WorldWideScience

Sample records for local background concentrations

  1. Characterizing the spatial variability of local and background concentration signals for air pollution at the neighbourhood scale

    Science.gov (United States)

    Shairsingh, Kerolyn K.; Jeong, Cheol-Heon; Wang, Jonathan M.; Evans, Greg J.

    2018-06-01

    Vehicle emissions represent a major source of air pollution in urban districts, producing highly variable concentrations of some pollutants within cities. The main goal of this study was to identify a deconvolving method so as to characterize variability in local, neighbourhood and regional background concentration signals. This method was validated by examining how traffic-related and non-traffic-related sources influenced the different signals. Sampling with a mobile monitoring platform was conducted across the Greater Toronto Area over a seven-day period during summer 2015. This mobile monitoring platform was equipped with instruments for measuring a wide range of pollutants at time resolutions of 1 s (ultrafine particles, black carbon) to 20 s (nitric oxide, nitrogen oxides). The monitored neighbourhoods were selected based on their land use categories (e.g. industrial, commercial, parks and residential areas). The high time-resolution data allowed pollutant concentrations to be separated into signals representing background and local concentrations. The background signals were determined using a spline of minimums; local signals were derived by subtracting the background concentration from the total concentration. Our study showed that temporal scales of 500 s and 2400 s were associated with the neighbourhood and regional background signals respectively. The percent contribution of the pollutant concentration that was attributed to local signals was highest for nitric oxide (NO) (37-95%) and lowest for ultrafine particles (9-58%); the ultrafine particles were predominantly regional (32-87%) in origin on these days. Local concentrations showed stronger associations than total concentrations with traffic intensity in a 100 m buffer (ρ:0.21-0.44). The neighbourhood scale signal also showed stronger associations with industrial facilities than the total concentrations. Given that the signals show stronger associations with different land use suggests that

  2. Analysis of local-scale background concentrations of methane and other gas-phase species in the Marcellus Shale

    Directory of Open Access Journals (Sweden)

    J. Douglas Goetz

    2017-02-01

    Full Text Available The Marcellus Shale is a rapidly developing unconventional natural gas resource found in part of the Appalachian region. Air quality and climate concerns have been raised regarding development of unconventional natural gas resources. Two ground-based mobile measurement campaigns were conducted to assess the impact of Marcellus Shale natural gas development on local scale atmospheric background concentrations of air pollution and climate relevant pollutants in Pennsylvania. The first campaign took place in Northeastern and Southwestern PA in the summer of 2012. Compounds monitored included methane (CH4, ethane, carbon monoxide (CO, nitrogen dioxide, and Proton Transfer Reaction Mass Spectrometer (PTR-MS measured volatile organic compounds (VOC including oxygenated and aromatic VOC. The second campaign took place in Northeastern PA in the summer of 2015. The mobile monitoring data were analyzed using interval percentile smoothing to remove bias from local unmixed emissions to isolate local-scale background concentrations. Comparisons were made to other ambient monitoring in the Marcellus region including a NOAA SENEX flight in 2013. Local background CH4 mole fractions were 140 ppbv greater in Southwestern PA compared to Northeastern PA in 2012 and background CH4 increased 100 ppbv from 2012 to 2015. CH4 local background mole fractions were not found to have a detectable relationship between well density or production rates in either region. In Northeastern PA, CO was observed to decrease 75 ppbv over the three year period. Toluene to benzene ratios in both study regions were found to be most similar to aged rural air masses indicating that the emission of aromatic VOC from Marcellus Shale activity may not be significantly impacting local background concentrations. In addition to understanding local background concentrations the ground-based mobile measurements were useful for investigating the composition of natural gas emissions in the region.

  3. Chemical Source Localization Fusing Concentration Information in the Presence of Chemical Background Noise.

    Science.gov (United States)

    Pomareda, Víctor; Magrans, Rudys; Jiménez-Soto, Juan M; Martínez, Dani; Tresánchez, Marcel; Burgués, Javier; Palacín, Jordi; Marco, Santiago

    2017-04-20

    We present the estimation of a likelihood map for the location of the source of a chemical plume dispersed under atmospheric turbulence under uniform wind conditions. The main contribution of this work is to extend previous proposals based on Bayesian inference with binary detections to the use of concentration information while at the same time being robust against the presence of background chemical noise. For that, the algorithm builds a background model with robust statistics measurements to assess the posterior probability that a given chemical concentration reading comes from the background or from a source emitting at a distance with a specific release rate. In addition, our algorithm allows multiple mobile gas sensors to be used. Ten realistic simulations and ten real data experiments are used for evaluation purposes. For the simulations, we have supposed that sensors are mounted on cars which do not have among its main tasks navigating toward the source. To collect the real dataset, a special arena with induced wind is built, and an autonomous vehicle equipped with several sensors, including a photo ionization detector (PID) for sensing chemical concentration, is used. Simulation results show that our algorithm, provides a better estimation of the source location even for a low background level that benefits the performance of binary version. The improvement is clear for the synthetic data while for real data the estimation is only slightly better, probably because our exploration arena is not able to provide uniform wind conditions. Finally, an estimation of the computational cost of the algorithmic proposal is presented.

  4. Concentration of 210Po in local foodstuffs grown nearby High Background Areas (HBRA)

    International Nuclear Information System (INIS)

    Kamesh Viswanathan, B.; Arunachalam, Kantha D.; Sathesh Kumar, A.; Jayakrishna, K.; Rao, D.D.

    2012-01-01

    210 Po is the decay product of natural radionuclide of 238 U series. The presence of a radionuclide migrates from soil > plant > food and ingested by the humans residing in the areas of syentite rocks nearby the High Background Radiation Area's (HBRA). The food samples were studied by Market Basket Study (MBS). The average concentration of 210 Po in foodstuffs like green leafy vegetables, other vegetables, roots and tubers; fruits, fish, other flesh foods, milk and cereals were 1671 ± 163.3, 28.2 ± 7.3, 320 ± 99, 53 ± 17.5, 251.5 ± 54.5, 37 ± 14.5, 16 ± 6 and 230 ± 75 mBq. Kg -1 fresh weight. (author)

  5. Application of nonparametric regression methods to study the relationship between NO2 concentrations and local wind direction and speed at background sites.

    Science.gov (United States)

    Donnelly, Aoife; Misstear, Bruce; Broderick, Brian

    2011-02-15

    Background concentrations of nitrogen dioxide (NO(2)) are not constant but vary temporally and spatially. The current paper presents a powerful tool for the quantification of the effects of wind direction and wind speed on background NO(2) concentrations, particularly in cases where monitoring data are limited. In contrast to previous studies which applied similar methods to sites directly affected by local pollution sources, the current study focuses on background sites with the aim of improving methods for predicting background concentrations adopted in air quality modelling studies. The relationship between measured NO(2) concentration in air at three such sites in Ireland and locally measured wind direction has been quantified using nonparametric regression methods. The major aim was to analyse a method for quantifying the effects of local wind direction on background levels of NO(2) in Ireland. The method was expanded to include wind speed as an added predictor variable. A Gaussian kernel function is used in the analysis and circular statistics employed for the wind direction variable. Wind direction and wind speed were both found to have a statistically significant effect on background levels of NO(2) at all three sites. Frequently environmental impact assessments are based on short term baseline monitoring producing a limited dataset. The presented non-parametric regression methods, in contrast to the frequently used methods such as binning of the data, allow concentrations for missing data pairs to be estimated and distinction between spurious and true peaks in concentrations to be made. The methods were found to provide a realistic estimation of long term concentration variation with wind direction and speed, even for cases where the data set is limited. Accurate identification of the actual variation at each location and causative factors could be made, thus supporting the improved definition of background concentrations for use in air quality modelling

  6. Effects of background music on concentration of workers.

    Science.gov (United States)

    Huang, Rong-Hwa; Shih, Yi-Nuo

    2011-01-01

    Background music is a common element in daily living and the workplace. Determination of whether background music affects human work concentration is a relevant concern. Studies have found background music influences human behavior, and this study attempts to understand how background music and listener fondness for types of music affects worker concentration. This study analyzes how different types of background music--and how listeners' degree of preference for the background music--can affect listener concentration in attention testing through Randomized Controlled Trial (RCT). Data were collected from 89 workers. The participants ranged in age between 19 and 28 years old, with an average age of 24 years old. We conclude background music influenced listener attention. This influence has more to do with listener fondness for the music than with type of music. Compared to situations without background music, the likelihood of background music affecting test-taker attention performance is likely to increase with the degree to which the test-taker likes or dislikes the music. It is important not to select music that workers strongly like or dislike when making a selection of background music to avoid negatively affecting worker concentration.

  7. The Interaction of Local Context and Cultural Background

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard; Holmqvist, Emma; Dhalman, Hanna

    2015-01-01

    Immigrants' housing position is often explained by (lack of) resources or differences in cultural backgrounds. Recent studies have included the importance of local context. The aim of this paper is to examine Somalis' perceptions of their possibilities in four Nordic capitals' housing markets...... and sometimes conflict with each other, but that the negotiation between cultural background and local context was individual. The conclusion is that local context and cultural background are important factors for understanding differences between Somalis on different housing markets, thus emphasising...

  8. Assessment of background particulate matter concentrations in small cities and rural locations--Prince George, Canada.

    Science.gov (United States)

    Veira, Andreas; Jackson, Peter L; Ainslie, Bruce; Fudge, Dennis

    2013-07-01

    This study investigates the development and application of a simple method to calculate annual and seasonal PM2.5 and PM10 background concentrations in small cities and rural areas. The Low Pollution Sectors and Conditions (LPSC) method is based on existing measured long-term data sets and is designed for locations where particulate matter (PM) monitors are only influenced by local anthropogenic emission sources from particular wind sectors. The LPSC method combines the analysis of measured hourly meteorological data, PM concentrations, and geographical emission source distributions. PM background levels emerge from measured data for specific wind conditions, where air parcel trajectories measured at a monitoring station are assumed to have passed over geographic sectors with negligible local emissions. Seasonal and annual background levels were estimated for two monitoring stations in Prince George, Canada, and the method was also applied to four other small cities (Burns Lake, Houston, Quesnel, Smithers) in northern British Columbia. The analysis showed reasonable background concentrations for both monitoring stations in Prince George, whereas annual PM10 background concentrations at two of the other locations and PM2.5 background concentrations at one other location were implausibly high. For those locations where the LPSC method was successful, annual background levels ranged between 1.8 +/- 0.1 microg/m3 and 2.5 +/- 0.1 microg/m3 for PM2.5 and between 6.3 +/- 0.3 microg/m3 and 8.5 +/- 0.3 microg/m3 for PM10. Precipitation effects and patterns of seasonal variability in the estimated background concentrations were detectable for all locations where the method was successful. Overall the method was dependent on the configuration of local geography and sources with respect to the monitoring location, and may fail at some locations and under some conditions. Where applicable, the LPSC method can provide a fast and cost-efficient way to estimate background PM

  9. Evaluation of Background Mercury Concentrations in the SRS Groundwater System

    International Nuclear Information System (INIS)

    Looney, B.B.

    1999-01-01

    Mercury analyses associated with the A-01 Outfall have highlighted the importance of developing an understanding of mercury in the Savannah River Site groundwater system and associated surface water streams. This activity is critical based upon the fact that the EPA Ambient Water Quality Criteria (AWQC) for this constituent is 0.012mg/L, a level that is well below conventional detection limits of 0.1 to 0.2 mg/L. A first step in this process is obtained by utilizing the existing investment in groundwater mercury concentrations (20,242 records) maintained in the SRS geographical information management system (GIMS) database. Careful use of these data provides a technically defensible initial estimate for total recoverable mercury in background and contaminated SRS wells

  10. Measuring Extinction in Local Group Galaxies Using Background Galaxies

    Science.gov (United States)

    Wyder, T. K.; Hodge, P. W.

    1999-05-01

    Knowledge of the distribution and quantity of dust in galaxies is important for understanding their structure and evolution. The goal of our research is to measure the total extinction through Local Group galaxies using measured properties of background galaxies. Our method relies on the SExtractor software as an objective and automated method of detecting background galaxies. In an initial test, we have explored two WFPC2 fields in the SMC and two in M31 obtained from the HST archives. The two pointings in the SMC are fields around the open clusters L31 and B83 while the two M31 fields target the globular clusters G1 and G170. Except for the G1 observations of M31, the fields chosen are very crowded (even when observed with HST) and we chose them as a particularly stringent test of the method. We performed several experiments using a series of completeness tests that involved superimposing comparison fields, adjusted to the equivalent exposure time, from the HST Medium-Deep and Groth-Westphal surveys. These tests showed that for crowded fields, such as the two in the core of the SMC and the one in the bulge of M31, this automated method of detecting galaxies can be completely dominated by the effects of crowding. For these fields, only a small fraction of the added galaxies was recovered. However, in the outlying G1 field in M31, almost all of the added galaxies were recovered. The numbers of actual background galaxies in this field are consistent with zero extinction. As a follow-up experiment, we used image processing techniques to suppress stellar objects while enhancing objects with non-stellar, more gradual luminosity profiles. This method yielded significant numbers of background galaxies in even the most crowded fields, which we are now analyzing to determine the total extinction and reddening caused by the foreground galaxy.

  11. The Local Contribution to the Microwave Background Radiation(MBR)

    Science.gov (United States)

    Narlikar, Jayant V.; Pecker, Jean-Claude; Wickramasinghe, N. Ch.

    2010-11-01

    In the early fifties, from the early theories of the big bang universe, Gamow, Alpher & Herman have predicted the existence of a "cosmological" microwave background radiation, corresponding to a black body of a few Kelvins. When, in 1964, Penzias & Wilson, observed a radiation at 2.7K, the scientific world concluded quickly it was a proof, a final proof, of the big bang type cosmologies. But it should be realized that, in the beginning of the XX-th century, several authors, from Guillaume to Eddington, have predicted the same thing in a static Universe. We have redone the calculations of Eddington, and based them on the recent and very accurate photometric results from the satellite Hipparcos. In the absence of any expansion, of any big bang type behaviour, we compute the local temperature induced by the reradiation by local matter of stellar radiation, and we found it to be in excellent agreement with the observations. This result, completed by a careful discussion, could lead to a dramatic revision of the classical cosmological concepts.

  12. A Method for Estimating Urban Background Concentrations in Support of Hybrid Air Pollution Modeling for Environmental Health Studies

    Directory of Open Access Journals (Sweden)

    Saravanan Arunachalam

    2014-10-01

    Full Text Available Exposure studies rely on detailed characterization of air quality, either from sparsely located routine ambient monitors or from central monitoring sites that may lack spatial representativeness. Alternatively, some studies use models of various complexities to characterize local-scale air quality, but often with poor representation of background concentrations. A hybrid approach that addresses this drawback combines a regional-scale model to provide background concentrations and a local-scale model to assess impacts of local sources. However, this approach may double-count sources in the study regions. To address these limitations, we carefully define the background concentration as the concentration that would be measured if local sources were not present, and to estimate these background concentrations we developed a novel technique that combines space-time ordinary kriging (STOK of observations with outputs from a detailed chemistry-transport model with local sources zeroed out. We applied this technique to support an exposure study in Detroit, Michigan, for several pollutants (including NOx and PM2.5, and evaluated the estimated hybrid concentrations (calculated by combining the background estimates that addresses this issue of double counting with local-scale dispersion model estimates using observations. Our results demonstrate the strength of this approach specifically by eliminating the problem of double-counting reported in previous hybrid modeling approaches leading to improved estimates of background concentrations, and further highlight the relative importance of NOx vs. PM2.5 in their relative contributions to total concentrations. While a key limitation of this approach is the requirement for another detailed model simulation to avoid double-counting, STOK improves the overall characterization of background concentrations at very fine spatial scales.

  13. Strong contributions of local background climate to urban heat islands

    Science.gov (United States)

    Zhao, Lei; Lee, Xuhui; Smith, Ronald B.; Oleson, Keith

    2014-07-01

    The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ΔT). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ΔT (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ΔT are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ΔT by 3.0 +/- 0.3 kelvin (mean and standard error) in humid climates but decreasing ΔT by 1.5 +/- 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ΔT in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ΔT on large scales.

  14. Vulnerability of Concentrated Critical Infrastructure: Background and Policy Options

    Science.gov (United States)

    2007-01-26

    absenteeism among workers during the peak weeks of a regional outbreak.26 Concentrations of livestock may be similarly vulnerable to infectious disease...Turning Capital to Wealth: A Ranking of U.S. Utilities.” Public Utilities Fortnightly. Dec. 1999. 43 M. Singer, and K. Turnipseed, “ Curing Capital...careful and complex CRS-18 64 R.C. Mireles, “A Cure for West Coast Congestion.” Logistics Today. Jan. 2005. 65 Congressional Budget Office (CBO

  15. Localities With Elevated Radiation Background in the High Karst Zone of Montenegro

    International Nuclear Information System (INIS)

    Vukotic, P.; Svrkota, R.; Andjelic, T.; Zekic, R.; Antovic, N.

    2011-01-01

    Research aimed to find localities in Montenegro with an elevated terrestrial gamma background was conducted during the period 2008-2009. For this purpose, 138 localities which have geological formations known to contain minerals with potentially high concentrations of U, Th and K, were selected throughout the country for a dosimetric survey. There are four distinctive geotectonic units in Montenegro: the Adriatic-Ionian Zone (JZ), the Budva-Cukali Zone (BZ), the High Karst Zone (VK), and the Durmitor Tectonic Unit (DTJ). The central and southern parts of Montenegro belong to the VK zone, whose geological structure is predominated by Mesozoic carbonate sediments, with occurrences of red and white bauxite formations, Triassic volcanic rocks, Paleogene flysch sediments and Quaternary sediments. In total, 38 localities belonging to the VK zone were selected for field investigations of terrestrial radiation. Knowing from earlier investigations that in Montenegro the average absorbed dose-rate in the air, 1 m above the ground, is 55 nGy/h, it was arbitrarily adopted that only localities with absorbed doses at least 50 % above this average value would be considered as having a relatively elevated radiation background. Field measurements have shown that 12 of the surveyed localities in the VK zone have such elevated dose values, five of them being with the highest dose rates in Montenegro. Among these five sites, the highest dose rate (192 nGy/h) was found at a locality which lies on andesite volcanic rock, while the other four localities (131 - 149 nGy/h) lie on bauxite deposits. Compared to the other areas in the world known to have a high natural radiation background, all of these localities in Montenegro have a moderately elevated radiation level. From the 12 localities with a relatively elevated radiation background, soil samples have been collected and analyzed by gamma spectrometry to determine activity concentrations of 40K, 232Th, 235U, 238U, 226Ra and 137Cs

  16. C2-C6 background hydrocarbon concentrations monitored at a roof top and green park site, in Dublin City centre.

    Science.gov (United States)

    O'Donoghue, R T; Broderick, B M

    2007-09-01

    A 5 week monitoring campaign was carried out in Dublin City centre, to establish which site gave a more accurate background city centre estimation: a roof-top or green field site. This background represented a conservative estimate of HC exposure in Dublin City centre, useful for quantifying health effects related to this form of pollution and also for establishing a local background relative to the four surrounding main roads when the wind direction is travelling towards each road with the background receptor upwind. Over the entire monitoring campaign, the lowest concentrations and relative standard deviations were observed at the green field site, regardless of time of day or meteorological effects.

  17. Hidden in the background: a local approach to CMB anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, Juan C. Bueno, E-mail: juan.c.bueno@correounivalle.edu.co [Centro de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Antonio Nariño, Cra 3 Este # 47A-15, Bogotá D.C. 110231 (Colombia)

    2016-09-01

    We investigate a framework aiming to provide a common origin for the large-angle anomalies detected in the Cosmic Microwave Background (CMB), which are hypothesized as the result of the statistical inhomogeneity developed by different isocurvature fields of mass m ∼ H present during inflation. The inhomogeneity arises as the combined effect of ( i ) the initial conditions for isocurvature fields (obtained after a fast-roll stage finishing many e -foldings before cosmological scales exit the horizon), ( ii ) their inflationary fluctuations and ( iii ) their coupling to other degrees of freedom. Our case of interest is when these fields (interpreted as the precursors of large-angle anomalies) leave an observable imprint only in isolated patches of the Universe. When the latter intersect the last scattering surface, such imprints arise in the CMB. Nevertheless, due to their statistically inhomogeneous nature, these imprints are difficult to detect, for they become hidden in the background similarly to the Cold Spot. We then compute the probability that a single isocurvature field becomes inhomogeneous at the end of inflation and find that, if the appropriate conditions are given (which depend exclusively on the preexisting fast-roll stage), this probability is at the percent level. Finally, we discuss several mechanisms (including the curvaton and the inhomogeneous reheating) to investigate whether an initial statistically inhomogeneous isocurvature field fluctuation might give rise to some of the observed anomalies. In particular, we focus on the Cold Spot, the power deficit at low multipoles and the breaking of statistical isotropy.

  18. The local contribution to the microwave background radiation

    International Nuclear Information System (INIS)

    Pecker, Jean-Claude; Narlikar, Jayant V.; Ochsenbein, Francois; Wickramasinghe, Chandra

    2015-01-01

    The observed microwave background radiation (MBR) is commonly interpreted as the relic of an early hot universe, and its observed features (spectrum and anisotropy) are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20 th century, and adapt it to modern observations. For example, the stellar Hipparcos data show that the energy density of starlight from the Milky Way, if suitably thermalized, yields a temperature of ∼2.81 K. This and other arguments given here strongly suggest that the origin of MBR may lie, at least in a very large part, in re-radiation of thermalized galactic starlight. The strengths and weaknesses of this alternative radical explanation are discussed. (paper)

  19. Personal exposure to grass pollen: relating inhaled dose to background concentration

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Smith, Matt

    2013-01-01

    Background: Very few studies on human exposure to allergenic pollen have been conducted using direct methods, with background concentrations measured at city center monitoring stations typically taken as a proxy for exposure despite the inhomogeneous nature of atmospheric pollen concentrations. A...

  20. [PM₂.₅ Background Concentration at Different Directions in Beijing in 2013].

    Science.gov (United States)

    Li, Yun-ting; Cheng, Niam-liang; Zhang, Da-wei; Sun, Rui-wen; Dong, Xin; Sun, Nai-di; Chen, Chen

    2015-12-01

    PM₂.₅, background concentration at different directions in 2013 in Beijing was analyzed combining the techniques of mathematical statistics, physical identification and numerical simulation (CMAQ4.7.1) as well as using monitoring data of six PM₂.₅ auto-monitoring sites and five meteorological sites in 2013. Results showed that background concentrations of PM₂.₅ at northwest, northeast, eastern, southeast, southern and southwest boundary sites were between 40.3 and 85.3 µg · m⁻³ in Beijing. From the lowest to the highest, PMPM₂.₅ background concentrations at different sites were: Miyun reservoir, Badaling, Donggaocun, Yufa, Yongledian and Liulihe. Background concentration of PM₂.₅ was the lowest under north wind, then under west wind, and significantly higher under south and east wind. Calculated PM₂.₅ background average concentrations were 6.5-27.9, 22.4-73.4, 67.2-91.7, 40.7-116.1 µg · m⁻³ respectively in different wind directions. Simulated PM₂.₅ background concentration showed a clear north-south gradient distribution and the surrounding area had a notable effect on the spatial distribution of PM₂.₅ background concentration in 2013 in Beijing.

  1. Increasing surface ozone concentrations in the background atmosphere of Southern China, 1994–2007

    Directory of Open Access Journals (Sweden)

    T. Wang

    2009-08-01

    Full Text Available Tropospheric ozone is of great importance with regard to air quality, atmospheric chemistry, and climate change. In this paper we report the first continuous record of surface ozone in the background atmosphere of South China. The data were obtained from 1994 to 2007 at a coastal site in Hong Kong, which is strongly influenced by the outflow of Asian continental air during the winter and the inflow of maritime air from the subtropics in the summer. Three methods are used to derive the rate of change in ozone. A linear fit to the 14-year record shows that the ozone concentration increased by 0.58 ppbv/yr, whereas comparing means in years 1994–2000 and 2001–2007 gives an increase of 0.87 ppbv/yr for a 7-year period. The ozone changes in air masses from various source regions are also examined. Using local wind and carbon monoxide (CO data to filter out local influence, we find that ozone increased by 0.94 ppbv/yr from 1994–2000 to 2001–2007 in air masses from Eastern China, with similar changes in the other two continent-influenced air-mass groups, but no statistically significant change in the marine air. An examination of the nitrogen dioxide (NO2 column obtained from GOME and SCIAMACHY reveals an increase in atmospheric NO2 in China's three fastest developing coastal regions, whereas NO2 in other parts of Asia decreased during the same period, and no obvious trend over the main shipping routes in the South China Sea was indicated. Thus the observed increase in background ozone in Hong Kong is most likely due to the increased emissions of NO2 (and possibly volatile organic compounds (VOCs as well in the upwind coastal regions of mainland China. The CO data at Hok Tsui showed less definitive changes compared to the satellite NO2 column. The increase in background ozone likely made a strong contribution (81% to the rate of increase in "total ozone" at an urban site in Hong Kong

  2. Correlation between work concentration level and background music: a pilot study.

    Science.gov (United States)

    Shih, Yi-Nuo; Huang, Rong-Hwa; Chiang, Han-Sun

    2009-01-01

    It is a common phenomenon for office workers {to listen to music} while executing daily routines at their desks. The aim of this study was to investigate the correlation between work concentration level and background music. This research would first follow examples in previous researches, and then explore the influence of background music on participants' scores on attention tests. We hope to gain a preliminary understanding of the possible influence of background music on people's focus and concentration when doing work. Thirty-two college students were separated into three controlled groups; all were given the attention test. Group [a] listened to background music while being tested for 10 minutes; group [b] had no background music at all; and group [c] listened to the music for 10 minutes prior to the attention test. The test was conducted in a "noise free" environment. The means and error rates for each group were then calculated. The findings showed that, in comparison with "no music at all", those who listened to music prior to testing obtained higher scores in attentiveness (most probably a supplemental effect of the music), whereas those who listened to music during attention test showed extremely high level of variation in attention test scoring. Background music does affect people's job-site behavior. In fact, all three test conditions - no background music at all, background music before the work shift, and background music during work - have affected worker performance on different levels.

  3. Effects of wind on background particle concentrations at truck freight terminals.

    Science.gov (United States)

    Garcia, Ronald; Hart, Jaime E; Davis, Mary E; Reaser, Paul; Natkin, Jonathan; Laden, Francine; Garshick, Eric; Smith, Thomas J

    2007-01-01

    Truck freight terminals are predominantly located near highways and industrial facilities. This proximity to pollution sources, coupled with meteorological conditions and wind patterns, may affect occupational exposures to particles at these work locations. To understand this process, data from an environmental sampling study of particles at U.S. trucking terminals, along with weather and geographic maps, were analyzed to determine the extent to which the transportation of particles from local pollutant sources elevated observed occupational exposures at these locations. To help identify potential upwind sources, wind direction weighted averages and speed measurements were used to construct wind roses that were superimposed on overhead photos of the terminal and examined for upwind source activity. Statistical tests were performed on these "source" and "nonsource" directions to determine whether there were significant differences in observed particle levels between the two groups. Our results provide evidence that nearby upwind pollution sources significantly elevated background concentrations at only a few of the locations sampled, whereas the majority provided little to no evidence of a significant upwind source effect.

  4. Simulated Pathogen Concentrations in Locally-Collected Greywater and Wastewater

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains simulated pathogen concentrations in locally-collected greywater and wastewater. Each .zip file includes 21 .csv files, each containing 10,000...

  5. Attention Drainage Effect: How Background Music Effects Concentration in Taiwanese College Students

    Science.gov (United States)

    Chou, Peter Tze-Ming

    2010-01-01

    The purpose of this study was to see whether different types of background music affect the performance of a reading comprehension task in Taiwanese college students. There are two major research questions in this study. First, this study tries to find out whether listening to music affect the learner's concentration when they are doing a task…

  6. Major and trace element geochemistry and background concentrations for soils in Connecticut

    Science.gov (United States)

    Brown, Craig; Thomas, Margaret A.

    2014-01-01

    Soil samples were collected throughout Connecticut (CT) to determine the relationship of soil chemistry with the underlying geology and to better understand background concentrations of major and trace elements in soils. Soil samples were collected (1) from the upper 5 cm of surficial soil at 100 sites, (2) from the A horizon at 86 of these sites, and (3) from the deeper horizon, typically the C horizon, at 79 of these sites. The Ca, Fe, K, Na, and Ti, but element concentrations showed a relatively similar pattern in A-horizon and surficial soil samples among the underlying geologic provinces. Trace element concentrations, including Ba, W, Ga, Ni, Cs, Rb, Sr, Th, Sc, and U, also were higher in C-horizon soil samples than in overlying soil samples. Concentrations of Mg, and several trace elements, including Mn, P, As, Nb, Sn, Be, Bi, Hg, Se, Sb, La, Co, Cr, Pb, V, Y, Cu, Pb, and Zn were highest in some A-horizon or surficial soils, and indicate possible contributions from anthropogenic sources. Because element concentrations in soils above the C horizon are more likely to be affected by anthropogenic factors, concentration ranges in C-horizon soils and their spatially varying geologic associations should be considered when estimating background concentrations of elements in CT soils.

  7. Acoustic resonance scattering by a system of concentrically multilayered shells: the inherent background and resonance coefficients

    CERN Document Server

    Choi, M S; Lee, S H

    1999-01-01

    The inherent background coefficients that exactly describe the background amplitudes in the scattered field have been presented for the scattering of plane acoustic waves by a system of concentrically multilayered solid and/or fluid shells submerged in a fluid. The coefficients have been obtained by replacing the mechanical surface admittance function with the zero-frequency limit of the admittance function for the analogous fluid system, where the shear wave speeds in the solid layers are set to zero. By taking advantage of the concept of incoming and outgoing waves, we find the surface admittance function for the fluid system in such a form that the analytical generalization for any number of layers and the physical interpretation are very easy. The background coefficients obtained are independent of the bulk wave speeds in the system: they depend on the mass densities and the thickness of the shells. With increasing frequency, the inherent background undergoes a transition from the soft to the rigid backgr...

  8. Sources and Dynamic Processes Controlling Background and Peak Concentrations of TGM in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Casey B. Hall

    2014-03-01

    Full Text Available Total gaseous mercury (TGM data from urban Nanjing, at the western edge of the Yangtze River Delta (YRD region in China, over nine months, were analyzed for peak and background mercury concentrations. The background concentration of TGM was found to be 2.2 ng∙m−3. In examining episodic influences of free tropospheric air masses on the surface TGM concentrations in Nanjing, we hypothesize heterogeneity in the global distribution of TGM concentrations in the free troposphere. The nine-month averaged diurnal cycles of TGM indicate a strong co-emission with SO2 and an underestimation of greater than 80% TGM emissions in current inventories. Regular peak concentrations of mercury were investigated and the major causes were YRD emissions, transport from rural areas, and monsoonal transport. Transport of rural emissions is hypothesized to be from illegal artisanal small-scale gold mining that are currently missing in the emission inventories. Enhancement of TGM associated with summer monsoon contributed to a maximum TGM concentration in mid-May–early June, an inverse seasonality in comparison to most other observations in China, North America, and Europe.

  9. The anisotropy of the cosmic background radiation from local dynamic density perturbations

    International Nuclear Information System (INIS)

    Dyer, C.C.; Ip, P.S.S.

    1988-01-01

    Contrary to the usual assumption, it is shown here that the anisotropy of the cosmic background radiation need not be dominated by perturbations at the last scattering surface. The results of computer simulations are shown in which local dynamic density perturbations, in the form of Swiss cheese holes with finite, uniform density central lumps, are the main source of anisotropy of the cosmic background radiation. (author)

  10. Ecological risk assessment: influence of texture on background concentration of microelements in soils of Russia.

    Science.gov (United States)

    Beketskaya, Olga

    2010-05-01

    In Russia quality standards of contaminated substances values in environment consist of ecological and sanitary rate-setting. The sanitary risk assessment base on potential risk that contaminants pose to protect human beings. The main purpose of the ecological risk assessment is to protect ecosystem. To determine negative influence on living organisms in the sanitary risk assessment in Russia we use MPC. This value of contaminants show how substances affected on different part of environment, biological activity and soil processes. The ecological risk assessment based on comparison compounds concentration with background concentration for definite territories. Taking into account high interval of microelements value in soils, we suggest using statistic method for determination of concentration levels of chemical elements concentration in soils of Russia. This method is based on determination middle levels of elements content in natural condition. The top limit of middle chemical elements concentration in soils is value, which exceed middle regional background level in three times standard deviation. The top limit of natural concentration excess we can explain as anthropogenic impact. At first we study changing in the middle content value of microelements in soils of geographic regions in European part of Russia on the basis of cartographical analysis. Cartographical analysis showed that the soil of mountainous and mountain surrounding regions is enriched with microelements. On the plain territory of European part of Russia for most of microelements was noticed general direction of increasing their concentration in soils from north to south, also in the same direction soil clay content rise for majority of soils. For all other territories a clear connection has been noticed between the distribution of sand sediment. By our own investigation and data from scientific literature data base was created. This data base consist of following soil properties: texture

  11. Measurement of local interfacial area concentration in boiling loop

    International Nuclear Information System (INIS)

    Kyoung, Ho Kang; Byong, Jo Yun; Goon, Cherl Park

    1995-01-01

    An accurate prediction of two-phase flow is essential to many energy systems, including nuclear reactors. To model the two-phase flow, detailed information on the internal flow structure is required. The void fraction and interfacial area concentration are important fundamental parameters characterizing the internal structure of two-phase flow. The interfacial area concentration is defined as the available interfacial area per unit volume of the two-phase mixture in calculations of the interfacial transport of mass, momentum, and energy. Although a number of studies have been made in this area, the interfacial area concentration in two-phase flow has not been sufficiently investigated either experimentally or analytically. Most existing models for interfacial area concentration are limited to area-averaged interfacial area concentration in a flow channel. And the studies on local interfacial area concentration are limited to the case of air-water two-phase flow. However, the internal flow structure of steam-water two-phase flow having various bubble sizes could be quite different from that of air-water two-phase flow, the reliability of which weak in practical applications. In this study, the local interfacial area concentration steam-water two-phase flow has been investigated experimentally in a circular boiling tube having a heating rod in the center, and for the low flow with liquid superficial velocity <1 m/s

  12. The Uncertainty of Local Background Magnetic Field Orientation in Anisotropic Plasma Turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Gerick, F.; Saur, J.; Papen, M. von, E-mail: felix.gerick@uni-koeln.de [Institute of Geophysics and Meteorology, University of Cologne, Cologne (Germany)

    2017-07-01

    In order to resolve and characterize anisotropy in turbulent plasma flows, a proper estimation of the background magnetic field is crucially important. Various approaches to calculating the background magnetic field, ranging from local to globally averaged fields, are commonly used in the analysis of turbulent data. We investigate how the uncertainty in the orientation of a scale-dependent background magnetic field influences the ability to resolve anisotropy. Therefore, we introduce a quantitative measure, the angle uncertainty, that characterizes the uncertainty of the orientation of the background magnetic field that turbulent structures are exposed to. The angle uncertainty can be used as a condition to estimate the ability to resolve anisotropy with certain accuracy. We apply our description to resolve the spectral anisotropy in fast solar wind data. We show that, if the angle uncertainty grows too large, the power of the turbulent fluctuations is attributed to false local magnetic field angles, which may lead to an incorrect estimation of the spectral indices. In our results, an apparent robustness of the spectral anisotropy to false local magnetic field angles is observed, which can be explained by a stronger increase of power for lower frequencies when the scale of the local magnetic field is increased. The frequency-dependent angle uncertainty is a measure that can be applied to any turbulent system.

  13. The Uncertainty of Local Background Magnetic Field Orientation in Anisotropic Plasma Turbulence

    International Nuclear Information System (INIS)

    Gerick, F.; Saur, J.; Papen, M. von

    2017-01-01

    In order to resolve and characterize anisotropy in turbulent plasma flows, a proper estimation of the background magnetic field is crucially important. Various approaches to calculating the background magnetic field, ranging from local to globally averaged fields, are commonly used in the analysis of turbulent data. We investigate how the uncertainty in the orientation of a scale-dependent background magnetic field influences the ability to resolve anisotropy. Therefore, we introduce a quantitative measure, the angle uncertainty, that characterizes the uncertainty of the orientation of the background magnetic field that turbulent structures are exposed to. The angle uncertainty can be used as a condition to estimate the ability to resolve anisotropy with certain accuracy. We apply our description to resolve the spectral anisotropy in fast solar wind data. We show that, if the angle uncertainty grows too large, the power of the turbulent fluctuations is attributed to false local magnetic field angles, which may lead to an incorrect estimation of the spectral indices. In our results, an apparent robustness of the spectral anisotropy to false local magnetic field angles is observed, which can be explained by a stronger increase of power for lower frequencies when the scale of the local magnetic field is increased. The frequency-dependent angle uncertainty is a measure that can be applied to any turbulent system.

  14. Local anomaly cancellation in heterotic E8 x E8 orbifold compactifications with Wilson line backgrounds

    International Nuclear Information System (INIS)

    Walter, M.G.A.

    2004-02-01

    We consider several examples of a special class of heterotic compactifications, i.e. heterotic E 8 x E 8 orbifolds with Wilson line backgrounds. By developing a local perspective we show that a brane world like picture emerges. As an important result we prove that the local massless spectrum at such a brane can always be traced back to the global spectrum of a (different) orbifold without Wilson lines. One particular implication of this result is that the use of (discrete) Wilson lines for the construction of phenomenologically interesting models has to be rethought. We show that stringy constraints render the brane spectra consistent. Using our local picture we are able to compute the local anomalies appearing at the different branes for our examples and show that they can all be cancelled by a local version of the Green-Schwarz mechanism at the same time. (orig.)

  15. PM10 concentration levels at an urban and background site in Cyprus: the impact of urban sources and dust storms.

    Science.gov (United States)

    Achilleos, Souzana; Evans, John S; Yiallouros, Panayiotis K; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

    2014-12-01

    Air quality in Cyprus is influenced by both local and transported pollution, including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993, through December 11, 2008, and in Ayia Marina (rural background representative) from January 1, 1999, through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records, and satellite data were used to identify dust storm days. We investigated long-term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000-2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact ofdust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. Implications: This

  16. Understanding how roadside concentrations of NOx are influenced by the background levels, traffic density, and meteorological conditions using Boosted Regression Trees

    Science.gov (United States)

    Sayegh, Arwa; Tate, James E.; Ropkins, Karl

    2016-02-01

    Oxides of Nitrogen (NOx) is a major component of photochemical smog and its constituents are considered principal traffic-related pollutants affecting human health. This study investigates the influence of background concentrations of NOx, traffic density, and prevailing meteorological conditions on roadside concentrations of NOx at UK urban, open motorway, and motorway tunnel sites using the statistical approach Boosted Regression Trees (BRT). BRT models have been fitted using hourly concentration, traffic, and meteorological data for each site. The models predict, rank, and visualise the relationship between model variables and roadside NOx concentrations. A strong relationship between roadside NOx and monitored local background concentrations is demonstrated. Relationships between roadside NOx and other model variables have been shown to be strongly influenced by the quality and resolution of background concentrations of NOx, i.e. if it were based on monitored data or modelled prediction. The paper proposes a direct method of using site-specific fundamental diagrams for splitting traffic data into four traffic states: free-flow, busy-flow, congested, and severely congested. Using BRT models, the density of traffic (vehicles per kilometre) was observed to have a proportional influence on the concentrations of roadside NOx, with different fitted regression line slopes for the different traffic states. When other influences are conditioned out, the relationship between roadside concentrations and ambient air temperature suggests NOx concentrations reach a minimum at around 22 °C with high concentrations at low ambient air temperatures which could be associated to restricted atmospheric dispersion and/or to changes in road traffic exhaust emission characteristics at low ambient air temperatures. This paper uses BRT models to study how different critical factors, and their relative importance, influence the variation of roadside NOx concentrations. The paper

  17. Background Concentrations for Use in the Operational Street Pollution Model (OSPM)

    DEFF Research Database (Denmark)

    Jensen, S. S.

    A background model has been developed for application in the Operational Street Pollution Model (OSPM) in context of long-term exposure modelling. The back ground model is based on a semi-empirical method founded on a few monitor stations that estimates standardised one hour time-series of urban...... and rural back ground concentrations of NO2, NOx, O3 and CO for different geographic regions in Denmark. The annual mean of selected monitor stations is used as a reference year and the development in estimated traffic emissions as an index is used to establish a historic trend. As an exception ozone trends...

  18. Background concentrations of selected radionuclides, organic compounds, and chemical constituents in ground water in the vicinity of the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Orr, B.R.; Cecil, L.D.; Knobel, L.L.

    1991-01-01

    Background concentrations of radionuclides, organic compounds, and other chemical constituents in water in the Snake River Plain aquifer in Idaho were estimated from groundwater sample analyses. Detectable concentrations of transuranic elements should not be present in water from the Snake River Plain aquifer. Background concentrations of tritium generally range from 75 to 150 pCi/L. Strontium-90 and iodine-129 concentrations generally are 0 and from 0.05 pCi/L, respectively. At the INEL, comparison of the mean and median concentrations of tritium, strontium-90, and iodine-129 indicates that operations locally have affected concentrations in groundwater. Gross alpha-particle and beta-particle radioactivity in water from the Snake River Plain aquifer ranges from 0 to 5 pCi/L and 0 to 8 pCi/L, respectively. Background gamma radiation in groundwater is attributed to cesium-137, cobalt-60, and potassium-40. Cesium-137 and cobalt-60 concentrations generally are zero in groundwater at the INEL. Naturally occurring concentrations of potassium-40 probably are about 300 pCi/L. Background concentrations of organic compounds in water from the Snake River Plain aquifer generally are less than 0.2 microg/L. Background arsenic and chromium concentrations both are about 2 to 3 microg/L. Barium concentrations are from about 50 to about 70 microg/L. Lead and mercury concentrations generally are less than 5 microg/L and 0.1 microg/L, respectively. Cadmium, selenium, and silver concentrations generally are less than 1 microg/L. Nitrate concentrations range from 0 to about 1.4 mg/L

  19. Concentration independent modulation of local micromechanics in a fibrin gel.

    Directory of Open Access Journals (Sweden)

    Maxwell A Kotlarchyk

    Full Text Available Methods for tuning extracellular matrix (ECM mechanics in 3D cell culture that rely on increasing the concentration of either protein or cross-linking molecules fail to control important parameters such as pore size, ligand density, and molecular diffusivity. Alternatively, ECM stiffness can be modulated independently from protein concentration by mechanically loading the ECM. We have developed a novel device for generating stiffness gradients in naturally derived ECMs, where stiffness is tuned by inducing strain, while local mechanical properties are directly determined by laser tweezers based active microrheology (AMR. Hydrogel substrates polymerized within 35 mm diameter Petri dishes are strained non-uniformly by the precise rotation of an embedded cylindrical post, and exhibit a position-dependent stiffness with little to no modulation of local mesh geometry. Here we present the device in the context of fibrin hydrogels. First AMR is used to directly measure local micromechanics in unstrained hydrogels of increasing fibrin concentration. Changes in stiffness are then mapped within our device, where fibrin concentration is held constant. Fluorescence confocal imaging and orbital particle tracking are used to quantify structural changes in fibrin on the micro and nano levels respectively. The micromechanical strain stiffening measured by microrheology is not accompanied by ECM microstructural changes under our applied loads, as measured by confocal microscopy. However, super-resolution orbital tracking reveals nanostructural straightening, lengthening, and reduced movement of fibrin fibers. Furthermore, we show that aortic smooth muscle cells cultured within our device are morphologically sensitive to the induced mechanical gradient. Our results demonstrate a powerful cell culture tool that can be used in the study of mechanical effects on cellular physiology in naturally derived 3D ECM tissues.

  20. Improved radiological/nuclear source localization in variable NORM background: An MLEM approach with segmentation data

    Energy Technology Data Exchange (ETDEWEB)

    Penny, Robert D., E-mail: robert.d.penny@leidos.com [Leidos Inc., 10260 Campus Point Road, San Diego, CA (United States); Crowley, Tanya M.; Gardner, Barbara M.; Mandell, Myron J.; Guo, Yanlin; Haas, Eric B.; Knize, Duane J.; Kuharski, Robert A.; Ranta, Dale; Shyffer, Ryan [Leidos Inc., 10260 Campus Point Road, San Diego, CA (United States); Labov, Simon; Nelson, Karl; Seilhan, Brandon [Lawrence Livermore National Laboratory, Livermore, CA (United States); Valentine, John D. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2015-06-01

    A novel approach and algorithm have been developed to rapidly detect and localize both moving and static radiological/nuclear (R/N) sources from an airborne platform. Current aerial systems with radiological sensors are limited in their ability to compensate for variable naturally occurring radioactive material (NORM) background. The proposed approach suppresses the effects of NORM background by incorporating additional information to segment the survey area into regions over which the background is likely to be uniform. The method produces pixelated Source Activity Maps (SAMs) of both target and background radionuclide activity over the survey area. The task of producing the SAMs requires (1) the development of a forward model which describes the transformation of radionuclide activity to detector measurements and (2) the solution of the associated inverse problem. The inverse problem is ill-posed as there are typically fewer measurements than unknowns. In addition the measurements are subject to Poisson statistical noise. The Maximum-Likelihood Expectation-Maximization (MLEM) algorithm is used to solve the inverse problem as it is well suited for under-determined problems corrupted by Poisson noise. A priori terrain information is incorporated to segment the reconstruction space into regions within which we constrain NORM background activity to be uniform. Descriptions of the algorithm and examples of performance with and without segmentation on simulated data are presented.

  1. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  2. Searching for concentric low variance circles in the cosmic microwave background

    Energy Technology Data Exchange (ETDEWEB)

    DeAbreu, Adam [Department of Physics, Simon Fraser University, Burnaby, BC, V5A 1S6 Canada (Canada); Contreras, Dagoberto; Scott, Douglas, E-mail: adeabreu@sfu.ca, E-mail: dagocont@phas.ubc.ca, E-mail: dscott@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 Canada (Canada)

    2015-12-01

    In a recent paper, Gurzadyan and Penrose claim to have found directions in the sky around which there are multiple concentric sets of annuli with anomalously low variance in the cosmic microwave background (CMB). These features are presented as evidence for a particular theory of the pre-Big Bang Universe. We are able to reproduce the analysis these authors presented for data from the WMAP satellite and we confirm the existence of these apparently special directions in the newer Planck data. However, we also find that these features are present at the same level of abundance in simulated Gaussian CMB skies, i.e., they are entirely consistent with the predictions of the standard cosmological model.

  3. Gravitational perturbation of the cosmic background radiation by density concentrations. [Swiss cheese model universe

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, C C [Cambridge Univ. (UK). Inst. of Theoretical Astronomy

    1976-05-01

    The gravitational effect of density concentrations in the Universe on the temperature distribution of the cosmic blackbody background radiation is considered, using the Swiss cheese model universe, and supposing each hole to contain an expanding, homogeneous dust sphere at its centre. The temperature profile across such a hole differs in an essential way from that obtained earlier by Rees et al (Nature; 217:511 (1968)). The evolution of this effect with the expansion of the Universe is considered for 'relatively increasing' density contrasts emerging from the same initial singular state as the rest of the Universe. This effect becomes comparable to the bremsstrahlung and Compton effects on the isotropy of the background radiation for masses of about 10/sup 19/ times the mass of the sun, and exceeds these other effects as about Msup(2/3) for larger masses. If large-scale condensations of the Universe can be found for z approximately 1 to 5, delineated, maybe, by the clustering of quasars, etc., then this effect may be observable.

  4. A comparison of methods used to calculate normal background concentrations of potentially toxic elements for urban soil

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, Katherine A., E-mail: k.rothwell@ncl.ac.uk; Cooke, Martin P., E-mail: martin.cooke@ncl.ac.uk

    2015-11-01

    To meet the requirements of regulation and to provide realistic remedial targets there is a need for the background concentration of potentially toxic elements (PTEs) in soils to be considered when assessing contaminated land. In England, normal background concentrations (NBCs) have been published for several priority contaminants for a number of spatial domains however updated regulatory guidance places the responsibility on Local Authorities to set NBCs for their jurisdiction. Due to the unique geochemical nature of urban areas, Local Authorities need to define NBC values specific to their area, which the national data is unable to provide. This study aims to calculate NBC levels for Gateshead, an urban Metropolitan Borough in the North East of England, using freely available data. The ‘median + 2MAD’, boxplot upper whisker and English NBC (according to the method adopted by the British Geological Survey) methods were compared for test PTEs lead, arsenic and cadmium. Due to the lack of systematically collected data for Gateshead in the national soil chemistry database, the use of site investigation (SI) data collected during the planning process was investigated. 12,087 SI soil chemistry data points were incorporated into a database and 27 comparison samples were taken from undisturbed locations across Gateshead. The SI data gave high resolution coverage of the area and Mann–Whitney tests confirmed statistical similarity for the undisturbed comparison samples and the SI data. SI data was successfully used to calculate NBCs for Gateshead and the median + 2MAD method was selected as most appropriate by the Local Authority according to the precautionary principle as it consistently provided the most conservative NBC values. The use of this data set provides a freely available, high resolution source of data that can be used for a range of environmental applications. - Highlights: • The use of site investigation data is proposed for land contamination studies

  5. The active titration method for measuring local hydroxyl radical concentration

    Science.gov (United States)

    Sprengnether, Michele; Prinn, Ronald G.

    1994-01-01

    We are developing a method for measuring ambient OH by monitoring its rate of reaction with a chemical species. Our technique involves the local, instantaneous release of a mixture of saturated cyclic hydrocarbons (titrants) and perfluorocarbons (dispersants). These species must not normally be present in ambient air above the part per trillion concentration. We then track the mixture downwind using a real-time portable ECD tracer instrument. We collect air samples in canisters every few minutes for roughly one hour. We then return to the laboratory and analyze our air samples to determine the ratios of the titrant to dispersant concentrations. The trends in these ratios give us the ambient OH concentration from the relation: dlnR/dt = -k(OH). A successful measurement of OH requires that the trends in these ratios be measureable. We must not perturb ambient OH concentrations. The titrant to dispersant ratio must be spatially invariant. Finally, heterogeneous reactions of our titrant and dispersant species must be negligible relative to the titrant reaction with OH. We have conducted laboratory studies of our ability to measure the titrant to dispersant ratios as a function of concentration down to the few part per trillion concentration. We have subsequently used these results in a gaussian puff model to estimate our expected uncertainty in a field measurement of OH. Our results indicate that under a range of atmospheric conditions we expect to be able to measure OH with a sensitivity of 3x10(exp 5) cm(exp -3). In our most optimistic scenarios, we obtain a sensitivity of 1x10(exp 5) cm(exp -3). These sensitivity values reflect our anticipated ability to measure the ratio trends. However, because we are also using a rate constant to obtain our (OH) from this ratio trend, our accuracy cannot be better than that of the rate constant, which we expect to be about 20 percent.

  6. Concentrations of radionuclides in cassava growing in high background radiation area and their transfer

    Energy Technology Data Exchange (ETDEWEB)

    Jialin, Huang; Yongru, Zha; Yicao, Guo

    1985-04-01

    The concentrations of several natural radionuclides in common cassava (Manihot esculenta Crantz) growing in Yangjiang County, a high background radiation area in Guangdong Province, and their uptake from soil and distribution in the plant were investigated. The results show that the concentrations of natural uranium and thorium in cassava root are of the order of 10/sup -6/ g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10/sup -11/ Ci/kg. The highest level is 9.30 +- 0.30 x 10/sup -11/ Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10/sup -11/ Ci/kg (radium-226). The levels of natural uranium, thorium, radium-226 and polonium-210 in cassava are below the limits stipulated by the regulations for food hygiene in China, while the lead-210 level approaches the limit. It is noticeable that the highest level of radium-228 is 7.28 +- 1.03 x 10/sup -11/ Ci/kg, 10.4 times higher than the limit. The transfer of all the nuclides from soil to different parts of cassava shows a pattern contrary to that of he nuclides in the other regions where uranium-and radium-containing waste water and phosphate fertilizer are used in agriculture.

  7. Concentrations of radionuclides in cassava growing in high background radiation area and their transfer

    International Nuclear Information System (INIS)

    Huang Jialin; Zha Yongru; Guo Yicao

    1985-01-01

    The concentrations of several natural radionuclides in common cassava (Manihot esculenta Crantz) growing in Yangjiang County, a high background radiation area in Guangdong Province, and their uptake from soil and distribution in the plant were investigated. The results show that the concentrations of natural uranium and thorium in cassava root are of the order of 10 -6 g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10 -11 Ci/kg. The highest level is 9.30 +- 0.30 x 10 -11 Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10 -11 Ci/kg (radium-226). The levels of natural uranium, thorium, radium-226 and polonium-210 in cassava are below the limits stipulated by the regulations for food hygiene in China, while the lead-210 level approaches the limit. It is noticeable that the highest level of radium-228 is 7.28 +- 1.03 x 10 -11 Ci/kg, 10.4 times higher than the limit. The transfer of all he nuclides from soil to different parts of cassava shows a pattern contrary to that of he nuclides in the other regions where uranium-and radium-containing waste water and phosphate fertilizer are used in agriculture

  8. Background concentrations and reference values for heavy metals in soils of Cuba.

    Science.gov (United States)

    Alfaro, Mirelys Rodríguez; Montero, Alfredo; Ugarte, Olegario Muñiz; do Nascimento, Clístenes Williams Araújo; de Aguiar Accioly, Adriana Maria; Biondi, Caroline Miranda; da Silva, Ygor Jacques Agra Bezerra

    2015-01-01

    The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.

  9. Associations of PM2.5 and black carbon concentrations with traffic, idling, background pollution, and meteorology during school dismissals.

    Science.gov (United States)

    Richmond-Bryant, J; Saganich, C; Bukiewicz, L; Kalin, R

    2009-05-01

    An air quality study was performed outside a cluster of schools in the East Harlem neighborhood of New York City. PM(2.5) and black carbon concentrations were monitored using real-time equipment with a one-minute averaging interval. Monitoring was performed at 1:45-3:30 PM during school days over the period October 31-November 17, 2006. The designated time period was chosen to capture vehicle emissions during end-of-day dismissals from the schools. During the monitoring period, minute-by-minute volume counts of idling and passing school buses, diesel trucks, and automobiles were obtained. These data were transcribed into time series of number of diesel vehicles idling, number of gasoline automobiles idling, number of diesel vehicles passing, and number of automobiles passing along the block adjacent to the school cluster. Multivariate regression models of the log-transform of PM(2.5) and black carbon (BC) concentrations in the East Harlem street canyon were developed using the observation data and data from the New York State Department of Environmental Conservation on meteorology and background PM(2.5). Analysis of variance was used to test the contribution of each covariate to variability in the log-transformed concentrations as a means to judge the relative contribution of each covariate. The models demonstrated that variability in background PM(2.5) contributes 80.9% of the variability in log[PM(2.5)] and 81.5% of the variability in log[BC]. Local traffic sources were demonstrated to contribute 5.8% of the variability in log[BC] and only 0.43% of the variability in log[PM(2.5)]. Diesel idling and passing were both significant contributors to variability in log[BC], while diesel passing was a significant contributor to log[PM(2.5)]. Automobile idling and passing did not contribute significant levels of variability to either concentration. The remainder of variability in each model was explained by temperature, along-canyon wind, and cross-canyon wind, which were

  10. Quantifying local traffic contributions to NO2 and NH3 concentrations in natural habitats

    International Nuclear Information System (INIS)

    Gadsdon, Sally R.; Power, Sally A.

    2009-01-01

    NO 2 and NH 3 concentrations were measured across a Special Area for Conservation in southern England, at varying distances from the local road network. Exceedances of the critical levels for these pollutants were recorded at nearly all roadside locations, extending up to 20 m away from roads at some sites. Further, paired measurements of NH 3 and NO 2 concentrations revealed differences between ground and tree canopy levels. At 'background' sites, away from the direct influence of roads, concentrations were higher within tree canopies than at ground level; the reverse pattern was, however, seen at roadside locations. Calculations of pollutant deposition rates showed that nitrogen inputs are dominated by NH 3 at roadside sites. This study demonstrates that local traffic emissions contribute substantially to the exceedance of critical levels and critical loads, and suggests that on-site monitoring is needed for sites of nature conservation value which are in close proximity to local transport routes. - NO x and NH 3 concentrations exceed vegetation critical levels up to 20 m from roadsides, both at ground level and in tree canopies.

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

    Science.gov (United States)

    Dimitriou, Konstantinos; Kassomenos, Pavlos

    2014-05-01

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

  12. Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

    Science.gov (United States)

    Puspitarini, L.; Lallement, R.; Snowden, Steven L.; Vergely, J.-L.; Snowden, S.

    2014-01-01

    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy

  13. Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

    Science.gov (United States)

    Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

    2014-12-01

    Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

  14. Experiments on how photo- and background ionization affect positive streamers: oxygen concentration, repetition and radioactivity

    NARCIS (Netherlands)

    Nijdam, S.; Veldhuizen, van E.M.; Ebert, U.

    2011-01-01

    Positive streamers in air and other oxygen-nitrogen mixtures are generally believed to propagate against the electron drift direction due to photo-ionization. Photo-ionization is the non-local ionization of O2-molecules by UV radiation from excited N2-molecules. This facilitates the streamer

  15. Local Group dSph radio survey with ATCA (I): observations and background sources

    Science.gov (United States)

    Regis, Marco; Richter, Laura; Colafrancesco, Sergio; Massardi, Marcella; de Blok, W. J. G.; Profumo, Stefano; Orford, Nicola

    2015-04-01

    Dwarf spheroidal (dSph) galaxies are key objects in near-field cosmology, especially in connection to the study of galaxy formation and evolution at small scales. In addition, dSphs are optimal targets to investigate the nature of dark matter. However, while we begin to have deep optical photometric observations of the stellar population in these objects, little is known so far about their diffuse emission at any observing frequency, and hence on thermal and non-thermal plasma possibly residing within dSphs. In this paper, we present deep radio observations of six local dSphs performed with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength. We mosaicked a region of radius of about 1 deg around three `classical' dSphs, Carina, Fornax, and Sculptor, and of about half of degree around three `ultrafaint' dSphs, BootesII, Segue2, and Hercules. The rms noise level is below 0.05 mJy for all the maps. The restoring beams full width at half-maximum ranged from 4.2 arcsec × 2.5 arcsec to 30.0 arcsec × 2.1 arcsec in the most elongated case. A catalogue including the 1392 sources detected in the six dSph fields is reported. The main properties of the background sources are discussed, with positions and fluxes of brightest objects compared with the FIRST, NVSS, and SUMSS observations of the same fields. The observed population of radio emitters in these fields is dominated by synchrotron sources. We compute the associated source number counts at 2 GHz down to fluxes of 0.25 mJy, which prove to be in agreement with AGN count models.

  16. Inter-comparison of interpolated background nitrogen dioxide concentrations across Greater Manchester, UK

    Science.gov (United States)

    Lindley, S. J.; Walsh, T.

    There are many modelling methods dedicated to the estimation of spatial patterns in pollutant concentrations, each with their distinctive advantages and disadvantages. The derivation of a surface of air quality values from monitoring data alone requires the conversion of point-based data from a limited number of monitoring stations to a continuous surface using interpolation. Since interpolation techniques involve the estimation of data at un-sampled points based on calculated relationships between data measured at a number of known sample points, they are subject to some uncertainty, both in terms of the values estimated and their spatial distribution. These uncertainties, which are incorporated into many empirical and semi-empirical mapping methodologies, could be recognised in any further usage of the data and also in the assessment of the extent of an exceedence of an air quality standard and the degree of exposure this may represent. There is a wide range of available interpolation techniques and the differences in the characteristics of these result in variations in the output surfaces estimated from the same set of input points. The work presented in this paper provides an examination of uncertainties through the application of a number of interpolation techniques available in standard GIS packages to a case study nitrogen dioxide data set for the Greater Manchester conurbation in northern England. The implications of the use of different techniques are discussed through application to hourly concentrations during an air quality episode and annual average concentrations in 2001. Patterns of concentrations demonstrate considerable differences in the estimated spatial pattern of maxima as the combined effects of chemical processes, topography and meteorology. In the case of air quality episodes, the considerable spatial variability of concentrations results in large uncertainties in the surfaces produced but these uncertainties vary widely from area to area

  17. Estimating representative background PM2.5 concentration in heavily polluted areas using baseline separation technique and chemical mass balance model

    Science.gov (United States)

    Gao, Shuang; Yang, Wen; Zhang, Hui; Sun, Yanling; Mao, Jian; Ma, Zhenxing; Cong, Zhiyuan; Zhang, Xian; Tian, Shasha; Azzi, Merched; Chen, Li; Bai, Zhipeng

    2018-02-01

    The determination of background concentration of PM2.5 is important to understand the contribution of local emission sources to total PM2.5 concentration. The purpose of this study was to exam the performance of baseline separation techniques to estimate PM2.5 background concentration. Five separation methods, which included recursive digital filters (Lyne-Hollick, one-parameter algorithm, and Boughton two-parameter algorithm), sliding interval and smoothed minima, were applied to one-year PM2.5 time-series data in two heavily polluted cities, Tianjin and Jinan. To obtain the proper filter parameters and recession constants for the separation techniques, we conducted regression analysis at a background site during the emission reduction period enforced by the Government for the 2014 Asia-Pacific Economic Cooperation (APEC) meeting in Beijing. Background concentrations in Tianjin and Jinan were then estimated by applying the determined filter parameters and recession constants. The chemical mass balance (CMB) model was also applied to ascertain the effectiveness of the new approach. Our results showed that the contribution of background PM concentration to ambient pollution was at a comparable level to the contribution obtained from the previous study. The best performance was achieved using the Boughton two-parameter algorithm. The background concentrations were estimated at (27 ± 2) μg/m3 for the whole year, (34 ± 4) μg/m3 for the heating period (winter), (21 ± 2) μg/m3 for the non-heating period (summer), and (25 ± 2) μg/m3 for the sandstorm period in Tianjin. The corresponding values in Jinan were (30 ± 3) μg/m3, (40 ± 4) μg/m3, (24 ± 5) μg/m3, and (26 ± 2) μg/m3, respectively. The study revealed that these baseline separation techniques are valid for estimating levels of PM2.5 air pollution, and that our proposed method has great potential for estimating the background level of other air pollutants.

  18. Chemical concentration of a new natural spontaneously fissionable nuclide from solutions with low salt background

    International Nuclear Information System (INIS)

    Korotkin, Yu.S.; Ter-Akop'yan, G.M.; Popeko, A.G.; Drobina, T.P.; Zhuravleva, E.L.

    1982-01-01

    The results of experiments on further concentration of a new natural spontaneously fissionable nuclide, the concentrates of which form the Cheleken geothermal brines have been obtained, are presented. The conclusions are drown about the chemical nature of a new spontaneously fissionable nuclide. It is a chalcophile element which copreipitates with sulphides of copper, lead, arsenic and mercury from weakly acid solutions. The behaviour of the new nuclide in sulphide systems in many respects is similar to the behaviour of polonium, astatine and probably of bismuth. The most probable stable valence of the new nuclide varies from +1 up to +3. The data available on the chemical behaviour of the new nuclide as well as the analysis over contamination by spontaneously fissionable isotopes permit to state that the new natural spontaneously fissionable nuclide does not relate to the known isotopes

  19. Variation of radon concentration in soil with different depth along the high background areas in Kerala

    International Nuclear Information System (INIS)

    Sonia, S.R.; Visnu Prasad, A.K.; Jojo, P.J.; Midhun, M.

    2016-01-01

    Radon is one of the naturally occurring radioactive gases in the environment produced from decay of radium isotopes, which are the decay product of 238 U, 232 Th and 235 U. Hence the concentration of uranium and thorium in the bed rock and soil materials determine the amount of radon produced in the soil. The radon produced in the soil migrates through the mechanism of diffusion and convection through pore spaces in the soil, fractures in the rock and along with weak zones such as shear faults, thrust etc. For some geological situations, radon migrates long distances from its place of origin and can be detected by alpha-particle recorders at the earth's surface. Concentration of radon in an area is governed by the radium content in the minerals, radon emanating power in the material, permeability of the soils and underlying rock, and moisture content in the soil

  20. Background concentrations and fluxes of atmospheric ammonia over a deciduous forest

    DEFF Research Database (Denmark)

    Hansen, K.; Pryor, S. C.; Boegh, E.

    2015-01-01

    . In this study, we present two months of half-hourly NH3 fluxes and concentrations measured using a Relaxed Eddy Accumulation system during late summer and fall 2013 above a remote forest site in the central Midwest in USA. Supplementary nitric acid (HNO3) flux and size-resolved aerosol-N measurements are used.......11 μg NH3-N m−2 s−1. The wetness of the forest surfaces (assessed using a proxy of time since precipitation) was found to be crucial in controlling both deposition and emission of atmospheric NH3. Size resolved aerosol concentrations (of NH4+, NO3−, Cl− and SO42−) indicated that the aerosol and gas...

  1. The joint effects of background selection and genetic recombination on local gene genealogies.

    Science.gov (United States)

    Zeng, Kai; Charlesworth, Brian

    2011-09-01

    Background selection, the effects of the continual removal of deleterious mutations by natural selection on variability at linked sites, is potentially a major determinant of DNA sequence variability. However, the joint effects of background selection and genetic recombination on the shape of the neutral gene genealogy have proved hard to study analytically. The only existing formula concerns the mean coalescent time for a pair of alleles, making it difficult to assess the importance of background selection from genome-wide data on sequence polymorphism. Here we develop a structured coalescent model of background selection with recombination and implement it in a computer program that efficiently generates neutral gene genealogies for an arbitrary sample size. We check the validity of the structured coalescent model against forward-in-time simulations and show that it accurately captures the effects of background selection. The model produces more accurate predictions of the mean coalescent time than the existing formula and supports the conclusion that the effect of background selection is greater in the interior of a deleterious region than at its boundaries. The level of linkage disequilibrium between sites is elevated by background selection, to an extent that is well summarized by a change in effective population size. The structured coalescent model is readily extendable to more realistic situations and should prove useful for analyzing genome-wide polymorphism data.

  2. Method of center localization for objects containing concentric arcs

    Science.gov (United States)

    Kuznetsova, Elena G.; Shvets, Evgeny A.; Nikolaev, Dmitry P.

    2015-02-01

    This paper proposes a method for automatic center location of objects containing concentric arcs. The method utilizes structure tensor analysis and voting scheme optimized with Fast Hough Transform. Two applications of the proposed method are considered: (i) wheel tracking in video-based system for automatic vehicle classification and (ii) tree growth rings analysis on a tree cross cut image.

  3. Local impermeant anions establish the neuronal chloride concentration

    DEFF Research Database (Denmark)

    Glykys, J; Dzhala, V; Egawa, K

    2014-01-01

    Neuronal intracellular chloride concentration [Cl(-)](i) is an important determinant of γ-aminobutyric acid type A (GABA(A)) receptor (GABA(A)R)-mediated inhibition and cytoplasmic volume regulation. Equilibrative cation-chloride cotransporters (CCCs) move Cl(-) across the membrane, but accumulat...

  4. Measurements of Background Gamma Radiation on Some Localities of North-East Kosovo

    OpenAIRE

    , G. Hodolli; , Y. Halimi; , R. Gashi; , Se. Kadiri; , B. Xhafa; , A. Jonuzaj

    2016-01-01

    The measurement of natural environmental radiations is one of the most important subjects in health physics. The main sources of background radiation are cosmic, terrestrial and cosmogenic radiation produced by reactions with cosmic rays and atmospheric nuclei. Terrestrial radiation varies in different regions in the world. Generally the background dose rate from cosmic rays depends on the latitude and altitude. The dose rate range obtained in some northeast Kosovo, the dose rate varies from ...

  5. Concentrations in the Local Association. 1. The southern concentrations NGC 2516, IC 2602, Centaurus-Lupus and Upper Scorpius

    Energy Technology Data Exchange (ETDEWEB)

    Eggen, O J [Cerro Tololo Inter-American Observatory, La Serena (Chile)

    1983-07-01

    Extensive intermediate band and H..beta.. observations and the available astrometry, have been used to support the suggestions that (1) several southern concentrations of stars are moving with the Pleiades and ..cap alpha.. Persei clusters (Local Association) and (2) the Local Association contains an appreciable percentage of the main-sequence stars near the Sun but the non-random distribution of the brighter association members focuses attention on a few concentrations, or 'clusters'. (3) All of the concentrations discussed here are larger than about 10 pc and the largest, in Lupus-Centaurus, is shown to be accompanied by A to G type main-sequence stars.

  6. Local anomaly cancellation in heterotic E{sub 8} x E{sub 8} orbifold compactifications with Wilson line backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Walter, M.G.A.

    2004-02-01

    We consider several examples of a special class of heterotic compactifications, i.e. heterotic E{sub 8} x E{sub 8} orbifolds with Wilson line backgrounds. By developing a local perspective we show that a brane world like picture emerges. As an important result we prove that the local massless spectrum at such a brane can always be traced back to the global spectrum of a (different) orbifold without Wilson lines. One particular implication of this result is that the use of (discrete) Wilson lines for the construction of phenomenologically interesting models has to be rethought. We show that stringy constraints render the brane spectra consistent. Using our local picture we are able to compute the local anomalies appearing at the different branes for our examples and show that they can all be cancelled by a local version of the Green-Schwarz mechanism at the same time. (orig.)

  7. Variability of sub-micrometer particle number size distributions and concentrations in the Western Mediterranean regional background

    Directory of Open Access Journals (Sweden)

    Michael Cusack

    2013-02-01

    Full Text Available This study focuses on the daily and seasonal variability of particle number size distributions and concentrations, performed at the Montseny (MSY regional background station in the western Mediterranean from October 2010 to June 2011. Particle number concentrations at MSY were shown to be within range of various other sites across Europe reported in literature, but the seasonality of the particle number size distributions revealed significant differences. The Aitken mode is the dominant particle mode at MSY, with arithmetic mean concentrations of 1698 cm3, followed by the accumulation mode (877 cm−3 and the nucleation mode (246 cm−3. Concentrations showed a strong seasonal variability with large increases in particle number concentrations observed from the colder to warmer months. The modality of median size distributions was typically bimodal, except under polluted conditions when the size distribution was unimodal. During the colder months, the daily variation of particle number size distributions are strongly influenced by a diurnal breeze system, whereby the Aitken and accumulation modes vary similarly to PM1 and BC mass concentrations, with nocturnal minima and sharp day-time increases owing to the development of a diurnal mountain breeze. Under clean air conditions, high levels of nucleation and lower Aitken mode concentrations were measured, highlighting the importance of new particle formation as a source of particles in the absence of a significant condensation sink. During the warmer months, nucleation mode concentrations were observed to be relatively elevated both under polluted and clean conditions due to increased photochemical reactions, with enhanced subsequent growth owing to elevated concentrations of condensable organic vapours produced from biogenic volatile organic compounds, indicating that nucleation at MSY does not exclusively occur under clean air conditions. Finally, mixing of air masses between polluted and non

  8. Theoretical background to orient the universitary projects management to local development.

    Directory of Open Access Journals (Sweden)

    Naybi Salas Vargas

    2012-03-01

    Full Text Available Nowadays the resources administration is a problem to be solved, and is remarkable the universities role to orient knowledge to the expected local development. With the communion of the university and the main decisors at local and territorial contexts, it is evident the development of alternatives that diminish existing breaches in the known projects management Anytime the projects development context is diverse and multicultural, all the knowledge elements that provide new forms are useful experiences without point out unique recipees. The development dynamic evolution in the territories continues being an urgency for human survival.The projects management, notable in international cooperation actions as the international dimension of the extensionist activity and in the science contributions, are reduced in their foccus to the promotion of local development, what points out the need to orient the universitary processes to the territorial development of the province, in particular the projects management. The objective of this work is to offer a guidance of foundations that allow to orient the management of universtary projects to local development.

  9. Diffuse X-ray Background Constraints on Models of the Local Interstellar Medium

    International Nuclear Information System (INIS)

    Snowden, S L

    2015-01-01

    There is a flux of soft X-rays (0.07–0.284 keV) of diffuse origin observable over the entire sky. As X-rays of this energy are strongly absorbed by the interstellar medium (ISM), one optical depth is 10 19 – 10 20 H cm −2 , they provide a unique probe of neutral material in the solar vicinity. However, to be an effective probe requires that the distribution of emission be well understood, a requirement that is currently unfulfilled (although progress is being made), with unclear fractions originating in the Galactic halo, Local Hot Bubble, heliosphere, and Earth's magnetosheath. The various available data, their consistency (or lack thereof), and their implications for understanding the very local ISM are briefly discussed

  10. Radioecology teaching: evaluation of the background radiation levels from areas with high concentrations of radionuclides in soil

    International Nuclear Information System (INIS)

    Anjos, R M; Okuno, E; Gomes, P R S; Veiga, R; Estellita, L; Mangia, L; Uzeda, D; Soares, T; Facure, A; Brage, J A P; Mosquera, B; Carvalho, C; Santos, A M A

    2004-01-01

    The study of environmental radioactivity is a topic which is not usually included in physics courses in Brazilian and Latin American universities. Consequently, high-school teachers are not able to show experimentally or discuss with their students the effects of exposure to terrestrial radiation. This paper presents a laboratory experiment in a teaching programme on the physics of ionizing radiation. It is based on the evaluation of the background radiation levels from areas with high concentrations of natural or artificial radionuclides in the soil. A brief analysis of the theory behind the technique and a description of some measurements, including their interpretations, are presented

  11. The concentrations of radionuclides, heavy metals, and poloychlorinated biphenyls in field mice collected from regional background areas. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, Philip R. [Los Alamos National Laboratory

    2016-01-21

    Field mice are effective indicators of contaminant presence. This paper reports the concentrations of various radionuclides, heavy metals, polychlorinated biphenyls, high explosives, perchlorate, and dioxin/furans in field mice (mostly deer mice) collected from regional background areas in northern New Mexico. These data, represented as the regional statistical reference level (the mean plus three standard deviations = 99% confidence level), are used to compare with data from field mice collected from areas potentially impacted by Laboratory operations, as per the Environmental Surveillance Program at Los Alamos National Laboratory.

  12. Impact of local and non-local sources of pollution on background US Ozone: synergy of a low-earth orbiting and geostationary sounder constellation

    Science.gov (United States)

    Bowman, K. W.; Lee, M.

    2015-12-01

    Dramatic changes in the global distribution of emissions over the last decade have fundamentally altered source-receptor pollution impacts. A new generation of low-earth orbiting (LEO) sounders complimented by geostationary sounders over North America, Europe, and Asia providing a unique opportunity to quantify the current and future trajectory of emissions and their impact on global pollution. We examine the potential of this constellation of air quality sounders to quantify the role of local and non-local sources of pollution on background ozone in the US. Based upon an adjoint sensitivity method, we quantify the role synoptic scale transport of non-US pollution on US background ozone over months representative of different source-receptor relationships. This analysis allows us distinguish emission trajectories from megacities, e.g. Beijing, or regions, e.g., western China, from natural trends on downwind ozone. We subsequently explore how a combination of LEO and GEO observations could help quantify the balance of local emissions against changes in distant sources . These results show how this unprecedented new international ozone observing system can monitor the changing structure of emissions and their impact on global pollution.

  13. Femoral nerve blockade using various concentrations of local anesthetic for knee arthroscopy in the pediatric population

    Directory of Open Access Journals (Sweden)

    Veneziano G

    2016-11-01

    Full Text Available Giorgio Veneziano,1,2 Jennifer Tripi,1 Dmitry Tumin,1 Mumin Hakim,1 David Martin,1,2 Ralph Beltran,1,2 Kevin Klingele,3,4 Tarun Bhalla,1,2 Joseph D Tobias1,2 1Department of Anesthesiology & Pain Medicine, Nationwide Children’s Hospital, 2Department of Anesthesiology & Pain Medicine, The Ohio State University College of Medicine, 3Department of Orthopedic Surgery, Nationwide Children’s Hospital, 4Department of Orthopedic Surgery, The Ohio State University College of Medicine, Columbus, OH, USA Background: Femoral nerve blockade (FNB provides effective postoperative analgesia in children undergoing arthroscopic knee surgery as evidenced by their opioid-sparing effects and decreased postoperative pain scores. Increasing the local anesthetic concentration in peripheral nerve blockade for adults undergoing orthopedic surgery has been shown to be beneficial, increasing block success rate, and providing a longer duration of analgesia. The effect of increasing the concentration of local anesthetic in extremity blocks in children remains largely unexplored.Methods: We retrospectively evaluated the effectiveness of FNB using three concentrations of local anesthetic (ropivacaine 0.2%, bupivacaine 0.25%, and ropivacaine 0.5% in children and adolescents undergoing arthroscopic knee surgery. The primary outcome evaluated was postoperative opioid consumption before discharge. Secondary outcomes included post-anesthesia care unit (PACU and hospital discharge times, first pain score in PACU, and the incidence of adverse events.Results: Two hundred and sixty-nine children and adolescents who received a FNB for arthroscopic knee surgery from January 2010 to December 2013 were included for analysis. Local anesthetic used in FNB was ropivacaine 0.2% in 116 (43% cases, ropivacaine 0.5% in 75 (28% cases, and bupivacaine 0.25% in 78 (29% cases. Median postoperative opioid consumption (mg/kg intravenous morphine equivalents in the ropivacaine 0.5% group was 0

  14. Long open-path TDL based system for monitoring background concentration for deployment at Jungfraujoch High Altitude Research Station- Switzerland

    Science.gov (United States)

    Simeonov, Valentin; van den Bergh, Hubert; Parlange, Marc

    2010-05-01

    A new, long open-path instrument for monitoring of path-averaged methane and water vapor concentrations will be presented. The instrument is built on the monostatic scheme (transceiver - distant retroreflector). A VCSEL tunable diode laser (TDL) with a central wavelength of 1654 nm is used as a light source. A specially designed, single-cell, hollow-cube retroreflector with 150 mm aperture will be installed at 1200 m from the transceiver in the final deployment at Jungfraujjoch and 100 mm retroreflectors will be used in the other applications. The receiver is built around a 20 cm Newtonian telescope. To avoid distortions in the shape of a methane line, caused by atmospheric turbulences, the line is scanned within 1 µs. Fast InGaAs photodiodes and 200 MHz are used to achieve this scanning rate. The expected concentration resolution for the above mentioned path lengths is of the order of 2 ppb. The instrument is developed at the Swiss Federal Institute of Technology - Lausanne (EPFL) Switzerland and will be used within the GAW+ CH program for long-term monitoring of background methane concentration in the Swiss Alps. After completing the initial tests at EPFL the instrument will be installed in 2012 at the High Altitude Research Station Jungfraujoch (HARSJ) located at 3580 m ASL. The HARSJ is one of the 24 global GAW stations and carries on continuous observations of a number of trace gasses, including methane. One of the goals of the project is to compare path-averaged to ongoing point measurements of methane in order to identify possible influence of the station. Future deployments of a copy of the instrument include the Colombian part of Amazonia and Siberian wetlands.

  15. Increase in local protein concentration by field-inversion gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Paulus Aran

    2007-09-01

    Full Text Available Abstract Background Proteins that migrate through cross-linked polyacrylamide gels (PAGs under the influence of a constant electric field experience negative factors, such as diffusion and non-specific trapping in the gel matrix. These negative factors reduce protein concentrations within a defined gel volume with increasing migration distance and, therefore, decrease protein separation efficiency. Enhancement of protein separation efficiency was investigated by implementing pulsed field-inversion gel electrophoresis (FIGE. Results Separation of model protein species and large protein complexes was compared between FIGE and constant field electrophoresis (CFE in different percentages of PAGs. Band intensities of proteins in FIGE with appropriate ratios of forward and backward pulse times were superior to CFE despite longer running times. These results revealed an increase in band intensity per defined gel volume. A biphasic protein relative mobility shift was observed in percentages of PAGs up to 14%. However, the effect of FIGE on protein separation was stochastic at higher PAG percentage. Rat liver lysates subjected to FIGE in the second-dimension separation of two-dimensional polyarcylamide gel electrophoresis (2D PAGE showed a 20% increase in the number of discernible spots compared with CFE. Nine common spots from both FIGE and CFE were selected for peptide sequencing by mass spectrometry (MS, which revealed higher final ion scores of all nine protein spots from FIGE. Native protein complexes ranging from 800 kDa to larger than 2000 kDa became apparent using FIGE compared with CFE. Conclusion The present investigation suggests that FIGE under appropriate conditions improves protein separation efficiency during PAGE as a result of increased local protein concentration. FIGE can be implemented with minimal additional instrumentation in any laboratory setting. Despite the tradeoff of longer running times, FIGE can be a powerful protein

  16. Development of concentration measurement system in a mini-channel using a local NMR sensor

    International Nuclear Information System (INIS)

    Ogawa, Kuniyasu; Haishi, Tomoyuki

    2008-01-01

    A local NMR sensor to measure methanol concentration of fluid flowing in a mini-channel was developed. The principle of the methanol sensor is based on the chemical shift of CH and OH species under high magnetic field. The sensor consists of a planar surface coil of 0.60 mm inside diameter. Using the sensors, local methanol concentration of water-methanol mixture in the mini-channel of 3.0 mm width and 1.5 mm depth was measured. The effects of flow velocity in the channel and the gravity direction on the methanol concentration distribution in the channel were investigated experimentally. (author)

  17. Temporal variability of the bioaerosol background at a subway station: concentration level, size distribution, and diversity of airborne bacteria.

    Science.gov (United States)

    Dybwad, Marius; Skogan, Gunnar; Blatny, Janet Martha

    2014-01-01

    Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 10(3) CFU m(-3) and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents.

  18. Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria

    Science.gov (United States)

    Dybwad, Marius; Skogan, Gunnar

    2014-01-01

    Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103 CFU m−3 and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents. PMID:24162566

  19. Flooding event impacts soil pH, Ca, and P concentration distribution in a cattle backgrounding site on karst topography.

    Science.gov (United States)

    Beef cattle backgrounding in US, function as an intermediate between cow-calf enterprises and feedlot finishing. Beef cattle backgrounding receives weaned calves of different growth stages from cow-calf operations and prepare them ready for feed lot finishing. Many beef cattle backgrounding operati...

  20. The role of sludge and fouling on local concentration processes in PWR steam generators

    International Nuclear Information System (INIS)

    Millett, D.J.; Paine, J.P.N.; Fenton, J.M.

    1992-01-01

    A detailed model of the transport processes in heated crevices is used to understand the role of corrosion product deposits on local concentration processes in PWR steam generators (SG). The model describes the heat, mass and momentum transfer processes which occur in the porous deposits found in tube support and tube sheet crevices and in the sludge pile on top of the tube sheet. The model is used to predict the concentration of a given specie in the liquid pore solution at steady-state, as a function of time, and may be readily expanded to multi-component solutions by the use of chemical thermodynamic models. In a previous paper the authors investigated the role of SG design and SG operating parameters on the concentration process. In this paper, several parametric studies were performed to investigate the sensitivity of the local concentration process to the corrosion product properties

  1. Determination of toxic and essential element concentrations in foodstuffs from local market

    International Nuclear Information System (INIS)

    Surtipanti; Suwirma; Yumiarti; June, M.; Syaifudin, S.

    1989-01-01

    Determination of toxic and essential elements concentrations in foodstuffs from local market in Jakarta. Concentration of toxic essential elements, such as, As, Hg, Cr, Pb, Cu, and Zn, in rice, corn bean, small green peas, wheat, vegetables, fruits, tea and coffee, have been determined. As, Hg, Sb, Cr, Se, and Zn, were determined using neutron activation analysis, after being irradiated at TRIGA-MARK II reactor, while Pb and Cu were determined using atomic absorption spectrophotometer. The results obtained were lower than the maximum permissible concentration allowed. (author). 8 refs

  2. Concentration gradient along the scala tympani after local application of gentamicin to the round window membrane.

    Science.gov (United States)

    Plontke, Stefan K; Mynatt, Robert; Gill, Ruth M; Borgmann, Stefan; Salt, Alec N

    2007-07-01

    The distribution of gentamicin along the fluid spaces of the cochlea after local applications has never previously been demonstrated. Computer simulations have predicted that significant basal-apical concentration gradients might be expected, and histologic studies indicate that hair cell damage is greater at the base than at the apex after local gentamicin application. In the present study, gradients of gentamicin along the cochlea were measured. A recently developed method of sampling perilymph from the cochlear apex of guinea pigs was used in which the samples represent fluid originating from different regions along the scala tympani. Gentamicin concentration was determined in sequential apical samples that were taken after up to 3 hours of local application to the round window niche. Substantial gradients of gentamicin along the length of the scala tympani were demonstrated and quantified, averaging more than 4,000 times greater concentration at the base compared with the apex at the time of sampling. Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow. The large gradients for gentamicin demonstrated here in guinea pigs account for how it is possible to suppress vestibular function in some patients with a local application of gentamicin without damaging auditory function. Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients.

  3. Concentration gradient along scala tympani following the local application of gentamicin to the round window membrane

    Science.gov (United States)

    Plontke, Stefan K.; Mynatt, Robert; Gill, Ruth M.; Borgmann, Stefan; Salt, Alec N.

    2008-01-01

    Objectives The distribution of gentamicin along the fluid spaces of the cochlea following local applications has never previously been demonstrated. Computer simulations have predicted that significant basal-apical concentration gradients might be expected and histological studies indicate that hair cell damage is greater at the base than at the apex following local gentamicin application. In the present study, gradients of gentamicin along the cochlea were measured. Methods A recently-developed method of sampling perilymph from the cochlear apex of guinea pigs was used, in which the samples represent fluid originating from different regions along scala tympani. Gentamicin concentration was determined in sequential apical samples which were taken following up to three hours of local application to the round window niche. Results Substantial gradients of gentamicin along the length of scala tympani were demonstrated and quantified, averaging more than 4000 times greater concentration at the base compared to the apex at the time of sampling. Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow. Conclusions The large gradients for gentamicin demonstrated here in guinea pigs account for how it is possible to suppress vestibular function in some patients with a local application of gentamicin without damaging auditory function. Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients. PMID:17603318

  4. Analgesic efficacy of local anaesthetic wound administration in knee arthroplasty: volume vs concentration

    DEFF Research Database (Denmark)

    Andersen, L Ø; Gaarn-Larsen, L; Kristensen, B B

    2010-01-01

    was reduced in both groups with ropivacaine administration 24 h postoperatively (p time intervals. No reduction in pain scores was observed with ropivacaine injection 6 h postoperatively. The median (IQR [range]) dose of oxycodone administered......Wound administration of local anaesthetic may be effective for postoperative pain management in knee arthroplasty, but the analgesic efficacy of local anaesthetic in relation to volume vs concentration has not been determined. In a double-blinded trial, 48 patients scheduled for total knee...... arthroplasty were randomly assigned to receive either a high volume/low concentration solution of ropivacaine (20 ml, 0.5%) or a low volume/high concentration solution of ropivacaine (10 ml, 1%), 6 and 24 h postoperatively through an intracapsular catheter. Pain was assessed for 2 h after administration. Pain...

  5. Local variations of atmospheric 222Rn and 210Pb concentrations in Badgastein (Austria)

    International Nuclear Information System (INIS)

    Wallner, G.; Ayromlou, S.

    2002-01-01

    222 Rn was measured and aerosols for 210 Pb determination were collected simultaneously outdoors at ground level near the train station of Badgastein (1080 m a.s.l.), and later on also on the nearby Stubnerkogel (2230 m a.s.l.). Radon concentrations at lower altitude were up to 140 Bq/m 3 , on the mountain the usual background levels were found. In contrary to the differing radon levels, the 210 Pb activity concentrations were in the same order of magnitude for both locations with values between 0.16 and 0.77 mBq/m 3 . (author)

  6. Estimation of local concentration from measurements of stochastic adsorption dynamics using carbon nanotube-based sensors

    International Nuclear Information System (INIS)

    Jang, Hong; Lee, Jay H.; Braatz, Richard D.

    2016-01-01

    This paper proposes a maximum likelihood estimation (MLE) method for estimating time varying local concentration of the target molecule proximate to the sensor from the time profile of monomolecular adsorption and desorption on the surface of the sensor at nanoscale. Recently, several carbon nanotube sensors have been developed that can selectively detect target molecules at a trace concentration level. These sensors use light intensity changes mediated by adsorption or desorption phenomena on their surfaces. The molecular events occurring at trace concentration levels are inherently stochastic, posing a challenge for optimal estimation. The stochastic behavior is modeled by the chemical master equation (CME), composed of a set of ordinary differential equations describing the time evolution of probabilities for the possible adsorption states. Given the significant stochastic nature of the underlying phenomena, rigorous stochastic estimation based on the CME should lead to an improved accuracy over than deterministic estimation formulated based on the continuum model. Motivated by this expectation, we formulate the MLE based on an analytical solution of the relevant CME, both for the constant and the time-varying local concentrations, with the objective of estimating the analyte concentration field in real time from the adsorption readings of the sensor array. The performances of the MLE and the deterministic least squares are compared using data generated by kinetic Monte Carlo (KMC) simulations of the stochastic process. Some future challenges are described for estimating and controlling the concentration field in a distributed domain using the sensor technology.

  7. Dendritic slow dynamics enables localized cortical activity to switch between mobile and immobile modes with noisy background input.

    Directory of Open Access Journals (Sweden)

    Hiroki Kurashige

    Full Text Available Mounting lines of evidence suggest the significant computational ability of a single neuron empowered by active dendritic dynamics. This motivates us to study what functionality can be acquired by a network of such neurons. The present paper studies how such rich single-neuron dendritic dynamics affects the network dynamics, a question which has scarcely been specifically studied to date. We simulate neurons with active dendrites networked locally like cortical pyramidal neurons, and find that naturally arising localized activity--called a bump--can be in two distinct modes, mobile or immobile. The mode can be switched back and forth by transient input to the cortical network. Interestingly, this functionality arises only if each neuron is equipped with the observed slow dendritic dynamics and with in vivo-like noisy background input. If the bump activity is considered to indicate a point of attention in the sensory areas or to indicate a representation of memory in the storage areas of the cortex, this would imply that the flexible mode switching would be of great potential use for the brain as an information processing device. We derive these conclusions using a natural extension of the conventional field model, which is defined by combining two distinct fields, one representing the somatic population and the other representing the dendritic population. With this tool, we analyze the spatial distribution of the degree of after-spike adaptation and explain how we can understand the presence of the two distinct modes and switching between the modes. We also discuss the possible functional impact of this mode-switching ability.

  8. ASSOCIATIONS BETWEEN SMALL-SCALE STRUCTURE IN LOCAL GALACTIC NEUTRAL HYDROGEN AND IN THE COSMIC MICROWAVE BACKGROUND OBSERVED BY PLANCK

    Energy Technology Data Exchange (ETDEWEB)

    Verschuur, Gerrit L., E-mail: gverschu@naic.edu [Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612 (United States)

    2015-11-01

    High-resolution galactic neutral hydrogen (HI) data obtained with the Green Bank Telescope (GBT) over 56 square degrees of sky around l = 132°, b = 25° are compared with small-scale structure in the Cosmic Microwave Background observed by PLANCK, specifically at 143 and 857 GHz, as well as with 100 μm observations from the IRIS survey. The analysis uses data in 13 2° × 2° sub-areas found in the IRSA database at IPAC. The results confirm what has been reported previously; nearby galactic HI features and high-frequency continuum sources believed to be cosmological are in fact clearly associated. While several attempts strongly suggest that the associations are statistically significant, the key to understanding the phenomenon lies in the fact that in any given area HI is associated with cirrus dust at certain HI velocities and with 143 GHz features at different velocities. At the same time, for the 13 sub-areas studied, there is very little overlap between the dust and 143 GHz features. The data do not imply that the HI itself gives rise to the high-frequency continuum emission. Rather, they appear to indicate undiagnosed brightness enhancements indirectly associated with the HI. If low density interstellar electrons concentrated into clumps, or observed in directions where their integrated line-of-sight column densities are greater than the background in a manner similar to the phenomena that give rise to structure in diffuse HI structure, they will profoundly affect attempts to create a foreground electron mask used for processing PLANCK as well as WMAP data.

  9. ASSOCIATIONS BETWEEN SMALL-SCALE STRUCTURE IN LOCAL GALACTIC NEUTRAL HYDROGEN AND IN THE COSMIC MICROWAVE BACKGROUND OBSERVED BY PLANCK

    International Nuclear Information System (INIS)

    Verschuur, Gerrit L.

    2015-01-01

    High-resolution galactic neutral hydrogen (HI) data obtained with the Green Bank Telescope (GBT) over 56 square degrees of sky around l = 132°, b = 25° are compared with small-scale structure in the Cosmic Microwave Background observed by PLANCK, specifically at 143 and 857 GHz, as well as with 100 μm observations from the IRIS survey. The analysis uses data in 13 2° × 2° sub-areas found in the IRSA database at IPAC. The results confirm what has been reported previously; nearby galactic HI features and high-frequency continuum sources believed to be cosmological are in fact clearly associated. While several attempts strongly suggest that the associations are statistically significant, the key to understanding the phenomenon lies in the fact that in any given area HI is associated with cirrus dust at certain HI velocities and with 143 GHz features at different velocities. At the same time, for the 13 sub-areas studied, there is very little overlap between the dust and 143 GHz features. The data do not imply that the HI itself gives rise to the high-frequency continuum emission. Rather, they appear to indicate undiagnosed brightness enhancements indirectly associated with the HI. If low density interstellar electrons concentrated into clumps, or observed in directions where their integrated line-of-sight column densities are greater than the background in a manner similar to the phenomena that give rise to structure in diffuse HI structure, they will profoundly affect attempts to create a foreground electron mask used for processing PLANCK as well as WMAP data

  10. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site during SAPUSS - diurnal variations and PMF receptor modelling

    Science.gov (United States)

    Dall'Osto, M.; Querol, X.; Amato, F.; Karanasiou, A.; Lucarelli, F.; Nava, S.; Calzolai, G.; Chiari, M.

    2013-04-01

    Hourly-resolved aerosol chemical speciation data can be a highly powerful tool to determine the source origin of atmospheric pollutants in urban environments. Aerosol mass concentrations of seventeen elements (Na, Mg, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb) were obtained by time (1 h) and size (PM2.5 particulate matter Spain) during September-October 2010: an urban background site (UB) and a street canyon traffic road site (RS). Elements related to primary non-exhaust traffic emission (Fe, Cu), dust resuspension (Ca) and anthropogenic Cl were found enhanced at the RS, whereas industrial related trace metals (Zn, Pb, Mn) were found at higher concentrations at the more ventilated UB site. When receptor modelling was performed with positive matrix factorization (PMF), nine different aerosol sources were identified at both sites: three types of regional aerosols (regional sulphate (S) - 27%, biomass burning (K) - 5%, sea salt (Na-Mg) - 17%), three types of dust aerosols (soil dust (Al-Ti) - 17%, urban crustal dust (Ca) - 6%, and primary traffic non-exhaust brake dust (Fe-Cu) - 7%), and three types of industrial aerosol plumes-like events (shipping oil combustion (V-Ni) - 17%, industrial smelters (Zn-Mn) - 3%, and industrial combustion (Pb-Cl) - 5%, percentages presented are average source contributions to the total elemental mass measured). The validity of the PMF solution of the PIXE data is supported by very good correlations with external single particle mass spectrometry measurements. Some important conclusions can be drawn about the PM2.5 mass fraction simultaneously measured at the UB and RS sites: (1) the regional aerosol sources impact both monitoring sites at similar concentrations regardless their different ventilation conditions; (2) by contrast, local industrial aerosol plumes associated with shipping oil combustion and smelters activities have a higher impact on the more ventilated UB site; (3) a unique source of Pb-Cl (associated with

  11. Analysis of local concentration in stomach fold pattern by using abdominal X-ray CT image

    International Nuclear Information System (INIS)

    Watanabe, Shigeto; Hasegawa, Jun-ichi; Mekada, Yoshito; Mori, Kensaku; Nawano, Shigeru

    2004-01-01

    The paper presents a method for analysis of stomach folds pattern in abdominal X-ray CT images. Many stomach cancers have local concentration of folds at cancer lesions. Therefore, in stomach diagnosis, it is very important to evaluate quantitatively such fold concentration. In this paper, a method for calculation of concentration index for line figure on a curved surface is proposed first. Then, using this method a processing procedure for detection of stomach cancer from an abdominal X-ray CT image is developed. In the experiment using practical X-ray CT images, it is shown that by the proposed procedure, higher values of concentration index are obtained at cancer area. (author)

  12. Trends in atmospheric ammonium concentrations in relation to atmospheric sulfate and local agriculture.

    Science.gov (United States)

    Kelly, Victoria R; Lovett, Gary M; Weathers, Kathleen C; Likens, Gene E

    2005-06-01

    Ammonium (NH(4)(+)) concentrations in air and precipitation at the Institute of Ecosystem Studies (IES) in southeastern New York, USA declined over an 11-year period from 1988 to 1999, but increased from 1999 to 2001. These trends in particulate NH(4)(+) correlated well with trends in particulate SO(4)(2-) over the 1988-2001 period. The NH(4)(+) trends were not as well correlated with local cattle and milk production, which declined continuously throughout the period. This suggests that regional transport of SO(4)(2-) may have a greater impact on concentrations of NH(4)(+) and subsequent deposition than local agricultural emissions of NH(3). Ammonium concentrations in precipitation correlated significantly with precipitation SO(4)(2-) concentrations for the 1984-2001 period although NH(4)(+) in precipitation increased after 1999 and SO(4)(2-) in precipitation continued to decline after 1999. The correlation between NH(4)(+) and SO(4)(2-) was stronger for particulates than for precipitation. Particulate NH(4)(+) concentrations were also correlated with particulate SO(4)(2-) concentrations at 31 of 35 eastern U.S. CASTNet sites that had at least 10 years of data. Air concentrations of NH(4)(+) and SO(4)(2-) were more strongly correlated at the sites that were located within an agricultural landscape than in forested sites. At most of the sites there was either no trend or a decrease in NH(4)(+) dry deposition during the 1988-2001 period. The sites that showed an increasing trend in NH(4)(+) dry deposition were generally located in the southeastern U.S. The results of this study suggest that, in the northeastern U.S., air concentrations of NH(4)(+) and subsequent deposition may be more closely linked to SO(4)(2-) and thus SO(2) emissions than with NH(3) emissions. These results also suggest that reductions in S emissions have reduced NH(4)(+) transport to and NH(4)(+)-N deposition in the Northeast.

  13. Evaluation of serum concentrations of the selected cytokines in patients with localized scleroderma

    Directory of Open Access Journals (Sweden)

    Jolanta Budzyńska-Włodarczyk

    2016-02-01

    Full Text Available Introduction : Localized scleroderma is an autoimmune disease primarily affecting the skin. The cause of disease remains unexplained although environmental factors are implicated, which are likely to be responsible for activation of the endothelium and subsequent inflammation leading to excessive synthesis of collagen and extracellular matrix components. Aim: To determine concentrations of interleukin (IL-27, transforming growth factor (TGF-β1, TGF-β2, IL-6, and sIL-6R in patients with localized scleroderma compared to controls and to assess the relations between their levels and laboratory markers. Material and methods: The study encompassed 17 females with localized scleroderma (aged 25–67. The control group consisted of 30 age-matched healthy women. The blood was sampled from the basilic vein. Serum levels of cytokines were determined using ELISA. Results : The TGF-β2 levels were found to be significantly lower in patients with localized scleroderma compared to controls. Concentrations of TGF-β1 were decreased in scleroderma patients when compared to controls but without statistical significance. There were no significant differences in serum IL-6, sIL-6R and IL-27 levels between patients and the control group; however, we found a significant positive correlation between the level of sIL-6 and ESR among subjects with localized scleroderma. Conclusions : The findings of decreased serum levels of TGF-β1 and TGF-β2 in patients with localized scleroderma demonstrate a possible association of these cytokines with pathogenesis of the disease. The results suggest also that sIL-6R is likely to be involved in inflammation in patients with localized scleroderma.

  14. Evaluation of serum concentrations of the selected cytokines in patients with localized scleroderma.

    Science.gov (United States)

    Budzyńska-Włodarczyk, Jolanta; Michalska-Jakubus, Małgorzata M; Kowal, Małgorzata; Krasowska, Dorota

    2016-02-01

    Localized scleroderma is an autoimmune disease primarily affecting the skin. The cause of disease remains unexplained although environmental factors are implicated, which are likely to be responsible for activation of the endothelium and subsequent inflammation leading to excessive synthesis of collagen and extracellular matrix components. To determine concentrations of interleukin (IL)-27, transforming growth factor (TGF)-β1, TGF-β2, IL-6, and sIL-6R in patients with localized scleroderma compared to controls and to assess the relations between their levels and laboratory markers. The study encompassed 17 females with localized scleroderma (aged 25-67). The control group consisted of 30 age-matched healthy women. The blood was sampled from the basilic vein. Serum levels of cytokines were determined using ELISA. The TGF-β2 levels were found to be significantly lower in patients with localized scleroderma compared to controls. Concentrations of TGF-β1 were decreased in scleroderma patients when compared to controls but without statistical significance. There were no significant differences in serum IL-6, sIL-6R and IL-27 levels between patients and the control group; however, we found a significant positive correlation between the level of sIL-6 and ESR among subjects with localized scleroderma. The findings of decreased serum levels of TGF-β1 and TGF-β2 in patients with localized scleroderma demonstrate a possible association of these cytokines with pathogenesis of the disease. The results suggest also that sIL-6R is likely to be involved in inflammation in patients with localized scleroderma.

  15. Assessment of external and internal doses due to farming in high background radiation areas in old tin mining localities in Jos-plateau, Nigeria

    International Nuclear Information System (INIS)

    Jibiri, N.N.; Farai, I.P.; Alausa, S.K.

    2009-01-01

    Farming on soils situated in high background radiation areas can result to enhanced radiation exposure scenarios and pathways to humans. To assess the likely levels of exposures, farm soil samples were collected from different farmlands in three old tin mining localities (Bitsichi, Bukuru and Ropp) in Jos Plateau Nigeria, known for high radiations. The soil samples were analyzed for the activity concentrations of 226 Ra, 232 Th and 40 K, using gamma-ray spectroscopy. The outdoor annual effective dose rates were calculated using the activity concentrations of the radionuclides and were found to vary from 0.07 mSv to 2.02 mSv across the three localities. Considering dust generation from soil tillage and inadvertent ingestion of soil particles, the likely internal radiation hazards were estimated using conservative dust and soil loading factors. The total average annual effective dose rates due to 226 Ra and 232 Th that could result from dust inhalation and ingestion of soil particles were 16.9 μSv, 8.1 μSv and 8.8 μSv, respectively for Bitsichi, Bukuru and Ropp. Though these values are about 5% the outdoor exposures to the farmers in those farms and greater than 1 μSv y-1, from the point of view of radiation protection and risk, they are significant. It suffices to say, therefore, that the results of this study will create the possibility of the importance to evaluate the health risk among the farming population and workplace environments which often is not covered by regulations concerning health protection. (author)

  16. A nonparametric approach to calculate critical micelle concentrations: the local polynomial regression method

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Fontan, J.L.; Costa, J.; Ruso, J.M.; Prieto, G. [Dept. of Applied Physics, Univ. of Santiago de Compostela, Santiago de Compostela (Spain); Sarmiento, F. [Dept. of Mathematics, Faculty of Informatics, Univ. of A Coruna, A Coruna (Spain)

    2004-02-01

    The application of a statistical method, the local polynomial regression method, (LPRM), based on a nonparametric estimation of the regression function to determine the critical micelle concentration (cmc) is presented. The method is extremely flexible because it does not impose any parametric model on the subjacent structure of the data but rather allows the data to speak for themselves. Good concordance of cmc values with those obtained by other methods was found for systems in which the variation of a measured physical property with concentration showed an abrupt change. When this variation was slow, discrepancies between the values obtained by LPRM and others methods were found. (orig.)

  17. Trends in air concentration and deposition at background monitoring sites in Sweden - major inorganic compounds, heavy metals and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Kindbom, K.; Svensson, Annika; Sjoeberg, K.; Pihl Karlsson, G.

    2001-09-01

    This report describes concentrations in air of sulphur compounds, soot, nitrogen compounds and ozone in Sweden between 1985-1998. Time trends of concentration in precipitation and deposition of sulphate, nitrate, ammonium, acidity, base cations and chloride in six different regions covering Sweden are evaluated during the period 1983-1998. Trends of heavy metals in precipitation have been analysed for the period 1983-1998 and the change in heavy metal concentration, 1975-1995, in mosses is described. Data used in the trend analyses originates from measurements performed at six Swedish EMEP stations and from approximately 25 stations within the national Precipitation Chemistry Network. Two different statistical methods, linear regression and the non-parametric Mann Kendall test, have been used to evaluate changes in annual mean values. Time trends of concentration of sulphur dioxide, particulate sulphate, soot, nitrogen dioxide, total nitrate and total ammonium in air show highly significant decreasing trends, except for soot at one station in northern Sweden. Concentrations of ozone have a strong seasonal variation with a peak occurring in spring every year. However, annual ozone concentrations show no obvious trends in spite of decreasing emissions of the precursors NOx and VOC. A slight indication of a decreasing trend in the number of ozone episodes might be seen from 1990 to 1998. Sulphate concentrations in precipitation and deposition show strongly significant decreasing trends in the whole country. Concentrations and deposition of nitrate and ammonium have been decreasing in all areas except for nitrate at stations in south-west and north-west Sweden and ammonium in south-west Sweden. Acidity has decreased in all areas since 1989, resulting in increasing pH values in Sweden. The interannual variations of concentration and deposition of base cations and chloride are large and few general trends can be seen during 1983-1997. Time trends of four heavy metals in

  18. Spatial distribution of ground-level urban background O3 concentrations in the Metropolitan Area of Buenos Aires, Argentina

    International Nuclear Information System (INIS)

    Pineda Rojas, Andrea L.; Venegas, Laura E.

    2013-01-01

    In this work, a recently developed urban-scale atmospheric dispersion model (DAUMOD-GRS) is applied to evaluate the ground-level ozone (O 3 ) concentrations resulting from anthropogenic area sources of NO x and VOC in the Metropolitan Area of Buenos Aires (MABA). The statistical comparison of model results with observations (including new available data from seventeen sites) shows a good model performance. Estimated summer highest diurnal O 3 1-h concentrations in the MABA vary between 15 ppb in the most urbanised area and 53 ppb in the suburbs. All values are below the air quality standard. Several runs are performed to evaluate the impact of possible future emission reductions on O 3 concentrations. Under all hypothetical scenarios, the maximum diurnal O 3 1-h concentration obtained for the area is slightly reduced (up to 4%). However, maximum diurnal O 3 concentrations could increase at some less urbanised areas of MABA depending on the relative reductions of the emissions of NO x and VOC. -- Highlights: ► A recently developed air quality model reproduces well observed O 3 levels in MABA. ► Modelled summer maximum diurnal O 3 concentrations vary in the area between 15 and 53 ppb. ► All hourly values are below the air quality standard (120 ppb). ► Possible future emission reductions would have small impact on the highest level. -- The distribution of summer maximum diurnal ground-level O 3 concentrations in the Metropolitan Area of Buenos Aires is evaluated applying a recently developed simple urban air quality model

  19. Concentric circular ring and nanodisk optical antenna enhanced multispectral quantum dot infrared photodetector with spectral localization

    International Nuclear Information System (INIS)

    Zhang, Yingjie; Kemsri, Thitikorn; Li, Lin; Lu, Xuejun; Gu, Guiru

    2017-01-01

    In this paper, we report a concentric circular ring and nanodisk plasmonic optical antenna (POA) enhanced multispectral quantum dot infrared photodetector (QDIP). The circular ring and the nanodisk POA structures are designed to have plasmonic resonant wavelengths in the longwave infrared (LWIR) and the midwave infrared (MWIR) spectral regimes, respectively. The electric field ( E -field) distributions are simulated and show spectral localization due to the distinct plasmonic resonant wavelengths of the POA structures. The circular ring is found to enhance the E -fields in the nanodisk regions due to the mutual coupling. A concentric circular ring and nanodisk POA enhanced multispectral QDIP was fabricated and tested. Multispectral enhancement was observed. The enhancement is compared to that of a QDIP with only the circular ring POA structure. The experiment data agree with the simulation. The concentric circular ring and nanodisk POA provides a compact planar structure for multispectral QDIP enhancement. (paper)

  20. Estimating concentration of fluoride in edible leaves locally grown around Raipur, Chhattisgarh

    Directory of Open Access Journals (Sweden)

    Anubhuti Jain

    2017-01-01

    Full Text Available Introduction: Fluorine is the 13th most abundant element in the earth crust and is available in various environmental, clinical, and food samples in varied concentrations. Aim: To estimate concentration of fluoride in five medicinal and five nonmedicinal edible leaves locally grown around Raipur, Chhattisgarh, India. Materials and Methods: Samples of ten medicinal and nonmedicinal edible leaves, namely, spinach (Spinacia oleracea, coriander leaves (Coriandrum sativum, chawli bhaji (Amaranthus spinach, lal bhaji (Alternanthera bettzickiana, mooli bhaji (Raphanus sativus, neem (Azadirachta indica, tulsi (Ocimum tenuiflorum, mint leaves (Mentha longifolia, betel leaves (Piper betle, and bael leaves (Aegle marmelos were collected in the clean polyethene bags. After thorough washing with water, leaves were left to dry in ambient temperature and crushed into powder using a mixer grinder. One gram of each of the powdered samples was taken and analyzed for fluoride concentration using a 2-(4-sulfophenylazo 1,8-dihydroxy-3,6-naphthalenedisulfonic acid trisodium salt spectrophotometric method. Results: The presence of fluoride in varied concentrations in locally grown edible leaves were analyzed. The highest concentration of fluoride was reported in tulsi (6.0 μg/g and lowest in mint leaves (1.1 μg/g. Two edible leaves, neem and bael, showed fluoride concentration below detection limit. Conclusion: Knowledge regarding the importance of edible leaves may be lost in the near future unless efforts are made to educate younger generations about their importance. Hence, the time has come to make good use of centuries-old knowledge through modern approaches for their better economic and therapeutic utilization.

  1. Simultaneous measurement of local particle movement, solids concentrations and bubble properties in fluidized bed reactors using a novel fiber optical technique

    Energy Technology Data Exchange (ETDEWEB)

    Tayebi, Davoud

    1999-12-31

    This thesis develops a new method for simultaneous measurements of local flow properties in highly concentrated multiphase flow systems such as gas-solid fluidized bed reactors. The method is based on fiber optical technique and tracer particles. A particle present in the measuring volume in front of the probe is marked with a fluorescent dye. A light source illuminates the particles and the detecting fibres receive reflected light from uncoated particles and fluorescent light from the tracer particle. Using optical filters, the fluorescent light can be distinguished and together with a small fraction of background light from uncoated particles can be used for determination of local flow properties. Using this method, one can simultaneously measure the local movement of a single tracer particle, local bubble properties and the local solids volume fractions in different positions in the bed. The method is independent of the physical properties of the tracer particles. It is also independent of the local solids concentrations in the range of 0 to 60 vol.-%, but is mainly designed for highly concentrated flow systems. A computer programme that uses good signals from at least three sensors simultaneously to calculate the tracer particle velocity in two dimensions have been developed. It also calculates the bubble properties and local solids volume fractions from the same time series. 251 refs., 150 figs., 5 tabs.

  2. Simultaneous measurement of local particle movement, solids concentrations and bubble properties in fluidized bed reactors using a novel fiber optical technique

    Energy Technology Data Exchange (ETDEWEB)

    Tayebi, Davoud

    1998-12-31

    This thesis develops a new method for simultaneous measurements of local flow properties in highly concentrated multiphase flow systems such as gas-solid fluidized bed reactors. The method is based on fiber optical technique and tracer particles. A particle present in the measuring volume in front of the probe is marked with a fluorescent dye. A light source illuminates the particles and the detecting fibres receive reflected light from uncoated particles and fluorescent light from the tracer particle. Using optical filters, the fluorescent light can be distinguished and together with a small fraction of background light from uncoated particles can be used for determination of local flow properties. Using this method, one can simultaneously measure the local movement of a single tracer particle, local bubble properties and the local solids volume fractions in different positions in the bed. The method is independent of the physical properties of the tracer particles. It is also independent of the local solids concentrations in the range of 0 to 60 vol.-%, but is mainly designed for highly concentrated flow systems. A computer programme that uses good signals from at least three sensors simultaneously to calculate the tracer particle velocity in two dimensions have been developed. It also calculates the bubble properties and local solids volume fractions from the same time series. 251 refs., 150 figs., 5 tabs.

  3. Sources of increase in lowermost stratospheric sulphurous and carbonaceous aerosol background concentrations during 1999–2008 derived from CARIBIC flights

    Directory of Open Access Journals (Sweden)

    Johan Friberg

    2014-03-01

    Full Text Available This study focuses on sulphurous and carbonaceous aerosol, the major constituents of particulate matter in the lowermost stratosphere (LMS, based on in situ measurements from 1999 to 2008. Aerosol particles in the size range of 0.08–2 µm were collected monthly during intercontinental flights with the CARIBIC passenger aircraft, presenting the first long-term study on carbonaceous aerosol in the LMS. Elemental concentrations were derived via subsequent laboratory-based ion beam analysis. The stoichiometry indicates that the sulphurous fraction is sulphate, while an O/C ratio of 0.2 indicates that the carbonaceous aerosol is organic. The concentration of the carbonaceous component corresponded on average to approximately 25% of that of the sulphurous, and could not be explained by forest fires or biomass burning, since the average mass ratio of Fe to K was 16 times higher than typical ratios in effluents from biomass burning. The data reveal increasing concentrations of particulate sulphur and carbon with a doubling of particulate sulphur from 1999 to 2008 in the northern hemisphere LMS. Periods of elevated concentrations of particulate sulphur in the LMS are linked to downward transport of aerosol from higher altitudes, using ozone as a tracer for stratospheric air. Tropical volcanic eruptions penetrating the tropical tropopause are identified as the likely cause of the particulate sulphur and carbon increase in the LMS, where entrainment of lower tropospheric air into volcanic jets and plumes could be the cause of the carbon increase.

  4. Estimating background denudation rates and delivery of landslide sediment from a time series of 10Be concentrations in landslide dominated basins in the southern Central Range of Taiwan

    Science.gov (United States)

    Chen, C. Y.; Willett, S.; West, A. J.; Dadson, S. J.; Hovius, N.; Christl, M.; Shyu, J. B. H.

    2017-12-01

    The southern Central Range of Taiwan is located at a tectonic transition zone between an oceanic subduction zone and the arc-continent collision forming the Taiwan orogen. The rapidly evolving tectonic setting, tropical climate and frequent typhoons result in a complex uplift pattern, transient landscapes and extensive landslides. For this study, we obtained a series of 10Be concentrations over the last decade for 13 major drainage basins in the southern Central Range, bracketing the occurrence of a major typhoon, Morakot, which hit Taiwan in 2009 and triggered thousands of landslides. This time series allows us to simultaneously estimate the background erosion rate and assess the impact of Morakot-triggered landslides on 10Be concentrations. The time series of 10Be concentrations shows temporally lower concentrations of 10Be indicating dilution following the Morakot event in most basins. The diluted 10Be concentrations imply erosion rates up to three times higher than the lowest measured rates in the same basins. We constructed a simple sediment-mixing model parameterized by a sudden input of sediment supplied from landslides superimposed on a background denudation rate. This model was calibrated to measured landslide inventories and the series of 10Be data. We obtain a range of permissible background erosion rate and fraction of landslide sediments over time for each basin. The inferred background erosion rate reveals a northward increasing trend, reflecting the initial stage of the mountain building and indicating tectonic forcing is the main driver of the landscape evolution in the southern Central Range. The temporal changes in fraction of landslide sediments show that the available landslide material generated by the Morakot event is decreasing over time with a timescale of several years.

  5. Influence of local and regional Mediterranean meteorology on SO₂ ground-level concentrations in SE Spain.

    Science.gov (United States)

    Santacatalina, Milagros; Carratalá, Adoración; Mantilla, Enrique

    2011-06-01

    This work presents the results of a 4-year study on sulfur dioxide (SO(2)) ground-level concentrations in an area of southeastern Spain, the L'Alacantí region, where the cement industry is important and coke use extends to other industries as well. The main source of SO(2) emissions in the area was found to be a the Lepold cement plant (one of the two cement plants in the area). The high levels of SO(2) probably extend back to 1920 when this plant began operations. Both local and Mediterranean-scale meteorological processes influence the SO(2) ground-level concentration and together explain the dispersion dynamics of this pollutant. The location and topography of the study zone result in NW Atlantic advections and E-SE sea breezes being the dominant atmospheric circulation patterns in the area. Under stable meteorological conditions, minor local circulations are also relevant to the SO(2) concentration levels. The high frequency of local circulations determines a concentration pattern that changes during the day, with impacts occurring preferentially in a W-NW direction from the source at midday (sea breeze and strong thermal mixture), and in a SE direction at night. This causes the SO(2) concentrations to present well-defined diurnal cycles with well-differentiated shapes depending on the location of the sampling station relative to the source. The dependence of SO(2) 10 min levels on the wind origin and speed throughout the day has been evaluated by studying statistical parameters including P95, P50 and arithmetic mean. Exceedances occur under specific dispersion conditions at distances less than 1 km from the source. However, the source is traceable at larger distances and the levels are higher than typical urban ones. P95 was used as an estimator of the occurrence of larger levels or impacts. Leeward of NW winds and the source, at night and in early morning, P95 levels are comprised between 30 and 55 µg m(-3). In contrast, with SE winds and at midday, P95

  6. Higher prices at Canadian gas pumps: international crude oil prices or local market concentration? An empirical investigation

    International Nuclear Information System (INIS)

    Anindya Sen

    2003-01-01

    There is little consensus on whether higher retail gasoline prices in Canada are the result of international crude oil price fluctuations or local market power exercised by large vertically-integrated firms. I find that although both increasing local market concentration and higher average monthly wholesale prices are positively and significantly associated with higher retail prices, wholesale prices are more important than local market concentration. Similarly, crude oil prices are more important than the number of local wholesalers in determining wholesale prices. These results suggest that movements in gasoline prices are largely the result of input price fluctuations rather than local market structure. (author)

  7. Drinking pattern and its relation to hemoglobin concentration in local brew consumers from the Kathmandu Region

    Institute of Scientific and Technical Information of China (English)

    Arun Kumar

    2009-01-01

    The study was conducted to determine the hemoglobin concentration in alcohol consumers (home made brew-Chang) and compare it with non- alcohohcs healthy subjects. Hemoglobin (Hb) concentration was determined in 2053 alcoholic consumers (males: 1056; females: 997) and was compared with 1 027 (males: 623; females: 404) healthy non-alcoholic con-trol subjects. The Hb concentration in alcoholic male and female were 13.42 ± 2.14 g/dL and 12.19 ± 1.55 g/dL compared with control showing 14.43 ± 1.07 g/dL and 12.73 ± 1.41 g/dL in males and females respectively. The differences in Hb concentration between alcoholic and non- alcoholic consumers were highly significant in both genders with a P value of 0. 000 674 in males and 0.004 732 in females. Alcohol Use Disorders Identification test (AUDIT) scores was advocated to alcoholic consum-ers to test the severity of drunkenness and disorders related to it. A total of 887 males and 663 females crossed the cut-off limits of ≥8 AUDIT scores showing the addiction towards drinking habits of local brew.

  8. The background concentration of the tritium in surface water before operation of the nuclear power plant Temelin

    International Nuclear Information System (INIS)

    Tomasek, M.; Wilhelmova, L.

    1997-01-01

    In this announcement the results of the tritium determination in surface waters in the period 1991-1996 are summarized. The water samples from Vltava river under the estuary of waste canal of the NPP Temelin and on the entrance in Prague water-work were taken away. Moreover, the samples from local rivers in the area of NPP Temelin construction which can be contaminated by scouring after condensation of the gaseous exhalation of the NPP were taken away. The samples by standard method in month interval were taken away. From every sample for the measurement of the tritium activity two parallel samples were prepared. The tritium activity with the scintillation spectrometer at the optimal conditions was measured. From measured values seasonal character and gradual decreasing of tritium activity in observed period is evident. Maximal activities obviously in the summer months are observed. From the exponential regression half time of decreasing of the tritium activity 8.1 year was calculated [sk

  9. Evaluation of local trace element status and 8-Iso-prostaglandin F2α concentrations in patients with Tinea pedis.

    Science.gov (United States)

    Miraloglu, Meral; Kurutas, Ergul Belge; Ozturk, Perihan; Arican, Ozer

    2016-01-01

    Tinea pedis (TP) is an infection of the feet caused by fungi. The infectious diseases caused by dermatophytes are mainly related to the enzymes produced by these fungi. Up to the now, the local 8-iso-prostaglandin F2α (8-iso-PGF2α), concentration as oxidative stress biomarker and trace elements status have not been published in patients with TP. The aim of this study is to evaluate the relationship between oxidative stress and trace elements (Cu, Zn, Se), and to evaluate the ratios of Cu/Zn and Cu/Se in this disorder. Forty-three consecutive patients with a diagnosis of unilateral interdigital TP were enrolled in this study. The samples were obtained by scraping the skin surface. 8-iso-PGF2α concentrations in scraping samples were determined by ELISA. In addition, the levels of Se, Zn and Cu in scraping samples were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction. Oxidative stress was confirmed by the significant elevation in 8-iso-PGF2α concentrations (p iso-PGF2α parameters, but negative correlations between Se-Cu; Se-8-iso-PGF2α parameters in lesional area. Furthermore, the ratios of Cu/Zn and Cu/Se were significantly higher on the lesional area than the non-lesional area (p iso-PGF2α and trace elements in patients with TP (p > 0.05). Our results showed that there is a possible link between oxidative stress (increased 8-iso-PGF2α concentrations) and imbalanced of trace elements status in lesional area of TP patients. The use of antifungal agents together with both Zn and Se drugs could be helpful in the both regression of disease and in shortening the duration of disease.

  10. Physical properties and concentration of aerosol particles over the Amazon tropical forest during background and biomass burning conditions

    Directory of Open Access Journals (Sweden)

    P. Guyon

    2003-01-01

    Full Text Available We investigated the size distribution, scattering and absorption properties of Amazonian aerosols and the optical thickness of the aerosol layer under the pristine background conditions typical of the wet season, as well as during the biomass-burning-influenced dry season. The measurements were made during two campaigns in 1999 as part of the European contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH. In moving from the wet to the dry season, median particle numbers were observed to increase from values comparable to those of the remote marine boundary layer (~400 cm-3 to values more commonly associated with urban smog (~4000 cm-3, due to a massive injection of submicron smoke particles. Aerosol optical depths at 500 nm increased from 0.05 to 0.8 on average, reaching a value of 2 during the dry season. Scattering and absorption coefficients, measured at 550 nm, showed a concomitant increase from average values of 6.8 and 0.4 Mm-1 to values of 91 and 10 Mm-1, respectively, corresponding to an estimated decrease in single-scattering albedo from ca. 0.97 to 0.91. The roughly tenfold increase in many of the measured parameters attests to the dramatic effect that extensive seasonal biomass burning (deforestation, pasture cleaning is having on the composition and properties of aerosols over Amazonia. The potential exists for these changes to impact on regional and global climate through changes to the extinction of solar radiation as well as the alteration of cloud properties.

  11. Quantitative analysis without standards using local peak-to-background ratios with the energy dispersive X-ray microanalyzer EDR-184

    International Nuclear Information System (INIS)

    Eggert, F.; Heckel, J.

    1986-01-01

    The method realized in program QMA-184 of the energy dispersive X-Ray-Microanalyzer EDR-184 for quantitative spectra analyzing of bulk materials by using local peak-to-background ratios is described in detail. The authors demonstrate efficiency and limitations of the used method by discussion of experimental results. (author)

  12. Method development for the enantiomeric purity determination of low concentrations of adrenaline in local anaesthetic solutions by capillary electrophoresis

    NARCIS (Netherlands)

    Sänger-Van De Griend, Cari E.; Ek, Anders G.; Widahl-Näsman, Monica E.; Andersson, E. K Margareta

    2006-01-01

    L-Adrenaline is often included in local anaesthetic (LA) solutions for injection to improve the quality of the anaesthetic block. The concentration of the LA is between 2.5 and 20 mg/ml and the concentration of adrenaline is typically ≤0.1% of the LA concentration. In order to follow the

  13. Local device parameter extraction of a concentrator photovoltaic cell under solar spot illumination

    Energy Technology Data Exchange (ETDEWEB)

    Munji, M.K.; Okullo, W.; van Dyk, E.E.; Vorster, F.J. [Physics Department, Nelson Mandela Metropolitan University, P O Box 77000, Port Elizabeth 6031 (South Africa)

    2010-12-15

    Focused sunlight can act as a localized source of excess minority carriers in a solar cell. Current signal generated by these carriers gives considerable information about the electrical properties of the cell's material. Point by point current-voltage data were measured for a back point-contact concentrator photovoltaic cell when illuminated by focused sunlight. Two numerical curve fitting procedures: a non-linear two-point interval division and particle swarm optimization algorithm were then applied to extract local parameters (i.e. as function of position) from the current-voltage data at each measurement point. Extracted parameters plotted yields relative spatial information about the electrical properties of a solar cell in a two or three dimensional mapping. The curve fitting routines applied to current-voltage data reveal that performance parameters: short circuit current, open circuit voltage, maximum power and fill factor show distinct variations in the vicinity of the observed current reducing feature. The relative values of the diode ideality factors, series resistance, shunt resistance and reverse saturation currents from both methods showed no significant measurable features that could be distinguished. This shows that the observed reduction in photo-induced current was due to severe recombination in the bulk or around the highly diffused point contacts and not the quality of the multiple p-n junctions of the cell. These approaches allow one to obtain a set of parameters at each local point on the cell which are reasonable and representative of the physical system. (author)

  14. Local concentration of fast-food outlets is associated with poor nutrition and obesity.

    Science.gov (United States)

    Kruger, Daniel J; Greenberg, Emily; Murphy, Jillian B; DiFazio, Lindsay A; Youra, Kathryn R

    2014-01-01

    We investigated the relationship of the local availability of fast-food restaurant locations with diet and obesity. We geocoded addresses of survey respondents and fast-food restaurant locations to assess the association between the local concentration of fast-food outlets, BMI, and fruit and vegetable consumption. The survey was conducted in Genesee County, Michigan. There were 1345 individuals included in this analysis, and the response rate was 25%. The Speak to Your Health! Community Survey included fruit and vegetable consumption items from the Behavioral Risk Factor Surveillance System, height, weight, and demographics. We used ArcGIS to map fast-food outlets and survey respondents. Stepwise linear regressions identified unique predictors of body mass index (BMI) and fruit and vegetable consumption. Survey respondents had 8 ± 7 fast-food outlets within 2 miles of their home. Individuals living in close proximity to fast-food restaurants had higher BMIs t(1342) = 3.21, p food availability, which may constrain the success of nutrition promotion efforts. Efforts to decrease the local availability of unhealthy foods as well as programs to help consumers identify strategies for obtaining healthy meals at fast-food outlets may improve health outcomes.

  15. Regional and local meteorology influences high-resolution tropospheric ozone concentration in the Los Angeles Basin

    Science.gov (United States)

    Koutzoukis, S.; Jenerette, D.; Chandler, M.; Wang, J.; Ge, C.; Ripplinger, J.

    2017-12-01

    Urban air quality and climate directly affect resident health. The Los Angeles (LA) Basin is a highly populated metropolitan area, with widespread point sources of ozone (O3) precursors (NOx , Volatile Organic Compounds, CO) from fossil fuel combustion. The LA basin exists on a coast-to-mountain gradient, with increasing temperatures towards the Transverse Ranges, which rise to 1700m. Frequently not compliant with 8-hour O3 standards, the LA and South Coast Air Basins are designated as severe and extreme non-attainment areas. Summer weather in the LA basin is characterized by a persistent high pressure system, creating an inversion that traps air pollutants, including O3 precursors, coupled with physical geography that blocks prevailing upper atmosphere air flow. These interactions make neighborhood-level O3 levels more variable than common regional models. Over the summer of 2017, we investigated the importance of local meteorology, wind patterns and air temperature, in transporting and mixing ozone precursors from point sources along the coast-to-mountain gradient. We deployed a network of six EPA federal equivalent method ozone and meteorological sensors in three campaigns in the LA basin along the coast-to-mountain transect. Each campaign, we collaborated with citizen scientists to deploy three sensor stations in two, 4 km2 quadrats, for a total of six high-resolution 4 km2 pixels. O3 concentrations vary greatly along the transect. At the coastal sites, daily O3 ranges from 0ppm to 60ppm and the range increases at the inland sites, to 100ppm. At all sites, there was a positive relationship between wind speed, air temperature, and O3 concentration, with increasing correlation inland. The Pearson correlation coefficient between wind speed and O3 concentration doubles from the coast to inland, and triples between air temperature and O3. The site-specific relationships between O3 and wind direction and temperature vary, suggesting neighborhood-effects from local

  16. Data and statistical summaries of background concentrations of metals in soils and streambed sediments in part of Big Soos Creek drainage basin, King County, Washington

    Science.gov (United States)

    Prych, E.A.; Kresch, D.L.; Ebbert, J.C.; Turney, G.L.

    1995-01-01

    Twenty-nine soil samples from 14 holes at 9 sites in part of the Big Soos Creek drainage basin in southwest King County, Washington, were collected and analyzed to obtain data on the magnitude and variability of background concentrations of metals in soils. Seven streambed-sediment samples and three streamwater samples from three sites also were collected and analyzed. These data are needed by regulating government agencies to determine if soils at sites of suspected contamination have elevated concentrations of metals, and to evaluate the effectiveness of remediation at sites with known contamination. Concentrations of 43 metals were determined by a total method, and concentrations of 17 metals were determined by a total-recoverable method and two different leaching methods. Metals analyzed for by all methods included most of those on the U.S. Environmental Protection agency list of priority pollutants, plus alluminum, iron, and manganese. Ranges of concentrations of metals determined by the total method are within ranges found by others for the conterminous United States. Concentrations of mercury, manganese, phosphorus, lead, selenium, antimony, and zinc as determined by the total method, and of some of these plus other metals as determined by the other methods were larger in shallow soil (less than 12 inches deep) than in deep soil (greater than 12 inches). Concentrations of metals in streambed sediments were more typical of shallow than deep soils.

  17. Development of an instantaneous local fuel-concentration measurement probe: an engine application

    Science.gov (United States)

    Guibert, P.; Boutar, Z.; Lemoyne, L.

    2003-11-01

    This work presents a new tool which can deliver instantaneous local measurements of fuel concentration in an engine cylinder with a high temporal resolution, particularly during compression strokes. Fuel concentration is represented by means of equivalence fuel-air ratio, i.e. the real engine mass ratio of fuel to air divided by the same ratio in ideal stoichiometry conditions. Controlling the mixture configuration for any strategy in a spark ignition engine and for auto-ignition combustion has a dominant effect on the subsequent processes of ignition, flame propagation and auto-ignition combustion progression, pollutant formation under lean or even stoichiometric operating conditions. It is extremely difficult, under a transient operation, to control the equivalence air/fuel ratio precisely at a required value and at the right time. This requires the development of a highly accurate equivalence air/fuel ratio control system and a tool to measure using crank angle (CA) resolution. Although non-intrusive laser techniques have considerable advantages, they are most of the time inappropriate due to their optical inaccessibility or the complex experimental set-up involved. Therefore, as a response to the demand for a relatively simple fuel-concentration measurement system a probe is presented that replaces a spark plug and allows the engine to run completely normally. The probe is based on hot-wire like apparatus, but involves catalytic oxidation at the wire surface. The development, characteristics and calibration of the probe are presented followed by applications to in-cylinder engine measurements.

  18. Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter

    Directory of Open Access Journals (Sweden)

    Yong Jiang

    2016-08-01

    Full Text Available In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity.

  19. Extreme concentration fluctuations due to local reversibility of mixing in turbulent flows

    Science.gov (United States)

    Xia, Hua; Francois, Nicolas; Punzmann, Horst; Szewc, Kamil; Shats, Michael

    2018-05-01

    Mixing of a passive scalar in a fluid (e.g. a radioactive spill in the ocean) is the irreversible process towards homogeneous distribution of a substance. In a moving fluid, due to the chaotic advection [H. Aref, J. Fluid Mech. 143 (1984) 1; J. M. Ottino, The Kinematics of Mixing: Stretching,Chaos and Transport (Cambridge University Press, Cambridge, 1989)] mixing is much faster than if driven by molecular diffusion only. Turbulence is known as the most efficient mixing flow [B. I. Shraiman and E. D. Siggia, Nature 405 (2000) 639]. We show that in contrast to spatially periodic flows, two-dimensional turbulence exhibits local reversibility in mixing, which leads to the generation of unpredictable strong fluctuations in the scalar concentration. These fluctuations can also be detected from the analysis of the fluid particle trajectories of the underlying flow.

  20. Molecular dynamics simulation of the local concentration and structure in multicomponent aerosol nanoparticles under atmospheric conditions.

    Science.gov (United States)

    Karadima, Katerina S; Mavrantzas, Vlasis G; Pandis, Spyros N

    2017-06-28

    Molecular dynamics (MD) simulations were employed to investigate the local structure and local concentration in atmospheric nanoparticles consisting of an organic compound (cis-pinonic acid or n-C 30 H 62 ), sulfate and ammonium ions, and water. Simulations in the isothermal-isobaric (NPT) statistical ensemble under atmospheric conditions with a prespecified number of molecules of the abovementioned compounds led to the formation of a nanoparticle. Calculations of the density profiles of all the chemical species in the nanoparticle, the corresponding radial pair distribution functions, and their mobility inside the nanoparticle revealed strong interactions developing between sulfate and ammonium ions. However, sulfate and ammonium ions prefer to populate the central part of the nanoparticle under the simulated conditions, whereas organic molecules like to reside at its outer surface. Sulfate and ammonium ions were practically immobile; in contrast, the organic molecules exhibited appreciable mobility at the outer surface of the nanoparticle. When the organic compound was a normal alkane (e.g. n-C 30 H 62 ), a well-organized (crystalline-like) phase was rapidly formed at the free surface of the nanoparticle and remained separate from the rest of the species.

  1. Tritium Concentrations in Environmental Samples and Transpiration Rates from the Vicinity of Mary's Branch Creek and Background Areas, Barnwell, South Carolina, 2007-2009

    Science.gov (United States)

    Vroblesky, Don A.; Canova, Judy L.; Bradley, Paul M.; Landmeyer, James E.

    2009-01-01

    Tritium in groundwater from a low-level radioactive waste disposal facility near Barnwell, South Carolina, is discharging to Mary's Branch Creek. The U.S. Geological Survey conducted an investigation from 2007 to 2009 to examine the tritium concentration in trees and air samples near the creek and in background areas, in groundwater near the creek, and in surface water from the creek. Tritium was found in trees near the creek, but not in trees from background areas or from sites unlikely to be in direct root contact with tritium-contaminated groundwater. Tritium was found in groundwater near the creek and in the surface water of the creek. Analysis of tree material has the potential to be a useful tool in locating shallow tritium-contaminated groundwater. A tritium concentration of 1.4 million picocuries per liter was measured in shallow groundwater collected near a tulip poplar located in an area of tritium-contaminated groundwater discharge. Evapotranspiration rates from the tree and tritium concentrations in water extracted from tree cores indicate that during the summer, this tulip poplar may remove more than 17.1 million picocuries of tritium per day from the groundwater that otherwise would discharge to Mary's Branch Creek. Analysis of air samples near the tree showed no evidence that the transpirative release of tritium to the air created a vapor hazard in the forest.

  2. Long open-path TDL based system for monitoring the background concentration for deployment at Jungfraujoch High Altitude Research Station- Switzerland

    Science.gov (United States)

    Simeonov, V.; van den Bergh, H.; Parlange, M. B.

    2009-12-01

    A new long-open-path instrument developed at EPFL for methane and water vapor observation will be presented. The instrument is developed and will be used within the GAW+ CH program and aims at long-term monitoring of background methane concentration at the High Altitude Research Station Jungfraujoch (3580 mASL). The instrument is built on the monostatic scheme (transceiver -distant retroreflector) using a 1.65 nm tunable diode laser (TDL) and a retroreflector at 1200 m from the transceiver. The data will be compared with in-situ measurements to evaluate the effect of the station on the in-situ data.

  3. Differential Cotton leaf crumple virus-VIGS-mediated gene silencing and viral genome localization in different Gossypium hirsutum genetic backgrounds

    KAUST Repository

    Idris, Ali

    2010-12-01

    A Cotton leaf crumple virus (CLCrV)-based gene silencing vector containing a fragment of the Gossypium hirsutum Magnesium chelatase subunit I was used to establish endogenous gene silencing in cotton of varied genetic backgrounds. Biolistic inoculation resulted in systemic and persistent photo-bleaching of the leaves and bolls of the seven cultivars tested, however, the intensity of silencing was variable. CLCrV-VIGS-mediated expression of green fluorescent protein was used to monitor the in planta distribution of the vector, indicating successful phloem invasion in all cultivars tested. Acala SJ-1, one of the cotton cultivars, was identified as a particularly optimal candidate for CLCrV-VIGS-based cotton reverse-genetics. © 2010 Elsevier Ltd.

  4. A multi-site analysis of the association between black carbon concentrations and vehicular idling, traffic, background pollution, and meteorology during school dismissals.

    Science.gov (United States)

    Richmond-Bryant, J; Bukiewicz, L; Kalin, R; Galarraga, C; Mirer, F

    2011-05-01

    A study was performed to assess the relationship between black carbon (BC), passing traffic, and vehicular idling outside New York City (NYC) schools during student dismissal. Monitoring was performed at three school sites in East Harlem, the Bronx, and Brooklyn for 1month per year over a two-year period from November 2006-October 2008. Monitoring at each site was conducted before and after the Asthma Free School Zone (AFSZ) asthma reduction education program was administered. Real-time equipment with a one-minute averaging interval was used to obtain the BC data, while volume counts of idling and passing school busses, trucks, and automobiles were collected each minute by study staff. These data were matched to ambient PM(2.5) and meteorology data obtained from the New York State Department of Environmental Conservation. A generalized additive model (GAM) model was run to examine the relationship between BC concentration and each variable while accounting for site-to-site differences. F-tests were employed to assess the significance of each of the predictor variables. The model results suggested that variability in ambient PM(2.5) concentration contributed 24% of the variability in transformed BC concentration, while variability in the number of idling busses and trucks on the street during dismissal contributed 20% of the variability in transformed BC concentration. The results of this study suggest that a combination of urban scale and local traffic control approaches in combination with cessation of school bus idling will produce improved local BC concentration outside schools. Published by Elsevier B.V.

  5. Increase in local protein concentration by field-inversion gel electrophoresis.

    Science.gov (United States)

    Tsai, Henghang; Low, Teck Yew; Freeby, Steve; Paulus, Aran; Ramnarayanan, Kalpana; Cheng, Chung-Pui Paul; Leung, Hon-Chiu Eastwood

    2007-09-26

    Proteins that migrate through cross-linked polyacrylamide gels (PAGs) under the influence of a constant electric field experience negative factors, such as diffusion and non-specific trapping in the gel matrix. These negative factors reduce protein concentrations within a defined gel volume with increasing migration distance and, therefore, decrease protein separation efficiency. Enhancement of protein separation efficiency was investigated by implementing pulsed field-inversion gel electrophoresis (FIGE). Separation of model protein species and large protein complexes was compared between FIGE and constant field electrophoresis (CFE) in different percentages of PAGs. Band intensities of proteins in FIGE with appropriate ratios of forward and backward pulse times were superior to CFE despite longer running times. These results revealed an increase in band intensity per defined gel volume. A biphasic protein relative mobility shift was observed in percentages of PAGs up to 14%. However, the effect of FIGE on protein separation was stochastic at higher PAG percentage. Rat liver lysates subjected to FIGE in the second-dimension separation of two-dimensional polyarcylamide gel electrophoresis (2D PAGE) showed a 20% increase in the number of discernible spots compared with CFE. Nine common spots from both FIGE and CFE were selected for peptide sequencing by mass spectrometry (MS), which revealed higher final ion scores of all nine protein spots from FIGE. Native protein complexes ranging from 800 kDa to larger than 2000 kDa became apparent using FIGE compared with CFE. The present investigation suggests that FIGE under appropriate conditions improves protein separation efficiency during PAGE as a result of increased local protein concentration. FIGE can be implemented with minimal additional instrumentation in any laboratory setting. Despite the tradeoff of longer running times, FIGE can be a powerful protein separation tool.

  6. Probing the quantum correlation and Bell non-locality for Dirac particles with Hawking effect in the background of Schwarzschild black hole

    International Nuclear Information System (INIS)

    Xu, Shuai; Song, Xue-ke; Shi, Jia-dong; Ye, Liu

    2014-01-01

    In this Letter, we analytically explore the effect of the Hawking radiation on the quantum correlation and Bell non-locality for Dirac particles in the background of Schwarzschild black hole. It is shown that when the Hawking effect is almost nonexistent, corresponding to the case of an almost extreme black hole, the quantum properties of physically accessible state are the same for the initial situation. For finite Hawking temperature T, the accessible quantum correlation monotonously decreases along with increasing T owing to the thermal fields generated by the Hawking effect, and the accessible quantum non-locality will be disappeared when the Hawking temperature is more than a fixed value which increases with the parameter r of Werner state growing. Then we analyze the redistribution of quantum correlation, and find that for the case of the Hawking temperature being infinite, corresponding to the case of the black hole evaporating completely, the quantum correlation of physically accessible state is equal to the one of the inaccessible states. Moreover, due to the Pauli exclusion principle and the differences between Fermi–Dirac and Bose–Einstein statistics, for the Dirac fields the accessible classical correlation decreases with increase of the Hawking temperature, which is different for the scalar fields. For Bell non-locality, we also find that the quantum non-locality is always extinct for physically inaccessible states, and the strength of the non-locality decreases with enlarging intensity of Hawking effect when the non-locality is existent in physically accessible state.

  7. Glutamate decarboxylase and. gamma. -aminobutyric acid transaminase activity in brain structures during action of high concentrated sulfide gas on a background of hypo- and hypercalcemia

    Energy Technology Data Exchange (ETDEWEB)

    Kadyrov, G.K.; Aliyev, A.M.

    Activity of the following enzymes was studied on the background of hypo- and hypercalcemia and exposure to high concentration of sulfide gas: glutamate decarboxylase (GDC) and {gamma}-aminobutyric acid transaminase (GABA-T). These enzymes regulate metabolism of GABA. The results showed that a 3.5 hr exposure to sulfide gas at a concentration of 0.3 mg/1 led to significantly increased activity of GDC in cerebral hemispheres, cerebellum and in brain stem. Activity of GABA-T dropped correspondingly. On the background of hypercalcemia induced by im. injection of 10% calcium gluconate (0.6 m1/200 g body weight of experimental rats) the negative effect caused by the exposure to sulfide gas was diminished. Under conditions of hypocalcemia (im. injection of 10 mg/200 g body weight of sodium oxalate), exposure to sulfide gas led to a significantly decreased activity of GDC and GABA-T in the hemispheres and in the brain stem, but in the cerebellum the activity of GDC increased sharply while that of GABA-T decreased correspondingly. 8 refs.

  8. Preliminary study of tissue concentrations of penicillin after local administration into the guttural pouches in four healthy horses.

    Science.gov (United States)

    Kendall, A; Mayhew, I G; Petrovski, K

    2016-08-01

    Treatment of subclinical carriers of Streptococcus equi subsp. equi with a gelatine-penicillin formulation deposited in the guttural pouch has been empirically proposed, but data on local tissue penicillin concentrations after treatment are lacking. We analysed tissue levels of penicillin after administration into the guttural pouches of four healthy horses. Two horses received local treatment with gelatine-penicillin and two horses received local treatment with an intramammary formulation of penicillin. Tissues were harvested for analysis either 12 or 24 h later. Results indicate that local treatment may be effective, but more research on optimal drug formulations in a larger sample size is warranted. © 2016 Australian Veterinary Association.

  9. Determination of Background Uranium Concentration in the Snake River Plain Aquifer under the Idaho National Engineering and Environmental Laboratory's Radioactive Waste Management Complex

    International Nuclear Information System (INIS)

    Molly K. Leecaster; L. Don Koeppen; Gail L. Olson

    2003-01-01

    Uranium occurs naturally in the environment and is also a contaminant that is disposed of at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory. To determine whether uranium concentrations in the Snake River Plain Aquifer, which underlies the laboratory, are elevated as a result of migration of anthropogenic uranium from the Subsurface Disposal Area in the RWMC, uranium background concentrations are necessary. Guideline values are calculated for total uranium, 234U, 235U, and 238U from analytical results from up to five datasets. Three of the datasets include results of samples analyzed using isotope dilution thermal ionization mass spectrometry (ID-TIMS) and two of the datasets include results obtained using alpha spectrometry. All samples included in the statistical testing were collected from aquifer monitoring wells located within 10 miles of the RWMC. Results from ID-TIMS and alpha spectrometry are combined when the data are not statistically different. Guideline values for total uranium were calculated using four of the datasets, while guideline values for 234U were calculated using only the alpha spectrometry results (2 datasets). Data from all five datasets were used to calculate 238U guideline values. No limit is calculated for 235U because the ID-TIMS results are not useful for comparison with routine monitoring data, and the alpha spectrometry results are too close to the detection limit to be deemed accurate or reliable for calculating a 235U guideline value. All guideline values presented represent the upper 95% coverage 95% confidence tolerance limits for background concentration. If a future monitoring result is above this guideline, then the exceedance will be noted in the quarterly monitoring report and assessed with respect to other aquifer information. The guidelines (tolerance limits) for total U, 234U, and 238U are 2.75 pCi/L, 1.92 pCi/L, and 0.90 pCi/L, respectively

  10. Evaluation of local stress and local hydrogen concentration at grain boundary using three-dimensional polycrystalline model

    International Nuclear Information System (INIS)

    Ebihara, Ken-ichi; Itakura, Mitsuhiro; Yamaguchi, Masatake; Kaburaki, Hideo; Suzudo, Tomoaki

    2010-01-01

    The decohesion model in which hydrogen segregating at grain boundaries reduces cohesive energy is considered to explain hydrogen embrittlement. Although there are several experimental and theoretical supports of this model, its total process is still unclear. In order to understand hydrogen embrittlement in terms of the decohesion model, therefore, it is necessary to evaluate stress and hydrogen concentration at grain boundaries under experimental conditions and to verify the grain boundary decohesion process. Under this consideration, we evaluated the stress and the hydrogen concentration at grain boundaries in the three-dimensional polycrystalline model which was generated by the random Voronoi tessellation. The crystallographic anisotropy was given to each grain. As the boundary conditions of the calculations, data extracted from the results calculated in the notched round-bar specimen model under the tensile test condition in which fracture of the steel specimen is observed was given to the polycrystalline model. As a result, it was found that the evaluated stress does not reach the fracture stress which was estimated under the condition of the evaluated hydrogen concentration by first principles calculations. Therefore, it was considered that the initiation of grain boundary fracture needs other factors except the stress concentration due to the crystallographic anisotropy. (author)

  11. Environmental 238U and 232Th concentration measurements in an area of high level natural background radiation at Palong, Johor, Malaysia.

    Science.gov (United States)

    Ramli, A Termizi; Hussein, A Wahab M A; Wood, A Khalik

    2005-01-01

    Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.

  12. A Study on Effect of Local Wall Thinning in Carbon Steel Elbow Pipe on Elastic Stress Concentration

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Seo, Jae Seok

    2009-01-01

    Feeder pipes that connect the inlet and outlet headers to the reactor core in CANDU nuclear power plants are considered as safety Class 1 piping items. Therefore, fatigue of feeder pipes should be assessed at design stage in order to verify structural integrity during design lifetime. In accordance with the fatigue assessment result, cumulative usage factors of some feeder pipes have significant values. The feeder pipes made of SA-106 Grade B or C carbon steel have some elbows and bends. An active degradation mechanism for the carbon steel outlet feeder piping is local wall thinning due to flow-accelerated corrosion. Inspection results from plants and metallurgical examinations of removed feeders indicated the presence of localized thinning in the vicinity of the welds in the lower portion of outlet feeders, such as Grayloc hub-to-bend weld, Grayloc hub-to-elbow weld, elbow-to-elbow, and elbow-to-pipe weld. This local wall thinning can cause increase of peak stress due to stress concentration by notch effect. The increase of peak stress results in increase of cumulative usage factor. However, present fatigue assessment doesn't consider the stress concentration due to local wall-thinning. Therefore, it is necessary to assess the effect of local wall thinning on stress concentration. This study investigates the effect of local wall thinning geometry on stress concentration by performing finite element elastic stress analysis

  13. An analysis on local hydrogen concentration in the large dry PWR containment of Ulchin 3,4 in Korea

    International Nuclear Information System (INIS)

    Hong, S.W.; Kim, H.D.; Chung, S.H.

    1994-01-01

    The local hydrogen concentration was analyzed during two different severe accident scenarios (TMLB' and medium size LOCA) using CONTAIN code for the Ulchin 3,4 PWR containment type which is under construction in Korea. Sensitivity studies on the equivalent fraction of zirconium oxidation in the reactor vessel and the flow loss coefficient in the flow path between compartments were also carried out in order to investigate the effect of the these parameters on the local hydrogen concentration. Finally, the effect of temperature and turbulence intensity on the flame velocity was evaluated, and a sample calculation was performed by updating the model of the CONTAIN code. The calculated results show that the maximum local hydrogen concentration appears in the cavity compartment. lie hydrogen burn, however, is not likely to occur in this compartment for both scenarios due to low oxygen concentrations. Hydrogen burns are more likely to occur at the stern generator compartments for TMLB' accident and at the reactor vessel annulus compartment during medium size LOCA When the equivalent fraction of in-vessel zirconium oxidation is assumed to be 75 %, the possibility of detonation is much more increased. The change of flow loss coefficients between flow paths about 2 times affects on the magnitude of the maximum local hydrogen concentration but nearly no influence on the timing and the location of the compartment attaining the maximum local hydrogen concentration. The local hydrogen concentration in the compartments seems to be stratified after vessel failure but to be stabilized afterwards. When temperature and turbulence intensity are considered in the flame velocity model, the flame speed is much greater than the previous results, but the containment load is not increased very much. (author)

  14. An associative and noncommutative product for the low energy effective theory of a D-brane in curved backgrounds and bi-local fields

    International Nuclear Information System (INIS)

    Hayasaka, Kiyoshi; Nakayama, Ryuichi

    2002-01-01

    We point out that when a D-brane is placed in an NS-NS B field background with nonvanishing field strength (H=dB) along the D-brane worldvolume, the coordinate of one end of the open string does not commute with that of the other in the low energy limit. The degrees of the freedom associated with both ends are not decoupled and accordingly, the effective action must be quite different from that of the ordinary noncommutative gauge theory for a constant B background. We construct an associative and noncommutative product * which operates on the coordinates of both ends of the string and propose a new type of noncommutative gauge action for the low energy effective theory of a Dp-brane. This effective theory is bi-local and lives in twice as large dimensions (2D=2(p+1)) as in the H=0 case. When viewed as a theory in the D-dimensional space, this theory is nonlocal and we must force the two ends of the string to coincide. We will then propose a prescription for reducing this bi-local effective action to that in D dimensions and obtaining a local effective action

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

    Science.gov (United States)

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

    2017-09-01

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

  16. Local Cytokine Concentrations and Oxygen Pressure Are Related to Maturation of the Collateral Circulation in Humans

    NARCIS (Netherlands)

    Schirmer, Stephan H.; van Royen, Niels; Moerland, Perry D.; Fledderus, Joost O.; Henriques, José P.; van der Schaaf, René J.; Vis, Marije M.; Baan, Jan; Koch, Karel T.; Horrevoets, Anton J. G.; Hoefer, Imo E.; Piek, Jan J.

    2009-01-01

    Objectives Our aim was to determine cytokine and oxygen gradients over the collateral circulation in humans. Background The molecular background of the maturation of the collateral circulation in response to coronary narrowing is poorly understood in humans, partly because of difficulties in

  17. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site during SAPUSS – diurnal variations and PMF receptor modelling

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2013-04-01

    Full Text Available Hourly-resolved aerosol chemical speciation data can be a highly powerful tool to determine the source origin of atmospheric pollutants in urban environments. Aerosol mass concentrations of seventeen elements (Na, Mg, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb were obtained by time (1 h and size (PM2.5 particulate matter 2.5 mass fraction simultaneously measured at the UB and RS sites: (1 the regional aerosol sources impact both monitoring sites at similar concentrations regardless their different ventilation conditions; (2 by contrast, local industrial aerosol plumes associated with shipping oil combustion and smelters activities have a higher impact on the more ventilated UB site; (3 a unique source of Pb-Cl (associated with combustion emissions is found to be the major (82% source of fine Cl in the urban agglomerate; (4 the mean diurnal variation of PM2.5 primary traffic non-exhaust brake dust (Fe-Cu suggests that this source is mainly emitted and not resuspended, whereas PM2.5 urban dust (Ca is found mainly resuspended by both traffic vortex and sea breeze; (5 urban dust (Ca is found the aerosol source most affected by land wetness, reduced by a factor of eight during rainy days and suggesting that wet roads may be a solution for reducing urban dust concentrations.

  18. Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

    Directory of Open Access Journals (Sweden)

    Christophe Waterlot

    2012-01-01

    Full Text Available Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method and the high-speed self-reversal method (HSSR method. Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

  19. Assessment of environmental (226)Ra, (232)Th and (40)K concentrations in the region of elevated radiation background in Segamat District, Johor, Malaysia.

    Science.gov (United States)

    Saleh, Muneer Aziz; Ramli, Ahmad Termizi; Alajerami, Yasser; Aliyu, Abubakar Sadiq

    2013-10-01

    Extensive environmental survey and measurements of gamma radioactivity in the soil samples collected from Segamat District were conducted. Two gamma detectors were used for the measurements of background radiation in the area and the results were used in the computation of the mean external radiation dose rate and mean weighted dose rate, which are 276 nGy h(-1) and 1.169 mSv y(-1), respectively. A high purity germanium (HPGe) detector was used in the assessment of activity concentrations of (232)Th, (226)Ra and (40)K. The results of the gamma spectrometry range from 11 ± 1 to 1210 ± 41 Bq kg(-1) for (232)Th, 12 ± 1 to 968 ± 27 Bq kg(-1) for (226)Ra, and 12 ± 2 to 2450 ± 86 Bq kg(-1) for (40)K. Gross alpha and gross beta activity concentrations range from 170 ± 50 to 4360 ± 170 Bq kg(-1) and 70 ± 20 to 4690 ± 90 Bq kg(-1), respectively. These results were used in the plotting of digital maps (using ARCGIS 9.3) for isodose. The results are compared with values giving in UNSCEAR 2000. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Estimation of the local and long-range contributions to particulate matter levels using continuous measurements in a single urban background site

    Science.gov (United States)

    Diamantopoulou, Marianna; Skyllakou, Ksakousti; Pandis, Spyros N.

    2016-06-01

    The Particulate Matter Source Apportionment Technology (PSAT) algorithm is used together with PMCAMx, a regional chemical transport model, to develop a simple observation-based method (OBM) for the estimation of local and regional contributions of sources of primary and secondary pollutants in urban areas. We test the hypothesis that the minimum of the diurnal average concentration profile of the pollutant is a good estimate of the average contribution of long range transport levels. We use PMCAMx to generate "pseudo-observations" for four different European cities (Paris, London, Milan, and Dusseldorf) and PSAT to estimate the corresponding "true" local and regional contributions. The predictions of the proposed OBM are compared to the "true" values for different definitions of the source area. During winter, the estimates by the OBM for the local contributions to the concentrations of total PM2.5, primary pollutants, and sulfate are within 25% of the "true" contributions of the urban area sources. For secondary organic aerosol the OBM overestimates the importance of the local sources and it actually estimates the contributions of sources within 200 km from the receptor. During summer for primary pollutants and cities with low nearby emissions (ratio of emissions in an area extending 100 km from the city over local emissions lower than 10) the OBM estimates correspond to the city emissions within 25% or so. For cities with relatively high nearby emissions the OBM estimates correspond to emissions within 100 km from the receptor. For secondary PM2.5 components like sulfate and secondary organic aerosol the OBM's estimates correspond to sources within 200 km from the receptor. Finally, for total PM2.5 the OBM provides approximately the contribution of city emissions during the winter and the contribution of sources within 100 km from the receptor during the summer.

  1. The activity concentration of radiocesium in mushrooms from locality Stare Ransko

    International Nuclear Information System (INIS)

    Kunova, V.; Dvorak, P.; Benova, K.

    2006-01-01

    In this paper, activity concentrations of radiocesium in mushrooms from Stare Ransko (Czech Republic) in the years 2003 - 2004 are presented. The highest activity concentrations of 137 Cs measured by gamma-spectrometry was 6 040 Bq/kg (on a dry mass basis) in Xerocomus badius. The lowest activity concentration of 137 Cs was < 2.4 Bq/kg in Lycoperdon perlatum. (authors)

  2. Local cytokine profile and cytological status in children with community-acquired pneumonia arising on the background of the reduced resistance of the organism

    Directory of Open Access Journals (Sweden)

    T. G. Malanicheva

    2017-01-01

    Full Text Available Research objective: to study the features of the cytokine profile and cytological status in children with community-acquired pneumonia, proceeding against a background of reduced resistance of the organism for improving treatment methods. 53 children aged 3 to 7 years were examined. The main group consisted of 30 children with community-acquired pneumonia, which ran against a background of reduced resistance of the body. The comparison group consisted of 23 children with community-acquired pneumonia who had good resistance. Local immunity was studied on the basis of  valuation of cytokine status parameters (tumor necrotic factor-α, interleukin-8, and interferon-γ and cellular composition with an estimate of destructive changes in neutrophils in induced sputum. It was revealed that in the main group of children there is a depression of the neutrophils’ release into the bronchial secretion and a marked increase in the number of neutrophils with maximum signs of destruction of the nucleus and cytoplasm against the background of cytokine status imbalance, manifested in an increase in the content of the tumor necrotic factor-α and a decrease in interleukin-8 and interferon- γ. Inclusion in the traditional therapy of community-acquired pneumonia in children who have a reduced resistance, anti-inflammatory drug fenspiride, eliminates the imbalance of proinflammatory cytokines and increases the release of functionally complete neutrophils in the bronchial secret.

  3. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  4. Assessment of environmental 226Ra, 232Th and 40K concentrations in the region of elevated radiation background in Segamat District, Johor, Malaysia

    International Nuclear Information System (INIS)

    Saleh, Muneer Aziz; Ramli, Ahmad Termizi; Alajerami, Yasser; Aliyu, Abubakar Sadiq

    2013-01-01

    Extensive environmental survey and measurements of gamma radioactivity in the soil samples collected from Segamat District were conducted. Two gamma detectors were used for the measurements of background radiation in the area and the results were used in the computation of the mean external radiation dose rate and mean weighted dose rate, which are 276 nGy h −1 and 1.169 mSv y −1 , respectively. A high purity germanium (HPGe) detector was used in the assessment of activity concentrations of 232 Th, 226 Ra and 40 K. The results of the gamma spectrometry range from 11 ± 1 to 1210 ± 41 Bq kg −1 for 232 Th, 12 ± 1 to 968 ± 27 Bq kg −1 for 226 Ra, and 12 ± 2 to 2450 ± 86 Bq kg −1 for 40 K. Gross alpha and gross beta activity concentrations range from 170 ± 50 to 4360 ± 170 Bq kg −1 and 70 ± 20 to 4690 ± 90 Bq kg −1 , respectively. These results were used in the plotting of digital maps (using ARCGIS 9.3) for isodose. The results are compared with values giving in UNSCEAR 2000. -- Highlights: • Assessment of the activities in region of elevated radiation in Segamat District. • The average dose rate found to be six times higher than the world average. • The activity of 232 Th is six times world average. • The activity of 226 Ra is four times and 40 K is lower than world average. • A digital map plotted for isodose

  5. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    International Nuclear Information System (INIS)

    Fix, D.; Estill, J.; Wong, L.; Rebak, R.

    2004-01-01

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water

  6. Interaction between local and regional pollution during Escompte 2001: impact on surface ozone concentrations (IOP2a and 2b)

    Science.gov (United States)

    Cousin, F.; Tulet, P.; Rosset, R.

    2005-03-01

    Escompte, a European programme which took place in the Marseille region in June-July 2001, has been designed as an exhaustive database to be used for the development and validation of air pollution models. The air quality Mesoscale NonHydrostatic Chemistry model (Meso-NH-C) is used to simulate 2 days of an Intensive Observation Period (IOP) documented during the Escompte campaign, June 23 and 24, 2001. We first study the synoptic and local meteorological situation on June 23 and 24, using surface and aircraft measurements. Then, we focus on the pollution episode of June 24. This study emphasizes the deep impact of synoptic and local dynamics on observed ozone concentrations. It is shown that ozone levels are due both to regional and local factors, with highlights of the importance of ozone layering. More generally this confirms, even in an otherwise predominant local sea-breeze regime, the need to consider larger scale regional pollutant transport.

  7. Analgesic efficacy of local anaesthetic wound administration in knee arthroplasty: volume vs concentration

    DEFF Research Database (Denmark)

    Andersen, L Ø; Gaarn-Larsen, L; Kristensen, B B

    2010-01-01

    arthroplasty were randomly assigned to receive either a high volume/low concentration solution of ropivacaine (20 ml, 0.5%) or a low volume/high concentration solution of ropivacaine (10 ml, 1%), 6 and 24 h postoperatively through an intracapsular catheter. Pain was assessed for 2 h after administration. Pain...... was reduced in both groups with ropivacaine administration 24 h postoperatively (p ropivacaine injection 6 h postoperatively. The median (IQR [range]) dose of oxycodone administered...

  8. Enhancement of delayed-rectifier potassium conductance by low concentrations of local anaesthetics in spinal sensory neurones

    Science.gov (United States)

    Olschewski, Andrea; Wolff, Matthias; Bräu, Michael E; Hempelmann, Gunter; Vogel, Werner; Safronov, Boris V

    2002-01-01

    Combining the patch-clamp recordings in slice preparation with the ‘entire soma isolation' method we studied action of several local anaesthetics on delayed-rectifier K+ currents in spinal dorsal horn neurones.Bupivacaine, lidocaine and mepivacaine at low concentrations (1–100 μM) enhanced delayed-rectifier K+ current in intact neurones within the spinal cord slice, while exhibiting a partial blocking effect at higher concentrations (>100 μM). In isolated somata 0.1–10 μM bupivacaine enhanced delayed-rectifier K+ current by shifting its steady-state activation characteristic and the voltage-dependence of the activation time constant to more negative potentials by 10–20 mV.Detailed analysis has revealed that bupivacaine also increased the maximum delayed-rectifier K+ conductance by changing the open probability, rather than the unitary conductance, of the channel.It is concluded that local anaesthetics show a dual effect on delayed-rectifier K+ currents by potentiating them at low concentrations and partially suppressing at high concentrations. The phenomenon observed demonstrated the complex action of local anaesthetics during spinal and epidural anaesthesia, which is not restricted to a suppression of Na+ conductance only. PMID:12055132

  9. Influence of local emissions on concentration and isotopic composition of trace gases (CO2 and CH4) under strong anthropopression: A case study from Krakow, southern Poland

    International Nuclear Information System (INIS)

    Florkowski, T.; Korus, A.; Kuc, T.; Lasa, J.; Necki, J.M.; Zimnoch, M.

    2002-01-01

    Full text: Measurements of the isotopic composition of carbon dioxide and methane together with their concentrations in the atmosphere, yield useful information on the contribution of anthropogenic sources to regional budgets of these gases and their seasonal changes. Observed correlation between isotopic composition and inverse concentration of these gases is used for estimation of mean isotopic composition of the local source. Monitoring of atmospheric CO 2 has been initiated in Krakow in 1982. The sampling point is located in a polluted urban area with strong contribution of anthropogenic gases originating both from local sources (coal burning, car traffic, leakages from city gas network, landfills) and large distant emitters - industrial district located ca. 80 km to the west from Krakow (Silesia district). Quasi-continuous measurements of CO 2 , and CH 4 concentrations in the low atmosphere are performed using gas chromatographic method. For isotope measurements, the atmospheric CO 2 is continuously sampled by sorption on molecular sieve in be-weekly intervals and radiocarbon concentration is measured by liquid scintillation spectrometer, while δ 13 C is determined by isotope ratio mass spectrometer. Measurement error (1σ for single measurement) is in the order of 0.1 ppm for CO 2 concentration, ±8 per mille for δ 14 C, and ± 0.1 per mille for δ 13 C. In 1994, a new station for regular observations of greenhouse gases in lower atmosphere was set up in the High Tatra mountains, at Kasprowy Wierch (49 deg. N, 20 deg. E, 1980 m a.s.l., 300 m above the tree line). Kasprowy Wierch, with only small influences from local sources of trace gases can be considered as a reference station for this region of Poland. The record of CO 2 and CH 4 concentration and their isotope composition obtained at Kasprowy Wierch is considered as a background level for Krakow observations. The presented study was aimed at better characterisation and quantification of the local

  10. Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

    Science.gov (United States)

    Collins, David J; Ma, Zhichao; Ai, Ye

    2016-05-17

    Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

  11. Sensitivity of the CSR self-interaction to the local longitudinal charge concentration of an electron bunch

    CERN Document Server

    Li, R

    2001-01-01

    Recent measurements of the coherent synchrotron radiation (CSR) effects indicated that the observed emittance growth and energy modulation due to the orbit-curvature-induced bunch self-interaction are sometimes bigger than predictions based on Gaussian longitudinal charge distributions. In this paper, by performing a model study, we show both analytically and numerically that when the longitudinal bunch charge distribution involves concentration of charges in a small fraction of the bunch length, enhancement of the CSR self-interaction beyond the Gaussian prediction may occur. The level of this enhancement is sensitive to the level of the local charge concentration.

  12. Local Knowledge and Professional Background Have a Minimal Impact on Volunteer Citizen Science Performance in a Land-Cover Classification Task

    Directory of Open Access Journals (Sweden)

    Carl Salk

    2016-09-01

    Full Text Available The idea that closer things are more related than distant things, known as ‘Tobler’s first law of geography’, is fundamental to understanding many spatial processes. If this concept applies to volunteered geographic information (VGI, it could help to efficiently allocate tasks in citizen science campaigns and help to improve the overall quality of collected data. In this paper, we use classifications of satellite imagery by volunteers from around the world to test whether local familiarity with landscapes helps their performance. Our results show that volunteers identify cropland slightly better within their home country, and do slightly worse as a function of linear distance between their home and the location represented in an image. Volunteers with a professional background in remote sensing or land cover did no better than the general population at this task, but they did not show the decline with distance that was seen among other participants. Even in a landscape where pasture is easily confused for cropland, regional residents demonstrated no advantage. Where we did find evidence for local knowledge aiding classification performance, the realized impact of this effect was tiny. Rather, the inherent difficulty of a task is a much more important predictor of volunteer performance. These findings suggest that, at least for simple tasks, the geographical origin of VGI volunteers has little impact on their ability to complete image classifications.

  13. Lead, zinc and pH concentrations of Enyigba soils in Abakaliki Local ...

    African Journals Online (AJOL)

    The concentrations of lead (Pb) and zinc (Zn) were quantitatively determined in surface and sub-surface soils in Enyigba, Ebonyi State, Nigerian's major lead mining area using atomic absorption spectrophotometer. pH status of the soils was similarly determined. The survey was conducted to establish a base line pollution ...

  14. Effect of chronic hypoglycaemia on glucose concentration and glycogen content in rat brain: a localized 13C NMR study

    OpenAIRE

    Lei, Hongxia; Gruetter, Rolf

    2006-01-01

    While chronic hypoglycaemia has been reported to increase unidirectional glucose transport across the blood-brain barrier (BBB) and to increase GLUT1 expression at the endothelium, the effect on steady-state brain d-glucose and brain glycogen content is currently unknown. Brain glucose and glycogen concentrations were directly measured in vivo using localized 13C magnetic resonance spectroscopy (MRS) following 12-14 days of hypoglycaemia. Brain glucose content was significantly increased by 4...

  15. The use of local concentrated heat versus topical acyclovir for a herpes labialis outbreak: results of a pilot study under real life conditions

    Directory of Open Access Journals (Sweden)

    Wohlrab J

    2013-11-01

    Full Text Available Johannes Wohlrab,1 Franziska Voß,2 Christian Müller,2 Lars C Brenn21Department of Dermatology and Venereology, Martin Luther University of Halle-Wittenberg, Halle, 2Department of Medical Science and Operations, Riemser Pharma GmbH, Greifswald, GermanyBackground: Frequent outbreak of herpes labialis can affect quality of life by prodromes like burning, itching, and swelling. Topical applied preparations aim to shorten the duration of symptoms, inhibit the virus replication and/or accelerate the healing process. Local concentrated heat (LCH can reduce burning, itching, or swelling of the skin by influence of mechano-heat sensitive afferent neurons.Patients and methods: To examine the effectiveness of two different topical applications (LCH versus topical acyclovir [TACV] under real life conditions, we conducted a prospective, observational, reference-controlled cohort pilot study with 103 patients. Occurrence of prodromal burning, itching, swelling, and quality of life were assessed.Results: The LCH observation group (OG showed a significantly faster improvement in all symptoms after 1-day of application than the TACV OG. The burden and duration of disease was lower and shorter in the LCH OG than in the TACV OG.Conclusions: The prodromal symptoms in recurrent herpes labialis were attenuated more effectively by LCH than by TACV.Keywords: herpes labialis, local concentrated heat, acyclovir

  16. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    1993-04-01

    The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples

  17. Efficient quantum repeater with respect to both entanglement-concentration rate and complexity of local operations and classical communication

    Science.gov (United States)

    Su, Zhaofeng; Guan, Ji; Li, Lvzhou

    2018-01-01

    Quantum entanglement is an indispensable resource for many significant quantum information processing tasks. However, in practice, it is difficult to distribute quantum entanglement over a long distance, due to the absorption and noise in quantum channels. A solution to this challenge is a quantum repeater, which can extend the distance of entanglement distribution. In this scheme, the time consumption of classical communication and local operations takes an important place with respect to time efficiency. Motivated by this observation, we consider a basic quantum repeater scheme that focuses on not only the optimal rate of entanglement concentration but also the complexity of local operations and classical communication. First, we consider the case where two different two-qubit pure states are initially distributed in the scenario. We construct a protocol with the optimal entanglement-concentration rate and less consumption of local operations and classical communication. We also find a criterion for the projective measurements to achieve the optimal probability of creating a maximally entangled state between the two ends. Second, we consider the case in which two general pure states are prepared and general measurements are allowed. We get an upper bound on the probability for a successful measurement operation to produce a maximally entangled state without any further local operations.

  18. Radiocarbon (14C) Concentration of Local Pollution in Street Trees Located at Intersections

    OpenAIRE

    Ogawa, Daisuke

    2018-01-01

    At large intersections, vehicles consume and generate a large amount of fossil fuel. Carbon derived from fossil fuels that do not contain radioactive carbon (14C), i.e., dead carbon, is released in large amounts in the roadside air environment. By means of photosynthesis, street trees along the roadside assimilate both dead carbon, not containing radioactive carbon (14C), and contemporary carbon, which includes radioactive carbon (14C). Therefore, the concentration of radioactive carbon (14C)...

  19. Local order and concentration fluctuations in K-Pb and Rb-Pb alloys

    International Nuclear Information System (INIS)

    Akinlade, O.

    1992-08-01

    The concentration fluctuations in the long wavelength limit S cc (0), short range order parameter and free energy of mixing of K-Pb and Rb-Pb alloys have been studied within the framework of the quasi-chemical theory. It is observed that the simple model could be used to shed more insight into the nature of chemical ordering that exists in such strongly compound forming binary alloys. (author). 19 refs, 6 figs, 1 tab

  20. Flow behaviour and local concentration of coarse particles-water mixture in inclined pipes

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zdeněk; Konfršt, Jiří

    2017-01-01

    Roč. 65, č. 2 (2017), s. 183-191 ISSN 0042-790X R&D Projects: GA ČR GAP105/10/1574 Institutional support: RVO:67985874 Keywords : coarse particle mixture * concentration distribution * effect of pipe inclination * gamma-ray radiometry * Hydraulic conveying * mixture flow behaviour Subject RIV: BK - Fluid Dynamics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.654, year: 2016

  1. Effect of local burn-up variation on computed mean nuclide concentrations

    International Nuclear Information System (INIS)

    Moeller, W.

    1982-01-01

    Mean concentrations of U-235, U-236, U-238, Pu-239, Pu-240, Pu-241 and Pu-242 in some volume areas of WWER-440 fuel assemblies have been calculated from corresponding burn-up microdistribution data and compared with those calculated from burn-up mean values. Differences occurring were below 3% for the uranium nuclides but, at low burn-ups, considerable for Pu-241 and Pu-242. (author)

  2. Sensing local pH and ion concentration at graphene electrode surfaces using in situ Raman spectroscopy.

    Science.gov (United States)

    Shi, Haotian; Poudel, Nirakar; Hou, Bingya; Shen, Lang; Chen, Jihan; Benderskii, Alexander V; Cronin, Stephen B

    2018-02-01

    We report a novel approach to probe the local ion concentration at graphene/water interfaces using in situ Raman spectroscopy. Here, the upshifts observed in the G band Raman mode under applied electrochemical potentials are used to determine the charge density in the graphene sheet. For voltages up to ±0.8 V vs. NHE, we observe substantial upshifts in the G band Raman mode by as much as 19 cm -1 , which corresponds to electron and hole carrier densities of 1.4 × 10 13 cm -2 and Fermi energy shifts of ±430 meV. The charge density in the graphene electrode is also measured independently using the capacitance-voltage characteristics (i.e., Q = CV), and is found to be consistent with those measured by Raman spectroscopy. From charge neutrality requirements, the ion concentration in solution per unit area must be equal and opposite to the charge density in the graphene electrode. Based on these charge densities, we estimate the local ion concentration as a function of electrochemical potential in both pure DI water and 1 M KCl solutions, which span a pH range from 3.8 to 10.4 for pure DI water and net ion concentrations of ±0.7 mol L -1 for KCl under these applied voltages.

  3. The Hyades cluster-supercluster connection - Evidence for a local concentration of dark matter

    Science.gov (United States)

    Casertano, Stefano; Iben, Icko, Jr.; Shiels, Aaron

    1993-01-01

    Stars that evaporate from the Hyades cluster will remain within a few hundred parsecs of the cluster only if they are dynamically bound to a much more massive entity containing the cluster. A local mass enhancement of at least (5-10) x 10 exp 5 solar masses, with a radius of about 100 pc, can trap stars with an origin related to that of the Hyades cluster and explains the excess of stars with velocities near the Hyades velocity that constitutes the Hyades supercluster. Part of this mass enhancement can be in visible stars, but a substantial fraction is likely to be in the form of dark matter.

  4. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks

    Science.gov (United States)

    Ghaly, Michael; Du, Yong; Links, Jonathan M.; Frey, Eric C.

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect’s fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were

  5. Osteonecrosis of the jaw: effect of bisphosphonate type, local concentration, and acidic milieu on the pathomechanism.

    Science.gov (United States)

    Otto, Sven; Pautke, Christoph; Opelz, Christine; Westphal, Ines; Drosse, Inga; Schwager, Joanna; Bauss, Frieder; Ehrenfeld, Michael; Schieker, Matthias

    2010-11-01

    Osteonecrosis of the jaw has been reported in patients receiving high doses of intravenous nitrogen-containing bisphosphonates (N-BPs) because of malignant disease. The exact pathomechanisms have been elusive and questions of paramount importance remain unanswered. Recent studies have indicated toxic effects of bisphosphonates on different cell types, apart from osteoclast inhibition. Multipotent stem cells play an important role in the processes of wound healing and bone regeneration, which seem to be especially impaired in the jaws of patients receiving high doses of N-BPs. Therefore, the aim of the present study was to investigate the effects of different bisphosphonate derivatives and dose levels combined with varying pH levels on the mesenchymal stem cells in vitro. The effect of 2 N-BPs (zoledronate and ibandronate) and 1 non-N-BP (clodronate) on immortalized mesenchymal stem cells was tested at different concentrations, reflecting 1, 3, and 6 months and 1, 3, 5, and 10 years of exposure to standard oncology doses of the 2 N-BPs and equimolar concentrations of clodronate at different pH values (7.4, 7.0, 6.7, and 6.3). Cell viability and activity were analyzed using a WST assay. Cell motility was investigated using scratch wound assays and visualized using time-lapse microscopy. Both types of bisphosphonates revealed remarkable differences. Zoledronate and ibandronate showed a dose- and pH-dependent cellular toxicity. Increasing concentrations of both N-BPs and an acidic milieu led to a significant decrease in cell viability and activity (P key role in the pathogenesis of osteonecrosis of the jaw in patients receiving high doses of N-BPs for malignant diseases. Also the potency of N-BPs might be different, suggesting a greater risk of osteonecrosis of the jaw with zoledronate. Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  6. On the local and regional influence on ground-level ozone concentrations in Hong Kong

    International Nuclear Information System (INIS)

    So, K.L.; Wang, T.

    2003-01-01

    It is imperative to consider regional scale emissions and dynamic transport in managing ozone pollution in Hong Kong. - Hong Kong is a densely populated city situated in the fast developing Pearl River Delta of southern China. In this study, the recent data on ozone (O 3 ) and related air pollutants obtained at three sites in Hong Kong are analyzed to show the variations of O 3 in urban, sub-urban and rural areas and the possible regional influences. Highest monthly averaged O 3 was found at a northeastern rural site and lowest O 3 level was observed at an urban site. The levels of NO x , CO, SO 2 and PM 10 showed a different spatial pattern with the highest level in the urban site and lowest at the rural site. Analysis of chemical species ratios such as SO 2 /NO x and CO/NO x indicated that the sites were under the influences of local and regional emissions to varying extents reflecting the characteristics of emission sources surround the respective sites. Seasonal pattern of O 3 is examined. Low O 3 level was found in summer and elevated levels occurred in autumn and spring. The latter appears different from the previous result obtained in 1996 indicating a single maximum occurring in autumn. Principal component analysis was used to further elucidate the relationships of air pollutants at each site. As expected, the O 3 variation in the northeastern rural area was largely determined by regional chemical and transport processes, while the O 3 variability at the southwestern suburban and urban sites were more influenced by local emissions. Despite the large difference in O 3 levels across the sites, total potential ozone (O 3 +NO 2 ) showed little variability. Cases of high O 3 episodes were presented and elevated O 3 levels were formed under the influence of tropical cyclone bringing in conditions of intense sunlight, high temperature and light winds. Elevated O 3 levels were also found to correlate with enhanced ratio of SO 2 to NO x , suggesting influence of

  7. Onset of local ordering in some copper-based alloys: critical solute concentration vis-a-vis various solutionhardening parameters

    Science.gov (United States)

    Butt, Muhammad Zakria; Noshi, Mozina; Bashir, Farooq

    2008-12-01

    The mode of planar distribution of solute atoms in Cu single crystals alloyed with 0.5 to 8.0 at.%Ge has been investigated via the temperature dependence of the critical resolved shear stress of these alloys. It is found that there exists a critical solute concentration c m ≈ 5 at.%Ge below which the distribution of solute atoms in the crystal is random, and above which some local ordering occurs. This together with such data available in the literature for Cu-Zn, Cu-Al and Cu-Mn alloys, i.e. c m ≈7 at. %Zn, 7 at.%Al and 1 at.%Mn, when examined as a function of the size-misfit factor δ = (1/ b)(d b/d c)of a given binary alloy system, shows that the value of c m strongly depends on δ; the smaller the magnitude of δ, the greater the value of c m and vice versa. Also, the value of c m is found to correlate well with the electron-to-atom ratio ( e/a)of the Cu-Zn, Cu-Al, Cu-Ge and Cu-Mn alloys with the solute concentration c = c m . However, no systematic correlation exists between the critical solute concentration c m for the onset of local ordering and the modulus-mismatch parameter η = (1/ G)(d G/d c).

  8. Direct measurement of local oxygen concentration in the bone marrow of live animals

    Science.gov (United States)

    Spencer, Joel A.; Ferraro, Francesca; Roussakis, Emmanuel; Klein, Alyssa; Wu, Juwell; Runnels, Judith M.; Zaher, Walid; Mortensen, Luke J.; Alt, Clemens; Turcotte, Raphaël; Yusuf, Rushdia; Côté, Daniel; Vinogradov, Sergei A.; Scadden, David T.; Lin, Charles P.

    2014-04-01

    Characterization of how the microenvironment, or niche, regulates stem cell activity is central to understanding stem cell biology and to developing strategies for the therapeutic manipulation of stem cells. Low oxygen tension (hypoxia) is commonly thought to be a shared niche characteristic in maintaining quiescence in multiple stem cell types. However, support for the existence of a hypoxic niche has largely come from indirect evidence such as proteomic analysis, expression of hypoxia inducible factor-1α (Hif-1α) and related genes, and staining with surrogate hypoxic markers (for example, pimonidazole). Here we perform direct in vivo measurements of local oxygen tension (pO2) in the bone marrow of live mice. Using two-photon phosphorescence lifetime microscopy, we determined the absolute pO2 of the bone marrow to be quite low (hypoxic as it is perfused with small arteries that are often positive for the marker nestin. These pO2 values change markedly after radiation and chemotherapy, pointing to the role of stress in altering the stem cell metabolic microenvironment.

  9. Control of local intracellular calcium concentration with dynamic-clamp controlled 2-photon uncaging.

    Directory of Open Access Journals (Sweden)

    Erwin Idoux

    Full Text Available The variations of the intracellular concentration of calcium ion ([Ca(2+](i are at the heart of intracellular signaling, and their imaging is therefore of enormous interest. However, passive [Ca(2+](i imaging provides no control over these variations, meaning that a full exploration of the functional consequences of [Ca(2+](i changes is difficult to attain. The tools designed so far to modify [Ca(2+](i, even qualitatively, suffer drawbacks that undermine their widespread use. Here, we describe an electro-optical technique to quantitatively set [Ca(2+](i, in real time and with sub-cellular resolution, using two-photon Ca(2+ uncaging and dynamic-clamp. We experimentally demonstrate, on neurons from acute olfactory bulb slices of Long Evans rats, various capabilities of this technique previously difficult to achieve, such as the independent control of the membrane potential and [Ca(2+](i variations, the functional knocking-in of user-defined virtual voltage-dependent Ca(2+ channels, and the standardization of [Ca(2+](i patterns across different cells. Our goal is to lay the groundwork for this technique and establish it as a new and versatile tool for the study of cell signaling.

  10. Middle East and North Africa Region Assessment of the Local Manufacturing Potential for Concentrated Solar Power (CSP) Projects

    Energy Technology Data Exchange (ETDEWEB)

    Gazzo, A.; Gousseland, P.; Verdier, J. [Ernst and Young et Associes, Neuilly-Sur-Seine (France); Kost, C.; Morin, G.; Engelken, M.; Schrof, J.; Nitz, P.; Selt, J.; Platzer, W. [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany); Ragwitz, M.; Boie, I.; Hauptstock, D.; Eichhammer, W. [Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe (Germany)

    2011-01-15

    The MENA CSP (Middle East and North Africa - Concentrated Solar Power) plan is an ambitious scheme with an appeal to anyone concerned about climate change and convinced by the need for clean, renewable power. But what does it really mean for the average citizen of say Morocco or Tunisia? The World Bank sees potential for significant job and wealth creation in solar energy producing countries. If the CSP market grows rapidly over the next few years, equipment manufacturing will be essential to supply this new sector. This study proposes roadmaps and an action plan to help develop the potential of locally manufactured CSP components in the existing industry and for new market entrants.

  11. A study on the prediction capability of GOTHIC and HYCA3D code for local hydrogen concentrations

    International Nuclear Information System (INIS)

    Choi, Y. S.; Lee, W. J.; Lee, J. J.; Park, K. C.

    2002-01-01

    In this study the prediction capability of GOTHIC and HYCA3D code for local hydrogen concentrations was verified with experimental results. Among the experiments, executed by SNU and other organization inside and outside of the country, the fast transient and the obstacle cases are selected. In case of large subcompartment both the code show good agreement with the experimental data. But in case of small and complex geometry or fast transient the results of GOTHIC code have the large difference from experimental ones. This represents that GOTHIC code is unsuitable for these cases. On the contrary HTCA3D code agrees well with all the experimental data

  12. Local magnetic moments in dilute Cr-Nb alloys: the effects of applied magnetic field and Nb concentration

    International Nuclear Information System (INIS)

    Souza, P E N de; Oliveira, L M de; Ortiz, W A; Camargo, P C de; Oliveira, A J A de

    2005-01-01

    In this work we present magnetic susceptibility results for Cr-x at.% Nb alloys (x = 0.2, 0.6, 0.7, 1.4, and 2.0), showing that a local short-range order spin-density wave (L-SDW) appears at a characteristic temperature (T loc ) above the Neel temperature. The evidence for L-SDW is based on a Curie-Weiss-like behaviour, which is suppressed when large magnetic fields are applied or for alloys with Nb concentration above x = 2.0 at.%

  13. Variation in the bone calcium concentration as a function of age and sex, studied by local neutron activation in vivo

    International Nuclear Information System (INIS)

    Mazieres, B.; Comar, D.

    An original method of local activation on the hand, using isotopic neutron sources, was used to determine bone Ca and P simultaneously. The calcium concentration variation with age and sex was studied on 120 normal subjects men and women aged between 20 and 80, divided into 10 year age groups. These standards were chosen amongst subjects free from complaints liable to affect bone mineralisation and with more or less normal blood calcium and phosphorus contents. The results are as follows: between 20 and 50 the relative standard derivation observed within a 10 year age group averages 8% in men and 9% in women, after 50 this physiological scattering is much greater in both sexes, after 60 the bone calcium concentration decreases quickly in women at an average rate of 1.15% a year [fr

  14. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, Melissa A., E-mail: melissa.mckinney@uconn.edu [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Dean, Kylie; Hussey, Nigel E. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Cliff, Geremy; Wintner, Sabine P. [KwaZulu-Natal Sharks Board, Umhlanga Rocks 4320 (South Africa); Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000 (South Africa); Dudley, Sheldon F.J. [KwaZulu-Natal Sharks Board, Umhlanga Rocks 4320 (South Africa); Department of Agriculture, Forestry and Fisheries, Cape Town 8012 (South Africa); Zungu, M. Philip [Department of Agriculture, Forestry and Fisheries, Cape Town 8012 (South Africa); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada)

    2016-01-15

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH{sub 3}Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n = 283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg{sup −1} dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg{sup −1} dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ{sup 15}N), whereas measures of foraging habitat (using carbon stable isotopes, δ{sup 13}C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. - Highlights: • Hg concentrations in 17 shark species from South Africa's east coast were measured. • Higher values relative to other regions suggested the importance of local

  15. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa

    International Nuclear Information System (INIS)

    McKinney, Melissa A.; Dean, Kylie; Hussey, Nigel E.; Cliff, Geremy; Wintner, Sabine P.; Dudley, Sheldon F.J.; Zungu, M. Philip; Fisk, Aaron T.

    2016-01-01

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH_3Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n = 283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg"−"1 dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg"−"1 dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ"1"5N), whereas measures of foraging habitat (using carbon stable isotopes, δ"1"3C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. - Highlights: • Hg concentrations in 17 shark species from South Africa's east coast were measured. • Higher values relative to other regions suggested the importance of local emissions. • Length and

  16. Localization, Concentration, and Transmission Efficiency of Banana bunchy top virus in Four Asexual Lineages of Pentalonia aphids

    Directory of Open Access Journals (Sweden)

    Alberto Bressan

    2013-02-01

    Full Text Available Banana bunchy top virus (BBTV is the most destructive pathogenic virus of banana plants worldwide. The virus is transmitted in a circulative non-propagative manner by the banana aphid, Pentalonia nigronervosa Coquerel. In this work, we examined the localization, accumulation, and transmission efficiency of BBTV in four laboratory-established lineages of Pentalonia aphids derived from four different host plants: taro (Colocasia esculenta, heliconia (Heliconia spp., red ginger (Alpinia purpurata, and banana (Musa sp.. Mitochondrial sequencing identified three and one lineages as Pentalonia caladii van der Goot, a recently proposed species, and P. nigronervosa, respectively. Microsatellite analysis separated the aphid lineages into four distinct genotypes. The transmission of BBTV was tested using leaf disk and whole-plant assays, both of which showed that all four lineages are competent vectors of BBTV, although the P. caladii from heliconia transmitted BBTV to the leaf disks at a significantly lower rate than did P. nigronervosa. The concentration of BBTV in dissected guts, haemolymph, and salivary glands was quantified by real-time PCR. The BBTV titer reached similar concentrations in the guts, haemolymph, and salivary glands of aphids from all four lineages tested. Furthermore, immunofluorescence assays showed that BBTV antigens localized to the anterior midguts and the principal salivary glands, demonstrating a similar pattern of translocations across the four lineages. The results reported in this study showed for the first time that P. caladii is a competent vector of BBTV.

  17. Localization, concentration, and transmission efficiency of Banana bunchy top virus in four asexual lineages of Pentalonia aphids.

    Science.gov (United States)

    Watanabe, Shizu; Greenwell, April M; Bressan, Alberto

    2013-02-22

    Banana bunchy top virus (BBTV) is the most destructive pathogenic virus of banana plants worldwide. The virus is transmitted in a circulative non-propagative manner by the banana aphid, Pentalonia nigronervosa Coquerel. In this work, we examined the localization, accumulation, and transmission efficiency of BBTV in four laboratory-established lineages of Pentalonia aphids derived from four different host plants: taro (Colocasia esculenta), heliconia (Heliconia spp.), red ginger (Alpinia purpurata), and banana (Musa sp.). Mitochondrial sequencing identified three and one lineages as Pentalonia caladii van der Goot, a recently proposed species, and P. nigronervosa, respectively. Microsatellite analysis separated the aphid lineages into four distinct genotypes. The transmission of BBTV was tested using leaf disk and whole-plant assays, both of which showed that all four lineages are competent vectors of BBTV, although the P. caladii from heliconia transmitted BBTV to the leaf disks at a significantly lower rate than did P. nigronervosa. The concentration of BBTV in dissected guts, haemolymph, and salivary glands was quantified by real-time PCR. The BBTV titer reached similar concentrations in the guts, haemolymph, and salivary glands of aphids from all four lineages tested. Furthermore, immunofluorescence assays showed that BBTV antigens localized to the anterior midguts and the principal salivary glands, demonstrating a similar pattern of translocations across the four lineages. The results reported in this study showed for the first time that P. caladii is a competent vector of BBTV.

  18. The crystal structure and morphology of NiO-YSZ composite that prepared from local zircon concentrate of Bangka Island

    Energy Technology Data Exchange (ETDEWEB)

    Rahmawati, F., E-mail: fitria@mipa.uns.ac.id; Apriyani, K.; Heraldy, E. [Research Group of Solid State Chemistry & Catalysis, Department of Chemistry, Sebelas Maret University, Jl. Ir. Sutami 36A Kentingan Surakarta (Indonesia); Soepriyanto, S. [Department of Metallurgical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132 (Indonesia)

    2016-03-29

    In order to increase the economic value of local zircon concentrate from Bangka Island, NiO-YSZ was synthesized from Zirconia, ZrO{sub 2} that was prepared from local zircon concentrate. The NiO-YSZ composite was synthesized by solid state reaction method. XRD analysis equipped with Le Bail refinement was carried out to analyze the crystal structure and cell parameters of the prepared materials. The result showed that zirconia was crystallized in tetragonal structure with a space group of P42/NMC. Yttria-Stabilized-Zirconia (YSZ) was prepared by doping 8% mol yttrium oxide into zirconia and then sintered at 1250°C for 3 hours. Doping of 8% mol Yttria allowed phase transformation of zirconia from tetragonal into the cubic structure. Meanwhile, the composite of NiO-YSZ consists of two crystalline phases, i.e. the NiO with cubic structure and the YSZ with cubic structure. SEM analysis of the prepared materials shows that the addition of NiO into YSZ allows the morphology to become more roughness with larger grain size.

  19. local

    Directory of Open Access Journals (Sweden)

    Abílio Amiguinho

    2005-01-01

    Full Text Available The process of socio-educational territorialisation in rural contexts is the topic of this text. The theme corresponds to a challenge to address it having as main axis of discussion either the problem of social exclusion or that of local development. The reasons to locate the discussion in this last field of analysis are discussed in the first part of the text. Theoretical and political reasons are there articulated because the question is about projects whose intentions and practices call for the political both in the theoretical debate and in the choices that anticipate intervention. From research conducted for several years, I use contributions that aim at discuss and enlighten how school can be a potential locus of local development. Its identification and recognition as local institution (either because of those that work and live in it or because of those that act in the surrounding context are crucial steps to progressively constitute school as a partner for development. The promotion of the local values and roots, the reconstruction of socio-personal and local identities, the production of sociabilities and the equation and solution of shared problems were the dimensions of a socio-educative intervention, markedly globalising. This scenario, as it is argued, was also, intentionally, one of transformation and of deliberate change of school and of the administration of the educative territoires.

  20. Is sonic Hedgehog involved in human fracture healing? --a prospective study on local and systemic concentrations of SHH.

    Science.gov (United States)

    Eipeldauer, Stefan; Thomas, Anita; Hoechtl-Lee, Leonard; Kecht, Mathias; Binder, Harald; Koettstorfer, Julia; Gregori, Markus; Sarahrudi, Kambiz

    2014-01-01

    Sonic Hedgehog (SHH) is a new signalling pathway in bone repair. Evidence exist that SHH pathway plays a significant role in vasculogenesis and limb development during embryogenesis. Some in vitro and animal studies has already proven its potential for bone regeneration. However, no data on the role of SHH in the human fracture healing have been published so far. Seventy-five patients with long bone fractures were included into the study and divided in 2 groups. First group contained 69 patients with normal fracture healing. Four patients with impaired fracture healing formed the second group. 34 volunteers donated blood samples as control. Serum samples were collected over a period of 1 year following a standardized time schedule. In addition, SHH levels were measured in fracture haematoma and serum of 16 patients with bone fractures. Fracture haematoma and patients serum both contained lower SHH concentrations compared to control serum. The comparison between the patients' serum SHH level and the control serum revealed lower levels for the patients at all measurement time points. Significantly lower concentrations were observed at weeks 1 and 2 after fracture. SHH levels were slightly decreased in patients with impaired fracture healing without statistical significance. This is the first study to report local and systemic concentration of SHH in human fracture healing and SHH serum levels in healthy adults. A significant reduction of the SHH levels during the inflammatory phase of fracture healing was found. SHH concentrations in fracture haematoma and serum were lower than the concentration in control serum for the rest of the healing period. Our findings indicate that there is no relevant involvement of SHH in human fracture healing. Fracture repair process seem to reduce the SHH level in human. Further studies are definitely needed to clarify the underlying mechanisms.

  1. Numerical evaluation of the five sensor probe method for measurement of local interfacial area concentration of cap bubbles

    International Nuclear Information System (INIS)

    Euh, D.J.; Yun, B.J.; Song, C.H.; Kwon, T.S.; Chung, M.K.; Lee, U.C.

    2000-01-01

    The interfacial area concentration (IAC) is one of the most important parameters in the two-fluid model for two-phase flow analysis. The IAC can be measured by a local conductivity probe method that uses the difference of conductivity between water and air/steam. The number of sensors in the conductivity probe may be differently chosen by considering the flow regime of two-phase flow. The four sensor conductivity probe method predicts the IAC without any assumptions of the bubble shape. The local IAC can be obtained by measuring the three dimensional velocity vector elements at the measuring point, and the directional cosines of the sensors. The five sensor conductivity probe method proposed in this study is based on the four sensor probe method. With the five sensor probe, the local IAC for a given referred measuring area of the probe can be predicted more exactly. In this paper, the mathematical approach of the five sensor probe method for measuring the IAC is described, and a numerical simulation is carried out for ideal cap bubbles of which the sizes and locations are determined by a random number generator. (author)

  2. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  3. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site during SAPUSS -diurnal variations and PMF receptor modelling

    NARCIS (Netherlands)

    Dall'Osto, M.; Querol, X.; Amato, F.; Karanasiou, A.; Lucarelli, F.; Nava, S.; Calzolai, G.; Chiari, M.

    2013-01-01

    Hourly-resolved aerosol chemical speciation data can be a highly powerful tool to determine the source origin of atmospheric pollutants in urban environments. Aerosol mass concentrations of seventeen elements (Na, Mg, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb) were obtained by time

  4. Are conventional statistical techniques exhaustive for defining metal background concentrations in harbour sediments? A case study: The Coastal Area of Bari (Southeast Italy).

    Science.gov (United States)

    Mali, Matilda; Dell'Anna, Maria Michela; Mastrorilli, Piero; Damiani, Leonardo; Ungaro, Nicola; Belviso, Claudia; Fiore, Saverio

    2015-11-01

    Sediment contamination by metals poses significant risks to coastal ecosystems and is considered to be problematic for dredging operations. The determination of the background values of metal and metalloid distribution based on site-specific variability is fundamental in assessing pollution levels in harbour sediments. The novelty of the present work consists of addressing the scope and limitation of analysing port sediments through the use of conventional statistical techniques (such as: linear regression analysis, construction of cumulative frequency curves and the iterative 2σ technique), that are commonly employed for assessing Regional Geochemical Background (RGB) values in coastal sediments. This study ascertained that although the tout court use of such techniques in determining the RGB values in harbour sediments seems appropriate (the chemical-physical parameters of port sediments fit well with statistical equations), it should nevertheless be avoided because it may be misleading and can mask key aspects of the study area that can only be revealed by further investigations, such as mineralogical and multivariate statistical analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Background radiation

    International Nuclear Information System (INIS)

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  6. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa.

    Science.gov (United States)

    McKinney, Melissa A; Dean, Kylie; Hussey, Nigel E; Cliff, Geremy; Wintner, Sabine P; Dudley, Sheldon F J; Zungu, M Philip; Fisk, Aaron T

    2016-01-15

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH3Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n=283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg(-1) dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg(-1) dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ(15)N), whereas measures of foraging habitat (using carbon stable isotopes, δ(13)C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Carbon-13 isotopic abundance and concentration of atmospheric methane for background air in the Southern and Northern Hemispheres from 1978 to 1989

    International Nuclear Information System (INIS)

    Stevens, C.M.; Sepanski; Morris, L.J.

    1995-03-01

    Atmospheric methane (CH 4 ) may become an increasingly important contributor to global warming in future years. Its atmospheric concentration has risen, doubling over the past several hundred years, and additional methane is thought to have a much greater effect on climate, on a per molecule basis, than additional C0 2 at present day concentrations (Shine et al. 1990). The causes of the increase of atmospheric CH 4 have been difficult to ascertain because of a lack of quantitative knowledge of the fluxes (i.e., net emissions) from the numerous anthropogenic and natural sources. The goal of CH 4 isotopic studies is to provide a constraint (and so reduce the uncertainties) in estimating the relative fluxes from the various isotopically distinct sources, whose combined fluxes must result in the measured atmospheric isotopic composition, after the fractionating effect of the atmospheric removal process is considered. In addition, knowledge of the spatial and temporal changes in the isotopic composition of atmospheric CH 4 , along with estimates of the fluxes from some of the major sources, makes it possible to calculate growth rates for sources whose temporal emissions trends would be difficult to measure directly

  8. An integrated system for the determination of the local, regional and long-transport contributions to Particulate Matter concentrations

    Science.gov (United States)

    Amodio, M.; Andriani, E.; Daresta, B. E.; de Gennaro, G.; di Gilio, A.; Ielpo, P.,; Placentino, C. M.; Trizio, L.; Tutino, M.

    2010-05-01

    Several epidemiological studies have shown the negative effects of air pollution on human health, which range from respiratory and cardiovascular disease to neurotoxic effects, and cancer. Most recent investigations have been focused on health toxicological features of Particulate Matter (PM) and its interactions with other pollutants: it was found that fine particles (PM2.5) could be an effective media to transport these pollutants deeply into the lung and to cause many kind of reactions which include oxidative stress, local pulmonary and systemic inflammatory responses (Künzli and Perez, 2009). Based on these implications on public health, many countries have developed plans to suggest effective control strategies which involve the identification of Particulate Matter sources, the quantitative estimation of the emission rates of the pollutants, the understanding of PM transport, mixing and transformation processes and the identification of main factors influencing PM concentrations. In this field, receptor models can be useful tools to estimate sources contributions to PM collected in an area under investigations. Different approaches to receptor model analysis can be distinguished on basis of whether chemical characteristics of emission sources are required to be known before the source apportionment. The multivariate approach could be preferred when a lack of information concerning sources profiles occurred (Hopke, 2003). In this work, the results obtained by applying an integrated approach in the monitoring of PM using several typologies of instrumentations will be shown. A prototype for the determination of the contributions of a single source (‘fugitive emission') on the fine PM concentrations has been developed: it consists of a Swam dual-channel sampler, an OPC Monitor, a sonic anemometer and a PBL Mixing monitor. The investigated site chosen for the application of prototype will be the iron and steel pole of Taranto (Apulia Region, South of Italy

  9. Influence of local meteorology and NO2 conditions on ground-level ozone concentrations in the eastern part of Texas, USA

    OpenAIRE

    Gorai, A. K.; Tuluri, F.; Tchounwou, P. B.; Ambinakudige, S.

    2015-01-01

    The influence of local climatic factors on ground-level ozone concentrations is an area of increasing interest to air quality management in regards to future climate change. This study presents an analysis on the role of temperature, wind speed, wind direction, and NO2 level on ground-level ozone concentrations over the region of Eastern Texas, USA. Ozone concentrations at the ground level depend on the formation and dispersion processes. Formation process mainly depends on the precursor sour...

  10. Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial.

    Science.gov (United States)

    Hamdani, Mehdi; Chassot, Olivier; Fournier, Roxane

    2014-01-01

    Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. One hundred one patients undergoing major shoulder surgery under general anesthesia with ultrasound-guided continuous interscalene block were randomly assigned to receive 0.2% ropivacaine via interscalene end-hole catheter either by continuous infusion 4 mL/h (n = 50) or as automated bolus 4 mL/h (n = 51). Both delivery methods were combined with 5 mL PRN boluses of 0.2% ropivacaine with a lockout time of 30 minutes. Postoperative number of PRN boluses, 24- and 48-hour local anesthetic consumption, pain scores, rescue analgesia (morphine), and adverse events were recorded. There were no significant differences in either the number of PRN ropivacaine boluses or total 48 hour local anesthetic consumption between the groups (18.5 [11-25.2] PRN boluses in the continuous infusion group vs 17 [8.5-29] PRN boluses in the automated bolus group). Postoperative pain was similar in both groups; on day 2, the median average pain score was 4 (2-6) in the continuous infusion group versus 3 (2-5) in the automated bolus group (P = 0.54). Nor were any statistically significant intergroup differences observed with respect to morphine rescue, incidence of adverse events, or patient satisfaction. In continuous interscalene blockade under

  11. Offshore wind farms in the local environment - an examination at Horns Rev Offshore Wind Farm. Background report; Havvindmoeller i lokalomraadet - en undersoegelse ved Horns Rev Havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Susanne

    2005-07-01

    Horns Rev Offshore Wind Farm was built in 2002. A presentation is made of a sociological, qualitative survey on the local community's reception of the offshore wind farm. The survey aims at identifying attitudes towards the farm before and after the construction, with a view to identifying possible changes in attitudes, and explain the reasons for these (ml)

  12. Offshore wind farms in the local community - a survey at Horns Rev wind farm. Background report; Havvindmoeller i lokalomraedet - en undersoegelse ved Horns Rev havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-07-15

    This report is part of a socio-economic project about offshore wind farms' influence on the local community. The project is part of the monitoring programme in connection with the establishment of the offshore wind farms at Horns Rev and Nysted. The socio-economic project consists of a sociological and an environment-economic project. This report is part of the sociological project which has the purpose of identifying attitudes towards the wind farm before and after the erection with a view to identify possible changes in opinions and reasons for these changes. (BA)

  13. Offshore wind farms in the local community - a survey at Nysted offshore wind farm. Background report; Havvindmoeller i lokalomraedet - en undersoegelse ved Nysted havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-07-15

    This report is part of a socio-economic project about offshore wind farms' influence on the local community. The project is part of the monitoring programme in connection with the establishment of the offshore wind farms at Horns Rev and Nysted. The socio-economic project consists of a sociological and an environment-economic project. This report is part of the sociological project which has the purpose of identifying attitudes towards the wind farm before and after the erection with a view to identify possible changes in opinions and reasons for these changes. (BA)

  14. Background of SAM atom-fraction profiles

    International Nuclear Information System (INIS)

    Ernst, Frank

    2017-01-01

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition

  15. Background of SAM atom-fraction profiles

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frank

    2017-03-15

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition.

  16. Evaluating Ambient Concentrations and Local Emissions of Greenhouse Gases (GHGs) in the San Francisco Bay Area of California Using a Comprehensive Fixed-site and Mobile Monitoring Network

    Science.gov (United States)

    Guha, A.; Bower, J. P.; Martien, P. T.; Randall, S.; Young, A.; Hilken, H.; Stevenson, E.

    2015-12-01

    The Bay Area Air Quality Management District (hence the Air District) is the greater San Francisco Bay metropolitan region's chief air quality regulatory agency. Aligning itself with Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 10-point Climate Action Work Program lays out the agency's priorities, actions and coordination with regional stakeholders. The Program has three core objectives: (1) to develop a technical and monitoring program to document the region's GHG sources and related emissions, (2) to implement a policy and rule-based approach to control and regulate GHG emissions, and finally, (3) to utilize local governance, incentives and partnerships to encourage GHG emissions reductions.As part of the technical program, the Air District has set up a long term, ambient GHG monitoring network at four sites. The first site is located north and upwind of the urban core at Bodega Bay by the Pacific Coast. It mostly receives clean marine inflow and serves as the regional background site. The other three sites are strategically located at regional exit points for Bay Area plumes that presumably contain GHG enhancements from local sources. These stations are at San Martin, located south of the San Jose metropolitan area; at Patterson Pass at the cross section with California's Central Valley; and at Bethel Island at the mouth of the Sacramento-San Joaquin Delta. At all sites, carbon dioxide (CO2) and methane (CH4) are being measured continuously, along with combustion tracer CO and other air pollutants. The GHG measurements are performed with high precision and fast laser instruments (Picarro Inc). In the longer term, the network will allow the Air District to monitor ambient concentrations of GHGs and thus evaluate the effectiveness of its policy, regulation and enforcement efforts. We present data from the sites in their first few months of operation and

  17. Natural and man-made hexavalent chromium, Cr(VI), in groundwater near a mapped plume, Hinkley, California—study progress as of May 2017, and a summative-scale approach to estimate background Cr(VI) concentrations

    Science.gov (United States)

    Izbicki, John A.; Groover, Krishangi D.

    2018-03-22

    This report describes (1) work done between January 2015 and May 2017 as part of the U.S. Geological Survey (USGS) hexavalent chromium, Cr(VI), background study and (2) the summative-scale approach to be used to estimate the extent of anthropogenic (man-made) Cr(VI) and background Cr(VI) concentrations near the Pacific Gas and Electric Company (PG&E) natural gas compressor station in Hinkley, California. Most of the field work for the study was completed by May 2017. The summative-scale approach and calculation of Cr(VI) background were not well-defined at the time the USGS proposal for the background Cr(VI) study was prepared but have since been refined as a result of data collected as part of this study. The proposed summative scale consists of multiple items, formulated as questions to be answered at each sampled well. Questions that compose the summative scale were developed to address geologic, hydrologic, and geochemical constraints on Cr(VI) within the study area. Each question requires a binary (yes or no) answer. A score of 1 will be assigned for an answer that represents data consistent with anthropogenic Cr(VI); a score of –1 will be assigned for an answer that represents data inconsistent with anthropogenic Cr(VI). The areal extent of anthropogenic Cr(VI) estimated from the summative-scale analyses will be compared with the areal extent of anthropogenic Cr(VI) estimated on the basis of numerical groundwater flow model results, along with particle-tracking analyses. On the basis of these combined results, background Cr(VI) values will be estimated for “Mojave-type” deposits, and other deposits, in different parts of the study area outside the summative-scale mapped extent of anthropogenic Cr(VI).

  18. Analysis of local scale tree-atmosphere interaction on pollutant concentration in idealized street canyons and application to a real urban junction

    NARCIS (Netherlands)

    Buccolieri, R.; Salim, S.M.; Leo, L.S.; Sabatino, Di S.; Chan, A.; Ielpo, P.; Gennaro, de G.; Gromke, C.B.

    2011-01-01

    This paper first discusses the aerodynamic effects of trees on local scale flow and pollutant concentration in idealized street canyon configurations by means of laboratory experiments and Computational Fluid Dynamics (CFD). These analyses are then used as a reference modelling study for the

  19. Systematic review of the systemic concentrations of local anaesthetic after transversus abdominis plane block and rectus sheath block

    NARCIS (Netherlands)

    Rahiri, J.; Tuhoe, J.; Svirskis, D.; Lightfoot, N. J.; Lirk, P. B.; Hill, A. G.

    2017-01-01

    Background. Safe and efficacious modalities of perioperative analgesia are essential for enhanced recovery after surgery. Truncal nerve blocks are one potential adjunct for analgesia of the abdominal wall, and in recent years their popularity has increased. Transversus abdominis plane block (TAPB)

  20. Detection of local birefringence in embedded fiber Bragg grating caused by concentrated transverse load using optical frequency domain reflectometry

    Science.gov (United States)

    Wada, D.; Murayama, H.; Igawa, H.

    2014-05-01

    We investigate the capability of local birefringence detection in an embedded fiber Bragg grating (FBG) using optical frequency domain reflectometry. We embed an FBG into carbon fiber reinforced plastic specimen, and conduct 3-point bending test. The cross-sectional stresses are applied to the FBG at the loading location in addition to the non-uniform longitudinal strain distribution over the length of the FBG. The local birefringence due to the cross-sectional stresses was successfully detected while the non-uniform longitudinal strain distribution was accurately measured.

  1. Evaluation of local free carrier concentrations in individual heavily-doped GaN:Si micro-rods by micro-Raman spectroscopy

    Science.gov (United States)

    Mohajerani, M. S.; Khachadorian, S.; Schimpke, T.; Nenstiel, C.; Hartmann, J.; Ledig, J.; Avramescu, A.; Strassburg, M.; Hoffmann, A.; Waag, A.

    2016-02-01

    Three-dimensional III-nitride micro-structures are being developed as a promising candidate for the future opto-electrical devices. In this study, we demonstrate a quick and straight-forward method to locally evaluate free-carrier concentrations and a crystalline quality in individual GaN:Si micro-rods. By employing micro-Raman mapping and analyzing lower frequency branch of A1(LO)- and E1(LO)-phonon-plasmon-coupled modes (LPP-), the free carrier concentrations are determined in axial and planar configurations, respectively. Due to a gradual doping profile along the micro-rods, a highly spatially resolved mapping on the sidewall is exploited to reconstruct free carrier concentration profile along the GaN:Si micro-rods. Despite remarkably high free carrier concentrations above 1 × 1020 cm-3, the micro-rods reveal an excellent crystalline quality, without a doping-induced stress.

  2. Chi-square spectral fitting for concentration retrieval, automatic local calibration, quality control, and water type detection

    NARCIS (Netherlands)

    Hommersom, A.; Peters, S.W.M.; van der Woerd, H.J.; Eleveld, M.A.; de Boer, J.

    2011-01-01

    In this study, the inverse bio-optical model HYDROPT was calibrated with regional specific inherent optical properties (SIOPs) and various local SIOPs to examine the effect of these calibrations on the retrievals. The study area, the Wadden Sea, is an estuary and tidal flat area with very high

  3. Analysis of local scale tree-atmosphere interaction on pollutant concentration in idealized street canyons and application to a real urban junction

    Science.gov (United States)

    Buccolieri, Riccardo; Salim, Salim Mohamed; Leo, Laura Sandra; Di Sabatino, Silvana; Chan, Andrew; Ielpo, Pierina; de Gennaro, Gianluigi; Gromke, Christof

    2011-03-01

    This paper first discusses the aerodynamic effects of trees on local scale flow and pollutant concentration in idealized street canyon configurations by means of laboratory experiments and Computational Fluid Dynamics (CFD). These analyses are then used as a reference modelling study for the extension a the neighbourhood scale by investigating a real urban junction of a medium size city in southern Italy. A comparison with previous investigations shows that street-level concentrations crucially depend on the wind direction and street canyon aspect ratio W/H (with W and H the width and the height of buildings, respectively) rather than on tree crown porosity and stand density. It is usually assumed in the literature that larger concentrations are associated with perpendicular approaching wind. In this study, we demonstrate that while for tree-free street canyons under inclined wind directions the larger the aspect ratio the lower the street-level concentration, in presence of trees the expected reduction of street-level concentration with aspect ratio is less pronounced. Observations made for the idealized street canyons are re-interpreted in real case scenario focusing on the neighbourhood scale in proximity of a complex urban junction formed by street canyons of similar aspect ratios as those investigated in the laboratory. The aim is to show the combined influence of building morphology and vegetation on flow and dispersion and to assess the effect of vegetation on local concentration levels. To this aim, CFD simulations for two typical winter/spring days show that trees contribute to alter the local flow and act to trap pollutants. This preliminary study indicates that failing to account for the presence of vegetation, as typically practiced in most operational dispersion models, would result in non-negligible errors in the predictions.

  4. Development of real-time measurement of methanol-concentration in polymer electrolyte membrane using a local NMR sensor

    International Nuclear Information System (INIS)

    Ogawa, Kuniyasu; Ito, Kohei; Haishi, Tomoyuki

    2007-01-01

    A real-time sensor to measure methanol concentration in polymer electrolyte membrane (PEM) was developed for reducing methanol cross-over in Direct Methanol Fuel Cell (DMFC). The principle of the methanol sensor is based on the chemical shift of CH and OH species under high magnetic field. The sensor consists of a planar surface coil of 1.3 mm outside diameter. NMR signal from PEM being exposed to CH3OH solvent was measured using NMR sensor. Time-dependence changes of methanol concentration in PEM were obtained from analyzing spectrum of NMR signal. (author)

  5. Influence of local meteorology and NO2 conditions on ground-level ozone concentrations in the eastern part of Texas, USA.

    Science.gov (United States)

    Gorai, A K; Tuluri, F; Tchounwou, P B; Ambinakudige, S

    2015-02-01

    The influence of local climatic factors on ground-level ozone concentrations is an area of increasing interest to air quality management in regards to future climate change. This study presents an analysis on the role of temperature, wind speed, wind direction, and NO 2 level on ground-level ozone concentrations over the region of Eastern Texas, USA. Ozone concentrations at the ground level depend on the formation and dispersion processes. Formation process mainly depends on the precursor sources, whereas, the dispersion of ozone depends on meteorological factors. Study results showed that the spatial mean of ground-level ozone concentrations was highly dependent on the spatial mean of NO 2 concentrations. However, spatial distributions of NO 2 and ozone concentrations were not uniformed throughout the study period due to uneven wind speeds and wind directions. Wind speed and wind direction also played a significant role in the dispersion of ozone. Temperature profile in the area rarely had any effects on the ozone concentrations due to low spatial variations.

  6. Suppression of local haze variations in MERIS images over turbid coastal waters for retrieval of suspended sediment concentration

    NARCIS (Netherlands)

    Shen, F.; Verhoef, W.

    2010-01-01

    Atmospheric correction over turbid waters can be problematic if atmospheric haze is spatially variable. In this case the retrieval of water quality is hampered by the fact that haze variations could be partly mistaken for variations in suspended sediment concentration (SSC). In this study we propose

  7. On the quantitative Amido Black B staining of protein spots in agar gel at low local protein concentrations

    NARCIS (Netherlands)

    Jansen, M.T.

    1962-01-01

    Protein spots in agar gel of identical protein content but different in surface area are found to bind different amounts of dye upon staining with Amido Black B. The lower the protein concentration within the agar gel, the more the Amido Black B content of the spot falls short of the value expected

  8. Assessment of local changes of cerebral perfusion and blood concentration by ultrasound harmonic B-mode contrast measurement in piglet.

    NARCIS (Netherlands)

    Wijk, M.C. van; Klaessens, J.H.G.M.; Hopman, J.C.W.; Liem, K.D.; Thijssen, J.M.

    2003-01-01

    This study tested the hypothesis that changes in the blood concentration, and possibly in the perfusion, of different areas in the brain can be assessed by the use of ultrasound contrast agent (CA) and (linear) echo densitometry. The experiments were performed with piglets (n=3) under general

  9. Concentration of the combined drag with antimicrobic and antiinflammatory action in rabbits eye anterior chamber at local introduction

    Directory of Open Access Journals (Sweden)

    I. N. Okolov

    2014-07-01

    Full Text Available Aim was to research objective consisted in an assessment of penetration of an antibacterial preparation of ciprofloxacin and a corticosteroid preparation of dexamethasone as a part of Kombinil-Duo’s combined medicinal form in moisture of the forward camera of an eye in experiment, and also in detection of the minimum overwhelmingconcentration (MOC of ciprofloxacin in VPKG for the most frequent causative agents of eye infections.Material and methods. In experiment on seven adult individuals of rabbits of breed the Chinchilla (fourteen eyes eye drops Kombinil — Duo, containing in quality of the main substance ciprofloxacin (3 mg / ml and dexamethasone(1 mg / ml are tested. Determination of concentration of the main substances of studied preparations in moisture of the eye camera carried out a method of a highly effective liquid chromatography (VEZhH in combination with mass and spectrometer detecting (MS on the liquid Shimadzu LC-20AB chromatograph with the mass and selectivedetector Shimadzu LCMS-2010EV (ESI.Results and conclusion. The maximum concentration of ciprofloxacin in moisture of the forward camera of rabbits eye made 0,25 mkg / ml, and minimum — 0,06 mkg / ml, average concentration — 0,13±0,06 mkg / ml. The anti-inflammatory component presented by dexamethasone in a studied eye form, is defined in the range from 0,14 to 0,63 mkg / ml. Average concentration of dexamethasone equaled 0,24±0,12 mkg / ml. The obtained data testify that average concentration of ciprofloxacin in VPKG exceeds average MPK90 for strains the grampolozhitelnykhof bacteria which are potential activators of postoperative infectious complications: metitsillinchuvstvitelny golden стафилококки (MPK90‑0,06 mkg / ml and ftorkhinolonchuvstvitelny koagulazonegativny стафилококки (mkg / ml MPK90–0,05. The revealed concentration are sufficient for minimization of risk of development of postoperativeinfectious complications. In

  10. Concentration of the combined drag with antimicrobic and antiinflammatory action in rabbits eye anterior chamber at local introduction

    Directory of Open Access Journals (Sweden)

    I. N. Okolov

    2014-01-01

    Full Text Available Aim was to research objective consisted in an assessment of penetration of an antibacterial preparation of ciprofloxacin and a corticosteroid preparation of dexamethasone as a part of Kombinil-Duo’s combined medicinal form in moisture of the forward camera of an eye in experiment, and also in detection of the minimum overwhelmingconcentration (MOC of ciprofloxacin in VPKG for the most frequent causative agents of eye infections.Material and methods. In experiment on seven adult individuals of rabbits of breed the Chinchilla (fourteen eyes eye drops Kombinil — Duo, containing in quality of the main substance ciprofloxacin (3 mg / ml and dexamethasone(1 mg / ml are tested. Determination of concentration of the main substances of studied preparations in moisture of the eye camera carried out a method of a highly effective liquid chromatography (VEZhH in combination with mass and spectrometer detecting (MS on the liquid Shimadzu LC-20AB chromatograph with the mass and selectivedetector Shimadzu LCMS-2010EV (ESI.Results and conclusion. The maximum concentration of ciprofloxacin in moisture of the forward camera of rabbits eye made 0,25 mkg / ml, and minimum — 0,06 mkg / ml, average concentration — 0,13±0,06 mkg / ml. The anti-inflammatory component presented by dexamethasone in a studied eye form, is defined in the range from 0,14 to 0,63 mkg / ml. Average concentration of dexamethasone equaled 0,24±0,12 mkg / ml. The obtained data testify that average concentration of ciprofloxacin in VPKG exceeds average MPK90 for strains the grampolozhitelnykhof bacteria which are potential activators of postoperative infectious complications: metitsillinchuvstvitelny golden стафилококки (MPK90‑0,06 mkg / ml and ftorkhinolonchuvstvitelny koagulazonegativny стафилококки (mkg / ml MPK90–0,05. The revealed concentration are sufficient for minimization of risk of development of postoperativeinfectious complications. In

  11. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-01-01

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  12. Polycyclic Aromatic Hydrocarbons Concentrations in Drinking Water in Villages along the Huai River in China and Their Association with High Cancer Incidence in Local Population.

    Science.gov (United States)

    Pan, En Chun; Sun, Hong; Xu, Qiu Jin; Zhang, Qin; Liu, Lin Fei; Chen, Xiao Dong; Xu, Yan

    2015-01-01

    This study aims to evaluate the carcinogenic risk of PAHs in the drinking water of counties along the Huai River in China and study their associations with high cancer incidence in local population. We investigated 20 villages with high cancer incidence rates as the risk group and 20 villages with low rates as the control group. Water samples from each village were collected in the winter and summer seasons to analyze the concentrations of 16 PAHs. The carcinogenic risks of the PAHs were calculated for each village using a health risk assessment approach. Results showed that PAHs concentrations in 27.2% of the water samples were higher than the allowable values in China. However, no significant difference in water PAHs concentrations was observed between the risk and control groups (P > 0.05), and no correlation was found between water PAHs concentrations and cancer incidence in these villages. The average upper bound carcinogenic risks were less than 1 × 10(-4) in both groups. In conclusion, PAHs were present in the drinking water of the studied villages, but their carcinogenic risks remained within acceptable limits. PAHs in local drinking water might not be the major environmental cause of the high cancer incidences.

  13. Local variance of atmospheric 14C concentrations around Fukushima Dai-ichi Nuclear Power Plant from 2010 to 2012

    DEFF Research Database (Denmark)

    Chen, Biying; Xu, Sheng; Cook, Gordon T.

    2017-01-01

    Radiocarbon (14C) has been measured in single tree ring samples collected from the southwest of the Fukushima Dai-ichi Nuclear Power Plant. Our data indicate south-westwards dispersion of radiocarbon and the highest 14C activity observed so far in the local environment during the 2011 accident....... The abnormally high 14C activity in the late wood of 2011 ring may imply an unknown source of radiocarbon nearby after the accident. The influence of 14C shrank from 30 km during normal reactor operation to 14 km for the accident in the northwest of FDNPP, but remains unclear in the southwest....

  14. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    .e. the schema enters into apparently contradictory constructions of the informants’ local home-base and, possibly, of their identity (cf. Hovmark, 2010). Second, I discuss the status and role of the specific linguistic category in question, i.e. the directional adverbs. On the one hand we claim that the DDAs......In this paper I pay a closer look at the use of the CENTRE-PERIPHERY schema in context. I address two specific issues: first, I show how the CENTRE-PERIPHERY schema, encoded in the DDAs, enters into discourses that conceptualize and characterize a local community as both CENTRE and PERIPHERY, i......; furthermore, the DDAs are backgrounded in discourse. Is it reasonable to claim, rather boldly, that “the informants express their identity in the use of the directional adverb ud ‘out’ etc.”? In the course of this article, however, I suggest that the DDAs in question do contribute to the socio...

  15. Millisecond single-molecule localization microscopy combined with convolution analysis and automated image segmentation to determine protein concentrations in complexly structured, functional cells, one cell at a time.

    Science.gov (United States)

    Wollman, Adam J M; Leake, Mark C

    2015-01-01

    We present a single-molecule tool called the CoPro (concentration of proteins) method that uses millisecond imaging with convolution analysis, automated image segmentation and super-resolution localization microscopy to generate robust estimates for protein concentration in different compartments of single living cells, validated using realistic simulations of complex multiple compartment cell types. We demonstrate its utility experimentally on model Escherichia coli bacteria and Saccharomyces cerevisiae budding yeast cells, and use it to address the biological question of how signals are transduced in cells. Cells in all domains of life dynamically sense their environment through signal transduction mechanisms, many involving gene regulation. The glucose sensing mechanism of S. cerevisiae is a model system for studying gene regulatory signal transduction. It uses the multi-copy expression inhibitor of the GAL gene family, Mig1, to repress unwanted genes in the presence of elevated extracellular glucose concentrations. We fluorescently labelled Mig1 molecules with green fluorescent protein (GFP) via chromosomal integration at physiological expression levels in living S. cerevisiae cells, in addition to the RNA polymerase protein Nrd1 with the fluorescent protein reporter mCherry. Using CoPro we make quantitative estimates of Mig1 and Nrd1 protein concentrations in the cytoplasm and nucleus compartments on a cell-by-cell basis under physiological conditions. These estimates indicate a ∼4-fold shift towards higher values in the concentration of diffusive Mig1 in the nucleus if the external glucose concentration is raised, whereas equivalent levels in the cytoplasm shift to smaller values with a relative change an order of magnitude smaller. This compares with Nrd1 which is not involved directly in glucose sensing, and which is almost exclusively localized in the nucleus under high and low external glucose levels. CoPro facilitates time-resolved quantification of

  16. The Impact of a Nickel-Copper Smelter on Concentrations of Toxic Elements in Local Wild Food from the Norwegian, Finnish, and Russian Border Regions.

    Science.gov (United States)

    Hansen, Martine D; Nøst, Therese H; Heimstad, Eldbjørg S; Evenset, Anita; Dudarev, Alexey A; Rautio, Arja; Myllynen, Päivi; Dushkina, Eugenia V; Jagodic, Marta; Christensen, Guttorm N; Anda, Erik E; Brustad, Magritt; Sandanger, Torkjel M

    2017-06-28

    Toxic elements emitted from the Pechenganickel complex on the Kola Peninsula have caused concern about potential effects on local wild food in the border regions between Norway, Finland and Russia. The aim of this study was to assess Ni, Cu, Co, As, Pb, Cd, and Hg concentrations in local wild foods from these border regions. During 2013-2014, we collected samples of different berry, mushroom, fish, and game species from sites at varying distances from the Ni-Cu smelter in all three border regions. Our results indicate that the Ni-Cu smelter is the main source of Ni, Co, and As in local wild foods, whereas the sources of Pb and Cd are more complex. We observed no consistent trends for Cu, one of the main toxic elements emitted by the Ni-Cu smelter; nor did we find any trend for Hg in wild food. Concentrations of all investigated toxic elements were highest in mushrooms, except for Hg, which was highest in fish. EU maximum levels of Pb, Cd, and Hg were exceeded in some samples, but most had levels considered safe for human consumption. No international thresholds exist for the other elements under study.

  17. A low-cost and temperature-insensitive fibre Bragg grating sensor for monitoring localized strain concentrations

    International Nuclear Information System (INIS)

    Davis, C E; Thompson, A; Li, H C H; Dethlefsen, A F; Stoddart, P R

    2009-01-01

    A simple, self-diagnostic strain sensor is described, based on a strongly reflective optical fibre Bragg grating illuminated by a broadband source. The total reflected power from these gratings is shown to be a function of the strain gradient experienced by the grating. This is because a change in pitch within a section of the grating results in the emergence of reflected energy in other spectral regions, without any significant reduction in the peak intensity at the Bragg wavelength. Thus, the presence of a localized strain can be inferred directly from an intensity measurement without the need for an optical filter or other more complex interrogation schemes. For spectrally flat light sources, the measurement is relatively insensitive to environmental temperature changes. The sensing mechanism can also be considered 'self-diagnostic' as a signal is returned by the grating even under zero load unless the sensor has failed. Modelling results are presented to determine the minimum grating strength required to achieve this effect, while the technique has been experimentally verified by measuring the strain transfer on a loaded scarf repair joint at room and elevated temperatures. The scarf repair was loaded to failure and a reduction in strain transfer was observed as the failure grew along the bondline, in accordance with finite element modelling results

  18. Predicting soil, water and air concentrations of environmental contaminants locally and regionally; multimedia transport and transformation models

    International Nuclear Information System (INIS)

    McKone, T.E.; Daniels, J.I.

    1991-01-01

    Environmental scientists recognize that the environment functions as a complex, interconnected system. A realistic risk-management strategy for many contaminants requires a comprehensive and integrated assessment of local and regional transport and transformation processes. In response to this need, we have developed multimedia models that simulate the movement and transformation of chemicals as they spread through air, water, biota, soils, sediments, surface water and ground water. Each component of the environment is treated as a homogeneous subsystem that can exchange water, nutrients, and chemical contaminants with other adjacent compartments. In this paper, we illustrate the use of multimedia models and measurements as tools for screening the potential risks of contaminants released to air and deposited onto soil and plants. The contaminant list includes the volatile organic compounds (VOCs) tetrachloroethylene (PCE) and trichloroethylene (TCE), the semi-volatile organic compound benzo(a)pyrene, and the radionuclides tritium and uranium-238. We examine how chemical properties effect both the ultimate route and quantity of human and ecosystem contact and identify sensitivities and uncertainties in the model results. We consider the advantages of multimedia models relative to environmental monitoring data. (au)

  19. Predicting soil, water, and air concentrations of environmental contaminants locally and regionally: Multimedia transport and transformation models

    International Nuclear Information System (INIS)

    McKone, T.E.; Daniels, J.I.

    1991-10-01

    Environmental scientists recognize that the environment functions as a complex, interconnected system. A realistic risk-management strategy for many contaminants requires a comprehensive and integrated assessment of local and regional transport and transformation processes. In response to this need, we have developed multimedia models that simulate the movement and transformation of chemicals as they spread through air, water, biota, soils, sediments, surface water, and ground water. Each component of the environment is treated as a homogeneous subsystem that can exchange water, nutrients, and chemical contaminants with other adjacent compartments. In this paper, we illustrate the use of multimedia models and measurements as tools for screening the potential risks of contaminants released to air and deposited onto soil and plants. The contaminant list includes the volatile organic compounds (VOCs) tetrachloroethylene (PCE) and trichloroethylene (TCE), the semi-volatile organic compound benzo(a)pyrene, and the radionuclides tritium and uranium-238. We examine how chemical properties effect both the ultimate route and quantity of human and ecosystem contact and identify sensitivities and uncertainties in the model results

  20. Blood and hair mercury concentrations among Cree First Nations of Eeyou Istchee (Quebec, Canada): time trends, prenatal exposure and links to local fish consumption.

    Science.gov (United States)

    Ripley, Susannah; Robinson, Elizabeth; Johnson-Down, Louise; Andermann, Anne; Ayotte, Pierre; Lucas, Michel; Nieboer, Evert

    2018-12-01

    To describe exposure to methylmercury among Cree, focusing on women of childbearing age, we used data from 2 studies. Multiple regression was employed to examine associations between blood and hair mercury concentrations and consumption of locally harvested fish. Approximately 9.9% of non-pregnant women aged 15-44 y and 3.9% of pregnant women required follow-up according to Health Canada's blood mercury guidance value of 40 nmol/L. 8% of hair mercury observations in the non-pregnant women and 2.5% among pregnant women exceeded the equivalent threshold of 10 nmol/g. The geometric mean blood mercury concentration was 12.7 nmol/L in 1,429 persons aged 8 and over, and 17.7 nmol/L in adults aged 18 and older. The proportion of hair mercury concentrations greater than 12.5 nmol/g decreased in all age-sex groups when comparing the 2002-2009 data to published values for 1993-1994. Among women of childbearing age, local fish consumption was associated with increased blood and hair mercury concentrations. While over 90% of women of childbearing age in this population have acceptable levels of mercury, ongoing intake of mercury suggests that their consumption of fish with known high mercury content be minimised. Reducing consumption of fish known to be high in mercury content needs to be balanced with promoting ongoing connection to Cree culture and land-based activities that are also important determinants of health.

  1. 210Pb and 210Po concentrations in the Venice lagoon ecosystem (Italy) and the potential radiological impact to the local public and environment

    International Nuclear Information System (INIS)

    Guogang Jia; Belli, M.; Sansone, U.; Rosamilia, S.; Blasi, M.

    2003-01-01

    In order to evaluate the possible radiological impact to the local public and environment from a phosphogypsum stockpile, 210 Po and 210 Pb concentrations in river water, lagoon water, suspended matter, superficial sediment, algae and bivalves samples collected in Venice lagoon area have been investigated. The results show that the mean 210 Po and 210 Pb concentrations in river water are 1.42 ± 0.36 mBq x l -1 and 1.46 ± 0.39 mBq x l -1 with a mean 210 Po/ 210 Pb ratio of 0.98 ± 0.17 and about 60% of them are associated with the particulate; 210 Po and 210 Pb contribution from the phosphogypsum stockpile to the river water is negligible. Higher 210 Po (2.61-5.67 mBq x l -1 ) and 210 Pb (1.31-3.62 mBq x l -1 ) concentrations in the lagoon waters have been observed if compared with the literature values. About 60% of 210 Po and 210 Pb are found in the soluble form with a mean 210 Po/ 210 Pb ratio of 1.79 ± 1.47. 210 Po and 210 Pb concentrations in 28 out 37 sediment samples ranged from 26 to 45 Bq x kg -1 (dry weight), only 9 sediments with 210 Po and 210 Pb concentrations greater than 45 Bq x kg -1 are found and most of them are located 1-4 km near the phosphogypsum stockpile. The elevated 210 Po and 210 Pb concentrations in the sediments may be due to the contamination from the phosphogypsum stockpile. The mean 210 Po/ 210 Pb ratio (0.986 ± 0.049) in the sediments shows that 210 Po and 210 Pb exist in nearly secular equilibrium. 210 Po and 210 Pb concentrations in algae vary with different species. The mean 210 Po and 210 Pb concentrations in Gracilaria compress and Ulva laetevirens which show a similar behavior, are 3.18 ± 1.23 Bq x kg -1 and 2.42 ± 1.26 Bq x kg -1 (fresh weight), respectively, with a mean 210 Po/ 210 Pb ratio of 1.45 ± 0.34. The mean concentration factors with respect to the filtered water are 1096 ± 424 for 210 Po and 1299 ± 680 for 210 Pb. The mean 210 Po and 210 Pb concentrations in the soft part of Mytilus edulis are 23.2 ± 9.7 Bq

  2. Analgesic effects of ultrasound-guided transverse abdominis plane block using different volumes and concentrations of local analgesics after laparoscopic cholecystectomy.

    Science.gov (United States)

    Şahin, Ayça Sultan; Ay, Necmiye; Şahbaz, Nuri Alper; Akay, Mehlika Kocabaş; Demiraran, Yavuz; Derbent, Abdurrahim

    2017-02-01

    Objective To evaluate the effects of an ultrasound-guided transverse abdominis plane (US-TAP) block used for postoperative pain relief by comparing the efficacy of two different volumes/concentrations of the local anaesthetic bupivacaine in patients undergoing laparoscopic cholecystectomies. Methods This randomized study enrolled patients undergoing laparoscopic cholecystectomies. They were randomized to two groups: group A received a 20 ml US-TAP block (50 mg bupivacaine +10 ml saline solution) and group B received a 30 ml US-TAP block (50 mg bupivacaine + 20 ml saline solution). The intraoperative consumption of remifentanil, the requirement for postoperative rescue analgesics, patient satisfaction scores, postoperative complications, and postoperative pain as measured by a visual analogue scale at 20 min, 12 h, and 24 h were recorded. Results A total of 60 patients enrolled in the study. There were no differences between the two groups with respect to demographic characteristics, duration of anaesthesia and patient satisfaction scores. The intraoperative consumption of remifentanil, postoperative VAS scores (20 min, 12 h and 24 h) and the requirement for postoperative analgesics were all significantly lower in group B who received a larger volume but a lower concentration of local anaesthetic solution compared with group A. Conclusion A US-TAP block can form part of a balanced postoperative analgesic regimen following laparoscopic cholecystectomy.

  3. Comparison of PM2.5 carbonaceous pollutants between an urban site in Shanghai and a background site in a coastal East China Sea island in summer: concentration, composition and sources.

    Science.gov (United States)

    Wang, Fengwen; Lin, Tian; Li, Yuanyuan; Guo, Zhigang; Rose, Neil L

    2017-06-21

    Nine paired samples of atmospheric particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM 2.5 ) were collected concurrently from an urban site in Shanghai, China and a background site in Huaniao Island (HNI) in the coastal East China Sea (ECS) between July 21 and 29, 2011. The samples were analyzed for 16 United States Environmental Protection Agency (USEPA) priority polycyclic aromatic hydrocarbons (PAHs), n-alkanes (20 species, C 14 -C 33 ), hopanes (10 species, C 29 -C 32 ), and steranes (12 species, C 27 -C 29 ). These two sites, approximately 66 km apart, are both on the pathway of land-based pollutants as they are transported to the ECS by seasonal winds. As expected, concentrations in Shanghai were higher (average: 8.4 and 67.8 ng m -3 for the 16 PAHs and n-alkanes, respectively) than those in HNI (average: 1.8 and 8.5 ng m -3 , respectively). The dominant contributor to the 16 PAHs in Shanghai was 5-6-ring PAHs (60.0%), whereas 2-3-ring PAHs contributed the most (72.5%) in HNI. Plant waxes contributed 45.7% and 25.9% of the n-alkanes in Shanghai and HNI, respectively, implying a relatively greater contribution from petroleum residues to the n-alkanes in HNI. Principal component analysis (PCA) and the compositions of hopanes and steranes highlighted a prominent contribution from traffic emissions to carbonaceous PM 2.5 aerosols. This study provides comprehensive details about the sources, formation, and transport of pollutants from eastern China to the coastal ECS.

  4. Background radioactivity in environmental materials

    International Nuclear Information System (INIS)

    Maul, P.R.; O'Hara, J.P.

    1989-01-01

    This paper presents the results of a literature search to identify information on concentrations of 'background' radioactivity in foodstuffs and other commonly available environmental materials. The review has concentrated on naturally occurring radioactivity in foods and on UK data, although results from other countries have also been considered where appropriate. The data are compared with established definitions of a 'radioactive' substance and radionuclides which do not appear to be adequately covered in the literature are noted. (author)

  5. A Case Study On the Relative Influence of Free Tropospheric Subsidence, Long Range Transport and Local Production in Modulating Ozone Concentrations over Qatar

    Science.gov (United States)

    Ayoub, Mohammed; Ackermann, Luis; Fountoukis, Christos; Gladich, Ivan

    2016-04-01

    The Qatar Environment and Energy Research Institute (QEERI) operates a network of air quality monitoring stations (AQMS) around the Doha metropolitan area and an ozonesonde station with regular weekly launches and occasional higher frequency launch experiments (HFLE). Six ozonesondes were launched at 0700 LT/0400 UTC and 1300 LT/1000 UTC over a three day period between 10-12 September, 2013. We present the analysis of the ozonesonde data coupled with regional chemical transport modeling over the same time period using WRF-Chem validated against both the ozonesonde and surface AQMS measurements. The HFLE and modeling show evidence of both subsidence and transboundary transport of ozone during the study period, coupled with a strong sea breeze circulation on the 11th of September resulting in elevated ozone concentrations throughout the boundary layer. The development of the sea breeze during the course of the day and influence of the early morning residual layer versus daytime production is quantified. The almost complete titration of ozone in the morning hours of 11 September, 2013 is attributed to local vehicular emissions of NOx and stable atmospheric conditions prevailing over the Doha area. The relative contribution of long range transport of ozone along the Arabian Gulf coast and local urban emissions are discussed.

  6. Hemodynamic changes following injection of local anesthetics with different concentrations of epinephrine during simple tooth extraction: A prospective randomized clinical trial.

    Science.gov (United States)

    Abu-Mostafa, Nedal; Al-Showaikhat, Fatimah; Al-Shubbar, Fatimah; Al-Zawad, Kawther; Al-Zawad, Fatimah

    2015-10-01

    Presence of epinephrine in local anesthetic cartridge increases the duration of local anesthesia (LA), decreases the risk of toxicity, and provides hemostasis. However, the unfavorable effects are increasing heart rate (HR) and raising blood pressure (BP). The aim was to evaluate hemodynamic changes in the BP, HR, and oxygen saturation (SpO2) of normal patients undergoing tooth extraction using LA with various epinephrine concentrations. A prospective randomized clinical trial was conducted on 120 patients who were divided randomly into 3 parallel groups according to the LA received. Group 1: lidocaine 2% with epinephrine 1:80,000 (L80). Group 2: articaine 4% with epinephrine 1:100,000 (A100). Group 3: articaine 4% with epinephrine 1:200,000 (A200). normal patients whose BP extraction. Systolic blood pressure (SBP) significantly increased after injection of L80 and continued after extraction to be significant than pre-injection. SBP significantly increased after injection of A100 then decreased after extraction. In the group of A200, SBP insignificantly decreased after injection then increased after extraction. The increasing of SBP between time point 1and 2 was significantly higher in G1 than G3 (p=0.014). Diastolic blood pressure decreased after LA in the 3 groups; however it was significant only with L80, then increased after extraction for all. The changings of DBP, HR and SpO2 after anesthesia and extraction showed no significant difference among the three groups. However, A200 had significant lesser effect on SBP than L80 and the least effect on other parameters. Therefore, A200 is considered safer than L80 and A100 and is recommended for LA before teeth extraction in normal patient. Local anesthesia, lidocaine, epinephrine 1:80,000, articaine, epinephrine 1:100,000, epinephrine 1:200,000, tooth extraction.

  7. Local and systemic response to intramammary lipopolysaccharide challenge during long-term manipulated plasma glucose and insulin concentrations in dairy cows.

    Science.gov (United States)

    Vernay, M C M B; Wellnitz, O; Kreipe, L; van Dorland, H A; Bruckmaier, R M

    2012-05-01

    in LPS-treated quarters only in treatments HypoG and NaCl. In conclusion, intramammary LPS induces local and systemic inflammatory responses, as well as systemic insulin resistance. The observed treatment differences of the mammary mRNA expression of several immune parameters both before and after LPS challenge indicate a direct influence of changed glucose and insulin concentrations during the course of lactation on the immune defense against mastitis pathogens. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Local food:

    DEFF Research Database (Denmark)

    Sundbo, Donna Isabella Caroline

    2013-01-01

    are identified and then categorised according to whether they pertain to the food product itself or the production methods and facilities and whether they describe physical or social properties of local food. From this a model with four categories is developed. It is found that properties of the product are more......Recently there has been more focus on food in general and local food in particular. But what is local food? And what are the perceptions of this concept according to theory and to providers and consumers of local food? This article first summarises and compares three different theoretical...... perspectives on local food, namely experience economy, local food systems and what is termed pro-industrialism. These have differing and sometimes opposite conceptualisations and aims for the concept of local food. Using the perspective of experience economy as theoretical background, the concept of local food...

  9. Background sources at PEP

    International Nuclear Information System (INIS)

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, γ-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs

  10. Cosmic Microwave Background Timeline

    Science.gov (United States)

    Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  11. A definition of background independence

    International Nuclear Information System (INIS)

    Gryb, Sean

    2010-01-01

    We propose a definition for background (in)/dependence in dynamical theories of the evolution of configurations that have a continuous symmetry and test this definition on particle models and on gravity. Our definition draws from Barbour's best matching framework developed for the purpose of implementing spatial and temporal relationalism. Among other interesting theories, general relativity can be derived within this framework in novel ways. We study the detailed canonical structure of a wide range of best matching theories and show that their actions must have a local gauge symmetry. When gauge theory is derived in this way, we obtain at the same time a conceptual framework for distinguishing between background-dependent and -independent theories. Gauge invariant observables satisfying Kuchar's criterion are identified and, in simple cases, explicitly computed. We propose a procedure for inserting a global background time into temporally relational theories. Interestingly, using this procedure in general relativity leads to unimodular gravity.

  12. Uncovering the local inelastic interactions during manufacture of ductile cast iron: How the substructure of the graphite particles can induce residual stress concentrations in the matrix

    Science.gov (United States)

    Andriollo, Tito; Hellström, Kristina; Sonne, Mads Rostgaard; Thorborg, Jesper; Tiedje, Niels; Hattel, Jesper

    2018-02-01

    Recent X-ray diffraction (XRD) measurements have revealed that plastic deformation and a residual elastic strain field can be present around the graphite particles in ductile cast iron after manufacturing, probably due to some local mismatch in thermal contraction. However, as only one component of the elastic strain tensor could be obtained from the XRD data, the shape and magnitude of the associated residual stress field have remained unknown. To compensate for this and to provide theoretical insight into this unexplored topic, a combined experimental-numerical approach is presented in this paper. First, a material equivalent to the ductile cast iron matrix is manufactured and subjected to dilatometric and high-temperature tensile tests. Subsequently, a two-scale hierarchical top-down model is devised, calibrated on the basis of the collected data and used to simulate the interaction between the graphite particles and the matrix during manufacturing of the industrial part considered in the XRD study. The model indicates that, besides the viscoplastic deformation of the matrix, the effect of the inelastic deformation of the graphite has to be considered to explain the magnitude of the XRD strain. Moreover, the model shows that the large elastic strain perturbations recorded with XRD close to the graphite-matrix interface are not artifacts due to e.g. sharp gradients in chemical composition, but correspond to residual stress concentrations induced by the conical sectors forming the internal structure of the graphite particles. In contrast to common belief, these results thus suggest that ductile cast iron parts cannot be considered, in general, as stress-free at the microstructural scale.

  13. The effect of long-range air mass transport pathways on PM10 and NO2 concentrations at urban and rural background sites in Ireland: Quantification using clustering techniques.

    Science.gov (United States)

    Donnelly, Aoife A; Broderick, Brian M; Misstear, Bruce D

    2015-01-01

    The specific aims of this paper are to: (i) quantify the effects of various long range transport pathways nitrogen dioxide (NO2) and particulate matter with diameter less than 10μm (PM10) concentrations in Ireland and identify air mass movement corridors which may lead to incidences poor air quality for application in forecasting; (ii) compare the effects of such pathways at various sites; (iii) assess pathways associated with a period of decreased air quality in Ireland. The origin of and the regions traversed by an air mass 96h prior to reaching a receptor is modelled and k-means clustering is applied to create air-mass groups. Significant differences in air pollution levels were found between air mass cluster types at urban and rural sites. It was found that easterly or recirculated air masses lead to higher NO2 and PM10 levels with average NO2 levels varying between 124% and 239% of the seasonal mean and average PM10 levels varying between 103% and 199% of the seasonal mean at urban and rural sites. Easterly air masses are more frequent during winter months leading to higher overall concentrations. The span in relative concentrations between air mass clusters is highest at the rural site indicating that regional factors are controlling concentration levels. The methods used in this paper could be applied to assist in modelling and forecasting air quality based on long range transport pathways and forecast meteorology without the requirement for detailed emissions data over a large regional domain or the use of computationally demanding modelling techniques.

  14. Optimal background matching camouflage.

    Science.gov (United States)

    Michalis, Constantine; Scott-Samuel, Nicholas E; Gibson, David P; Cuthill, Innes C

    2017-07-12

    Background matching is the most familiar and widespread camouflage strategy: avoiding detection by having a similar colour and pattern to the background. Optimizing background matching is straightforward in a homogeneous environment, or when the habitat has very distinct sub-types and there is divergent selection leading to polymorphism. However, most backgrounds have continuous variation in colour and texture, so what is the best solution? Not all samples of the background are likely to be equally inconspicuous, and laboratory experiments on birds and humans support this view. Theory suggests that the most probable background sample (in the statistical sense), at the size of the prey, would, on average, be the most cryptic. We present an analysis, based on realistic assumptions about low-level vision, that estimates the distribution of background colours and visual textures, and predicts the best camouflage. We present data from a field experiment that tests and supports our predictions, using artificial moth-like targets under bird predation. Additionally, we present analogous data for humans, under tightly controlled viewing conditions, searching for targets on a computer screen. These data show that, in the absence of predator learning, the best single camouflage pattern for heterogeneous backgrounds is the most probable sample. © 2017 The Authors.

  15. Cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1979-01-01

    The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

  16. 40 CFR 93.123 - Procedures for determining localized CO, PM10, and PM2.5 concentrations (hot-spot analysis).

    Science.gov (United States)

    2010-07-01

    ... CO, PM10, and PM2.5 concentrations (hot-spot analysis). 93.123 Section 93.123 Protection of... concentrations (hot-spot analysis). (a) CO hot-spot analysis. (1) The demonstrations required by § 93.116... make a categorical hot-spot finding that (93.116(a) is met without further hot-spot analysis for any...

  17. The Cosmic Infrared Background Experiment

    Science.gov (United States)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  18. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  19. Effects of background radiation

    International Nuclear Information System (INIS)

    Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

    1987-01-01

    The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

  20. The cosmic microwave background

    International Nuclear Information System (INIS)

    Silk, J.

    1991-01-01

    Recent limits on spectral distortions and angular anisotropies in the cosmic microwave background are reviewed. The various backgrounds are described, and the theoretical implications are assessed. Constraints on inflationary cosmology dominated by cold dark matter (CDM) and on open cosmological models dominated by baryonic dark matter (BDM), with, respectively, primordial random phase scale-invariant curvature fluctuations or non-gaussian isocurvature fluctuations are described. More exotic theories are addressed, and I conclude with the 'bottom line': what theories expect experimentalists to be measuring within the next two to three years without having to abandon their most cherished theorists. (orig.)

  1. The Cosmic Background Explorer

    Science.gov (United States)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  2. Investigations on the local structures of Cu2+ at various BaO concentrations in 59B2O3-10K2O-(30-x)ZnO-xBaO-1CuO glasses

    Science.gov (United States)

    Jin, Jia-Rui; Wu, Shao-Yi; Hong, Jian; Liu, Shi-Nan; Song, Min-Xian; Teng, Bao-Hua; Wu, Ming-He

    2017-11-01

    The local structures and electron paramagnetic resonance (EPR) parameters for Cu2+ in 59B2O3-10K2O-(30-x)ZnO-xBaO-1CuO (BKZBC) glasses are theoretically investigated with distinct modifier BaO concentrations x (= 0, 6, 12, 18, 24 and 30 mol %). The ? clusters are found to undergo the relative tetragonal elongations of about 13.5 and 5.0% at zero and higher BaO concentrations. The concentration dependences of the measured d-d transition bands, g factors and A// are suitably reproduced from the Fourier type functions or sign functions of the relevant quantities with x by using only six adjustable parameters. The features of the EPR parameters and the local structures of Cu2+ are analysed in a consistent way by considering the differences in the local ligand field strength and electronic cloud admixtures around Cu2+ under addition of Ba2+ with the highest ionicity and polarisability. The present theoretical studies would be helpful to the researches on the structures, optical and EPR properties for the similar potassium barium zinc borate glasses containing copper with variation concentration of modifier BaO.

  3. Thermal background noise limitations

    Science.gov (United States)

    Gulkis, S.

    1982-01-01

    Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

  4. Soil dioxin concentrations in Baden-Wuerttemberg

    International Nuclear Information System (INIS)

    Wolf, D.

    1993-01-01

    Soil dioxin levels in Baden-Wuerttemberg are generally low. Where high dioxin concentrations have been reported like in Rastatt, Rheinfelden, Crailsheim-Maulach and Eppingen these phenomena are local. Already at less than 100 metres distance, drastically lower concentrations are measured. At 1500 to 2000 metres distance the values are back to the ordinary background level. A programme for detecting sources of emission in the entire state revealed no further sites of heavy contamination. For this assessment of soil dioxin concentrations in Baden-Wuerttemberg 1275 soil samples were used, which is a vast amount also in comparison with nation-wide surveys. The average dioxin content in farmland is about 1 ng I-TEq/kg m T . Soil dioxin concentrations are the higher the greater the density of settlements and industry. In cities they are about three to five times higher than the ubiquitous background concentration. The highest concentrations measured were 5-20 ng I-TE/kg in garden soils in cities. Sewage sludge may be a significant source of dioxin contamination for farmland, far beyond the ubiquitous background concentration. Automobile exhaust gas caused higher soil contamination within 10 m along both sides of the roads as a function of traffic. Because scavengers in gasoline are now prohibited and catalysts are becoming more and more common the rate of additional dioxin and furan contamination due to traffic will decrease. Currently, traffic-related emissions in Baden-Wuerttemberg are well below 2 g I-TEq. (orig./EF) [de

  5. Spatial variability of POPs in European background air

    Directory of Open Access Journals (Sweden)

    A. K. Halse

    2011-02-01

    Full Text Available Passive air samplers (PAS were deployed at 86 European background sites during summer 2006 in order (i to gain further insight into spatial patterns of persistent organic pollutants (POPs in European background air and, (ii to evaluate PAS as an alternative sampling technique under EMEP (Co-operative programme for monitoring and evaluation of the long-range transmissions of air pollutants in Europe. The samples were analyzed for selected PCBs, HCHs, DDTs, HCB, PAHs and chlordanes, and air concentrations were calculated on the basis of losses of performance reference compounds. Air concentrations of PCBs were generally lowest in more remote areas of northern Europe with elevated levels in more densely populated areas. γ-HCH was found at elevated levels in more central parts of Europe, whereas α-HCH, β-HCH and DDTs showed higher concentrations in the south-eastern part. There was no clear spatial pattern in the concentrations for PAHs, indicative of influence by local sources, rather than long range atmospheric transport (LRAT. HCB was evenly distributed across Europe, while the concentrations of chlordanes were typically low or non-detectable. A comparison of results obtained on the basis of PAS and active air sampling (AAS illustrated that coordinated PAS campaigns have the potential serve as useful inter-comparison exercises within and across existing monitoring networks. The results also highlighted limitations of the current EMEP measurement network with respect to spatial coverage. We finally adopted an existing Lagrangian transport model (FLEXPART as recently modified to incorporate key processes relevant for POPs to evaluate potential source regions affecting observed concentrations at selected sites. Using PCB-28 as an example, the model predicted concentrations which agreed within a factor of 3 with PAS measurements for all except 1 out of the 17 sites selected for this analysis.

  6. Executive Summary - Historical background

    International Nuclear Information System (INIS)

    2005-01-01

    The Institute of Nuclear Physics (INP) was established in Cracow in 1955. The post-war excitement of engaging in scientific activity, can certainly be credited to the talent, experience and unusual personality of Professor Henryk Niewodniczanski, the founder and first Director of the INP. In the 60's the INP research activity was concentrated around the Russian U120 Cyclotron, built in 1958 which provided deuteron beams up to 14.5 MeV and of alpha particles up to 29 MeV. A small 48 cm pole-piece cyclotron with was in-house constructed, and used for PIXE analyses and RBA material studies. In 1960's, the nuclear spectroscopy group began building several types of magnetic beta ray spectrometers to study excited levels of neutron-deficient isotopes provided by the 660 MeV cyclotron of the JINR. In parallel, studies of spin polarization of n and p emitted in the deuteron stripping reaction were performed. Studies of condensed matter using pulsed neutron beams from the IBR30 and Kjeller (Norway) reactors had also began. The NMR signal was first observed in Poland by physicists from the Jagiellonian University, and a well equipped NMR Laboratory was also created at the INP. A small theoretical physics department was established to support experimental research. Applied physics, based on the research performed in the INP was also developed. Following the interest in fast neutron radiotherapy, initiated by the Gray Laboratory in Hammersmith, a beam of fast neutrons was produced on a Be target by 13.5 MeV deuterons from the U120 and applied for cancer therapy, in a collaborative effort with the Centre of Oncology in Cracow. Over a period of 10 years, some 500 patients were treated, in selected types of salivary gland cancer and post-mastectomy recurrences. In the late 60's a technology of thermoluminescent dosimeters (TLD) was developed at the INP, based on specially activated LiF. The method was patented and TLDs, manufactured at the INP, are nowadays applied by in over 30

  7. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  8. Background concentrations of radon and radon daughters in Canadian homes

    International Nuclear Information System (INIS)

    McGregor, R.G.; Vasudev, P.; Letourneau, E.G.; McCullough, R.S.; Prantl, F.A.; Taniguchi, H.

    1980-01-01

    Measurements of radon and radon daughters were carried out in 14 Canadian cities on a total of 9999 homes selected in a statistically random manner. The geometric means of the different cities varied from 0.14 to 0.88 pCi/l. for radon and 0.0009 to 0.0036 Working Levels for radon daughters. The radon originates from natural radioactivity in the soil surrounding the homes. (author)

  9. Fermionic bound states in distinct kinklike backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)

    2017-04-15

    This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)

  10. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  11. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s recen...

  12. Local emission of primary air pollutants and its contribution to wet deposition and concentrations of aerosols and gases in ambient air in Japan

    Science.gov (United States)

    Aikawa, Masahide; Hiraki, Takatoshi; Tomoyose, Nobutaka; Ohizumi, Tsuyoshi; Noguchi, Izumi; Murano, Kentaro; Mukai, Hitoshi

    2013-11-01

    We studied wet deposition by precipitation and the concentrations of aerosols and gases in ambient air in relation to the primary air pollutants discharged from domestic areas. The concentrations of aerosols and gases were influenced by nearby emissions except for non-sea-salt SO, which is transported long distances. The area facing the Sea of Japan showed much larger wet deposition than other areas, although the domestic emissions of the primary air pollutants there were small and showed a peak in wet deposition from October to March, as distinct from April to September in other areas. We performed the correlation analyses between wet deposition of each component and the product of the concentrations of corresponding aerosols and gases in ambient air and the two-thirds power of the precipitation. From the results, following scavenging processes were suggested. • Sulfate and ammonium were scavenged in precipitation as particulate matter such as (NH4)2SO4 and NH4HSO4. • Nitrate was scavenged mainly in precipitation through gaseous HNO3. • Ammonium was complementarily scavenged in precipitation through aerosols such as (NH4)2SO4 and NH4HSO4 and through gaseous NH3.

  13. Inclusion in the simulation of air pollutants recorded over the borders of test areas in Niedersachsen and forecasting of local ground level concentrations

    International Nuclear Information System (INIS)

    Mueller-Reissmann, K.F.; Schaffner, J.

    1991-08-01

    In 1987-1989 an emission-ground level concentration-model (conversion of emission into ground level concentration) was established for the pollutant sulphur dioxide (SO 2 ) by the ISP (Hannover) in cooperation with GEOS (Berlin) and was with emission data of the environs of Braunschweig for 1987 subjected to different trial runs. The pollution sources were devided into four groups: - Large Emitters (particularly power plants) - medium emitters (particularly industry) - space heating and small consumers - traffic. The pollution emitters of the first two groups were considered as point sources and the last two groups as surface sources, their emissions being evently distributed over squares of 1 km x 1 km, each surface unit of one km 2 being represented by 400 point sources in a distance of 50 m from each other. The conversion of emissions into ground level concentration is based on the Gaussian dispersion model on which also the dispersion calculation of the TA Luft (technical regulation about air pollution) is based. (orig./KW) [de

  14. Importance of background values in assessing the impact of heavy metals in river ecosystems: case study of Tisza River, Serbia.

    Science.gov (United States)

    Štrbac, Snežana; Kašanin Grubin, Milica; Vasić, Nebojša

    2017-11-30

    The main objective of this paper is to evaluate how a choice of different background values may affect assessing the anthropogenic heavy metal pollution in sediments from Tisza River (Serbia). The second objective of this paper is to underline significance of using geochemical background values when establishing quality criteria for sediment. Enrichment factor (EF), geoaccumulation index (I geo ), pollution load index (PLI), and potential ecological risk index (PERI) were calculated using different background values. Three geochemical (average metal concentrations in continental crust, average metal concentrations in shale, and average metal concentrations in non-contaminated core sediment samples) and two statistical methods (delineation method and principal component analyses) were used for calculating background values. It can be concluded that obtained information of pollution status can be more dependent on the use of background values than the index/factor chosen. The best option to assess the potential river sediment contamination is to compare obtained concentrations of analyzed elements with concentrations of mineralogically and texturally comparable, uncontaminated core sediment samples. Geochemical background values should be taken into account when establishing quality criteria for soils, sediments, and waters. Due to complexity of the local lithology, it is recommended that environmental monitoring and assessment include selection of an appropriate background values to gain understanding of the geochemistry and potential source of pollution in a given environment.

  15. Background music: effects on attention performance.

    Science.gov (United States)

    Shih, Yi-Nuo; Huang, Rong-Hwa; Chiang, Hsin-Yu

    2012-01-01

    Previous studies indicate that noise may affect worker attention. However, some background music in the work environment can increase worker satisfaction and productivity. This study compared how music with, and without, lyrics affects human attention. One hundred and two participants, aged 20-24 years, were recruited into this study. Fifty-six males and 46 females participated in this study. Background music with, and without lyrics, was tested for effects on listener concentration in attention testing using a randomized controlled trial (RCT) study. The comparison results revealed that background music with lyrics had significant negative effects on concentration and attention. The findings suggest that, if background music is played in the work environment, music without lyrics is preferable because songs with lyrics are likely to reduce worker attention and performance.

  16. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10(exp -7), where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  17. The effect of local hyperglycemia on skin cells in vitro and on wound healing in euglycemic rats

    DEFF Research Database (Denmark)

    Kruse, Carla R; Singh, Mansher; Sørensen, Jens A

    2016-01-01

    BACKGROUND: Multiple previous studies have established that high systemic blood glucose concentration impairs skin wound healing. However, the effects of local hyperglycemia on wound healing are not well defined. Comprehensive animal studies and in vitro studies using both fibroblasts and keratin......BACKGROUND: Multiple previous studies have established that high systemic blood glucose concentration impairs skin wound healing. However, the effects of local hyperglycemia on wound healing are not well defined. Comprehensive animal studies and in vitro studies using both fibroblasts...

  18. A study of trace element concentrations in human hair of some local populations in Japan. II. Inhabitants of a Japanese rural area

    International Nuclear Information System (INIS)

    Sakurai, S.; Tsunoda, H.; Terai, M.; Yukawa, M.; Tomura, K.; Suzuki-Yasumoto, M.

    1979-01-01

    Hair, as a route by which many metals are excreted, has advantages over other tissues as an indicator of body burden. However, as few data exist on trace element concentrations in hair, a study was made on a rural population in Japan. Hair was collected from 107 residents engaged mainly in dairy farming in a rural area in the northern part of the country. Samples were taken from subjects who had been born and bred in the area which is believed to be free from environmental pollution. A large number of the families had lived there for generations. Nineteen trace elements were detected. The mean values for Hg in hair were 6.8+-2.9 ppm for males and 4.5+-2.7 ppm for females. There was a low statistical correlation between Hg and Se. The mean value for Cu in hair was 17+-7.2 ppm for males and 16+-5.7 ppm for females and that for Zn was 140+-61 ppm for males and 130+-63 ppm for females. A comparison of the mean values of the trace elements in the hair of the subjects aged 20-39 and 40-59 years showed significant differences for Mn in males and Mn and Br in females. A comparison of the findings for the two sexes showed that the concentrations of Mn, Mg, Ca and Br were much higher in females than in males. In contrast, the concentrations of Hg were higher in males than in females. It is suggested that the values obtained for the trace elements in the present study are examples of normal values for trace elements in hair of the Japanese populations. (author)

  19. OCRWM Backgrounder, January 1987

    International Nuclear Information System (INIS)

    1987-01-01

    The Nuclear Waste Policy Act of 1982 (NWPA) assigns to the US Department of Energy (DOE) responsibility for developing a system to safely and economically transport spent nuclear fuel and high-level radioactive waste from various storage sites to geologic repositories or other facilities that constitute elements of the waste management program. This transportation system will evolve from technologies and capabilities already developed. Shipments of spent fuel to a monitored retrievable storage (MRS) facility could begin as early as 1996 if Congress authorizes its construction. Shipments of spent fuel to a geologic repository are scheduled to begin in 1998. The backgrounder provides an overview of DOE's cask development program. Transportation casks are a major element in the DOE nuclear waste transportation system because they are the primary protection against any potential radiation exposure to the public and transportation workers in the event an accident occurs

  20. Monitored background radiometer

    International Nuclear Information System (INIS)

    Ruel, C.

    1988-01-01

    A monitored background radiometer is described comprising: a thermally conductive housing; low conductivity support means mounted on the housing; a sensing plate mounted on the low conductivity support means and spaced from the housing so as to be thermally insulated from the housing and having an outwardly facing first surface; the sensing plate being disposed relative to the housing to receive direct electromagnetic radiation from sources exterior to the radiometer upon the first surface only; means for controllably heating the sensing plate; first temperature sensitive means to measure the temperature of the housing; and second temperature sensitive means to measure the temperature of the sensing plate, so that the heat flux at the sensing plate may be determined from the temperatures of the housing and sensing plate after calibration of the radiometer by measuring the temperatures of the housing and sensing plate while controllably heating the sensing plate

  1. Uncovering the local inelastic interactions during manufacture of ductile cast iron: How the substructure of the graphite particles can induce residual stress concentrations in the matrix

    DEFF Research Database (Denmark)

    Andriollo, Tito; Hellström, Kristina; Sonne, Mads Rostgaard

    2018-01-01

    Recent X-ray diffraction (XRD) measurements have revealed that plastic deformation and a residual elastic strain field can be present around the graphite particles in ductile cast iron after manufacturing, probably due to some local mismatch in thermal contraction. However, as only one component...... of the elastic strain tensor could be obtained from the XRD data, the shape and magnitude of the associated residual stress field have remained unknown. To compensate for this and to provide theoretical insight into this unexplored topic, a combined experimental-numerical approach is presented in this paper...... the graphite particles and the matrix during manufacturing of the industrial part considered in the XRD study. The model indicates that, besides the vis- coplastic deformation of the matrix, the effect of the inelastic deformation of the graphite has to be considered to explain the magnitude of the XRD strain...

  2. Background radiation map of Thailand

    International Nuclear Information System (INIS)

    Angsuwathana, P.; Chotikanatis, P.

    1997-01-01

    The radioelement concentration in the natural environment as well as the radiation exposure to man in day-to-day life is now the most interesting topic. The natural radiation is frequently referred as a standard for comparing additional sources of man-made radiation such as atomic weapon fallout, nuclear power generation, radioactive waste disposal, etc. The Department of Mineral Resources commenced a five-year project of nationwide airborne geophysical survey by awarding to Kenting Earth Sciences International Limited in 1984. The original purpose of survey was to support mineral exploration and geological mapping. Subsequently, the data quantity has been proved to be suitable for natural radiation information. In 1993 the Department of Mineral Resources, with the assistance of IAEA, published a Background Radiation Map of Thailand at the scale of 1:1,000,000 from the existing airborne radiometric digital data. The production of Background Radiation Map of Thailand is the result of data compilation and correction procedure developed over the Canadian Shield. This end product will be used as a base map in environmental application not only for Thailand but also Southeast Asia region. (author)

  3. Do instantons like a colorful background?

    Energy Technology Data Exchange (ETDEWEB)

    Gies, H.; Pawlowski, J.M.; Wetterich, C. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Jaeckel, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-08-15

    We investigate chiral symmetry breaking and color symmetry breaking in QCD. The effective potential of the corresponding scalar condensates is discussed in the presence of non-perturbative contributions from the semiclassical one-instanton sector. We concentrate on a color singlet scalar background which can describe chiral condensation, as well as a color cotet scalar background which can generate mass for the gluons. Whereas a non-vanishing singlet chiral field is favored by the instantons, we have found no indication for a preference of color octet backgrounds. (orig.)

  4. Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

    DEFF Research Database (Denmark)

    Rehling, M; Hyldstrup, L; Henriksen, Jens Henrik Sahl

    1989-01-01

    , whereas the difference was very sensitive to even small changes in forearm blood flow within the physiological range. For measurement of renal plasma clearance it is recommended to use one long period: from the time of injection until 300 min p.i. or longer. If the clearance period is too short, the use...... introduced in the measurement of renal plasma clearance and total plasma clearance by using venous blood samples instead of arterial. In 13 patients with GFR ranging from 29 to 150 ml min-1, Ca was higher than Cv immediately after the injection. After mean 38 min (range 12-82 min) the two curves crossed...... of venous samples will overestimate the true renal clearance. Plasma clearance determined by venous and arterial blood samples does not differ significantly as long as the concentration is followed from the time of injection and a long period is applied. When simplified plasma clearance techniques are used...

  5. Spectrum of the extragalactic background light

    Energy Technology Data Exchange (ETDEWEB)

    Bruzual A, G [Centro de Investigacion de Astronomia, Merida (Venezuela)

    1981-01-01

    The observed spectrum of the extragalactic background light in the range from ultraviolet to optical wavelengths is compared with a model prediction. The model uses the locally observed luminosity function of galaxies as well as evolutionary models for galaxy spectral energy distributions. The predicition is too faint by a factor of about 10.

  6. Determination of local concentration of H2O molecules and gas temperature in the process of hydrogen – oxygen gas mixture heating by means of linear and nonlinear laser spectroscopy

    International Nuclear Information System (INIS)

    Kozlov, D N; Kobtsev, V D; Stel'makh, O M; Smirnov, Valery V; Stepanov, E V

    2013-01-01

    Employing the methods of linear absorption spectroscopy and nonlinear four-wave mixing spectroscopy using laserinduced gratings we have simultaneously measured the local concentrations of H 2 O molecules and the gas temperature in the process of the H 2 – O 2 mixture heating. During the measurements of the deactivation rates of pulsed-laser excited singlet oxygen O 2 (b 1 Σ + g ) in collisions with H 2 in the range 294 – 850 K, the joint use of the two methods made it possible to determine the degree of hydrogen oxidation at a given temperature. As the mixture is heated, H 2 O molecules are formed by 'dark' reactions of H 2 with O 2 in the ground state. The experiments have shown that the measurements of tunable diode laser radiation absorption along an optical path through the inhomogeneously heated gas mixture in a cell allows high-accuracy determination of the local H 2 O concentration in the O 2 laser excitation volume, if the gas temperature in this volume is known. When studying the collisional deactivation of O 2 (b 1 Σ + g ) molecules, the necessary measurements of the local temperature can be implemented using laser-induced gratings, arising due to spatially periodic excitation of O 2 (X 3 Σ - g ) molecules to the b 1 Σ + g state by radiation of the pump laser of the four-wave mixing spectrometer. (laser spectroscopy)

  7. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  8. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  9. Natural background radiation in Jordan

    International Nuclear Information System (INIS)

    Daoud, M.N.S.

    1997-01-01

    An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ''digital and analogue''. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in (μR/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author)

  10. Natural background radiation in Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Daoud, M N.S. [National Resources Authority, Ministry of Energy and Mineral Resources, Amman (Jordan)

    1997-11-01

    An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ``digital and analogue``. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in ({mu}R/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author). 8 refs, 10 figs, 7 tabs.

  11. A systemic increase in the recombination frequency upon local infection of Arabidopsis thaliana plants with oilseed rape mosaic virus depends on plant age, the initial inoculum concentration and the time for virus replication

    Directory of Open Access Journals (Sweden)

    Youli eYao

    2013-03-01

    Full Text Available In the past, we showed that local infection of tobacco leaves with either Tobacco mosaic virus (TMV or Oilseed rape mosaic virus (ORMV resulted in a systemic increase in the homologous recombination frequency (HRF. Later on, we showed that a similar phenomenon occurs in Arabidopsis thaliana plants infected with ORMV. Here, we tested whether the time of removing the infected leaves as well as viral titer have any effect on the degree of changes in HRF in systemic tissues. An increase in HRF in systemic non-infected tissues was more pronounced when the infected leaves were detached from the infected plants at 60-96 hours post infection, rather than at earlier time. Next, we found that exposure to higher concentrations of inoculum was much more efficient in triggering an increase in HRF than exposure to lower concentrations. Finally, we showed that older plants exhibited a higher increase in HRF than younger plants. We found that an increase in genome instability in systemic tissues of locally infected plants depends on plant age, the concentration of initial inoculums and the time of viral replication.

  12. Electron-beam-induced current measurements with applied bias provide insight to locally resolved acceptor concentrations at p-n junctions

    Directory of Open Access Journals (Sweden)

    D. Abou-Ras

    2015-07-01

    Full Text Available Electron-beam-induced current (EBIC measurements have been employed for the investigation of the local electrical properties existing at various types of electrical junctions during the past decades. In the standard configuration, the device under investigation is analyzed under short-circuit conditions. Further insight into the function of the electrical junction can be obtained when applying a bias voltage. The present work gives insight into how EBIC measurements at applied bias can be conducted at the submicrometer level, at the example of CuInSe2 solar cells. From the EBIC profiles acquired across ZnO/CdS/CuInSe2/Mo stacks exhibiting p-n junctions with different net doping densities in the CuInSe2 layers, values for the width of the space-charge region, w, were extracted. For all net doping densities, these values decreased with increasing applied voltage. Assuming a linear relationship between w2 and the applied voltage, the resulting net doping densities agreed well with the ones obtained by means of capacitance-voltage measurements.

  13. A study of trace element concentrations in human hair of some local populations in Japan. I. Inhabitants of the Tokyo metropolitan area

    International Nuclear Information System (INIS)

    Imahori, A.; Fukushima, I.; Shiobara, S.; Terai, M.

    1979-01-01

    By applying instrumental neutron activation analysis techniques, a survey was carried out to determine the levels of a variety of trace element concentrations in human hair of the inhabitants of the Tokyo metropolitan area. A total of 202 scalp hair samples were collected from the inhabitants of the residential district in the western part of the Tokyo metropolitan area. The donors were divided into five age groups, ranging from pre-school age to sixty years and above. Each group consisted of twenty males and twenty or more females. The sampling method and washing procedure recommended by the IAEA Advisory Group on the applications of nuclear methods in environmental research were strictly followed. Irradiation of the samples was made in the Rikkyo University 100-kW TRIGA MARK II reactor. By using several combinations of irradiation time, cooling time and counting time, the following 37 elements were quantitatively analysed: Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Fe, Hg, I, K, La, Mg, Mn, Mo, Na, Ni, Rb, S, Sb, Sc, Se, Sm, Sn, Te, Ti, U, V, W and Zn. NBS standard reference orchard leaves and bovine liver were also analysed in the course of the hair analysis to assess the precision of the analytical techniques. (author)

  14. Note on bouncing backgrounds

    Science.gov (United States)

    de Haro, Jaume; Pan, Supriya

    2018-05-01

    The theory of inflation is one of the fundamental and revolutionary developments of modern cosmology that became able to explain many issues of the early Universe in the context of the standard cosmological model (SCM). However, the initial singularity of the Universe, where physics is indefinite, is still obscure in the combined SCM +inflation scenario. An alternative to SCM +inflation without the initial singularity is thus always welcome, and bouncing cosmology is an attempt at that. The current work is thus motivated to investigate the bouncing solutions in modified gravity theories when the background universe is described by the spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry. We show that the simplest way to obtain the bouncing cosmologies in such spacetime is to consider some kind of Lagrangian whose gravitational sector depends only on the square of the Hubble parameter of the FLRW universe. For these modified Lagrangians, the corresponding Friedmann equation, a constraint in the dynamics of the Universe, depicts a curve in the phase space (H ,ρ ), where H is the Hubble parameter and ρ is the energy density of the Universe. As a consequence, a bouncing cosmology is obtained when this curve is closed and crosses the axis H =0 at least twice, and whose simplest particular example is the ellipse depicting the well-known holonomy corrected Friedmann equation in loop quantum cosmology (LQC). Sometimes, a crucial point in such theories is the appearance of the Ostrogradski instability at the perturbative level; however, fortunately enough, in the present work, as long as the linear level of perturbations is concerned, this instability does not appear, although it may appear at the higher order of perturbations.

  15. Conserved quantities in background independent theories

    Energy Technology Data Exchange (ETDEWEB)

    Markopoulou, Fotini [Perimeter Institute for Theoretical Physics, 35 King Street North, Waterloo, Ontario N2J 2W9 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2007-05-15

    We discuss the difficulties that background independent theories based on quantum geometry encounter in deriving general relativity as the low energy limit. We follow a geometrogenesis scenario of a phase transition from a pre-geometric theory to a geometric phase which suggests that a first step towards the low energy limit is searching for the effective collective excitations that will characterize it. Using the correspondence between the pre-geometric background independent theory and a quantum information processor, we are able to use the method of noiseless subsystems to extract such coherent collective excitations. We illustrate this in the case of locally evolving graphs.

  16. Background noise levels in Europe

    OpenAIRE

    Gjestland, Truls

    2008-01-01

    - This report gives a brief overview of typical background noise levels in Europe, and suggests a procedure for the prediction of background noise levels based on population density. A proposal for the production of background noise maps for Europe is included.

  17. Gentamicin serum concentrations in patients with gentamicin-PMMA beads for infected hip joints : A prospective observational cohort study

    NARCIS (Netherlands)

    De Klaver, Paul A.G.; Hendriks, Johannes G.E.; Van Onzenoort, Hein A.W.; Schreurs, Berend W.; Touw, Daan J.; Derijks, Luc J.J.

    Background: Gentamicin-polymethylmethacrylate (PMMA) beads release gentamicin gradually, and high concentrations develop only locally. It is unclear how frequent and in which patients gentamicin serum concentrations are measurable and possibly lead to toxicity. The aim of this study was to

  18. Monte Carlo simulations of low background detectors

    International Nuclear Information System (INIS)

    Miley, H.S.; Brodzinski, R.L.; Hensley, W.K.; Reeves, J.H.

    1995-01-01

    An implementation of the Electron Gamma Shower 4 code (EGS4) has been developed to allow convenient simulation of typical gamma ray measurement systems. Coincidence gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra for the purpose of extremely low-level assay. Monte Carlo calculations of this sort can be extremely successful since low background detectors are usually free of significant contributions from poorly localized radiation sources, such as cosmic muons, secondary cosmic neutrons, and radioactive construction or shielding materials. Previously, validation of this code has been obtained from a series of comparisons between measurements and blind calculations. An example of the application of this code to an exceedingly low background spectrum stripping will be presented. (author) 5 refs.; 3 figs.; 1 tab

  19. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Center for Mountain Ecosystem Studies, Kunming Institute of Botany of the Chinese Academy of Sciences, China: $1,526,000 to inform effective water governance in the Asian highlands of China, Nepal, and Pakistan. • Ashoka Trust for Research in Ecology and the Environment (ATREE), India: $1,499,300 for research on ...

  20. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    demographic trends, socio-economic development pathways, and strong ... knowledge and experience, and encourage innovation. ... choices, and will work with stakeholders in government, business, civil society, and regional economic.

  1. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Safe and Inclusive Cities: ... improving urban environments and public spaces might have on reducing the city's high ... violence against women among urban youth of working class neighbourhoods of Islamabad, Rawalpindi, and Karachi,.

  2. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    CARIAA's research agenda addresses gaps and priorities highlighted in the ... Research focuses on climate risk, institutional and regulatory frameworks, markets, and ... The researchers will identify relevant drivers and trends and use develop ...

  3. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    achieving long‐term food security in Africa, with a focus on post‐harvest loss, ... nutrion and health, and the socio‐economic factors that affect food supply ... Water use. Agricultural producvity in sub‐Saharan Africa is the lowest in the world.

  4. Concentrated Ownership

    DEFF Research Database (Denmark)

    Rose, Caspar

    2014-01-01

    This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors......, especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control....

  5. Diffuse Cosmic Infrared Background Radiation

    Science.gov (United States)

    Dwek, Eli

    2002-01-01

    The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

  6. Background current of radioisotope manometer

    International Nuclear Information System (INIS)

    Vydrik, A.A.

    1987-01-01

    The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

  7. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  8. Elliptical concentrators.

    Science.gov (United States)

    Garcia-Botella, Angel; Fernandez-Balbuena, Antonio Alvarez; Bernabeu, Eusebio

    2006-10-10

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used to produce optical devices, including the use of reflective and refractive components or inverse engineering techniques. However, many of these optical components are based on translational symmetries, rotational symmetries, or free-form surfaces. We study a new family of nonimaging concentrators called elliptical concentrators. This new family of concentrators provides new capabilities and can have different configurations, either homofocal or nonhomofocal. Translational and rotational concentrators can be considered as particular cases of elliptical concentrators.

  9. Backgrounds and characteristics of arsonists

    NARCIS (Netherlands)

    Labree, W.; Nijman, H.L.I.; Marle, H.J.C. van; Rassin, E.

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n = 25), sentenced to forced treatment in the maximum security forensic hospital “De Kijvelanden”, were

  10. Measurement of natural background neutron

    CERN Document Server

    Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

    1982-01-01

    A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

  11. Multisite study of particle number concentrations in urban air.

    Science.gov (United States)

    Harrison, Roy M; Jones, Alan M

    2005-08-15

    Particle number concentration data are reported from a total of eight urban site locations in the United Kingdom. Of these, six are central urban background sites, while one is an urban street canyon (Marylebone Road) and another is influenced by both a motorway and a steelworks (Port Talbot). The concentrations are generally of a similar order to those reported in the literature, although higher than those in some of the other studies. Highest concentrations are at the Marylebone Road site and lowest are at the Port Talbot site. The central urban background locations lie somewhere between with concentrations typically around 20 000 cm(-3). A seasonal pattern affects all sites, with highest concentrations in the winter months and lowest concentrations in the summer. Data from all sites show a diurnal variation with a morning rush hour peak typical of an anthropogenic pollutant. When the dilution effects of windspeed are accounted for, the data show little directionality at the central urban background sites indicating the influence of sources from all directions as might be expected if the major source were road traffic. At the London Marylebone Road site there is high directionality driven by the air circulation in the street canyon, and at the Port Talbot site different diurnal patterns are seen for particle number count and PM10 influenced by emissions from road traffic (particle number count) and the steelworks (PM10) and local meteorological factors. Hourly particle number concentrations are generally only weakly correlated to NO(x) and PM10, with the former showing a slightly closer relationship. Correlations between daily average particle number count and PM10 were also weak. Episodes of high PM10 concentration in summer typically show low particle number concentrations consistent with transport of accumulation mode secondary aerosol, while winter episodes are frequently associated with high PM10 and particle number count arising from poor dispersion of

  12. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  13. Aluminum as a source of background in low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Majorovits, B., E-mail: bela@mppmu.mpg.de [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Abt, I. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, S.S.17/bis, km 18 plus 910, I-67100 Assergi (Italy); Volynets, O. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

    2011-08-11

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10{sup -5} counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of {sup 22}Na, {sup 26}Al, {sup 226}Ra and {sup 228}Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  14. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.

    2003-01-01

    Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula...... on revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors...

  15. Concentrator Photovoltaics

    CERN Document Server

    Luque, Antonio L

    2007-01-01

    Photovoltaic solar-energy conversion is one of the most promising technologies for generating renewable energy, and conversion of concentrated sunlight can lead to reduced cost for solar electricity. In fact, photovoltaic conversion of concentrated sunlight insures an efficient and cost-effective sustainable power resource. This book gives an overview of all components, e.g. cells, concentrators, modules and systems, for systems of concentrator photovoltaics. The authors report on significant results related to design, technology, and applications, and also cover the fundamental physics and market considerations. Specific contributions include: theory and practice of sunlight concentrators; an overview of concentrator PV activities; a description of concentrator solar cells; design and technology of modules and systems; manufacturing aspects; and a market study.

  16. Measured and calculated NO2 concentrations in Amsterdam in 2008

    International Nuclear Information System (INIS)

    Wesseling, J.P.; Nguyen, P.L.; Van der Zee, S.

    2010-08-01

    Calculations using the Dutch standard calculation method for air quality in urban streets performed for 38 streets in Amsterdam in 2008 yield, on average, lower Nitrogen dioxide concentrations than measurements at those locations. This follows from research by the RIVM and the Public Health Service of Amsterdam (GGD Amsterdam). The average difference between measured and calculated concentrations is 11 %. At measuring locations of the National Air Quality Measuring Network in the Netherlands no significant underestimation of concentrations by the model is observed. The research was performed by the Dutch ministry of Housing, Spatial Planning en the Environment (VROM). The air quality in the streets that were investigated is mainly determined by emissions from local traffic. The measurements have been performed during thirteen periods of four weeks each, using so called 'Palmes' diffusion tubes. These measurements have been calibrated using the European reference method that is operational in the permanent measuring stations of the GGD Amsterdam. The calculations were performed using the geometry of the roads and information of the traffic at the measuring locations. Part of the differences can be explained, as some locations are not within the scope of the model. In these situations the model is known to perform slightly less. Apart from local traffic, other sources, like shipping, also contribute to the NO2 background concentrations in streets in Amsterdam. Sources that have only globally been included in the calculation of this background concentration may influence concentrations at specific locations. Further studies on this subject will be conducted in 2010. [nl

  17. Dim point target detection against bright background

    Science.gov (United States)

    Zhang, Yao; Zhang, Qiheng; Xu, Zhiyong; Xu, Junping

    2010-05-01

    For target detection within a large-field cluttered background from a long distance, several difficulties, involving low contrast between target and background, little occupancy, illumination ununiformity caused by vignetting of lens, and system noise, make it a challenging problem. The existing approaches to dim target detection can be roughly divided into two categories: detection before tracking (DBT) and tracking before detection (TBD). The DBT-based scheme has been widely used in practical applications due to its simplicity, but it often requires working in the situation with a higher signal-to-noise ratio (SNR). In contrast, the TBD-based methods can provide impressive detection results even in the cases of very low SNR; unfortunately, the large memory requirement and high computational load prevents these methods from real-time tasks. In this paper, we propose a new method for dim target detection. We address this problem by combining the advantages of the DBT-based scheme in computational efficiency and of the TBD-based in detection capability. Our method first predicts the local background, and then employs the energy accumulation and median filter to remove background clutter. The dim target is finally located by double window filtering together with an improved high order correlation which speeds up the convergence. The proposed method is implemented on a hardware platform and performs suitably in outside experiments.

  18. Partition function for a singular background

    International Nuclear Information System (INIS)

    McKenzie-Smith, J.J.; Naylor, W.

    2005-01-01

    We present a method for evaluating the partition function in a varying external field. Specifically, we look at the case of a non-interacting, charged, massive scalar field at finite temperature with an associated chemical potential in the background of a delta-function potential. Whilst we present a general method, valid at all temperatures, we only give the result for the leading order term in the high temperature limit. Although the derivative expansion breaks down for inhomogeneous backgrounds we are able to obtain the high temperature expansion, as well as an analytic expression for the zero point energy, by way of a different approximation scheme, which we call the local Born approximation (LBA)

  19. Partition function for a singular background

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie-Smith, J.J. [Financial Risk Management Ltd, 15 Adam Street, London WC2N 6AH (United Kingdom)]. E-mail: julian.mckenzie-smith@frmhedge.com; Naylor, W. [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)]. E-mail: naylor@yukawa.kyoto-u.ac.jp

    2005-03-17

    We present a method for evaluating the partition function in a varying external field. Specifically, we look at the case of a non-interacting, charged, massive scalar field at finite temperature with an associated chemical potential in the background of a delta-function potential. Whilst we present a general method, valid at all temperatures, we only give the result for the leading order term in the high temperature limit. Although the derivative expansion breaks down for inhomogeneous backgrounds we are able to obtain the high temperature expansion, as well as an analytic expression for the zero point energy, by way of a different approximation scheme, which we call the local Born approximation (LBA)

  20. Cosmic microwave background bispectrum from recombination.

    Science.gov (United States)

    Huang, Zhiqi; Vernizzi, Filippo

    2013-03-08

    We compute the cosmic microwave background temperature bispectrum generated by nonlinearities at recombination on all scales. We use CosmoLib2nd, a numerical Boltzmann code at second order to compute cosmic microwave background bispectra on the full sky. We consistently include all effects except gravitational lensing, which can be added to our result using standard methods. The bispectrum is peaked on squeezed triangles and agrees with the analytic approximation in the squeezed limit at the few percent level for all the scales where this is applicable. On smaller scales, we recover previous results on perturbed recombination. For cosmic-variance limited data to l(max)=2000, its signal-to-noise ratio is S/N=0.47, corresponding to f(NL)(eff)=-2.79, and will bias a local signal by f(NL)(loc) ~/= 0.82.

  1. Stochastic backgrounds of gravitational waves

    International Nuclear Information System (INIS)

    Maggiore, M.

    2001-01-01

    We review the motivations for the search for stochastic backgrounds of gravitational waves and we compare the experimental sensitivities that can be reached in the near future with the existing bounds and with the theoretical predictions. (author)

  2. Berkeley Low Background Counting Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Sensitive low background assay detectors and sample analysis are available for non-destructive direct gamma-ray assay of samples. Neutron activation analysis is also...

  3. Spectral characterization of natural backgrounds

    Science.gov (United States)

    Winkelmann, Max

    2017-10-01

    As the distribution and use of hyperspectral sensors is constantly increasing, the exploitation of spectral features is a threat for camouflaged objects. To improve camouflage materials at first the spectral behavior of backgrounds has to be known to adjust and optimize the spectral reflectance of camouflage materials. In an international effort, the NATO CSO working group SCI-295 "Development of Methods for Measurements and Evaluation of Natural Background EO Signatures" is developing a method how this characterization of backgrounds has to be done. It is obvious that the spectral characterization of a background will be quite an effort. To compare and exchange data internationally the measurements will have to be done in a similar way. To test and further improve this method an international field trial has been performed in Storkow, Germany. In the following we present first impressions and lessons learned from this field campaign and describe the data that has been measured.

  4. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  5. Emergence of oscillons in an expanding background

    International Nuclear Information System (INIS)

    Farhi, E.; Guth, A. H.; Iqbal, N.; Graham, N.; Rosales, R. R.; Stamatopoulos, N.

    2008-01-01

    We consider a (1+1) dimensional scalar field theory that supports oscillons, which are localized, oscillatory, stable solutions to nonlinear equations of motion. We study this theory in an expanding background and show that oscillons now lose energy, but at a rate that is exponentially small when the expansion rate is slow. We also show numerically that a universe that starts with (almost) thermal initial conditions will cool to a final state where a significant fraction of the energy of the universe--on the order of 50%--is stored in oscillons. If this phenomenon persists in realistic models, oscillons may have cosmological consequences.

  6. JOURNALISM STUDIES IN ARGENTINA: BACKGROUND AND QUESTIONS

    Directory of Open Access Journals (Sweden)

    Adriana Amado

    2014-06-01

    Full Text Available This article summarizes the background of empirical journalism studies in Argentina.  In recent publications, researchers have consistently underscored the lack of data on the profession and the scarce development of theoretical frameworks related to journalism studies.  The local investigations have prioritized approaches and methods that do not give the whole picture of the population of journalists. Most of the research tends to equate media analysis and media messages with journalism study and keeps on failing to provide data that allows for learning about the working conditions and the professional profile of the Argentinean journalists.

  7. Looking for Cosmic Neutrino Background

    Directory of Open Access Journals (Sweden)

    Chiaki eYanagisawa

    2014-06-01

    Full Text Available Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for 1 measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s, and the sign of mass splitting between the mass eigenstates m3 and m1, and 2 better measurements to determine whether the mixing angle theta23 is less than pi/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles is also in progress with continuous improvement. On the other hand, although the ideas of detecting cosmic neutrino background have been discussed since 1960s, there has not been a serious concerted effort to achieve this goal. One of the reasons is that it is extremely difficult to detect such low energy neutrinos from the Big Bang. While there has been tremendous accumulation of information on Cosmic Microwave Background since its discovery in 1965, there is no direct evidence for Cosmic Neutrino Background. The importance of detecting Cosmic Neutrino Background is that, although detailed studies of Big Bang Nucleosynthesis and Cosmic Microwave Background give information of the early Universe at ~a few minutes old and ~300 k years old, respectively, observation of Cosmic Neutrino Background allows us to study the early Universe at $sim$ 1 sec old. This article reviews progress made in the past 50 years on detection methods of Cosmic Neutrino Background.

  8. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  9. LOFT gamma densitometer background fluxes

    International Nuclear Information System (INIS)

    Grimesey, R.A.; McCracken, R.T.

    1978-01-01

    Background gamma-ray fluxes were calculated at the location of the γ densitometers without integral shielding at both the hot-leg and cold-leg primary piping locations. The principal sources for background radiation at the γ densitometers are 16 N activity from the primary piping H 2 O and γ radiation from reactor internal sources. The background radiation was calculated by the point-kernel codes QAD-BSA and QAD-P5A. Reasonable assumptions were required to convert the response functions calculated by point-kernel procedures into the gamma-ray spectrum from reactor internal sources. A brief summary of point-kernel equations and theory is included

  10. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  11. Background metric in supergravity theories

    International Nuclear Information System (INIS)

    Yoneya, T.

    1978-01-01

    In supergravity theories, we investigate the conformal anomaly of the path-integral determinant and the problem of fermion zero modes in the presence of a nontrivial background metric. Except in SO(3) -invariant supergravity, there are nonvanishing conformal anomalies. As a consequence, amplitudes around the nontrivial background metric contain unpredictable arbitrariness. The fermion zero modes which are explicitly constructed for the Euclidean Schwarzschild metric are interpreted as an indication of the supersymmetric multiplet structure of a black hole. The degree of degeneracy of a black hole is 2/sup 4n/ in SO(n) supergravity

  12. Background music and cognitive performance.

    Science.gov (United States)

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance.

  13. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    media products and toys just as they will have knowledge of different media texts, play genres, rhymes etc. This has consequences for their ability to access social settings, for instance in play. New research in this field will focus on how children themselves make sense of this balancing of cultures......Children of ethnic minority background balance their everyday life between a cultural background rooted in their ethnic origin and a daily life in day care, schools and with peers that is founded in a majority culture. This means, among other things, that they often will have access to different...

  14. Generative electronic background music system

    International Nuclear Information System (INIS)

    Mazurowski, Lukasz

    2015-01-01

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  15. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  16. Heterotic string in an arbitrary background field

    International Nuclear Information System (INIS)

    Sen, A.

    1985-01-01

    An expression for the light-cone gauge action for the first-quantized heterotic string in the presence of arbitrary background gauge, gravitational, and antisymmetric tensor fields is derived. The result is a two-dimensional local field theory with N = 1/2 supersymmetry. The constraints imposed on the background fields in order to make this theory one-loop finite are derived. These constraints are identical to the equations of motion for the massless fields at the linearized level. Finally, it is shown that if there is no background antisymmetric tensor field, and if the gauge connection is set equal to the spin connection, the effective action is that of an N = 1 supersymmetric nonlinear and N = 2 supersymmetric Georgi-Glashow models the occurrence of the fermion fractionization is the necessity; the ignorance of it results in the inconsistency in the perturbative calculation of the mass splittings among the members of the supermultiplets. The notable feature of our result is that the degeneracy due to the Jackiw-Rebbi zero mode is not independent of the one required by the supersymmetry, suggesting a nontrivial structure in embedding the topology of Higgs fields into supersymmetric gauge theories

  17. Low Background Micromegas in CAST

    DEFF Research Database (Denmark)

    Garza, J G; Aune, S.; Aznar, F.

    2014-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micr...

  18. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  19. Educational Choice. A Background Paper.

    Science.gov (United States)

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  20. Kerr metric in cosmological background

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, P C [Gujarat Univ., Ahmedabad (India). Dept. of Mathematics

    1977-06-01

    A metric satisfying Einstein's equation is given which in the vicinity of the source reduces to the well-known Kerr metric and which at large distances reduces to the Robertson-Walker metric of a nomogeneous cosmological model. The radius of the event horizon of the Kerr black hole in the cosmological background is found out.

  1. Low Background Micromegas in CAST

    CERN Document Server

    Garza, J.G.; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

    2015-11-16

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

  2. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  3. Geochemistry of regional background aerosols in the Western Mediterranean

    Science.gov (United States)

    Pey, J.; Pérez, N.; Castillo, S.; Viana, M.; Moreno, T.; Pandolfi, M.; López-Sebastián, J. M.; Alastuey, A.; Querol, X.

    2009-11-01

    The chemical composition of regional background aerosols, and the time variability and sources in the Western Mediterranean are interpreted in this study. To this end 2002-2007 PM speciation data from an European Supersite for Atmospheric Aerosol Research (Montseny, MSY, located 40 km NNE of Barcelona in NE Spain) were evaluated, with these data being considered representative of regional background aerosols in the Western Mediterranean Basin. The mean PM 10, PM 2.5 and PM 1 levels at MSY during 2002-2007 were 16, 14 and 11 µg/m 3, respectively. After compiling data on regional background PM speciation from Europe to compare our data, it is evidenced that the Western Mediterranean aerosol is characterised by higher concentrations of crustal material but lower levels of OM + EC and ammonium nitrate than at central European sites. Relatively high PM 2.5 concentrations due to the transport of anthropogenic aerosols (mostly carbonaceous and sulphate) from populated coastal areas were recorded, especially during winter anticyclonic episodes and summer midday PM highs (the latter associated with the transport of the breeze and the expansion of the mixing layer). Source apportionment analyses indicated that the major contributors to PM 2.5 and PM 10 were secondary sulphate, secondary nitrate and crustal material, whereas the higher load of the anthropogenic component in PM 2.5 reflects the influence of regional (traffic and industrial) emissions. Levels of mineral, sulphate, sea spray and carbonaceous aerosols were higher in summer, whereas nitrate levels and Cl/Na were higher in winter. A considerably high OC/EC ratio (14 in summer, 10 in winter) was detected, which could be due to a combination of high biogenic emissions of secondary organic aerosol, SOA precursors, ozone levels and insolation, and intensive recirculation of aged air masses. Compared with more locally derived crustal geological dusts, African dust intrusions introduce relatively quartz-poor but clay

  4. Thermodynamically efficient solar concentrators

    Science.gov (United States)

    Winston, Roland

    2012-10-01

    Non-imaging Optics is the theory of thermodynamically efficient optics and as such depends more on thermodynamics than on optics. Hence in this paper a condition for the "best" design is proposed based on purely thermodynamic arguments, which we believe has profound consequences for design of thermal and even photovoltaic systems. This new way of looking at the problem of efficient concentration depends on probabilities, the ingredients of entropy and information theory while "optics" in the conventional sense recedes into the background.

  5. Background paper on aquaculture research

    OpenAIRE

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto; Torrissen, Ole

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including ...

  6. The isotropic radio background revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

    2014-04-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  7. The isotropic radio background revisited

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

  8. Backgrounds and characteristics of arsonists.

    Science.gov (United States)

    Labree, Wim; Nijman, Henk; van Marle, Hjalmar; Rassin, Eric

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n=25), sentenced to forced treatment in the maximum security forensic hospital "De Kijvelanden", were compared to the characteristics of a control group of patients (n=50), incarcerated at the same institution for other severe crimes. Apart from DSM-IV Axis I and Axis II disorders, family backgrounds, level of education, treatment history, intelligence (WAIS scores), and PCL-R scores were included in the comparisons. Furthermore, the apparent motives for the arson offences were explored. It was found that arsonists had more often received psychiatric treatment, prior to committing their index offence, and had a history of severe alcohol abuse more often in comparison to the controls. The arsonists turned out to be less likely to suffer from a major psychotic disorder. Both groups did not differ significantly on the other variables, among which the PCL-R total scores and factor scores. Exploratory analyses however, did suggest that arsonists may differentiate from non-arsonists on three items of the PCL-R, namely impulsivity (higher scores), superficial charm (lower scores), and juvenile delinquency (lower scores). Although the number of arsonists with a major psychotic disorder was relatively low (28%), delusional thinking of some form was judged to play a role in causing arson crimes in about half of the cases (52%).

  9. Background as a residual radioactivity criterion for decommissioning: Appendix A to the Generic Environmental Impact Statement in support of rulemaking on radiological criteria for decommissioning of NRC-licensed nuclear facilities. Draft report

    International Nuclear Information System (INIS)

    Huffert, A.M.; Meck, R.A.; Miller, K.M.

    1994-08-01

    This report was originally published as an appendix to the draft U.S. Nuclear Regulatory Commission (NRC) document entitled, open-quotes Generic Environmental Impact Statement in Support of Rulemaking on Radiological Criteria for Decommissioning of NRC-Licensed Nuclear Facilities.close quotes Because of the great interest in this report by members of the public, citizen and environmental organizations, academicians, licensees, and regulators, the NRC staff is publishing this report separately, so that it can be readily available to a diverse audience. This report was created to assist both the NRC staff and interested members of the public in evaluating background radiation (background) as a decommissioning criterion, by serving as a primer on background and providing information on the existing applications of background in regulatory criteria and standards. This report also discusses some of the methods available to measure and distinguish between the very low radiation levels associated with background and man-made sources of radiation. Two approaches are considered for applying background as a decommissioning criterion; these are the use of background dose rates and background radionuclide concentrations. This report concludes that the temporal and spatial variability of background produces a wide range of doses to United States residents, which prevents the application of background dose rates as a decommissioning criterion. Instead, this report recommends that local background radionuclide concentrations serve as a benchmark for decommissioning criteria, while taking into account the concept of reducing residual radioactivity to a level as low as is reasonably achievable

  10. Family Background and Educational Choices

    DEFF Research Database (Denmark)

    McIntosh, James; D. Munk, Martin

    enrollments, especially for females. Not only did the educational opportunities for individuals with disadvantaged backgrounds improve absolutely, but their relative position also improved. A similarly dramatic increase in attendance at university for the period 1985-2005 was found for these cohorts when......We examine the participation in secondary and tertiary education of five cohorts of Danish males and females who were aged twenty starting in 1982 and ending in 2002. We find that the large expansion of secondary education in this period was characterized by a phenomenal increase in gymnasium...

  11. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  12. The Cosmic Microwave Background Anisotropy

    Science.gov (United States)

    Bennett, C. L.

    1994-12-01

    The properties of the cosmic microwave background radiation provide unique constraints on the history and evolution of the universe. The first detection of anisotropy of the microwave radiation was reported by the COBE Team in 1992, based on the first year of flight data. The latest analyses of the first two years of COBE data are reviewed in this talk, including the amplitude of the microwave anisotropy as a function of angular scale and the statistical nature of the fluctuations. The two-year results are generally consistent with the earlier first year results, but the additional data allow for a better determination of the key cosmological parameters. In this talk the COBE results are compared with other observational anisotropy results and directions for future cosmic microwave anisotropy observations will be discussed. The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the Cosmic Background Explorer (COBE). Scientific guidance is provided by the COBE Science Working Group.

  13. Trace gases over Northern Eurasia: background level and disturbing factors

    Science.gov (United States)

    Skorokhod, A.; Shumsky, R.; Pankratova, N.; Moiseenko, K.; Vasileva, A.; Berezina, E.; Elansky, N.

    2012-04-01

    Atmospheric air composition over the vast and low inhabited areas of Northern Eurasia is still poorly studied because of lack of the precise direct measurements. This harms to accuracy of both global and regional models which simulate climatological and ecosystem changes in that highly important region. In this work background trace gases (such as O3, NO, NO2, CO) concentrations and their variability are considered on base of results of continuous measurements at ZOTTO station in the middle of Siberia which have been carried out since March, 2007. Also factors implying background regime (like long-range transport, wild fires emissions) are analyzed. To compliment study data of TROICA train-based campaigns which have been regularly provided across Russia for many years (1995-2010) are used. The concentration of ozone has a pronounced seasonal variation with a clear peak in spring (40-45 ppbv in average and up to 80 ppbv in extreme cases) and minimum in winter. Average ozone level is about 20 ppbv that corresponds to the background conditions. Enhanced concentration in March-July is due to increased stratospheric-tropospheric exchange. In autumn and winter distribution of ozone is close to uniform. Photochemical processes under low light and air temperature does not cause the generation of ozone. Sink on the snow surface is very small, and therefore the diurnal variations are absent. In general, seasonal variations correspond to the average seasonal course, which is typical for Russia. The analysis of diurnal ozone variations in Zotino in different seasons showed that the maximum rate of ozone formation is observed in summer from 9 to 15 h local time and is 1-2 ppbv/hour. It correlates well with the data on the isoprene emissions and others biogenic VOC reacting with OH- radical. Thus they are biogenic VOC emissions that seem to be the main factor of the lower troposphere oxidation power in summer. In other seasons it is significantly lower. NOx concentration does

  14. Natural background radiation exposures world-wide

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1993-01-01

    The average radiation dose to the world's population from natural radiation sources has been assessed by UNSCEAR to be 2.4 mSv per year. The components of this exposure, methods of evaluation and, in particular, the variations in the natural background levels are presented in this paper. Exposures to cosmic radiation range from 0.26 mSv per year at sea level to 20 times more at an altitude of 6000 m. Exposures to cosmogenic radionuclides ( 3 H, 14 C) are relatively insignificant and little variable. The terrestrial radionuclides 40 K, 238 U, and 232 Th and the decay products of the latter two constitute the remainder of the natural radiation exposure. Wide variations in exposure occur for these components, particularly for radon and its decay products, which can accumulate to relatively high levels indoors. Unusually high exposures to uranium and thorium series radionuclides characterize the high natural background areas which occur in several localized regions in the world. Extreme values in natural radiation exposures have been estimated to range up to 100 times the average values. (author). 15 refs, 3 tabs

  15. Estimation of thorium intake due to consumption of vegetables by inhabitants of high background radiation area by INAA

    International Nuclear Information System (INIS)

    Sathyapriya, R.S.; Suma Nair; Prabhath, R.K.; Madhu Nair; Rao, D.D.

    2012-01-01

    A study was conducted to estimate the thorium concentration in locally grown vegetables in high background radiation area (HBRA) of southern coastal regions of India. Locally grown vegetables were collected from HBRA of southern coastal regions of India. Thorium concentration was quantified using instrumental neutron activation analysis. The samples were irradiated at CIRUS reactor and counted using a 40% relative efficiency HPGe detector coupled to MCA. The annual intake of thorium was evaluated using the consumption data provided by National Nutrition Monitoring Board. The daily intake of 232 Th from the four food categories (green leafy vegetables, others vegetables, roots and tubers, and fruits) ranged between 0.27 and 5.352 mBq d -1 . The annual internal dose due to ingestion of thorium from these food categories was 46.8 x 10 -8 for female and 58.6 x 10 -8 Sv y -1 for male. (author)

  16. Low background techniques for SuperNEMO

    International Nuclear Information System (INIS)

    Liu, Xin Ran; Mott, James

    2015-01-01

    The UK contribution to achieving the ultra-low background conditions required inside the detectors of the SuperNEMO experiment are described. A dedicated facility has been established for the screening and selection of materials through gamma ray spectroscopy using germanium detectors. Initial results from two detectors are shown. The radon level inside the SuperNEMO detector must be less than 150 μBq/m 3 in order to achieve the target sensitivity. A Radon Concentration Line (RnCL) has been developed capable of measuring radon levels in large gas volumes down to 5 μBq/m 3 , improving on standard state-of-the-art radon detectors by 3 orders of magnitude. The development, commissioning and first measurements of radon content using the RnCL are also presented. (paper)

  17. Low background aspects of GERDA

    International Nuclear Information System (INIS)

    Simgen, Hardy

    2011-01-01

    The GERDA experiment operates bare Germanium diodes enriched in 76 Ge in an environment of pure liquid argon to search for neutrinoless double beta decay. A very low radioactive background is essential for the success of the experiment. We present here the research done in order to remove radio-impurities coming from the liquid argon, the stainless steel cryostat and the front-end electronics. We found that liquid argon can be purified efficiently from 222 Rn. The main source of 222 Rn in GERDA is the cryostat which emanates about 55 mBq. A thin copper shroud in the center of the cryostat was implemented to prevent radon from approaching the diodes. Gamma ray screening of radio-pure components for front-end electronics resulted in the development of a pre-amplifier with a total activity of less than 1 mBq 228 Th.

  18. The cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1980-01-01

    The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

  19. Polarization of Cosmic Microwave Background

    International Nuclear Information System (INIS)

    Buzzelli, A; Cabella, P; De Gasperis, G; Vittorio, N

    2016-01-01

    In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross- correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales. (paper)

  20. Exposure to background radiation in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Lab., Melbourne, VIC (Australia)

    1997-12-31

    The average effective dose received by the Australian population is estimated to be {approx}1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m{sup -3} in Queensland to 16 Bq m{sup -3} in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year. 9 refs., 2 tabs., 4 figs.

  1. Exposure to background radiation in Australia

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1997-01-01

    The average effective dose received by the Australian population is estimated to be ∼1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m -3 in Queensland to 16 Bq m -3 in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year

  2. Background compensation methodologies for contamination monitoring systems

    International Nuclear Information System (INIS)

    Raman, Anand; Chaudhury, Probal; Pradeepkumar, K.S.

    2014-01-01

    Radiation surveillance program in the various nuclear facilities incorporate contamination monitoring as an important component. Contamination monitoring programs constitute monitoring for alpha and beta contamination of the physical entities associated with the working personnel that include his hands, feet, clothing, shoes as well as the general surface areas in the working environment like floors. All these measurements are fraught with the contribution of the ambient gamma background radiation fields. These inhibit a proper and precise estimation of the contamination concentration being monitored. This paper investigates the efficacy of two methodologies that have been incorporated in two of the contamination monitoring systems developed in the Division. In the first system discussed, a high degree of gamma compensation has been achieved for an uniform exposure of the order of 50 nSv/hr to 100 mSv/hr. In the second system discussed, the degree of gamma compensation achieved is equal to those dictated by the statistical nature of the uncertainties associated with the subtraction of background from the source data. These two methods can be very effectively employed depending on the application requirement. A minimum detection level equivalent to 0.37 Bq/cdm 2 has been achieved in both these cases

  3. Zero modes in de Sitter background

    Energy Technology Data Exchange (ETDEWEB)

    Einhorn, Martin B. [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Jones, D.R. Timothy [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Dept. of Mathematical Sciences, University of Liverpool,Liverpool L69 3BX (United Kingdom)

    2017-03-28

    There are five well-known zero modes among the fluctuations of the metric of de Sitter (dS) spacetime. For Euclidean signature, they can be associated with certain spherical harmonics on the S{sup 4} sphere, viz., the vector representation 5 of the global SO(5) isometry. They appear, for example, in the perturbative calculation of the on-shell effective action of dS space, as well as in models containing matter fields. These modes are shown to be associated with collective modes of S{sup 4} corresponding to certain coherent fluctuations. When dS space is embedded in flat five dimensions E{sup 5}, they may be seen as a legacy of translation of the center of the S{sup 4} sphere. Rigid translations of the S{sup 4}-sphere on E{sup 5} leave the classical action invariant but are unobservable displacements from the point of view of gravitational dynamics on S{sup 4}. Thus, unlike similar moduli, the center of the sphere is not promoted to a dynamical degree of freedom. As a result, these zero modes do not signify the possibility of physically realizable fluctuations or flat directions for the metric of dS space. They are not associated with Killing vectors on S{sup 4} but can be identified with certain non-isometric, conformal Killing forms that locally correspond to a rescaling of the volume element dV{sub 4}. We frame much of our discussion in the context of renormalizable gravity, but, to the extent that they only depend upon the global symmetry of the background, the conclusions should apply equally to the corresponding zero modes found in Einstein gravity. Although their existence has only been demonstrated at one-loop, we expect that these zero modes will be present to all orders in perturbation theory. They will occur for Lorentzian signature as well, so long as the hyperboloid H{sup 4} is locally stable, but there remain certain infrared issues that need to be clarified. We conjecture that they will appear in any gravitational theory having dS background as a

  4. Interaction of Socio-Demographic Background Variables with Inter ...

    African Journals Online (AJOL)

    Interaction of Socio-Demographic Background Variables with Inter-Spousal Communication Among Married Couples in Alimosho Local Government Area of Lagos State, Nigeria. ... marriage will increase from 20-24years to 25-29years due to the number of years of couple's educational pursuit in Lagos state of Nigeria.

  5. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy

    2016-10-01

    Full Text Available Local content refers to materials and products made in a country as opposed those that are imported. There is an increasing interest in the concept of local content as a means of supporting local economies and providing jobs (Belderbos & Sleuwaegen...

  6. Plenoptic background oriented schlieren imaging

    International Nuclear Information System (INIS)

    Klemkowsky, Jenna N; Fahringer, Timothy W; Clifford, Christopher J; Thurow, Brian S; Bathel, Brett F

    2017-01-01

    The combination of the background oriented schlieren (BOS) technique with the unique imaging capabilities of a plenoptic camera, termed plenoptic BOS, is introduced as a new addition to the family of schlieren techniques. Compared to conventional single camera BOS, plenoptic BOS is capable of sampling multiple lines-of-sight simultaneously. Displacements from each line-of-sight are collectively used to build a four-dimensional displacement field, which is a vector function structured similarly to the original light field captured in a raw plenoptic image. The displacement field is used to render focused BOS images, which qualitatively are narrow depth of field slices of the density gradient field. Unlike focused schlieren methods that require manually changing the focal plane during data collection, plenoptic BOS synthetically changes the focal plane position during post-processing, such that all focal planes are captured in a single snapshot. Through two different experiments, this work demonstrates that plenoptic BOS is capable of isolating narrow depth of field features, qualitatively inferring depth, and quantitatively estimating the location of disturbances in 3D space. Such results motivate future work to transition this single-camera technique towards quantitative reconstructions of 3D density fields. (paper)

  7. Concerning background from calorimeter ports

    International Nuclear Information System (INIS)

    Digiacomo, N.J.

    1985-01-01

    Any detector system viewing a port or slit in a calorimeter wall will see, in addition to the primary particles of interest, a background of charged and neutral particles and photons generated by scattering from the port walls and by leakage from incompletely contained primary particle showers in the calorimeter near the port. The signal to noise ratio attainable outside the port is a complex function of the primary source spectrum, the calorimeter and port design and, of course, the nature and acceptance of the detector system that views the port. Rather than making general statements about the overall suitability (or lack thereof) of calorimeter ports, we offer here a specific example based on the external spectrometer and slit of the NA34 experiment. This combination of slit and spectrometer is designed for fixed-target work, so that the primary particle momentum spectrum contains higher momentum particles than expected in a heavy ion colliding beam environment. The results are, nevertheless, quite relevant for the collider case

  8. Establishing geochemical background levels of selected trace elements in areas having geochemical anomalies: The case study of the Orbetello lagoon (Tuscany, Italy)

    International Nuclear Information System (INIS)

    Romano, Elena; Bergamin, Luisa; Croudace, Ian W.; Ausili, Antonella; Maggi, Chiara; Gabellini, Massimo

    2015-01-01

    The determination of background concentration values (BGVs) in areas, characterised by the presence of natural geochemical anomalies and anthropogenic impact, appears essential for a correct pollution assessment. For this purpose, it is necessary to establish a reliable method for determination of local BGVs. The case of the Orbetello lagoon, a geologically complex area characterized by Tertiary volcanism, is illustrated. The vertical concentration profiles of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were studied in four sediment cores. Local BGVs were determined considering exclusively samples not affected by anthropogenic influence, recognized by means of multivariate statistics and radiochronological dating ( 137 Cs and 210 Pb). Results showed BGVs well-comparable with mean crustal or shale values for most of the considered elements except for Hg (0.87 mg/kg d.w.) and As (16.87 mg/kg d.w.), due to mineralization present in the catchment basin draining into the lagoon. - Highlights: • Pollution assessment in areas with geochemical anomalies needs local reference values. • A new method for the determination of background values (BGV) was established. • Geochemical data from unpolluted samples of sediment cores were used. • Statistics and geochronology were applied to recognize unpolluted sediments. • Anthropogenically influenced samples were not considered for BGV determination. - A method including multivariate statistics and radiochronological dating is proposed for determining local background values for trace elements using analytical data form sediment cores

  9. Concentrating Solar Power Systems

    Science.gov (United States)

    Pitz-Paal, R.

    2017-07-01

    Development of Concentrating Solar Power Systems has started about 40 years ago. A first commercial implementation was performed between 1985 and 1991 in California. However, a drop in gas prices caused a longer period without further deployment. It was overcome in 2007 when new incentive schemes for renewables in Spain and the US enabled a commercial restart. In 2016, almost 100 commercial CSP plants with more than 5GW are installed worldwide. This paper describes the physical background of CSP technology, its technical characteristics and concepts. Furthermore, it discusses system performances, cost structures and the expected advancement.

  10. Scientific background of the project

    International Nuclear Information System (INIS)

    Christofidis, I.

    1997-01-01

    The main objective of the proposed project is the development of radioimmunometric assay(s) for the determination of free and total PSA in serum samples from normal and pathological individuals (BPH, PCa). This will be achieved by: A. Selection of appropriate antibody pairs (capture and labelled antibody) for determination of total PSA (free and complex) and for determination of free PSA. From bibliography we have already spotted some antibody pairs. B. Radiolabelling of antibodies. Several labelling and purification procedures will be followed in order to obtain the required analytical sensitivity and dynamic range of the assays. Special attention will be given to the affinity constant as well as to the stability of the radiolabelled molecules. C. Development of protocols for immobilisation of capture antibodies. We will use several solid support formats (plastic tubes, beads and magnetizable particles). Direct adsorption or covalent binding will be used. Immunoadsorption through immobilised second antibody will be also tested in order to decrease the preparation cost of the solid phase reagents. D. Preparation of standards of suitable purity levels. We will test different PSA-free matrices (Bovine serum, buffer solutions etc.) in order to select the most appropriate among them in terms of low background determination and low reagents cost. E. Optimisation of the immunoassays conditions for the free PSA and total PSA (e.g. assay buffers, incubation time, temperature, one or two step procedure, washings). F. Optimisation and standardisation of assay protocols for kit production. G. Production of kits for distribution in clinical laboratories in Greece for comparison with commercial kits. H. Evaluation of the developed assays in real clinical conditions using well characterised human serum samples. This will be performed in co-operation with the Hellenic Society for Tumor Markers, and other anticancer institutions and hospital clinicians of long standing relation

  11. Observations and modeling of seismic background noise

    Science.gov (United States)

    Peterson, Jon R.

    1993-01-01

    deployed by the California Institute of Technology in cooperation with other institutions.A map showing the approximate locations of the stations used in this study is provided in Figure 1. One might hope for a better distribution of stations in the southern hemisphere, especially Africa and South America, in order to look for regional variations in seismic noise (apart from the major differences between continental, coastal and island sites). Unfortunately, anyone looking for subtle regional variations in seismic noise is probably going to be disappointed by the spectral data presented in this report because much of the station data appear to be dominated by local disturbances caused by instrumental, environmental, cultural, or surf noise. Better instruments and better instrument siting, or a well-funded field program, will be needed before a global isoseismal noise map can be produced. However, by assembling a composite of background noise from a large network of stations, many of the local station variables are masked, and it is possible to create generalized spectral plots of Earth noise for hypothetical quiet and noisy station sites.

  12. Gamma background irradiation. Standards and reality

    International Nuclear Information System (INIS)

    Miloslavov, V.

    1998-01-01

    The systematic deviation of the results of measuring the power of air dose absorbed from the natural gamma background radiation in Bulgaria is inadmissibly large and variable. This in turn augments the dispersion of results as well as the mean value relative to worldwide data, to an implausible level, hardly attributable to the variegated geographical relief of the country. Thus in practice local anthropogenic increases hardly lend themselves to detection and demonstration. In the Radiation Protection Standards (RPS-92) in effect in Bulgaria, and in other documents concerning the same radiation factors as well, the maximum allowable limits for the population as a whole are clearly specified on the basis of worldwide expertise along this line. As a rule these limits are being exceeded by the actually measured values, and for this reason the cited documents contain a clause stipulating that these limits do not refer to the natural radiation background and therefore the latter may be virtually ignored. Thus the basic risk factor for the population goes beyond control at levels commensurable with the officially established limits, its twofold increase inclusive. The maximum allowable limit becomes undefinable. Bearing in mind the fact that in compliance with the cited RPS-92 elimination of the technogenic ionizing radiation sources incorporated in the environment prior to 1992 is 'freezed', it is evident that exposure of the population to anthropogenic radiation becomes legally allowable in a much wider range than the one specified by world legislators. One may anticipate radiation induced health noxae for the population directly or by anthropogenic radiation stress on biocenosis. A relatively large part of the population is susceptible to the effect of low radiation doses. Presumably this contingent will augment as a result of eventual fluctuations. The casual relationship which is difficult to establish should be given due consideration in the analysis of the causes

  13. Radon exhalation rate and natural radionuclide content in building materials of high background areas of Ramsar, Iran

    International Nuclear Information System (INIS)

    Bavarnegin, E.; Fathabadi, N.; Vahabi Moghaddam, M.; Vasheghani Farahani, M.; Moradi, M.; Babakhni, A.

    2013-01-01

    Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m −2 h −1 . The 226 Ra, 232 Th and 40 K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of 226 Ra, 232 Th and 40 K content varied from below the minimum detection limit up to 86,400 Bq kg −1 , 187 Bq kg −1 and 1350 Bq kg −1 , respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. -- Highlights: ► In the selection process of local samples, portable scintillometer (NaI) was used. ► The activity concentration of 226 Ra varied from below the MDL up to 86400 Bq kg −1 . ► The activity concentration of 232 Th varied from below the MDL up to 187 Bq kg −1 . ► The activity concentration of 40 K varied from below the MDL up to 1350 Bq kg −1

  14. Prospects for the direct detection of the cosmic neutrino background

    International Nuclear Information System (INIS)

    Ringwald, Andreas

    2009-01-01

    The existence of a cosmic neutrino background - the analogue of the cosmic microwave background - is a fundamental prediction of standard big bang cosmology. Up to now, the observational evidence for its existence is rather indirect and rests entirely on cosmological observations of, e.g., the light elemental abundances, the anisotropies in the cosmic microwave background, and the large scale distribution of matter. Here, we review more direct, weak interaction based detection techniques for the cosmic neutrino background in the present epoch and in our local neighbourhood. We show that, with current technology, all proposals are still off by some orders of magnitude in sensitivity to lead to a guaranteed detection of the relic neutrinos. The most promising laboratory search, based on neutrino capture on beta decaying nuclei, may be done in future experiments designed to measure the neutrino mass through decay kinematics.

  15. On the background independence of two-dimensional topological gravity

    Science.gov (United States)

    Imbimbo, Camillo

    1995-04-01

    We formulate two-dimensional topological gravity in a background covariant Lagrangian framework. We derive the Ward identities which characterize the dependence of physical correlators on the background world-sheet metric defining the gauge-slice. We point out the existence of an "anomaly" in Ward identitites involving correlators of observables with higher ghost number. This "anomaly" represents an obstruction for physical correlators to be globally defined forms on moduli space which could be integrated in a background independent way. Starting from the anomalous Ward identities, we derive "descent" equations whose solutions are cocycles of the Lie algebra of the diffeomorphism group with values in the space of local forms on the moduli space. We solve the descent equations and provide explicit formulas for the cocycles, which allow for the definition of background independent integrals of physical correlators on the moduli space.

  16. Prospects for the direct detection of the cosmic neutrino background

    International Nuclear Information System (INIS)

    Ringwald, Andreas

    2009-01-01

    The existence of a cosmic neutrino background - the analogue of the cosmic microwave background - is a fundamental prediction of standard big bang cosmology. Up to now, the observational evidence for its existence is rather indirect and rests entirely on cosmological observations of, e.g., the light elemental abundances, the anisotropies in the cosmic microwave background, and the large scale distribution of matter. Here, we review more direct, weak interaction based detection techniques for the cosmic neutrino background in the present epoch and in our local neighbourhood. We show that, with current technology, all proposals are still off by some orders of magnitude in sensitivity to lead to a guaranteed detection of the relic neutrinos. The most promising laboratory search, based on neutrino capture on beta decaying nuclei, may be done in future experiments designed to measure the neutrino mass through decay kinematics. (orig.)

  17. Natural background radiation in Canada

    International Nuclear Information System (INIS)

    Grasty, R.L.; Carson, J.M.; Charbonneau, B.W.; Holman, P.B.

    1984-01-01

    Published airborne gamma ray survey data from 33 areas of Canada were used to compile information on the average ground level exposure from natural radiation. The exposures at ground level were calculated from the surface concentrations of potassium, uranium and thorium. The highest levels of radioactivity were found in northern Canada and were generally related to granitic rocks; the lowest levels with the Athabasca sandstone. Summer outdoor exposure rates have a population-weighted average of 3.7 +- 2.3 μR.h -1 , of which 48 percent orginated from potassium, 43 percent from the thorium series and 9 percent from the uranium series. This low level of radioactivity, compared to worldwide data, has resulted from erosion of a geologically old continental crust in which radioactivity decreases with depth. When seasonal variations of soil moisture and snow cover are considered, the annual population-weighted average outdoor exposure rate decreases to 2.8 +- 1.7 μR.h -1 corresponding to an annual outdoor dose-equivalent of 150 +- 90 μSV. Factors increasing the annual outdoor dose-equivalent are cosmic radiation (320 +- 30 μSV) and the internal radioactivity of the body (190 μSV). Using the ratio between indoor and outdoor values for worldwide published data, the average annual Canadian whole-body dose-equivalent from all sources of natural radiation is estimated to be 690 +-130 μSV

  18. German Undergraduate Mathematics Enrolment Numbers: Background and Change

    Science.gov (United States)

    Ammann, Claudia; Frauendiener, Jorg; Holton, Derek

    2010-01-01

    Before we consider the German tertiary system, we review the education system and consider other relevant background details. We then concentrate on the tertiary system and observe that the mathematical enrolments are keeping up with the overall student enrolments. At the same time, the first year mathematics enrolments for women are greater than…

  19. Neutron therapy: The historical background

    International Nuclear Information System (INIS)

    Svensson, H.; Landberg, T.

    1994-01-01

    Neutron therapy was first introduced by Stone et al. in 1938, i.e. more than 10 years earlier than electron beam therapy and only 6 years after the discovery of neutrons. In spite of the impressive accomplishment in generating an adequate therapy beam, time was also found for careful radiobiological studies of neutron beams. However, it was not considered that for a certain early reaction the late effects were much greater with neutrons than with X-rays. The severe late sequelae in proportion to the few good results motivated the closure of this therapy. Neutron therapy was again introduced in Hammersmith hospital at the end of the 1960's. The major reason seems to have been to overcome the oxygen effect. Encouraging results were reported. It was argued that the very favourable statistics on local tumour control were obtained at the expense of more frequent and more severe complications. A clinical trial in Edinburgh seemed to indicate this, but it was not proved in the end as the two trials differed regarding fractionation. Today about 16000 patients have been treated with neutrons. The neutron beams now used differ significantly, both regarding dose distributions and microdosimetrical properties, from those utilized earlier. The advantage of neutrons is still, however, controversial. There are indications that neutron treatment may be favourable for some tumours. A careful cost-benefit study ought to be performed before the creation of a neutron therapy centre in Sweden as the group of patients suitable for neutrons is limited, and there may be new possibilities for improvement of photon and electron treatment with much smaller resources. (orig.)

  20. Preparation of 'dead water' for low background liquid scintillation counting

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Kawai, Hiroshi

    1987-01-01

    'Dead water', low level tritiated water is indispensable to measure tritium concentration in environmental waters using a low background liquid scintillation counter. Water produced by combustion of natural gas, or deep sea water etc. are usually used for the above purpose. A new method of reducing tritium concentration in natural water has been introduced for preparation of 'dead water'. This method is to combine hydrogen-oxygen mixture produced by water electrolysis with hopcalite catalyzer at 700 deg C. Deep well water was electrolized up to 2/3 volume, and tritium concentration of recombined water was reduced to be about one third of that of the original one. (author)

  1. Concerning evaluation of eco-geochemical background in remediation strategy

    Science.gov (United States)

    Korobova, Elena; Romanov, Sergey

    2015-04-01

    The geochemical concept of biosphere developed by V.I. Vernadsky states the geological role of the living organisms in the course of their active chemical interaction with the inert matter (Vernadsky, 1926, 1960). Basing on this theory it is reasonable to suggest that coevolution of living organisms and their environment led to development of the dynamically stable biogeocenoses precisely adequate to their geochemical environment. Soil cover was treated by V.I. Vernadsky as a balanced bio-inert matter resulting from this interaction. Appearance of human mind and then a civilization led to global expansion of human beings, first able to survive in unfavorable geochemical conditions and then starting chemical transformation of the environment to satisfy the growing demands of mankind in food and energy. The residence in unfavorable environment and local contamination was followed by appearance of endemic diseases of plants, animals and man. Therefore zonal, regional and local chemical composition of the soil cover formed in natural conditions may be used for estimation of the optimum geochemical background, most adequate for the corresponding zonal biogeocenoses and species. Moreover, the natural geochemical background and technogenic fields have unequal spatial structure and this facilitates their identification that may be relatively easy realized in remediation strategy. On the assumption of the foregoing, the adequate methodical approach to remediation of technogenically affected areas should account of the interaction of the existing natural and the newly formed technogenic geochemical fields and include the following steps: 1) the study and mapping of geochemical structure of the natural geochemical background basing on soil maps; 2) the study of contaminants and mapping spatial distribution of technogenic releases; 3) construction of risk maps for the target risk groups with due regard to natural ecological threshold concentration in context of risk degree for

  2. Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

    Science.gov (United States)

    Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant

  3. Concentrating Solar Power Projects - Khi Solar One | Concentrating Solar

    Science.gov (United States)

    Power | NREL Khi Solar One This page provides information on Khi Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: February 8, 2016 Project Overview Project Name: Khi Solar One Country: South Africa Location

  4. Development of background reduced Fresnel phase zone plate

    International Nuclear Information System (INIS)

    Tamari, Yohei; Azechi, Hiroshi

    2004-01-01

    In study of hot and dense plasma, a high spatial resolution (a few microns) x-ray imaging is very important to observe these plasmas. The Fresnel phase zone plate (FPZP) consists of alternately material and transparent circular annuli placed concentrically, which image x rays using diffraction x rays from all annuli. FPZP have imaged 4.7-4.77 keV x rays with 2.2 μm spatial resolution. However FPZP has a problem that background level is comparable to signal level. In subtraction of background, the error of 10% is caused. For the accurate background subtraction, we designed new FPZP, which consist of three β layers of a transparent zone and two material zones. The new design FPZP parameters (thickness of material zones, each zone width) have been optimized, and in that optimum design signal-to-background ratio is 4 times better than conventional two layers FPZP

  5. Foreground-background segmentation and attention: a change blindness study.

    Science.gov (United States)

    Mazza, Veronica; Turatto, Massimo; Umiltà, Carlo

    2005-01-01

    One of the most debated questions in visual attention research is what factors affect the deployment of attention in the visual scene? Segmentation processes are influential factors, providing candidate objects for further attentional selection, and the relevant literature has concentrated on how figure-ground segmentation mechanisms influence visual attention. However, another crucial process, namely foreground-background segmentation, seems to have been neglected. By using a change blindness paradigm, we explored whether attention is preferentially allocated to the foreground elements or to the background ones. The results indicated that unless attention was voluntarily deployed to the background, large changes in the color of its elements remained unnoticed. In contrast, minor changes in the foreground elements were promptly reported. Differences in change blindness between the two regions of the display indicate that attention is, by default, biased toward the foreground elements. This also supports the phenomenal observations made by Gestaltists, who demonstrated the greater salience of the foreground than the background.

  6. Simulation of off-energy electron background in DELPHI

    CERN Document Server

    Falk, E; Von Holtey, Georg

    1997-01-01

    Monte Carlo simulations of off-energy electron background in the DELPHI luminometer STIC are reported. The study simulates the running conditions at 68 GeV with and without bunch trains. The electrostatic separators, which create the vertical separation bumps for the the bunch trains, cause a high concentration of background in the vertical plane. The simulations are compared to LEP data taken under similar running conditions. A comparison between the simulated running conditions at 68 GeV and those of the new LEP2 beam optics at 80.5 GeV is made. Moreover, the study investigates background components entering STIC elsewhere that through the front of the detector, and a significant portion is found to enter either from the back or from below. Possible improvements of the background situation are also discussed.

  7. An empirical model for predicting urban roadside nitrogen dioxide concentrations in the UK

    International Nuclear Information System (INIS)

    Stedman, J.R.; Goodwin, J.W.L.; King, K.; Murrells, T.P.; Bush, T.J.

    2001-01-01

    An annual mean concentration of 40μgm -3 has been proposed as a limit value within the European Union Air Quality Directives and as a provisional objective within the UK National Air Quality Strategy for 2010 and 2005, respectively. Emissions reduction measures resulting from current national and international policies are likely to deliver significant reductions in emissions of oxides of nitrogen from road traffic in the near future. It is likely that there will still be exceedances of this target value in 2005 and in 2009 if national measures are considered in isolation, particularly at the roadside. It is envisaged that this 'policy gap' will be addressed by implementing local air quality management to reduce concentrations in locations that are at risk of exceeding the objective. Maps of estimated annual mean NO 2 concentrations in both urban background and roadside locations are a valuable resource for the development of UK air quality policy and for the identification of locations at which local air quality management measures may be required. Maps of annual mean NO 2 concentrations at both background and roadside locations for 1998 have been calculated using modelling methods, which make use of four mathematically straightforward, empirically derived linear relationships. Maps of projected concentrations in 2005 and 2009 have also been calculated using an illustrative emissions scenario. For this emissions scenario, annual mean urban background NO 2 concentrations in 2005 are likely to be below 40μgm -3 , in all areas except for inner London, where current national and international policies are expected to lead to concentrations in the range 40-41μgm -3 . Reductions in NO x emissions between 2005 and 2009 are expected to reduce background concentrations to the extent that our modelling results indicate that 40μgm -3 is unlikely to be exceeded in background locations by 2009. Roadside NO 2 concentrations in urban areas in 2005 and 2009 are expected to be

  8. Background suppression of infrared small target image based on inter-frame registration

    Science.gov (United States)

    Ye, Xiubo; Xue, Bindang

    2018-04-01

    We propose a multi-frame background suppression method for remote infrared small target detection. Inter-frame information is necessary when the heavy background clutters make it difficult to distinguish real targets and false alarms. A registration procedure based on points matching in image patches is used to compensate the local deformation of background. Then the target can be separated by background subtraction. Experiments show our method serves as an effective preliminary of target detection.

  9. The Role of Local Government in Evictions

    Directory of Open Access Journals (Sweden)

    J van Wyk

    2011-06-01

    Full Text Available Local government occupies a unique place in the South African system of government. This is circumscribed by the Constitution which contains directives. Enjoining municipalities inter alia to provide democratic and accountable government for local communities and to promote social and economic development (section 152 as well as to undertake developmentally-oriented planning (section 153. In addition local government has a specific role to play regarding access to adequate housing and, in that context, evictions. In terms of sections 25 and 26 of the Constitution as well as legislation enacted in terms of these provisions new and different procedures have been put in place to demarcate the role of municipalities in evictions. The interpretation, by the courts, of these legislative provisions, has created a framework within which municipalities must react to and deal with evictions. In terms of that framework a number of duties and responsibilities are placed on municipalities, which include that they do the following: have policies, actions and programmes in place, draw up proper housing plans, be notified of evictions, mediate and engage with all stakeholders and provide temporary - and suitable alternative - accommodation of a specific standard, all of which must be consistent with principles of human dignity and be reasonable. Against this background this paper will interrogate the role of local government in evictions, concentrating on the constitutional directives for municipalities, the different eviction procedures and the duties and responsibilities of municipalities.

  10. Non-renormalization theorems andN=2 supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Butter, Daniel; Wit, Bernard de; Lodato, Ivano

    2014-01-01

    The conditions for fully supersymmetric backgrounds of general N = 2 locally supersymmetric theories are derived based on the off-shell superconformal multiplet calculus. This enables the derivation of a non-renormalization theorem for a large class of supersymmetric invariants with higher-derivative couplings. The theorem implies that the invariant and its first order variation must vanish in a fully supersymmetric background. The conjectured relation of one particular higher-derivative invariant with a specific five-dimensional invariant containing the mixed gauge-gravitational Chern-Simons term is confirmed

  11. Integrated wide-band low-background amplifiers

    International Nuclear Information System (INIS)

    Il'yushchenko, I.I.

    1980-01-01

    Ways of increasing stability and reproduction of characteristics of wide-band integral amplifiers that would to the least extent increase their background noises, are discussed. Considered are some certain flowsheets of integral wide-band amplifiers with low background noise of foreign production which differ from one another by construction of inlet cascades as well as by the applied feedback type. The principal flowsheets of the amplifiers and their main performances are presented. The analysis of the data obtained has revealed that microcircuits made of cascades with a common emitter and local combined feedback are most wide-band among all the considered microcircuits [ru

  12. Correlation between galactic HI and the cosmic microwave background

    International Nuclear Information System (INIS)

    Land, Kate; Slosar, Anze

    2007-01-01

    We revisit the issue of a correlation between the atomic hydrogen gas in our local galaxy and the cosmic microwave background, a detection of which has been claimed in some literature. We cross correlate the 21-cm emission of galactic atomic hydrogen as traced by the Leiden/Argentine/Bonn Galactic Hi survey with the 3-year cosmic microwave background data from the Wilkinson microwave anisotropy probe. We consider a number of angular scales, masks, and Hi velocity slices and find no statistically significant correlation

  13. A digital local studies collection

    Directory of Open Access Journals (Sweden)

    Simona Resman

    2005-01-01

    Full Text Available Local studies and local studies departments reflect the entire spectrum of knowledge within the local community. Transition to the new digital environment means just continuing the basic functions of local studies collections: acquisition, cataloguing and preservation of materials in different formats on different media. The background of each digital library is the technical architecture of system that enables interaction between the user and the library, saving digital material and building a platform for searching and indexing digital objects. Using advanced ICT requests from librarians, designers of digital local studies collections a reflection about traditional roles. A digital local studies collection with new technology enlarges local boarders, local contents become more and more interesting for a wider sphere of people. In collecting of local materials a collaboration with archives and museums, with academic community, with community groups and with individuals comes in forefront. Digital local studies collections with their contents support local diversity, lifelong learning and social inclusion. The crucial elements of a digital local studies collection are attractive local contents with fast and simple access from one place – a portal. In the digital age public libraries become managers of knowledge also by establishing digital local studies collections.

  14. Ground Level Ozone Regional Background Characteristics In North-west Pacific Rim

    Science.gov (United States)

    Chiang, C.; Fan, J.; Chang, J. S.

    2007-12-01

    Understanding the ground level ozone regional background characteristics is essential in understanding the contribution of long-range transport of pollutants from Asia Mainland to air quality in downwind areas. In order to understand this characteristic in north-west Pacific Rim, we conducted a coupled study using ozone observation from regional background stations and 3-D regional-scale chemical transport model simulations. We used O3, CO, wind speed and wind direction data from two regional background stations and ¡§other stations¡¨ over a ten year period and organized several numerical experiments to simulate one spring month in 2003 to obtain a deeper understanding. The so called ¡§other stations¡¨ had actually been named as background stations under various governmental auspices. But we found them to be often under strong influence of local pollution sources with strong diurnal or slightly longer time variations. We found that the Yonagunijima station (24.74 N, 123.02 E) and Heng-Chuen station (21.96 N,120.78 E), about a distance of 400 km apart, have almost the same ozone time series pattern. For these two stations in 2003, correlation coefficients (R2) for annual observed ozone concentration is about 0.64, in the springtime it is about 0.7, and in a one-month period at simulation days it is about 0.76. These two stations have very little small scale variations in all the variables studied. All variations are associated with large scale circulation changes. This is especially so at Yonagunijima station. Using a 3-D regional-scale chemical transport model for East Asia region including contribution from Asia continental outflow and neighboring island pollution areas we found that the Yonagunijima and HengChuen station are indeed free of pollutants from all neighboring areas keeping in mind that pollutants from Taiwan area is never far away. Ozone concentrations in these two stations are dominated by synoptic scale weather patterns, with diffused

  15. Geostatistics as a tool to improve the natural background level definition: An application in groundwater.

    Science.gov (United States)

    Dalla Libera, Nico; Fabbri, Paolo; Mason, Leonardo; Piccinini, Leonardo; Pola, Marco

    2017-11-15

    The Natural Background Level (NBL), suggested by UE BRIDGE project, is suited for spatially distributed datasets providing a regional value that could be higher than the Threshold Value (TV) set by every country. In hydro-geochemically dis-homogeneous areas, the use of a unique regional NBL, higher than TV, could arise problems to distinguish between natural occurrences and anthropogenic contaminant sources. Hence, the goal of this study is to improve the NBL definition employing a geostatistical approach, which reconstructs the contaminant spatial structure accounting geochemical and hydrogeological relationships. This integrated mapping is fundamental to evaluate the contaminant's distribution impact on the NBL, giving indications to improve it. We decided to test this method on the Drainage Basin of Venice Lagoon (DBVL, NE Italy), where the existing NBL is seven times higher than the TV. This area is notoriously affected by naturally occurring arsenic contamination. An available geochemical dataset collected by 50 piezometers was used to reconstruct the spatial distribution of arsenic in the densely populated area of the DBVL. A cokriging approach was applied exploiting the geochemical relationships among As, Fe and NH4+. The obtained spatial predictions of arsenic concentrations were divided into three different zones: i) areas with an As concentration lower than the TV, ii) areas with an As concentration between the TV and the median of the values higher than the TV, and iii) areas with an As concentration higher than the median. Following the BRIDGE suggestions, where enough samples were available, the 90th percentile for each zone was calculated to obtain a local NBL (LNBL). Differently from the original NBL, this local value gives more detailed water quality information accounting the hydrogeological and geochemical setting, and contaminant spatial variation. Hence, the LNBL could give more indications about the distinction between natural occurrence and

  16. Supersymmetric Yang-Mills theory on conformal supergravity backgrounds in ten dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Paul de; Figueroa-O’Farrill, José [Maxwell Institute and School of Mathematics, The University of Edinburgh,James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD (United Kingdom)

    2016-03-14

    We consider bosonic supersymmetric backgrounds of ten-dimensional conformal supergravity. Up to local conformal isometry, we classify the maximally supersymmetric backgrounds, determine their conformal symmetry superalgebras and show how they arise as near-horizon geometries of certain half-BPS backgrounds or as a plane-wave limit thereof. We then show how to define Yang-Mills theory with rigid supersymmetry on any supersymmetric conformal supergravity background and, in particular, on the maximally supersymmetric backgrounds. We conclude by commenting on a striking resemblance between the supersymmetric backgrounds of ten-dimensional conformal supergravity and those of eleven-dimensional Poincaré supergravity.

  17. Effect of high-volume systematic local infiltration analgesia in Caesarean section

    DEFF Research Database (Denmark)

    Larsen, Klaus Richter; Kristensen, B B; Rasmussen, M A

    2015-01-01

    BACKGROUND: Pain after Caesarean section is often treated with opioids with a risk of side effects. Wound infiltration with local anaesthetics is effective and has few side effects, but volume vs. dose concentration has not been examined. METHODS: Ninety patients scheduled for elective Caesarean...... found concerning time spent in the PACU, to first mobilisation or in number of women with nausea/vomiting (P ≥ 0.05). No complications related to ropivacaine were observed. CONCLUSIONS: Systematic infiltration with a high concentration, low volume compared with low concentration, high volume showed...

  18. Localized superconductors

    International Nuclear Information System (INIS)

    Ma, M.; Lee, P.A.

    1985-01-01

    We study the effects of Anderson localization on superconductivity by using a Bardeen-Cooper-Schrieffer (BCS)-type trial wave function which pairs electrons in exact time-reversed eigenstates of the single-particle Hamiltonian. Within this approximation, and neglecting localization effects on the effective Coulomb repulsion and the electron-phonon coupling, we find that superconductivity persists below the mobility edge. In fact, Anderson's theorem is valid in the localized phase as long as rhoΔ 0 L/sup d/ > 1 (rho is the density of states averaged over +- Δ 0 of the Fermi energy, Δ 0 the BCS gap parameter, and L the localization length). Hence the gap order parameter Δ(r) remains uniform in space at the BCS value Δ 0 . The superfluid density and response to electromagnetic perturbations, however, show marked differences from the ''dirty superconductor'' regime. For rhoΔ 0 L/sup d/ < 1, Δ(r) fluctuates spatially and eventually drops to zero. In the limit when states are site localized, the system crosses over into the ''Anderson negative-U glass.'' Considerations beyond the trial wave-function approximation will speed up the destruction of superconductivity. The superconductor formed from localized states has the property that its quasiparticle excitations are also localized. Such excitations can be probed by observing the normal current in a tunneling junction

  19. Microfabricated Collector-Generator Electrode Sensor for Measuring Absolute pH and Oxygen Concentrations.

    Science.gov (United States)

    Dengler, Adam K; Wightman, R Mark; McCarty, Gregory S

    2015-10-20

    Fast-scan cyclic voltammetry (FSCV) has attracted attention for studying in vivo neurotransmission due to its subsecond temporal resolution, selectivity, and sensitivity. Traditional FSCV measurements use background subtraction to isolate changes in the local electrochemical environment, providing detailed information on fluctuations in the concentration of electroactive species. This background subtraction removes information about constant or slowly changing concentrations. However, determination of background concentrations is still important for understanding functioning brain tissue. For example, neural activity is known to consume oxygen and produce carbon dioxide which affects local levels of oxygen and pH. Here, we present a microfabricated microelectrode array which uses FSCV to detect the absolute levels of oxygen and pH in vitro. The sensor is a collector-generator electrode array with carbon microelectrodes spaced 5 μm apart. In this work, a periodic potential step is applied at the generator producing transient local changes in the electrochemical environment. The collector electrode continuously performs FSCV enabling these induced changes in concentration to be recorded with the sensitivity and selectivity of FSCV. A negative potential step applied at the generator produces a transient local pH shift at the collector. The generator-induced pH signal is detected using FSCV at the collector and correlated to absolute solution pH by postcalibration of the anodic peak position. In addition, in oxygenated solutions a negative potential step at the generator produces hydrogen peroxide by reducing oxygen. Hydrogen peroxide is detected with FSCV at the collector electrode, and the magnitude of the oxidative peak is proportional to absolute oxygen concentrations. Oxygen interference on the pH signal is minimal and can be accounted for with a postcalibration.

  20. Influence of background particulate matter (PM) on urban air quality in the Pacific Northwest.

    Science.gov (United States)

    Timonen, H; Wigder, N; Jaffe, D

    2013-11-15

    Elevated particulate matter concentrations due to Asian long-range transport (LRT) are frequently observed in the free troposphere (FT) above the Pacific Northwest, U.S. Transport of this aerosol from the FT to the boundary layer (BL) and its effect to local air quality remain poorly constrained. We used data collected at the Mount Bachelor observatory (MBO, 2.8 km a.s.l) and from ground stations in the Pacific Northwest to study transport of fine particulate matter (PM) from the FT to the BL. During Asian LRT episodes PM concentrations were clearly elevated above the corresponding monthly averages at MBO as well as at low elevation sites across Washington and Oregon. Also, a clear correlation between MBO and low elevation sites was observed, indicating that LRT episodes are seen in both the FT and BL. In addition, drum impactor measurements show that the chemical composition of PM at MBO was similar to that measured at the BL sites. Using a simple regression model, we estimate that during springtime, when the transport from Asia is most effective, the contribution of Asian sources to PM2.5 in clean background areas of the Pacific Northwest was on average 1.7 μg m(-3) (representing approximately 50-80% of PM). The influence of LRT PM was also seen in measurement stations situated in the urban and urban background areas. However, the fraction of LRT PM was less pronounced (36-50% of PM) due to larger local emissions in the urban areas. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Local variances in biomonitoring

    International Nuclear Information System (INIS)

    Wolterbeek, H.Th; Verburg, T.G.

    2001-01-01

    The present study was undertaken to explore possibilities to judge survey quality on basis of a limited and restricted number of a-priori observations. Here, quality is defined as the ratio between survey and local variance (signal-to-noise ratio). The results indicate that the presented surveys do not permit such judgement; the discussion also suggests that the 5-fold local sampling strategies do not merit any sound judgement. As it stands, uncertainties in local determinations may largely obscure possibilities to judge survey quality. The results further imply that surveys will benefit from procedures, controls and approaches in sampling and sample handling, to assess both average, variance and the nature of the distribution of elemental concentrations in local sites. This reasoning is compatible with the idea of the site as a basic homogeneous survey unit, which is implicitly and conceptually underlying any survey performed. (author)

  2. Diffusion of ion-implanted B in high concentration P- and As-doped silicon

    International Nuclear Information System (INIS)

    Fair, R.B.; Pappas, P.N.

    1975-01-01

    The diffusion of ion-implanted B in Si in the presence of a uniform background of high concentration P or As was studied by correlating numerical profile calculations with profiles determined by secondary-ion mass spectrometry (SIMS). Retarded B diffusion is observed in both As- and P-doped Si, consistent with the effect of the local Fermi-level position in the Si band gap on B diffusivity, D/sub B/. It is shown that D/sub B/ is linearly dependent on the free hole concentration, p, over the range 0.1 less than p/n/sub ie/ less than 30, where n/sub ie/ is the effective intrinsic electron concentration. This result does not depend on the way in which the background dopant has been introduced (implantation predeposition or doped-oxide source), nor the type of dopant used (P or As). (U.S.)

  3. Nonrelativistic fluids on scale covariant Newton-Cartan backgrounds

    Science.gov (United States)

    Mitra, Arpita

    2017-12-01

    The nonrelativistic covariant framework for fields is extended to investigate fields and fluids on scale covariant curved backgrounds. The scale covariant Newton-Cartan background is constructed using the localization of space-time symmetries of nonrelativistic fields in flat space. Following this, we provide a Weyl covariant formalism which can be used to study scale invariant fluids. By considering ideal fluids as an example, we describe its thermodynamic and hydrodynamic properties and explicitly demonstrate that it satisfies the local second law of thermodynamics. As a further application, we consider the low energy description of Hall fluids. Specifically, we find that the gauge fields for scale transformations lead to corrections of the Wen-Zee and Berry phase terms contained in the effective action.

  4. Localized Scleroderma

    Science.gov (United States)

    ... How Is Localized Scleroderma Diagnosed? Doctors who are familiar with scleroderma, or who are experts at examining ... systemic treatment with a medication or other treatment interventions (for example, ultraviolet light), are reserved for more ...

  5. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  6. Florida's ground water quality monitoring program: background hydrogeochemistry

    OpenAIRE

    Maddox, Gary; Upchurch, Sam; Lloyd, Jacqueline; Scott, Tom

    1992-01-01

    The purpose of this report is to present the results of the initial quantification of background water quality in each of the state's major potable aquifer systems. Results are presented and interpreted in light of the influencing factors which locally and regionally affect ambient ground-water quality. This initial data will serve as a baseline from which future sampling results can be compared. Future sampling of the Network will indicate the extent to which Flori...

  7. Origin and variability in volatile organic compounds observed at an Eastern Mediterranean background site (Cyprus)

    Science.gov (United States)

    Debevec, Cécile; Sauvage, Stéphane; Gros, Valérie; Sciare, Jean; Pikridas, Michael; Stavroulas, Iasonas; Salameh, Thérèse; Leonardis, Thierry; Gaudion, Vincent; Depelchin, Laurence; Fronval, Isabelle; Sarda-Esteve, Roland; Baisnée, Dominique; Bonsang, Bernard; Savvides, Chrysanthos; Vrekoussis, Mihalis; Locoge, Nadine

    2017-09-01

    More than 7000 atmospheric measurements of over 60 C2 - C16 volatile organic compounds (VOCs) were conducted at a background site in Cyprus during a 1-month intensive field campaign held in March 2015. This exhaustive dataset consisted of primary anthropogenic and biogenic VOCs, including a wide range of source-specific tracers, and oxygenated VOCs (with various origins) that were measured online by flame ionization detection-gas chromatography and proton transfer mass spectrometry. Online submicron aerosol chemical composition was performed in parallel using an aerosol mass spectrometer. This study presents the high temporal variability in VOCs and their associated sources. A preliminary analysis of their time series was performed on the basis of independent tracers (NO, CO, black carbon), meteorological data and the clustering of air mass trajectories. Biogenic compounds were mainly attributed to a local origin and showed compound-specific diurnal cycles such as a daily maximum for isoprene and a nighttime maximum for monoterpenes. Anthropogenic VOCs as well as oxygenated VOCs displayed higher mixing ratios under the influence of continental air masses (i.e., western Asia), indicating that long-range transport significantly contributed to the VOC levels in the area. Source apportionment was then conducted on a database of 20 VOCs (or grouped VOCs) using a source receptor model. The positive matrix factorization and concentration field analyses were hence conducted to identify and characterize covariation factors of VOCs that were representative of primary emissions as well as chemical transformation processes. A six-factor PMF solution was selected, namely two primary biogenic factors (relative contribution of 43 % to the total mass of VOCs) for different types of emitting vegetation; three anthropogenic factors (short-lived combustion source, evaporative sources, industrial and evaporative sources; 21 % all together), identified as being either of local origin

  8. Spatial & temporal variations of PM10 and particle number concentrations in urban air.

    Science.gov (United States)

    Johansson, Christer; Norman, Michael; Gidhagen, Lars

    2007-04-01

    The size of particles in urban air varies over four orders of magnitude (from 0.001 microm to 10 microm in diameter). In many cities only particle mass concentrations (PM10, i.e. particles tires and traction sand on streets during winter; up to 90% of the locally emitted PM10 may be due to road abrasion. PM10 emissions and concentrations, but not PNC, at kerbside are controlled by road moisture. Annual mean urban background PM10 levels are relatively uniformly distributed over the city, due to the importance of long range transport. For PNC local sources often dominate the concentrations resulting in large temporal and spatial gradients in the concentrations. Despite these differences in the origin of PM10 and PNC, the spatial gradients of annual mean concentrations due to local sources are of equal magnitude due to the common source, namely traffic. Thus, people in different areas experiencing a factor of 2 different annual PM10 exposure due to local sources will also experience a factor of 2 different exposure in terms of PNC. This implies that health impact studies based solely on spatial differences in annual exposure to PM10 may not separate differences in health effects due to ultrafine and coarse particles. On the other hand, health effect assessments based on time series exposure analysis of PM10 and PNC, should be able to observe differences in health effects of ultrafine particles versus coarse particles.

  9. Source contributions to PM2.5 and PM10 at an urban background and a street location

    Science.gov (United States)

    Keuken, M. P.; Moerman, M.; Voogt, M.; Blom, M.; Weijers, E. P.; Röckmann, T.; Dusek, U.

    2013-06-01

    The contribution of regional, urban and traffic sources to PM2.5 and PM10 in an urban area was investigated in this study. The chemical composition of PM2.5 and PM10 was measured over a year at a street location and up- and down-wind of the city of Rotterdam, the Netherlands. The 14C content in EC and OC concentrations was also determined, to distinguish the contribution from "modern" carbon (e.g., biogenic emissions, biomass burning and wildfires) and fossil fuel combustion. It was concluded that the urban background of PM2.5 and PM10 is dominated by the regional background, and that primary and secondary PM emission by urban sources contribute less than 15%. The 14C analysis revealed that 70% of OC originates from modern carbon and 30% from fossil fuel combustion. The corresponding percentages for EC are, respectively 17% and 83%. It is concluded that in particular the urban population living in street canyons with intense road traffic has potential health risks. This is due to exposure to elevated concentrations of a factor two for EC from exhaust emissions in PM2.5 and a factor 2-3 for heavy metals from brake and tyre wear, and re-suspended road dust in PM10. It follows that local air quality management may focus on local measures to street canyons with intense road traffic.

  10. Hanford Site background: Evaluation of existing soil radionuclide data

    International Nuclear Information System (INIS)

    1995-07-01

    This report is an evaluation of the existing data on radiological background for soils in the vicinity of the Hanford Site. The primary purpose of this report is to assess the adequacy of the existing data to serve as a radiological background baseline for use in environmental restoration and remediation activities at the Hanford Site. The soil background data compiled and evaluated in this report were collected by the Pacific Northwest Laboratory (PNL) and Washington State Department of Health (DOH) radiation surveillance programs in southeastern Washington. These two programs provide the largest well-documented, quantitative data sets available to evaluate background conditions at the Hanford Site. The data quality objectives (DQOs) considered in this evaluation include the amount of data, number of sampling localities, spatial coverage, number and types of radionuclides reported, frequency of reporting, documentation and traceability of sampling and laboratory methods used, and comparability between sets of data. Although other data on soil radionuclide abundances around the Hanford Site exist, they are generally limited in scope and lack the DQOs necessary for consideration with the PNL and DOH data sets. Collectively, these two sources provide data on the activities of 25 radionuclides and four other parameters (gross alpha, gross beta, total uranium, and total thorium). These measurements were made on samples from the upper 2.5 cm of soil at over 70 localities within the region

  11. Climate Impacts on Northern Canada: Regional Background

    Energy Technology Data Exchange (ETDEWEB)

    Prowse, Terry D.; Peters, Daniel L. (Water and Climate Impacts Research Centre, Environment Canada, Dept. of Geography, Univ. of Victoria, Victoria, BC (Canada)). e-mail: terry.prowse@ec.gc.caa; Furgal, Chris (Indigenous Environmental Studies Program, Trent Univ., Peterborough, ON (Canada)); Bonsal, Barrie R. (National Water Research Inst., National Hydrology Research Centre, Environment Canada, Saskatoon, SK (Canada))

    2009-07-15

    Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 deg C in the south to as low as -20 deg C in the high Arctic islands. A similar contrast characterizes precipitation, which can be >700 mm y-1 in some southern alpine regions to as low as 50 mm y-1 over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

  12. Methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments

    International Nuclear Information System (INIS)

    Van Poppel, Martine; Peters, Jan; Bleux, Nico

    2013-01-01

    A case study is presented to illustrate a methodology for mobile monitoring in urban environments. A dataset of UFP, PM 2.5 and BC concentrations was collected. We showed that repeated mobile measurements could give insight in spatial variability of pollutants at different micro-environments in a city. Streets of contrasting traffic intensity showed increased concentrations by a factor 2–3 for UFP and BC and by 2.5 . The first quartile (P25) of the mobile measurements at an urban background zone seems to be good estimate of the urban background concentration. The local component of the pollutant concentrations was determined by background correction. The use of background correction reduced the number of runs needed to obtain representative results. The results presented, are a first attempt to establish a methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments. -- Highlights: ► Mobile measurements are used to assess the variability of air pollutants in urban environments. ► PM 2.5 , BC and UFP concentrations are presented for zones with different traffic characteristics. ► A methodology for background correction based on the mobile measurements is presented. ► The background concentration is estimated as the 25th percentile of the urban background data. ► The minimum numbers of runs for a representative estimate is reduced after background correction. -- This paper shows that the spatial variability of air pollutants in an urban environment can be assessed by a mobile monitoring methodology including background correction

  13. Locals Collection

    Directory of Open Access Journals (Sweden)

    Stephen Hastings-King

    2010-03-01

    Full Text Available A locals collection is a set of parameters that are used to delimit data-mining operations. This piece uses a collection of locals from around Essex Massachusetts to shape and delimit an interrogation of post-reality in contemporary America. It explores the notion of crisis, the possibility of a crisis of empire that may or may not emerge in a media-space that does not allow crisis of empire to be mentioned and relations this maybe-crisis to the various levels of economic dysfunction that have become evident since late 2008. But mostly this piece explores ways in which particular stories about particular people do and do not link/link to these larger-scale narratives. This is the first of a potential series of locals collections that will mine the American post-real.

  14. Natural radiation background in the ancient city of Palmyra

    International Nuclear Information System (INIS)

    Shweikani, R.; Al-Masri, M.S.; Hushari, M.; Raja, G.; Aissa, M.; Al-Hent, R.

    2012-01-01

    Natural radiation background has been determined for the Ancient City of Palmyra and its surrounding areas. Car-borne gamma spectrometry, indoor radon gas concentration and natural radionuclides levels in environmental samples (soil, water and plants) have been determined. Two types of dwelling were involved in this study, one with cancer cases, and the others without. The results showed that indoor radon gas concentrations and radiation exposure rates are within reported mean background levels in Syria (45 Bq m −3 and less than 0.1 μSv h −1 , respectively); no differences were noticed between the dwelling groups. In addition, the results did not indicate any relation between recorded cancers and measured natural radioactivity.

  15. Stochastic background of gravitational waves from hybrid preheating.

    Science.gov (United States)

    García-Bellido, Juan; Figueroa, Daniel G

    2007-02-09

    The process of reheating the Universe after hybrid inflation is extremely violent. It proceeds through the nucleation and subsequent collision of large concentrations of energy density in bubblelike structures, which generate a significant fraction of energy in the form of gravitational waves. We study the power spectrum of the stochastic background of gravitational waves produced at reheating after hybrid inflation. We find that the amplitude could be significant for high-scale models, although the typical frequencies are well beyond what could be reached by planned gravitational wave observatories. On the other hand, low-scale models could still produce a detectable stochastic background at frequencies accessible to those detectors. The discovery of such a background would open a new window into the very early Universe.

  16. Cavern background measurement with the ATLAS RPC system

    CERN Document Server

    Aielli, G; The ATLAS collaboration

    2012-01-01

    The measurement of cavern background has been carried out systematically since the beginning of LHC, as soon as the luminosity produced a detectable signal, from L = 10^28 cm^2s^1 of the early 2010 operation up to L=10^28 cm^2s^1 at the end of 2011 proton-proton run, which is just 1/3 of the nominal LHC luminosity. The reason for this is to early foresee the running condition for the detector for the nominal LHC luminosity and beyond, in view of the super-LHC upgrade. Background Montecarlo calculations have been validated against data and the background map analysis pointed out hotspots due to localized cracks in the radiation shielding. The RPCs participated to this effort since the earliest stages providing an accurate correlation between luminosity and background, a 3D background map in the barrel region and a direct measurement of the cavern activation. Moreover due to the high sensitivity and very good signal to noise ratio of the proposed method, based on the gap current, the measurement was provided in...

  17. Cavern background measurement with the ATLAS RPC system

    CERN Document Server

    Aielli, G; The ATLAS collaboration

    2012-01-01

    The measurement of cavern background has been carried out systematically since the beginning of LHC, as soon as the luminosity produced a detectable signal, from L=1028 cm-2s-1 of the early 2010 operation up to L=3.5x1033 cm-2s-1 at the end of 2011 proton-proton run, which is just 1/3 of the nominal LHC luminosity. The reason for this is to early foresee the running condition for the detector for the nominal LHC luminosity and beyond, in view of the super-LHC upgrade. Background Montecarlo calculations have been validated against data and the background map analysis pointed out hotspots due to localized cracks in the radiation shielding. The RPCs participated to this effort since the earliest stages providing an accurate correlation between luminosity and background, a 3D background map in the barrel region and a direct measurement of the cavern activation. Moreover due to the high sensitivity and very good signal to noise ratio of the proposed method, based on the gap current, the measurement was provided in...

  18. Simulation of Experimental Background using FLUKA

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, Sayed

    1999-05-11

    In November 1997, Experiment T423 began acquiring data with the intentions of understanding the energy spectra of high-energy neutrons generated in the interaction of electrons with lead. The following describes a series of FLUKA simulations studying (1) particle yields in the absence of all background; (2) the background caused from scattering in the room; (3) the effects of the thick lead shielding which surrounded the detector; (4) the sources of neutron background created in this lead shielding; and (5) the ratio of the total background to the ideal yield. In each case, particular attention is paid to the neutron yield.

  19. Modeling the Thermal Signature of Natural Backgrounds

    National Research Council Canada - National Science Library

    Gamborg, Marius

    2002-01-01

    Two measuring stations have been established the purpose being to collect comprehensive databases of thermal signatures of background elements in addition to the prevailing meteorological conditions...

  20. Local equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    From 3-6 September the First International Workshop on Local Equilibrium in Strong Interaction Physics took place in Bad-Honnef at the Physics Centre of the German Physical Society. A number of talks covered the experimental and theoretical investigation of the 'hotspots' effect, both in high energy particle physics and in intermediate energy nuclear physics.

  1. Final report on the Background Soil Characterization Project at the Oak Ridge Reservation, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Watkins, D.R.; Ammons, J.T.; Branson, J.L.

    1993-10-01

    This report presents, evaluates, and documents data and results obtained in the Background Soil Characterization Project (BSCP). It is intended to be a stand-alone document for application and use in structuring and conducting remedial investigation and remedial action projects in the Environmental Restoration (ER) Program. The objectives of the BSCP consist of the following: determine background concentrations of organics, metals, and radionuclides in natural soils that are key to environmental restoration projects; provide remediation projects with 100% validated data on background concentrations, which are technically and legally defensible; and quantify baseline risks from background constituents for comparison of risks associated with contaminated sites

  2. Infrared image background modeling based on improved Susan filtering

    Science.gov (United States)

    Yuehua, Xia

    2018-02-01

    When SUSAN filter is used to model the infrared image, the Gaussian filter lacks the ability of direction filtering. After filtering, the edge information of the image cannot be preserved well, so that there are a lot of edge singular points in the difference graph, increase the difficulties of target detection. To solve the above problems, the anisotropy algorithm is introduced in this paper, and the anisotropic Gauss filter is used instead of the Gauss filter in the SUSAN filter operator. Firstly, using anisotropic gradient operator to calculate a point of image's horizontal and vertical gradient, to determine the long axis direction of the filter; Secondly, use the local area of the point and the neighborhood smoothness to calculate the filter length and short axis variance; And then calculate the first-order norm of the difference between the local area of the point's gray-scale and mean, to determine the threshold of the SUSAN filter; Finally, the built SUSAN filter is used to convolution the image to obtain the background image, at the same time, the difference between the background image and the original image is obtained. The experimental results show that the background modeling effect of infrared image is evaluated by Mean Squared Error (MSE), Structural Similarity (SSIM) and local Signal-to-noise Ratio Gain (GSNR). Compared with the traditional filtering algorithm, the improved SUSAN filter has achieved better background modeling effect, which can effectively preserve the edge information in the image, and the dim small target is effectively enhanced in the difference graph, which greatly reduces the false alarm rate of the image.

  3. A statistical background noise correction sensitive to the steadiness of background noise.

    Science.gov (United States)

    Oppenheimer, Charles H

    2016-10-01

    A statistical background noise correction is developed for removing background noise contributions from measured source levels, producing a background noise-corrected source level. Like the standard background noise corrections of ISO 3741, ISO 3744, ISO 3745, and ISO 11201, the statistical background correction increases as the background level approaches the measured source level, decreasing the background noise-corrected source level. Unlike the standard corrections, the statistical background correction increases with steadiness of the background and is excluded from use when background fluctuation could be responsible for measured differences between the source and background noise levels. The statistical background noise correction has several advantages over the standard correction: (1) enveloping the true source with known confidence, (2) assuring physical source descriptions when measuring sources in fluctuating backgrounds, (3) reducing background corrected source descriptions by 1 to 8 dB for sources in steady backgrounds, and (4) providing a means to replace standardized background correction caps that incentivize against high precision grade methods.

  4. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site.

  5. Comparing statistical tests for detecting soil contamination greater than background

    International Nuclear Information System (INIS)

    Hardin, J.W.; Gilbert, R.O.

    1993-12-01

    The Washington State Department of Ecology (WSDE) recently issued a report that provides guidance on statistical issues regarding investigation and cleanup of soil and groundwater contamination under the Model Toxics Control Act Cleanup Regulation. Included in the report are procedures for determining a background-based cleanup standard and for conducting a 3-step statistical test procedure to decide if a site is contaminated greater than the background standard. The guidance specifies that the State test should only be used if the background and site data are lognormally distributed. The guidance in WSDE allows for using alternative tests on a site-specific basis if prior approval is obtained from WSDE. This report presents the results of a Monte Carlo computer simulation study conducted to evaluate the performance of the State test and several alternative tests for various contamination scenarios (background and site data distributions). The primary test performance criteria are (1) the probability the test will indicate that a contaminated site is indeed contaminated, and (2) the probability that the test will indicate an uncontaminated site is contaminated. The simulation study was conducted assuming the background concentrations were from lognormal or Weibull distributions. The site data were drawn from distributions selected to represent various contamination scenarios. The statistical tests studied are the State test, t test, Satterthwaite's t test, five distribution-free tests, and several tandem tests (wherein two or more tests are conducted using the same data set)

  6. 41 CFR 128-1.8001 - Background.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Background. 128-1.8001 Section 128-1.8001 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF JUSTICE 1-INTRODUCTION 1.80-Seismic Safety Program § 128-1.8001 Background. The...

  7. Introduction to the background field method

    International Nuclear Information System (INIS)

    Abbott, L.F.; Brandeis Univ., Waltham, MA

    1982-01-01

    The background field approach to calculations in gauge field theories is presented. Conventional functional techniques are reviewed and the background field method is introduced. Feynman rules and renormalization are discussed and, as an example, the Yang-Mills β function is computed. (author)

  8. 12 CFR 408.1 - Background.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Background. 408.1 Section 408.1 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES PROCEDURES FOR COMPLIANCE WITH THE NATIONAL ENVIRONMENTAL POLICY ACT General § 408.1 Background. (a) The National Environmental Policy Act (NEPA) of 1969 (42 U.S.C...

  9. Observing a Gravitational Wave Background With Lisa

    National Research Council Canada - National Science Library

    Tinto, M; Armstrong, J; Estabrook, F

    2000-01-01

    .... Comparison of the conventional Michelson interferometer observable with the fully-symmetric Sagnac data-type allows unambiguous discrimination between a gravitational wave background and instrumental noise. The method presented here can be used to detect a confusion-limited gravitational wave background.

  10. 28 CFR 23.2 - Background.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Background. 23.2 Section 23.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is... potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally...

  11. 16 CFR 1404.2 - Background.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Background. 1404.2 Section 1404.2 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CELLULOSE INSULATION § 1404.2 Background. Based on available fire incident information, engineering analysis of the probable...

  12. Segmentation of Moving Object Using Background Subtraction Method in Complex Environments

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2016-06-01

    Full Text Available Background subtraction is an extensively used approach to localize the moving object in a video sequence. However, detecting an object under the spatiotemporal behavior of background such as rippling of water, moving curtain and illumination change or low resolution is not a straightforward task. To deal with the above-mentioned problem, we address a background maintenance scheme based on the updating of background pixels by estimating the current spatial variance along the temporal line. The work is focused to immune the variation of local motion in the background. Finally, the most suitable label assignment to the motion field is estimated and optimized by using iterated conditional mode (ICM under a Markovian framework. Performance evaluation and comparisons with the other well-known background subtraction methods show that the proposed method is unaffected by the problem of aperture distortion, ghost image, and high frequency noise.

  13. Geometry of all supersymmetric four-dimensional N = 1 supergravity backgrounds

    International Nuclear Information System (INIS)

    Gran, U.; Gutowski, J.; Papadopoulos, G.

    2008-01-01

    We solve the Killing spinor equations of N = 1 supergravity, with four supercharges, coupled to any number of vector and scalar multiplets in all cases. We find that backgrounds with N = 1 supersymmetry admit a null, integrable, Killing vector field. There are two classes of N = 2 backgrounds. The spacetime in the first class admits a parallel null vector field and so it is a pp-wave. The spacetime of the other class admits three Killing vector fields, and a vector field that commutes with the three Killing directions. These backgrounds are of cohomogeneity one with homogenous sections either R 2,1 or AdS 3 and have an interpretation as domain walls. The N = 3 backgrounds are locally maximally supersymmetric. There are N = 3 backgrounds which arise as discrete identifications of maximally supersymmetric ones. The maximally supersymmetric backgrounds are locally isometric to either R 3,1 or AdS 4 .

  14. Mobile localization in nonlinear Schroedinger lattices

    International Nuclear Information System (INIS)

    Gomez-Gardenes, J.; Falo, F.; Floria, L.M.

    2004-01-01

    Using continuation methods from the integrable Ablowitz-Ladik lattice, we have studied the structure of numerically exact mobile discrete breathers in the standard discrete nonlinear Schroedinger equation. We show that, away from that integrable limit, the mobile pulse is dressed by a background of resonant plane waves with wavevectors given by a certain selection rule. This background is seen to be essential for supporting mobile localization in the absence of integrability. We show how the variations of the localized pulse energy during its motion are balanced by the interaction with this background, allowing the localization mobility along the lattice

  15. Beam-gas Background Observations at LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00214737; The ATLAS collaboration; Alici, Andrea; Lazic, Dragoslav-Laza; Alemany Fernandez, Reyes; Alessio, Federico; Bregliozzi, Giuseppe; Burkhardt, Helmut; Corti, Gloria; Guthoff, Moritz; Manousos, Athanasios; Sjoebaek, Kyrre; D'Auria, Saverio

    2017-01-01

    Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

  16. The Physics of the Cosmic Microwave Background

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, John [Royal Observatory, Edinburgh (United Kingdom)

    2007-04-07

    The award of the 2006 Nobel Prize for Physics is a reminder to non-specialists that the cosmic microwave background (CMB) has yielded astonishing advances in our understanding of cosmology. Mather and Smoot received their prize for work done with NASA's COBE satellite in the early 1990s, but the subject has if anything accelerated since then. The results from NASA's WMAP satellite, reported in 2003 and 2006, have proved COBE's equal in importance and have generated huge worldwide interest. There could therefore hardly be a better time to be writing a detailed textbook to explain what the fuss is all about to a new generation of research students. A comprehensive treatment of the physics of the CMB is not easy to achieve, because it is connected to so much else in cosmology. A student must have a background knowledge of the geometry and dynamics of an expanding universe, plus a deep exposure to the physics of quantum fields, in order to understand the modern 'inflationary' view in which the universe was set expanding by the tension of the vacuum, and was seeded with small inhomogeneities as a result of quantum fluctuations. Although the theory of inflation is not yet verified, the CMB has the potential to accomplish this; testing inflation is undoubtedly one of the principal aims of cosmology over the next decade. Even with this preparation, understanding the properties of the CMB is quite hard at the professional level, requiring the perturbation expansion of the relativistic Boltzmann equation. These technical difficulties are particularly strong in the frontier area of CMB polarization. Naselsky and his collaborators have allocated themselves a relatively brief 255 pages in which to meet these challenges, so some compromise is inevitable. Although the preface is not explicit about the assumed prior knowledge, no systematic material on background cosmology or on inflation is to be found. The former is reasonable in a graduate-level text

  17. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  18. PENGARUH BACKGROUND MAHASISWA TERHADAP KINERJA AKADEMIK

    Directory of Open Access Journals (Sweden)

    Trianasari Angkawijaya

    2014-09-01

    Full Text Available Abstract: The Effect of Students’ Background on Academic Performance. This study examines the effect of background variables on the academic performance of accounting students in a private university in Surabaya. The background variables under study included previous academic performance, prior knowledge on accounting, sex, motivation, preparedness, and expectations. The results show that previous academic performance, motivation, and expectations have positive and significant effects on the students’ overall academic performance in accounting, while preparedness affects only the students’ performance in management accounting. In contrast, prior knowledge on accounting and sex do not give significant impacts to the students’ overall academic performance.These findings indicate the importance of previous aca­demic performance as well as motivation and expectations as background variables in current academic performance. Keywords: students’ background, academic performance, accounting Abstrak: Pengaruh Background Mahasiswa terhadap Kinerja Akademik. Penelitian ini mengkaji pengaruh variabel background terhadap kinerja akademik mahasiswa akuntansi di Universitas Surabaya. Lima variabel background utama dipergunakan, yaitu kinerja akademik sebelumnya, pengetahuan akun­tansi sebelumnya, jenis kelamin, motivasi, kesiapan, dan ekspektasi. Hipotesis diuji menggunakan model regresi linier berganda OLS dan Robust Standar Error. Hasil penelitian memerlihatkan bahwa kinerja akademik sebelumnya, motivasi, dan ekspektasi memiliki pengaruh positif signifikan terhadap kinerja akademik keseluruhan, sementara kesiapan memberikan pengaruh positif hanya pada kinerja akademik akuntansi manajemen. Sebaliknya, pengetahuan akuntansi sebelumnya dan jenis kelamin tidak memberi­kan pengaruh signifikan terhadap kinerja akademik keseluruhan. Temuan ini mengindikasikan bahwa kinerja akademik sebelumnya beserta motivasi dan ekspektasi adalah variabel background

  19. Local supertwistors

    International Nuclear Information System (INIS)

    Merkulov, S.A.

    1987-01-01

    Geometry of local supertwistors is investigated. It is proved that the Yang-Mills equations for the introduced ansatz for supertwistor connection are equivalent to free bach equations, describing the dynamics of N=1 conformal supergravity. Analogous interpretation of the dynamics of N=1 conformal supergravity coupled to a vector superfield is proposed. It is proved that any complex conformally right or left flat superspace automatically satisfies the Bach equations

  20. Background area effects on feature detectability in CT and uncorrelated noise

    International Nuclear Information System (INIS)

    Swensson, R.G.; Judy, P.F.

    1987-01-01

    Receiver operating characteristic curve measures of feature detectability decrease substantially when the surrounding area of uniform-noise background is small relative to that of the feature itself. The effect occurs with both fixed and variable-level backgrounds, but differs in form for CT and uncorrelated noise. Cross-correlation image calculations can only predict these effects by treating feature detection as the discrimination of a local change (a ''feature'') from the estimated level of an assumed-uniform region of background

  1. Identification of backgrounds in the EDELWEISS-I dark matter search experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fiorucci, S. [CEA, Centre d' Etudes Nucleaires de Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette Cedex (France); Benoit, A. [Centre de Recherche sur les Tres Basses Temperatures, SPM-CNRS, BP 166, 38042 Grenoble (France); Berge, L. [Centre de Spectroscopie Nucleaire et de Spectroscopie de Masse, UMR8609 IN2P3-CNRS, Univ. Paris Sud, bat 108, 91405 Orsay Campus (France)] (and others)

    2007-05-15

    This paper presents our interpretation and understanding of the different backgrounds in the EDELWEISS-I data sets. We analyze in detail the several populations observed, which include gammas, alphas, neutrons, thermal sensor events and surface events, and try to combine all data sets to provide a coherent picture of the nature and localization of the background sources. In light of this interpretation, we draw conclusions regarding the background suppression scheme for the EDELWEISS-II phase. (authors)

  2. A Parameter Study of Localization

    Directory of Open Access Journals (Sweden)

    Sandor Stephen Mester

    1996-01-01

    Full Text Available Extensive work has been done on the vibration characteristics of perfectly periodic structures. Disorder in the periodic pattern has been found to lead to localization in one-dimensional periodic structures. It is important to understand localization because it causes energy to be concentrated near the disorder and may cause an overestimation of structural damping. A numerical study is conducted to obtain a better understanding of localization. It is found that any mode, even the first, can localize due to the presence of small imperfections.

  3. Quantum theory and local causality

    CERN Document Server

    Hofer-Szabó, Gábor

    2018-01-01

    This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR (Einstein-Podolsky-Rosen) scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics and physicists working in foundation of physics.

  4. New and precise construction of the local interstellar electron spectrum from the radio background and an application to the solar modulation of cosmic rays showing an incompatability of the electron and nuclei modulation using the spherically symmetric Fokker-Planck equation

    International Nuclear Information System (INIS)

    Rockstroh, J.M.

    1977-01-01

    Cosmic-ray electrons generate the observed radio-frequency background. Previous attempts in the literature to reconcile quantitatively the measured radio-frequency intensity with the intensity deduced from the electron spectrum measured at earth have culminated in the problem that to get the respective emissivities to agree, an unacceptably high interstellar B field must be chosen. In the light of new experimental data on the emissivity as deduced from H II region studies and on the functional dependence of the diffusion coefficient with solar radius and particle rigidity, the assumptions under which the electron emissivity comparison has been made have been reexamined closely. The paradox between predicted and measured emissivity was resolved by ascribing to the magnetic fields of the galaxy a distribution of magnetic field strengths. From modified synchrotron formulas, the interstellar electron spectrum has been constructed from the radio frequency emission data with greatly improved precision. The interstellar electron spectrum has been determined independently of the solar modulation and provides, therefore, an estimate of the absolute depth of the electron modulation. Then the measured electron, proton, and helium-nuclei fluxes were systematically compared to the predictions of the spherically symmetric Fokker-Planck equation using the electron modulation as a base. A previously unnoticed non-tracking of the modulation parameters was observed during the recent recovery that did not occur during the 1965 to 1969 period. Although the argument could be presented just as well by attributing the anomaly to the nuclei, the discussion here arbitrarily tailored it to the electrons, and this new phenomenon was named, the modulation reluctance of the cosmic-ray electrons

  5. String pair production in non homogeneous backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, S. [Department of Physics “E. Fermi” University of Pisa, and INFN - Sezione di Pisa,Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Rabinovici, E. [Racah Institute of Physics, The Hebrew University of Jerusalem,91904 Jerusalem (Israel); Tallarita, G. [Departamento de Ciencias, Facultad de Artes Liberales,Universidad Adolfo Ibáñez, Santiago 7941169 (Chile)

    2016-04-28

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  6. String pair production in non homogeneous backgrounds

    International Nuclear Information System (INIS)

    Bolognesi, S.; Rabinovici, E.; Tallarita, G.

    2016-01-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  7. Slavnov-Taylor constraints for nontrivial backgrounds

    International Nuclear Information System (INIS)

    Binosi, D.; Quadri, A.

    2011-01-01

    We devise an algebraic procedure for the evaluation of Green's functions in SU(N) Yang-Mills theory in the presence of a nontrivial background field. In the ghost-free sector the dependence of the vertex functional on the background is shown to be uniquely determined by the Slavnov-Taylor identities in terms of a certain 1-PI correlator of the covariant derivatives of the ghost and the antighost fields. At nonvanishing background this amplitude is shown to encode the quantum deformations to the tree-level background-quantum splitting. The approach only relies on the functional identities of the model (Slavnov-Taylor identities, b-equation, antighost equation) and thus it is valid beyond perturbation theory, and, in particular, in a lattice implementation of the background field method. As an example of the formalism we analyze the ghost two-point function and the Kugo-Ojima function in an instanton background in SU(2) Yang-Mills theory, quantized in the background Landau gauge.

  8. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  9. Extragalactic background light measurements and applications.

    Science.gov (United States)

    Cooray, Asantha

    2016-03-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

  10. Atmospheric tritium concentrations under influence of AREVA NC La Hague reprocessing plant (France) and background levels.

    Science.gov (United States)

    Connan, O; Hébert, D; Solier, L; Maro, D; Pellerin, G; Voiseux, C; Lamotte, M; Laguionie, P

    2017-10-01

    In-air tritium measurements were conducted around the AREVA NC La Hague reprocessing plant, as well as on other sites that are not impacted by the nuclear industry in northwest of France. The results indicate that the dominant tritium form around the AREVA site is HT (86%). HT and HTO levels are lower than 5 and 1 Bq. m -3 for hourly samples taken in the plume. No tritiated organic molecules (TOM) were detected. 26 measurement campaigns were performed and links were established between near-field 85 Kr, HT and HTO activities. Environmental measurements are in line with those taken at the discharge stack, and tend to demonstrate that there are no rapid changes in the tritium forms released. Out of the influence of any nuclear activities, the levels measured were below 13 mBq.m -3 for HT and 5 mBq.m -3 for HTO (<0.5 Bq. L -1 ). HTO level in air seems to be influenced by HTO activities in surrounding seawater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The Chandra Source Catalog: Background Determination and Source Detection

    Science.gov (United States)

    McCollough, Michael; Rots, Arnold; Primini, Francis A.; Evans, Ian N.; Glotfelty, Kenny J.; Hain, Roger; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Danny G. Gibbs, II; Grier, John D.; Hall, Diane M.; Harbo, Peter N.; He, Xiang Qun (Helen); Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Siemiginowska, Aneta L.; Sundheim, Beth A.; Tibbetts, Michael S.; van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

    2009-09-01

    The Chandra Source Catalog (CSC) is a major project in which all of the pointed imaging observations taken by the Chandra X-Ray Observatory are used to generate one of the most extensive X-ray source catalog produced to date. Early in the development of the CSC it was recognized that the ability to estimate local background levels in an automated fashion would be critical for essential CSC tasks such as source detection, photometry, sensitivity estimates, and source characterization. We present a discussion of how such background maps are created directly from the Chandra data and how they are used in source detection. The general background for Chandra observations is rather smoothly varying, containing only low spatial frequency components. However, in the case of ACIS data, a high spatial frequency component is added that is due to the readout streaks of the CCD chips. We discuss how these components can be estimated reliably using the Chandra data and what limitations and caveats should be considered in their use. We will discuss the source detection algorithm used for the CSC and the effects of the background images on the detection results. We will also touch on some the Catalog Inclusion and Quality Assurance criteria applied to the source detection results. This work is supported by NASA contract NAS8-03060 (CXC).

  12. Chandra Source Catalog: Background Determination and Source Detection

    Science.gov (United States)

    McCollough, Michael L.; Rots, A. H.; Primini, F. A.; Evans, I. N.; Glotfelty, K. J.; Hain, R.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Grier, J. D.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; Van Stone, D. W.; Winkelman, S. L.; Zografou, P.

    2009-01-01

    The Chandra Source Catalog (CSC) is a major project in which all of the pointed imaging observations taken by the Chandra X-Ray Observatory will used to generate the most extensive X-ray source catalog produced to date. Early in the development of the CSC it was recognized that the ability to estimate local background levels in an automated fashion would be critical for essential CSC tasks such as source detection, photometry, sensitivity estimates, and source characterization. We present a discussion of how such background maps are created directly from the Chandra data and how they are used in source detection. The general background for Chandra observations is rather smoothly varying, containing only low spatial frequency components. However, in the case of ACIS data, a high spatial frequency component is added that is due to the readout streaks of the CCD chips. We discuss how these components can be estimated reliably using the Chandra data and what limitations and caveats should be considered in their use. We will discuss the source detection algorithm used for the CSC and the effects of the background images on the detection results. We will also touch on some the Catalog Inclusion and Quality Assurance criteria applied to the source detection results. This work is supported by NASA contract NAS8-03060 (CXC).

  13. Local supertwistors

    International Nuclear Information System (INIS)

    Merkulov, S.A.

    1987-01-01

    The geometry of local supertwistors is investigated. An ansatz on the form of the supertwistor superconnection is introduced. Because of this restriction on the form of such a superconnection the Yang-Mills equations for the superconnection turn out to be equivalent to the free Bach equations describing the dynamics of simple conformal supergravity. It is shown that the equations of motion of conformal supergravity interacting with a vector superfield admit an analogous interpretation. It is proved that an arbitrary conformally right-flat or left-flat superspace is automatically a solution of the Bach equations

  14. Fluctuations from cosmic strings and the microwave background

    International Nuclear Information System (INIS)

    Brandenberger, R.H.; Turok, N.

    1986-01-01

    The spectrum of energy-density perturbations and anisotropies in the microwave background radiation are calculated in models with cosmic strings. The computations are based on a mathematical model of the network of cosmic strings as a combination of a random walk of infinite strings and a distribution of string loops. The energy-density distribution is scale invariant at Hubble radius crossing, but the k dependence of the spectrum is nontrivial and not equal to the result for adiabatic linear perturbations. The anisotropies in the microwave background radiation are smaller than the observational upper bounds on all angular scales for a value μGapprox.2 x 10 -6 obtained from independent astrophysical considerations. We include both the effects due to gravitational lensing from long strings and from local gravitational perturbations due to loops (the Sachs-Wolfe effect)

  15. Lattice worldline representation of correlators in a background field

    International Nuclear Information System (INIS)

    Epelbaum, Thomas; Gelis, François; Wu, Bin

    2015-01-01

    We use a discrete worldline representation in order to study the continuum limit of the one-loop expectation value of dimension two and four local operators in a background field. We illustrate this technique in the case of a scalar field coupled to a non-Abelian background gauge field. The first two coefficients of the expansion in powers of the lattice spacing can be expressed as sums over random walks on a d-dimensional cubic lattice. Using combinatorial identities for the distribution of the areas of closed random walks on a lattice, these coefficients can be turned into simple integrals. Our results are valid for an anisotropic lattice, with arbitrary lattice spacings in each direction.

  16. On the background independence of string field theory

    International Nuclear Information System (INIS)

    Sen, A.

    1990-01-01

    Given a solution Ψ cl of the classical equations of motion in either closed or open string field theory formulated around a given conformal field theory background, we can construct a new operator Q B in the corresponding two-dimensional field theory such that (Q B ) 2 =0. It is shown that in the limit when the background field Ψ cl is weak, Q B can be identified with the BRST charge of a new local conformal field theory. This indicates that the string field theories formulated around these two different conformal field theories are actually the same theory, and that these two conformal field theories may be regarded as different classical solutions of this string field theory. (orig.)

  17. The Physics of the Cosmic Microwave Background

    International Nuclear Information System (INIS)

    Peacock, John

    2007-01-01

    The award of the 2006 Nobel Prize for Physics is a reminder to non-specialists that the cosmic microwave background (CMB) has yielded astonishing advances in our understanding of cosmology. Mather and Smoot received their prize for work done with NASA's COBE satellite in the early 1990s, but the subject has if anything accelerated since then. The results from NASA's WMAP satellite, reported in 2003 and 2006, have proved COBE's equal in importance and have generated huge worldwide interest. There could therefore hardly be a better time to be writing a detailed textbook to explain what the fuss is all about to a new generation of research students. A comprehensive treatment of the physics of the CMB is not easy to achieve, because it is connected to so much else in cosmology. A student must have a background knowledge of the geometry and dynamics of an expanding universe, plus a deep exposure to the physics of quantum fields, in order to understand the modern 'inflationary' view in which the universe was set expanding by the tension of the vacuum, and was seeded with small inhomogeneities as a result of quantum fluctuations. Although the theory of inflation is not yet verified, the CMB has the potential to accomplish this; testing inflation is undoubtedly one of the principal aims of cosmology over the next decade. Even with this preparation, understanding the properties of the CMB is quite hard at the professional level, requiring the perturbation expansion of the relativistic Boltzmann equation. These technical difficulties are particularly strong in the frontier area of CMB polarization. Naselsky and his collaborators have allocated themselves a relatively brief 255 pages in which to meet these challenges, so some compromise is inevitable. Although the preface is not explicit about the assumed prior knowledge, no systematic material on background cosmology or on inflation is to be found. The former is reasonable in a graduate-level text (which this certainly is

  18. English language support: A dialogical multi-literacies approach to teaching students from CALD backgrounds

    Directory of Open Access Journals (Sweden)

    Berniz Kate

    2017-12-01

    Full Text Available Students in Western university contexts require multiple literacies, numeracies, and critical capacities to succeed. Participation requires a blend of English language capacity, cultural knowhow, and cognisance of the often-hidden racialized assumptions and dispositions underpinning literate performance. Students from Culturally and Linguistically Diverse (CALD backgrounds transitioning to Western university settings from local and international contexts often find themselves floundering in this complex sociocultural web. Many students struggle with the English language preferences of their institutions despite meeting International English Language Testing System (IELTS requirements. Once enrolled, students from CALD backgrounds need to navigate the linguistic, semiotic, and cultural landscape of the university, both physically and virtually, to enter the discourses and practices of their chosen disciplines. Universities cannot afford to allow students to ‘sink or swim’ or struggle through with non-specialist or ad-hoc support. In response to a clear need for explicit and ongoing English language support for students from CALD backgrounds, the Student Learning Centre (SLC at Flinders University in South Australia created the English Language Support Program (ELSP. The ELSP sets out to overcome prescriptive and assimilationist approaches to language support by adopting an eclectic blend of learner-centred, critical-creative, and multi-literacies approaches to learning and teaching. Rather than concentrate on skills and/or language appropriateness, the ELSP broadens its reach by unpacking the mechanics and machinations of university study through an intensive—and transgressive—multi-module program. This paper outlines the theoretical and pedagogical challenges of implementing the ELSP.

  19. Cerebral Lactate Concentration in Neonatal Hypoxic-Ischemic Encephalopathy: In Relation to Time, Characteristic of Injury, and Serum Lactate Concentration

    Directory of Open Access Journals (Sweden)

    Tai-Wei Wu

    2018-05-01

    Full Text Available BackgroundCerebral lactate concentration can remain detectable in neonatal hypoxic-ischemic encephalopathy (HIE after hemodynamic stability. The temporal resolution of regional cerebral lactate concentration in relation to the severity or area of injury is unclear. Furthermore, the interplay between serum and cerebral lactate in neonatal HIE has not been well defined. The study aims to describe cerebral lactate concentration in neonatal HIE in relation to time, injury, and serum lactate.Design/methodsFifty-two newborns with HIE undergoing therapeutic hypothermia (TH were enrolled. Magnetic resonance imaging and spectroscopy (MRI + MR spectroscopy were performed during and after TH at 54.6 ± 15.0 and 156 ± 57.6 h of life, respectively. Severity and predominant pattern of injury was scored radiographically. Single-voxel 1H MR spectra were acquired using short-echo (35 ms PRESS sequence localized to the basal ganglia (BG, thalamus (Thal, gray matter (GM, and white matter. Cerebral lactate concentration was quantified by LCModel software. Serum and cerebral lactate concentrations were plotted based on age at time of measurement. Multiple comparisons of regional cerebral lactate concentration based on severity and predominant pattern of injury were performed. Spearman’s Rho was computed to determine correlation between serum lactate and cerebral lactate concentration at the respective regions of interest.ResultsOverall, serum lactate concentration decreased over time. Cerebral lactate concentration remained low for less severe injury and decreased over time for more severe injury. Cerebral lactate remained detectable even after TH. During TH, there was a significant higher concentration of cerebral lactate at the areas of injury and also when injury was more severe. However, these differences were no longer observed after TH. There was a weak correlation between serum lactate and cerebral lactate concentration at the BG (rs

  20. Neural network model for the prediction of PM10 daily concentrations in two sites in the Western Mediterranean.

    Science.gov (United States)

    de Gennaro, Gianluigi; Trizio, Livia; Di Gilio, Alessia; Pey, Jorge; Pérez, Noemi; Cusack, Michael; Alastuey, Andrés; Querol, Xavier

    2013-10-01

    An artificial neural network (ANN) was developed and tested to forecast PM10 daily concentration in two contrasted environments in NE Spain, a regional background site (Montseny), and an urban background site (Barcelona-CSIC), which was highly influenced by vehicular emissions. In order to predict 24-h average PM10 concentrations, the artificial neural network previously developed by Caselli et al. (2009) was improved by using hourly PM concentrations and deterministic factors such as a Saharan dust alert. In particular, the model input data for prediction were the hourly PM10 concentrations 1-day in advance, local meteorological data and information about air masses origin. The forecasted performance indexes for both sites were calculated and they showed better results for the regional background site in Montseny (R(2)=0.86, SI=0.75) than for urban site in Barcelona (R(2)=0.73, SI=0.58), influenced by local and sometimes unexpected sources. Moreover, a sensitivity analysis conducted to understand the importance of the different variables included among the input data, showed that local meteorology and air masses origin are key factors in the model forecasts. This result explains the reason for the improvement of ANN's forecasting performance at the Montseny site with respect to the Barcelona site. Moreover, the artificial neural network developed in this work could prove useful to predict PM10 concentrations, especially, at regional background sites such as those on the Mediterranean Basin which are primarily affected by long-range transports. Hence, the artificial neural network presented here could be a powerful tool for obtaining real time information on air quality status and could aid stakeholders in their development of cost-effective control strategies. © 2013 Elsevier B.V. All rights reserved.

  1. On the microwave background spectrum and noise

    International Nuclear Information System (INIS)

    De Bernardis, P.; Masi, S.

    1982-01-01

    We show that the combined measurement of the cosmic background radiation (CBR) intensity and noise can provide direct information on the temperature and the emissivity of the source responsible for the CBR. (orig.)

  2. Quantum background independence in string theory

    International Nuclear Information System (INIS)

    Witten, E.

    1994-01-01

    Not only in physical string theories, but also in some highly simplified situations, background independence has been difficult to understand. It is argued that the ''holomorphic anomaly'' of Bershadsky, Cecotti, Ooguri and Vafa gives a fundamental explanation of some of the problems. Moreover, their anomaly equation can be interpreted in terms of a rather peculiar quantum version of background independence: in systems afflicted by the anomaly, background independence does not hold order by order in perturbation theory, but the exact partition function as a function of the coupling constants has a background independent interpretation as a state in an auxiliary quantum Hilbert space. The significance of this auxiliary space is otherwise unknown. (author). 23 refs

  3. Background-cross-section-dependent subgroup parameters

    International Nuclear Information System (INIS)

    Yamamoto, Toshihisa

    2003-01-01

    A new set of subgroup parameters was derived that can reproduce the self-shielded cross section against a wide range of background cross sections. The subgroup parameters are expressed with a rational equation which numerator and denominator are expressed as the expansion series of background cross section, so that the background cross section dependence is exactly taken into account in the parameters. The advantage of the new subgroup parameters is that they can reproduce the self-shielded effect not only by group basis but also by subgroup basis. Then an adaptive method is also proposed which uses fitting procedure to evaluate the background-cross-section-dependence of the parameters. One of the simple fitting formula was able to reproduce the self-shielded subgroup cross section by less than 1% error from the precise evaluation. (author)

  4. REQUEST FOR EXPRESSIONS OF INTEREST For Background ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    sbickram

    2012-07-10

    Jul 10, 2012 ... the applicant's qualifications and ability to undertake the hot spot background study. ... any interviews, presentations and subsequent proposals, are the sole ... The program will focus on increasing the resilience of the most ...

  5. History and background of the project

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.; Nair, R.R.

    The history of oceanography, the discovery of manganese nodules and the background of the developments in nodule research and mining is given The first nodules were collected in 1981 on board the research vessel R V Gaveshani Following the success...

  6. 47 CFR 215.1 - Background.

    Science.gov (United States)

    2010-10-01

    ... POINT FOR ELECTROMAGNETIC PULSE (EMP) INFORMATION § 215.1 Background. (a) The nuclear electromagnetic pulse (EMP) is part of the complex environment produced by nuclear explosions. It consists of transient...

  7. 32 CFR 770.49 - Background.

    Science.gov (United States)

    2010-07-01

    ..., Washington § 770.49 Background. (a) Puget Sound Naval Shipyard is a major naval ship repair facility, with... interruption. Additionally, most of Puget Sound Naval Shipyard is dedicated to heavy industrial activity where...

  8. Mathematical Background of Public Key Cryptography

    DEFF Research Database (Denmark)

    Frey, Gerhard; Lange, Tanja

    2005-01-01

    The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material.......The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material....

  9. A Practical Theorem on Gravitational Wave Backgrounds

    OpenAIRE

    Phinney, E. S.

    2001-01-01

    There is an extremely simple relationship between the spectrum of the gravitational wave background produced by a cosmological distribution of discrete gravitational wave sources, the total time-integrated energy spectrum of an individual source, and the present-day comoving number density of remnants. Stated in this way, the background is entirely independent of the cosmology, and only weakly dependent on the evolutionary history of the sources. This relationship allows one easily to compute...

  10. Isotherms clustering in cosmic microwave background

    International Nuclear Information System (INIS)

    Bershadskii, A.

    2006-01-01

    Isotherms clustering in cosmic microwave background (CMB) has been studied using the 3-year WMAP data on cosmic microwave background radiation. It is shown that the isotherms clustering could be produced by the baryon-photon fluid turbulence in the last scattering surface. The Taylor-microscale Reynolds number of the turbulence is estimated directly from the CMB data as Re λ ∼10 2

  11. Classification of supersymmetric backgrounds of string theory

    International Nuclear Information System (INIS)

    Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

    2007-01-01

    We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to nearly maximally supersymmetric backgrounds. We then demonstrate its effectiveness by classifying the maximally supersymmetric IIB G-backgrounds and by showing that N=31 IIB solutions do not exist. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. Superstring gravitational wave backgrounds with spacetime supersymmetry

    CERN Document Server

    Kiritsis, Elias B; Lüst, Dieter; Kiritsis, E; Kounnas, C; Lüst, D

    1994-01-01

    We analyse the stringy gravitational wave background based on the current algebra E.sup(c).sub(2). We determine its exact spectrum and construct the modular invariant vacuum energy. The corresponding N=1 extension is also constructed. The algebra is again mapped to free bosons and fermions and we show that this background has N=4 (N=2) unbroken spacetime supersymmetry in the type II (heterotic case).

  13. Background dose subtraction in personnel dosimetry

    International Nuclear Information System (INIS)

    Picazo, T.; Llorca, N.; Alabau, J.

    1997-01-01

    In this paper it is proposed to consider the mode of the frequency distribution of the low dose dosemeters from each clinic that uses X rays as the background environmental dose that should be subtracted from the personnel dosimetry to evaluate the doses due to practice. The problems and advantages of this indirect method to estimate the environmental background dose are discussed. The results for 60 towns are presented. (author)

  14. Moving object detection using background subtraction

    CERN Document Server

    Shaikh, Soharab Hossain; Chaki, Nabendu

    2014-01-01

    This Springer Brief presents a comprehensive survey of the existing methodologies of background subtraction methods. It presents a framework for quantitative performance evaluation of different approaches and summarizes the public databases available for research purposes. This well-known methodology has applications in moving object detection from video captured with a stationery camera, separating foreground and background objects and object classification and recognition. The authors identify common challenges faced by researchers including gradual or sudden illumination change, dynamic bac

  15. Aircraft and background noise annoyance effects

    Science.gov (United States)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  16. Low energy background radiation in India

    International Nuclear Information System (INIS)

    Gopinath, D.V.

    1980-01-01

    Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

  17. Non-collision backgrounds in ATLAS

    CERN Document Server

    Gibson, S M; The ATLAS collaboration

    2012-01-01

    The proton-proton collision events recorded by the ATLAS experiment are on top of a background that is due to both collision debris and non-collision components. The latter comprises of three types: beam-induced backgrounds, cosmic particles and detector noise. We present studies that focus on the first two of these. We give a detailed description of beam-related and cosmic backgrounds based on the full 2011 ATLAS data set, and present their rates throughout the whole data-taking period. Studies of correlations between tertiary proton halo and muon backgrounds, as well as, residual pressure and resulting beam-gas events seen in beam-condition monitors will be presented. Results of simulations based on the LHC geometry and its parameters will be presented. They help to better understand the features of beam-induced backgrounds in each ATLAS sub-detector. The studies of beam-induced backgrounds in ATLAS reveal their characteristics and serve as a basis for designing rejection tools that can be applied in physic...

  18. Renormalization ambiguities and conformal anomaly in metric-scalar backgrounds

    International Nuclear Information System (INIS)

    Asorey, M.; Berredo-Peixoto, G. de; Shapiro, I. L.

    2006-01-01

    We analyze the problem of the existing ambiguities in the conformal anomaly in theories with an external scalar field in curved backgrounds. In particular, we consider the anomaly of a self-interacting massive scalar field theory and of a Yukawa model in the massless conformal limit. In all cases the ambiguities are related to finite renormalizations of local nonminimal terms in the effective action. We point out the generic nature of this phenomenon and provide a general method to identify the theories where such an ambiguity can arise

  19. Installation of a muon veto for low background gamma spectroscopy at the LBNL low-background facility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K.J., E-mail: kjthomas@lbl.gov [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Norman, E.B. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Smith, A.R.; Chan, Y.D. [Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States)

    2013-10-01

    An active veto system consisting of plastic scintillation panels was installed outside the Pb shielding of a 115% n-type HPGe detector in an effort to reduce background continuum generated by cosmic ray muons on the surface. The Low Background Facility at the Lawrence Berkeley National Laboratory performs low level assay (generally of primordial U, Th, K) of candidate construction materials for experiments that require a high level of radiopurity. The counting is performed in two facilities: one local surface site and a remote underground site of approximately 600 m.w.e. For the recently installed veto system at the surface location, the top scintillator panel has been in use for nearly 1 year and the full 3π anticoincidence shield was commissioned into normal counting operations in January 2013. The integrated background from 20 to 3600 keV is reduced overall by a factor of 8, where most of the energy spectrum above 100 keV achieves an overall reduction that varies from 8 to 10. A dramatic improvement of peak-to-background across the entire continuum is observed, greatly enhancing low-level peaks that would otherwise be obscured.

  20. Characterizing local traffic contributions to particulate air pollution in street canyons using mobile monitoring techniques

    Science.gov (United States)

    Zwack, Leonard M.; Paciorek, Christopher J.; Spengler, John D.; Levy, Jonathan I.

    2011-05-01

    Traffic within urban street canyons can contribute significantly to ambient concentrations of particulate air pollution. In these settings, it is challenging to separate within-canyon source contributions from urban and regional background concentrations given the highly variable and complex emissions and dispersion characteristics. In this study, we used continuous mobile monitoring of traffic-related particulate air pollutants to assess the contribution to concentrations, above background, of traffic in the street canyons of midtown Manhattan. Concentrations of both ultrafine particles (UFP) and fine particles (PM 2.5) were measured at street level using portable instruments. Statistical modeling techniques accounting for autocorrelation were used to investigate the presence of spatial heterogeneity of pollutant concentrations as well as to quantify the contribution of within-canyon traffic sources. Measurements were also made within Central Park, to examine the impact of offsets from major roadways in this urban environment. On average, an approximate 11% increase in concentrations of UFP and 8% increase in concentrations of PM 2.5 over urban background was estimated during high-traffic periods in street canyons as opposed to low traffic periods. Estimates were 8% and 5%, respectively, after accounting for temporal autocorrelation. Within Central Park, concentrations were 40% higher than background (5% after accounting for temporal autocorrelation) within the first 100 m from the nearest roadway for UFP, with a smaller but statistically significant increase for PM 2.5. Our findings demonstrate the viability of a mobile monitoring protocol coupled with spatiotemporal modeling techniques in characterizing local source contributions in a setting with street canyons.

  1. Study of Uranium Concentrations in Water and Organic Material from Streams in Sweden

    International Nuclear Information System (INIS)

    Ek, J.

    1981-12-01

    The purpose of the investigation has been to study how uranium concentrations in stream water and organic material are related to various geological parameters such as rock types, average uranium content and radioactivity, fracturing, leachability of uranium from the bedrock, occurrence of uranium mineralisations and thickness and type of Quarternary deposits. The investigation has also taken account of the effects of environmental factors such as climate , precipitation, height above sea level and topography. The background concentration of uranium in organic stream sediment varies from 1 ppm to 45 ppm, with a background value of 10 ppm for all 14 areas considered together. The threshold value for organic stream material varies from 3 ppm U to 303 ppm U with a threshold value of 133 ppm U for all 14 areas considered together. For water, the background concentration varies between the 5 areas from 0.2 ppb U to 0.7 ppb U with a background value of 0.4 ppb U for all 5 areas together. The threshold value varies from 0.3 ppb U to 5.2 ppb U with a threshold value of 2.9 ppb U for all 5 areas together. An investigation of the correlation between uranium concentrations in water and organic stream material from one and the same sampling point shows a positive correlation for high concentrations, but the correlation becomes successively less significant with lower concentrations. Uranium concentrations in organic stream material and water are positively correlated with the following geological parameters:1) Background concentrations of uranium in the bedrock. 2) Abundance of fractures in the bedrock. 3) Leachability of uranium from the bedrock. 4) Presence of uranium mineralisations. For organic stream material, this positive correlation is obtained for both high and low uranium concentrations whereas for water it occurs only with high concentrations. In areas of broken topography and high relief, there is a more clearly defined correlation to the bedrock than in areas of

  2. Adjustment of geochemical background by robust multivariate statistics

    Science.gov (United States)

    Zhou, D.

    1985-01-01

    Conventional analyses of exploration geochemical data assume that the background is a constant or slowly changing value, equivalent to a plane or a smoothly curved surface. However, it is better to regard the geochemical background as a rugged surface, varying with changes in geology and environment. This rugged surface can be estimated from observed geological, geochemical and environmental properties by using multivariate statistics. A method of background adjustment was developed and applied to groundwater and stream sediment reconnaissance data collected from the Hot Springs Quadrangle, South Dakota, as part of the National Uranium Resource Evaluation (NURE) program. Source-rock lithology appears to be a dominant factor controlling the chemical composition of groundwater or stream sediments. The most efficacious adjustment procedure is to regress uranium concentration on selected geochemical and environmental variables for each lithologic unit, and then to delineate anomalies by a common threshold set as a multiple of the standard deviation of the combined residuals. Robust versions of regression and RQ-mode principal components analysis techniques were used rather than ordinary techniques to guard against distortion caused by outliers Anomalies delineated by this background adjustment procedure correspond with uranium prospects much better than do anomalies delineated by conventional procedures. The procedure should be applicable to geochemical exploration at different scales for other metals. ?? 1985.

  3. Scheme dependence of quantum gravity on de Sitter background

    Energy Technology Data Exchange (ETDEWEB)

    Kitamoto, Hiroyuki, E-mail: kitamoto@post.kek.jp [KEK Theory Center, Tsukuba, Ibaraki 305-0801 (Japan); Kitazawa, Yoshihisa, E-mail: kitazawa@post.kek.jp [KEK Theory Center, Tsukuba, Ibaraki 305-0801 (Japan); The Graduate University for Advanced Studies (Sokendai), Department of Particle and Nuclear Physics, Tsukuba, Ibaraki 305-0801 (Japan)

    2013-08-11

    We extend our investigation of the IR effects on the local dynamics of matter fields in quantum gravity. Specifically we clarify how the IR effects depend on the change of the quantization scheme: different parametrization of the metric and the matter field redefinition. Conformal invariance implies effective Lorentz invariance of the matter system in de Sitter space. An arbitrary choice of the parametrization of the metric and the matter field redefinition does not preserve the effective Lorentz invariance of the local dynamics. As for the effect of different parametrization of the metric alone, the effective Lorentz symmetry breaking term can be eliminated by shifting the background metric. In contrast, we cannot compensate the matter field redefinition dependence by such a way. The effective Lorentz invariance can be retained only when we adopt the specific matter field redefinitions where all dimensionless couplings become scale invariant at the classical level. This scheme is also singled out by unitarity as the kinetic terms are canonically normalized.

  4. Defining and modeling the soil geochemical background of heavy metals from the Hengshi River watershed (southern China): Integrating EDA, stochastic simulation and magnetic parameters

    International Nuclear Information System (INIS)

    Zhou Xu; Xia Beicheng

    2010-01-01

    It is crucial to separate the soil geochemical background concentrations from anthropogenic anomalies and to provide a realistic environmental geochemical map honoring the fluctuations in original data. This study was carried out in the Hengshi River watershed, north of Guangdong, China and the method proposed combined exploratory data analysis (EDA), sequential indicator co-simulation (SIcS) and the ratio of isothermal remnant magnetization (S 100 = -IRM -100mT /SIRM). The results showed that this is robust procedure for defining and mapping soil geochemical background concentrations in mineralized regions. The rock magnetic parameter helps to improve the mapping process by distinguishing anthropogenic influences. In this study, the geochemical backgrounds for four potentially toxic heavy metals (copper 200 mg/kg; zinc 230 mg/kg; lead 190 mg/kg and cadmium 1.85 mg/kg) Cu, Zn and Cd exceeded the soil Grade II limits (for pH < 6.5) from the Chinese Environmental Quality Standard for Soils (GB 15618-1995) (EQSS) which are 100, 200, 250 and 0.3 mg/kg for Cu, Zn, Pb and Cd, respectively. In particular, the geochemical background level for Cd exceeds standard six times. Results suggest that local public health is at high-risk along the riparian region of the Hengshi River, although the watershed ecosystem has not been severely disturbed.

  5. Background enhancement in breast MR: Correlation with breast density in mammography and background echotexture in ultrasound

    International Nuclear Information System (INIS)

    Ko, Eun Sook; Lee, Byung Hee; Choi, Hye Young; Kim, Rock Bum; Noh, Woo-Chul

    2011-01-01

    Objective: This study aimed to determine whether background enhancement on MR was related to mammographic breast density or ultrasonographic background echotexture in premenopausal and postmenopausal women. Materials and methods: We studied 142 patients (79 premenopausal, 63 postmenopausal) who underwent mammography, ultrasonography, and breast MR. We reviewed the mammography for overall breast density of the contralateral normal breast according to the four-point scale of the BI-RADS classification. Ultrasound findings were classified as homogeneous or heterogeneous background echotexture according to the BI-RADS lexicon. We rated background enhancement on a contralateral breast MR into four categories based on subtraction images: absent, mild, moderate, and marked. All imaging findings were interpreted independently by two readers without knowledge of menstrual status, imaging findings of other modalities. Results: There were significant differences between the premenopausal and postmenopausal group in distribution of mammographic breast density, ultrasonographic background echotexture, and degree of background enhancement. Regarding the relationship between mammographic density and background enhancement, there was no significant correlation. There was significant relationship between ultrasonographic background echotexture and background enhancement in both premenopausal and postmenopausal groups. Conclusion: There is a significant correlation between ultrasonographic background echotexture and background enhancement in MR regardless of menopausal status. Interpreting breast MR, or scheduling for breast MR of women showing heterogeneous background echotexture needs more caution.

  6. Measurements of Worldwide Radioxenon Backgrounds - The "EU" Project

    Energy Technology Data Exchange (ETDEWEB)

    Bowyer, Ted W.; Cooper, Matthew W.; Hayes, James C.; Forrester, Joel B.; Haas, Derek A.; Hansen, Randy R.; Keller, Paul E.; Kirkham, Randy R.; Lidey, Lance S.; McIntyre, Justin I.; Miley, Harry S.; Payne, Rosara F.; Saey, Paul R.; Thompson, Robert C.; Woods, Vincent T.; Williams, Richard M.

    2009-09-24

    Under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), radioactive xenon (radioxenon) measurements are one of the principle techniques used to detect nuclear underground nuclear explosions, and specifically, the presence of one or more radioxenon isotopes allows one to determine whether a suspected event was a nuclear explosion or originated from an innocent source. During the design of the International Monitoring System (IMS), which was designed as the verification mechanism for the Treaty, it was determined that radioxenon measurements should be performed at 40 or more stations worldwide. At the time of the design of the IMS, however, very few details about the background of the xenon isotopes was known and it is now recognized that the backgrounds were probably evolving anyhow. This paper lays out the beginning of a study of the worldwide concentrations of xenon isotopes that can be used to detect nuclear explosions and several sources that also release radioxenons, and will have to be accounted for during analysis of atmospheric levels. Although the global concentrations of the xenon isotopes are the scope of a much larger activity that could span over several years, this study measures radioxenon concentrations in locations where there was either very little information or there was a unique opportunity to learn more about emissions from known sources. The locations where radioxenon levels were measured and reported are included.

  7. Ambient air quality of karachi city as reflected by atmospheric particulate matter (PM/sub 10/) concentrations

    International Nuclear Information System (INIS)

    Hashmi, D.R.; Shareef, A.

    2016-01-01

    The present study examines the variation of ambient aerosol (PM/sub 10/) concentrations in Karachi, city. Samples were collected from ten different locations, representative of urban background, residential, traffic and industrial areas from 2007 to 2011. At each location, PM/sub 10/) was measured continuously from 08:00 am to 06:00 pm at local time. The maximum 10 h average particulate matter (PM/sub 10/) mass concentrations were found at Tibet Centre (440.1 mg/m/sup 3/) and minimum at PCSIR Campus (21.7 mg/m/sup 3/) during 2008. A rising trend during 2008 may be due to the civil works for bridges and extension of roads at different locations in Karachi. The results also suggest that urban traffic and industrial areas appeared to have higher PM/sub 10/) concentration than residential and background areas. (author)

  8. Th, U, Ra and rare earth element distributions in farm animal tissues from an elevated natural radiation background environment

    International Nuclear Information System (INIS)

    Linsalata, Paul; Morse, Robert; Ford, Helen; Eisenbud, Merril; Franca, E.P.; de Castro, M.B.; Lobao, Nazyo; Sachett, Ivanor; Carlos, Marcia

    1991-01-01

    A field study was conducted in an area of elevated natural background radioactivity (the Pocos de Caldas plateau, Brazil) to assess tissue concentrations and the comparative bioavailability of isotopic Th (IV), U (IV, VI), Ra (II) and light rare earth elements (REE), i.e. La (III) and Ce (III, IV) in adult steers, pigs and chickens. The assessment of comparative bioavailability was aided by normalizing tissue concentrations to local soil concentrations, i.e. by calculating soil-to-tissue concentration ratios (CRs). Mean CRs (for muscle/soil) in these animals were very similar for U, La and Th which, as a group, decreased among the farm animals sampled as (all x 10 -4 ): chicken (1) ≥ steer (0.7) ≥ pig (0.4). For 226 Ra, CRs in muscle decreased in the same order among animals although mean values were 3-5 times greater than those quoted. Much greater values and greater differences among the elements are noted for bone/soil CRs, which for all animals decreased as: Ra >> U > La=Th, indicating the order of elemental bioavailability (assuming bone to be the major retention compartment). Isotopic ratios in farm animal tissue are shown to resemble closely those in soils over which the animals forage, with few exceptions, indicating the importance of the soil component in the transfer of these elements to tissues. (author)

  9. A Numerical and Experimental Study of Local Exhaust Capture Efficiency

    DEFF Research Database (Denmark)

    Madsen, U.; Breum, N. O.; Nielsen, Peter Vilhelm

    1993-01-01

    Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods for estim...... location is less important for the case studied. The choice of sampling strategy to obtain a representative background concentration is essential as substantial differences on direct capture efficiency are found. Recommendations are given......Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods...... for estimation of direct capture efficiency are given: (1) a numerical method based on the time-averaged Navier-Stokes equations for turbulent flows; and (2) a field method based on a representative background concentration. Direct capture efficiency is sensitive to the size of the control box, whereas its...

  10. The background in the experiment Gerda

    Science.gov (United States)

    Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barnabé Heider, M.; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Cossavella, F.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Ferella, A.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Guthikonda, K. K.; Hampel, W.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Liu, X.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Machado, A. A.; Majorovits, B.; Maneschg, W.; Nemchenok, I.; Nisi, S.; O'Shaughnessy, C.; Palioselitis, D.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Tarka, M.; Ur, C. A.; Vasenko, A. A.; Volynets, O.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2014-04-01

    The GERmanium Detector Array ( Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta () decay of Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the value of the decay. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around . The main parameters needed for the analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around with a background index ranging from 17.6 to 23.8 cts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model are consistent. The observed number of events in this energy region is consistent with the background model. The background at is dominated by close sources, mainly due to K, Bi, Th, Co and emitting isotopes from the Ra decay chain. The individual fractions depend on the assumed locations of the contaminants. It is shown, that after removal of the known peaks, the energy spectrum can be fitted in an energy range of 200 keV around with a constant background. This gives a background index consistent with the full model and uncertainties of the same size.

  11. The spinorial geometry of supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Gillard, J; Gran, U; Papadopoulos, G

    2005-01-01

    We propose a new method to solve the Killing spinor equations of 11-dimensional supergravity based on a description of spinors in terms of forms and on the Spin(1, 10) gauge symmetry of the supercovariant derivative. We give the canonical form of Killing spinors for backgrounds preserving two supersymmetries, N = 2, provided that one of the spinors represents the orbit of Spin(1, 10) with stability subgroup SU(5). We directly solve the Killing spinor equations of N = 1 and some N = 2, N = 3 and N = 4 backgrounds. In the N = 2 case, we investigate backgrounds with SU(5) and SU(4) invariant Killing spinors and compute the associated spacetime forms. We find that N = 2 backgrounds with SU(5) invariant Killing spinors admit a timelike Killing vector and that the space transverse to the orbits of this vector field is a Hermitian manifold with an SU(5)-structure. Furthermore, N = 2 backgrounds with SU(4) invariant Killing spinors admit two Killing vectors, one timelike and one spacelike. The space transverse to the orbits of the former is an almost Hermitian manifold with an SU(4)-structure. The spacelike Killing vector field leaves the almost complex structure invariant. We explore the canonical form of Killing spinors for backgrounds preserving more than two supersymmetries, N > 2. We investigate a class of N = 3 and N = 4 backgrounds with SU(4) invariant spinors. We find that in both cases the space transverse to a timelike vector field is a Hermitian manifold equipped with an SU(4)-structure and admits two holomorphic Killing vector fields. We also present an application to M-theory Calabi-Yau compactifications with fluxes to one dimension

  12. The spinorial geometry of supersymmetric backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, J; Gran, U; Papadopoulos, G [Department of Mathematics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2005-03-21

    We propose a new method to solve the Killing spinor equations of 11-dimensional supergravity based on a description of spinors in terms of forms and on the Spin(1, 10) gauge symmetry of the supercovariant derivative. We give the canonical form of Killing spinors for backgrounds preserving two supersymmetries, N = 2, provided that one of the spinors represents the orbit of Spin(1, 10) with stability subgroup SU(5). We directly solve the Killing spinor equations of N = 1 and some N = 2, N = 3 and N = 4 backgrounds. In the N = 2 case, we investigate backgrounds with SU(5) and SU(4) invariant Killing spinors and compute the associated spacetime forms. We find that N = 2 backgrounds with SU(5) invariant Killing spinors admit a timelike Killing vector and that the space transverse to the orbits of this vector field is a Hermitian manifold with an SU(5)-structure. Furthermore, N = 2 backgrounds with SU(4) invariant Killing spinors admit two Killing vectors, one timelike and one spacelike. The space transverse to the orbits of the former is an almost Hermitian manifold with an SU(4)-structure. The spacelike Killing vector field leaves the almost complex structure invariant. We explore the canonical form of Killing spinors for backgrounds preserving more than two supersymmetries, N > 2. We investigate a class of N = 3 and N = 4 backgrounds with SU(4) invariant spinors. We find that in both cases the space transverse to a timelike vector field is a Hermitian manifold equipped with an SU(4)-structure and admits two holomorphic Killing vector fields. We also present an application to M-theory Calabi-Yau compactifications with fluxes to one dimension.

  13. Environmental gamma background measurements in China Jinping Underground Laboratory

    International Nuclear Information System (INIS)

    Zhi Zeng; Jian Su; Hao Ma; Hengguan Yi; Jianping Cheng; Qian Yue; Junli Li; Hui Zhang

    2014-01-01

    To determine the environmental gamma background levels which affects rare events experiments, we measured in situ gamma spectrum at four locations in the China Jinping Underground Laboratory. The integral background count rates (40-2,700 keV) varied from 3.76 to 74.1 cps. The average count rate of the measurements inside the CJPL was 73.4 cps. The spectrometer was calibrated with a 152 Eu point source and Monte Carlo simulation to obtain the activity conversion factors for the rock and the air, respectively. The rocks that surrounded the CJPL was characterized by very low activity concentrations of 238 U (3.69-4.21 Bq kg -1 ), 232 Th (0.52-0.64 Bq kg -1 ) and 40 K (4.28 Bq kg -1 ). (author)

  14. The Milky Way, the Local Group & the IR Tully-Fisher Diagram

    Science.gov (United States)

    Malhotra, S.; Spergel, D.; Rhoads, J.; Li, J.

    1996-01-01

    Using the near infrared fluxes of local group galaxies derived from Cosmic Background Explorer/Diffuse Infrared Background Experiment band maps and published Cepheid distances, we construct Tully-Fisher diagrams for the Local Group.

  15. Ablation plume dynamics in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during the expa......The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during...... the expansion. The model also leads to an insightful treatment of the stopping behavior in dimensionless units for plumes and background gases of different atomic/molecular masses. The energetics of the plume dynamics can also be treated with this model. Experimental time-of-flight data of silver ions in a neon...... background gas show a fair agreement with predictions from the PM-model. Finally we discuss the validity of the model, if the work done by the pressure of the background gas is neglected....

  16. Measurements of the cosmic background radiation

    International Nuclear Information System (INIS)

    Weiss, R.

    1980-01-01

    Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed. Attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist

  17. Background radioactivity in sediments near Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    McLin, Stephen G.

    2004-01-01

    remained relatively constant since the early 1980s. These results suggest that clay contents in terrestrial sediments are often more important at concentrating background radionuclides than many other environmental factors, including geology, climate and vegetation. Hence, reservoirs and floodplains represent ideal radionuclide sampling locations because fine-grained materials are more easily trapped here. Ultimately, most of these differences still reflect spatial and temporal variability originating from global atmospheric nuclear weapons testing and disintegration of nuclear-powered satellites upon atmospheric reentry

  18. Local posterior concentration rate for multilevel sparse sequences

    NARCIS (Netherlands)

    Belitser, E.N.; Nurushev, N.

    2017-01-01

    We consider empirical Bayesian inference in the many normal means model in the situation when the high-dimensional mean vector is multilevel sparse, that is,most of the entries of the parameter vector are some fixed values. For instance, the traditional sparse signal is a particular case (with one

  19. [Establishment and assessment of QA/QC method for sampling and analysis of atmosphere background CO2].

    Science.gov (United States)

    Liu, Li-xin; Zhou, Ling-xi; Xia, Ling-jun; Wang, Hong-yang; Fang, Shuang-xi

    2014-12-01

    To strengthen scientific management and sharing of greenhouse gas data obtained from atmospheric background stations in China, it is important to ensure the standardization of quality assurance and quality control method for background CO2 sampling and analysis. Based on the greenhouse gas sampling and observation experience of CMA, using portable sampling observation and WS-CRDS analysis technique as an example, the quality assurance measures for atmospheric CO,sampling and observation in the Waliguan station (Qinghai), the glass bottle quality assurance measures and the systematic quality control method during sample analysis, the correction method during data processing, as well as the data grading quality markers and data fitting interpolation method were systematically introduced. Finally, using this research method, the CO2 sampling and observation data at the atmospheric background stations in 3 typical regions were processed and the concentration variation characteristics were analyzed, indicating that this research method could well catch the influences of the regional and local environmental factors on the observation results, and reflect the characteristics of natural and human activities in an objective and accurate way.

  20. Diffuse material, background radiation and the early universe

    International Nuclear Information System (INIS)

    Rees, M.J.

    1980-01-01

    Observations that relate to a qualitative picture of how galaxies formed, and what the Universe was really like at still earlier times, are presented. Some lines of evidence on the universe at redshifts out to z approximately equal to 5 are discussed, concentrating on the evidence which suggests that intergalactic medium has evolved in a 'multi phase' fashion. Some aspects of the less recent history of the Universe (i.e z approximately greater than 100) are considered, particularly the microwave background and the spectrum of inhomogeneities. (Auth.)

  1. Background harmonic superfields in N=2 supergravity

    International Nuclear Information System (INIS)

    Zupnik, B.M.

    1998-01-01

    A modification of the harmonic superfield formalism in D=4, N=2 supergravity using a subsidiary condition of covariance under the background supersymmetry with a central charge (B-covariance) is considered. Conservation of analyticity together with the B-covariance leads to the appearance of linear gravitational superfields. Analytic prepotentials arise in a decomposition of the background linear superfields in terms of spinor coordinates and transform in a nonstandard way under the background supersymmetry. The linear gravitational superfields can be written via spinor derivatives of nonanalytic spinor prepotentials. The perturbative expansion of supergravity action in terms of the B-covariant superfields and the corresponding version of the differential-geometric formalism are considered. We discuss the dual harmonic representation of the linearized extended supergravity, which corresponds to the dynamical condition of Grassmann analyticity

  2. Background modeling for the GERDA experiment

    Science.gov (United States)

    Becerici-Schmidt, N.; Gerda Collaboration

    2013-08-01

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qββ come from 214Bi, 228Th, 42K, 60Co and α emitting isotopes in the 226Ra decay chain, with a fraction depending on the assumed source positions.

  3. Background modeling for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, N. [Max-Planck-Institut für Physik, München (Germany); Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  4. In-beam background suppression shield

    DEFF Research Database (Denmark)

    Santoro, V.; Cai, Xiao Xiao; DiJulio, D. D.

    2015-01-01

    The long (3 ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument's capabilities will be limited by its Signal to Noise (S/N) ratio. The instruments with a direct view of the moderator......, which do not use a bender to help mitigate the fast neutron background, are the most challenging. For these beam lines we propose the innovative shielding of placing blocks of material directly into the guide system, which allow a minimum attenuation of the cold and thermal fluxes relative...... to the background suppression. This shielding configuration has been worked into a beam line model using Geant4. We study particularly the advantages of single crystal sapphire and silicon blocks....

  5. Background Model for the Majorana Demonstrator

    Science.gov (United States)

    Cuesta, C.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Combs, D. C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.

  6. Background compensation for a radiation level monitor

    Science.gov (United States)

    Keefe, D.J.

    1975-12-01

    Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

  7. Non-perturbative background field calculations

    International Nuclear Information System (INIS)

    Stephens, C.R.; Department of Physics, University of Utah, Salt Lake City, Utah 84112)

    1988-01-01

    New methods are developed for calculating one loop functional determinants in quantum field theory. Instead of relying on a calculation of all the eigenvalues of the small fluctuation equation, these techniques exploit the ability of the proper time formalism to reformulate an infinite dimensional field theoretic problem into a finite dimensional covariant quantum mechanical analog, thereby allowing powerful tools such as the method of Jacobi fields to be used advantageously in a field theory setting. More generally the methods developed herein should be extremely valuable when calculating quantum processes in non-constant background fields, offering a utilitarian alternative to the two standard methods of calculation: perturbation theory in the background field or taking the background field into account exactly. The formalism developed also allows for the approximate calculation of covariances of partial differential equations from a knowledge of the solutions of a homogeneous ordinary differential equation. copyright 1988 Academic Press, Inc

  8. Origin of the diffuse background gamma radiation

    International Nuclear Information System (INIS)

    Stecker, F.W.; Puget, J.L.

    1974-05-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

  9. Cosmic microwave background distortions at high frequencies

    International Nuclear Information System (INIS)

    Peter, W.; Peratt, A.L.

    1988-01-01

    The authors analyze the deviation of the cosmic background radiation spectrum from the 2.76+-0.02 0 Κ blackbody curve. If the cosmic background radiation is due to absorption and re-emission of synchrotron radiation from galactic-width current filaments, higher-order synchrotron modes are less thermalized than lower-order modes, causing a distortion of the blackbody curve at higher frequencies. New observations of the microwave background spectrum at short wavelengths should provide an indication of the number of synchrotron modes thermalized in this process. The deviation of the spectrum from that of a perfect blackbody can thus be correlated with astronomical observations such as filament temperatures and electron energies. The results are discussed and compared with the theoretical predictions of other models which assume the presence of intergalactic superconducting cosmic strings

  10. Non-perturbative background field calculations

    Science.gov (United States)

    Stephens, C. R.

    1988-01-01

    New methods are developed for calculating one loop functional determinants in quantum field theory. Instead of relying on a calculation of all the eigenvalues of the small fluctuation equation, these techniques exploit the ability of the proper time formalism to reformulate an infinite dimensional field theoretic problem into a finite dimensional covariant quantum mechanical analog, thereby allowing powerful tools such as the method of Jacobi fields to be used advantageously in a field theory setting. More generally the methods developed herein should be extremely valuable when calculating quantum processes in non-constant background fields, offering a utilitarian alternative to the two standard methods of calculation—perturbation theory in the background field or taking the background field into account exactly. The formalism developed also allows for the approximate calculation of covariances of partial differential equations from a knowledge of the solutions of a homogeneous ordinary differential equation.

  11. Project plan for the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1992-08-01

    The Background Soil characterization Project (BSCP) will provide background concentration levels of selected metals, organic compounds, and radionuclides in soils from uncontaminated on-site areas at the Oak Ridge Reservation (ORR), and off-site in the western part of Roane County and the eastern part of Anderson County. The BSCP will establish a database, recommend how to use the data for contaminated site assessment, and provide estimates of the potential human health and environmental risks associated with the background level concentrations of potentially hazardous constituents

  12. Project plan for the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    The Background Soil characterization Project (BSCP) will provide background concentration levels of selected metals, organic compounds, and radionuclides in soils from uncontaminated on-site areas at the Oak Ridge Reservation (ORR), and off-site in the western part of Roane County and the eastern part of Anderson County. The BSCP will establish a database, recommend how to use the data for contaminated site assessment, and provide estimates of the potential human health and environmental risks associated with the background level concentrations of potentially hazardous constituents.

  13. Background characterization for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, Neslihan [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The GERmanium Detector Array (Gerda) experiment at the LNGS laboratory of INFN searches for the neutrinoless double beta (0νββ) decay of {sup 76}Ge. A discovery of this decay can greatly advance our knowledge on the nature and properties of neutrinos. The current best limit on the half-life of {sup 76}Ge 0νββ decay is 1.9 . 10{sup 25} years (90% C.L.). In order to increase the sensitivity on the half-life with respect to past experiments, the background rate in the energy region of interest (ROI) around Q{sub ββ} = 2039 keV has been reduced by a factor 10. Gerda started data-taking with the full set of Phase I detectors in November 2011. Identification of the background in the first phase of the experiment is of major importance to further mitigate the background for Gerda Phase II. An analysis of the Phase I data resulted in a good understanding of the individual components in the Gerda background spectrum. The background components in the ROI have been identified to be mainly due to β- and γ-induced events originating from {sup 214}Bi ({sup 238}U-series), {sup 208}Tl ({sup 232}Th-series), {sup 42}K (progeny of {sup 42}Ar) and α-induced events coming from isotopes in the {sup 226}Ra decay chain. A background decomposition in the ROI will be presented, with a special emphasis on the contribution from α-induced events.

  14. Background simulation for the GENIUS project

    International Nuclear Information System (INIS)

    Ponkratenko, O.A.; Tretyak, V.I.; Zdesenko, Yu.G.

    1999-01-01

    The background simulations for the GENIUS experiment were performed with the help of GEANT 3.21 package and event generator DECAY 4.Contributions from the cosmogenic activity produced in the Ge detectors and from its radioactive impurities as well as from contamination of the liquid nitrogen and other materials were calculated.External gamma and neutron background were taking into consideration also.The results of calculations evidently show feasibility of the GENIUS project,which can substantially promote development of modern astroparticle physics

  15. Electromagnetic wave collapse in a radiation background

    International Nuclear Information System (INIS)

    Marklund, Mattias; Brodin, Gert; Stenflo, Lennart

    2003-01-01

    The nonlinear interaction, due to quantum electrodynamical (QED) effects between an electromagnetic pulse and a radiation background, is investigated by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse, we obtain a Zakharov-like system, where the radiation pressure of the pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently intense pulse and/or background energy density, there is focusing and the subsequent collapse of the pulse. The relevance of our results for various astrophysical applications are discussed

  16. Optimization of the ECT background coil

    International Nuclear Information System (INIS)

    Ballou, J.K.; Luton, J.N.

    1975-01-01

    This study was begun to optimize the Eccentric Coil Test (ECT) background coil. In the course of this work a general optimization code was obtained, tested, and applied to the ECT problem. So far this code has proven to be very satisfactory. The results obtained with this code and earlier codes have illustrated the parametric behavior of such a coil system and that the optimum for this type system is broad. This study also shows that a background coil with a winding current density of less than 3000 A/cm 2 is not feasible for the ECT models presented in this paper

  17. Elastic lattice in an incommensurate background

    International Nuclear Information System (INIS)

    Dickman, R.; Chudnovsky, E.M.

    1995-01-01

    We study a harmonic triangular lattice, which relaxes in the presence of an incommensurate short-wavelength potential. Monte Carlo simulations reveal that the elastic lattice exhibits only short-ranged translational correlations, despite the absence of defects in either lattice. Extended orientational order, however, persists in the presence of the background. Translational correlation lengths exhibit approximate power-law dependence upon cooling rate and background strength. Our results may be relevant to Wigner crystals, atomic monolayers on crystals surfaces, and flux-line and magnetic bubble lattices

  18. Cognitive psychology and depth psychology backgrounds

    International Nuclear Information System (INIS)

    Fritzsche, A.F.

    1986-01-01

    The sixth chapter gives an insight into the risk perception process which is highly determined by emotions, and, thus, deals with the psychological backgrounds of both the conscious cognitive and the subconscious intuitive realms of the human psyche. The chapter deals with the formation of opinion and the origination of an attitude towards an issue; cognitive-psychological patterns of thinking from the field of risk perception; the question of man's rationality; pertinent aspects of group behaviour; depth psychological backgrounds of the fear of technology; the collective subconscious; nuclear energy as a preferred object of projection for various psychological problems of modern man. (HSCH) [de

  19. A low background pulsed neutron polyenergetic beam

    International Nuclear Information System (INIS)

    Adib, M.; Abdelkawy, A.; Habib, N.; abuelela, M.; Wahba, M.; kilany, M.; Kalebebin, S.M.

    1992-01-01

    A low background pulsed neutron polyenergetic thermal beam at ET-R R-1 is produced by a rotor and rotating collimator suspended in magnetic fields. Each of them is mounted on its mobile platform and whose centres are 66 cm apart, rotating synchronously at speeds up to 16000 rpm. It was found that the neutron burst produced by the rotor with almost 100% transmission passes through the collimator, when the rotation phase between them is 28.8 degree Moreover the background level achieved at the detector position is low, constant and free from peaks due to gamma rays and fast neutrons accompanying the reactor thermal beam.3 fig

  20. Noise correlations in cosmic microwave background experiments

    Science.gov (United States)

    Dodelson, Scott; Kosowsky, Arthur; Myers, Steven T.

    1995-01-01

    Many analysis of microwave background experiments neglect the correlation of noise in different frequency of polarization channels. We show that these correlations, should they be present, can lead to serve misinterpretation of an experiment. In particular, correlated noise arising from either electronics or atmosphere may mimic a cosmic signal. We quantify how the likelihood function for a given experiment varies with noise correlation, using both simple analytic models and actual data. For a typical microwave background anisotropy experiment, noise correlations at the level of 1% of the overall noise can seriously reduce the significance of a given detection.