WorldWideScience

Sample records for water mass distribution

  1. Mass size distribution of particle-bound water

    Science.gov (United States)

    Canepari, S.; Simonetti, G.; Perrino, C.

    2017-09-01

    The thermal-ramp Karl-Fisher method (tr-KF) for the determination of PM-bound water has been applied to size-segregated PM samples collected in areas subjected to different environmental conditions (protracted atmospheric stability, desert dust intrusion, urban atmosphere). This method, based on the use of a thermal ramp for the desorption of water from PM samples and the subsequent analysis by the coulometric KF technique, had been previously shown to differentiate water contributes retained with different strength and associated to different chemical components in the atmospheric aerosol. The application of the method to size-segregated samples has revealed that water showed a typical mass size distribution in each one of the three environmental situations that were taken into consideration. A very similar size distribution was shown by the chemical PM components that prevailed during each event: ammonium nitrate in the case of atmospheric stability, crustal species in the case of desert dust, road-dust components in the case of urban sites. The shape of the tr-KF curve varied according to the size of the collected particles. Considering the size ranges that better characterize the event (fine fraction for atmospheric stability, coarse fraction for dust intrusion, bi-modal distribution for urban dust), this shape is coherent with the typical tr-KF shape shown by water bound to the chemical species that predominate in the same PM size range (ammonium nitrate, crustal species, secondary/combustion species - road dust components).

  2. Water masses and property distribution in the EEZ of Mauritius

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Singbal, S.Y.S.; George, M.D.

    Water masses and their properties have been studied in the Mauritian during September-October, 1987. Surface water is characterizEd. by two water masses: 1) a warm (temp. 27 degrees C) and relatively saline water (salinity 35.3 x 10 sup(-3)) which...

  3. Water masses in the Humboldt Current System: Properties, distribution, and the nitrate deficit as a chemical water mass tracer for Equatorial Subsurface Water off Chile

    Science.gov (United States)

    Silva, Nelson; Rojas, Nora; Fedele, Aldo

    2009-07-01

    Three sections are used to analyze the physical and chemical characteristics of the water masses in the eastern South Pacific and their distributions. Oceanographic data were taken from the SCORPIO (May-June 1967), PIQUERO (May-June 1969), and KRILL (June 1974) cruises. Vertical sections of temperature, salinity, σ θ, dissolved oxygen, nitrate, nitrite, phosphate, and silicate were used to analyze the water column structure. Five water masses were identified in the zone through T- S diagrams: Subantarctic Water, Subtropical Water, Equatorial Subsurface Water, Antarctic Intermediate Water, and Pacific Deep Water. Their proportions in the sea water mixture are calculated using the mixing triangle method. Vertical sections were used to describe the geographical distributions of the water mass cores in the upper 1500 m. Several characteristic oceanographic features in the study area were analyzed: the shallow salinity minimum displacement towards the equator, the equatorial subsurface salinity maximum associated with a dissolved oxygen minimum zone and a high nutrient content displacement towards the south, and the equatorward intermediate Antarctic salinity minimum associated with a dissolved oxygen maximum. The nitrate deficit generated in the denitrification area off Peru and northern Chile is proposed as a conservative chemical tracer for the Equatorial Subsurface Waters off the coast of Chile, south of 25°S.

  4. Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

    Science.gov (United States)

    García-Ibáñez, Maribel I.; Pérez, Fiz F.; Lherminier, Pascale; Zunino, Patricia; Mercier, Herlé; Tréguer, Paul

    2018-04-01

    We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP) analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW) dominated the upper part of the GEOTRACES-GA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland-Scotland Overflow Water (ISOW) and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section) by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014 OVIDE line and the 2002-2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002-2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002-2010, with the increase being consistent with other estimates of ISOW transports along 58-59° N. We also observed an increase in SPMW in the East Greenland Irminger Current in 2014 with respect to 2002-2010, which supports the recent deep convection events in the Irminger Sea. From the assessment of the relative water mass contribution to the Atlantic Meridional Overturning Circulation (AMOC) across the OVIDE line, we conclude that the larger AMOC intensity in

  5. Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

    Directory of Open Access Journals (Sweden)

    M. I. García-Ibáñez

    2018-04-01

    Full Text Available We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW dominated the upper part of the GEOTRACES-GA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland–Scotland Overflow Water (ISOW and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014 OVIDE line and the 2002–2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002–2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002–2010, with the increase being consistent with other estimates of ISOW transports along 58–59° N. We also observed an increase in SPMW in the East Greenland Irminger Current in 2014 with respect to 2002–2010, which supports the recent deep convection events in the Irminger Sea. From the assessment of the relative water mass contribution to the Atlantic Meridional Overturning Circulation (AMOC across the OVIDE line, we conclude

  6. Large-Scale Ichthyoplankton and Water Mass Distribution along the South Brazil Shelf

    Science.gov (United States)

    de Macedo-Soares, Luis Carlos Pinto; Garcia, Carlos Alberto Eiras; Freire, Andrea Santarosa; Muelbert, José Henrique

    2014-01-01

    Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27′ and 34°51′S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients. PMID:24614798

  7. Large-scale ichthyoplankton and water mass distribution along the South Brazil Shelf.

    Directory of Open Access Journals (Sweden)

    Luis Carlos Pinto de Macedo-Soares

    Full Text Available Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27' and 34°51'S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients.

  8. Large-scale ichthyoplankton and water mass distribution along the South Brazil Shelf.

    Science.gov (United States)

    de Macedo-Soares, Luis Carlos Pinto; Garcia, Carlos Alberto Eiras; Freire, Andrea Santarosa; Muelbert, José Henrique

    2014-01-01

    Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27' and 34°51'S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients.

  9. Spatial Distributions of DDTs in the Water Masses of the Arctic Ocean.

    Science.gov (United States)

    Carrizo, Daniel; Sobek, Anna; Salvadó, Joan A; Gustafsson, Örjan

    2017-07-18

    There is a scarcity of data on the amount and distribution of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolites in intermediate and deep ocean water masses. Here, the distribution and inventories of DDTs in water of the Arctic shelf seas and the interior basin are presented. The occurrence of ∑ 6 DDT (0.10-66 pg L -1 ) in the surface water was dominated by 4,4'-DDE. In the Central Arctic Ocean increasing concentrations of DDE with depth were observed in the Makarov and Amundsen basins. The increasing concentrations down to 2500 m depth is in accordance with previous findings for PCBs and PBDEs. Similar concentrations of DDT and DDEs were found in the surface water, while the relative contribution of DDEs increased with depth, demonstrating a transformation over time and depth. Higher concentrations of DDTs were found in the European part of the Arctic Ocean; these distributions likely reflect a combination of different usage patterns, transport, and fate of these compounds. For instance, the elevated concentrations of DDTs in the Barents and Atlantic sectors of the Arctic Ocean indicate the northbound Atlantic current as a significant conveyor of DDTs. This study contributes to the very rare data on OCPs in the vast deep-water compartments and combined with surface water distribution across the Arctic Ocean helps to improve our understanding of the large-scale fate of DDTs in the Arctic.

  10. Distribution and ventilation of water masses in the western Ross Sea inferred from CFC measurements

    Science.gov (United States)

    Rivaro, Paola; Ianni, Carmela; Magi, Emanuele; Massolo, Serena; Budillon, Giorgio; Smethie, William M.

    2015-03-01

    During the CLIMA Project (R.V. Italica cruise PNRA XVI, January-February 2001), hydrographic and chlorofluorocarbons (CFCs) observations were obtained, particularly in the western Ross Sea. Their distribution demonstrated water mass structure and ventilation processes in the investigated areas. In the surface waters (AASW) the CFC saturation levels varied spatially: CFCs were undersaturated in all the areas (range from 80 to 90%), with the exception of few stations sampled near Ross Island. In particular, the Terra Nova Bay polynya, where high salinity shelf water (HSSW) is produced, was a low-saturated surface area (74%) with respect to CFCs. Throughout most of the shelf area, the presence of modified circumpolar deep water (MCDW) was reflected in a mid-depth CFC concentration minima. Beneath the MCDW, CFC concentrations generally increased in the shelf waters towards the seafloor. We estimated that the corresponding CFCs saturation level in the source water region for HSSW was about 68-70%. Waters with high CFC concentrations were detected in the western Ross Sea on the down slope side of the Drygalski Trough, indicating that AABW was being supplied to the deep Antarctic Basin. Estimates of ventilation ages depend strongly on the saturation levels. We calculated ventilation ages using the saturation level calibrated tracer ratio, CFC11/CFC12. We deduced a mean residence time of the shelf waters of about 6-7 years between the western Ross Sea source and the shelf break.

  11. The Martian hydrologic cycle - Effects of CO2 mass flux on global water distribution

    Science.gov (United States)

    James, P. B.

    1985-01-01

    The Martian CO2 cycle, which includes the seasonal condensation and subsequent sublimation of up to 30 percent of the planet's atmosphere, produces meridional winds due to the consequent mass flux of CO2. These winds currently display strong seasonal and hemispheric asymmetries due to the large asymmetries in the distribution of insolation on Mars. It is proposed that asymmetric meridional advection of water vapor on the planet due to these CO2 condensation winds is capable of explaining the observed dessication of Mars' south polar region at the current time. A simple model for water vapor transport is used to verify this hypothesis and to speculate on the effects of changes in orbital parameters on the seasonal water cycle.

  12. Water mass distribution in Fram Strait and over the Yermak Plateau in summer 1997

    Directory of Open Access Journals (Sweden)

    B. Rudels

    Full Text Available The water mass distribution in northern Fram Strait and over the Yermak Plateau in summer 1997 is described using CTD data from two cruises in the area. The West Spitsbergen Current was found to split, one part recirculated towards the west, while the other part, on entering the Arctic Ocean separated into two branches. The main inflow of Atlantic Water followed the Svalbard continental slope eastward, while a second, narrower, branch stayed west and north of the Yermak Plateau. The water column above the southeastern flank of the Yermak Plateau was distinctly colder and less saline than the two inflow branches. Immediately west of the outer inflow branch comparatively high temperatures in the Atlantic Layer suggested that a part of the extraordinarily warm Atlantic Water, observed in the boundary current in the Eurasian Basin in the early 1990s, was now returning, within the Eurasian Basin, toward Fram Strait. The upper layer west of the Yermak Plateau was cold, deep and comparably saline, similar to what has recently been observed in the interior Eurasian Basin. Closer to the Greenland continental slope the salinity of the upper layer became much lower, and the temperature maximum of the Atlantic Layer was occasionally below 
    0.5 °C, indicating water masses mainly derived from the Canadian Basin. This implies that the warm pulse of Atlantic Water had not yet made a complete circuit around the Arctic Ocean. The Atlantic Water of the West Spitsbergen Current recirculating within the strait did not extend as far towards Greenland as in the 1980s, leaving a broader passage for waters from the Atlantic and intermediate layers, exiting the Arctic Ocean. A possible interpretation is that the circulation pattern alternates between a strong recirculation of the West Spitsbergen Current in the strait, and a larger exchange of Atlantic Water between the Nordic Seas and the inner parts of the Arctic Ocean.

    Key words: Oceanography: general

  13. Seasonal water mass distribution in the Indonesian throughflow entering the Indian Ocean

    Science.gov (United States)

    Coatanoan, C.; Metzl, N.; Fieux, M.; Coste, B.

    1999-09-01

    A multiparametric approach is used to analyze the seasonal properties of water masses in the eastern Indian Ocean. The data were measured during two cruises of the Java Australia Dynamic Experiment (JADE) program carried out during two opposite seasons: August 1989 (SE monsoon) and February-March 1992 (NW monsoon). These cruises took place at the end of a La Niña event and during an El Niño episode, respectively. Seven sources have been identified in the studied region for the 200-800 m layer: the Subtropical Indian Water, the Indian Central Water, the modified Antarctic Intermediate Water, the Indonesian Subsurface Water, the Indonesian Intermediate Water, the Arabian Sea-Persian Gulf Water (AS-PGW), and the Arabian Sea-Red Sea Water (AS-RSW). The selected tracers are potential temperature, salinity and oxygen with mass conservation and positive mixing coefficients as constraints. The analysis indicates the proportion of each water source along the Australia-Bali section and into the Indonesian channels. Although no large changes are observed for Indonesian waters, significant seasonal variations are found for the southern and northern Indian Ocean water. During the NW monsoon, the contribution of the AS-RSW increases at the entrance of the Indonesian archipelago whereas the contribution of the south Indian waters decreases in the northwest Australia basin. In a complementary study, nutrients are introduced into the multiparametric analysis in order to more clearly separate the signature of the north Indian waters (AS-PGW, AS-RSW) and to provide supplementary information on the biological history of the water masses, which is compared to large-scale primary production estimates.

  14. Calculation of mass flow and steam quality distribution on fuel elements of light-water cooled boiling water nuclear reactors

    International Nuclear Information System (INIS)

    Hermanns, H.J.

    1977-04-01

    By the example of light-water cooled nuclear reactors, the state of the calculation methods at disposal for calculating mass flow and steam quality distribution (sub-channel analysis) is indicated. Particular regard was paid to the transport phenomena occurring in reactor fuel elements in the range of two phase flow. Experimentally determined values were compared with recalculations of these experiments with the sub-channel code COBRA; from the results of these comparing calculations, conclusions could be drawn on the suitability of this code for defined applications. Limits of reliability could be determined to some extent. Based on the experience gained and the study of individual physical model concepts, recognized as being important, a sub-channel model was drawn up and the corresponding numerical computer code (SIEWAS) worked out. Experiments made at GE could be reproduced with the code SIEWAS with sufficient accuracy. (orig.) [de

  15. Distribution of oxygen isotopes in the water masses of Drake Passage and the South Atlantic

    Science.gov (United States)

    Meredith, Michael P.; Grose, Katie E.; McDonagh, Elaine L.; Heywood, Karen J.; Frew, Russell D.; Dennis, Paul F.

    1999-09-01

    Measurements of the ratio of stable isotopes of oxygen (18O and 16O) from samples collected on World Ocean Circulation Experiment sections SR1b (eastern Drake Passage) and A11 (Punta Arenas to Cape Town) are used, together with hydrographic data, to deduce information about the formation and variability of South Atlantic and Southern Ocean water masses. The Drake Passage surface waters south of the Polar Front (PF) are isotopically light (δ18O around -0.4‰) owing to the influence of meteoric waters. The salinity and δ18O of the A11 surface waters yield an apparent freshwater end-member which is much isotopically lighter than the local precipitation, thus advection of these waters from farther south dominates over local effects in determining the surface water properties. The Drake Passage section shows unusual proximity of the two main fronts of the Antarctic Circumpolar Current (the PF and Subantarctic Front (SAF)), and we observe cold, fresh, and isotopically light water derived from the temperature-minimum Winter Water at the SAF. This water is of the correct density to freshen the intermediate water north of the SAF and thus play a role in the formation of the comparatively fresh Antarctic Intermediate Water (AAIW) of the South Atlantic. This confirms the role of Antarctic water in forming the South Atlantic variety of AAIW. Across the A11 section the oxygen isotope and salinity data at the AAIW core show very similar traces, with waters in the Malvinas Current loop showing lowest values of both. At the eastern boundary of the South Atlantic, the input of Red Sea Water from east of South Africa is observed via the presence of anomalously isotopically heavy AAIW. We deduce potentially significant temporal variability in the isotopic composition of Weddell Sea Deep Water (WSDW) by comparing the Drake Passage data to earlier data covering the outflow of the Weddell Sea. The A11 data show WSDW consistent with such variability, indicating that its effects could

  16. Seasonal water mass distribution in the Indonesian throughflow entering the Indian Ocean

    OpenAIRE

    Coatanoan, Christine; Metzl, N; Fieux, M; Coste, B

    1999-01-01

    A multiparametric approach is used to analyze the seasonal properties of water masses in the eastern Indian Ocean. The data were measured during two cruises of the Java Australia Dynamic Experiment (JADE) program carried out during two opposite seasons: August 1989 (SE monsoon) and February-March 1992 (NW monsoon). These cruises took place at the end of a La Nina event and during an EI. Nino episode, respectively. Seven sources have been identified in the studied region for the 200-800 m laye...

  17. [Characteristics of mass size distributions of water-soluble, inorganic ions during summer and winter haze days of Beijing].

    Science.gov (United States)

    Huang, Yi-Min; Liu, Zi-Rui; Chen, Hong; Wang, Yue-Si

    2013-04-01

    To investigate the size distribution characteristics of water soluble inorganic ions in haze days, the particle samples were collected by two Andersen cascade impactors in Beijing during summer and winter time and each sampling period lasted two weeks. Online measurement of PM10 and PM2.5 using TEOM were also conducted at the same time. Sources and formation mechanism of water soluble inorganic ions were analyzed based on their size distributions. The results showed that average concentrations of PM10 and PM 2.5 were (245.5 +/- 8.4) microg x m(-3) and (120.2 +/- 2.0) microg x m(-3) during summer haze days (SHD), and were (384.2 +/- 30.2) microg x m(-3) and (252.7 +/- 47.1) microg x m(-3) during winter haze days (WHD), which suggested fine particles predominated haze pollution episode in both seasons. Total water-soluble inorganic ions concentrations were higher in haze days than those in non-haze days, especially in fine particles. Furthermore, concentrations of secondary inorganic ions (SO4(2-), NO3(-) and NH4(+)) increased quicker than other inorganic ions in fine particles during haze days, indicating secondary inorganic ions played an important role in the formation of haze pollution. Similar size distributions were found for all Sinorganic water soluble ions except for NO3(-), during SHD and WHD. SO4(2-) and NH4(+) dominated in the fine mode (PM1.0) while Mg2+ and Ca2+ accumulated in coarse fraction, Na+, Cl- and K+ showed a bimodal distribution. For NO3(-), however, it showed a bimodal distribution during SHD and a unimodal distribution dominated in the fine fraction was found during WHD. The average mass median aerodynamic diameter (MMAD) of SO4(2-) was 0.64 microm in SHD, which suggested the formation of SO4(2-) was mainly attributed to in-cloud processes. Furthermore, a higher apparent conversion rate of sulfur dioxide (SOR) was found in SHD, indicating more fine particles were produced by photochemical reaction in haze days than that in non-haze days. The

  18. Evaluation of Water Distribution and Oxygen Mass Transfer in Sponge Support Media for a Down-flow Hanging Sponge Reactor

    International Nuclear Information System (INIS)

    Uemura, S.; Okubo, T.; Maeno, K.; Takahashi, M.; Kubota, K.; Harada, H.

    2016-01-01

    A down-flow hanging sponge reactor has been developed for sewage treatment, mainly in developing countries. This novel reactor employs polyurethane sponge material as a support medium, which promises a proliferation of a large amount of biomass, offering excellent pollutant removal capability. Three types of sponge medium were evaluated with respect to water distribution and oxygen mass transfer. Water was supplied to the device, which consisted of 40 pieces of sponge media connected in series, and a tracer experiment was carried out. The ratios of actual hydraulic retention time to theoretical hydraulic retention time were in the range of 25-67% depending on the type of support medium. By supplying deoxygenated water from the top of the device, the overall volumetric oxygen transfer coefficient, K L a, was evaluated. Despite the non-aerated conditions, the K L a values of the support media were very high, in the range of 0.56-4.88 (1/min), surpassing those of other mechanically aerated processes. Furthermore, it was found that the suspended solids concentration in the influent played a role in increasing the actual hydraulic retention time/theoretical hydraulic retention time ratio, suggesting that managing the influent suspended solids concentration is prerequisite for preventing clogging problems in the down-flow hanging.

  19. Gas exchange and mass distribution of the cowpea (Vigna unguiculata [L.] Walp. under water deficit

    Directory of Open Access Journals (Sweden)

    Cardona-Ayala Carlos Enrique

    2013-12-01

    Full Text Available Drought tolerance is important for the survival and productivity of plants in environments where drought periods are increasing as a result of climate variability attributable to natural causes and climate change caused by human activities. The objective of this study was to evaluate the dynamics of photosynthesis (A, stomatal conductance (gs and intrinsic water-use efficiency (WUE=A/gs as a function of soil moisture content over a period of drought and the post-stress recovery of 14 cowpea genotypes. The studied genotypes tolerated soil moisture tensions close to -2 Mpa with no permanent wilting. Starting at a soil hydric potential of -0.7 MP a, decreases in photosynthesis (A, stomatal conductance (gs and transpiration (E were evident, as well as an increase in A/gs, which varied by genotype. Estimating with regression models allowed for the discrimination of the degrees of drought tolerance between the cultivars. At 4 days after resuming hydration, no significant differences were found between the means of A, gs, A/gs and E, suggesting drought tolerance in all genotypes. The genotypes: L-047 and L-034 conserved between 4 and 6 leaves, displaying the highest delayed leaf senescence during drought. Furthermore, they presented the highest biomass at 16 days post-stress recovery

  20. Drinking Water Distribution Systems

    Science.gov (United States)

    Learn about an overview of drinking water distribution systems, the factors that degrade water quality in the distribution system, assessments of risk, future research about these risks, and how to reduce cross-connection control risk.

  1. Mass distributions in disk galaxies

    NARCIS (Netherlands)

    Martinsson, Thomas; Verheijen, Marc; Bershady, Matthew; Westfall, Kyle; Andersen, David; Swaters, Rob

    We present results on luminous and dark matter mass distributions in disk galaxies from the DiskMass Survey. As expected for normal disk galaxies, stars dominate the baryonic mass budget in the inner region of the disk; however, at about four optical scale lengths (hR ) the atomic gas starts to

  2. The neutron star mass distribution

    Energy Technology Data Exchange (ETDEWEB)

    Kiziltan, Bülent [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kottas, Athanasios; De Yoreo, Maria [Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064 (United States); Thorsett, Stephen E., E-mail: bkiziltan@cfa.harvard.edu [Department of Astronomy and Astrophysics, University of California and UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)

    2013-11-20

    In recent years, the number of pulsars with secure mass measurements has increased to a level that allows us to probe the underlying neutron star (NS) mass distribution in detail. We critically review the radio pulsar mass measurements. For the first time, we are able to analyze a sizable population of NSs with a flexible modeling approach that can effectively accommodate a skewed underlying distribution and asymmetric measurement errors. We find that NSs that have evolved through different evolutionary paths reflect distinctive signatures through dissimilar distribution peak and mass cutoff values. NSs in double NS and NS-white dwarf (WD) systems show consistent respective peaks at 1.33 M {sub ☉} and 1.55 M {sub ☉}, suggesting significant mass accretion (Δm ≈ 0.22 M {sub ☉}) has occurred during the spin-up phase. The width of the mass distribution implied by double NS systems is indicative of a tight initial mass function while the inferred mass range is significantly wider for NSs that have gone through recycling. We find a mass cutoff at ∼2.1 M {sub ☉} for NSs with WD companions, which establishes a firm lower bound for the maximum NS mass. This rules out the majority of strange quark and soft equation of state models as viable configurations for NS matter. The lack of truncation close to the maximum mass cutoff along with the skewed nature of the inferred mass distribution both enforce the suggestion that the 2.1 M {sub ☉} limit is set by evolutionary constraints rather than nuclear physics or general relativity, and the existence of rare supermassive NSs is possible.

  3. Mass conservative three-dimensional water tracer distribution from MCMC inversion of time-lapse GPR data

    NARCIS (Netherlands)

    Lalov, E.; Linde, N.; Vrugt, J.A.

    2012-01-01

    Time-lapse geophysical measurements are widely used to monitor the movement of water and solutes through the subsurface. Yet commonly used deterministic least squares inversions typically suffer from relatively poor mass recovery, spread overestimation, and limited ability to appropriately estimate

  4. Modeled ground water age distributions

    Science.gov (United States)

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  5. Cooling water distribution system

    Science.gov (United States)

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  6. Vertical water mass structure in the North Atlantic influences the bathymetric distribution of species in the deep-sea coral genus Paramuricea

    Science.gov (United States)

    Radice, Veronica Z.; Quattrini, Andrea M.; Wareham, Vonda E.; Edinger, Evan N.; Cordes, Erik E.

    2016-10-01

    Deep-sea corals are the structural foundation of their ecosystems along continental margins worldwide, yet the factors driving their broad distribution are poorly understood. Environmental factors, especially depth-related variables including water mass properties, are thought to considerably affect the realized distribution of deep-sea corals. These factors are governed by local and regional oceanographic conditions that directly influence the dispersal of larvae, and therefore affect the ultimate distribution of adult corals. We used molecular barcoding of mitochondrial and nuclear sequences to identify species of octocorals in the genus Paramuricea collected from the Labrador Sea to the Grand Banks of Newfoundland, Canada at depths of 150-1500 m. The results of this study revealed overlapping bathymetric distributions of the Paramuricea species present off the eastern Canadian coast, including the presence of a few cryptic species previously designated as Paramuricea placomus. The distribution of Paramuricea species in the western North Atlantic differs from the Gulf of Mexico, where five Paramuricea species exhibit strong segregation by depth. The different patterns of Paramuricea species in these contrasting biogeographic regions provide insight into how water mass structure may shape species distribution. Investigating Paramuricea prevalence and distribution in conjunction with oceanographic conditions can help demonstrate the factors that generate and maintain deep-sea biodiversity.

  7. An Empirical Mass Function Distribution

    Science.gov (United States)

    Murray, S. G.; Robotham, A. S. G.; Power, C.

    2018-03-01

    The halo mass function, encoding the comoving number density of dark matter halos of a given mass, plays a key role in understanding the formation and evolution of galaxies. As such, it is a key goal of current and future deep optical surveys to constrain the mass function down to mass scales that typically host {L}\\star galaxies. Motivated by the proven accuracy of Press–Schechter-type mass functions, we introduce a related but purely empirical form consistent with standard formulae to better than 4% in the medium-mass regime, {10}10{--}{10}13 {h}-1 {M}ȯ . In particular, our form consists of four parameters, each of which has a simple interpretation, and can be directly related to parameters of the galaxy distribution, such as {L}\\star . Using this form within a hierarchical Bayesian likelihood model, we show how individual mass-measurement errors can be successfully included in a typical analysis, while accounting for Eddington bias. We apply our form to a question of survey design in the context of a semi-realistic data model, illustrating how it can be used to obtain optimal balance between survey depth and angular coverage for constraints on mass function parameters. Open-source Python and R codes to apply our new form are provided at http://mrpy.readthedocs.org and https://cran.r-project.org/web/packages/tggd/index.html respectively.

  8. Distribution of the prokaryotic biomass and community respiration in the main water masses of the Southern Tyrrhenian Sea (June and December 2005

    Directory of Open Access Journals (Sweden)

    Rosabruna La Ferla

    2010-12-01

    Full Text Available The distribution of the prokaryotic biomass (from both abundance and cell volume measurements and microbial community respiration (by ETS activity in the main water masses of the Southern Tyrrhenian Sea were studied. The data were collected from surface to the bottom depth (max 3600 m in July and December 2005. Prokaryotic abundance and microbial respiration were higher in summer than late-autumn and decreased with depth in accordance with the water masses. The opposite was found for the prokaryotic cell volumes that increased with depth and were higher in December. The cell carbon content varied within the water masses and study periods (range 9–34 fg C cell−1 and overestimations and underestimations of biomass there would have been by using the routinely adopted conversion factor (20 fg C cell−1. The depth-integrated respiratory rates resulted comparable in the photic and aphotic layers. In July, 210 and 225 mg C m−2 day−1 in the euphotic and aphotic zones, respectively, were remineralized while in December, 112 and 134 mg C m−2 day−1, respectively, were. Speculations to quantify the carbon flow mediated by microbial community suggested the occurrence of different microbial behavior within the different water masses.

  9. The spatial distribution of silicoflagellates in the region of the Gulf Stream warm-core ring 82B: application to water mass tracer studies

    Science.gov (United States)

    Takahashi, Kozo; Blackwelder, Patricia L.

    1992-03-01

    To delineate potential water mass affinities, we investigated silicoflagellates from the region of Gulf Stream warm-core ring (WCR) 82B in the northwestern Atlantic. Silicoflagellates from 202 samples from N-S and an E-W transects across WCR 82B during late April were analysed. Shelf to Sargasso Sea transects, one completed in early May and the other in June 1982 were also examined. Eight to 11 vertical profiles to 200 m comprised each of the transects. Six taxa of silicoflagellates were found in the samples studied and a total of more than 8000 specimens were encountered. Three major taxa dominated standing stocks: Distephanus speculum, Dictyocha messanensis (intermediate-sized form) and D. mandrai. D. speculum, considered a cold-water taxon in the literature, showed a higher standing stock in the cooler high-velocity region (HVR) of the warm-core ring, continental shelf (SH) and slope (SL) waters. Fewer were present in the wanner ring center (RC), Gulf Stream (GS) and Sargasso Sea (SS). D. mandrai showed a similar distribution to that of D. speculum, but its preference for slightly warmer waters (>~10°C) was noted. In contrast, Dictyocha messanensis (intermediate-sized) and Distephanus pulchra, known to be warm-water taxa, were relatively abundant in the warm ring center. In contrast to standing stock data, ratios between cold- and warm-water taxa correlate well with temperature and salinity in the warm-core ring. Since these ratios are not effected by convective loss, they are excellent water mass tracers in this system. Distribution of the silicoflagellate taxa suggests that WCR82B April had a higher affinity with the Gulf Stream than the Sargasso Sea. Scores derived from factor analysis indicate that silicoflagellate species distributions are highly correlative with water masses. This was evident from correlations with temperature, salinity and with distance from ring center. Nutrients were generally not correlated with species data. This may be due to deep

  10. Water mass circulation and weathering inputs in the Labrador Sea based on coupled Hf-Nd isotope compositions and rare earth element distributions

    Science.gov (United States)

    Filippova, Alexandra; Frank, Martin; Kienast, Markus; Rickli, Jörg; Hathorne, Ed; Yashayaev, Igor M.; Pahnke, Katharina

    2017-02-01

    The Labrador Sea is one of the key areas for deep water formation driving the Atlantic thermohaline circulation and thus plays an important role in Northern Hemisphere climatic fluctuations. In order to better constrain the overturning processes and the origins of the distinct water masses, combined dissolved Hf-Nd isotopic compositions and rare earth element (REE) distribution patterns were obtained from four water depth profiles along a section across the Labrador Sea. These were complemented by one surface sample off the southern tip of Greenland, three shallow water samples off the coast of Newfoundland, and two deep water samples off Nova Scotia. Although light REEs are markedly enriched in the surface waters off the coast of Newfoundland compared to north Atlantic waters, the REE concentration profiles are essentially invariant throughout the water column across the Labrador Sea. The hafnium concentrations of surface waters exhibit a narrow range between 0.6 and 1 pmol/kg but are not significantly higher than at depth. Neodymium isotope signatures (ɛNd) vary from unradiogenic values between -16.8 and -14.9 at the surface to more radiogenic values near -11.0 at the bottom of the Labrador Sea mainly reflecting the advection of the Denmark Strait Overflow Water and North East Atlantic Deep Water, the signatures of which are influenced by weathering contributions from Icelandic basalts. Unlike Nd, water column radiogenic Hf isotope signatures (ɛHf) are more variable representing diverse weathering inputs from the surrounding landmasses. The least radiogenic seawater ɛHf signatures (up to -11.7) are found in surface waters close to Greenland and near the Canadian margin. This reflects the influence of recirculating Irminger Current Waters, which are affected by highly unradiogenic inputs from Greenland. A three to four ɛHf unit difference is observed between Denmark Strait Overflow Water (ɛHf ∼ -4) and North East Atlantic Deep Water (ɛHf ∼ -0

  11. Water Technology Lecture 3: Water Distribution

    OpenAIRE

    Gray, Nicholas Frederick

    2017-01-01

    This is the third lecture in the course Water Technology dealing with water distribution. This is a PowerPoint lecture which is free to use and modify. It was designed to be used in conjunction with the course text Gray, N.F. (2017) Water Science and Technology: An Introduction, published by CRC Press, Oxford. The basis of water distribution is explored including water pipe materials, distribution systems, leakage, water quality problems, pressure issue, water hydrants, effect of floods,...

  12. On the Mass Distribution of Stellar-Mass Black Holes

    Directory of Open Access Journals (Sweden)

    Malkov O. Yu.

    2014-12-01

    Full Text Available The observational stellar-mass black hole mass distribution exhibits a maximum at about 8 M⊙. It can be explained via the details of the massive star evolution, supernova explosions, or consequent black hole evolution. We propose another explanation, connected with an underestimated influence of the relation between the initial stellar mass and the compact remnant mass. We show that an unimodal observational mass distribution of black holes can be produced by a power-law initial mass function and a monotonic “remnant mass versus initial mass” relation.

  13. THE MASS DISTRIBUTION OF STELLAR-MASS BLACK HOLES

    International Nuclear Information System (INIS)

    Farr, Will M.; Sravan, Niharika; Kalogera, Vicky; Cantrell, Andrew; Kreidberg, Laura; Bailyn, Charles D.; Mandel, Ilya

    2011-01-01

    We perform a Bayesian analysis of the mass distribution of stellar-mass black holes using the observed masses of 15 low-mass X-ray binary systems undergoing Roche lobe overflow and 5 high-mass, wind-fed X-ray binary systems. Using Markov Chain Monte Carlo calculations, we model the mass distribution both parametrically—as a power law, exponential, Gaussian, combination of two Gaussians, or log-normal distribution—and non-parametrically—as histograms with varying numbers of bins. We provide confidence bounds on the shape of the mass distribution in the context of each model and compare the models with each other by calculating their relative Bayesian evidence as supported by the measurements, taking into account the number of degrees of freedom of each model. The mass distribution of the low-mass systems is best fit by a power law, while the distribution of the combined sample is best fit by the exponential model. This difference indicates that the low-mass subsample is not consistent with being drawn from the distribution of the combined population. We examine the existence of a 'gap' between the most massive neutron stars and the least massive black holes by considering the value, M 1% , of the 1% quantile from each black hole mass distribution as the lower bound of black hole masses. Our analysis generates posterior distributions for M 1% ; the best model (the power law) fitted to the low-mass systems has a distribution of lower bounds with M 1% >4.3 M sun with 90% confidence, while the best model (the exponential) fitted to all 20 systems has M 1% >4.5 M sun with 90% confidence. We conclude that our sample of black hole masses provides strong evidence of a gap between the maximum neutron star mass and the lower bound on black hole masses. Our results on the low-mass sample are in qualitative agreement with those of Ozel et al., although our broad model selection analysis more reliably reveals the best-fit quantitative description of the underlying mass

  14. ON THE MASS DISTRIBUTION AND BIRTH MASSES OF NEUTRON STARS

    International Nuclear Information System (INIS)

    Özel, Feryal; Psaltis, Dimitrios; Santos Villarreal, Antonio; Narayan, Ramesh

    2012-01-01

    We investigate the distribution of neutron star masses in different populations of binaries, employing Bayesian statistical techniques. In particular, we explore the differences in neutron star masses between sources that have experienced distinct evolutionary paths and accretion episodes. We find that the distribution of neutron star masses in non-recycled eclipsing high-mass binaries as well as of slow pulsars, which are all believed to be near their birth masses, has a mean of 1.28 M ☉ and a dispersion of 0.24 M ☉ . These values are consistent with expectations for neutron star formation in core-collapse supernovae. On the other hand, double neutron stars, which are also believed to be near their birth masses, have a much narrower mass distribution, peaking at 1.33 M ☉ , but with a dispersion of only 0.05 M ☉ . Such a small dispersion cannot easily be understood and perhaps points to a particular and rare formation channel. The mass distribution of neutron stars that have been recycled has a mean of 1.48 M ☉ and a dispersion of 0.2 M ☉ , consistent with the expectation that they have experienced extended mass accretion episodes. The fact that only a very small fraction of recycled neutron stars in the inferred distribution have masses that exceed ∼2 M ☉ suggests that only a few of these neutron stars cross the mass threshold to form low-mass black holes.

  15. Volcanisme, activité anthropique et circulation des masses océaniques : leur influence respective sur la distribution des populations d'ostracodes dans la baie de Kagoshima (île de Kyushu, Japon)Impact of volcanism, human activities, and water mass circulation on the distribution of ostracod populations in Kagoshima Bay (Kyushu Island, southern Japan)

    Science.gov (United States)

    Bodergat, Anne-Marie; Oki, Kimihiko; Ishizaki, Kunihiro; Rio, Michel

    2002-11-01

    The distribution of ostracod populations in Kagoshima Bay (Japan) is analysed with reference to different environmental parameters. The bay is an area of volcanic activity of Sakurajima volcano under the influence of the Kuroshio Current. Most of the Head environment is occupied by an acidic water mass. Numbers of individual and species decrease from the Mouth of the bay towards the Basin and Head environments. In this latter, acidic water mass has a drastic effect on ostracod populations, whereas volcanic ashes and domestic inputs are not hostile. Ostracod distribution is influenced by the quality and structure of water masses. To cite this article: A.-M. Bodergat et al., C. R. Geoscience 334 (2002) 1053-1059.

  16. On the water-soluble organic nitrogen concentration and mass size distribution during the fog season in the Po Valley, Italy.

    Science.gov (United States)

    Montero-Martínez, Guillermo; Rinaldi, Matteo; Gilardoni, Stefania; Giulianelli, Lara; Paglione, Marco; Decesari, Stefano; Fuzzi, Sandro; Facchini, Maria Cristina

    2014-07-01

    The study of organic nitrogen gained importance in recent decades due to its links with acid rain, pollution, and eutrophication. In this study, aerosol and fog water samples collected from two sites in Italy during November 2011 were analyzed to characterize their organic nitrogen content. Organic nitrogen contributed 19-25% of the total soluble nitrogen in the aerosol and around 13% in fog water. The largest water soluble organic nitrogen concentrations in the PM1.2 fraction occurred during the diurnal period with mean values of 2.03 and 2.16 μg-N m(-3) (154 and 145 nmol-N m(-3)) at Bologna and San Pietro Capofiume (SPC), respectively. The mean PM10 WSON concentration during diurnal periods at SPC was 2.30 μg-N m(-3) (164 nmol-N m(-3)) while it was 1.34 and 0.82 μg-N m(-3) (95.7 and 58.5 nmol-N m(-3)) in the night and fog water samples, respectively. Aerosol mass distribution profiles obtained during fog changed significantly with respect to those estimated in periods without fog periods due to fog scavenging, which proved to be over 80% efficient. Linear correlations suggested secondary processes related to combustion and, to a lesser extent, biomass burning, as plausible sources of WSON. Regarding the inorganic nitrogen fraction, the results showed that ammonium was the largest soluble inorganic nitrogen component in the samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Benthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough:dependance on water masses and food supply

    Institute of Scientific and Technical Information of China (English)

    向荣; 李铁刚; 杨作升; 阎军; 曹奇原

    2003-01-01

    Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Oki-nawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidlywith increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm themodem shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to thebottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corre-sponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, domi-nated by Cassidulina carinata, Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispi-da, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4) lower con-tinental slope- trough bottom assemblage, dominated by Pullenia bulloides, Epistominella exigua andCibicidoides hyalinus, corresponds to deep water mass of the Okinawa Trough; and (5) trough bottomagglutinated assemblage, dominated by Rhabdammina spp., Bathysiphon flavidus, corresponds tostrongly dissolved environment of the trough bottom. The benthic foraminiferal fauna in the southemOkinawa Trough are controlled jointly by water masses and food supply. Water temperature, oxygenconcentration and carbonate dissolution of the water masses are important controlling factors especiallyfor the continental shelf break and trough bottom assemblages. The food supply also plays an importantrole in these benthic foraminiferal assemblages along the westem slope of the Okinawa Trough. Both theabundance and the 5 assemblages of benthic foraminifera correspond well to the organic matter supplyalong the continental slope and a lateral transport of TSM (total suspended matter) and POC (particulateorganic

  18. On the Mass Distribution of Animal Species

    Science.gov (United States)

    Redner, Sidney; Clauset, Aaron; Schwab, David

    2009-03-01

    We develop a simple diffusion-reaction model to account for the broad and asymmetric distribution of adult body masses for species within related taxonomic groups. The model assumes three basic evolutionary features that control body mass: (i) a fixed lower limit that is set by metabolic constraints, (ii) a species extinction risk that is a weakly increasing function of body mass, and (iii) cladogenetic diffusion, in which daughter species have a slight tendency toward larger mass. The steady-state solution for the distribution of species masses in this model can be expressed in terms of the Airy function. This solution gives mass distributions that are in good agreement with data on 4002 terrestrial mammal species from the late Quaternary and 8617 extant bird species.

  19. Water Treatment Technology - Distribution Systems.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

  20. The jet mass distribution after Soft Drop

    Science.gov (United States)

    Marzani, Simone; Schunk, Lais; Soyez, Gregory

    2018-02-01

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects.

  1. Invariant mass distributions in cascade decays

    International Nuclear Information System (INIS)

    Miller, David J.; Osland, Per; Raklev, Are R.

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D→Cc→Bbc→Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through 'feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be included in the distributions

  2. Invariant mass distributions in cascade decays

    CERN Document Server

    Miller, D J; Raklev, A R

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D -> Cc -> Bbc -> Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through `feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be inclu...

  3. The jet mass distribution after Soft Drop

    Energy Technology Data Exchange (ETDEWEB)

    Marzani, Simone [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN, Sezione di Genova (Italy); Schunk, Lais [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Soyez, Gregory [IPhT, CEA Saclay, CNRS UMR 3681, Gif-Sur-Yvette (France)

    2018-02-15

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects. (orig.)

  4. Reconsideration of mass-distribution models

    Directory of Open Access Journals (Sweden)

    Ninković S.

    2014-01-01

    Full Text Available The mass-distribution model proposed by Kuzmin and Veltmann (1973 is revisited. It is subdivided into two models which have a common case. Only one of them is subject of the present study. The study is focused on the relation between the density ratio (the central one to that corresponding to the core radius and the total-mass fraction within the core radius. The latter one is an increasing function of the former one, but it cannot exceed one quarter, which takes place when the density ratio tends to infinity. Therefore, the model is extended by representing the density as a sum of two components. The extension results into possibility of having a correspondence between the infinite density ratio and 100% total-mass fraction. The number of parameters in the extended model exceeds that of the original model. Due to this, in the extended model, the correspondence between the density ratio and total-mass fraction is no longer one-to-one; several values of the total-mass fraction can correspond to the same value for the density ratio. In this way, the extended model could explain the contingency of having two, or more, groups of real stellar systems (subsystems in the diagram total-mass fraction versus density ratio. [Projekat Ministarstva nauke Republike Srbije, br. 176011: Dynamics and Kinematics of Celestial Bodies and Systems

  5. Features of Red Sea Water Masses

    Science.gov (United States)

    Kartadikaria, Aditya; Hoteit, Ibrahim

    2015-04-01

    Features of Red Sea water mass can be divided into three types but best to be grouped into two different classes that are split at the potential density line σθ=27.4. The surface water (0-50 m) and the intermediate water (50-200 m) have nearly identical types of water mass. They appear as a maxima salinity layer for the water mass that has σθ > 26.0, and as a minimum salinity layer for water mass that has σθ water masses are strongly affected by mixing that is controlled by seasonal variability, fresh water intrusion of the Gulf of Aden Intermediate Water (GAIW), and eddies variability. Two types of mixing; isopycnal and diapycnal mixing are part of important physical phenomena that explain the change of water mass in the Red Sea. The isopycnal mixing occurs at the neutral potential density line, connecting the Red Sea with its adjacent channel, the Gulf of Aden. Diapycnal mixing is found as a dominant mixing mode in the surface of the Red Sea Water and mainly due to energetic eddy activity. Density gradients, across which diapycnal mixing occurs, in the Red Sea are mainly due to large variations in salinity. The isolation of an extreme haline water mass below the thermocline contributes to the generation of the latitudinal shift and low diapycnal mixing. This finding further explains the difference of spatial kinetic mixing between the RSW and the Indian Ocean basin.

  6. Features of Red Sea Water Masses

    KAUST Repository

    Kartadikaria, Aditya R.

    2015-04-01

    Features of Red Sea water mass can be divided into three types but best to be grouped into two different classes that are split at the potential density line σθ=27.4. The surface water (0-50 m) and the intermediate water (50-200 m) have nearly identical types of water mass. They appear as a maxima salinity layer for the water mass that has σθ > 26.0, and as a minimum salinity layer for water mass that has σθ < 26.0. These types of water masses are strongly affected by mixing that is controlled by seasonal variability, fresh water intrusion of the Gulf of Aden Intermediate Water (GAIW), and eddies variability. Two types of mixing; isopycnal and diapycnal mixing are part of important physical phenomena that explain the change of water mass in the Red Sea. The isopycnal mixing occurs at the neutral potential density line, connecting the Red Sea with its adjacent channel, the Gulf of Aden. Diapycnal mixing is found as a dominant mixing mode in the surface of the Red Sea Water and mainly due to energetic eddy activity. Density gradients, across which diapycnal mixing occurs, in the Red Sea are mainly due to large variations in salinity. The isolation of an extreme haline water mass below the thermocline contributes to the generation of the latitudinal shift and low diapycnal mixing. This finding further explains the difference of spatial kinetic mixing between the RSW and the Indian Ocean basin.

  7. Condensation driven water hammer studies for feed water distribution pipe

    International Nuclear Information System (INIS)

    Savolainen, S.; Katajala, S.; Elsing, B.; Nurkkala, P.; Longvinov, S.A.; Trunov, N.B.; Sitnik, Yu.K.

    1997-01-01

    Special T-shaped feedwater distribution pipes were installed in steam generators at the Loviisa (Finland) and Rovno (Russia) nuclear power plants. The new shape was tested in an extensive testing programme. Since the tubes frequently suffer from corrosion damage, large-scale water hammer experiments were performed on a model facility in 1996. The main objectives of the water hammer experiments were to find out the prevailing parameters leading to water hammers, as well as the sensitivity of hammering to boundary conditions. A water hammer may occur when the mass flow rate into the steam generator exceeds 6 kg/s and the temperature difference between steam generator and feedwater exceeds 100 degC. Visual experiments and stress analyses of the pipe were also carried out. The weakest part, the T-joint, may hold against such water hammers only for a limited time of the order of few minutes. (M.D.)

  8. Mass Distribution in Galaxy Cluster Cores

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, M. T.; McNamara, B. R.; Pulido, F.; Vantyghem, A. N. [Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1 (Canada); Nulsen, P. E. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Russell, H. R. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Edge, A. C. [Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Main, R. A., E-mail: m4hogan@uwaterloo.ca [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON, M5S 3H8 (Canada)

    2017-03-01

    Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and active galactic nucleus feedback, are dependent upon local dynamical timescales. However, accurate mapping of the mass distribution within individual clusters is challenging, particularly toward cluster centers where the total mass budget has substantial radially dependent contributions from the stellar ( M {sub *}), gas ( M {sub gas}), and dark matter ( M {sub DM}) components. In this paper we use a small sample of galaxy clusters with deep Chandra observations and good ancillary tracers of their gravitating mass at both large and small radii to develop a method for determining mass profiles that span a wide radial range and extend down into the central galaxy. We also consider potential observational pitfalls in understanding cooling in hot cluster atmospheres, and find tentative evidence for a relationship between the radial extent of cooling X-ray gas and nebular H α emission in cool-core clusters. At large radii the entropy profiles of our clusters agree with the baseline power law of K ∝ r {sup 1.1} expected from gravity alone. At smaller radii our entropy profiles become shallower but continue with a power law of the form K ∝ r {sup 0.67} down to our resolution limit. Among this small sample of cool-core clusters we therefore find no support for the existence of a central flat “entropy floor.”.

  9. Water Distribution and Removal Model

    International Nuclear Information System (INIS)

    Y. Deng; N. Chipman; E.L. Hardin

    2005-01-01

    The design of the Yucca Mountain high level radioactive waste repository depends on the performance of the engineered barrier system (EBS). To support the total system performance assessment (TSPA), the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is developed to describe the thermal, mechanical, chemical, hydrological, biological, and radionuclide transport processes within the emplacement drifts, which includes the following major analysis/model reports (AMRs): (1) EBS Water Distribution and Removal (WD and R) Model; (2) EBS Physical and Chemical Environment (P and CE) Model; (3) EBS Radionuclide Transport (EBS RNT) Model; and (4) EBS Multiscale Thermohydrologic (TH) Model. Technical information, including data, analyses, models, software, and supporting documents will be provided to defend the applicability of these models for their intended purpose of evaluating the postclosure performance of the Yucca Mountain repository system. The WD and R model ARM is important to the site recommendation. Water distribution and removal represents one component of the overall EBS. Under some conditions, liquid water will seep into emplacement drifts through fractures in the host rock and move generally downward, potentially contacting waste packages. After waste packages are breached by corrosion, some of this seepage water will contact the waste, dissolve or suspend radionuclides, and ultimately carry radionuclides through the EBS to the near-field host rock. Lateral diversion of liquid water within the drift will occur at the inner drift surface, and more significantly from the operation of engineered structures such as drip shields and the outer surface of waste packages. If most of the seepage flux can be diverted laterally and removed from the drifts before contacting the wastes, the release of radionuclides from the EBS can be controlled, resulting in a proportional reduction in dose release at the accessible environment

  10. Water Distribution and Removal Model

    Energy Technology Data Exchange (ETDEWEB)

    Y. Deng; N. Chipman; E.L. Hardin

    2005-08-26

    The design of the Yucca Mountain high level radioactive waste repository depends on the performance of the engineered barrier system (EBS). To support the total system performance assessment (TSPA), the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is developed to describe the thermal, mechanical, chemical, hydrological, biological, and radionuclide transport processes within the emplacement drifts, which includes the following major analysis/model reports (AMRs): (1) EBS Water Distribution and Removal (WD&R) Model; (2) EBS Physical and Chemical Environment (P&CE) Model; (3) EBS Radionuclide Transport (EBS RNT) Model; and (4) EBS Multiscale Thermohydrologic (TH) Model. Technical information, including data, analyses, models, software, and supporting documents will be provided to defend the applicability of these models for their intended purpose of evaluating the postclosure performance of the Yucca Mountain repository system. The WD&R model ARM is important to the site recommendation. Water distribution and removal represents one component of the overall EBS. Under some conditions, liquid water will seep into emplacement drifts through fractures in the host rock and move generally downward, potentially contacting waste packages. After waste packages are breached by corrosion, some of this seepage water will contact the waste, dissolve or suspend radionuclides, and ultimately carry radionuclides through the EBS to the near-field host rock. Lateral diversion of liquid water within the drift will occur at the inner drift surface, and more significantly from the operation of engineered structures such as drip shields and the outer surface of waste packages. If most of the seepage flux can be diverted laterally and removed from the drifts before contacting the wastes, the release of radionuclides from the EBS can be controlled, resulting in a proportional reduction in dose release at the accessible environment. The purposes

  11. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  12. Water masses in the Gulf of Aden

    Digital Repository Service at National Institute of Oceanography (India)

    Al Saafani, M.A.; Shenoi, S.S.C.

    Hydrographic data collected from Gulf of Aden since 1920 have been compiled to identify and refine the definitions of water masses in the Gulf of Aden (GA) and to describe their spatio-temporal variability. Four water masses have been identified...

  13. Scaling analysis of meteorite shower mass distributions

    DEFF Research Database (Denmark)

    Oddershede, Lene; Meibom, A.; Bohr, Jakob

    1998-01-01

    Meteorite showers are the remains of extraterrestrial objects which are captivated by the gravitational field of the Earth. We have analyzed the mass distribution of fragments from 16 meteorite showers for scaling. The distributions exhibit distinct scaling behavior over several orders of magnetude......; the observed scaling exponents vary from shower to shower. Half of the analyzed showers show a single scaling region while the orther half show multiple scaling regimes. Such an analysis can provide knowledge about the fragmentation process and about the original meteoroid. We also suggest to compare...... the observed scaling exponents to exponents observed in laboratory experiments and discuss the possibility that one can derive insight into the original shapes of the meteoroids....

  14. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  15. Water masses of Visakhapatnam shelf

    Digital Repository Service at National Institute of Oceanography (India)

    RamaRaju, V.S.; Sarma, V.V.; Rao, B.P.; Rao, V.S.

    The T-S relationships of shelf waters off Visakhapatnam in the Bay of Bengal are studied for the different seasons with the data collected during February 1979 to January 1981. The T-S relationships indicate distinct characteristics of the water...

  16. Features of Red Sea Water Masses

    KAUST Repository

    Kartadikaria, Aditya R.; Hoteit, Ibrahim

    2015-01-01

    by seasonal variability, fresh water intrusion of the Gulf of Aden Intermediate Water (GAIW), and eddies variability. Two types of mixing; isopycnal and diapycnal mixing are part of important physical phenomena that explain the change of water mass in the Red

  17. Mass imbalances in EPANET water-quality simulations

    Science.gov (United States)

    Davis, Michael J.; Janke, Robert; Taxon, Thomas N.

    2018-04-01

    EPANET is widely employed to simulate water quality in water distribution systems. However, in general, the time-driven simulation approach used to determine concentrations of water-quality constituents provides accurate results only for short water-quality time steps. Overly long time steps can yield errors in concentration estimates and can result in situations in which constituent mass is not conserved. The use of a time step that is sufficiently short to avoid these problems may not always be feasible. The absence of EPANET errors or warnings does not ensure conservation of mass. This paper provides examples illustrating mass imbalances and explains how such imbalances can occur because of fundamental limitations in the water-quality routing algorithm used in EPANET. In general, these limitations cannot be overcome by the use of improved water-quality modeling practices. This paper also presents a preliminary event-driven approach that conserves mass with a water-quality time step that is as long as the hydraulic time step. Results obtained using the current approach converge, or tend to converge, toward those obtained using the preliminary event-driven approach as the water-quality time step decreases. Improving the water-quality routing algorithm used in EPANET could eliminate mass imbalances and related errors in estimated concentrations. The results presented in this paper should be of value to those who perform water-quality simulations using EPANET or use the results of such simulations, including utility managers and engineers.

  18. Possible mass distributions in the nebulae of other solar systems

    International Nuclear Information System (INIS)

    Brown, W.K.

    1987-01-01

    The supernova shell fragmentation model of solar system formation - previously shown to be successful in describing the mass distribution of our solar system - is used to calculate the mass distributions of other solar nebulae. (Auth.)

  19. Intermediate mass distribution of the dual resonance pomeron

    International Nuclear Information System (INIS)

    Chiu, C.B.; Matsuda, S.

    1978-01-01

    The intermediate mass distribution of the dual resonance pomeron is determined at the one-loop level and it is shown that the mass distribution obtained is remarkably similar to a suitably defined mass distribution in the dual multiperipheral model. Thus it is suggestive to identify the intermediate states of the dual resonance pomeron with multiperipheral processes. (Auth.)

  20. Prioritising alternatives for maintenance of water distribution ...

    African Journals Online (AJOL)

    ... for maintenance of water distribution networks: A group decision approach. ... Difficulties related to the group decision-making process in the water supply sector, ... This study focused on the rational use of water resources and reduction of ...

  1. STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Presented within the report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. To allow comparison of new construction with rehabilitation of e...

  2. A cluster-randomised controlled trial integrating a community-based water, sanitation and hygiene programme, with mass distribution of albendazole to reduce intestinal parasites in Timor-Leste: the WASH for WORMS research protocol

    Science.gov (United States)

    Nery, Susana Vaz; McCarthy, James S; Traub, Rebecca; Andrews, Ross M; Black, Jim; Gray, Darren; Weking, Edmund; Atkinson, Jo-An; Campbell, Suzy; Francis, Naomi; Vallely, Andrew; Williams, Gail; Clements, Archie

    2015-01-01

    Introduction There is limited evidence demonstrating the benefits of community-based water, sanitation and hygiene (WASH) programmes on infections with soil-transmitted helminths (STH) and intestinal protozoa. Our study aims to contribute to that evidence base by investigating the effectiveness of combining two complementary approaches for control of STH: periodic mass administration of albendazole, and delivery of a community-based WASH programme. Methods and analysis WASH for WORMS is a cluster-randomised controlled trial to test the hypothesis that a community-based WASH intervention integrated with periodic mass distribution of albendazole will be more effective in reducing infections with STH and protozoa than mass deworming alone. All 18 participating rural communities in Timor-Leste receive mass chemotherapy every 6 months. Half the communities also receive the community-based WASH programme. Primary outcomes are the cumulative incidence of infection with STH. Secondary outcomes include the prevalence of protozoa; intensity of infection with STH; as well as morbidity indicators (anaemia, stunting and wasting). Each of the trial outcomes will be compared between control and intervention communities. End points will be measured 2 years after the first albendazole distribution; and midpoints are measured at 6 months intervals (12 months for haemoglobin and anthropometric indexes). Mixed-methods research will also be conducted in order to identify barriers and enablers associated with the acceptability and uptake of the WASH programme. Ethics and dissemination Ethics approval was obtained from the human ethics committees at the University of Queensland, Australian National University, Timorese Ministry of Health, and University of Melbourne. The results of the trial will be published in peer-reviewed journals presented at national and international conferences, and disseminated to relevant stakeholders in health and WASH programmes. This study is funded

  3. DIFFERENTIATION OF AEROMONAS ISOLATES OBTAINED FROM DRINKING WATER DISTRIBUTION SYSTEM USING MATRIX-ASSISTED LASER DESCRIPTION/IONIZATION-MASS SPECTROMETRY (MALDI-MS)

    Science.gov (United States)

    The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the...

  4. Intermediate and deep water mass distribution in the Pacific during the Last Glacial Maximum inferred from oxygen and carbon stable isotopes

    Science.gov (United States)

    Herguera, J. C.; Herbert, T.; Kashgarian, M.; Charles, C.

    2010-05-01

    Intermediate ocean circulation changes during the last Glacial Maximum (LGM) in the North Pacific have been linked with Northern Hemisphere climate through air-sea interactions, although the extent and the source of the variability of the processes forcing these changes are still not well resolved. The ventilated volumes and ages in the upper wind driven layer are related to the wind stress curl and surface buoyancy fluxes at mid to high latitudes in the North Pacific. In contrast, the deeper thermohaline layers are more effectively ventilated by direct atmosphere-sea exchange during convective formation of Subantarctic Mode Waters (SAMW) and Antarctic Intermediate Waters (AAIW) in the Southern Ocean, the precursors of Pacific Intermediate Waters (PIW) in the North Pacific. Results reported here show a fundamental change in the carbon isotopic gradient between intermediate and deep waters during the LGM in the eastern North Pacific indicating a deepening of nutrient and carbon rich waters. These observations suggest changes in the source and nature of intermediate waters of Southern Ocean origin that feed PIW and enhanced ventilation processes in the North Pacific, further affecting paleoproductivity and export patters in this basin. Furthermore, oxygen isotopic results indicate these changes may have been accomplished in part by changes in circulation affecting the intermediate depths during the LGM.

  5. Silver disinfection in water distribution systems

    Science.gov (United States)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  6. Income Distribution Impacts of Irrigation Water Distribution Policy

    Science.gov (United States)

    Sampath, Rajan K.

    1984-06-01

    In the majority of lesser developed countries (LDC's) there is acute inequality in income distribution in the rural sector, particularly between large and small farms on the one hand and between land owners and the landless on the other. Irrigation water distribution policy of the government is both an economic and political problem. It has both equity and efficiency implications. It has effects on both the level and distribution of income. This paper deals with the conditions under which using water redistribution as an effective governmental policy variable can reduce inequality in the distribution of income. This paper also deals with the relationship between the objectives of equity and efficiency in water distribution under different objective realities, such as dualistic versus nondualistic conditions, two-sector versus three-sector modeling, optimum versus equal water distribution, specifically to derive the conditions under which promotion of equity promotes efficiency and vice versa and the conditions under which it does not.

  7. Mass imbalances in EPANET water-quality simulations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Michael J.; Janke, Robert; Taxon, Thomas N.

    2018-04-06

    EPANET is widely employed to simulate water quality in water distribution systems. However, the time-driven simulation approach used to determine concentrations of water-quality constituents provides accurate results, in general, only for small water-quality time steps; use of an adequately short time step may not be feasible. Overly long time steps can yield errors in concentrations and result in situations in which constituent mass is not conserved. Mass may not be conserved even when EPANET gives no errors or warnings. This paper explains how such imbalances can occur and provides examples of such cases; it also presents a preliminary event-driven approach that conserves mass with a water-quality time step that is as long as the hydraulic time step. Results obtained using the current approach converge, or tend to converge, to those obtained using the new approach as the water-quality time step decreases. Improving the water-quality routing algorithm used in EPANET could eliminate mass imbalances and related errors in estimated concentrations.

  8. 129I and its species in the East China Sea: level, distribution, sources and tracing water masses exchange and movement

    DEFF Research Database (Denmark)

    Liu, Dan; Hou, Xiaolin; Du, Jinzhou

    2016-01-01

    and their inorganic chemical species in the first time. The measured 129I/127I ratio is 1–3 orders of magnitude higher than the pre-nuclear level, indicating its dominantly anthropogenic sources. Relatively high 129I levels were observed in the Yangtze River and its estuary, as well as in the southern Yellow Sea......, and 129I level in seawater declines towards the ECS shelf. In the open sea, 129I and 127I in surface water exists mainly as iodate, while in Yangtze River estuary and some locations, iodide is dominated. The results indicate that the Fukushima nuclear accident has no detectable effects in the ECS until...

  9. Water sample-collection and distribution system

    Science.gov (United States)

    Brooks, R. R.

    1978-01-01

    Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

  10. Passive containment cooling water distribution device

    Science.gov (United States)

    Conway, Lawrence E.; Fanto, Susan V.

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

  11. 4DVAR data Assimilation with the Regional Ocean Modeling System (ROMS): Impact on the Water Mass Distributions in the Yellow Sea

    Science.gov (United States)

    Lee, Joon-Ho; Kim, Taekyun; Pang, Ig-Chan; Moon, Jae-Hong

    2018-04-01

    In this study, we evaluate the performance of the recently developed incremental strong constraint 4-dimensional variational (4DVAR) data assimilation applied to the Yellow Sea (YS) using the Regional Ocean Modeling System (ROMS). Two assimilation experiments are compared: assimilating remote-sensed sea surface temperature (SST) and both the SST and in-situ profiles measured by shipboard CTD casts into a regional ocean modeling from January to December of 2011. By comparing the two assimilation experiments against a free-run without data assimilation, we investigate how the assimilation affects the hydrographic structures in the YS. Results indicate that the SST assimilation notably improves the model behavior at the surface when compared to the nonassimilative free-run. The SST assimilation also has an impact on the subsurface water structure in the eastern YS; however, the improvement is seasonally dependent, that is, the correction becomes more effective in winter than in summer. This is due to a strong stratification in summer that prevents the assimilation of SST from affecting the subsurface temperature. A significant improvement to the subsurface temperature is made when the in-situ profiles of temperature and salinity are assimilated, forming a tongue-shaped YS bottom cold water from the YS toward the southwestern seas of Jeju Island.

  12. Optimal Intermittent Operation of Water Distribution Networks under Water Shortage

    Directory of Open Access Journals (Sweden)

    mohamad Solgi

    2017-07-01

    Full Text Available Under water shortage conditions, it is necessary to exercise water consumption management practices in water distribution networks (WDN. Intermittent supply of water is one such practice that makes it possible to supply consumption nodal demands with the required pressure via water cutoff to some consumers during certain hours of the day. One of the most important issues that must be observed in this management practice is the equitable and uniform water distribution among the consumers. In the present study, uniformity in water distribution and minimum supply of water to all consumers are defined as justice and equity, respectively. Also, an optimization model has been developed to find an optimal intermittent supply schedule that ensures maximum number of demand nodes are supplied with water while the constraints on the operation of water distribution networks are also observed. To show the efficiency of the proposed model, it has been used in the Two-Loop distribution network under several different scenarios of water shortage. The optimization model has been solved using the honey bee mating optimization algorithm (HBMO linked to the hydraulic simulator EPANET. The results obtained confirm the efficiency of the proposed model in achieving an optimal intermittent supply schedule. Moreover, the model is found capable of distributing the available water in an equitable and just manner among all the consumers even under severe water shoratges.

  13. A cluster-randomised controlled trial integrating a community-based water, sanitation and hygiene programme, with mass distribution of albendazole to reduce intestinal parasites in Timor-Leste: the WASH for WORMS research protocol.

    Science.gov (United States)

    Nery, Susana Vaz; McCarthy, James S; Traub, Rebecca; Andrews, Ross M; Black, Jim; Gray, Darren; Weking, Edmund; Atkinson, Jo-An; Campbell, Suzy; Francis, Naomi; Vallely, Andrew; Williams, Gail; Clements, Archie

    2015-12-30

    There is limited evidence demonstrating the benefits of community-based water, sanitation and hygiene (WASH) programmes on infections with soil-transmitted helminths (STH) and intestinal protozoa. Our study aims to contribute to that evidence base by investigating the effectiveness of combining two complementary approaches for control of STH: periodic mass administration of albendazole, and delivery of a community-based WASH programme. WASH for WORMS is a cluster-randomised controlled trial to test the hypothesis that a community-based WASH intervention integrated with periodic mass distribution of albendazole will be more effective in reducing infections with STH and protozoa than mass deworming alone. All 18 participating rural communities in Timor-Leste receive mass chemotherapy every 6 months. Half the communities also receive the community-based WASH programme. Primary outcomes are the cumulative incidence of infection with STH. Secondary outcomes include the prevalence of protozoa; intensity of infection with STH; as well as morbidity indicators (anaemia, stunting and wasting). Each of the trial outcomes will be compared between control and intervention communities. End points will be measured 2 years after the first albendazole distribution; and midpoints are measured at 6 months intervals (12 months for haemoglobin and anthropometric indexes). Mixed-methods research will also be conducted in order to identify barriers and enablers associated with the acceptability and uptake of the WASH programme. Ethics approval was obtained from the human ethics committees at the University of Queensland, Australian National University, Timorese Ministry of Health, and University of Melbourne. The results of the trial will be published in peer-reviewed journals presented at national and international conferences, and disseminated to relevant stakeholders in health and WASH programmes. This study is funded by a Partnership for Better Health--Project grant from the National

  14. Octanol-water distribution of engineered nanomaterials.

    Science.gov (United States)

    Hristovski, Kiril D; Westerhoff, Paul K; Posner, Jonathan D

    2011-01-01

    The goal of this study was to examine the effects of pH and ionic strength on octanol-water distribution of five model engineered nanomaterials. Distribution experiments resulted in a spectrum of three broadly classified scenarios: distribution in the aqueous phase, distribution in the octanol, and distribution into the octanol-water interface. Two distribution coefficients were derived to describe the distribution of nanoparticles among octanol, water and their interface. The results show that particle surface charge, surface functionalization, and composition, as well as the solvent ionic strength and presence of natural organic matter, dramatically impact this distribution. Distributions of nanoparticles into the interface were significant for nanomaterials that exhibit low surface charge in natural pH ranges. Increased ionic strengths also contributed to increased distributions of nanoparticle into the interface. Similarly to the octanol-water distribution coefficients, which represent a starting point in predicting the environmental fate, bioavailability and transport of organic pollutants, distribution coefficients such as the ones described in this study could help to easily predict the fate, bioavailability, and transport of engineered nanomaterials in the environment.

  15. Optimizing Mexico’s Water Distribution Services

    Science.gov (United States)

    2011-10-28

    government pursued a decentralization policy in the water distribution infrastructure sector.5 This is evident in Article 115 of the Mexican Constitution ...infrastructure, monitoring water 5 Ibid, 47. 6 Mexican Constitution . http://www.oas.org/juridico...54 Apogee Research International, Ltd., Innovative Financing of Water and Wastewater Infrastructure in the NAFTA Partners: A Focus on

  16. Distribution of water in fresh cod

    DEFF Research Database (Denmark)

    Andersen, Charlotte Møller; Rinnan, A.

    2002-01-01

    Low-field (1)H nuclear magnetic resonance (NMR) transverse relaxation was used to measure water mobility and distribution of water in fresh cod fillets. The NMR relaxations were analysed with the so-called SLICING method giving uni-exponential profiles from which the transverse relaxation time (T(2......)-values) and the relative sizes of the water populations were calculated. Two water populations with the T(2)-values of 50 and 94 ms were obtained. The shortest relaxation time was primarily found near the head, and water with the longest relaxation time was primarily found near the tail. This variation...... can he explained by the smaller muscle cells and muscle fibers in the tail, which may influence the distributions of water into the different pools. The amount of one of the water populations was correlated to the overall water content with a correlation coefficient of -0.94. (C) 2002 Elsevier Science...

  17. Transport and transformation of surface water masses across the ...

    African Journals Online (AJOL)

    Transport and transformation of surface water masses across the Mascarene Plateau during the Northeast Monsoon season. ... Mixing occurs in the central gap between intermediate water masses (Red Sea Water [RSW] and Antarctic Intermediate Water [AAIW]) as well as in the upper waters (Subtropical Surface Water ...

  18. Characterization of Cloud Water-Content Distribution

    Science.gov (United States)

    Lee, Seungwon

    2010-01-01

    The development of realistic cloud parameterizations for climate models requires accurate characterizations of subgrid distributions of thermodynamic variables. To this end, a software tool was developed to characterize cloud water-content distributions in climate-model sub-grid scales. This software characterizes distributions of cloud water content with respect to cloud phase, cloud type, precipitation occurrence, and geo-location using CloudSat radar measurements. It uses a statistical method called maximum likelihood estimation to estimate the probability density function of the cloud water content.

  19. Effect of distributive mass of spring on power flow in engineering test

    Science.gov (United States)

    Sheng, Meiping; Wang, Ting; Wang, Minqing; Wang, Xiao; Zhao, Xuan

    2018-06-01

    Mass of spring is always neglected in theoretical and simulative analysis, while it may be a significance in practical engineering. This paper is concerned with the distributive mass of a steel spring which is used as an isolator to simulate isolation performance of a water pipe in a heating system. Theoretical derivation of distributive mass effect of steel spring on vibration is presented, and multiple eigenfrequencies are obtained, which manifest that distributive mass results in extra modes and complex impedance properties. Furthermore, numerical simulation visually shows several anti-resonances of the steel spring corresponding to impedance and power flow curves. When anti-resonances emerge, the spring collects large energy which may cause damage and unexpected consequences in practical engineering and needs to be avoided. Finally, experimental tests are conducted and results show consistency with that of the simulation of the spring with distributive mass.

  20. Mass formula dependence of calculated spallation reaction product distributions

    International Nuclear Information System (INIS)

    Nishida, Takahiko; Nakahara, Yasuaki

    1990-01-01

    A new version of the spallation reaction simulation code NUCLEUS was developed by incorporating Uno and Yamada's mass formula. This version was used to calculate the distribution of products from the spallation of uranium nuclei by high-energy protons. The dependence of the distributions on the mass formula was examined by comparing the results with those from the original version, which is based on Cameron's mass formula and the mass table compiled by Wapstra et al. As regards the fission component of spallation products, the new version reproduces the reaction product data obtained from thin foil experiments much better, especially on the neutron excess side. (orig.) [de

  1. Systems Measures of Water Distribution System Resilience

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Murray, Regan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walker, La Tonya Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Resilience is a concept that is being used increasingly to refer to the capacity of infrastructure systems to be prepared for and able to respond effectively and rapidly to hazardous events. In Section 2 of this report, drinking water hazards, resilience literature, and available resilience tools are presented. Broader definitions, attributes and methods for measuring resilience are presented in Section 3. In Section 4, quantitative systems performance measures for water distribution systems are presented. Finally, in Section 5, the performance measures and their relevance to measuring the resilience of water systems to hazards is discussed along with needed improvements to water distribution system modeling tools.

  2. Seismic Characterization of Oceanic Water Masses, Water Mass Boundaries, and Mesoscale Eddies SE of New Zealand

    Science.gov (United States)

    Gorman, Andrew R.; Smillie, Matthew W.; Cooper, Joanna K.; Bowman, M. Hamish; Vennell, Ross; Holbrook, W. Steven; Frew, Russell

    2018-02-01

    The Subtropical and Subantarctic Fronts, which separate Subtropical, Subantarctic, and Antarctic Intermediate Waters, are diverted to the south of New Zealand by the submerged continental landmass of Zealandia. In the upper ocean of this region, large volumes of dissolved or suspended material are intermittently transported across the Subtropical Front; however, the mechanisms of such transport processes are enigmatic. Understanding these oceanic boundaries in three dimensions generally depends on measurements collected from stationary vessels and moorings. The details of these data sets, which are critical for understanding how water masses interact and mix at the fine-scale (seismic reflection images of oceanic water masses have been produced using petroleum industry data. These seismic sections clearly show three main water masses, the boundary zones (fronts) between them, and associated thermohaline fine structure that may be related to the mixing of water masses in this region. Interpretations of the data suggest that the Subtropical Front in this region is a landward-dipping zone, with a width that can vary between 20 and 40 km. The boundary zone between Subantarctic Waters and the underlying Antarctic Intermediate Waters is also observed to dip landward. Several isolated lenses have been identified on the three data sets, ranging in size from 9 to 30 km in diameter. These lenses are interpreted to be mesoscale eddies that form at relatively shallow depths along the south side of the Subtropical Front.

  3. Impact of RO-desalted water on distribution water qualities.

    Science.gov (United States)

    Taylor, J; Dietz, J; Randall, A; Hong, S

    2005-01-01

    A large-scale pilot distribution study was conducted to investigate the impacts of blending different source waters on distribution water qualities, with an emphasis on metal release (i.e. corrosion). The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. The blending ratio of different treated waters determined the quality of finished waters. Iron release from aged cast iron pipes increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Copper release to drinking water, however, increased with increasing alkalinity and decreasing pH. Lead release, on the other hand, increased with increasing chloride and decreasing sulfate. The effect of pH and alkalinity on lead release was not clearly observed from pilot blending study. The flat and compact corrosion scales observed for lead surface exposed to S1 water may be attributable to lead concentration less than that of RO water blends.

  4. Mass transfer in water-saturated concretes

    International Nuclear Information System (INIS)

    Atkinson, A.; Claisse, P.A.; Harris, A.W.; Nickerson, A.K.

    1990-01-01

    Cements and concretes are often considered as components of barriers for the containment of radioactive waste. The performance of such materials as mainly physical barriers to the transport of dissolved radionuclides depends on the mass transfer characteristics of the material. In particular the diffusion and sorption behavior of the radionuclides and the water permeability are important. These parameters also influence how the chemistry of the concrete is imposed on the repository. In addition, the transport of gas through concrete controls the way in which gases escape from the repository. Diffusion and gas transport have been measured in a variety of cementitious materials, covering both structural concretes and cementitious backfills; all possible repository construction materials. Measurements have been made using aqueous iodide, strontium and caesium ions and tritiated water as diffusants. The results show that the diffusion of tritiated water is more rapid than that of other species, whilst the transport of strontium and caesium is hindered by sorption; particularly in materials containing blast furnace slag. The transport of gas in these materials has been found to be very sensitive to the degree of water saturation and is extremely low in fully saturated structural concretes. Cementitious backfills have, nevertheless, been identified that have appreciable gas transport even when almost water saturated. The consequences of the results for the performance of cementitious barriers are discussed

  5. Water distribution systems design optimisation using metaheuristics ...

    African Journals Online (AJOL)

    The topic of multi-objective water distribution systems (WDS) design optimisation using metaheuristics is investigated, comparing numerous modern metaheuristics, including several multi-objective evolutionary algorithms, an estimation of distribution algorithm and a recent hyperheuristic named AMALGAM (an evolutionary ...

  6. BIOFILMS IN DRINKING WATER DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Virtually anywhere a surface comes into contact with the water in a distribution system, one can find biofilms. Biofilms are formed in distribution system pipelines when microbial cells attach to pipe surfaces and multiply to form a film or slime layer on the pipe. Probably withi...

  7. Hydrology and heterogeneneous distribution of water quality ...

    African Journals Online (AJOL)

    A study was carried out on the hydrology and heterogeneous distribution of water quality characteristics in the Lagoon of Porto-Novo between July 2014 and June 2015. The water body was stratified into 12 strata for sampling. Data and samples were collected based on season and stations. The results were analyzed in the ...

  8. Fission fragment mass distributions via prompt γ-ray spectroscopy

    Indian Academy of Sciences (India)

    The distribution of fragment masses formed in nuclear fission is one of the most strik- ing features .... 80. 100. 120. 140. 160. 10. 3. 10. 4. Fragment Mass. Relative yield. Sn. Cd. Te. Pd ... the secondary fragment at Z = 50 and N = 82 shells, where the yields are depleted. Both ... More systematic experimental data are required.

  9. Search for new physics in dijet mass and angular distributions

    Indian Academy of Sciences (India)

    We present a search for physics beyond the Standard Model in proton–proton collisions at a centre-of-mass energy of s = 7 TeV, performed with the ATLAS detector at the Large Hadron Collider (LHC). No evidence for new physics is found in dijet mass and angular distributions and stringent limits are set on a variety of ...

  10. Thermobaricity, cabbeling, and water-mass conversion

    Science.gov (United States)

    McDougall, Trevor J.

    1987-05-01

    The efficient mixing of heat and salt along neutral surfaces (by mesoscale eddies) is shown to lead to vertical advection through these neutral surfaces. This is due to the nonlinearities of the equation of state of seawater through terms like ∂2ρ/∂θ∂p (thermobaric effect) and ∂2ρ/∂ θ2 (cabbeling). Cabbeling always causes a sinking or downwelling of fluid through neutral surfaces, whereas thermobaricity can lead to a vertical velocity (relative to neutral surfaces) of either sign. In this paper it is shown that for reasonable values of the lateral scalar diffusivity (especially below a depth of 1000 m), these two processes cause vertical velocities of the order of 10-7 m s-1 through neutral surfaces (usually downward!) and cause water-mass conversion of a magnitude equal to that caused by a vertical diffusivity of 10-4 m2 s-1 (often equivalent to a negative diffusivity). Both thermobaricity and cabbeling can occur in the presence of any nonzero amount of small-scale turbulence and so will not be detected by microstructure measurements. The conservation equations for tracers are considered in a nonorthogonal coordinate frame that moves with neutral surfaces in the ocean. Since only mixing processes cause advection across neutral surfaces, it is useful to regard this vertical advection as a symptom of various mixing processes rather than as a separate physical process. It is possible to derive conservative equations for scalars that do not contain the vertical advective term explicity. In these conservation equations, the terms that represent mixing processes are substantially altered. It is argued that this form of the conservation equations is the most appropriate when considering water-mass transformation, and some examples are given of its application in the North Atlantic. It is shown that the variation of the vertical diffusivity with height does not cause water-mass transformation. Also, salt fingering is often 3-4 times more effective at

  11. Biomarker Pigment Divinyl Chlorophyll a as a Tracer of Water Masses?

    Science.gov (United States)

    Mejdandzic, Maja; Mihanovic, Hrvoje; Silovic, Tina; Henderiks, Jorijntje; Supraha, Luka; Polovic, Dorotea; Bosak, Suncica; Bosnjak, Ivana; Cetinic, Ivona; Olujic, Goran; hide

    2015-01-01

    The ecological preferences of different Phytoplankton types drive their temporal and spatial distributions, reflecting their dependence on certain temperature ranges, light levels, nutrient availability and other environmental gradients. Hence, some phytoplankton taxa can be used as water mass tracers (biotracers).

  12. Radon levels in a water distribution network

    International Nuclear Information System (INIS)

    Alabdula'aly, A.I.

    1997-01-01

    The capital city of Saudi Arabia, Riyadh, relies on both desalinated sea water as well as treated groundwater to meet all its water requirements. About 66% of the water demand is met by desalinated sea water, and the remaining is supplied by six groundwater treatment plants located in the vicinity of the city and supplied with water from 161 wells. The desalinated sea water is blended with only one plant product water and pumped to the distribution network, whereas the other five plants product water is pumped directly to the network. A study of 222 Rn levels in the city distribution network was carried out in which 89 samples were collected from different locations representing the city districts. All samples have shown low radon levels with an average concentration of 0.2 Bq l -1 and a range values of 0.1-1.0 Bq l -1 . The level of radon in different parts of the network was found to be influenced by the water sources to which they are supplied. The lowest radon levels were observed in districts supplied mostly by desalinated sea water. (Author)

  13. Water Mass Classification on a Highly Variable Arctic Shelf Region: Origin of Laptev Sea Water Masses and Implications for the Nutrient Budget

    Science.gov (United States)

    Bauch, D.; Cherniavskaia, E.

    2018-03-01

    Large gradients and inter annual variations on the Laptev Sea shelf prevent the use of uniform property ranges for a classification of major water masses. The central Laptev Sea is dominated by predominantly marine waters, locally formed polynya waters and riverine summer surface waters. Marine waters enter the central Laptev Sea from the northwestern Laptev Sea shelf and originate from the Kara Sea or the Arctic Ocean halocline. Local polynya waters are formed in the Laptev Sea coastal polynyas. Riverine summer surface waters are formed from Lena river discharge and local melt. We use a principal component analysis (PCA) in order to assess the distribution and importance of water masses within the Laptev Sea. This mathematical method is applied to hydro-chemical summer data sets from the Laptev Sea from five years and allows to define water types based on objective and statistically significant criteria. We argue that the PCA-derived water types are consistent with the Laptev Sea hydrography and indeed represent the major water masses on the central Laptev Sea shelf. Budgets estimated for the thus defined major Laptev Sea water masses indicate that freshwater inflow from the western Laptev Sea is about half or in the same order of magnitude as freshwater stored in locally formed polynya waters. Imported water dominates the nutrient budget in the central Laptev Sea; and only in years with enhanced local polynya activity is the nutrient budget of the locally formed water in the same order as imported nutrients.

  14. Procedure of non-contacting local mass density and mass density distribution measurements

    International Nuclear Information System (INIS)

    Menzel, M.; Winkler, K.

    1985-01-01

    The invention has been aimed at a procedure of non-contacting local mass density and/or mass density distribution measurements i.e. without the interfering influence of sensors or probes. It can be applied to installations, apparatuses and pipings of chemical engineering, to tank constructions and transportation on extreme temperature and/or pressure conditions and aggressive media influences respectively. The procedure has utilized an ionizing quantum radiation whereby its unknown weakening and scattering is compensated by a suitable combination of scattering and transmission counter rate measurements in such a way that the local mass densities and the mass density distribution respectively are determinable

  15. THE MASS DISTRIBUTION OF COMPANIONS TO LOW-MASS WHITE DWARFS

    International Nuclear Information System (INIS)

    Andrews, Jeff J.; Price-Whelan, Adrian M.; Agüeros, Marcel A.

    2014-01-01

    Measuring the masses of companions to single-line spectroscopic binary stars is (in general) not possible because of the unknown orbital plane inclination. Even when the mass of the visible star can be measured, only a lower limit can be placed on the mass of the unseen companion. However, since these inclination angles should be isotropically distributed, for a large enough, unbiased sample, the companion mass distribution can be deconvolved from the distribution of observables. In this work, we construct a hierarchical probabilistic model to infer properties of unseen companion stars given observations of the orbital period and projected radial velocity of the primary star. We apply this model to three mock samples of low-mass white dwarfs (LMWDs; M ≲ 0.45 M ☉ ) and a sample of post-common-envelope binaries. We use a mixture of two Gaussians to model the WD and neutron star (NS) companion mass distributions. Our model successfully recovers the initial parameters of these test data sets. We then apply our model to 55 WDs in the extremely low-mass (ELM) WD Survey. Our maximum a posteriori model for the WD companion population has a mean mass μ WD = 0.74 M ☉ , with a standard deviation σ WD = 0.24 M ☉ . Our model constrains the NS companion fraction f NS to be <16% at 68% confidence. We make samples from the posterior distribution publicly available so that future observational efforts may compute the NS probability for newly discovered LMWDs

  16. Mass distribution law of systems of protocluster fragments

    Energy Technology Data Exchange (ETDEWEB)

    Ferraioli, F; Virgopia, N [Rome Univ. (Italy). Ist. di Matematica

    1979-02-01

    Starting from the hypothesis of coalescence through inelastic collisions of small fast moving interstellar gas clouds, an attempt has been made to study the evolutionary mass distribution of a system of fragments simulating a protocluster. The assumption of a mass spectrum with a continuous injection of newly formed entities into the primeval system, and the condition of gravitational reduction of the impact cross-section, have been considered. Comparisons of numerical experiments with the mass spectrum in some well-known young galactic clusters, confirm the mass distribution power-law already obtained by other authors. The empirical Schmidt's law concerning the rate of star formation is also confirmed. The hypothesis of the universal validity of the luminosity function, should not be 'a priori' rejected.

  17. Fission profits of thorium: Distribution in charge and mass

    International Nuclear Information System (INIS)

    Guarnieri, A.A.

    1985-01-01

    It is presented the improvement of a semi-empiric model to describe behavior fo the 235 U + thermal neutrons system. The model is applied to fission of the 232 Th case reproducing the distribution of mass profits of fission products from the behavior of independent profits of fragments related the mass and charge, and the emission of prompt neutrons per fragment. (M.C.K.) [pt

  18. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly...

  19. Distribution of mass in the planetary system and solar nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Weidenschilling, S J [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism

    1977-09-01

    A model 'solar nebula' is constructed by adding the solar complement of light elements to each planet, using recent models of planetary compositions. Uncertainties in this approach are estimated. The computed surface density varies approximately as rsup(-3/2). Mercury, Mars and the asteroid belt are anomalously low in mass, but processes exist which would preferentially remove matter from these regions. Planetary masses and compositions are generally consistent with a monotonic density distribution in the primordial solar nebula.

  20. Sustainable Water Distribution Strategy with Smart Water Grid

    Directory of Open Access Journals (Sweden)

    Seongjoon Byeon

    2015-04-01

    Full Text Available Many problems that are encountered in regards to water balance and resources management are related to challenges of economic development under limited resources and tough competition among various water uses. The development of major infrastructure like airports in remote areas that have limited water resources is becoming a common problem. In order to overcome these difficulties, water management has to articulate and combine several resources in order to respond to various demands while preserving the ecological quality of the environment. The paper discusses the interest in implementing the Smart Water Grid concept on Yeongjongdo Island, which is the location of Korea’s main airport. This new concept is based on the connection of various water resources and their optimized management with new information technology solutions. The proposed system integrates water generated through rainfall, external water resources (i.e., metropolitan water distribution system, gray water and other types of alternative water resources. The paper analyses the feasibility of this approach and explores interest in the Smart Water Grid concept.

  1. Flood impacts on a water distribution network

    Science.gov (United States)

    Arrighi, Chiara; Tarani, Fabio; Vicario, Enrico; Castelli, Fabio

    2017-12-01

    Floods cause damage to people, buildings and infrastructures. Water distribution systems are particularly exposed, since water treatment plants are often located next to the rivers. Failure of the system leads to both direct losses, for instance damage to equipment and pipework contamination, and indirect impact, since it may lead to service disruption and thus affect populations far from the event through the functional dependencies of the network. In this work, we present an analysis of direct and indirect damages on a drinking water supply system, considering the hazard of riverine flooding as well as the exposure and vulnerability of active system components. The method is based on interweaving, through a semi-automated GIS procedure, a flood model and an EPANET-based pipe network model with a pressure-driven demand approach, which is needed when modelling water distribution networks in highly off-design conditions. Impact measures are defined and estimated so as to quantify service outage and potential pipe contamination. The method is applied to the water supply system of the city of Florence, Italy, serving approximately 380 000 inhabitants. The evaluation of flood impact on the water distribution network is carried out for different events with assigned recurrence intervals. Vulnerable elements exposed to the flood are identified and analysed in order to estimate their residual functionality and to simulate failure scenarios. Results show that in the worst failure scenario (no residual functionality of the lifting station and a 500-year flood), 420 km of pipework would require disinfection with an estimated cost of EUR 21 million, which is about 0.5 % of the direct flood losses evaluated for buildings and contents. Moreover, if flood impacts on the water distribution network are considered, the population affected by the flood is up to 3 times the population directly flooded.

  2. On widths of mass distributions in statistical theory of fission

    International Nuclear Information System (INIS)

    Volkov, N.G.; Emel'yanov, V.M.

    1979-01-01

    The process of nucleon tunneling from one fragment to another near the point of the compoUnd-nucleus fragmentation has been studied in the model of a two-center oscillator. The effect of the number of transferred nucleons on the mass distribution of fragments is estimated. Sensitivity of the model to the form of the single-particle potential, excitation eneraies and deformation of fragments is examined. The calculations performed show that it is possible to calculate the mass distributions at the point of fragment contact in the statistical fission model, taking account of the nucleon exchange between fragments

  3. Mass distribution in 20Ne+232Th reaction

    International Nuclear Information System (INIS)

    Sodaye, Suparna; Tripathi, R.; Sudarshan, K.

    2011-01-01

    Mass distribution was measured in 20 Ne+ 232 Th reaction at E lab =145 MeV using recoil catcher technique followed by off-line gamma-ray spectrometry. Significant contribution from transfer fission was observed in the yield of comparatively neutron rich fission products. The variance of mass distribution for complete fusion fission, obtained by excluding neutron rich fission products, was observed to be consistent with the values reported in literature for similar reaction systems which showed a deviation from the systematics obtained using random neck rupture and liquid drop model. (author)

  4. Distilled Water Distribution Systems. Laboratory Design Notes.

    Science.gov (United States)

    Sell, J.C.

    Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

  5. Water hammer analysis in a water distribution system

    Directory of Open Access Journals (Sweden)

    John Twyman

    2017-04-01

    Full Text Available The solution to water hammer in a water distribution system (WDS is shown by applying three hybrid methods (HM based on the Box’s scheme, McCormack's method and Diffusive Scheme. Each HM formulation in conjunction with their relative advantages and disadvantages are reviewed. The analyzed WDS has pipes with different lengths, diameters and wave speeds, being the Courant number different in each pipe according to the adopted discretization. The HM results are compared with the results obtained by the Method of Characteristics (MOC. In reviewing the numerical attenuation, second order schemes based on Box and McCormack are more conservative from a numerical point of view, being recommendable their application in the analysis of water hammer in water distribution systems.

  6. The Distribution of Water in a Viscous Protoplanetary Disk

    Science.gov (United States)

    Ciesla, F. J.; Cuzzi, J. N.

    2005-01-01

    The distribution of water in the solar nebula is important to understand for a number of reasons. Firstly, in the inner regions of the solar nebula, the concentration of water vapor is expected to have played a major role in determining its oxidation state, and therefore would control which minerals would form there. Secondly, in the outer nebula, water would be a major condensable, making up nearly 50% of the mass of the solids and thus possibly playing a role in determining where giant planets formed. Lastly, liquid water is important for forming and sustaining life, and therefore understanding where and how water was transported to the habitable zone of a a star is critical to understanding how common life may be in the galaxy. Because of its importance, the distribution of water in the solar nebula has been studied by a number of authors. The main transport mechanisms which would determine the distribution of water would be diffusion and gas drag migration. Water vapor and small solids would diffuse in the nebula, moving away from areas of high concentrations. Larger bodies, while also subject to diffusion, though to a lesser extent, would experience gas drag migration, causing them to move inwards with time. The bodies most affected by this transport mechanism would be on the order of 1 meter in size. As objects continued to grow larger, their inertia would also grow, making them nearly immobile to gas drag. While efforts have been made to understand how water would be distributed in a protoplanetary disk, none of the published models simultaneously consider the effects of nebular evolution, transport of material throughout the nebula, and the existence of solids of various sizes at a given location of the nebula. We are currently developing a model which allows for these effects and is consistent with models for the accretion of bodies in the solar nebula.

  7. Reduction of water losses by rehabilitation of water distribution network.

    Science.gov (United States)

    Güngör, Mahmud; Yarar, Ufuk; Firat, Mahmut

    2017-09-11

    Physical or real losses may be indicated as the most important component of the water losses occurring in a water distribution network (WDN). The objective of this study is to examine the effects of piping material management and network rehabilitation on the physical water losses and water losses management in a WDN. For this aim, the Denizli WDN consisting of very old pipes that have exhausted their economic life is selected as the study area. The fact that the current network is old results in the decrease of pressure strength, increase of failure intensity, and inefficient use of water resources thus leading to the application of the rehabilitation program. In Denizli, network renewal works have been carried out since the year 2009 under the rehabilitation program. It was determined that the failure rate at regions where network renewal constructions have been completed decreased down to zero level. Renewal of piping material enables the minimization of leakage losses as well as the failure rate. On the other hand, the system rehabilitation has the potential to amortize itself in a very short amount of time if the initial investment cost of network renewal is considered along with the operating costs of the old and new systems, as well as water loss costs. As a result, it can be stated that renewal of piping material in water distribution systems, enhancement of the physical properties of the system, provide significant contributions such as increase of water and energy efficiency and more effective use of resources.

  8. Mass distribution studies in 28Si + 232Th

    International Nuclear Information System (INIS)

    Sodaye, Suparna; Tripathi, R.; Sudarshan, K.; Pujari, P.K.

    2014-01-01

    Mass distribution is one of the important observables to understand the fusion-fission potential energy landscape. In the fission involving composite systems with Z ∼ 100, the fission barrier is lower and the saddle point is compact. Thus, apart from transfer induced fission,various non compound nucleus (NCN) fission processes like quasi-fission, pre-equilibrium fission and fast fission compete with the complete fusion fission (CFF). This would be further affected by the entrance channel parameters like choice of the target-projectile combination (mass asymmetry) and the projectile energy. Charge and mass distribution studies in such system would provide information about various fission processes such as complete fusion fission, non-compound nucleus fission and transfer induced fission, which would help in understanding the fusion-fission process in heavy ion collisions forming composite system in the heavy and trans-actinide region. In view of this, a systematic study of the charge and mass distribution in 28 Si+ 232 Th reaction was planned at beam energy close to and above the entrance channel Coulomb barrier. The experiments were carried out at the TIFR-LINAC booster facility. Self supporting foils of 232 Th were bombarded with 180 and 160 MeV 28 Si beam in a stack foil arrangement. The recoiling fission products were assayed radiochemically by off-line gamma-ray spectrometry. Results of charge distribution studies at E lab =180 MeV have been reported earlier. In the poster, the data on charge and mass distribution distribution will be presented.The results of the present studies will be compared with those from the reactions involving lighter and heavier composite systems

  9. A rationale for continuing mass antibiotic distributions for trachoma

    Directory of Open Access Journals (Sweden)

    House Jenafir

    2007-08-01

    Full Text Available Abstract Background The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. Methods We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Results Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Conclusion Local

  10. A rationale for continuing mass antibiotic distributions for trachoma.

    Science.gov (United States)

    Ray, Kathryn J; Porco, Travis C; Hong, Kevin C; Lee, David C; Alemayehu, Wondu; Melese, Muluken; Lakew, Takele; Yi, Elizabeth; House, Jenafir; Chidambaram, Jaya D; Whitcher, John P; Gaynor, Bruce D; Lietman, Thomas M

    2007-08-07

    The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Local elimination from a community is theoretically possible, even in the

  11. The Mass-Ratio Distribution of Visual Binary Stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1990-01-01

    The selection effects that govern the observations of Visual Binary Stars are in- vestigated, in order to obtain a realistic statistical distribution of the mass-ratio q = Msec=Mprim. To this end a numerical simulation programme has been developed, which `generates' binary stars and `looks' at

  12. Implications of the Cosmological Constant for Spherically Symmetric Mass Distributions

    Science.gov (United States)

    Zubairi, Omair; Weber, Fridolin

    2013-04-01

    In recent years, scientists have made the discovery that the expansion rate of the Universe is increasing rather than decreasing. This acceleration leads to an additional term in Albert Einstein's field equations which describe general relativity and is known as the cosmological constant. This work explores the aftermath of a non-vanishing cosmological constant for relativistic spherically symmetric mass distributions, which are susceptible to change against Einstein's field equations. We introduce a stellar structure equation known as the Tolman-Oppenhiemer-Volkoff (TOV) equation modified for a cosmological constant, which is derived from Einstein's modified field equations. We solve this modified TOV equation for these spherically symmetric mass distributions and obtain stellar properties such as mass and radius and investigate changes that may occur depending on the value of the cosmological constant.

  13. Hydraulic Network Modelling of Small Community Water Distribution ...

    African Journals Online (AJOL)

    Prof Anyata

    ... design of a small community (Sakwa) water distribution network in North Eastern geopolitical region of Nigeria using ..... self cleansing drinking water distribution system is set at 0.4m/s, .... distribution network offers advantages over manual ...

  14. BINARY FORMATION MECHANISMS: CONSTRAINTS FROM THE COMPANION MASS RATIO DISTRIBUTION

    International Nuclear Information System (INIS)

    Reggiani, Maddalena M.; Meyer, Michael R.

    2011-01-01

    We present a statistical comparison of the mass ratio distribution of companions, as observed in different multiplicity surveys, to the most recent estimate of the single-object mass function. The main goal of our analysis is to test whether or not the observed companion mass ratio distribution (CMRD) as a function of primary star mass and star formation environment is consistent with having been drawn from the field star initial mass function (IMF). We consider samples of companions for M dwarfs, solar-type stars, and intermediate-mass stars, both in the field as well as clusters or associations, and compare them with populations of binaries generated by random pairing from the assumed IMF for a fixed primary mass. With regard to the field we can reject the hypothesis that the CMRD was drawn from the IMF for different primary mass ranges: the observed CMRDs show a larger number of equal-mass systems than predicted by the IMF. This is in agreement with fragmentation theories of binary formation. For the open clusters α Persei and the Pleiades we also reject the IMF random-pairing hypothesis. Concerning young star-forming regions, currently we can rule out a connection between the CMRD and the field IMF in Taurus but not in Chamaeleon I. Larger and different samples are needed to better constrain the result as a function of the environment. We also consider other companion mass functions and we compare them with observations. Moreover the CMRD both in the field and clusters or associations appears to be independent of separation in the range covered by the observations. Combining therefore the CMRDs of M (1-2400 AU) and G (28-1590 AU) primaries in the field and intermediate-mass primary binaries in Sco OB2 (29-1612 AU) for mass ratios, q = M 2 /M 1 , from 0.2 to 1, we find that the best chi-square fit follows a power law dN/dq∝q β , with β = -0.50 ± 0.29, consistent with previous results. Finally, we note that the Kolmogorov-Smirnov test gives a ∼1

  15. THE MASS DISTRIBUTION OF COMPANIONS TO LOW-MASS WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Jeff J.; Price-Whelan, Adrian M.; Agüeros, Marcel A. [Department of Astronomy, Columbia University, 550 W 120th Street, New York, NY 10027 (United States)

    2014-12-20

    Measuring the masses of companions to single-line spectroscopic binary stars is (in general) not possible because of the unknown orbital plane inclination. Even when the mass of the visible star can be measured, only a lower limit can be placed on the mass of the unseen companion. However, since these inclination angles should be isotropically distributed, for a large enough, unbiased sample, the companion mass distribution can be deconvolved from the distribution of observables. In this work, we construct a hierarchical probabilistic model to infer properties of unseen companion stars given observations of the orbital period and projected radial velocity of the primary star. We apply this model to three mock samples of low-mass white dwarfs (LMWDs; M ≲ 0.45 M {sub ☉}) and a sample of post-common-envelope binaries. We use a mixture of two Gaussians to model the WD and neutron star (NS) companion mass distributions. Our model successfully recovers the initial parameters of these test data sets. We then apply our model to 55 WDs in the extremely low-mass (ELM) WD Survey. Our maximum a posteriori model for the WD companion population has a mean mass μ{sub WD} = 0.74 M {sub ☉}, with a standard deviation σ{sub WD} = 0.24 M {sub ☉}. Our model constrains the NS companion fraction f {sub NS} to be <16% at 68% confidence. We make samples from the posterior distribution publicly available so that future observational efforts may compute the NS probability for newly discovered LMWDs.

  16. Nitrification in Chloraminated Drinking Water Distribution Systems: Factors Affecting Occurrence

    Science.gov (United States)

    Drinking water distribution systems with ammonia present from either naturally occurring ammonia or ammonia addition during chloramination are at risk for nitrification. Nitrification in drinking water distribution systems is undesirable and may result in water quality degradatio...

  17. Water group ion distributions in the midcometosheath of comet Halley

    Science.gov (United States)

    Huddleston, D. E.; Neugebauer, M.; Goldstein, Bruce E.

    1993-01-01

    In the midcometosheath of comet Halley (1 x 10(exp 5) to 2 x 10(exp 5) km from the nucleus) the center-of-mass plasma frame is approximately the bulk flow velocity of the cometary ions, and the Alfven wave speed is an appreciable fraction of the flow speed. Here, the peaks of the water group ion distributions observed by the Giotto ion mass spectrometer are at velocities consistently below the expected pickup speed. It is shown that this effect is consistent with the scattering of the new pickup ions onto a bispherical shell distribution. The model does not fit the data inside approximately 1.2 x 10(exp 5) km, however, possibly as a result of the growing importance of collisions or the presence of other processes such as scattering on obliquely propagating magnetosonic waves.

  18. Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice.

    Science.gov (United States)

    Andersen, Steven Arild Wuyts; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

    2015-10-01

    Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal in understanding skills acquisition and best-practice implementation and organization of training. To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training. A prospective trial with a 2 × 2 design was conducted at an academic teaching hospital. Participants included 43 novice medical students. Of these, 21 students completed time-distributed practice from October 14 to November 29, 2013, and a separate group of 19 students completed massed practice on May 16, 17, or 18, 2014. Data analysis was performed from June 6, 2014, to March 3, 2015. Participants performed 12 repeated virtual mastoidectomies using a temporal bone surgical simulator in either a distributed (practice blocks spaced in time) or massed (all practice in 1 day) training program with randomization for simulator-integrated tutoring during the first 5 sessions. Performance was assessed using a modified Welling Scale for final product analysis by 2 blinded senior otologists. Compared with the 19 students in the massed practice group, the 21 students in the distributed practice group were older (mean age, 25.1 years), more often male (15 [62%]), and had slightly higher mean gaming frequency (2.3 on a 1-5 Likert scale). Learning curves were established and distributed practice was found to be superior to massed practice, reported as mean end score (95% CI) of 15.7 (14.4-17.0) in distributed practice vs. 13.0 (11.9-14.1) with massed practice (P = .002). Simulator-integrated tutoring accelerated the initial performance, with mean score for tutored sessions of 14.6 (13.9-15.2) vs. 13.4 (12.8-14.0) for

  19. Mechanisms of flow and water mass variability in Denmark Strait

    Science.gov (United States)

    Moritz, Martin; Jochumsen, Kerstin; Quadfasel, Detlef; Mashayekh Poul, Hossein; Käse, Rolf H.

    2017-04-01

    The dense water export through Denmark Strait contributes significantly to the lower limb of the Atlantic Meridional Overturning Circulation. Overflow water is transported southwestward not only in the deep channel of the Strait, but also within a thin bottom layer on the Greenland shelf. The flow on the shelf is mainly weak and barotropic, exhibiting many recirculations, but may eventually contribute to the overflow layer in the Irminger Basin by spilling events in the northern Irminger Basin. Especially the circulation around Dohrn Bank and the Kangerdlussuaq Trough contribute to the shelf-basin exchange. Moored observations show the overflow in Denmark Strait to be stable during the last 20 years (1996-2016). Nevertheless, flow variability was noticed on time scales of eddies and beyond, i.e. on weekly and interannual scales. Here, we use a combination of mooring data and shipboard hydrographic and current data to address the dominant modes of variability in the overflow, which are (i) eddies, (ii) barotropic pulsations of the plume, (iii) lateral shifts of the plume core position, and (iv) variations in vertical extension, i.e. varying overflow thickness. A principle component analysis is carried out and related to variations in sea surface height and wind stress, derived from satellite measurements. Furthermore, a test for topographic waves is performed. Shelf contributions to the overflow core in the Irminger Basin are identified from measurements of temperature and salinity, as well as velocity, which were obtained during recent cruises in the region. The flow and water mass pattern obtained from the observational data is compared to simulations in a high resolution regional model (ROMS), where tracer release experiments and float deployments were carried out. The modelling results allow a separation between different atmospheric forcing modes (NAO+ vs NAO- situations), which impact the water mass distribution and alter the dense water pathways on the

  20. A multivariate rank test for comparing mass size distributions

    KAUST Repository

    Lombard, F.

    2012-04-01

    Particle size analyses of a raw material are commonplace in the mineral processing industry. Knowledge of particle size distributions is crucial in planning milling operations to enable an optimum degree of liberation of valuable mineral phases, to minimize plant losses due to an excess of oversize or undersize material or to attain a size distribution that fits a contractual specification. The problem addressed in the present paper is how to test the equality of two or more underlying size distributions. A distinguishing feature of these size distributions is that they are not based on counts of individual particles. Rather, they are mass size distributions giving the fractions of the total mass of a sampled material lying in each of a number of size intervals. As such, the data are compositional in nature, using the terminology of Aitchison [1] that is, multivariate vectors the components of which add to 100%. In the literature, various versions of Hotelling\\'s T 2 have been used to compare matched pairs of such compositional data. In this paper, we propose a robust test procedure based on ranks as a competitor to Hotelling\\'s T 2. In contrast to the latter statistic, the power of the rank test is not unduly affected by the presence of outliers or of zeros among the data. © 2012 Copyright Taylor and Francis Group, LLC.

  1. Mass and charge distribution in heavy-ion collisions

    International Nuclear Information System (INIS)

    Beck, F.; Dworzecka, M.; Feldmeier, H.

    1978-01-01

    A statistical model based on the independent particle picture is used to calculate mass and charge distributions in deep inelastic heavy-ion collisions. Different assumptions on volume and charge equilibrations are compared with measured variances of charge distributions. One combination of assumptions is clearly favoured by experiment, and gives a reasonable description of the variance versus energy loss curves up to energy losses of about 200 MeV in the heavy systems Kr+Ho and Xe+Bi, and up to about 60 MeV for the light system Ar+Ca [af

  2. Evaluation of mass distribution data from 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Liu Tingjin

    2003-01-01

    The mass distribution data of 252 Cf spontaneous fission were evaluated based on 7 sets of available experimental data. The measured data were corrected for the standards and γ intensity used by using the new evaluated ones. The errors were made necessary adjusting. The evaluated experimental data were fitted with spline function without any restriction and with symmetric restriction. These two sets of fit data were recommended as reference data of the mass distribution of 252 Cf spontaneous fission. The errors of the recommended data were considerably reduced comparing with the measured ones. The light and heavy peaks are not completely symmetric. Also there are fine structures on the right side of the light peak at A=109-111 and left side of the heavy peak at A=137-139. These should be paid attention and studied further. (author)

  3. Unexplained structure in (μ,π) invariant mass distribution

    International Nuclear Information System (INIS)

    Ramm, C.A.

    2000-01-01

    Structures in invariant mass distributions from (μ,π) combinations in the range 0.380 μ -π 0.470 GeV from neutrino and kaon experiments are presented in comparable formats. No artifacts have been found to account for any part of the structure. Hypotheses that the similarities are due to recurrent statistical fluctuations are beyond credibility. My conclusion is that the similarities are overwhelming evidence that the structure is of an unexplained physical origin. It includes an enhancement which would accord with the decay of a narrow (μ,π) state of mass 0.429 GeV. The purpose of this report is to request and enable every experimenter with precise M μ , π distributions to investigate their degree of correspondence with these analyses (author)

  4. Mass distribution for the two-photon channel

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Mass distribution for the two-photon channel. The strongest evidence for this new particle comes from analysis of events containing two photons. The smooth dotted line traces the measured background from known processes. The solid line traces a statistical fit to the signal plus background. The new particle appears as the excess around 126.5 GeV. The full analysis concludes that the probability of such a peak is three chances in a million.

  5. Mass distribution for the four-lepton channel.

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Mass distribution for the four-lepton channel. The search with the purest expected signal is done by examining events with two Z bosons that have decayed to pairs of electrons or muons. In the region from 120 to 130 GeV, 13 events are seen where only 5.3 were expected. The complete analysis concludes that the probability of such an excess would be three times in ten thousand if there were no new particle.

  6. High mass-asymmetry distributions of fissioning nuclei

    International Nuclear Information System (INIS)

    Sandulescu, A.; Lusting, H.J.; Hahn, J.; Greiner, W.

    1978-07-01

    It is shown that new mass-asymmetry valleys are appearing in the fragmentation potential V(l,eta) as function of the length l and mass-asymmetry coordinate eta = (A 1 - A 2 )to a correct treatment of the shell effects such that for separated fragments the shell effects equal the sum of the shell effects of the individual fragments and correspond to the double magic fragments 48 Ca, 78 Ni, 132 Sn and 208 Pb or may be 56 Ni. Also is shown that the fission mass-distributions have additional peaks corresponding to the bottom of these new valleys. The calculations are illustrated for 252 No and 238 U. The preliminary results show for 238 U relatively high percent yields in agreement with present available experimental data. (author)

  7. Distribution of tropical tropospheric water vapor

    Science.gov (United States)

    Sun, De-Zheng; Lindzen, Richard S.

    1993-01-01

    Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

  8. Mass measurement errors of Fourier-transform mass spectrometry (FTMS): distribution, recalibration, and application.

    Science.gov (United States)

    Zhang, Jiyang; Ma, Jie; Dou, Lei; Wu, Songfeng; Qian, Xiaohong; Xie, Hongwei; Zhu, Yunping; He, Fuchu

    2009-02-01

    The hybrid linear trap quadrupole Fourier-transform (LTQ-FT) ion cyclotron resonance mass spectrometer, an instrument with high accuracy and resolution, is widely used in the identification and quantification of peptides and proteins. However, time-dependent errors in the system may lead to deterioration of the accuracy of these instruments, negatively influencing the determination of the mass error tolerance (MET) in database searches. Here, a comprehensive discussion of LTQ/FT precursor ion mass error is provided. On the basis of an investigation of the mass error distribution, we propose an improved recalibration formula and introduce a new tool, FTDR (Fourier-transform data recalibration), that employs a graphic user interface (GUI) for automatic calibration. It was found that the calibration could adjust the mass error distribution to more closely approximate a normal distribution and reduce the standard deviation (SD). Consequently, we present a new strategy, LDSF (Large MET database search and small MET filtration), for database search MET specification and validation of database search results. As the name implies, a large-MET database search is conducted and the search results are then filtered using the statistical MET estimated from high-confidence results. By applying this strategy to a standard protein data set and a complex data set, we demonstrate the LDSF can significantly improve the sensitivity of the result validation procedure.

  9. Formation rate of water masses in the Japan Sea

    International Nuclear Information System (INIS)

    Kawamura, Hideyuki; Ito, Toshimichi; Yoon, Jong-Hwan

    2007-01-01

    Water masses in the subsurface and the intermediate layer are actively formed due to strong winter convection in the Japan Sea. It is probable that some fraction of pollution is carried into the layer below the sea surface together with these water masses, so it is important to estimate the formation rate and turnover time of water masses to study the fate of pollutants. The present study estimates the annual formation rate and the turnover time of water masses using a three-dimensional ocean circulation model and a particle chasing method. The total annual formation rate of water masses below the sea surface amounted to about 3.53±0.55 Sv in the Japan Sea. Regarding representative intermediate water masses, the annual formation rate of the Upper portion of the Japan Sea Proper Water (UJSPW) and the Japan Sea Intermediate Water (JSIW) were estimated to be about 0.38±0.11 and 1.43±0.16 Sv, respectively, although there was little evidence of the formation of deeper water masses below a depth of about 1500 m in a numerical experiment. An estimate of turnover time shows that the UJSPW and the JSIW circulate in the intermediate layer of the Japan Sea with timescales of about 22.1 and 2.2 years, respectively. (author)

  10. In situ diagnostic of water distribution in thickness direction of MEA by neutron imaging. Focused on characteristics of water distribution in gas diffusion layer

    International Nuclear Information System (INIS)

    Tasaki, Yutaka; Ichikawa, Yasushi; Kobo, Norio; Shinohara, Kazuhiko; Boillat, Pierre; Kramer, Denis; Scherer, Gunther G.; Lehmann, Eberhard H.

    2008-01-01

    The mass transfer characteristics of gas diffusion layer (GDL) are closely related to cell performance in PEFC. In this study, In situ diagnostic of water distribution in thickness direction of MEA by Neutron Imaging has been carried out for three MEAs with different GDLs on cathode side as well as I-V characteristics. It was confirmed that this method is useful for analyzing water distribution in thickness direction of MEA. The relationship between I-V characteristics and liquid water distribution has been studied. (author)

  11. Corroded scale analysis from water distribution pipes

    Directory of Open Access Journals (Sweden)

    Rajaković-Ognjanović Vladana N.

    2011-01-01

    Full Text Available The subject of this study was the steel pipes that are part of Belgrade's drinking water supply network. In order to investigate the mutual effects of corrosion and water quality, the corrosion scales on the pipes were analyzed. The idea was to improve control of corrosion processes and prevent impact of corrosion on water quality degradation. The instrumental methods for corrosion scales characterization used were: scanning electron microscopy (SEM, for the investigation of corrosion scales of the analyzed samples surfaces, X-ray diffraction (XRD, for the analysis of the presence of solid forms inside scales, scanning electron microscopy (SEM, for the microstructural analysis of the corroded scales, and BET adsorption isotherm for the surface area determination. Depending on the composition of water next to the pipe surface, corrosion of iron results in the formation of different compounds and solid phases. The composition and structure of the iron scales in the drinking water distribution pipes depends on the type of the metal and the composition of the aqueous phase. Their formation is probably governed by several factors that include water quality parameters such as pH, alkalinity, buffer intensity, natural organic matter (NOM concentration, and dissolved oxygen (DO concentration. Factors such as water flow patterns, seasonal fluctuations in temperature, and microbiological activity as well as water treatment practices such as application of corrosion inhibitors can also influence corrosion scale formation and growth. Therefore, the corrosion scales found in iron and steel pipes are expected to have unique features for each site. Compounds that are found in iron corrosion scales often include goethite, lepidocrocite, magnetite, hematite, ferrous oxide, siderite, ferrous hydroxide, ferric hydroxide, ferrihydrite, calcium carbonate and green rusts. Iron scales have characteristic features that include: corroded floor, porous core that contains

  12. 30 CFR 71.602 - Drinking water; distribution.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in sanitary containers. Water systems and appurtenances thereto shall be constructed and maintained in accordance with...

  13. Water in the Earth's Interior: Distribution and Origin

    Science.gov (United States)

    Peslier, Anne H.; Schönbächler, Maria; Busemann, Henner; Karato, Shun-Ichiro

    2017-10-01

    The concentration and distribution of water in the Earth has influenced its evolution throughout its history. Even at the trace levels contained in the planet's deep interior (mantle and core), water affects Earth's thermal, deformational, melting, electrical and seismic properties, that control differentiation, plate tectonics and volcanism. These in turn influenced the development of Earth's atmosphere, oceans, and life. In addition to the ubiquitous presence of water in the hydrosphere, most of Earth's "water" actually occurs as trace amounts of hydrogen incorporated in the rock-forming silicate minerals that constitute the planet's crust and mantle, and may also be stored in the metallic core. The heterogeneous distribution of water in the Earth is the result of early planetary differentiation into crust, mantle and core, followed by remixing of lithosphere into the mantle after plate-tectonics started. The Earth's total water content is estimated at 18_{-15}^{+81} times the equivalent mass of the oceans (or a concentration of 3900_{-3300}^{+32700} ppm weight H2O). Uncertainties in this estimate arise primarily from the less-well-known concentrations for the lower mantle and core, since samples for water analyses are only available from the crust, the upper mantle and very rarely from the mantle transition zone (410-670 km depth). For the lower mantle (670-2900 km) and core (2900-4500 km), the estimates rely on laboratory experiments and indirect geophysical techniques (electrical conductivity and seismology). The Earth's accretion likely started relatively dry because it mainly acquired material from the inner part of the proto-planetary disk, where temperatures were too high for the formation and accretion of water ice. Combined evidence from several radionuclide systems (Pd-Ag, Mn-Cr, Rb-Sr, U-Pb) suggests that water was not incorporated in the Earth in significant quantities until the planet had grown to ˜60-90% of its current size, while core formation

  14. Elemental mass size distribution of the Debrecen urban aerosol

    International Nuclear Information System (INIS)

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

    2007-01-01

    Complete text of publication follows. Size distribution is one of the basic properties of atmospheric aerosol. It is closely related to the origin, chemical composition and age of the aerosol particles, and it influences the optical properties, environmental effects and health impact of aerosol. As part of the ongoing aerosol research in the Group of Ion Beam Applications of the Atomki, elemental mass size distribution of urban aerosol were determined using particle induced X-ray emission (PIXE) analytical technique. Aerosol sampling campaigns were carried out with 9-stage PIXE International cascade impactors, which separates the aerosol into 10 size fractions in the 0.05-30 ?m range. Five 48-hours long samplings were done in the garden of the Atomki, in April and in October, 2007. Both campaigns included weekend and working day samplings. Basically two different kinds of particles could be identified according to the size distribution. In the size distribution of Al, Si, Ca, Fe, Ba, Ti, Mn and Co one dominant peak can be found around the 3 m aerodynamic diameter size range, as it is shown on Figure 1. These are the elements of predominantly natural origin. Elements like S, Cl, K, Zn, Pb and Br appears with high frequency in the 0.25-0.5 mm size range as presented in Figure 2. These elements are originated mainly from anthropogenic sources. However sometimes in the size distribution of these elements a 2 nd , smaller peak appears at the 2-4 μm size ranges, indicating different sources. Differences were found between the size distribution of the spring and autumn samples. In the case of elements of soil origin the size distribution was shifted towards smaller diameters during October, and a 2 nd peak appeared around 0.5 μm. A possible explanation to this phenomenon can be the different meteorological conditions. No differences were found between the weekend and working days in the size distribution, however the concentration values were smaller during the weekend

  15. A study of jet mass distributions with grooming

    Science.gov (United States)

    Marzani, Simone; Schunk, Lais; Soyez, Gregory

    2017-07-01

    We perform a phenomenological study of the invariant mass distribution of hadronic jets produced in proton-proton collisions, in conjunction with a grooming algorithm. In particular, we consider the modified MassDrop Tagger (mMDT), which corresponds to Soft Drop with angular exponent β = 0. Our calculation, which is differential in both jet mass and jet transverse momentum, resums large logarithms of the jet mass, including the full dependence on the groomer's energy threshold z cut, and it is matched to fixed-order QCD matrix elements at next-to-leading order. In order to account for non-perturbative contributions, originating from the hadronisation process and from the underlying event, we also include a phenomenological correction factor derived from Monte Carlo parton shower simulations. Furthermore, we consider two different possibilities for the jet transverse momentum: before or after grooming. We show that the former should be preferred for comparisons with upcoming experimental data essentially because the mMDT transverse momentum spectrum is not collinear safe, though the latter exhibits less sensitivity to underlying event and displays properties that may provide complementary information for probing non-perturbative effects.

  16. Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Maganas, A.

    1993-01-01

    An experiment was designed to measure the fully-developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a BWR-5 rod bundle. Data collected with Refrigerant-144 at pressures ranging from 7 to 14 bar, simulating operation with water in the range 55 to 103 bar are reported. The average mass flux and quality in the test section were in the ranges 1300 to 1750 kg/m s and -0.03 to 0.25, respectively. The data are analyzed and presented in various forms

  17. Mass distributions in nucleon-induced fission at intermediate energies

    CERN Document Server

    Duijvestijn, M C; Hambsch, F J

    2001-01-01

    Temperature-dependent fission barriers and fission-fragment mass distributions are calculated in the framework of the multimodal random neck-rupture model (MM-RNRM). It is shown how the distinction between the different fission modes disappears at higher excitation energies, due to the melting of shell effects. The fission-fragment mass yield calculations are coupled to the nuclear reaction code ALICE-91, which takes into account the competition between the other reaction channels and fission. With the combination of the temperature-dependent MM-RNRM and ALICE-91 nucleon-induced fission is investigated at energies between 10 and 200 MeV for nuclei varying from Au to Am. (72 refs).

  18. Water-Pressure Distribution on Seaplane Float

    Science.gov (United States)

    Thompson, F L

    1929-01-01

    The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author)

  19. Advanced feed water distributing system for WWER 440 steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O.; Klinga, J. [Energovyzkum Ltd, Brno (Switzerland); Grazl, K. [Vitkovice s.c., Ostrava (Switzerland); Tischler, J.; Mihalik, M. [SEP Atomove Elektrarne Bohunice (Slovakia)

    1995-12-31

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.). 3 refs.

  20. Advanced feed water distributing system for WWER 440 steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O; Klinga, J [Energovyzkum Ltd, Brno (Switzerland); Grazl, K [Vitkovice s.c., Ostrava (Switzerland); Tischler, J; Mihalik, M [SEP Atomove Elektrarne Bohunice (Slovakia)

    1996-12-31

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.). 3 refs.

  1. Advanced feed water distributing system for WWER 440 steam generators

    International Nuclear Information System (INIS)

    Matal, O.; Klinga, J.; Grazl, K.; Tischler, J.; Mihalik, M.

    1995-01-01

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.)

  2. Compression behavior of cellular metals with inhomogeneous mass distribution

    International Nuclear Information System (INIS)

    Foroughi, B.

    2001-05-01

    Mechanical behavior of two types of closed cell metals (ALULIGHT and ALPORAS) is investigated experimentally and numerically. Compressive tests performed on prismatic specimens indicate that inhomogeneities in the mass density distribution are a key factor in the deformation behavior of cellular metals. The three dimensional cellular structure of the investigated specimens is recorded using x-ray medical computed tomography (CT). A special procedure called density mapping method has been used to transfer the recorded CT data into a continuum by averaging over a certain domain (averaging domain). This continuum model is implemented using finite elements to study the effect of variations in local mass densities. The finite element model is performed by a simple regular discretization of a specimen's volume with elements which have constant edge length. Mechanical properties derived from compression tests of ALPORAS samples are assigned to the corresponding mesoscopic density value of each element. The effect of averaging domain size is studied to obtain a suitable dimension which fulfils the homogenization requirements and allows the evaluation of inhomogenities in the specimens. The formation and propagation of deformation band(s) and stress-strain responses of tested cellular metals are modeled with respect to their mass distribution. It is shown that the inhomogeneous density distribution leads to plastic strain localization and causes a monotonically increase of the stress in the plateau regime although no hardening response was considered for homogeneous material in this regime. The simulated plastic strain localization and the calculated stress-strain responses are compared with the experimental results. The stiffness values of experiment and simulation agree very well for both cellular materials. The values of plateau strength as well, but it differs in some cases of ALULIGHT samples, where the hardening response can be predicted at least qualitatively

  3. Hydraulic Network Modelling of Small Community Water Distribution ...

    African Journals Online (AJOL)

    Prof Anyata

    community (Sakwa) water distribution network in North Eastern geopolitical region of Nigeria using. WaterCAD ..... Table 1: Criteria Relating Population to Water Demand (NWSP, 2000) ..... timely manner ... Department, Middle East Technical.

  4. Drinking Water Microbiome as a Screening Tool for Nitrification in Chloraminated Drinking Water Distribution Systems

    Science.gov (United States)

    Many water utilities in the US using chloramine as disinfectant treatment in their distribution systems have experienced nitrification episodes, which detrimentally impact the water quality. A chloraminated drinking water distribution system (DWDS) simulator was operated throug...

  5. Phenotyping polyclonal kappa and lambda light chain molecular mass distributions in patient serum using mass spectrometry.

    Science.gov (United States)

    Barnidge, David R; Dasari, Surendra; Ramirez-Alvarado, Marina; Fontan, Adrian; Willrich, Maria A V; Tschumper, Renee C; Jelinek, Diane F; Snyder, Melissa R; Dispenzieri, Angela; Katzmann, Jerry A; Murray, David L

    2014-11-07

    We previously described a microLC-ESI-Q-TOF MS method for identifying monoclonal immunoglobulins in serum and then tracking them over time using their accurate molecular mass. Here we demonstrate how the same methodology can be used to identify and characterize polyclonal immunoglobulins in serum. We establish that two molecular mass distributions observed by microLC-ESI-Q-TOF MS are from polyclonal kappa and lambda light chains using a combination of theoretical molecular masses from gene sequence data and the analysis of commercially available purified polyclonal IgG kappa and IgG lambda from normal human serum. A linear regression comparison of kappa/lambda ratios for 74 serum samples (25 hypergammaglobulinemia, 24 hypogammaglobulinemia, 25 normal) determined by microflowLC-ESI-Q-TOF MS and immunonephelometry had a slope of 1.37 and a correlation coefficient of 0.639. In addition to providing kappa/lambda ratios, the same microLC-ESI-Q-TOF MS analysis can determine the molecular mass for oligoclonal light chains observed above the polyclonal background in patient samples. In 2 patients with immune disorders and hypergammaglobulinemia, we observed a skewed polyclonal molecular mass distribution which translated into biased kappa/lambda ratios. Mass spectrometry provides a rapid and simple way to combine the polyclonal kappa/lambda light chain abundance ratios with the identification of dominant monoclonal as well as oligoclonal light chain immunoglobulins. We anticipate that this approach to evaluating immunoglobulin light chains will lead to improved understanding of immune deficiencies, autoimmune diseases, and antibody responses.

  6. Factors that may compromise bulk water distribution reliability

    OpenAIRE

    2012-01-01

    D.Ing. This thesis considers water supply and divides the water supply environment into three categories; the macro water supply environment, the water supply scheme and the consumers. Each of the categories is briefly explored in terms of the factors that may influence it. Subsequently, some of the unique features of a bulk water distribution system are dealt with, as well as different approaches related to bulk water distribution system design and assessment. One of these approaches, the...

  7. Critical mass variation of 239Pu with water dilution

    International Nuclear Information System (INIS)

    Pearlstein, S.

    1996-01-01

    The critical mass of an unreflected solid sphere of 239 Pu is ∼ 10 kg. The increase in critical mass observed for small water dilutions of unreflected 239 Pu spheres is paradoxical. Introducing small amounts of water uniformly throughout the sphere increases the spherical volume containing the same amount of 239 Pu as the critical solid sphere. The increase in radius decreases the surface-to-volume ratio of the sphere, which has the effect to first order of decreasing the neutron leakage, which is proportional to the surface, relative to the fissions, which are proportional to the volume. The reduction in neutron leakage is expected to reduce the critical mass, but instead, the critical mass is observed to increase. It is discussed how changes in the fast neutron spectrum with corresponding changes in the nuclear parameters result in an increase in critical mass for small water dilutions

  8. EQUITY EVALUATION OF PADDY IRRIGATION WATER DISTRIBUTION BY SOCIETY-JUSTICE-WATER DISTRIBUTION RULE HYPOTHESIS

    Science.gov (United States)

    Tanji, Hajime; Kiri, Hirohide; Kobayashi, Shintaro

    When total supply is smaller than total demand, it is difficult to apply the paddy irrigation water distribution rule. The gap must be narrowed by decreasing demand. Historically, the upstream served rule, rotation schedule, or central schedule weight to irrigated area was adopted. This paper proposes the hypothesis that these rules are dependent on social justice, a hypothesis called the "Society-Justice-Water Distribution Rule Hypothesis". Justice, which means a balance of efficiency and equity of distribution, is discussed under the political philosophy of utilitarianism, liberalism (Rawls), libertarianism, and communitarianism. The upstream served rule can be derived from libertarianism. The rotation schedule and central schedule can be derived from communitarianism. Liberalism can provide arranged schedule to adjust supply and demand based on "the Difference Principle". The authors conclude that to achieve efficiency and equity, liberalism may provide the best solution after modernization.

  9. Mathematical modeling of water mass balance for proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Wan Ramli Wan Daud; Kamaruzzaman Sopian; Jaafar Sahari; Nik Suhaimi Mat Hassan

    2006-01-01

    Gas and water management are key to achieving good performance from a proton exchange membrane fuel cell (PEMFC) stack. Water plays a critical role in PEMFC. The proton conductivity is increase with the water content. In order to achieve enough hydration, water is normally introduced into the cell externally by a variety of methods such as liquid injection, steam introduction, and humidification of reactants by passing them through humidifiers before entering the cell. In this paper, mathematical modeling of water mass balance for PEMFC at anode and cathode side are proposed by using external humidification and assume that steady state, constant pressure, constant temperature and gases distribution are uniform

  10. Generalised extreme value distributions provide a natural hypothesis for the shape of seed mass distributions.

    Directory of Open Access Journals (Sweden)

    Will Edwards

    Full Text Available Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually log-transformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs, a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm.

  11. Attentionally splitting the mass distribution of hand-held rods.

    Science.gov (United States)

    Burton, G; Turvey, M T

    1991-08-01

    Two experiments on the length-perception capabilities of effortful or dynamic touch differed only in terms of what the subject intended to perceive, while experimental conditions and apparatus were held constant. In each trial, a visually occluded rod was held as still as possible by the subject at an intermediate position. For two thirds of the trials, a weight was attached to the rod above or below the hand. In Experiment 1, in which the subject's task was to perceive the distance reachable with the portion of the rod forward of the hand, perceived extent was a function of the first moment of the mass distribution associated with the forward portion of the rod, and indifferent to the first moment of the entire rod. In Experiment 2, in which the task was to perceive the distance reachable with the entire rod if it was held at an end, the pattern of results was reversed. These results indicate the capability of selective sensitivity to different aspects of a hand-held object's mass distribution, without the possibility of differential exploration specific to these two tasks. Results are discussed in relation to possible roles of differential information, intention, and self-organization in the explanations of selective perceptual abilities.

  12. Mass and Angular Distributions of Charged Dihadron Production

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Mary Clare [Michigan U.

    1990-01-01

    Experiment 711, conducted at Fermilab. provided a unique handle towards understanding valence quark scattering by studying pairs of single. charged, high transverse momentum hadrons produced in collisions of 800 GeV /c protons on fixed metal targets. The apparatus consisted of a double-arm spectrometer. calorimetrically triggered. with high momentum resolution and a large angular acceptance for all charge states of particle pairs. The experiment was designed to select those hadron pairs that carrted most of the momentum and energy of the underlying scattered quarks and gluons. The charge of such "leading" hadrons is correlated with the charge of the quark that produced it. Quantum Chromodynamics (QCD) assumes that the scattering behavior of quarks ts independent of their charge, or "flavour": Experiment 711 could test this assumption. Tilis dissertation descrtbes the analysis of the mass and angular distributions of hadron pair production for three separate charge states: +-, ++ and --. The angular distributions are found to deviate from theory predictions of flavour symmetry. Also. the mass cross sections indicate ratios of positive to negative hard-scattered particles that are larger than expected from theory. These results could warrant reconsideration of the assumptions and approximations currently made in leading-order QCD calculations.

  13. Mass and charge distributions in Fe-induced reactions

    International Nuclear Information System (INIS)

    Madani, H.; Mignerey, A.C.; Marchetti, A.A.; Weston-Dawkes, A.P.; Kehoe, W.L.; Obenshain, F.

    1995-01-01

    The charge and mass of the projectile-like fragments produced in the 12-MeV/nucleon 56 Fe + 165 Ho reaction were measured at a laboratory scattering angle of 16 degrees. The mass and charge distributions of the projectile-like fragments were generated as a function of total kinetic energy loss (TKEL), and characterized by their neutron and proton centroids and variances, and correlation factors. A weak drift of the system towards mass asymmetry, opposite to the direction which minimizes the potential energy of the composite system, was observed. The increase in the variances with energy loss is consistent with a nucleon exchange mechanism as a means for energy dissipation. Predictions of two nucleon exchange models, Randrup's and, Tassan-Got's models, are compared to the experimental results of the 672-MeV 56 Fe + 165 Ho reaction and to other Fe-induced reactions. The proton and neutron centroids were found to be generally better reproduced by Tassan-Got's model than by Randrup's model. The variances and correlation factor are well reproduced for asymmetric systems by both models

  14. Manganese deposition in drinking water distribution systems.

    Science.gov (United States)

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Distribution of radioactive constituents in river waters

    International Nuclear Information System (INIS)

    Herranz, M.; Elejalde, C.; Legarda, F.; Romero, F.

    1994-01-01

    For a research project on the distribution and evaluation of natural and artificial radioactive constituents in ecological segments of Biscay (northeast spain), the amounts of nuclides present in the main river waters were measured. Radioactive procedures include i) total alpha and beta indexes with a gas flow detector, dry residues near to 2 and 10 mg/ cm sup 2, respectively and counting periods of 1000 mn, ii) gamma emitters with a low level gamma spectrometer (Ge-HP detector + 8000 channels analyser) using the dry residue from 8 litres and a counting period of 4 days and iii) statistical treatment of data at 95% confidence.In this paper, ten water samples from the nervion river basin are included. Physical and chemical parameters of samples were also determined by standard procedures, because there is a sharp change in the composition of this river in the first part of the course. Radioactive constituents were identified as follows: a sample has a detectable alpha index, all samples contains beta emitters with a high variability, natural nuclides from uranium and thorium families were detected in some cases. A parallel behaviour is found between samples where K-40 and Cs-137 were found. The paper tries at last to find relations among chemical and radioactive constituents by the application of multivariate statistical methods, specially for the case of Cs-137, the only artificial nuclide identified in this work. 1 tab., 2 figs., 5 refs. (author)

  16. Identifying water mass depletion in northern Iraq observed by GRACE

    NARCIS (Netherlands)

    Mulder, G.; Olsthoorn, T.N.; Al-manmi, D.A.M.A.; Schrama, E.J.O.; Smidt, E.H.

    2015-01-01

    Observations acquired by Gravity Recovery And Climate Experiment (GRACE) mission indicate a mass loss of 146 ± 6 mm equivalent water height (EWH) in northern Iraq between 2007 and 2009. These data are used as an independent validation of lake mass variations and a rainfall-runoff model, which is

  17. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    Science.gov (United States)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  18. Mass and charge distributions in chlorine-induced nuclear reactions

    International Nuclear Information System (INIS)

    Marchetti, A.A.

    1991-01-01

    Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions 37 Cl on 40 Ca and 209 Bi at E/A = 7.3 MeV, and 35 Cl, on 209 Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corresponding to the 31 Cl on 209 Bi reaction was very poor. This prompted the study and application of a deconvolution technique for peak enhancement. The drifts of the charge and mass centroids for the system 37 Cl on 40 Ca are consistent with a process of mass and charge equilibration mediated by nucleon exchange between the two partners, followed by evaporation. The asymmetric systems show a strong drift towards larger asymmetry, with the production of neutron-rich nuclei. It was concluded that this is indicative of a net transfer of protons from the light to the heavy partner, and a net flow of neutrons in the opposite direction. The variances for all systems increase with energy loss, as it would be expected from a nucleon exchange mechanism; however, the variances for the reaction 37 Cl on 40 Ca are higher than those expected from that mechanism. The coefficients of correlation indicate that the transfer of nucleons between projectile and target is correlated. The results were compared to the predictions of two current models based on a stochastic nucleon exchange mechanism. In general, the comparisons between experimental and predicted variances support this mechanism; however, the need for more realistic driving forces in the model calculations is indicated by the disagreement between predicted and experimental centroids

  19. IDENTIFICATION OF THE MASS DISTRIBUTIONS OF THE MILK FAT PHASE USING UNIVERSAL PEARSON DISTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    A. A. Khvostov

    2015-01-01

    Full Text Available In this paper we consider the problem of approximating the experimental values of the coefficient of attenuation of ultrasonic oscillations and the mass distribution of the fat globules in the milk and milk products. The analysis of experimental data in terms of the choice of the method of approximation was done. A approximating dependence is based on the solution of Pearson differential equations. The advantages of the proposed method for the type of approximation of the experimental data obtained. An algorithm for constructing a mathematical model describing the relaxation spectrum and mass distribution of the fat globules in the milk and milk products was implemented. As a result, a family of Pearson approximation curves of the experimental data shows the ability to qualitatively correctly describe the change in the distribution of the fat phase in the process of homogenization. It estimates the error of approximating dependence, which amounted to 18 %. It is shown that during of the process of homogenization of dairy products changes shape of the curve describing the distribution of the fat globules, in view of the fact that there is a local extremum, caused by the presence of the non-homogenized fat globules. The accuracy of the selected mathematical model is significantly reduced. At the same time, it loses its physical meaning and its parameters. To address the identified deviations in the proposed mass distribution of fat globules as a function with two modes. It is proved that the complexity of the model is not only doubles the number of its parameters, but also complicates the interpretation of measurement results in a control system, and makes it difficult to analyze the obtained parameters of approximation by decision-maker. As a result of approximation of experimental data suggested to use statistical moments of the distribution for problem decision.

  20. Spatiotemporal Dynamics of Ammonia-Oxidizing Thaumarchaeota in Distinct Arctic Water Masses

    Directory of Open Access Journals (Sweden)

    Oliver Müller

    2018-01-01

    Full Text Available One of the most abundant archaeal groups on Earth is the Thaumarchaeota. They are recognized as major contributors to marine ammonia oxidation, a crucial step in the biogeochemical cycling of nitrogen. Their universal success is attributed to a high genomic flexibility and niche adaptability. Based on differences in the gene coding for ammonia monooxygenase subunit A (amoA, two different ecotypes with distinct distribution patterns in the water column have been identified. We used high-throughput sequencing of 16S rRNA genes combined with archaeal amoA functional gene clone libraries to investigate which environmental factors are driving the distribution of Thaumarchaeota ecotypes in the Atlantic gateway to the Arctic Ocean through an annual cycle in 2014. We observed the characteristic vertical pattern of Thaumarchaeota abundance with high values in the mesopelagic (>200 m water throughout the entire year, but also in the epipelagic (<200 m water during the dark winter months (January, March and November. The Thaumarchaeota community was dominated by three OTUs which on average comprised 76% ± 11 and varied in relative abundance according to water mass characteristics and not to depth or ammonium concentration, as suggested in previous studies. The ratios of the abundance of the different OTU types were similar to that of the functional amoA water cluster types. Together, this suggests a strong selection of ecotypes within different water masses, supporting the general idea of water mass characteristics as an important factor in defining microbial community structure. If indeed, as suggested in this study, Thaumarchaeota population dynamics are controlled by a set of factors, described here as water mass characteristics and not just depth alone, then changes in water mass flow will inevitably affect the distribution of the different ecotypes.

  1. Radial distributions of surface mass density and mass-to-luminosity ratio in spiral galaxies

    Science.gov (United States)

    Sofue, Yoshiaki

    2018-03-01

    We present radial profiles of the surface mass density (SMD) in spiral galaxies directly calculated using rotation curves of two approximations of flat-disk (SMD-F) and spherical mass distribution (SMD-S). The SMDs are combined with surface brightness using photometric data to derive radial variations of the mass-to-luminosity ratio (ML). It is found that the ML generally has a central peak or a plateau, and decreases to a local minimum at R ˜ 0.1-0.2 h, where R is the radius and h is the scale radius of optical disk. The ML, then, increases rapidly until ˜0.5 h, and is followed by gradual rise till ˜2 h, remaining at around ˜2 [M_{⊙} L^{-1}_{⊙}] in the w1 band (infrared λ3.4 μm) and ˜ 10 [M_⊙ L_⊙ ^{-1}] in the r band (λ6200-7500 Å). Beyond this radius, the ML increases steeply with approaching the observed edges at R ˜ 5 h, attaining to as high values as ˜20 in w1 and ˜ 10^2 [M_⊙ L_⊙ ^{-1}] in the r band, which are indicative of dominant dark matter. The general properties of the ML distributions will be useful for constraining cosmological formation models of spiral galaxies.

  2. Effects of fissioning nuclei distributions on fragment mass distributions for high energy fission

    Directory of Open Access Journals (Sweden)

    Rossi P C R

    2012-02-01

    Full Text Available We study the effects of fissioning nuclei mass- and energy-distributions on the formation of fragments for fission induced by high energy probes. A Monte Carlo code called CRISP was used for obtaining mass distributions and spectra of the fissioning nuclei for reactions induced by 660 MeV protons on 241Am and on 239Np, by 500 MeV protons on 208Pb, and by Bremsstrahlung photons with end-point energies at 50 MeV and 3500 MeV on 238U. The results show that even at high excitation energies, asymmetric fission may still contribute significantly to the fission cross section of actinide nuclei, while it is the dominante mode in the case of lead. However, more precise data for high energy fission on actinide are necessary in order to allow definite conclusions.

  3. Charge and mass distribution in 20Ne induced fission of 181Ta

    International Nuclear Information System (INIS)

    Tripathi, R.; Sudarshan, K.; Goswami, A.; Reddy, A.V.R.; Guin, R.

    2005-01-01

    Charge and mass distribution studies have been carried out at E lab =180 MeV in 20 Ne induced fission of 181 Ta. The mass distribution has been found to be symmetric. The width of the mass distribution has been theoretically calculated using the random neck rupture of Brosa et al. A good agreement between the calculated and experimental mass distribution has been observed. (author)

  4. Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Maganas, A.

    1995-01-01

    An experiment was designed to measure the fully developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a boiling water reactor (BWR-5) rod bundle. Data collected with Refrigerant-114 at pressures ranging from 7 to 14 bars, simulating operation with water in the range 55 to 103 bars are reported. The average mass flux and quality in the test section were in the ranges 1,300 to 1,750 kg/m 2 · s and -0.03 to 0.25, respectively. The data are analyzed and presented in various forms

  5. Imaging of mass distribution in paper by electrography technique, (3)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Baba, Susumu; Luner, P.

    1991-01-01

    Characteristics of photographic films and a TV monitor system as electron beam detectors were studied. A photographic film with thin emulsion layer showed a peak in the basis weight calibration curve because of its limited absorption of electron energy. On the other hand, a photographic film with thick emulsion layer showed no peak and provided wide measurable basis weight range. However, films with thick emulsion layer were found unsuitable for practical use since it requires very long development time. Real-time mass distribution image of a paper sample were obtained with a TV monitor system for transmission electron microscope combined with an image analyzer. The system can image the sample of 11x9 mm with spatial resolution of 20 μm at different electron accelerating voltages. The TV monitor system gave no peak in the basis weight calibration curve and provided wide measurable basis weight range. (author)

  6. Deterioration and optimal rehabilitation modelling for urban water distribution systems

    NARCIS (Netherlands)

    Zhou, Y.

    2018-01-01

    Pipe failures in water distribution systems can have a serious impact and hence it’s important to maintain the condition and integrity of the distribution system. This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. It combines a pipe breakage

  7. Mass distribution and evolutionary scheme for central stars of planetary nebulae

    International Nuclear Information System (INIS)

    Heap, S.R.; Augensen, H.J.; Widener Univ., Chester, PA)

    1987-01-01

    IUE data and a distance measuring method that considered central stars in optically thick nebulae were used to examine mass distributions of planetary nebulae. Other data such as spectral type, spatial and kinematic characteristics, etc., were studied to derive relationships between population type and mass distribution. A central star mass range of at least 0.55 solar mass was obtained. Stars with masses of at least 0.64 solar mass, concentrated in the galactic disk, originated from 1.5 solar mass stars. Low mass nuclei originated in old disk or halo populations and evolved from 1.0 solar mass objects. A mass-loss parameter value of 1/3 was calculated for red giants, implying that white dwarfs evolve from stars of under 5 solar masses. Mass distributions around planetary nuclei were concluded to follow patterns associated with the individual mass. 75 references

  8. Mass Distribution and Gravitational Potential of the Milky Way

    Directory of Open Access Journals (Sweden)

    Ninković Slobodan

    2017-04-01

    Full Text Available Models of mass distribution in the Milky Way are discussed where those yielding the potential analytically are preferred. It is noted that there are three main contributors to the Milky Way potential: bulge, disc and dark halo. In the case of the disc the Miyamoto-Nagai formula, as simple enough, has shown as a very good solution, but it has not been able to satisfy all requirements. Therefore, improvements, such as adding new terms or combining several Miyamoto-Nagai terms, have been attempted. Unlike the disc, in studying the bulge and dark halo the flattening is usually neglected, which offers the possibility of obtaining an exact solution of the Poisson equation. It is emphasized that the Hernquist formula, used very often for the bulge potential, is a special case of another formula and the properties of that formula are analysed. In the case of the dark halo, the slopes of its cumulative mass for the inner and outer parts are explained through a new formalism presented here for the first time.

  9. Topological Taxonomy of Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Carlo Giudicianni

    2018-04-01

    Full Text Available Water Distribution Networks (WDNs can be regarded as complex networks and modeled as graphs. In this paper, Complex Network Theory is applied to characterize the behavior of WDNs from a topological point of view, reviewing some basic metrics, exploring their fundamental properties and the relationship between them. The crucial aim is to understand and describe the topology of WDNs and their structural organization to provide a novel tool of analysis which could help to find new solutions to several arduous problems of WDNs. The aim is to understand the role of the topological structure in the WDNs functioning. The methodology is applied to 21 existing networks and 13 literature networks. The comparison highlights some topological peculiarities and the possibility to define a set of best design parameters for ex-novo WDNs that could also be used to build hypothetical benchmark networks retaining the typical structure of real WDNs. Two well-known types of network ((a square grid; and (b random graph are used for comparison, aiming at defining a possible mathematical model for WDNs. Finally, the interplay between topology and some performance requirements of WDNs is discussed.

  10. Stochastic water demand modelling for a better understanding of hydraulics in water distribution networks

    NARCIS (Netherlands)

    Blokker, E.J.M.

    2010-01-01

    In the water distribution network water quality process take place influenced by de flow velocity and residence time of the water in the network. In order to understand how the water quality changes in the water distribution network, a good understanding of hydraulics is required. Specifically in

  11. Intracellular water exchange for measuring the dry mass, water mass and changes in chemical composition of living cells.

    Directory of Open Access Journals (Sweden)

    Francisco Feijó Delgado

    Full Text Available We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell's buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell's water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell's dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density - the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein, we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell.

  12. Intracellular Water Exchange for Measuring the Dry Mass, Water Mass and Changes in Chemical Composition of Living Cells

    Science.gov (United States)

    Hecht, Vivian C.; Son, Sungmin; Li, Yingzhong; Knudsen, Scott M.; Olcum, Selim; Higgins, John M.; Chen, Jianzhu; Grover, William H.; Manalis, Scott R.

    2013-01-01

    We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell’s buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell’s water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell’s dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density – the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein), we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell. PMID:23844039

  13. Underground Water Distribution System, Fort Belvoir, Virginia. Leak Detection Survey

    National Research Council Canada - National Science Library

    1995-01-01

    .... The survey was conducted by myself, Donald Muir, Operations Coordinator, and required 12.25 working days. This was not a survey of the entire water distribution system but instead a survey of water mains 8 inch and larger...

  14. Nitrification in Chloraminated Drinking Water Distribution Systems - Occurrence

    Science.gov (United States)

    This chapter discusses available information on nitrification occurrence in drinking water chloraminated distribution systems. Chapter 4 provides an introduction to causes and controls for nitrification in chloraminated drinking water systems. Both chapters are intended to serve ...

  15. Drinking water distribution systems: assessing and reducing risks

    National Research Council Canada - National Science Library

    Committee on Public Water Supply Distribution Systems: Assessing and Reducing Risks, National Research Council

    2006-01-01

    .... Distribution systems -- consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances -- carry drinking water from a centralized treatment plant...

  16. Running title: Water distribution in chickpea seeds

    African Journals Online (AJOL)

    agriphy20

    2012-07-24

    Jul 24, 2012 ... molecular mobility of cellular water in magnetically exposed seeds as compared to unexposed seeds. Analysis of ... protrusion takes place through the seed coat and absorption .... directly related to water activity (aw) of the cell water. (Gambhir ..... plants, including photosynthesis, respiration and enzymatic ...

  17. Mass and charge transfer within a floating water bridge

    Science.gov (United States)

    Fuchs, Elmar C.; Agostinho, Luewton L. F.; Eisenhut, Mathias; Woisetschläger, Jakob

    2010-11-01

    When high voltage is applied to pure water filled into two beakers close to each other, a connection forms spontaneously, giving the impression of a floating water bridge 1-8. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the charge and mass transfer through the water bridge are investigated with schlieren visualization and laser interferometry. It can be shown that the addition of a pH dye increases the H+ and OH- production with subsequent electrolysis, whereas schlieren and interferometric methods reveal another mechanism where charge and mass transfer appear to be coupled. Whereas this mechanism seems to be responsible for the electrolysis-less charge and mass transfer in the water bridge, it is increasingly superseded by the electrochemical mechanism with rising conductivity. Thus it can be shown that a pH dye does only indirectly visualize the charge transfer in the water bridge since it is dragged along with the water flow like any other dye, and additionally promotes conventional electrochemical conduction mechanisms, thereby enhancing electrolysis and reducing the masscoupled charge transport and thus destabilizing the bridge.

  18. Density, distribution, and orientation of water molecules inside and outside carbon nanotubes.

    Science.gov (United States)

    Thomas, J A; McGaughey, A J H

    2008-02-28

    The behavior of water molecules inside and outside 1.1, 2.8, 6.9, and 10.4 nm diameter armchair carbon nanotubes (CNTs) is predicted using molecular dynamics simulations. The effects of CNT diameter on mass density, molecular distribution, and molecular orientation are identified for both the confined and unconfined fluids. Within 1 nm of the CNT surface, unconfined water molecules assume a spatially varying density profile. The molecules distribute nonuniformly around the carbon surface and have preferred orientations. The behavior of the unconfined water molecules is invariant with CNT diameter. The behavior of the confined water, however, can be correlated to tube diameter. Inside the 10.4 nm CNT, the molecular behavior is indistinguishable from that of the unconfined fluid. Within the smaller CNTs, surface curvature effects reduce the equilibrium water density and force water molecules away from the surface. This effect changes both the molecular distribution and preferred molecular orientations.

  19. THE EFFECTS OF VIEWING ANGLE ON THE MASS DISTRIBUTION OF EXOPLANETS

    International Nuclear Information System (INIS)

    Lopez, S.; Jenkins, J. S.

    2012-01-01

    We present a mathematical method to statistically decouple the effects of unknown inclination angles on the mass distribution of exoplanets that have been discovered using radial-velocity (RV) techniques. The method is based on the distribution of the product of two random variables. Thus, if one assumes a true mass distribution, the method makes it possible to recover the observed distribution. We compare our prediction with available RV data. Assuming that the true mass function is described by a power law, the minimum mass function that we recover proves a good fit to the observed distribution at both mass ends. In particular, it provides an alternative explanation for the observed low-mass decline, usually explained as sample incompleteness. In addition, the peak observed near the low-mass end arises naturally in the predicted distribution as a consequence of imposing a low-mass cutoff in the true distribution. If the low-mass bins below 0.02 M J are complete, then the mass distribution in this regime is heavily affected by the small fraction of lowly inclined interlopers that are actually more massive companions. Finally, we also present evidence that the exoplanet mass distribution changes form toward low mass, implying that a single power law may not adequately describe the sample population.

  20. Review on Water Distribution of Cooling Tower in Power Station

    Science.gov (United States)

    Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu

    2018-04-01

    As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.

  1. Seasonal to Mesoscale Variability of Water Masses in Barrow Canyon,Chukchi Sea

    Science.gov (United States)

    Nobre, C.; Pickart, R. S.; Moore, K.; Ashjian, C. J.; Arrigo, K. R.; Grebmeier, J. M.; Vagle, S.; Itoh, M.; Berchok, C.; Stabeno, P. J.; Kikuchi, T.; Cooper, L. W.; Hartwell, I.; He, J.

    2016-02-01

    Barrow Canyon is one of the primary conduits by which Pacific-origin water exits the Chukchi Sea into the Canada Basin. As such, it is an ideal location to monitor the different water masses through the year. At the same time, the canyon is an energetic environment where mixing and entrainment can occur, modifying the pacific-origin waters. As part of the Distributed Biological Observatory (DBO) program, a transect across the canyon was occupied 24 times between 2010-2013 by international ships of opportunity passing through the region during summer and early-fall. Here we present results from an analysis of these sections to determine the seasonal evolution of the water masses and to investigate the nature of the mesoscale variability. The mean state shows the clear presence of six water masses present at various times through the summer. The seasonal evolution of these summer water masses is characterized both in depth space and in temperature-salinity (T-S) space. Clear patterns emerge, including the arrival of Alaskan coastal water and its modification in early-fall. The primary mesoscale variability is associated with wind-driven upwelling events which occur predominantly in September. The atmospheric forcing of these events is investigated as is the oceanic response.

  2. The hydromedusae and water masses of the Indian Ocean

    Directory of Open Access Journals (Sweden)

    D. Navas-Pereira

    1991-01-01

    Full Text Available This analysis of distribution and abundance of species of Hydromedusae completes a report (Vannucci & Navas, 1973b on the ecology of Indian Ocean Hydromedusae based on the zooplankton collected during the International Indian Ocean Expedition (IIOE. Distribution and abundance are taken here to be the ecological expression of variability of species in space and time. The aim was to identify the biological signature of below surface water masses that cannot be identified by remote sensing techniques. Selected species were taken as biological units, the oceanic water masses as defined by their T-S and T-O2 diagrammes were taken as the non biological units. Taken together they define different ecosystems of the Indian Ocean. About 45,000 specimens of hydromedusae taken at 480 stations were sorted from 900 plankton samples and all specimens were determined and counted. Several hauls, mostly stratified, were taken with closing nets, but not all contained hydromedusae. The distribution of each species was studied in relation to water salinity, temperature and dissolved oxygen; the limits of ecological tolerance and preference were defined by the environmental characteristics of the layers sampled by the nets and are given for each species. These can be grouped as follows: 1. Deep water species, cold tolerant, often eurytopic; 2. Antarctic species, cold loving, usually stenothermal with preference for low salinity; 3. Indian Ocean Central Water species, with preference for temperature lower than 19ºC and salinity not much higher than 35%o, usually found at sub-surface or intermediate depths, they may spread into the Arabian Sea and Bay of Bengal in surface layers; 4. Indian Ocean Equatorial System species, warm tolerant, usually prefer comparatively low salinity, high temperature and high oxygen content; 5. Bay of Bengal Surface Water species, found in surface layers of the Bay, with preference for low salinity, high temperature and high oxygen content

  3. Biological stability in drinking water distribution systems : A novel approach for systematic microbial water quality monitoring

    NARCIS (Netherlands)

    Prest, E.I.E.D.

    2015-01-01

    Challenges to achieve biological stability in drinking water distribution systems Drinking water is distributed from the treatment facility to consumers through extended man-made piping systems. The World Health Organization drinking water guidelines (2006) stated that “Water entering the

  4. The vertical distribution of Mars water vapor

    Science.gov (United States)

    Davies, D. W.

    1979-01-01

    Analysis of observations made from the Viking 1 Orbiter indicates that the water vapor over the Viking 1 landing site is uniformly mixed with the atmosphere and not concentrated near the surface. The analysis incorporates the effects of atmospheric scattering and explains why previous earth-based observations showed a strong diurnal variation in water content. It also explains the lack of an early morning fog and removes the necessity of daily exchange of large amounts of water between the surface and the atmosphere. A water vapor volume mixing ratio of 1.5 x 10 to the -4th is inferred for the Viking 1 site in late summer.

  5. Vertical Distribution of Water at Phoenix

    Science.gov (United States)

    Tamppari, L. K.; Lemmon, M. T.

    2011-01-01

    Phoenix results, combined with coordinated observations from the Mars Reconnaissance Orbiter of the Phoenix lander site, indicate that the water vapor is nonuniform (i.e., not well mixed) up to a calculated cloud condensation level. It is important to understand the mixing profile of water vapor because (a) the assumption of a well-mixed atmosphere up to a cloud condensation level is common in retrievals of column water abundances which are in turn used to understand the seasonal and interannual behavior of water, (b) there is a long history of observations and modeling that conclude both that water vapor is and is not well-mixed, and some studies indicate that the water vapor vertical mixing profile may, in fact, change with season and location, (c) the water vapor in the lowest part of the atmosphere is the reservoir that can exchange with the regolith and higher amounts may have an impact on the surface chemistry, and (d) greater water vapor abundances close to the surface may enhance surface exchange thereby reducing regional transport, which in turn has implications to the net transport of water vapor over seasonal and annual timescales.

  6. Impacts of water quality on the corrosion of cast iron pipes for water distribution and proposed source water switch strategy.

    Science.gov (United States)

    Hu, Jun; Dong, Huiyu; Xu, Qiang; Ling, Wencui; Qu, Jiuhui; Qiang, Zhimin

    2018-02-01

    Switch of source water may induce "red water" episodes. This study investigated the impacts of water quality on iron release, dissolved oxygen consumption (ΔDO), corrosion scale evolution and bacterial community succession in cast iron pipes used for drinking water distribution at pilot scale, and proposed a source water switch strategy accordingly. Three sets of old cast iron pipe section (named BP, SP and GP) were excavated on site and assembled in a test base, which had historically transported blended water, surface water and groundwater, respectively. Results indicate that an increasing Cl - or SO 4 2- concentration accelerated iron release, but alkalinity and calcium hardness exhibited an opposite tendency. Disinfectant shift from free chlorine to monochloramine slightly inhibited iron release, while the impact of peroxymonosulfate depended on the source water historically transported in the test pipes. The ΔDO was highly consistent with iron release in all three pipe systems. The mass ratio of magnetite to goethite in the corrosion scales of SP was higher than those of BP and GP and kept almost unchanged over the whole operation period. Siderite and calcite formation confirmed that an increasing alkalinity and hardness inhibited iron release. Iron-reducing bacteria decreased in the BP but increased in the SP and GP; meanwhile, sulfur-oxidizing, sulfate-reducing and iron oxidizing bacteria increased in all three pipe systems. To avoid the occurrence of "red water", a source water switch strategy was proposed based on the difference between local and foreign water qualities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O. [Energovyzkum, Brno (Switzerland); Schmidt, S.; Mihalik, M. [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1997-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  8. Effect of the Distribution System on Drinking Water Quality

    Directory of Open Access Journals (Sweden)

    A. Grünwald

    2001-01-01

    Full Text Available The overall objective of this paper is to characterise the main aspects of water quality deterioration in a distribution system. The effect of residence time on chlorine uptake and the formation and evolution of disinfection by-products in distributed drinking water are discussed.

  9. A Geology-Based Estimate of Connate Water Salinity Distribution

    Science.gov (United States)

    2014-09-01

    poses serious environmental concerns if connate water is mobilized into shallow aquifers or surface water systems. Estimating the distribution of...groundwater flow and salinity transport near the Herbert Hoover Dike (HHD) surrounding Lake Okeechobee in Florida . The simulations were conducted using the...on the geologic configuration at equilibrium, and the horizontal salinity distribution is strongly linked to aquifer connectivity because

  10. Particulate fingerprinting of water quality in the distribution system ...

    African Journals Online (AJOL)

    Particles in the distribution system play an important role in the perception? Not clear what is meant) of drinking water quality, particularly in association with discolouration. In The Netherlands the water quality in the distribution system is traditionally monitored by turbidity measurements. However, turbidity is hard to quantify ...

  11. GROWTH OF HETROTROPHIC BIOFILMS IN A WATER DISTRIBUTION SYSTEM SIMULATOR

    Science.gov (United States)

    The U.S. EPA has designed and constructed a distribution system simulator (DSS) to evaluate factors which influence water quality within water distribution systems. Six individual 25 meter lengths of 15 cm diameter ductile iron pipe are arranged into loop configurations. Each lo...

  12. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O [Energovyzkum, Brno (Switzerland); Schmidt, S; Mihalik, M [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1998-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  13. Succession of Biofilm Microbial Community during Nitrification in Lab-Scale Reactors Simulating Chloraminated Drinking Water Distribution System Conditions: the Impact of Simultaneously Increasing Monochloramine and Chlorine to Nitrogen Mass Ratios

    Science.gov (United States)

    Chloramination has been shown to promote nitrifying bacteria and 30 to 63% of utility plants using secondary chloramine disinfection experience nitrification episodes. Although nitrifying bacteria are not considered human pathogens, nitrification can affect drinking water qualit...

  14. Residential hot water distribution systems: Roundtablesession

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  15. Numerical analysis of heat and mass transfer for water recovery in an evaporative cooling tower

    Science.gov (United States)

    Lee, Hyunsub; Son, Gihun

    2017-11-01

    Numerical analysis is performed for water recovery in an evaporative cooling tower using a condensing heat exchanger, which consists of a humid air channel and an ambient dry air channel. The humid air including water vapor produced in an evaporative cooling tower is cooled by the ambient dry air so that the water vapor is condensed and recovered to the liquid water. The conservation equations of mass, momentum, energy and vapor concentration in each fluid region and the energy equation in a solid region are simultaneously solved with the heat and mass transfer boundary conditions coupled to the effect of condensation on the channel surface of humid air. The present computation demonstrates the condensed water film distribution on the humid air channel, which is caused by the vapor mass transfer between the humid air and the colder water film surface, which is coupled to the indirect heat exchange with the ambient air. Computations are carried out to predict water recovery rate in parallel, counter and cross-flow type heat exchangers. The effects of air flow rate and channel interval on the water recovery rate are quantified.

  16. Innovated feed water distributing system of VVER steam generators

    International Nuclear Information System (INIS)

    Matal, O.; Sousek, P.; Simo, T.; Lehota, M.; Lipka, J.; Slugen, V.

    2000-01-01

    Defects in feed water distributing system due to corrosion-erosion effects have been observed at many VVER 440 steam generators (SG). Therefore analysis of defects origin and consequently design development and testing of a new feed water distributing system were performed. System tests in-situ supported by calculations and comparison of measured and calculated data were focused on demonstration of long term reliable operation, definition of water flow and water chemical characteristics at the SG secondary side and their measurements and study of dynamic characteristics needed for the innovated feed water distributing system seismic features approval. The innovated feed water distributing system was installed in the SGs of two VVER units already. (author)

  17. Mass-storage management for distributed image/video archives

    Science.gov (United States)

    Franchi, Santina; Guarda, Roberto; Prampolini, Franco

    1993-04-01

    The realization of image/video database requires a specific design for both database structures and mass storage management. This issue has addressed the project of the digital image/video database system that has been designed at IBM SEMEA Scientific & Technical Solution Center. Proper database structures have been defined to catalog image/video coding technique with the related parameters, and the description of image/video contents. User workstations and servers are distributed along a local area network. Image/video files are not managed directly by the DBMS server. Because of their wide size, they are stored outside the database on network devices. The database contains the pointers to the image/video files and the description of the storage devices. The system can use different kinds of storage media, organized in a hierarchical structure. Three levels of functions are available to manage the storage resources. The functions of the lower level provide media management. They allow it to catalog devices and to modify device status and device network location. The medium level manages image/video files on a physical basis. It manages file migration between high capacity media and low access time media. The functions of the upper level work on image/video file on a logical basis, as they archive, move and copy image/video data selected by user defined queries. These functions are used to support the implementation of a storage management strategy. The database information about characteristics of both storage devices and coding techniques are used by the third level functions to fit delivery/visualization requirements and to reduce archiving costs.

  18. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    International Nuclear Information System (INIS)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M.; Paes Leme, A.F.; Benede, S.; Molina, E.

    2012-01-01

    Full text: The β-Lactoglobulin (β-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on β-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the β-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of β-Lg w/w in distilled water; 25 U enzyme g 1 of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g 1 protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The β-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified βLg -A showed 18.362 Da and the non modified βLg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified β-Lg showed fragments that present high antigenicity (such as Leu 95 - Leu 104 , Asp 95 - Phe 105 , Tyr 42 - Leu 54 , lle 29 - Val 41 ), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr 42 - Leu 54 was still present, however the other fragments that were observed in the non modified β-Lg were not detected by LC-MS/MS, suggesting that structural change occurred in

  19. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Benede, S.; Molina, E. [Universidad Autonoma de Madrid (Spain)

    2012-07-01

    Full text: The {beta}-Lactoglobulin ({beta}-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on {beta}-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the {beta}-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of {beta}-Lg w/w in distilled water; 25 U enzyme g{sup 1} of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g{sup 1} protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The {beta}-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified {beta}Lg -A showed 18.362 Da and the non modified {beta}Lg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified {beta}-Lg showed fragments that present high antigenicity (such as Leu{sub 95} - Leu{sub 104}, Asp{sub 95} - Phe{sub 105}, Tyr{sub 42} - Leu{sub 54}, lle{sub 29} - Val{sub 41}), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr{sub 42} - Leu{sub 54} was still present, however the other fragments that were observed in the non

  20. Habitat quality, water quality and otter distribution

    Directory of Open Access Journals (Sweden)

    Christopher Mason

    1995-12-01

    Full Text Available Abstract In recent decades the otter (Lutra lutra has declined over much of Europe. Good habitat has been shown to be essential to otters. Specific elements of cover have been identified in some studies but the minimum cover requirements to support otter populations are not known. These are likely to vary in relation to other factors, such as disturbance. Habitat destruction has been severe in many areas of Europe. Water quantity is important to otters, especially where low flows destroy the food base, namely fish. However the minimum food requirements to support populations are not known. The main cause of the decline in otter populations is almost certainly bioaccumulating pollutants, especially PCBs. These are likely to be inhibiting recolonization in many areas. In Britain, catchment distribution of otters within regions is negatively correlated to mean PCB levels in otter spraints, and these are indicative of tissue levels. PCBs have been found in all samples studied. Current EC statutory monitoring is inadequate to protect otter populations from bioaccumulating contaminants. Standards are presented here for otter protection. More fundamental research is required to refine our understanding of the requirements of the otter. Riassunto Qualità ambientale, qualità dell'acqua e distribuzione della lontra - Negli ultimi decenni la lontra (Lutra lutra è diminuita su buona parte del suo areale europeo, dove particolarmente pesante è stata la distruzione di ambienti favorevoli. Habitat qualitativamente idonei sono essenziali per la sopravvivenza della specie. In alcuni studi, specifici parametri di copertura vegetale dei corpi idrici sono stati ritenuti importanti per la specie, ma quale sia il valore minimo di copertura riparia in grado di supportare una popolazione resta sconosciuto. I parametri di copertura variano probabilmente in relazione ad altri fattori, quali, ad

  1. Cumulus convection and the terrestrial water-vapor distribution

    Science.gov (United States)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  2. Organizational problems of Water Distribution in Khorezm, Uzbekistan

    NARCIS (Netherlands)

    Wegerich, K.

    2004-01-01

    The paper addresses problems of water resource management on the district and provincial level in the Khorezm province, Uzbekistan. The district water organizations are responsible for equitable water distribution to the agricultural users. These organizations do not have the necessary logistical

  3. Leakage detection algorithm integrating water distribution networks hydraulic model

    CSIR Research Space (South Africa)

    Adedeji, K

    2017-06-01

    Full Text Available Water loss through leaking pipes is inexorable in water distribution networks (WDNs) and has been recognized as a major challenge facing the operation of municipal water services. This is strongly linked with financial costs due to economic loss...

  4. Convergent surface water distributions in U.S. cities

    Science.gov (United States)

    M.K. Steele; J.B. Heffernan; N. Bettez; J. Cavender-Bares; P.M. Groffman; J.M. Grove; S. Hall; S.E. Hobbie; K. Larson; J.L. Morse; C. Neill; K.C. Nelson; J. O' Neil-Dunne; L. Ogden; D.E. Pataki; C. Polsky; R. Roy Chowdhury

    2014-01-01

    Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution at broad spatial scales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and...

  5. Unified Framework for Deriving Simultaneous Equation Algorithms for Water Distribution Networks

    Science.gov (United States)

    The known formulations for steady state hydraulics within looped water distribution networks are re-derived in terms of linear and non-linear transformations of the original set of partly linear and partly non-linear equations that express conservation of mass and energy. All of ...

  6. Theory and calculation of water distribution in bentonite in a thermal field

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1988-09-01

    Highly compacted bentonite is under consideration for use as a buffer material in geological repositories for high-level radioactive wastes. To assess the suitability of bentonite for this use, it is necessary to be able to predict the rate and spatial extent of water uptake and water distribution in highly compacted bentonite in the presence of thermal gradients. The ''Buffer Mass Test'' (BMT) was conducted by workers in Sweden as part of the Stripa Project. The BMT measured uptake and spatial distributions of water infiltrating annuli of compacted MX-80 sodium bentonite heated from within and surrounded by granite rock; the measurements provided a body of data very valuable for comparison to results of theoretical calculations. Results of experiments on adsorption of water by highly compacted MX-80 bentonite have been reported by workers in Switzerland. The experiments included measurements of heats of immersion and adsorption-desorption isotherms. These measurements provide the basis for prediction of water vapor pressures in equilibrium with bentonite having specified adsorbed water contents at various temperatures. The present work offers a phenomenological description of the processes influencing movement of water in compacted bentonite in the presence of a variable thermal field. The theory is applied to the bentonite buffer-water system in an assumed steady state of heat and mass transport, using critical data derived from the experimental work done in Switzerland. Results of the theory are compared to distributions of absorbed water in buffers observed in the Swedish BMT experiments. 9 refs., 2 figs

  7. Salinity maxima associated with some sub-surface water masses in the upper layers of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varadachari, V.V.R.; Murty, C.S.; Reddy, C.V.G.

    The distribution of some sub-surface water masses in the western bay of Bengal during the south-west monsoon period is presented. Based on the salinity maxima and sigma t values the existence of waters of Persian Gulf and Red Sea origin could...

  8. Water mass modification at the Agulhas retroflection: chlorofluoromethane studies

    Science.gov (United States)

    Fine, Rana A.; Warner, Mark J.; Weiss, Ray F.

    1988-03-01

    Chlorofluoromethane (CFM) and hydrographic data from the 1983 Agulhas Retroflection cruise are used to show the importance of the region in ventilating thermocline and Intermediate Waters of the southwest Indian ocean gyre. Generally South Atlantic waters are more recently ventilated by at least two years than those of the South Indian Ocean, probably because the latter are farther downstream from the source regions near the South Atlantic subantarctic sector. A two-component mixing model shows that the outflow from the Agulhas Retroflection (14-4°C) was composed of South Indian water and at least 23% South Atlantic water. However, at the density of Indian sector Subantarctic Mode Water the inflow into the Agulhas Retroflection was well preserved in the outflow, and the South Atlantic and Indian waters appear to be ventilated by different water masses. In addition, strong interleaving was found throughout the survey area (between 14 and 4°C), characterized by correlations of negative salinity anomalies with high CFM concentrations. At the density of Antarctic Intermediate Water (AAIW) there was interleaving of both low salinity water and higher salinity Red Sea Water. Using estimates of past atmospheric ratios of two CFMs, we calculate that AAIW within the retroflection was 50-75% diluted by mixing with CFM-free water since leaving the source region. Results from the two-component mixing model, which show substantial contributions of South Atlantic water in the outflow, suggest that the return flow for the 10 Sv leakage of Indian Ocean water via the Agulhas Current into the South Atlantic [ GORDON (1985) Science, 227, 1030-1033; GORDONet al. (1987) Deep-Sea Research, 34, 565-600] is occurring at thermocline and intermediate depths. A combination of active mixing in this region and similarity in the ventilation processes may be the reason that the South Atlantic and Indian thermoclines are coincident in temperature and salinity space (between 15 and 7°C) as noted

  9. The relationship between phytoplankton distribution and water column characteristics in North West European shelf sea waters.

    Science.gov (United States)

    Fehling, Johanna; Davidson, Keith; Bolch, Christopher J S; Brand, Tim D; Narayanaswamy, Bhavani E

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the "Ellett Line" cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN:DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN:DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of

  10. The relationship between phytoplankton distribution and water column characteristics in North West European shelf sea waters.

    Directory of Open Access Journals (Sweden)

    Johanna Fehling

    Full Text Available Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the "Ellett Line" cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA, of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations clearly discriminated between shelf and oceanic stations on the basis of DIN:DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS demonstrating spatial variability in its composition. Redundancy analysis (RDA was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community, and both salinity and DIN:DSi (diatoms alone. Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi

  11. Assessment of the Quality of Water Treated and Distributed By the Akwa Ibom State Water Company

    OpenAIRE

    N. O. Eddy; A. S. Ekop

    2007-01-01

    The quality of water treated and distributed by the Akwa Ibom Water Company has been assessed by analyzing samples of water collected from different distribution points for their physiochemical parameters, major ions, nutrients and bacteriological quality. The observed values were compared with standard values given by the World Health Organization for portable water. The quality of the analysed water is found fit for human consumption.

  12. Distribution of crayfish species in Hungarian waters

    NARCIS (Netherlands)

    Mercédesz, Ludányi; Peeters, E.T.H.M.; Kiss, B.; Roessink, I.

    2016-01-01

    Three native crayfish species, i.e.~Astacus astacus, Astacus leptodactylus and Austropotamobius torrentium, occur in Hungary. Lately, however, non-indigenous crustaceans have also invaded the country Their most recent distribution and impact on the occurrences of the native species is not clear.

  13. Distribution of {sup 129}I in terrestrial surface water environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuegao [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Gong, Meng [College of Hydrology and Water Resources, Hohai University, Nanjing (China); Yi, Peng, E-mail: pengyi1915@163.com [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Aldahan, Ala [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); Department of Geology, United Arab Emirates University, Al Ain (United Arab Emirates); Yu, Zhongbo [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Possnert, Göran [Tandem Laboratory, Uppsala University, Uppsala (Sweden); Chen, Li [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China)

    2015-10-15

    The global distribution of the radioactive isotope iodine-129 in surface waters (lakes and rivers) is presented here and compared with the atmospheric deposition and distribution in surface marine waters. The results indicate relatively high concentrations in surface water systems in close vicinity of the anthropogenic release sources as well as in parts of Western Europe, North America and Central Asia. {sup 129}I level is generally higher in the terrestrial surface water of the Northern hemisphere compared to the southern hemisphere. The highest values of {sup 129}I appear around 50°N and 40°S in the northern and southern hemisphere, separately. Direct gaseous and marine atmospheric emissions are the most likely avenues for the transport of {sup 129}I from the sources to the terrestrial surface waters. To apply iodine-129 as process tracer in terrestrial surface water environment, more data are needed on {sup 129}I distribution patterns both locally and globally.

  14. Seismic Fragility of the LANL Fire Water Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mertz

    2007-03-30

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10{sup -3} that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  15. Seismic Fragility of the LANL Fire Water Distribution System

    International Nuclear Information System (INIS)

    Greg Mertz Jason Cardon Mike Salmon

    2007-01-01

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10 -3 that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  16. SOME ASPECTS REGARING CHLORINE DECAY IN WATER DISTRIBUTION NETWORKS

    Directory of Open Access Journals (Sweden)

    LIANA IOANA VUŢĂ

    2011-03-01

    Full Text Available A major objective of drinking water treatment is to provide microbiologically safe drinking water. The combination of conventional drinking water treatment and disinfection has proved to be one of the major public health advances in modern times. The quality of drinking water delivered to the customer’s tap is influenced by a number of processes; namely water treatment, disinfection and changes during transport of treated water via the distribution system. All natural waters and even treated drinking water exerts disinfectant demand due to the reactions with NOM and other constituents in water. Therefore, the applied disinfectant dose must be sufficient to meet the inherent demand in the treated water, to provide sufficient protection against microbial infection. Thus, controlling free residual chlorine properly is definitely important to ensure meeting regulatory requirements and satisfying customer needs.This paper presents the main aspects regarding chlorine decay in drinking-water distribution networks and, also a free chlorine decay simulation with EPANET2 on Ramnicu Valcea water distribution system.

  17. Patient distribution in a mass casualty event of an airplane crash

    NARCIS (Netherlands)

    Postma, Ingri L. E.; Weel, Hanneke; Heetveld, Martin J.; van der Zande, Ineke; Bijlsma, Taco S.; Bloemers, Frank W.; Goslings, J. Carel

    2013-01-01

    Difficulties have been reported in the patient distribution during Mass Casualty Incidents. In this study we analysed the regional patient distribution protocol (PDP) and the actual patient distribution after the 2009 Turkish Airlines crash near Amsterdam. Analysis of the patient distribution of 126

  18. Water masses as a unifying framework for understanding the Southern Ocean Carbon Cycle

    Directory of Open Access Journals (Sweden)

    D. Iudicone

    2011-05-01

    Full Text Available The scientific motivation for this study is to understand the processes in the ocean interior controlling carbon transfer across 30° S. To address this, we have developed a unified framework for understanding the interplay between physical drivers such as buoyancy fluxes and ocean mixing, and carbon-specific processes such as biology, gas exchange and carbon mixing. Given the importance of density in determining the ocean interior structure and circulation, the framework is one that is organized by density and water masses, and it makes combined use of Eulerian and Lagrangian diagnostics. This is achieved through application to a global ice-ocean circulation model and an ocean biogeochemistry model, with both components being part of the widely-used IPSL coupled ocean/atmosphere/carbon cycle model.

    Our main new result is the dominance of the overturning circulation (identified by water masses in setting the vertical distribution of carbon transport from the Southern Ocean towards the global ocean. A net contrast emerges between the role of Subantarctic Mode Water (SAMW, associated with large northward transport and ingassing, and Antarctic Intermediate Water (AAIW, associated with a much smaller export and outgassing. The differences in their export rate reflects differences in their water mass formation processes. For SAMW, two-thirds of the surface waters are provided as a result of the densification of thermocline water (TW, and upon densification this water carries with it a substantial diapycnal flux of dissolved inorganic carbon (DIC. For AAIW, principal formatin processes include buoyancy forcing and mixing, with these serving to lighten CDW. An additional important formation pathway of AAIW is through the effect of interior processing (mixing, including cabelling that serve to densify SAMW.

    A quantitative evaluation of the contribution of mixing, biology and gas exchange to the DIC evolution per water mass reveals that

  19. Fresh water distribution problematic in Nouakchott

    OpenAIRE

    BABAH, Isselmou A.; DEIDA, Mohamed F.; BLAKE, Gérard; FROELICH, Daniel

    2012-01-01

    Because of its geographical location, Mauritania is characterized by an arid climate. The water resources are thus limited. The annual average rainfall calculated by M.Yeslem [1] over a 60-years period (1931-1991) is 112 mm. Nouakchott, the Mauritanian capital, knew an exceptional growth of the population, carrying it to more than 700 000 inhabitants in the year 2005 [2]. These brisk demographic trends generated a fast expansion of occupied space and a strong pressure on the social equipments...

  20. Disappearance of a detached vapor mass in subcooled water

    International Nuclear Information System (INIS)

    Inada, Shigeaki; Miyasaka, Yoshiki; Izumi, Ryotaro.

    1986-01-01

    Experiments on pool transition boiling of water under atmospheric pressure on a heated surface 10 mm in diameter were conducted for subcooling 15 - 50 K. The mass flux of condensation of a detached coalescent vapor bubble was experimentally estimated by a mathematical model based on the mass transfer mechanism of condensation. As a result, it is clarified that the mass flux of condensation of the detached bubble was influenced by the initial growing velocity of a vapor bubble immediately following the detached bubble. The disappearance velocity of the detached bubble defined as a ratio of the bubble diameter at the departure to the time required until the disappearance, is in the range 0.2 to 2.0 m/sec. The disappearance velocity is proportional to the initial growing velocity of the bubble, to the square of the heat flux of the heated surface and to the cube of the wall superheat, separately. (author)

  1. Nuclear equipment to determine soil and water mass attenuation coefficients

    International Nuclear Information System (INIS)

    Zucchi, O.L.A.D.; Nascimento Filho, V.F. do

    1984-01-01

    The feasibility of substituting the monochannel gamma spectrometer, traditionally used in the gamma ray attenuation technique, for a less sophisticated and less expensive system of integral counting is studied. The proposed system can be operated by a non-specialized person. Three detection systems were used in the determination of the mass attenuation coefficients for different types of soil and for water. (M.A.C.) [pt

  2. Mass distributions of a macromolecular assembly based on ...

    Indian Academy of Sciences (India)

    Unknown

    Because of variation in the number and masses of subunits, ... and scanning transmission electron microscopy (STEM) appearances ... 36 linker chains, in agreement with the model proposed ... Each of them is determined by the two integer.

  3. The water masses and volumetry of the southern Agulhas Current region

    Science.gov (United States)

    Valentine, H. R.; Lutjeharms, J. R. E.; Brundrit, G. B.

    1993-06-01

    It has been suggested that the southern termination of the Agulhas Current plays a crucial role in the global circulation of thermocline water and thus in global climate. Due to a lack of modern hydrographic observations in this region, no detailed description of water masses or a fine-scale volumetric census for this geographic area had been carried out. Such an analysis of a collection of recent high-quality hydrographic measurements shows that the warm, saline, surface water of Agulhas Current origin contributes very little to the overall volume of the upper 1500 m of the water column in the area. Occasional equatorward leakages from south of the Subtropical Convergence are represented by a range of low-salinity outliers, but they represent <1% of the total volume. The distribution of water volume in temperature/salinity space for the Agulhas Retroflection is less diverse that that of the world ocean as a whole, 25% of the total volume of the region being contained in only 21 fine-scale temperature/salinity classes. North Atlantic Deep Water is the dominant water mass, accounting for 40% of the total volume. Deep Water in general accounts for 60% of the total volume.

  4. Drinking water distribution systems: assessing and reducing risks

    National Research Council Canada - National Science Library

    Committee on Public Water Supply Distribution Systems: Assessing and Reducing Risks, National Research Council

    2006-01-01

    ... or well supplies to consumers’ taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management...

  5. Characteristic relation for the mass and energy distribution of the nuclear fission products

    International Nuclear Information System (INIS)

    Alexandru, G.

    1977-01-01

    The dispersion relation for nuclear fission is written in the two part fragmentation approach which allows to obtain the characteristic relation for the mass and energy distribution of the nuclear fission products. One explains the resonance approximation in the mass distribution of the fission products taking into account the high order resonances too. (author)

  6. The distribution of water frost on Charon

    Science.gov (United States)

    Buie, Marc W.; Shriver, Scott K.

    1994-01-01

    We present high-spatial-resolution imaging observations of the Pluto-Charon system taken with ProtoCAM on the Infrared Telescope Facility (IRTF). Our dataset consists of measurements from eight nights at widely separated rotational longitudes and covering five wavelengths -- standard J, H, and K, plus two special narrow band filters at 1.5 and 1.75 microns. The relative flux contributions of Pluto and Charon were extracted, when possible, by fitting a two-source Gaussian image model to the observed images. At K, we find the Charon-Pluto magnitude difference to be on average 1.8 mag, somewhat less than the value of 2.2 mag found by Bosh et al. (1992). The average differential magnitude at 1.5 and 1.75 microns is 2.0 and 1.6, respectively. The larger magnitude difference at 1.5 microns is due to a water-frost absorption band on the surface of Charon. Our observations are consistent with a surface of Charon dominated by water frost at all longitudes.

  7. A Dual Power Law Distribution for the Stellar Initial Mass Function

    Science.gov (United States)

    Hoffmann, Karl Heinz; Essex, Christopher; Basu, Shantanu; Prehl, Janett

    2018-05-01

    We introduce a new dual power law (DPL) probability distribution function for the mass distribution of stellar and substellar objects at birth, otherwise known as the initial mass function (IMF). The model contains both deterministic and stochastic elements, and provides a unified framework within which to view the formation of brown dwarfs and stars resulting from an accretion process that starts from extremely low mass seeds. It does not depend upon a top down scenario of collapsing (Jeans) masses or an initial lognormal or otherwise IMF-like distribution of seed masses. Like the modified lognormal power law (MLP) distribution, the DPL distribution has a power law at the high mass end, as a result of exponential growth of mass coupled with equally likely stopping of accretion at any time interval. Unlike the MLP, a power law decay also appears at the low mass end of the IMF. This feature is closely connected to the accretion stopping probability rising from an initially low value up to a high value. This might be associated with physical effects of ejections sometimes (i.e., rarely) stopping accretion at early times followed by outflow driven accretion stopping at later times, with the transition happening at a critical time (therefore mass). Comparing the DPL to empirical data, the critical mass is close to the substellar mass limit, suggesting that the onset of nuclear fusion plays an important role in the subsequent accretion history of a young stellar object.

  8. Molecular Isotopic Distribution Analysis (MIDAs) with adjustable mass accuracy.

    Science.gov (United States)

    Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo

    2014-01-01

    In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

  9. Determination of the mass-ratio distribution, I: single-lined spectroscopic binary stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1992-01-01

    For single-lined spectroscopic binary stars (sbi), the mass ratio q = Msec=Mprim is calculated from the mass function f(m), which is determined from observations. For statistical investigations of the mass-ratio distribution, the term sin^3 i, that remains in the cubic equation from which q is

  10. The effect of gas double-dynamic on mass distribution in solid-state fermentation.

    Science.gov (United States)

    Chen, Hong-Zhang; Zhao, Zhi-Min; Li, Hong-Qiang

    2014-05-10

    The mass distribution regularity in substrate of solid-state fermentation (SSF) has rarely been reported due to the heterogeneity of solid medium and the lack of suitable instrument and method, which limited the comprehensive analysis and enhancement of the SSF performance. In this work, the distributions of water, biomass, and fermentation product in different medium depths of SSF were determined using near-infrared spectroscopy (NIRS) and the developed models. Based on the mass distribution regularity, the effects of gas double-dynamic on heat transfer, microbial growth and metabolism, and product distribution gradient were systematically investigated. Results indicated that the maximum temperature of substrate and the maximum carbon dioxide evolution rate (CER) were 39.5°C and 2.48mg/(hg) under static aeration solid-state fermentation (SASSF) and 33.9°C and 5.38mg/(hg) under gas double-dynamic solid-state fermentation (GDSSF), respectively, with the environmental temperature for fermentation of 30±1°C. The fermentation production (cellulase activity) ratios of the upper, middle, and lower levels were 1:0.90:0.78 at seventh day under SASSF and 1:0.95:0.89 at fifth day under GDSSF. Therefore, combined with NIRS analysis, gas double-dynamic could effectively strengthen the solid-state fermentation performance due to the enhancement of heat transfer, the stimulation of microbial metabolism and the increase of the homogeneity of fermentation products. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Significance of losses in water distribution systems in India

    OpenAIRE

    Raman, V.

    1983-01-01

    Effective management of water supply systems consists in supplying adequate quantities of clean water to the population. Detailed pilot studies of water distribution systems were carried out in 9 cities in India during 1971-81 to establish the feasibility of a programme of assessment, detection, and control of water losses from supply systems. A cost-benefit analysis was carried out. Water losses from mains and service pipes in the areas studied amounted to 20-35% of the total flow in the sys...

  12. Conservation laws and mass distribution in the planet formation process

    International Nuclear Information System (INIS)

    Farinella, P.; Paolicchi, P.

    1977-01-01

    Within the framework of the nebular theory of the origin of the solar system, conservation laws are applied to the condensation of a ring-shaped cloud of orbiting particles. The final configuration is assumed to be a point-like planet in a circular orbit around the Sun. On this ground, it is possible to relate the masses of the planets with the interplanetary distances. This relation is confirmed satisfactorily by the observed masses and orbital radii of several planets and satellites of the solar system. (Auth.)

  13. Pesticides distribution in surface waters and sediments of lotic and ...

    African Journals Online (AJOL)

    An investigation on the availability and distribution of Lindane (HCHs) and Total organochlorine phosphate (TOCP) in the surface waters and sediments of selected water bodies in Agbede wetlands was carried out from December, 2012 to May, 2014 in order to cover seasonal trends in both matrixes. A Gas Chromatograph ...

  14. Using WNTR to Model Water Distribution System Resilience

    Science.gov (United States)

    The Water Network Tool for Resilience (WNTR) is a new open source Python package developed by the U.S. Environmental Protection Agency and Sandia National Laboratories to model and evaluate resilience of water distribution systems. WNTR can be used to simulate a wide range of di...

  15. Water Distribution Network Modelling of a Small Community using ...

    African Journals Online (AJOL)

    ... of a small community (Sakwa) water distribution network in North Eastern geopolitical region of Nigeria using WaterCAD simulator. The analysis included a review of pressures, velocities and head loss gradients under steady state average day demand, maximum day demand conditions, and fire flow under maximum day ...

  16. Distribution of genes associated with yield potential and water ...

    Indian Academy of Sciences (India)

    Supplementary data: Distribution of genes associated with yield potential and water-saving in. Chinese Zone II wheat detected by developed functional markers. Zhenxian Gao, Zhanliang Shi, Aimin Zhang and Jinkao Guo. J. Genet. 94, 35–42. Table 1. Functional markers for high-yield or water-saving genes in wheat and ...

  17. Smart optimisation and sensitivity analysis in water distribution systems

    CSIR Research Space (South Africa)

    Page, Philip R

    2015-12-01

    Full Text Available optimisation of a water distribution system by keeping the average pressure unchanged as water demands change, by changing the speed of the pumps. Another application area considered, using the same mathematical notions, is the study of the sensitivity...

  18. Spatial distribution of saline water and possible sources of intrusion ...

    African Journals Online (AJOL)

    The spatial distribution of saline water and possible sources of intrusion into Lekki lagoon and transitional effects on the lacustrine ichthyofaunal characteristics were studied during March, 2006 and February, 2008. The water quality analysis indicated that, salinity has drastically increased recently in the lagoon (0.007 to ...

  19. Water and nitrogen distribution in uncropped ridgetilled soil under ...

    African Journals Online (AJOL)

    A ridge-tillage configuration, with placement of nitrate nitrogen (NO3--N) or its source in the elevated portion of the ridge, can potentially isolate fertilizer from downward water flow and minimize nitrate leaching. In the experiment, the simultaneous distribution of water, nitrate, and ammonium under three ridge widths was ...

  20. A multivariate rank test for comparing mass size distributions

    KAUST Repository

    Lombard, F.; Potgieter, C. J.

    2012-01-01

    Particle size analyses of a raw material are commonplace in the mineral processing industry. Knowledge of particle size distributions is crucial in planning milling operations to enable an optimum degree of liberation of valuable mineral phases

  1. Distribution of pagerank mass among principle components of the web

    NARCIS (Netherlands)

    Avrachenkov, Konstatin; Litvak, Nelli; Pham, Kim Son; Bonato, A.; Chung, F.R.K.

    2007-01-01

    We study the PageRank mass of principal components in a bow-tie Web Graph, as a function of the damping factor c. Using a singular perturbation approach, we show that the PageRank share of IN and SCC components remains high even for very large values of the damping factor, in spite of the fact that

  2. Fission fragment mass and angular distributions: Probes to study ...

    Indian Academy of Sciences (India)

    In the following discussion, we shall attempt to broadly classify the nuclear landscape. (what we ... need for extra push energy (excess energy over the Coulomb barrier) to achieve fusion. It ... τM (∼ 5 × 10−21 s) of mass degree of freedom. 304.

  3. [Research on controlling iron release of desalted water transmitted in existing water distribution system].

    Science.gov (United States)

    Tian, Yi-Mei; Liu, Yang; Zhao, Peng; Shan, Jin-Lin; Yang, Suo-Yin; Liu, Wei

    2012-04-01

    Desalted water, with strong corrosion characteristics, would possibly lead to serious "red water" when transmitted and distributed in existing municipal water distribution network. The main reason for red water phenomenon is iron release in water pipes. In order to study the methods of controlling iron release in existing drinking water distribution pipe, tubercle analysis of steel pipe and cast iron pipe, which have served the distribution system for 30-40 years, was carried out, the main construction materials were Fe3O4 and FeOOH; and immersion experiments were carried in more corrosive pipes. Through changing mixing volume of tap water and desalted water, pH, alkalinity, chloride and sulfate, the influence of different water quality indexes on iron release were mainly analyzed. Meanwhile, based on controlling iron content, water quality conditions were established to meet with the safety distribution of desalted water: volume ratio of potable water and desalted water should be higher than or equal to 2, pH was higher than 7.6, alkalinity was higher than 200 mg x L(-1).

  4. Performance Monitoring of Residential Hot Water Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Anna; Lanzisera, Steven; Lutz, Jim; Fitting, Christian; Kloss, Margarita; Stiles, Christopher

    2014-08-11

    Current water distribution systems are designed such that users need to run the water for some time to achieve the desired temperature, wasting energy and water in the process. We developed a wireless sensor network for large-scale, long time-series monitoring of residential water end use. Our system consists of flow meters connected to wireless motes transmitting data to a central manager mote, which in turn posts data to our server via the internet. This project also demonstrates a reliable and flexible data collection system that could be configured for various other forms of end use metering in buildings. The purpose of this study was to determine water and energy use and waste in hot water distribution systems in California residences. We installed meters at every end use point and the water heater in 20 homes and collected 1s flow and temperature data over an 8 month period. For a typical shower and dishwasher events, approximately half the energy is wasted. This relatively low efficiency highlights the importance of further examining the energy and water waste in hot water distribution systems.

  5. Detection of mutagens in water-distribution systems after disinfection.

    Science.gov (United States)

    Guzzella, Licia; Di Caterino, Filomena; Monarca, Silvano; Zani, Claudia; Feretti, Donatella; Zerbini, Ilaria; Nardi, Giuseppe; Buschini, Annamaria; Poli, Paola; Rossi, Carlo

    2006-09-19

    This research examined the quality of water-before and after distribution-of four drinking-water production plants located in Northern Italy, two of which collected water from local aquifers and two from the River Po. A battery of genotoxicity assays for monitoring drinking-water was performed to assess the quality of the water produced by the treatment plants under study. Three different sampling stations were selected at each plant, one right at the outlet of the treatment plant and two along with the distribution pipelines. Raw river water was also sampled and analysed as a control. The water samples (500 l) were concentrated on silica C18 cartridges and the extracts were tested in in vitro mutagenicity assays (Salmonella/microsome assay with strains TA 98 and TA 100; SOS Chromotest with Escherichia coli strain PQ37); gene conversion, point mutation and mitochondrial DNA mutability assays with the diploid Saccharomyces cerevisiae strain D7 and a toxicity test using the bioluminescent bacterium Vibrio fischeri (Microtox). The Microtox test and the mitochondrial DNA mutability assay showed the greatest sensitivity towards toxic or mutagenic substances in the water extracts considered. The results show that this battery of short-term tests is applicable in the routine monitoring of drinking-water quality before and after distribution.

  6. Effect of sprinkler structure on water distribution uniformity

    International Nuclear Information System (INIS)

    Xu, M; Li, H; Chen, C; Tu, Q; Liu, J P

    2012-01-01

    Structures of sprinklers play important roles in the uniformity of water distribution. The advances and achievements to improve the distribution uniformity through the innovation in the sprinkler structures at home and abroad were presented in details. Analyses showed that three types of structure can ameliorate the water distribution efficiently. First, novel nozzle structures were applied, including the application of non-circle nozzle and special spread nozzles. Second, new structures of flow channel were used. Third, assistant device was added so as to improve the uneven water distribution, such as an assistant stream interrupter, pressure or flow rate regulator and so on. Compared to domestic sprinklers, sprinklers produced abroad have novel and special structures with better hydraulic performance. Basic theoretical researches should be strengthened and new materials, new manufacturing processes and new technique should be applied. Then new kinds of sprinkler will be produced and the hydraulic performance of sprinklers will be promoted to a higher level.

  7. Biocides in the Yangtze River of China: Spatiotemporal distribution, mass load and risk assessment

    International Nuclear Information System (INIS)

    Liu, Wang-Rong; Zhao, Jian-Liang; Liu, You-Sheng; Chen, Zhi-Feng; Yang, Yuan-Yuan; Zhang, Qian-Qian; Ying, Guang-Guo

    2015-01-01

    Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems. - Highlights: • Biocides were ubiquitous in the surface water and sediment of the Yangtze River. • The dominant biocides in the Yangtze River were DEET and methylparaben. • Annual flux of biocides was 152 tons from the Yangtze River to the East China Sea. • Domestic wastewater was the main source of the biocides. • Carbendazim and triclosan posed high ecological risks. - Biocides showed wide presence in the Yangtze River and some of them could pose high ecological risks to aquatic organisms

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

    Directory of Open Access Journals (Sweden)

    Brian C. Houle

    2010-01-01

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

  9. Mass transfer resistance in ASFF reactors for waste water treatment.

    Science.gov (United States)

    Ettouney, H M; Al-Haddad, A A; Abu-Irhayem, T M

    1996-01-01

    Analysis of mass transfer resistances was performed for an aerated submerged fixed-film reactor (ASFF) for the treatment of waste water containing a mixture of sucrose and ammonia. Both external and internal mass transfer resistances were considered in the analysis, and characterized as a function of feed flow-rate and concentration. Results show that, over a certain operating regime, external mass transfer resistance in the system was greater for sucrose removal than ammonia. This is because the reaction rates for carbon removal were much larger than those of nitrogen. As a result, existence of any form of mass transfer resistance caused by inadequate mixing or diffusion limitations, strongly affects the overall removal rates of carbon more than nitrogen. Effects of the internal måss transfer resistance were virtually non-existent for ammonia removal. This behaviour was found over two orders of magnitude range for the effective diffusivity for ammonia, and one order of magnitude for the film specific surface area. However, over the same parameters' range, it is found that sucrose removal was strongly affected upon lowering its effective diffusivity and increasing the film specific surface area.

  10. Imaging of mass distribution in paper by electrography technique, (2)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Luner, P.

    1991-01-01

    Four paper imaging techniques (β-radiography, electrography, light transmission, and soft x-radiography) were compared in terms of their process parameters and image characteristics (exposure time, spatial variation, contrast, spatial resolution, correlation with mass, and limitation in basis weight range) with the same newsprint sample and electron microscope film. As far as the imaging conditions chosen here are concerned, electrography gave a higher spatial resolution, shorter exposure time, and the wider basis weight range than β-radiography. Light transmission image could be obtained in a very short time, but gave the poorest spatial resolution and correlation with mass. Soft x-radiography gave the highest spatial resolution, but the poorest spatial variation and contrast. The proper imaging technique and conditions need to be selected depending on the specific paper property in question. (author)

  11. Identification and characterization of steady and occluded water in drinking water distribution systems.

    Science.gov (United States)

    Tong, Huiyan; Zhao, Peng; Zhang, Hongwei; Tian, Yimei; Chen, Xi; Zhao, Weigao; Li, Mei

    2015-01-01

    Deterioration and leakage of drinking water in distribution systems have been a major issue in the water industry for years, which are associated with corrosion. This paper discovers that occluded water in the scales of the pipes has an acidic environment and high concentration of iron, manganese, chloride, sulfate and nitrate, which aggravates many pipeline leakage accidents. Six types of water samples have been analyzed under the flowing and stagnant periods. Both the water in the exterior of the tubercles and stagnant water carry suspended iron particles, which explains the occurrence of "red water" when the system hydraulic conditions change. Nitrate is more concentrated in occluded water under flowing condition in comparison with that in flowing water. However, the concentration of nitrate in occluded water under stagnant condition is found to be less than that in stagnant water. A high concentration of manganese is found to exist in steady water, occluded water and stagnant water. These findings impact secondary pollution and the corrosion of pipes and containers used in drinking water distribution systems. The unique method that taking occluded water from tiny holes which were drilled from the pipes' exteriors carefully according to the positions of corrosion scales has an important contribution to research on corrosion in distribution systems. And this paper furthers our understanding and contributes to the growing body of knowledge regarding occluded environments in corrosion scales. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. STRESS DISTRIBUTION IN THE STRATIFIED MASS CONTAINING VERTICAL ALVEOLE

    Directory of Open Access Journals (Sweden)

    Bobileva Tatiana Nikolaevna

    2017-08-01

    Full Text Available Almost all subsurface rocks used as foundations for various types of structures are stratified. Such heterogeneity may cause specific behaviour of the materials under strain. Differential equations describing the behaviour of such materials contain rapidly fluctuating coefficients, in view of this, solution of such equations is more time-consuming when using today’s computers. The method of asymptotic averaging leads to getting homogeneous medium under study to averaged equations with fixed factors. The present article is concerned with stratified soil mass consisting of pair-wise alternative isotropic elastic layers. In the results of elastic modules averaging, the present soil mass with horizontal rock stratification is simulated by homogeneous transversal-isotropic half-space with isotropy plane perpendicular to the standing axis. Half-space is loosened by a vertical alveole of circular cross-section, and virgin ground is under its own weight. For horizontal parting planes of layers, the following two types of surface conditions are set: ideal contact and backlash without cleavage. For homogeneous transversal-isotropic half-space received with a vertical alveole, the analytical solution of S.G. Lekhnitsky, well known in scientific papers, is used. The author gives expressions for stress components and displacements in soil mass for different marginal conditions on the alveole surface. Such research problems arise when constructing and maintaining buildings and when composite materials are used.

  13. Biological instability in a chlorinated drinking water distribution network.

    Science.gov (United States)

    Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

    2014-01-01

    The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3) cells mL(-1) to 4.66×10(5) cells mL(-1) in the network. While this parameter did not exceed 2.1×10(4) cells mL(-1) in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5) cells mL(-1). This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.

  14. Asellus aquaticus and other invertebrates in drinking water distribution systems

    DEFF Research Database (Denmark)

    Christensen, Sarah Christine

    hygiene. Whereas invertebrates in drinking water are known to host parasites in tropical countries they are largely regarded an aesthetical problem in temperate countries. Publications on invertebrate distribution in Danish systems have been completely absent and while reports from various countries have...... other crustaceans and nematodes protect bacteria from treatment processes. The influence of A. aquaticus has never previously been investigated. Investigations in this PhD project revealed that presence of A. aquaticus did not influence microbial water quality measurably in full scale distribution...... Campylobacter jejuni. Invertebrates enter drinking water systems through various routes e.g. through deficiencies in e.g. tanks, pipes, valves and fittings due to bursts or maintenance works. Some invertebrates pass treatment processes from ground water or surface water supplies while other routes may include...

  15. Significance of losses in water distribution systems in India.

    Science.gov (United States)

    Raman, V

    1983-01-01

    Effective management of water supply systems consists in supplying adequate quantities of clean water to the population. Detailed pilot studies of water distribution systems were carried out in 9 cities in India during 1971-81 to establish the feasibility of a programme of assessment, detection, and control of water losses from supply systems. A cost-benefit analysis was carried out. Water losses from mains and service pipes in the areas studied amounted to 20-35% of the total flow in the system. At a conservative estimate, the national loss of processed water through leaks in the water distribution systems amounts to 10(12) litres per year, which is equivalent to 500 million rupees.It is possible to bring down the water losses in the pipe mains to 3-5% of the total flow, and the cost incurred on the control programme can be recovered in 6-18 months. Appropriate conservation measures will help in achieving the goals of the International Water Supply and Sanitation Decade to provide clean water for all.

  16. [Distribution of virtual water of crops in Beijing].

    Science.gov (United States)

    Wang, Hong-Rui; Dong, Yan-Yan; Wang, Jun-Hong; Wang, Yan; Han, Zhao-Xing

    2007-11-01

    Virtual water content of grains and vegetables in Beijing's districts is calculated and analyzed for many years by irrigating water quota method, which is compared with the distribution and exploitation of groundwater in Beijing. The results indicate the virtual water content of grains shows a downward trend in all the districts, but the grain production in Yanqing district brings great pressure to the local groundwater. Secondly, the virtual water content of vegetables shows an upward trend in Shunyi District, Daxing district and Pinggu District and is accounting for more and more gradually. Thirdly, the total virtual water volume of grains is decreasing, and the total virtual water volume of vegetables is increasing and the total virtual water volume of crops in Beijing is reducing in recent years, which corresponds with the structural adjustment of policies.

  17. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    Science.gov (United States)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-05

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Upper Arctic Ocean water masses harbor distinct communities of heterotrophic flagellates

    Directory of Open Access Journals (Sweden)

    A. Monier

    2013-06-01

    Full Text Available The ubiquity of heterotrophic flagellates (HFL in marine waters has been recognized for several decades, but the phylogenetic diversity of these small (ca. 0.8–20 μm cell diameter, mostly phagotrophic protists in the upper pelagic zone of the ocean is underappreciated. Community composition of microbes, including HFL, is the result of past and current environmental selection, and different taxa may be indicative of food webs that cycle carbon and energy very differently. While all oceanic water columns can be density stratified due to the temperature and salinity characteristics of different water masses, the Arctic Ocean is particularly well stratified, with nutrients often limiting in surface waters and most photosynthetic biomass confined to a subsurface chlorophyll maximum layer, where light and nutrients are both available. This physically well-characterized system provided an opportunity to explore the community diversity of HFL from different water masses within the water column. We used high-throughput DNA sequencing techniques as a rapid means of surveying the diversity of HFL communities in the southern Beaufort Sea (Canada, targeting the surface, the subsurface chlorophyll maximum layer (SCM and just below the SCM. In addition to identifying major clades and their distribution, we explored the micro-diversity within the globally significant but uncultivated clade of marine stramenopiles (MAST-1 to examine the possibility of niche differentiation within the stratified water column. Our results strongly suggested that HFL community composition was determined by water mass rather than geographical location across the Beaufort Sea. Future work should focus on the biogeochemical and ecological repercussions of different HFL communities in the face of climate-driven changes to the physical structure of the Arctic Ocean.

  19. The supernova progenitor mass distributions of M31 and M33: further evidence for an upper mass limit

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Weisz, Daniel R. [University of California Observatories, Santa Cruz, CA 95064 (United States); Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan [Box 351580, The University of Washington Seattle, WA 98195 (United States); Murphy, Jeremiah W. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Dolphin, Andrew E., E-mail: zgjennin@ucsc.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States)

    2014-11-10

    Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form dN/dM∝M {sup –α}. Our new larger sample of M31 progenitors follows a distribution with α=4.4{sub −0.4}{sup +0.4}, and the M33 sample follows a distribution with α=3.8{sub −0.5}{sup +0.4}. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives α=4.2{sub −0.3}{sup +0.3}. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function, which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix α = 2.35 and treat the maximum mass as a free parameter, we find M {sub max} ∼ 35-45 M {sub ☉}, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.

  20. Resilience-based optimal design of water distribution network

    Science.gov (United States)

    Suribabu, C. R.

    2017-11-01

    Optimal design of water distribution network is generally aimed to minimize the capital cost of the investments on tanks, pipes, pumps, and other appurtenances. Minimizing the cost of pipes is usually considered as a prime objective as its proportion in capital cost of the water distribution system project is very high. However, minimizing the capital cost of the pipeline alone may result in economical network configuration, but it may not be a promising solution in terms of resilience point of view. Resilience of the water distribution network has been considered as one of the popular surrogate measures to address ability of network to withstand failure scenarios. To improve the resiliency of the network, the pipe network optimization can be performed with two objectives, namely minimizing the capital cost as first objective and maximizing resilience measure of the configuration as secondary objective. In the present work, these two objectives are combined as single objective and optimization problem is solved by differential evolution technique. The paper illustrates the procedure for normalizing the objective functions having distinct metrics. Two of the existing resilience indices and power efficiency are considered for optimal design of water distribution network. The proposed normalized objective function is found to be efficient under weighted method of handling multi-objective water distribution design problem. The numerical results of the design indicate the importance of sizing pipe telescopically along shortest path of flow to have enhanced resiliency indices.

  1. Mass transfer behavior of tritium from air to water through the water surface

    International Nuclear Information System (INIS)

    Takata, Hiroki; Nishikawa, Masabumi; Kamimae, Kozo

    2005-01-01

    It is anticipated that a certain amount of tritiated water exists in the atmosphere of tritium handling facilities, and it is recognized that the hazardous potential of tritiated water is rather high. Then, it is important to grasp the behavior of tritiated water for preserving of the radiation safety. The mass transfer behavior of tritium from air to water through the water surface was discussed in this study. The evaporation rate of water and the condensation rate of water were experimentally examined from measurement of change of the weight of distilled water. The tritium transfer rate from the tritiated water in air to the distilled water was also experimentally examined by using a liquid scintillation counter. Experimental results about change of tritium level in a small beaker placed in the atmosphere with tritiated water showed that diffusion of tritium in water and gas flow in the atmosphere gives considerable effect on tritium transfer. The estimation method of the tritium transfer made in this study was applied to explain the data at The Japan Atomic Power Company second power station at Tsuruga and good agreement was obtained. (author)

  2. [Development and application of a multi-species water quality model for water distribution systems with EPANET-MSX].

    Science.gov (United States)

    Sun, Fu; Chen, Ji-ning; Zeng, Si-yu

    2008-12-01

    A conceptual multi-species water quality model for water distribution systems was developed on the basis of the toolkit of the EPANET-MSX software. The model divided the pipe segment into four compartments including pipe wall, biofilm, boundary layer and bulk liquid. The involved processes were substrate utilization and microbial growth, decay and inactivation of microorganisms, mass transfer of soluble components through the boundary layer, adsorption and desorption of particular components between bulk liquid and biofilm, oxidation and halogenation of organic matter by residual chlorine, and chlorine consumption by pipe wall. The fifteen simulated variables included the seven common variables both in the biofilm and in the bulk liquid, i.e. soluble organic matter, particular organic matter, ammonia nitrogen, residual chlorine, heterotrophic bacteria, autotrophic bacteria and inert solids, as well as biofilm thickness on the pipe wall. The model was validated against the data from a series of pilot experiments, and the simulation accuracy for residual chlorine and turbidity were 0.1 mg/L and 0.3 NTU respectively. A case study showed that the model could reasonably reflect the dynamic variation of residual chlorine and turbidity in the studied water distribution system, while Monte Carlo simulation, taking into account both the variability of finished water from the waterworks and the uncertainties of model parameters, could be performed to assess the violation risk of water quality in the water distribution system.

  3. Distribution Channel Intensity among Table Water Producers in Nigeria

    Directory of Open Access Journals (Sweden)

    Joseph Edewor Agbadudu

    2017-09-01

    Full Text Available Planning for and making reasonable decisions regarding reaching the target market with an organization’s product is a critical task on the part of management, which involves a careful evaluation and selection of its channel structure and intensity.This study therefore examines distribution channel intensity among table water producers in Edo State, Nigeria. The focus of the study is to ascertain the variables that significantly predict distribution intensity among the firms in the table water industry in Edo State. The study seeks to proffer answer to fundamental question of why brands within a single category of a given consumer good differ significantly in their distribution intensity. Using a survey research design, the data used for this study were obtained by taking a sample of 110 table water firms within the three senatorial districts in the State. The data obtained were presented and analyzed using different statistical tools such as mean and multiple regression through Statistical Packages for Social Sciences (SPSS version 22 software. Findings revealed that manufacturers’ target focus, manufacturers’ support program, brand quality and level of firm’s technological advancement were significant predictors of distribution channel intensity among the industrial players in table water industry in the State. Based on the findings, the study recommended that table water firms within the State can secure a competitive edge over their fellow counterpart in the industry by designing an optimal distribution intensity that will meet up their marketing objectives. It is also recommended that the adoption of modern technology in form of online sales is an efficient way of sales and distribution which could be used to enhance their distribution techniques if there is a need to cut down on middle men due to increased cost. The study concluded that optimal distribution intensity could be achieved not by mere imitation of competitors but through

  4. Risk classification and uncertainty propagation for virtual water distribution systems

    International Nuclear Information System (INIS)

    Torres, Jacob M.; Brumbelow, Kelly; Guikema, Seth D.

    2009-01-01

    While the secrecy of real water distribution system data is crucial, it poses difficulty for research as results cannot be publicized. This data includes topological layouts of pipe networks, pump operation schedules, and water demands. Therefore, a library of virtual water distribution systems can be an important research tool for comparative development of analytical methods. A virtual city, 'Micropolis', has been developed, including a comprehensive water distribution system, as a first entry into such a library. This virtual city of 5000 residents is fully described in both geographic information systems (GIS) and EPANet hydraulic model frameworks. A risk classification scheme and Monte Carlo analysis are employed for an attempted water supply contamination attack. Model inputs to be considered include uncertainties in: daily water demand, seasonal demand, initial storage tank levels, the time of day a contamination event is initiated, duration of contamination event, and contaminant quantity. Findings show that reasonable uncertainties in model inputs produce high variability in exposure levels. It is also shown that exposure level distributions experience noticeable sensitivities to population clusters within the contaminant spread area. High uncertainties in exposure patterns lead to greater resources needed for more effective mitigation strategies.

  5. Spatial and mass distributions of molecular clouds and spiral structure

    International Nuclear Information System (INIS)

    Kwan, J.; Valdes, F.; National Optical Astronomy Observatories, Tucson, AZ)

    1987-01-01

    The growth of molecular clouds resulting from cloud-cloud collisions and coalescence in the Galactic ring between 4 and 8 kpc are modeled, taking into account the presence of a spiral potential and the mutual cloud-cloud gravitational attraction. The mean lifetime of molecular clouds is determined to be about 200 million years. The clouds are present in both spiral arm and interarm regions, but a spiral pattern in their spatial distribution is clearly discernible, with the more massive clouds showing a stronger correlation with the spiral arms. As viewed from within the Galactic disk, however, it is very difficult to ascertain that the molecular cloud distribution in longitude-velocity space has a spiral pattern. 19 references

  6. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jingqing [College of Engineering and Architecture, Zhejiang University, Hangzhou 310058 (China); Chen, Huanyu [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Binhai Industrial Technology Research Institute of Zhejiang University, Tianjin 300000 (China); Yao, Lingdan; Wei, Zongyuan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Lou, Liping, E-mail: loulp@zju.edu.cn [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda [Environmental Protection Agency, Office of Research and Development, NRMRL, Cincinnati, OH 45220 (United States); Hu, Baolan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhou, Xiaoyan [Shaoxing Water Environmental Science Institute Co. Ltd, Zhejiang 312000 (China)

    2016-11-05

    Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  7. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

    International Nuclear Information System (INIS)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-01-01

    Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  8. Mass change distribution inverted from space-borne gravimetric data using a Monte Carlo method

    Science.gov (United States)

    Zhou, X.; Sun, X.; Wu, Y.; Sun, W.

    2017-12-01

    Mass estimate plays a key role in using temporally satellite gravimetric data to quantify the terrestrial water storage change. GRACE (Gravity Recovery and Climate Experiment) only observes the low degree gravity field changes, which can be used to estimate the total surface density or equivalent water height (EWH) variation, with a limited spatial resolution of 300 km. There are several methods to estimate the mass variation in an arbitrary region, such as averaging kernel, forward modelling and mass concentration (mascon). Mascon method can isolate the local mass from the gravity change at a large scale through solving the observation equation (objective function) which represents the relationship between unknown masses and the measurements. To avoid the unreasonable local mass inverted from smoothed gravity change map, regularization has to be used in the inversion. We herein give a Markov chain Monte Carlo (MCMC) method to objectively determine the regularization parameter for the non-negative mass inversion problem. We first apply this approach to the mass inversion from synthetic data. Result show MCMC can effectively reproduce the local mass variation taking GRACE measurement error into consideration. We then use MCMC to estimate the ground water change rate of North China Plain from GRACE gravity change rate from 2003 to 2014 under a supposition of the continuous ground water loss in this region. Inversion result show that the ground water loss rate in North China Plain is 7.6±0.2Gt/yr during past 12 years which is coincident with that from previous researches.

  9. Mass fluxes and spatial trends of xenobiotics in the waters of the city of Halle, Germany

    International Nuclear Information System (INIS)

    Reinstorf, F.; Strauch, G.; Schirmer, K.; Glaeser, H.-R.; Moeder, M.; Wennrich, R.; Osenbrueck, K.; Schirmer, M.

    2008-01-01

    The behaviour and the effects of xenobiotics including pharmaceuticals and fragrances in the environment are widely unknown. In order to improve our knowledge, field investigations and modelling approaches for the entire area of the city of Halle/Saale, Germany, were performed. The distribution of the concentration values and mass fluxes are exemplified using indicators such as Bisphenol A, t-Nonylphenol, Carbamacepine, Galaxolide, Tonalide, Gadolinium and isotopes. Concentrations at a magnitude of ng/L to μg/L were found ubiquitously in the ground and surface waters. Using the concentration values, the impact of the city concerning the indicators was not always evident. Only the assessment of the mass fluxes shows significant urban impacts along the city passage. The calculation of the mass fluxes shows increasing values for all investigated xenobiotics during the city passage; only Bisphenol A stagnates. A balance model of water and indicator mass fluxes was built up for the entire city area. - Xenobiotics are ubiquitous in the investigated urban aquatic system and are quantified by a large scale mass balance to find spatial trends

  10. A Numerical Study of Water Loss Rate Distributions in MDCT-based Human Airway Models

    Science.gov (United States)

    Wu, Dan; Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long

    2015-01-01

    Both three-dimensional (3D) and one-dimensional (1D) computational fluid dynamics (CFD) methods are applied to study regional water loss in three multi-detector row computed-tomography (MDCT)-based human airway models at the minute ventilations of 6, 15 and 30 L/min. The overall water losses predicted by both 3D and 1D models in the entire respiratory tract agree with available experimental measurements. However, 3D and 1D models reveal different regional water loss rate distributions due to the 3D secondary flows formed at bifurcations. The secondary flows cause local skewed temperature and humidity distributions on inspiration acting to elevate the local water loss rate; and the secondary flow at the carina tends to distribute more cold air to the lower lobes. As a result, the 3D model predicts that the water loss rate first increases with increasing airway generation, and then decreases as the air approaches saturation, while the 1D model predicts a monotonic decrease of water loss rate with increasing airway generation. Moreover, the 3D (or 1D) model predicts relatively higher water loss rates in lower (or upper) lobes. The regional water loss rate can be related to the non-dimensional wall shear stress (τ*) by the non-dimensional mass transfer coefficient (h0*) as h0* = 1.15 τ*0.272, R = 0.842. PMID:25869455

  11. Differential distributions for top-quark hadro-production with a running mass

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2013-05-15

    We take a look at how the differential distributions for top-quark production are affected by changing to the running mass scheme. Specifically we consider the transverse momentum, rapidity and pair-invariant mass distributions at NLO for the top-quark mass in the MS scheme. It is found that, similar to the total cross section, the perturbative expansion converges faster and the scale dependence improves using the mass in the MS scheme as opposed to the on-shell scheme. We also update the analysis for the total cross section using the now available full NNLO contribution.

  12. Differential distributions for top-quark hadro-production with a running mass

    International Nuclear Information System (INIS)

    Dowling, M.; Moch, S.; Hamburg Univ.

    2013-05-01

    We take a look at how the differential distributions for top-quark production are affected by changing to the running mass scheme. Specifically we consider the transverse momentum, rapidity and pair-invariant mass distributions at NLO for the top-quark mass in the MS scheme. It is found that, similar to the total cross section, the perturbative expansion converges faster and the scale dependence improves using the mass in the MS scheme as opposed to the on-shell scheme. We also update the analysis for the total cross section using the now available full NNLO contribution.

  13. Analysis of residual chlorine in simple drinking water distribution system with intermittent water supply

    Science.gov (United States)

    Goyal, Roopali V.; Patel, H. M.

    2015-09-01

    Knowledge of residual chlorine concentration at various locations in drinking water distribution system is essential final check to the quality of water supplied to the consumers. This paper presents a methodology to find out the residual chlorine concentration at various locations in simple branch network by integrating the hydraulic and water quality model using first-order chlorine decay equation with booster chlorination nodes for intermittent water supply. The explicit equations are developed to compute the residual chlorine in network with a long distribution pipe line at critical nodes. These equations are applicable to Indian conditions where intermittent water supply is the most common system of water supply. It is observed that in intermittent water supply, the residual chlorine at farthest node is sensitive to water supply hours and travelling time of chlorine. Thus, the travelling time of chlorine can be considered to justify the requirement of booster chlorination for intermittent water supply.

  14. Study of mass transfer at the air-water interface by an isotopic method

    International Nuclear Information System (INIS)

    Merlivat, L.

    1975-01-01

    It is shown by analysing the hydrogen and oxygen stable isotopes distribution in liquid and water vapor, that the processes taking place on a very small scale near the liquid can be investigated. The effect of molecular mass transfer is directly obtained without having to perform difficult measurements in the air in the immediate vicinity of the water surface. Experiments are carried out in the air-water tunnel especially designed for the simulation of ocean atmosphere energy exchanges. The wind velocities vary from 0.7 to 7m/sec. The experimental results obtained do not support the classical Reynolds' analogy between momentum and mass transfer down to the interface and the theory proposed by Sheppard, but they are in agreement with Sverdrup's, Kitaigorodskiy and Volkov's and Brutsaert's theories, all of which involve a layer just above the air-water interface through which mass transfer is dominated by molecular diffusion. The thickness of this layer in the two first theories is shown to decrease with increasing wind velocity. Direct application of Brutsaert's theory for roughness Reynolds numbers smaller than one is in good agreement with the experimental data obtained [fr

  15. Potential impacts of changing supply-water quality on drinking water distribution: A review.

    Science.gov (United States)

    Liu, Gang; Zhang, Ya; Knibbe, Willem-Jan; Feng, Cuijie; Liu, Wentso; Medema, Gertjan; van der Meer, Walter

    2017-06-01

    Driven by the development of water purification technologies and water quality regulations, the use of better source water and/or upgraded water treatment processes to improve drinking water quality have become common practices worldwide. However, even though these elements lead to improved water quality, the water quality may be impacted during its distribution through piped networks due to the processes such as pipe material release, biofilm formation and detachment, accumulation and resuspension of loose deposits. Irregular changes in supply-water quality may cause physiochemical and microbiological de-stabilization of pipe material, biofilms and loose deposits in the distribution system that have been established over decades and may harbor components that cause health or esthetical issues (brown water). Even though it is clearly relevant to customers' health (e.g., recent Flint water crisis), until now, switching of supply-water quality is done without any systematic evaluation. This article reviews the contaminants that develop in the water distribution system and their characteristics, as well as the possible transition effects during the switching of treated water quality by destabilization and the release of pipe material and contaminants into the water and the subsequent risks. At the end of this article, a framework is proposed for the evaluation of potential transition effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Bacterial communities associated with an occurrence of colored water in an urban drinking water distribution system.

    Science.gov (United States)

    Wu, Hui Ting; Mi, Zi Long; Zhang, Jing Xu; Chen, Chao; Xie, Shu Guang

    2014-08-01

    This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was observed among the different waters, with the predominance of Proteobacteria. While Verrucomicrobia was also a major phylum group in colored water. Limnobacter was the major genus group in colored water, but Undibacterium predominated in normal tap water. The coexistence of Limnobacter as well as Sediminibacterium and Aquabacterium might contribute to the formation of colored water. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  17. Observational Constraints on Quasar Black Hole Mass Distributions, Eddington Ratio Distributions, and Lifetimes

    DEFF Research Database (Denmark)

    Kelly, Brandon C.; Vestergaard, Marianne; Fan, X.

    2010-01-01

    I will present the black hole mass function (BHMF) of broad line quasars in the SDSS DR3. We employ a powerful Bayesian statistical technique that corrects for incompleteness and the statistical uncertainty in the mass estimates. We find evidence that the most massive black hole appeared as quasars...... earlier in the universe, and that most quasars are not radiating at or near the Eddington limit. I will also present constraints on the quasar lifetime and maximum black hole mass, derived from the mass functions....

  18. Rack Distribution Effects on MPLM Center of Mass

    Science.gov (United States)

    Tester, John T.

    2005-01-01

    This research was in support of exploring the need for more flexible "center of gravity (CG) specifications than those currently established by NASA for the Multi-Purpose Logistics Module (MPLM). The MPLM is the cargo carrier for International Space Station (ISS) missions. The MPLM provides locations for 16 standard racks, as shown in Figure 1; not all positions need to be filled in any given flight. The MPLM coordinate system (X(sub M), Y(sub M), Z(sub M)) is illustrated as well. For this project, the primary missions of interest were those which supply the ISS and remove excess materials on the return flights. These flights use a predominate number of "Resupply Stowage Racks" (RSR) and "Resupply Stowage Platforms" (RSP). In these two types of racks, various smaller items are stowed. Hence, these racks will exhibit a considerable range of mass values as well as a range as to where their individual CG are located.

  19. THE DEPENDENCE OF PRESTELLAR CORE MASS DISTRIBUTIONS ON THE STRUCTURE OF THE PARENTAL CLOUD

    International Nuclear Information System (INIS)

    Parravano, Antonio; Sánchez, Néstor; Alfaro, Emilio J.

    2012-01-01

    The mass distribution of prestellar cores is obtained for clouds with arbitrary internal mass distributions using a selection criterion based on the thermal and turbulent Jeans mass and applied hierarchically from small to large scales. We have checked this methodology by comparing our results for a log-normal density probability distribution function with the theoretical core mass function (CMF) derived by Hennebelle and Chabrier, namely a power law at large scales and a log-normal cutoff at low scales, but our method can be applied to any mass distributions representing a star-forming cloud. This methodology enables us to connect the parental cloud structure with the mass distribution of the cores and their spatial distribution, providing an efficient tool for investigating the physical properties of the molecular clouds that give rise to the prestellar core distributions observed. Simulated fractional Brownian motion (fBm) clouds with the Hurst exponent close to the value H = 1/3 give the best agreement with the theoretical CMF derived by Hennebelle and Chabrier and Chabrier's system initial mass function. Likewise, the spatial distribution of the cores derived from our methodology shows a surface density of companions compatible with those observed in Trapezium and Ophiucus star-forming regions. This method also allows us to analyze the properties of the mass distribution of cores for different realizations. We found that the variations in the number of cores formed in different realizations of fBm clouds (with the same Hurst exponent) are much larger than the expected root N statistical fluctuations, increasing with H.

  20. Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems.

    Science.gov (United States)

    Douterelo, I; Husband, S; Loza, V; Boxall, J

    2016-07-15

    The majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance. This research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers. Copyright © 2016 Douterelo et al.

  1. Using ELECTRE TRI to support maintenance of water distribution networks

    Directory of Open Access Journals (Sweden)

    Flavio Trojan

    2012-08-01

    Full Text Available Problems encountered in the context of the maintenance management of water supply are evidenced by the lack of decision support models which gives a manager overview of the system. This paper, therefore, develops a model that uses, in its framework, the multicriteria outranking method ELECTRE TRI. The objective is to sort the areas of water flow measurement of a water distribution network, by priority of maintenance, with data collected from an automated system of abnormalities detection. This sorting is designed to support maintenance decisions in terms of the measure more appropriate to be applied per region. To illustrate the proposed model, an application was performed in a city with 100 thousand water connections. With this model it becomes possible to improve the allocation of maintenance measures for regions and mainly to improve the operation of the distribution network.

  2. Water distribution function across the curved lipid bilayer: SANS study

    International Nuclear Information System (INIS)

    Kiselev, M.A.; Zemlyanaya, E.V.; Ryabova, N.Y.; Hauss, T.; Dante, S.; Lombardo, D.

    2008-01-01

    The neutron scattering length density across the membrane is simulated on the basis of fluctuated model of lipid bilayer. The use of a separated form factors method has been applied for the identification of the structural features of the polydispersed unilamellar DMPC vesicle system. The hydration of vesicle is described by sigmoid distribution function of the water molecules. The application of the model to the obtained SANS spectra allow the determination of the main parameters of the system, such as the average vesicle radius (and its polydispersity), the membrane thickness, the thickness of hydrocarbon chain region, the number of water molecules located per lipid molecule, and the phospholipid surface area. Moreover the approach allow the calculation of some relevant parameters connected with the water distribution function across the bilayer system. The main features of the obtained results furnish an explanation of why lipid membrane is easily penetrated by the water molecules of the solution

  3. Performance of water distribution systems in a pilot cooling tower

    International Nuclear Information System (INIS)

    Tognotti, L.; Giacomelli, A.; Zanelli, S.; Bellagamba, B.; Lotti, G.; Mattachini, F.

    1990-01-01

    An experimental study has been carried out on the water distribution system of a Pilot cooling tower of 160 m 3 /hr The performances of different industrial water distributors have been evaluated by changing the operative conditions of the pilot tower. In particular, the efficiency and the uniformity of the water distribution have been investigated and compared with the results obtained in a small-scale loop, in which the single nozzles were tested. Measurements in both systems, pilot tower and small scale loop, included the geometric characteristics of the jet umbrella by ensemble photography, the wetted zone by measuring the specific flowrate, the drop-size distribution and liquid concentration by high-speed photography. The results show that correlations exist between the nozzle behaviour in single and pilot tower configuration. The uniformity of water distribution in the pilot tower is strongly related to the nozzle installation pattern and to the operative conditions. Coalescence plays an important role on the drop size distribution in the pilot-tower. Comments upon the influence of these parameters on tower behaviour are also included

  4. Power distribution effects on boiling water reactor stability

    International Nuclear Information System (INIS)

    Damiano, B.; March-Leuba, J.

    1989-01-01

    The work presented in this paper deals with the effects of spatial power distributions on the stability of boiling water reactors (BWRs). It is shown that a conservative power distribution exists for which the stability is minimal. These results are relevant because they imply that bounding stability calculations are possible and, thus, a worst-possible scenario may be defined for a particular BWR geometry. These bounding calculations may, then, be used to determine the maximum expected limit-cycle peak powers

  5. Mass distribution of fission fragments within the Born-Oppenheimer approximation

    Energy Technology Data Exchange (ETDEWEB)

    Pomorski, K.; Nerlo-Pomorska, B. [M.C.S. University, Department of Theoretical Physics, Lublin (Poland); Ivanyuk, F.A. [Institute for Nuclear Research, Kiev (Ukraine)

    2017-03-15

    The fission fragments mass-yield of {sup 236} U is obtained by an approximate solution of the eigenvalue problem of the collective Hamiltonian that describes the dynamics of the fission process whose degrees of freedom are: the fission (elongation), the neck and mass-asymmetry modes. The macroscopic-microscopic method is used to evaluate the potential energy surface. The macroscopic energy part is calculated using the liquid drop model and the microscopic corrections are obtained using a Woods-Saxon single-particle levels. The four-dimensional modified Cassini ovals shape parametrization is used to describe the shape of the fissioning nucleus. The mass tensor is taken within a cranking-type approximation. The final fragment mass distribution is obtained by weighting the adiabatic density distribution in the collective space with the neck-dependent fission probability. The neck degree of freedom is found to play a significant role in determining the final fragment mass distribution. (orig.)

  6. PAH distribution and mass fluxes in the Three Gorges Reservoir after impoundment of the Three Gorges Dam.

    Science.gov (United States)

    Deyerling, Dominik; Wang, Jingxian; Hu, Wei; Westrich, Bernhard; Peng, Chengrong; Bi, Yonghong; Henkelmann, Bernhard; Schramm, Karl-Werner

    2014-09-01

    Mass fluxes of polycyclic aromatic hydrocarbons (PAHs) were calculated for the Three Gorges Reservoir (TGR) in China, based on concentration and discharge data from the Yangtze River. Virtual Organisms (VOs) have been applied during four campaigns in 2008, 2009 (twice) and 2011 at sampling sites distributed from Chongqing to Maoping. The total PAH mass fluxes ranged from 110 to 2,160 mg s(-1). Highest loads were determined at Chongqing with a decreasing trend towards Maoping in all four sampling campaigns. PAH remediation capacity of the TGR was found to be high as the mass flux reduced by more than half from upstream to downstream. Responsible processes are thought to be adsorption of PAH to suspended particles, dilution and degradation. Furthermore, the dependence of PAH concentration upon water depth was investigated at Maoping in front of the Three Gorges Dam. Although considerable differences could be revealed, there was no trend observable. Sampling of water with self-packed filter cartridges confirmed more homogenous PAH depth distribution. Moreover, PAH content of suspended particles was estimated from water concentrations gathered by VOs based on a water-particle separation model and subsequently compared to PAH concentration measured in water and in filter cartridges. It could be shown that the modeled data predicts the concentration caused by particle-bound PAHs to be about 6 times lower than PAHs dissolved in water. Besides, the model estimates the proportions of 5- and 6-ring PAHs being higher than in water phase. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Topographical distribution of phosphorylation sites of phosvitins by mass spectrometry.

    Science.gov (United States)

    Czernick, Drew; Liu, Jess; Serge, Dibart; Salih, Erdjan

    2013-05-27

    Phosvitin, derived from the vitellogenin II gene protein, is a highly phosphorylated protein found in egg yolk. A second hypothetical protein has been predicted based on the vitellogenin I gene, but has not been defined at the protein level. Mass spectrometric analysis was used to identify the phosphopeptide sequences and the precise sites of phosphorylation of two phosvitins, phosvitin 1 and phosvitin 2 derived from vitellogenins I and II, respectively. Samples of native phosvitin were subjected to tryptic digestion followed by mass spectrometric analysis: (i) native phosvitin peptides, (ii) after treatment with NaOH, and (iii) after chemical derivatization of P-Ser/P-Thr residues by dithiothreitol under base-catalyzed conditions. A combination of these approaches led to the identification of 68 and 35 phosphopeptides with 89 (81 P-Ser and 8 P-Thr residues) and 62 (57 P-Ser and 5 P-Thr residues) phosphorylation sites of phosvitin 1 and phosvitin 2, respectively. These data for the first time documented on a large scale the major states and sites of phosphorylation of phosvitins with a total of 151 phosphorylation sites. Importantly, the present work also provided the first direct de novo protein amino-acid sequence data for phosvitin 1 protein and evidence for the full expression of vitellogenin I gene. We have for the first time generated a large number of phosphopeptides (~100) and identified 151 phosphorylation sites of phosvitin 1 and phosvitin 2, respectively. Importantly, this study also led to the discovery of a novel phosvitin 1 and provided the first direct de novo protein amino-acid sequence data for the full expression of vitellogenin I gene. There is considerable interest in naturally occurring phosphopeptides/phosphoproteins and their application in biomedical fields and in the food industry because of their molecular characteristics and non-toxic nature, hence, our work opens new avenues to pursue such endeavors. In addition, the results provide

  8. Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice

    DEFF Research Database (Denmark)

    Andersen, Steven Arild Wuyts; Konge, Lars; Cayé-Thomasen, Per

    2015-01-01

    IMPORTANCE: Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal...... in understanding skills acquisition and best-practice implementation and organization of training. OBJECTIVE: To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training. DESIGN, SETTING...... plateaued on a score of 16.0 (15.3-16.7) at approximately the ninth repetition, but the individual learning curves were highly variable. CONCLUSIONS AND RELEVANCE: Novices can acquire basic mastoidectomy competencies with self-directed VR simulation training. Training should be organized with distributed...

  9. The accumulation of radioactive contaminants in drinking water distribution systems.

    Science.gov (United States)

    Lytle, Darren A; Sorg, Thomas; Wang, Lili; Chen, Abe

    2014-03-01

    The accumulation of trace contaminants in drinking water distribution system sediment and scales has been documented, raising concerns that the subsequent release of the contaminants back to the water is a potential human exposure pathway. Radioactive contaminants are of concern because of their known health effects and because of their persistence within associated distribution system materials. The objective of this work was to measure the amount of a number of radioactive contaminants (radium, thorium, and uranium isotopes, and gross alpha and beta activity) in distribution solids collected from water systems in four states (Wisconsin, Illinois, Minnesota, and Texas). The water utilities chosen had measurable levels of radium in their source waters. In addition, 19 other elements in the solids were quantified. Water systems provided solids primarily collected during routine fire hydrant flushing. Iron was the dominant element in nearly all of the solids and was followed by calcium, phosphorus, magnesium, manganese, silicon, aluminum and barium in descending order. Gross alpha and beta radiation averaged 255 and 181 pCi/g, and were as high as 1602 and 1169 pCi/g, respectively. Total radium, thorium and uranium averaged 143, 40 and 6.4 pCi/g, respectively. Radium-226 and -228 averaged 74 and 69 pCi/g, and were as high as 250 and 351 pCi/g, respectively. Published by Elsevier Ltd.

  10. Fragment mass distribution of proton-induced spallation reaction with intermediate energy

    International Nuclear Information System (INIS)

    Fan Sheng; Ye Yanlin; Xu Chuncheng; Chen Tao; Sobolevsky, N.M.

    2000-01-01

    The test of part benchmark of SHIELD code is finished. The fragment cross section and mass distribution and excitation function of the residual nuclei from proton-induced spallation reaction on thin Pb target with intermediate energy have been calculated by SHIELD code. And the results are in good agreement with measured data. The fragment mass distribution of the residual nuclei from proton-induced spallation reaction on thick Pb target with incident energy 1.6 GeV have been simulated

  11. Optimization of orthotropic distributed-mode loudspeaker using attached masses and multi-exciters.

    Science.gov (United States)

    Lu, Guochao; Shen, Yong; Liu, Ziyun

    2012-02-01

    Based on the orthotropic model of the plate, the method to optimize the sound response of the distributed-mode loudspeaker (DML) using the attached masses and the multi-exciters has been investigated. The attached masses method will rebuild the modes distribution of the plate, based on which multi-exciter method will smooth the sound response. The results indicate that the method can be used to optimize the sound response of the DML. © 2012 Acoustical Society of America

  12. District cool water distribution; Reseau urbain et distribution d`eau glacee

    Energy Technology Data Exchange (ETDEWEB)

    Schabaillie, D. [Ste Climespace (France)

    1997-12-31

    The city of Paris has developed several district cool water distribution networks (Climespace) for air conditioning purposes, one in the Halles district (central Paris) linked with the Louvre museum, one in the Opera district (with large department stores) and one in the east of paris (Bercy). Each of these networks has a cool water production plant, the one at the Halles producing also hot water and safety electric power. The characteristics of the equipment (heat pumps, refrigerating machinery, storage...) are described. The pipes are laid in the city sewage network, and the cool carrier is water. The various networks are centrally supervised at the Halles center

  13. Distribution of Tritium and {sup 137}CS in South Indian Ocean Waters - Implications of Water Transport Processes

    Energy Technology Data Exchange (ETDEWEB)

    Povinec, P. P.; Jeskovsky, M.; Sykora, I. [Comenius University, Faculty of Mathematics, Physics and Informatics, Bratislava (Slovakia); Aoyama, M. [Meteorological Research Institute, Tsukuba (Japan); Gastaud, J.; Levy, I. [International Atomic Energy Agency, Marine Environment Laboratories (Monaco); Hamajima, Y. [Kanazawa University, Low-Level Radioactivity Laboratory, Nomi (Japan); Hirose, K. [Sophia University, Faculty of Science and Technology, Tokyo (Japan); Sanchez-Cabeza, J. A. [Universitat Autonoma de Barcelona, Bellaterra (Spain)

    2013-07-15

    The World Ocean, and specifically the Indian Ocean, plays a significant role in the better understanding of the climate. The distribution of global fallout {sup 3}H, {sup 14}C, {sup 90}Sr, {sup 129}I and {sup 137}Cs in the seawater of the Indian Ocean, after their main injection from atmospheric nuclear weapons tests during the 1960s, have been investigated. Results obtained in the framework of the SHOTS (Southern Hemisphere Ocean Tracer Studies) project are evaluated and compared with previously published data. The enhanced {sup 3}H and {sup 137}Cs levels observed in the south Indian ocean indicate transport of water masses labelled with these radionuclides from the central Pacific Ocean via the Indonesian Seas to the Indian Ocean. The observed surface gradients and presence of several water masses in the south Indian ocean makes this ocean one of the most dynamic parts of the World ocean. (author)

  14. Nuclear analysis of the Chornobyl fuel containing masses with heterogeneous fuel distribution

    International Nuclear Information System (INIS)

    Turski, R. B.

    1998-01-01

    Although significant data has been obtained on the condition and composition of the fuel containing masses (FCM) located in the concrete chambers under the Chernobyl Unit 4 reactor cavity, there is still uncertainty regarding the possible recriticality of this material. The high radiation levels make access extremely difficult, and most of the samples are from the FCM surface regions. There is little information on the interior regions of the FCM, and one cannot assume with confidence that the surface measurements are representative of the interior regions. Therefore, reasonable assumptions on the key parameters such as fuel concentration, the concentrations of impurities and neutron poisons (especially boron), the void fraction of the FCM due to its known porosity, and the degrees of fuel heterogeneity, are necessary to evaluate the possibility of recriticality. The void fraction is important since it introduces the possibility of water moderator being distributed throughout the FCM. Calculations indicate that the addition of 10 to 30 volume percent (v/o) water to the FCM has a significant impact on the calculated reactivity of the FCM. Therefore, water addition must be considered carefully. The other possible moderators are graphite and silicone dioxide. As discussed later in this paper, silicone dioxide moderation does not represent a criticality threat. For graphite, both heterogeneous fuel arrangements and very large volume fractions of graphite are necessary for a graphite moderated system to go critical. Based on the observations and measurements of the FCM compositions, these conditions do not appear creditable for the Chernobyl FCM. Therefore, the focus of the analysis reported in this paper will be on reasonable heterogeneous fuel arrangements and water moderation. The analysis will evaluate a range of fuel and diluent compositions

  15. Hydrophysical correlation and water mass indication of optical physiological parameters of picophytoplankton in Prydz Bay during autumn 2008.

    Science.gov (United States)

    Zhang, Fang; Ma, Yuxin; Lin, Ling; He, Jianfeng

    2012-12-01

    Flow cytometry (FCM) is efficient in detecting both abundance and optical physiological parameters including cell size and cellular carbon content-side scatter (SSC), carotenoids-green and orange fluorescence (FL1 and FL2), and red fluorescence-chlorophylls (FL3) can be obtained by FCM. The utilization of these physiological parameters in indicating water masses in Prydz Bay was investigated for the first time. Picophytoplankton were very sensitive to hydrophysical changes and present distinct characteristics of water masses: Picophytoplankton in water closer to the Amery Ice Shelf were more affected by salinity than by temperature, while temperature became more important than salinity the nearer the picophytoplankton were to the deep sea. The picophytoplankton dealt with declines in light by increasing the size of cells, which increase the fixation of carbon. This can also be increased by high temperature and salinity. Pure water masses can increase the content of chlorophylls and cellular carbon. Generally, the distributions of all the five parameters at upper water depths were less affected by temperature and salinity than by water masses; and these parameters can be as indicators to Summer Surface Water (SSW), Winter Water (WW) and Continental Shelf Water (CSW). Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Mass Distribution in Rotating Thin-Disk Galaxies According to Newtonian Dynamics

    Directory of Open Access Journals (Sweden)

    James Q. Feng

    2014-04-01

    Full Text Available An accurate computational method is presented for determining the mass distribution in a mature spiral galaxy from a given rotation curve by applying Newtonian dynamics for an axisymmetrically rotating thin disk of finite size with or without a central spherical bulge. The governing integral equation for mass distribution is transformed via a boundary-element method into a linear algebra matrix equation that can be solved numerically for rotation curves with a wide range of shapes. To illustrate the effectiveness of this computational method, mass distributions in several mature spiral galaxies are determined from their measured rotation curves. All the surface mass density profiles predicted by our model exhibit approximately a common exponential law of decay, quantitatively consistent with the observed surface brightness distributions. When a central spherical bulge is present, the mass distribution in the galaxy is altered in such a way that the periphery mass density is reduced, while more mass appears toward the galactic center. By extending the computational domain beyond the galactic edge, we can determine the rotation velocity outside the cut-off radius, which appears to continuously decrease and to gradually approach the Keplerian rotation velocity out over twice the cut-off radius. An examination of circular orbit stability suggests that galaxies with flat or rising rotation velocities are more stable than those with declining rotation velocities especially in the region near the galactic edge. Our results demonstrate the fact that Newtonian dynamics can be adequate for describing the observed rotation behavior of mature spiral galaxies.

  17. An Optimal Design Model for New Water Distribution Networks in ...

    African Journals Online (AJOL)

    The mathematical formulation is a Linear Programming Problem (LPP) which involves the design of a new network of water distribution considering the cost in the form of unit price of pipes, the hydraulic gradient and the loss of pressure. The objective function minimizes the cost of the network which is computed as the sum ...

  18. Distribution of slipper lobsters (Decapoda: Scyllaridae in Uruguayan waters

    Directory of Open Access Journals (Sweden)

    Fabrizio Scarabino

    2017-09-01

    Full Text Available Abstract Scyllarid lobsters are commonly found in tropical waters with scarce records from temperate zones in the southwestern Atlantic. Here, we provide new information about the distribution of Scyllarides deceptor Holthuis, 1963 along the Uruguayan continental shelf and include a new austral record for Scyllarus depressus (Smith, 1881.

  19. Optimal dimensioning model of water distribution systems | Gomes ...

    African Journals Online (AJOL)

    This study is aimed at developing a pipe-sizing model for a water distribution system. The optimal solution minimises the system's total cost, which comprises the hydraulic network capital cost, plus the capitalised cost of pumping energy. The developed model, called Lenhsnet, may also be used for economical design when ...

  20. Optimal operation of water distribution networks by predictive control ...

    African Journals Online (AJOL)

    This paper presents an approach for the operational optimisation of potable water distribution networks. The maximisation of the use of low-cost power (e.g. overnight pumping) and the maintenance of a target chlorine concentration at final delivery points were defined as important optimisation objectives. The first objective ...

  1. Modelling flow dynamics in water distribution networks using ...

    African Journals Online (AJOL)

    One such approach is the Artificial Neural Networks (ANNs) technique. The advantage of ANNs is that they are robust and can be used to model complex linear and non-linear systems without making implicit assumptions. ANNs can be trained to forecast flow dynamics in a water distribution network. Such flow dynamics ...

  2. Pattern Recognition for Reliability Assessment of Water Distribution Networks

    NARCIS (Netherlands)

    Trifunovi?, N.

    2012-01-01

    The study presented in this manuscript investigates the patterns that describe reliability of water distribution networks focusing to the node connectivity, energy balance, and economics of construction, operation and maintenance. A number of measures to evaluate the network resilience has been

  3. Surface water assessment on the influence of space distribution on ...

    African Journals Online (AJOL)

    In this work, the influence of space distribution on physico-chemical parameters of refinery effluent discharge has been studied, using treated effluent water discharged from the Port Harcourt Refinery Company (PHRC) into the Ekerekana Creek in Okrika as reference. Samples were collected at surface level from the ...

  4. Distribution and seasonality of cetaceans in tropical waters between ...

    African Journals Online (AJOL)

    The species richness, spatial distribution, seasonality and interspecific associations of cetaceans in tropical oceanic waters between the Gulf of Guinea and Angola were examined using 5 905.3 h of dedicated survey effort collected from 13 platforms of opportunity (geophysical vessels) between 2004 and 2009, and from ...

  5. Sediment distribution and composition on the shallow water ...

    African Journals Online (AJOL)

    Sediments of the shallow water carbonate basin in Zanzibar channel were investigated for composition and grain size distribution. The surface sediment composition was dominated by carbonate sands (with CaCO3 > 30%), except in the area adjacent to mainland coastline and a thin lobe which projects from Ruvu River to ...

  6. Optimum reliable operation of water distribution networks by ...

    African Journals Online (AJOL)

    In recent decades much attention has been paid to optimal operation of water distribution networks (WDNs). In this regard, the system operation costs, including energy and disinfection chemicals, as well as system reliability should be simultaneously considered in system performance optimisation, to provide the minimum ...

  7. Abiotic water quality control on mangrove distribution in estuarine ...

    African Journals Online (AJOL)

    Therefore, to replace the mangrove that has been lost due to die-off, the red mangrove maybe used in viable restoration efforts for the protection of inland areas from floods, as well as to provide ecosystem goods and services. Keywords: electromagnetic-induction, tropical wetland, water quality, mangrove distribution ...

  8. Numerical study of coupled heat and mass transfer in geothermal water cooling tower

    International Nuclear Information System (INIS)

    Bourouni, K.; Bassem, M.M.; Chaibi, M.T.

    2008-01-01

    Cross flow mechanical cooling towers, widely spreads all over the south region of Tunisia are used for cooling geothermal water for agriculture and domestic ends. These towers are sized empirically and present several problems in regard to operation and electrical energy consumption. This work aims to study the thermal behaviour of this type of cooling towers through a developed mathematical model considering the variation of the water mass flow rate inside the tower. The analysis of the water and air temperatures distribution along the cooling tower had underlined the negative convection phenomenon at a certain height of the tower. This analysis has shown also that the difference in water temperature between the inlet and the outlet of the tower is much higher than the one of air due to the dominance of the evaporative potential compared to the convective one. In addition, the variations of the air humidity along the cooling tower and the quantity of evaporated water have been investigated. The loss of water by evaporation is found to be 5.1% of the total quantity of water feeding the cooling tower. Interesting future prospects are expected for validation of the developed model to optimize the operating of the cooling tower

  9. Eastern South Pacific water mass geometry during the last glacial-interglacial transition

    Science.gov (United States)

    De Pol-Holz, R.; Reyes, D.; Mohtadi, M.

    2012-12-01

    The eastern South Pacific is characterized today by a complex thermocline structure where large salinity and oxygen changes as a function of depth coexist. Surface waters from tropical origin float on top of subantarctic fresher water (the so-called 'shallow salinity minimum of the eastern south Pacific'), which in turn, flow above aged equatorial and deeper recently ventilated Antarctic Intermediate waters. Little is known however about the water mass geometry changes that could have occurred during the last glacial maximum boundary conditions (about 20,000 years before the present), despite this information being critical for the assessment of potential mechanisms that have been proposed as explanations for the deglacial onset of low oxygen conditions in the area and the atmospheric CO2 increase during the same time. Here we present benthic and planktonic foraminifera stable isotope and radiocarbon data from a set of sediment cores from the Chilean continental margin covering a large -yet still limited- geographical area and depth range. Sedimentations rates were relatively high (>10 cm/kyr) precluding major caveats from bioturbation in all of our archives. The distribution of δ13C of ΣCO2 shows the presence of a very depleted (δ13C < -1‰ V-PDB) water mass overlaying more recently ventilated waters at intermediate depths as indicated by thermocline foraminifer dwellers being more depleted in 13C than the benthic species. The origin of this depleted end-member is probably upwelling from the Southern Ocean as expressed by the radiocarbon content and the large reservoir effect associated with the last glacial maximum and the beginning of the deglaciation along the margin. Our data suggest that the Tropical waters that today bath the lower latitude cores was displaced by surface waters of southern origin and therefore in line with the evidence of a latitudinal shift of the frontal systems.

  10. Radial transport processes as a precursor to particle deposition in drinking water distribution systems.

    Science.gov (United States)

    van Thienen, P; Vreeburg, J H G; Blokker, E J M

    2011-02-01

    Various particle transport mechanisms play a role in the build-up of discoloration potential in drinking water distribution networks. In order to enhance our understanding of and ability to predict this build-up, it is essential to recognize and understand their role. Gravitational settling with drag has primarily been considered in this context. However, since flow in water distribution pipes is nearly always in the turbulent regime, turbulent processes should be considered also. In addition to these, single particle effects and forces may affect radial particle transport. In this work, we present an application of a previously published turbulent particle deposition theory to conditions relevant for drinking water distribution systems. We predict quantitatively under which conditions turbophoresis, including the virtual mass effect, the Saffman lift force, and the Magnus force may contribute significantly to sediment transport in radial direction and compare these results to experimental observations. The contribution of turbophoresis is mostly limited to large particles (>50 μm) in transport mains, and not expected to play a major role in distribution mains. The Saffman lift force may enhance this process to some degree. The Magnus force is not expected to play any significant role in drinking water distribution systems. © 2010 Elsevier Ltd. All rights reserved.

  11. Insecticide-treated nets mass distribution campaign: benefits and lessons in Zambia.

    Science.gov (United States)

    Masaninga, Freddie; Mukumbuta, Nawa; Ndhlovu, Ketty; Hamainza, Busiku; Wamulume, Pauline; Chanda, Emmanuel; Banda, John; Mwanza-Ingwe, Mercy; Miller, John M; Ameneshewa, Birkinesh; Mnzava, Abraham; Kawesha-Chizema, Elizabeth

    2018-04-24

    Zambia was an early adopter of insecticide-treated nets strategy in 2001, and policy for mass distribution with long-lasting insecticidal nets (LLINs) in 2005. Since then, the country has implemented mass distribution supplemented with routine delivery through antenatal care and under five clinics in health facilities. The national targets of universal (100%) coverage and 80% utilization of LLINs have not been attained. Free mass LLIN distribution campaign in Zambia offers important lessons to inform future campaigns in the African region. This study reviewed LLIN free mass distribution campaign information derived from Zambia's national and World Health Organization Global Malaria Programme annual reports and strategic plans published between 2001 and 2016. In 2014, a nationwide mass distribution campaign in Zambia delivered all the 6.0 million LLINs in 6 out of 10 provinces in 4 months between June and September before the onset of the rainy season. Compared with 235,800 LLINs and 2.9 million LLINs distributed on a rolling basis in 2008 and 2013, respectively, the 2014 mass campaign, which distributed 6 million LLINs represented the largest one-time-nationwide LLIN distribution in Zambia. The province (Luapula) with highest malaria transmission, mostly with rural settings recorded 98-100% sleeping spaces in homes covered with LLINs. The percentage of households owning at least 1 LLIN increased from 50.9% in 2006 to 77.7% in 2015. The 2014 mass campaign involved a coordinated response with substantial investments into macro (central) and micro (district) level planning, capacity building, tracking and logistics management supported by a new non-health sector partnership landscape. Coordination of LLIN distribution and logistics benefited from the mobile phone technology to transmit "real time" data on commodity tracking that facilitated timely delivery to districts. Free mass distribution of LLINs policy was adopted in 2005 in Zambia. Consistently implemented

  12. Dynamical Mass Measurements of Contaminated Galaxy Clusters Using Support Distribution Machines

    Science.gov (United States)

    Ntampaka, Michelle; Trac, Hy; Sutherland, Dougal; Fromenteau, Sebastien; Poczos, Barnabas; Schneider, Jeff

    2018-01-01

    We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach. We create two mock catalogs from Multidark’s publicly available N-body MDPL1 simulation, one with perfect galaxy cluster membership infor- mation and the other where a simple cylindrical cut around the cluster center allows interlopers to contaminate the clusters. In the standard approach, we use a power-law scaling relation to infer cluster mass from galaxy line-of-sight (LOS) velocity dispersion. Assuming perfect membership knowledge, this unrealistic case produces a wide fractional mass error distribution, with a width E=0.87. Interlopers introduce additional scatter, significantly widening the error distribution further (E=2.13). We employ the support distribution machine (SDM) class of algorithms to learn from distributions of data to predict single values. Applied to distributions of galaxy observables such as LOS velocity and projected distance from the cluster center, SDM yields better than a factor-of-two improvement (E=0.67) for the contaminated case. Remarkably, SDM applied to contaminated clusters is better able to recover masses than even the scaling relation approach applied to uncon- taminated clusters. We show that the SDM method more accurately reproduces the cluster mass function, making it a valuable tool for employing cluster observations to evaluate cosmological models.

  13. Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

    Science.gov (United States)

    Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.

    2018-03-01

    The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236-246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the Born-Oppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.

  14. Water Distribution in the Continental and Oceanic Upper Mantle

    Science.gov (United States)

    Peslier, Anne H.

    2015-01-01

    Nominally anhydrous minerals such as olivine, pyroxene and garnet can accommodate tens to hundreds of ppm H2O in the form of hydrogen bonded to structural oxygen in lattice defects. Although in seemingly small amounts, this water can significantly alter chemical and physical properties of the minerals and rocks. Water in particular can modify their rheological properties and its distribution in the mantle derives from melting and metasomatic processes and lithology repartition (pyroxenite vs peridotite). These effects will be examined here using Fourier transform infrared spectrometry (FTIR) water analyses on minerals from mantle xenoliths from cratons, plume-influenced cratons and oceanic settings. In particular, our results on xenoliths from three different cratons will be compared. Each craton has a different water distribution and only the mantle root of Kaapvaal has evidence for dry olivine at its base. This challenges the link between olivine water content and survival of Archean cratonic mantle, and questions whether xenoliths are representative of the whole cratonic mantle. We will also present our latest data on Hawaii and Tanzanian craton xenoliths which both suggest the intriguing result that mantle lithosphere is not enriched in water when it interacts with melts from deep mantle upwellings (plumes).

  15. Coupling of mass and charge distributions for low excited nuclear fission

    International Nuclear Information System (INIS)

    Salamatin, V.S.; )

    2000-01-01

    The simple model for calculation of charge distributions of fission fragments for low exited nuclear fission from experimental mass distributions is offered. The model contains two parameters, determining amplitude of even-odd effect of charge distributions and its dependence on excitation energy. Results for reactions 233 U(n th ,f), 235 U(n th ,f), 229 Th(n th ,f), 249 Cf(n th ,f) are spent [ru

  16. Intracellular water distribution and aging as examined by X-ray microanalysis

    International Nuclear Information System (INIS)

    von Zglinicki, T.

    1988-01-01

    The results reviewed here demonstrate that 1. the distribution of dry mass as observed in frozen-dried cryosections might be used as an unbiased measure of intracellular dry mass resp. water distributions in the tissue in vivo and 2. the well-known loss of water from cells during aging is solely due to a water loss from mitochondria without changes in the water content of all other components of the cell in the case of rat liver and heart muscle. The reason for the water loss might be increased counter ion binding by membrane-bound enzymes due to decreased fluidity of the inner mitochondrial membrane with aging rather than changes of the permeability of the membrane or chemical modifications of mitochondrial proteins or DNA. It is assumed that the observed changes lead to decreased intramitochondrial diffusion of substrates and to conformational changes of enzymes. This would decrease both the velocity and the binding constants of certain energy-supplying reactions and could therefore play an important role in the aging process

  17. Does mass azithromycin distribution impact child growth and nutrition in Niger? A cluster-randomized trial.

    Directory of Open Access Journals (Sweden)

    Abdou Amza

    2014-09-01

    Full Text Available Antibiotic use on animals demonstrates improved growth regardless of whether or not there is clinical evidence of infectious disease. Antibiotics used for trachoma control may play an unintended benefit of improving child growth.In this sub-study of a larger randomized controlled trial, we assess anthropometry of pre-school children in a community-randomized trial of mass oral azithromycin distributions for trachoma in Niger. We measured height, weight, and mid-upper arm circumference (MUAC in 12 communities randomized to receive annual mass azithromycin treatment of everyone versus 12 communities randomized to receive biannual mass azithromycin treatments for children, 3 years after the initial mass treatment. We collected measurements in 1,034 children aged 6-60 months of age.We found no difference in the prevalence of wasting among children in the 12 annually treated communities that received three mass azithromycin distributions compared to the 12 biannually treated communities that received six mass azithromycin distributions (odds ratio = 0.88, 95% confidence interval = 0.53 to 1.49.We were unable to demonstrate a statistically significant difference in stunting, underweight, and low MUAC of pre-school children in communities randomized to annual mass azithromycin treatment or biannual mass azithromycin treatment. The role of antibiotics on child growth and nutrition remains unclear, but larger studies and longitudinal trials may help determine any association.

  18. Mass and chemically speciated size distribution of Prague aerosol using an aerosol dryer - The influence of air mass origin

    Czech Academy of Sciences Publication Activity Database

    Schwarz, Jaroslav; Štefancová, Lucia; Maenhaut, W.; Smolík, Jiří; Ždímal, Vladimír

    2012-01-01

    Roč. 437, OCT 15 (2012), s. 348-362 ISSN 0048-9697 R&D Projects: GA ČR GA205/09/2055; GA ČR GAP209/11/1342; GA MŠk ME 941 Grant - others:SRF GU(BE) 01S01306 Institutional support: RVO:67985858 Keywords : atmospheric aerosols * mass size distribution * chemical composition Subject RIV: DI - Air Pollution ; Quality Impact factor: 3.258, year: 2012

  19. Productivity growth and price regulation of Slovenian water distribution utilities

    Directory of Open Access Journals (Sweden)

    Jelena Zorić

    2010-06-01

    Full Text Available This paper aims to analyse the price regulation method and performance of thewater industry in Slovenia. A stochastic cost frontier model is employed to estimate and decompose the total factor productivity (TFP growth of water distribution utilities in the 1997-2003 period. The main goal is to find out whether the lack of proper incentives to improve performance has resulted in the low TFP growth of Slovenian water distribution utilities. The evidence suggests that cost inefficiencies are present in water utilities, which indicates considerable cost saving potential in the analysed industry. Technical change is found to have positively affected the TFP growth over time, while cost inefficiency levels remained essentially unchanged. Overall, the average annual TFP growth in the analysed period is estimated to be only slightly above zero, which is a relatively poor result. This can largely be contributed to the present institutional and regulatory setting that does not stimulate utilities to improve productivity. Therefore, the introduction of an independent regulatory agency and an incentive-based price regulation scheme should be seriously considered in order to enhance the performance of Slovenian water distribution utilities.

  20. Drinking Water Microbiome as a Screening Tool for Nitrification in Chloraminated Drinking Water Distribution Systems (abstract)

    Science.gov (United States)

    Many water utilities in the US using chloramine as disinfectant treatment in their distribution systems have experienced nitrification episodes, which detrimentally impact the water quality. Here, we used 16S rRNA sequencing data to generate high-resolution taxonomic profiles of...

  1. Attitude dynamics and control of a spacecraft using shifting mass distribution

    Science.gov (United States)

    Ahn, Young Tae

    Spacecraft need specific attitude control methods that depend on the mission type or special tasks. The dynamics and the attitude control of a spacecraft with a shifting mass distribution within the system are examined. The behavior and use of conventional attitude control actuators are widely developed and performing at the present time. However, the advantage of a shifting mass distribution concept can complement spacecraft attitude control, save mass, and extend a satellite's life. This can be adopted in practice by moving mass from one tank to another, similar to what an airplane does to balance weight. Using this shifting mass distribution concept, in conjunction with other attitude control devices, can augment the three-axis attitude control process. Shifting mass involves changing the center-of-mass of the system, and/or changing the moments of inertia of the system, which then ultimately can change the attitude behavior of the system. This dissertation consists of two parts. First, the equations of motion for the shifting mass concept (also known as morphing) are developed. They are tested for their effects on attitude control by showing how shifting the mass changes the spacecraft's attitude behavior. Second, a method for optimal mass redistribution is shown using a combinatorial optimization theory under constraints. It closes with a simple example demonstrating an optimal reconfiguration. The procedure of optimal reconfiguration from one mass distribution to another to accomplish attitude control has been demonstrated for several simple examples. Mass shifting could work as an attitude controller for fine-tuning attitude behavior in small satellites. Various constraints can be applied for different situations, such as no mass shift between two tanks connected by a failed pipe or total amount of shifted mass per pipe being set for the time optimum solution. Euler angle changes influenced by the mass reconfiguration are accomplished while stability

  2. Three-dimensional distributions of sewage markers in Tokyo Bay water-fluorescent whitening agents (FWAs)

    International Nuclear Information System (INIS)

    Managaki, Satoshi; Takada, Hideshige; Kim, Dong-Myung; Horiguchi, Toshihiro; Shiraishi, Hiroaki

    2006-01-01

    Three-dimensional distributions of fluorescent whitening agents (FWAs: more specifically, DSBP and DAS1), which are sewage-derived water-soluble markers, were observed in Tokyo Bay water through multi-layer sampling of water at 20 locations. In summer, FWAs predominated in the surface layers, with trace but significant concentration of FWAs in bottom water due to stratification of seawater. In winter, on the other hand, FWAs were extensively mixed into the bottom layers because of the vertical mixing of seawater. In the surface layer, FWA concentrations and the DSBP/DAS1 ratio (the concentration ratio of DSBP to DAS1) were lower in summer than in winter, suggesting more efficient photodegradation of FWAs in euphotic zones during the summer due to stronger solar radiation. Horizontally, FWAs were widely distributed over the surface layer of Tokyo Bay. Surface water with DSBP concentrations above 50 ng/L, corresponding to <200 times dilution of sewage effluent, was found to have spread up to 10 km from the coastline. In addition, an offshore decline in FWA concentrations was observed, showing a half-distance of 10-20 km. The decrease was caused by dilution by seawater of fresh water containing FWAs. The eastern part of the bay was different with respect to surface layers, with higher concentrations seen in northeastern parts. Furthermore, dispersion of combined sewer overflow (CSO)-derived water mass was observed in Tokyo Bay after heavy rain

  3. The size distribution of dissolved uranium in natural waters

    International Nuclear Information System (INIS)

    Mann, D.K.; Wong, G.T.F.

    1987-01-01

    The size distribution of dissolved uranium in natural waters is poorly known. Some fraction of dissolved uranium is known to associate with organic matter which had a wide range of molecular weights. The presence of inorganic colloidal uranium has not been reported. Ultrafiltration has been used to quantify the size distribution of a number of elements, such as dissolved organic carbon, selenium, and some trace metals, in both the organic and/or the inorganic forms. The authors have applied this technique to dissolved uranium and the data are reported here

  4. Water leakage management by district metered areas at water distribution networks.

    Science.gov (United States)

    Özdemir, Özgür

    2018-03-01

    The aim of this study is to design a district metered area (DMA) at water distribution network (WDN) for determination and reduction of water losses in the city of Malatya, Turkey. In the application area, a pilot DMA zone was built by analyzing the existing WDN, topographic map, length of pipes, number of customers, service connections, and valves. In the DMA, International Water Association standard water balance was calculated considering inflow rates and billing records. The ratio of water losses in DMAs was determined as 82%. Moreover, 3124 water meters of 2805 customers were examined while 50% of water meters were detected as faulty. This study revealed that DMA application is useful for the determination of water loss rate in WDNs and identify a cost-effective leakage reduction program.

  5. Myths and methodologies: Making sense of exercise mass and water balance.

    Science.gov (United States)

    Cheuvront, Samuel N; Montain, Scott J

    2017-09-01

    What is the topic of this review? There is a need to revisit the basic principles of exercise mass and water balance, the use of common equations and the practice of interpreting outcomes. What advances does it highlight? We propose use of the following equation as a way of simplifying exercise mass and water balance calculations in conditions where food is not consumed and waste is not excreted: ∆body mass - 0.20 g/kcal -1  = ∆body water. The relative efficacy of exercise drinking behaviours can be judged using the following equation: percentage dehydration = [(∆body mass - 0.20 g kcal -1 )/starting body mass] × 100. Changes in body mass occur because of flux in liquids, solids and gases. This knowledge is crucial for understanding metabolism, health and human water needs. In exercise science, corrections to observed changes in body mass to estimate water balance are inconsistently applied and often misinterpreted, particularly after prolonged exercise. Although acute body mass losses in response to exercise can represent a close surrogate for body water losses, the discordance between mass and water balance equivalence becomes increasingly inaccurate as more and more energy is expended. The purpose of this paper is briefly to clarify the roles that respiratory water loss, gas exchange and metabolic water production play in the correction of body mass changes for fluid balance determinations during prolonged exercise. Computations do not include waters of association with glycogen because any movement of water among body water compartments contributes nothing to water or mass flux from the body. Estimates of sweat loss from changes in body mass should adjust for non-sweat losses when possible. We propose use of the following equation as a way of simplifying the study of exercise mass and water balance: ∆body mass - 0.20 g kcal -1  = ∆body water. This equation directly controls for the influence of energy expenditure on body mass

  6. The Challenge of Providing Safe Water with an Intermittently Supplied Piped Water Distribution System

    Science.gov (United States)

    Kumpel, E.; Nelson, K. L.

    2012-12-01

    An increasing number of urban residents in low- and middle-income countries have access to piped water; however, this water is often not available continuously. 84% of reporting utilities in low-income countries provide piped water for fewer than 24 hours per day (van den Berg and Danilenko, 2010), while no major city in India has continuous piped water supply. Intermittent water supply leaves pipes vulnerable to contamination and forces households to store water or rely on alternative unsafe sources, posing a health threat to consumers. In these systems, pipes are empty for long periods of time and experience low or negative pressure even when water is being supplied, leaving them susceptible to intrusion from sewage, soil, or groundwater. Households with a non-continuous supply must collect and store water, presenting more opportunities for recontamination. Upgrading to a continuous water supply, while an obvious solution to these challenges, is currently out of reach for many resource-constrained utilities. Despite its widespread prevalence, there are few data on the mechanisms causing contamination in an intermittent supply and the frequency with which it occurs. Understanding the impact of intermittent operation on water quality can lead to strategies to improve access to safe piped water for the millions of people currently served by these systems. We collected over 100 hours of continuous measurements of pressure and physico-chemical water quality indicators and tested over 1,000 grab samples for indicator bacteria over 14 months throughout the distribution system in Hubli-Dharwad, India. This data set is used to explore and explain the mechanisms influencing water quality when piped water is provided for a few hours every 3-5 days. These data indicate that contamination occurs along the distribution system as water travels from the treatment plant to reservoirs and through intermittently supplied pipes to household storage containers, while real

  7. Modeling The GRB Host Galaxy Mass Distribution: Are GRBs Unbiased Tracers of Star Formation?

    Energy Technology Data Exchange (ETDEWEB)

    Kocevski, Daniel; /KIPAC, Menlo Park; West, Andrew A.; /UC, Berkeley, Astron. Dept. /MIT, MKI; Modjaz, Maryam; /UC, Berkeley, Astron. Dept.

    2009-08-03

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity (M-Z) relationship for galaxies, along with a sharp host metallicity cut-off suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that sub-solar metallicity cut-offs effectively limit GRBs to low stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low metallicity cut-offs of 0.1 to 0.5 Z{sub {circle_dot}} are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H){sub KK04} = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z {approx} 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  8. MODELING THE GRB HOST GALAXY MASS DISTRIBUTION: ARE GRBs UNBIASED TRACERS OF STAR FORMATION?

    International Nuclear Information System (INIS)

    Kocevski, Daniel; West, Andrew A.; Modjaz, Maryam

    2009-01-01

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low-metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity relationship for galaxies, along with a sharp host metallicity cutoff suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that subsolar metallicity cutoffs effectively limit GRBs to low-stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low-metallicity cutoffs of 0.1 to 0.5 Z sun are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H) KK04 = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z ∼ 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity-biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  9. The distribution of branched octanols between dodecane and water

    International Nuclear Information System (INIS)

    Sagert, N.H.; Lau, D.W.P.

    1985-01-01

    The distribution of four branched chain octanols, 3-ethyl-3-hexanol, 4-ethyl-3-hexanol, 2-ethyl-4-methylpentanol, and 4-octanol, has been measured between dodecane and water. Measurements were made at alcohol concentrations in the dodecane of less than 0.1 mol/dmsup(3), and as a function of temperature from 10 degrees C to 35 degrees C. From these distribution data, standard thermodynamic functions for transfer were calculated. Standard Gibbs energies of transfer from water to dodecane at 25 degrees C were in the range -14.1 to -15.l kJ/mol, whereas the standard enthalpies of transfer at 25 degrees C varied from 29 to 39 kJ/mol. Thus, the change in the standard enthalpy tends to inhibit transfer, but a large standard entropy of transfer results in dodecane being the favoured phase

  10. Apparent distribution coefficients of transuranium elements in UK coastal waters

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Pentreath, R.J.; Harvey, B.R.; Lovett, M.B.; Boggis, S.J.

    1986-01-01

    The authorized inputs of low-level radioactive waste into the Irish Sea from the British Nuclear Fuels plc reprocessing plant at Sellafield may be used to advantage to study the distribution and behaviour of artificial radionuclides in the marine environment. Apparent distribution coefficients (Ksub(d)) for the transuranium elements Np, Pu, Am and Cm have been determined by the analysis of environmental samples collected from UK coastal waters. The sampling methodology for obtaining suspended sediment-seawater Ksub(d)s by filtration is described and critically evaluated. Artefacts may be introduced in the sample collection stage. Ksub(d) values have also been determined for seabed sediment-interstitial waters and the precautions taken to preserve in-situ chemical conditions are described. Variations in Ksub(d) values are discussed in relation to distance from Sellafield, suspended load, redox conditions and oxidation state changes. (author)

  11. Water-Group Ion Distributions in the Mid-Cometosheath of Comet Halley

    Science.gov (United States)

    Huddleston, D. E.; Neugebauer, M.; Goldstein, B. E.

    1993-01-01

    In the mid-cometosheath of comet Halley (1-2x10^5 km from the nucleus) the center- of-mass plasma frame is approximately the bulk flow velocity of the cometary ions, and the Alfven wave speed is an appreciable fraction of the flow speed. Here, the peaks of the water-group ion distributions observed by the Giotto Ion Mass Spectrometer are at velocities consistently below the expected pickup speed. It is shown that this effect is consistent with the scattering of the new pickup ions onto a bispherical shell distribution. The model does not fit the data inside similar 1.2x10^5 km however, possibly as a result of the growing importance of collisions or the presence of other processes such as scattering on obliquely-propagating magnetosonic waves.

  12. Radar meteors range distribution model. II. Shower flux density and mass distribution index

    Czech Academy of Sciences Publication Activity Database

    Pecinová, Drahomíra; Pecina, Petr

    2007-01-01

    Roč. 37, č. 2 (2007), s. 107-124 ISSN 1335-1842 R&D Projects: GA ČR GA205/03/1405 Institutional research plan: CEZ:AV0Z10030501 Keywords : physics of meteors * radar meteors * range distribution Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  13. Robust Meter Network for Water Distribution Pipe Burst Detection

    OpenAIRE

    Donghwi Jung; Joong Hoon Kim

    2017-01-01

    A meter network is a set of meters installed throughout a water distribution system to measure system variables, such as the pipe flow rate and pressure. In the current hyper-connected world, meter networks are being exposed to meter failure conditions, such as malfunction of the meter’s physical system and communication system failure. Therefore, a meter network’s robustness should be secured for reliable provision of informative meter data. This paper introduces a multi-objective optimal me...

  14. The octanol/water distribution of mercury compounds

    International Nuclear Information System (INIS)

    Halbach, S.

    1985-01-01

    Lipophilicity plays an important role in the biological action of mercurials. The distribution of one inorganic and five organic mercury compounds was determined in an n-octanol/water system. Lipophilicity decreased in the order CH 3 HgCl, bromomercurihydroxypropane HgCl 2 chlormerodrin, p-chloromercuribenzoic acid (PCMB), p-chloromercuriphenylsulfonic acid (PCMBS). The toxicity of mercurials, as reported in the literature, appears to parallel their lipophilicity. (orig.)

  15. Contamination potential of drinking water distribution network biofilms.

    Science.gov (United States)

    Wingender, J; Flemming, H C

    2004-01-01

    Drinking water distribution system biofilms were investigated for the presence of hygienically relevant microorganisms. Early biofilm formation was evaluated in biofilm reactors on stainless steel, copper, polyvinyl chloride (PVC) and polyethylene coupons exposed to unchlorinated drinking water. After 12 to 18 months, a plateau phase of biofilm development was reached. Surface colonization on the materials ranged between 4 x 10(6) and 3 x 10(7) cells/cm2, with heterotrophic plate count (HPC) bacteria between 9 x 10(3) and 7 x 10(5) colony-forming units (cfu)/cm2. Established biofilms were investigated in 18 pipe sections (2 to 99 years old) cut out from distribution pipelines. Materials included cast iron, galvanized steel, cement and PVC. Colonization ranged from 4 x 10(5) to 2 x 10(8) cells/cm2, HPC levels varied between 1 and 2 x 10(5) cfu/cm2. No correlation was found between extent of colonization and age of the pipes. Using cultural detection methods, coliform bacteria were rarely found, while Escherichia coli, Pseudomonas aeruginosa and Legionella spp. were not detected in the biofilms. In regular operation, distribution system biofilms do not seem to be common habitats for pathogens. However, nutrient-leaching materials like rubber-coated valves were observed with massive biofilms which harboured coliform bacteria contaminating drinking water.

  16. Langevin description of mass distributions of fragments originating from the fission of excited nuclei

    International Nuclear Information System (INIS)

    Vanin, D.V.; Nadtochy, P.N.; Adeev, G.D.; Kosenko, G.I.

    2000-01-01

    A stochastic approach to fission dynamics is proposed. The approach, which is based on Langevin equations, is used to calculate the mass distributions of fragments originating from the fission of excited nuclei. The effect of viscosity and light-particle emission on the variance of mass distributions is studied. The results of the calculations based on the above approach reveal that, in order to obtain a simultaneous description of mass-distribution parameters and the multiplicities of prescission particles, it is necessary to use sufficiently large values of nuclear viscosity both for the one-body and for the two-body viscosity mechanism, anomalously large values of the viscosity coefficient being required in the latter case

  17. Mass and angular distributions of the reaction products in heavy ion collisions

    Science.gov (United States)

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Kayumov, B. M.; Tashkhodjaev, R. B.

    2018-05-01

    The optimal reactions and beam energies leading to synthesize superheavy elements is searched by studying mass and angular distributions of fission-like products in heavy-ion collisions since the evaporation residue cross section consists an ignorable small part of the fusion cross section. The intensity of the yield of fission-like products allows us to estimate the probability of the complete fusion of the interacting nuclei. The overlap of the mass and angular distributions of the fusion-fission and quasifission products causes difficulty at estimation of the correct value of the probability of the compound nucleus formation. A study of the mass and angular distributions of the reaction products is suitable key to understand the interaction mechanism of heavy ion collisions.

  18. Search for Z' --> e+ e- using dielectron mass and angular distribution.

    Science.gov (United States)

    Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cresciolo, F; Cruz, A; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciveres, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giokaris, N; Giolo, K; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Heijboer, A; Heinemann, B; Heinrich, J; Herndon, M; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Mitra, A; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spezziga, M; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

    2006-06-02

    We search for Z' bosons in dielectron events produced in pp collisions at square root of s = 1.96 TeV, using 0.45 fb(-1) of data accumulated with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. To identify the Z' --> e+ e- signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z' mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z', as well as on the contact-interaction mass scales for different helicity structure scenarios.

  19. Nitrate, Nitrite, and Ammonium Variability in Drinking Water Distribution Systems.

    Science.gov (United States)

    Schullehner, Jörg; Stayner, Leslie; Hansen, Birgitte

    2017-03-09

    Accurate assessments of exposure to nitrate in drinking water is a crucial part of epidemiological studies investigating long-term adverse human health effects. However, since drinking water nitrate measurements are usually collected for regulatory purposes, assumptions on (1) the intra-distribution system variability and (2) short-term (seasonal) concentration variability have to be made. We assess concentration variability in the distribution system of nitrate, nitrite, and ammonium, and seasonal variability in all Danish public waterworks from 2007 to 2016. Nitrate concentrations at the exit of the waterworks are highly correlated with nitrate concentrations within the distribution net or at the consumers' taps, while nitrite and ammonium concentrations are generally lower within the net compared with the exit of the waterworks due to nitrification. However, nitrification of nitrite and ammonium in the distribution systems only results in a relatively small increase in nitrate concentrations. No seasonal variation for nitrate, nitrite, or ammonium was observed. We conclude that nitrate measurements taken at the exit of the waterworks are suitable to calculate exposures for all consumers connected to that waterworks and that sampling frequencies in the national monitoring programme are sufficient to describe temporal variations in longitudinal studies.

  20. 210Pb and 226Ra distributions in the circumpolar waters

    International Nuclear Information System (INIS)

    Chung, Y.

    1981-01-01

    210 Pb and 226 Ra profiles have been measured at five GEOSECS stations in the Circumpolar region. These profiles show that 226 Ra is quite uniformly distributed throughout the Circumpolar region, with slightly lower activities in surface waters, while 210 Pb varies with depth as well as location or area. There is a subsurface 210 Pb maximum which matches the oxygen minimum in depth and roughly correlates with the temperature and salinity maxima. This 210 Pb maximum has its highest concentrations in the Atlantic sector and appears to originate near the South Sandwich Islands northeast of the Weddell Sea. Concentrations in this maximum decrease toward the Indian Ocean sector and then become fairly constant along the easterly Circumpolar Current. Relative to 226 Ra, the activity of 210 Pb is deficient in the entire water column of the Circumpolar waters. The deficiency increases from the depth of the 210 Pb maximum toward the bottom, and the 210 Pb/ 226 Ra activity ratio is lowest in the Antarctic Bottom Water, indicating a rapid removal of Pb by particulate scavenging in the bottom layer and/or a short mean residence time of the Antarctic Bottom Water in the Circumpolar region. 226 Ra is essentially linearly correlated with silica and barium in the Circumpolar waters. However, close examination of the vertical profiles reveals that Ba and Si are more variable than 226 Ra in this region. (orig.)

  1. The optimisation of a water distribution system using Bentley WaterGEMS software

    Directory of Open Access Journals (Sweden)

    Świtnicka Karolina

    2017-01-01

    Full Text Available The proper maintenance of water distribution systems (WDSs requires from operators multiple actions in order to ensure optimal functioning. Usually, all requirements should be adjusted simultaneously. Therefore, the decision-making process is often supported by multi-criteria optimisation methods. Significant improvements of exploitation conditions of WDSs functioning can be achieved by connecting small water supply networks into group systems. Among many potential tools supporting advanced maintenance and management of WDSs, significant improvements have tools that can find the optimal solution by the implemented mechanism of metaheuristic methods, such as the genetic algorithm. In this paper, an exemplary WDS functioning optimisation is presented, in relevance to a group water supply system. The action range of optimised parameters included: maximisation of water flow velocity, regulation of pressure head, minimisation of water retention time in a network (water age and minimisation of pump energy consumption. All simulations were performed in Bentley WaterGEMS software.

  2. Condensation driven water hammer studies for feedwater distribution pipe

    International Nuclear Information System (INIS)

    Savolainen, S.; Katajala, S.; Elsing, B.; Nurkkala, P.; Hoikkanen, J.; Pullinen, J.; Logvinov, S.A.; Trunov, N.B.; Sitnik, J.K.

    1997-01-01

    Imatran Voima Oy, IVO, operates two VVER 440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of the feed water distribution (FWD) pipes were observed in 1989. In closer examinations FWD-pipe T-connection turned out to suffer from severe erosion corrosion damages. Similar damages have been found also in other VVER 440 type NPPs. In 1994 the first new FWD-pipe was replaced and in 1996 extensive water hammer experiments were carried out together with EDO Gidropress in Podolsk. After the first phase of the experiments some fundamental changes were made to the construction of the FWD-pipe. The object of this paper is to give short insight to the design of the new FWD-pipe concentrating on water hammer experiments. (orig.)

  3. Condensation driven water hammer studies for feedwater distribution pipe

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, S.; Katajala, S.; Elsing, B.; Nurkkala, P.; Hoikkanen, J. [Imatran Voima Oy, Vantaa (Finland); Pullinen, J. [IVO Power Engineering Ltd., Vantaa (Finland); Logvinov, S.A.; Trunov, N.B.; Sitnik, J.K. [EDO Gidropress (Russian Federation)

    1997-12-31

    Imatran Voima Oy, IVO, operates two VVER 440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of the feed water distribution (FWD) pipes were observed in 1989. In closer examinations FWD-pipe T-connection turned out to suffer from severe erosion corrosion damages. Similar damages have been found also in other VVER 440 type NPPs. In 1994 the first new FWD-pipe was replaced and in 1996 extensive water hammer experiments were carried out together with EDO Gidropress in Podolsk. After the first phase of the experiments some fundamental changes were made to the construction of the FWD-pipe. The object of this paper is to give short insight to the design of the new FWD-pipe concentrating on water hammer experiments. (orig.).

  4. Condensation driven water hammer studies for feedwater distribution pipe

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, S; Katajala, S; Elsing, B; Nurkkala, P; Hoikkanen, J [Imatran Voima Oy, Vantaa (Finland); Pullinen, J [IVO Power Engineering Ltd., Vantaa (Finland); Logvinov, S A; Trunov, N B; Sitnik, J K [EDO Gidropress (Russian Federation)

    1998-12-31

    Imatran Voima Oy, IVO, operates two VVER 440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of the feed water distribution (FWD) pipes were observed in 1989. In closer examinations FWD-pipe T-connection turned out to suffer from severe erosion corrosion damages. Similar damages have been found also in other VVER 440 type NPPs. In 1994 the first new FWD-pipe was replaced and in 1996 extensive water hammer experiments were carried out together with EDO Gidropress in Podolsk. After the first phase of the experiments some fundamental changes were made to the construction of the FWD-pipe. The object of this paper is to give short insight to the design of the new FWD-pipe concentrating on water hammer experiments. (orig.).

  5. Asymmetry distributions and mass effects in dijet-events at a polarized HERA

    CERN Document Server

    Maul, M; Mirkes, E; Rädel, G

    1998-01-01

    The asymmetry distributions for several kinematic variables are considered for finding a systematic way to maximize the signal for the extraction of the polarized gluon density. The relevance of mass effects for the corresponding dijet cross section is discussed and the different approximations for including mass effects are compared. We also compare via the programs PEPSI and MEPJET two different Monte Carlo (MC) approaches for simulating the expected signal in the dijet asymmetry at a polarized HERA.

  6. Gas puff radiation performance as a function of radial mass distribution

    International Nuclear Information System (INIS)

    Coleman, Philip L.; Krishnan, Mahadevan; Prasad, Rahul; Qi, Niansheng; Waisman, Eduardo; Failor, B.H.; Levine, J.S.; Sze, H.

    2002-01-01

    The basic concept of a z-pinch, that JxB forces implode a shell of mass, creating a hot dense plasma on-axis, is coming under closer scrutiny. Wire arrays may start with an initial cold mass in a near 'ideal' shell, but in fact they appear to develop complex radial mass distributions well before the final x-ray output. We consider here the situation for gas puff z-pinches. While the ideal of a gas 'shell' has been the nominal objective for many years, detailed measurements of gas flow show that nozzles used for plasma radiation sources (PRS) also have complex radial distributions. In particular, there are significant data showing that the best x-ray yield comes from the least shell-like distributions. Recent experiments on the Double Eagle generator with argon have further enhanced this view. For those tests with a double 'shell' nozzle, there was a factor of almost 4 increase in yield when the relative mass (outer:inner) in the two shells was changed from 2:1 to less than 1:1. We suggest the following explanation. A configuration with most of its mass at large radii is subject to severe disruption by instabilities during the implosion. A more continuous radial mass distribution with dρ/dr < 0 may mitigate instability development (via the 'snowplow stabilization' mechanism) and thus enhance the thermalization of the kinetic energy of the imploding mass. In addition, the appropriate balance of outer to inner mass maximizes the formation of a strong shock in the core of the pinch that heats the plasma and leads to x-ray emission

  7. The distribution of mass in the planetary system and solar nebulae

    International Nuclear Information System (INIS)

    Weidenschilling, S.J.

    1977-01-01

    A model 'solar nebula' is constructed by adding the solar complement of light elements to each planet, using recent models of planetary compositions. Uncertainties in this approach are estimated. The computed surface density varies approximately as rsup(-3/2). Mercury, Mars and the asteroid belt are anomalously low in mass, but processes exist which would preferentially remove matter from these regions. Planetary masses and compositions are generally consistent with a monotonic density distribution in the primordial solar nebula. (Auth.)

  8. Surface micro-distributions of pigment and the relation between smearing and local mass distribution

    International Nuclear Information System (INIS)

    Buelow, K.; Kristiansson, P.; Larsson, T.; Malmberg, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

    2001-01-01

    In this work, the process of smearing and its time evolution have been investigated. When smearing occurs, the print is removed from the printed paper and colours other parts of the paper or the printing press and destroys the final product. To study the re-distribution of ink, cyan ink with Cu as a tracer in the coloured pigment has been used. Non-printed paper has been pressed against the paper, 1 and 5 s after the printing. The micro-distributions of ink on both printed and non-printed papers have then been studied using particle-induced X-ray emission (PIXE). Basis weight was measured with the off-axis scanning transmission ion microscopy (STIM) technique and this data was correlated with the data from the print. One conclusion is that the process of smearing is not dependent on the shape of the pigment distribution, i.e. copper, or the content of copper in a specific pixel. On the contrary, the smearing was found to be related to the structure of the paper and that it mainly occurs where the paper is thicker

  9. Vibration Analysis of Inclined Laminated Composite Beams under Moving Distributed Masses

    Directory of Open Access Journals (Sweden)

    E. Bahmyari

    2014-01-01

    Full Text Available The dynamic response of laminated composite beams subjected to distributed moving masses is investigated using the finite element method (FEM based on the both first-order shear deformation theory (FSDT and the classical beam theory (CLT. Six and ten degrees of freedom beam elements are used to discretize the CLT and FSDT equations of motion, respectively. The resulting spatially discretized beam governing equations including the effect of inertial, Coriolis, and centrifugal forces due to moving distributed mass are evaluated in time domain by applying Newmark’s scheme. The presented approach is first validated by studying its convergence behavior and comparing the results with those of existing solutions in the literature. Then, the effect of incline angle, mass, and velocity of moving body, layer orientation, load length, and inertial, Coriolis, and centrifugal forces due to the moving distributed mass and friction force between the beam and the moving distributed mass on the dynamic behavior of inclined laminated composite beams are investigated.

  10. Mass resolved angular distribution of fission products in 20Ne + 232Th reaction

    International Nuclear Information System (INIS)

    Tripathi, R.; Sodaye, S.; Sudarshan, K.; Kumar, Amit; Guin, R.

    2011-01-01

    Mass resolved angular distribution of fission products was measured in 20 Ne + 232 Th reaction at beam energy of 120 MeV. A preliminary analysis of the angular distribution data of fission products shows higher average anisotropy compared to that calculated using statistical theory. A signature of rise in anisotropy near symmetry, as reported in earlier studies in literature, is also seen. Further study is in progress to get more detailed information about the contribution from non-compound nucleus fission and dependence of angular anisotropy on asymmetry of mass division

  11. Subchannel measurements of the equilibrium quality and mass flux distribution in a rod bundle

    International Nuclear Information System (INIS)

    Lahey, R.T. Jr.

    1986-01-01

    An experiment was performed to measure the equilibrium subchannel void and mass flux distribution in a simulated BWR rod bundle. These new equilibrium subchannel data are unique and represent an excellent basis for subchannel ''void drift'' model development and assessment. Equilibrium subchannel void and mass flux distributions have been determined from the data presented herein. While the form of these correlations agree with the results of previous theoretical investigations, they should be generalized with caution since the current data base has been taken at only one (low) system pressure. Clearly there is a need for equilibrium subchannel data at higher system pressures if mechanistic subchannel models are to be developed

  12. The effect of nuclear gas distribution on the mass determination of supermassive black holes

    Science.gov (United States)

    Mejía-Restrepo, J. E.; Lira, P.; Netzer, H.; Trakhtenbrot, B.; Capellupo, D. M.

    2018-01-01

    Supermassive black holes reside in the nuclei of most galaxies. During their active episodes, black holes are powered by accretion discs where gravitational energy is converted into radiation1. Accurately determining black hole masses is key to understand how the population evolves over time and how the black holes relate to their host galaxies2-4. Beyond the local universe, z ≳ 0.2, the mass is commonly estimated assuming a virialized motion of gas in the close vicinity of the active black holes, traced through broad emission lines5,6. However, this procedure has uncertainties associated with the unknown distribution of the gas clouds. Here, we show that the black hole masses derived from the properties of the accretion disk and virial mass estimates differ by a factor that is inversely proportional to the width of the broad emission lines. This leads to virial mass misestimations up to a factor of six. Our results suggest that a planar gas distribution that is inclined with respect to the line of sight may account for this effect. However, radiation pressure effects on the distribution of gas can also reproduce our results. Regardless of the physical origin, our findings contribute to mitigating the uncertainties in current black hole mass estimations and, in turn, will help us to better understand the evolution of distant supermassive black holes and their host galaxies.

  13. Black sea annual and inter-annual water mass variations from space

    DEFF Research Database (Denmark)

    Yildiz, H.; Andersen, Ole Baltazar; Simav, M.

    2011-01-01

    influenced by the leakage of hydrological signals from the surrounding land. After applying the corresponding correction, we found a good agreement with water mass variations derived from steric-corrected satellite altimetry observations. Both GRACE and altimetry show significant annual water mass variations......This study evaluates the performance of two widely used GRACE solutions (CNES/GRGS RL02 and CSR RL04) in deriving annual and inter-annual water mass variations in the Black Sea for the period 2003–2007. It is demonstrated that the GRACE derived water mass variations in the Black Sea are heavily...

  14. Measurement of mass distribution of U-235 fission products in the intermediate neutron region

    International Nuclear Information System (INIS)

    Nakagomi, Yoshihiro; Kobayashi, Shohei; Yamamoto, Shuji; Kanno, Ikuo; Wakabayashi, Hiroaki.

    1982-01-01

    The mass distribution and the momentum distribution of U-235 fission products in the intermediate neutron region were measured by using a combination system of the Yayoi intermediate neutron column and an electron linear accelerator. The double energy measurement method was applied. A fission chamber, which consists of an enriched uranium target and two Si surface barrier detectors, was used for the measurement of the neutrons with energy above 1.3 eV. The linear accelerator was operated at the repetition rate of 100 Hz and the pulse width of 10 ns. The data obtained by the two-dimensional pulse height analysis were analyzed by the Schmitt's method. The preliminary results of the mass distribution and the momentum distribution of fission fragments were obtained. (Kato, T.)

  15. Mass exchange and angular distribution in a dynamical treatment of heavy ion collisions

    International Nuclear Information System (INIS)

    Ngo, C.; Hofmann, H.

    1977-01-01

    One presents a first numerical computation of the absolute value of the double differential cross section as a function of mass asymmetry and detection angle including a dynamical coupling between relative motion and mass asymmetry. One applies it to the 63 Cu+ 197 Au experiment at two different energies. The equation of motion used is a Fokker-Planck equation for distribution function in classical phase space. The coefficients needed are those known from classical model calculations, besides a friction coefficient introduced for the mass asymmetry degree. Encouraging agreement between the calculated and experimental curves is found

  16. Water masses transform at mid-depths over the Antarctic Continental Slope

    Science.gov (United States)

    Mead Silvester, Jess; Lenn, Yueng-Djern; Polton, Jeffrey; Phillips, Helen E.; Morales Maqueda, Miguel

    2017-04-01

    The Meridional Overturning Circulation (MOC) controls the oceans' latitudinal heat distribution, helping to regulate the Earth's climate. The Southern Ocean is the primary place where cool, deep waters return to the surface to complete this global circulation. While water mass transformations intrinsic to this process predominantly take place at the surface following upwelling, recent studies implicate vertical mixing in allowing transformation at mid-depths over the Antarctic continental slope. We deployed an EM-Apex float near Elephant Island, north of the Antarctic Peninsula's tip, to profile along the slope and use potential vorticity to diagnose observed instabilities. The float captures direct heat exchange between a lens of Upper Circumpolar Deep Water (UCDW) and surrounding Lower Circumpolar Deep Waters (LCDW) at mid-depths and over the course of several days. Heat fluxes peak across the top and bottom boundaries of the UCDW lens and peak diffusivities across the bottom boundary are associated with shear instability. Estimates of diffusivity from shear-strain finestructure parameterisation and heat fluxes are found to be in reasonable agreement. The two-dimensional Ertel potential vorticity is elevated both inside the UCDW lens and along its bottom boundary, with a strong contribution from the shear term in these regions and instabilities are associated with gravitational and symmetric forcing. Thus, shear instabilities are driving turbulent mixing across the lower boundary between these two water masses, leading to the observed heat exchange and transformation at mid-depths over the Antarctic continental slope. This has implications for our understanding of the rates of upwelling and ocean-atmosphere exchanges of heat and carbon at this critical location.

  17. A mass conservative numerical solution of vertical water flow and mass transport equations in unsaturated porous media

    International Nuclear Information System (INIS)

    Lim, S.C.; Lee, K.J.

    1993-01-01

    The Galerkin finite element method is used to solve the problem of one-dimensional, vertical flow of water and mass transport of conservative-nonconservative solutes in unsaturated porous media. Numerical approximations based on different forms of the governing equation, although they are equivalent in continuous forms, can result in remarkably different solutions in an unsaturated flow problem. Solutions given by a simple Galerkin method based on the h-based Richards equation yield a large mass balance error and an underestimation of the infiltration depth. With the employment of the ROMV (restoration of main variable) concept in the discretization step, the mass conservative numerical solution algorithm for water flow has been derived. The resulting computational schemes for water flow and mass transport are applied to sandy soil. The ROMV method shows good mass conservation in water flow analysis, whereas it seems to have a minor effect on mass transport. However, it may relax the time-step size restriction and so ensure an improved calculation output. (author)

  18. Steam Generator control in Nuclear Power Plants by water mass inventory

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States); Doster, J. Michael [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)], E-mail: doster@eos.ncsu.edu; Mayo, Charles W. [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)

    2008-04-15

    Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.

  19. Steam Generator control in Nuclear Power Plants by water mass inventory

    International Nuclear Information System (INIS)

    Dong Wei; Doster, J. Michael; Mayo, Charles W.

    2008-01-01

    Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators

  20. Air-sea fluxes and satellite-based estimation of water masses formation

    Science.gov (United States)

    Sabia, Roberto; Klockmann, Marlene; Fernandez-Prieto, Diego; Donlon, Craig

    2015-04-01

    Recent work linking satellite-based measurements of sea surface salinity (SSS) and sea surface temperature (SST) with traditional physical oceanography has demonstrated the capability of generating routinely satellite-derived surface T-S diagrams [1] and analyze the distribution/dynamics of SSS and its relative surface density with respect to in-situ measurements. Even more recently [2,3], this framework has been extended by exploiting these T-S diagrams as a diagnostic tool to derive water masses formation rates and areas. A water mass describes a water body with physical properties distinct from the surrounding water, formed at the ocean surface under specific conditions which determine its temperature and salinity. The SST and SSS (and thus also density) at the ocean surface are largely determined by fluxes of heat and freshwater. The surface density flux is a function of the latter two and describes the change of the density of seawater at the surface. To obtain observations of water mass formation is of great interest, since they serve as indirect observations of the thermo-haline circulation. The SSS data which has become available through the SMOS [4] and Aquarius [5] satellite missions will provide the possibility of studying also the effect of temporally-varying SSS fields on water mass formation. In the present study, the formation of water masses as a function of SST and SSS is derived from the surface density flux by integrating the latter over a specific area and time period in bins of SST and SSS and then taking the derivative of the total density flux with respect to density. This study presents a test case using SMOS SSS, OSTIA SST, as well as Argo ISAS SST and SSS for comparison, heat fluxes from the NOCS Surface Flux Data Set v2.0, OAFlux evaporation and CMORPH precipitation. The study area, initially referred to the North Atlantic, is extended over two additional ocean basins and the study period covers the 2011-2012 timeframe. Yearly, seasonal

  1. Quantitative determination and monitoring of water distribution in Aespoe granite

    International Nuclear Information System (INIS)

    Zimmer, U.

    1998-01-01

    To identify possible zones of two-phase-flow and the extension of the excavation disturbed zone, geoelectric measurements are conducted in the ZEDEX- and the DEMO-tunnel. The electric resistivity of a hard rock is usually determined by its water content, its water salinity and its porosity structure. By calibration measurements of the resistivity on rocks with well known water content, a relation between resistivity and water content for Aespoe granite is determined. This relation is used to correlate the in-situ resistivity with the water content of the rock. To determine the in-situ resistivity between the ZEDEX- and the DEMO-tunnel an electrode array of nearly 300 electrodes was installed along the tunnel walls and in one borehole. With a semiautomatic recording unit which is operated by a telephone connection from the GRS-office in Braunschweig/Germany, the resistivity is monitored between and around the tunnels. To correlate the resistivity with the water content, the measured apparent resistivity has to be converted into a resistivity model of the underground. Since many thin water bearing fractures complicate this inversion process, the accuracy and resolution of the different inversion programs are checked before their application to the data. It was found that an acceptable quantitative reconstruction of the resistivity requires the integration of geometric information about the fracture zones into the inversion process. For a rough estimation of the position of possible fracture zones, a simple inversion without any geometric boundary conditions can be used. Since the maximum investigation area is limited along a single tunnel for profile measurements, tomographic measurements were also applied to estimate the resistivity distribution between the ZEDEX- and the DEMO-tunnel. These tomographic measurements have a lower resolution than the profile measurements due to the required large computer power, but result in reconstructions that give an estimate of

  2. Applications of Graph Spectral Techniques to Water Distribution Network Management

    Directory of Open Access Journals (Sweden)

    Armando di Nardo

    2018-01-01

    Full Text Available Cities depend on multiple heterogeneous, interconnected infrastructures to provide safe water to consumers. Given this complexity, efficient numerical techniques are needed to support optimal control and management of a water distribution network (WDN. This paper introduces a holistic analysis framework to support water utilities on the decision making process for an efficient supply management. The proposal is based on graph spectral techniques that take advantage of eigenvalues and eigenvectors properties of matrices that are associated with graphs. Instances of these matrices are the adjacency matrix and the Laplacian, among others. The interest for this application is to work on a graph that specifically represents a WDN. This is a complex network that is made by nodes corresponding to water sources and consumption points and links corresponding to pipes and valves. The aim is to face new challenges on urban water supply, ranging from computing approximations for network performance assessment to setting device positioning for efficient and automatic WDN division into district metered areas. It is consequently created a novel tool-set of graph spectral techniques adapted to improve main water management tasks and to simplify the identification of water losses through the definition of an optimal network partitioning. Two WDNs are used to analyze the proposed methodology. Firstly, the well-known network of C-Town is investigated for benchmarking of the proposed graph spectral framework. This allows for comparing the obtained results with others coming from previously proposed approaches in literature. The second case-study corresponds to an operational network. It shows the usefulness and optimality of the proposal to effectively manage a WDN.

  3. Reliability analysis of water distribution systems under uncertainty

    International Nuclear Information System (INIS)

    Kansal, M.L.; Kumar, Arun; Sharma, P.B.

    1995-01-01

    In most of the developing countries, the Water Distribution Networks (WDN) are of intermittent type because of the shortage of safe drinking water. Failure of a pipeline(s) in such cases will cause not only the fall in one or more nodal heads but also the poor connectivity of source with various demand nodes of the system. Most of the previous works have used the two-step algorithm based on pathset or cutset approach for connectivity analysis. The computations become more cumbersome when connectivity of all demand nodes taken together with that of supply is carried out. In the present paper, network connectivity based on the concept of Appended Spanning Tree (AST) is suggested to compute global network connectivity which is defined as the probability of the source node being connected with all the demand nodes simultaneously. The concept of AST has distinct advantages as it attacks the problem directly rather than in an indirect way as most of the studies so far have done. Since the water distribution system is a repairable one, a general expression for pipeline avialability using the failure/repair rate is considered. Furthermore, the sensitivity of global reliability estimates due to the likely error in the estimation of failure/repair rates of various pipelines is also studied

  4. Water Pressure Distribution on a Twin-Float Seaplane

    Science.gov (United States)

    Thompson, F L

    1930-01-01

    This is the second of a series of investigations to determine water pressure distribution on various types of seaplane floats and hulls, and was conducted on a twin-float seaplane. It consisted of measuring water pressures and accelerations on a TS-1 seaplane during numerous landing and taxiing maneuvers at various speeds and angles. The results show that water pressures as great as 10 lbs. per sq. in.may occur at the step in various maneuvers and that pressures of approximately the same magnitude occur at the stern and near the bow in hard pancake landings with the stern way down. At the other parts of the float the pressures are less and are usually zero or slightly negative for some distance abaft the step. A maximum negative pressure of 0.87 lb. Per square inch was measured immediately abaft the step. The maximum positive pressures have a duration of approximately one-twentieth to one-hundredth second at any given location and are distributed over a very limited area at any particular instant.

  5. Analysis of the tropospheric water distribution during FIRE 2

    Science.gov (United States)

    Westphal, Douglas L.

    1993-01-01

    The Penn State/NCAR mesoscale model, as adapted for use at ARC, was used as a testbed for the development and validation of cloud models for use in General Circulation Models (GCM's). This modeling approach also allows us to intercompare the predictions of the various cloud schemes within the same dynamical framework. The use of the PSU/NCAR mesoscale model also allows us to compare our results with FIRE-II (First International Satellite Cloud Climatology Project Regional Experiment) observations, instead of climate statistics. Though a promising approach, our work to date revealed several difficulties. First, the model by design is limited in spatial coverage and is only run for 12 to 48 hours at a time. Hence the quality of the simulation will depend heavily on the initial conditions. The poor quality of upper-tropospheric measurements of water vapor is well known and the situation is particularly bad for mid-latitude winter since the coupling with the surface is less direct than in summer so that relying on the model to spin-up a reasonable moisture field is not always successful. Though one of the most common atmospheric constituents, water vapor is relatively difficult to measure accurately, especially operationally over large areas. The standard NWS sondes have little sensitivity at the low temperatures where cirrus form and the data from the GOES 6.7 micron channel is difficult to quantify. For this reason, the goals of FIRE Cirrus II included characterizing the three-dimensional distribution of water vapor and clouds. In studying the data from FIRE Cirrus II, it was found that no single special observation technique provides accurate regional distributions of water vapor. The Raman lidar provides accurate measurements, but only at the Hub, for levels up to 10 km, and during nighttime hours. The CLASS sondes are more sensitive to moisture at low temperatures than are the NWS sondes, but the four stations only cover an area of two hundred kilometers on a side

  6. Catalytic Enzyme-Based Methods for Water Treatment and Water Distribution System Decontamination. 1. Literature Survey

    Science.gov (United States)

    2006-06-01

    best examples of this is glucose isomerase, which has been used in the commercial production of high fructose corn syrup (HFCS) since 1967.230 Most...EDGEWOOD CHEMICAL BIOLOGICAL CENTER U.S. ARMY RESEARCH, DEVELOPMENT AND ENGINEERING COMMAND ECBC-TR-489 CATALYTIC ENZYME-BASED METHODS FOR WATER ...TREATMENT AND WATER DISTRIBUTION SYSTEM DECONTAMINATION 1. LITERATURE SURVEY Joseph J. DeFrank RESEARCH AND TECHNOLOGY DIRECTORATE June 2006 Approved for

  7. In-situ Mass Distribution Quotient (iMDQ) - A New Factor to Compare Bioavailability of Pesticides in Soils?

    Science.gov (United States)

    Schroll, R.; Folberth, C.; Scherb, H.; Suhadolc, M.; Munch, J. C.

    2009-04-01

    Aim of this work was the development of a new non-biological factor to determine microbial in-situ bioavailability of chemicals in soils. Pesticide residues were extracted from ten highly different agricultural soils that had been incubated with the 14C-herbicide isoproturon (IPU) under comparable soil conditions (water tension - 15 kPa; soil density 1.3 g cm 3). Two different pesticide extraction approaches were compared: (i) 14C-Pesticide residues were measured in the pore water (PW) which was extracted from soil by centrifugation; (ii) 14C-Pesticide residues were extracted from soil samples with an excess of water (EEW). We introduce the pesticide's in-situ mass distribution quotient (iMDQ) as a measure for pesticide bioavailability, which is calculated as a quotient of adsorbed and dissolved chemical amounts for both approaches (iMDQPW, iMDQEEW). Pesticide mineralization in soils served as a reference for real microbial availability. A highly significant correlation between iMDQPW and mineralization showed that pore water extraction is adequate to assess IPU bioavailability. In contrast, no correlation exists between IPU mineralization and its extractability from soil with an excess of water. Therefore, it can be concluded that soil equilibration at comparable conditions and subsequent pore water extraction is vital for a isoproturon bioavailability ranking of soils.

  8. Physical conditions, dynamics and mass distribution in the center of the galaxy

    Science.gov (United States)

    Genzel, R.; Townes, C. H.

    1987-01-01

    Investigations of the central 10 pc of the Galaxy, and conclusions on energetics, dynamics, and mass distribution derived from X and gamma ray measurements and from infrared and microwave studies, especially from spectroscopy, high resolution imaging, and interferometry are reviewed. Evidence for and against a massive black hole is analyzed.

  9. The dijet mass spectrum and angular distributions with the D0 detector

    International Nuclear Information System (INIS)

    Abachi, S.

    1996-07-01

    We present preliminary results from an analysis of dijet data collected during the 1994-95 Tevatron Collider run with an integrated luminosity of 91 pb -1 . Measurements of dijet mass spectra and dijet angular distributions in anti pp collisions at √s- = 1.8 TeV are compared with next-to-leading order QCD theory

  10. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    Energy Technology Data Exchange (ETDEWEB)

    Chempath, Shaji [Los Alamos National Laboratory; Pratt, Lawrence R [TULANE UNIV

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  11. Analysis for mass distribution of proton-induced reactions in intermediate energy range

    CERN Document Server

    Xiao Yu Heng

    2002-01-01

    The mass and charge distribution of residual products produced in the spallation reactions needs to be studied, because it can provide useful information for the disposal of nuclear waste and residual radioactivity generated by the spallation neutron target system. In present work, the Many State Dynamical Model (MSDM) is based on the Cascade-Exciton Model (CEM). The authors use it to investigate the mass distribution of Nb, Au and Pb proton-induced reactions in energy range from 100 MeV to 3 GeV. The agreement between the MSDM simulations and the measured data is good in this energy range, and deviations mainly show up in the mass range of 90 - 150 for the high energy proton incident upon Au and Pb

  12. The link between the baryonic mass distribution and the rotation curve shape

    Science.gov (United States)

    Swaters, R. A.; Sancisi, R.; van der Hulst, J. M.; van Albada, T. S.

    2012-09-01

    The observed rotation curves of disc galaxies, ranging from late-type dwarf galaxies to early-type spirals, can be fitted remarkably well simply by scaling up the contributions of the stellar and H I discs. This 'baryonic scaling model' can explain the full breadth of observed rotation curves with only two free parameters. For a small fraction of galaxies, in particular early-type spiral galaxies, H I scaling appears to fail in the outer parts, possibly due to observational effects or ionization of H I. The overall success of the baryonic scaling model suggests that the well-known global coupling between the baryonic mass of a galaxy and its rotation velocity (known as the baryonic Tully-Fisher relation) applies at a more local level as well, and it seems to imply a link between the baryonic mass distribution and the distribution of total mass (including dark matter).

  13. The global distribution of deep-water Antipatharia habitat

    Science.gov (United States)

    Yesson, Chris; Bedford, Faye; Rogers, Alex D.; Taylor, Michelle L.

    2017-11-01

    Antipatharia are a diverse group of corals with many species found in deep water. Many Antipatharia are habitat for associates, have extreme longevity and some species can occur beyond 8500 m depth. As they are major constituents of'coral gardens', which are Vulnerable Marine Ecosystems (VMEs), knowledge of their distribution and environmental requirements is an important pre-requisite for informed conservation planning particularly where the expense and difficulty of deep-sea sampling prohibits comprehensive surveys. This study uses a global database of Antipatharia distribution data to perform habitat suitability modelling using the Maxent methodology to estimate the global extent of black coral habitat suitability. The model of habitat suitability is driven by temperature but there is notable influence from other variables of topography, surface productivity and oxygen levels. This model can be used to predict areas of suitable habitat, which can be useful for conservation planning. The global distribution of Antipatharia habitat suitability shows a marked contrast with the distribution of specimen observations, indicating that many potentially suitable areas have not been sampled, and that sampling effort has been disproportionate to shallow, accessible areas inside marine protected areas (MPAs). Although 25% of Antipatharia observations are located in MPAs, only 7-8% of predicted suitable habitat is protected, which is short of the Convention on Biological Diversity target to protect 10% of ocean habitats by 2020.

  14. The distribution of mass for spiral galaxies in clusters and in the field

    International Nuclear Information System (INIS)

    Forbes, D.A.; Whitmore, B.C.

    1989-01-01

    A comparison is made between the mass distributions of spiral galaxies in clusters and in the field using Burstein's mass-type methodology. Both the H-alpha emission-line rotation curves and more extended H I rotation curves are used. The fitting technique for determining mass types used by Burstein and coworkers has been replaced by an objective chi-sq method. Mass types are shown to be a function of both the Hubble type and luminosity, contrary to earlier results. The present data show a difference in the distribution of mass types for spiral galaxies in the field and in clusters, in the sense that mass type I galaxies, where the inner and outer velocity gradients are similar, are generally found in the field rather than in clusters. This can be understood in terms of the results of Whitmore, Forbes, and Rubin (1988), who find that the rotation curves of galaxies in the central region of clusters are generally failing, while the outer galaxies in a cluster and field galaxies tend to have flat or rising rotation curves. 15 refs

  15. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Energy Technology Data Exchange (ETDEWEB)

    Dai, De-Chang, E-mail: diedachung@gmail.com [Institute of Natural Sciences, Shanghai Key Lab for Particle Physics and Cosmology, and Center for Astrophysics and Astronomy, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Stojkovic, Dejan [HEPCOS, Department of Physics, SUNY, University at Buffalo, Buffalo, NY 14260-1500 (United States)

    2016-07-10

    Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  16. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Directory of Open Access Journals (Sweden)

    De-Chang Dai

    2016-07-01

    Full Text Available Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  17. Calculating the mass distribution of heavy nucleus fission product by neutrons

    International Nuclear Information System (INIS)

    Gudkov, A.N.; Koldobskij, A.B.; Kolobashkin, V.M.; Semenova, E.V.

    1981-01-01

    The technique of calculating the fission product mass yields by neutrons which are necessary for performing nucleus physical calculations in designing nuclear reactor cores is considered. The technique is based on the approximation of fission product mass distribution over the whole mass range by five Gauss functions. New analytical expressions for determining energy weights of used gaussians are proposed. The results of comparison of experimental data with calculated values for fission product mass obtained for reference processes in the capacity of which the fission reactions are chosen: 233 U, 235 U fission by thermal neutrons, 232 Th, 233 U, 235 U, 238 U by fission spectrum neutrons and 14 MeV neutrons and for 232 Th fission reactions by 11 MeV neutrons and 238 U by 7.7 MeV neutrons. On the basis of the analysis of results obtained the conclusion is drawn on a good agreement of fission product mass yield calculation values obtained using recommended values of mass distribution parameters with experimental data [ru

  18. Throwing behavior and mass distribution of stone selection in tufted capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Cleveland, A; Rocca, A R; Wendt, E L; Westergaard, G C

    2003-12-01

    Cannell [Journal of Archaeological Science 29:335-339, 2002] argued that sex-based differences among humans in terms of the mass of chosen throwing stones could be used to infer body mass and patterns of sexual dimorphism in early hominids from Olduvai and Koobi Fora by examining the mass distributions of unaltered stone tools at those sites. We examined this hypothesis in tufted capuchin monkeys using a comparative approach, by investigating the relationships among body mass, sex, stone weight preference, and accuracy in a throwing task. The subject sample consisted of nine monkeys trained to perform an aimed-throwing task in which a food reward could be obtained by throwing a stone into a bucket. We found that 1) the subjects showed a strong mean stone mass preference; 2) the females chose heavier stones than the males, in terms of absolute mean selected stone mass and selected stone mass relative to body mass; 3) subjects threw more accurately when they used stones of preferred mass vs. stones of nonpreferred mass; and 4) overall, the males were more accurate in the throwing task than the females. We conclude that capuchins are highly selective when choosing throwing stones, and that this confers an advantage for throwing accuracy. Our results indicate that the sexually dimorphic pattern in stone mass preference observed among humans does not generalize to Cebus apella. We suggest that researchers examining this pattern in humans in an attempt to explain early hominid patterns of dimorphism and behavior should take into account not only stone weight preference, but also its adaptive advantage. Copyright 2003 Wiley-Liss, Inc.

  19. Energy management techniques: SRP cooling water distribution system

    International Nuclear Information System (INIS)

    Edenfield, A.B.

    1979-10-01

    Cooling water for the nuclear reactors at the Savannah River Plant is supplied by a pumping and distribution system that includes about 50 miles of underground pipeline. The energy management program at SRP has thus far achieved a savings of about 5% (186 x 10 9 Btu) of the energy consumed by the electrically powered cooling water pumps; additional savings of about 14% (535 x 10 9 Btu) can be achieved by capital expenditures totaling about $3.7 million. The present cost of electricity for operation of this system is about $25 million per year. A computer model of the system was adapted and field test data were used to normalize the program to accurately represent pipeline physical characteristics. Alternate pumping schemes are analyzed to determine projected energy costs and impact on system safety and reliability

  20. Fundamentals and control of nitrification in chloraminated drinking water distribution systems

    National Research Council Canada - National Science Library

    American Water Works Association

    2006-01-01

    ... Introduction, 25 Nitrification in Drinking Water Distribution System, 25 Nitrification in Pipelines and Effects of Biofilms, 31 Nitrification in Water Storage Facilities, 34 Conclusions, 39 Refere...

  1. Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems.

    Science.gov (United States)

    Kurek, Wojciech; Ostfeld, Avi

    2013-01-30

    A multi-objective methodology utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) linked to EPANET for trading-off pumping costs, water quality, and tanks sizing of water distribution systems is developed and demonstrated. The model integrates variable speed pumps for modeling the pumps operation, two water quality objectives (one based on chlorine disinfectant concentrations and one on water age), and tanks sizing cost which are assumed to vary with location and diameter. The water distribution system is subject to extended period simulations, variable energy tariffs, Kirchhoff's laws 1 and 2 for continuity of flow and pressure, tanks water level closure constraints, and storage-reliability requirements. EPANET Example 3 is employed for demonstrating the methodology on two multi-objective models, which differ in the imposed water quality objective (i.e., either with disinfectant or water age considerations). Three-fold Pareto optimal fronts are presented. Sensitivity analysis on the storage-reliability constraint, its influence on pumping cost, water quality, and tank sizing are explored. The contribution of this study is in tailoring design (tank sizing), pumps operational costs, water quality of two types, and reliability through residual storage requirements, in a single multi-objective framework. The model was found to be stable in generating multi-objective three-fold Pareto fronts, while producing explainable engineering outcomes. The model can be used as a decision tool for both pumps operation, water quality, required storage for reliability considerations, and tank sizing decision-making. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

    Science.gov (United States)

    Delaunois, F; Tosar, F; Vitry, V

    2014-06-01

    Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rader, D.J.; Benson, D.A.

    1995-05-01

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 {mu}m and a geometric standard deviation, {sigma}{sub g} of about 2; the CMD was found to increase and {sigma}{sub g} decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 {mu}m and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented.

  4. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    International Nuclear Information System (INIS)

    Rader, D.J.; Benson, D.A.

    1995-05-01

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 μm and a geometric standard deviation, σ g of about 2; the CMD was found to increase and σ g decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 μm and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented

  5. Impact of fat mass distribution body shapes on muscles strength and the joints pain

    Directory of Open Access Journals (Sweden)

    Zerf Mohammed

    2016-01-01

    Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

  6. Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

    Science.gov (United States)

    Carton, X.; L'Hegaret, P.; Baraille, R.

    2012-03-01

    By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described. The Red Sea Outflow Water (RSOW) is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relatively barotropic gyres mix it with Indian ocean Central Water. RSOW is also detected along the northeastern coast of Socotra, and fragments of RSOW are found between one and three degrees of latitude north of this island. In the whole Gulf of Aden, the correlation between the deep motions of the floats and the sea-level anomaly measured by altimetry is strong, at regional scale. The finer scale details of the float trajectories are not sampled by altimetry and are often related to the anomalous water masses that the floats encounter. The Persian Gulf Water (PGW) is found in the float profiles near Ras ash Sharbatat (near 57° E, 18° N), again with 36.5 in salinity and about 18-19 °C in temperature. These observations were achieved in winter when the southwestward monsoon currents can advect PGW along the South Arabian coast. Fragments of PGW were also observed in the Arabian Sea between 18 and 20° N and 63 and 65° E in summer, showing that this water mass can escape the Gulf of Oman southeastward, during that season. Kinetic energy distributions of floats with respect to distance or angle share common features between the two regions (Gulf of Aden and Arabian Sea), in particular peaks at 30, 50 and 150 km scales and along the axis of monsoon currents. Hydrological measurements by floats are also influenced by the seasonal variations of PGW and RSOW in these regions.

  7. Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

    Directory of Open Access Journals (Sweden)

    X. Carton

    2012-03-01

    Full Text Available By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described.

    The Red Sea Outflow Water (RSOW is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relatively barotropic gyres mix it with Indian ocean Central Water. RSOW is also detected along the northeastern coast of Socotra, and fragments of RSOW are found between one and three degrees of latitude north of this island. In the whole Gulf of Aden, the correlation between the deep motions of the floats and the sea-level anomaly measured by altimetry is strong, at regional scale. The finer scale details of the float trajectories are not sampled by altimetry and are often related to the anomalous water masses that the floats encounter.

    The Persian Gulf Water (PGW is found in the float profiles near Ras ash Sharbatat (near 57° E, 18° N, again with 36.5 in salinity and about 18–19 °C in temperature. These observations were achieved in winter when the southwestward monsoon currents can advect PGW along the South Arabian coast. Fragments of PGW were also observed in the Arabian Sea between 18 and 20° N and 63 and 65° E in summer, showing that this water mass can escape the Gulf of Oman southeastward, during that season.

    Kinetic energy distributions of floats with respect to distance or angle share common features between the two regions (Gulf of Aden and Arabian Sea, in particular peaks at 30, 50 and 150 km scales and along the axis of monsoon currents. Hydrological measurements by floats are also influenced by the seasonal variations of PGW and RSOW in these regions.

  8. Hydrography and water masses in the southeastern Arabian Sea

    Indian Academy of Sciences (India)

    The surface hydrography during March –April was dominated by the intrusion of low-salinity waters from the south;during May –June,the low-salinity waters were beginning to be replaced by the high- salinity waters from the north.There was considerable mixing at the bottom of the surface mixed layer,leading to interleaving ...

  9. Modelling income distribution impacts of water sector projects in Bangladesh.

    Science.gov (United States)

    Ahmed, C S; Jones, S

    1991-09-01

    Dynamic analysis was conducted to assess the long-term impacts of water sector projects on agricultural income distribution, and sensitivity analysis was conducted to check the robustness of the 5 assumptions in this study of income distribution and water sector projects in Bangladesh. 7 transitions are analyzed for mutually exclusive irrigation and flooding projects: Nonirrigation to 1) LLP irrigation, 2) STW irrigation, 3) DTW irrigation, 4) major gravity irrigation, and manually operated shallow tubewell irrigation (MOSTI) and Flood Control Projects (FCD) of 6) medium flooded to shallow flooded, and 7) deeply flooded to shallow flooded. 5 analytical stages are involved: 1) farm budgets are derived with and without project cropping patterns for each transition. 2) Estimates are generated for value added/hectare from each transition. 3) Assumptions are made about the number of social classes, distribution of land ownership between classes, extent of tenancy for each social class, term of tenancy contracts, and extent of hiring of labor for each social class. 4) Annual value added/hectare is distributed among social classes. 5) Using Gini coefficients and simple ratios, the distribution of income between classes is estimated for with and without transition. Assumption I is that there are 4 social classes defined by land acreage: large farmers (5 acres), medium farmers (1.5-5.0), small farmers, (.01-1.49), and landless. Assumption II is that land distribution follows the 1978 Land Occupancy Survey (LOS). Biases, if any, are indicated. Assumption III is that large farmers sharecrop out 15% of land to small farmers. Assumption IV is that landlords provide nonirrigated crop land and take 50% of the crop, and, under irrigation, provide 50% of the fertilizer, pesticide, and irrigation costs and take 50% of the crop. Assumption V is that hired and family labor is assumed to be 40% for small farmers, 60% for medium farmers, and 80% for large farmers. It is understood that

  10. Free Vibrations of a Cantilevered SWCNT with Distributed Mass in the Presence of Nonlocal Effect

    Directory of Open Access Journals (Sweden)

    M. A. De Rosa

    2015-01-01

    Full Text Available The Hamilton principle is applied to deduce the free vibration frequencies of a cantilever single-walled carbon nanotube (SWCNT in the presence of an added mass, which can be distributed along an arbitrary part of the span. The nonlocal elasticity theory by Eringen has been employed, in order to take into account the nanoscale effects. An exact formulation leads to the equations of motion, which can be solved to give the frequencies and the corresponding vibration modes. Moreover, two approximate semianalytical methods are also illustrated, which can provide quick parametric relationships. From a more practical point of view, the problem of detecting the mass of the attached particle has been solved by calculating the relative frequency shift due to the presence of the added mass: from it, the mass value can be easily deduced. The paper ends with some numerical examples, in which the nonlocal effects are thoroughly investigated.

  11. Prediction of corrosion rates of water distribution pipelines according to aggressive corrosive water in Korea.

    Science.gov (United States)

    Chung, W S; Yu, M J; Lee, H D

    2004-01-01

    The drinking water network serving Korea has been used for almost 100 years. Therefore, pipelines have suffered various degrees of deterioration due to aggressive environments. The pipe breaks were caused by in-external corrosion, water hammer, surface loading, etc. In this paper, we focused on describing corrosion status in water distribution pipes in Korea and reviewing some methods to predict corrosion rates. Results indicate that corrosive water of lakes was more aggressive than river water and the winter was more aggressive compared to other seasons. The roughness growth rates of Dongbok lake showed 0.23 mm/year. The high variation of corrosion rates is controlled by the aging pipes and smaller diameter. Also the phenolphthalein test on a cementitious core of cement mortar lined ductile cast iron pipe indicated the pipes over 15 years old had lost 50-100% of their lime active cross sectional area.

  12. IMPACT ON WATER DISTRIBUTION SYSTEM BIOFILM DENSITIES FROM REVERSE OSMOSIS MEMBRANE TREATMENT OF SUPPLY WATER

    Science.gov (United States)

    The quality of potable water is such that the concentration of nutrients available for growth of microorganisms within distribution systems is limited. In such systems carbon is often the growth limiting nutrient. Research conducted in the Netherlands has indicated that low level...

  13. Higher water plants in a lake contaminated with radionuclides: composition, distribution, reserves and accumulation of Cs-137

    International Nuclear Information System (INIS)

    Pavlyutin, A.P.; Babitskij, V.A.

    1996-01-01

    Species composition, specials distribution, seasonal pattern and accumulation of cesium-137 by aquatic plants had been investigated in the small not flowing meso trophic lake (Belarus) during vegetative season of 1993. Macrophyte phytomass storage is equal 10,56 t, and mass of its roots is 4.28 t of dry weight. Cesium-137 stock's in green mass and macrophytes roots are equal to 108.6 and 96.4 MBK respectively. Total accumulation of cesium-137 by macrophyte constituted 5% from its stock in the whole lake water mass

  14. Optimized mass flow rate distribution analysis for cooling the ITER Blanket System

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, Germán, E-mail: German.Perez@iter.org; Mitteau, Raphaël; Furmanek, Andreas; Martin, Alex; Raffray, René; Merola, Mario; Sabourin, Flavien

    2014-10-15

    Highlights: • Optimized water distribution in ITER blanket modules is presented. • All key challenging constraints are included. • The methodology and the successful result are presented. - Abstract: This paper presents the rationale to the optimization of water distribution in ITER blanket modules, meeting both Blanket System requirements and interface compliance requirements. The key challenging constraints include to: be compatible with the overall water allocation (3140 kg/s for 440 wall mounted BMs); meet the critical heat flux margin of 1.4 in the plasma facing units; meet a maximum temperature increase of 70 °C at the outlet of each single BM; and ensure that water velocity is less than 7 m/s in all manifolds, and that the pressure drops of all BMs can be equilibrated. The methodology and the successful result are presented.

  15. Optimized mass flow rate distribution analysis for cooling the ITER Blanket System

    International Nuclear Information System (INIS)

    Pérez, Germán; Mitteau, Raphaël; Furmanek, Andreas; Martin, Alex; Raffray, René; Merola, Mario; Sabourin, Flavien

    2014-01-01

    Highlights: • Optimized water distribution in ITER blanket modules is presented. • All key challenging constraints are included. • The methodology and the successful result are presented. - Abstract: This paper presents the rationale to the optimization of water distribution in ITER blanket modules, meeting both Blanket System requirements and interface compliance requirements. The key challenging constraints include to: be compatible with the overall water allocation (3140 kg/s for 440 wall mounted BMs); meet the critical heat flux margin of 1.4 in the plasma facing units; meet a maximum temperature increase of 70 °C at the outlet of each single BM; and ensure that water velocity is less than 7 m/s in all manifolds, and that the pressure drops of all BMs can be equilibrated. The methodology and the successful result are presented

  16. On line determination of deuterium in hydrogen water exchange reaction by mass spectrometry. IRP-10

    International Nuclear Information System (INIS)

    Sharma, J.D.; Alphonse, K.P.; Mishra, Sushama; Prabhu, S.A.; Mohan, Sadhana; Tangri, V.K.

    2007-01-01

    The Deuterium (D)/Hydrogen (H) analysis at low Concentration is generally carried out by Mass Spectrometry. Mass Spectrometer is specially designed for the measurement of Mass 2 and 3 ratio. The Deuterium analysis of water and hydrogen in concentration range of a few ppm to about 1% plays an important role in the Heavy Water Production Plants. For the enrichment of the Deuterium concentration in H 2 O by H 2 - H 2 O exchange a catalyst is essential as reaction is relatively slow. Heavy Water Division has developed in house Platinum based catalyst for the isotopic exchange of Hydrogen and Water

  17. Nutrient characteristics of the water masses and their seasonal variability in the eastern equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Shetye, S.; Maya, M.V.; Mangala, K.R.; PrasannaKumar, S.

    . (Position of Fig 1.) 3. Results and Discussion 3.1. Water masses in the area of observation You and Tomczak (1993) has reviewed the water masses in the Indian Ocean identified by the earlier workers ( Sverdrup et al. 1942; Mamalev, 1975; and Shcherbinin... at 200 m at 5° S in the meridional region of our observations and flows down to 800 m to the north and termed as Indian central water (ICW) (You and Tomczak, 1993). (position of Fig.2) 3.2. Seasonal variability of water masses The seasonal...

  18. Automatic generation of water distribution systems based on GIS data.

    Science.gov (United States)

    Sitzenfrei, Robert; Möderl, Michael; Rauch, Wolfgang

    2013-09-01

    In the field of water distribution system (WDS) analysis, case study research is needed for testing or benchmarking optimisation strategies and newly developed software. However, data availability for the investigation of real cases is limited due to time and cost needed for data collection and model setup. We present a new algorithm that addresses this problem by generating WDSs from GIS using population density, housing density and elevation as input data. We show that the resulting WDSs are comparable to actual systems in terms of network properties and hydraulic performance. For example, comparing the pressure heads for an actual and a generated WDS results in pressure head differences of ±4 m or less for 75% of the supply area. Although elements like valves and pumps are not included, the new methodology can provide water distribution systems of varying levels of complexity (e.g., network layouts, connectivity, etc.) to allow testing design/optimisation algorithms on a large number of networks. The new approach can be used to estimate the construction costs of planned WDSs aimed at addressing population growth or at comparisons of different expansion strategies in growth corridors.

  19. Effect of water table fluctuations on phreatophytic root distribution.

    Science.gov (United States)

    Tron, Stefania; Laio, Francesco; Ridolfi, Luca

    2014-11-07

    The vertical root distribution of riparian vegetation plays a relevant role in soil water balance, in the partition of water fluxes into evaporation and transpiration, in the biogeochemistry of hyporheic corridors, in river morphodynamics evolution, and in bioengineering applications. The aim of this work is to assess the effect of the stochastic variability of the river level on the root distribution of phreatophytic plants. A function describing the vertical root profile has been analytically obtained by coupling a white shot noise representation of the river level variability to a description of the dynamics of root growth and decay. The root profile depends on easily determined parameters, linked to stream dynamics, vegetation and soil characteristics. The riparian vegetation of a river characterized by a high variability turns out to have a rooting system spread over larger depths, but with shallower mean root depths. In contrast, a lower river variability determines root profiles with higher mean root depths. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Online modelling of water distribution systems: a UK case study

    Directory of Open Access Journals (Sweden)

    J. Machell

    2010-03-01

    Full Text Available Hydraulic simulation models of water distribution networks are routinely used for operational investigations and network design purposes. However, their full potential is often never realised because, in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and, as such, reflect the network operational conditions that were prevalent at that time, and they are then applied as part of a reactive, desktop investigation. In order to use a hydraulic model to assist proactive distribution network management its element asset information must be up to date and it should be able to access current network information to drive simulations. Historically this advance has been restricted by the high cost of collecting and transferring the necessary field measurements. However, recent innovation and cost reductions associated with data transfer is resulting in collection of data from increasing numbers of sensors in water supply systems, and automatic transfer of the data to point of use. This means engineers potentially have access to a constant stream of current network data that enables a new era of "on-line" modelling that can be used to continually assess standards of service compliance for pressure and reduce the impact of network events, such as mains bursts, on customers. A case study is presented here that shows how an online modelling system can give timely warning of changes from normal network operation, providing capacity to minimise customer impact.

  1. Bacteriological challenges to asbestos cement water distribution pipelines.

    Science.gov (United States)

    Wang, Dunling; Cullimore, D Roy

    2010-01-01

    Asbestos cement (AC) pipes were commonly installed in the drinking water distribution systems from the mid 1920s to the late 1980s. In recent years, an increase in the number of water main breaks has occurred in the AC portions of some pipe networks, which can be partially attributed to the corrosion of the aged pipes. This study evaluated the potential role that microorganisms may have played in the degeneration and failure of AC pipes. In this study, a fresh AC pipe section was collected from the distribution network of the City of Regina, Canada and examined for microbiological activities and growth on inside surfaces of pipe sample. Black slime bacterial growths were found to be attached to inner pipe surfaces and a distinctively fibrous internal coating (patina) with iron oxides was formed over the time. The microbial populations inside the patina and the black slime were tested with BART testers. Heterotrophic aerobic bacteria (HAB) and slime forming bacteria (SLYM) dominated in both the black growths and inside the patina. Iron related bacteria, denitrification bacteria and sulfate reducing bacteria were also commonly present. Microbial challenge assays were conducted by submerging the cut segments of the AC pipe into selected bacterial cultures for a period of 10 days under both aerobic and anaerobic environments. Weight changes were determined and the surface morphology was examined for each of the assayed pipe segments. Results indicated that acid producing bacteria, SLYM and HAB could facilitate the pipe weight loss under anaerobicenvironments.

  2. Radium-226 and barium as tracers of water masses in the North Atlantic (GA01-GEOTRACES)

    Science.gov (United States)

    Le Roy, Emilie; Sanial, Virginie; Charette, Matthew; Henderson, Paul; Jacquet, Stéphanie; García-Ibáñez, Maribel; Pérez, Fiz; Lherminer, Pascale; Souhaut, Marc; Jeandel, Catherine; Lacan, François; van Beek, Pieter

    2017-04-01

    In this study, we report concentrations of radium-226 (226Ra, t1/2=1602 y) and barium determined along the GEOVIDE section conducted in the North Atlantic (May-July 2014; Portugal-Greenland-Canda) in the framework of the international GEOTRACES program. A high vertical resolution (up to 22 depths per station) was achieved by analyzing small volumes (˜10 L) of seawater for 226Ra using a radon emanation technique. We will present the distribution of 226Ra activities and barium concentrations in contrasting biogeochemical regions of the North Atlantic (Iberian margin, West European Basin, Reykjanes Ridge, Irminger Sea, Greenland margin and Labrador Sea). These regions strongly differ in terms of boundary inputs, biogeochemistry and deep water formation. We observe a linear correlation between 226Ra and barium along the GEOVIDE section, which results from the dominantly conservative behavior of the two tracers. However, deviations from the linear correlation between 226Ra and Ba are found in several places. The potential causes for such deviations are investigated. Optimum multi-parameter (OMP) analysis was thus used to distinguish the relative importance of physical transport (i.e., water mass mixing) from non-conservative processes (sedimentary, river or hydrothermal inputs; uptake by particles) on the 226Ra and Ba distribution in the North Atlantic.

  3. Evaluation of a distributed catchment scale water balance model

    Science.gov (United States)

    Troch, Peter A.; Mancini, Marco; Paniconi, Claudio; Wood, Eric F.

    1993-01-01

    The validity of some of the simplifying assumptions in a conceptual water balance model is investigated by comparing simulation results from the conceptual model with simulation results from a three-dimensional physically based numerical model and with field observations. We examine, in particular, assumptions and simplifications related to water table dynamics, vertical soil moisture and pressure head distributions, and subsurface flow contributions to stream discharge. The conceptual model relies on a topographic index to predict saturation excess runoff and on Philip's infiltration equation to predict infiltration excess runoff. The numerical model solves the three-dimensional Richards equation describing flow in variably saturated porous media, and handles seepage face boundaries, infiltration excess and saturation excess runoff production, and soil driven and atmosphere driven surface fluxes. The study catchments (a 7.2 sq km catchment and a 0.64 sq km subcatchment) are located in the North Appalachian ridge and valley region of eastern Pennsylvania. Hydrologic data collected during the MACHYDRO 90 field experiment are used to calibrate the models and to evaluate simulation results. It is found that water table dynamics as predicted by the conceptual model are close to the observations in a shallow water well and therefore, that a linear relationship between a topographic index and the local water table depth is found to be a reasonable assumption for catchment scale modeling. However, the hydraulic equilibrium assumption is not valid for the upper 100 cm layer of the unsaturated zone and a conceptual model that incorporates a root zone is suggested. Furthermore, theoretical subsurface flow characteristics from the conceptual model are found to be different from field observations, numerical simulation results, and theoretical baseflow recession characteristics based on Boussinesq's groundwater equation.

  4. Core-powered mass-loss and the radius distribution of small exoplanets

    Science.gov (United States)

    Ginzburg, Sivan; Schlichting, Hilke E.; Sari, Re'em

    2018-05-01

    Recent observations identify a valley in the radius distribution of small exoplanets, with planets in the range 1.5-2.0 R⊕ significantly less common than somewhat smaller or larger planets. This valley may suggest a bimodal population of rocky planets that are either engulfed by massive gas envelopes that significantly enlarge their radius, or do not have detectable atmospheres at all. One explanation of such a bimodal distribution is atmospheric erosion by high-energy stellar photons. We investigate an alternative mechanism: the luminosity of the cooling rocky core, which can completely erode light envelopes while preserving heavy ones, produces a deficit of intermediate sized planets. We evolve planetary populations that are derived from observations using a simple analytical prescription, accounting self-consistently for envelope accretion, cooling and mass-loss, and demonstrate that core-powered mass-loss naturally reproduces the observed radius distribution, regardless of the high-energy incident flux. Observations of planets around different stellar types may distinguish between photoevaporation, which is powered by the high-energy tail of the stellar radiation, and core-powered mass-loss, which depends on the bolometric flux through the planet's equilibrium temperature that sets both its cooling and mass-loss rates.

  5. Modeling particle transport and discoloration risk in drinking water distribution networks

    Directory of Open Access Journals (Sweden)

    J. van Summeren

    2017-10-01

    Full Text Available Discoloration of drinking water is a worldwide phenomenon caused by accumulation and subsequent remobilization of particulate matter in drinking water distribution systems (DWDSs. It contributes a substantial fraction of customer complaints to water utilities. Accurate discoloration risk predictions could improve system operation by allowing for more effective programs on cleaning and prevention actions and field measurements, but are challenged by incomplete understanding on the origins and properties of particles and a complex and not fully understood interplay of processes in distribution networks. In this paper, we assess and describe relevant hydraulic processes that govern particle transport in turbulent pipe flow, including gravitational settling, bed-load transport, and particle entrainment into suspension. We assess which transport mechanisms are dominant for a range of bulk flow velocities, particle diameters, and particle mass densities, which includes common conditions for DWDSs in the Netherlands, the UK, and Australia. Our analysis shows that the theoretically predicted particle settling velocity and threshold shear stresses for incipient particle motion are in the same range as, but more variable than, previous estimates from lab experiments, field measurements, and modeling. The presented material will be used in the future development of a numerical modeling tool to determine and predict the spatial distribution of particulate material and discoloration risk in DWDSs. Our approach is aimed at understanding specific causalities and processes, which can complement data-driven approaches.

  6. Application of the Regional Water Mass Variations from GRACE Satellite Gravimetry to Large-Scale Water Management in Africa

    Directory of Open Access Journals (Sweden)

    Guillaume Ramillien

    2014-08-01

    Full Text Available Time series of regional 2° × 2° Gravity Recovery and Climate Experiment (GRACE solutions of surface water mass change have been computed over Africa from 2003 to 2012 with a 10-day resolution by using a new regional approach. These regional maps are used to describe and quantify water mass change. The contribution of African hydrology to actual sea level rise is negative and small in magnitude (i.e., −0.1 mm/y of equivalent sea level (ESL mainly explained by the water retained in the Zambezi River basin. Analysis of the regional water mass maps is used to distinguish different zones of important water mass variations, with the exception of the dominant seasonal cycle of the African monsoon in the Sahel and Central Africa. The analysis of the regional solutions reveals the accumulation in the Okavango swamp and South Niger. It confirms the continuous depletion of water in the North Sahara aquifer at the rate of −2.3 km3/y, with a decrease in early 2008. Synergistic use of altimetry-based lake water volume with total water storage (TWS from GRACE permits a continuous monitoring of sub-surface water storage for large lake drainage areas. These different applications demonstrate the potential of the GRACE mission for the management of water resources at the regional scale.

  7. Factors controlling the regional distribution of vanadium in ground water

    Science.gov (United States)

    Wright, Michael T.; Belitz, Kenneth

    2010-01-01

    Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or = 50 μg/L) and moderate (25 to 49 μg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.

  8. Demonstration of a Model-Based Technology for Monitoring Water Quality and Corrosion in Water-Distribution systems

    Science.gov (United States)

    2016-12-01

    that Fort Drum uses water from two sources: (1) treated groundwater from its on-post wells and (2) treated surface water supplied by the Development...Complete replacement of distribution system piping $21 million Year 10 and Year 30 Leak repair $40,000 Annual Bottled water for drinking $20,000 per...about effects of the instal- lation’s dual water supplies on operation of the water -distribution system. 5.2 Recommendations 5.2.1 Applicability Model

  9. Spatial distribution of water supply reliability and critical links of water supply to crucial water consumers under an earthquake

    International Nuclear Information System (INIS)

    Wang Yu; Au, S.-K.

    2009-01-01

    This paper describes a process to characterize spatial distribution of water supply reliability among various consumers in a water system and proposes methods to identify critical links of water supply to crucial water consumers under an earthquake. Probabilistic performance of water supply is reflected by the probability of satisfying consumers' water demand, Damage Consequence Index (DCI) and Upgrade Benefit Index (UBI). The process is illustrated using a hypothetical water supply system, where direct Monte Carlo simulation is used for estimating the performance indices. The reliability of water supply to consumers varies spatially, depending on their respective locations in the system and system configuration. The UBI is adopted as a primary index in the identification of critical links for crucial water consumers. A pipe with a relatively large damage probability is likely to have a relatively large UBI, and hence, to be a critical link. The concept of efficient frontier is employed to identify critical links of water supply to crucial water consumers. It is found that a group of links that have the largest UBI individually do not necessarily have the largest group UBI, or be the group of critical links

  10. Radionuclide distribution in LWR [light-water reactor] spent fuel

    International Nuclear Information System (INIS)

    Guenther, R.J.; Blahnik, D.E.; Thomas, L.E.; Baldwin, D.L.; Mendel, J.E.

    1990-09-01

    The Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) provides well-characterized spent fuel from light-water reactors (LWRs) for use in laboratory tests relevant to nuclear waste disposal in the proposed Yucca Mountain repository. Interpretation of results from tests on spent fuel oxidation, dissolution, and cladding degradation requires information on the inventory and distribution of radionuclides in the initial test materials. The MCC is obtaining this information from examinations of Approved Testing Materials (ATMs), which include spent fuel with burnups from 17 to 50 MWd/kgM and fission gas releases (FGR) from 0.2 to 18%. The concentration and distribution of activation products and the release of volatile fission products to the pellet-cladding gap and rod plenum are of particular interest because these characteristics are not well understood. This paper summarizes results that help define the 14 C inventory and distribution in cladding, the ''gap and grain boundary'' inventory of radionuclides in fuels with different FGRs, and the structure and radionuclide inventory of the fuel rim region within a few hundred micrometers from the fuel edge. 6 refs., 5 figs., 1 tab

  11. Teacher candidates' mastery of phoneme-grapheme correspondence: massed versus distributed practice in teacher education.

    Science.gov (United States)

    Sayeski, Kristin L; Earle, Gentry A; Eslinger, R Paige; Whitenton, Jessy N

    2017-04-01

    Matching phonemes (speech sounds) to graphemes (letters and letter combinations) is an important aspect of decoding (translating print to speech) and encoding (translating speech to print). Yet, many teacher candidates do not receive explicit training in phoneme-grapheme correspondence. Difficulty with accurate phoneme production and/or lack of understanding of sound-symbol correspondence can make it challenging for teachers to (a) identify student errors on common assessments and (b) serve as a model for students when teaching beginning reading or providing remedial reading instruction. For students with dyslexia, lack of teacher proficiency in this area is particularly problematic. This study examined differences between two learning conditions (massed and distributed practice) on teacher candidates' development of phoneme-grapheme correspondence knowledge and skills. An experimental, pretest-posttest-delayed test design was employed with teacher candidates (n = 52) to compare a massed practice condition (one, 60-min session) to a distributed practice condition (four, 15-min sessions distributed over 4 weeks) for learning phonemes associated with letters and letter combinations. Participants in the distributed practice condition significantly outperformed participants in the massed practice condition on their ability to correctly produce phonemes associated with different letters and letter combinations. Implications for teacher preparation are discussed.

  12. Demonstrating demand response from water distribution system through pump scheduling

    International Nuclear Information System (INIS)

    Menke, Ruben; Abraham, Edo; Parpas, Panos; Stoianov, Ivan

    2016-01-01

    Highlights: • Water distribution systems can profitably provide demand response energy. • STOR and FFR are financially viable under a wide range of operating conditions. • Viability depends on the pump utilisation and peak price of the electricity tariff. • Total GHG emissions caused by the provision of reserve energy are <300 gCO_2/kW h. • These are lower than those from the major reserve energy provision technologies. - Abstract: Significant changes in the power generation mix are posing new challenges for the balancing systems of the grid. Many of these challenges are in the secondary electricity grid regulation services and could be met through demand response (DR) services. We explore the opportunities for a water distribution system (WDS) to provide balancing services with demand response through pump scheduling and evaluate the associated benefits. Using a benchmark network and demand response mechanisms available in the UK, these benefits are assessed in terms of reduced green house gas (GHG) emissions from the grid due to the displacement of more polluting power sources and additional revenues for water utilities. The optimal pump scheduling problem is formulated as a mixed-integer optimisation problem and solved using a branch and bound algorithm. This new formulation finds the optimal level of power capacity to commit to the provision of demand response for a range of reserve energy provision and frequency response schemes offered in the UK. For the first time we show that DR from WDS can offer financial benefits to WDS operators while providing response energy to the grid with less greenhouse gas emissions than competing reserve energy technologies. Using a Monte Carlo simulation based on data from 2014, we demonstrate that the cost of providing the storage energy is less than the financial compensation available for the equivalent energy supply. The GHG emissions from the demand response provision from a WDS are also shown to be smaller than

  13. System effectiveness of a targeted free mass distribution of long lasting insecticidal nets in Zanzibar, Tanzania

    Directory of Open Access Journals (Sweden)

    Abass Ali K

    2010-06-01

    Full Text Available Abstract Background Insecticide-treated nets (ITN and long-lasting insecticidal treated nets (LLIN are important means of malaria prevention. Although there is consensus regarding their importance, there is uncertainty as to which delivery strategies are optimal for dispensing these life saving interventions. A targeted mass distribution of free LLINs to children under five and pregnant women was implemented in Zanzibar between August 2005 and January 2006. The outcomes of this distribution among children under five were evaluated, four to nine months after implementation. Methods Two cross-sectional surveys were conducted in May 2006 in two districts of Zanzibar: Micheweni (MI on Pemba Island and North A (NA on Unguja Island. Household interviews were conducted with 509 caretakers of under-five children, who were surveyed for socio-economic status, the net distribution process, perceptions and use of bed nets. Each step in the distribution process was assessed in all children one to five years of age for unconditional and conditional proportion of success. System effectiveness (the accumulated proportion of success and equity effectiveness were calculated, and predictors for LLIN use were identified. Results The overall proportion of children under five sleeping under any type of treated net was 83.7% (318/380 in MI and 91.8% (357/389 in NA. The LLIN usage was 56.8% (216/380 in MI and 86.9% (338/389 in NA. Overall system effectiveness was 49% in MI and 87% in NA, and equity was found in the distribution scale-up in NA. In both districts, the predicting factor of a child sleeping under an LLIN was caretakers thinking that LLINs are better than conventional nets (OR = 2.8, p = 0.005 in MI and 2.5, p = 0.041 in NA, in addition to receiving an LLIN (OR = 4.9, p Conclusions Targeted free mass distribution of LLINs can result in high and equitable bed net coverage among children under five. However, in order to sustain high effective coverage, there

  14. Using WNTR to Model Water Distribution System Resilience ...

    Science.gov (United States)

    The Water Network Tool for Resilience (WNTR) is a new open source Python package developed by the U.S. Environmental Protection Agency and Sandia National Laboratories to model and evaluate resilience of water distribution systems. WNTR can be used to simulate a wide range of disruptive events, including earthquakes, contamination incidents, floods, climate change, and fires. The software includes the EPANET solver as well as a WNTR solver with the ability to model pressure-driven demand hydraulics, pipe breaks, component degradation and failure, changes to supply and demand, and cascading failure. Damage to individual components in the network (i.e. pipes, tanks) can be selected probabilistically using fragility curves. WNTR can also simulate different types of resilience-enhancing actions, including scheduled pipe repair or replacement, water conservation efforts, addition of back-up power, and use of contamination warning systems. The software can be used to estimate potential damage in a network, evaluate preparedness, prioritize repair strategies, and identify worse case scenarios. As a Python package, WNTR takes advantage of many existing python capabilities, including parallel processing of scenarios and graphics capabilities. This presentation will outline the modeling components in WNTR, demonstrate their use, give the audience information on how to get started using the code, and invite others to participate in this open source project. This pres

  15. Water quality modeling in the dead end sections of drinking water distribution networks.

    Science.gov (United States)

    Abokifa, Ahmed A; Yang, Y Jeffrey; Lo, Cynthia S; Biswas, Pratim

    2016-02-01

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Water quality models developed so far apply spatial aggregation and temporal averaging techniques for hydraulic parameters by assigning hourly averaged water demands to the main nodes of the network. Although this practice has generally resulted in minimal loss of accuracy for the predicted disinfectant concentrations in main water transmission lines, this is not the case for the peripheries of the distribution network. This study proposes a new approach for simulating disinfectant residuals in dead end pipes while accounting for both spatial and temporal variability in hydraulic and transport parameters. A stochastic demand generator was developed to represent residential water pulses based on a non-homogenous Poisson process. Dispersive solute transport was considered using highly dynamic dispersion rates. A genetic algorithm was used to calibrate the axial hydraulic profile of the dead-end pipe based on the different demand shares of the withdrawal nodes. A parametric sensitivity analysis was done to assess the model performance under variation of different simulation parameters. A group of Monte-Carlo ensembles was carried out to investigate the influence of spatial and temporal variations in flow demands on the simulation accuracy. A set of three correction factors were analytically derived to adjust residence time, dispersion rate and wall demand to overcome simulation error caused by spatial aggregation approximation. The current model results show better agreement with field-measured concentrations of conservative fluoride tracer and free chlorine disinfectant than the simulations of recent advection dispersion reaction models published in the literature. Accuracy of the simulated

  16. Determination of isotope ratio of elements by mass distribution in molecules of varied chemical compounds

    International Nuclear Information System (INIS)

    Gladkikh, I.S.; Babichev, A.P.

    1999-01-01

    The procedure and program for calculation of isotope ratio of elements involving in the compound being studied using data of mass spectrometry were elaborated. The methods developed for the O 2 , SiH 4 , Cd(CH 3 ) 2 molecules were demonstrated for the illustration. The results of calculation provide support for the efficiency of the program and satisfactory reliability of the results during calculation of the isotope and complex compound concentrations. The program may be used for the estimation of the degree of nonequilibrium isotope distributions, it may indicate on the errors of the mass spectroscopy results [ru

  17. Generalized conditions for the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space

    International Nuclear Information System (INIS)

    Manoukian, E.B.

    1986-01-01

    Generalized conditions (rules) are set up for the existence of the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space. These rules are generalizations of rules that have been set up earlier by us and hence are applicable to a larger class of graphs. The study is very general as the vanishing masses are led to vanish at different rates. All subtractions of renormalization are carried out directly in momentum space, about the origin, with the degree of divergence of a subtraction coinciding with the dimensionality of the corresponding subdiagram

  18. Rational designing of the internal water supply system in reconstructed residential buildings of mass standard series

    OpenAIRE

    Orlov Evgeny

    2018-01-01

    The issues of water supply system reconstruction in mass series buildings are reviewed with consideration of water- and resource saving. Principal points for location of plumbing cells in apartments, arrangement of water devices and wastewater receivers, selection of pipelines for reconstructed water line are described. Comparative analysis of design variants of inner water line before and following reconstruction are given. It was found that applying the developed system design approaches th...

  19. Environmental complexity of a port: Evidence from circulation of the water masses, and composition and contamination of bottom sediments.

    Science.gov (United States)

    Cutroneo, L; Carbone, C; Consani, S; Vagge, G; Canepa, G; Capello, M

    2017-06-15

    Ports are complex environments due to their complicated geometry (quays, channels, and piers), the presence of human activities (vessel traffic, shipyards, industries, and discharges), and natural factors (stream and torrent inputs, sea action, and currents). Taking these factors into consideration, we have examined the marine environment of a port from the point of view of the circulation of the water masses, hydrological characteristics, distribution of the sediment grain-size, mineralogical characteristics, and metal concentrations of the bottom sediments. Our results show that, in the case of the Port of Genoa (north-western Italy), the impact of human activities (such as a coal power-plant, oil depots, shipyards, dredging of the bottom sediments, etc.), natural processes (such as currents, fresh water and sediment inputs from the torrents), and the morphology of the basin, are important factors in the sediment, water, and metal distributions that have given rise to a complex environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mid-winter European dabbling duck distributions are not linked to species body mass

    DEFF Research Database (Denmark)

    Dalby, Lars; Delany, Simon; Fox, Anthony David

    are likely to play a major role in determining the wintering distribution of short- to medium-distance migratory bird species and its inter-annual variability. As avian thermoregulatory costs scale allometrically with body size, we predicted that the mean mid-winter temperature experienced by six species...... of dabbling ducks wintering in Western Europe would be negatively correlated with body mass. We found no evidence for such a relationship in a large-scale analysis testing for a link between temperature and dabbling duck distributions, suggesting that other factors such as those related to feeding ecology......In order to understand the current changes and to predict future changes in wintering dabbling duck (Anas sp.) distributions in response to climate change, it is important to understand how species distribute themselves on a continental scale in response to temperature. Thermoregulatory costs...

  1. Topological clustering as a tool for planning water quality monitoring in water distribution networks

    DEFF Research Database (Denmark)

    Kirstein, Jonas Kjeld; Albrechtsen, Hans-Jørgen; Rygaard, Martin

    2015-01-01

    ) identify steady clusters for a part of the network where an actual contamination has occurred; (2) analyze this event by the use of mesh diagrams; and (3) analyze the use of mesh diagrams as a decision support tool for planning water quality monitoring. Initially, the network model was divided...... into strongly and weakly connected clusters for selected time periods and mesh diagrams were used for analysing cluster connections in the Nørrebro district. Here, areas of particular interest for water quality monitoring were identified by including user-information about consumption rates and consumers...... particular sensitive towards water quality deterioration. The analysis revealed sampling locations within steady clusters, which increased samples' comparability over time. Furthermore, the method provided a simplified overview of water movement in complex distribution networks, and could assist...

  2. Evaluation of a mass-balance approach to determine consumptive water use in northeastern Illinois

    Science.gov (United States)

    Mills, Patrick C.; Duncker, James J.; Over, Thomas M.; Marian Domanski,; ,; Engel, Frank

    2014-01-01

    A principal component of evaluating and managing water use is consumptive use. This is the portion of water withdrawn for a particular use, such as residential, which is evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. The amount of consumptive use may be estimated by a water (mass)-balance approach; however, because of the difficulty of obtaining necessary data, its application typically is restricted to the facility scale. The general governing mass-balance equation is: Consumptive use = Water supplied - Return flows.

  3. Mass Customization og Postponement - strategier og modeller for integreret produktion og distribution af kundespecifikke produkter

    DEFF Research Database (Denmark)

    Michelsen, Aage U.; Janus, Pagh

    2002-01-01

    Mass Customization er et produktionskoncept, der søger at kombinere masseproduktion og enkeltstyksproduktion på en sådan måde, at det er muligt at "masseproducere" kundespecifikke produkter. Postponement er i denne forbindelse et centralt begreb, idet det vedrører placeringen af dekoblingspunktet...... ("customer order decoupling point"), dvs. placeringen af det lager, hvorfra efterfølgende produktion og distribution er styret af kundespecifikke produkter. I artiklen fokuseres på, at hvis produktion og distribution ikke opfattes som to sekventielle systemer, men som ét integreret system, så opstår der en...

  4. Developing Fluorescence Sensor Systems for Early Detection of Nitrification Events in Chloraminated Drinking Water Distribution Systems

    Science.gov (United States)

    Detection of nitrification events in chloraminated drinking water distribution systems remains an ongoing challenge for many drinking water utilities, including Dallas Water Utilities (DWU) and the City of Houston (CoH). Each year, these utilities experience nitrification events ...

  5. Fluorescence Sensors for Early Detection of Nitrification in Drinking Water Distribution Systems – Interference Corrections (Poster)

    Science.gov (United States)

    Nitrification event detection in chloraminated drinking water distribution systems (DWDSs) remains an ongoing challenge for many drinking water utilities, including Dallas Water Utilities (DWU) and the City of Houston (CoH). Each year, these utilities experience nitrification eve...

  6. Fluorescence Sensors for Early Detection of Nitrification in Drinking Water Distribution Systems – Interference Corrections (Abstract)

    Science.gov (United States)

    Nitrification event detection in chloraminated drinking water distribution systems (DWDSs) remains an ongoing challenge for many drinking water utilities, including Dallas Water Utilities (DWU) and the City of Houston (CoH). Each year, these utilities experience nitrification eve...

  7. Analysis of fission-fragment mass distribution within the quantum-mechanical fragmentation theory

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pardeep; Kaur, Harjeet [Guru Nanak Dev University, Department of Physics, Amritsar (India)

    2016-11-15

    The fission-fragment mass distribution is analysed for the {sup 208}Pb({sup 18}O, f) reaction within the quantum-mechanical fragmentation theory (QMFT). The reaction potential has been calculated by taking the binding energies, Coulomb potential and proximity potential of all possible decay channels and a stationary Schroedinger equation has been solved numerically to calculate the fission-fragment yield. The overall results for mass distribution are compared with those obtained in experiment. Fine structure dips in yield, corresponding to fragment shell closures at Z = 50 and N=82, which are observed by Bogachev et al., are reproduced successfully in the present calculations. These calculations will help to estimate the formation probabilities of fission fragments and to understand many related phenomena occurring in the fission process. (orig.)

  8. Fission fragment mass distribution in the 13C+182W and 176Yb reactions

    International Nuclear Information System (INIS)

    Ramachandran, K.; Hinde, D.J.; Dasgupta, M.; Williams, E.; Wakhle, A.; Luong, D.H.; Evers, M.; Carter, I.P.; Das, S.

    2014-01-01

    Fission fragment mass distributions have been measured for many systems and found to be asymmetric in the fission of nuclei with nucleon number A in the range 228-258 and proton number Z in the range 90-100. For lighter systems, it has been observed that fission fragment mass distributions are usually symmetric. At high excitation energies the shell effects are expected to vanish and the nuclei are expected to behave like a charged liquid drop; hence, only symmetric fission is expected for all the nuclei. Even after much experimental and theoretical work in this field, the rate of damping of shell effects with excitation energy is not well known. This abstract reports our measurements with 13 C beams on 182 W and 176 Yb targets

  9. Relativistic Mechanics in Gravitational Fields Exterior to Rotating Homogeneous Mass Distributions within Spherical Geometry

    Directory of Open Access Journals (Sweden)

    Chifu E. N.

    2009-07-01

    Full Text Available General Relativistic metric tensors for gravitational fields exterior to homogeneous spherical mass distributions rotating with constant angular velocity about a fixed di- ameter are constructed. The coeffcients of affine connection for the gravitational field are used to derive equations of motion for test particles. The laws of conservation of energy and angular momentum are deduced using the generalized Lagrangian. The law of conservation of angular momentum is found to be equal to that in Schwarzschild’s gravitational field. The planetary equation of motion and the equation of motion for a photon in the vicinity of the rotating spherical mass distribution have rotational terms not found in Schwarzschild’s field.

  10. Measurement of particle size distribution and mass concentration of nuclear fuel aerosols

    International Nuclear Information System (INIS)

    Pickering, S.

    1982-01-01

    The particle size distribution and particle mass concentration of a nuclear fuel aerosol is measured by admitting the aerosol into a vertically-extending container, positioning an alpha particle detector within the container so that its window is horizontal and directed vertically, stopping the admission of aerosol into the container, detecting the alpha-activity of the particles of the aerosol sedimenting onto the detector window (for example in a series of equal time intervals until a constant level is reached), and converting the alpha-activity measurements into particle size distribution and/or particle mass concentration measurements. The detector is attached to a pivotted arm and by raising a counterweight can be lowered from the container for cleaning. (author)

  11. Formation of fission-fragment mass distribution for nuclei lighter than thorium

    International Nuclear Information System (INIS)

    Itkis, M.G.; Mul'gin, S.I.; Rusanov, A.Y.; Okolovich, A.N.; Smirenkin, G.N.

    1986-01-01

    A phenomenological approach to description of fission-fragment mass distribution Y(M) for nuclei in the vicinity of Pb is developed and used to extract from the experimental Y(M) data the nuclear deformation potential energy V(M) and its components: the macroscopic (liquid-drop) part and the shell correction in the transition state. The results of the analysis are compared with the theoretically obtained V(M) and Y(M). The three-hump fragment-mass distributions observed in Ra fission are satisfactorily described within the framework of the approach developed. The properties of the symmetric and asymmetric fission valleys and the related Y(M) components are discussed

  12. Binary star statistics: the mass ratio distribution for very wide systems

    International Nuclear Information System (INIS)

    Trimble, V.

    1987-01-01

    The distribution of mass ratios for a sample of common proper motion (CPM) binaries is determined and compared with that of 798 visual binaries (VB's) studied earlier, in hopes of answering the question: Can the member stars of these systems have been drawn at random from the normal initial mass function for single stars? The observed distributions peak strongly toward q = 1.0 for both kinds of systems, but less strongly for the CPM's than for the VB's. Due allowance having been made for assorted observational selection effects, it seems quite probable that the CPM's represent the observed part of a population drawn at random from the normal IMF, while the VB's are much more difficult to interpret that way and could, perhaps, result from a formation mechanism that somewhat favors sytems with roughly equal components. (author)

  13. Reduction of chemical formulas from the isotopic peak distributions of high-resolution mass spectra.

    Science.gov (United States)

    Roussis, Stilianos G; Proulx, Richard

    2003-03-15

    A method has been developed for the reduction of the chemical formulas of compounds in complex mixtures from the isotopic peak distributions of high-resolution mass spectra. The method is based on the principle that the observed isotopic peak distribution of a mixture of compounds is a linear combination of the isotopic peak distributions of the individual compounds in the mixture. All possible chemical formulas that meet specific criteria (e.g., type and number of atoms in structure, limits of unsaturation, etc.) are enumerated, and theoretical isotopic peak distributions are generated for each formula. The relative amount of each formula is obtained from the accurately measured isotopic peak distribution and the calculated isotopic peak distributions of all candidate formulas. The formulas of compounds in simple spectra, where peak components are fully resolved, are rapidly determined by direct comparison of the calculated and experimental isotopic peak distributions. The singular value decomposition linear algebra method is used to determine the contributions of compounds in complex spectra containing unresolved peak components. The principles of the approach and typical application examples are presented. The method is most useful for the characterization of complex spectra containing partially resolved peaks and structures with multiisotopic elements.

  14. Cognitive load in distributed and massed practice in virtual reality mastoidectomy simulation.

    Science.gov (United States)

    Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

    2016-02-01

    Cognitive load theory states that working memory is limited. This has implications for learning and suggests that reducing cognitive load (CL) could promote learning and skills acquisition. This study aims to explore the effect of repeated practice and simulator-integrated tutoring on CL in virtual reality (VR) mastoidectomy simulation. Prospective trial. Forty novice medical students performed 12 repeated virtual mastoidectomy procedures in the Visible Ear Simulator: 21 completed distributed practice with practice blocks spaced in time and 19 participants completed massed practice (all practices performed in 1 day). Participants were randomized for tutoring with the simulator-integrated tutor function. Cognitive load was estimated by measuring reaction time in a secondary task. Data were analyzed using linear mixed models for repeated measurements. The mean reaction time increased by 37% during the procedure compared with baseline, demonstrating that the procedure placed substantial cognitive demands. Repeated practice significantly lowered CL in the distributed practice group but not in massed practice group. In addition, CL was found to be further increased by 10.3% in the later and more complex stages of the procedure. The simulator-integrated tutor function did not have an impact on CL. Distributed practice decreased CL in repeated VR mastoidectomy training more consistently than was seen in massed practice. This suggests a possible effect of skills and memory consolidation occurring over time. To optimize technical skills learning, training should be organized as time-distributed practice rather than as a massed block of practice, which is common in skills-training courses. N/A. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  15. The distributed control system of Shanghai mini-cyclotron accelerator mass spectrometer (SMCAMS)

    International Nuclear Information System (INIS)

    Shao Yuhe

    2001-01-01

    It is mainly introduced the composition, structure, hardware and software designing, function, and the method of communication between the host computer and the ADAM modules of the distributed control system on Shanghai Mini-cyclotron Accelerator Mass Spectrometer (SMCAMS). Some detail problems such as controlling the devices staying on high voltage by ADAM-4541 (RS-485 to Fiber Optic Convertor) and optical fiber are also introduced

  16. Measurement of the Moments of the Hadronic Invariant Mass Distribution in Semileptonic B Decays

    International Nuclear Information System (INIS)

    Acosta, D.

    2005-01-01

    Using 180 pb -1 of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the non-perturbative Heavy Quark Effective Theory parameters Λ and λ 1 used to relate the B meson semileptonic branching ratio to the CKM matrix element |V cb |

  17. Mass spectrometric probes of metal cluster distributions and metastable ion decay

    International Nuclear Information System (INIS)

    Parks, E.K.; Liu, K.; Cole, S.K.; Riley, S.J.

    1988-01-01

    The study of metal clusters has provided both an opportunity and a challenge to the application of mass spectrometry. These days the most often-used technique for cluster generation - laser vaporization - leads to extensive distributions of cluster sizes, from one to perhaps thousands of atoms, and most studies reported to date use excimer laser ionization and time-of-flight mass spectrometry for cluster detection. Our apparatus is a simple one-stage TOF design employing Wiley-McLauren spatial focusing and a one-meter drift tube. In a second apparatus employing a pulsed valve in the cluster source, we see asymmetric broadening of niobium cluster mass peaks under multiphoton ionization conditions, indicating metastable decay of parent cluster ions. Other studies of niobium clusters have shown no such asymmetric peaks. 2 figs

  18. Extension of the pseudo dynamic method to test structures with distributed mass

    International Nuclear Information System (INIS)

    Renda, V.; Papa, L.; Bellorini, S.

    1993-01-01

    The PsD method is a mixed numerical and experimental procedure. At each time step the dynamic deformation of the structure, computed by solving the equation of the motion for a given input signal, is reproduced in the laboratory by means of actuators attached to the sample at specific points. The reaction forces at those points are measured and used to compute the deformation for the next time step. The reaction forces being known, knowledge of the stiffness of the structure is not needed, so that the method can be effective also for deformations leading to strong nonlinear behaviour of the structure. On the contrary, the mass matrix and the applied forces must be well known. For this reason the PsD method can be applied without approximations when the masses can be considered as lumped at the testing points of the sample. The present work investigates the possibility to extend the PsD method to test structures with distributed mass. A standard procedure is proposed to provide an equivalent mass matrix and force vector reduced to the testing points and to verify the reliability of the model. The verification is obtained comparing the results of multi-degrees of freedom dynamic analysis, done by means of a Finite Elements (FE) numerical program, with a simulation of the PsD method based on the reduced degrees of freedom mass matrix and external forces, assuming in place of the experimental reactions, those computed with the general FE model. The method has been applied to a numerical simulation of the behaviour of a realistic and complex structure with distributed mass consisting of a masonry building of two floors. The FE model consists of about two thousand degrees of freedom and the condensation has been made for four testing points. A dynamic analysis has been performed with the general FE model and the reactions of the structure have been recorded in a file and used as input for the PsD simulation with the four degree of freedom model. The comparison between

  19. Nitrogen Transformation and Microbial Spatial Distribution in Drinking Water Biofilter

    Science.gov (United States)

    Qian, Yongxing; Zhang, Huining; Jin, Huizheng; Wu, Chengxia

    2018-02-01

    Well understanding the rule of nitrogen mutual transformation in biofilters is important for controlling the DBPs formation in the subsequent disinfection process. Ammonia nitrogen removal effect and nitrogen transformation approach in biofilter of drinking water was researched in the study. The biofilter removed ammonia of 48.5% and total phosphorus of 72.3%. And the removal rate of TN, NO3 --N, DON were 37.1%, 33.1%, 46.9%, respectively. Biomass and bioactivity of different depth of the biofilter were determined, too. The overall distribution of biomass showed a decreasing trend from top to bottom. The bioactivity in lower layer gradually increased. Especially the bioactivity of heterotrophic microorganisms showed a gradual increase trend. The amount of the nitrogen loss was 3.06mg/L. Non-nitrification pathway of “nitrogen loss” phenomenon in biofilter might exist assimilation, nitrification and denitrification in autotrophic.

  20. Joint physical and numerical modeling of water distribution networks.

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, Adam; O' Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei

    2009-01-01

    This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.

  1. Transients of Water Distribution and Transport in PEFCs

    KAUST Repository

    Hussaini, Irfan

    2008-01-01

    Response of PEM fuel cells to a step-change in load is investigated experimentally in this work. Voltage undershoot, a characteristic feature of such transient response, is shown to be due to transients of water distribution in membrane phase occurring at sub-second time scales. Use of humidified reactants as a means to control magnitude of voltage undershoot has been demonstrated. Constant stoichiometry operation under certain current-step conditions is found to result in reactant starvation, potentially leading to cell shut down. Further, response under step decrease in current density has been explored to determine existence of hysteresis. Under sufficiently humidified conditions, response under forward and reverse step changes are found to be symmetric, but under low RH conditions, voltage undershoot is found to be twice as large as the overshoot. © The Electrochemical Society.

  2. Transients of Water Distribution and Transport in PEM Fuel Cells

    KAUST Repository

    Hussaini, Irfan S.; Wang, Chao-Yang

    2009-01-01

    The response of polymer electrolyte membrane (PEM) fuel cells to a step change in load is investigated experimentally in this work. Voltage undershoot, a characteristic feature of transient response following a step increase in current, is due to transients of water distribution in the membrane and ionomers occurring at subsecond time scales. The use of humidified reactants as a means to control the magnitude of voltage undershoot is demonstrated. Further, the response under a step decrease in current density is explored to determine the existence of hysteresis. Under sufficiently humidified conditions, the responses under forward and reverse step changes are symmetric, but under low relative humidity conditions, voltage undershoot is twice as large as the overshoot. © 2009 The Electrochemical Society.

  3. THE MASS DISTRIBUTION OF STARLESS AND PROTOSTELLAR CORES IN GOULD BELT CLOUDS

    International Nuclear Information System (INIS)

    Sadavoy, Sarah I.; Di Francesco, James; Bontemps, Sylvain; Megeath, S. Thomas; Allgaier, Erin; Rebull, Luisa M.; Carey, Sean; McCabe, Caer-Eve; Noriega-Crespo, Alberto; Padgett, Deborah; Gutermuth, Robert; Hora, Joe; Huard, Tracy; Muzerolle, James; Terebey, Susan

    2010-01-01

    Using data from the SCUBA Legacy Catalogue (850 μm) and Spitzer Space Telescope (3.6-70 μm), we explore dense cores in the Ophiuchus, Taurus, Perseus, Serpens, and Orion molecular clouds. We develop a new method to discriminate submillimeter cores found by Submillimeter Common-User Bolometer Array (SCUBA) as starless or protostellar, using point source photometry from Spitzer wide field surveys. First, we identify infrared sources with red colors associated with embedded young stellar objects (YSOs). Second, we compare the positions of these YSO candidates to our submillimeter cores. With these identifications, we construct new, self-consistent starless and protostellar core mass functions (CMFs) for the five clouds. We find best-fit slopes to the high-mass end of the CMFs of -1.26 ± 0.20, -1.22 ± 0.06, -0.95 ± 0.20, and -1.67 ± 0.72 for Ophiuchus, Taurus, Perseus, and Orion, respectively. Broadly, these slopes are each consistent with the -1.35 power-law slope of the Salpeter initial mass function at higher masses, but suggest some differences. We examine a variety of trends between these CMF shapes and their parent cloud properties, potentially finding a correlation between the high-mass slope and core temperature. We also find a trend between core mass and effective size, but we are very limited by sensitivity. We make similar comparisons between core mass and size with visual extinction (for A V ≥ 3) and find no obvious trends. We also predict the numbers and mass distributions of cores that future surveys with SCUBA-2 may detect in each of these clouds.

  4. Node vulnerability of water distribution networks under cascading failures

    International Nuclear Information System (INIS)

    Shuang, Qing; Zhang, Mingyuan; Yuan, Yongbo

    2014-01-01

    Water distribution networks (WDNs) are important in modern lifeline system. Its stability and reliability are critical for guaranteeing high living quality and continuous operation of urban functions. The aim of this paper is to evaluate the nodal vulnerability of WDNs under cascading failures. Vulnerability is defined to analyze the effects of the consequent failures. A cascading failure is a step-by-step process which is quantitatively investigated by numerical simulation with intentional attack. Monitored pressures in different nodes and flows in different pipes have been used to estimate the network topological structure and the consequences of nodal failure. Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. A load variation function is established to record the nodal failure reason and describe the relative differences between the load and the capacity. The proposed method is validated by an illustrative example. The results revealed that the network vulnerability should be evaluated with the consideration of hydraulic analysis and network topology. In the case study, 70.59% of the node failures trigger the cascading failures with different failure processes. It is shown that the cascading failures result in severe consequences in WDNs. - Highlights: • The aim of this paper is to evaluate the nodal vulnerability of water distribution networks under cascading failures. • Monitored pressures and flows have been used to estimate the network topological structure and the consequences of nodal failure. • Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. • A load variation function is established to record the failure reason and describe the relative differences between load and capacity. • The results show that 70.59% of the node failures trigger the cascading failures with different failure processes

  5. Eddington's demon: inferring galaxy mass functions and other distributions from uncertain data

    Science.gov (United States)

    Obreschkow, D.; Murray, S. G.; Robotham, A. S. G.; Westmeier, T.

    2018-03-01

    We present a general modified maximum likelihood (MML) method for inferring generative distribution functions from uncertain and biased data. The MML estimator is identical to, but easier and many orders of magnitude faster to compute than the solution of the exact Bayesian hierarchical modelling of all measurement errors. As a key application, this method can accurately recover the mass function (MF) of galaxies, while simultaneously dealing with observational uncertainties (Eddington bias), complex selection functions and unknown cosmic large-scale structure. The MML method is free of binning and natively accounts for small number statistics and non-detections. Its fast implementation in the R-package dftools is equally applicable to other objects, such as haloes, groups, and clusters, as well as observables other than mass. The formalism readily extends to multidimensional distribution functions, e.g. a Choloniewski function for the galaxy mass-angular momentum distribution, also handled by dftools. The code provides uncertainties and covariances for the fitted model parameters and approximate Bayesian evidences. We use numerous mock surveys to illustrate and test the MML method, as well as to emphasize the necessity of accounting for observational uncertainties in MFs of modern galaxy surveys.

  6. Impact of Mass and Weight Distribution on Manual Wheelchair Propulsion Torque.

    Science.gov (United States)

    Sprigle, Stephen; Huang, Morris

    2015-01-01

    Propulsion effort of manual wheelchairs, a major determinant of user mobility, is a function of human biomechanics and mechanical design. Human studies that investigate both variables simultaneously have resulted in largely inconsistent outcomes, motivating the implementation of a robotic propulsion system that characterizes the inherent mechanical performance of wheelchairs. This study investigates the impacts of mass and mass distribution on manual wheelchair propulsion by configuring an ultra-lightweight chair to two weights (12-kg and 17.6-kg) and two load distributions (70% and 55% on drive wheels). The propulsion torques of these four configurations were measured for a straight maneuver and a fixed-wheel turn, on both tile and carpet. Results indicated that increasing mass to 17.6-kg had the largest effect on straight acceleration, requiring 7.4% and 5.8% more torque on tile and carpet, respectively. Reducing the drive wheel load to 55% had the largest effect on steady-state straight motion and on both turning acceleration and steady-state turning; for tile and carpet, propulsion torque increased by 13.5% and 11.8%, 16.5% and 4.1%, 73% and 5.1%, respectively. These results demonstrate the robot's high sensitivity, and support the clinical importance of evaluating effects of wheelchair mass and axle position on propulsion effort across maneuvers and surfaces.

  7. Combined uses of water-table fluctuation (WTF), chloride mass ...

    African Journals Online (AJOL)

    Agadaga

    isotopes methods to investigate groundwater recharge ... and isotopic characterization of groundwater, rainfall and the unsaturated zone were also carried out using a ..... Chloride concentrations in soil water extracted by lixiviation from.

  8. Effect of the Discharge Water which Mixed Sewage Disposal Water with Seawater Desalting Treated Sewage for Bottom Sediment and Hypoxic Water Mass

    Science.gov (United States)

    Watanabe, Ryoichi; Yamasaki, Koreyoshi; Minagawa, Tomoko; Iyooka, Hiroki; Kitano, Yoshinori

    For every time in summer season, hypoxic water mass has formed at the inner part of Hakata Bay. Field observation study has carried out at the inner part of Hakata Bay since 2004 with the particular aim of tracking the movement of hypoxic water mass. Hypoxic water masses form the end of June to September on this area because the consumption of oxygen in bottom water layers exceeds the re-supply of oxygen from the atmosphere. Under such hypoxic conditions, the seawater desalination plant has begun to use in 2005. After seawater desalination plant operation starting, hypoxic water mass tends to improve. In this research, the authors show the following result. After seawater desalination plant has begun to operate, the hypoxia around the mixed discharge water outlet tends to be improved.

  9. Heavy water stratification in a low-mass protostar

    NARCIS (Netherlands)

    Coutens, A.; Vastel, C.; Cazaux, S.; Bottinelli, S.; Caux, E.; Ceccarelli, C.; Demyk, K.; Taquet, V.; Wakelam, V.

    Context. Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular deuterium fractionation has been found in the environments of low-mass star-forming regions and, in particular, the Class 0 protostar IRAS 16293-2422. Aims. The key program Chemical HErschel Surveys of Star

  10. Water distribution systems design optimisation using metaheuristics and hyperheuristics

    Directory of Open Access Journals (Sweden)

    DN Raad

    2011-06-01

    Full Text Available The topic of multi-objective water distribution systems (WDS design optimisation using metaheuristics is investigated, comparing numerous modern metaheuristics, including sev- eral multi-objective evolutionary algorithms, an estimation of distribution algorithm and a recent hyperheuristic named AMALGAM (an evolutionary framework for the simultaneous incorporation of multiple metaheuristics, in order to determine which approach is most capa- ble with respect to WDS design optimisation. Novel metaheuristics and variants of existing algorithms are developed, for a total of twenty-three algorithms examined. Testing with re- spect to eight small-to-large-sized WDS benchmarks from the literature reveal that the four top-performing algorithms are mutually non-dominated with respect to the various perfor- mance metrics used. These algorithms are NSGA-II, TAMALGAMJndu , TAMALGAMndu and AMALGAMSndp (the last three being novel variants of AMALGAM. However, when these four algorithms are applied to the design of a very large real-world benchmark, the AMALGAM paradigm outperforms NSGA-II convincingly, with AMALGAMSndp exhibiting the best performance overall.

  11. Increase of Total Body Water with Decrease of Body Mass while Running 100 km Nonstop--Formation of Edema?

    Science.gov (United States)

    Knechtle, Beat; Wirth, Andrea; Knechtle, Patrizia; Rosemann, Thomas

    2009-01-01

    We investigated whether ultraendurance runners in a 100-km run suffer a decrease of body mass and whether this loss consists of fat mass, skeletal muscle mass, or total body water. Male ultrarunners were measured pre- and postrace to determine body mass, fat mass, and skeletal muscle mass by using the anthropometric method. In addition,…

  12. Modeling the improvement of ultrafiltration membrane mass transfer when using biofiltration pretreatment in surface water applications.

    Science.gov (United States)

    Netcher, Andrea C; Duranceau, Steven J

    2016-03-01

    In surface water treatment, ultrafiltration (UF) membranes are widely used because of their ability to supply safe drinking water. Although UF membranes produce high-quality water, their efficiency is limited by fouling. Improving UF filtrate productivity is economically desirable and has been attempted by incorporating sustainable biofiltration processes as pretreatment to UF with varying success. The availability of models that can be applied to describe the effectiveness of biofiltration on membrane mass transfer are lacking. In this work, UF water productivity was empirically modeled as a function of biofilter feed water quality using either a quadratic or Gaussian relationship. UF membrane mass transfer variability was found to be governed by the dimensionless mass ratio between the alkalinity (ALK) and dissolved organic carbon (DOC). UF membrane productivity was optimized when the biofilter feed water ALK to DOC ratio fell between 10 and 14. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    Science.gov (United States)

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.

  14. Classification of breast masses in ultrasonic B scans using Nakagami and K distributions

    International Nuclear Information System (INIS)

    Shankar, P M; Dumane, Vishruta A; George, Thomas; Piccoli, Catherine W; Reid, John M; Forsberg, Flemming; Goldberg, Barry B

    2003-01-01

    Classification of breast masses in greyscale ultrasound images is undertaken using a multiparameter approach. Five parameters reflecting the non-Rayleigh nature of the backscattered echo were used. These parameters, based mostly on the Nakagami and K distributions, were extracted from the envelope of the echoes at the site, boundary, spiculated region and shadow of the mass. They were combined to create a linear discriminant. The performance of this discriminant for the classification of breast masses was studied using a data set consisting of 70 benign and 29 malignant cases. The A z value for the discriminant was 0.96 ± 0.02, showing great promise in the classification of masses into benign and malignant ones. The discriminant was combined with the level of suspicion values of the radiologist leading to an A z value of 0.97 ± 0.014. The parameters used here can be calculated with minimal clinical intervention, so the method proposed here may therefore be easily implemented in an automated fashion. These results also support the recent reports suggesting that ultrasound may help as an adjunct to mammography in breast cancer diagnostics to enhance the classification of breast masses

  15. Mass distributions in monoenergetic-neutron-induced fission of 232Th

    International Nuclear Information System (INIS)

    Glendenin, L.E.; Gindler, J.E.; Ahmad, I.; Henderson, D.J.; Meadows, J.W.

    1980-01-01

    Fission product yields for 38 masses were determined for the fission of 232 Th with essentially monoenergetic neutrons of 2.0, 3.0, 4.0, 5.9, 6.4, 6.9, 7.6, and 8.0 MeV. Fission product activities were measured by Ge(Li) γ-ray spectrometry of irradiated 232 Th foils and by chemical separation of the fission product elements followed by β counting. The mass yield data for 232 Th(n,f ) show a sensitive increase of fission yields in the near-symmetric mass region (valley) with increasing incident neutron energy E/sub n/ and a pronounced dip in yield at the onset of second-chance fission just above the neutron binding energy (at approx. 6 MeV) where the excitation energy is lowered by competition with neutron evaporation prior to fission. The effect of second-chance fission is also seen in the yields of asymmetric peak products. A distinct third peak is observed at symmetry in the valley of the mass distribution, and enhanced yields are observed in the asymmetric peaks at masses associated with even Z (proton pairing effect). The fission yeilds of 232 Th(n,f ) are compared with those of 238 U(n,f ) and 232 Th

  16. Visualizing metabolite distribution and enzymatic conversion in plant tissues by desorption electrospray ionization mass spectrometry imaging

    DEFF Research Database (Denmark)

    Li, Bin; Baden, Camilla Knudsen; Hansen, Natascha Kristine Krahl

    2013-01-01

    In comparison to the technology platforms developed to localize transcripts and proteins, imaging tools for visualization of metabolite distributions in plant tissues are less well developed and lack versatility. This hampers our understanding of plant metabolism and dynamics. In this study we...... demonstrate that Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) of tissue imprints on porous Teflon can be used to accurately image the distribution of even labile plant metabolites such as hydroxynitrile glucosides, which normally undergo enzymatic hydrolysis by specific ß......-glucosidases upon cell disruption. This fast and simple sample preparation resulted in no substantial differences in the distribution and ratios of all hydroxynitrile glucosides between leaves from wildtype Lotus japonicus and a ß-glucosidase mutant plant lacking the ability to hydrolyze certain hydroxynitrile...

  17. Patient distribution in a mass casualty event of an airplane crash.

    Science.gov (United States)

    Postma, Ingri L E; Weel, Hanneke; Heetveld, Martin J; van der Zande, Ineke; Bijlsma, Taco S; Bloemers, Frank W; Goslings, J Carel

    2013-11-01

    Difficulties have been reported in the patient distribution during Mass Casualty Incidents. In this study we analysed the regional patient distribution protocol (PDP) and the actual patient distribution after the 2009 Turkish Airlines crash near Amsterdam. Analysis of the patient distribution of 126 surviving casualties of the crash by collecting data on medical treatment capacity, number of patients received per hospital, triage classification, Injury Severity Score (ISS), secondary transfers, distance from the crash site, and the critical mortality rate. The PDP holds ambiguous definitions of medical treatment capacity and was not followed. There were 14 receiving hospitals (distance from crash: 5.8-53.5 km); four hospitals received 133-213% of their treatment capacity, and 5 hospitals received 1 patient. Three hospitals within 20 km of the crash did not receive any casualties. Level I trauma centres received 89% of the 'critical' casualties and 92% of the casualties with ISS ≥ 16. Only 3 casualties were secondarily transferred, and no casualties died in, or on the way to hospital (critical mortality rate=0%). Patient distribution worked out well after the crash as secondary transfers were low and critical mortality rate was zero. However, the regional PDP was not followed in this MCI and casualties were unevenly distributed among hospitals. The PDP is indistinctive, and should be updated in cooperation between Emergency Services, surrounding hospitals, and Schiphol International Airport as a high risk area. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Bacterial composition in a metropolitan drinking water distribution system utilizing different source waters.

    Science.gov (United States)

    Gomez-Alvarez, Vicente; Humrighouse, Ben W; Revetta, Randy P; Santo Domingo, Jorge W

    2015-03-01

    We investigated the bacterial composition of water samples from two service areas within a drinking water distribution system (DWDS), each associated with a different primary source of water (groundwater, GW; surface water, SW) and different treatment process. Community analysis based on 16S rRNA gene clone libraries indicated that Actinobacteria (Mycobacterium spp.) and α-Proteobacteria represented nearly 43 and 38% of the total sequences, respectively. Sequences closely related to Legionella, Pseudomonas, and Vibrio spp. were also identified. In spite of the high number of sequences (71%) shared in both areas, multivariable analysis revealed significant differences between the GW and SW areas. While the dominant phylotypes where not significantly contributing in the ordination of samples, the populations associated with the core of phylotypes (1-10% in each sample) significantly contributed to the differences between both service areas. Diversity indices indicate that the microbial community inhabiting the SW area is more diverse and contains more distantly related species coexisting with local assemblages as compared with the GW area. The bacterial community structure of SW and GW service areas were dissimilar, suggesting that their respective source water and/or water quality parameters shaped by the treatment processes may contribute to the differences in community structure observed.

  19. Water-Exit Process Modeling and Added-Mass Calculation of the Submarine-Launched Missile

    Directory of Open Access Journals (Sweden)

    Yang Jian

    2017-11-01

    Full Text Available In the process that the submarine-launched missile exits the water, there is the complex fluid solid coupling phenomenon. Therefore, it is difficult to establish the accurate water-exit dynamic model. In the paper, according to the characteristics of the water-exit motion, based on the traditional method of added mass, considering the added mass changing rate, the water-exit dynamic model is established. And with help of the CFX fluid simulation software, a new calculation method of the added mass that is suit for submarine-launched missile is proposed, which can effectively solve the problem of fluid solid coupling in modeling process. Then by the new calculation method, the change law of the added mass in water-exit process of the missile is obtained. In simulated analysis, for the water-exit process of the missile, by comparing the results of the numerical simulation and the calculation of theoretical model, the effectiveness of the new added mass calculation method and the accuracy of the water-exit dynamic model that considers the added mass changing rate are verified.

  20. Structure of electron tracks in water. 2. Distribution of primary ionizations and excitations in water radiolysis

    International Nuclear Information System (INIS)

    Pimblott, S.M.; Mozumder, A.

    1991-01-01

    A procedure for the calculation of entity-specific ionization and excitation probabilities for water radiolysis at low linear energy transfer (LET) has been developed. The technique pays due attention to the effects of the ionization threshold and the energy dependence of the ionization efficiency. The numbers of primary ionizations and excitations are not directly proportional to the spur energy. At a given spur energy, ionization follows a binomial distribution subject to an energetically possible maximum. The excitation distribution for a spur of given energy and with a given number of ionizations is given by a geometric series. The occurrence probabilities depend upon the cross sections of ionization, excitation, and other inferior processes. Following the low-LET radiolysis of liquid water the most probable spurs contain one ionization, two ionizations, or one ionization and one excitation, while in water vapor they contain either one ionization or one excitation. In liquid water the most probable outcomes for spurs corresponding to the most probable energy loss (22 eV) and to the mean energy loss (38 eV) are one ionization and one excitation, and two ionizations and one excitation, respectively. In the vapor, the most probable energy loss is 14 eV which results in one ionization or one excitation and the mean energy loss is 34 eV for which the spur of maximum probability contains one ionization and two excitations. The total calculated primary yields for low-LET radiolysis are in approximate agreement with experiment in both phases

  1. Recharge Estimation Using Water, Chloride and Isotope Mass Balances

    Science.gov (United States)

    Dogramaci, S.; Firmani, G.; Hedley, P.; Skrzypek, G.; Grierson, P. F.

    2014-12-01

    Discharge of surplus mine water into ephemeral streams may elevate groundwater levels and alter the exchange rate between streams and underlying aquifers but it is unclear whether volumes and recharge processes are within the range of natural variability. Here, we present a case study of an ephemeral creek in the semi-arid subtropical Hamersley Basin that has received continuous mine discharge for more than five years. We used a numerical model coupled with repeated measurements of water levels, chloride concentrations and the hydrogen and oxygen stable isotope composition (δ2H and δ18O) to estimate longitudinal evapotranspiration and recharge rates along a 27 km length of Weeli Wolli Creek. We found that chloride increased from 74 to 120 mg/L across this length, while δ18O increased from -8.24‰ to -7.00‰. Groundwater is directly connected to the creek for the first 13 km and recharge rates are negligible. Below this point, the creek flows over a highly permeable aquifer and water loss by recharge increases to a maximum rate of 4.4 mm/d, which accounts for ~ 65% of the total water discharged to the creek. Evapotranspiration losses account for the remaining ~35%. The calculated recharge from continuous flow due to surplus water discharge is similar to that measured for rainfall-driven flood events along the creek. Groundwater under the disconnected section of the creek is characterised by a much lower Cl concentration and more depleted δ18O value than mining discharge water but is similar to flood water generated by large episodic rainfall events. Our results suggest that the impact of recharge from continuous flow on the creek has not extended beyond 27 km from the discharge point. Our approach using a combination of hydrochemical and isotope methods coupled with classical surface flow hydraulic modelling allowed evaluation of components of water budget otherwise not possible in a highly dynamic system that is mainly driven by infrequent but large episodic

  2. Characterization of Bacteria in Ballast Water Using MALDI-TOF Mass Spectrometry

    Digital Repository Service at National Institute of Oceanography (India)

    Emami, K.; Askari, V.; Ullrich, M.; Mohinudeen, K.; Anil, A.C.; Khandeparker, L.; Burgess, J.G.; Mesbahi, E.

    To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Since...

  3. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains data presented in the figures of the paper "On the implications of aerosol liquid water and phase separation for organic aerosol mass"...

  4. Seasonal spreading of the Persian Gulf water mass in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Prasad, T.G.; Ikeda, M.; PrasannaKumar, S.

    The characteristics of the subsurface salinity maximum associated with the Persian Gulf Water mass (PGW) are used to quantify the spreading and mixing of PGW in the thermocline of the Arabian Sea based on a bimonthly climatology of temperature...

  5. Mycobacteria in water and loose deposits of drinking water distribution systems in Finland.

    Science.gov (United States)

    Torvinen, Eila; Suomalainen, Sini; Lehtola, Markku J; Miettinen, Ilkka T; Zacheus, Outi; Paulin, Lars; Katila, Marja-Leena; Martikainen, Pertti J

    2004-04-01

    Drinking water distribution systems were analyzed for viable counts of mycobacteria by sampling water from waterworks and in different parts of the systems. In addition, loose deposits collected during mechanical cleaning of the main pipelines were similarly analyzed. The study covered 16 systems at eight localities in Finland. In an experimental study, mycobacterial colonization of biofilms on polyvinyl chloride tubes in a system was studied. The isolation frequency of mycobacteria increased from 35% at the waterworks to 80% in the system, and the number of mycobacteria in the positive samples increased from 15 to 140 CFU/liter, respectively. Mycobacteria were isolated from all 11 deposits with an accumulation time of tens of years and from all 4 deposits which had accumulated during a 1-year follow-up time. The numbers of mycobacteria were high in both old and young deposits (medians, 1.8 x 10(5) and 3.9 x 10(5) CFU/g [dry weight], respectively). Both water and deposit samples yielded the highest numbers of mycobacteria in the systems using surface water and applying ozonation as an intermediate treatment or posttreatment. The number and growth of mycobacteria in system waters correlated strongly with the concentration of assimilable organic carbon in the water leaving the waterworks. The densities of mycobacteria in the developing biofilms were highest at the distal sites of the systems. Over 90% of the mycobacteria isolated from water and deposits belonged to Mycobacterium lentiflavum, M. tusciae, M. gordonae, and a previously unclassified group of mycobacteria. Our results indicate that drinking water systems may be a source for recently discovered new mycobacterial species.

  6. Circulation and water masses of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Gouveia, A.D.; Shenoi, S.S.C.

    1500-3500 m). It is further speculated that the flow in this layer consists of a poleward western boundary current and a weak equatorward flow in the interior. It is not known if there is an annual cycle associated with the deep and the bottom water...

  7. Guidelines for transient analysis in water transmission and distribution systems

    NARCIS (Netherlands)

    Pothof, I.W.M.; Karney, B.W.

    2012-01-01

    All water systems leak, and many supply systems do so considerably, with water losses typically of approximately 20% of the water production. The IWA Water Loss Task Force aims for a significant reduction of annual water losses by drafting documents to assist practitioners and others to prevent,

  8. Mass photosynthesis and distribution of photo assimilates of winter wheat varieties with different maturity feature

    International Nuclear Information System (INIS)

    Wang Fahong; Zhao Junshi

    1996-01-01

    The mass photosynthesis rate and distribution of photoassimilates of winter wheat varieties with different maturity feature were studied using GXH-305 portable CO 2 infrared ray analyzer. The mass photosynthesis rate of winter wheat varieties with better maturity feature showed little difference from the varieties with general maturity feature during the early stage of grain filling phase. However, the mass photosynthesis rate of the former was significantly higher than that of the later during the middle and late stage of grain filling. The study with 14 CO 2 -tracing method showed that the relative activity in different organs of varieties with better maturity feature was significantly higher than that of varieties with worse maturity feature during the later growth stage of winter wheat. The rate of photoassimilates distribution in stalk and root system of winter wheat varieties with better maturity was higher than that in the others organs. The physiological mechanism of difference of grain yield and plant decay in varieties with different maturity feature were also discussed

  9. Derivation from first principles of the statistical distribution of the mass peak intensities of MS data.

    Science.gov (United States)

    Ipsen, Andreas

    2015-02-03

    Despite the widespread use of mass spectrometry (MS) in a broad range of disciplines, the nature of MS data remains very poorly understood, and this places important constraints on the quality of MS data analysis as well as on the effectiveness of MS instrument design. In the following, a procedure for calculating the statistical distribution of the mass peak intensity for MS instruments that use analog-to-digital converters (ADCs) and electron multipliers is presented. It is demonstrated that the physical processes underlying the data-generation process, from the generation of the ions to the signal induced at the detector, and on to the digitization of the resulting voltage pulse, result in data that can be well-approximated by a Gaussian distribution whose mean and variance are determined by physically meaningful instrumental parameters. This allows for a very precise understanding of the signal-to-noise ratio of mass peak intensities and suggests novel ways of improving it. Moreover, it is a prerequisite for being able to address virtually all data analytical problems in downstream analyses in a statistically rigorous manner. The model is validated with experimental data.

  10. Water vapor mass balance method for determining air infiltration rates in houses

    Science.gov (United States)

    David R. DeWalle; Gordon M. Heisler

    1980-01-01

    A water vapor mass balance technique that includes the use of common humidity-control equipment can be used to determine average air infiltration rates in buildings. Only measurements of the humidity inside and outside the home, the mass of vapor exchanged by a humidifier/dehumidifier, and the volume of interior air space are needed. This method gives results that...

  11. Analysis of combined heat and mass transfer of water- Vapor in a ...

    African Journals Online (AJOL)

    In this paper, the combined heat and mass transfer of water-vapor into a cylindrical zeolite adsorber has been numerically simulated The twodimensional heat and mass transfer equations are numerically solved using gPROMS program - a general Process Modeling System {lJ program, inserting the proper initial and ...

  12. Analysis of combined heat and mass transfer of water-vapor in a ...

    African Journals Online (AJOL)

    Jn this paper, the combined heat and mass transfer of water-vapor into a cylindrical zeolite adsorber has been numerically simulated The twodimensional heat and mass transfer equations are numerically solved using gPROMS program - a general Process Modeling System [J] program, inserting the proper initial and ...

  13. Model description of dibenzothiophene mass transfer in oil/water dispersions with respect to biodesulfurization

    NARCIS (Netherlands)

    Marcelis, C.L.M.; Leeuwen, van M.; Polderman, H.G.; Janssen, A.J.H.; Lettinga, G.

    2003-01-01

    A mathematical model was developed in order to describe the mass transfer rate of dibenzothiophene within the oil droplet to the oil/water interface of droplets created in a stirred tank reactor. The mass transfer rate of dibenzothiophene was calculated for various complex hydrocarbon distillates

  14. Assessment of water quality in distribution networks through the lens ...

    African Journals Online (AJOL)

    2016-04-02

    Apr 2, 2016 ... method, which identifies the regions with relatively poor water quality and highlights the potential locations for ... intelligent decision-making based on the results and the imple- ... A water supply system where water is treated.

  15. Estrogenic activity, chemical levels and health risk assessment of municipal distribution point water from Pretoria and Cape Town, South Africa.

    Science.gov (United States)

    Van Zijl, Magdalena Catherina; Aneck-Hahn, Natalie Hildegard; Swart, Pieter; Hayward, Stefan; Genthe, Bettina; De Jager, Christiaan

    2017-11-01

    Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. The samples were collected seasonally over four sampling periods. The samples were also analysed for bisphenol A (BPA), nonylphenol (NP), di(2-ethylhexyl) adipate (DEHA), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononylphthalate (DINP), 17β-estradiol (E 2 ), estrone (E 1 ) and ethynylestradiol (EE 2 ) using ultra-performance liquid chromatography-tandem mass spectrophotometry (UPLC-MS/MS). This was followed by a scenario based health risk assessment to assess the carcinogenic and toxic human health risks associated with the consumption of distribution point water. None of the water extracts from the distribution points were above the detection limit in the YES bioassay, but the EEq values ranged from 0.002 to 0.114 ng/L using the T47D-KBluc bioassay. BPA, DEHA, DBP, DEHP, DINP E 1 , E 2, and EE 2 were detected in distribution point water samples. NP was below the detection limit for all the samples. The estrogenic activity and levels of target chemicals were comparable to the levels found in other countries. Overall the health risk assessment revealed acceptable health and carcinogenic risks associated with the consumption of distribution point water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The Study of Prompt and Delayed Muon Induced Fission. I.Total kinetic energies and mass distributions

    NARCIS (Netherlands)

    David, P; Hartfiel, J.; Janszen, H.; Petitjean, C.; Reist, H.W.; Polikanov, S.M.; Konijn, J.; Laat, de C.T.A.M.; Taal, A.; Krogulski, T.; Johansson, T.; Tibell, G.; Achard van Enschut, d' J.F.M.

    1987-01-01

    Mass yield and total kinetic energy release (TKE) distributions of fragments from prompt and delayed muon induced fission, separately, have been measured for the isotopes235U,238U,237Np and242Pu. The distributions from prompt muon induced fission are compared with the corresponding distributions

  17. Sunflower petals: Some physical properties and modeling distribution of their number, dimensions, and mass

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mirzabe

    2018-06-01

    Full Text Available Sunflower petal is one of the parts of the sunflower which has drawn attention and has several applications these days. These applications justify getting information about physical properties, mechanical properties, drying trends, etc. in order to design new machines and use new methods to harvest or dry the sunflower petals. For three varieties of sunflower, picking force of petals was measured; number of petals of each head was counted; unit mass and 1000-unit mass of fresh petals were measured and length, width, and projected area of fresh petals were calculated based on image processing technique; frequency distributions of these parameters were modeled using statistical distribution models namely Gamma, Generalized Extreme Value (G. E. V, Lognormal, and Weibull. Results of picking force showed that with increasing number of days after appearing the first petal on each head from 5 to 14 and decreasing loading rate from 150 g min−1 to 50 g min−1 values of picking force were decreased for three varieties, but diameter of sunflower head had different effects on picking force for each variety. Length, width, and number of petals of Dorsefid variety ranged from 38.52 to 95.44 mm, 3.80 to 9.28 mm and 29 to 89, respectively. The corresponding values ranged from 34.19 to 88.18 mm, 4.28 to 10.60 mm and 21 to 89, respectively for Shamshiri variety and ranged from 44.47 to 114.63 mm, 7.03 to 20.31 mm and 29 to 89 for Sirena variety. Results of frequency distribution modeling indicated that in most cases, G. E. V and Weibull distributions had better performance than other distributions. Keywords: Sunflower (Helianthus annus L. petal, Picking force, Image processing, Fibonacci sequence, Lucas sequence

  18. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    Science.gov (United States)

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  19. Assessing microbiological water quality in drinking water distribution systems with disinfectant residual using flow cytometry.

    Science.gov (United States)

    Gillespie, Simon; Lipphaus, Patrick; Green, James; Parsons, Simon; Weir, Paul; Juskowiak, Kes; Jefferson, Bruce; Jarvis, Peter; Nocker, Andreas

    2014-11-15

    Flow cytometry (FCM) as a diagnostic tool for enumeration and characterization of microorganisms is rapidly gaining popularity and is increasingly applied in the water industry. In this study we applied the method to obtain a better understanding of total and intact cell concentrations in three different drinking water distribution systems (one using chlorine and two using chloramines as secondary disinfectants). Chloramine tended to result in lower proportions of intact cells than chlorine over a wider residual range, in agreement with existing knowledge that chloramine suppresses regrowth more efficiently. For chlorinated systems, free chlorine concentrations above 0.5 mg L(-1) were found to be associated with relatively low proportions of intact cells, whereas lower disinfectant levels could result in substantially higher percentages of intact cells. The threshold for chlorinated systems is in good agreement with guidelines from the World Health Organization. The fact that the vast majority of samples failing the regulatory coliform standard also showed elevated proportions of intact cells suggests that this parameter might be useful for evaluating risk of failure. Another interesting parameter for judging the microbiological status of water, the biological regrowth potential, greatly varied among different finished waters providing potential help for investment decisions. For its measurement, a simple method was introduced that can easily be performed by water utilities with FCM capability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  1. Spatiotemporal distribution and mass loadings of perfluoroalkyl substances in the Yangtze River of China.

    Science.gov (United States)

    Pan, Chang-Gui; Ying, Guang-Guo; Zhao, Jian-Liang; Liu, You-Sheng; Jiang, Yu-Xia; Zhang, Qian-Qian

    2014-09-15

    A systematic investigation into contamination profiles of eighteen perfluoroalkyl substances (PFASs) in both surface water and sediments of Yangtze River was carried out by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in summer and winter of 2013. The total concentrations of the PFASs in the water and sediment of Yangtze River ranged from 2.2 to 74.56 ng/L and 0.05 to 1.44 ng/g dry weights (dw), respectively. The PFAS concentrations were correlated to some selected water quality parameters such as pH, total phosphorus (TP), total nitrogen (TN) and conductivity in water, and some sediment properties, such as total organic carbon (TOC), TP, and TN in sediment. The monitoring results for the water and sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctanoic acid (PFOA) was the dominant PFAS compound found both in water and sediment for the two seasons with its maximum concentration of 18.03 ng/L in water and 0.72 ng/g in sediment, followed by perfluorobutane sulfonic acid (PFBS) with its maximum concentration of 41.9 ng/L in water in Wuhan, whereas the lowest concentrations of PFASs were observed at Poyang lake. The annual loadings of PFOA, perfluorohexanoic acid (PFHxA), PFBS, perfluorooctane sulfonic acid (PFOS) and the total PFASs in the Yangtze River were 6.8 tons, 2.2 tons, 8.2 tons, 0.88 tons, and 20.7 tons, respectively. Wuhan and Er'zhou of Hubei contributed the most amounts of PFASs into the Yangtze River. A correlation was found between some PFASs, for example PFBS and PFOS, which suggests that both of these PFASs originate from common sources in the region. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Using high performance interconnects in a distributed computing and mass storage environment

    International Nuclear Information System (INIS)

    Ernst, M.

    1994-01-01

    Detector Collaborations of the HERA Experiments typically involve more than 500 physicists from a few dozen institutes. These physicists require access to large amounts of data in a fully transparent manner. Important issues include Distributed Mass Storage Management Systems in a Distributed and Heterogeneous Computing Environment. At the very center of a distributed system, including tens of CPUs and network attached mass storage peripherals are the communication links. Today scientists are witnessing an integration of computing and communication technology with the open-quote network close-quote becoming the computer. This contribution reports on a centrally operated computing facility for the HERA Experiments at DESY, including Symmetric Multiprocessor Machines (84 Processors), presently more than 400 GByte of magnetic disk and 40 TB of automoted tape storage, tied together by a HIPPI open-quote network close-quote. Focussing on the High Performance Interconnect technology, details will be provided about the HIPPI based open-quote Backplane close-quote configured around a 20 Gigabit/s Multi Media Router and the performance and efficiency of the related computer interfaces

  3. Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses

    Directory of Open Access Journals (Sweden)

    Marte Gutierrez

    2015-12-01

    Full Text Available Fracture systems have strong influence on the overall mechanical behavior of fractured rock masses due to their relatively lower stiffness and shear strength than those of the rock matrix. Understanding the effects of fracture geometrical distribution, such as length, spacing, persistence and orientation, is important for quantifying the mechanical behavior of fractured rock masses. The relation between fracture geometry and the mechanical characteristics of the fractured rock mass is complicated due to the fact that the fracture geometry and mechanical behaviors of fractured rock mass are strongly dependent on the length scale. In this paper, a comprehensive study was conducted to determine the effects of fracture distribution on the equivalent continuum elastic compliance of fractured rock masses over a wide range of fracture lengths. To account for the stochastic nature of fracture distributions, three different simulation techniques involving Oda's elastic compliance tensor, Monte Carlo simulation (MCS, and suitable probability density functions (PDFs were employed to represent the elastic compliance of fractured rock masses. To yield geologically realistic results, parameters for defining fracture distributions were obtained from different geological fields. The influence of the key fracture parameters and their relations to the overall elastic behavior of the fractured rock mass were studied and discussed. A detailed study was also carried out to investigate the validity of the use of a representative element volume (REV in the equivalent continuum representation of fractured rock masses. A criterion was also proposed to determine the appropriate REV given the fracture distribution of the rock mass.

  4. Developing a Mass Casualty Surge Capacity Protocol for Emergency Medical Services to Use for Patient Distribution.

    Science.gov (United States)

    Shartar, Samuel E; Moore, Brooks L; Wood, Lori M

    2017-12-01

    Metropolitan areas must be prepared to manage large numbers of casualties related to a major incident. Most US cities do not have adequate trauma center capacity to manage large-scale mass casualty incidents (MCIs). Creating surge capacity requires the distribution of casualties to hospitals that are not designated as trauma centers. Our objectives were to extrapolate MCI response research into operational objectives for MCI distribution plan development; formulate a patient distribution model based on research, hospital capacities, and resource availability; and design and disseminate a casualty distribution tool for use by emergency medical services (EMS) personnel to distribute patients to the appropriate level of care. Working with hospitals within the region, we refined emergency department surge capacity for MCIs and developed a prepopulated tool for EMS providers to use to distribute higher-acuity casualties to trauma centers and lower-acuity casualties to nontrauma hospitals. A mechanism to remove a hospital from the list of available resources, if it is overwhelmed with patients who self-transport to the location, also was put into place. The number of critically injured survivors from an MCI has proven to be consistent, averaging 7% to 10%. Moving critically injured patients to level 1 trauma centers can result in a 25% reduction in mortality, when compared with care at nontrauma hospitals. US cities face major gaps in the surge capacity needed to manage an MCI. Sixty percent of "walking wounded" casualties self-transport to the closest hospital(s) to the incident. Directing critically ill patients to designated trauma centers has the potential to reduce mortality associated with the event. When applied to MCI responses, damage-control principles reduce resource utilization and optimize surge capacity. A universal system for mass casualty triage was identified and incorporated into the region's EMS. Flagship regional coordinating hospitals were designated

  5. Mass transfer of H2O between petroleum and water: implications for oil field water sample quality

    International Nuclear Information System (INIS)

    McCartney, R.A.; Ostvold, T.

    2005-01-01

    Water mass transfer can occur between water and petroleum during changes in pressure and temperature. This process can result in the dilution or concentration of dissolved ions in the water phase of oil field petroleum-water samples. In this study, PVT simulations were undertaken for 4 petroleum-water systems covering a range of reservoir conditions (80-185 o C; 300-1000 bar) and a range of water-petroleum mixtures (volume ratios of 1:1000-300:1000) to quantify the extent of H 2 O mass transfer as a result of pressure and temperature changes. Conditions were selected to be relevant to different types of oil field water sample (i.e. surface, downhole and core samples). The main variables determining the extent of dilution and concentration were found to be: (a) reservoir pressure and temperature, (b) pressure and temperature of separation of water and petroleum, (c) petroleum composition, and (d) petroleum:water ratio (PWR). The results showed that significant dilution and concentration of water samples could occur, particularly at high PWR. It was not possible to establish simple guidelines for identifying good and poor quality samples due to the interplay of the above variables. Sample quality is best investigated using PVT software of the type used in this study. (author)

  6. Infrared Tomography: Data Distribution System for Real-time Mass Flow Rate Measurement

    Directory of Open Access Journals (Sweden)

    Ruzairi Abdul Rahim

    2007-06-01

    Full Text Available The system developed in this research has the objective of measuring mass flow rate in an online mode. If a single computer is used as data processing unit, a longer time is needed to produce a measurement result. In the research carried out by previous researcher shows about 11.2 seconds is needed to obtain one mass flow rate result in the offline mode (using offline data. This insufficient real-time result will cause problems in a feedback control process when applying the system on industrial plants. To increase the refreshing rate of the measurement result, an investigation on a data distribution system is performed to replace the existing data processing unit.

  7. Influence of mass-asymmetry and ground state spin on fission fragment angular distributions

    International Nuclear Information System (INIS)

    Thomas, R.G.; Biswas, D.C.; Saxena, A.; Pant, L.M.; Nayak, B.K.; Vind, R.P.; Sahu, P.K.; Sinha, Shrabani; Choudhury, R.K.

    2001-01-01

    The strong influence of the target or/and projectile ground state spin on the anomalously large anisotropies of fission fragments produced in the heavy-ion induced fission of actinide targets were reported earlier. Interestingly, all those systems studied were having a mass asymmetry greater than the Businaro-Gallone critical asymmetry and hence the presence of pre-equilibrium fission was unambiguously ruled out. The observed anisotropies were successfully explained using the ECD-K-States model. It is of interest to know the influence of the target/projectile ground state spin on systems having an entrance channel mass asymmetry less than the critical value where pre-equilibrium fission cannot be ignored. With this motivation we performed measurements of fission fragment angular distributions of the 16 O+ 235 U (spin=7/2) system

  8. Feed water distribution pipe replacement at Loviisa NPP

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, S.; Elsing, B. [Imatran Voima Loviisa NPP (Finland)

    1995-12-31

    Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

  9. Feed water distribution pipe replacement at Loviisa NPP

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, S; Elsing, B [Imatran Voima Loviisa NPP (Finland)

    1996-12-31

    Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

  10. Multi-year analysis of distributed glacier mass balance modelling and equilibrium line altitude on King George Island, Antarctic Peninsula

    Science.gov (United States)

    Falk, Ulrike; López, Damián A.; Silva-Busso, Adrián

    2018-04-01

    The South Shetland Islands are located at the northern tip of the Antarctic Peninsula (AP). This region was subject to strong warming trends in the atmospheric surface layer. Surface air temperature increased about 3 K in 50 years, concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. The positive trend in surface air temperature has currently come to a halt. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to ±1.0 K (100 m)-1) and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns. The increased mesocyclonic activity during the wintertime over the past decades in the study area results in intensified advection of warm, moist air with high temperatures and rain and leads to melt conditions on the ice cap, fixating surface air temperatures to the melting point. Its impact on winter accumulation results in the observed negative mass balance estimates. Six years of continuous glaciological measurements on mass balance stake transects as well as 5 years of climatological data time series are presented and a spatially distributed glacier energy balance melt model adapted and run based on these multi-year data sets. The glaciological surface mass balance model is generally in good agreement with observations, except for atmospheric conditions promoting snow drift by high wind speeds, turbulence-driven snow deposition and snow layer erosion by rain. No drift in the difference between simulated mass balance and mass balance measurements can be seen over the course of the 5-year model run period. The winter accumulation does not suffice to compensate for the high variability in summer ablation. The results are analysed to assess changes in meltwater input to the coastal waters, specific glacier mass balance and the equilibrium line altitude (ELA). The Fourcade Glacier catchment drains

  11. Mass and galaxy distributions of four massive galaxy clusters from Dark Energy Survey Science Verification data

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, P.; Suchyta, E.; Huff, E.; Hirsch, M.; Kacprzak, T.; Rykoff, E.; Gruen, D.; Armstrong, R.; Bacon, D.; Bechtol, K.; Bernstein, G. M.; Bridle, S.; Clampitt, J.; Honscheid, K.; Jain, B.; Jouvel, S.; Krause, E.; Lin, H.; MacCrann, N.; Patton, K.; Plazas, A.; Rowe, B.; Vikram, V.; Wilcox, H.; Young, J.; Zuntz, J.; Abbott, T.; Abdalla, F. B.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Castander, F. J.; da Costa, L. N.; Cunha, C. E.; Depoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; Evrard, A. E.; Neto, A. F.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Frieman, J. A.; Gaztanaga, E.; Gerdes, D.; Gruendl, R. A.; Gutierrez, G. R.; Jarvis, M.; Karliner, I.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marriner, J.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Mohr, J.; Neilsen, E.; Nichol, R. C.; Nord, B. D.; Reil, K.; Roe, N. A.; Roodman, A.; Sako, M.; Sanchez, E.; Santiago, B. X.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, C.; Soares-Santos, M.; Swanson, M. E. C.; Sypniewski, A. J.; Tarle, G.; Thaler, J.; Thomas, D.; Tucker, D. L.; Walker, A.; Wechsler, R.; Weller, J.; Wester, W.

    2015-03-31

    We measure the weak-lensing masses and galaxy distributions of four massive galaxy clusters observed during the Science Verification phase of the Dark Energy Survey. This pathfinder study is meant to 1) validate the DECam imager for the task of measuring weak-lensing shapes, and 2) utilize DECam's large field of view to map out the clusters and their environments over 90 arcmin. We conduct a series of rigorous tests on astrometry, photometry, image quality, PSF modeling, and shear measurement accuracy to single out flaws in the data and also to identify the optimal data processing steps and parameters. We find Science Verification data from DECam to be suitable for the lensing analysis described in this paper. The PSF is generally well-behaved, but the modeling is rendered difficult by a flux-dependent PSF width and ellipticity. We employ photometric redshifts to distinguish between foreground and background galaxies, and a red-sequence cluster finder to provide cluster richness estimates and cluster-galaxy distributions. By fitting NFW profiles to the clusters in this study, we determine weak-lensing masses that are in agreement with previous work. For Abell 3261, we provide the first estimates of redshift, weak-lensing mass, and richness. In addition, the cluster-galaxy distributions indicate the presence of filamentary structures attached to 1E 0657-56 and RXC J2248.7-4431, stretching out as far as 1 degree (approximately 20 Mpc), showcasing the potential of DECam and DES for detailed studies of degree-scale features on the sky.

  12. MEASUREMENT OF THE MASS AND STELLAR POPULATION DISTRIBUTION IN M82 WITH THE LBT

    Energy Technology Data Exchange (ETDEWEB)

    Greco, Johnny P.; Martini, Paul; Thompson, Todd A., E-mail: greco.40@buckeyemail.osu.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2012-09-20

    We present a K-band spectroscopic study of the stellar and gas kinematics, mass distribution, and stellar populations of the archetypical starburst galaxy M82. Our results are based on a single spectrum at a position angle of 67.{sup 0}5 through the K-band nucleus. We used the {sup 12}CO stellar absorption band head at 2.29 {mu}m (CO{sub 2.29}) to measure the rotation curve out to nearly 4 kpc radius on both the eastern and western sides of the galaxy. Our data show that the rotation curve is flat from 1 to 4 kpc. This stands in sharp contrast to some previous studies, which have interpreted H I and CO emission-line position-velocity diagrams as evidence for a declining rotation curve. The kinematics of the Br{gamma}, H{sub 2}, and He I emission lines are consistent with, although characterized by slightly higher velocities than, the stellar kinematics. We derived M82's mass distribution from our stellar kinematic measurements and estimate that its total dynamical mass is {approx}10{sup 10} M{sub Sun }. We measured the equivalent width of CO{sub 2.29} (W{sub 2.29}) as a function of distance from the center of the galaxy to investigate the spatial extent of the red supergiant (RSG) population. The variation in W{sub 2.29} with radius clearly shows that RSGs dominate the light inside 500 pc radius. M82's superwind is likely launched from this region, where we estimate that the enclosed mass is {approx}<2 Multiplication-Sign 10{sup 9} M{sub Sun }.

  13. [Mass maritime casualty incidents in German waters: structures and resources].

    Science.gov (United States)

    Castan, J; Paschen, H-R; Wirtz, S; Dörges, V; Wenderoth, S; Peters, J; Blunk, Y; Bielstein, A; Kerner, T

    2012-07-01

    The Central Command for Maritime Emergencies was founded in Germany in 2003 triggered by the fire on board of the cargo ship "Pallas" in 1998. Its mission is to coordinate and direct measures at or above state level in maritime emergency situations in the North Sea and the Baltic Sea. A special task in this case is to provide firefighting and medical care. To face these challenges at sea emergency doctors and firemen have been specially trained. This form of organization provides a concept to counter mass casualty incidents and peril situations at sea. Since the foundation of the Central Command for Maritime Emergencies there have been 5 operations for firefighting units and 4 for medical response teams. Assignments and structure of the Central Command for Maritime Emergencies are unique in Europe.

  14. Channel Extension in Deep-Water Distributive Systems

    Science.gov (United States)

    Hoyal, D. C.; Sheets, B. A.

    2007-12-01

    acceleration to Fr'-critical conditions and the formation of a depositional hydraulic jump, which perturbs sediment transport and ends channel extension. Similar morphodynamic length scale controls are observed in shallow water fan-delta experiments (e.g., SAFL DB-03) and in 2-D depositional cyclic steps. The experiments seem to explain two interesting observations from the earlier self-organized fan experiments and from real submarine fans. Firstly, the observation of 'perched' fills at the steep entrances to salt withdrawal minibasins (e.g., in the Gulf of Mexico) suggesting higher sedimentation rates (or inefficient sediment transport) on higher slopes (initially higher than at the slope break downstream). Secondly, strong progradation as the fan evolves and slope decreases in 'perched' fans suggests increasing flow efficiency on lower slopes, at least over a certain window of parameter space. Apparently deep water systems have a tendency to self-regulate even when flows differ significantly in initial density. The observed modulation to Fr'-critical flow appears to be an important control on length scales in deep- water distributive channel systems, potentially explaining strong deepwater progradation or 'delta-like' patterns that have remained paradoxical. Near critical conditions have been inferred from observations of many active submarine fans but the extent to which these results from conservative density currents apply to non-conservative and potentially 'ignitive' turbidity currents is the subject of ongoing investigation.

  15. Fitting probability distributions to component water quality data from ...

    African Journals Online (AJOL)

    The treatment of water is carried out to make the available water meet the standards for its intended use. Such use may be for drinking and other household needs, industries,livestock rearing or fisheries etc. poor quality water is commonly treated to ensure potability. Potable water should be free from unpleasant tastes and ...

  16. Partition distribution of selected organochlorine pesticides in water ...

    African Journals Online (AJOL)

    Organochlorine pesticides (OCPs) were analysed in surface water, pore water and surface sediment samples collected from the uMngeni River, which is one of the largest rivers in the province of KwaZulu-Natal, South Africa. Liquid-liquid extraction was used to extract the analytes from water and pore water samples and ...

  17. Spreading of water masses and regeneration of silica and sup(226)Ra in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; Yuan-Hui, Li

    The magnitudes of silica and sup(226) RA inputs to water (through particle regeneration, in situ, and from sediments) and the validity of observed Si and sup(226) Ra as tracers of water masses and advective processes were examined in the Indian...

  18. Water masses and general hydrography along the west coast of India during early March

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Varkey, M.J.; Das, V.K.; Gouveia, A.D.

    Structure of water masses along the west coast of India from Bombay to Trivandrum has been studied through vertical sections of temperature, salinity and density during 3-17 March 1977. The Arabian Sea high salinity water spreads south as a core...

  19. Experimental and Numerical Studies of Controlling Thermal Cracks in Mass Concrete Foundation by Circulating Water

    Directory of Open Access Journals (Sweden)

    Wenchao Liu

    2016-04-01

    Full Text Available This paper summarizes an engineering experience of solving the problem of thermal cracking in mass concrete by using a large project, Zhongguancun No.1 (Beijing, China, as an example. A new method is presented for controlling temperature cracks in the mass concrete of a foundation. The method involves controlled cycles of water circulating between the surface of mass concrete foundation and the atmospheric environment. The temperature gradient between the surface and the core of the mass concrete is controlled at a relatively stable state. Water collected from the well-points used for dewatering and from rainfall is used as the source for circulating water. Mass concrete of a foundation slab is experimentally investigated through field temperature monitoring. Numerical analyses are performed by developing a finite element model of the foundation with and without water circulation. The calculation parameters are proposed based on the experiment, and finite element analysis software MIDAS/CIVIL is used to calculate the 3D temperature field of the mass concrete during the entire process of heat of hydration. The numerical results are in good agreement with the measured results. The proposed method provides an alternative practical basis for preventing thermal cracks in mass concrete.

  20. MAVEN Observations of Escaping Planetary Ions from the Martian Atmosphere: Mass, Velocity, and Spatial Distributions

    Science.gov (United States)

    Dong, Yaxue; Fang, Xiaohua; Brain, D. A.; McFadden, James P.; Halekas, Jasper; Connerney, Jack

    2015-04-01

    The Mars-solar wind interaction accelerates and transports planetary ions away from the Martian atmosphere through a number of processes, including ‘pick-up’ by electromagnetic fields. The MAVEN spacecraft has made routine observations of escaping planetary ions since its arrival at Mars in September 2014. The SupraThermal And Thermal Ion Composition (STATIC) instrument measures the ion energy, mass, and angular spectra. It has detected energetic planetary ions during most of the spacecraft orbits, which are attributed to the pick-up process. We found significant variations in the escaping ion mass and velocity distributions from the STATIC data, which can be explained by factors such as varying solar wind conditions, contributions of particles from different source locations and different phases during the pick-up process. We also study the spatial distributions of different planetary ion species, which can provide insight into the physics of ion escaping process and enhance our understanding of atmospheric erosion by the solar wind. Our results will be further interpreted within the context of the upstream solar wind conditions measured by the MAVEN Solar Wind Ion Analyzer (SWIA) instrument and the magnetic field environment measured by the Magnetometer (MAG) instrument. Our study shows that the ion spatial distribution in the Mars-Sun-Electric-Field (MSE) coordinate system and the velocity space distribution with respect to the local magnetic field line can be used to distinguish the ions escaping through the polar plume and those through the tail region. The contribution of the polar plume ion escape to the total escape rate will also be discussed.