and depth of women contributing to open source.

  11. Photon Science at Modern Light Sources

    Science.gov (United States)

    Arthur, John

    2009-12-01

    More than 50 large x-ray and UV light sources based on high-energy electron accelerators are in operation around the world, serving a scientific community numbering in the tens of thousands. These sources generate synchrotron radiation from accelerated electrons or positrons. The development of synchrotron light sources over the last 40 years has fueled an exponential increase in x-ray source brightness of more than 10 orders of magnitude. The next large advance in source potential is now underway, with the commissioning of the first x-ray Free-Electron Laser (FEL) sources. Using high-energy electron linear accelerators, these facilities produce sub-picosecond pulses of hard x-rays with peak brightness more than 10 orders of magnitude greater than current synchrotron facilities. FEL x-ray facilities will soon be operational in the US, Japan, and Germany. Research at modern light sources makes use of a wide range of experimental techniques. Many experiments are designed to study the structure of matter at the atomic scale using elastic x-ray scattering. This technique has been particularly effective for determining the structures of biological molecules, such as proteins, viruses, and drugs. Inelastic x-ray scattering, or x-ray absorption followed by emission of electrons or photons, can give information about the electronic structures of atoms, which can be used to deduce local environment information such as atomic species, bonding state, geometry of neighboring atoms, or magnetic state. For some techniques involving x-ray emission from a sample, cryogenic detectors with energy resolution at the ˜10 eV level or better would be very helpful. Shifts in electron energy levels associated with bonding states and magnetic states are typically several eV, while the energy structure associated with Compton inelastic scattering is typically in the range of a few tens of eV. Current energy-resolving detectors used at synchrotron light sources are hampered by either poor

  12. Use of plasma-source multicollector magnetic-sector mass spectrometry for uranium and plutonium analysis in environmental samples

    International Nuclear Information System (INIS)

    Price Russ, G.; Williams, Ross

    2001-01-01

    Full text: The ability to detect and isotopically characterize uranium and plutonium in environmental samples is of primary importance in the search for nuclear proliferation. The utility of isotope ratio measurements for environmental monitoring is limited by sample preparation costs, measurement precision, and sensitivity. This is particularly true for wide-area monitoring where the number of samples required varies inversely with obtainable precision and sensitivity. Historically isotopic measurements have been made by thermal ionization mass spectrometry (TIMS). While requiring extensive sample preparation, no other technique matched its precision and sensitivity for such measurements. Inductively-coupled-plasma, magnetic-sector, multicollector, mass spectrometry offers the prospect of extending the state-of-the-art to higher precision while increasing sensitivity and reducing costs through more rapid analysis and reduced sample preparation. At LLNL this technique is being implemented in the form of an IsoProbe (Micromass, UK). This paper will present data for both standards and IAEA supplied samples demonstrating the power and limitations of the technique. The precision and sensitivity of the IsoProbe results will be compared to TIMS performance for comparable samples. For 48 determinations of natural uranium, using the double spike to correct for bias, a relative standard deviation of 0.04% (1σ) for 238 U/ 235 U has been obtained in a preliminary study. This is a substantial improvement over the TIMS result of 0.1% reported at the previous conference. Further improvements can be expected as we gain a better understanding of the background peaks occurring in the IsoProbe spectra. (author)

  13. Investigation of the effect of Hollow Cathode in a Grimm-type source (Ar) on the excitation processes using Fe samples

    International Nuclear Information System (INIS)

    Weinstein, V.; Steers, E.B.M.

    2009-01-01

    Complete text of publication follows. Analytical spectroscopic applications using a Grimm Glow Discharge source sometimes require an increased sensitivity and therefore a higher signal to background ratio, which can be reached by using hollow cathode (HC) instead of plane samples. At the beginning of the 20 th century, intensity enhancements of emission lines using HC were observed and explained by longer residence time of sample atoms and consequently more collisional excitation. Later a HC was used with a Grimm source, to achieve higher sensitivity for lines of minor constituents. Recently the HC effect was further investigated for several metallic samples with a commercial GD-OES instrument (T.Gusarova., J. Anal. At. Spectrom., 2009., DOI: 10.1039/b814977a) for improvement of the signal to background ratio (SBR). The intensities and SBR from HC and plane cathode were compared, but only one or two lines could be observed for each element in the sample. The line intensities using plane and HC samples depend on the excitation processes occurring in the two cases. To make conclusions about the excitation mechanism differences, a large number of lines should be examined. Therefore we have recorded spectra over a wide wavelength range (approx. 200-600 nm) using a Fourier Transform Spectrometer (FTS), which allows simultaneous recording of spectra with a very high resolution. The 15 mm deep Fe HC sample and Fe plane cathode sample were analysed using argon as the carrier gas. The comparison of the data was made by calculating the ratio of intensities obtained from the HC sample to intensities of the plane cathode sample and plotting this against the excitation energy of Fe I, Fe II and Ar I, Ar II emission lines. Such plots link the intensity differences with the upper levels of the transitions and so help to clarify the relative importance of excitation processes. The experiments were also carried out at different currents, therefore the effect of the current on

  14. Dietary sources of methylated arsenic species in urine of the United States population, NHANES 2003-2010.

    Directory of Open Access Journals (Sweden)

    B Rey deCastro

    Full Text Available BACKGROUND: Arsenic is an ubiquitous element linked to carcinogenicity, neurotoxicity, as well as adverse respiratory, gastrointestinal, hepatic, and dermal health effects. OBJECTIVE: Identify dietary sources of speciated arsenic: monomethylarsonic acid (MMA, and dimethylarsinic acid (DMA. METHODS: Age-stratified, sample-weighted regression of NHANES (National Health and Nutrition Examination Survey 2003-2010 data (∼8,300 participants ≥6 years old characterized the association between urinary arsenic species and the additional mass consumed of USDA-standardized food groups (24-hour dietary recall data, controlling for potential confounders. RESULTS: For all arsenic species, the rank-order of age strata for median urinary molar concentration was children 6-11 years > adults 20-84 years > adolescents 12-19 years, and for all age strata, the rank-order was DMA > MMA. Median urinary molar concentrations of methylated arsenic species ranged from 0.56 to 3.52 µmol/mol creatinine. Statistically significant increases in urinary arsenic species were associated with increased consumption of: fish (DMA; fruits (DMA, MMA; grain products (DMA, MMA; legumes, nuts, seeds (DMA; meat, poultry (DMA; rice (DMA, MMA; rice cakes/crackers (DMA, MMA; and sugars, sweets, beverages (MMA. And, for adults, rice beverage/milk (DMA, MMA. In addition, based on US (United States median and 90th percentile consumption rates of each food group, exposure from the following food groups was highlighted: fish; fruits; grain products; legumes, nuts, seeds; meat, poultry; and sugars, sweets, beverages. CONCLUSIONS: In a nationally representative sample of the US civilian, noninstitutionalized population, fish (adults, rice (children, and rice cakes/crackers (adolescents had the largest associations with urinary DMA. For MMA, rice beverage/milk (adults and rice cakes/crackers (children, adolescents had the largest associations.

  15. Radiological study of brackish and fresh water food samples in Lagos and Ondo states, southwestern Nigeria

    International Nuclear Information System (INIS)

    Ojo, T.J.; Ojo, O.C.

    2007-01-01

    Measurement of the average radioactivity concentration in brackish and fresh water food samples in Lagos and Ondo States of Nigeria was carried out using a very sensitive gamma spectroscopic system consisting of a 76 mm x 76 mm Nal (TI) scintillation detector coupled to a computerized ACCUSPEC installation. All the radionuclide detected are traceable to the naturally occurring 4 ''0K and ''2''3''2Th. The average concentrations of ''2''3''8U and ''2''3''2Th were found to be higher in brackish water food samples, 50.92±7.04 Bq/kg and 24.60± 6.47 Bq/kg respectively. The average concentration of ''4''0K was found to be higher in food samples got from freshwater, 738.94±84.81Bq/kg

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-01

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

  17. A principal-component and least-squares method for allocating polycyclic aromatic hydrocarbons in sediment to multiple sources

    International Nuclear Information System (INIS)

    Burns, W.A.; Mankiewicz, P.J.; Bence, A.E.; Page, D.S.; Parker, K.R.

    1997-01-01

    A method was developed to allocate polycyclic aromatic hydrocarbons (PAHs) in sediment samples to the PAH sources from which they came. The method uses principal-component analysis to identify possible sources and a least-squares model to find the source mix that gives the best fit of 36 PAH analytes in each sample. The method identified 18 possible PAH sources in a large set of field data collected in Prince William Sound, Alaska, USA, after the 1989 Exxon Valdez oil spill, including diesel oil, diesel soot, spilled crude oil in various weathering states, natural background, creosote, and combustion products from human activities and forest fires. Spill oil was generally found to be a small increment of the natural background in subtidal sediments, whereas combustion products were often the predominant sources for subtidal PAHs near sites of past or present human activity. The method appears to be applicable to other situations, including other spills

  18. 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.

  19. Target life time of laser ion source for low charge state ion production

    Energy Technology Data Exchange (ETDEWEB)

    Kanesue,T.; Tamura, J.; Okamura, M.

    2008-06-23

    Laser ion source (LIS) produces ions by irradiating pulsed high power laser shots onto the solid state target. For the low charge state ion production, laser spot diameter on the target can be over several millimeters using a high power laser such as Nd:YAG laser. In this case, a damage to the target surface is small while there is a visible crater in case of the best focused laser shot for high charge state ion production (laser spot diameter can be several tens of micrometers). So the need of target displacement after each laser shot to use fresh surface to stabilize plasma is not required for low charge state ion production. We tested target lifetime using Nd:YAG laser with 5 Hz repetition rate. Also target temperature and vacuum condition were recorded during experiment. The feasibility of a long time operation was verified.

  20. The state of the art of the impact of sampling uncertainty on measurement uncertainty

    Science.gov (United States)

    Leite, V. J.; Oliveira, E. C.

    2018-03-01

    The measurement uncertainty is a parameter that marks the reliability and can be divided into two large groups: sampling and analytical variations. Analytical uncertainty is a controlled process, performed in the laboratory. The same does not occur with the sampling uncertainty, which, because it faces several obstacles and there is no clarity on how to perform the procedures, has been neglected, although it is admittedly indispensable to the measurement process. This paper aims at describing the state of the art of sampling uncertainty and at assessing its relevance to measurement uncertainty.

  1. Developing a Vacuum Electrospray Source To Implement Efficient Atmospheric Sampling for Miniature Ion Trap Mass Spectrometer.

    Science.gov (United States)

    Yu, Quan; Zhang, Qian; Lu, Xinqiong; Qian, Xiang; Ni, Kai; Wang, Xiaohao

    2017-12-05

    The performance of a miniature mass spectrometer in atmospheric analysis is closely related to the design of its sampling system. In this study, a simplified vacuum electrospray ionization (VESI) source was developed based on a combination of several techniques, including the discontinuous atmospheric pressure interface, direct capillary sampling, and pneumatic-assisted electrospray. Pulsed air was used as a vital factor to facilitate the operation of electrospray ionization in the vacuum chamber. This VESI device can be used as an efficient atmospheric sampling interface when coupled with a miniature rectilinear ion trap (RIT) mass spectrometer. The developed VESI-RIT instrument enables regular ESI analysis of liquid, and its qualitative and quantitative capabilities have been characterized by using various solution samples. A limit of detection of 8 ppb could be attained for arginine in a methanol solution. In addition, extractive electrospray ionization of organic compounds can be implemented by using the same VESI device, as long as the gas analytes are injected with the pulsed auxiliary air. This methodology can extend the use of the proposed VESI technique to rapid and online analysis of gaseous and volatile samples.

  2. A comparative study of some physico-chemical properties of human serum albumin samples from different sources--I : Some physico-chemical properties of isoionic human serum albumin solutions

    NARCIS (Netherlands)

    Dröge, J.H.M.; Janssen, L.H.M.; Wilting, J.

    1982-01-01

    Human serum albumin samples from different sources were investigated. The fatty acid content of the albumin before and after deionization on a mixed bed ion-exchange column varied from sample to sample. When an albumin sample from one source was deionized under standard conditions the amount of

  3. Methods for Characterisation of unknown Suspect Radioactive Samples

    International Nuclear Information System (INIS)

    Sahagia, M.; Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

    2001-01-01

    Full text: The paper presents various identification and measurement methods, used for the expertise of a wide variety of suspect radioactive materials, whose circulation was not legally stated. The main types of examined samples were: radioactive sources, illegally trafficked; suspect radioactive materials or radioactively contaminated devices; uranium tablets; fire detectors containing 241 Am sources; osmium samples containing radioactive 185 Os or enriched 187 Os. The types of analyses and determination methods were as follows: the chemical composition was determined by using identification reagents or by neutron activation analysis; the radionuclide composition was determined by using gamma-ray spectrometry; the activity and particle emission rates were determined by using calibrated radiometric equipment; the absorbed dose rate at the wall of all types of containers and samples was determined by using calibrated dose ratemeters. The radiation exposure risk for population, due to these radioactive materials, was evaluated for every case. (author)

  4. OCCIPITAL SOURCES OF RESTING STATE ALPHA RHYTHMS ARE RELATED TO LOCAL GRAY MATTER DENSITY IN SUBJECTS WITH AMNESIC MILD COGNITIVE IMPAIRMENT AND ALZHEIMER’S DISEASE

    Science.gov (United States)

    Claudio, Babiloni; Claudio, Del Percio; Marina, Boccardi; Roberta, Lizio; Susanna, Lopez; Filippo, Carducci; Nicola, Marzano; Andrea, Soricelli; Raffaele, Ferri; Ivano, Triggiani Antonio; Annapaola, Prestia; Serenella, Salinari; Rasser Paul, E; Erol, Basar; Francesco, Famà; Flavio, Nobili; Görsev, Yener; Durusu, Emek-Savaş Derya; Gesualdo, Loreto; Ciro, Mundi; Thompson Paul, M; Rossini Paolo, M.; Frisoni Giovanni, B

    2014-01-01

    Occipital sources of resting state electroencephalographic (EEG) alpha rhythms are abnormal, at the group level, in patients with amnesic mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Here we evaluated the hypothesis that amplitude of these occipital sources is related to neurodegeneration in occipital lobe as measured by magnetic resonance imaging (MRI). Resting-state eyes-closed EEG rhythms were recorded in 45 healthy elderly (Nold), 100 MCI, and 90 AD subjects. Neurodegeneration of occipital lobe was indexed by weighted averages of gray matter density (GMD), estimated from structural MRIs. EEG rhythms of interest were alpha 1 (8–10.5 Hz) and alpha 2 (10.5–13 Hz). EEG cortical sources were estimated by low resolution brain electromagnetic tomography (LORETA). Results showed a positive correlation between occipital GMD and amplitude of occipital alpha 1 sources in Nold, MCI and AD subjects as a whole group (r=0.3, p=0.000004, N=235). Furthermore, there was a positive correlation between amplitude of occipital alpha 1 sources and cognitive status as revealed by Mini Mental State Evaluation (MMSE) score across all subjects (r=0.38, p=0.000001, N=235). Finally, amplitude of occipital alpha 1 sources allowed a moderate classification of individual Nold and AD subjects (sensitivity: 87.8%; specificity: 66.7%; area under the Receiver Operating Characteristic (ROC) curve: 0.81). These results suggest that the amplitude of occipital sources of resting state alpha rhythms is related to AD neurodegeneration in occipital lobe along pathological aging. PMID:25442118

  5. Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae.

    Science.gov (United States)

    Arraes, Maria Luisa Bezerra de Macedo; Holanda, Maísa Viana de; Lima, Luana Nepomuceno Gondim Costa; Sabadia, José Antônio Beltrão; Duarte, Cynthia Romariz; Almeida, Rosa Livia Freitas; Kendall, Carl; Kerr, Ligia Regina Sansigolo; Frota, Cristiane Cunha

    2017-12-01

    The detection of live Mycobacterium leprae in soil and animals other than humans suggests that the environment plays a role in the transmission of leprosy. The objective of this study was to investigate the presence of viable M. leprae in natural water sources used by the local population in five municipalities in the state of Ceará, northeastern Brazil. Samples were collected from 30 different sources. Viable bacilli were identified by reverse transcriptase polymerase chain reaction (PCR) of the M. leprae gyrA gene and sequencing of the PCR products. Physicochemical properties of each water source were also assessed. M. leprae gyrA mRNA was found in 23 (76.7%) of the water sources. No association was found between depth of the water and sample positivity, nor was there any association between the type of water used by the population and sample positivity. An association between viable M. leprae and temperature and pH was found. Georeferencing showed a relation between the residences of leprosy cases and water source containing the bacterium. The finding of viable M. leprae in natural water sources associated with human contact suggests that the environment plays an important role in maintaining endemic leprosy in the study region.

  6. Lead isotope ratios in lichen samples evaluated by ICP-ToF-MS to assess possible atmospheric pollution sources in Havana, Cuba.

    Science.gov (United States)

    Alvarez, Alfredo Montero; Estévez Alvarez, Juan R; do Nascimento, Clístenes Williams Araújo; González, Iván Pupo; Rizo, Oscar Díaz; Carzola, Lázaro Lima; Torres, Roberto Ayllón; Pascual, Jorge Gómez

    2017-01-01

    Epiphytic lichens, collected from 119 sampling sites grown over "Roistonea Royal Palm" trees, were used to assess the spatial distribution pattern of lead (Pb) and identify possible pollution sources in Havana (Cuba). Lead concentrations in lichens and topsoils were determined by flame atomic absorption spectrophotometry and inductively coupled plasma (ICP) atomic emission spectrometry, respectively, while Pb in crude oils and gasoline samples were measured by ICP-time of flight mass spectrometry (ICP-ToF-MS). Lead isotopic ratios measurements for lichens, soils, and crude oils were obtained by ICP-ToF-MS. We found that enrichment factors (EF) reflected a moderate contamination for 71% of the samples (EF > 10). The 206 Pb/ 207 Pb ratio values for lichens ranged from 1.17 to 1.20 and were a mixture of natural radiogenic and industrial activities (e.g., crude oils and fire plants). The low concentration of Pb found in gasoline (leaded gasoline is no longer used in Cuba.

  7. DEVELOPMENT OF SAMPLING AND ANALYTICAL METHODS FOR THE MEASUREMENT OF NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION SOURCES

    Science.gov (United States)

    The report documents the technical approach and results achieved while developing a grab sampling method and an automated, on-line gas chromatography method suitable to characterize nitrous oxide (N2O) emissions from fossil fuel combustion sources. The two methods developed have...

  8. 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...

  9. The Kansas State University revolving sputter source

    International Nuclear Information System (INIS)

    Tipping, T.N.

    1989-01-01

    It has been that the perfect ion source is one which runs in a very stable mode, runs continuously, and has the ability to change ion species without sacrificing the previous two requirements. This paper presents an approximation to the perfect ion source, the KSU Revolving Sputter Source. The source consists of an Aarhus-geometry sputter source with the addition of a rotating wheel which holds eight sputter cathodes. The wheel consists of a front plate with eight fixed Macor insulators and a back plate with eight Macor insulators held in place by the tension of eight springs. The cathode assembly consists of a copper cartridge with a threaded rod on one end and a sputter cathode with a threaded hole on the back. The cathode is screwed onto the cartridge and the whole assembly may be loaded into the wheel. A small spring on the side of the cartridge holds the assembly in the wheel

  10. Characterization of different cassava samples by nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Iulianelli, Gisele C.V.; Tavares, Maria I.B.

    2011-01-01

    Cassava root (Manihot esculenta Crantz) is grown in all Brazilian states, being an important product in the diet of Brazilians. For many families of the North and Northeast states, it may represent the main energy source. The cassava root flour has high levels of starch, in addition to containing fiber, lipids and some minerals. There is, however, great genetic variability, which results in differentiation in its chemical composition and structural aspect. Motivated by the economic, nutritional and pharmacological importance of this product, this work is aimed at characterizing six cassava flour samples by NMR spectroscopy. The spectra revealed the main chemical groups. Furthermore, the results confirmed differences on chemical and structural aspect of the samples. For instance, the F1 sample is richer in carbohydrates, while the F4 sample has higher proportion of glycolipids, the F2 sample has higher amylose content and the F6 sample exhibits a greater diversity of glycolipid types. Regarding the molecular structure, the NMR spectra indicated that the F1 sample is more organized at the molecular level, while the F3 and F5 samples are similar in amorphicity and in the molecular packing. (author)

  11. Replicability of time-varying connectivity patterns in large resting state fMRI samples.

    Science.gov (United States)

    Abrol, Anees; Damaraju, Eswar; Miller, Robyn L; Stephen, Julia M; Claus, Eric D; Mayer, Andrew R; Calhoun, Vince D

    2017-12-01

    The past few years have seen an emergence of approaches that leverage temporal changes in whole-brain patterns of functional connectivity (the chronnectome). In this chronnectome study, we investigate the replicability of the human brain's inter-regional coupling dynamics during rest by evaluating two different dynamic functional network connectivity (dFNC) analysis frameworks using 7 500 functional magnetic resonance imaging (fMRI) datasets. To quantify the extent to which the emergent functional connectivity (FC) patterns are reproducible, we characterize the temporal dynamics by deriving several summary measures across multiple large, independent age-matched samples. Reproducibility was demonstrated through the existence of basic connectivity patterns (FC states) amidst an ensemble of inter-regional connections. Furthermore, application of the methods to conservatively configured (statistically stationary, linear and Gaussian) surrogate datasets revealed that some of the studied state summary measures were indeed statistically significant and also suggested that this class of null model did not explain the fMRI data fully. This extensive testing of reproducibility of similarity statistics also suggests that the estimated FC states are robust against variation in data quality, analysis, grouping, and decomposition methods. We conclude that future investigations probing the functional and neurophysiological relevance of time-varying connectivity assume critical importance. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. A cautionary note on substituting spatial subunits for repeated temporal sampling in studies of site occupancy

    Science.gov (United States)

    Kendall, William L.; White, Gary C.

    2009-01-01

    1. Assessing the probability that a given site is occupied by a species of interest is important to resource managers, as well as metapopulation or landscape ecologists. Managers require accurate estimates of the state of the system, in order to make informed decisions. Models that yield estimates of occupancy, while accounting for imperfect detection, have proven useful by removing a potentially important source of bias. To account for detection probability, multiple independent searches per site for the species are required, under the assumption that the species is available for detection during each search of an occupied site. 2. We demonstrate that when multiple samples per site are defined by searching different locations within a site, absence of the species from a subset of these spatial subunits induces estimation bias when locations are exhaustively assessed or sampled without replacement. 3. We further demonstrate that this bias can be removed by choosing sampling locations with replacement, or if the species is highly mobile over a short period of time. 4. Resampling an existing data set does not mitigate bias due to exhaustive assessment of locations or sampling without replacement. 5. Synthesis and applications. Selecting sampling locations for presence/absence surveys with replacement is practical in most cases. Such an adjustment to field methods will prevent one source of bias, and therefore produce more robust statistical inferences about species occupancy. This will in turn permit managers to make resource decisions based on better knowledge of the state of the system.

  13. Self Inflicted Injuries among Children in United States - estimates from a nationwide emergency department sample.

    Directory of Open Access Journals (Sweden)

    Naseem Sulyman

    Full Text Available OBJECTIVE: The objectives of the current study are to provide nationally representative estimates of hospital based emergency department visits (ED attributed to self inflicted injuries and attempted suicides among children in United States; and to identify potential methods of such intentional self inflicted injuries and attempted suicides. METHODS: The Nationwide Emergency Department Sample (year 2007 was used. All ED visits occurring among children (aged ≤18 years with an External Cause of Injury for any of self inflicted injuries were selected. Outcomes examined include hospital ED charges and hospitalization charges. All estimates were projected to national levels. RESULTS: 77,420 visits to hospital based emergency departments were attributed to self inflicted injuries among children (26,045 males and 51,370 females. The average age of the ED visits was 15.7 years. 134 patients died in ED's (106 males and 28 females and 93 died in hospitals following in-patient admission (75 males and 18 females. A greater proportion of male ED visits were discharged routinely as opposed to female ED visits (51.1% versus 44%. A greater proportion of male ED visits also died in the emergency departments compared to female visits (0.4% versus 0.05%. 17,965 ED visits necessitated admission into same hospital. The mean charge for each ED visit was $1,874. Self inflicted injuries by poisoning were the most frequently reported sources accounting for close to 70% of all ED visits. CONCLUSIONS: Females comprise a greater proportion of ED visits attributed to self inflicted injuries. 227 children died either in the ED's or in hospitals. The current study results highlight the burden associated with such injuries among children.

  14. A practical algorithm for distribution state estimation including renewable energy sources

    Energy Technology Data Exchange (ETDEWEB)

    Niknam, Taher [Electronic and Electrical Department, Shiraz University of Technology, Modares Blvd., P.O. 71555-313, Shiraz (Iran); Firouzi, Bahman Bahmani [Islamic Azad University Marvdasht Branch, Marvdasht (Iran)

    2009-11-15

    Renewable energy is energy that is in continuous supply over time. These kinds of energy sources are divided into five principal renewable sources of energy: the sun, the wind, flowing water, biomass and heat from within the earth. According to some studies carried out by the research institutes, about 25% of the new generation will be generated by Renewable Energy Sources (RESs) in the near future. Therefore, it is necessary to study the impact of RESs on the power systems, especially on the distribution networks. This paper presents a practical Distribution State Estimation (DSE) including RESs and some practical consideration. The proposed algorithm is based on the combination of Nelder-Mead simplex search and Particle Swarm Optimization (PSO) algorithms, called PSO-NM. The proposed algorithm can estimate load and RES output values by Weighted Least-Square (WLS) approach. Some practical considerations are var compensators, Voltage Regulators (VRs), Under Load Tap Changer (ULTC) transformer modeling, which usually have nonlinear and discrete characteristics, and unbalanced three-phase power flow equations. The comparison results with other evolutionary optimization algorithms such as original PSO, Honey Bee Mating Optimization (HBMO), Neural Networks (NNs), Ant Colony Optimization (ACO), and Genetic Algorithm (GA) for a test system demonstrate that PSO-NM is extremely effective and efficient for the DSE problems. (author)

  15. Fecal steroid hormones reveal reproductive state in female blue whales sampled in the Gulf of California, Mexico.

    Science.gov (United States)

    Valenzuela-Molina, Marcia; Atkinson, Shannon; Mashburn, Kendall; Gendron, Diane; Brownell, Robert L

    2018-05-15

    Steroid hormone assessment using non-invasive sample collection techniques can reveal the reproductive status of aquatic mammals and the physiological mechanisms by which they respond to changes in their environment. A portion of the eastern North Pacific blue whale (Balaenoptera musculus) population that seasonally visits the Gulf of California, Mexico has been monitored using photo-identified individuals for over 30 years. The whales use the area in winter-early spring for nursing their calves and feeding and it therefore is well suited for fecal sample collection. Using radioimmunoassays in 25 fecal samples collected between 2009 and 2012 to determine reproductive state and stress, we validated three steroid hormones (progesterone, corticosterone and cortisol) in adult female blue whales. Females that were categorized as pregnant had higher mean fecal progesterone metabolite concentrations (1292.6 ± 415.6 ng·g -1 ) than resting and lactating females (14.0 ± 3.7 ng·g -1 ; 23.0 ± 5.4 ng·g -1 , respectively). Females classified as pregnant also had higher concentrations of corticosterone metabolites (37.5 ± 9.9 ng·g -1 ) than resting and lactating females (17.4 ± 2.0 ng·g -1 ; 16.8 ± 2.8 ng·g -1 , respectively). In contrast, cortisol metabolite concentrations showed high variability between groups and no significant relationship to reproductive state. We successfully determined preliminary baseline parameters of key steroid hormones by reproductive state in adult female blue whales. The presence of pregnant or with luteal activity and known lactating females confirms that the Gulf of California is an important winter-spring area for the reproductive phase of these blue whales. The baseline corticosterone levels we are developing will be useful for assessing the impact of the increasing coastal development and whale-watching activities on the whales in the Gulf of California. Copyright © 2018 Elsevier Inc. All

  16. Triplet excited States as a source of relevant (bio)chemical information.

    Science.gov (United States)

    Jiménez, M Consuelo; Miranda, Miguel A

    2014-01-01

    The properties of triplet excited states are markedly medium-dependent, which turns this species into valuable tools for investigating the microenvironments existing in protein binding pockets. Monitoring of the triplet excited state behavior of drugs within transport proteins (serum albumins and α1-acid glycoproteins) by laser flash photolysis constitutes a valuable source of information on the strength of interaction, conformational freedom and protection from oxygen or other external quenchers. With proteins, formation of spatially confined triplet excited states is favored over competitive processes affording ionic species. Remarkably, under aerobic atmosphere, the triplet decay of drug@protein complexes is dramatically longer than in bulk solution. This offers a convenient dynamic range for assignment of different triplet populations or for stereochemical discrimination. In this review, selected examples of the application of the laser flash photolysis technique are described, including drug distribution between the bulk solution and the protein cavities, or between two types of proteins, detection of drug-drug interactions inside proteins, and enzyme-like activity processes mediated by proteins. Finally, protein encapsulation can also modify the photoreactivity of the guest. This is illustrated by presenting an example of retarded photooxidation.

  17. Source Water Protection Contaminant Sources

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Simplified aggregation of potential contaminant sources used for Source Water Assessment and Protection. The data is derived from IDNR, IDALS, and US EPA program...

  18. Uranium in groundwater--Fertilizers versus geogenic sources.

    Science.gov (United States)

    Liesch, Tanja; Hinrichsen, Sören; Goldscheider, Nico

    2015-12-01

    Due to its radiological and toxicological properties even at low concentration levels, uranium is increasingly recognized as relevant contaminant in drinking water from aquifers. Uranium originates from different sources, including natural or geogenic, mining and industrial activities, and fertilizers in agriculture. The goal of this study was to obtain insights into the origin of uranium in groundwater while differentiating between geogenic sources and fertilizers. A literature review concerning the sources and geochemical processes affecting the occurrence and distribution of uranium in the lithosphere, pedosphere and hydrosphere provided the background for the evaluation of data on uranium in groundwater at regional scale. The state of Baden-Württemberg, Germany, was selected for this study, because of its hydrogeological and land-use diversity, and for reasons of data availability. Uranium and other parameters from N=1935 groundwater monitoring sites were analyzed statistically and geospatially. Results show that (i) 1.6% of all water samples exceed the German legal limit for drinking water (10 μg/L); (ii) The range and spatial distribution of uranium and occasional peak values seem to be related to geogenic sources; (iii) There is a clear relation between agricultural land-use and low-level uranium concentrations, indicating that fertilizers generate a measurable but low background of uranium in groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Narrowband solid state vuv coherent source for laser cooling of antihydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Michan, J. Mario [TRIUMF (Canada); Polovy, Gene; Madison, Kirk W. [The University of British Columbia, Department of Physics and Astronomy (Canada); Fujiwara, Makoto C. [TRIUMF (Canada); Momose, Takamasa, E-mail: momose@chem.ubc.ca [The University of British Columbia, Department of Chemistry, Department of Physics and Astronomy (Canada)

    2015-11-15

    We describe the design and performance of a solid-state pulsed source of narrowband (< 100 MHz) Lyman-α radiation designed for the purpose of laser cooling magnetically trapped antihydrogen. Our source utilizes an injection seeded Ti:Sapphire amplifier cavity to generate intense radiation at 729.4 nm, which is then sent through a frequency doubling stage and a frequency tripling stage to generate 121.56 nm light. Although the pulse energy at 121.56 nm is currently limited to 12 nJ with a repetition rate of 10 Hz, we expect to obtain greater than 0.1 μJ per pulse at 10 Hz by further optimizing the alignment of the pulse amplifier and the efficiency of the frequency tripling stage. Such a power will be sufficient for cooling a trapped antihydrogen atom from 500 mK to 20mK.

  20. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    Science.gov (United States)

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Effects of sample preparation conditions on biomolecular solid-state NMR lineshapes

    Energy Technology Data Exchange (ETDEWEB)

    Jakeman, David L.; Mitchell, Dan J.; Shuttleworth, Wendy A.; Evans, Jeremy N.S. [Washington State University, Department of Biochemistry and Biophysics (United States)

    1998-10-15

    Sample preparation conditions with the 46 kDa enzyme complex of 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase, shikimate-3-phosphate (S3P) and glyphosate (GLP) have been examined in an attempt to reduce linewidths in solid-state NMR spectra. The linewidths of {sup 13}P resonances associated with enzyme bound S3P and GLP in the lyophilized ternary complex have been reduced to 150 {+-} 12 Hz and 125 {+-} 7 Hz respectively, by a variety of methods involving additives and freezing techniques.

  2. Laser Scribed Graphene Biosensor for Detection of Biogenic Amines in Food Samples Using Locally Sourced Materials

    Directory of Open Access Journals (Sweden)

    Diana C. Vanegas

    2018-04-01

    Full Text Available In foods, high levels of biogenic amines (BA are the result of microbial metabolism that could be affected by temperatures and storage conditions. Thus, the level of BA is commonly used as an indicator of food safety and quality. This manuscript outlines the development of laser scribed graphene electrodes, with locally sourced materials, for reagent-free food safety biosensing. To fabricate the biosensors, the graphene surface was functionalized with copper microparticles and diamine oxidase, purchased from a local supermarket; and then compared to biosensors fabricated with analytical grade materials. The amperometric biosensor exhibits good electrochemical performance, with an average histamine sensitivity of 23.3 µA/mM, a lower detection limit of 11.6 µM, and a response time of 7.3 s, showing similar performance to biosensors constructed from analytical grade materials. We demonstrated the application of the biosensor by testing total BA concentration in fish paste samples subjected to fermentation with lactic acid bacteria. Biogenic amines concentrations prior to lactic acid fermentation were below the detection limit of the biosensor, while concentration after fermentation was 19.24 ± 8.21 mg histamine/kg, confirming that the sensor was selective in a complex food matrix. The low-cost, rapid, and accurate device is a promising tool for biogenic amine estimation in food samples, particularly in situations where standard laboratory techniques are unavailable, or are cost prohibitive. This biosensor can be used for screening food samples, potentially limiting food waste, while reducing chances of foodborne outbreaks.

  3. Research on point source simulating the γ-ray detection efficiencies of stander source

    International Nuclear Information System (INIS)

    Tian Zining; Jia Mingyan; Shen Maoquan; Yang Xiaoyan; Cheng Zhiwei

    2010-01-01

    For φ 75 mm x 25 mm sample, the full energy peak efficiencies on different heights of sample radius were obtained using the point sources, and the function parameters about the full energy peak efficiencies of point sources based on radius was fixed. The 59.54 keV γ-ray, 661.66 keV γ-ray, 1173.2 keV γ-ray, 1332.5 keV γ-ray detection efficiencies on different height of samples were obtained, based on the full energy peak efficiencies of point sources and its height, and the function parameters about the full energy peak efficiencies of surface sources based on sample height was fixed. The detection efficiency of (75 mm x 25 mm calibration source can be obtained by integrality, the detection efficiencies simulated by point sources are consistent with the results of stander source in 10%. Therefore, the calibration method of stander source can be substituted by the point source simulation method, and it tis feasible when there is no stander source.) (authors)

  4. Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream.

    Science.gov (United States)

    Byrne, Patrick; Runkel, Robert L; Walton-Day, Katherine

    2017-07-01

    Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion Creek, Colorado, USA) under low flow conditions to (i) quantify the impacts of mining activity on stream water quality; (ii) quantify the spatial pattern of constituent loading; and (iii) identify inflow sources most responsible for observed changes in stream chemistry and constituent loading. Several of the constituents investigated (Al, Cd, Cu, Fe, Mn, Zn) fail to meet chronic aquatic life standards along most of the study reach. The spatial pattern of constituent loading suggests four primary sources of contamination under low flow conditions. Three of these sources are associated with acidic (pH mine water in the Minnesota Mine shaft located to the north-east of the river channel. In addition, water chemistry data during a rainfall-runoff event suggests the spatial pattern of constituent loading may be modified during rainfall due to dissolution of efflorescent salts or erosion of streamside tailings. These data point to the complexity of contaminant mobilisation processes and constituent loading in mining-affected watersheds but the combined synoptic sampling and PCA approach enables a conceptual model of contaminant dynamics to be developed to inform remediation.

  5. Design of a thermal neutron field by 252Cf source for measurement of 10B concentrations in the blood samples for BNCT

    International Nuclear Information System (INIS)

    Naito, H.; Sakurai, Y.; Maruhashi, A.

    2006-01-01

    10 B concentrations in the blood samples for BNCT has been estimated due to amounts of prompt gamma rays from 10 B in the fields of thermal neutrons from a special guide tube attached to research reactor. A system using radioisotopes as the source of thermal neutron fields has advantages that are convenient and low cost because it doesn't need running of a reactor or an accelerator. The validity of 252 Cf as a neutron source for 10 B concentrations detection system was investigated. This system is composed of D 2 O moderator, Pb reflector/filter, C reflector, and LiF filter. A thermal neutron field with low background gamma-rays is obtained. A large source of 252 Cf is required to obtain a sufficient flux. (author)

  6. Radiation traces in exportation food samples of Parana State, Brazil; Tracos radioativos em amostras alimentares de exportacao do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Scheibel, Viviane

    2002-02-01

    This work deals with radioactive traces measurements in foodstuffs produced at the State of Parana, with large export rate and also of nutritious products of some regional trading companies. The measured foods were: sulfite treated sugar, tea, mint candy, soy in grain, soy crumb, gross soy oil, gum free oil and commercial refined soy oil. Six samples of each lot of the analyzed material were prepared, which represent a sampling with 90% of confidence. The samples were sealed in Marinelli beaker of 2.1 L completely filled and kept during 40 days until secular equilibrium was achieved. The counting time for each measure was of 48 hours. Measurements were carried out by gamma-ray spectrometry employing a HPGe detector with 10% of relative efficiency, coupled to standard nuclear electronics and a 8 l multichannel card. The acquisition of the data was accomplished with the software Maestro{sup TM}, version 3.2. The energy resolution of the {sup 137} Cs 661.62 keV gamma line was 1.75 keV. The larger intensity gamma lines observed in the spectra were from the following radionuclides: {sup 228} Ac, {sup 208} Tl, {sup 212} Pb of the {sup 232} Th series, {sup 214} Bi and {sup 214} Pb from the {sup 238} U series, {sup 227} Ac from the {sup 235} U series and {sup 40} K. Activities and lower level of detection limits were calculated according to the International Agency of Atomic Energy norms.The detector efficiency was measured using a {sup 152} Eu certified source and IAEA-375 and IAEA-326 certified reference materials. For most of the radionuclides it was possible only the measurement of the minimum activity detectable in the foodstuffs. Self-attenuation corrections were accomplished with support literature results. The most important activity observed was that of {sup 40} K, whose value measured for soy in natura was 745.0 {sup +}-{sup 9}.1 Bq/kg and for the crumb soy 1473 {+-} 15 Bq/kg.. he measured activities of the several analyzed foods were compatible with the values

  7. Calculation of the secondary gamma radiation by the Monte Carlo method at displaced sampling from distributed sources

    International Nuclear Information System (INIS)

    Petrov, Eh.E.; Fadeev, I.A.

    1979-01-01

    A possibility to use displaced sampling from a bulk gamma source in calculating the secondary gamma fields by the Monte Carlo method is discussed. The algorithm proposed is based on the concept of conjugate functions alongside the dispersion minimization technique. For the sake of simplicity a plane source is considered. The algorithm has been put into practice on the M-220 computer. The differential gamma current and flux spectra in 21cm-thick lead have been calculated. The source of secondary gamma-quanta was assumed to be a distributed, constant and isotropic one emitting 4 MeV gamma quanta with the rate of 10 9 quanta/cm 3 xs. The calculations have demonstrated that the last 7 cm of lead are responsible for the whole gamma spectral pattern. The spectra practically coincide with the ones calculated by the ROZ computer code. Thus the algorithm proposed can be offectively used in the calculations of secondary gamma radiation transport and reduces the computation time by 2-4 times

  8. Source-Drain Punch-Through Analysis of High Voltage Off-State AlGaN/GaN HEMT Breakdown

    Science.gov (United States)

    Jiang, H.; Li, X.; Wang, J.; Zhu, L.; Wang, H.; Liu, J.; Wang, M.; Yu, M.; Wu, W.; Zhou, Y.; Dai, G.

    2017-06-01

    AlGaN/GaN high-electron mobility transistor’s (HEMT’s) off-state breakdown is investigated using conventional three-terminal off-state breakdown I-V measurement. Competition between gate leakage and source-injection buffer leakage (SIBL) is discussed in detail. It is found that the breakdown is dominated by source-injection which is sensitive to gate voltage and gate length at large gate-to-drain spacing (Lgd > 7μm), where a threshold drain voltage of the occurrence of the SIBL current in GaN buffer exists, and after this threshold voltage the SIBL current continually increased till the buffer breakdown. Our analysis showed that due to the punch-through effect in the buffer, a potential barrier between 2DEG and GaN buffer at the source side mainly controlled by the drain voltage determines the buffer leakage current and the occurrence of the following buffer breakdown, which could explain the experimentally observed breakdown phenomenon.

  9. State survey of silviculture nonpoint source programs: a comparison of the 2000 northeastern and national results

    Science.gov (United States)

    Pamela J. Edwards; Gordon W. Stuart

    2002-01-01

    The National Association of State Foresters conducts surveys of silviculture nonpoint source (NPS) pollution control programs to measure progress and identify needs. The 2000 survey results are summarized here for the nation and for the 20-state northeastern region. Current emphasis of NPS pollution programs is on education, training, and monitoring. Educational...

  10. Detecting alcohol and illicit drugs in oral fluid samples collected from truck drivers in the state of São Paulo, Brazil.

    Science.gov (United States)

    Yonamine, Mauricio; Sanches, Livia Rentas; Paranhos, Beatriz Aparecida Passos Bismara; de Almeida, Rafael Menck; Andreuccetti, Gabriel; Leyton, Vilma

    2013-01-01

    Alcohol and drug use by truck drivers is a current problem in Brazil. Though there is evidence that alcohol consumption is occurring in higher proportions, the use of stimulant drugs to avoid fatigue and to maintain the work schedule has also been reported. The purpose of this study was to estimate the incidence of alcohol and illicit drug use among truck drivers on São Paulo state roads. São Paulo is the most populous state in Brazil and has the largest industrial park and economic production in the country. Data were assessed not only using a questionnaire but also, and more reliably, through toxicological analysis of oral fluid samples. Between the years 2002 and 2008, 1250 oral fluid samples were collected from truck drivers on the roads during morning hours. The samples were tested for the presence of alcohol, cocaine, tetrahydrocannabinol (THC), and amphetamine/methamphetamine. A previously published, validated gas chromatographic (gas chromatography-flame ionization detection and gas chromatography-mass spectrometry) method was applied to the samples for alcohol and drug detection. Of the total analyzed samples, 3.1 percent (n = 39) were positive: 1.44 percent (n = 18) were positive for alcohol, 0.64 percent (n = 8) for amphetamines, 0.56 percent (n = 7) for cocaine, and 0.40 percent (n = 5) for THC. In one case, cocaine and THC were detected. The results are indicative of the extent of alcohol and drug use by truck drivers in the state of São Paulo, Brazil. This research provides evidence that not only alcohol but also illicit drug use is a real problem among professional drivers. The use of these substances should be controlled to better promote safe driving conditions on Brazilian roads.

  11. Natural Leishmania sp. reservoirs and phlebotomine sandfly food source identification in Ibitipoca State Park, Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Flávia Quaresma

    2012-06-01

    Full Text Available Leishmania spp are distributed throughout the world and different species are associated with varying degrees of disease severity. However, leishmaniasis is thought to be confined to areas of the world where its insect vectors, sandflies, are present. Phlebotomine sandflies obtain blood meals from a variety of wild and domestic animals and sometimes from humans. These vectors transmit Leishmania spp, the aetiological agent of leishmaniasis. Identification of sandfly blood meals has generally been performed using serological methods, although a few studies have used molecular procedures in artificially fed insects. In this study, cytochrome b gene (cytB polymerase chain reaction (PCR was performed in DNA samples isolated from 38 engorged Psychodopygus lloydi and the expected 359 bp fragment was identified from all of the samples. The amplified product was digested using restriction enzymes and analysed for restriction fragment length polymorphisms (RFLPs. We identified food sources for 23 females; 34.8% yielded a primate-specific banding profile and 26.1% and 39.1% showed banding patterns specific to birds or mixed restriction profiles (rodent/marsupial, human/bird, rodent/marsupial/human, respectively. The food sources of 15 flies could not be identified. Two female P. lloydi were determined to be infected by Leishmania using internal transcribed spacer 1 and heat shock protein 70 kDa PCR-RFLP. The two female sandflies, both of which fed on rodents/marsupials, were further characterised as infected with Leishmania (Viannia braziliensis. These results constitute an important step towards applying methodologies based on cytB amplification as a tool for identifying the food sources of female sandflies.

  12. Sample preparation in foodomic analyses.

    Science.gov (United States)

    Martinović, Tamara; Šrajer Gajdošik, Martina; Josić, Djuro

    2018-04-16

    Representative sampling and adequate sample preparation are key factors for successful performance of further steps in foodomic analyses, as well as for correct data interpretation. Incorrect sampling and improper sample preparation can be sources of severe bias in foodomic analyses. It is well known that both wrong sampling and sample treatment cannot be corrected anymore. These, in the past frequently neglected facts, are now taken into consideration, and the progress in sampling and sample preparation in foodomics is reviewed here. We report the use of highly sophisticated instruments for both high-performance and high-throughput analyses, as well as miniaturization and the use of laboratory robotics in metabolomics, proteomics, peptidomics and genomics. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Acrolein and asthma attack prevalence in a representative sample of the United States adult population 2000-2009.

    Science.gov (United States)

    deCastro, B Rey

    2014-01-01

    Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment) and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old) in the NHIS (National Health Interview Survey) 2000-2009 (n = 271,348 subjects). A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. In the highest quintile of outdoor acrolein exposure (0.05-0.46 µg/m3), there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19]) relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29]) in a model limited to never smokers (n = 153,820). Chronic exposure to outdoor acrolein of 0.05-0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population.

  14. Acrolein and asthma attack prevalence in a representative sample of the United States adult population 2000-2009.

    Directory of Open Access Journals (Sweden)

    B Rey deCastro

    Full Text Available BACKGROUND: Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. OBJECTIVES: Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. METHODS: NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old in the NHIS (National Health Interview Survey 2000-2009 (n = 271,348 subjects. A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. RESULTS: In the highest quintile of outdoor acrolein exposure (0.05-0.46 µg/m3, there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19] relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29] in a model limited to never smokers (n = 153,820. CONCLUSIONS: Chronic exposure to outdoor acrolein of 0.05-0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population.

  15. Plasmonics for solid-state lighting : enhanced excitation and directional emission of highly efficient light sources

    NARCIS (Netherlands)

    Lozano, G.; Louwers, Davy J.; Rodriguez, S.R.K.; Murai, S.; Jansen, O.T.A.; Verschuuren, M.A.; Gomez Rivas, J.

    2013-01-01

    Light sources based on reliable and energy-efficient light-emitting diodes (LEDs) are instrumental in the development of solid-state lighting (SSL). Most research efforts in SSL have focused on improving both the intrinsic quantum efficiency (QE) and the stability of light emitters. For this reason,

  16. Combining land use information and small stream sampling with PCR-based methods for better characterization of diffuse sources of human fecal pollution.

    Science.gov (United States)

    Peed, Lindsay A; Nietch, Christopher T; Kelty, Catherine A; Meckes, Mark; Mooney, Thomas; Sivaganesan, Mano; Shanks, Orin C

    2011-07-01

    Diffuse sources of human fecal pollution allow for the direct discharge of waste into receiving waters with minimal or no treatment. Traditional culture-based methods are commonly used to characterize fecal pollution in ambient waters, however these methods do not discern between human and other animal sources of fecal pollution making it difficult to identify diffuse pollution sources. Human-associated quantitative real-time PCR (qPCR) methods in combination with low-order headwatershed sampling, precipitation information, and high-resolution geographic information system land use data can be useful for identifying diffuse source of human fecal pollution in receiving waters. To test this assertion, this study monitored nine headwatersheds over a two-year period potentially impacted by faulty septic systems and leaky sanitary sewer lines. Human fecal pollution was measured using three different human-associated qPCR methods and a positive significant correlation was seen between abundance of human-associated genetic markers and septic systems following wet weather events. In contrast, a negative correlation was observed with sanitary sewer line densities suggesting septic systems are the predominant diffuse source of human fecal pollution in the study area. These results demonstrate the advantages of combining water sampling, climate information, land-use computer-based modeling, and molecular biology disciplines to better characterize diffuse sources of human fecal pollution in environmental waters.

  17. Chlorinated solvents in groundwater of the United States

    Science.gov (United States)

    Moran, M.J.; Zogorski, J.S.; Squillace, P.J.

    2007-01-01

    Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents were among the most frequently detected. Mixtures of solvents in groundwater were common and may be the result of common usage of solvents or degradation of one solvent to another. Relative to other VOCs with Maximum Contaminant Levels (MCLs), PCE and TCE ranked high in terms of the frequencies of concentrations greater than or near MCLs. The probability of occurrence of solvents in groundwater was associated with dissolved oxygen content of groundwater, sources such as urban land use and population density, and hydraulic properties of the aquifer. The results reinforce the importance of understanding the redox conditions of aquifers and the hydraulic properties of the saturated and vadose zones in determining the intrinsic susceptibility of groundwater to contamination by solvents. The results also reinforce the importance of controlling sources of solvents to groundwater. ?? 2007 American Chemical Society.

  18. Unraveling the sources of ground level ozone in the Intermountain Western United States using Pb isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, John N. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Weiss-Penzias, Peter [University of California at Santa Cruz, Santa Cruz, CA (United States); Fine, Rebekka [University of Nevada, Reno, NV (United States); McDade, Charles E.; Trzepla, Krystyna [University of California at Davis, Crocker Nuclear Laboratory, Davis, CA (United States); Brown, Shaun T. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Gustin, Mae Sexauer [University of Nevada, Reno, NV (United States)

    2015-10-15

    Ozone as an atmospheric pollutant is largely produced by anthropogenic precursors and can significantly impact human and ecosystem health, and climate. The U.S. Environmental Protection Agency has recently proposed lowering the ozone standard from 75 ppbv (MDA8 = Maximum Daily 8-Hour Average) to between 65 and 70 ppbv. This will result in remote areas of the Intermountain West that includes many U.S. National Parks being out of compliance, despite a lack of significant local sources. We used Pb isotope fingerprinting and back-trajectory analysis to distinguish sources of imported ozone to Great Basin National Park in eastern Nevada. During discrete Chinese Pb events (> 1.1 ng/m{sup 3} & > 80% Asian Pb) trans-Pacific transported ozone was 5 ± 5.5 ppbv above 19 year averages for those dates. In contrast, concentrations during regional transport from the Los Angeles and Las Vegas areas were 15 ± 2 ppbv above the long-term averages, and those characterized by high-altitude transport 3 days prior to sampling were 19 ± 4 ppbv above. However, over the study period the contribution of trans-Pacific transported ozone increased at a rate of 0.8 ± 0.3 ppbv/year, suggesting that Asian inputs will exceed regional and high altitude sources by 2015–2020. All of these sources will impact regulatory compliance with a new ozone standard, given increasing global background. - Highlights: • Ozone can significantly impact human and ecosystem health and climate. • Pb isotopes and back-trajectory analysis were used to distinguish sources of O{sub 3}. • Baseline concentrations in the Western US are ~ 54 ppbv. • During discrete Asia events O{sub 3} increased by 5 ± 5.5 ppbv and during S CA events by 15 ± 2 ppbv. • Data indicate that Asian ozone inputs will exceed other sources by 2015–2020.

  19. Radiation sources safety and radioactive materials security regulation in Ukraine

    International Nuclear Information System (INIS)

    Smyshliaiev, A.; Holubiev, V.; Makarovska, O.

    2001-01-01

    Radiation sources are widely used in Ukraine. There are about 2500 users in industry, science, education and about 2800 in medicine. About 80,000 sealed radiation sources with total kerma-equivalent of 450 Gy*M 2 /sec are used in Ukraine. The exact information about the radiation sources and their users will be provided in 2001 after the expected completion of the State inventory of radiation sources in Ukraine. In order to ensure radiation source safety in Ukraine, a State System for regulation of activities dealing with radiation sources has been established. The system includes the following elements: establishment of norms, rules and standards of radiation safety; authorization activity, i.e. issuance of permits (including those in the form of licences) for activities dealing with radiation sources; supervisory activity, i.e. control over observance of norms, rules and standards of radiation safety and fulfilment of conditions of licences for activities dealing with radiation sources, and also enforcement. Comprehensive nuclear legislation was developed and implemented from 1991 to 2000. Radiation source safety is regulated by three main nuclear laws in Ukraine: On the use of nuclear energy and radiation safety (passed on 8 February 1995); On Human Protection from Impact of Ionizing Radiation (passed on 14 January 1998); On permissive activity in the area of nuclear energy utilization (passed on 11 January 2000). The regulatory authorities in Ukraine are the Ministry for Ecology and Natural Resources (Nuclear Regulatory Department) and the Ministry of Health (State sanitary-epidemiology supervision). According to the legislation, activities dealing with radiation sources are forbidden without an officially issued permit in Ukraine. Permitted activities with radiation sources are envisaged: licensing of production, storage and maintenance of radiation sources; licensing of the use of radiation sources; obligatory certification of radiation sources and transport

  20. Tracing sediment sources in Royal Drainage basin, Iran

    International Nuclear Information System (INIS)

    Feiznia, S.; Kouhpelma, A.; Ahmadi, H.; Hashemi, S. A.

    2009-01-01

    For successful soil conservation measures, obtaining information about the relative importance of sediment source and their shares in sediment production is required. Tracing or source studies are emphasized in recent years due to their privileges. In this research, sediment sources were identified using tracing method. A small earth dam is constructed at the outlet of Royan Drainage Basin in 1993. In this study, sediments were sampled from dam reservoir, different sources were also sampled. The results of this research can be used in soil conservation projects for execution of suitable management strategies. (Author) 6 refs.

  1. Tracing sediment sources in Royal Drainage basin, Iran

    Energy Technology Data Exchange (ETDEWEB)

    Feiznia, S.; Kouhpelma, A.; Ahmadi, H.; Hashemi, S. A.

    2009-07-01

    For successful soil conservation measures, obtaining information about the relative importance of sediment source and their shares in sediment production is required. Tracing or source studies are emphasized in recent years due to their privileges. In this research, sediment sources were identified using tracing method. A small earth dam is constructed at the outlet of Royan Drainage Basin in 1993. In this study, sediments were sampled from dam reservoir, different sources were also sampled. The results of this research can be used in soil conservation projects for execution of suitable management strategies. (Author) 6 refs.

  2. Why Do I Feel More Confident? Bandura's Sources Predict Preservice Teachers' Latent Changes in Teacher Self-Efficacy

    Science.gov (United States)

    Pfitzner-Eden, Franziska

    2016-01-01

    Teacher self-efficacy (TSE) is associated with a multitude of positive outcomes for teachers and students. However, the development of TSE is an under-researched area. Bandura (1997) proposed four sources of self-efficacy: mastery experiences, vicarious experiences, verbal persuasion, and physiological and affective states. This study introduces a first instrument to assess the four sources for TSE in line with Bandura's conception. Gathering evidence of convergent validity, the contribution that each source made to the development of TSE during a practicum at a school was explored for two samples of German preservice teachers. The first sample (N = 359) were beginning preservice teachers who completed an observation practicum. The second sample (N = 395) were advanced preservice teachers who completed a teaching practicum. The source measure showed good reliability, construct validity, and convergent validity. Latent true change modeling was applied to explore how the sources predicted changes in TSE. Three different models were compared. As expected, results showed that TSE changes in both groups were significantly predicted by mastery experiences, with a stronger relationship in the advanced group. Further, the results indicated that mastery experiences were largely informed by the other three sources to varying degrees depending on the type of practicum. Implications for the practice of teacher education are discussed in light of the results. PMID:27807422

  3. Sampling-based exploration of folded state of a protein under kinematic and geometric constraints

    KAUST Repository

    Yao, Peggy

    2011-10-04

    Flexibility is critical for a folded protein to bind to other molecules (ligands) and achieve its functions. The conformational selection theory suggests that a folded protein deforms continuously and its ligand selects the most favorable conformations to bind to. Therefore, one of the best options to study protein-ligand binding is to sample conformations broadly distributed over the protein-folded state. This article presents a new sampler, called kino-geometric sampler (KGS). This sampler encodes dominant energy terms implicitly by simple kinematic and geometric constraints. Two key technical contributions of KGS are (1) a robotics-inspired Jacobian-based method to simultaneously deform a large number of interdependent kinematic cycles without any significant break-up of the closure constraints, and (2) a diffusive strategy to generate conformation distributions that diffuse quickly throughout the protein folded state. Experiments on four very different test proteins demonstrate that KGS can efficiently compute distributions containing conformations close to target (e.g., functional) conformations. These targets are not given to KGS, hence are not used to bias the sampling process. In particular, for a lysine-binding protein, KGS was able to sample conformations in both the intermediate and functional states without the ligand, while previous work using molecular dynamics simulation had required the ligand to be taken into account in the potential function. Overall, KGS demonstrates that kino-geometric constraints characterize the folded subset of a protein conformation space and that this subset is small enough to be approximated by a relatively small distribution of conformations. © 2011 Wiley Periodicals, Inc.

  4. Natural radioactivity analysis in commercial marble samples of Southeast region in Espirito Santo state, Brazil: preliminary results

    International Nuclear Information System (INIS)

    Aquino, Reginaldo R.; Pecequilo, Brigitte R.S.

    2011-01-01

    The natural radioactivity in commercial marble samples of 6 quarries in 'Cachoeiro do Itapemirim' and 'Castelo' municipalities of the south region of Espirito Santo State, southeast Brazil, was determined from the 226 Ra, 232 Th and 40 K contents. In 'Cachoeiro do Itapemirim' municipality were assessed the localities of 'Alto Moledo', 'Baleeira', 'Alto Gironda' and 'Itaoca' and, in 'Castelo' municipality, was assessed the locality of 'Sao Cristovao'. Three samples of each quarry were sealed in standard 100-mL HDPE polyethylene flasks and stored in order to obtain secular equilibrium in the 238 U and 232 Th series. All samples were measured by high resolution gamma spectrometry after a 30-days ingrowth period. Preliminary results show concentrations varying from 1,0 +- 0,2 Bq.kg-1 to 6,5 +- 0,8 Bq.kg-1 for 226 Ra, from 1,5 +- 1,2 Bq.kg -1 to 3,2 +- 1,7 Bq.kg -1 for 232 Th and from 5 +- 4 Bq.kg -1 to 27 +- 5 Bq.kg -1 for 40 K. (author)

  5. Unidentified point sources in the IRAS minisurvey

    Science.gov (United States)

    Houck, J. R.; Soifer, B. T.; Neugebauer, G.; Beichman, C. A.; Aumann, H. H.; Clegg, P. E.; Gillett, F. C.; Habing, H. J.; Hauser, M. G.; Low, F. J.

    1984-01-01

    Nine bright, point-like 60 micron sources have been selected from the sample of 8709 sources in the IRAS minisurvey. These sources have no counterparts in a variety of catalogs of nonstellar objects. Four objects have no visible counterparts, while five have faint stellar objects visible in the error ellipse. These sources do not resemble objects previously known to be bright infrared sources.

  6. Los Alamos Scientific Laboratory approach to hydrogeochemical and stream sediment reconnaissance for uranium in the United States

    International Nuclear Information System (INIS)

    Bolivar, S.L.

    1981-01-01

    The Los Alamos Scientific Laboratory of the United States is conducting a geochemical survey for uranium in the Rocky Mountain states of New Mexico, Colorado, Wyoming, and Montana and in Alaska. This survey is part of a national hydrogeochemical and stream sediment reconnaissance in which four Department of Energy laboratories will study the uranium resources of the United States to provide data for the National Uranium Resource Evaluation program. The reconnaissance will identify areas having higher than background concentrations of uranium in ground waters, surface waters, and water-transported sediments. Water and sediment samples are collected at a nominal density of one sample location per 10 km 2 except for lake areas of Alaska where the density is one sample location per 23 km 2 . Water samples are analyzed for uranium by fluorometry which has a 0.02 parts per billion lower limit of detection. Concentrations of 12 additional elements in water are determined by plasma-source emission spectrography. All sediments are analyzed for uranium by delayed-neutron counting with a 20 parts per billion lower limit of detection, which is well below the range of uranium concentrations in natural sediment samples. Elemental concentrations in sediments are also determined by neutron activation analysis for 31 elements by x-ray fluorescence for 9 elements, and by arc-source emission spectrography for 2 elements. The multielement analyses provide valuable data for studies concerning pathfinder elements, environmental pollution, elemental distributions, dispersion halos, and economic ore deposits other than uranium. To date, all of four Rocky Mountain states and about 80% of Alaska have been sampled. About 220,000 samples have been collected from an area of nearly 2,500,000 km 2

  7. Determining contributions of biomass burning and other sources to fine particle contemporary carbon in the western United States

    Science.gov (United States)

    Holden, Amanda S.; Sullivan, Amy P.; Munchak, Leigh A.; Kreidenweis, Sonia M.; Schichtel, Bret A.; Malm, William C.; Collett, Jeffrey L., Jr.

    2011-02-01

    Six-day integrated fine particle samples were collected at urban and rural sampling sites using Hi-Volume samplers during winter and summer 2004-2005 as part of the IMPROVE (Interagency Monitoring of PROtected Visual Environments) Radiocarbon Study. Filter samples from six sites (Grand Canyon, Mount Rainier, Phoenix, Puget Sound, Rocky Mountain National Park, and Tonto National Monument) were analyzed for levoglucosan, a tracer for biomass combustion, and other species by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD). Contemporary carbon concentrations were available from previous carbon isotope measurements at Lawrence Livermore National Laboratory. Primary contributions of biomass burning to measured fine particle contemporary carbon were estimated for residential wood burning (winter) and wild/prescribed fires (summer). Calculated contributions ranged from below detection limit to more than 100% and were typically higher at rural sites and during winter. Mannitol, a sugar alcohol emitted by fungal spores, was analyzed and used to determine contributions of fungal spores to fine particle contemporary carbon. Contributions reached up to 13% in summer samples, with higher contributions at rural sites. Concentrations of methyltetrols, oxidation products of isoprene, were also measured by HPAEC-PAD. Secondary organic aerosol (SOA) from isoprene oxidation was estimated to contribute up to 22% of measured contemporary carbon. For each sampling site, a substantial portion of the contemporary carbon was unexplained by primary biomass combustion, fungal spores, or SOA from isoprene oxidation. This unexplained fraction likely contains contributions from other SOA sources, including oxidation products of primary smoke emissions and plant emissions other than isoprene, as well as other primary particle emissions from meat cooking, plant debris, other biological aerosol particles, bio-diesel combustion, and other sources. Loss

  8. Methods for evaluating potential sources of chloride in surface waters and groundwaters of the conterminous United States

    Science.gov (United States)

    Granato, Gregory E.; DeSimone, Leslie A.; Barbaro, Jeffrey R.; Jeznach, Lillian C.

    2015-09-04

    Chloride exists as a major ion in most natural waters, but many anthropogenic sources are increasing concentrations of chloride in many receiving waters. Although natural concentrations in continental waters can be as high as 200,000 milligrams per liter, chloride concentrations that are suitable for freshwater ecology, human consumption, and agricultural and industrial water uses commonly are on the order of 10 to 1,000 milligrams per liter. “Road salt” frequently is identified as the sole source of anthropogenic chloride, but only about 30 percent of the salt consumed and released to the environment is used for deicing. Furthermore, several studies in Southern States where the use of deicing salt is minimal also show anthropogenic chloride in rising concentrations and in strong correlation to imperviousness and road density. This is because imperviousness and road density also are strongly correlated to population density. The term “road salt” is a misnomer because deicers applied to parking lots, sidewalks, and driveways can be a substantial source of chloride in some catchments because these land covers are comparable to roadways as a percentage of the total impervious area and commonly receive higher salt application rates than some roadways. Other sources of anthropogenic chloride include wastewater, dust control on unpaved roads, fertilizer, animal waste, irrigation, aquaculture, energy production wastes, and landfill leachates. The assumption that rising chloride concentrations in surface water or groundwater is indicative of contamination by deicing chemicals rather than one or more other potential sources may preclude the identification of toxic, carcinogenic, mutagenic, or endocrine-disrupting contaminants that are associated with many sources of elevated chloride concentrations. Once the sources of anthropogenic chloride in an area of interest have been identified and measured, water and solute budgets can be estimated to guide decisionmakers to

  9. Effect of highways and local activities on the quality of underground water in Ogun State, Nigeria: a case study of three districts in Ogun State, Nigeria.

    Science.gov (United States)

    Odukoya, Olusegun O; Onianwa, Percy C; Sanusi, Olanrewaju I

    2010-09-01

    The effect of highways and local activities on the quality of groundwater in Ogun State, Nigeria was investigated. This was done by collecting groundwater samples from three different districts in the state, located in Southwestern Nigeria. The water samples collected at 5 m from the highway and control samples collected at 3 km from the highway were analyzed for the following physicochemical parameters: pH, conductivity, chemical oxygen demand, alkalinity, total hardness, total solid, suspended solid, dissolved solid, chloride, sulfate, phosphate, nitrate, phenol, and the metals-lead, zinc, iron, aluminum, sodium, and potassium. The levels of chromium, copper, and cadmium in the samples were below the detectable limit. The levels of the parameters show that there are significant differences between those in the samples and the controls (F test) except for phosphate and phenol. Also, anthropogenic sources (local activities) elevate the levels of different specific parameters, which are related to these activities. Good correlation was observed between traffic density and lead levels as well as between conductivity and dissolved solids. Comparisons with the World Health Organization guidelines indicate that most of the water samples are not suitable for human consumption.

  10. A New Source Biasing Approach in ADVANTG

    International Nuclear Information System (INIS)

    Bevill, Aaron M.; Mosher, Scott W.

    2012-01-01

    The ADVANTG code has been developed at Oak Ridge National Laboratory to generate biased sources and weight window maps for MCNP using the CADIS and FW-CADIS methods. In preparation for an upcoming RSICC release, a new approach for generating a biased source has been developed. This improvement streamlines user input and improves reliability. Previous versions of ADVANTG generated the biased source from ADVANTG input, writing an entirely new general fixed-source definition (SDEF). Because volumetric sources were translated into SDEF-format as a finite set of points, the user had to perform a convergence study to determine whether the number of source points used accurately represented the source region. Further, the large number of points that must be written in SDEF-format made the MCNP input and output files excessively long and difficult to debug. ADVANTG now reads SDEF-format distributions and generates corresponding source biasing cards, eliminating the need for a convergence study. Many problems of interest use complicated source regions that are defined using cell rejection. In cell rejection, the source distribution in space is defined using an arbitrarily complex cell and a simple bounding region. Source positions are sampled within the bounding region but accepted only if they fall within the cell; otherwise, the position is resampled entirely. When biasing in space is applied to sources that use rejection sampling, current versions of MCNP do not account for the rejection in setting the source weight of histories, resulting in an 'unfair game'. This problem was circumvented in previous versions of ADVANTG by translating volumetric sources into a finite set of points, which does not alter the mean history weight ((bar w)). To use biasing parameters without otherwise modifying the original cell-rejection SDEF-format source, ADVANTG users now apply a correction factor for (bar w) in post-processing. A stratified-random sampling approach in ADVANTG is under

  11. Study the Possibility of measuring Heavy Metals Arising from Gold Mining Sample using 252Cf Neutron Source

    International Nuclear Information System (INIS)

    Soliman, N.F.

    2012-01-01

    Mining activities contribute immensely to trace element pollution .The present work studied the possibility of measuring heavy metals arising from gold mining areas Eastern Desert in Egypt using the isotopic 252 Cf neutron source. 38.5 g of the sample is irradiated in a neutron field of 252 Cf for 36.75 days and 0.3 mg of the sample is irradiated at the Pneumatic Irradiation Rabbit System (PIRS) built in the vertical thermal column of the ET-RR-2 reactor . The induced activities in the samples are measured using two high resolution f ray spectrometry systems (including two calibrated HPGe detectors). The kο standardization neutron activation analysis (kο-NAA) method was used to analyze the sample under investigation. Thermal to epithermal flux ratio fat the two irradiation positions are measured. The obtained results indicated that the values of the suspected heavy metals such as sodium, magnesium, potassium, manganese, arsenic, ruthenium and tantalum were higher than the background values, signifying accumulation of these heavy metals due to gold mining activities .The accuracy and precision of the method has been evaluated

  12. Sources of variability among replicate samples separated by two-dimensional gel electrophoresis.

    Science.gov (United States)

    Bland, Alison M; Janech, Michael G; Almeida, Jonas S; Arthur, John M

    2010-04-01

    Two-dimensional gel electrophoresis (2DE) offers high-resolution separation for intact proteins. However, variability in the appearance of spots can limit the ability to identify true differences between conditions. Variability can occur at a number of levels. Individual samples can differ because of biological variability. Technical variability can occur during protein extraction, processing, or storage. Another potential source of variability occurs during analysis of the gels and is not a result of any of the causes of variability named above. We performed a study designed to focus only on the variability caused by analysis. We separated three aliquots of rat left ventricle and analyzed differences in protein abundance on the replicate 2D gels. As the samples loaded on each gel were identical, differences in protein abundance are caused by variability in separation or interpretation of the gels. Protein spots were compared across gels by quantile values to determine differences. Fourteen percent of spots had a maximum difference in intensity of 0.4 quantile values or more between replicates. We then looked individually at the spots to determine the cause of differences between the measured intensities. Reasons for differences were: failure to identify a spot (59%), differences in spot boundaries (13%), difference in the peak height (6%), and a combination of these factors (21). This study demonstrates that spot identification and characterization make major contributions to variability seen with 2DE. Methods to highlight why measured protein spot abundance is different could reduce these errors.

  13. IAEA sends out samples of uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-06-15

    last being useful for checking methods of analysing trace elements in uranium. Meanwhile, requests are increasing for the other samples being supplied from the Seibersdorf laboratories. During 1965, twenty different calibrated radionuclides were provided, more than 1500 samples being sent out. Other radionuclides being added to the range are carbon-14, calcium-45, calcium-47, cobalt-58, silver-llOm, europium-152, iridium-192 and radium-228. Some solid calibrated gamma-emitting sources will be provided for calibrating dosimeters; these will have activities in the millicurie range. In addition, solid beta-emitting sources will be developed. Another service, designed to help health and safety monitoring, is the provision of environmental and biological materials which have been 'spiked' with known amounts of radionuclides. These and other services which the laboratories are providing for Member States are being developed by gradual stages. The programme is essentially flexible, and is intended to be adapted to the demonstrated requirements of Member States for work which of its nature is best carried out on an international basis. (author)

  14. Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream

    Science.gov (United States)

    Byrne, Patrick; Runkel, Robert L.; Walton-Day, Katie

    2017-01-01

    Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion Creek, Colorado, USA) under low flow conditions to (i) quantify the impacts of mining activity on stream water quality; (ii) quantify the spatial pattern of constituent loading; and (iii) identify inflow sources most responsible for observed changes in stream chemistry and constituent loading. Several of the constituents investigated (Al, Cd, Cu, Fe, Mn, Zn) fail to meet chronic aquatic life standards along most of the study reach. The spatial pattern of constituent loading suggests four primary sources of contamination under low flow conditions. Three of these sources are associated with acidic (pH metal and major ion) chemistry using PCA suggests a hydraulic connection between many of the left bank inflows and mine water in the Minnesota Mine shaft located to the north-east of the river channel. In addition, water chemistry data during a rainfall-runoff event suggests the spatial pattern of constituent loading may be modified during rainfall due to dissolution of efflorescent salts or erosion of streamside tailings. These data point to the complexity of contaminant mobilisation processes and constituent loading in mining-affected watersheds but the combined synoptic sampling and PCA approach enables a conceptual model of contaminant dynamics to be developed to inform remediation.

  15. Factors affecting reservoir and stream-water quality in the Cambridge, Massachusetts, drinking-water source area and implications for source-water protection

    Science.gov (United States)

    Waldron, Marcus C.; Bent, Gardner C.

    2001-01-01

    This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the city of Cambridge, Massachusetts, Water Department, to assess reservoir and tributary-stream quality in the Cambridge drinking-water source area, and to use the information gained to help guide the design of a comprehensive water-quality monitoring program for the source area. Assessments of the quality and trophic state of the three primary storage reservoirs, Hobbs Brook Reservoir, Stony Brook Reservoir, and Fresh Pond, were conducted (September 1997-November 1998) to provide baseline information on the state of these resources and to determine the vulnerability of the reservoirs to increased loads of nutrients and other contaminants. The effects of land use, land cover, and other drainage-basin characteristics on sources, transport, and fate of fecal-indicator bacteria, highway deicing chemicals, nutrients, selected metals, and naturally occurring organic compounds in 11 subbasins that contribute water to the reservoirs also was investigated, and the data used to select sampling stations for incorporation into a water-quality monitoring network for the source area. All three reservoirs exhibited thermal and chemical stratification, despite artificial mixing by air hoses in Stony Brook Reservoir and Fresh Pond. The stratification produced anoxic or hypoxic conditions in the deepest parts of the reservoirs and these conditions resulted in the release of ammonia nitrogen orthophosphate phosphorus, and dissolved iron and manganese from the reservoir bed sediments. Concentrations of sodium and chloride in the reservoirs usually were higher than the amounts recommended by the U.S. Environmental Protection agency for drinking-water sources (20 milligrams per liter for sodium and 250 milligrams per liter for chloride). Maximum measured sodium concentrations were highest in Hobbs Brook Reservoir (113 milligrams per liter), intermediate in Stony Brook Reservoir (62

  16. Inferring source attribution from a multiyear multisource data set of Salmonella in Minnesota.

    Science.gov (United States)

    Ahlstrom, C; Muellner, P; Spencer, S E F; Hong, S; Saupe, A; Rovira, A; Hedberg, C; Perez, A; Muellner, U; Alvarez, J

    2017-12-01

    Salmonella enterica is a global health concern because of its widespread association with foodborne illness. Bayesian models have been developed to attribute the burden of human salmonellosis to specific sources with the ultimate objective of prioritizing intervention strategies. Important considerations of source attribution models include the evaluation of the quality of input data, assessment of whether attribution results logically reflect the data trends and identification of patterns within the data that might explain the detailed contribution of different sources to the disease burden. Here, more than 12,000 non-typhoidal Salmonella isolates from human, bovine, porcine, chicken and turkey sources that originated in Minnesota were analysed. A modified Bayesian source attribution model (available in a dedicated R package), accounting for non-sampled sources of infection, attributed 4,672 human cases to sources assessed here. Most (60%) cases were attributed to chicken, although there was a spike in cases attributed to a non-sampled source in the second half of the study period. Molecular epidemiological analysis methods were used to supplement risk modelling, and a visual attribution application was developed to facilitate data exploration and comprehension of the large multiyear data set assessed here. A large amount of within-source diversity and low similarity between sources was observed, and visual exploration of data provided clues into variations driving the attribution modelling results. Results from this pillared approach provided first attribution estimates for Salmonella in Minnesota and offer an understanding of current data gaps as well as key pathogen population features, such as serotype frequency, similarity and diversity across the sources. Results here will be used to inform policy and management strategies ultimately intended to prevent and control Salmonella infection in the state. © 2017 Blackwell Verlag GmbH.

  17. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  18. Occurrence and implications of methyl tert-butyl ether and gasoline hydrocarbons in ground water and source water in the United States and in drinking water in 12 Northeast and Mid-Atlantic States, 1993-2002

    Science.gov (United States)

    Moran, Michael J.; Zogorski, John S.; Squillace, Paul J.

    2004-01-01

    The occurrence and implications of methyl tert-butyl ether (MTBE) and gasoline hydrocarbons were examined in three surveys of water quality conducted by the U.S. Geological Survey?one national-scale survey of ground water, one national-scale survey of source water from ground water, and one regional-scale survey of drinking water from ground water. The overall detection frequency of MTBE in all three surveys was similar to the detection frequencies of some other volatile organic compounds (VOCs) that have much longer production and use histories in the United States. The detection frequency of MTBE was higher in drinking water and lower in source water and ground water. However, when the data for ground water and source water were limited to the same geographic extent as drinking-water data, the detection frequencies of MTBE were comparable to the detection frequency of MTBE in drinking water. In all three surveys, the detection frequency of any gasoline hydrocarbon was less than the detection frequency of MTBE. No concentration of MTBE in source water exceeded the lower limit of U.S. Environmental Protection Agency's Drinking-Water Advisory of 20 ?g/L (micrograms per liter). One concentration of MTBE in ground water exceeded 20 ?g/L, and 0.9 percent of drinking-water samples exceeded 20 ?g/L. The overall detection frequency of MTBE relative to other widely used VOCs indicates that MTBE is an important concern with respect to ground-water management. The probability of detecting MTBE was strongly associated with population density, use of MTBE in gasoline, and recharge, and weakly associated with density of leaking underground storage tanks, soil permeability, and aquifer consolidation. Only concentrations of MTBE above 0.5 ?g/L were associated with dissolved oxygen. Ground water underlying areas with high population density, ground water underlying areas where MTBE is used as a gasoline oxygenate, and ground water underlying areas with high recharge has a greater

  19. Open-Source Sequence Clustering Methods Improve the State Of the Art.

    Science.gov (United States)

    Kopylova, Evguenia; Navas-Molina, Jose A; Mercier, Céline; Xu, Zhenjiang Zech; Mahé, Frédéric; He, Yan; Zhou, Hong-Wei; Rognes, Torbjørn; Caporaso, J Gregory; Knight, Rob

    2016-01-01

    Sequence clustering is a common early step in amplicon-based microbial community analysis, when raw sequencing reads are clustered into operational taxonomic units (OTUs) to reduce the run time of subsequent analysis steps. Here, we evaluated the performance of recently released state-of-the-art open-source clustering software products, namely, OTUCLUST, Swarm, SUMACLUST, and SortMeRNA, against current principal options (UCLUST and USEARCH) in QIIME, hierarchical clustering methods in mothur, and USEARCH's most recent clustering algorithm, UPARSE. All the latest open-source tools showed promising results, reporting up to 60% fewer spurious OTUs than UCLUST, indicating that the underlying clustering algorithm can vastly reduce the number of these derived OTUs. Furthermore, we observed that stringent quality filtering, such as is done in UPARSE, can cause a significant underestimation of species abundance and diversity, leading to incorrect biological results. Swarm, SUMACLUST, and SortMeRNA have been included in the QIIME 1.9.0 release. IMPORTANCE Massive collections of next-generation sequencing data call for fast, accurate, and easily accessible bioinformatics algorithms to perform sequence clustering. A comprehensive benchmark is presented, including open-source tools and the popular USEARCH suite. Simulated, mock, and environmental communities were used to analyze sensitivity, selectivity, species diversity (alpha and beta), and taxonomic composition. The results demonstrate that recent clustering algorithms can significantly improve accuracy and preserve estimated diversity without the application of aggressive filtering. Moreover, these tools are all open source, apply multiple levels of multithreading, and scale to the demands of modern next-generation sequencing data, which is essential for the analysis of massive multidisciplinary studies such as the Earth Microbiome Project (EMP) (J. A. Gilbert, J. K. Jansson, and R. Knight, BMC Biol 12:69, 2014, http

  20. 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.

  1. Application of leftover sample material from waterborne protozoa monitoring for the molecular detection of Bacteroidales and fecal source tracking markers

    Science.gov (United States)

    In this study, we examined the potential for detecting fecal bacteria and microbial source tracking markers in samples discarded during the concentration of Cryptosporidium and Giardia using USEPA Method 1623. Recovery rates for different fecal bacteria were determined using sp...

  2. Hierarchical sampling of multiple strata: an innovative technique in exposure characterization

    International Nuclear Information System (INIS)

    Ericson, J.E.; Gonzalez, Elisabeth J.

    2003-01-01

    Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 μg/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P 2 =0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P 2 =0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be useful in

  3. Design and development of a highly sensitive, field portable plasma source instrument for on-line liquid stream monitoring and real-time sample analysis

    International Nuclear Information System (INIS)

    Duan, Yixiang; Su, Yongxuan; Jin, Zhe; Abeln, Stephen P.

    2000-01-01

    The development of a highly sensitive, field portable, low-powered instrument for on-site, real-time liquid waste stream monitoring is described in this article. A series of factors such as system sensitivity and portability, plasma source, sample introduction, desolvation system, power supply, and the instrument configuration, were carefully considered in the design of the portable instrument. A newly designed, miniature, modified microwave plasma source was selected as the emission source for spectroscopy measurement, and an integrated small spectrometer with a charge-coupled device detector was installed for signal processing and detection. An innovative beam collection system with optical fibers was designed and used for emission signal collection. Microwave plasma can be sustained with various gases at relatively low power, and it possesses high detection capabilities for both metal and nonmetal pollutants, making it desirable to use for on-site, real-time, liquid waste stream monitoring. An effective in situ sampling system was coupled with a high efficiency desolvation device for direct-sampling liquid samples into the plasma. A portable computer control system is used for data processing. The new, integrated instrument can be easily used for on-site, real-time monitoring in the field. The system possesses a series of advantages, including high sensitivity for metal and nonmetal elements; in situ sampling; compact structure; low cost; and ease of operation and handling. These advantages will significantly overcome the limitations of previous monitoring techniques and make great contributions to environmental restoration and monitoring. (c)

  4. A New Attribute Control Chart using Multiple Dependent State Repetitive Sampling

    KAUST Repository

    Aldosari, Mansour Sattam; Aslam, Muhammad; Jun, Chi-Hyuck

    2017-01-01

    In this manuscript, a new attribute control chart using multiple dependent state repetitive sampling is designed. The operational procedure and structure of the proposed control chart is given. The required measures to determine the average run length (ARL) for in-control and out-of-control processes are given. Tables of ARLs are reported for various control chart parameters. The proposed control chart is more sensitive in detecting a small shift in the process as compared to the existing attribute control charts. The simulation study shows the efficiency of the proposed chart over the existing charts. An example is given for the illustration purpose.

  5. A New Attribute Control Chart using Multiple Dependent State Repetitive Sampling

    KAUST Repository

    Aldosari, Mansour Sattam

    2017-03-25

    In this manuscript, a new attribute control chart using multiple dependent state repetitive sampling is designed. The operational procedure and structure of the proposed control chart is given. The required measures to determine the average run length (ARL) for in-control and out-of-control processes are given. Tables of ARLs are reported for various control chart parameters. The proposed control chart is more sensitive in detecting a small shift in the process as compared to the existing attribute control charts. The simulation study shows the efficiency of the proposed chart over the existing charts. An example is given for the illustration purpose.

  6. Effect of state feedback coupling on the transient performance of voltage source inverters with LC filter

    DEFF Research Database (Denmark)

    Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz

    2016-01-01

    State feedback coupling between the capacitor voltage and inductor current deteriorates notably the performance during transients of voltage and current regulators in stand-alone systems based on voltage source inverters. A decoupling technique is proposed, considering the limitations introduced...

  7. MMPI-2 Characteristics of the Old Order Amish: A Comparison of Clinical, Nonclinical, and United States Normative Samples

    Science.gov (United States)

    Knabb, Joshua J.; Vogt, Ronald G.; Newgren, Kevin P.

    2011-01-01

    In the current study, we investigated Minnesota Multiphasic Personality Inventory-2 (MMPI-2) characteristics in an Old Order Amish nonclinical sample (N = 84), comparing these data with both the United States normative sample (N = 2,600) and a sample of Old Order Amish outpatients (N = 136). Consistent with our hypothesis, the Old Order Amish…

  8. ADHD knowledge, perceptions, and information sources: perspectives from a community sample of adolescents and their parents.

    Science.gov (United States)

    Bussing, Regina; Zima, Bonnie T; Mason, Dana M; Meyer, Johanna M; White, Kimberly; Garvan, Cynthia W

    2012-12-01

    The chronic illness model advocates for psychoeducation within a collaborative care model to enhance outcomes. To inform psychoeducational approaches for ADHD, this study describes parent and adolescent knowledge, perceptions, and information sources and explores how these vary by sociodemographic characteristics, ADHD risk, and past child mental health service use. Parents and adolescents were assessed 7.7 years after initial school district screening for ADHD risk. The study sample included 374 adolescents (56% high and 44% low ADHD risk) aged, on average, 15.4 (standard deviation = 1.8) years, and 36% were African American. Survey questions assessed ADHD knowledge, perceptions, and cues to action and elicited used and preferred information sources. Multiple logistic regression was used to determine potential independent predictors of ADHD knowledge. McNemar tests compared information source utilization against preference. Despite relatively high self-rated ADHD familiarity, misperceptions among parents and adolescents were common, including a sugar etiology (25% and 27%, respectively) and medication overuse (85% and 67%, respectively). African American respondents expressed less ADHD awareness and greater belief in sugar etiology than Caucasians. Parents used a wide range of ADHD information sources, whereas adolescents relied on social network members and teachers/school. However, parents and adolescents expressed similar strong preferences for the Internet (49% and 51%, respectively) and doctor (40% and 27%, respectively) as ADHD information sources. Culturally appropriate psychoeducational strategies are needed that combine doctor-provided ADHD information with reputable Internet sources. Despite time limitations during patient visits, both parents and teens place high priority on receiving information from their doctor. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  9. An ultracold neutron source at the NC State University PULSTAR reactor

    Science.gov (United States)

    Korobkina, E.; Wehring, B. W.; Hawari, A. I.; Young, A. R.; Huffman, P. R.; Golub, R.; Xu, Y.; Palmquist, G.

    2007-08-01

    Research and development is being completed for an ultracold neutron (UCN) source to be installed at the PULSTAR reactor on the campus of North Carolina State University (NCSU). The objective is to establish a university-based UCN facility with sufficient UCN intensity to allow world-class fundamental and applied research with UCN. To maximize the UCN yield, a solid ortho-D 2 converter will be implemented coupled to two moderators, D 2O at room temperature, to thermalize reactor neutrons, and solid CH 4, to moderate the thermal neutrons to cold-neutron energies. The source assembly will be located in a tank of D 2O in the space previously occupied by the thermal column of the PULSTAR reactor. Neutrons leaving a bare face of the reactor core enter the D 2O tank through a 45×45 cm cross-sectional area void between the reactor core and the D 2O tank. Liquid He will cool the disk-shaped UCN converter to below 5 K. Independently, He gas will cool the cup-shaped CH 4 cold-neutron moderator to an optimum temperature between 20 and 40 K. The UCN will be transported from the converter to experiments by a guide with an inside diameter of 16 cm. Research areas being considered for the PULSTAR UCN source include time-reversal violation in neutron beta decay, neutron lifetime determination, support measurements for a neutron electric-dipole-moment search, and nanoscience applications.

  10. Natural radioactivity of beach sand samples in Port Sudan, red sea state

    International Nuclear Information System (INIS)

    Kambal, Wala Haider Hussein

    2015-01-01

    Natural radioactivity is a source of continuous exposure to human beings. In Port Sudan city, the main port of Sudan, data on the levels of natural radioactivity in soil is required. The aim of this study was to measure the activity concentration as well as the absorbed dose and annual effective dose of the naturally occurring radionuclides 238 U, 232 Th, and 40 K in soil samples collected from different locations around Red Sea costa areas in Port Sudan city. Activity concentrations were measured using gamma ray spectrometry (Nal) detector. Results showed that the average activity concentration of 238 U, 232 Th and 40 K were found to be 21.86, 17.55, 85.50 Bqkg 1 , respectively, with an average absorbed dose of 10.42, 9.40 and 3.57 nGyh 1 , respectively. The average annual effective dose values were found to be 11.89, 11.54 and 4.37 μSvy 1 for 238 U, 232 Th and 40 K, respectively. The measured values were comparable with other global radioactivity measurements and found to be safe for public and environment.(Author)

  11. Renewable energy, coal as a baseload power source, and greenhouse gas emissions: Evidence from U.S. state-level data

    International Nuclear Information System (INIS)

    Squalli, Jay

    2017-01-01

    This paper examines the relationship between renewable energy production and greenhouse gas emissions (GHG) using U.S. state-level data for 2010. After controlling for other sources of emissions, U.S. states that produce a larger share of renewable energy are found to have lower GHG emissions. It is estimated that a 10% increase in the share of renewable energy could decrease CH_4 emissions by about 0.26%. Since the use of renewable energy sources does not release GHG emissions, this effect can be interpreted as stabilizing if renewable energy is added to coal use or as corrective if it replaces coal. After accounting for the role of coal as a baseload power source, an increase in the share of renewable energy is estimated to mitigate N_2O emissions at the U.S. state level only if states individually decrease their share of coal use to levels below 41.47%. These findings have significant policy implications for the provision of guidance to policymakers in identifying optimal energy mixes and in pursuing realistic goals to enhance renewable energy penetration and to contribute to the current efforts of tackling climate change. - Highlights: • The paper examines the link between renewable energy, coal, and GHG emissions. • The analysis accounts for the role of coal as a baseload power source. • A 10% increase in renewable energy share decreases CH_4 emissions by about 0.26%. • Renewable energy can mitigate emissions if the share of coal drops below 41.47%.

  12. Study of Coal Burst Source Locations in the Velenje Colliery

    Directory of Open Access Journals (Sweden)

    Goran Vižintin

    2016-06-01

    Full Text Available The Velenje coal mine (VCM is situated on the largest Slovenian coal deposit and in one of the thickest layers of coal known in the world. The thickness of the coal layer causes problems for the efficiency of extraction, since the majority of mining operations is within the coal layer. The selected longwall coal mining method with specific geometry, increasing depth of excavations, changes in stress state and naturally given geomechanical properties of rocks induce seismic events. Induced seismic events can be caused by caving processes, blasting or bursts of coal or the surrounding rock. For 2.5D visualization, data of excavations, ash content and calorific value of coal samples, hanging wall and footwall occurrence, subsidence of the surface and coal burst source locations were collected. Data and interpolation methods available in software package Surfer®12 were statistically analyzed and a Kriging (KRG interpolation method was chosen. As a result 2.5D visualizations of coal bursts source locations with geomechanical properties of coal samples taken at different depth in the coal seam in the VCM were made with data-visualization packages Surfer®12 and Voxler®3.

  13. Micro-sampling method based on high-resolution continuum source graphite furnace atomic absorption spectrometry for calcium determination in blood and mitochondrial suspensions.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Mª Jesús; Sevilla, Mª Teresa; Satrústegui, Jorgina; Procopio, Jesús R

    2017-08-01

    A micro-sampling and straightforward method based on high resolution continuum source atomic absorption spectrometry (HR-CS AAS) was developed to determine extracellular and intracellular Ca in samples of interest in clinical and biomedical analysis. Solid sampling platforms were used to introduce the micro-samples into the graphite furnace atomizer. The secondary absorption line for Ca, located at 239.856nm, was selected to carry out the measurements. Experimental parameters such as pyrolysis and atomization temperatures and the amount of sample introduced for the measurements were optimized. Calibration was performed using aqueous standards and the approach to measure at the wings of the absorption lines was employed for the expansion of the linear response range. The limit of detection was of 0.02mgL -1 Ca (0.39ng Ca) and the upper limit of linear range was increased up to 8.0mgL -1 Ca (160ng Ca). The proposed method was used to determine Ca in mitochondrial suspensions and whole blood samples with successful results. Adequate recoveries (within 91-107%) were obtained in the tests performed for validation purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Determination of phospholipids in soybean lecithin samples via the phosphorus monoxide molecule by high-resolution continuum source graphite furnace molecular absorption spectrometry.

    Science.gov (United States)

    Pires, Laís N; Brandão, Geovani C; Teixeira, Leonardo S G

    2017-06-15

    This paper presents a method for determining phospholipids in soybean lecithin samples by phosphorus determination using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) via molecular absorption of phosphorus monoxide. Samples were diluted in methyl isobutyl ketone. The best conditions were found to be 213.561nm with a pyrolysis temperature of 1300°C, a volatilization temperature of 2300°C and Mg as a chemical modifier. To increase the analytical sensitivity, measurement of the absorbance signal was obtained by summing molecular transition lines for PO surrounding 213nm: 213.561, 213.526, 213.617 and 213.637nm. The limit of detection was 2.35mgg -1 and the precision, evaluated as relative standard deviation (RSD), was 2.47% (n=10) for a sample containing 2.2% (w/v) phosphorus. The developed method was applied for the analysis of commercial samples of soybean lecithin. The determined concentrations of phospholipids in the samples varied between 38.1 and 45% (w/v). Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Analysis of source spectra, attenuation, and site effects from central and eastern United States earthquakes

    International Nuclear Information System (INIS)

    Lindley, G.

    1998-02-01

    This report describes the results from three studies of source spectra, attenuation, and site effects of central and eastern United States earthquakes. In the first study source parameter estimates taken from 27 previous studies were combined to test the assumption that the earthquake stress drop is roughly a constant, independent of earthquake size. 200 estimates of stress drop and seismic moment from eastern North American earthquakes were combined. It was found that the estimated stress drop from the 27 studies increases approximately as the square-root of the seismic moment, from about 3 bars at 10 20 dyne-cm to 690 bars at 10 25 dyne-cm. These results do not support the assumption of a constant stress drop when estimating ground motion parameters from eastern North American earthquakes. In the second study, broadband seismograms recorded by the United States National Seismograph Network and cooperating stations have been analysed to determine Q Lg as a function of frequency in five regions: the northeastern US, southeastern US, central US, northern Basin and Range, and California and western Nevada. In the third study, using spectral analysis, estimates have been made for the anelastic attenuation of four regional phases, and estimates have been made for the source parameters of 27 earthquakes, including the M b 5.6, 14 April, 1995, West Texas earthquake

  16. Source term determination from subcritical multiplication measurements at Koral-1 reactor

    International Nuclear Information System (INIS)

    Blazquez, J.B.; Barrado, J.M.

    1978-01-01

    By using an AmBe neutron source two independent procedures have been settled for the zero-power experimental fast-reactor Coral-1 in order to measure the source term which appears in the point kinetical equations. In the first one, the source term is measured when the reactor is just critical with source by taking advantage of the wide range of the linear approach to critical for Coral-1. In the second one, the measurement is made in subcritical state by making use of the previous calibrated control rods. Several applications are also included such as the measurement of the detector dead time, the determinations of the reactivity of small samples and the shape of the neutron importance of the source. (author)

  17. Sources of HO x and production of ozone in the upper troposphere over the United States

    OpenAIRE

    Jaeglé, L.; Jacob, Daniel James; Brune, W. H.; Tan, D.; Faloona, I. C.; Weinheimer, A. J.; Ridley, B. A.; Campos, T. L.; Sachse, G. W.

    1998-01-01

    The sources of HOx (OH+peroxy radicals) and the associated production of ozone at 8–12 km over the United States are examined by modeling observations of OH, HO2, NO, and other species during the SUCCESS aircraft campaign in April–May 1996. The HOx concentrations measured in SUCCESS are up to a factor of 3 higher than can be calculated from oxidation of water vapor and photolysis of acetone. The highest discrepancy was seen in the outflow of a convective storm. We show that convective injecti...

  18. X-ray fluorescence analysis of low concentrations metals in geological samples and technological products

    Science.gov (United States)

    Lagoida, I. A.; Trushin, A. V.

    2016-02-01

    For the past several years many nuclear physics methods of quantitative elemental analysis have been designed. Many of these methods have applied in different devices which have become useful and effective instrument in many industrial laboratories. Methods of a matter structure analysis are based on the intensity detection of the X-ray radiation from the nuclei of elements which are excited by external X-ray source. The production of characteristic X-rays involves transitions of the orbital electrons of atoms in the target material between allowed orbits, or energy states, associated with ionization of the inner atomic shells. One of these methods is X-ray fluorescence analysis, which is widespread in metallurgical and processing industries and is used to identify and measure the concentration of the elements in ores and minerals on a conveyor belt. Samples of copper ore with known concentrations of elements, were taken from the Ural deposit. To excite the characteristic X-rays radionuclide sources 109Cd, with half-life 461.4 days were used. After finding the calibration coefficients, control measurements of samples and averaging of overall samples were made. The measurement error did not exceed 3%.

  19. Source characterization of major emission sources in the Imperial and Mexicali Valleys along the US/Mexico border

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.G.; Chow, J.C. [Desert Research Institute, 2215 Raggio Pkwy., 89512 Reno, NV (United States)

    2001-08-10

    Chemical profiles for particle emissions are needed for source apportionment studies using the chemical mass balance (CMB) receptor model. Source measurements of geological sources, motor vehicle exhaust, vegetative burning (e.g. asparagus, field burning, charbroil cooking), and industrial sources (e.g. oil-fueled glass plant, manure-fueled power plants) were acquired as part of the Imperial/Mexicali Valley Cross Border PM{sub 10} Transport Study in 1992. Six different source sampling techniques (i.e. hot- and diluted-exhaust sampling, ground-based source sampling, particle sweeping/grab sampling, vacuum sampling, and laboratory resuspension sampling) were applied to acquire filter samples of PM{sub 2.5} and PM{sub 10} (particulate matter with aerodynamic diameters <2.5 and 10 {mu}m, respectively). Filter samples were analyzed for mass by gravimetry, elements (Na to U) by X-ray fluorescence, anions (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup =}) by ion chromatography, ammonium (NH{sub 4}{sup +}) by automated colorimetry, soluble sodium (Na{sup +}) and potassium (K{sup +}) by atomic absorption spectrophotometry, and organic and elemental carbon (OC, EC) by thermal/optical reflectance. Concentration data were acquired for a total of 50 chemical species. Elevated abundances of crustal components (Al, Si, K, Ca, Fe) from geological material, carbon (OC, EC) and trace elements (Br, Pb) from vehicle exhausts, carbon (OC, EC) and ions (K{sup +}, Cl{sup -}) from vegetative burning, ions (SO{sub 4}{sup =}, NH{sub 4}{sup +}, Na{sup +}, K{sup +}, Cl{sup -}) and elements (Cl, Se) from a manure-fueled power plants, and sulfur and trace elements (Na{sup +}, Pb, Se, Ni, V) from an oil-fueled glass plant were found in the resulting source profiles. Abundances of crustal species (e.g. Al, Si, Ca) in the Imperial/Mexicali Valley geological profiles are more than twice those found in central and southern California. Abundances of lead in motor vehicle exhausts indicate different

  20. Virtual sampling in variational processing of Monte Carlo simulation in a deep neutron penetration problem

    International Nuclear Information System (INIS)

    Allagi, Mabruk O.; Lewins, Jeffery D.

    1999-01-01

    In a further study of virtually processed Monte Carlo estimates in neutron transport, a shielding problem has been studied. The use of virtual sampling to estimate the importance function at a certain point in the phase space depends on the presence of neutrons from the real source at that point. But in deep penetration problems, not many neutrons will reach regions far away from the source. In order to overcome this problem, two suggestions are considered: (1) virtual sampling is used as far as the real neutrons can reach, then fictitious sampling is introduced for the remaining regions, distributed in all the regions, or (2) only one fictitious source is placed where the real neutrons almost terminate and then virtual sampling is used in the same way as for the real source. Variational processing is again found to improve the Monte Carlo estimates, being best when using one fictitious source in the far regions with virtual sampling (option 2). When fictitious sources are used to estimate the importances in regions far away from the source, some optimization has to be performed for the proportion of fictitious to real sources, weighted against accuracy and computational costs. It has been found in this study that the optimum number of cells to be treated by fictitious sampling is problem dependent, but as a rule of thumb, fictitious sampling should be employed in regions where the number of neutrons from the real source fall below a specified limit for good statistics

  1. Study on atmospheric aerosol in Khartoum and River Nile States, Sudan

    International Nuclear Information System (INIS)

    Elhag, A. S; Sirelkatim, D.A.; Osman, O. I.

    2006-12-01

    In the present study, air samples have been collected from different areas in Khartoum and River Nile States. Sample collection was performed over different periods of time (1-2 hours). The average elemental concentrations for Ca, Cr, Fe, Co, Ni, Br and Pb have been determined using energy dispersive x-ray fluorescence (EDXRF). The accuracy of measurements has been investigated by using Standard Reference Material (SRM) IAEA- Soil-7. In Khartoum State, the average elemental concentrations of Ca, Cr, Fe, Co, Ni, Br and Pb in the expected contaminated sites were 83.27, 0.001, 36.12, 14.051, 0.1, 7.057 and 11.122 μg/m 3 , respectively. In River Nile State proposed contaminated sites the average elemental concentrations of Ca, Cr, Fe, Co, Ni, Br and Pb were 19.387, 3 , respectively. The results showed that higher values were found for the crustal elements (Ca, Fe) while lower values were found for the elements emitted from other sources. Enrichment factors were calculated for the elements which showed that the elements Ca, Cr and Ni were not enriched, while Pb and Co were enriched possibly through anthropogenic emission. A ratio of Br/Pb in aerosol similar to the ratio in the petrol burned is indicative of a source of both lead and bromine.(Author)

  2. Ion sources in AMS

    International Nuclear Information System (INIS)

    Iyer, Indira S.

    1997-01-01

    Accelerator Mass Spectrometry (AMS) entails the sputtering of various samples in an ion source followed by high precision mass analysis of the sputtered ion species in a Tandem Electrostatic Accelerator. A brief account is given

  3. Spectral state transitions of the Ultraluminous X-ray Source IC 342 X-1

    Science.gov (United States)

    Marlowe, H.; Kaaret, P.; Lang, C.; Feng, H.; Grisé, F.; Miller, N.; Cseh, D.; Corbel, S.; Mushotzky, R. F.

    2014-10-01

    We observed the Ultraluminous X-ray Source (ULX) IC 342 X-1 simultaneously in X-ray and radio with Chandra and the JVLA to investigate previously reported unresolved radio emission coincident with the ULX. The Chandra data reveal a spectrum that is much softer than observed previously and is well modelled by a thermal accretion disc spectrum. No significant radio emission above the rms noise level was observed within the region of the ULX, consistent with the interpretation as a thermal state though other states cannot be entirely ruled out with the current data. We estimate the mass of the black hole using the modelled inner disc temperature to be 30 M_{⊙} ≲ M√{cosi}≲ 200 M_{⊙} based on a Shakura-Sunyaev disc model. Through a study of the hardness and high-energy curvature of available X-ray observations, we find that the accretion state of X-1 is not determined by luminosity alone.

  4. Shallow Aquifer Methane Gas Source Assessment

    Science.gov (United States)

    Coffin, R. B.; Murgulet, D.; Rose, P. S.; Hay, R.

    2014-12-01

    Shale gas can contribute significantly to the world's energy demand. Hydraulic fracturing (fracking) on horizontal drill lines developed over the last 15 years makes formerly inaccessible hydrocarbons economically available. From 2000 to 2035 shale gas is predicted to rise from 1% to 46% of the total natural gas for the US. A vast energy resource is available in the United States. While there is a strong financial advantage to the application of fracking there is emerging concern about environmental impacts to groundwater and air quality from improper shale fracking operations. Elevated methane (CH4) concentrations have been observed in drinking water throughout the United States where there is active horizontal drilling. Horizontal drilling and hydraulic-fracturing can increase CH4 transport to aquifers, soil and the vadose zone. Seepage can also result from casing failure in older wells. However, there is strong evidence that elevated CH4 concentrations can be associated with topographic and hydrogeologic features, rather than shale-gas extraction processes. Carbon isotope geochemistry can be applied to study CH4source(s) in shallow vadose zone and groundwater systems. A preliminary TAMU-CC isotope data set from samples taken at different locations in southern Texas shows a wide range of CH4 signatures suggesting multiple sources of methane and carbon dioxide. These data are interpreted to distinguish regions with methane contributions from deep-sourced horizontal drilling versus shallow system microbial production. Development of a thorough environmental assessment using light isotope analysis can provide understanding of shallow anthropogenic versus natural CH4sources and assist in identifying regions that require remedial actions.

  5. Methodology for Quantitative Analysis of Large Liquid Samples with Prompt Gamma Neutron Activation Analysis using Am-Be Source

    International Nuclear Information System (INIS)

    Idiri, Z.; Mazrou, H.; Beddek, S.; Amokrane, A.

    2009-01-01

    An optimized set-up for prompt gamma neutron activation analysis (PGNAA) with Am-Be source is described and used for large liquid samples analysis. A methodology for quantitative analysis is proposed: it consists on normalizing the prompt gamma count rates with thermal neutron flux measurements carried out with He-3 detector and gamma attenuation factors calculated using MCNP-5. The relative and absolute methods are considered. This methodology is then applied to the determination of cadmium in industrial phosphoric acid. The same sample is then analyzed by inductively coupled plasma (ICP) method. Our results are in good agreement with those obtained with ICP method.

  6. Techniques for enhancing the performance of high charge state ECR ion sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.

    1999-01-01

    Electron Cyclotron Resonance ion source (ECRIS), which produces singly to highly charged ions, is widely used in heavy ion accelerators and is finding applications in industry. It has progressed significantly in recent years thanks to a few techniques, such as multiple-frequency plasma heating, higher mirror magnetic fields and a better cold electron donor. These techniques greatly enhance the production of highly charged ions. More than 1 emA of He 2+ and O 6+ , hundreds of eμA of O 7+ , Ne 8+ , Ar 12+ , more than 100 eμA of intermediate heavy ions with charge states up to Ne 9+ , Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , tens of eμA of heavy ions with charge states up to Xe 28+ , Au 35+ , Bi 34+ and U 34+ were produced at cw mode operation. At an intensity of about 1 eμA, the charge states for the heavy ions increased up to Xe 36+ , Au 46+ , Bi 47+ and U 48+ . More than an order of magnitude enhancement of fully stripped argon ions was achieved (I≥0.1 and h;eμA). Higher charge state ions up to Kr 35+ , Xe 46+ and U 64+ at low intensities were produced for the first time from an ECRIS. copyright 1999 American Institute of Physics

  7. Recommended operating procedure number 56: Collection of gaseous grab samples from combustion sources for nitrous oxide measurement. Final report, Jan-Dec 91

    International Nuclear Information System (INIS)

    Ryan, J.V.; Karns, S.A.

    1992-07-01

    The document is a recommended operating procedure (ROP), prepared for use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). The procedure applies to the collection of gaseous grab samples from fossil fuel combustion sources for subsequent analysis of nitrous oxide. The procedure details only the grab sampling methodology and associated equipment

  8. Opportunities of Gallium Sage experiment with artificial neutrino sources for investigation of neutrino to sterile states

    International Nuclear Information System (INIS)

    Gavrin, V.N.; Gorbachiev, V.V.; Veretenkin, E.P.

    2011-01-01

    The unexpectedly low capture rate of neutrino in Ga source experiments in SAGE and GALLEX can be explained assuming electron neutrino transitions to sterile states with a mass-squared difference ∼ 1eV 2 . To test this oscillation hypothesis, we propose to place a very intense 51 Cr source at the center of a 50 tonne target of gallium metal that is divided into two zones and to measure the neutrino capture rate in each zone. The Experiment has the potential to test neutrino oscillation transitions with mass-squared difference Δm 2 > 0.5 eV 2 . An optimized SAGE setup and 3 MCi source of 51 Cr would provide a sensitivity to electron neutrino disappearance of a few percent.

  9. A comparison of data sources for the surveillance of work-related carpal tunnel syndrome in Massachusetts.

    Science.gov (United States)

    Davis, Letitia; Wellman, Helen; Hart, James; Cleary, Robert; Gardstein, Betsey M; Sciuchetti, Paul

    2004-09-01

    This study examined whether a state surveillance system for work-related carpal tunnel syndrome (WR-CTS) based on workers' compensation claims (Sentinel Event Notification System for Occupational Risks, SENSOR) and the Annual Survey of Occupational Injuries and Illnesses (SOII) identified the same industries, occupations, sources of injury, and populations for intervention. Trends in counts, rates, and female/male ratios of WR-CTS during 1994-1997, and age distributions were compared across three data sources: SENSOR, Massachusetts SOII, and National SOII. SENSOR and National SOII data on WR-CTS were compared by industry, occupation, and injury source. Due to small sample size and subsequent gaps in available information, state SOII data on WR-CTS were of little use in identifying specific industries and occupations for intervention. SENSOR and National SOII data on the frequency of WR-CTS cases identified many similar occupations and industries, and both surveillance systems pointed to computer use as a risk factor for WR-CTS. Some high rate industries identified by SENSOR were not identified using National SOII rates even when national findings were restricted to take into account the distribution of the Massachusetts workforce. Use of national SOII data on rates of WR-CTS for identifying state industry priorities for WR-CTS prevention should be undertaken with caution. Options for improving state SOII data and use of other state data systems should be pursued.

  10. Los Alamos Scientific Laboratory approach to hydrogeochemical and stream sediment reconnaissance for uranium in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Bolivar, S.L.

    1981-01-01

    The Los Alamos Scientific Laboratory of the United States is conducting a geochemical survey for uranium in the Rocky Mountain states of New Mexico, Colorado, Wyoming, and Montana and in Alaska. This survey is part of a national hydrogeochemical and stream sediment reconnaissance in which four Department of Energy laboratories will study the uranium resources of the United States to provide data for the National Uranium Resource Evaluation program. The reconnaissance will identify areas having higher than background concentrations of uranium in ground waters, surface waters, and water-transported sediments. Water and sediment samples are collected at a nominal density of one sample location per 10 km/sup 2/ except for lake areas of Alaska where the density is one sample location per 23 km/sup 2/. Water samples are analyzed for uranium by fluorometry which has a 0.02 parts per billion lower limit of detection. Concentrations of 12 additional elements in water are determined by plasma-source emission spectrography. All sediments are analyzed for uranium by delayed-neutron counting with a 20 parts per billion lower limit of detection, which is well below the range of uranium concentrations in natural sediment samples. Elemental concentrations in sediments are also determined by neutron activation analysis for 31 elements by x-ray fluorescence for 9 elements, and by arc-source emission spectrography for 2 elements. The multielement analyses provide valuable data for studies concerning pathfinder elements, environmental pollution, elemental distributions, dispersion halos, and economic ore deposits other than uranium. To date, all of four Rocky Mountain states and about 80% of Alaska have been sampled. About 220,000 samples have been collected from an area of nearly 2,500,000 km/sup 2/.

  11. Uncovering extreme AGN variability in serendipitous X-ray source surveys

    Science.gov (United States)

    Moran, Edward C.; Garcia Soto, Aylin; LaMassa, Stephanie; Urry, Meg

    2018-01-01

    Constraints on the duty cycle and duration of accretion episodes in active galactic nuclei (AGNs) are vital for establishing how most AGNs are fueled, which is essential for a complete picture of black hole/galaxy co-evolution. Perhaps the best handle we have on these activity parameters is provided by AGNs that have displayed dramatic changes in their bolometric luminosities and, in some cases, spectroscopic classifications. Given that X-ray emission is directly linked to black-hole accretion, X-ray surveys should provide a straightforward means of identifying AGNs that have undergone dramatic changes in their accretion states. However, it appears that such events are very rare, so wide-area surveys separated in time by many years are needed to maximize discovery rates. We have cross-correlated the Einstein IPC Two-Sigma Catalog with the ROSAT All-Sky Survey Faint Source Catalog to identify a sample of soft X-ray sources that varied by factors ranging from 7 to more than 100 over a ten year timescale. When possible, we have constructed long-term X-ray light curves for the sources by combining the Einstein and RASS fluxes with those obtained from serendipitous pointed observations by ROSAT, Chandra,XMM, and Swift. Optical follow-up observations indicate that many of the extremely variable sources in our sample are indeed radio-quiet AGNs. Interestingly, the majority of objects that dimmed between ~1980 and ~1990 are still (or are again) broad-line AGNs rather than“changing-look” candidates that have more subtle AGN signatures in their spectra — despite the fact that none of the sources examined thus far has returned to its highest observed luminosity. Future X-ray observations will provide the opportunity to characterize the X-ray behavior of these anonymous, extreme AGNs over a four decade span.

  12. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    International Nuclear Information System (INIS)

    Virgilio, Alex; Nóbrega, Joaquim A.; Rêgo, Jardes F.; Neto, José A. Gomes

    2012-01-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 °C and 2400 °C, respectively. Slopes of calibration curves (50–750 pg Cr, R 2 > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3–17.7 μg g −1 Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 ± 2.1 μg g −1 Cr. The limit of detection was 3.3 ng g −1 Cr. - Highlights: ► Direct solid sampling is first time employed for Cr in plant materials. ► Calibration curves with liquids and solids are coincident. ► Microanalysis of plants for Cr is validated by reference materials. ► The proposed HR-CS GF AAS method is environmental friendly.

  13. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Virgilio, Alex; Nobrega, Joaquim A. [Department of Chemistry, Federal University of Sao Carlos, Post Office Box 676, 13560-970, Sao Carlos-SP (Brazil); Rego, Jardes F. [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil); Neto, Jose A. Gomes, E-mail: anchieta@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil)

    2012-12-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 Degree-Sign C and 2400 Degree-Sign C, respectively. Slopes of calibration curves (50-750 pg Cr, R{sup 2} > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3-17.7 {mu}g g{sup -1} Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 {+-} 2.1 {mu}g g{sup -1} Cr. The limit of detection was 3.3 ng g{sup -1} Cr. - Highlights: Black-Right-Pointing-Pointer Direct solid sampling is first time employed for Cr in plant materials. Black-Right-Pointing-Pointer Calibration curves with liquids and solids are coincident. Black-Right-Pointing-Pointer Microanalysis of plants for Cr is validated by reference materials. Black-Right-Pointing-Pointer The proposed HR-CS GF AAS method is environmental friendly.

  14. Preparation of solid-state samples of a transition metal coordination compound for synchrotron radiation photoemission studies

    CERN Document Server

    Crotti, C; Celestino, T; Fontana, S

    2003-01-01

    The aim of this research was to identify a sample preparation method suitable for the study of transition metal complexes by photoemission spectroscopy with synchrotron radiation as the X-ray source, even in the case where the compound is not evaporable. Solid-phase samples of W(CO) sub 4 (dppe) [dppe=1,2-bis(diphenylphosphino)ethane] were prepared according to different methods and their synchrotron radiation XPS spectra measured. The spectra acquired from samples prepared by spin coating show core level peaks only slightly broader than the spectrum recorded from UHV evaporated samples. Moreover, for these samples the reproducibility of the binding energy values is excellent. The dependence of the spin coating technique on parameters such as solvent and solution concentration, spinning speed and support material was studied. The same preparation method also allowed the acquisition of valence band spectra, the main peaks of which were clearly resolved. The results suggest that use of the spin coating techniqu...

  15. Cosmology from angular size counts of extragalactic radio sources

    International Nuclear Information System (INIS)

    Kapahi, V.K.

    1975-01-01

    The cosmological implications of the observed angular sizes of extragalactic radio sources are investigated using (i) the log N-log theta relation, where N is the number of sources with an angular size greater than a value theta, for the complete sample of 3CR sources, and (ii) the thetasub(median) vs flux density (S) relation derived from the 3CR, the All-sky, and the Ooty occulation surveys, spanning a flux density range of about 300:1. The method of estimating the expected N(theta) and thetasub(m)(S) relations for a uniform distribution of sources in space is outlined. Since values of theta>approximately 100second arc in the 3C sample arise from sources of small z, the slope of the N(theta) relation in this range is practically independent of the world model and the distribution of source sizes, but depends strongly on the radio luminosity function (RLF). From the observed slope the RLF is derived in the luminosity range of about 10 23 178 26 W Hz -1 sr -1 to be of the form rho(P)dP proportional to Psup(-2.1)dP. It is shown that the angular size data provide independent evidence of evolution in source properties with epoch. It is difficult to explain the data with the simple steady-state theory even if identified QSOs are excluded from ths source samples and a local deficiency of strong source is postulated. The simplest evolutionary scheme that fits the data in the Einstein-de Sitter cosmology indicates that (a) the local RLF steepens considerably at high luminosities, (b) the comoving density of high luminosity sources increases with z in a manner similar to that implied by the log N-log S data and by the V/Vsub(m) test for QSOs, and (c) the mean physical sizes of radio sources evolve with z approximately as (1+z) -1 . Similar evolutionary effects appear to be present for QSOs as well as radio galaxies. (author)

  16. Acrolein and Asthma Attack Prevalence in a Representative Sample of the United States Adult Population 2000 – 2009

    Science.gov (United States)

    deCastro, B. Rey

    2014-01-01

    Background Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment) and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. Objectives Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. Methods NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old) in the NHIS (National Health Interview Survey) 2000 – 2009 (n = 271,348 subjects). A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. Results In the highest quintile of outdoor acrolein exposure (0.05 – 0.46 µg/m3), there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19]) relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29]) in a model limited to never smokers (n = 153,820). Conclusions Chronic exposure to outdoor acrolein of 0.05 – 0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population. PMID:24816802

  17. Sample positioning effects in x-ray spectrometry

    International Nuclear Information System (INIS)

    Carpenter, D.

    Instrument error due to variation in sample position in a crystal x-ray spectrometer can easily exceed the total instrumental error. Lack of reproducibility in sample position in the x-ray optics is the single largest source of system error. The factors that account for sample positioning error are described, and many of the details of flat crystal x-ray optics are discussed

  18. Present state of the SOURCES computer code

    International Nuclear Information System (INIS)

    Shores, Erik F.

    2002-01-01

    In various stages of development for over two decades, the SOURCES computer code continues to calculate neutron production rates and spectra from four types of problems: homogeneous media, two-region interfaces, three-region interfaces and that of a monoenergetic alpha particle beam incident on a slab of target material. Graduate work at the University of Missouri - Rolla, in addition to user feedback from a tutorial course, provided the impetus for a variety of code improvements. Recently upgraded to version 4B, initial modifications to SOURCES focused on updates to the 'tape5' decay data library. Shortly thereafter, efforts focused on development of a graphical user interface for the code. This paper documents the Los Alamos SOURCES Tape1 Creator and Library Link (LASTCALL) and describes additional library modifications in more detail. Minor improvements and planned enhancements are discussed.

  19. Investigations of the inductively coupled plasma source for analyzing NURE water samples at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Apel, C.T.; Bieniewski, T.M.; Cox, L.E.; Steinhaus, D.W.

    1977-03-01

    A 3.4-meter direct-reading spectrograph is being used with an inductively coupled plasma source for the simultaneous determination of Ag, Bi, Cd, Cu, Nb, Ni, Pb, Sn, and W in water samples. We have attached a small digital computer to the system in order to obtain intensity data on each element once a second. After the intensities during a run on a sample have stabilized, the computer records the intensity data and outputs the average concentration for each element. To approach the published detection limits, a peristaltic pump must be used to force the water sample into the usual cross-flow nebulizer. We have studied several different nebulizer designs with the goal of improving efficiency and hence sensitivity. One design, the fritted-disk nebulizer, has an efficiency over 60 percent, as compared with the 5 percent efficiency of the original nebulizer

  20. Reducing nonpoint source pollution through collaboration: policies and programs across the U.S. States.

    Science.gov (United States)

    Hardy, Scott D; Koontz, Tomas M

    2008-03-01

    Nonpoint source (NPS) pollution has emerged as the largest threat to water quality in the United States, influencing policy makers and resource managers to direct more attention toward NPS prevention and remediation. In response, the United States Environmental Protection Agency (USEPA) spent more than $204 million in fiscal year (FY) 2006 on the Clean Water Act's Section 319 program to combat NPS pollution, much of it on the development and implementation of watershed-based plans. State governments have also increasingly allocated financial and technical resources to collaborative watershed efforts within their own borders to fight NPS pollution. With increased collaboration among the federal government, states, and citizens to combat NPS pollution, more information is needed to understand how public resources are being used, by whom, and for what, and what policy changes might improve effectiveness. Analysis from a 50-state study suggests that, in addition to the average 35% of all Section 319 funds per state that are passed on to collaborative watershed groups, 35 states have provided financial assistance beyond Section 319 funding to support collaborative watershed initiatives. State programs frequently provide technical assistance and training, in addition to financial resources, to encourage collaborative partnerships. Such assistance is typically granted in exchange for requirements to generate a watershed action plan and/or follow a mutually agreed upon work plan to address NPS pollution. Program managers indicated a need for greater fiscal resources and flexibility to achieve water quality goals.

  1. Analysis of Frankincense in Archaeological Samples by Gas Chromatography-Mass Spectrometry

    International Nuclear Information System (INIS)

    Mathe, C.; Archier, P.; Vieillescazes, C.; Connan, J.; Mouton, M.

    2007-01-01

    Four archaeological samples, unearthed from Qana in Yemen were analysed by analytical technique, currently applied in the field of petroleum geochemistry, and by gas chromatography coupled with a mass spectrometer (GC-MS). Sample no 1286 comes from a burned warehouse and samples no 964, 963 and 962 from the central sanctuary. These specimens were probably exposed to a heating source. In each case olibanum resin was identified according to the presence of their chemical markers corresponding to α-, β-boswellic and lupeolic acids (3α-hydroxy-olean-12-en-24-oic, 3α-hydroxy-urs-12-en-24-oic and 3α-hydroxy-lup-20(29)en-24-oic acids) and their respective O-acetyled derivatives (3α- O-acetyl -olean-12-en-24-oic, 3α-O-acetyl-urs-12-en-24-oic and 3α-O-acetyl-lup-20(29)-en-24-oic acids). Concerning the thermal degradation state of samples, the GC-MS results are in agreement with the geochemical ones. Sample no 1286 and 964 correspond to ageing incense which has not undergone any heating action and are consequently relatively well preserved. Lastly, samples no 963 and 962 are thermally degraded resins and their gross composition data permits to conclude that sample no 963 is only partially burnt while sample no 962 has been much more degraded

  2. Discrete-Time Domain Modelling of Voltage Source Inverters in Standalone Applications

    DEFF Research Database (Denmark)

    Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel

    2017-01-01

    modelling of the LC plant with consideration of delay and sample-and-hold effects on the state feedback cross-coupling decoupling is derived. From this plant formulation, current controllers with wide bandwidth and good relative stability properties are developed. Two controllers based on lead compensation......The decoupling of the capacitor voltage and inductor current has been shown to improve significantly the dynamic performance of voltage source inverters in standalone applications. However, the computation and PWM delays still limit the achievable bandwidth. In this paper a discrete-time domain...

  3. Quantum electrodynamics with nonrelativistic sources. V. Electromagnetic field correlations and intermolecular interactions between molecules in either ground or excited states

    International Nuclear Information System (INIS)

    Power, E.A.; Thirunamachandran, T.

    1993-01-01

    Spatial correlations between electromagnetic fields arising from neutral sources with electric-dipole transition moments are calculated using nonrelativistic quantum electrodynamics in the multipolar formalism. Expressions for electric-electric, magnetic-magnetic, and electric-magnetic correlation functions at two points r and r' are given for a source molecule in either a ground or an excited state. In contrast to the electric-electric and magnetic-magnetic cases there are no electric-magnetic correlations for a ground-state molecule. For an excited molecule the downward transitions contribute additional terms which have modulating factors depending on (r-r')/λ. From these correlation functions electric and magnetic energy densities are found by setting r=r'. These energy densities are then used in a response formalism to calculate intermolecular energy shifts. In the case of two ground-state molecules this leads to the Casimir-Polder potential. However, for a pair of molecules, one or both excited, there are additional terms arising from downward transitions. An important feature of these energies is that they exhibit an R -2 dependence for large intermolecular separations R. This dependence is interpreted in terms of the Poynting vector, which itself can be obtained by setting r=r' in the electric-magnetic correlation function

  4. Fast Ordered Sampling of DNA Sequence Variants

    Directory of Open Access Journals (Sweden)

    Anthony J. Greenberg

    2018-05-01

    Full Text Available Explosive growth in the amount of genomic data is matched by increasing power of consumer-grade computers. Even applications that require powerful servers can be quickly tested on desktop or laptop machines if we can generate representative samples from large data sets. I describe a fast and memory-efficient implementation of an on-line sampling method developed for tape drives 30 years ago. Focusing on genotype files, I test the performance of this technique on modern solid-state and spinning hard drives, and show that it performs well compared to a simple sampling scheme. I illustrate its utility by developing a method to quickly estimate genome-wide patterns of linkage disequilibrium (LD decay with distance. I provide open-source software that samples loci from several variant format files, a separate program that performs LD decay estimates, and a C++ library that lets developers incorporate these methods into their own projects.

  5. Fast Ordered Sampling of DNA Sequence Variants.

    Science.gov (United States)

    Greenberg, Anthony J

    2018-05-04

    Explosive growth in the amount of genomic data is matched by increasing power of consumer-grade computers. Even applications that require powerful servers can be quickly tested on desktop or laptop machines if we can generate representative samples from large data sets. I describe a fast and memory-efficient implementation of an on-line sampling method developed for tape drives 30 years ago. Focusing on genotype files, I test the performance of this technique on modern solid-state and spinning hard drives, and show that it performs well compared to a simple sampling scheme. I illustrate its utility by developing a method to quickly estimate genome-wide patterns of linkage disequilibrium (LD) decay with distance. I provide open-source software that samples loci from several variant format files, a separate program that performs LD decay estimates, and a C++ library that lets developers incorporate these methods into their own projects. Copyright © 2018 Greenberg.

  6. Use of slurry sampling for the direct determination of zinc in yogurt by high resolution-continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Brandao, Geovani C; de Jesus, Raildo M; da Silva, Erik G P; Ferreira, Sergio L C

    2010-06-15

    This paper presents an analytical procedure for the direct determination of zinc in yogurt employing sampling slurry and high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The step optimization established the experimental conditions of: 2.0molL(-1) hydrochloric acid, a sonication time of 20min and a sample mass of 1.0g for a slurry volume of 25mL. This method allows the determination of zinc with a limit of quantification of 0.32microgg(-1). The precision expressed as relative standard deviation (RSD) were 0.82 and 2.08% for yogurt samples containing zinc concentrations of 4.85 and 2.49microgg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of non-fat milk powder furnished by the National Institute of Standard and Technology. The proposed method was applied for the determination of zinc in seven yogurt samples. The zinc content was varied from 2.19 to 4.85microgg(-1). These results agreed with those reported in the literature. The samples were also analyzed after acid digestion and zinc determination by FAAS. No statistical difference was observed between the results obtained by both of the procedures performed.

  7. On-demand generation of background-free single photons from a solid-state source

    Science.gov (United States)

    Schweickert, Lucas; Jöns, Klaus D.; Zeuner, Katharina D.; Covre da Silva, Saimon Filipe; Huang, Huiying; Lettner, Thomas; Reindl, Marcus; Zichi, Julien; Trotta, Rinaldo; Rastelli, Armando; Zwiller, Val

    2018-02-01

    True on-demand high-repetition-rate single-photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi-photon emission. Here, we present a solid-state source of on-demand single photons yielding a raw second-order coherence of g(2 )(0 )=(7.5 ±1.6 )×10-5 without any background subtraction or data processing. To this date, this is the lowest value of g(2 )(0 ) reported for any single-photon source even compared to the previously reported best background subtracted values. We achieve this result on GaAs/AlGaAs quantum dots embedded in a low-Q planar cavity by employing (i) a two-photon excitation process and (ii) a filtering and detection setup featuring two superconducting single-photon detectors with ultralow dark-count rates of (0.0056 ±0.0007 ) s-1 and (0.017 ±0.001 ) s-1, respectively. Re-excitation processes are dramatically suppressed by (i), while (ii) removes false coincidences resulting in a negligibly low noise floor.

  8. Impurity radiation from a beam-plasma neutron source

    International Nuclear Information System (INIS)

    Molvik, A.W.

    1995-01-01

    Impurity radiation, in a worst case evaluation for a beam-plasma neutron source (BPNS), does not limit performance. Impurities originate from four sources: (a) sputtering from walls by charge exchange or alpha particle bombardment, (b) sputtering from limiters, (c) plasma desorption of gas from walls and (d) injection with neutral beams. Sources (c) and (d) are negligible; adsorbed gas on the walls of the confinement chamber and the neutral beam sources is removed by the steady state discharge. Source (b) is negligible for impinging ion energies below the sputtering threshold (T i ≤ 0.025 keV on tungsten) and for power densities to the limiter within the capabilities of water cooling (30-40 MW/m 2 ); both conditions can be satisfied in the BPNS. Source (a) radiates 0.025 MW/m 2 to the neutron irradiation samples, compared with 5 to 10 MW/m 2 of neutrons; and radiates a total of 0.08 MW from the plasma column, compared with 60 MW of injected power. The particle bombardment that yields source (a) deposits an average of 2.7 MW/m 2 on the samples, within the capabilities of helium gas cooling (10 MW/m 2 ). An additional worst case for source (d) is evaluated for present day 2 to 5 s pulsed neutral beams with 0.1% impurity density and is benchmarked against 2XIIB. The total radiation would increase a factor of 1.5 to ≤ 0.12 MW, supporting the conclusion that impurities will not have a significant impact on a BPN. (author). 61 refs, 7 figs, 2 tabs

  9. Heavy metal analysis in groundwater samples by SR-TXRF

    International Nuclear Information System (INIS)

    Moreira, Silvana; Ficaris, Maria; Vives, Ana Elisa S. de; Zucchi, Orgheda L.A.D.; Nascimento Filho, Virgilio Franco do Centro de Energia Nuclear na Agricultura , Piracicaba, SP . Lab. Instrumentacao Nuclear.; Brazil)

    2005-01-01

    In order to obtain information about levels of heavy metals in groundwater, analysis were carried out on samples from monitoring and supplying wells located in Campinas, Sao Paulo State, Southeastern Brazil. The analytical technique used was Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) and all the measurements were performed at Synchrotron Light Source Laboratory, using a white beam and a Si(Li) detector in total reflection condition. The determined elements were Al, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. The results were compared with the maximum allowed values (MPV) established by the Brazilian Health Department. The detection limits obtained varying from 0.10 up to 8 μg.L -1 were in agreement with the values presented by others analytical techniques. (author)

  10. Heavy metal analysis in groundwater samples by SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana; Ficaris, Maria [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Zucchi, Orgheda L.A.D. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

    2005-07-01

    In order to obtain information about levels of heavy metals in groundwater, analysis were carried out on samples from monitoring and supplying wells located in Campinas, Sao Paulo State, Southeastern Brazil. The analytical technique used was Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) and all the measurements were performed at Synchrotron Light Source Laboratory, using a white beam and a Si(Li) detector in total reflection condition. The determined elements were Al, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. The results were compared with the maximum allowed values (MPV) established by the Brazilian Health Department. The detection limits obtained varying from 0.10 up to 8 {mu}g.L{sup -1} were in agreement with the values presented by others analytical techniques. (author)

  11. The interprocess NIR sampling as an alternative approach to multivariate statistical process control for identifying sources of product-quality variability.

    Science.gov (United States)

    Marković, Snežana; Kerč, Janez; Horvat, Matej

    2017-03-01

    We are presenting a new approach of identifying sources of variability within a manufacturing process by NIR measurements of samples of intermediate material after each consecutive unit operation (interprocess NIR sampling technique). In addition, we summarize the development of a multivariate statistical process control (MSPC) model for the production of enteric-coated pellet product of the proton-pump inhibitor class. By developing provisional NIR calibration models, the identification of critical process points yields comparable results to the established MSPC modeling procedure. Both approaches are shown to lead to the same conclusion, identifying parameters of extrusion/spheronization and characteristics of lactose that have the greatest influence on the end-product's enteric coating performance. The proposed approach enables quicker and easier identification of variability sources during manufacturing process, especially in cases when historical process data is not straightforwardly available. In the presented case the changes of lactose characteristics are influencing the performance of the extrusion/spheronization process step. The pellet cores produced by using one (considered as less suitable) lactose source were on average larger and more fragile, leading to consequent breakage of the cores during subsequent fluid bed operations. These results were confirmed by additional experimental analyses illuminating the underlying mechanism of fracture of oblong pellets during the pellet coating process leading to compromised film coating.

  12. Selenium content in milk and diary samples

    International Nuclear Information System (INIS)

    Kira, Carmen S.; Maihara, Vera A.

    2005-01-01

    Food is the primary source of Se for human beings. As such determining Se levels in foodstuffs become very important. However, information concerning Se levels in different sources of nutrition in different country, particularly in Brazil, is limited. Instrumental Neutron Activation Analysis (INAA) has been used to effectively determine micronutrient levels in foodstuffs, such as milk and dairy samples. The advantage of using the INAA technique is that the samples do not require previous dissolution before analysis. In this study, INAA was applied to determine Se concentration in milk and dairy products. The samples were acquired in the markets of Sao Paulo city. After a 8-hour irradiation in the research reactor IEA-R1, selenium was analyzed by gamma-ray spectrometry. Methodology validation was done analyzing NIST reference materials (Whole Milk Powder and Non Fat Milk Powder). Se concentrations in the sample analyzed were below 0.300 μg g -1 . (author)

  13. Uranium and radium activities in samples of aquifers of the main cities of the Estado de Chihuahua

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero S, L.; Montero C, M.E.

    2003-01-01

    The natural uranium is in four valence states +3, +4, +5 and +6 being the hexavalent state the more soluble, which plays an important role in the transport of the uranium in the environment. The high concentrations of uranium in water not only in near waters to uranium mines, but also are in some mineral waters or in waters that are extracted of deep wells as it happens in the State of Chihuahua, where the underground waters are the fundamental source of consumption. The radium is a disintegration product of the uranium, the radio content in water is considered the second source of natural radioactivity. The distribution of radium in water is in function of the uranium content present in the aquifer. It was determined the uranium and radium content in samples of underground water of the main cities of the State of Chihuahua according to their number of inhabitants. The extraction methods for uranium and sulfates precipitation of Ba-Ra by means of the addition of barium carriers for the radium were used. The measures of the activities of uranium and radium were carried out by means of a portable liquid scintillation detector trade mark Thiathler-OY HIDEX. The obtained results have demonstrated that the content of uranium and radium in dissolution are in most of the sampling wells above the permissible maximum levels that manage the Mexican regulations. The high contents of uranium and radio can be attributed since to the influence of the geologic substrate characteristic of the zone in the State of Chihuahua they exist but of 50 uranium deposits. (Author)

  14. Financial management skills are associated with food insecurity in a sample of households with children in the United States.

    Science.gov (United States)

    Gundersen, Craig G; Garasky, Steven B

    2012-10-01

    Food insecurity is one of the leading public health challenges facing children in the United States today. Reducing food insecurity and its attendant consequences requires an understanding of the determinants of food insecurity. Although previous work has greatly advanced our understanding of these determinants, the role of one of the oft-speculated important determinants of food insecurity, household financial management skills, has not been considered. To address this research lacuna, we use a recently conducted survey, the Survey of Household Finances and Childhood Obesity, that has information on specific financial management practices, impressions of financial management skills, and households' food insecurity. The sample included 904 households with children. Within this sample, 19.3% were food insecure and, for our central financial management skill variable, the mean value was 3.55 on a 5-point scale. Probit regression models estimated the probability of a household being food insecure as conditional on financial management skills and other covariates. We found a large and significant inverse relationship between a respondent's use of specific financial management practices and food insecurity and between a respondent's confidence in his or her financial management skills and food insecurity. That is, households with greater financial management abilities are less likely to be food insecure. This finding also holds when the sample is restricted to households with incomes <200% of the poverty line. These results suggest that improving households' financial management skills has the potential to reduce food insecurity in the United States.

  15. Effects of demographic factors and information sources on United States consumer perceptions of animal welfare.

    Science.gov (United States)

    McKendree, M G S; Croney, C C; Widmar, N J O

    2014-07-01

    As consumers have become more interested in understanding how their food is produced, scrutiny and criticism have increased regarding intensified food animal production methods. Resolution of public concerns about animal agricultural practices depends on understanding the myriad factors that provide the basis for concerns. An online survey of 798 U.S. households was conducted to investigate relationships between household characteristics (demographics, geographic location, and experiences) and level of concern for animal welfare as well as sources used to obtain information on the subject. Because recent media attention has focused on animal care practices used in the U.S. swine industry, respondents were also asked specific questions pertaining to their perceptions of pig management practices and welfare issues and their corresponding pork purchasing behavior. Respondents reporting higher levels of concern about animal welfare were more frequently female, younger, and self-reported members of the Democratic Party. Fourteen percent of respondents reported reduction in pork consumption because of animal welfare concerns with an average reduction of 56%. Over half of the respondents (56%) did not have a primary source for animal welfare information; those who identified a primary information source most commonly used information provided by animal protection organizations, the Humane Society of the United States (HSUS), and People for the Ethical Treatment of Animals (PETA). Midwest participants were significantly, at the 5% significance level, less concerned about domestic livestock animal welfare and more frequently reported not having a source for animal welfare information than those from other regions of the United States. Overall, the U.S. livestock and poultry industries and other organizations affiliated with animal agriculture appear to be less used public sources of information on animal welfare than popular animal protection organizations. Improved

  16. Determination of geostatistically representative sampling locations in Porsuk Dam Reservoir (Turkey)

    Science.gov (United States)

    Aksoy, A.; Yenilmez, F.; Duzgun, S.

    2013-12-01

    Several factors such as wind action, bathymetry and shape of a lake/reservoir, inflows, outflows, point and diffuse pollution sources result in spatial and temporal variations in water quality of lakes and reservoirs. The guides by the United Nations Environment Programme and the World Health Organization to design and implement water quality monitoring programs suggest that even a single monitoring station near the center or at the deepest part of a lake will be sufficient to observe long-term trends if there is good horizontal mixing. In stratified water bodies, several samples can be required. According to the guide of sampling and analysis under the Turkish Water Pollution Control Regulation, a minimum of five sampling locations should be employed to characterize the water quality in a reservoir or a lake. The European Union Water Framework Directive (2000/60/EC) states to select a sufficient number of monitoring sites to assess the magnitude and impact of point and diffuse sources and hydromorphological pressures in designing a monitoring program. Although existing regulations and guidelines include frameworks for the determination of sampling locations in surface waters, most of them do not specify a procedure in establishment of monitoring aims with representative sampling locations in lakes and reservoirs. In this study, geostatistical tools are used to determine the representative sampling locations in the Porsuk Dam Reservoir (PDR). Kernel density estimation and kriging were used in combination to select the representative sampling locations. Dissolved oxygen and specific conductivity were measured at 81 points. Sixteen of them were used for validation. In selection of the representative sampling locations, care was given to keep similar spatial structure in distributions of measured parameters. A procedure was proposed for that purpose. Results indicated that spatial structure was lost under 30 sampling points. This was as a result of varying water

  17. Study on natural radioactive elements in soil and rock samples around Mandya district, India

    International Nuclear Information System (INIS)

    Shivakumara, B.C.; Paramesh, L.; Shashikumar, T.S.; Chandrashekara, M.S.

    2012-01-01

    The soil is a complex mixture of different compounds and rocks. In the natural environment, it is an important source of exposure to radiation due to naturally occurring, gamma emitting radionuclides which include 226 Ra, 232 Th and 40 K present in the soil. The study of distribution of these radionuclides in soil and rock is of great importance for radiation protection and measurements. The activity concentrations of 226 Ra, 232 Th, and 40 K in soil and rock samples collected in Mandya District, Karnataka state, India have been measured by gamma ray spectrometry. The average activity concentrations of 226 Ra, 232 Th, and 40 K (Bq/kg) are found to be 40.2, 62.3, and 317.5 Bq/kg, respectively, in soil samples and 30.5, 34.4, and 700.2 Bq/kg, respectively, in rock samples. The concentrations of radionuclides in soil samples are found to higher than in rock samples. The concentrations of radionuclides in soil and rock samples in the study area are slightly higher than Indian average and world average values. (author)

  18. 40 CFR 141.703 - Sampling locations.

    Science.gov (United States)

    2010-07-01

    ... samples prior to the point of filter backwash water addition. (d) Bank filtration. (1) Systems that... applicable, must collect source water samples in the surface water prior to bank filtration. (2) Systems that use bank filtration as pretreatment to a filtration plant must collect source water samples from the...

  19. Radiochemical analysis of phosphorus in milk samples

    International Nuclear Information System (INIS)

    Oliveira, R.M. de; Cunha, I.I.L.

    1991-01-01

    The determination of phosphorus in milk samples by thermal neutron activation analysis employing radiochemical separation is described. The radiochemical separation consists of the simultaneous irradiation of samples and standards, dissolution of the milk samples in a perchloric acid and nitric acid mixture, addition of zinc hold-back carrier, precipitation of phosphorus as ammonium phospho molybdate (A.M.P.) and sample counting in a Geiger-Mueller detector. The analysis sources of error were studied and the established method was applied to phosphorus analyses in commercial milk samples. (author)

  20. ANALYSIS OF THE ROLE OF AGRICULTURAL COOPERATIVES' IN FUNDING PROCESSING MILLS IN CROSS RIVER STATE, NIGERIA

    OpenAIRE

    Adinya, I.B; Odey S.O.; Oniah M.O; Umeh G.N; Agiopu, B.F; Ogbonna ,K.I.

    2008-01-01

    A study was undertaken to determine the role of agricultural co-operative societies as institutional source of finance to processing mills in Cross River State, Nigeria. Data were obtained from a random sample of 150 respondents in the study area by means of structured questionnaire. The first stage involved random selection of fifteen local government areas from eighteen local government areas in Cross River State. This was followed by random selection of one village in each of the fifteen l...

  1. TU-AB-BRC-11: Moving a GPU-OpenCL-Based Monte Carlo (MC) Dose Engine Towards Routine Clinical Use: Automatic Beam Commissioning and Efficient Source Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Z; Folkerts, M; Jiang, S; Jia, X [UT Southwestern Medical Ctr, Dallas, TX (United States); Li, Y [Beihang University, Beijing (China)

    2016-06-15

    Purpose: We have previously developed a GPU-OpenCL-based MC dose engine named goMC with built-in analytical linac beam model. To move goMC towards routine clinical use, we have developed an automatic beam-commissioning method, and an efficient source sampling strategy to facilitate dose calculations for real treatment plans. Methods: Our commissioning method is to automatically adjust the relative weights among the sub-sources, through an optimization process minimizing the discrepancies between calculated dose and measurements. Six models built for Varian Truebeam linac photon beams (6MV, 10MV, 15MV, 18MV, 6MVFFF, 10MVFFF) were commissioned using measurement data acquired at our institution. To facilitate dose calculations for real treatment plans, we employed inverse sampling method to efficiently incorporate MLC leaf-sequencing into source sampling. Specifically, instead of sampling source particles control-point by control-point and rejecting the particles blocked by MLC, we assigned a control-point index to each sampled source particle, according to MLC leaf-open duration of each control-point at the pixel where the particle intersects the iso-center plane. Results: Our auto-commissioning method decreased distance-to-agreement (DTA) of depth dose at build-up regions by 36.2% averagely, making it within 1mm. Lateral profiles were better matched for all beams, with biggest improvement found at 15MV for which root-mean-square difference was reduced from 1.44% to 0.50%. Maximum differences of output factors were reduced to less than 0.7% for all beams, with largest decrease being from1.70% to 0.37% found at 10FFF. Our new sampling strategy was tested on a Head&Neck VMAT patient case. Achieving clinically acceptable accuracy, the new strategy could reduce the required history number by a factor of ∼2.8 given a statistical uncertainty level and hence achieve a similar speed-up factor. Conclusion: Our studies have demonstrated the feasibility and effectiveness of

  2. Natural radioactivity in groundwater sources in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Currivan, L.; Dowdall, A.; Mcginnity, P.; Ciara, M. [Radiological Protection Institute of Ireland (Ireland); Craig, M. [Environmental Protection Agency (Ireland)

    2014-07-01

    The Radiological Protection Institute of Ireland (RPII) in collaboration with the Irish Environmental Protection Agency (EPA) undertook a national survey of radioactivity in groundwater sources for compliance with parameters set out in the European Communities Drinking Water Directive. The Directive outlines the minimum requirements for the quality of drinking water and water intended for human consumption. Over two hundred samples were screened for radioactivity. Where indicated, analysis for individual radionuclide activity was undertaken and the radiation dose arising calculated. Furthermore, samples were analysed for radon concentration. This survey is the first comprehensive national survey of radioactivity in groundwater sources in Ireland. Approximately 18 per cent of drinking water in Ireland originates from groundwater and springs with the remainder from surface water. Between 2007 and 2011, water samples from a representative network of groundwater sources were analysed and assessed for compliance with the radioactivity parameters set out in the Drinking Water Directive. The assessment was carried out using the methodology for screening drinking water set out by the WHO. For practical purposes the WHO recommended screening levels for drinking water below which no further action is required of 100 mBq/l for gross alpha activity and 1000 mBq/l for gross beta activity were applied. Of the 203 groundwater sources screened for gross alpha and gross beta all met the gross beta activity criteria of less than 1000 mBq/l and 175 supplies had gross alpha activity concentrations of less than 100 mBq/l. For these sources no further analysis was required. The remaining 28 sources required further (radionuclide-specific) analysis from an alpha activity perspective. Results on ranges and distributions of radionuclide concentrations in groundwater as well as ingestion doses estimated for consumers of these water supplies will be presented. Document available in abstract

  3. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

    Directory of Open Access Journals (Sweden)

    Andreas Steimer

    Full Text Available Oscillations between high and low values of the membrane potential (UP and DOWN states respectively are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs of the exponential integrate and fire (EIF model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing

  4. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

    Science.gov (United States)

    Steimer, Andreas; Schindler, Kaspar

    2015-01-01

    Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational

  5. Factors associated with sources, transport, and fate of chloroform and three other trihalomethanes in untreated groundwater used for drinking water

    Science.gov (United States)

    Carter, Janet M.; Moran, Michael J.; Zogorski, John S.; Price, Curtis V.

    2012-01-01

    Multiple lines of evidence for indicating factors associated with the sources, transport, and fate of chloroform and three other trihalomethanes (THMs) in untreated groundwater were revealed by evaluating low-level analytical results and logistic regression results for THMs. Samples of untreated groundwater from wells used for drinking water were collected from 1996-2007 from 2492 wells across the United States and analyzed for chloroform, bromodichloromethane, dibromochloromethane, and bromoform by a low-level analytical method implemented in April 1996. Using an assessment level of 0.02 μg/L, chloroform was detected in 36.5% of public-well samples and 17.6% of domestic-well samples, with most concentrations less than 1 μg/L. Brominated THMs occurred less frequently than chloroform but more frequently in public-well samples than domestic-well samples. For both public and domestic wells, THMs occurred most frequently in urban areas. Logistic regression analyses showed that the occurrence of THMs was related to nonpoint sources such as urban land use and to point sources like septic systems. The frequent occurrence and concentration distribution pattern of THMs, as well as their frequent co-occurrence with other organic compounds and nitrate, all known to have anthropogenic sources, and the positive associations between THM occurrence and dissolved oxygen and recharge indicate the recycling of water that contains THMs and other anthropogenic contaminants.

  6. Factors associated with sources, transport, and fate of chloroform and three other trihalomethanes in untreated groundwater used for drinking water.

    Science.gov (United States)

    Carter, Janet M; Moran, Michael J; Zogorski, John S; Price, Curtis V

    2012-08-07

    Multiple lines of evidence for indicating factors associated with the sources, transport, and fate of chloroform and three other trihalomethanes (THMs) in untreated groundwater were revealed by evaluating low-level analytical results and logistic regression results for THMs. Samples of untreated groundwater from wells used for drinking water were collected from 1996-2007 from 2492 wells across the United States and analyzed for chloroform, bromodichloromethane, dibromochloromethane, and bromoform by a low-level analytical method implemented in April 1996. Using an assessment level of 0.02 μg/L, chloroform was detected in 36.5% of public-well samples and 17.6% of domestic-well samples, with most concentrations less than 1 μg/L. Brominated THMs occurred less frequently than chloroform but more frequently in public-well samples than domestic-well samples. For both public and domestic wells, THMs occurred most frequently in urban areas. Logistic regression analyses showed that the occurrence of THMs was related to nonpoint sources such as urban land use and to point sources like septic systems. The frequent occurrence and concentration distribution pattern of THMs, as well as their frequent co-occurrence with other organic compounds and nitrate, all known to have anthropogenic sources, and the positive associations between THM occurrence and dissolved oxygen and recharge indicate the recycling of water that contains THMs and other anthropogenic contaminants.

  7. Alternative sources in Slovakia, problems and resorts

    International Nuclear Information System (INIS)

    Hanzel, A.

    2005-01-01

    In this presentation author deals with power generation from renewable energy sources in some states (USA, Germany, Japan, Denmark, European Union) and in the Slovak Republic. Cost of electric power from different renewable energy sources is compared.

  8. External heating and current drive source requirements towards steady-state operation in ITER

    Science.gov (United States)

    Poli, F. M.; Kessel, C. E.; Bonoli, P. T.; Batchelor, D. B.; Harvey, R. W.; Snyder, P. B.

    2014-07-01

    Steady state scenarios envisaged for ITER aim at optimizing the bootstrap current, while maintaining sufficient confinement and stability to provide the necessary fusion yield. Non-inductive scenarios will need to operate with internal transport barriers (ITBs) in order to reach adequate fusion gain at typical currents of 9 MA. However, the large pressure gradients associated with ITBs in regions of weak or negative magnetic shear can be conducive to ideal MHD instabilities, reducing the no-wall limit. The E × B flow shear from toroidal plasma rotation is expected to be low in ITER, with a major role in the ITB dynamics being played by magnetic geometry. Combinations of heating and current drive (H/CD) sources that sustain reversed magnetic shear profiles throughout the discharge are the focus of this work. Time-dependent transport simulations indicate that a combination of electron cyclotron (EC) and lower hybrid (LH) waves is a promising route towards steady state operation in ITER. The LH forms and sustains expanded barriers and the EC deposition at mid-radius freezes the bootstrap current profile stabilizing the barrier and leading to confinement levels 50% higher than typical H-mode energy confinement times. Using LH spectra with spectrum centred on parallel refractive index of 1.75-1.85, the performance of these plasma scenarios is close to the ITER target of 9 MA non-inductive current, global confinement gain H98 = 1.6 and fusion gain Q = 5.

  9. TRACING THE REVERBERATION LAG IN THE HARD STATE OF BLACK HOLE X-RAY BINARIES

    International Nuclear Information System (INIS)

    De Marco, B.; Ponti, G.; Nandra, K.; Muñoz-Darias, T.

    2015-01-01

    We report results obtained from a systematic analysis of X-ray lags in a sample of black hole X-ray binaries, with the aim of assessing the presence of reverberation lags and studying their evolution during outburst. We used XMM-Newton and simultaneous Rossi X-ray Timing Explorer (RXTE) observations to obtain broadband energy coverage of both the disk and the hard X-ray Comptonization components. In most cases the detection of reverberation lags is hampered by low levels of variability-power signal-to-noise ratio (typically when the source is in a soft state) and/or short exposure times. The most detailed study was possible for GX 339-4 in the hard state, which allowed us to characterize the evolution of X-ray lags as a function of luminosity in a single source. Over all the sampled frequencies (∼0.05–9 Hz), we observe the hard lags intrinsic to the power-law component, already well known from previous RXTE studies. The XMM-Newton soft X-ray response allows us to detail the disk variability. At low frequencies (long timescales) the disk component always leads the power-law component. On the other hand, a soft reverberation lag (ascribable to thermal reprocessing) is always detected at high frequencies (short timescales). The intrinsic amplitude of the reverberation lag decreases as the source luminosity and the disk fraction increase. This suggests that the distance between the X-ray source and the region of the optically thick disk where reprocessing occurs gradually decreases as GX 339-4 rises in luminosity through the hard state, possibly as a consequence of reduced disk truncation

  10. Renewable energy sources in Bulgaria: Current state and trends

    Science.gov (United States)

    Kolev, K.

    The over-dependency of Bulgaria on imported fuel stressed the importance of developing a new energy strategy based on energy saving which includes also using renewable energy sources (RES). The target is the substitution of at least 2 percent of the real primary energy consumption with RES by 2010. The author gives a generalized analysis of the available RES in Bulgaria -solar, wind, geothermal, biomass and mini-hydraulic. The potentialities of each source for its usage as a suitable energy supply are pointed out, as well as the current status of research and implementation work, problems connected with legislation, financing and production of particular facilities. The governmental policy concerning RES is considered briefly. A description is given to the project 'Technical and Economical Assessment of Possibilities for Expansion of the RES-part in the Energy Balance of the Country' developed and started in 1994 in the framework of the PHARE program.

  11. Report on water quality, sediment and water chemistry data for water and sediment samples collected from source areas to Melton Hill and Watts Bar reservoirs

    International Nuclear Information System (INIS)

    Tomaszewski, T.M.; Bruggink, D.J.; Nunn, D.L.

    1995-01-01

    Contamination of surface water and sediments in the Clinch River and Watts Bar Reservoir (CR/WBR) system as a result of past and present activities by the US Department of Energy (DOE) on the Oak Ridge Reservation (ORR) and also activities by non-ORR facilities are being studied by the Clinch River Environmental Restoration Program (CR-ERP). Previous studies have documented the presence of heavy metals, organics, and radionuclides in the sediments of reservoirs in the vicinity. In support of the CR-ERP, during the summer of 1991, TVA collected and evaluated water and sediment samples from swimming areas and municipal water intakes on Watts Bar Reservoir, Melton Hill Reservoir and Norris Reservoir, which was considered a source of less-contaminated reference or background data. Despite the numerous studies, until the current work documented by this report, relatively few sediment or water samples had been collected by the CR-ERP in the immediate vicinity of contaminant point sources. This work focused on water and sediment samples taken from points immediately downstream from suspected effluent point sources both on and off the ORR. In August and September, 1994, TVA sampled surface water and sediment at twelve locations in melton Hill and Watts Bar Reservoirs

  12. A new approach for the determination of sulphur in food samples by high-resolution continuum source flame atomic absorption spectrometer.

    Science.gov (United States)

    Ozbek, N; Baysal, A

    2015-02-01

    The new approach for the determination of sulphur in foods was developed, and the sulphur concentrations of various fresh and dried food samples determined using a high-resolution continuum source flame atomic absorption spectrometer with an air/acetylene flame. The proposed method was optimised and the validated using standard reference materials, and certified values were found to be within the 95% confidence interval. The sulphur content of foods ranged from less than the LOD to 1.5mgg(-1). The method is accurate, fast, simple and sensitive. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Zinc estimates in ore and slag samples and analysis of ash in coal samples

    International Nuclear Information System (INIS)

    Umamaheswara Rao, K.; Narayana, D.G.S.; Subrahmanyam, Y.

    1984-01-01

    Zinc estimates in ore and slag samples were made using the radioisotope X-ray fluorescence method. A 10 mCi 238 Pu was employed as the primary source of radiation and a thin crystal NaI(Ti) spectrometer was used to accomplish the detection of the 8.64 keV Zinc K-characteristic X-ray line. The results are reported. Ash content of coal concerning about 100 samples from Ravindra Khani VI and VII mines in Andhra Pradesh were measured using X-ray backscattering method with compensation for varying concentrations of iron in different coal samples through iron-X-ray fluorescent intensity measurements. The ash percent is found to range from 10 to 40. (author)

  14. Laboratory and field evaluations of a methodology for determining hexavalent-chromium emissions from stationary sources. Final report

    International Nuclear Information System (INIS)

    Carver, A.C.

    1991-10-01

    The study was initiated to determine whether chromium emissions should be regulated under Section 112 of the Clean Air Act National Emissions Standards for Hazardous Air Pollutants (NESHAP). To support stationary source regulations, it is important that (1) the sampling procedure not change the chromium valence state during sampling and (2) an analytical technique for measuring low concentration levels of chromium be available. These goals are achieved with the current EPA 'Draft Method for Sampling and Analysis of Hexavalent Chromium at Stationary Sources.' The draft method utilizes a recirculating system to flush impinger reagent into the sampling nozzle during sample collection. Immediate contact of the stack gas with impinger reagent 'fixes' the chromium valence state. Ion chromatography coupled with post column derivatization and ultraviolet visible detector is used to analyze Cr(VI) in the parts per trillion range. Field tests were conducted at metal plating facilities, industrial cooling towers, municipal waste incinerators, sewage sludge incinerators, and hazardous waste incinerators. It was at the hazardous waste facility that the new method was proven to have acceptable precision and essentially no conversion in the sample train

  15. Monte Carlo calculations and neutron spectrometry in quantitative prompt gamma neutron activation analysis (PGNAA) of bulk samples using an isotopic neutron source

    International Nuclear Information System (INIS)

    Spyrou, N.M.; Awotwi-Pratt, J.B.; Williams, A.M.

    2004-01-01

    An activation analysis facility based on an isotopic neutron source (185 GBq 241 Am/Be) which can perform both prompt and cyclic activation analysis on bulk samples, has been used for more than 20 years in many applications including 'in vivo' activation analysis and the determination of the composition of bio-environmental samples, such as, landfill waste and coal. Although the comparator method is often employed, because of the variety in shape, size and elemental composition of these bulk samples, it is often difficult and time consuming to construct appropriate comparator samples for reference. One of the obvious problems is the distribution and energy of the neutron flux in these bulk and comparator samples. In recent years, it was attempted to adopt the absolute method based on a monostandard and to make calculations using a Monte Carlo code (MCNP4C2) to explore this further. In particular, a model of the irradiation facility has been made using the MCNP4C2 code in order to investigate the factors contributing to the quantitative determination of the elemental concentrations through prompt gamma neutron activation analysis (PGNAA) and most importantly, to estimate how the neutron energy spectrum and neutron dose vary with penetration depth into the sample. This simulation is compared against the scattered and transmitted neutron energy spectra that are experimentally and empirically determined using a portable neutron spectrometry system. (author)

  16. Gender pay gap and employment sector: sources of earnings disparities in the United States, 1970-2010.

    Science.gov (United States)

    Mandel, Hadas; Semyonov, Moshe

    2014-10-01

    Using data from the IPUMS-USA, the present research focuses on trends in the gender earnings gap in the United States between 1970 and 2010. The major goal of this article is to understand the sources of the convergence in men's and women's earnings in the public and private sectors as well as the stagnation of this trend in the new millennium. For this purpose, we delineate temporal changes in the role played by major sources of the gap. Several components are identified: the portion of the gap attributed to gender differences in human-capital resources; labor supply; sociodemographic attributes; occupational segregation; and the unexplained portion of the gap. The findings reveal a substantial reduction in the gross gender earnings gap in both sectors of the economy. Most of the decline is attributed to the reduction in the unexplained portion of the gap, implying a significant decline in economic discrimination against women. In contrast to discrimination, the role played by human capital and personal attributes in explaining the gender pay gap is relatively small in both sectors. Differences between the two sectors are not only in the size and pace of the reduction but also in the significance of the two major sources of the gap. Working hours have become the most important factor with respect to gender pay inequality in both sectors, although much more dominantly in the private sector. The declining gender segregation may explain the decreased impact of occupations on the gender pay gap in the private sector. In the public sector, by contrast, gender segregation still accounts for a substantial portion of the gap. The findings are discussed in light of the theoretical literature on sources of gender economic inequality and in light of the recent stagnation of the trend.

  17. The EnzymeTracker: an open-source laboratory information management system for sample tracking.

    Science.gov (United States)

    Triplet, Thomas; Butler, Gregory

    2012-01-26

    In many laboratories, researchers store experimental data on their own workstation using spreadsheets. However, this approach poses a number of problems, ranging from sharing issues to inefficient data-mining. Standard spreadsheets are also error-prone, as data do not undergo any validation process. To overcome spreadsheets inherent limitations, a number of proprietary systems have been developed, which laboratories need to pay expensive license fees for. Those costs are usually prohibitive for most laboratories and prevent scientists from benefiting from more sophisticated data management systems. In this paper, we propose the EnzymeTracker, a web-based laboratory information management system for sample tracking, as an open-source and flexible alternative that aims at facilitating entry, mining and sharing of experimental biological data. The EnzymeTracker features online spreadsheets and tools for monitoring numerous experiments conducted by several collaborators to identify and characterize samples. It also provides libraries of shared data such as protocols, and administration tools for data access control using OpenID and user/team management. Our system relies on a database management system for efficient data indexing and management and a user-friendly AJAX interface that can be accessed over the Internet. The EnzymeTracker facilitates data entry by dynamically suggesting entries and providing smart data-mining tools to effectively retrieve data. Our system features a number of tools to visualize and annotate experimental data, and export highly customizable reports. It also supports QR matrix barcoding to facilitate sample tracking. The EnzymeTracker was designed to be easy to use and offers many benefits over spreadsheets, thus presenting the characteristics required to facilitate acceptance by the scientific community. It has been successfully used for 20 months on a daily basis by over 50 scientists. The EnzymeTracker is freely available online at http

  18. Monitoring maternal, newborn, and child health interventions using lot quality assurance sampling in Sokoto State of northern Nigeria.

    Science.gov (United States)

    Abegunde, Dele; Orobaton, Nosa; Shoretire, Kamil; Ibrahim, Mohammed; Mohammed, Zainab; Abdulazeez, Jumare; Gwamzhi, Ringpon; Ganiyu, Akeem

    2015-01-01

    Maternal mortality ratio and infant mortality rate are as high as 1,576 per 100,000 live births and 78 per 1,000 live births, respectively, in Nigeria's northwestern region, where Sokoto State is located. Using applicable monitoring indicators for tracking progress in the UN/WHO framework on continuum of maternal, newborn, and child health care, this study evaluated the progress of Sokoto toward achieving the Millennium Development Goals (MDGs) 4 and 5 by December 2015. The changes in outcomes in 2012-2013 associated with maternal and child health interventions were assessed. We used baseline and follow-up lot quality assurance sampling (LQAS) data obtained in 2012 and 2013, respectively. In each of the surveys, data were obtained from 437 households sampled from 19 LQAS locations in each of the 23 local government areas (LGAs). The composite state-level coverage estimates of the respective indicators were aggregated from estimated LGA coverage estimates. None of the nine indicators associated with the continuum of maternal, neonatal, and child care satisfied the recommended 90% coverage target for achieving MDGs 4 and 5. Similarly, the average state coverage estimates were lower than national coverage estimates. Marginal improvements in coverage were obtained in the demand for family planning satisfied, antenatal care visits, postnatal care for mothers, and exclusive breast-feeding. Antibiotic treatment for acute pneumonia increased significantly by 12.8 percentage points. The majority of the LGAs were classifiable as low-performing, high-priority areas for intensified program intervention. Despite the limited time left in the countdown to December 2015, Sokoto State, Nigeria, is not on track to achieving the MDG 90% coverage of indicators tied to the continuum of maternal and child care, to reduce maternal and childhood mortality by a third by 2015. Targeted health system investments at the primary care level remain a priority, for intensive program scale-up to

  19. Thermal Analysis of the Linac3 GTS-LHC ECR Ion Source

    CERN Document Server

    Fichera, Claudio; Toivanen, Ville Aleksi; Kuchler, Detlef; CERN. Geneva. ATS Department

    2017-01-01

    The Linac3 ion source produces lead beams by the vaporization of solid samples inside internal ovens. The geometry, materials and surface state of the oven elements are critical parameters influencing the temperature distribution in the environment, and thus the performance of the source. A finite element approach is proposed to evaluate the thermal response of the system at increasing heating powers. Comparisons between the simulations results and experimental measurements are given in order to validate the numerical model. Based on the obtained results, improvements to the existing setup are suggested.

  20. THE XMM-NEWTON LONG LOOK OF NGC 1365: LACK OF A HIGH/SOFT STATE IN ITS ULTRALUMINOUS X-RAY SOURCES

    International Nuclear Information System (INIS)

    Soria, R.; Risaliti, G.; Elvis, M.; Fabbiano, G.; Bianchi, S.; Kuncic, Z.

    2009-01-01

    Based on our long (∼300 ks) 2007 XMM-Newton observation of the Seyfert galaxy NGC 1365, we report here on the spectral and timing behavior of two ultraluminous X-ray sources (ULXs), which had previously reached isotropic X-ray luminosities L X ∼ 4 x 10 40 erg s -1 (0.3-10 keV band). In 2007, they were in a lower state (L X ∼ 5 x 10 39 and 1.5 x 10 39 erg s -1 for X1 and X2, respectively). Their X-ray spectra were dominated by power laws with photon indices Γ ∼ 1.8 and 1.2, respectively. Thus, their spectra were similar to those at their outburst peaks. Both sources have been seen to vary by a factor of 20 in luminosity over the years, but their spectra are always dominated by a hard power law; unlike most stellar-mass black holes, they have never been found in a canonical high/soft state dominated by a standard disk. The lack of a canonical high/soft state seems to be a common feature of ULXs. We speculate that the different kind of donor star and/or a persistently super-Eddington accretion rate during their outbursts may prevent accretion flows in ULXs from settling into steady standard disks.

  1. ISOFORMAL: isotopic tracing of formaldehyde sources in housing. Intermediary report

    International Nuclear Information System (INIS)

    2011-01-01

    The authors report an investigation which comprised a sampling and a chemical and isotopic analysis of emissions from the main indoor formaldehyde pollution sources in order to create a exhaustive database. Emissions which are characteristic of motorcar traffic, are also sampled in order to asses their possible contribution in the housing air. This step will be used to develop emission simulations of formaldehyde sources in a laboratory-house in order to validate the isotopic approach as tracing tool for sources of this compound. The report describes the carbon and hydrogen steady isotopes. It presents the sampling procedure, reports the determination of formaldehyde concentrations by high performance liquid chromatography with UV detectors, the use of gas source mass spectrometry, and the analytic development of the isotopic analysis of formaldehyde by gas chromatography combustion isotope ratio mass spectrometry. Outdoor and indoor pollution sources are discussed

  2. Solution to the inversely stated transient source-receptor problem

    International Nuclear Information System (INIS)

    Sajo, E.; Sheff, J.R.

    1995-01-01

    Transient source-receptor problems are traditionally handled via the Boltzmann equation or through one of its variants. In the atmospheric transport of pollutants, meteorological uncertainties in the planetary boundary layer render only a few approximations to the Boltzmann equation useful. Often, due to the high number of unknowns, the atmospheric source-receptor problem is ill-posed. Moreover, models to estimate downwind concentration invariably assume that the source term is known. In this paper, an inverse methodology is developed, based on downwind measurement of concentration and that of meterological parameters to estimate the source term

  3. Use of wood as an energy source in the state of Maine

    Energy Technology Data Exchange (ETDEWEB)

    von Foerster, T.

    1978-09-01

    A detailed study is presented of the availability and use of wood as an energy resource for the State of Maine. Although there are no good data on the total resources of Maine's forests, the best estimates indicate that one could obtain about 1/2 quad (10/sup 15/ Btu) per year from thinning overstocked stands and harvesting dead trees; current logging operations could produce about the same amount of energy in the form of logging residues and thinnings, an amount that could be increased manyfold by intensive forest management. The costs of wood for fuel can be estimated on the basis of current logging and transportation costs. The corresponding energy prices, while high, are competitive with current fossil fuel prices. Using any energy source requires not only the fuel but also a furnace. The total energy costs are thus not only the cost of current fuel use but also those of the capital investment in the furnace. We have estimated these for systems of two sizes, one for a small house, the other for an apartment building or small commercial establishment. In both cases, our estimated indicate, that woodfueled systems can be economically competitive. Wood is currently used as a fuel on a large scale in the pulp and paper industry. With some increase in wood harvesting efforts and some alterations of furnaces that industry could achieve energy self sufficiency. Other large-scale uses are still speculative but deserve further investigation. A state-owned energy corporation could serve to provide a market for currently wasted wood and to investigate the conversion of wood to other forms of energy. The combustion of wood is not associated with environmental effects that are different kind in magnitude from those associated with the combustion of fossil fuel.

  4. Specification of brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    BCRU recommends that the following specification of gamma-ray brachytherapy sources be adopted. Unless otherwise stated, the output of a cylindrical source should be specified in air kerma rate at a point in free space at a distance of 1 m from the source on the radial plane of symmetry, i.e. the plane bisecting the active length and perpendicular to the cylindrical axis of the source. For a wire source the output should be specified for a 1 cm length. For any other construction of source, the point at which the output is specified should be stated. It is also recommended that the units in which the air kerma rate is expressed should be micrograys per hour (..mu..Gy/h).

  5. Inconsistencies among secondary sources of Chukar Partridge (Alectoris chukar introductions to the United States

    Directory of Open Access Journals (Sweden)

    Michael P. Moulton

    2015-11-01

    Full Text Available The propagule pressure hypothesis asserts that the number of individuals released is the key determinant of whether an introduction will succeed or not. It remains to be shown whether propagule pressure is more important than either species-level or site-level factors in determining the fate of an introduction. Studies claiming to show that propagule pressure is the primary determinant of introduction success must assume that the historical record as reported by secondary sources is complete and accurate. Here, examine a widely introduced game bird, the Chukar (Alectoris chukar, to the USA. We compare the records reported by two secondary sources (Long, 1981; Lever, 1987 to those in a primary source (Christensen, 1970 and to a recent study by Sol et al. (2012. Numerous inconsistencies exist in the records reported by Sol et al. (2012, Long (1981 and Lever (1987 when compared to the primary record of Christensen (1970. As reported by Christensen (1970, very large numbers of Chukars were released unsuccessfully in some states. Our results strongly imply that factors other than sheer numbers are more important. Site-to-site differences are the most likely explanation for the variation in success.

  6. Sample presentation, sources of error and future perspectives on the application of vibrational spectroscopy in the wine industry.

    Science.gov (United States)

    Cozzolino, Daniel

    2015-03-30

    Vibrational spectroscopy encompasses a number of techniques and methods including ultra-violet, visible, Fourier transform infrared or mid infrared, near infrared and Raman spectroscopy. The use and application of spectroscopy generates spectra containing hundreds of variables (absorbances at each wavenumbers or wavelengths), resulting in the production of large data sets representing the chemical and biochemical wine fingerprint. Multivariate data analysis techniques are then required to handle the large amount of data generated in order to interpret the spectra in a meaningful way in order to develop a specific application. This paper focuses on the developments of sample presentation and main sources of error when vibrational spectroscopy methods are applied in wine analysis. Recent and novel applications will be discussed as examples of these developments. © 2014 Society of Chemical Industry.

  7. Sample intake position and loading rates from nonpoint source pollution

    Science.gov (United States)

    McGuire, P. E.; Daniel, T. C.; Stoffel, D.; Andraski, B.

    1980-01-01

    Paired water samples were simultaneously activated from two different vertical positions within the approach section of a flow-control structure to determine the effect of sample intake position on nonpoint runoff parameter concentrations and subsequent event loads. Suspended solids (SS), total phosphorus (TP) and organic plus exchangeable nitrogen [(Or+Ex)-N] were consistently higher throughout each runoff event when sampled from the floor of the approach section as opposed to those samples taken at midstage. Dissolved molybdate reactive phosphorus (DMRP) and ammonium (NH4-N) concentrations did not appear to be significantly affected by the vertical difference in intake position. However, the nitrate plus nitrite nitrogen [(NO3+NO2)-N] concentrations were much higher when sampled from the midstage position. Although the concentration differences between the two methods were not appreciable, when evaluated in terms of event loads, discrepancies were evident for all parameters. Midstage sampling produced event loads for SS, TP, (Or + Ex)-N, DMRP, NH4-N, and (NO3+NO2)-N that were 44,39,35,80,71, and 181%, respectively, of floor sampling loads. Differences in loads between the two methods are attributed to the midstage position, sampling less of the bed load. The correct position will depend on the objective; however, such differences should be recognized during the design phase of the monitoring program.

  8. Occurrence of Giardia intestinalis and Cryptosporidium sp. in wastewater samples from São Paulo State, Brazil, and Lima, Peru.

    Science.gov (United States)

    Ulloa-Stanojlović, Francisco Miroslav; Aguiar, Bruna; Jara, Luis M; Sato, Maria Inês Zanoli; Guerrero, Juana Arzola; Hachich, Elayse; Matté, Glavur Rogério; Dropa, Milena; Matté, Maria Helena; de Araújo, Ronalda Silva

    2016-11-01

    The objectives of the study were to detect and genotype Cryptosporidium spp. and Giardia intestinalis in wastewater samples obtained from five cities with high transit of people in the State of São Paulo, Brazil, and at the entrance of a Wastewater Treatment Plant (WWTP) in Lima, Peru. Samples were collected and concentrated by centrifugation. The genomic DNA was extracted for molecular characterization by nested PCR for Cryptosporidium and double nested PCR for Giardia, followed by sequencing and phylogenetic analysis. G. intestinalis was found in 63.6 % of the samples, and the human assemblages A and B were identified. Cryptosporidium sp. was found in 36.4 % of the samples, and the species were corresponding to Cryptosporidium hominis, Cryptosporidium cuniculus, and Cryptosporidium muris. Results revealed the presence of human pathogenic Cryptosporidium species and G. intestinalis human pathogenic assemblages. Molecular tools highlight the importance to map the genetic diversity of these parasites, as well as to detect their epidemiological circulation pathway in the environment.

  9. Responsibilities of the exporting state derived from the application of the code of conduct on the safety and security of radioactive sources and the guidance on the import and export

    International Nuclear Information System (INIS)

    Vidal, Dora

    2008-01-01

    Full text: 'The exporting state in deciding whether to authorize an export of radioactive sources should satisfy itself, insofar as practicable: 1) That the recipient is authorized by the importing state to receive and possess the source in accordance with its laws and regulations; 2) That the importing state has the appropriate technical and administrative capability, resources and regulatory structure needed for the management of the source(s) in a manner consistent with the guidance in the code, and consider, based upon available information: i) Whether the recipient has been engaged in clandestine or illegal procurement of radioactive sources; ii) Whether an import or export authorization for radioactive sources has been denied to the recipient or importing state, or whether the recipient or importing state has made diverted for purposes inconsistent with the code any import or export of radioactive sources previously authorized; and iii) The risk of diversion or malicious acts involving radioactive sources'. It also should take, once it has decided to authorize the export, 'appropriate steps to ensure that the export is conducted in a manner consistent with existing relevant international standards relating to the transport of radioactive materials an the importing State is notified in advance of each shipment'. The Guidance has done a great effort in fixing the requirements that the importing State has to fulfill and it is the exporting State which has to verify, satisfy, and consider if these requirements are in place. It is remarkable the responsibility of the exporting state in analyzing the export from the point of view of the capabilities of the importing State to manage the sources with the purpose of use it has and even once it is not useful any more. This paper has the intention of bringing to reflect the responsibility of the exporting State in relation to those radioactive sources that are exported or are to be exported and have to fulfill with the

  10. SURFACE AND LIGHTNING SOURCES OF NITROGEN OXIDES OVER THE UNITED STATES: MAGNITUDES, CHEMICAL EVOLUTION, AND OUTFLOW

    Science.gov (United States)

    We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3-D model of tropospheric chemistry (GEOS-Chem) to test current understanding of regional sources, chemical evolution...

  11. On-line sample processing methods in flow analysis

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald

    2008-01-01

    In this chapter, the state of the art of flow injection and related approaches thereof for automation and miniaturization of sample processing regardless of the aggregate state of the sample medium is overviewed. The potential of the various generation of flow injection for implementation of in...

  12. Sample Based Unit Liter Dose Estimates

    International Nuclear Information System (INIS)

    JENSEN, L.

    1999-01-01

    The Tank Waste Characterization Program has taken many core samples, grab samples, and auger samples from the single-shell and double-shell tanks during the past 10 years. Consequently, the amount of sample data available has increased, both in terms of quantity of sample results and the number of tanks characterized. More and better data is available than when the current radiological and toxicological source terms used in the Basis for Interim Operation (BIO) (FDH 1999) and the Final Safety Analysis Report (FSAR) (FDH 1999) were developed. The Nuclear Safety and Licensing (NS and L) organization wants to use the new data to upgrade the radiological and toxicological source terms used in the BIO and FSAR. The NS and L organization requested assistance in developing a statistically based process for developing the source terms. This report describes the statistical techniques used and the assumptions made to support the development of a new radiological source term for liquid and solid wastes stored in single-shell and double-shell tanks

  13. Sealed radioactive source management

    International Nuclear Information System (INIS)

    2005-01-01

    Sealed radioactive sources have been used in a wide range of application in medicine, agriculture, geology, industry and other fields. Since its utilization many sources have become out of use and became waste but no proper management. This has lead to many accidents causing deaths and serious radiation injuries worldwide. Spent sources application is expanding but their management has seen little improvements. Sealed radioactive sources have become a security risk calling for prompt action. Source management helps to maintain sources in a good physical status and provide means of source tracking and control. It also provides a well documented process of the sources making any future management options safe, secure and cost effective. Last but not least good source management substantially reduces the risk of accidents and eliminates the risk of malicious use. The International Atomic Energy Agency assists Member States to build the infrastructure to properly manage sealed radioactive sources. The assistance includes training of national experts to handle, condition and properly store the sources. For Member States that do not have proper facilities, we provide the technical assistance to design a proper facility to properly manage the radioactive sources and provide for their proper storage. For Member States that need to condition their sources properly but don't have the required infrastructure we provide direct assistance to physically help them with source recovery and provide an international expert team to properly condition their sources and render them safe and secure. We offer software (Radioactive Waste Management Registry) to properly keep a complete record on the sources and provide for efficient tracking. This also helps with proper planning and decision making for long term management

  14. Certification of Public Librarians in the United States. A Detailed Summary of Legally Mandated and Voluntary Certification Plans for Public Librarians Based on Information Supplied by the Various Certificating State Agencies or Other Appropriate Sources. 3rd Edition.

    Science.gov (United States)

    Coe, Mary J., Ed.

    This report contains summaries of legally mandated and voluntary certification plans for public librarians in the United States based on information supplied by the various certifying state agencies or other appropriate sources in April 1979. Each plan is identified by the descriptive terms "mandatory" (certification required by law--23 states),…

  15. Trends in darunavir resistance-associated mutations and phenotypic resistance in commercially tested United States clinical samples between 2006 and 2012.

    Science.gov (United States)

    Lathouwers, Erkki; Gupta, Soumi; Haddad, Mojgan; Paquet, Agnes; de Meyer, Sandra; Baugh, Bryan

    2015-06-01

    HIV-1 samples submitted by clinicians from the United States for routine drug susceptibility testing (PhenoSense GT) were evaluated for genotypic and phenotypic resistance to darunavir and other protease inhibitors (PIs). Among these samples (Monogram Biosciences database January 2006-June 2012; N=78,843), isolates harboring zero IAS-USA darunavir resistance-associated mutations (RAMs) increased from 77.7% in 2006 to 92.8% through the first half of 2012 (H1 2012; upward trend, p=0.0008); a downward trend seen for samples with three or more darunavir RAMs (7.5% in 2006 and 2.6% in H1 2012; p=0.002). Among samples with any PI resistance (N=15,932), samples harboring zero darunavir RAMs gradually increased (39.9% in 2006 vs. 55.0% in H1 2012; upward trend, p=0.005), but three or more darunavir RAMs did not change over time (21.7% in 2006 and 19.2% in H1 2012; p=0.27). During this period, the frequency of the 11 individual darunavir RAMs (IAS-USA 2011 list) decreased among all samples. The frequency of each darunavir RAM in PI-resistant samples decreased or remained relatively stable. The prevalence of samples with phenotypic resistance to darunavir (partial-to-full) decreased over time in all samples (8.2% in 2006 vs. 2.3% in H1 2012), as did resistance to other PIs (p<0.006 for all PIs). Phenotypic resistance to darunavir and other PIs also decreased in PI-resistant samples (darunavir: 23.9% in 2006 vs. 17.1% in H1 2012; p<0.013 for all PIs). Since approval of darunavir in 2006, there was a significant decrease in prevalence of samples with genotypic and phenotypic resistance to darunavir in commercially tested HIV-1 isolates. Furthermore, the prevalence of phenotypic resistance to darunavir was lower than all other PIs.

  16. Evolutionary tracks of extended radio sources

    International Nuclear Information System (INIS)

    Baldwin, J.E.

    1982-01-01

    We know almost nothing about the evolutionary tracks of extragalactic radio sources but those tracks are, however, strongly constrained by the distribution of sources in the radio luminosity, P, overall physical size, D, diagram. The P-D diagram for the 3CR 166 source sample of Jenkins et al. (1977) is presented with later additions. Most of the sources are identified and have known redshifts. Because of doubts about the completeness of the sample in this region, the author has made searches in the 6C 151MHz survey for sources with specific surface brightnesses. The numbers found to a limiting flux density of 1-2 Jy suggest that there is no serious underestimate of the numbers in 166 source sample. (Auth.)

  17. Tritium distribution in the environment in the vicinity of a chronic atmospheric source-assessment of the steady state hypothesis

    International Nuclear Information System (INIS)

    Murphy, C.E. Jr.; Bauer, L.R.; Zeigler, C.C.

    1990-01-01

    The Savannah River Site (SRS) is a major radionuclide production center. Tritium has been released to the atmosphere over the 36 year period of operation. The tritiated water concentration of the atmosphere, rain, vegetation and food have been routinely monitored during this period. Special studies have been made of tritium in soils and in the organic fractions of these same materials. The available data suggest that the average tritium concentration in the components of the terrestrial environment have approached a steady state with the two main sources of tritium, rainfall and atmospheric water vapor

  18. Los Alamos Scientific Laboratory approach to hydrogeochemical and stream sediment reconnaissance for uranium in the United States

    International Nuclear Information System (INIS)

    Bolivar, S.L.

    1980-01-01

    The Los Alamos Scientific Laboratory of the United States is conducting a geochemical survey for uranium in the Rocky Mountain states of New Mexico, Colorado, Wyoming, and Montana and in Alaska. This survey is part of a national hydrogeochemical and stream sediment reconnaissance in which four Department of Energy laboratories will study the uranium resources of the United States to provide data for the National Uranium Resource Evaluation program. The reconnaissance will identify areas having higher than background concentrations of uranium in ground waters, surface waters, and water-transported sediments. The reconnaissance data will be combined with data from airborne radiometric surveys and geological and geophysical investigations to provide an improved estimate for the economics and availability of nuclear fuel resources in the United States and to make information available to industry for use in the exploration and development of uranium resources. Water samples are analyzed for uranium by fluorometry which has a 0.02 parts per billion lower limit of detection. Concentrations of 12 additional elements in water are determined by plasma-source emission spectrography. All sediments are analyzed for uranium by delayed-neutron counting and a 20 parts per billion lower limit of detection. Elemental concentrations in sediments are also determined by neutron activation analysis, x-ray fluorescence, and by arc-source emission spectrography. To date, all of four Rocky Mountain states and about 80% of Alaska have been sampled. About 220,000 samples have been collected from an area of nearly 2,500,000 km 2 . The philosophy, sampling methodology, analytical techniques, and progress of the reconnaissance are described in several published pilot study, reconnaissance, and technical reports. The Los Alamos program was designed to maximize the identification of uranium in terrains of varied geography, geology, and climate

  19. Determination of volatile organic compounds pollution sources in malaysian drinking water using multivariate analysis.

    Science.gov (United States)

    Soh, Shiau-Chian; Abdullah, Md Pauzi

    2007-01-01

    A field investigation was conducted at all water treatment plants throughout 11 states and Federal Territory in Peninsular Malaysia. The sampling points in this study include treatment plant operation, service reservoir outlet and auxiliary outlet point at the water pipelines. Analysis was performed by solid phase micro-extraction technique with a 100 microm polydimethylsiloxane fibre using gas chromatography with mass spectrometry detection to analyse 54 volatile organic compounds (VOCs) of different chemical families in drinking water. The concentration of VOCs ranged from undetectable to 230.2 microg/l. Among all of the VOCs species, chloroform has the highest concentration and was detected in all drinking water samples. Average concentrations of total trihalomethanes (THMs) were almost similar among all states which were in the range of 28.4--33.0 microg/l. Apart from THMs, other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichloro - benzene. Principal component analysis (PCA) with the aid of varimax rotation, and parallel factor analysis (PARAFAC) method were used to statistically verify the correlation between VOCs and the source of pollution. The multivariate analysis pointed out that the maintenance of auxiliary pipelines in the distribution systems is vital as it can become significant point source pollution to Malaysian drinking water.

  20. Funding Sources for Visually Impaired Students in Higher Education.

    Science.gov (United States)

    Traber, M.

    1987-01-01

    Financial aid sources available to visually handicapped students for postsecondary educational, vocational, or technical programs are outlined. Sources include national and state blindness agencies, colleges and universities, state vocational rehabilitation agencies, and the federal government. (Author/JDD)

  1. Effects of Childhood Adversity on Bullying and Cruelty to Animals in the United States: Findings from a National Sample

    Science.gov (United States)

    Vaughn, Michael G.; Fu, Qiang; Beaver, Kevin M.; DeLisi, Matt; Perron, Brian E.; Howard, Matthew O.

    2011-01-01

    This study examined effects of type of and cumulative burden of childhood adversities on bullying and cruelty to animals in the United States. Data were derived from Waves I and II of the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample of U.S. adults. Structured psychiatric interviews were…

  2. Dynamically polarized samples for neutron protein crystallography at the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Zhao, Jinkui; Pierce, Josh; Robertson, J. L.; Herwig, Kenneth W.; Myles, Dean; Cuneo, Matt; Li, Le; Meilleur, Flora; Standaert, Bob

    2016-01-01

    To prepare for the next generation neutron scattering instruments for the planned second target station at the Spallation Neutron Source (SNS) and to broaden the scientific impact of neutron protein crystallography at the Oak Ridge National Laboratory, we have recently ramped up our efforts to develop a dynamically polarized target for neutron protein crystallography at the SNS. Proteins contain a large amount of hydrogen which contributes to incoherent diffraction background and limits the sensitivity of neutron protein crystallography. This incoherent background can be suppressed by using polarized neutron diffraction, which in the same time also improves the coherent diffraction signal. Our plan is to develop a custom Dynamic Nuclear Polarization (DNP) setup tailored to neutron protein diffraction instruments. Protein crystals will be polarized at a magnetic field of 5 T and temperatures of below 1 K. After the dynamic polarization process, the sample will be brought to a frozen-spin mode in a 0.5 T holding field and at temperatures below 100 mK. In a parallel effort, we are also investigating various ways of incorporating polarization agents needed for DNP, such as site specific spin labels, into protein crystals. (paper)

  3. On-line measurement of the microwave power in ECR ion source

    International Nuclear Information System (INIS)

    Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang

    2005-01-01

    It is a new technology that ECR ion source is applied in the neutron generator. Because of effect of the structure, working state of ECR ion source could not be judged by the color of gas discharging in discharging chamber as doing in high frequency ion source. Therefore, state adjusting of ECR ion source was difficult in running of the neutron generator. The method to resolve the question is described in this paper. The micro-wave power was measured in case of running by using the method of directional coupler adding small microwave power meter. Because both were in the direct proportion, the ion beam current could be educed from microwave incidence power measured, and discharge state in discharge chamber could be judged. Finally, the neutron generator might be operated in best running state. (authors)

  4. Mapping of tritium in drinking water from various Indian states

    International Nuclear Information System (INIS)

    Shah, Chirag A.; Baburajan, A.; Ravi, P.M.; Tripathi, R.M.

    2015-01-01

    The tritium in fresh water used for drinking purpose across five state of India was analyzed for tritium activity. The tritium data obtained were compared with the monitoring data of tritium in drinking water sources at Tarapur site, which houses a number of nuclear facilities. It is observed that the tritium activity in the water sample from various out station locations were in the range of < 0.48 to 1.33 Bq/l. The tritium value obtained in the drinking water sources at Tarapur was found to be in the range of 0.91 to 3.10 Bq/l. The monitoring of tritium in drinking water from Tarapur and from various out station location indicate that the level is negligible compared to the USEPA limit of 10000 Bq/l and the contribution of operation nuclear facilities to the tritium activity in drinking water source at Tarapur is insignificant. (author)

  5. Elemental Composition of Mars Return Samples Using X-Ray Fluorescence Imaging at the National Synchrotron Light Source II

    Science.gov (United States)

    Thieme, J.; Hurowitz, J. A.; Schoonen, M. A.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

    2018-04-01

    NSLS-II at BNL provides a unique and critical capability to perform assessments of the elemental composition and the chemical state of Mars returned samples using synchrotron radiation X-ray fluorescence imaging and X-ray absorption spectroscopy.

  6. Geochemical characterization of critical dust source regions in the American West

    Science.gov (United States)

    Aarons, Sarah M.; Blakowski, Molly A.; Aciego, Sarah M.; Stevenson, Emily I.; Sims, Kenneth W. W.; Scott, Sean R.; Aarons, Charles

    2017-10-01

    The generation, transport, and deposition of mineral dust are detectable in paleoclimate records from land, ocean, and ice, providing valuable insight into earth surface conditions and cycles on a range of timescales. Dust deposited in marine and terrestrial ecosystems can provide critical nutrients to nutrient-limited ecosystems, and variations in dust provenance can indicate changes in dust production, sources and transport pathways as a function of climate variability and land use change. Thus, temporal changes in locations of dust source areas and transport pathways have implications for understanding interactions between mineral dust, global climate, and biogeochemical cycles. This work characterizes dust from areas in the American West known for dust events and/or affected by increasing human settlement and livestock grazing during the last 150 years. Dust generation and uplift from these dust source areas depends on climate and land use practices, and the relative contribution of dust has likely changed since the expansion of industrialization and agriculture into the western United States. We present elemental and isotopic analysis of 28 potential dust source area samples analyzed using Thermal Ionization Mass Spectrometry (TIMS) for 87Sr/86Sr and 143Nd/144Nd composition and Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) for 176Hf/177Hf composition, and ICPMS for major and trace element concentrations. We find significant variability in the Sr, Nd, and Hf isotope compositions of potential source areas of dust throughout western North America, ranging from 87Sr/86Sr = 0.703699 to 0.740236, εNd = -26.6 to 2.4, and εHf = -21.7 to -0.1. We also report differences in the trace metal and phosphorus concentrations in the geologic provinces sampled. This research provides an important resource for the geochemical tracing of dust sources and sinks in western North America, and will aid in modeling the biogeochemical impacts of increased

  7. A regional modeling framework of phosphorus sources and transport in streams of the southeastern United States

    Science.gov (United States)

    Garcia, Ana Maria.; Hoos, Anne B.; Terziotti, Silvia

    2011-01-01

    We applied the SPARROW model to estimate phosphorus transport from catchments to stream reaches and subsequent delivery to major receiving water bodies in the Southeastern United States (U.S.). We show that six source variables and five land-to-water transport variables are significant (p < 0.05) in explaining 67% of the variability in long-term log-transformed mean annual phosphorus yields. Three land-to-water variables are a subset of landscape characteristics that have been used as transport factors in phosphorus indices developed by state agencies and are identified through experimental research as influencing land-to-water phosphorus transport at field and plot scales. Two land-to-water variables – soil organic matter and soil pH – are associated with phosphorus sorption, a significant finding given that most state-developed phosphorus indices do not explicitly contain variables for sorption processes. Our findings for Southeastern U.S. streams emphasize the importance of accounting for phosphorus present in the soil profile to predict attainable instream water quality. Regional estimates of phosphorus associated with soil-parent rock were highly significant in explaining instream phosphorus yield variability. Model predictions associate 31% of phosphorus delivered to receiving water bodies to geology and the highest total phosphorus yields in the Southeast were catchments with already high background levels that have been impacted by human activity.

  8. Determination of 40K in water samples

    International Nuclear Information System (INIS)

    Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R.

    2014-10-01

    The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of 40 K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the 40 K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the 40 K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of 137 Cs, diameter 22 Na and 7.62 cm of height, using containers Marinelli and 60 Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the 40 K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of 40 K deposits an effective dose which contributes to annual dose received by people. (Author)

  9. An Empirical State Error Covariance Matrix for Batch State Estimation

    Science.gov (United States)

    Frisbee, Joseph H., Jr.

    2011-01-01

    State estimation techniques serve effectively to provide mean state estimates. However, the state error covariance matrices provided as part of these techniques suffer from some degree of lack of confidence in their ability to adequately describe the uncertainty in the estimated states. A specific problem with the traditional form of state error covariance matrices is that they represent only a mapping of the assumed observation error characteristics into the state space. Any errors that arise from other sources (environment modeling, precision, etc.) are not directly represented in a traditional, theoretical state error covariance matrix. Consider that an actual observation contains only measurement error and that an estimated observation contains all other errors, known and unknown. It then follows that a measurement residual (the difference between expected and observed measurements) contains all errors for that measurement. Therefore, a direct and appropriate inclusion of the actual measurement residuals in the state error covariance matrix will result in an empirical state error covariance matrix. This empirical state error covariance matrix will fully account for the error in the state estimate. By way of a literal reinterpretation of the equations involved in the weighted least squares estimation algorithm, it is possible to arrive at an appropriate, and formally correct, empirical state error covariance matrix. The first specific step of the method is to use the average form of the weighted measurement residual variance performance index rather than its usual total weighted residual form. Next it is helpful to interpret the solution to the normal equations as the average of a collection of sample vectors drawn from a hypothetical parent population. From here, using a standard statistical analysis approach, it directly follows as to how to determine the standard empirical state error covariance matrix. This matrix will contain the total uncertainty in the

  10. STRAIN LOCALIZATION PECULIARITIES AND DISTRIBUTION OF ACOUSTIC EMISSION SOURCES IN ROCK SAMPLES TESTED BY UNIAXIAL COMPRESSION AND EXPOSED TO ELECTRIC PULSES

    Directory of Open Access Journals (Sweden)

    V. A. Mubassarova

    2014-01-01

    Full Text Available Results of uniaxial compression tests of rock samples in electromagnetic fields are presented. The experiments were performed in the Laboratory of Basic Physics of Strength, Institute of Continuous Media Mechanics, Ural Branch of RAS (ICMM. Deformation of samples was studied, and acoustic emission (AE signals were recorded. During the tests, loads varied by stages. Specimens of granite from the Kainda deposit in Kyrgyzstan (similar to samples tested at the Research Station of RAS, hereafter RS RAS were subject to electric pulses at specified levels of compression load. The electric pulses supply was galvanic; two graphite electrodes were fixed at opposite sides of each specimen. The multichannel Amsy-5 Vallen System was used to record AE signals in the six-channel mode, which provided for determination of spatial locations of AE sources. Strain of the specimens was studied with application of original methods of strain computation based on analyses of optical images of deformed specimen surfaces in LaVISION Strain Master System.Acoustic emission experiment data were interpreted on the basis of analyses of the AE activity in time, i.e. the number of AE events per second, and analyses of signals’ energy and AE sources’ locations, i.e. defects.The experiment was conducted at ICMM with the use of the set of equipment with advanced diagnostic capabilities (as compared to earlier experiments described in [Zakupin et al., 2006a, 2006b; Bogomolov et al., 2004]. It can provide new information on properties of acoustic emission and deformation responses of loaded rock specimens to external electric pulses.The research task also included verification of reproducibility of the effect (AE activity when fracturing rates responded to electrical pulses, which was revealed earlier in studies conducted at RS RAS. In terms of the principle of randomization, such verification is methodologically significant as new effects, i.e. physical laws, can be considered

  11. Trace uranium analysis in Indian coal samples using the fission track technique

    International Nuclear Information System (INIS)

    Jojo, P.J.; Rawat, A.; Kumar, Ashavani; Prasad, Rajendra

    1993-01-01

    The ever-growing demand for energy has resulted in the extensive use of fossil fuels, especially coal, for power generation. Coal and its by-products often contain significant amounts of radionuclides, including uranium, which is the ultimate source of the radioactive gas Radon-222. The present study gives the concentration of uranium in coal samples of different collieries in India, collected from various thermal power plants in the state of Uttar Pradesh. The estimates were made using the fission track technique. Latent damage tracks were not found to be uniformly distributed but showed sun bursts and clusters. Non-uniform distributions of trace elements are a very common phenomenon in rocks. The levels of uranium in the coal samples were found to vary from 2.0 to 4.9 ppm in uniform distributions and from 21.3 to 41.0 ppm in non-uniform distributions. Measurements were also made on fly ash samples where the average uranium concentration was found to be 8.4 and 49.3 ppm in uniform and non-uniform distributions, respectively. (author)

  12. Effect of sample moisture and bulk density on performance of the 241Am-Be source based prompt gamma rays neutron activation analysis setup. A Monte Carlo study

    International Nuclear Information System (INIS)

    Almisned, Ghada

    2010-01-01

    Monte Carlo simulations were carried out using the dependence of gamma ray yield on the bulk density and moisture content for five different lengths of Portland cement samples in a thermal neutron capture based Prompt Gamma ray Neutron Activation Analysis (PGNAA) setup for source inside moderator geometry using an 241 Am-Be neutron source. In this study, yields of 1.94 and 6.42 MeV prompt gamma rays from calcium in the five Portland cement samples were calculated as a function of sample bulk density and moisture content. The study showed a strong dependence of the 1.94 and 6.42 MeV gamma ray yield upon the sample bulk density but a weaker dependence upon sample moisture content. For an order of magnitude increase in the sample bulk density, an order of magnitude increase in the gamma rays yield was observed, i.e., a one-to-one correspondence. In case of gamma ray yield dependence upon sample moisture content, an order of magnitude increase in the moisture content of the sample resulted in about 16-17% increase in the yield of 1.94 and 6.42 MeV gamma rays from calcium. (author)

  13. Pneumatic sample-transfer system for use with the Lawrence Livermore National Laboratory rotating target neutron source (RTNS-I)

    International Nuclear Information System (INIS)

    Williams, R.E.

    1981-07-01

    A pneumatic sample-transfer system is needed to be able to rapidly retrieve samples irradiated with 14-MeV neutrons at the Rotating Target Neutron Source (RTNS-I). The rabbit system, already in place for many years, has been refurbished with modern system components controlled by an LSI-11 minicomputer. Samples can now be counted three seconds after an irradiation. There are many uses for this expanded 14-MeV neutron activation capability. Several fission products difficult to isolate from mixed fission fragments can be produced instead through (n,p) or (n,α) reactions with stable isotopes. Mass-separated samples of Nd, Mo, and Se, for example, can be irradiated to produce Pr, Nb, and As radionuclides sufficient for decay scheme studies. The system may also be used for multielement fast-neutron activation analysis because the neutron flux is greater than 2 x 10 11 n/cm 2 -sec. Single element analyses of Si and O are also possible. Finally, measurements of fast-neutron cross sections producing short-lived activation products can be performed with this system. A description of the rabbit system and instructions for its use are presented in this report

  14. Study of nonpoint source nutrient loading in the Patuxent River basin, Maryland

    Science.gov (United States)

    Preston, S.D.

    1997-01-01

    Study of nonpoint-source (NPS) nutrient loading in Maryland has focused on the Patuxent watershed because of its importance and representativeness of conditions in the State. Evaluation of NPS nutrient loading has been comprehensive and has included long-term monitoring, detailed watershed modeling, and synoptic sampling studies. A large amount of information has been compiled for the watershed and that information is being used to identify primary controls and efficient management strategies for NPS nutrient loading. Results of the Patuxent NPS study have identified spatial trends in water quality that appear to be related to basin charcteristics such as land use, physiography, andgeology. Evaluation of the data compiled by the study components is continuing and is expected to provide more detailed assessments of the reasons for spatial trends. In particular, ongoing evaluation of the watershed model output is expected to provide detailed information on the relative importance of nutrient sources and transport pathways across the entire watershed. Planned future directions of NPS evaluation in the State of Maryland include continued study of water quality in the Patuxent watershed and a shift in emphasis to a statewide approach. Eventually, the statewide approach will become the primary approach usedby the State to evaluate NPS loading. The information gained in the Patuxent study and the tools developed will represent valuable assets indeveloping the statewide NPS assessment program.

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

    Directory of Open Access Journals (Sweden)

    Soydemir E.

    2014-07-01

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

  16. Legal status and source of offenders' firearms in states with the least stringent criteria for gun ownership.

    Science.gov (United States)

    Vittes, Katherine A; Vernick, Jon S; Webster, Daniel W

    2013-02-01

    Gun possession by high-risk individuals presents a serious threat to public safety. U.S. federal law establishes minimum criteria for legal purchase and possession of firearms; many states have laws disqualifying additional categories for illegal possession. We used data from a national survey of state prison inmates to calculate: 1) the proportion of offenders, incarcerated for crimes committed with firearms in 13 states with the least restrictive firearm purchase and possession laws, who would have been prohibited if their states had stricter gun laws; and 2) the source of gun acquisition for offenders who were and were not legally permitted to purchase and possess firearms. Nearly three of ten gun offenders (73 of 253 or 28.9%) were legal gun possessors but would have been prohibited from purchasing or possessing firearms when committing their most recent offense if their states had stricter prohibitions. Offenders who were already prohibited under current law acquired their gun from a licensed dealer, where a background check is required, five times less often than offenders who were not prohibited (3.9% vs. 19.9%; χ(2)=13.31; p≤0.001). Nearly all (96.1%) offenders who were legally prohibited, acquired their gun from a supplier not required to conduct a background check. Stricter gun ownership laws would have made firearm possession illegal for many state prison inmates who used a gun to commit a crime. Requiring all gun sales to be subject to a background check would make it more difficult for these offenders to obtain guns.

  17. Size distribution, directional source contributions and pollution status of PM from Chengdu, China during a long-term sampling campaign.

    Science.gov (United States)

    Shi, Guo-Liang; Tian, Ying-Ze; Ma, Tong; Song, Dan-Lin; Zhou, Lai-Dong; Han, Bo; Feng, Yin-Chang; Russell, Armistead G

    2017-06-01

    Long-term and synchronous monitoring of PM 10 and PM 2.5 was conducted in Chengdu in China from 2007 to 2013. The levels, variations, compositions and size distributions were investigated. The sources were quantified by two-way and three-way receptor models (PMF2, ME2-2way and ME2-3way). Consistent results were found: the primary source categories contributed 63.4% (PMF2), 64.8% (ME2-2way) and 66.8% (ME2-3way) to PM 10 , and contributed 60.9% (PMF2), 65.5% (ME2-2way) and 61.0% (ME2-3way) to PM 2.5 . Secondary sources contributed 31.8% (PMF2), 32.9% (ME2-2way) and 31.7% (ME2-3way) to PM 10 , and 35.0% (PMF2), 33.8% (ME2-2way) and 36.0% (ME2-3way) to PM 2.5 . The size distribution of source categories was estimated better by the ME2-3way method. The three-way model can simultaneously consider chemical species, temporal variability and PM sizes, while a two-way model independently computes datasets of different sizes. A method called source directional apportionment (SDA) was employed to quantify the contributions from various directions for each source category. Crustal dust from east-north-east (ENE) contributed the highest to both PM 10 (12.7%) and PM 2.5 (9.7%) in Chengdu, followed by the crustal dust from south-east (SE) for PM 10 (9.8%) and secondary nitrate & secondary organic carbon from ENE for PM 2.5 (9.6%). Source contributions from different directions are associated with meteorological conditions, source locations and emission patterns during the sampling period. These findings and methods provide useful tools to better understand PM pollution status and to develop effective pollution control strategies. Copyright © 2016. Published by Elsevier B.V.

  18. California Air Quality State Implementation Plans; Final Approval; Butte County Air Quality Management District; Stationary Source Permits

    Science.gov (United States)

    EPA is taking final action to approve a revision to the Butte County Air Quality Management District (BCAQMD) portion of the California State Implementation Plan (SIP). This revision concerns the District's New Source Review (NSR) permitting program.

  19. Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

    Science.gov (United States)

    Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

    2009-11-01

    Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space.

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

    Science.gov (United States)

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

    2009-07-01

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