WorldWideScience

Sample records for natural water conditions

  1. Effects of Soil Management Practices on Water Erosion under Natural Rainfall Conditions on a Humic Dystrudept

    Directory of Open Access Journals (Sweden)

    Vinicius Ferreira Chaves de Souza

    Full Text Available ABSTRACT Water erosion is the main cause of soil degradation and is influenced by rainfall, soil, topography, land use, soil cover and management, and conservation practices. The objective of this study was to quantify water erosion in a Humic Dystrudept in two experiments. In experiment I, treatments consisted of different rates of fertilizer applied to the soil surface under no-tillage conditions. In experiment II, treatments consisted of a no-tillage in natural rangeland, burned natural rangeland and natural rangeland. Forage turnip, black beans, common vetch, and corn were used in rotation in the treatments with crops in the no-tillage during study period. The treatments with crops and the burned rangeland and natural rangeland were compared to a bare soil control, without cultivation and without fertilization. Increasing fertilization rates increased organic carbon content, soil resistance to disintegration, and the macropore volume of the soil, due to the increase in the dry mass of the crops, resulting in an important reduction in water erosion. The exponential model of the ŷ = ae-bx type satisfactorily described the reduction in water and soil losses in accordance with the increase in fertilization rate and also described the decrease in soil losses in accordance with the increase in dry mass of the crops. Water erosion occurred in the following increasing intensity: in natural rangeland, in cultivated natural rangeland, and in burned natural rangeland. Water erosion had less effect on water losses than on soil losses, regardless of the soil management practices.

  2. Changes in Isotopic Composition of Bottled Natural Waters Due to Different Storage Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ferjan, T. [Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Brencic, M. [Faculty of Natural Sciences and Engineering, Department of Geology, and Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Vreca, P. [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia)

    2013-07-15

    To establish the influence of environmental conditions on processes affecting the stable isotopic composition of bottled water during storage, various brands of bottled water were exposed for 2 years in different conditions. Selected low mineralized natural mineral water of one particular brand stored in polyethylene terephthalate (PET) bottles was placed at three different locations with different physical conditions (temperature, relative humidity, air pressure, exposure to sunlight). For comparison, bottles of three other low mineralized natural mineral water brands, each from a different aquifer source, were placed in parallel at one of the locations. Each location was characterized by temperature, relative humidity and air pressure measurements. pH, conductivity and stable isotopic composition of oxygen, hydrogen and carbon in dissolved inorganic carbon ({delta}{sup 18}O, {delta}{sup 2}H, {delta}{sup 13}C{sub DIC}) were measured in regular intervals for nearly two years. Preliminary results from each location show noticeable changes in isotopic composition as well as the physical parameters of water with time of storage.

  3. Numerical prediction of the natural frequency of an Oscillating Water Column operating under resonant conditions

    Directory of Open Access Journals (Sweden)

    Marco Torresi

    2016-12-01

    Full Text Available Among the different technologies developed in order to harness wave energy, the Oscillating Water Column devices are the most accredited for an actual diffusion. Recently, Boccotti has patented the REWEC1 (REsonant sea Wave Energy Converter solution 1, a submerged breakwater that performs an active coast protection, embedding an Oscillating Water Column device, which is capable of operating under resonant conditions with that sea state, which gives the highest yearly energy contribution. The REWEC1 dynamic behavior can be approximated by means of a mass-spring-damper system. According to this approximation, a criterion for evaluating the oscillating natural frequency of the REWEC1 has been derived. This criterion has been validated against both experimental results and computational fluid dynamics simulations, performed on a REWEC1 laboratory-scale model. The numerical simulations have shown a good agreement between measurements and predictions.

  4. Zone peculiarities of natural conditions, affecting ran food stuffs and drinking water contamination with radionuclides

    International Nuclear Information System (INIS)

    Marej, A.N.

    1980-01-01

    The effect of natural conditions on the USSR territory connected with peculiar types of soil on the behaviour of radionuclides fallen from stratosphere is considered. Characteristics of tundra, taiga partially-wooded steppe, step.oe, mountain and semi-desert zones are presented. Peculiarities of soils in different geographical zones of the USSR conditioned by various properties and compositions have a significant effect on 90 Sr and especially 137 Cs migration intensity from the soil into plants and organisms of animals through biological chains. The administration of radionuclides in the ration with food stuffs obtained on the surface of reservoirs where zonality low is also rightful, is studied. It is established that indexes of 90 Sr and 137 Cs buildup in tissues of hydrobionts are in reverse dependence on calcium and potassium content in water. Therefore, maximum levels of 90 Sr and 137 Cs buildup in fish is characteristic of zones with the low content of these elements. The degree of water mineralization in ponds has a clear zonality which increases in the direction from the North to the South. The degree of pond well-drained nature is of great importance

  5. Conditions of competition between the production of water by desalination and natural resources

    International Nuclear Information System (INIS)

    Gaussens, J.

    1969-01-01

    A close examination of the local supply and demand for fresh water is involved when considering a sea water desalination plant in a given region. This examination makes it possible in most cases to undertake a thorough study of the natural resources, resulting in the use of desalination being rejected. After confirming this fact by precise examples, the authors consider that the preliminary study should be extended, taking into account the complementary character of natural resources and desalination systems: contribution to peak demand, contribution to base demand. This analysis results in a classification of the main user regions according to certain economic criteria defining their suitability for the use of desalination processes. (author) [fr

  6. Natural Babesia bovis Infection in Water Buffaloes (Bubalus bubalis and Crossbred Cattle under Field Conditions in Egypt: a Preliminary Study.

    Directory of Open Access Journals (Sweden)

    Yasser Mahmmod

    2014-06-01

    Full Text Available There is a little or no data available on the natural Babesia bovis (B. bovis infection in water buffaloes (Bubalus bubalis comparing to the available one for cattle. This study was conducted to investigate the natural B. bovis infection in water buffaloes in comparison to crossbred cattle under field conditions in Egypt.A total of 35 buffaloes and cattle were clinically and laboratory investigated from March to June 2008. Twenty-nine buffaloes and cattle out of 35 were naturally infected with B. bovis and showed signs of bovine babesiosis. Three cows and three buffaloes showed no clinical signs and were free from external, internal, and blood parasites served as control group.Babesia bovis-infected cattle showed typical signs of bovine babesiosis while B. bovis-infected buffaloes showed a milder form (less severe of the clinical signs. Advanced cases of cattle showed dark brown to dark red (coffee-color urine, hemoglobinuria and nervous manifestations while these manifestations were not detected in the infected buffaloes. Hematological changes in both species however, these changes were less significant in buffaloes than those reported in cattle.This paper documents the first description of natural B. bovis infection in water buffaloes which were found to be more likely to be tolerant than cattle to the natural clinical infection with B. bovis and its subsequent haematological changes. Our finding may lead to a better understanding of the disease pattern of B. bovis infection under field conditions in buffaloes.

  7. Transport of perfluoroalkyl acids in a water-saturated sediment column investigated under near-natural conditions

    International Nuclear Information System (INIS)

    Vierke, Lena; Möller, Axel; Klitzke, Sondra

    2014-01-01

    The aim of this study was to gain an understanding of the transport of C 4–10 perfluoroalkyl carboxylic acids (PFCAs) and C 4,6,8 perfluoroalkyl sulfonic acids (PFSAs) in a water-saturated sediment column representing a riverbank filtration scenario under near-natural conditions. Short-chain PFCAs and PFSAs with up to six C-atoms showed complete tracer-like breakthrough. Longer chain ones were retarded due to sorption to the sediment or due to other processes in the aqueous phase. The study reports the first column derived sediment–water partition coefficients ranging from 0.01 cm 3 g −1 to 0.41 cm 3 g −1 for C 4,6 PFSAs and from 0.0 cm 3 g −1 to 6.5 cm 3 g −1 for C 4,5,6,8,9 PFCAs. The results clearly indicate that short-chain PFCAs and PFSAs may pose a problem if contaminated surface waters are used for drinking water production via riverbank filtration. Highlights: • Transport of per- and polyfluorinated compounds in a riverbank filtration scenario. • Investigations under near-natural conditions with a water-saturated sediment column. • Processes in water and sediment control the transport of analytes. • Short chain PFCAs and PFSAs are not retarded in the water-saturated sediment column. • First column derived sediment–water partition coefficients. -- Quantification of breakthrough of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) under conditions simulating a riverbank filtration scenario

  8. The features of element concentration in natural waters of the Kola North in conditions of environmental contamination

    Science.gov (United States)

    Bazova, Mariya; Moiseenko, Tatyana

    2016-04-01

    main processes that determine the conditions of residence and the behavior of elements in the water lakes. It was found that a key role in the formation of natural waters has the cumulative effect of landscape-geochemical conditions and anthropogenic impact. A great contribution, as shown by factorial analysis, make humic acid, which enhance the migratory activity elements. Jeffries D.S. (1997) Canadian acid rain assessment. Toronto. 3, 113 p. Moiseenko T.I. (1999) The fate of metals in Arctic surface waters: Method for defining critical levels Sci. Total Environ. 236, 19-39. Mannio J. (2001) Responces of headwater lakes to air pollution changes in Finland: Acad. Diss. Helsinki: Univ. Helsinki, 226 p. Moiseenko T.I., Gashkina N.A. (2007) Distribution of trace elements in surface waters and feature of their migration // Water resources. V. 34, № 4. P. 454-468. Moiseenko T.I. (2005) Water acidification and behavior of trace elements // Geochemistry. V.10. P.1120-1127. This work has done under the grant of the Russian Foundation of Fundamental Research (ofi_m) №15-29-06948 «The features formation of water quality conditions in Arctic regions of development mineral resources: algorithms settlements of permissible impact»

  9. Assessment of spatial and temporal patterns of green and blue water flows under natural conditions in inland river basins in Northwest China

    Directory of Open Access Journals (Sweden)

    C. F. Zang

    2012-08-01

    Full Text Available In arid and semi-arid regions freshwater resources have become scarcer with increasing demands from socio-economic development and population growth. Until recently, water research and management has mainly focused on blue water but ignored green water. Furthermore, in data poor regions hydrological flows under natural conditions are poorly characterised but are a prerequisite to inform future water resources management. Here we report on spatial and temporal patterns of both blue and green water flows that can be expected under natural conditions as simulated by the Soil and Water Assessment Tool (SWAT for the Heihe river basin, the second largest inland river basin in Northwest China. Calibration and validation at two hydrological stations show good performance of the SWAT model in modelling hydrological processes. The total green and blue water flows were 22.05–25.51 billion m3 in the 2000s for the Heihe river basin. Blue water flows are larger in upstream sub-basins than in downstream sub-basins mainly due to high precipitation and a large amount of snow and melting water in upstream. Green water flows are distributed more homogeneously among different sub-basins. The green water coefficient was 87%–89% in the 2000s for the entire river basin, varying from around 80%–90% in up- and mid-stream sub-basins to above 90% in downstream sub-basins. This is much higher than reported green water coefficients in many other river basins. The spatial patterns of green water coefficients were closely linked to dominant land covers (e.g. snow cover upstream and desert downstream and climate conditions (e.g. high precipitation upstream and low precipitation downstream. There are no clear consistent historical trends of change in green and blue water flows and the green water coefficient at both the river basin and sub-basin levels. This study provides insights into green and blue water endowments under natural conditions for the entire

  10. Variations on seepage water geochemistry induced by natural and anthropogenic microclimatic changes: Implications for the speleothems growth conditions

    Science.gov (United States)

    Fernandez-Cortes, A.; Sanchez-Moral, S.; Canaveras, J. C.; Cuevas, J.; Cuezva, S.; Andreu, J. M.; Abella, R.

    2009-04-01

    During an annual cycle the effect of microclimatic changes (natural and anthropogenic origin) on the geochemical characteristics of seepage water and mineral precipitation rates was analyzed, for two karstic caves under opposing environmental stability and energy exchange with exterior. On the one hand Castañar cave (Caceres, Spain), an extremely controlled show cave with limited visitation showing a minimum exchange rate of energy with the outer atmosphere and, secondly, Canelobre cave (Alicante, Spain), a widely visited cave where the anthropogenic impact generates both high-speed and high-energy environmental changes. Microclimatic variations play a key role in CO2-dessgasing caused by the imbalance of pCO2 between the karstic water and the cave air, favoring the slow processes of mineral precipitation. Thus, a pCO2-range of seepage water have been detected for each cave (from 10-2.30/-2.35 to 10-2.47/-2.52 bar for Castañar cave, and from 10-2.8/-2.85 to 10-2.95/-3.0 bar for Canelobre cave) where the mineral oversaturation prevails, determining the type and rate of mineral precipitation in each cave. Finally, it analyzes how the changes on the oversaturation/ precipitation states are controlled by microclimatic variations, such as: 1) natural underground air renewal through the porous system of upper soil and the network of host-rock fissures (isolating membranes), or else through the cave entrance, 2) cumulative disruptions in the pCO2 levels of cave air due to the presence of visitors, and 3) forced ventilation of the subterranean atmosphere due to the uncontrolled opening of cave entrances. The obtained results reinforce the significance of the microclimatic fluctuations on short time scales in the dynamic and evolution of the subterranean karst system, in terms of rates of mineral precipitation and growth of speleothems. Likewise the interpretations are useful in order to ensure the constant climate required for the conservation of caves.

  11. Natural radioactivity in water supplies

    International Nuclear Information System (INIS)

    Horner, J.K.

    1985-01-01

    This book outlines the scientific aspects of the control of natural radioactivity in water supplies, as well as the labyrinthine uncertainties in water quality regulation concerning natural radiocontamination of water. The author provides an introduction to the theory of natural radioactivity; addresses risk assessment, sources of natural radiocontamination of water, radiobiology of natural radioactivity in water, and federal water law concerning natural radiocontamination. It presents an account of how one city dealt with the perplexes that mark the rapidly evolving area of water quality regulation. The contents include: radioactivity and risk; an introduction to the atomic theory; an introduction to natural radioactivity; risk assessment; uranium and radium contamination of water; radiobiology of uranium and radium in water. Determination of risk from exposure to uranium and radium in water; the legal milieu; one city's experience; and summary: the determinants of evolving regulation

  12. Assessment of natural and technogenic conditions of the area of the water-supply system upgrade in Dudinka (Krasnoyarsk Region, Russia

    Directory of Open Access Journals (Sweden)

    Bryukhan Fedor

    2018-01-01

    Full Text Available Territories of the subarctic forest-tundra of Taymyr are characterized by an insufficient state of exploration of their natural conditions. Another feature is vulnerability of natural landscapes to man-made impacts. Along with this, the increased public attention to preservation of the ecological status of these territories necessitates detailed studies of environment components during construction activities. This work is devoted to the geoecological substantiation of the water-supply system upgrade in Dudinka (Taimyr Dolgan-Nenets Autonomous District of the Krasnoyarsk Region, Russia, considering specific natural conditions of the sub-arctic forest-tundra and technogenic impacts of the upgrade project. This work describes primary results of engineering and environmental surveys, which provided necessary and sufficient basic data. It was established that due to a localized nature of technogenic impacts during environmental activities, the combined impact of technogenic factors is insignificant and will not cause environment degradation. A set of recommendations and proposals for environment protection and ecological monitoring organization was developed.

  13. Changes in water and sediment exchange between the Changjiang River and Poyang Lake under natural and anthropogenic conditions, China.

    Science.gov (United States)

    Gao, Jian Hua; Jia, Jianjun; Kettner, Albert J; Xing, Fei; Wang, Ya Ping; Xu, Xia Nan; Yang, Yang; Zou, Xin Qing; Gao, Shu; Qi, Shuhua; Liao, Fuqiang

    2014-05-15

    To study the fluvial interaction between Changjiang River and Poyang Lake, we analyze the observed changes of riverine flux of the mid-upstream of Changjiang River catchment, the five river systems of Poyang Lake and Poyang Lake basin. Inter-annual and seasonal variations of the water discharge and sediment exchange processes between Changjiang River and Poyang Lake are systematically explored to determine the influence of climate change as well as human impact (especially the Three Gorges Dam (TGD)). Results indicate that climate variation for the Changjiang catchment and Poyang Lake watershed is the main factor determining the changes of water exchanges between Changjiang River and Poyang Lake. However, human activities (including the emplacement of the TGD) accelerated this rate of change. Relative to previous years (1956-1989), the water discharge outflow from Poyang Lake during the dry season towards the Changjiang catchment increased by 8.98 km(3)y(-1) during 2003-2010. Evidently, the water discharge flowing into Poyang Lake during late April-late May decreased. As a consequence, water storage of Poyang Lake significantly reduced during late April-late May, resulting in frequent spring droughts after 2003. The freshwater flux of Changjiang River towards Poyang Lake is less during the flood season as well, significantly lowering the magnitude and frequency of the backflow of the Changjiang River during 2003-2010. Human activities, especially the emplacement and operation of the TGD and sand mining at Poyang Lake impose a major impact on the variation of sediment exchange between Changjiang main river and Poyang Lake. On average, sediments from Changjiang River deposited in Poyang Lake before 2000. After 2000, Changjiang River no longer supplied sediment to Poyang Lake. As a consequence, the sediment load of Changjiang River entering the sea increasingly exists of sediments from Lake Poyang during 2003-2010. As a result, Poyang Lake converted from a

  14. Natural gas adsorption on coal in anhydrous and in water saturated conditions: study of the adsorbed quantities and of the isotopic fractionation

    International Nuclear Information System (INIS)

    Caja, M.

    2000-02-01

    In order to understand the influence of adsorption in the migration of natural gas in sedimentary basins. we have developed an experimental device to measure the quantity of gas adsorbed on organic matter. We quantify the isotopic and chemical fractionation due to adsorption of natural gas on coal at representative gas field conditions (20 - 200 deg C and 1 - 1000 bar). These effects are investigated for gas / solid systems and for gas dissolved in water/water saturated solid systems. The solid sample considered in this work is a natural coal of Carboniferous age, taken from a mine in Lorraine, France. Its maturity corresponds to the end of the diagenesis zone. A first set of high pressure methane adsorption experiments on dry coal are compared with measurements done by another laboratory on the same solid. This allowed us to validate the experimental procedure. This measurements performed in the presence of water have shown that methane adsorption is significant even in presence of water. We have developed a simple adsorption model (Langmuir model in which fugacity is used in stead of partial pressure) in order to represent this phenomena. For a depth profile we compare the part of methane adsorbed on sedimentary rocks organic matter to methane dissolved in pore water. A second set of experiments realised on a multicomponent gas (C1, C2, C3, C4, CO 2 ) shows a preferential adsorption of carbon dioxide, but no significant fractionation on hydrocarbon gases of the mixture has been observed. Adsorption experiments of methane on dry medium and on water saturated medium yield on the same result: adsorption equilibrium do not induce a significant isotopic fractionation between 13 CH 4 and 12 CH 4 . However, we observe a significant fractionation during gas desorption. The interpretation is that we are not at equilibrium and diffusion phenomena is superimposed on adsorption. From this study two important geological consequences can be drawn. First. for rocks containing

  15. Cyanobacterial diversity and related sedimentary facies as a function of water flow conditions: Example from the Monasterio de Piedra Natural Park (Spain)

    Science.gov (United States)

    Berrendero, Esther; Arenas, Concha; Mateo, Pilar; Jones, Brian

    2016-05-01

    The River Piedra in the Monasterio de Piedra Natural Park (NE Spain) is a modern tufa-depositing river that encompasses various depositional environments that are inhabited by different cyanobacterial populations. Molecular (16S rDNA) and morphological analyses of the cyanobacteria from different facies showed that Phormidium incrustatum dominates in the fast-flowing water areas where the mean depositional rate is 1.6 cm/year. Stromatolites in these areas are formed of palisades of hollow calcite tubes (inner diameter of 6.0-7.5 μm, walls 2-12 μm thick) that formed through calcite encrustation around the filaments followed by decay of the trichomes. In contrast, in slow-flowing water areas with lower depositional rates (mean depositional rate of 0.3 cm/year), Phormidium aerugineo-caeruleum is the dominant species. In these areas, randomly oriented calcite tubes (inner diameter of 5-6 μm, walls 3-8 μm thick) formed by calcite encrustation, are found in thin and uneven laminae and as scattered tubes in the loose lime mud and sand-sized carbonate sediment. Although this species did not build laminated deposits, it gave cohesiveness to the loose sediment. In the stepped and low waterfalls, with intermediate deposition rates (mean depositional rate of 0.9 cm/year), both species of Phormidium are found in association with spongy moss and algal boundstones, which is consistent with the variable flow conditions in this setting. The calcite encrustations on the cyanobacteria from different environments exhibit irregular patterns that may be linked to changes in the calcite saturation index. The physicochemical conditions associated with extracellular polymeric substances may be more significant to CaCO3 precipitation in microbial mats in slow-flowing water conditions than in fast-flowing water conditions. These results show that flow conditions may influence the distribution of different cyanobacteria that, in turn, leads to the development of different sedimentary

  16. Microbiological quality of natural waters.

    Science.gov (United States)

    Borrego, J J; Figueras, M J

    1997-12-01

    Several aspects of the microbiological quality of natural waters, especially recreational waters, have been reviewed. The importance of the water as a vehicle and/or a reservoir of human pathogenic microorganisms is also discussed. In addition, the concepts, types and techniques of microbial indicator and index microorganisms are established. The most important differences between faecal streptococci and enterococci have been discussed, defining the concept and species included. In addition, we have revised the main alternative indicators used to measure the water quality.

  17. Feasibility of Mapping Riparian Habitats Under Natural Conditions in California

    Science.gov (United States)

    David R. Dawdy

    1989-01-01

    The California State Water Resources Control Board is conducting hearings to set quantity and quality standards for river flows into San Francisco Bay. Comparisons of present conditions with "natural conditions" prior to European settlement were introduced into the hearings. Consumptive use relations were developed for various riparian and water-related...

  18. Regional scenario building as a tool to support vulnerability assessment of food & water security and livelihood conditions under varying natural resources managements

    Science.gov (United States)

    Reinhardt, Julia; Liersch, Stefan; Dickens, Chris; Kabaseke, Clovis; Mulugeta Lemenih, Kassaye; Sghaier, Mongi; Hattermann, Fred

    2013-04-01

    Participatory regional scenario building was carried out with stakeholders and local researchers in four meso-scale case studies (CS) in Africa. In all CS the improvement of food and / or water security and livelihood conditions was identified as the focal issue. A major concern was to analyze the impacts of different plausible future developments on these issues. The process of scenario development is of special importance as it helps to identify main drivers, critical uncertainties and patterns of change. Opportunities and constraints of actors and actions become clearer and reveal adaptation capacities. Effective strategies must be furthermore reasonable and accepted by local stakeholders to be implemented. Hence, developing scenarios and generating strategies need the integration of local knowledge. The testing of strategies shows how they play out in different scenarios and how robust they are. Reasons and patterns of social and natural vulnerability can so be shown. The scenario building exercise applied in this study is inspired by the approach from Peter Schwartz. It aims at determining critical uncertainties and to identify the most important driving forces for a specific focal issue which are likely to shape future developments of a region. The most important and uncertain drivers were analyzed and systematized with ranking exercises during meetings with local researchers and stakeholders. Cause-effect relationships were drawn in the form of concept maps either during the meetings or by researchers based on available information. Past observations and the scenario building outcomes were used to conduct a trend analysis. Cross-comparisons were made to find similarities and differences between CS in terms of main driving forces, patterns of change, opportunities and constraints. Driving forces and trends which aroused consistently over scenarios and CS were identified. First results indicate that livelihood conditions of people rely often directly on the

  19. Waste water discharges into natural waters

    International Nuclear Information System (INIS)

    Marri, P.; Barsanti, P.; Mione, A.; Posarelli, M.

    1996-12-01

    The aqueous discharges into natural waters is a very technical solution expecially for surface buoyant discharges. It is not only convenient to limit the concentration levels of the discharges, but also to improve the turbolent processes that diluite the discharge. Mostly these processes depend by some geometric parameters of the discharge and by some physical parameters of the effluent and of the receiving water body. An appropriate choice of some parameters, using also suitable mathematical models, allows to design discharges with a very high dilution; so the decreasing of the pollutant levels is improved and the environmental impact can be reduced versus a not diluted effluent. The simulations of a mathematical model, here described, prove that in some circumstances, expecially in case of discharges of fresh water into saline water bodies with a low velocity of the current, the dilution is poor; the effluent can be trapped in a narrow water surface layer where the pollutant concentrations remain high. also far away from the discharge point

  20. Natural Babesia bovis infection in water buffaloes (Bubalus bubalis) and crossbred cattle under field conditions in Egypt

    DEFF Research Database (Denmark)

    Mahmmod, Yasser

    2014-01-01

    showed no clinical signs and were free from external, internal, and blood parasites served as control group. Results: Babesia bovis-infected cattle showed typical signs of bovine babesiosis while B. bovis-infected buffaloes showed a milder form (less severe) of the clinical signs. Advanced cases...... cattle under field conditions in Egypt. Methods: A total of 35 buffaloes and cattle were clinically and laboratory investigated from March to June 2008. Twenty-nine buffaloes and cattle out of 35 were naturally infected with B. bovis and showed signs of bovine babesiosis. Three cows and three buffaloes...

  1. Plasma and brain angiotensin concentrations associated with water response behavior in the desert anuran, Scaphiopus couchii under natural conditions in the field.

    Science.gov (United States)

    Johnson, William E; Hillyard, Stanley D; Propper, Catherine R

    2010-12-01

    Terrestrial amphibians obtain water by absorption across a specialized region of the ventral skin and exhibit a behavior, the water absorption response (WR) to place that region in contact with moist surfaces. Spadefoot toads (Scaphiopus couchii) spend dry months of the year in burrows, then emerge during brief periods of summer rainfall and seek water sources for rehydration and reproduction. We tested the hypothesis that these toads have changes in plasma and/or central angiotensin concentrations that are associated with seasonal emergence and WR behavior. Immunoreactive concentrations of combined angiotensin II and III (ir-ANG) were measured in plasma samples and microdissected regions of brain tissue taken from toads moving across the road or toads showing WR behavior in shallow puddles on the road. Plasma ir-ANG concentrations were not significantly different between these groups, but were significantly higher in the periventricular region of the hypothalamus in toads showing WR behavior. Concentrations in other brain regions, while highly variable among individuals, were not different between groups. Within the context of the natural history of a specialized desert toad, these results support the hypothesis that ir-ANG is associated with WR behavior in spadefoot toads in a manner analogous to oral drinking exhibited by other vertebrate clades. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Boundary conditions for natural supply ventilation

    NARCIS (Netherlands)

    Jansen, D.W.L.; Loomans, M.G.L.C.; Wit, de M.H.; Zeiler, W.; Seppänen, O.; Säteri, J.

    2007-01-01

    The development of an air jet from a controlled natural ventilation grill for different outdoor conditions is studied. Extensive laboratory measurements are taken in different situations, while the air flow rate through the grill is kept constant. The grill setting and supply temperature are varied.

  3. Ammonium ion interaction with conditioned natural zeolite with silver and its effect on the disinfection of polluted water in front of a consortium of gram (+) and gram (-) microorganisms

    International Nuclear Information System (INIS)

    Gonzaga G, V. E.

    2013-01-01

    Clinoptilolite zeolite material is a relative abundance in Mexico, which has ion exchange properties, therefore, has the ability to retain metal ions giving it an application in the process of disinfecting of water contaminated with pathogenic microorganisms. In this research, we conducted a study of disinfection of water contaminated with a microbial consortium, from a zeolite rock clinoptilolite from a deposit located in the State of Guerrero. Initially, the zeolite prepared by the grinding and sieving, for conditioning with NaCl and subsequently with AgNO 3 , finally to be characterized using the techniques of scanning electron microscopy and X-ray diffraction. Tests using columns packed with zeolite material, the effect of zeolite bactericidal conditioned with silver (ZGAg) against a microbial consortium consisting of Escherichia coli and Sthapyloccocus aureus in aqueous solution in the presence of ammonium ions used to increase the ion exchange with zeolite fitted with silver. To describe curves disinfecting a continuous flow system is adapted Gu pta model, which describes the kinetics and equilibrium adsorption process, considering the microorganisms as the adsorbate and the sanitizing agent (conditioned with silver zeolite) as the adsorbent. Characterization results show that in the scanning electron microscopy (Sem), no changes were obtained on the morphology of typical clinoptilolite crystals before and after that was modified with sodium and then with silver, it is worth mentioning however that fitted with silver zeolite (ZGAg), small particles are seen on the zeolite material which when analyzed by energy dispersive spectroscopy (EDS), we found a high concentration of Ag +. The disinfection period is increased as the concentration increased ammonium ions, this behavior is attributed to the ion exchange that occurs between the ammonium ions and silver ions. A lower percentage of inactivation is due, therefore, to a lesser amount of money available to be

  4. Effectiveness of solar disinfection using batch reactors with non-imaging aluminium reflectors under real conditions: Natural well-water and solar light.

    Science.gov (United States)

    Navntoft, C; Ubomba-Jaswa, E; McGuigan, K G; Fernández-Ibáñez, P

    2008-12-11

    Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compound parabolic collector (CPC) mirrors to enhance the efficiency of solar disinfection (SODIS) for batch reactors under real, solar radiation (cloudy and cloudless) conditions. On clear days, the system with CPC reflectors achieved complete inactivation (more than 5-log unit reduction in bacterial population to below the detection limit of 4CFU/mL) one hour sooner than the system fitted with no CPC. On cloudy days, only systems fitted with CPCs achieved complete inactivation. Degradation of the mirrors under field conditions was also evaluated. The reflectivity of CPC systems that had been in use outdoors for at least 3 years deteriorated in a non-homogeneous fashion. Reflectivity values for these older systems were found to vary between 27% and 72% compared to uniform values of 87% for new CPC systems. The use of CPC has been proven to be a good technological enhancement to inactivate bacteria under real conditions in clear and cloudy days. A comparison between enhancing optics and thermal effect is also discussed.

  5. Influence of weather conditions on natural radioactivity

    International Nuclear Information System (INIS)

    Simion, Florin; Simion, Elena; Cuculeanu, Vasile; Mihalcea, Ion

    2011-01-01

    This paper presents the dependence of the natural radioactivity on atmospheric weather conditions: air temperature, atmospheric pressure, wind speed, atmospherical precipitations and relative humidity. The values used in the paper were taken from the environmental radioactivity monitoring in Botosani city, Romania, as measured by the Environmental Radioactivity Surveillance Station. Daily global measurements of atmospheric deposition beta and atmospheric aerosols as well were carried out, including the indirect determination of radon and thoron, and the absorbed gamma dose rate in air, as well. Sampling and measurement frequency depended on the type of sample analyzed as follows: atmospheric deposition were taken daily, atmospheric aerosols were collected 4 times/day, with a sampling interval of 5 hours while the air absorbed dose rate was determined at a hourly rate. The coefficient of multiple correlation between the type of analysis and weather conditions, was determined. By using multiple linear regression it was highlighted the natural radioactivity dependence on the atmospheric conditions and meteorological parameters by a mathematical expression that can be used to determine missing values in a time series of measured data. By predicting the measured values our procedure can be considered as a validation process of the measurement accuracy

  6. Natural mineral waters: chemical characteristics and health effects

    Science.gov (United States)

    Quattrini, Sara; Pampaloni, Barbara; Brandi, Maria Luisa

    2016-01-01

    Summary Water contributes significantly to health and a daily intake of 1.5 to 2 liters of water should be guaranteed, because a good hydration is essential to maintain the body water equilibrium, although needs may vary among people. However, worldwide population is far from the Recommended Allowance for water intake. Among the waters for human uses, there are ‘waters (treated or not), intended for drinking, used for the food and beverages preparation or for other domestic purposes’ and natural mineral waters, that are ‘originated from an aquifer or underground reservoir, spring from one or more natural or bore sources and have specific hygienic features and, eventually, healthy properties’. According to the European Legislation (2009/54/EC Directive), physical and chemical characterization is used to make a classification of the different mineral waters, basing on the analysis of main parameters. Mineral composition enables to classify natural mineral waters as bicarbonate mineral waters, sulphate mineral waters, chloride mineral waters, calcic mineral waters, magnesiac mineral waters, fluorurate mineral waters, ferrous mineral waters and sodium-rich mineral waters. Although the concerns about bottled mineral waters (due to plasticizers and endocrine disruptors), many are the health effects of natural mineral waters and several studies explored their properties and their role in different physiological and pathological conditions. PMID:28228777

  7. Technetium sorption by stibnite from natural water

    International Nuclear Information System (INIS)

    Peretroukhine, V.; Sergeant, C.; Deves, G.; Poulain, S.; Vesvres, M.H.; Thomas, B.; Simonoff, M.

    2006-01-01

    The sorption of technetium by powdered and polished mineral stibnite Sb 2 S 3 has been investigated in simulated and natural underground waters from the Meuse/Haute-Marne region (France). The sorption by powdered stibnite has been found to be complete under both aerobic and anaerobic conditions in batch experiments. The sorption rate is higher in the absence of oxygen than under aerobic condition. Increasing the temperature from 30 C to 60 C results in a rise of the sorption rate by 9.1 and 27 times under anaerobic and aerobic conditions, respectively. The observed differences in sorption kinetics in the presence and in absence of oxygen are explained by the interaction of oxygen with sulfide ion in aerobic conditions and by the reduction of technetium(VII) by iron(II) and by other impurities present in natural water and in the mineral, and by the subsequent sorption of Tc(IV) on stibnite under anaerobic conditions. The sorption on a polished mineral surface resulted in the formation of a technetium film, probably Tc 2 S 7 , with a thickness of 1-3 μg Tc/cm 2 pH 3-6 and 4-12 μg Tc/cm 2 at 9-12. The simultaneous formation of stibnite colloids with adsorbed technetium occurs at pH 9-12. The study of the technetium film on the mineral by proton induced X-ray emission analysis showed it to be at least one order of magnitude thinner on the SiO 2 impurities than on the main Sb 2 S 3 component and the iron impurities. (orig.)

  8. Conditions of competition between the production of water by desalination and natural resources; Les conditions de concurrence entre la production d'eau par dessalement et les ressources naturelles

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    A close examination of the local supply and demand for fresh water is involved when considering a sea water desalination plant in a given region. This examination makes it possible in most cases to undertake a thorough study of the natural resources, resulting in the use of desalination being rejected. After confirming this fact by precise examples, the authors consider that the preliminary study should be extended, taking into account the complementary character of natural resources and desalination systems: contribution to peak demand, contribution to base demand. This analysis results in a classification of the main user regions according to certain economic criteria defining their suitability for the use of desalination processes. (author) [French] Envisager une installation d'eau de mer dans une region donnee, entraine un examen attentif de l'offre et de la demande locale en eau douce. Cet examen permet de conduire dans la plupart des cas a une etude approfondie des ressources naturelles qui aboutit a ecarter le recours au dessalement. Apres avoir constate ce fait, par des exemples precis, les auteurs estiment que l'on doit pousser plus loin l'etude preliminaire en tenant compte de la complementarite entre les ressources naturelles et les systemes de dessalement: contribution a la demande de pointe, contribution a la demande de base. Cette analyse conduit a classer les regions utilisatrices essentielles selon certains criteres economiques definissant leur aptitude a l'utilisation des procedes de dessalement. (auteur)

  9. Conditions of competition between the production of water by desalination and natural resources; Les conditions de concurrence entre la production d'eau par dessalement et les ressources naturelles

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, J. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    A close examination of the local supply and demand for fresh water is involved when considering a sea water desalination plant in a given region. This examination makes it possible in most cases to undertake a thorough study of the natural resources, resulting in the use of desalination being rejected. After confirming this fact by precise examples, the authors consider that the preliminary study should be extended, taking into account the complementary character of natural resources and desalination systems: contribution to peak demand, contribution to base demand. This analysis results in a classification of the main user regions according to certain economic criteria defining their suitability for the use of desalination processes. (author) [French] Envisager une installation d'eau de mer dans une region donnee, entraine un examen attentif de l'offre et de la demande locale en eau douce. Cet examen permet de conduire dans la plupart des cas a une etude approfondie des ressources naturelles qui aboutit a ecarter le recours au dessalement. Apres avoir constate ce fait, par des exemples precis, les auteurs estiment que l'on doit pousser plus loin l'etude preliminaire en tenant compte de la complementarite entre les ressources naturelles et les systemes de dessalement: contribution a la demande de pointe, contribution a la demande de base. Cette analyse conduit a classer les regions utilisatrices essentielles selon certains criteres economiques definissant leur aptitude a l'utilisation des procedes de dessalement. (auteur)

  10. Oklo natural reactors: geological and geochemical conditions

    International Nuclear Information System (INIS)

    Jakubick, A.T.; Church, W.

    1986-02-01

    Published as well as unpublished material on the Oklo natural reactors in Gabon was evaluated with regard to the long-term aspects of nuclear waste disposal. Even though the vast data base available at present can provide only a site specific description of the phenomenon, already this material gives relevant information on plutonium retention, metamictization, fission product release, hydrogeochemical stability and migration of fission products. Generalized conclusions applicable to other nuclear waste repository would require the quantitative reconstruction of t s coupled thermo-hydrologic-chemical processes. This could be achieved by studying the deviations in the 2 H/ 1 H and 18 O/ 16 O ratios of minerals at Oklo. A further generalization of the findings from Oklo could be realized by examining the newly-discovered reactor zone 10, which was active under very different thermal conditions than the other reactors. 205 refs

  11. Natural radionuclides in drinking water in Argentina

    International Nuclear Information System (INIS)

    Bomben, A.M.; Palacios, M.A.

    2000-01-01

    As part of the national survey to evaluate natural radioactivity in the environment, concentration levels of natural uranium and 226 Ra have been analyzed in over 300 drinking water samples taken from different locations in Argentina. 226 Ra was determined by 222 Rn emanation and liquid scintillation counting, and natural uranium by a fluorimetric procedure. Values ranging from 0.03 to 24 μg.l -1 of natural uranium and from 0.06 to 50 μg.l -1 , were measured on drinking water samples taken from tap water systems and private wells, respectively. Concentrations up to 15 mBq.l -1 and to 22 mBq.l -1 of 226 Ra were found in drinking water samples taken from tap water systems and private wells, respectively. These values are compared with the reference values accepted for drinking water. Based on the water intake rate, the age distribution and the measured concentrations, an annual collective effective dose of 1.9 man Sv and an individual committed effective dose of 0.49 μSv.y -1 were calculated for the city of Buenos Aires adult inhabitants, for the ingestion of both natural radionuclides analyzed in drinking water. (author)

  12. Ground-water conditions in Utah, spring of 1995

    Science.gov (United States)

    Allen, D.V.; Steiger, J.I.; Sory, J.D.; Garrett, R.B.; Burden, Carole B.; Danner, M.R.; Herbert, L.R.; Gerner, S.J.; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.; Bagley, A.D.

    1995-01-01

    This is the thirty-second in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1994. Much of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources.

  13. Effluent dispersion in natural water receivers (tracer examination)

    International Nuclear Information System (INIS)

    Szpilowski, S.; Owczarczyk, A.; Chmielewski, A.G.

    1993-01-01

    Tracer methods constitute very convenient means for observation and examination of effluent dispersion and dilution processes in natural water receivers. In the report there are presented methods developed and used by the Institute of Nuclear Chemistry and Technology (INCT) to measure mixing parameters in natural streams to determine distances of complete transverse mixing as well as to assess and predict dispersion of sewage in large water reservoirs. There are also presented the methods of predicting initial stage of dispersion of sewage discharged into large water reservoirs through underwater out falls and the method for determining the decomposition rates of effluent entering a natural water receiver. The methods presented can be used in analysis of pollution in a given water region, in selection of optimal sewage out fall locations as well as in prediction of effluent dilution intensity at different hydro- and meteorological conditions. (author). 27 refs, 15 figs, 2 tabs

  14. Natural circulation under severe accident conditions

    International Nuclear Information System (INIS)

    Pafford, D.J.; Hanson, D.J.; Tung, V.X.; Chmielewski, S.V.

    1992-01-01

    Research is being conducted to better understand natural circulation phenomena in mixtures of steam and noncondensibles and its influence on the temperature of the vessel internals and the hot leg, pressurizer surge line, and steam generator tubes. The temperature of these structures is important because their failure prior to reactor vessel lower head failure could reduce the likelihood of containment failure as a result of direct containment heating. Computer code calculations (MELPROG, SCDAP/RELAP5/MOD3) predict high fluid temperatures in the upper plenum resulting from in-vessel natural circulation. Using a simple model for the guide tube phenomena, high upper plenum temperatures are shown to be consistent with the relatively low temperatures that were deduced metallurgically from leadscrews removed from the TMI-2 upper plenum. Evaluation of the capabilities of the RELAP5/MOD3 computer code to predict natural circulation behavior was also performed. The code was used to model the Westinghouse natural circulation experimental facility. Comparisons between code calculations and results from experiments show good agreement

  15. Natural radio-nuclides in drinking water

    International Nuclear Information System (INIS)

    Deflorin, O.

    2003-01-01

    This article discusses the presence of radio-nuclides in Switzerland's drinking water. The article describes research done into the natural radioactivity to be found in various drinking water samples taken from the public water supply in the Canton of Grisons in eastern Switzerland. The various natural nuclides to be expected are listed and the methods used to take the samples are described. The results of the analysis are presented in the form of sketches showing the geographical distribution of the nuclide samples. Diagrams of the cumulative frequency of the quantities of nuclides found are presented, as are such diagrams for the yearly radioactive doses that the population is exposed to. The results and their consequences for the water supply are discussed in detail and further investigations to be made in the region are proposed

  16. Thermonuclear 36Cl pulse in natural water

    International Nuclear Information System (INIS)

    Bentley, H.W.; Davis, S.N.; Gifford, S.; Phillips, E.M.; Elmore, D.; Tubbs, L.E.; Gove, H.E.

    1982-01-01

    The enhanced concentration of 3 6Cl, produced by neutron activation of seawater and released into the environment during atmospheric thermonuclear tests in the 1950s, has been used as a tracer in natural water systems. The results of numerical modelling and analyses of water samples are presented which indicate that in the mid-latitudes the fallout peak was 3 orders of magnitude above the natural background, and that the period of enhanced 36 Cl fallout was 1953 to about 1964. The advantages of 36Cl as an environmental tracer are discussed. (U.K.)

  17. Ground-water conditions in Utah, spring of 1994

    Science.gov (United States)

    Allen, D.V.; Garrett, R.B.; Sory, J.D.; Burden, Carole B.; Danner, M.R.; Herbert, L.R.; Steiger, J.I.; ReMillard, M.D.; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.; Bagley, A.D.

    1994-01-01

    This is the thirty-first in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1993. Water-level fluctuations and selected related data, however, are described from the spring of 1989 to the spring of 1994. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Divisions of Water Rights and Water Resources, Utah Department of Natural Resources.

  18. Solar Hot Water Heating by Natural Convection.

    Science.gov (United States)

    Noble, Richard D.

    1983-01-01

    Presents an undergraduate laboratory experiment in which a solar collector is used to heat water for domestic use. The working fluid is moved by natural convection so no pumps are required. Experimental apparatus is simple in design and operation so that data can be collected quickly and easily. (Author/JN)

  19. Chemical speciation of Pu in natural waters

    International Nuclear Information System (INIS)

    Nelson, D.M.; Larsen, R.P.; Penrose, W.R.

    1983-01-01

    The behavior of plutonium in natural waters is determined to a major degree by the chemical forms which are present. We have characterized the ambient Pu in a number of surface waters with regard to its oxidation state and association with natural colloidal organic carbon compounds using a combination of field measurements and laboratory experiments. Both of these factors are shown to have a profound effect on the adsorption of Pu to natural sediments, since both complexation with organic matter and oxidation compete with adsorption. The concentration of organic carbon in the water is the key variable influencing both oxidation state and organic binding. The adsorption process conforms to the laws applicable to a reversible equilibrium with values of the distribution coefficient, K/sub D/, measured in laboratory experiments being similar to those observed for ambient Pu. Experiments using natural waters and sediments in which the Pu concentration was varied show the forms present at typical ambient concentrations (10 -17 - 10 -14 M) are the same as those found at concentrations up to 10 -7 M. Moreover, the affinity for sediments did not change with concentration indicating the binding sites for Pu had not become saturated. Thus, the behavior observed for Pu at ultratrace concentrations should remain unchanged throughout this concentration range. The studies in this report all deal with Pu in exchangeable (and hence source independent) forms and should therefore reflect the behavior toward which the plutonium from any source will tend with time. 13 references, 7 figures, 10 tables

  20. Natural uranium lattice in heavy water

    International Nuclear Information System (INIS)

    Girard, Y.; Koechlin, J.C.; Moreau, J.; Naudet, R.

    1959-01-01

    A group of Laplacian determinations have been made under critical running conditions in a heavy water pile specially constructed to this end using either complete lattices or samples of lattices employing a two-zone method. The experimental equipment is briefly described: it has been devised to allow rapid modifications of the charge. The methods of measurement employed are also summarily described one operates either by flux charts in the case of lattices which are then used as references, or by progressive replacement of the bars by concentric rings and measurements of the reactivity. In this case, one attempts to obtain the difference between the material laplacian of the central unknown lattice and that of the reference lattice. The method has been specially develop ped to give precision. Results of Laplacian measurements for all these lattice types are presented, allowing the construction of a set of curves as a function of the separation. Various other effects have also been measured: the equivalent reactivity of a mm of water - anisotropy - temperature effect, etc. However in this first attack on the problem, the measurement of a large variety of Laplacian has been carried out, rather than careful measurements in particular cases. It is in this spirit that the interpretation of the results has been made. As a large number of very complex phenomena still escape the possibilities of the calculation, it is considered that a certain number of adjustments are necessary; now these can only give the desired efficiency in forecasting results if they refer to a sufficiently great number of experimental data. It is necessary then to connect the measurements closely on with the other whilst, at the same time, subdividing them according to logically deduced formulae. The principal source of trouble has been that of coherence. The rules governing the calculations employed in the interpretation of the data are given. In the first instance simple formula are used: first of

  1. WATER CONDITIONING FOR FOOD INDUSTRY USES

    Directory of Open Access Journals (Sweden)

    RAISA NASTAS

    2011-03-01

    Full Text Available Water conditioning for food industry uses. Tap (drinkingwater from many localities of Moldova doesn’t always correspond to the “Sanitarystandards for drinking water quality” or to the requirements of the “Regulation fornon-alcoholic beverages”, requiring the need for additional purification/conditioning. This paper presents research regarding the removal/adsorption of themain pollutants in tap water (iron, manganese, aluminum, humic substances,trihalomethanes on supports of local carbon adsorbents made from vegetableproducts (stones of peach and plum, walnut shells. Experiments were performedin dynamic conditions in columns of carbon adsorbents. As work solutions wasused tap water where pollutants have been introduced in amounts equivalent to 3maximum allowable concentrations. Carbonaceous adsorbents used forremoval/adsorption of pollutants in dynamic conditions, reveal a capacity of up to1:400 volumes adsorbent: solution before breakthrough. Combined filter, utilizingactive carbons, was constructed and tested for conditioning of tap water forbeverage and food production. The results demonstrated efficient remove oforganic substances and heavy metals by filtering of about 700 volumes of waterper volume of filter.

  2. Absorption coefficient instrument for turbid natural waters

    Science.gov (United States)

    Friedman, E.; Cherdak, A.; Poole, L.; Houghton, W.

    1980-01-01

    The paper presents an instrument that directly measures multispectral absorption coefficient of turbid natural water. Attention is given to the design, which is shown to incorporate methods for the compensation of variation in the internal light source intensity, correction of the spectrally dependent nature of the optical elements, and correction for variation in the background light level. In addition, when used in conjunction with a spectrally matched total attenuation instrument, the spectrally dependent scattering coefficient can also be derived. Finally, it is reported that systematic errors associated with multiple scattering have been estimated using Monte Carlo techniques.

  3. Potentiometric assay for hydrogenocarbonate in natural waters

    OpenAIRE

    Milla González, Miguel

    2008-01-01

    Potentiometry is often used for the determination of hydrogenocarbonate in natural water samples. In this exercise, a volume V of the titrant HCl is required for the potentiometric analysis of the mentioned species in 50 mL of water sample. The titrant concentration is M molar. The user should calculate the concentration of hydrogenocarbonate and express it either in mg/L or in g/L of calcium carbonate by building up the corresponding stoichiometric expressions. All results entered in the sys...

  4. Natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Bastos, J.L.F.; Loureiro, L.V.; Rocha, R.T.V. da; Umbehaun, P.E.

    1992-01-01

    Several analytical modelling have been done for steady-state and slow transients conditions, besides more sophisticated studies considering two and three dimensional effects in a very simple geometry. Under severe accident conditions for PWR a code to analyse natural circulation has been developed by Westinghouse. This paper discusses the problem of natural circulation in a complex geometry similar to that of nuclear power plants. A first experiment has been done at the integral test facility of 'Co-ordination of Special Projects-Ministry of Naval Affairs' (Coordenadoria para Projetos Especiais -Ministerio da Marinha, COPESP) for several flux conditions. The results obtained were compared with numerical simulations for the steady-state regime. 09 refs, 05 figs, 01 tab. (B.C.A.)

  5. Natural circulation cooling in a PWR geometry under accident-induced conditions

    International Nuclear Information System (INIS)

    Shimeck, D.J.; Johnsen, G.W.

    1983-01-01

    The characteristics and limits of natural circulation heat rejection over a wide range of conditions were experimentally investigated in a small-scale model of a pressurized water reactor. Conditions that were varied included primary and secondary coolant inventory, decay heat power, and primary noncondensable gas content. The results have defined three distinct modes of natural circulation, their limits and transition points, and the characteristic signatures accompanying natural circulation behavior. Particular emphasis is focused on the limits of natural circulation under severely degraded primary and secondary conditions

  6. The light water natural uranium reactor

    International Nuclear Information System (INIS)

    Radkowsky, A.

    A new type of light water seed blanket with the seed having 20% enrichment and the blanket a special combination of elements of natural uranium and thorium, relatively close packed, but sufficient spacing for heat transfer purpose is described. The blanket would deliver approximately half the total energy for about 10,000 MWDIT, so this type of core would be just as economical or better in uranium ore consumation as present cores. (author)

  7. Natural Circulation Characteristics of an Integral Pressurized Water Reactor

    International Nuclear Information System (INIS)

    Junli Gou; Suizheng Qiu; Guanghui Su; Dounan Jia

    2006-01-01

    Natural circulation potential is of great importance to the inherent safety of a nuclear reactor. This paper presents a theoretical investigation on the natural circulation characteristics of an integrated pressurized water reactor. Through numerically solved the one-dimensional model, the steady-state single phase conservative equations for the primary circuit and the steady-state two-phase drift-flux conservative equations for the secondary side of the once-through steam generator, the natural circulation characteristics are studied. Based on the preliminary calculation analysis, it is found that natural circulation mass flow rate is proportional to the exponential function of the power, and the value of the exponent is related to working conditions of the steam generator secondary side. The higher height difference between the core center and the steam generator center is favorable to the heat removal capacity of the natural circulation. (authors)

  8. Investigation of the role of water-structured conditions in forming physics-chemical and biological features of the natural and model systems exposed to the energy influences (ecological and technological problems)

    International Nuclear Information System (INIS)

    Eremin, Y.; Belyashov, D.; Yuskov, A.; Kupchishin, A.; Polyakov, A.; Abishev, D.; Bekturov, E.; Adashkin, O.; Sultanbaev, E.; Davydov, G.; Aliev, M.; Verbolovich, V.; Kleinbok, I.; Fryazinova, T.

    1996-01-01

    The project is devoted to solve ecological and technological goals of Semipalatinsk Nuclear Testing Site and uranium industry of Kazakstan. Its anticipated basic results include: - Creation of common systemic research methodology using the spectral, physical-chemical and biological tests; - Development of new testing methods for molecular-structural variations in water systems; evaluation of effect of water and water systems after radiation irradiation upon physical-chemical and biological properties of subjects, which are contacted with these systems; - Determination of a pattern of interaction between the water and the coarse- and fine-dispersions as well as effect of molecular-structural variations in systems upon physical-chemical and biological processes occurred in these systems; - Determination of water role in radiation-chemical reactions by means of electron, gamma- and ion irradiation of water-mineral model systems. There are following basic goals to be solved to reach a general objective of Project: In Water-Mineralogical Section: - To determine a pattern of interaction between the radiant energy and ion and dispersed (hydrophilic and hydrophobic) components; - To clarify a relationship between physical-chemical properties of water with its isotope composition; - To establish a transfer mechanism of micro dispersed radionuclides in geological and soil conditions of SNTS and a role of water structures in hydrophobic interactions between micro dispersions and non-polar radicals of chemical agents; - To determine the water-molecular structure in acid and alkaline water fractions and interspersion interactions within these fractions; - To establish the interaction with water minerals in ice-like and clathrate-like conditions. - In Biological Section: - To study a role of water structure formation and hydrophobic interactions in the modification of humor immunity components for biological liquids being effected by electron and gamma rays beams; - To study the

  9. Surface-Water Conditions in Georgia, Water Year 2005

    Science.gov (United States)

    Painter, Jaime A.; Landers, Mark N.

    2007-01-01

    INTRODUCTION The U.S. Geological Survey (USGS) Georgia Water Science Center-in cooperation with Federal, State, and local agencies-collected surface-water streamflow, water-quality, and ecological data during the 2005 Water Year (October 1, 2004-September 30, 2005). These data were compiled into layers of an interactive ArcReaderTM published map document (pmf). ArcReaderTM is a product of Environmental Systems Research Institute, Inc (ESRI?). Datasets represented on the interactive map are * continuous daily mean streamflow * continuous daily mean water levels * continuous daily total precipitation * continuous daily water quality (water temperature, specific conductance dissolved oxygen, pH, and turbidity) * noncontinuous peak streamflow * miscellaneous streamflow measurements * lake or reservoir elevation * periodic surface-water quality * periodic ecological data * historical continuous daily mean streamflow discontinued prior to the 2005 water year The map interface provides the ability to identify a station in spatial reference to the political boundaries of the State of Georgia and other features-such as major streams, major roads, and other collection stations. Each station is hyperlinked to a station summary showing seasonal and annual stream characteristics for the current year and for the period of record. For continuous discharge stations, the station summary includes a one page graphical summary page containing five graphs, a station map, and a photograph of the station. The graphs provide a quick overview of the current and period-of-record hydrologic conditions of the station by providing a daily mean discharge graph for the water year, monthly statistics graph for the water year and period of record, an annual mean streamflow graph for the period of record, an annual minimum 7-day average streamflow graph for the period of record, and an annual peak streamflow graph for the period of record. Additionally, data can be accessed through the layer's link

  10. Sustainable Water Management in Urban, Agricultural, and Natural Systems

    Directory of Open Access Journals (Sweden)

    Tess Russo

    2014-12-01

    Full Text Available Sustainable water management (SWM requires allocating between competing water sector demands, and balancing the financial and social resources required to support necessary water systems. The objective of this review is to assess SWM in three sectors: urban, agricultural, and natural systems. This review explores the following questions: (1 How is SWM defined and evaluated? (2 What are the challenges associated with sustainable development in each sector? (3 What are the areas of greatest potential improvement in urban and agricultural water management systems? And (4 What role does country development status have in SWM practices? The methods for evaluating water management practices range from relatively simple indicator methods to integration of multiple models, depending on the complexity of the problem and resources of the investigators. The two key findings and recommendations for meeting SWM objectives are: (1 all forms of water must be considered usable, and reusable, water resources; and (2 increasing agricultural crop water production represents the largest opportunity for reducing total water consumption, and will be required to meet global food security needs. The level of regional development should not dictate sustainability objectives, however local infrastructure conditions and financial capabilities should inform the details of water system design and evaluation.

  11. Thermodynamics of natural and industrial waters

    Energy Technology Data Exchange (ETDEWEB)

    Pitzer, K.S.

    1991-08-01

    The most effective general formulations of thermodynamic equations for multicomponent aqueous solutions are discussed with respect to various ranges of temperature, pressure and composition with emphasis on solutes important in natural or industrial waters. A familiar equation in molality and in excess Gibbs energy is very successful up to 300{degree}C and ionic strength 6 mol{center dot}kg{sup {minus}1}, and can often be extended to 350{degree}C or above at high pressure and in favorable cases to ionic strength 12 or even 20. Alternate methods valid to higher solute compositions, even to pure fused salts, are described. A more difficult situation arises near the critical point of water where the compressibility becomes infinite and a Helmholtz energy basis must be adopted. Existing equations for this range and still higher temperatures and pressures are considered and possible improvements discussed. 85 refs., 13 figs., 3 tabs.

  12. Fluorometric analysis for uranium in natural waters

    International Nuclear Information System (INIS)

    Waterbury, G.R.

    1977-01-01

    A fluorometric method is used for the routine determination of uranium at 0.2 to parts-per-billion (ppB) concentrations in natural surface waters. Duplicate 200-μl aliquots of the water samples are pipetted onto 0.4-g pellets of 98 percent NaF-2 percent LiF flux contained in platinum dishes. The pellets are dried under heat lamps and fused over special propane burners. The fused pellets are subjected to ultraviolet radiation and the fluorescence is measured in a fluorometer. The lower limit of detection is 0.2 ppB of uranium, and the precision is about 15 relative percent in the 0.2 to 10 ppB uranium concentration range. Two analysts determine uranium in 750 to 900 samples per week using this method. Samples containing solids or more than 19 ppB of uranium are analyzed by a delayed neutron counting method

  13. Natural convection accidental conditions in nuclear power plants

    International Nuclear Information System (INIS)

    Delmastro, D.F.; Clausse, A.

    1990-01-01

    Under certain conditions, wether accidental or in nuclear reactor design, a nuclear reactor core may be found to be refrigerated by a fluid in natural circulation. Before the possible density waves phenomenon occurrence, it is essential to have a good knowledge of the flow evolution and thermohydraulic variables under these conditions. (Author) [es

  14. Study on irradiation conditions of producing 153Sm with natural abundance samarium target

    International Nuclear Information System (INIS)

    Du Jin; Jin Xiaohai; Bai Hongsheng; Liu Yuemin; Chen Daming; Wang Fan

    1998-01-01

    Irradiation conditions of natural abundance 152 Sm targets in different forms are studied in the heavy water reactor and the light water swimming pool reactor at the China Institute of Atomic Energy. The result shows that the specific activity of 153 Sm in liquid form target irradiated in the light water swimming pool reactor is two times greater than that in solid form target. The radionuclide purity of 153 Sm is more than 99%, which can meet the needs of clinical application

  15. Natural radionuclides in Austrian bottled mineral waters

    International Nuclear Information System (INIS)

    Gabriele Wallner; Tania Jabbar

    2010-01-01

    All commercially available mineral waters of Austrian origin were investigated with regard to the natural radionuclides 228 Ra, 226 Ra, 210 Pb, 210 Po, 238 U and 234 U. From 1 to 1.5 L of sample the nuclides were extracted and measured sequentially: the radium isotopes as well as 210 Pb were measured by liquid scintillation counting after separation on a membrane loaded with element-selective particles (Empore Radium Disks), 210 Po was determined by α-particle spectroscopy after spontaneous deposition onto a copper planchette and uranium was determined also by α-particle spectroscopy after anion separation and microprecipitation with NdF 3 . The calculated committed effective doses for adults, teens and babies were compared to the total indicative dose of 0.1 mSv/year given in the EC Drinking Water Directive. The dominant portion of the committed effective dose was due to 228 Ra. Highly mineralised waters showed also higher 226 Ra and 228 Ra levels. (author)

  16. Organic acids in naturally colored surface waters

    Science.gov (United States)

    Lamar, William L.; Goerlitz, D.F.

    1966-01-01

    Most of the organic matter in naturally colored surface waters consists of a mixture of carboxylic acids or salts of these acids. Many of the acids color the water yellow to brown; however, not all of the acids are colored. These acids range from simple to complex, but predominantly they are nonvolatile polymeric carboxylic acids. The organic acids were recovered from the water by two techniques: continuous liquid-liquid extraction with n-butanol and vacuum evaporation at 50?C (centigrade). The isolated acids were studied by techniques of gas, paper, and column chromatography and infrared spectroscopy. About 10 percent of the acids recovered were volatile or could be made volatile for gas chromatographic analysis. Approximately 30 of these carboxylic acids were isolated, and 13 of them were individually identified. The predominant part of the total acids could not be made volatile for gas chromatographic analysis. Infrared examination of many column chromatographic fractions indicated that these nonvolatile substances are primarily polymeric hydroxy carboxylic acids having aromatic and olefinic unsaturation. The evidence suggests that some of these acids result from polymerization in aqueous solution. Elemental analysis of the sodium fusion products disclosed the absence of nitrogen, sulfur, and halogens.

  17. [Mineral waters from several Brazilian natural sources].

    Science.gov (United States)

    Rebelo, M A; Araujo, N C

    1999-01-01

    To divulge information on the chemical composition and physical-chemical features of some mineral waters from Brazilian natural sources that will be of useful protocol investigation and patient advice. The survey was based on bottle labels of non-gaseous mineral waters commercially available in the city of Rio de Janeiro. The íon concentration of each mineral was calculated from the salt content. 36 springs were enralled from different states of the country. The pH (25 degrees C), 4.1 to 9.3, varied on dependence of the source and it was linearey correlated with the cations calcium, magnesium and sodium and the anion bicarbonate. It was atributed to high alkalinity (about 70% of bicarbonate in the molecula-gram) of these salts. The calcium (0.3 to 42 mg/l), magnesium (0.0 to 18 mg/l) and bicarbonate (4 to 228 mg/l) contents are relatively low. The mineral content of the Brazilian springs enrolled in this survey is low; about 70% of the sources having calcium and magnesium less than 10 mg/l and 1.0 mg/l, respectively, similar to local tap water.

  18. Isolation of plutonium physical--chemical states from natural waters

    International Nuclear Information System (INIS)

    Weimer, W.C.

    1978-08-01

    The purpose of this research program was to evaluate the feasibility, on a bench scale, of methods for preconcentrating selectively individual plutonium forms from very dilute natural water samples, and to apply these results to use with the Battelle large volume water sampler. From the results of the current investigations, several alternative water sampling strategies have been recommended. The preferred water sampling technique has been field tested at several groundwater wells in the 200 East and 200 West areas of the U.S. Department of Energy Hanford Reservation. These laboratory investigations, in combination with field testing of the proposed water sampling techniques, have yielded the following conclusions: (1) The use of polypropylene microporous filters (0.04μ pore size) in conjunction with glass fiber filters (3.0μ pore size) enables the characterization of two size fractions of particulate plutonium forms in groundwater samples. Those species which pass the microporous polypropylene filters are considered to be in solution. (2) The sorption and ion exchange media evaluated do not show the selectivity necessary to allow preconcentration of individual plutonium forms from natural water samples by any of these media beds under the conditions evaluated. (3) Al 2 O 3 is the most effective sorption media that was examined for removing any plutonium species from natural water samples at neutral pH values. On the basis of these investigations, a standard field testing methodology has been proposed for sampling ground waters near nuclear waste management areas. Additional laboratory evaluations of plutonium species interactions with sorption and ion exchange media have also been recommended

  19. Behaviour of steels in natural environments: focus on stainless steels in natural sea water

    International Nuclear Information System (INIS)

    Feron, D.

    2005-01-01

    Corrosion behaviour of steels and alloys in natural environments is not only dependent to material parameters and environmental chemistry, but also to micro-organisms which may be there. The global approach used to investigate the behaviour of alloys in natural environments is illustrated by the work done on stainless steels in seawater. In aerated seawater, studies led to the proposal of an 'enzymatic model' based on the enzymatic catalyze of the cathodic reaction and which allows reproducing the electrochemical behaviour of stainless steels in natural seawater and the crevice corrosion phenomena observed in natural sea waters. Coupling areas under aerobic and anaerobic conditions leads to the worst situation for stainless steel behaviour: the catalysis of the cathodic reaction on aerobic exposed surfaces and the decrease of the corrosion resistance of anaerobic surfaces due to sulphides. These results lead to the concept of electro-active bio-films. (author)

  20. Molecular concepts of water splitting. Nature's approach

    International Nuclear Information System (INIS)

    Cox, Nicholas; Lubitz, Wolfgang

    2013-01-01

    Based on studies of natural systems, much has also been learned concerning the design principles required for biomimetic catalysis of water splitting and hydrogen evolution. In summary, these include use of abundant and inexpensive metals, the effective protection of the active sites in functional environments, repair/replacement of active components in case of damage, and the optimization of reaction rates. Biomimetic chemistry aims to mimic all these features; many labs are working toward this goal by developing new approaches in the design and synthesis of such systems, encompassing not only the catalytic center, but also smart matrices and assembly via self-organization. More stable catalysts that do not require self-repair may be obtained from fully artificial (inorganic) catalytic systems that are totally different from the biological ones and only apply some basic principles learned from nature. Metals other than Mn/Ca, Fe, and Ni could be used (e.g. Co) in new ligand spheres and other matrices. For light harvesting, charge separation/stabilization, and the effective coupling of the oxidizing/reducing equivalents to the redox catalysts, different methods have been proposed - for example, covalently linked molecular donor-acceptor systems, photo-voltaic devices, semiconductor-based systems, and photoactive metal complexes. The aim of all these approaches is to develop catalytic systems that split water with sunlight into hydrogen and oxygen while displaying high efficiency and long-term stability. Such a system - either biological, biomimetic, or bioinspired - has the potential to be used on a large scale to produce 'solar fuels' (e.g. hydrogen or secondary products thereof). (orig.)

  1. WATER CONDITION IN CELLS OF CHLORELLA

    Directory of Open Access Journals (Sweden)

    I. V. Kuznetsova

    2015-01-01

    Full Text Available The water condition in cages of the paste of chlorella was investigated by the method of thermogravimetric analysis. With increasing heating rate endothermic effect corresponding to the dehydration process is shifted towards higher temperatures. Temperature intervals of chlorella dehydration are defined at rate of heating 2 К/min - 308-368 K, 5 К/min - 323-403 K, and 10 К/min - 348-403 K. Quantitative characteristics of kinetic unequal water in chlorella have been received for each step (∆, ∆Т, a mass fraction (w, energy of activation (Еа. This process is similar to the process of the dehydration in ion exchange membranes. The derived kinetic characteristics give the possibility to define an optimum temperature interval and rate of drying microalgae for the purpose of increase of periods of storage in the form of paste or a solid substance for the further use as the bioadditive. In addition the presence of three types of water chlorella in a cell set according to NMR with pulsed magnetic field gradient. Since free water is involved in biochemical, chemical and microbiological processes, it is desirable to remove during drying of the preparation. The resulting temperature range of 323-343 K (step 2 at a heating rate of 2 K / min corresponds to a temperature range of drying the chlorella in a production environment. It should be noted that the highest number of algae in a tightly-water (the last stage. Apparently, this is determined by a unique cell structure. Temperature ranges dehydration process are not clear and vary depending on the heating rate, which is fully in line with previous studies of thermal analysis for grains, vegetables and bakery products.

  2. Energy Saving Potential by Utilizing Natural Ventilation under Warm Conditions

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    The objective of this article is to show the potential of natural ventilation as a passive cooling method within the residential sector of countries which are located in warm conditions using Mexico as a case study. The method is proposed as performing, with a simplified ventilation model, thermal......–airflow simulations of 27 common cases of dwellings (considered as one thermal zone) based on the combination of specific features of the building design, occupancy and climate conditions. The energy saving potential is assessed then by the use of a new assessment method suitable for large-scale scenarios using...... the actual number of air-conditioned dwellings distributed among the 27 cases. Thereby, the energy saving is presented as the difference in the cooling demand of the dwelling during one year without and with natural ventilation, respectively. Results indicate that for hot-dry conditions, buildings with high...

  3. Light energy dissipation under water stress conditions

    International Nuclear Information System (INIS)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P.

    1990-01-01

    Using 14 CO 2 gas exchange and metabolite analyses, stomatal as well as total internal CO 2 uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to -2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO 2 exchange was drastically reduced, whereas the total CO 2 uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO 2 . This CO 2 -recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO 2 recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations

  4. Light energy dissipation under water stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P. (Universitaet Kaiserslautern (West Germany))

    1990-04-01

    Using {sup 14}CO{sub 2} gas exchange and metabolite analyses, stomatal as well as total internal CO{sub 2} uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to {minus}2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO{sub 2} exchange was drastically reduced, whereas the total CO{sub 2} uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO{sub 2}. This CO{sub 2}-recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO{sub 2} recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations.

  5. 7 CFR 989.701 - Minimum grade and condition standards for natural condition raisins.

    Science.gov (United States)

    2010-01-01

    ...) Golden Seedless. Natural condition Golden Seedless raisins shall have been prepared from sound, wholesome.... Definitely dark berries means raisins which are definitely darker than dark amber and characteristic of...

  6. 7 CFR 989.158 - Natural condition raisins.

    Science.gov (United States)

    2010-01-01

    ... GROWN IN CALIFORNIA Administrative Rules and Regulations Quality Control § 989.158 Natural condition... determined by deducting the sand tare and box tare from the gross weight of the raisins. The sand tare shall be the weight of the sand and other foreign material removed from the raisins by passing the raisins...

  7. Thermoregulation under semi-natural conditions in speckled ...

    African Journals Online (AJOL)

    We recorded body temperature (Tb) in speckled mousebirds (Colius striatus) under semi-natural conditions in outdoor aviaries, and examined interactions between behavioural and metabolic thermoregulation by experimentally manipulating food availability and communal roosting behaviour. When food was available ad ...

  8. Remote methods of indicating oil products in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Shlyakhova, L A

    1981-01-01

    A survey is made of domestic and foreign publications covering remote methods of monitoring film petroleum products and oil in natural waters. The given methods are realized in practice with the use of different sections of the electromagnetic spectrum. Remote quality control of the natural waters at the modern level may be an indicator of water pollution with film petroleum products.

  9. Preconcentration of plutonium radionuclides from natural waters

    International Nuclear Information System (INIS)

    Wong, K.M.; Nioshkin, V.E.; Jokela, T.A.

    1978-02-01

    A large volume water sampler using manganese dioxide impregnated cartridges for the in situ separation of plutonium in sea water and ground water was studied. Plutonium concentrations obtained by this technique are compared with a radiochemical coprecipitation method. Consistent results were obtained between the two methods for water samples from the Pacific Ocean and Enewetak lagoon. Different results were noted from samples collected in the Enewetak reef and ground water stations. Using this preconcentration technique and the coprecipitation method it was shown that the physical-chemical characteristics of Pu in Enewetak reef and ground water are different from the lagoon and open ocean

  10. The conditions for exercising eligibility for natural gas purchasing

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    Since the electricity and natural gas markets were opened to all non-household customers, the CRE (the French commission of energy regulation) has received requests for information about the conditions for exercising eligibility, coming mainly from consumers with questions about the diverging practices of historical suppliers. The commission therefore launched a public investigation into this subject in 2004. Out of the 38 responses received, some criticized the way in which access to the network operates and the conditions for market opening while others raised questions falling outside the direct scope of the public investigation. The CRE's answers to these observations are explained in this article

  11. Analysis of results obtained from field tracing test under natural rain condition

    International Nuclear Information System (INIS)

    Mukai, M.; Kamiyama, H.; Tanaka, T.; Wang Zhiming; Zhao Yingjie; Li Zhengtang

    1993-01-01

    As one of the tests arranged by the cooperative research between CIRP and JAERI, field tracing tests using 3 H, 60 Co, 85 Sr and 134 Cs were conducted in pits at the CIRP's field test site located on a loess tableland under natural rain condition. Precipitation amount and evaporation rate were measured to study complicated spatial-temporal behavior of soil water movement under that condition. The evaporation rate was obtained through an analysis on the measured data by a combined method of heat balance and eddy correlation. Numerical model, that is based on piston flow assumption of soil water movement, was developed and applied to determine the behavior of the soil water movement in the pits. Using the determined water movement, 3 H migration was evaluated by numerical simulation. Change of 3 H distribution as a function of elapsed time as well explained by careful evaluation of the soil water movement that carried out before the analysis. (5 figs.)

  12. Canopy management and water use efficiency in vineyards under Mediterranean semiarid conditions

    Directory of Open Access Journals (Sweden)

    de la Fuente Mario

    2015-01-01

    In addition, both positive effects of sprawl treatments (crop load and training system resulted in better yield and quality in Mediterranean semiarid conditions under the same inputs (sun, water and soil, causing higher efficiency of natural resources.

  13. VUV spectroscopy of water under cellular conditions

    International Nuclear Information System (INIS)

    Mota, R.; Parafita, R.; Maneira, M. J. P.; Mason, N. J.; Garcia, G.; Ribeiro, P. A.; Raposo, M.; Limao-Vieira, P.

    2006-01-01

    The understanding of radiation damage within cells, and thence mutagenesis, depends upon a detailed knowledge of the spectroscopy and dissociation dynamics of water. Results of a new study of the electronic state spectroscopy of water, using synchrotron radiation are reported. In order to gain some insight into how the spectroscopy and dissociation dynamics of water is influenced by its environment we also report photo-absorption spectra of water within thin films of poly(o-methoxyaniline) which have been suggested as a good mimic for biological membranes in the cellular environment. Comparison of these spectra with those of gaseous water and condensed amorphous water ice suggest that water in such films is similar to gaseous water and does not show the blue shift suggested in some cellular models. The lowest energy of OH production from dissociation of water in the cellular environment may therefore be around 6.7 eV (185 nm). (authors)

  14. Radiologic evaluation of the maxillary natural pathologic conditions in children

    International Nuclear Information System (INIS)

    Prk, Tae Won; Choi, Soon Chul

    1992-01-01

    The authors evaluated the distribution of the antral pathologic conditions and their radiographic features on the Waters' radiographs of 151 children patients who had been radiographed at the department of Oral Radiology, Seoul National University Hospitals. The obtained results were as follows : 1. The most common pathologic condition was inflammatory change (58%). Percentage of cases showing cystic lesion and fibro-osseous lesion were 25% and 11% respectively. 2. In cases of inflammatory change, odontogenic origins were 12 cases (13%) and bilateral occurrences were 37 cases (39%). 3. The most common radiographic feature of the inflammatory conditions was various types of mucosal thickening (78%). Percentage of cases showing totally increased radiopacity was 18%. 4. Intrinsic cystic lesions were 26 cases (65%) and dentigerous cyst was the most common extrinsic cyst. 5. Most of the fibro-osseous lesions (15 from 17 cases) were fobrous dysplasea. 6. Maxillary sinus hypoplasia (5 cases) and Burkitt's lymphoma (4 cases) were also observed.

  15. Radiologic evaluation of the maxillary natural pathologic conditions in children

    Energy Technology Data Exchange (ETDEWEB)

    Prk, Tae Won; Choi, Soon Chul [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1992-08-15

    The authors evaluated the distribution of the antral pathologic conditions and their radiographic features on the Waters' radiographs of 151 children patients who had been radiographed at the department of Oral Radiology, Seoul National University Hospitals. The obtained results were as follows : 1. The most common pathologic condition was inflammatory change (58%). Percentage of cases showing cystic lesion and fibro-osseous lesion were 25% and 11% respectively. 2. In cases of inflammatory change, odontogenic origins were 12 cases (13%) and bilateral occurrences were 37 cases (39%). 3. The most common radiographic feature of the inflammatory conditions was various types of mucosal thickening (78%). Percentage of cases showing totally increased radiopacity was 18%. 4. Intrinsic cystic lesions were 26 cases (65%) and dentigerous cyst was the most common extrinsic cyst. 5. Most of the fibro-osseous lesions (15 from 17 cases) were fobrous dysplasea. 6. Maxillary sinus hypoplasia (5 cases) and Burkitt's lymphoma (4 cases) were also observed.

  16. 42 CFR 494.40 - Condition: Water and dialysate quality.

    Science.gov (United States)

    2010-10-01

    ... demonstrate the following: (a) Standard: Water purity. Water and equipment used for dialysis meets the water... Boulevard, Suite 400, Arlington, VA 22201-4598. (b) Standard: Chlorine/chloramines. (1) The water treatment... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Water and dialysate quality. 494.40...

  17. The fluid nature of water grabbing

    NARCIS (Netherlands)

    Bont, de Chris; Veldwisch, Gert Jan; Komakech, Hans Charles; Vos, Jeroen

    2016-01-01

    This article contributes to the contemporary debate on land and water grabbing through a detailed, qualitative case study of horticultural agribusinesses which have settled in Tanzania, disrupting patterns of land and water use. In this paper we analyse how capitalist settler farms and their

  18. Potential of Natural Ventilation in Cold Conditions Countries

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    The objective of this article is to investigate the energy performance of natural ventilation as a passive cooling method of buildings within houses located in temperate countries using Denmark as a case study. The method consists in running simulations with a thermal-airflow program of a household...... the simulations are validated with measured data, and by applying a new assessment method presented in this article as the cooling rate due to natural ventilation instead of a constant mechanical ventilation rate in the thermal balance within the dwelling, the energy saving is calculated. Results show...... ventilation rather mechanical one on large-scale scenarios located in temperate conditions. Finally, as a practical implication example, an assessment for Denmark is carried out....

  19. Study on natural circulation flow under reactor cavity flooding condition in advanced PWRs

    International Nuclear Information System (INIS)

    Tao Jun; Yang Jiang; Cao Jianhua; Lu Xianghui; Guo Dingqing

    2015-01-01

    Cavity flooding is an important severe accident management measure for the in-vessel retention of a degraded core by external reactor vessel cooling in advanced PWRs. A code simulation study on the natural circulation flow in the gap between the reactor vessel wall and insulation material under cavity flooding condition is performed by using a detailed mechanistic thermal-hydraulic code package RELAP 5. By simulating of an experiment carried out for studying the natural circulation flow for APR1400 shows that the code is applicable for analyzing the circulation flow under this condition. The analysis results show that heat removal capacity of the natural circulation flow in AP1000 is sufficient to prevent thermal failure of the reactor vessel under bounding heat load. Several conclusions can be drawn from the sensitivity analysis. Larger coolant inlet area induced larger natural circulation flow rate. The outlet should be large enough and should not be submerged by the cavity water to vent the steam-water mixture. In the implementation of cavity flooding, the flooding water level should be high enough to provide sufficient natural circulation driven force. (authors)

  20. Effect of gamma radiation on garlic storage under natural conditions

    International Nuclear Information System (INIS)

    Ayyoubi, Zouhair; Sharabi, N.E.

    1993-02-01

    Garlic cloves were exposed to 30, 60, and 100 Gy of gamma radiation using Co 60 as a sources, to study the effect of different doses on the sprout inhibition of garlic. All the doses applied were effective. No sprout occurred in any of the treatments subjected to natural storage conditions. The effect of irradiation was evident in limiting the weight decrease. It reached 12 - 19% in 1987 and 1988 experiments respectively after 320 days of storage. Irradiation had no effect on the garlic consumptive specifications compared to the control. (author). 4 refs., 2 figs., 5 tabs

  1. Hybrid protocols plus natural treatments for inflammatory conditions.

    Science.gov (United States)

    1998-01-01

    Hybrid protocols combine one, two, or three pharmaceutical drugs with several nutritional or immune-based therapies. These protocols are not limited solely to FDA-approved drugs or strictly to alternative therapies. The rationale for using a hybrid protocol is to find an effective antiviral regimen that also restores immune function. The goal is to obtain the benefits of protease inhibitors without viral resistance and side effects which include problems with fat metabolism and cholesterol levels. Natural treatments for inflammatory conditions are also described. Options include licorice root, ginger root, and slippery elm.

  2. Natural radionuclides in some romanian medicinal mineral water

    Energy Technology Data Exchange (ETDEWEB)

    Botezatu, E.; Iacob, O. [Institute of Public Health, Iasi (Romania)

    2006-07-01

    Radioactive minerals occur irregularly in the bedrock, similar to other minerals and they dissolve easily in water. Bedrock contains naturally occurring radioactivity including uranium, thorium, radium and potassium. The natural radioactivity results from water passing through deposits of naturally occurring radioactive materials.Many mineral water springs are traditionally used as drinking mineral water sources in the area.During the period from 1997 to 2000, we accomplished a study that had as basic objectives the radioacty control of the drinking mineral waters according to existing standards and evaluation of doses to population by ingestion of mineral water (bottled waters commercially available for human intake and some spring waters).For this reason, we were interested in finding out the extent to which these waters can be a natural radiation source. This survey aimed at assessing the radioactive content of these waters and their contribution to the population exposure.The presented data contribute to a national database concerning the natural radioactive content of Romanian mineral waters. A hypothetical person that undergoes a cure of mineral water by ingestion, inhalation and immersion is receiving an average supplementary dose of 3 {mu}Sv over background radiation of 2,512 {mu}Sv.y{sup -1} due to all natural radiation sources in Romania. The contribution of mineral water used in therapeutic purposes to the natural irradiation of population is very slight, almost insignificant. This supports the conclusion that these spring mineral waters can be used without any restrictions for drinking or bathing / washing for medical therapy of ailing persons even other sources of exposure are also taken into account. (N.C.)

  3. Safety distance between underground natural gas and water pipeline facilities

    International Nuclear Information System (INIS)

    Mohsin, R.; Majid, Z.A.; Yusof, M.Z.

    2014-01-01

    A leaking water pipe bursting high pressure water jet in the soil will create slurry erosion which will eventually erode the adjacent natural gas pipe, thus causing its failure. The standard 300 mm safety distance used to place natural gas pipe away from water pipeline facilities needs to be reviewed to consider accidental damage and provide safety cushion to the natural gas pipe. This paper presents a study on underground natural gas pipeline safety distance via experimental and numerical approaches. The pressure–distance characteristic curve obtained from this experimental study showed that the pressure was inversely proportional to the square of the separation distance. Experimental testing using water-to-water pipeline system environment was used to represent the worst case environment, and could be used as a guide to estimate appropriate safety distance. Dynamic pressures obtained from the experimental measurement and simulation prediction mutually agreed along the high-pressure water jetting path. From the experimental and simulation exercises, zero effect distance for water-to-water medium was obtained at an estimated horizontal distance at a minimum of 1500 mm, while for the water-to-sand medium, the distance was estimated at a minimum of 1200 mm. - Highlights: • Safe separation distance of underground natural gas pipes was determined. • Pressure curve is inversely proportional to separation distance. • Water-to-water system represents the worst case environment. • Measured dynamic pressures mutually agreed with simulation results. • Safe separation distance of more than 1200 mm should be applied

  4. Comparison of electrical conductivity calculation methods for natural waters

    Science.gov (United States)

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Ryan, Joseph N.

    2012-01-01

    The capability of eleven methods to calculate the electrical conductivity of a wide range of natural waters from their chemical composition was investigated. A brief summary of each method is presented including equations to calculate the conductivities of individual ions, the ions incorporated, and the method's limitations. The ability of each method to reliably predict the conductivity depends on the ions included, effective accounting of ion pairing, and the accuracy of the equation used to estimate the ionic conductivities. The performances of the methods were evaluated by calculating the conductivity of 33 environmentally important electrolyte solutions, 41 U.S. Geological Survey standard reference water samples, and 1593 natural water samples. The natural waters tested include acid mine waters, geothermal waters, seawater, dilute mountain waters, and river water impacted by municipal waste water. The three most recent conductivity methods predict the conductivity of natural waters better than other methods. Two of the recent methods can be used to reliably calculate the conductivity for samples with pH values greater than about 3 and temperatures between 0 and 40°C. One method is applicable to a variety of natural water types with a range of pH from 1 to 10, temperature from 0 to 95°C, and ionic strength up to 1 m.

  5. Microbiological composition of untreated water during different weather conditions

    Directory of Open Access Journals (Sweden)

    Adna Bešić

    2011-09-01

    Full Text Available Introduction: Water can support the growth of different microorganisms which may result in contamination. Therefore, the microbiological examination is required for testing the hygienic probity of water. In the study of microbial composition of untreated, natural spring and mineral water differences in the presence and number of bacteria during the two periods, winter and summer, are detectable.Methods: In our study, we analyzed and compared the following parameters, specified in the Rulebook: total bacteria and total aerobic bacteria (ml/22 and 37°C, total Coliform bacteria and Coliforms of fecalorigin (MPN/100ml, fecal streptococci as Streptococcus faecalis  (MPN/100ml, Proteus spp (MPN/100ml, and Pseudomonas aeruginosa (MPN/100 ml Sulphoreducing Clostridia (cfu / ml. The paper is a retrospective study in which we processed data related to the period of 2005-2009 year. While working, we used the descriptive-analytical comparative statistical treatment.Results: The obtained results show statistically significant differences in the microbial composition of untreated water in the two observed periods,Conclusions: Findings were consequence of different weather conditions in these periods, which imply a number of other variable factors.

  6. Natural Circulation Characteristics of a Symmetric Loop under Inclined Conditions

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available Natural circulation is an important process for primary loops of some marine integrated reactors. The reactor works under inclined conditions when severe accidents happen to the ship. In this paper, to investigate the characteristics of natural circulation, experiments were conducted in a symmetric loop under the inclined angle of 0~45°. A CFD model was also set up to predict the behaviors of the loop beyond the experimental scope. Total circulation flow rate decreases with the increase of inclined angle. Meanwhile one circulation is depressed while the other is enhanced, and accordingly the disparity between the branch circulations arises and increases with the increase of inclined angle. Circulation only takes place in one branch circuit at large inclined angle. Also based on the CFD model, the influences of flow resistance distribution and loop configuration on natural circulation are predicted. The numerical results show that to design the loop with the configuration of big altitude difference and small width, it is favorable to reduce the influence of inclination; however too small loop width will cause severe reduction of circulation ability at large angle inclination.

  7. Thermodynamic stability and kinetic dissolution of perovskite in natural waters

    International Nuclear Information System (INIS)

    Nesbitt, H.W.; Bancroft, G.M.; Fyfe, W.S.; Karkhanis, S.; Melling, P.; Nishijima, A.

    1981-01-01

    Ringwood and coworkers have recently proposed using titanates and zirconates as hosts for nuclear waste in the Synroc B process. Three minerals are used as hosts: perovskite (CaTiO 3 ), Ba-hollandite (BaAl 2 Ti 6 O 16 ), and zirconolite (CaZrTi 2 O 7 ). The Synroc philosophy relies heavily on geological and geochemical observations in selecting stable host minerals. Although it has been recognized that the Synroc minerals are not thermodynamically compatible with siliceous rocks, the minerals are considered to be thermodynamically stable in the presence of water, and it has been reported that these minerals are kinetically stable under high-temperature (up to 900 0 C) hydrothermal conditions. Detailed thermodynamic calculations and leach tests have been performed which demonstrate: first, that perovskite is thermodynamically unstable in all known natural waters; and second, that pervoskite leaches at a significant rate even at 100 0 C. Hydrothermal leach tests have been made on natural and synthetic perovskite and perovskite analogues between 100 0 C and 300 0 C. Weight losses and solution concentrations were monitored. The results reported previously in the literature also show that perovskite is kinetically unstable in the presence of common silicates. Our results show that perovskite may be no more stable than siliceous glasses, such as rhyolite, which have been studied previously. Geologic evidence from common alkaline rocks also indicates that hollandite and zirconolite probably will not survive in common rock matrices

  8. Natural organic matter (NOM) in South African waters: NOM ...

    African Journals Online (AJOL)

    In order to remove natural organic matter (NOM) from water in a water treatment train, the composition of the NOM in the source water must be taken into account, especially as it may not necessarily be uniform since the composition is dependent on the local environment. The main thrust of this study was to ascertain ...

  9. Aggradation, Degradation, and Water Quality Conditions

    National Research Council Canada - National Science Library

    1993-01-01

    The purpose of this study is to compile a record of pertinent data and information relative to aggradation, degradation, and water quality within the system of six Missouri River mainstem reservoirs...

  10. Cooling tower water conditioning study. [using ozone

    Science.gov (United States)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  11. Water wizards : reshaping wet nature and society

    NARCIS (Netherlands)

    Vleuten, van der E.B.A.; Disco, C.

    2004-01-01

    The article investigates how humans ‘networked’ wet nature and how this affected the shaping of Dutch society. First, it takes a grand view of Dutch history and describes how wet network building intertwined with the shaping of the Dutch landscape, its economy and its polity. Second, it investigates

  12. Water absorption and mechanical properties of water-swellable natural rubber

    Directory of Open Access Journals (Sweden)

    Diew Saijun

    2009-11-01

    Full Text Available Water-swellable rubber (WSR was prepared by blending superabsorbent polymer (SAP of crosslinked poly(acrylamide-co-sodium acrylate with natural rubber in latex condition. The crosslinked poly(acrylamide-co-sodium acrylate was first prepared by inverse suspension polymerization from acrylamide and sodium acrylate monomers with potassiumpersulfate initiator and N,N-methylenebisacrylamide crosslinker. The reaction was carried out at 60oC for 40 mins. Water absorption properties, such as the degree of water absorption, water absorption rate, degree of weight loss, and mechanicalproperties of WSR were then investigated. It was found that the degree of water absorption, water absorption rate, and thedegree of weight loss increased, while tensile strength and elongation at break decreased with increasing quantity of SAP inthe blends. However, the degree of water absorption, degree of weight loss, and elongation at break decreased, but tensilestrength increased with increasing quantity of the N-tert-butyl-2-benzothiazyl sulphenamide (TBBS accelerator used in thecompounds formulation.

  13. Evaluation of the corrosion of aluminum tubes under conditions of natural imersion in aqueous medium

    International Nuclear Information System (INIS)

    Oliveira, M.F. de

    1985-01-01

    This work evaluates the corrosion of aluminum tubes under conditions of natural immersion in aqueous medium. Local attack was observed on the surface of the tubes for all temperatures studied. It was found that the mass flucturation of the samples tested in deionized water at room temperatures is practically inexistent. However, at temperatures of 45 and 60 0 C the aluminum react rapidly with water forming a film of hydrated oxide of aluminum known as bayerite. It was verified that the contact of graphite and particles containing high content of Cu with aluminum forms a galvanic couple which should be avoided. (Author) [pt

  14. Accumulation of uranium by filamentous green algae under natural environmental conditions

    International Nuclear Information System (INIS)

    Aleissa, K.A.; Shabana, El-Said K.; Al-Masoud, F.L.S.

    2004-01-01

    The capacity of algae to concentrate uranium under natural environmental conditions is measured by a-spectrometry. Spirogyra, a filamentous green fresh-water alga, has concentrated uranium from a surface concrete ponds with elevated uranium levels (140-1140 ppb). The concentration factors (CFs) ranged from 8.9-67 with an average value of 22. Cladophora spp, a filamentous green marine alga has concentrated uranium from the marine water with a concentration factor ranged from 220-280. The average concentration factor was 250. The factors affecting the sorption process are discussed in detail. (author)

  15. Influence of natural and recombinant interferons on development of antiviral condition and activity of natural killers

    International Nuclear Information System (INIS)

    Kuznetsov, V.P.; Avdeev, G.I.; Vyadro, M.M.; Leikin, Yu.D.; Frolova, I.S.

    1986-01-01

    For the purpose of a preliminary estimate of the therapeutic potential of domestic recombinant alpha 2 -component of human leukocytic interferon (rl) in vitro tests, the authors studied its ability to induce development of antiviral condition in diploid culture of human embryo fibroblasts and to activate the cytolytic effect of natural killers in relation to tumor cells, of the K-562 leukemia line and cells of lung adenocarcinoma. The authors used a medicinal form of rL which was derived by expression of a reconstructed gene in Escherichia coli cells. Part of the tests were conducted with an analogous preparation synthesized using another producer, Pseudomonas sp). The biological effect of both preparations was the same. For comparison, a natural preparation was used in all tests: human leukocytic interferon for injection, II(le). The authors studied activity of natural killers in a fraction of mononuclears isolated from blood of essentially healthy donors and from cancer patients. Cells were incubated for 2 h with various concentrations of interferons, then combined in a ratio of 25-50:1 with target cells labeled with 51 Cr. Cytotoxic reaction was conducted for 4 (4-CTR) or 18 h (18-CTR) at 37 0 C. Natural killers could thus be divided into two subpopulations: killer (4-CTR) and cytotoxic (18-CTR) cells. In preliminary tests, both preparations possessed the ability to active natural killers. The effective concentration for rL was within the limits of 1000-2000 IU/ml, and 50-200 Iu/ml for Le. The data on activation of natural killers in 16 oncological patients (primarily with lung cancer), the authors established that both rL and Le induced activation of natural killers in the overwhelming majority of cases in relation to K-562 target cells and adenocarcinomas of the lung

  16. Chironomidae (Diptera, Chironomidae) as biological indicators of water bodies ecological condition

    International Nuclear Information System (INIS)

    Bakhtin, M.M.; Sejsebaev, A.T.

    2002-01-01

    The paper presents data confirming that Chironomidae are good to be used as an indicative criterion when classifying lakes. It was found that their quantity and presence of certain species could serve as an index in assessment of water body ecological condition. Results of cytotaxonomic analysis helped to reveal the nature of Chironomini species diversity in STS water bodies. (author)

  17. Natural Circulation Characteristics at Low-Pressure Conditions through PANDA Experiments and ATHLET Simulations

    Directory of Open Access Journals (Sweden)

    Domenico Paladino

    2008-01-01

    Full Text Available Natural circulation characteristics at low pressure/low power have been studied by performing experimental investigations and numerical simulations. The PANDA large-scale facility was used to provide valuable, high quality data on natural circulation characteristics as a function of several parameters and for a wide range of operating conditions. The new experimental data allow for testing and improving the capabilities of the thermal-hydraulic computer codes to be used for treating natural circulation loops in a range with increased attention. This paper presents a synthesis of a part of the results obtained within the EU-Project NACUSP “natural circulation and stability performance of boiling water reactors.” It does so by using the experimental results produced in PANDA and by showing some examples of numerical simulations performed with the thermal-hydraulic code ATHLET.

  18. Research of Distribution of Elements in Natural Waters of the Selenga River Pool

    CERN Document Server

    Ganbold, G; Gerbish, S; Dalhsuren, B; Bayarmaa, Z; Maslov, O D; Sevastiyanov, D V

    2001-01-01

    The distribution of heavy metals in natural waters of the Selenga river pool was investigated. The contents of elements were determined using X-ray analysis with complete external reflection (XRACER). The zones with excess of the average contents of elements in comparison with reference samples were found out, that specifies their pollution by metals. It is offered in these zones to organize the regular water quality monitoring for supervision over the condition of the water ecosystems and to carry out actions on decrease of anthropogenous load and pollution of natural waters.

  19. Chlorination of organophosphorus pesticides in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: jlacero@unex.es; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 {sup o}C and pH 7 were determined to be 110.9, 0.004 and 191.6 M{sup -1} s{sup -1} for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L{sup -1} was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.

  20. Chlorination of organophosphorus pesticides in natural waters

    International Nuclear Information System (INIS)

    Acero, Juan L.; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel

    2008-01-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 o C and pH 7 were determined to be 110.9, 0.004 and 191.6 M -1 s -1 for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L -1 was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety

  1. Chromium fractionation and speciation in natural waters.

    Science.gov (United States)

    Pereira, Catarinie Diniz; Techy, João Gabriel; Ganzarolli, Edgard Moreira; Quináia, Sueli Pércio

    2012-05-01

    It is common for leather industries to dump chromium-contaminated effluent into rivers and other bodies of water. Thus, it is crucial to know the impacts caused by this practice to the environment. A study on chromium partitioning and speciation, with determination at trace levels, was carried out in a potentially contaminated creek. Chromium fractionation and speciation was performed using a flow-injection preconcentration system and detection by flame atomic absorption spectrometry. High levels of this element were found in the particulate material (449-9320 mg kg(-1)), which indicates its compatibility with this fraction. The concentration of Cr(iii) in the water samples collected ranged from 5.2-105.2 μg L(-1). Cr(vi) was always below of the DL (0.3 μg L(-1)). Chromium accumulation observed in the sediment (873-1691 mg kg(-1)) may confirm contamination due to the long term release of contaminated effluents in the creek.

  2. Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Gordo, E.; Canete, S.; Perez, M.

    2011-01-01

    Water has a vast importance for numerous human activities, so that securing supplies of drinking water of a standard quality is becoming more and more difficult. The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. The occurrence of radionuclides in drinking water gives rise to internal exposure of humans, directly on the decay of radionuclides taken into the body through ingestion and inhalation and indirectly when they are incorporated as part of the food-chain The measurement of radioactivity in drinking water permits us to determine the exposure of population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha activities, gross beta activities and natural and artificial radionuclides present in drinking water. A data base on natural and artificial radioactivity in water was produced. The results indicated that a high percentage of the water sample contains a total gross alpha and beta less than 0.10 Bq/l and 1 Bq/l respectively. The main objectives were: 1) to analyses gross alpha and gross beta activities and to know the statistical distributions. 2) to study the levels of natural and artificial radionuclides 3) to determine a possible mathematical correlation between the radionuclides and several factors.

  3. Fluorometric determination of uranium in natural waters

    International Nuclear Information System (INIS)

    Hues, A.D.; Henicksman, A.L.; Ashley, W.H.; Romero, D.

    1977-03-01

    Duplicate 200-μl aliquots of the water samples, as received, are transferred by means of Eppendorf pipettors onto 0.4-g pellets of 2 percent LiF-98 percent NaF flux, contained in platinum dishes. The pellets are dried under heat lamps; then fused over special propane burners. The fused pellets are transferred to a Galvanek-Morrison fluorometer, where they are excited with ultraviolet radiation and the fluorescence is measured. The uranium is calculated by comparing the measured fluorescence with that of other pellets, carried through the same procedure, which contain aliquots of standard uranium solutions. The sensitivity of the method is about 0.2 ppB of uranium, and the precision is approximately 15 relative percent in the 0.2- to 10-ppB uranium concentration range

  4. Factors effecting carbonate equilibria in natural waters

    International Nuclear Information System (INIS)

    Snellman, M.

    1987-12-01

    This study is related to preliminary stie evaluations to be carried out in 1987-1992 for spent nuclear fuel disposal in Finland. Near surface and shallow groundwaters are characterized by high concentration of calcium and bicarbonate due to dissolution of calcite. The input of carbon dioxide in the upper zone of the bedrock has a strong influence on the pH giving a pH around neutral. In deep groundwaters when the system is no longer open to the input of carbon dioxide the pH rises as the carbonate system is displaced towards the bicarbonate-carbonate site. In still deeper parts of the rock weathering of other minerals such as feldspars affects the chemistry raising the pH and resulting in saturation and precipitation of calcite. The more advanced these reactions become the higher is the pH and the lower is the carbonate content. The equilibrium concentrations of carbonate species are affected both by temperature and ionic strength of the waters, at high ionic strength especially the distribution between bicarbonate and carbonate ions is affected. The total concentration of carbonates in groundwaters is determined through complex interaction between calcite and carbonates in the water. In deep groundwaters which are closed for input of CO 2 the concentration is stated to be regulated by dissolution of calcium carbonate. In deep granitic groundwaters pH is stated to be buffered to 6.5 to 10, where a high pH would correspond to a low total carbonate concentration and often also a low calcium concentration and a low pH would correspond to high carbonae and calcium concentrations

  5. Biomimetic water-collecting materials inspired by nature.

    Science.gov (United States)

    Zhu, Hai; Guo, Zhiguang; Liu, Weimin

    2016-03-11

    Nowadays, water shortage is a severe issue all over the world, especially in some arid and undeveloped areas. Interestingly, a variety of natural creatures can collect water from fog, which can provide a source of inspiration to develop novel and functional water-collecting materials. Recently, as an increasingly hot research topic, bioinspired materials with the water collection ability have captured vast scientific attention in both practical applications and fundamental research studies. In this review, we summarize the mechanisms of water collection in various natural creatures and present the fabrications, functions, applications, and new developments of bioinspired materials in recent years. The theoretical basis related to the phenomenon of water collection containing wetting behaviors and water droplet transportations is described in the beginning, i.e., the Young's equation, Wenzel model, Cassie model, surface energy gradient model and Laplace pressure equation. Then, the water collection mechanisms of three typical and widely researched natural animals and plants are discussed and their corresponding bioinspired materials are simultaneously detailed, which are cactus, spider, and desert beetles, respectively. This is followed by introducing another eight animals and plants (butterfly, shore birds, wheat awns, green bristlegrass, the Cotula fallax plant, Namib grass, green tree frogs and Australian desert lizards) that are rarely reported, exhibiting water collection properties or similar water droplet transportation. Finally, conclusions and outlook concerning the future development of bioinspired fog-collecting materials are presented.

  6. Fluoride removal studies in water using natural materials : technical ...

    African Journals Online (AJOL)

    Excess fluoride in water causes health hazards to the natural environment. The removal of fluoride was attempted using natural materials such as red soil, charcoal, brick, fly-ash and serpentine. Each material was set up in a column for a known volume and the defluoridation capacities of these materials were studied with ...

  7. Field technique for the measurement of uranium in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, J C [Scintrex Ltd., Concord, Ontario

    1978-05-01

    An analytical method suitable for field determination of trace levels of uranium in natural waters is described. Laser UV radiation causes persistent fluorescence of a uranyl complex. Electronic gating substantially rejects detection of short-lived natural organic matter fluorescence. Further work is required on effects of interferences in samples with complex matrices and interpretative aids such as concurrent conductivity and organic content measurements.

  8. Reduction of Turbidity of Water Using Locally Available Natural Coagulants

    Science.gov (United States)

    Asrafuzzaman, Md.; Fakhruddin, A. N. M.; Hossain, Md. Alamgir

    2011-01-01

    Turbidity imparts a great problem in water treatment. Moringa oleifera, Cicer arietinum, and Dolichos lablab were used as locally available natural coagulants in this study to reduce turbidity of synthetic water. The tests were carried out, using artificial turbid water with conventional jar test apparatus. Optimum mixing intensity and duration were determined. After dosing water-soluble extracts of Moringa oleifera, Cicer arietinum, and Dolichos lablab reduced turbidity to 5.9, 3.9, and 11.1 nephelometric turbidity unit (NTU), respectively, from 100 NTU and 5, 3.3, and 9.5, NTU, respectively, after dosing and filtration. Natural coagulants worked better with high, turbid, water compare to medium, or low, turbid, water. Highest turbidity reduction efficiency (95.89%) was found with Cicer arietinum. About 89 to 96% total coliform reduction were also found with natural coagulant treatment of turbid water. Using locally available natural coagulants, suitable, easier, and environment friendly options for water treatment were observed. PMID:23724307

  9. A system for tritium analysis in natural water

    International Nuclear Information System (INIS)

    Mozeto, A.A.

    1977-01-01

    A method for the analysis, by scintillation counting, of tritium in natural water enriched electrolytically, is presented. The characteristics of the proposed system are indicated by experimental parameters, and by the performance obtained in the analysis of rain and under ground waters. An evaluation of the precison and reproducibility of the measurements is also made [pt

  10. Determination of water content in natural zeolites by reflection method

    International Nuclear Information System (INIS)

    Sarria, Lopez P.; Desdin Garcia, V.; Freixas Lemus, V.; Dominguez Ley, O.; Csikai, G.

    1989-01-01

    Water content in natural zeolites collected from different site places in Cuba has been determined by neutron reflection method. Results show that it is possible to separate the minerals abundant in zeolite from the surrounding barren rocks. Water content of about 10% can be determined with 2-3% relative accuracy for different matrices, using 10 m measuring time

  11. Overcoming water challenges through nature-based solutions

    NARCIS (Netherlands)

    Boelee, Eline; Janse, Jan; Gal, Le Antoine; Kok, Marcel; Alkemade, Rob; Ligtvoet, Willem

    2017-01-01

    Freshwater is a key resource and medium for various economic sectors and domestic purposes but its use is often at the expense of natural ecosystems. Water management must change to deal with urgent issues and protect aquatic ecosystems and their services, while addressing the demand for water from

  12. Pasteurization of naturally contaminated water with solar energy.

    OpenAIRE

    Ciochetti, D A; Metcalf, R H

    1984-01-01

    A solar box cooker (SBC) was constructed with a cooking area deep enough to hold several 3.7-liter jugs of water, and this was used to investigate the potential of using solar energy to pasteurize naturally contaminated water. When river water was heated either in the SBC or on a hot plate, coliform bacteria were inactivated at temperatures of 60 degrees C or greater. Heating water in an SBC to at least 65 degrees C ensures that the water will be above the milk pasteurization temperature of 6...

  13. True colour classification of natural waters with medium-spectral resolution satellites: SeaWiFS, MODIS, MERIS and OLCI.

    NARCIS (Netherlands)

    van der Woerd, H.J.; Wernand, M.R.

    2015-01-01

    The colours from natural waters differ markedly over the globe, depending on the water composition and illumination conditions. The space-borne “ocean colour” instruments are operational instruments designed to retrieve important water-quality indicators, based on the measurement of water leaving

  14. True Colour Classification of Natural Waters with Medium-Spectral Resolution Satellites: SeaWiFS, MODIS, MERIS and OLCI

    NARCIS (Netherlands)

    van der Woerd, H.J.; Wernand, M.

    2015-01-01

    The colours from natural waters differ markedly over the globe, depending on the water composition and illumination conditions. The space-borne “ocean colour” instruments are operational instruments designed to retrieve important water-quality indicators, based on the measurement of water leaving

  15. Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.

    Directory of Open Access Journals (Sweden)

    Yan Yang

    Full Text Available A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions.

  16. Neutron-activation analysis of natural water applied to hydrogeology

    Energy Technology Data Exchange (ETDEWEB)

    Landstroem, O [AB Atomenergi, Stockholm (Sweden); Wenner, C G [Stockholm Univ. (Sweden). Dept. of Quaternary Research

    1965-12-15

    The natural content of elements in water has been utilized to characterize different groundwater supplies and reveal the presence of groundwater streams. A neutron-activation method including chemical group separation techniques has been used for the determination of trace elements. Analyzed water samples from three different places in northern Sweden illustrate the application to common and important hydrogeological problems, such as the quality and capacity of water supplies, the origin and existence of groundwater streams and groundwater exchange with rivers.

  17. Neutron-activation analysis of natural water applied to hydrogeology

    International Nuclear Information System (INIS)

    Landstroem, O.; Wenner, C.G.

    1965-12-01

    The natural content of elements in water has been utilized to characterize different groundwater supplies and reveal the presence of groundwater streams. A neutron-activation method including chemical group separation techniques has been used for the determination of trace elements. Analyzed water samples from three different places in northern Sweden illustrate the application to common and important hydrogeological problems, such as the quality and capacity of water supplies, the origin and existence of groundwater streams and groundwater exchange with rivers

  18. Influence of packaging and conditions of storaging on content of mineral water Guber-Srebrenica

    OpenAIRE

    Blagojević Dragana D.; Lazić Dragica; Škundrić Branko; Škundrić Jelena; Vukić Ljiljana

    2008-01-01

    Mineral waters are found in nature in greater depths most often in reduction conditions, so after surfacing their content alters in contact with oxygen, which is caused by oxidation of certain components. Due to this, efforts were made to make these waters more stabile so they could be used after certain time. This work monitors the stability of Guber (Argentaria)-Srebrenica water exposed to light and with addition of ascorbic acid. The methods of analysis and the parameters analyzed are: gra...

  19. Natural Circulation Phenomena and Modelling for Advanced Water Cooled Reactors

    International Nuclear Information System (INIS)

    2012-03-01

    The role of natural circulation in advanced water cooled reactor design has been extended with the adoption of passive safety systems. Some designs utilize natural circulation to remove core heat during normal operation. Most passive safety systems used in evolutionary and innovative water cooled reactor designs are driven by natural circulation. The use of passive systems based on natural circulation can eliminate the costs associated with the installation, maintenance and operation of active systems that require multiple pumps with independent and redundant electric power supplies. However, considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to ensure that the systems perform their intended functions. Several IAEA Member States with advanced reactor development programmes are actively conducting investigations of natural circulation to support the development of advanced water cooled reactor designs with passive safety systems. To foster international collaboration on the enabling technology of passive systems that utilize natural circulation, in 2004 the IAEA initiated a coordinated research project (CRP) on Natural Circulation Phenomena, Modelling and Reliability of Passive Systems that Utilize Natural Circulation. Three reports were published within the framework of this CRP. The first report (IAEA-TECDOC-1474) contains the material developed for the first IAEA training course on natural circulation in water cooled nuclear power plants. The second report (IAEA-TECDOC-1624) describes passive safety systems in a wide range of advanced water cooled nuclear power plant designs, with the goal of gaining insights into system design, operation and reliability. This third, and last, report summarizes the research studies completed by participating institutes during the CRP period.

  20. Water hammer reduces fouling during natural water ultrafiltration.

    Science.gov (United States)

    Broens, F; Menne, D; Pothof, I; Blankert, B; Roesink, H D W; Futselaar, H; Lammertink, R G H; Wessling, M

    2012-03-15

    Today's ultrafiltration processes use permeate flow reversal to remove fouling deposits on the feed side of ultrafiltration membranes. We report an as effective method: the opening and rapid closing of a valve on the permeate side of an ultrafiltration module. The sudden valve closure generates pressure fluctuations due to fluid inertia and is commonly known as "water hammer". Surface water was filtrated in hollow fiber ultrafiltration membranes with a small (5%) crossflow. Filtration experiments above sustainable flux levels (>125 l (m2h)(-1)) show that a periodic closure of a valve on the permeate side improves filtration performance as a consequence of reduced fouling. It was shown that this effect depends on flux and actuation frequency of the valve. The time period that the valve was closed proved to have no effect on filtration performance. The pressure fluctuations generated by the sudden stop in fluid motion due to the valve closure are responsible for the effect of fouling reduction. High frequency recording of the dynamic pressure evolution shows water hammer related pressure fluctuations to occur in the order of 0.1 bar. The pressure fluctuations were higher at higher fluxes (higher velocities) which is in agreement with the theory. They were also more effective at higher fluxes with respect to fouling mitigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Natural radionuclides in ground water in western Spain

    International Nuclear Information System (INIS)

    Fernandez, F.; Lozano, J.C.; Gomez, J.M.G.

    1992-01-01

    A survey of natural radioactivity in drinking water was carried out in a granitic area in western Spain covering the so-called greywacke-schist complex. This region is known to be rich in uranium ores, such that natural radionuclides should be expected in the groundwater. During 1988, 345 water samples were collected from the water supplies of 115 different villages. These samples were analysed for gross alpha U, Th and Ra. The average concentrations of radionuclides were found to be 5-30 times higher in groundwater from bedrock than in groundwater from soil. The results indicate that Ra makes the highest contribution to the effective dose equivalent. (author)

  2. Natural radionuclides in ground water in western Spain

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, F.; Lozano, J.C.; Gomez, J.M.G. (Salamanca Univ. (Spain). Lab. de Radioactividad Ambiental)

    1992-01-01

    A survey of natural radioactivity in drinking water was carried out in a granitic area in western Spain covering the so-called greywacke-schist complex. This region is known to be rich in uranium ores, such that natural radionuclides should be expected in the groundwater. During 1988, 345 water samples were collected from the water supplies of 115 different villages. These samples were analysed for gross alpha U, Th and Ra. The average concentrations of radionuclides were found to be 5-30 times higher in groundwater from bedrock than in groundwater from soil. The results indicate that Ra makes the highest contribution to the effective dose equivalent. (author).

  3. Biodegradation of poly(ε-caprolactone in natural water environments

    Directory of Open Access Journals (Sweden)

    Heimowska Aleksandra

    2017-03-01

    Full Text Available The environmental degradation of poly(ε-caprolactone[PCL] in natural fresh water (pond and in The Baltic Sea is presented in this paper. The characteristic parameters of both environments were measured during experiment and their influence on the biodegradation of the samples was discussed. The loss of weight and changes of surface morphology of polymer samples were tested during the period of incubation. The poly(ε-caprolactone was more biodegradable in natural sea water than in pond. PCL samples were completely assimilated over the period of six weeks incubation in The Baltic Sea water, but after forty two weeks incubation in natural fresh water the polymer weight loss was about 39%. The results have confirmed that the investigated polymers are susceptible to an enzymatic attack of microorganisms, but their activity depends on environments.

  4. Sorption-scintillation determination of 90Sr in natural water

    International Nuclear Information System (INIS)

    Andryushchenko, A.Yu.; Blank, A.B.; Budakovsky, S.V.; Tarasenko, O.A.; Shevtsov, N.I.

    2003-01-01

    A porous composite material is described for determination of radionuclides in aquatic objects of the environment. Possibilities have been studied for the use of this material in monitoring of 90 Sr content in natural waters. The composite is a scintillator with through pores, the surface of which is impregnated by a sorbent that is selective with respect to strontium. The structure of the material allows combination of two processes--concentrating the radionuclide and measuring its activity. Studies were carried out using both model systems based on reference radioactive solutions and samples of natural water contaminated with radionuclides. It is shown that the use of the proposed method for analysis of natural water allows determination in water of 4x10 -2 Bq l -1 of 90 Sr, which is by two orders of magnitude lower than its maximum acceptable concentration

  5. TAILORING ACTIVATED CARBONS FOR ENHANCED REMOVAL OF NATURAL ORGANIC MATTER FROM NATURAL WATERS. (R828157)

    Science.gov (United States)

    Several pathways have been employed to systematically modify two granular activated carbons (GACs), F400 (coal-based) and Macro (wood-based), for examining adsorption of dissolved natural organic matter (DOM) from natural waters. A total of 24 activated carbons with different ...

  6. Pasteurization of naturally contaminated water with solar energy.

    Science.gov (United States)

    Ciochetti, D A; Metcalf, R H

    1984-02-01

    A solar box cooker (SBC) was constructed with a cooking area deep enough to hold several 3.7-liter jugs of water, and this was used to investigate the potential of using solar energy to pasteurize naturally contaminated water. When river water was heated either in the SBC or on a hot plate, coliform bacteria were inactivated at temperatures of 60 degrees C or greater. Heating water in an SBC to at least 65 degrees C ensures that the water will be above the milk pasteurization temperature of 62.8 degrees C for at least an hour, which appears sufficient to pasteurize contaminated water. On clear or partly cloudy days, with the SBC facing magnetic south in Sacramento, bottom water temperatures of at least 65 degrees C could be obtained in 11.1 liters of water during the 6 weeks on either side of the summer solstice, in 7.4 liters of water from mid-March through mid-September, and in 3.7 liters of water an additional 2 to 3 weeks at the beginning and end of the solar season. Periodic repositioning of the SBC towards the sun, adjusting the back reflective lid, and preheating water in a simple reflective device increased final water temperatures. Simultaneous cooking and heating water to pasteurizing temperatures was possible. Additional uses of the SBC to pasteurize soil and to decontaminate hospital materials before disposal in remote areas are suggested.

  7. Supercritical water natural circulation flow stability experiment research

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Dongliang; Zhou, Tao; Li, Bing [North China Electric Power Univ., Beijing (China). School of Nuclear Science and Engineering; North China Electric Power Univ., Beijing (China). Inst. of Nuclear Thermalhydraulic Safety and Standardization; North China Electric Power Univ., Beijing (China). Beijing Key Lab. of Passive Safety Technology for Nuclear Energy; Huang, Yanping [Nuclear Power Institute of China, Chengdu (China). Science and Technology on Reactor System Design Technology Lab.

    2017-12-15

    The Thermal hydraulic characteristics of supercritical water natural circulation plays an important role in the safety of the Generation-IV supercritical water-cooled reactors. Hence it is crucial to conduct the natural circulation heat transfer experiment of supercritical water. The heat transfer characteristics have been studied under different system pressures in the natural circulation systems. Results show that the fluctuations in the subcritical flow rate (for natural circulation) is relatively small, as compared to the supercritical flow rate. By increasing the heating power, it is observed that the amplitude (and time period) of the fluctuation tends to become larger for the natural circulation of supercritical water. This tends to show the presence of flow instability in the supercritical water. It is possible to observe the flow instability phenomenon when the system pressure is suddenly reduced from the supercritical pressure state to the subcritical state. At the test outlet section, the temperature is prone to increase suddenly, whereas the blocking effect may be observed in the inlet section of the experiment.

  8. THE WATER FROM NATURE AND THE EROSION PROCESS

    Directory of Open Access Journals (Sweden)

    G. PANDI

    2015-03-01

    Full Text Available The water from nature and the erosion process. Studying earth's surface erosion process is necessary for practical reasons. The theoretical approach requires knowledge of the alluvial system’s structure and operation as the cascade sequence of fluvial system’s mass and energy. Geosystem research methodology requires that the water energy and the role of adjacent surface must be expressed. The expression of water power can be grouped according to the shape of movement and action in the basin. A particular, important case is the energy variation in a basin-slope. An important role in energy expressions is considering the existence in nature of biphasic fluid - water as dispersion phase and solid particles as dispersed phase. The role of the adjacent surface is taken into account by using the erosion resistance indicator, which is calculated using the indicator of geological resistance and the indicator of plant protection. The evolution of natural systems, therefore of river basins too, leads to energy diminishing, thus affecting their dynamic balance. This can be expressed using the concept of entropy. Although erosion processes are usual natural phenomena for the evolution of river basins, they induce significant risks in certain circumstances. Depending on the circulated water energies, water basins can be ranked in terms of potential risks.

  9. Analysis of reverse flow in inverted U-tubes of steam generator under natural circulation condition

    International Nuclear Information System (INIS)

    Yang Ruichang; Liu Ruolei; Liu Jinggong; Qin Shiwei

    2008-01-01

    In this paper, we report on the analysis of reverse flow in inverted U-tubes of a steam generator under natural circulation condition. The mechanism of reverse flow in inverted U-tubes of the steam generator with natural circulation is graphically analyzed by using the full-range characteristic curve of parallel U-tubes. The mathematical model and numerical calculation method for analyzing the reverse flow in inverted U-tubes of the steam generator with natural circulation have been developed. The reverse flow in an inverted U-tube steam generator of a simulated pressurized water reactor with natural circulation in analyzed. Through the calculation, the mass flow rates of normal and reverse flows in individual U-tubes are obtained. The predicted sharp drop of the fluid temperature in the inlet plenum of the steam generator due to reverse flow agrees very well with the experimental data. This indicates that the developed mathematical model and solution method can be used to correctly predict the reverse flow in the inverted U-tubes of the steam generator with natural circulation. The obtained results also show that in the analysis of natural circulation flow in the primary circuit, the reverse flow in the inverted U-tubes of the steam generator must be taken into account. (author)

  10. Toxicity of aluminium in natural waters controlled by type rather than quantity of natural organic matter

    International Nuclear Information System (INIS)

    Papathanasiou, Grigorios; White, Keith N.; Walton, Rachel; Boult, Stephen

    2011-01-01

    Extension of the conditions under which Al toxicity is tested is required. Environmentally representative preparation of waters is used in investigating roles of alginate (AA) and humic acids (HA) in partitioning of Al (0.5 mg L -1 ), subsequent uptake and accumulation by and toxicity to Lymnaea stagnalis. HA and AA did not alter precipitation of Al(OH) 3 , but altered subsequent behaviour of Al. High (40 mg L -1 ) HA concentrations, and to a lesser extent AA, prevented settling and availability for benthic grazing but made deposited Al more likely to be ingested. HA detoxified but AA increased toxicity relative to Al alone. Low concentration (4 mg L -1 ) AA and HA do not change partitioning but increase uptake; they both detoxify, but AA less than HA. The study shows OC:Al ratio is critical in predicting Al behaviour in natural waters, also uptake is mediated by snail behaviour, not solely a function of concentration and form of Al. Therefore, predicting Al behaviour will be subject to errors in determining relevant water composition and response of biota to the new speciation. However, with respect to toxicity, rather than other aspects of Al behaviour, different ratios of HA and Al are insignificant compared to whether AA is present rather than HA. - Highlights: → Toxicity assessment in which environmental relevance is of primary concern. → Mass balance of Al monitored throughout the exposure period. → Al behaviour influenced by concentration of organic matter. → Strong dependence of toxicity on type rather than concentration of organic matter. → Toxicity is a function of Al behaviour but also animal behaviour.

  11. Bridge pressure flow scour for clear water conditions

    Science.gov (United States)

    2009-10-01

    The equilibrium scour at a bridge caused by pressure flow with critical approach velocity in clear-water simulation conditions was studied both analytically and experimentally. The flume experiments revealed that (1) the measured equilibrium scour pr...

  12. Natural radioactivity in hot and mineral waters in Syria

    International Nuclear Information System (INIS)

    Othman, I.; Abbass, M.; Kattan, Z.

    1994-08-01

    A study of water chemistry and radioactivity of hot and mineral ground waters was conducted in Syria in order to determine the natural radioactivity levels as well as the mobility process of major radionuclides in the studied systems. The water samples were collected generally from carbonate and basaltic aquifer systems. The chemistry of groundwaters was a reflection of the rock type, while no relationship was found between the radionuclide activities and water temperatures. The increase of 222 Rn concentration in hot and mineral waters was accompanied by a similar increase of the concentration of its patent radionuclides (U t ot and 226 Ra). In parallel, the relative increase of 222 Rn concentration was correlated significantly with the presence of the large faults systems prevailing in the studied areas (Palmyrides and Great African Faults Systems). In all the cases, the radionuclide activity levels were below the maximum contaminant levels given for drinking water and health effects. (author). 11 refs., 7 figs., 8 tabs

  13. [The fate of nuclides in natural water systems

    International Nuclear Information System (INIS)

    Turekian, K.K.

    1989-01-01

    Our research at Yale on the fate of nuclides in natural water systems has three components to it: the study of the atmospheric precipitation of radionuclides and other chemical species; the study of the behavior of natural radionuclides in groundwater and hydrothermal systems; and understanding the controls on the distribution of radionuclides and stable nuclides in the marine realm. In this section a review of our progress in each of these areas is presented

  14. Removal of arsenic from drinking water by natural adsorbents

    OpenAIRE

    MD SHAHNOOR ALAM KHAN

    2017-01-01

    The presence of arsenic in groundwater has been reported in many countries across the world and it is a serious threat to public health. The aim of this study was to identify prospective natural materials with high arsenic adsorption capacity and durable hydraulic property to produce adequate flow of water. The comparative study identified Skye sand as the best natural adsorbent. The prototype household filter with Skye sand achieved complete removal of arsenic and iron. Arsenic removal by du...

  15. Distinguishing natural hydrocarbons from anthropogenic contamination in ground water

    International Nuclear Information System (INIS)

    Lesage, S.; Xu, H.; Novakowski, K.S.

    1997-01-01

    Differentiation between natural and anthropogenic sources of ground-water contamination by petroleum hydrocarbons is necessary in areas where natural hydrocarbons may be present in the subsurface. Because of the similarity in composition between natural and refined petroleum, the use of statistical techniques to discern trends is required. In this study, both multivariate plotting techniques and principal component analysis were used to investigate the origin of hydrocarbons from a variety of study sites. Ground-water and gas samples were collected from the Niagara Falls area and from three gasoline stations where leaking underground storage tanks had been found. Although soil gas surveys are used to indicate the presence of hydrocarbons, they were not useful in differentiating between natural and anthropogenic sources of contamination in ground water. Propane and pentene were found to be the most useful chemical parameters in discriminating between the natural and anthropogenic sources. These chemicals are not usually measured in investigations of ground-water contamination, yet analysis can be conducted by most environmental laboratories using conventional methods

  16. Evaluation of Chitin as Natural Coagulant in Water Treatment

    Directory of Open Access Journals (Sweden)

    V. Saritha

    2012-04-01

    Full Text Available The use of synthetic coagulants is not regarded as suitable due to health and economic considerations. The present study was aimed to investigate the effects of alum as coagulant in conjunction with chitin as coagulant aid on the removal of turbidity, hardness and Escherichia coli from water. A conventional jar test apparatus was employed for the tests. The experiment was conducted at three different pH conditions of 6, 7 and 8. The dosages chosen were 0.5, 1, 1.5 and 2mg/l. The results showed that turbidity decrease provided also a primary Escherichia coli reduction. Hardness removal efficiency was observed to be 93% at pH 7 with 1mg/l concentration by alum whereas chitin was stable at all the pH ranges showing highest removal at 1 and 1.5mg/l with pH 7. At low concentration chitin showed marginally better performance on hardness. In conclusion, using natural coagulants results in considerable savings in chemicals and sludge handling cost may be achieved.

  17. Startup transient simulation for natural circulation boiling water reactors in PUMA facility

    International Nuclear Information System (INIS)

    Kuran, S.; Xu, Y.; Sun, X.; Cheng, L.; Yoon, H.J.; Revankar, S.T.; Ishii, M.; Wang, W.

    2006-01-01

    In view of the importance of instabilities that may occur at low-pressure and -flow conditions during the startup of natural circulation boiling water reactors, startup simulation experiments were performed in the Purdue University Multi-Dimensional Integral Test Assembly (PUMA) facility. The simulations used pressure scaling and followed the startup procedure of a typical natural circulation boiling water reactor. Two simulation experiments were performed for the reactor dome pressures ranging from 55 kPa to 1 MPa, where the instabilities may occur. The experimental results show the signature of condensation-induced oscillations during the single-phase-to-two-phase natural circulation transition. The results also suggest that a rational startup procedure is needed to overcome the startup instabilities in natural circulation boiling water reactor designs

  18. Ammonium ion interaction with conditioned natural zeolite with silver and its effect on the disinfection of polluted water in front of a consortium of gram (+) and gram (-) microorganisms; Interaccion del ion amonio con zeolita natural acondicionada con plata y su efecto sobre la desinfeccion de agua contaminada frente a un consorcio de microorganismos gram (+) y gram (-)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzaga G, V. E.

    2013-07-01

    Clinoptilolite zeolite material is a relative abundance in Mexico, which has ion exchange properties, therefore, has the ability to retain metal ions giving it an application in the process of disinfecting of water contaminated with pathogenic microorganisms. In this research, we conducted a study of disinfection of water contaminated with a microbial consortium, from a zeolite rock clinoptilolite from a deposit located in the State of Guerrero. Initially, the zeolite prepared by the grinding and sieving, for conditioning with NaCl and subsequently with AgNO{sub 3}, finally to be characterized using the techniques of scanning electron microscopy and X-ray diffraction. Tests using columns packed with zeolite material, the effect of zeolite bactericidal conditioned with silver (ZGAg) against a microbial consortium consisting of Escherichia coli and Sthapyloccocus aureus in aqueous solution in the presence of ammonium ions used to increase the ion exchange with zeolite fitted with silver. To describe curves disinfecting a continuous flow system is adapted Gu pta model, which describes the kinetics and equilibrium adsorption process, considering the microorganisms as the adsorbate and the sanitizing agent (conditioned with silver zeolite) as the adsorbent. Characterization results show that in the scanning electron microscopy (Sem), no changes were obtained on the morphology of typical clinoptilolite crystals before and after that was modified with sodium and then with silver, it is worth mentioning however that fitted with silver zeolite (ZGAg), small particles are seen on the zeolite material which when analyzed by energy dispersive spectroscopy (EDS), we found a high concentration of Ag +. The disinfection period is increased as the concentration increased ammonium ions, this behavior is attributed to the ion exchange that occurs between the ammonium ions and silver ions. A lower percentage of inactivation is due, therefore, to a lesser amount of money available to

  19. 7 CFR 932.8 - Natural condition olives.

    Science.gov (United States)

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE OLIVES GROWN IN CALIFORNIA Order... their fresh harvested state, whether or not placed in a water or other preserving medium. [33 FR 11266...

  20. Determination of naturally occurring radionuclides in El-Sin Water

    International Nuclear Information System (INIS)

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

    2000-01-01

    Naturally occurring radionuclides levels have been determined in El-Sin water for the period of 1995 and 1996. water samples were collected from four sites, which are the main drinking water sources of the area. Radon concentration was found to vary between 0.88 Bq/1 in Lattakia main water supply site and 8.4 Bq/1 in El-Sin springs.The highest values found for other radionuclides were 51.6 mBq/1, 18.6 mB/1 and 24.8 mBq/1 for sup 2 sup 2 sup 6 Ra, sup 2 sup 1 sup 0 Po and total uranium (sup 2 sup 3 sup 4 U and sup 2 sup 3 sup 8 U) respectively. These levels are much lower than the maximum permissible levels in drinking water set by international organization.(author)

  1. Protecting Consumers from Contaminated Drinking Water during Natural Disasters

    Science.gov (United States)

    Natural disasters can cause damage and destruction to local water supplies affecting millions of people. Communities should plan for and designate an authorized team to manage and prioritize emergency response in devastated areas. Sections 2.0 and 3.0 describe the Environmental...

  2. Radiological assessment of dam water and sediments for natural ...

    African Journals Online (AJOL)

    Radiological assessment of dam water and sediments for natural radioactivity and its overall health detriments. ... No artificial gamma emitting radionuclide was detected in the samples. The projected ... However, the chances of radiological hazard to the health of human from radioactivity in the soil were generally low.

  3. The Determination of Anionic Surfactants in Natural and Waste Waters.

    Science.gov (United States)

    Crisp, P. T.; And Others

    1983-01-01

    Background information, procedures, and results of an experiment suitable for measuring subpart per million concentrations of anionic surfactants in natural waters and waste effluents are provided. The experiment required only a spectrophotometer or filter photometer and has been successfully performed by students in an undergraduate environmental…

  4. Proton cycling, buffering, and reaction stoichiometry in natural waters

    NARCIS (Netherlands)

    Hofmann, A.F.; Middelburg, J.J.; Soetaert, K.; Wolf-Gladrow, D.A.; Meysman, F.J.R.

    2010-01-01

    Ongoing acidification of the global ocean necessitates a solid understanding of how biogeochemical processes are driving proton cycling and observed pH changes in natural waters. The standard way of calculating the pH evolution of an aquatic system is to specify first how biogeochemical processes

  5. Experimental research on the indoor temperature and humidity fields in radiant ceiling air-conditioning system under natural ventilation

    Science.gov (United States)

    Huang, Tao; Xiang, Yutong; Wang, Yonghong

    2017-05-01

    In this paper, the indoor temperature and humidity fields of the air in a metal ceiling radiant panel air conditioning system with fresh air under natural ventilation were researched. The temperature and humidity distributions at different height and different position were compared. Through the computation analysis of partial pressure of water vapor, the self-recovery characteristics of humidity after the natural ventilation was discussed.

  6. Natural radioactivity in bottled mineral water available in Australia

    International Nuclear Information System (INIS)

    Cooper, M.B.; Ralph, B.J.; Wilks, M.J.

    1981-08-01

    The levels of naturally-occurring radioactive elements in bottled mineral water, commercially available in Australia, have been assessed. The survey concentrated upon 226 Ra, 228 Ra and 210 Pb, radionuclides which have a high toxicity in drinking water. Detectable levels of 226 Ra were found to range from 0.02Bq/1 to 0.32Bq/1 in locally-bottled water and from 0.02Bq/1 to 0.44Bq/1 in imported brands. 210 Pb levels were found to be generally very low ( 228 Ra content of bottled water will have a similar distribution to that of 226 Ra. Concentrations of 228 Ra in excess of 0.7Bq/1 were measured in a number of samples. The radiological health implications of the consumption of bottled mineral water are discussed with reference to existing drinking water standards and also in terms of radiation exposure and the increased risk to health. It was concluded that, although some brands of water contain radioactivity in excess of the drinking-water limits recommended by Australian and overseas authorities, the annual radiation dose to an individual will be below the dose-equivalent limits recommended by the International Commission on Radiological Protection for life-long exposure. The increased risk of radiation-induced fatal disease due to the consumption of bottled mineral water is estimated to be less than 10 -5 and is therefore negligible

  7. Thermodynamic Modeling of Natural Gas Systems Containing Water

    DEFF Research Database (Denmark)

    Karakatsani, Eirini K.; Kontogeorgis, Georgios M.

    2013-01-01

    As the need for dew point specifications remains very urgent in the natural gas industry, the development of accurate thermodynamic models, which will match experimental data and will allow reliable extrapolations, is needed. Accurate predictions of the gas phase water content in equilibrium...... with a heavy phase were previously obtained using cubic plus association (CPA) coupled with a solid phase model in the case of hydrates, for the binary systems of water–methane and water–nitrogen and a few natural gas mixtures. In this work, CPA is being validated against new experimental data, both water...... content and phase equilibrium data, and solid model parameters are being estimated for four natural gas main components (methane, ethane, propane, and carbon dioxide). Different tests for the solid model parameters are reported, including vapor-hydrate-equilibria (VHE) and liquid-hydrate-equilibria (LHE...

  8. The Bare Critical Assembly of Natural Uranium and Heavy Water

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, D [Boris Kidric Institute of Nuclear Sciences, Vinca, Belgrade (Yugoslavia)

    1958-07-01

    The first reactor built in Yugoslavia was the bare zero energy heavy water and natural uranium assembly at the Boris Kidric Institute of Nuclear Sciences, Belgrade. The reactor went critical on April 29, 1958. The possession of four tons of natural uranium metal and the temporary availability of seven tons of heavy water encouraged the staff of the Institute to build a critical assembly. A critical assembly was chosen, rather than high flux reactor, because the heavy water was available only temporarily. Besides, a 10 MW, enriched uranium, research reactor is being built at the same Institute and should be ready for operation late this year. It was supposed that the zero energy reactor would provide experience in carrying out critical experiments, operational experience with nuclear reactors, and the possibility for an extensive program in reactor physics. (author)

  9. Presence and patterns of alkaline phosphatase activity and phosphorus cycling in natural riparian zones under changing nutrient conditions

    OpenAIRE

    Peifang Wang; Lingxiao Ren; Chao Wang; Jin Qian; Jun Hou

    2014-01-01

    Phosphorus (P) is an important limiting nutrient in aquatic ecosystems and knowledge of P cycling is fundamental for reducing harmful algae blooms and other negative effects in water. Despite their importance, the characteristics of P cycling under changing nutrient conditions in shallow lakes were poorly investigated. In this study, in situ incubation experiments were conducted in a natural riparian zone in the main diversion channel used for water transfer into Lake Taihu (Wangyu River). Va...

  10. 7 CFR 989.8 - Natural condition raisins.

    Science.gov (United States)

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE RAISINS PRODUCED FROM GRAPES... condition raisins means raisins the production of which includes sun-drying or artificial dehydration but...

  11. Natural Radioactivity Pattern of Surabaya Water Environmental Samples

    International Nuclear Information System (INIS)

    Rosidi; Agus Taftazani

    2007-01-01

    The gross β radioactivity and natural radionuclide of Surabaya environmental samples pattern have been evaluated. The environmental samples were chosen randomly at 12 locations. The environment samples were water (fresh, estuary and coastal), sediment, eichhornia crassipes (Mart) Solms, Mangrove (Rhizophora stylosa), (Moolgarda delicatus) fish and (Johnius (Johnieops) borneensis) (Sharpnose hammer croaker) fish. The water sample was evaporated; the sediment sample was dried and ground; the biotic samples was burnt at the temperature 500 °C ; The gross β measurement using GM detector and the radionuclides has been identified by γ spectrometer. From the investigation results could be concluded that the natural radioactivity of environmental samples was very low. gross-β of water samples were lower than the threshold value of local government regulation of Surabaya no: 2 year 2004 (1 Bq/L). The distribution of gross-β activity of eichhornia crassipes (Mart) Solms was higher than the other biotic, water and sediment samples as well as the accumulation of radionuclides in the water organism was taken place. The result of identification using γ spectrometer has detected 7 of radionuclides, i.e 210 Pb, 212 Pb, 214 Pb, 208 Tl, 214 Bi, 228 Ac, and 40 K in all sample. The distribution factor of sediment F D was less than bioaccumulation factor of biotic F B and it indicates that there the radionuclide accumulation migration follows the pattern of water - sediment - biotic sample. (author)

  12. Calculation of the eroei coefficient for natural gas hydrates in laboratory conditions

    Science.gov (United States)

    Siažik, Ján; Malcho, Milan; Čaja, Alexander

    2017-09-01

    In the 1960s, scientists discovered that methane hydrate existed in the gas field in Siberia. Gas hydrates are known to be stable under conditions of high pressure and low temperature that have been recognized in polar regions and in the uppermost part of deep -water sediments below the sea floor. The article deals with the determination of the EROEI coefficient to generate the natural gas hydrate in the device under specific temperature and pressure conditions. Energy returned on energy invested expresses ratio of the amount of usable energy delivered from a particular energy resource to the amount of exergy used to obtain that energy resource. Gas hydrates have been also discussed before decades like potential source mainly for regions with restricted access to conventional hydrocarbons also tactic interest in establishing alternative gas reserves.

  13. Analysis of nuclide transport under natural convection and time dependent boundary condition using TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Javeri, V. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany)

    1995-03-01

    After implementation of TOUGH2 at GRS in summer 91, it was first used to analyse the gas transport in a repository for the nuclear waste with negligible heat generation and to verify the results obtained with ECLIPSE/JAV 92/. Since the original version of TOUGH2 does not directly simulate the decay of radionuclide and the time dependent boundary conditions, it is not a appropriate tool to study the nuclide transport in a porous medium/PRU 87, PRU 91/. Hence, in this paper some modifications are proposed to study the nuclide transport under combined influence of natural convection diffusion, dispersion and time dependent boundary condition. Here, a single phase fluid with two liquid components is considered as in equation of state model for water and brine/PRU 91A/.

  14. On Stability of Natural-circulation-cooled Boiling Water Reactors during Start-up (Experimental Results)

    International Nuclear Information System (INIS)

    Manera, A.; Van der Hagen, T.H.J.J.

    2002-01-01

    The characteristics of flashing-induced instabilities, which are of importance during the start-up phase of natural-circulation Boiling Water Reactors (BWRs), are studied. Experiments at typical start-up conditions (low power and low pressure) are carried out on a steam/water natural circulation loop. The mechanism of flashing-induced instability is analyzed in detail and it is found that non-equilibrium between phases and enthalpy transport plays an important role in the instability process. Pressure and steam volume in the steam dome are found to have a stabilizing effect. The main characteristics of the instabilities have been analyzed. (authors)

  15. Simultaneous effects of water spray and crosswind on performance of natural draft dry cooling tower

    Directory of Open Access Journals (Sweden)

    Ahmadikia Hossein

    2013-01-01

    Full Text Available To investigate the effect of water spray and crosswind on the effectiveness of the natural draft dry cooling tower (NDDCT, a three-dimensional model has been developed. Efficiency of NDDCT is improved by water spray system at the cooling tower entrance for high ambient temperature condition with and without crosswind. The natural and forced heat convection flow inside and around the NDDCT is simulated numerically by solving the full Navier-Stokes equations in both air and water droplet phases. Comparison of the numerical results with one-dimensional analytical model and the experimental data illustrates a well-predicted heat transfer rate in the cooling tower. Applying water spray system on the cooling tower radiators enhances the cooling tower efficiency at both no wind and windy conditions. For all values of water spraying rate, NDDCTs operate most effectively at the crosswind velocity of 3m/s and as the wind speed continues to rise to more than 3 m/s up to 12 m/s, the tower efficiency will decrease by approximately 18%, based on no-wind condition. The heat transfer rate of radiator at wind velocity 10 m/s is 11.5% lower than that of the no wind condition. This value is 7.5% for water spray rate of 50kg/s.

  16. The man-made creators of the imbalance of water in Nature

    Science.gov (United States)

    Shlafman, L. M.; Kontar, V. A.

    2013-12-01

    these are different places where the water taken, where the water used to grow crops, where the crop had eaten and where waste throw out. It creates a lot of the man-made imbalances of redeployment, which generate the new chains of different types of the man-made imbalances of water, other components and processes. The waste is one of the most important man-made creators of the imbalance of Nature. Some of water from the waste comes back into circulation in the clean or dirty conditions. Another part of water from waste will join into numerous water-based or water-use components of Nature, and fall out of the hydrological cycle for a long time. The quantity and diversity of waste are rising much faster than the recycles industries and it is creating a lot of dangerous imbalances of Nature. The wastes are is the time bombs, which man made, and which will soon explode. The traditional balanced science and practice are not prepared to deal with the waste problem. The concept of the imbalance of Nature can help prevent this catastrophic explosion. People are creating a lot of the man-made imbalances of Nature which bring the dangerous 'unexpected surprises'. The concept of the imbalance of Nature give possibilities to create the man-made imbalances of Nature with the predictable parameters and it can help do Mother Nature to be friendlier to humanity.

  17. Green Fodder Production and Water Use Efficiency of Some Forage Crops under Hydroponic Conditions

    OpenAIRE

    Ghazi N. Al-Karaki; M. Al-Hashimi

    2012-01-01

    The objectives of this study were to evaluate five forage crops (alfalfa (Medicago sativa), barley (Hordeum vulgare), cowpea (Vigna unguiculata), sorghum (Sorghum bicolor), and wheat (Triticum aestivum)) for green fodder production and water use efficiency under hydroponic conditions. The experiment has been conducted under temperature-controlled conditions (24 ± 1°C) and natural window illumination at growth room of Soilless Culture Laboratory, Arabian Gulf University, Manama, Bahrain. The r...

  18. The Existing Regulatory Conditions for 'Energy Smart Water Utilities'

    DEFF Research Database (Denmark)

    Basse, Ellen Margrethe

    2014-01-01

    This chapter is focused on the legal conditions that exist for the energy–smart water utilities in the European Union (EU). In section 2 the interdependencies of water and energy services and the growing interest in solving these problems that may arise from this interdependence by regulatory ini...... legal design and the problems that it causes for the water utilities that want to be resource–efficient and have a low–carbon footprint.......This chapter is focused on the legal conditions that exist for the energy–smart water utilities in the European Union (EU). In section 2 the interdependencies of water and energy services and the growing interest in solving these problems that may arise from this interdependence by regulatory...... initiatives are shortly described. One of the solutions needed is a reduction of energy use in the water utilities by their utilisation of renewable sources – acting as energy–smart water utilities. Such utilities are described in section 3. The policy and law regulating the water utilities are important...

  19. Probability of detecting perchlorate under natural conditions in deep groundwater in California and the Southwestern United States

    Science.gov (United States)

    Fram, Miranda S.; Belitz, Kenneth

    2011-01-01

    We use data from 1626 groundwater samples collected in California, primarily from public drinking water supply wells, to investigate the distribution of perchlorate in deep groundwater under natural conditions. The wells were sampled for the California Groundwater Ambient Monitoring and Assessment Priority Basin Project. We develop a logistic regression model for predicting probabilities of detecting perchlorate at concentrations greater than multiple threshold concentrations as a function of climate (represented by an aridity index) and potential anthropogenic contributions of perchlorate (quantified as an anthropogenic score, AS). AS is a composite categorical variable including terms for nitrate, pesticides, and volatile organic compounds. Incorporating water-quality parameters in AS permits identification of perturbation of natural occurrence patterns by flushing of natural perchlorate salts from unsaturated zones by irrigation recharge as well as addition of perchlorate from industrial and agricultural sources. The data and model results indicate low concentrations (0.1-0.5 μg/L) of perchlorate occur under natural conditions in groundwater across a wide range of climates, beyond the arid to semiarid climates in which they mostly have been previously reported. The probability of detecting perchlorate at concentrations greater than 0.1 μg/L under natural conditions ranges from 50-70% in semiarid to arid regions of California and the Southwestern United States to 5-15% in the wettest regions sampled (the Northern California coast). The probability of concentrations above 1 μg/L under natural conditions is low (generally <3%).

  20. Correlation Water Velocity and TSS with Natural Radionuclides Activity

    International Nuclear Information System (INIS)

    Tri Harningsih; Muzakky; Agus Taftazani

    2007-01-01

    Correlation water velocity and TSS with natural radionuclides activity has been studied. For that purpose, the study is to correlation water velocity and TSS with radionuclides on water and sediment samples in alongside river Code Yogyakarta. This research selected radionuclides, for examples Ra-226, Pb-212, Ac- 228, and K-40. Election of this radionuclides to spread over gamma gross composition alongside river of Code. Gamma gross influenced by water velocity and TSS, so that require to correct between water velocity and TSS to radionuclides. Sampling water and sediment conducted when dry season of August, 2006 at 11 locations, start from Boyong Bridge until Pacar Bridge. Result of analysis showed that water velocity range from 8-1070 L/dt and TSS range from 2.81 E-06 - 8.02 E-04 mg/L. The accumulation of radionuclides in water samples non correction water velocity for Ra-226: 0.302-2.861 Bq/L, Pb-212: 0.400-3.390 Bq/L, Ac- 228: 0.0029-0.0047 Bq/L and K-40: 0.780-9.178 Bq/L. The accumulation of radionuclide in water samples correction water velocity for Ra-226: 1.112-70.454 Bq/L, Pb-212: 0.850-77.113 Bq/L, Ac-228: 0.7187- 60.859 Bq/L and K-40: 2.420-208.8 Bq/L. While distribution of radionuclide in sediment for the Ra-226: 0.0012-0.0211 Bq/kg, Pb-212: 0.0017-0.0371 Bq/kg, Ac-228: 0.0021-0.0073 Bq/kg and K-40: 0.0006-0.0084 Bq/kg. (author)

  1. Uranium and radium geochemistry. Radioactive disequilibrium in natural waters

    International Nuclear Information System (INIS)

    Beaucaire, C.

    1987-09-01

    Rock-water interactions play a primary part in uranium-series disequilibrium either by different chemical behavior or by recoiling alpha emitting nuclei in solution. Three series of thermal water containing CO 2 (Vichy, Vals and Cezallier) and one from Lodeve uranium deposit are studied to define parameters (pH, Eh, pCO 2 , T,...) controlling studied nuclei. For U complexation by carbonates is in competition with redox conditions. Ra is coprecipitated by barium. For thermal waters keeping their deep characteristics there is a low disequilibriums 234 U- 238 U between 1 and 2. On the contrary important disequilibrium (up to 12) in Vichy Saint Yorre water are due to secondary remobilization. In the same way for these waters 234 U and 226 Ra are correlated. Then leaching is essential for the radioactive disequilibrium but alpha recoil of 234 Th is of secondary importance in this case [fr

  2. Assessment of integrated watershed health based on the natural environment, hydrology, water quality, and aquatic ecology

    Directory of Open Access Journals (Sweden)

    S. R. Ahn

    2017-11-01

    Full Text Available Watershed health, including the natural environment, hydrology, water quality, and aquatic ecology, is assessed for the Han River basin (34 148 km2 in South Korea by using the Soil and Water Assessment Tool (SWAT. The evaluation procedures follow those of the Healthy Watersheds Assessment by the U.S. Environmental Protection Agency (EPA. Six components of the watershed landscape are examined to evaluate the watershed health (basin natural capacity: stream geomorphology, hydrology, water quality, aquatic habitat condition, and biological condition. In particular, the SWAT is applied to the study basin for the hydrology and water-quality components, including 237 sub-watersheds (within a standard watershed on the Korea Hydrologic Unit Map along with three multipurpose dams, one hydroelectric dam, and three multifunction weirs. The SWAT is calibrated (2005–2009 and validated (2010–2014 by using each dam and weir operation, the flux-tower evapotranspiration, the time-domain reflectometry (TDR soil moisture, and groundwater-level data for the hydrology assessment, and by using sediment, total phosphorus, and total nitrogen data for the water-quality assessment. The water balance, which considers the surface–groundwater interactions and variations in the stream-water quality, is quantified according to the sub-watershed-scale relationship between the watershed hydrologic cycle and stream-water quality. We assess the integrated watershed health according to the U.S. EPA evaluation process based on the vulnerability levels of the natural environment, water resources, water quality, and ecosystem components. The results indicate that the watershed's health declined during the most recent 10-year period of 2005–2014, as indicated by the worse results for the surface process metric and soil water dynamics compared to those of the 1995–2004 period. The integrated watershed health tended to decrease farther downstream within the watershed.

  3. Comparison of East African and Iran natural feeding condition based ...

    African Journals Online (AJOL)

    In this scientific work, we used soils from Zanzibar (Tansania region east African), Guilan (north of Iran), Tehran (center of Iran) and two type of soils from Zabol and Saravan regions (southeastern of Iran) in a condition simulated like atmospheric ones. The amounts of reduced Fe, Mn, Cu, Zn, pH, Ec, carbohydrate and lipid ...

  4. Natural and induced endoreic hydrological conditions in the Alta Murgia karstic region (Apulia, Southern Italy)

    Science.gov (United States)

    Canora, F.; Fidelibus, M. D.; Spilotro, G.

    2009-04-01

    A study aimed at understanding the hydrological processes in karst areas related to the presence of natural and artificial endoreic basins and their modification due to land use change, as well as the influence of above factors on the infiltration rate has been carried out in the Alta Murgia region (Apulia, Southern Italy). The region is a Cretaceous limestone plateau of the Apulian platform, characterized by a mature karstic landscape: due to its elevation, climatic conditions and lithology, the plateau constitutes the main recharge area of the Murgia aquifer. The typical karst topography is essentially related to the subterranean drainage (sinkholes, caves, conduit): surface and subsurface karst geomorphology is strictly interrelated with hydrology. The morphological features of the karstic plateau are defined by the high density of surface karstic forms (mainly dolines), the presence of exposed karst and karren fields, as well as by the extensive outcrop of fractured rocks. Karst surface shows, on the bottom of the morpho-structural depressions called "lame", natural distribution of modest deposits of "terra rossa" and regolith. The "lame" work as streams during and after intense rainfall events, often outlining a primordial ephemeral hydrographical network, frequently convergent towards dolines, poljes or endoreic basins. Alta Murgia shows many natural endoreic basin conditions in a quite flat morphology. In this environment, when intense rainfall events cover large areas and rainfall intensity exceeds the infiltration capacity of soils and/or sinkholes, significant runoff amounts are produced and stored in the basins causing floods. Most of the natural endoreic basins are small and independent: while the majority of them continue functioning as endoreic even in presence of extreme events of high return time, others (quasi-endoreic), under the same circumstances can start contributing to other basins, due to exceeding their water storage capability. This way

  5. Optimization of the Determination Method for Dissolved Cyanobacterial Toxin BMAA in Natural Water.

    Science.gov (United States)

    Yan, Boyin; Liu, Zhiquan; Huang, Rui; Xu, Yongpeng; Liu, Dongmei; Lin, Tsair-Fuh; Cui, Fuyi

    2017-10-17

    There is a serious dispute on the existence of β-N-methylamino-l-alanine (BMAA) in water, which is a neurotoxin that may cause amyotrophic lateral sclerosis/Parkinson's disease (ALS/PDC) and Alzheimer' disease. It is believed that a reliable and sensitive analytical method for the determination of BMAA is urgently required to resolve this dispute. In the present study, the solid phase extraction (SPE) procedure and the analytical method for dissolved BMAA in water were investigated and optimized. The results showed both derivatized and underivatized methods were qualified for the measurement of BMAA and its isomer in natural water, and the limit of detection and the precision of the two methods were comparable. Cartridge characteristics and SPE conditions could greatly affect the SPE performance, and the competition of natural organic matter is the primary factor causing the low recovery of BMAA, which was reduced from approximately 90% in pure water to 38.11% in natural water. The optimized SPE method for BMAA was a combination of rinsed SPE cartridges, controlled loading/elution rates and elution solution, evaporation at 55 °C, reconstitution of a solution mixture, and filtration by polyvinylidene fluoride membrane. This optimized method achieved > 88% recovery of BMAA in both algal solution and river water. The developed method can provide an efficient way to evaluate the actual concentration levels of BMAA in actual water environments and drinking water systems.

  6. Effects of sucrose concentration and water deprivation on Pavlovian conditioning and responding for conditioned reinforcement.

    Science.gov (United States)

    Tabbara, Rayane I; Maddux, Jean-Marie N; Beharry, Priscilla F; Iannuzzi, Jessica; Chaudhri, Nadia

    2016-04-01

    An appetitive Pavlovian conditioned stimulus (CS) can predict an unconditioned stimulus (US) and acquire incentive salience. We tested the hypothesis that US intensity and motivational state of the subject would influence Pavlovian learning and impact the attribution of incentive salience to an appetitive Pavlovian CS. To this end, we examined the effects of sucrose concentration and water deprivation on the acquisition of Pavlovian conditioning and responding for a conditioned reinforcer. Male Long-Evans rats (Harlan; 220-240 g) receiving 3% (3S) or 20% (20S) sucrose were either non-water deprived or given water for 1 hr per day. During Pavlovian conditioning sessions, half the rats in each concentration and deprivation condition received a 10-s CS paired with 0.2 ml of sucrose (16 trials/session; 3.2 ml/session). The remainder received unpaired CS and US presentations. Entries into a port where sucrose was delivered were recorded. Next, responding for conditioned reinforcement was tested, wherein pressing an active lever produced the CS and pressing an inactive lever had no consequences. CS-elicited port entries increased, and latency to the first CS-elicited port entry decreased across sessions in paired groups. Water deprivation augmented these effects, whereas sucrose concentration had no significant impact on behavior. Responding for conditioned reinforcement was observed in the 20S water-deprived, paired group. Thus, water deprivation can facilitate the acquisition of Pavlovian conditioning, potentially by enhancing motivational state, and a high-intensity US and a high motivational state can interact to heighten the attribution of incentive salience to an appetitive Pavlovian CS. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Salinity and cationic nature of irrigation water on castor bean cultivation

    Directory of Open Access Journals (Sweden)

    Geovani S. de Lima

    Full Text Available ABSTRACT This study aimed to evaluate the water relations, cell damage percentage and growth of the castor bean cv. ‘BRS Energia’ as a function of salinity and cationic nature of the water used in irrigation. The experiment was conducted in drainage lysimeters under greenhouse conditions in eutrophic Grey Argisol of sandy loam texture. Six combinations of water salinity and cations were studied (S1 - Control; S2 - Na+, S3 - Ca2+, S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+, in a randomized block design with four replicates. In the control (S1, plants were irrigated with 0.6 dS m-1 water, whereas the other treatments received 4.5 dS m-1 water, obtained by adding different salts, all in the chloride form. Higher relative water content in the leaf blade of plants irrigated with K+-salinized water associated with leaf succulence are indicative of tolerance of the castor bean cv. ‘BRS Energia’ to salinity. Saline stress negatively affected castor bean growth, regardless of cationic nature of water. Among the ions studied, ‘BRS Energia’ castor bean was more sensitive to the presence of sodium in the irrigation water, in terms of both water relations and leaf succulence.

  8. Compared studies of natural and artificial deuterium depleted water

    International Nuclear Information System (INIS)

    Butnaru, Gallia; Mihacea, Sorina; Sirbovan, Alina; Butnariu, H.; Titescu, Gh.

    2001-01-01

    The biological influence of the deuterium on animals was studied insensitively in the last years. When animal cell cultures were analyzed it turned out an inhibition of the development, due to the reduced deuterium concentration. In the in vivo experiments a decreasing of the number of tumoral cells was pointed out when performing the depleted water treatment. It is obvious that the presence of deuterium in water is necessary for the development, especially for the tumoral cell proliferation. The aim of this work was to establish influence of the natural and artificial deuterium depleted water on the vegetal organisms development. For this purpose, the developmental stages of Lactuca sativa L. growth were followed. The experimental data were compared with the data obtained with distilled water. The birch, wine sap and some fruit juices are considered 'natural depleted' water sources because their deuterium content is smaller in comparison to natural water (D 2 =150 ppm). The effect of artificial deuterium depleted water (29 ppm D 2 ) was analyzed in comparison to three types of wine saps, which also have a reduced deuterium concentration (125-130 ppm D 2 ). If the deuterium depleted water was used, the germination percent and the root and shoot length were higher compared to control in the first stages. In wine sap it had a negative effect on germination and development. After three days the plants were transferred to soil and their development was followed. The foliage area was larger for all of the experimental variants compared to control. The differences were without significance when deuterium depleted water was tested but they were high and very significant in case of wine sap. The experiment pointed out a stimulative effect of the artificial deuterium depleted water. In case of wine sap the effect was negative when the contact was direct, but the growth was stimulated after the stress cessation. The first ontogenetic stages were represented by direct action

  9. Iron speciation in natural hyperacid water investigated by Mossbauer spectroscopy

    DEFF Research Database (Denmark)

    Koch, C. Bender; Rasmussen, Helge Kildahl; Mørup, Steen

    2009-01-01

    We have demonstrated the usefulness of the archetypical solid state-technique of Mössbauer spectroscopy to non-invasive studies of the redox and coordination chemistry of iron in a natural hyperacid solution from Iron Mountain, CA. Suitable fast cooling conditions were used to prepare a glass from...

  10. Contact heating of water products of combustion of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Aronov, I Z

    1978-01-01

    The USSR's NIIST examined the processes and equipment for heating water by submerged combustion using natural gas. Written for engineers involved with the design and application of thermal engineering equipment operating with natural gas, the book emphasizes equipment, test results, and methods of calculating heat transfer for contact gas economizers developed by Scientific Research Institute of Sanitary Engineering and other Soviet organizations. The economic effectiveness of submerged-combustion heating depends on several factors, including equipment design. Recommendations cover cost-effective designs and applications of contact economizers and boilers.

  11. Express-analysis of Radiocaesium Traces in Natural Water

    International Nuclear Information System (INIS)

    Remez, V.P.; Belyakova, E.G.

    1999-01-01

    To determine traces of radiocaesium in water solution, the sorbent on the base of ferric potassium hexacyanoferrate on cellulose carrier ANFEZH was worked out. The sorbent is capable to extract effectively the isotopes of caesium from various natural solutions (fresh and sea water, milk, juices and so on). The usage of sorbent allows practically completely concentrate the isotopes of caesium from water samples with the volume of tens and hundreds litres. The sorbent in quantity of 50-500 grams allows to extract 98±1% of caesium from natural water samples with the volume up to 1000 litres during 1-5 hours. The usage of this sorbent allowed to conduct the express analysis of multiple bore holes within the area of 30 km of Chernobyl Skaya NPP , drinking water and milk in the regions of Belorussia, Ukraine and Russia, hit by Chernobyl disaster and around NPP in Russia and America. The use of this express analysis reduced the time and required labour as compared with to precipitation methods

  12. TBA biodegradation in surface-water sediments under aerobic and anaerobic conditions.

    Science.gov (United States)

    Bradley, Paul M; Landmeyer, James E; Chapelle, Francis H

    2002-10-01

    The potential for [U-14C] TBA biodegradation was examined in laboratory microcosms under a range of terminal electron accepting conditions. TBA mineralization to CO2 was substantial in surface-water sediments under oxic, denitrifying, or Mn(IV)-reducing conditions and statistically significant but low under SO4-reducing conditions. Thus, anaerobic TBA biodegradation may be a significant natural attenuation mechanism for TBA in the environment, and stimulation of in situ TBA bioremediation by addition of suitable terminal electron acceptors may be feasible. No degradation of [U-14C] TBA was observed under methanogenic or Fe(III)-reducing conditions.

  13. Measurement of natural and anthropogenic radiation in surface waters

    International Nuclear Information System (INIS)

    Turcotte, Jacques

    1981-01-01

    The use of alumina gel in municipal water treatment plants is proving very promising for the measurement of radioactivity in watercourses. The amazing fixation power of aluminum hydroxide and the large volume of water treated daily in one plant permits alumina gel to concentrate traces of natural and artificial radioisotopes to a level at which it becomes possible to observe very small amounts of radioactive fallout from nuclear tests, or even to follow over hundreds of kilometers the wastes of nuclear stations, no matter how weak the radioactivity may be [fr

  14. Practical isolation of methyl mercury in natural waters

    International Nuclear Information System (INIS)

    Schintu, M.; Kauri, T.; Contu, A.; Kudo, A.

    1987-01-01

    A simple method to isolate both organic and inorganic mercury in natural waters is described. The mercuric compounds were quantitatively extracted with dithizone from six different kinds of water spiked at nanogram levels with radioactive mercuric chloride and methylmercuric chloride. After the separation from the inorganic mercury with sodium nitrite, methyl mercury was transferred to aqueous medium with sodium thiosulfate. The method provides a high recovery of organic as well as inorganic mercury to an aqueous medium, prior to their determination by gold-trap cold vapor atomic absorption spectrophotometry. This method is easy, rapid, and inexpensive. Furthermore, the limited number of analytical steps should reduce loss and contamination

  15. Natural attenuation of antimony in mine drainage water

    International Nuclear Information System (INIS)

    Manaka, Mitsuo; Yanase, Nobuyuki; Sato, Tsutomu; Fukushi, Keisuke

    2007-01-01

    In this study, we investigated the natural attenuation of antimony (Sb) in the drainage water of an abandoned mine. Drainage water, waste rocks, and ocherous precipitates collected from the mine were investigated in terms of their mineralogy and chemistry. The chemistry of the drainage water was analyzed by measuring pH, oxidation-reduction potential (ORP), and electric conductivity on site as well as by inductively coupled plasma mass spectrometry and ion chromatography. As the drainage flowed downstream, the pH decreased rapidly from 7.05 to 3.26 and then increased slowly to 3.50. In a section where the pH increased, ocherous precipitates occur on a drainage water channel. We determined Sb levels in the drainage water, and the distribution of Sb in the mineral phases of waste rocks and precipitates was estimated by means of a sequential extraction procedure. The results of these investigations indicated that Sb, which is generated by the dissolution of stibnite (Sb 2 S 3 ) and secondary formed Sb minerals in waste rocks, was attenuated by iron-bearing ocherous precipitates, especially schwertmannite, that form over time in the drainage water. The Sb concentrations in the ocherous precipitates were up to 370 mg/kg, whereas the Sb concentrations in the drainage water downstream were below background levels (0.6 μg/L). Bulk distribution coefficients (K d ) for this Sb adsorption to the precipitates ranges up to at least 10 5 L/kg. (author)

  16. Colloids removal from water resources using natural coagulant: Acacia auriculiformis

    Science.gov (United States)

    Abdullah, M.; Roslan, A.; Kamarulzaman, M. F. H.; Erat, M. M.

    2017-09-01

    All waters, especially surface waters contain dissolved, suspended particles and/or inorganic matter, as well as several biological organisms, such as bacteria, algae or viruses. This material must be removed because it can affect the water quality that can cause turbidity and colour. The objective of this study is to develop water treatment process from Seri Alam (Johor, Malaysia) lake water resources by using natural coagulant Acacia auriculiformis pods through a jar test experiment. Jar test is designed to show the effectiveness of the water treatment. This process is a laboratory procedure that will simulate coagulation/flocculation with several parameters selected namely contact time, coagulant dosage and agitation speed. The most optimum percentage of colloids removal for each parameter is determined at 0.2 g, 90 min and 80 rpm. FESEM (Field-emission Scanning Electron Microscope) observed the small structures of final floc particles for optimum parameter in this study to show that the colloids coagulated the coagulant. All result showed that the Acacia auriculiformis pods can be a very efficient coagulant in removing colloids from water.

  17. Parameters, which effect the mass flow in the PRHRS under a natural convection condition

    International Nuclear Information System (INIS)

    Chung, Y. J.; Lee, G. H.; Kim, H. C.; Kim, K. K.; Zee, S. Q.

    2004-01-01

    Small and medium sized integral type reactors for the diverse utilization of nuclear energy are getting much attention from the international nuclear community. They diversify the peaceful uses of nuclear energy in the areas of seawater desalination, district heating, industrial heat-generation process and ship propulsion. The SMART (System integrated Modular Advanced ReacTor) is a small modular integral type pressurized water reactor, which was developed for the dual purposes application of seawater desalination and small-scaled power generation in KOREA. The reactor is designed for a forced convection core cooling during start-up and normal operating conditions and for a natural circulation core cooling during accidental conditions. The main safety objective of the SMART is to increase the degree of inherent safety features by advanced designs such as a passive residual heat removal system (PRHRS). The passive residual heat removal system removes the core decay heat and sensible heat by a natural circulation in the case of emergency conditions. This study focuses on the flow behavior in the passive residual heat removal system of the integral reactor. The system necessitates a hydraulic head to achieve the required natural circulation flow rate, which in turn, may cause a larger two-phase pressure drop and flow oscillation. Also, it is of interest to investigate the complex effects of the boiling and condensation in such low frequency thermo-hydraulic oscillations. Thermal hydraulic analysis for the passive residual heat removal system has been carried out by means of the MARS code for a full range of reactor operating conditions. The MARS code has been developed at the Korea Atomic Energy Research Institute by consolidating and restructuring the RELAP5/MOD3.2 and COBRA-TF which has the capabilities of analyzing the one-dimensional or three-dimensional best estimated thermal-hydraulic system and the fuel responses of the light water reactor transients. A selected

  18. Cooling water conditioning and quality control for tokamaks

    International Nuclear Information System (INIS)

    Gootgeld, A.M.

    1995-01-01

    Designers and operators of Tokamaks and all associated water cooled, peripheral equipment, are faced with the task of providing and maintaining closed-loop, low conductivity, low impurity, cooling water systems. The primary reason for supplying low conductivity water to the DIII-D vacuum vessel coils, power supplies and auxiliary heating components is to assure, along with the use of a non-conducting break in the supply piping, sufficient electrical resistance and thus an acceptable current-leakage path to ground at operating voltage potentials. As important, good quality cooling water significantly reduces the likelihood of scaling and fouling of flow passages and heat transfer surfaces. Dissolved oxygen gas removal is also required in one major DIII-D cooling water system to minimize corrosion in the ion sources of the neutral beam injectors. Currently, the combined pumping capacity of the high quality cooling water systems at DIII-D is ∼5,000 gpm. Another area that receives close attention at DIII-D is the chemical treatment of the water used in the cooling towers. This paper discusses the DIII-D water quality requirements, the means used to obtain the necessary quality and the instrumentation used for control and monitoring. Costs to mechanically and chemically condition and maintain water quality are discussed as well as the various aspects of complying with government standards and regulations

  19. Stability of niclosamide in water under local conditions

    International Nuclear Information System (INIS)

    El Hindi, A.M.; Sidra, M.S.

    1986-01-01

    The stability of 14 C-labelled niclosamide was studied in distilled water at two different pH values and in canal water. 2 mg/1 niclosamide solutions were exposed to direct atmospheric conditions. The activity was followed by radioassay and the concentration of niclosamide was determined by GLC. The total activity was found to decrease to 46.0% in weakly acidic solution (pH 6.5), 45% in neutral solution (pH 7.0) and 16.7% in filtered canal water after three weeks. GLC analysis showed that niclosamide concentration had dropped to 0.05, 0.06 and 0.03 mg/1 in weakly acidic, neutral medium and canal water after the same period. GLC analysis as compared to radioassay indicated the presence of increasing amounts of degradation product(s), in the chloroform extracts of water with time, which were not detected by GLC

  20. Cooling water conditioning and quality control for tokamaks

    International Nuclear Information System (INIS)

    Gootgeld, A.M.

    1995-10-01

    Designers and operators of Tokamaks and all associated water cooled, peripheral equipment, are faced with the task of providing and maintaining closed-loop, low conductivity, low impurity, cooling water systems. Most of these systems must provide large volumes of high quality cooling water at reasonable cost and comply with local and state government orders and EPA mandated national pretreatment standards and regulations. This paper discusses the DIII-D water quality requirements, the means used to obtain the necessary quality and the instrumentation used for control and monitoring. Costs to mechanically and chemically condition and maintain water quality are discussed as well as the various aspects of complying with government standards and regulations

  1. 226Ra and natural uranium in egyptian bottled mineral waters

    International Nuclear Information System (INIS)

    Higgy, R.H.

    2000-01-01

    Concentration levels of 226 Ra and natural uranium have been analysed bottled mineral water commercially available in egypt. 226 Ra was determined by applying a chemical procedure in which Ra was coprecipitated with Ba as sulphate. The precipitate was then dissolved with EDTA and then measured by liquid scintillation system, after mixing with a scintillation cocktail. Natural uranium was determined by applying a chemical procedure for uranium extraction using MIBK and then measured using laser fluorimeter system. The concentration values obtained were compared with concentrations reported by other countries and with reference values accepted for drinking water. Based on the consumption rate and the measured concentrations, the collective committed effective doses were calculated. In addition, Ca, Mg and Na were measured using Icp system and compared with some worldwide values

  2. Measurement of Antioxidant Activity Towards Superoxide in Natural Waters.

    Directory of Open Access Journals (Sweden)

    D. Whitney King

    2016-11-01

    Full Text Available Antioxidants are a class of molecules that provide a protective function against reactive oxygen species (ROS in biological systems by out competing physiologically important molecules for ROS oxidation. In natural waters, the reactivity of antioxidants gives an estimate of oxidative stress and may determine the reactivity and distribution of reactive oxidants. We present an analytical method to measure antioxidant activity in natural waters through the competition between ascorbic acid, an antioxidant, and MCLA, a chemiluminescent probe for superoxide. A numerical kinetic model of the analytical method has been developed to optimize analytical performance. Measurements of antioxidant concentrations in pure and seawater are possible with detection limits below 0.1 nM. Surface seawater samples collected at solar noon contained over 0.4 nM of antioxidants and exhibited first-order decay with a half-life of 3-7 minutes, consistent with a reactive species capable of scavenging photochemically produced superoxide.

  3. Public understandings of nature: a case study of local knowledge about "natural" forest conditions

    Science.gov (United States)

    R. Bruce Hull; David P. Robertson; Angelina Kendra

    2001-01-01

    This study is intended to serve as an explicit and specific example of the social construction of nature. It is motivated by the need to develop a more sophisticated language for a critical public dialogue about society's relationship with nature. We conducted a case study of environmental discourse in one local population in hopes of better understanding how a...

  4. Formation of secondary minerals and uptake of various anions under naturally-occurring hyper-alkaline conditions in Oman - 16344

    International Nuclear Information System (INIS)

    Anraku, Sohtaro; Sato, Tsutomu; Yoneda, Tetsuro; Morimoto, Kazuya

    2009-01-01

    In Japanese transuranic (TRU) waste disposal facilities, 129 I is the most important key nuclide for the long-term safety assessment. Thus, the K d values of I to natural minerals are important factor in the safety assessment. However, the degradation of cement materials in the repositories can produce high pH pore fluid which can affect the anion transport behavior. Therefore, it is necessary to understand the behavior of anions such as I- under the hyper-alkaline conditions. The natural hyper-alkaline spring water (pH>11) in the Oman ophiolite is known to be generated from the partly serpentinized peridotites. The spring water is characteristically hyper-alkaline, reducing, low-Mg, Si and HCO 3 - , and high-Ca, while the river water is moderately alkaline, oxidizing, high-Mg and HCO 3 - . The mixing of these spring and river water resulted in the formation of secondary minerals. In the present study, the naturally occurring hyper-alkaline conditions near the springs in Oman were used as natural analogue for the interaction between cement pore fluid and natural Mg-HCO 3 - groundwater. The present aim of this paper is to examine the conditions of secondary mineral formation and the anion uptake capacity of these mineral in this system. Water and precipitate samples were collected from the different locations around the spring vent to identify the effect of mixing ratios between spring and river water on mineral composition and water-mineral distribution coefficient of various anions. On-site synthesis was also carried out to support these data quantitatively. Aragonite was observed in all precipitates, while calcite, brucite and Mg-Al hydrotalcite-like compounds (HTlc) were also determined in some samples. Calcite was observed only closed to the springs. At locations far from the springs, calcite formation was inhibited due to high-Mg fluid from river water. Brucite was observed from the springs with relatively low-Al concentration and HTlc was the opposite. During

  5. Water for wood products versus nature, food or feed

    Science.gov (United States)

    Schyns, Joep; Booij, Martijn; Hoekstra, Arjen

    2017-04-01

    more water available for the generation of other ecosystem services. Our findings contribute to a more complete picture of the human appropriation of water and the understanding of the interlinkages between the SDGs, thus feeding the debate on water for wood products versus nature, food or feed.

  6. Isolation and characterization of humics from natural waters

    International Nuclear Information System (INIS)

    Allard, B.; Arsenie, I.; Boren, H.; Ephraim, J.; Pettersson, C.; Gaardhammar, G.

    1990-05-01

    A method has been developed for quantitative recovery of humic substances from aqueous systems based on ion exchange on DEAE-cellulose. A scheme is suggested for the characterization of dissolved humic substances (UV-, IR- and 1 H NMR-spectroscopy, elemental analysis, molecular weight determination, 14 C-age, functionality, carbohydrate content and acid-base properties) as a routine in the chemical analysis of natural waters. (orig.)

  7. Natural uranium fueled light water moderated breeding hybrid power reactors

    International Nuclear Information System (INIS)

    Greenspan, E.; Schneider, A.; Misolovin, A.; Gilai, D.; Levin, P.

    The feasibility of fission-fusion hybrid reactors based on breeding light water thermal fission systems is investigated. The emphasis is on fuel-self-sufficient (FSS) hybrid power reactors that are fueled with natural uranium. Other LWHRs considered include FSS-LWHRs that are fueled with spent fuel from LWRs, and LWHRs which are to supplement LWRs to provide a tandem LWR-LWHR power economy that is fuel-self-sufficient

  8. Analysis of nature of brazed joints fracture under operating conditions

    International Nuclear Information System (INIS)

    Orlov, A.V.; Gura, P.M.

    1985-01-01

    Technique establishing causes leading to brazed joint fracture in pressure boundary components, operating under heavy conditions of high temperature and corrosive medium is described. Some cases of tube brazed joint fractures in a superheater of 12Kh1MF and 08Kh18N10T steels are considered. The attention is paid on using metallography for determination of mechanical or corrosion fracture properties. The diagram is developed permitting to take into account the interrelation between the fracture area in the given zone and its strength

  9. Laboratory simulation studies of uranium mobility in natural waters

    International Nuclear Information System (INIS)

    Giblin, A.M.; Swaine, D.J.; Batts, B.D.

    1981-01-01

    The effects of imposed variations of pH and Eh on aqueous uranium mobility at 25 0 C have been studied in three simulations of natural water systems. Constituents tested for their effect on uranium mobility were: (a) hydrous ferric oxide, to represent adsorptive solids which precipitate or dissolve in response to variations in pH and Eh; (b) kaolinite, representing minerals which, although modified by pH and Eh changes, are present as solids over the pH-Eh range of natural waters; and (c) carbonate, to represent a strong uranium-complexing species. Uranium mobility measurements from each simulation were regressed against pH and Eh within a range appropriate to natural waters. Hydrous ferric oxide and kaolinite each affected uranium mobility, but in separate pH-Eh domains. Aqueous carbonate increased mobility of uranium, and adsorption of UO 2 (CO 3 ) 3 4- caused colloidal dispersion of hydrous ferric oxide, possibly explaining the presence of 'hydrothermal hematite' in some uranium deposits. Enhanced uranium mobility observed in the pH-Eh domains of thermodynamically insoluble uranium oxides could be explained if the oxides were present as colloids. Uranium persisting as a mobile species, even after reduction, has implications for the near surface genesis of uranium ores. (author)

  10. The Natural History and Risk Factors of Musculoskeletal Conditions Resulting in Disability Among US Army Personnel

    National Research Council Canada - National Science Library

    Lincoln, Andrew

    2002-01-01

    We describe the natural history of 13 musculoskeletal conditions requiring hospitalization and identify demographic, behavioral, psychosocial, occupational, and clinical characteristics most strongly...

  11. DEVELOPMENT OF RAPID TECHNIQUE FOR DETERMINATION OF THE TOTAL MINERALIZATION OF NATURAL WATERS

    Directory of Open Access Journals (Sweden)

    T. A. Kuchmenko

    2015-01-01

    Full Text Available A new approach has been proposed for rapid and easy evaluation of a indicator of quality and properties of natural water - soluble salt content (mineralization. The method of quartz crystal microbalance is employed at load of the mass-sensitive resonator electrode (BAW-type with investigated water. The degree of correlation between the various indicators related to the contents of salts and insoluble compounds and the level of mineralization obtained by the standard method (gravimetry has been studied. A procedure for salt weighing by single sensor at unilateral load with small sample of natural water has been developed. The optimal conditions for measurement is established using the design of experiment by model 23 . The possibilities of quartz crystal microbalance for determination of non-volatile compounds in the water are described. The calibration of piezosensor is produced by standard solution NaCl (c = 1.000 g / dm3 at optimal conditions of experiment. The adequacy and accuracy of proposed technique is assessed by the correlation between the results of quartz crystal microbalance and conductometry. The correlation between indicators of mineralization established by quartz crystal microbalance and gravimetry is found. It has been obtained an equation that can be used to calculate the standard indicator of the mineralization by the results of a quartz crystal microbalance using single sensor. The approaches to enhance the analytical capabilities of the developed technique for water with low and high mineralization are proposed. The metrological characteristics of quartz crystal microbalance of insoluble compounds in natural water are estimated. A new technique of determination of the mass concentration of the dry residue in water with a conductivity of 0.2 mS or above has been developed, which can be used for rapid analysis of the water at nonlaboratory conditions and in the laboratory for rapid obtaining the information about a sample.

  12. Innovative Treatment Technologies for Natural Waters and Wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Childress, Amy E.

    2011-07-01

    The research described in this report focused on the development of novel membrane contactor processes (in particular, forward osmosis (FO), pressure retarded osmosis (PRO), and membrane distillation (MD)) in low energy desalination and wastewater treatment applications and in renewable energy generation. FO and MD are recently gaining national and international attention as viable, economic alternatives for removal of both established and emerging contaminants from natural and process waters; PRO is gaining worldwide attention as a viable source of renewable energy. The interrelationship of energy and water are at the core of this study. Energy and water are inextricably bound; energy usage and production must be considered when evaluating any water treatment process for practical application. Both FO and MD offer the potential for substantial energy and resource savings over conventional treatment processes and PRO offers the potential for renewable energy or energy offsets in desalination. Combination of these novel technologies with each other, with existing technologies (e.g., reverse osmosis (RO)), and with existing renewable energy sources (e.g., salinity gradient solar ponds) may enable much less expensive water production and also potable water production in remote or distributed locations. Two inter-related projects were carried out in this investigation. One focused on membrane bioreactors for wastewater treatment and PRO for renewable energy generation; the other focused on MD driven by a salinity gradient solar pond.

  13. Tritium volume activity in natural waters of NPP Temelin region

    Energy Technology Data Exchange (ETDEWEB)

    Tomasek, M; Wilhelmova, L [Academy of Sciences of the Czech Rep., Prague (Czech Republic). Nuclear Physics Inst., Dept. of Radiation Dosimetry

    1996-12-31

    This paper presents the results of tritium measurement in selected rivers of NPP Temelin before its operation obtained during the period 1991-1994. Particular attention is paid to Vltava river into which liquid effluents will be discharged and which is also utilized as a drinking water supply for the capital Prague. Samples from the Vltava river were collected near the mouth of NPP waste canal (point Hladna)and in front of the intake into Prague water works (point Podoli). Tritium content was analysed also in surface waters of Paleckuv, Temelinsky and Strouha streams which can be affected by gaseous effluents due to atmospheric removal processes. Tritium activity was measured with Tric-Carb 1050 TR/LL liquid scintillation counter. The mean annual tritium activities of investigated river waters varied within 1.9-3.0 Bq/l during the period 1991-1994 and that their trend has been slowly decreasing. This fact, as well as seasonal variability, suggests, that tritium level in the surface waters of studied region is largely governed by this radionuclide global atmospheric fallout. The results of this work indicate the trend of background tritium in examined natural waters and make possible the evaluation of their potential future contamination. (J.K.) 1 tab., 2 figs., 4 refs.

  14. Annual effective dose due to natural radioactivity in drinking water

    International Nuclear Information System (INIS)

    Padma Savithri, P.; Srivastava, S.K.; Balbudhe, A.Y.; Vishwa Prasad, K.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    Natural radioactivity concentration in drinking water supply in and round Hyderabad, Secunderabad was determined. The observed gross alpha activity found in water samples vary from 0.027±0.014 Bq/L to 0.042±0.015 Bq/L with average 0.035 Bq/L while beta activity in all the samples are less than 0.076 Bq/l. Contributions of the drinking water samples to total annual effective dose equivalent from 238 U, 234 U, 230 Th, 26 Ra, 210 Po, 232 Th, 228 Th 210 Pb and 228 Ra are 1.14, 1.24, 5.30, 7.07, 30.3, 5.81, 1.82, 38.3 and 38.3 μSvy -1 for adults. The results indicate that the annual effective doses are below the WHO recommended reference level for α and β in food and drinking samples. (author)

  15. Natural radioactivity in Brazilian bottled mineral waters and consequent doses

    International Nuclear Information System (INIS)

    Oliveira, J. de; Paci Mazzilli, B.; Costa, P. da; Akiko Tanigava, P.

    2001-01-01

    The natural activity concentration levels of 226 Ra, 228 Ra and 210 Pb were analyzed in 17 brands of bottled mineral waters commercially available in the Southeast region of Brazil. Concentrations up to 647 mBq x l -1 and 741 mBq x l -1 were observed for 226 Ra and 228 Ra, whereas 210 Pb concentrations reached 85 mBq x l -1 . Average committed effective doses of 1.3 x 10 -2 mSv x y -1 for 226 Ra, 3.4 x 10 -2 mSv x y -1 for 228 Ra and 9.4 x 10 -3 mSv x y -1 for 210 Pb were estimated for the ingestion of these waters. A collective dose of 90 manSv was evaluated, considering the annual production of the bottled mineral waters analyzed in this study. (author)

  16. Assessing the effects of adaptation measures on optimal water resources allocation under varied water availability conditions

    Science.gov (United States)

    Liu, Dedi; Guo, Shenglian; Shao, Quanxi; Liu, Pan; Xiong, Lihua; Wang, Le; Hong, Xingjun; Xu, Yao; Wang, Zhaoli

    2018-01-01

    Human activities and climate change have altered the spatial and temporal distribution of water availability which is a principal prerequisite for allocation of different water resources. In order to quantify the impacts of climate change and human activities on water availability and optimal allocation of water resources, hydrological models and optimal water resource allocation models should be integrated. Given that increasing human water demand and varying water availability conditions necessitate adaptation measures, we propose a framework to assess the effects of these measures on optimal allocation of water resources. The proposed model and framework were applied to a case study of the middle and lower reaches of the Hanjiang River Basin in China. Two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP4.5) were employed to project future climate, and the Variable Infiltration Capacity (VIC) hydrological model was used to simulate the variability of flows under historical (1956-2011) and future (2012-2099) conditions. The water availability determined by simulating flow with the VIC hydrological model was used to establish the optimal water resources allocation model. The allocation results were derived under an extremely dry year (with an annual average water flow frequency of 95%), a very dry year (with an annual average water flow frequency of 90%), a dry year (with an annual average water flow frequency of 75%), and a normal year (with an annual average water flow frequency of 50%) during historical and future periods. The results show that the total available water resources in the study area and the inflow of the Danjiangkou Reservoir will increase in the future. However, the uneven distribution of water availability will cause water shortage problems, especially in the boundary areas. The effects of adaptation measures, including water saving, and dynamic control of flood limiting water levels (FLWLs) for reservoir operation, were

  17. Study on natural circulation characteristics of an IPWR under inclined and rolling condition

    Energy Technology Data Exchange (ETDEWEB)

    He, Lihui [College of Computer Science and Information Technology, Harbin Normal University, Harbin (China); Wang, Bing [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China); Xia, Genglei, E-mail: xiagenglei@163.com [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China); Peng, Minjun [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China)

    2017-06-15

    Highlights: • An ocean-based thermal-hydraulic analysis code was developed based on RELAP5 codes. • The inclination condition can reduce the mass flow rate of reactor core. • The system parameters asymmetry increases with the increasing inclination angle. • Flow oscillation of different loops cancel each other due to the symmetrical arrangement of the reactor. • The off-center roll axis location can break the symmetry and enlarge fluctuation amplitude of the core flow rate. - Abstract: An ocean-based thermal-hydraulic system analysis code was developed based on RELAP5/MOD3 code by adding additional force model of ocean condition and control volume coordinate solver model. The natural circulation operation characteristics of integrated pressurized water reactor (IPWR) under ocean conditions were studied and the effects of inclination and rolling motions were analyzed. The results conclude that, the inclination condition can reduce the mass flow rate of reactor core and lead to inconsistent coolant flow rates of the left and right loops, furthermore, it affects the heat transfer of once-through steam generators (OTSGs). In the case of rolling motion, the additional pressure drop of the loop is dominated by tangential force, and flow oscillation of different loops cancel each other due to the symmetrical arrangement of the reactor. The off-center roll axis location, the combination of the inclination and rolling motion, both can break the thermal-hydraulic symmetry among different loops and enlarge fluctuation amplitude of the core flow rate.

  18. Experimental and theoretical study on natural circulation capacity under rolling motion condition

    International Nuclear Information System (INIS)

    Tan Sichao; Gao Puzhen

    2007-01-01

    Effect of rolling motion on natural circulation capacity was studied experimentally and theoretically. Experiments were conducted under the conditions of rolling and unrolling motions. The experimental results show that natural circulation capacity decreases under rolling motion condition. A mathematic model was developed to calculate the natural circulation capacity under rolling motion condition, considering the characteristics of natural circulation, the model was modified. The calculated results agree with experimental data well. Effect of rolling motion on natural circulation was analyzed through calculation and the following conclusions were obtained: (1) The increase of flow resistance coefficient is the main reason that the natural circulation capacity decreases under rolling motion condition; (2) Non-uniform distribution of fluid mass in the pipe has also influence on natural circulation capacity. (author)

  19. Increased cesium uptake by water tupelo under inundated conditions

    International Nuclear Information System (INIS)

    McLeod, K.W.

    1980-01-01

    Low level releases of 137 Cs to streams has resulted in concentrations greater than background levels in soils, sediments and plants of the Savannah River swamp. The object of this study was to determine the effect of inundation on the absorption of 137 Cs by water tupelo (Nyssa aquatica) which is dominant in the swamp and is able to survive and grow well under flooded conditions. Results show that actively growing young water tupelo absorb about twice as much 137 Cs when grown in the laboratory under inundated conditions suggesting that in the spring, when inundated conditions usually exist and rapid growth occurs, uptake of 137 Cs is high. Some Cs is transported from soil depths and returned to soil surface via incorporation into leaves and subsequent leaf fall, thus continually mixing Cs which was buried below the soil surface. (U.K.)

  20. Influence of surface condition on the corrosion resistance of copper alloy condenser tubes in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S; Nagata, K; Yamauchi, S

    1979-07-01

    Investigation was made on the influence of various surface conditions of aluminum brass tube. The corrosion behavior of aluminum brass tube, with nine kinds of surface conditions, was studied in stagnant 0.1N NaHCo/sub 3/ solution and flowing sea water (natural, Fe/sup + +/ containing and S/sup - -/ containing water). Surface treatments investigated contained bright annealing, special annealing to form carbon film, hot oxidizing and pickling. Anodic polarization measurements in 0.1N NaHCO/sub 3/ solution showed that the oxidized surface was superior and that the pickled surface was inferior. However, relation between these characteristics and corrosion resistance in sea water has not been established. Electrochemical characteristics in flowing sea water were dependent on the surface conditions in the very beginning of immersion time; nobler corrosion potential for the surface with carbon film, higher polarization resistance for the bright annealed and the oxidized surface, and faster decrease of polarization resistance in S/sup - -/ containing sea water for the pickled surface. However, these differences disappeared in the immersion time of only 2 to 7 days. It was revealed, by the statistical analysis on the corrosion depth in corrosion test in flowing sea water and in jet impingement test, that the corrosion behavior was not influenced by surface conditions, but was significantly influenced by quality of sea water and sponge ball cleaning. Sulfide ion of 0.05 ppm caused severe pitting corrosion, and sponge ball cleaning of 5 chances a week caused erosion corrosion. From above results, it was concluded that surface conditions of aluminum brass were not important to sea water corrosion, and that quality of sea water and operating condition such as sponge ball cleaning were more significant.

  1. Natural isotope technique for the exploration and exploitation of ground water

    International Nuclear Information System (INIS)

    Zainal Abidin; Hudi Hastowo; Aang Hanafiah

    2007-01-01

    In line with the condition of climate and hydrology, Indonesia has a fast amount of aquifers which are sources of ground water. In several areas large number of springs occurred with small to large debits which is a sign of ground water potential. Ground water is a potential reservoir to be use at maximum for several purposes such as drinking water, industry and tourism. Large cities such as Jakarta, Bandung and others depend on ground water for their industries and hotels. The exploitation of ground water use has to be controlled and monitoring of a management system have to be done. Research carried out only on the exploitation of geophysics and hydrology showed that the amount of ground water reservoirs is not enough to be used when it comes to justification to explore it. Other parameters are still be needed which are the origins and dating of the ground water, these last two factors mentioned have to be taken into consideration in the system of conversion and balance of water. An alternative technology to determine the two factors mentioned in a short time is the natural isotope technique of 18 O, 2 H and 14 C. This technique is used to determine the origin of water, and isotope 14 C is carried out to determine the age of ground water. Isotopes 18 H and 2 H are stable isotopes in the form of water and is integrated in the hydrological cycle. Their specific concentrations in rain water at several elevations are used as fingerprints to locate the area of ground water supplement and its origin. Isotope 14 C is a natural radioactive isotope with a half-life of 5.730 years and is found in the hydrology cycle and enters the ground water system through CO 2 gas which is dissolved in water. 14 C isotope could determine the age of ground water and is also able to indicate the potential/amount of ground water. Studies of exploration and exploration monitoring of ground water should be an integrated study by geohydrology, geophysics and isotope and could be a solution of

  2. Evaluation method for regional water cycle health based on nature-society water cycle theory

    Science.gov (United States)

    Zhang, Shanghong; Fan, Weiwei; Yi, Yujun; Zhao, Yong; Liu, Jiahong

    2017-08-01

    Regional water cycles increasingly reflect the dual influences of natural and social processes, and are affected by global climate change and expanding human activities. Understanding how to maintain a healthy state of the water cycle has become an important proposition for sustainable development of human society. In this paper, natural-social attributes of the water cycle are synthesized and 19 evaluation indices are selected from four dimensions, i.e., water-based ecosystem integrity, water quality, water resource abundance and water resource use. A hierarchical water-cycle health evaluation system is established. An analytic hierarchy process is used to set the weight of the criteria layer and index layer, and the health threshold for each index is defined. Finally, a water-cycle health composite-index assessment model and fuzzy recognition model are constructed based on the comprehensive index method and fuzzy mathematics theory. The model is used to evaluate the state of health of the water cycle in Beijing during 2010-2014 and in the planning year (late 2014), considering the transfer of 1 billion m3 of water by the South-to-North Water Diversion Project (SNWDP). The results show health scores for Beijing of 2.87, 3.10, 3.38, 3.11 and 3.02 during 2010-2014. The results of fuzzy recognition show that the sub-healthy grade accounted for 54%, 49%, 61% and 49% of the total score, and all years had a sub-healthy state. Results of the criteria layer analysis show that water ecosystem function, water quality and water use were all at the sub-healthy level and that water abundance was at the lowest, or sick, level. With the water transfer from the SNWDP, the health score of the water cycle in Beijing reached 4.04. The healthy grade accounted for 60% of the total score, and the water cycle system was generally in a healthy state. Beijing's water cycle health level is expected to further improve with increasing water diversion from the SNWDP and industrial

  3. Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

    Science.gov (United States)

    Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

    2009-11-15

    Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

  4. Neutron radiography experiments for verification of soluble boron mixing and transport modeling under natural circulation conditions

    International Nuclear Information System (INIS)

    Morlang, M.M.; Feltus, M.A.

    1996-01-01

    The use of neutron radiography for visualization of fluid flow through flow visualization modules has been very successful. Current experiments at the Penn State Breazeale Reactor serve to verify the mixing and transport of soluble boron under natural flow conditions as would be experienced in a pressurized water reactor. Different flow geometries have been modeled including holes, slots, and baffles. Flow modules are constructed of aluminum box material 1 1/2 inches by 4 inches in varying lengths. An experimental flow system was built which pumps fluid to a head tank and natural circulation flow occurs from the head tank through the flow visualization module to be radio-graphed. The entire flow system is mounted on a portable assembly to allow placement of the flow visualization module in front of the neutron beam port. A neutron-transparent fluor-inert fluid is used to simulate water at different densities. Boron is modeled by gadolinium oxide powder as a tracer element, which is placed in a mixing assembly and injected into the system a remotely operated electric valve, once the reactor is at power. The entire sequence is recorded on real-time video. Still photographs are made frame-by-frame from the video tape. Computers are used to digitally enhance the video and still photographs. The data obtained from the enhancement will be used for verification of simple geometry predictions using the TRAC and RELAP thermal-hydraulic codes. A detailed model of a reactor vessel inlet plenum, downcomer region, flow distribution area and core inlet is being constructed to model the APGOO plenum. Successive radiography experiments of each section of the model under identical conditions will provide a complete vessel / core model for comparison with the thermal-hydraulic codes

  5. Neutron radiography experiments for verification of soluble boron mixing and transport modeling under natural circulation conditions

    International Nuclear Information System (INIS)

    Feltus, M.A.; Morlang, G.M.

    1996-01-01

    The use of neutron radiography for visualization of fluid flow through flow visualization modules has been very successful. Current experiments at the Penn State Breazeale Reactor serve to verify the mixing and transport of soluble boron under natural flow conditions as would be experienced in a pressurized water reactor. Different flow geometries have been modeled including holes, slots, and baffles. Flow modules are constructed of aluminum box material 1 1/2 inches by 4 inches in varying lengths. An experimental flow system was built which pumps fluid to a head tank and natural circulation flow occurs from the head tank through the flow visualization module to be radiographed. The entire flow system is mounted on a portable assembly to allow placement of the flow visualization module in front of the neutron beam port. A neutron-transparent fluorinert fluid is used to simulate water at different densities. Boron is modeled by gadolinium oxide powder as a tracer element, which is placed in a mixing assembly and injected into the system by remote operated electric valve, once the reactor is at power. The entire sequence is recorded on real-time video. Still photographs are made frame-by-frame from the video tape. Computers are used to digitally enhance the video and still photographs. The data obtained from the enhancement will be used for verification of simple geometry predictions using the TRAC and RELAP thermal-hydraulic codes. A detailed model of a reactor vessel inlet plenum, downcomer region, flow distribution area and core inlet is being constructed to model the AP600 plenum. Successive radiography experiments of each section of the model under identical conditions will provide a complete vessel/core model for comparison with the thermal-hydraulic codes

  6. A Neutron Radiology Application to Natural Absorption (Imbibition) of Water into Porous Rocks

    International Nuclear Information System (INIS)

    Middleton, M.F.; de Beer, Frikkie

    2005-01-01

    Full text: Dynamic neutron radiology provides a method of evaluating the concentration of water in porous media. A study of water imbibition (absorption of a wetting liquid into a porous medium with a non-wetting fluid, air), which is imaged by dynamic neutron radiology , provides an excellent method of determining the fluid diffusivity parameter, D. This parameter enables one to model water-air regimes in surface hydrological systems and aquifers; analogies can also be made for deeper petroleum systems. A methodology of pixel-by-pixel analysis for the estimation of water concentration, as a function of time under natural absorption conditions, is proposed which provides a good mapping of D within a rock sample. The proposed method entails the discrete mapping of the differential equation for horizontal flow of a partial water concentration, c, in an air-filled rock/soil. (authors)

  7. Minimal climate change impacts on natural organic matter forecasted for a potable water supply in Ireland.

    Science.gov (United States)

    O'Driscoll, Connie; Ledesma, José L J; Coll, John; Murnane, John G; Nolan, Paul; Mockler, Eva M; Futter, Martyn N; Xiao, Liwen W

    2018-07-15

    Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants. Copyright © 2018. Published by Elsevier B.V.

  8. Transcriptome profiling of tobacco under water deficit conditions

    Directory of Open Access Journals (Sweden)

    Roel C. Rabara

    2015-09-01

    Full Text Available Drought is one of the limiting environmental factors that affect crop production. Understanding the molecular basis of how plants respond to this water deficit stress is key to developing drought tolerant crops. In this study we generated time course-based transcriptome profiles of tobacco plants under water deficit conditions using microarray technology. In this paper, we describe in detail the experimental procedures and analyses performed in our study. The data set we generated (available in the NCBI/GEO database under GSE67434 has been analysed to identify genes that are involved in the regulation of tobacco's responses to drought.

  9. Emergency Response Planning to Reduce the Impact of Contaminated Drinking Water during Natural Disasters

    Science.gov (United States)

    Natural disasters can be devastating to local water supplies affecting millions of people. Disaster recovery plans and water industry collaboration during emergencies protect consumers from contaminated drinking water supplies and help facilitate the repair of public water system...

  10. CIRCUS and DESIRE: Experimental facilities for research on natural-circulation-cooled boiling water reactors

    International Nuclear Information System (INIS)

    Kruijf, W.J.M. de; Haden, T.H.J.J. van der; Zboray, R.; Manera, A.; Mudde, R.F.

    2002-01-01

    At the Delft University of Technology two thermohydraulic test facilities are being used to study the characteristics of Boiling Water Reactors (BWRs) with natural circulation core cooling. The focus of the research is on the stability characteristics of the system. DESIRE is a test facility with freon-12 as scaling fluid in which one fuel bundle of a natural-circulation BWR is simulated. The neutronic feedback can be simulated artificially. DESIRE is used to study the stability of the system at nominal and beyond nominal conditions. CIRCUS is a full-height facility with water, consisting of four parallel fuel channels and four parallel bypass channels with a common riser or with parallel riser sections. It is used to study the start-up characteristics of a natural-circulation BWR at low pressures and low power. In this paper a description of both facilities is given and the research items are presented. (author)

  11. Varietal improvement of irrigated rice under minimal water conditions

    International Nuclear Information System (INIS)

    Abdul Rahim Harun; Marziah Mahmood; Sobri Hussein

    2010-01-01

    Varietal improvement of irrigated rice under minimal water condition is a research project under Program Research of Sustainable Production of High Yielding Irrigated Rice under Minimal Water Input (IRPA- 01-01-03-0000/ PR0068/ 0504). Several agencies were involved in this project such as Malaysian Nuclear Agency (MNA), Malaysian Agricultural Research and Development Institute (MARDI), Universiti Putra Malaysia (UPM) and Ministry of Agriculture (MOA). The project started in early 2004 with approved IRPA fund of RM 275,000.00 for 3 years. The main objective of the project is to generate superior genotypes for minimal water requirement through induced mutation techniques. A cultivated rice Oryza sativa cv MR219 treated with gamma radiation at 300 and 400 Gray were used in the experiment. Two hundred gm M2 seeds from each dose were screened under minimal water stress in greenhouse at Mardi Seberang Perai. Five hundred panicles with good filled grains were selected for paddy field screening with simulate precise water stress regime. Thirty eight potential lines with required adaptive traits were selected in M3. After several series of selection, 12 promising mutant line were observed tolerance to minimal water stress where two promising mutant lines designated as MR219-4 and MR219-9 were selected for further testing under several stress environments. (author)

  12. Study and interpretation of the chemical characteristics of natural water

    Science.gov (United States)

    Hem, John David

    1985-01-01

    The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater.

  13. Natural radioactivity in drinking water in private wells in Finland

    International Nuclear Information System (INIS)

    Vesterbacka, P.; Maekaeinen, I.; Arvela, H.

    2005-01-01

    Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of 222 Rn, 226 Ra, 234 U, 238 U, 210 Pb and 210 Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l -1 , and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l -1 , respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l -1 and 18% a uranium concentration of 15 μg l -1 . The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from 222 Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, 210 Po and 210 Pb caused the largest portion of the effective dose. The dose arising from 238 U, 234 U and 226 Ra was only 8% of the total of all natural radionuclides. (authors)

  14. Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review.

    Science.gov (United States)

    Sillanpää, Mika; Ncibi, Mohamed Chaker; Matilainen, Anu; Vepsäläinen, Mikko

    2018-01-01

    Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs). Nonetheless, with the increased fluctuation of NOM in water (concentration and composition), the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH), developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. THE NATURAL ENVIRONMENT OF THE UBSUNUR HOLLOW AND ITS ANTHROPOGENIC CONDITIONALITY

    Directory of Open Access Journals (Sweden)

    T. N. Prudnikova

    2017-06-01

    Full Text Available Research of the early historical epochs anthropogenic activity impact on the environment proves its influence on ecosystems dynamics and its substantial role in changing natural and climatic conditions. Methods and results. With the help of remote sensing (deciphering space images (Google resources, free access and landscape observations on the area of Ubsunur Hollow, one of the largest arid hollows of Central Asia, in the neighbourhood of the Agar-Dag range numerous tracks of irrigation agriculture have been found. The absence of fresh water continuous supply in the area of ancient irrigation presupposes milder climatic conditions and the presence of forest flora maintaining the level of ground waters in the past. The presence of forest steppe landscapes on arid areas of Ubsunur Hollow in the recent past has been proved by the results of paleobotanic research on ancient agroirrigation landscapes to the south-west of Lake Shara Nur in the Upper Naryin Gol River. Conclusion. A big number of land allotments found in north-eastern part of Ubsunur Hollow near the Agar-Dag range (Lake Shara Nur allows us to speak about significant water reserves (and forestry area of this territory as well as about a big number of people living there in early epochs and who needed fuel, wood as a source of construction materials, etc., consequently forests were destroyed. They were also being destroyed during numerous wars: Central Asia is the region of constant battles between western and eastern civilizations. The conducted research proves the presence of forest flora (spruce-larch-grass-sedge communities, steppificated pine forests in the Late Quaternary period in the central part of Ubsunur Hollow on the area which is now deserted. The most probable reason of desertisation of the area is destruction of the forest. Forest devastation is the major reason of landscape degradation not only of Ubsunur Hollow but also of the whole steppe Asian belt.

  16. The quality of Albanian natural waters and the human impact.

    Science.gov (United States)

    Cullaj, Alqiviadh; Hasko, Agim; Miho, Aleko; Schanz, Ferdinand; Brandl, Helmut; Bachofen, Reinhard

    2005-01-01

    Albania possesses a wealth of aquatic ecosystems, many of enormous natural and biological value, such as the Lakes Ohrid, Prespa and Shkodra, glacial lakes, river valleys, and coastal lagoons. Although many habitats are highly polluted by inorganic and organic wastes, detailed knowledge on the water quality is still lacking. For the first time, an environmental assessment of the water quality is presented and the main polluting sources identified. As a consequence, a systematic control and the establishment of routine monitoring of surface and groundwater is proposed, which elucidates the present environmental state and helps to develop new strategies of waste and wastewater management. It would help allow Albania to reach an international standard in environmental protection, as a part of UNECE Convention, the Mediterranean Action Plan, the MAP/UNEP Medpol Program and the Basel Convention.

  17. Uranium concentrations in natural waters, South Park, Colorado

    International Nuclear Information System (INIS)

    Sharp, R.R. Jr.; Aamodt, P.L.

    1976-08-01

    During the summer of 1975, 464 water samples from 149 locations in South Park, Colorado, were taken for the Los Alamos Scientific Laboratory in order to test the field sampling and analytical methodologies proposed for the NURE Hydrogeochemical and Stream Sediment Reconnaissance for uranium in the Rocky Mountain states and Alaska. The study showed, in the South Park area, that the analytical results do not vary significantly between samples which were untreated, filtered and acidified, filtered only, or acidified only. Furthermore, the analytical methods of fluorometry and delayed-neutron counting, as developed at the LASL for the reconnaissance work, provide fast, adequately precise, and complementary procedures for analyzing a broad range of uranium in natural waters. The data generated using this methodology does appear to identify uraniferous areas, and when applied using sound geochemical, geological, and hydrological principles, should prove a valuable tool in reconnaissance surveying to delineate new districts or areas of interest for uranium exploration

  18. Water: Challenges at the Intersection of Human and Natural Systems

    Energy Technology Data Exchange (ETDEWEB)

    Futrell, J.H.; Gephart, R. E.; Kabat-Lensch, E.; McKnight, D. M.; Pyrtle, A.; Schimel, J. P.; Smyth, R. L.; Skole, D. L. Wilson, J. L.; Gephart, J. M.

    2005-09-01

    There is a growing recognition about the critical role water plays in sustaining people and society. This workshop established dialog between disciplinary scientists and program managers from diverse backgrounds in order to share perspectives and broaden community understanding of ongoing fundamental and applied research on water as a complex environmental problem. Three major scientific themes emerged: (1) coupling of cycles and process, with emphasis on the role of interfaces; (2) coupling of human and natural systems across spatial and temporal scales; and (3) prediction in the face of uncertainty. In addition, the need for observation systems, sensors, and infrastructure; and the need for data management and synthesis were addressed. Current barriers to progress were noted as educational and institutional barriers and the integration of science and policy.

  19. Determination of inorganic ions in natural water by ion chromatography

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Mohd Suhaimi Hamzah; Eewiat Edin Put; Abdul Khalik Wood; Shamsiah Abdul Rahman; Md Suhaimi Elia

    2010-01-01

    Ion chromatography (IC) is a well established methodology for analysis of ionic species. The concentration of ionic species was determined using suppressed IC with conductivity detection. Anion species were determined in a single 15-min run with Na 2 CO 3 and NaHCO 3 eluent. Cation species were analysed by direct injection of 1 ml and isocratic elution with a methanesulfonic acid (MSA) eluent. Natural water were collected from various sources such as rainwater, lake, river and groundwater. Analysis performance of IC system was validated by evaluating the linear regression of calibration curve, recovery of spike sample and quality control sample. (author)

  20. Natural product antifoulants from the octocorals of Indian waters

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; LimnaMol, V.P.; Parameswaran, P.S.

    stream_size 22497 stream_content_type text/plain stream_name Int_Biodeterior_Biodegrad_65_265a.pdf.txt stream_source_info Int_Biodeterior_Biodegrad_65_265a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8... 1 Author version: International Biodeterioration & Biodegradation, vol.65(1); 2011; 265-268 Natural Product Antifoulants from the Octocorals of Indian waters T.V. Raveendran * , V.P. Limna Mol, P.S. Parameswaran National Institute...

  1. 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

  2. Natural radioactivity in private water supplies in Devon

    International Nuclear Information System (INIS)

    Talbot, D.; Davis, J.; Rainey, M.

    2000-01-01

    This report details a study of the occurrence of natural radioactivity in private water Supplies in West Devon. Supplies sourced from wells, springs boreholes and a small number surface supplies were sampled. The findings of a laboratory simulation of the radon content in drinks such as tea, coffee and squash are also presented. Of supplies sampled in phase one of the work approximately 8% of tap water and 9% of samples directly from the supply contained radon at concentrations exceeding the draft European Union Commission Recommendation action level of 1000 Bq/I for individual and public water supplies. In a small number of supplies 238 U is present at levels exceeding 2 μg/I, the World Health Organisation (WHO) provisional guideline value for uranium in drinking water. The final aspect of the study looked at seasonal variation in the radon content of selected supplies. This showed considerable variability in radon concentration over the course of a week and between studies carried out several months apart. (author)

  3. Transient computational fluid dynamics analysis of emergency core cooling injection at natural circulation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Scheuerer, Martina, E-mail: Martina.Scheuerer@grs.de [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Forschungsinstitute, 85748 Garching (Germany); Weis, Johannes, E-mail: Johannes.Weis@grs.de [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Forschungsinstitute, 85748 Garching (Germany)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Pressurized thermal shocks are important phenomena for plant life extension and aging. Black-Right-Pointing-Pointer The thermal-hydraulics of PTS have been studied experimentally and numerically. Black-Right-Pointing-Pointer In the Large Scale Test Facility a loss of coolant accident was investigated. Black-Right-Pointing-Pointer CFD software is validated to simulate the buoyancy driven flow after ECC injection. - Abstract: Within the framework of the European Nuclear Reactor Integrated Simulation Project (NURISP), computational fluid dynamics (CFD) software is validated for the simulation of the thermo-hydraulics of pressurized thermal shocks. A proposed validation experiment is the test series performed within the OECD ROSA V project in the Large Scale Test Facility (LSTF). The LSTF is a 1:48 volume-scaled model of a four-loop Westinghouse pressurized water reactor (PWR). ROSA V Test 1-1 investigates temperature stratification under natural circulation conditions. This paper describes calculations which were performed with the ANSYS CFD software for emergency core cooling injection into one loop at single-phase flow conditions. Following the OECD/NEA CFD Best Practice Guidelines (Mahaffy, 2007) the influence of grid resolution, discretisation schemes, and turbulence models (shear stress transport and Reynolds stress model) on the mixing in the cold leg were investigated. A half-model was used for these simulations. The transient calculations were started from a steady-state solution at natural circulation conditions. The final calculations were obtained in a complete model of the downcomer. The results are in good agreement with data.

  4. Transient computational fluid dynamics analysis of emergency core cooling injection at natural circulation conditions

    International Nuclear Information System (INIS)

    Scheuerer, Martina; Weis, Johannes

    2012-01-01

    Highlights: ► Pressurized thermal shocks are important phenomena for plant life extension and aging. ► The thermal-hydraulics of PTS have been studied experimentally and numerically. ► In the Large Scale Test Facility a loss of coolant accident was investigated. ► CFD software is validated to simulate the buoyancy driven flow after ECC injection. - Abstract: Within the framework of the European Nuclear Reactor Integrated Simulation Project (NURISP), computational fluid dynamics (CFD) software is validated for the simulation of the thermo-hydraulics of pressurized thermal shocks. A proposed validation experiment is the test series performed within the OECD ROSA V project in the Large Scale Test Facility (LSTF). The LSTF is a 1:48 volume-scaled model of a four-loop Westinghouse pressurized water reactor (PWR). ROSA V Test 1-1 investigates temperature stratification under natural circulation conditions. This paper describes calculations which were performed with the ANSYS CFD software for emergency core cooling injection into one loop at single-phase flow conditions. Following the OECD/NEA CFD Best Practice Guidelines (Mahaffy, 2007) the influence of grid resolution, discretisation schemes, and turbulence models (shear stress transport and Reynolds stress model) on the mixing in the cold leg were investigated. A half-model was used for these simulations. The transient calculations were started from a steady-state solution at natural circulation conditions. The final calculations were obtained in a complete model of the downcomer. The results are in good agreement with data.

  5. Electrochemical noise measurements under pressurized water reactor conditions

    International Nuclear Information System (INIS)

    Van Nieuwenhove, R.

    2000-01-01

    Electrochemical potential noise measurements on sensitized stainless steel pressure tubes under pressurized water reactor (PWR) conditions were performed for the first time. Very short potential spikes, believed to be associated to crack initiation events, were detected when stressing the sample above the yield strength and increased in magnitude until the sample broke. Sudden increases of plastic deformation, as induced by an increased tube pressure, resulted in slower, high-amplitude potential transients, often accompanied by a reduction in noise level

  6. Pressurized water reactor iodine spiking behavior under power transient conditions

    International Nuclear Information System (INIS)

    Ho, J.C.

    1992-01-01

    The most accepted theory explaining the cause of pressurized water reactor iodine spiking is steam formation and condensation in damaged fuel rods. The phase transformation of the primary coolant from water to steam and back again is believed to cause the iodine spiking phenomenon. But due to the complex nature of the phenomenon, a comprehensive model of the behavior has not yet been successfully developed. This paper presents a new model based on an empirical approach, which gives a first-order estimation of the peak iodine spiking magnitude. Based on the proposed iodine spiking model, it is apparent that it is feasible to derive a correlation using the plant operating data base to monitor and control the peak iodine spiking magnitude

  7. Occupational risk and toxicology evaluations of industrial water conditioning.

    Science.gov (United States)

    Broussard, G; Bramanti, O; Marchese, F M

    1997-08-01

    This study addresses the chemical and toxicological questions due to the wide use of chemical treatment programmes for industrial cooling water. First, natural problems encountered in cooling tower systems were presented and grouped into three categories: (i) scaling; (ii) corrosion and (iii) biofouling. Chemical solutions adopted in industrial plants were outlined for each one in order to minimize damage and categorized as shut-down, production loss, heat transfer reduction, upsets, etc. Above all, the purpose of the work was to identify the most dangerous chemicals normally used, which means sources of chemical risk for safety workers and their environment; thus, symptoms of exposure, prevention measures and protection tools are also described.

  8. Natural radioactivity levels in different mineral waters from Bulgaria

    Energy Technology Data Exchange (ETDEWEB)

    Kamenova-Totzeva, R.; Kotova, R.; Tenev, J.; Ivanova, G.; Badulin, V. [Public Exposure Monitoring Laboratory, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

    2013-07-01

    The total radioactivity content of 76 mineral waters from different districts in Bulgaria was determined. Natural radioactivity levels resulting from uranium, radium-226, gross alpha and gross beta activity were measured. The results show that the specific activity range from < 0.02 Bq/l to 1.34 (12) Bq/l and from 0.068 (23) Bq/l to 2.60 (50) Bq/l for gross alpha and gross beta activity respectively. For natural Uranium the results vary between 0.020 (5) μg/l and 180(50) μg/l. Radium-226 content is between < 0.03 Bq/l to 0.296 (75) Bq/l. Due to differences in the geological structure of the aquifer, a large difference in values of the radioactive content was mSv/year. Excluding one value, TID do not exceed the permissible limit of 0.10 mSv/year. The correlations between investigated isotopes and Total Dissolved observed. The estimated Total Indicative Dose (TID) ranged from 0.0113 (57) mSv/year to 0.1713 (481) Solvents (TDS) in water were carried out. The results do not show a strong correlation between TDS values and dissolved radionuclides. (author)

  9. The water-food nexus of natural rubber production

    Science.gov (United States)

    Chiarelli, D. D.; Rosa, L.; Rulli, M. C.; D'Odorico, P.

    2017-12-01

    The increasing global demand for natural rubber (100% increase in the last 15 years) is for most part met by Malaysia and Indonesia, and - to a lesser extent - other countries in south-east Asia and Africa. The consequent expansion of rubber plantation has often occurred at the expenses of agricultural land for staple food, particularly in southeast Asia, where most of the land suitable for agriculture is already harvested for food crops or other uses. Here we investigate the extent to which the ongoing increase in rubber production is competing with the food system and affecting the livelihoods of rural communities in the areas of production and their appropriation of natural resources, such as water. We also investigate to what extent the expansion of rubber plantations is taking place through large scale land acquisitions (LSLAs) and evaluate the impacts on rural communities. Our results show how rubber production has strong environmental, social and economic impacts. Despite their ability to bring employment and increase the average income of economically disadvantaged areas, rubber plantations may threaten the local water and food security and induce a loss of rural livelihoods, particularly when the new plantations result from LSLAs that displace semi-subsistence forms of production thereby forcing the local populations to depend on global markets.

  10. Microbial Condition of Water Samples from Foreign Fuel Storage Facilities

    International Nuclear Information System (INIS)

    Berry, C.J.

    1998-01-01

    In order to assess the microbial condition of foreign spent nuclear fuel storage facilities and their possible impact on SRS storage basins, twenty-three water samples were analyzed from 12 different countries. Fifteen of the water samples were analyzed and described in an earlier report (WSRC-TR-97-00365 [1]). This report describes nine additional samples received from October 1997 through March 1998. The samples include three from Australia, two from Denmark and Germany and one sample from Italy and Greece. Each water sample was analyzed for microbial content and activity as determined by total bacteria, viable aerobic bacteria, viable anaerobic bacteria, viable sulfate-reducing bacteria, viable acid-producing bacteria and enzyme diversity. The results for each water sample were then compared to all other foreign samples analyzed to date and monthly samples pulled from the receiving basin for off-site fuel (RBOF), at SRS. Of the nine samples analyzed, four samples from Italy, Germany and Greece had considerably higher microbiological activity than that historically found in the RBOF. This microbial activity included high levels of enzyme diversity and the presence of viable organisms that have been associated with microbial influenced corrosion in other environments. The three samples from Australia had microbial activities similar to that in the RBOF while the two samples from Denmark had lower levels of microbial activity. These results suggest that a significant number of the foreign storage facilities have water quality standards that allow microbial proliferation and survival

  11. Hydrologic conditions in New Hampshire and Vermont, water year 2011

    Science.gov (United States)

    Kiah, Richard G.; Jarvis, Jason D.; Hegemann, Robert F.; Hilgendorf, Gregory S.; Ward, Sanborn L.

    2013-01-01

    Record-high hydrologic conditions in New Hampshire and Vermont occurred during water year 2011, according to data from 125 streamgages and lake gaging stations, 27 creststage gages, and 41 groundwater wells. Annual runoff for the 2011 water year was the sixth highest on record for New Hampshire and the highest on record for Vermont on the basis of a 111-year reference period (water years 1901–2011). Groundwater levels for the 2011 water year were generally normal in New Hampshire and normal to above normal in Vermont. Record flooding occurred in April, May, and August of water year 2011. Peak-of-record streamflows were recorded at 38 streamgages, 25 of which had more than 10 years of record. Flooding in April 2011 was widespread in parts of northern New Hampshire and Vermont; peak-of-record streamflows were recorded at nine streamgages. Flash flooding in May 2011 was isolated to central and northeastern Vermont; peakof- record streamflows were recorded at five streamgages. Devastating flooding in August 2011 occurred throughout most of Vermont and in parts of New Hampshire as a result of the heavy rains associated with Tropical Storm Irene. Peak-ofrecord streamflows were recorded at 24 streamgages.

  12. Determination of trace metals in natural fresh waters

    International Nuclear Information System (INIS)

    Holm, K.; Borg, H.; Korhonen, M.

    1989-06-01

    The determination method still most widely used is atomic absorption spectrometry with graphite furnace. The natural levels of several elements are however too low to be accurately determined without any preconcentration. Besides, in sea water, the high salt content causes matric effects, which require time consuming separation steps as solvent extraction or ion exchange. The report describes two procedures for preconcentration of fresh water samples, freeze-drying and replicate injections in the furnace, respectively. The procedures are designed to be used on a routine basis. All water samples are collected in polypropylene bottles which are soaked before use in HCl 1+1, rinsed and allowed to stand until use filled with 0.1 M HNO 3 . The samples are preserved by addition of conc. HNO 3 (2 ml/l, sub boiling distilled). In the freeze-drying procedure, the samples are weighed and frozen in the pre-weighed polypropylene sampling bottles and evaporated to about one tenth of the original volume in the vaccum chamber of a freeze dryer. The samples are then weighed again for determination of the concentration factor and alayzed by graphite furnace AAS. When using the other procedure, the water samples are directly injected into the frunace for several times (2-8) before atomization and measurement of the absorption signal. The drying and ashing step is allowed to proceed after every injection. Comparisons of the two procedures have shown good agreement. The advantage of the replicate injection technique is primarily that the concentration factor is more esily controlled and repeated than by the freeze drying procedure. Further, the latter procedure sometimes suffers from precipitates being formed during the evaporation,especially in humic waters rich in iron. (12 figs., 7 tabs., 14 refs.)

  13. Processes Driving Natural Acidification of Western Pacific Coral Reef Waters

    Science.gov (United States)

    Shamberger, K. E.; Cohen, A. L.; Golbuu, Y.; McCorkle, D. C.; Lentz, S. J.; Barkley, H. C.

    2013-12-01

    Rising levels of atmospheric carbon dioxide (CO2) are acidifying the oceans, reducing seawater pH, aragonite saturation state (Ωar) and the availability of carbonate ions (CO32-) that calcifying organisms use to build coral reefs. Today's most extensive reef ecosystems are located where open ocean CO32- concentration ([CO32-]) and Ωar exceed 200 μmol kg-1 and 3.3, respectively. However, high rates of biogeochemical cycling and long residence times of water can result in carbonate chemistry conditions within coral reef systems that differ greatly from those of nearby open ocean waters. In the Palauan archipelago, water moving across the reef platform is altered by both biological and hydrographic processes that combine to produce seawater pH, Ωar, [CO32-] significantly lower than that of open ocean source water. Just inshore of the barrier reefs, average Ωar values are 0.2 to 0.3 and pH values are 0.02 to 0.03 lower than they are offshore, declining further as water moves across the back reef, lagoon and into the meandering bays and inlets that characterize the Rock Islands. In the Rock Island bays, coral communities inhabit seawater with average Ωar values of 2.7 or less, and as low as 1.9. Levels of Ωar as low as these are not predicted to occur in the western tropical Pacific open ocean until near the end of the century. Calcification by coral reef organisms is the principal biological process responsible for lowering Ωar and pH, accounting for 68 - 99 % of the difference in Ωar between offshore source water and reef water at our sites. However, in the Rock Island bays where Ωar is lowest, CO2 production by net respiration contributes between 17 - 30 % of the difference in Ωar between offshore source water and reef water. Furthermore, the residence time of seawater in the Rock Island bays is much longer than at the well flushed exposed sites, enabling calcification and respiration to drive Ωar to very low levels despite lower net ecosystem

  14. Soil Water Retention and Relative Permeability for Conditions from Oven-Dry to Full Saturation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.

    2011-11-04

    Common conceptual models for unsaturated flow often rely on the oversimplified representation of medium pores as a bundle of cylindrical capillaries and assume that the matric potential is attributed to the capillary force only. The adsorptive surface forces are ignored. It is often assumed that aqueous flow is negligible when a soil is near or at the residual water content. These models are successful at high and medium water contents but often give poor results at low water contents. These models do not apply to conditions at which the water content is less than the residual water content. We extend the lower bound of existing water-retention functions and conductivity models from residual water content to the oven-dry condition (i.e., zero water content) by defining a state-dependent, residual-water content for a soil drier than a critical value. Furthermore, a hydraulic conductivity model for smooth uniform spheres was modified by introducing a correction factor to describe the film flow-induced hydraulic conductivity for natural porous media. The total unsaturated hydraulic conductivity is the sum of those due to capillary and film flow. The extended retention and conductivity models were verified measurements. Results show that, when the soil is at high and intermediate water content, there is no difference between the un-extended and the extended models; when the soil is at low water content, the un-extended models overestimate the water content but underestimate the conductivity. The extended models match the retention and conductivity measurements well.

  15. Generation risk assessment in volatile conditions with wind, hydro, and natural gas units

    International Nuclear Information System (INIS)

    Sahin, Cem; Shahidehpour, Mohammad; Erkmen, Ismet

    2012-01-01

    Highlights: ► Stochastic price-based unit commitment (PBUC) for a generation company (GENCO). ► Water inflow, wind, and NG interruption uncertainties are considered. ► Diversification of assets and bilateral contracts enhance payoff and decrease financial risk. ► The utilization of NG in the risk-neutral GENCO case increases as the wind uncertainty increases. ► NG utilization is lowered by the algorithm to decrease in risk-considered case. -- Abstract: This paper studies a generating company (GENCO)’s midterm (a few months to a year) scheduling payoffs and risks in volatile operating conditions. The proposed algorithm considers the integration of intermittent wind units into a GENCO’s generation assets and coordinates the GENCO’s hourly wind generation schedule with that of natural gas (NG) units (with volatile gas prices) and hydro units (with water inflow forecast) for maximizing the GENCO’s payoff. The proposed midterm GENCO model applies market price forecasts to the risk-constrained stochastic price-based unit commitment (PBUC) for calculating the GENCO’s risk in energy and ancillary services markets. The proposed PBUC minimizes the cost of (a) NG contracts, storage, startup and shutdown, (b) startup and shutdown of cascaded hydro units, and (c) penalty for defaulting on the scheduled power delivery. Simulation results show that the diversification of generating assets including bilateral contracts (BCs) could enhance the GENCO’s midterm planning by increasing the expected payoff and decreasing the financial risk.

  16. 76 FR 6491 - San Diego County Water Authority Subregional Natural Community Conservation Program/Habitat...

    Science.gov (United States)

    2011-02-04

    ...] San Diego County Water Authority Subregional Natural Community Conservation Program/Habitat Conservation Plan, San Diego and Riverside Counties, CA; Final Environmental Impact Statement and Habitat... also announce the availability of the Water Authority's Subregional Natural Community Conservation...

  17. In situ measurement of inelastic light scattering in natural waters

    Science.gov (United States)

    Hu, Chuanmin

    Variation in the shape of solar absorption (Fraunhofer) lines are used to study the inelastic scattering in natural waters. In addition, oxygen absorption lines near 689nm are used to study the solar stimulated chlorophyll fluorescence. The prototype Oceanic Fraunhofer Line Discriminator (OFLD) has been further developed and improved by using a well protected fiber optic - wire conductor cable and underwater electronic housing. A Monte-Carlo code and a simple code have been modified to simulate the Raman scattering, DOM fluorescence and chlorophyll fluorescence. A series of in situ measurements have been conducted in clear ocean waters in the Florida Straits, in the turbid waters of Florida Bay, and in the vicinity of a coral reef in the Dry Tortugas. By comparing the reduced data with the model simulation results, the Raman scattering coefficient, b r with an excitation wavelength at 488nm, has been verified to be 2.6 × 10-4m-1 (Marshall and Smith, 1990), as opposed to 14.4 × 10- 4m-1 (Slusher and Derr, 1975). The wavelength dependence of b r cannot be accurately determined from the data set as the reported values (λ m-4 to λ m- 5) have an insignificant effect in the natural underwater light field. Generally, in clear water, the percentage of inelastic scattered light in the total light field at /lambda 510nm. At low concentrations (a y(/lambda = 380nm) less than 0.1m-1), DOM fluorescence plays a small role in the inelastic light field. However, chlorophyll fluorescence is much stronger than Raman scattering at 685nm. In shallow waters where a sea bottom affects the ambient light field, inelastic light is negligible for the whole visible band. Since Raman scattering is now well characterized, the new OFLD can be used to measure the solar stimulated in situ fluorescence. As a result, the fluorescence signals of various bottom surfaces, from coral to macrophytes, have been measured and have been found to vary with time possibly due to nonphotochemical quenching

  18. The role of solar ultraviolet radiation in 'natural' water purification

    International Nuclear Information System (INIS)

    Calkins, J.; Buckles, J.D.; Moeller, J.R.

    1976-01-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated. (author)

  19. Role of solar ultraviolet radiation in 'natural' water purification

    Energy Technology Data Exchange (ETDEWEB)

    Calkins, J; Buckles, J D; Moeller, J R [Kentucky Univ., Lexington (USA)

    1976-07-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated.

  20. Water quality of hydrologic bench marks; an indicator of water quality in the natural environment

    Science.gov (United States)

    Biesecker, James E.; Leifeste, Donald K.

    1974-01-01

    Water-quality data, collected at 57 hydrologic bench-mark stations in 37 States, allow the definition of water quality in the 'natural' environment and the comparison of 'natural' water quality with water quality of major streams draining similar water-resources regions. Results indicate that water quality in the 'natural' environment is generally very good. Streams draining hydrologic bench-mark basins generally contain low concentrations of dissolved constituents. Water collected at the hydrologic bench-mark stations was analyzed for the following minor metals: arsenic, barium, cadmium, hexavalent chromium, cobalt, copper, lead, mercury, selenium, silver, and zinc. Of 642 analyses, about 65 percent of the observed concentrations were zero. Only three samples contained metals in excess of U.S. Public Health Service recommended drinking-water standards--two selenium concentrations and one cadmium concentration. A total of 213 samples were analyzed for 11 pesticidal compounds. Widespread but very low-level occurrence of pesticide residues in the 'natural' environment was found--about 30 percent of all samples contained low-level concentrations of pesticidal compounds. The DDT family of pesticides occurred most commonly, accounting for 75 percent of the detected occurrences. The highest observed concentration of DDT was 0.06 microgram per litre, well below the recommended maximum permissible in drinking water. Nitrate concentrations in the 'natural' environment generally varied from 0.2 to 0.5 milligram per litre. The average concentration of nitrate in many major streams is as much as 10 times greater. The relationship between dissolved-solids concentration and discharge per unit area in the 'natural' environment for the various physical divisions in the United States has been shown to be an applicable tool for approximating 'natural' water quality. The relationship between dissolved-solids concentration and discharge per unit area is applicable in all the physical

  1. Water Reserves Program. An adaptation strategy to prevent imbalance of water in nature

    Science.gov (United States)

    Salinas-Rodriguez, S. A.; López Pérez, M.; Barrios Ordóñez, J.; Wickel, B.; Villón Bracamonte, R. A.

    2013-12-01

    Freshwater ecosystems occupy approximately 1% of the earth's surface yet possess about 12% of all known animal species. By virtue of their position in the landscape they connect terrestrial and coastal marine biomes and provide and sustain ecosystem services vital to the health and persistence of human communities. These services include the supply of water for food production, urban and industrial consumption, among others. Over the past century many freshwater ecosystems around the world have been heavily modified or lost due to the alteration of flow regimes (e.g. damming, canalization, diversion, over-abstraction). The synergistic impacts of land use change, changes in flows, chemical deterioration, and climate change have left many systems and their species very little room to adjust to change, while future projections indicate a steady increase imbalance in water demand for food and energy production and water supply to suit the needs of a growing world population. In Mexico, the focus has been to secure water for human development and maximize economic growth, which has resulted in allocation of water beyond available amounts, and that in many river basins has led imbalance of water in nature. As a consequence episodic water scarcity severely constrains freshwater ecosystems and the services they provide. Climatic change and variability are presenting serious challenges to a country that already is experiencing serious strain on its water resources. However, freshwater ecosystems are recognized by law as legitimate user of water, and mandate a flow allocation for the environment ('water reserve' or 'environmental flows'). Based on this legal provision the Mexican government through the National Water Commission (Conagua), with support of the Alliance WWF - Fundación Gonzalo Río Arronte, and the Interamerican Development Bank, has launched a national program to identify and implement 'water reserves': basins where environmental flows will be secured and

  2. Natural radioactivity in ground water near the Savannah River Site

    International Nuclear Information System (INIS)

    Price, V. Jr.; Michel, J.

    1990-08-01

    A study of natural radioactivity in groundwater on and adjacent to the Savannah River Site (SRS) in Aiken (SC) was conducted to determine the spatial and temporal variations in the concentration of specific radionuclides. All available measurements for gross alpha particle activity, gross beta activity, uranium, Ra-226, Ra-228, and radon were collated. Relatively few radionuclide-specific results were found. Twenty samples from drinking water supplies in the area were collected in October 1987 and analyzed for U-238, U-234, Ra-226, Ra-228, and Rn-222. The aquifer type for each public water supply system was determined, and statistical analyses were conducted to detect differences among aquifer types and geographic areas defined at the country level. For samples from the public water wells and distribution systems on and adjacent to the site, most of the gross alpha particle activity could be attributed to Ra-226. Aquifer type was an important factor in determining the level of radioactivity in groundwater. The distribution and geochemical factors affecting the distribution of each radionuclide for the different aquifer types are discussed in detail. Statistical analyses were also run to test for aerial differences, among counties and the site. For all types of measurements, there were no differences in the distribution of radioactivity among the ten counties in the vicinity of the site or the site itself. The mean value for the plant was the lowest of all geographic areas for gross alpha particle activity and radon, intermediate for gross beta activity, and in the upper ranks for Ra-226 and Ra-228. It is concluded that the drinking water quality onsite is comparable with that in the vicinity. 19 refs., 5 figs., 5 tabs

  3. Natural and Social Conditions for Economic Development: Case Study Northeastern Montenegro

    Directory of Open Access Journals (Sweden)

    Goran Rajovic

    2013-12-01

    Full Text Available This paper analyzes the natural and social conditions for the development economy in northeastern Montenegro, in the example municipalities Berane, Andrejevica and Plav in the geographical context of its utilization and use. Spatial distribution of the economy is determined by the natural and social conditions. The natural conditions in terms of the economy are of particular significance relief, climatic and hydrographic conditions, soil... According to degree benefits of natural conditions extracted are three relatively homogeneous regions. That is, which rational production of this part of north-eastern Montenegro, can be organized taking into account the natural conditions and the level of socio-economic development. For collocation and the structure of the economy have an important role in the social conditions which the economy is formed. Our research the records clearly pointed to the forefront some very obvious problems: first, is related to the population, especially in workforce, respectively, for the aging; second, that there is a strong migration of people whose intensive processes of differentiation and left behind an unfavorable structure of the population - age and education what the any negative impact on economic development; third, the characteristics of land area, its small size, inadequate and outdated processing, low technical capacity. The natural resources of this part of north-eastern Montenegro, as well as the population as a factor of economic development need to have met: economic, social, developmental organizational and management dimension to be on benefit the present, but also future generations

  4. Estimating water consumption of potential natural vegetation on global dry lands: building an LCA framework for green water flows.

    Science.gov (United States)

    Núñez, Montserrat; Pfister, Stephan; Roux, Philippe; Antón, Assumpció

    2013-01-01

    This study aimed to provide a framework for assessing direct soil-water consumption, also termed green water in the literature, in life cycle assessment (LCA). This was an issue that LCA had not tackled before. The approach, which is applied during the life cycle inventory phase (LCI), consists of quantifying the net change in the evapo(transpi)ration of the production system compared to the natural reference situation. Potential natural vegetation (PNV) is used as the natural reference situation. In order to apply the method, we estimated PNV evapotranspiration adapted to local biogeographic conditions, on global dry lands, where soil-water consumption impacts can be critical. Values are reported at different spatial aggregation levels: 10-arcmin global grid, ecoregions (501 units), biomes (14 units), countries (124 units), continents, and a global average, to facilitate the assessment for different spatial information detail levels available in the LCI. The method is intended to be used in rain-fed agriculture and rainwater harvesting contexts, which includes direct soil moisture uptake by plants and rainwater harvested and then reused in production systems. The paper provides the necessary LCI method and data for further development of impact assessment models and characterization factors to evaluate the environmental effects of the net change in evapo(transpi)ration.

  5. Condition, use, and management of water resources among ...

    African Journals Online (AJOL)

    The study found that water supply in Harshin district is 100% surface water ... Besides, 76% of the respondents were not satisfied with the quality of drinking water. ... Key words: Water resources, pastoralists, rainwater, water-harvesting, gender ...

  6. Biological iron oxidation by Gallionella spp. in drinking water production under fully aerated conditions.

    Science.gov (United States)

    de Vet, W W J M; Dinkla, I J T; Rietveld, L C; van Loosdrecht, M C M

    2011-11-01

    Iron oxidation under neutral conditions (pH 6.5-8) may be a homo- or heterogeneous chemically- or a biologically-mediated process. The chemical oxidation is supposed to outpace the biological process under slightly alkaline conditions (pH 7-8). The iron oxidation kinetics and growth of Gallionella spp. - obligatory chemolithotrophic iron oxidizers - were assessed in natural, organic carbon-containing water, in continuous lab-scale reactors and full-scale groundwater trickling filters in the Netherlands. From Gallionella cell numbers determined by qPCR, balances were made for all systems. The homogeneous chemical iron oxidation occurred in accordance with the literature, but was retarded by a low water temperature (13 °C). The contribution of the heterogeneous chemical oxidation was, despite the presence of freshly formed iron oxyhydroxides, much lower than in previous studies in ultrapure water. This could be caused by the adsorption of natural organic matter (NOM) on the iron oxide surfaces. In the oxygen-saturated natural water with a pH ranging from 6.5 to 7.7, Gallionella spp. grew uninhibited and biological iron oxidation was an important, and probably the dominant, process. Gallionella growth was not even inhibited in a full-scale filter after plate aeration. From this we conclude that Gallionella spp. can grow under neutral pH and fully aerated conditions when the chemical iron oxidation is retarded by low water temperature and inhibition of the autocatalytic iron oxidation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Natural organic matter interactions with polyamide and polysulfone membranes: Formation of conditioning film

    KAUST Repository

    Gutierrez, Leonardo; Aubry, Cyril; Valladares Linares, Rodrigo; Croue, Jean-Philippe

    2015-01-01

    A conditioning film changes the physicochemical properties of the membrane surface and strongly affects subsequent fouling behavior. Results from this Atomic Force Microscopy study indicate that Natural Organic Matter (NOM) characteristics, membrane

  8. Role of natural dissolved organic compounds in determining the concentrations of americium in natural waters

    International Nuclear Information System (INIS)

    Nelson, D.M.; Orlandini, K.A.

    1985-01-01

    Concentrations of 241 Am, both in solution and bound to suspended particulate matter, have been measured in several North American lakes. Dissolved concentrations vary from 0.4 μBq/L to 85 μBq/L. The 241 Am in these lakes originated solely from global fallout and hence entered all lakes in the same physiocochemical form. The observed differences in solubility behavior must, therefore, be attributable to chemical and/or hydrological differences among the lakes. Concentrations of dissolved 241 Am are highly correlated with the corresponding concentrations of /sup 239, 240/Pu(III,IV), suggesting that a common factor is responsible for maintaining both in solution. The K/sub D/ values for 241 Am and /sup 239, 240/Pu(III,IV) are highly correlated with the concentrations of dissolved organic carbon (DOC) in the waters, suggesting that the common factor is the formation of soluble complexes with natural DOC for both elements. This hypothesis was tested in a series of laboratory experiments in which the DOC from several of the lakes was isolated by ultrafiltration. Plots of K/sub D/, as a function of DOC concentration, show K/sub D/ to be very high (approx.10 6 ) at low DOC concentrations. Above critical concentrations (a few mg/L DOC) the K/sub D/ values begin a progressive decrease with increasing DOC. We conclude that in most surface waters, the dissolved 241 Am concentration is regulated by an adsorption/desorption equilibrium with the sediments (and suspended solids) and the value of K/sub D/ that characterizes this equilibrium is largely determined by the concentration of natural DOC in the water. 11 refs., 3 figs., 2 tabs

  9. Regulation No. 100/2006 Coll. of the Ministry of Health of the Slovak Republic dated as of February 6, 2006 laying down the requirements for natural healing water and natural mineral water, Balneology details of the report, distribution, extent of monitoring and content analysis of natural healing waters and natural mineral waters and their products and requirements for entry to the list of accredited laboratories maintained by the State Commission bathroom

    International Nuclear Information System (INIS)

    2006-01-01

    This Regulation provides: (a) requirements for natural healing water and natural mineral water; (b) requirements for the recognition of natural mineral water; (c) details of balneology report; (d) distribution of natural healing waters and natural mineral water; (e) the extent of tracking of natural healing waters and natural mineral waters and their products; (f) content analysis of natural healing waters and natural mineral waters and their products; (g) registration requirements for accredited laboratories in the list maintained by the State Commission bathroom. This Regulation came into force on March 1, 2006.

  10. Sustainable Management of Flowback Water during Hydraulic Fracturing of Marcellus Shale for Natural Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Vidic, Radisav [Univ. of Pittsburgh, PA (United States)

    2015-01-24

    This study evaluated the feasibility of using abandoned mine drainage (AMD) as make- up water for the reuse of produced water for hydraulic fracturing. There is an abundance of AMD sources near permitted gas wells as documented in this study that can not only serve as makeup water and reduce the demand on high quality water resources but can also as a source of chemicals to treat produced water prior to reuse. The assessment of AMD availability for this purpose based on proximity and relevant regulations was accompanied by bench- and pilot-scale studies to determine optimal treatment to achieve desired water quality for use in hydraulic fracturing. Sulfate ions that are often present in AMD at elevated levels will react with Ba²⁺ and Sr²⁺ in produced water to form insoluble sulfate compounds. Both membrane microfiltration and gravity separation were evaluated for the removal of solids formed as a result of mixing these two impaired waters. Laboratory studies revealed that neither AMD nor barite formed in solution had significant impact on membrane filtration but that some produced waters contained submicron particles that can cause severe fouling of microfiltration membrane. Coagulation/flocculation was found to be an effective process for the removal of suspended solids and both bench- and pilot-scale studies revealed that optimal process conditions can consistently achieve the turbidity of the finished water below 5 NTU. Adjusting the blending ratio of AMD and produced water can achieve the desired effluent sulfate concentration that can be accurately predicted by chemical thermodynamics. Co-treatment of produced water and AMD will result in elevated levels of naturally occurring radioactive materials (NORM) in the solid waste generated in this process due to radium co-precipitation with barium sulfate. Laboratory studies revealed that the mobility of barite that may form in the subsurface due to the presence of sulfate in the fracturing fluid can be

  11. Molecular concepts of water splitting. Nature's approach

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Nicholas; Lubitz, Wolfgang [Max-Planck-Institut fuer Chemische Energiekonversion, Muelheim an der Ruhr (Germany)

    2013-07-01

    Based on studies of natural systems, much has also been learned concerning the design principles required for biomimetic catalysis of water splitting and hydrogen evolution. In summary, these include use of abundant and inexpensive metals, the effective protection of the active sites in functional environments, repair/replacement of active components in case of damage, and the optimization of reaction rates. Biomimetic chemistry aims to mimic all these features; many labs are working toward this goal by developing new approaches in the design and synthesis of such systems, encompassing not only the catalytic center, but also smart matrices and assembly via self-organization. More stable catalysts that do not require self-repair may be obtained from fully artificial (inorganic) catalytic systems that are totally different from the biological ones and only apply some basic principles learned from nature. Metals other than Mn/Ca, Fe, and Ni could be used (e.g. Co) in new ligand spheres and other matrices. For light harvesting, charge separation/stabilization, and the effective coupling of the oxidizing/reducing equivalents to the redox catalysts, different methods have been proposed - for example, covalently linked molecular donor-acceptor systems, photo-voltaic devices, semiconductor-based systems, and photoactive metal complexes. The aim of all these approaches is to develop catalytic systems that split water with sunlight into hydrogen and oxygen while displaying high efficiency and long-term stability. Such a system - either biological, biomimetic, or bioinspired - has the potential to be used on a large scale to produce 'solar fuels' (e.g. hydrogen or secondary products thereof). (orig.)

  12. The utilization of natural resources under the conditions of intersectoral intergration

    OpenAIRE

    Dankevych, Ye.; Данкевич, Є. М.

    2013-01-01

    The paper studies and analyses the present-day state of the utilization of natural resources by agricultural commodity producers. Some changes of the natural components under the conditions of the increased anthropological load on landscape have been revealed. The author investigates the basic production factors which essentially influence the agrolandscape. It has been established that the increase in the technical level stipulates the human interference with natural complexes, land resource...

  13. Natural Circulation Characteristics at Low-Pressure Conditions through PANDA Experiments and ATHLET Simulations

    OpenAIRE

    Paladino, Domenico; Huggenberger, Max; Schäfer, Frank

    2008-01-01

    Natural circulation characteristics at low pressure/low power have been studied by performing experimental investigations and numerical simulations. The PANDA large-scale facility was used to provide valuable, high quality data on natural circulation characteristics as a function of several parameters and for a wide range of operating conditions. The new experimental data allow for testing and improving the capabilities of the thermal-hydraulic computer codes to be used for treating natural c...

  14. THE STUDY OF CADMIUM UPTAKE BY WATER HYACINTH (EICHHORNIA CRASSIPES USING A NATURAL MODELLING APPROACH

    Directory of Open Access Journals (Sweden)

    Tamara E. Romanova

    2012-06-01

    Full Text Available The results of the investigation on the accumulation of cadmium by water hyacinth, depending on the conditions of pollutant exposure and the presence of various additives are discussed. The main specialty of this study is that all the experiments were carried out in natural conditions using the approach based on the application of the capacities called minicosms. It allowed estimating hit consequences of pollutant on ecosystem most really having made experiment in the conditions as much as possible close to the natural. In this article a very important problem of an accuracy and reliability of the results of trace elements determination in plants is also debated. As a result of carried investigations it was shown that the degree of cadmium extraction by hyacinth from contaminated natural water while maintaining the viability of the plants depends on the way of pollutant introducing into the reservoir and the maximum (about 79% value is observed in the case of it’s gradual entry.

  15. Stability analysis on natural circulation boiling water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Metz, Peter

    1999-05-01

    The purpose of the study is a stability analysis of the simplified boiling water reactor concept. A fluid dynamics code, DYNOS, was developed and successfully validated against FRIGG and DESIRE data and a stability benchmark on the Ringhals 1 forced circulation BWR. Three simplified desings were considered in the analysis: The SWRIOOO by Siemens and the SBWR and ESBWR from the General Electric Co. For all three design operational characteristics, i.e. power versus flow rate maps, were calculated. The effects which different geometric and operational parameters, such as the riser height, inlet subcooling etc., have on the characteristics have been investigated. Dynamic simulations on the three simplified design revealed the geysering and the natural circulation oscillations modes only. They were, however, only encountered at pressure below 0.6 MPa. Stability maps for all tree simplified BWRs were calculated and plotted. The study concluded that a fast pressurisation of the reactor vessel is necessary to eliminate the possibility of geysering or natural circulation oscillations mode instability. (au) 26 tabs., 88 ills.

  16. Stability analysis on natural circulation boiling water reactors

    International Nuclear Information System (INIS)

    Metz, Peter

    1999-05-01

    The purpose of the study is a stability analysis of the simplified boiling water reactor concept. A fluid dynamics code, DYNOS, was developed and successfully validated against FRIGG and DESIRE data and a stability benchmark on the Ringhals 1 forced circulation BWR. Three simplified desings were considered in the analysis: The SWRIOOO by Siemens and the SBWR and ESBWR from the General Electric Co. For all three design operational characteristics, i.e. power versus flow rate maps, were calculated. The effects which different geometric and operational parameters, such as the riser height, inlet subcooling etc., have on the characteristics have been investigated. Dynamic simulations on the three simplified design revealed the geysering and the natural circulation oscillations modes only. They were, however, only encountered at pressure below 0.6 MPa. Stability maps for all tree simplified BWRs were calculated and plotted. The study concluded that a fast pressurisation of the reactor vessel is necessary to eliminate the possibility of geysering or natural circulation oscillations mode instability. (au)

  17. Separation and determination of dimethylarsenate in natural waters

    Directory of Open Access Journals (Sweden)

    Ben Issa Nureddin

    2012-01-01

    Full Text Available A simple and efficient method for separation and determination of dimethylarsenate DMAs(V was developed in this work. Two resins, a strong base anion exchange (SBAE resin and iron-oxide coated hybrid (HY resin were tested. By simple adjusting pH value of water at 7.00, DMAs(V passed through the HY column without any changes, while all other arsenic species [inorganic arsenic and monomethylarsonate, MMAs(V] were quantitatively bonded on HY resin. The resin capacity was calculated according to the breakthrough points in a fixed bed flow system. At pH 7.00 the HY resins bonded more than 4150 μg g-1 of As(III, 3500 μg g-1 of As(V and 1500 μg g1 of MMAs(V. Arsenic adsorption behavior in the presence of impurities showed tolerance with the respect to potential interference of anions commonly found in natural water. DMAs(V was determined in the effluent by ICP-MS. The detection limit was 0.03 μg L?1 and relative standard deviation (RSD was between 1.1?7.5 %. Proposed method was established performing standard procedures: with external standard, certified reference material and the standard addition method.

  18. RESEARCH METHODOLOGY ON NATURAL NUTRITION OF FRESH-WATER FISH

    Directory of Open Access Journals (Sweden)

    Marina Piria

    2001-03-01

    Full Text Available This paper offers the entire review on the research methodology in natural nutrition of fresh-water fish. The data on fresh-water fish nutrition, particularly on fish of lower economic value, is inadequate. Reviewing the literature on assesment of nutritional parameters, the authors obviously use differenet approaches and methods. This paper is about most frequently used parameteres in qualitative and quantitative analysis. The qualitative analysis of food structure is the overall list of determinable taxa (mostlyu species and genera. The quantitative analysis comprises the assessment of particular nutritional categories by nutritional indices and coefficients. Bio-identification and numeric data processing can have numerous drawbacsk such as effect of regurgitation or the degree of digestion of the prey. The analyses of those effects proceed through statistical data processing in order to include spatial distribution of certain prey categories as well. The importance of this data is to determine the nutritional needs of potential species for culture as well as to come up with new insights on a particular aquatic ecosystem.

  19. Removing NDMA (N,N-dimethylnitrosamine) from natural waters

    International Nuclear Information System (INIS)

    Mezyk, S.P.; Cooper, W.J.; Bartels, D.M.

    2003-01-01

    Nitrosoamines are ubiquitous in water environments, and are of concern as they are potent carcinogens. In particular, N,N-dimethylnitrosamine (NDMA, (CH 3 ) 2 NNO) is volatile, and therefore has been detected around factories producing secondary amines or rocket fuel, in areas near industrial plants that use dimethylamine in organic synthesis, and even in foods and beverages that contain nitrite or which have been exposed to nitrous oxides. Various technologies have been suggested for removing trace levels of NDMA contamination from aqueous systems. However, Advanced Oxidation Technologies (AOTs), such as ozone, UV/ozone, and UV/H 2 O 2 , which use oxidation via the hydroxyl radical ( . OH), or heterogeneous catalysis by TiO 2 , sonolysis, or the electron beam process, which produce a mixture of oxidizing . OH radicals with reducing hydrated electrons (e - aq ) and hydrogen atoms ( . H), may also produce unwanted stable products in the treatment. Some of these stable products, such as secondary amines, allow regeneration of NDMA to occur. To ensure that any process applied to NDMA contaminated water occurs efficiently and quantitatively a complete understanding of the chemistry involved under the conditions of use is necessary. This requires mathematical modeling of the process, which in turn needs reaction rate constants and mechanisms. In this study, absolute rate constants at room temperature for the reaction of the hydroxyl radical, hydrated electron, and hydrogen atom with NDMA in water have been determined using electron pulse radiolysis and absorption spectroscopy, (e - aq and . OH) and EPR free induction decay attenuation ( . H) measurements. The specific values of (4.30± 0.12) x 10 8 , (1.41 ± 0.02) x 10 10 , and (2.01 ± 0.03) x 10 8 M -1 s -1 , respectively, demonstrate that the reductive destruction of this nitrosoamine would be the dominant removal pathway in any remediation process. Based on these data we have begun modeling the large-scale electron

  20. Water Reserves Program. An adaptation strategy to balance water in nature

    Science.gov (United States)

    Lopez Perez, M.; Barrios, E.; Salinas-Rodriguez, S.; Wickel, B.; Villon, R. A.

    2013-05-01

    -allocation takes place. The strategy is to identify and protect basins with an availability of water that is close to their natural flow regime and that also have a high conservation value (based on prior national conservation priority definitions such as protected areas, and biodiversity conservation gap analyses) in order to implement legal restrictions on water resource development. With such protection, these systems will be best positioned to adjust and respond to water shortages, and regime shifts. To date, 189 basins around the country were identified as potential water reserves. The next step will be the nomination of these water reserves to be integrated in the National Water Reserves Program. This program forms the core of the official Mexican government adaptation strategy towards climate prepared water management, which recognizes that water reserves are the buffer society needs to face uncertainty, and reduce water scarcity risk. The development of activities that alter the natural flow regime such as dams and levees are closely examined, and would potentially be restricted.

  1. Dispersion of C(60) in natural water and removal by conventional drinking water treatment processes.

    Science.gov (United States)

    Hyung, Hoon; Kim, Jae-Hong

    2009-05-01

    The first objective of this study is to examine the fate of C(60) under two disposal scenarios through which pristine C(60) is introduced to water containing natural organic matter (NOM). A method based on liquid-liquid extraction and HPLC to quantify nC(60) in water containing NOM was also developed. When pristine C(60) was added to water either in the form of dry C(60) or in organic solvent, it formed water stable aggregates with characteristics similar to nC(60) prepared by other methods reported in the literature. The second objective of this study is to examine the fate of the nC(60) in water treatment processes, which are the first line of defense against ingestion from potable water -- a potential route for direct human consumption. Results obtained from jar tests suggested that these colloidal aggregates of C(60) were efficiently removed by a series of alum coagulation, flocculation, sedimentation and filtration processes, while the efficiency of removal dependent on various parameters such as pH, alkalinity, NOM contents and coagulant dosage. Colloidal aggregates of functionalized C(60) could be well removed by the conventional water treatment processes but with lesser efficiency compared to those made of pristine C(60).

  2. Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

    Science.gov (United States)

    De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

    2009-06-15

    The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS.

  3. Determination of iron in natural and mineral waters by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    ROLANDAS KAZLAUSKAS

    2004-05-01

    Full Text Available Simple methods for the determination of Fe in natural and mineral waters by flame atomic absorption spectrometry (AAS are suggested. The results of the investigation of selectivity of the proposed AAS method proved that this procedure is not affected by high concentrations of other metals. The calibration graph for iron was linear at levels near the detection limit up to at least 0.10 mg ml-1. For the determination of microamounts of iron in mineral waters, an extraction AAS technique was developed. Iron was retained as Fe-8-oxyquinoline complex and extracted into chloroform. The optimal conditions for the extraction of the iron complex were determined. The AAS method was applied to the determination of Fe in mineral waters and natural waters from different areas of Lithuania. The accuracy of the developed method was sufficient and evaluated in comparison with a photometric method. The obtained results demonstrated that the procedure could be successfully applied for the analysis of water samples with satisfactory accuracy.

  4. Optimization of Water Allocation between Different Crops in Water Stress Conditions in Qazvin Irrigation Network

    Directory of Open Access Journals (Sweden)

    Mehdi Mohammad khani

    2017-06-01

    Full Text Available Introduction: Evaluations show the necessity of using optimization models in order to determine optimal allocation of water in different water conditions. Its use can be proposed according to developed model abilities in this study in order to optimize water productivity and provide sustainable management and development of water resources over irrigation and drainage networks. Basic needs of the earth growing population and limitation of water and soil resources remindnecessity of optimal use of resources. World’s more than 280 million hectare lands are covered by irrigation networks (Khalkhali et al., 2006. The efficiency of most projects is between 30-50 percent and studies show that performance of most irrigation and drainage networks is not desirable and they have not achieved their aims. Hirich et al. (2014 Used deficit irrigation to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season 2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of a crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of the full irrigation during the vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity. Moghaddasi et al. (2010 worked examines and compares this approach with that based on the optimization method to manage agricultural water demand during drought to minimize damage. The results show that the optimization method resulted in 42% more income for the agricultural sector using the

  5. Natural frequency analysis of fluid conveying pipeline with different boundary conditions

    International Nuclear Information System (INIS)

    Huang Yimin; Liu Yongshou; Li Baohui; Li Yanjiang; Yue Zhufeng

    2010-01-01

    In this study, the natural frequency of fluid-structure interaction in pipeline conveying fluid is investigated by eliminated element-Galerkin method, and the natural frequency equations with different boundary conditions are obtained. Furthermore, the expressions of first natural frequency are simplified in the case of different boundary conditions. Taking into account the Coriolis force, as an example, the natural frequency of a straight pipe simply supported at both ends is studied. In a given boundary condition, the four components (mass, stiffness, length and flow velocity) which relate to the natural frequency of pipeline conveying fluid are studied in detail and the results indicate that the effect of Coriolis force on natural frequency is inappreciable. Then the relationship between natural frequency of the pipeline conveying fluid and that of Euler beam is analyzed. Finally, a dimensionless flow velocity and limit values are presented, and they can be used to estimate the effect of the flow velocity on natural frequency. All the conclusions are well suited to nuclear plant and other industry fields.

  6. Experimental Investigation of a Natural Circulation Solar Domestic Water Heater Performance under Standard Consumption Rate

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Taherian, H.; Ganji, D. D.

    2012-01-01

    This paper reports experimental studies on the performance of a natural circulation solar water heater considering the weather condition of a city in north of Iran. The tests are done on clear and partly cloudy days. The variations of storage tank temperature due to consumption from the tank, daily...... consumption influence on the solar water heater efficiency, and on the input temperature of the collector are studied and the delivered daily useful energy has been obtained. The results show that by withdrawing from storage tank, the system as well as its collector efficiency will increase. Considering...... the value of the coefficient FRUL and τα, which are obtained experimentally as 6.03 and 0.83 respectively, average. monthly total load that is covered by this solar water heating system is estimated....

  7. PILOT PLANT STUDY ON NATURAL WATER COAGULANTS AS COAGULAN AIDS FOR WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    B BINA

    2001-06-01

    Full Text Available Introduction: Natural plant coagulants have an important role to play in provision of portable water to rural communities in the developing world. The plant material that their coagulation properties have been confirmed in previous lab scale studies and can be found widely in Iran was selected as coagulant aids. Pilot plant study was done to evaluate the efficiency of natural material such as Starch/Gum Tragacanth, Fenugreek and Yeast as coagulant aids in conjunction with comercial alum. Methods: The pilot was placed in Isfahan Water Treatment Plant (IWTP and efficiency of these materials in removal of turbidity from raw water enters the IWTP was evaluated. The results indicated while these materials were used as coagulant aids in concentration of 1-5 mg/l conjunction with alum are able to reduced the turbidity and final residuals turbidity meets the standards limits. Results: The coagulation efficiency of these material were found to be effected by certain physico-chemical factors, namely, concentration of suspended solids, divalent cation metal and time of agitation. The relative importance of these variable was evaluated. The results of COD test proved that the natural coagulant aids in the optimum doses produce no any significant organic residual. Discussion: Economical considerations showed that using of these material as coagulant aids can cause reduction in alum consumption and in some cases are more econmical than synthetic polyelectrolyte.

  8. A CFD study for evaluating the effects of natural ventilation on indoor comfort conditions

    Directory of Open Access Journals (Sweden)

    Miguel Mora-Pérez

    2017-03-01

    Full Text Available There is an increasing interest in improving energy efficiency in buildings due to the increased awareness about environmental impact and energy cost. Natural ventilation is an environmentally friendly technique which has become more attractive way for reducing energy use while it also provides acceptable comfort conditions. The research shows a case study building in which the natural ventilation effect due to wind-driven forces on indoor comfort conditions is evaluated. Moreover, the architectural solutions selected during the building design phase to improve the natural ventilation behaviour are successfully validated in a full-scale building. The indoor comfort conditions are evaluated through contrasted performance indicators: draught risk (DR, predicted percentage of dissatisfied people (PPD and predicted mean vote (PMV indexes. The results show that air movement due to natural ventilation allows increasing indoor air temperature maintaining the initial comfort conditions. Therefore, the mechanical air conditioning use can be postponed until the indoor air temperature is high and would, consequently, reduce the total building energy consumption. Thereby, a proper natural ventilation focus during the initial design stage could improve the building energy efficiency without compromising the indoor comfort conditions.

  9. Germination of Ocotea pulchella (Nees Mez (Lauraceae seeds in laboratory and natural restinga environment conditions

    Directory of Open Access Journals (Sweden)

    LA. Pires

    Full Text Available The germination response of Ocotea pulchella (Nees Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 ºC, the minimum or base temperature estimated was 11 ºC and the maximum ranged between 33 and 42 ºC. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.

  10. Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions.

    Science.gov (United States)

    Pires, L A; Cardoso, V J M; Joly, C A; Rodrigues, R R

    2009-08-01

    The germination response of Ocotea pulchella (Nees) Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 degrees C, the minimum or base temperature estimated was 11 degrees C and the maximum ranged between 33 and 42 degrees C. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.

  11. The Imbalance of Water in Nature as System

    Science.gov (United States)

    Kontar, V. A.; Imbalance of Water in Nature

    2011-12-01

    will not be obtained any reliable results. For example, the real water arrival occurs in the modes of imbalances such as increasing or decreasing. Water departure also is some set of the several imbalance increase and decrease types. The processes with various orientations interact between each other and reinforce or depress the conjoint effect. This creates some unstable situation, which are not visible by the balanced approach. Therefore some natural disasters actually are coming as unexpected. But in really there are some consequences of the methodological blindness. The Nature is unstable. The imbalance is the main state of the Nature. But mankind does not yet have adequate tools to describing imbalance as it is. In generally now is used more or less successful extrapolation and interpolation of the balance logic. But this is not enough now. So we tried to sharpen here the importance of the works with the imbalance directly.

  12. Influence of the initial state of carbon nanotubes on their colloidal stability under natural conditions

    International Nuclear Information System (INIS)

    Schwyzer, Irene; Kaegi, Ralf; Sigg, Laura; Magrez, Arnaud; Nowack, Bernd

    2011-01-01

    The colloidal stability of dry and suspended carbon nanotubes (CNTs) in the presence of amphiphilic compounds (i.e. natural organic matter or surfactants) at environmentally realistic concentrations was investigated over several days. The suspensions were analyzed for CNT concentration (UV-vis spectroscopy), particle size (nanoparticle tracking analysis), and CNT length and dispersion quality (TEM). When added in dry form, around 1% of the added CNTs remained suspended. Pre-dispersion in organic solvent or anionic detergent stabilized up to 65% of the added CNTs after 20 days of mild shaking and 5 days of settling. The initial state of the CNTs (dry vs. suspended) and the medium composition hence are critical determinants for the partitioning of CNTs between sediment and the water column. TEM analysis revealed that single suspended CNTs were present in all suspensions and that shaking and settling resulted in a fractionation of the CNTs with shorter CNTs remaining predominantly in suspension. - Highlights: → Individually suspended CNTs are present under environment relevant conditions. → The number of suspended CNTs varies depending on the medium composition. → Surfactants at environmental concentrations have no suspending effect on dry CNTs. → Pre-dispersed CNTs are more stable in suspension than dry CNTs. - The colloidal stability of CNTs varies a lot depending on the initial state of the CNTs (dry vs. pre-dispersed), the applied dispersant for pre-suspension, and the composition of the medium.

  13. Microwave-enhanced pyrolysis of natural algae from water blooms.

    Science.gov (United States)

    Zhang, Rui; Li, Linling; Tong, Dongmei; Hu, Changwei

    2016-07-01

    Microwave-enhanced pyrolysis (MEP) of natural algae under different reaction conditions was carried out. The optimal conditions for bio-oil production were the following: algae particle size of 20-5 mesh, microwave power of 600W, and 10% of activated carbon as microwave absorber and catalyst. The maximum liquid yield obtained under N2, 10% H2/Ar, and CO2 atmosphere was 49.1%, 51.7%, and 54.3% respectively. The energy yield of bio-products was 216.7%, 236.9% and 208.7% respectively. More long chain fatty acids were converted into hydrocarbons by hydrodeoxygenation under 10% H2/Ar atmosphere assisted by microwave over activated carbon containing small amounts of metals. Under CO2 atmosphere, carboxylic acids (66.6%) were the main products in bio-oil because the existence of CO2 vastly inhibited the decarboxylation. The MEP of algae was quick and efficient for bio-oil production, which provided a way to not only ameliorate the environment but also obtain fuel or chemicals at the same time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Experimental study of critical heat flux enhancement with hypervapotron structure under natural circulation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Fangxin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Chang, Huajian [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhao, Yufeng, E-mail: zhaoyufeng@snptc.com.cn [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhang, Ming; Gao, Tianfang [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Chen, Peipei [State Power Investment Corporation, Beijing (China)

    2017-05-15

    Highlights: • Natural circulation tests are performed to study the effect of hypervapotron on CHF. • Hypervapotron structure improves CHF under natural circulation conditions. • Visualization data illustrate vapor blanket behavior under subcooled flow conditions. - Abstract: The enhancement of critical heat flux with a hypervapotron structure under natural circulation conditions is investigated in this study. Subcooled flow boiling CHF experiments are performed using smooth and hypervapotron surfaces at different inclination angles under natural circulation conditions. The experimental facility, TESEC (Test of External Vessel Surface with Enhanced Cooling), is designed to conduct CHF experiments in a 30 mm by 61 mm rectangular flow channel with a 200 mm long heated surface along the flow direction. The two-phase flow of subcooled flow boiling on both smooth and hypervapotron heating plates is observed and analyzed by the high-speed visualization technology. The results show that both smooth surface and hypervapotron surface CHF data exhibit a similar trend against inclination angles compared with the CHF results under forced flow condition on the same facility in earlier studies. However, the CHF enhancement of the hypervapotron structure is evidently more significant than the one under forced flow conditions. The experiments also indicate that the natural flow rates are higher with hypervapotron structure. The initiation of CHF is analyzed under transient subcooling and flow rate conditions for both smooth and hypervapotron heating surfaces. An explanation is given for the significant enhancement effect caused by the hypervapotron surface under natural circulation conditions. The visualization data are exhibited to demonstrate the behavior of the vapor blanket at various inclination angles and on different surfaces. The geometric data of the vapor blanket are quantified by an image post-processing method. It is found that the thickness of the vapor blanket

  15. Cable condition monitoring in a pressurized water reactor environment

    International Nuclear Information System (INIS)

    Al-Hussaini, T.J.

    1988-01-01

    Oconee Nuclear Station is the first nuclear plant designed, engineered and constructed by Duke Power Company. Even though the accelerated aging method was available to determine the life expectancy of the cable used in the reactor building, no natural aging data was available at that time. In order to be able to verify the condition of the reactor building cable over the life of the plant, an on-going cable monitoring plan was instituted. Various types of cable were selected to be monitored, and they were installed in cable life evaluation circuits in the reactor building. At five year intervals over the life of the plant, cable samples would be removed from these cable life evaluation circuits and tested to determine the effects of the reactor building environment on the integrity of the cable. A review of the cable life evaluation circuits and the results of the evaluation program to date is presented

  16. Chemical speciation and adsorption behavior of plutonium in natural waters

    International Nuclear Information System (INIS)

    Sanchez, A.L.

    1983-01-01

    Dissolved Pu profiles in two partially anoxic basins--Saanich Inlet, an intermittently anoxic marine fiord in Vancouver Island, British Columbia, and Soap Lake, a saline, alkaline lake in eastern Washington state, revealed minimum concentrations at the O 2 /H 2 S interface. The Pu concentrations in the anoxic waters of Saanich Inlet were less than the surface concentrations; however, in Soap Lake, a 15- to 50-fold increase in Pu concentration in the anoxic monimolimnion correlated with large increases in the major ions, total alkalinity, and dissolved organic carbon. Laboratory experiments were designed to investigate the effects of pH, ionic strength, dissolved organic carbon, and carbonate ions on the adsorption of tracer amounts of Pu IV and Pu V. The Pu-goethite adsorption system provided the data base for developing a thermodynamic model of Pu interaction with an oxide surface and with dissolved ligands, using the MINEQL computer program. Pu IV and Pu V interacted very differently with goethite, which is consistent with their different hydrolytic character. A reduction of Pu V to Pu IV occurred on the goethite surface and also on montmorillonite and silica gel, suggesting that redox transformations are an important aspect of Pu adsorption. Increases in ionic strength (up to 3 M NaCl or NaNO 3 ) did not affect Pu IV or V adsorption. In the presence of dissolved organic carbon (DOC), Pu V reduction to Pu IV occurred in solution. Pu IV adsorption on goethite decreased only 30% in the presence of 240 ppm of natural DOC from Soap Lake; however, carbonate anions inhibited Pu IV adsorption on goethite at the alkalinity levels (1500 meq/L total alkalinity, 0.57 M CO 3 =) measured for Soap Lake monimolimnion waters

  17. Geological report on water conditions at Platt National Park, Oklahoma

    Science.gov (United States)

    Gould, Charles Newton; Schoff, Stuart Leeson

    1939-01-01

    Platt National Park, located in southern Oklahoma, containing 842 acres, was established by Acts of Congress in 1902, 1904, and 1906. The reason for the setting aside of this area was the presence in the area of some 30 'mineral' springs, the water from which contains sulphur, bromide, salt, and other minerals, which are believed to possess medicinal qualities. For many generations the sulphur springs of the Chickasaw Nation had been known for their reputed healing qualities. It had long been the custom for families to come from considerable distances on horseback and in wagons and camp near the springs, in order to drink the water. In course of time a primitive town, known as Sulphur Springs, grew up near a group of springs known since as Pavilion Springs at the mouth of Sulphur Creek, now known as Travertine Creek. This town was still in existence at the time of my first visit to the locality in July, 1901. At this time, in company with Joseph A. Taff, of the United States Geological Survey, I spent a week riding over the country making a preliminary survey looking toward the setting aside of the area for a National Park. After the establishment of the National Park, the old town of Sulphur Springs was abandoned, and when the present boundaries of the park had been established the present town of Sulphur, now county seat of Murray County, grew up. In July 1906, on request of Superintendent Joseph F. Swords, I visited the park and made an examination of the various springs and submitted a report, dated August 15, 1906, to Secretary of the Interior E.A. Hitchcock. Copies of this report are on file in the Regional Office and at Platt National Park. In this report I set forth the approximate amount of flow of the various springs, the character of the water in each, and the conditions of the springs as of that date. I also made certain recommendations regarding proposed improvements of each spring. In this report I say: 'In the town of Sulphur, four wells have been

  18. Ground-water and geohydrologic conditions in Queens County, Long Island, New York

    Science.gov (United States)

    Soren, Julian

    1971-01-01

    Queens County is a heavily populated borough of New York City, at the western end of Long Island, N. Y., in which large amounts of ground water are used, mostly for public supply. Ground water, pumped from local aquifers, by privately owned water-supply companies, supplied the water needs of about 750,000 of the nearly 2 million residents of the county in 1967; the balance was supplied by New York City from surface sources outside the county in upstate New York. The county's aquifers consist of sand and gravel of Late Cretaceous and of Pleistocene ages, and the aquifers comprise a wedge-shaped ground-water reservoir lying on a southeastward-sloping floor of Precambrian(?) bedrock. Beds of clay and silt generally confine water in the deeper parts of the reservoir; water in the deeper aquifers ranges from poorly confined to well confined. Wisconsin-age glacial deposits in the uppermost part of the reservoir contain ground water under water-table conditions. Ground water pumpage averaged about 60 mgd (million gallons per day) in Queens County from about 1900 to 1967. Much of the water was used in adjacent Kings County, another borough of New York City, prior to 1950. The large ground-water withdrawal has resulted in a wide-spread and still-growing cone of depression in the water table, reflecting a loss of about 61 billion gallons of fresh water from storage. Significant drawdown of the water table probably began with rapid urbanization of Queens County in the 1920's. The county has been extensively paved, and storm and sanitary sewers divert water, which formerly entered the ground, to tidewater north and south of the county. Natural recharge to the aquifers has been reduced to about one half of the preurban rate and is below the withdrawal rate. Ground-water levels have declined more than 40. feet from the earliest-known levels, in 1903, to 1967, and the water table is below sea level in much of the county. The aquifers are being contaminated by the movement of

  19. Contribution of analytical techniques coupled to the knowledge of the uranium speciation in natural conditions

    International Nuclear Information System (INIS)

    Petit, J.

    2009-06-01

    To understand the transport mechanisms and the radionuclides behaviour in the bio-geosphere is necessary to evaluate healthy and environmental risks of nuclear industry. These mechanisms are monitored by radioelements speciation, namely the distribution between their different physico-chemical forms in the environment. From this perspective, this PhD thesis deals with uranium speciation in a natural background. A detailed summary of uranium biogeochemistry has been written, which enables to restrict the PhD issue to uranium complexation with oxalic acid, a hydrophilic organic acid with good binding properties, ubiquitous in soil waters. Analytical conditions have been established by means of speciation diagrams. The speciation diagrams building by means of literature stability constants has allowed to define the analytical conditions of complex formation. The chosen analytical technique is the hyphenation of a separative technique (liquid chromatography LC or capillary electrophoresis CE) with mass spectrometry (ICPMS). The studied complexes presence in the synthetic samples has been confirmed with UV/visible spectrophotometry. LC-ICPMS analyses have proved the lability of the uranyl-organic acid complexes, namely their tendency to dissociate during analysis, which prevents from studying uranium speciation. CE-ICPMS study of labile complexes from a metal-ligand system has been made possible by employing affinity capillary electrophoresis, which enables to determine stability constants and electrophoretic mobilities. This PhD thesis has allowed to compare the different mathematical treatments of binding isotherm and to take into account ionic strength and real ligand concentration. Affinity CE has been applied successfully to lanthanum-oxalate (model system) and uranium-oxalate systems. The obtained results have been applied to a real system (situated in Le Bouchet). This shows the contribution of the developed method to the modelling of uranium speciation. (author)

  20. Motion of air bubbles in stagnant water condition

    International Nuclear Information System (INIS)

    Bezdegumeli, U.; Ozdemir, S.; Yesin, O.

    2004-01-01

    Full text: In this study, air bubble motion in stagnant water condition in a vertical pipe is investigated experimentally. For this purpose, a test set-up was designed and constructed. Motions of single bubbles, having different diameters in the range of 3.0-4.8 mm, were recorded by using a monochrome camera, an image capture card and a PC. Recorded video images were processed to analyse bubble motion and to obtain the necessary data. The purpose of the study is to determine the variation of bubble axial velocity and bubble drag coefficient as a function of equivalent bubble diameter and bubble Reynolds number, Re b . Therefore, detailed information for this range of bubble diameters was obtained. The results have shown good consistency with the previous studies found in the literature

  1. Motion of air bubbles in stagnant water condition

    International Nuclear Information System (INIS)

    Bezdegumeli, U.; Ozdemir, S.; Yesin, O.

    2004-01-01

    In this study, air bubble motion in stagnant water condition in a vertical pipe of 4.6 cm diameter is investigated experimentally. For this purpose, a test set-up was designed and constructed. Motions of single bubbles, having different diameters in the range of 3.0-4.8 mm, were recorded by using a monochrome camera, an image capture card and a PC. Recorded video images were processed to analyse bubble motion and to obtain the necessary data. The purpose of the study is to determine the variation of bubble axial velocity and bubble drag coefficient as a function of equivalent bubble diameter and bubble Reynolds number, Re b . Therefore, detailed information for this range of bubble diameters was obtained. The results have shown good consistency with the previous studies found in the literature. (author)

  2. Bulk water phase and biofilm growth in drinking water at low nutrient conditions

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    , and cell-specific leucine incorporation rate. Bacteria in the bulk water phase incubated without the presence of biofilmexhibited a bacterial growth rate of 0.30 day1. The biofilmwas radioactively labelled by the addition of 14C-benzoic acid. Subsequently, a biofilmdetachm ent rate of 0.013 day1...... the formation of a mature quasi-stationary biofilm. At retention times of 12 h, total bacterial counts increased equivalent to a net bacterial growth rate of 0.048 day1. The bulk water phase bacteria exhibited a higher activity than the biofilmbacteria in terms of culturability, cell-specific ATP content......In this study, the bacterial growth dynamics of a drinking water distribution system at low nutrient conditions was studied in order to determine bacterial growth rates by a range of methods, and to compare growth rates in the bulk water phase and the biofilm. A model distribution system was used...

  3. Removing NDMA (N,N-dimethylnitrosamine) from natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Mezyk, S P [California State University Long Beach, (United States); Cooper, W J [University of North Carolina at Wilmington, (United States); Bartels, D M [Argonne National Laboratory, (United States)

    2003-07-01

    Nitrosoamines are ubiquitous in water environments, and are of concern as they are potent carcinogens. In particular, N,N-dimethylnitrosamine (NDMA, (CH{sub 3}){sub 2} NNO) is volatile, and therefore has been detected around factories producing secondary amines or rocket fuel, in areas near industrial plants that use dimethylamine in organic synthesis, and even in foods and beverages that contain nitrite or which have been exposed to nitrous oxides. Various technologies have been suggested for removing trace levels of NDMA contamination from aqueous systems. However, Advanced Oxidation Technologies (AOTs), such as ozone, UV/ozone, and UV/H{sub 2}O{sub 2} , which use oxidation via the hydroxyl radical ({sup .}OH), or heterogeneous catalysis by TiO{sub 2} , sonolysis, or the electron beam process, which produce a mixture of oxidizing {sup .}OH radicals with reducing hydrated electrons (e{sup -}{sub aq} ) and hydrogen atoms ({sup .} H), may also produce unwanted stable products in the treatment. Some of these stable products, such as secondary amines, allow regeneration of NDMA to occur. To ensure that any process applied to NDMA contaminated water occurs efficiently and quantitatively a complete understanding of the chemistry involved under the conditions of use is necessary. This requires mathematical modeling of the process, which in turn needs reaction rate constants and mechanisms. In this study, absolute rate constants at room temperature for the reaction of the hydroxyl radical, hydrated electron, and hydrogen atom with NDMA in water have been determined using electron pulse radiolysis and absorption spectroscopy, (e{sup -}{sub aq} and {sup .}OH) and EPR free induction decay attenuation ({sup .}H) measurements. The specific values of (4.30{+-} 0.12) x 10 8 , (1.41 {+-} 0.02) x 10 10 , and (2.01 {+-} 0.03) x 10{sup 8} M{sup -1} s{sup -1} , respectively, demonstrate that the reductive destruction of this nitrosoamine would be the dominant removal pathway in any

  4. Characteristics of lead(II) adsorption onto "Natural Red Earth" in simulated environmental conditions

    Science.gov (United States)

    Mahatantila, K.; Vithanage, M. S.; Seike, Y.; Okumura, M.

    2011-12-01

    Lead is considered as a non-biodegradable and potentially toxic heavy metal and it is found as a common environmental pollutant. Adsorption characteristics of Pb(II) onto natural iron and aluminum coated sand, which is called Natural Red Earth (NRE), have been studied to ascertain the effect of pH, ionic strength, initial sorbate concentrations, temperature and time. Lead(II) adsorption achieved its maximum adsorption of nearly 100% at neutral to slightly acidic conditions. The optimum pH was nearly 5.5 and 6.5 for 2.41 and 24.1 μmol/L initial Pb(II) concentrations, respectively. Lead(II) adsorption was independent of 100 fold variation of ionic strength (0.001 - 0.1), indirectly evidencing dominance of an inner-sphere surface complexation mechanism for 10 fold variation of initial Pb(II) concentrations (2.41 and 24.1 μmol/L). Adsorption edges were quantified with a 2pK generalized diffuse double layer model considering two site types, >FeOH and >AlOH, for Pb(II) binding. The modeling results better fit with the mixture of monodentate and bidentated binding of Pb(II) onto >FeOH site and bidentate binding of Pb(II) onto >AlOH site. The intrinsic constants obtained were log KFeOPb=13.93, log K(FeO)2Pb=11.88 and log K(AlO)2Pb=13.21. Time required to reach the equilibrium was also increase from 15 min to 1hr with increasing Pb(II) concentrations from 2.41 to 24.1 μmol/L. Kinetic data fitted better to pseudo second order kinetic model. Lead(II) adsorption onto NRE was better explained by Two-site Langmuir isotherm with sorption maximum of 1.39x10-2 and 2.30x10-3 mol/kg for two sites with different affinities. Negative Gibbs free energy values indicated spontaneity of Pb(II) adsorption onto NRE, and entropy and enthalpy of adsorption were 124.04 J/K mol and 17.71 KJ/mol, respectively. These results suggested that the NRE could be effectively used as a low cost candidate for removal of Pb(II) from environmental water, since use of low cost materials to treat

  5. Determination of molybdenum in natural waters by laser thermal-lens spectrometry

    International Nuclear Information System (INIS)

    Proskurnin, M.A.; Abroskin, A.G.; Artemova, S.I.; Belyaeva, T.V.; Ivanova, E.K.

    1992-01-01

    As before, the determination of nanogram quantities of heavy metals from small sample volumes of natural water represents an acute problem. This task has been solved more or less successfully by the use of different and sufficiently developed physicochemical methods. In most cases the determination requires a 100-fold preconcentration of the component determined (for instance, when using atomic absorption spectrometry). This significant disadvantage can be avoided by the use of thermal-lens laser spectrometry (TLS); some alternatives of the method have already found applications in analytical practice. The objective of the present study has been to investigate the optimum conditions for the determination of molybdenum in natural waters from small sample volumes by TLS. The resulting method based on the reaction with thiocyanate ions in the presence of ascorbic acid, has a detection limit of 19 pg/ml. Masking of iron(III) with a 1000-fold excess of tartrate ions has been proposed and it has been shown that a 10-fold excess of iron does not interfere in the determination of molybdenum. The procedure has been applied to the determination of molybdenum in drinking and natural waters

  6. Studies of the water adsorption on Lampung’s natural zeolite of Indonesia for cooling application

    Science.gov (United States)

    Wulandari, D. A.; Nasruddin; Lemington

    2018-03-01

    Part of minerals that originally formed from volcanic rock and ash layers reacting further with alkaline groundwater is called natural zeolite, where its sources are not always available in all countries. Indonesia is located in the ring of fire which have a huge sources of zeolite, one of the area is Lampung, South Sumatra. Natural zeolite has been considered as one of potential heat adsorbent medium which can contribute to the energy consumption and reduce air pollution in the using of cooling application. The characteristic of this Lampung natural zeolite such as adsorption kinetics, adsorption water uptake, and adsorption capacity were test with ASAP 2020 system. Sorption kinetics by this experiment of zeolite samples were carried out in a constant temperature and humidity chamber. The chamber can supply constant air condition with deviations of ±0.5 °C for temperature and ±3% for relative humidity. The data based on rate of adsorption and the defined working condition was set as 20°C and 70% RH. Pore volume is a significant parameter for determining the limitation of water uptake, which can describe the saturated condition of zeolite. Sorption isotherm models used to describe sorption phenomena are commonly deduced from the Polanyi potential theory were investigated. The water adsorption quantity increased with the increase of relative pressure. To sum up, this pure zeolite has a less heat and mass transfer performance so its need to be activated before using in cooling application to get their great potential and by being coated in a desiccant heat exchanger systems.

  7. Effects of acid deposition on microbial processes in natural waters

    International Nuclear Information System (INIS)

    Gilmour, C.C.

    1992-01-01

    Biogeochemical processes mediated by microorganisms are not adversely affected by the acidification of natural waters to the same extent as are the life cycles of higher organisms. Basic processes, e.g., primary production and organic matter decomposition, are not slowed in moderately acidified systems and do not generally decline above a pH of 5. More specifically, the individual components of the carbon, nitrogen, and sulfur cycles are, with few exceptions, also acid resistant. The influence of acid deposition on microbial processes is more often stimulation of nitrogen and sulfur cycling, often leading to alkalinity production, which mitigates the effect of strong acid deposition. Bacterial sulfate reduction and denitrification in sediments are two of the major processes that can be stimulated by sulfate and nitrate deposition, respectively, and result in ANC (acid-neutralizing capacity) generation. One of the negative effects of acid deposition is increased mobilization and bioaccumulation of some metals. Bacteria appear to play an important role, especially in mercury cycling, with acidification leading to increased bacterial methylation of mercury and subsequent bioaccumulation in higher organisms

  8. Heat transfer enhancement in a natural draft dry cooling tower under crosswind operation with heterogeneous water distribution

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohsen; Amooie, Hossein [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2016-04-15

    Crosswind significantly decreases cooling efficiency of a natural draft dry cooling tower. The possibility of improving cooling efficiency with heterogeneous water distribution within the cooling tower radiators under crosswind condition is analysed. A CFD approach was used to model the flow field and heat transfer phenomena within the cooling tower and airflow surrounding the cooling tower. A mathematical model was developed from various CFD results. Having used a trained Genetic Algorithm with the result of mathematical model, the best water distribution was found among the others. Remodeling the best water distribution with the CFD approach showed that the highest enhancement of the heat transfer compared to the usual uniform water distribution.

  9. Heat transfer enhancement in a natural draft dry cooling tower under crosswind operation with heterogeneous water distribution

    International Nuclear Information System (INIS)

    Goodarzi, Mohsen; Amooie, Hossein

    2016-01-01

    Crosswind significantly decreases cooling efficiency of a natural draft dry cooling tower. The possibility of improving cooling efficiency with heterogeneous water distribution within the cooling tower radiators under crosswind condition is analysed. A CFD approach was used to model the flow field and heat transfer phenomena within the cooling tower and airflow surrounding the cooling tower. A mathematical model was developed from various CFD results. Having used a trained Genetic Algorithm with the result of mathematical model, the best water distribution was found among the others. Remodeling the best water distribution with the CFD approach showed that the highest enhancement of the heat transfer compared to the usual uniform water distribution.

  10. Experiments in a natural circulation loop with supercritical water at low powers

    International Nuclear Information System (INIS)

    Pilkhwal, D.S.; Sharma, Manish; Jana, S.S.; Vijayan, P.K.

    2013-05-01

    Earlier, 1/2 ″ uniform diameter Supercritical Pressure Natural Circulation Loop (SPNL) was set-up in hall-7, BARC for carrying out experiments related to supercritical fluids. The loop is a rectangular loop having two heaters and two coolers. Experiments were carried out with CO 2 under supercritical conditions for various pressures and different combinations of heater and cooler orientations. Since, the design conditions are more severe for supercritical water (SCW) experiments, the loop was modified for SCW by installing new test sections, pressurizer and power supply for operation with supercritical water. Experimental data were generated on steady state, heat transfer and stability under natural circulation conditions for the horizontal heater and horizontal cooler (HHHC) orientation with SCW up to a heater power of 8.5 kW. The flow rate data and instability data were compared with the predictions of in-house developed 1-D code NOLSTA, which showed reasonable agreement. The heat transfer coefficient data were also compared with the predictions of various correlations exhibit peak at bulk temperature lower than that obtained in the experiments. Most of these correlations predicted experimental data well in the pseudo-critical region. However, all correlations are matching well with experimental data beyond the pseudo-critical region. The details of the experimental facility, Experiments carried out and the results presented in this report. (author)

  11. Water-rock interaction in a high-FeO olivine rock in nature

    International Nuclear Information System (INIS)

    Hellmuth, K.H.; Lindberg, A.; Tullborg, E.L.

    1992-12-01

    The long-term behaviour in nature of high-FeO olivine rock in contact with surface water has been studied at the Lovasjaervi instrusion, SE-Finland. The rock has been proposed as a high-capasity, higly reactive redox-buffer backfill in a repository for spent fuel. Favourable groundwater chemistry is a major parameter relevant to safety of such a repository. Reducing conditions favour the retardation of long-lived, redox-sensitive radionuclides. Weathering influences have been studied at the natural outcrop of the rock mass. The interaction of oxidizing surface waters with rock at greater depths has been studied by using fissure filling minerals. Investigation of weathered rock from the outcrop indicates that the olivine rock is highly reactive on a geological time scale and its redox capasity is available although the instrusion as a whole is surprisingly well preserved. The fissure fillings studied allow the conclusion that oxygen seems to be efficiently removed from intruding surface water. Oxidation seem to have caused visible effects only along very conducting fractures and near the contact zones of the surrounding granitic rock. Stable isotope data of fissure filling calcites indicate that the influence of surface waters can be traced clearly down to a depth of about 50 m, but also at greater depths re-equilibration has occurred. Groundwater data from the site were not available. (orig.)

  12. 75 FR 11194 - San Diego County Water Authority Natural Communities Conservation Program/Habitat Conservation...

    Science.gov (United States)

    2010-03-10

    ... Diego County Water Authority Natural Communities Conservation Program/Habitat Conservation Plan, San... meetings for the San Diego County Water Authority's (Water Authority/Applicant) draft Natural Communities Conservation Plan (NCCP)/Habitat Conservation Plan (HCP) prepared in application to us for an incidental take...

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

    Science.gov (United States)

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

    2011-01-01

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

  14. Experimental study of gas–liquid two-phase flow through packed bed under natural circulation conditions

    International Nuclear Information System (INIS)

    Chen, Shao-Wen; Miwa, Shuichiro; Griffiths, Matt

    2016-01-01

    Dry-out phenomena in packed beds or porous media may cause a significant digression of cooling/reaction performance in heat transfer/chemical reactor systems. One of the phenomena responsible for the dry-out in packed beds is known as the counter-current flow limitation (CCFL). In order to investigate the CCFL phenomena induced by gas–liquid two-phase flow in packed beds inside a pool, a natural circulation packed bed test facility was designed and constructed. A total of 27 experimental conditions covering various packing media sizes (sphere diameters: 3.0, 6.4 and 9.5 mm), packed bed heights (15, 35 and 50 cm) and water level heights (1.0, 1.5 and 2.0 m) were tested to examine the CCFL criteria with adiabatic air–water two-phase flow under natural circulation conditions. Both CCFL and flow reversal phenomena were observed, and the experimental data including instantaneous and time-averaged void fraction, differential pressure and superficial gas–liquid velocities were collected. The CCFL criteria were determined when periodical oscillations of void fraction and differential pressure appear. In addition, the Wallis correlation for CCFL was utilized for data analysis, and the Wallis coefficient, C, was determined experimentally from the packed bed CCFL tests. Compared to the existing data-sets in literature, the higher C values obtained in the present experiment suggest a possibly higher dry-out heat flux for natural circulation debris systems, which may be due to the water supply from both top and bottom surfaces of the packed beds. Considering the effects of bed height and hydraulic diameter of the packing media, a newly developed model for the Wallis coefficient, C, under natural circulation CCFL is presented. The present model can predict the experimental data with an averaged absolute error of ±7.9%. (author)

  15. The origin and fate of arsenic in coalbed natural gas-produced water ponds.

    Science.gov (United States)

    Sowder, J T; Kelleners, T J; Reddy, K J

    2010-01-01

    Coalbed natural gas (CBNG)-produced water contains small amounts of trace metals that can accumulate over time in produced water retention ponds. Within the Powder River Basin (PRB) of Wyoming, high concentrations of trace metals in pond water and their effect on shallow groundwater are potential concerns. A pond with a maximum As concentration of 146 microg L(-1) was studied in detail to determine the potential for groundwater pollution and to explain the cause for the high concentration of As. Infiltration characteristics, subsurface hydrology, our fall and pond water quality, isotope signatures, and trace metal balances were examined to assess the hydrology and geochemistry of the pond. The results indicated minimum or no infiltration of pond water and no measurable contamination of the shallow groundwater. The high As concentrations in the pond were determined to be the result of semi-continuous inputs of CBNG-produced water with low As concentrations (0.20-0.48 microg L(-1)), exasperated by low pond volumes during drought conditions. Because of reduced infiltration and high evaporation rates, As became concentrated over time. Reduced infiltration was most likely caused by the high sodium concentration and high sodium adsorption ratio of the CBNG-produced water, which disrupt soil structure. The findings for the pond and the techniques used may serve as a template for future impact assessments of other CBNG-produced water ponds and are relevant for the approximately 4000 ponds currently permitted in the PRB and for future ponds. Further studies are recommended in the use of playa landforms to store marginal-quality produced water.

  16. Bulk water phase and biofilm growth in drinking water at low nutrient conditions.

    Science.gov (United States)

    Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik; Jørgensen, Claus

    2002-11-01

    In this study, the bacterial growth dynamics of a drinking water distribution system at low nutrient conditions was studied in order to determine bacterial growth rates by a range of methods, and to compare growth rates in the bulk water phase and the biofilm. A model distribution system was used to quantify the effect of retention times at hydraulic conditions similar to those in drinking water distribution networks. Water and pipe wall samples were taken and examined during the experiment. The pipes had been exposed to drinking water at approximately 13 degrees C, for at least 385 days to allow the formation of a mature quasi-stationary biofilm. At retention times of 12 h, total bacterial counts increased equivalent to a net bacterial growth rate of 0.048 day(-1). The bulk water phase bacteria exhibited a higher activity than the biofilm bacteria in terms of culturability, cell-specific ATP content, and cell-specific leucine incorporation rate. Bacteria in the bulk water phase incubated without the presence of biofilm exhibited a bacterial growth rate of 0.30 day(-1). The biofilm was radioactively labelled by the addition of 14C-benzoic acid. Subsequently, a biofilm detachment rate of 0.013 day(-1) was determined by measuring the release of 14C-labelled bacteria of the biofilm. For the quasi-stationary phase biofilm, the detachment rate was equivalent to the net growth rate. The growth rates determined in this study by different independent experimental approaches were comparable and within the range of values reported in the literature.

  17. Plant Water Stress Affects Interactions Between an Invasive and a Naturalized Aphid Species on Cereal Crops.

    Science.gov (United States)

    Foote, N E; Davis, T S; Crowder, D W; Bosque-Pérez, N A; Eigenbrode, S D

    2017-06-01

    In cereal cropping systems of the Pacific Northwestern United States (PNW), climate change is projected to increase the frequency of drought during summer months, which could increase water stress for crop plants. Yet, it remains uncertain how interactions between herbivore species are affected by drought stress. Here, interactions between two cereal aphids present in PNW cereal systems, Metopolophium festucae (Theobald) subsp. cerealium (a newly invasive species) and Rhopalosiphum padi L. (a naturalized species), were tested relative to wheat water stress. When aphids were confined in leaf cages on wheat, asymmetrical facilitation occurred; per capita fecundity of R. padi was increased by 46% when M. festucae cerealium was also present, compared to when only R. padi was present. Imposed water stress did not influence this interaction. When aphids were confined on whole wheat plants, asymmetrical competition occurred; cocolonization inhibited M. festucae cerealium population growth but did not affect R. padi population growth. Under conditions of plant water stress, however, the inhibitory effect of R. padi on M. festucae cerealium was not observed. We conclude that beneficial effects of cocolonization on R. padi are due to a localized plant response to M. festucae cerealium feeding, and that cocolonization of plants is likely to suppress M. festucae cerealium populations under ample water conditions, but not when plants are water stressed. This suggests that plant responses to water stress alter the outcome of competition between herbivore species, with implications for the structure of pest communities on wheat during periods of drought. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  18. Influence of packaging and conditions of storaging on content of mineral water Guber-Srebrenica

    Directory of Open Access Journals (Sweden)

    Blagojević Dragana D.

    2008-01-01

    Full Text Available Mineral waters are found in nature in greater depths most often in reduction conditions, so after surfacing their content alters in contact with oxygen, which is caused by oxidation of certain components. Due to this, efforts were made to make these waters more stabile so they could be used after certain time. This work monitors the stability of Guber (Argentaria-Srebrenica water exposed to light and with addition of ascorbic acid. The methods of analysis and the parameters analyzed are: gravimetric (SO2-4, suspended solids, total dry residue at 180°C, conductometry (electric conductivity, volumetric (Al3+, spectrometric (SiO2 and atomic-absorption spectrophotometry (Fe2+, Mg2+, Mn2+, Zn2+, K+, Ca2+, Na+ i Cu2+. Obtained results of water analysis, after retaining water in PET (polyethylentereftalate and glass bottles, in certain time intervals, show that significant changes of concentration of Fe2+, Al3+, K+, Ca2+, pH value and electric conductivity occurred. Concentration of iron Fe2+ has been slightly changed after 120 days, in sample stabilized with 0,2 g ascorbic acid, while concentrations of Al and K+ were changing the same as without adding of stabilizer. Samples of water in glass packaging without added stabilizer are less stable compared to samples which were retained in PET packaging.

  19. Study on scaling law of PWR natural circulation with motion condition

    International Nuclear Information System (INIS)

    Lu Donghua; Xiao Zejun; Chen Bingde

    2009-01-01

    For some nuclear reactors installed on automobiles, boats or deep sea vehicles, it is an important way to investigate their system safety by performing natural circulation experiments under motion condition. This paper studied the natural circulation on moving plants based on work of static natural circulation scaling method. With rigid motion theory, acceleration at each point was obtained on primary system and introduced to momentum equation. Thus a set of motion similar criteria were obtained. Furthermore, equal and unequal height simulation were analyzed. As to the unequal one, non isochronous simulation was needed for displacement and angular acceleration. (authors)

  20. Return of naturally sourced Pb to Atlantic surface waters

    NARCIS (Netherlands)

    Bridgestock, L.; van de Flierdt, T.; Rehkämper, M.; Paul, P.; Middag, R.; Milne, A.; Lohan, M.C.; Baker, A.; Chance, R.; Khondoker, R.; Strekopytov, S.; Humphreys-Williams, E.; Achterberg, E.P.; Rijkenberg, M.J.A.; Gerringa, L.J.A.; De Baar, H.J.W.

    2016-01-01

    Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources duringthe past century, predominantly due to leaded petrol usage. Here, based on Pb isotopemeasurements, we reassess the importance of natural and anthropogenic Pb sources to thetropical North Atlantic following the

  1. In field arsenic removal from natural water by zero-valent iron assisted by solar radiation

    International Nuclear Information System (INIS)

    Cornejo, Lorena; Lienqueo, Hugo; Arenas, Maria; Acarapi, Jorge; Contreras, David; Yanez, Jorge; Mansilla, Hector D.

    2008-01-01

    An in situ arsenic removal method applicable to highly contaminated water is presented. The method is based in the use of steel wool, lemon juice and solar radiation. The method was evaluated using water from the Camarones River, Atacama Desert in northern Chile, in which the arsenic concentration ranges between 1000 and 1300 μg L -1 . Response surface method analysis was used to optimize the amount of zero-valent iron (steel wool) and the citrate concentration (lemon juice) to be used. The optimal conditions when using solar radiation to remove arsenic from natural water from the Camarones river are: 1.3 g L -1 of steel wool and one drop (ca. 0.04 mL) of lemon juice. Under these conditions, removal percentages are higher than 99.5% and the final arsenic concentration is below 10 μg L -1 . This highly effective arsenic removal method is easy to use and inexpensive to implement. - An in situ arsenic removal method applicable to highly contaminated waters by using zero-valent iron, citrate and solar radiation was developed

  2. In field arsenic removal from natural water by zero-valent iron assisted by solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo, Lorena [Departamento de Quimica, Facultad de Ciencias, Universidad de Tarapaca, Casilla 7-D, Arica (Chile); Laboratorio de Investigaciones Medioambientales de Zonas Aridas, LIMZA, Centro de Investigaciones del Hombre en el Desierto, CIHDE, Arica (Chile)], E-mail: lorenacp@uta.cl; Lienqueo, Hugo; Arenas, Maria [Departamento de Quimica, Facultad de Ciencias, Universidad de Tarapaca, Casilla 7-D, Arica (Chile); Acarapi, Jorge [Departamento de Quimica, Facultad de Ciencias, Universidad de Tarapaca, Casilla 7-D, Arica (Chile); Laboratorio de Investigaciones Medioambientales de Zonas Aridas, LIMZA, Centro de Investigaciones del Hombre en el Desierto, CIHDE, Arica (Chile); Contreras, David; Yanez, Jorge; Mansilla, Hector D. [Facultad de Ciencias Quimicas, Universidad de Concepcion, Casilla 160C, Concepcion (Chile)

    2008-12-15

    An in situ arsenic removal method applicable to highly contaminated water is presented. The method is based in the use of steel wool, lemon juice and solar radiation. The method was evaluated using water from the Camarones River, Atacama Desert in northern Chile, in which the arsenic concentration ranges between 1000 and 1300 {mu}g L{sup -1}. Response surface method analysis was used to optimize the amount of zero-valent iron (steel wool) and the citrate concentration (lemon juice) to be used. The optimal conditions when using solar radiation to remove arsenic from natural water from the Camarones river are: 1.3 g L{sup -1} of steel wool and one drop (ca. 0.04 mL) of lemon juice. Under these conditions, removal percentages are higher than 99.5% and the final arsenic concentration is below 10 {mu}g L{sup -1}. This highly effective arsenic removal method is easy to use and inexpensive to implement. - An in situ arsenic removal method applicable to highly contaminated waters by using zero-valent iron, citrate and solar radiation was developed.

  3. Release of natural radionuclides in the Czech Republic - from water treatment plants where water from underground water sources is treated

    International Nuclear Information System (INIS)

    Sinaglova, R.

    2014-01-01

    In this abstract author deals with the treatment of drinking water in the Czech Republic with removing of natural radionuclides as well as with treatment of filter cartridges. The advantage of these technologies is that flushing is not required so no wastewater occurs. Used ion exchangers with higher content of uranium are processed in the chemical treatment of uranium ores, managed by DIAMO, state enterprise. (authors)

  4. Emergency field water supply system using natural filtration elements

    Science.gov (United States)

    Vikneswaran, M.; Yahya, Muhamad Azani; Yusof, Mohammed Alias; Ismail, Siti Nor Kamariah

    2018-02-01

    Water is the most important resource in times of emergency and during military missions. In addition, if there is a war in a country, sources of clean water are essential for life. But, the safety and cleanliness of the river water for the campers and hikers still uncertain. Usually, polluted and contaminated river water is not safe to be directly consumed by human. However, this problem can be partly resolved by using water filter where the river water can be consumed directly after the filtration process. In respect of that, this study was conducted to design the filter media for personal water purification system. Hence, the objective of this work also is to develop a personal, portable dual purpose handy water filter to provide an easier way to get safe, clean and healthy drinking water for human wherever they go. The water quality of samples collected before and after filtration were analyzed. Water samples were taken from a waterfall near Lestari Block and Lake beside Marine Centre UPNM Campus. The experimental results were analyzed based on the assessment of water quality parameters. Overall, the analysis of the results showed that the water filter was designed with basic mix tabs aqua filter water purification tablets is showing a better result where it achieve the class I of water quality index (WQI). In details, the water sample taken from waterfall near Lestari Block shown the WQI around 93 which is higher than WQI of water sample from Lake near Marine Centre UPNM which is 86, class II A which can be used for external purpose only.

  5. The therapeutic effect of carbogaseous natural mineral waters in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Cinteza Delia

    2013-02-01

    Full Text Available Metabolic syndrome (syndrome X or insulin resistance syndrome is a complex of metabolic disturbances that increase the risk of developing cardiovascular disease. Entity includes: dyslipidemia (altered lipid profile, with increasing levels of serum triglycerides and low serum levels of HDL-cholesterol, which promotes the development of atherosclerosis, high blood sugar (diabetes type II or increased insulin resistance, hypertension, abdominal obesity syndrome, proinflammatory, prothrombotic syndrome. In the last 20 years, there was a continuous increase in individuals suffering from this syndrome, the cause remains unknown, but several studies also claim that it is a complex interaction between genetic, metabolic and environmental factors. Of environmental factors, diet low in micronutrients such as calcium, magnesium and potassium seems to be an essential contributor element (Feldsein et al, 2007, Cidalia Pereira et al, 2011. Decreased intake of sodium and increased intake of calcium, magnesium and potassium, proposed by Dietary Approaches to Stop Hypertension - DASH diet (Van Leer et al 1995, Meigl et al 2008 leads to optimized blood pressure. Even in the absence of increased sodium intake, low levels of magnesium in the blood and cells can induce in some conditions, hypertension, diabetes, insulin resistance or completely metabolic syndrom.Among the methods proposed to correct dietary intake of micronutrients, natural mineral water, often very complex in terms of chemical composition and versatile in terms of the intended effect is one handy, safe and simple.Although used in order to preserve the health from ancient times, scientific studies proving natural mineral water effects on the human body takes place only since the twentieth century. Carbonated mineral waters are the result of deep water filtering through volcanic soils, which contain CO2, carbon dioxide, thus obtained, will help dissolve other elements contained in the soil layers

  6. Evaluation of pressure transducers under turbid natural waters

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desa, E.; Desa, E.; Smith, D.; Peshwe, V.B.; VijayKumar, K.; Desa, J.A.E.

    , the use of rho sub(eff) in contrast to the bulk density, significantly improves the measurement accuracy. For celar waters, precision density measurements made on discrete water samples agreed with rho sub(eff) values derived from pressure measurements...

  7. Study of water nature in tungstoboric acid by thermochemical method

    International Nuclear Information System (INIS)

    Kosmodem'yanskaya, G.V.; Sadykova, M.M.; Spitsyn, V.I.

    1976-01-01

    The kinetics of the dehydration of the crystalline higher hydrates of tungstoboric acid (TBA) were studied. The dehydration of TBA shows first order behaviour. An appreciable proportion of the water in TBA is zeolitic water

  8. Concentration of natural radionuclides in private drinking water wells

    International Nuclear Information System (INIS)

    Cerny, R.; Otahal, P.; Merta, J.; Burian, I.

    2017-01-01

    Water is one of the most important resources for a human being; therefore, its quality should be properly tested. According to Council Directive No. 2013/51/Euroatom, there shall be established requirements for the general public health protection with regard to radioactive substances in water intended for human consumption. This article summarises measurement results of selected water samples at 444 private drinking water wells, which are not subject to regular inspection in terms of the Czech legislation. (authors)

  9. Water and chemical budgets in an urbanized river system under various hydrological conditions

    Science.gov (United States)

    Brion, Natacha; Carbonnel, Vincent; Elskens, Marc; Claeys, Philippe; Verbanck, Michel A.

    2017-04-01

    Since historical times, riversides are preferential settlement places for human life and activities, ultimately leading to the development of Cities. Available water resources are not only essential to ensure human's vital functions, they are also used for the production of food, goods, and energy, as transport routes and as evacuation ways for domestic and industrial waste products. All these activities profoundly modify natural water circulation as well as water quality, with increased hydrological risks (floods, droughts,…) and chemical hazards (untreated sewage releases, industrial pollution,…) as consequence. An extreme example of strongly modified river system is the river Zenne crossing the city of Brussels. In and around the city, the river together with its connected navigation canal, determine a small vertical urbanized area (800 km2) combining extreme land-use landscapes. While the southern upstream part of this area lies in a region of intensive agricultural activities, the central part is occupied by a dense cityscape including a forested area, and the downstream part is mainly under industrial influence. In this context, we established a box-model representation of water and selected polluting chemicals (N and P, biological oxygen demand, and a selection of metals, pesticides and PAHs) budgets for the studied area under variable hydrological conditions. We first have identified the general distribution of water and pollutant tracers in the various background sources of the system: waters in streams located in the very upstream parts of the catchment, and untreated and treated sewage. Secondly we have assessed the distribution of water flows, and pollutant tracer concentrations at the boundaries of the studied water systems for different stable hydrological conditions and during flood events. Finally we will discuss water budgets and pollution tracer budgets for a yearly average hydrological situation and for dry and wet weather conditions in order

  10. Effects of alloy composition and flow condition on the flow accelerated corrosion in neutral water condition

    International Nuclear Information System (INIS)

    Satoh, Tomonori; Ugachi, Hirokazu; Tsukada, Takashi; Uchida, Shunsuke

    2008-01-01

    The major mechanism of Flow accelerated corrosion (FAC) is the dissolution of the protective oxide on carbon steel, which is enhanced by mass transfer and erosion under high flow velocity conditions. In this study, the effects of alloy composition and flow velocity on FAC of carbon steel were evaluated by measuring FAC rate of tube type carbon steel specimens in the neutral water condition at 150degC. Obtained results are summarized in follows. 1) High FAC rate was depended upon the v 1.2 in the tube type specimen made of the standard alloy. 2) FAC was mitigated for the carbon steel with more than 0.03% of Cr content. 3) FAC rate decreased as Ni content increased in more than 0.1% of Ni content. 4) The difference in chemical composition of oxide film between Ni added carbon steel and Cr added one was confirmed. The hematite rich oxide was observed for Ni added carbon steel. 5) The effects of Cu on FAC rate was not observed up to 0.1% of Cu content. (author)

  11. The Influence of Safety, Efficacy, and Medical Condition Severity on Natural versus Synthetic Drug Preference.

    Science.gov (United States)

    Meier, Brian P; Lappas, Courtney M

    2016-11-01

    Research indicates that there is a preference for natural v. synthetic products, but the influence of this preference on drug choice in the medical domain is largely unknown. We present 5 studies in which participants were asked to consider a hypothetical situation in which they had a medical issue requiring pharmacological therapy. Participants ( N = 1223) were asked to select a natural, plant-derived, or synthetic drug. In studies 1a and 1b, approximately 79% of participants selected the natural v. synthetic drug, even though the safety and efficacy of the drugs were identical. Furthermore, participants rated the natural drug as safer than the synthetic drug, and as that difference increased, the odds of choosing the natural over synthetic drug increased. In studies 2 and 3, approximately 20% of participants selected the natural drug even when they were informed that it was less safe (study 2) or less effective (study 3) than the synthetic drug. Finally, in study 4, approximately 65% of participants chose a natural over synthetic drug regardless of the severity of a specific medical condition (mild v. severe hypertension), and this choice was predicted by perceived safety and efficacy differences. Overall, these data indicate that there is a bias for natural over synthetic drugs. This bias could have implications for drug choice and usage. © The Author(s) 2015.

  12. Characterizing natural organic matter in drinking water treatment processes and trains

    NARCIS (Netherlands)

    Baghoth, S.A.

    2012-01-01

    Natural organic matter (NOM) generally influences water treatment processes such as coagulation, oxidation, adsorption, and membrane filtration. NOM contributes colour, taste and odour in drinking water, fouls membranes, serves as a precursor for disinfection by-products, increases the exhaustion

  13. Study of the separation of strontium from solutions which imitate natural waters of increased mineralization

    International Nuclear Information System (INIS)

    Golub, A.M.; Voitko, I.N.; Glushchenko, L.V.; Mitrofanova, O.G.; Zyryanova, N.P.

    1976-01-01

    It has been shown by experiments on synthetically prepared solutions that it is possible to separate strontium and calcium by carbonate precipitation from the larger part of the magnesium accompanying them in natural high mineral waters. In this way the residual content of strontium is reduced to a value of 40-50 mg/liter and, under conditions of removing CO 2 from the solution, to 5-10 mg/liter. The high ionic strength of the solution prevented a more complete precipitation of strontium. Magnesium may be isolated from the filtrate after precipitation of the calcium-strontium mixture. The possibility has been shown of isolating strontium from the mixture of carbonates by means of pyrolysis at 1100-1200 0 and the selective solution of SrO in hot water

  14. Aluminum uptake from natural waters by a radiation-grafted membrane

    Energy Technology Data Exchange (ETDEWEB)

    Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, Jose E.; Geraldo, Aurea B.C., E-mail: ageraldo@ipen.br, E-mail: ryamaguishi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Styrene grafted, chemically modified polymeric membranes were used to carry off aluminum of drinking water from wells located at Billings dam region. The membranes comprised polymeric substrates of PVC (polyvinylchloride) and PP (polypropylene), which were mutually grafted with gamma radiation. The chemical modification included three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation; this modification enables aluminum selectivity on the membrane. This chemical process inserts a salicylated derivative bonded onto the aromatic ring of styrene; such molecular arrangement is responsible for complexation of aluminum ions. The aluminum sorption capacity of these membranes was evaluated firstly from an aluminum control solution, where parameters like the ideal pH value for aluminum sorption and the interfering species were studied and correlated to know the best conditions for aluminum uptake. Later, the membranes were used for aluminum remediation of natural waters (real-life samples). The applicability results and limits are then discussed. (author)

  15. Aluminum uptake from natural waters by a radiation-grafted membrane

    International Nuclear Information System (INIS)

    Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, Jose E.; Geraldo, Aurea B.C.

    2013-01-01

    Styrene grafted, chemically modified polymeric membranes were used to carry off aluminum of drinking water from wells located at Billings dam region. The membranes comprised polymeric substrates of PVC (polyvinylchloride) and PP (polypropylene), which were mutually grafted with gamma radiation. The chemical modification included three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation; this modification enables aluminum selectivity on the membrane. This chemical process inserts a salicylated derivative bonded onto the aromatic ring of styrene; such molecular arrangement is responsible for complexation of aluminum ions. The aluminum sorption capacity of these membranes was evaluated firstly from an aluminum control solution, where parameters like the ideal pH value for aluminum sorption and the interfering species were studied and correlated to know the best conditions for aluminum uptake. Later, the membranes were used for aluminum remediation of natural waters (real-life samples). The applicability results and limits are then discussed. (author)

  16. Evaluation of dissolved oxygen and organic substances concentrations in water of the nature reserve Alluvium Zitavy

    International Nuclear Information System (INIS)

    Palaticka, A.; Noskovic, J.; Babosova, M.

    2007-01-01

    In 2006 concentrations of dissolved oxygen and organic substances were evaluated in water in the Nature Reserve Alluvium Zitavy (indirect method based on their oxidation by K 2 Cr 2 0 7 was used). The results are represented in mg of O 2 · dm -3 . Taking of samples took place in 6 sampling sites in regular month intervals. Based on obtained data and according to the standard STN 75 7221 (Water quality -The classification of the water surface quality) water in individual sampling sites was ranked into the classes of the .water surface quality. From the data it is clear that the concentrations of dissolved oxygen and organic substances in the Nature Reserve Alluvium Zitavy changed in dependence on sampling sites and time. The highest mean concentrations of dissolved oxygen in dependence on sampling time were found out in spring months and the lowest concentrations in summer months. They ranged from 1.6 mg 0 2 · dm -3 (July) to 9.0 mg O 2 · dm -3 (March). Falling dissolved oxygen values can be related to successive increase of water temperature, thus good conditions were created for decomposition of organic matter by microorganisms in water and sediments in which they use dissolved oxygen. In dependence on sampling place the highest mean concentration of dissolved oxygen was in sampling site No. 4 (6.0 mg 0 2 · dm -3 ) which is situated in the narrowest place in the NR. The lowest value was in sampling site No. 2 (3.6 mg 0 2 · dm -3 ) which is a typical wetland ecosystem. High mean values of COD Cr in dependence on sampling time were determined in summer months and low values during winter moths. Dependence of COD Cr values on sampling site was also manifested. The lowest mean value was obtained in sampling site No. 4 (59.5 mg · dm -3 ) and the highest value in sampling site No. 5 (97.1 mg · dm -3 ) which is also a typical wetland. Based on the results and according to the STN 75 7221 we ranked water in all sampling sites into the 5 th class of the water

  17. Earth, Wind and Fire. Natural air conditioning; Earth, Wind and Fire. Natuurlijke airconditioning

    Energy Technology Data Exchange (ETDEWEB)

    Bronsema, B.

    2013-06-07

    Starting point for the Earth, Wind and Fire research, of which the sub-concepts of Ventec roof, Climate Cascade and Solar Chimney are an integral part of the (Architectural) building design, are the following hypotheses: (1) An integrated approach of Architecture / Constructions and Climate Design is capable of using the available ambient energy in the form of earth mass, wind, and sun, to condition the air mainly naturally in a building; (2) The sub-concepts can be modeled and validated, in order to be able to reliably support the design process in practice; and (3) The sub-concepts can individually or in combination contribute to the realization of zero energy buildings [Dutch] Airconditioning van gebouwen kan volledig met natuurlijke middelen, zonder mechanische ventilatie. Dat stelt de auteur in zijn proefschrift. Hij wil met vallend water, zon en wind een energiepositief kantoor realiseren. Bronsema is nu op zoek naar een gebouw voor een grootschalige praktijkproef met zijn Earth, Wind and Fire-concept. Het systeem bestaat uit drie hoofdonderdelen: het Ventecdak, de Klimaatcascade en de Zonneschoorsteen. Het Ventecdak zorgt voor aanvoer van verse en afvoer van vuile lucht door gebruikmaking van over- en onderdrukken. Die lucht wordt via de klimaatcascade toegevoerd en via een Zonneschoorsteen afgevoerd. Een mock-up van de Zonneschoorsteen is gerealiseerd als een elf meter hoge toren, die met opgevangen warmte van invallend zonlicht ventilatielucht verwarmt. Het op gang brengen van de luchtstroom gebeurt in de Klimaatcascade. Dit is een bouwkundige schacht waarin van bovenaf waterdruppels worden gesproeid waarmee de lucht kan worden gekoeld of verwarmd.

  18. Estimation of natural historical flows for the Manitowish River near Manitowish Waters, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Reneau, Paul C.; Robertson, Dale M.

    2012-01-01

    The Wisconsin Department of Natural Resources is charged with oversight of dam operations throughout Wisconsin and is considering modifications to the operating orders for the Rest Lake Dam in Vilas County, Wisconsin. State law requires that the operation orders be tied to natural low flows at the dam. Because the presence of the dam confounds measurement of natural flows, the U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, installed streamflow-gaging stations and developed two statistical methods to improve estimates of natural flows at the Rest Lake Dam. Two independent methods were used to estimate daily natural flow for the Manitowish River approximately 1 mile downstream of the Rest Lake Dam. The first method was an adjusted drainage-area ratio method, which used a regression analysis that related measured water yield (flow divided by watershed area) from short-term (2009–11) gaging stations upstream of the Manitowish Chain of Lakes to the water yield from two nearby long-term gaging stations in order to extend the flow record (1991–2011). In this approach, the computed flows into the Chain of Lakes at the upstream gaging stations were multiplied by a coefficient to account for the monthly hydrologic contributions (precipitation, evaporation, groundwater, and runoff) associated with the additional watershed area between the upstream gaging stations and the dam at the outlet of the Chain of Lakes (Rest Lake Dam). The second method used to estimate daily natural flow at the Rest Lake Dam was a water-budget approach, which used lake stage and dam outflow data provided by the dam operator. A water-budget model was constructed and then calibrated with an automated parameter-estimation program by matching simulated flow-duration statistics with measured flow-duration statistics at the upstream gaging stations. After calibration of the water-budget model, the model was used to compute natural flow at the dam from 1973 to

  19. Dinamics of radiating conditions in the natural complexes of a near zone of the Chernobyl NPP

    International Nuclear Information System (INIS)

    Bondar', Yu.I.; Kalinichenko, S.A.; Marchenko, Yu.D.

    2010-01-01

    The analysis of radiating conditions in exclusion zone of Chernobyl NPP is resulted. Annual and seasonal fluctuations of capacity of a dose, and also change of parameters of vertical migration Cs 137, Sr 90, Am 241 in a vertical profile of soils of various territorially-natural complexes are considered. (authors)

  20. 75 FR 9921 - San Diego County Water Authority Natural Communities Conservation Program/Habitat Conservation...

    Science.gov (United States)

    2010-03-04

    ... Diego County Water Authority Natural Communities Conservation Program/Habitat Conservation Plan, San... the NCCP/HCP's conservation strategy. Covered Activities would include developing new water... permit application, and notice of public meetings. SUMMARY: The San Diego County Water Authority (Water...

  1. Surprisingly low natural gas consumption for hot water in the Netherlands in 1996

    International Nuclear Information System (INIS)

    Geerse, C.

    1997-01-01

    The Dutch use hot water more efficient than previously expected. This conclusion is drawn from a recent study of hot water consumption in Dutch households and the corresponding natural gas consumption. Based on that (once-only) hot water use survey the hot water use models, as applied in the annual Basic Survey of Natural Gas Consumption of Small-scale Consumers in the Netherlands (BAK), will be modified. 6 tabs

  2. Operating experience of natural circulation core cooling in boiling water reactors

    International Nuclear Information System (INIS)

    Kullberg, C.; Jones, K.; Heath, C.

    1993-01-01

    General Electric (GE) has proposed an advanced boiling water reactor, the Simplified Boiling Water Reactor (SBWR), which will utilize passive, gravity-driven safety systems for emergency core coolant injection. The SBWR design includes no recirculation loops or recirculation pumps. Therefore the SBWR will operate in a natural circulation (NC) mode at full power conditions. This design poses some concerns relative to stability during startup, shutdown, and at power conditions. As a consequence, the NRC has directed personnel at several national labs to help investigate SBWR stability issues. This paper will focus on some of the preliminary findings made at the INEL. Because of the broad range of stability issues this paper will mainly focus on potential geysering instabilities during startup. The two NC designs examined in detail are the US Humboldt Bay Unit 3 BWR-1 plant and Dodewaard plant in the Netherlands. The objective of this paper will be to review operating experience of these two plants and evaluate their relevance to planned SBWR operational procedures. For completeness, experimental work with early natural circulation GE test facilities will also be briefly discussed

  3. Importance of the nature of comparison conditions for testing theory-based interventions: reply.

    Science.gov (United States)

    Michie, Susan; Prestwich, Andrew; de Bruin, Marijn

    2010-09-01

    The nature of comparison conditions is a much overlooked feature of designing and interpreting the results of randomized controlled trials, as outlined by Williams (see record 2010-18776-001). We agree that understanding the components and mechanisms of the comparison condition is necessary for making inferences about both intervention effectiveness (whether the intervention worked and which components may have contributed to such an effect) and about theoretical mediators (how it worked). The extent to which one can draw strong inferences regarding the efficacy and mechanisms of an intervention over the comparison is conditional upon a number of key points. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  4. Effect of marine condition on feature of natural circulation after accident in floating nuclear power plant

    International Nuclear Information System (INIS)

    Yang Fan; Zhang Dan; Tan Changlu; Ran Xu; Yu Hongxing

    2015-01-01

    The incline and swing effect on natural circulation of floating nuclear power plant under site black out (SBO) accident is studied using self-developing marine condition system code RELAP5/MC. It shows that, for floating nuclear power plant under marine condition, the pressurizer fluctuating flow rate, the parallel heat sink (steam generator) have significant influences on the direct passive reactor heat removal (PRHR) system, which is different from other secondary PRHR under marine condition. The flow exchange between the loop and the pressurizer have major effect on cooling capacity for the left side loop. (authors)

  5. Dynamics and developing of natural circulation cooling from vertical upflow and downflow conditions

    International Nuclear Information System (INIS)

    Yang, B.W.; Ouyang, W.

    2004-01-01

    Several research programs have been conducted to evaluate the capability of natural circulation cooling of reactors following a loss of cooling accident. Both experimental and RELAP5 simulation results were obtained for these studies in a facility with vertical heated tube(s) and a unheated bypass channel. The analytical results showed that, under a certain power level, a natural circulation pattern can be developed from both initial upflow and downflow conditions, and maintained for a significant cooling period. This power level, for the discussion of this paper, is defined as the natural circulation cooling (NCC) power limit. Two import factors, namely the pump coastdown rate and the initial flow direction, are examined in this paper. In the benchmark case, as compared to the experimental results, the RELAP5 simulation program accurately predicted the transient phenomena from forced convection through flow reversal, then, into natural circulation cooling. Generally, the two-phase NCC power limit is higher and also more stable for the cases with initial upflow forced convection than for the cases with initial downflow. The transient phenomena (dynamics) of the natural circulation cooling was examined by varying the pump coast down rate in approaching the flow reversal natural circulation. A significant pump coastdown effect on the NCC power limit was observed for the analytical tests with initial downflow forced convection. For the tests with initial downflow condition, the higher the coastdown rate (or the shorter the coastdown period), the higher the NCC power limit. For the case with initial upflow forced convection, there may be an optimal coastdown rate for a given subcooled condition. However, for the subcooled condition used in this study, the effect of pump coast down rate is not as significant as in the downward forced convection. (author)

  6. Corrosion behaviour of hyper duplex stainless steel in various metallurgical conditions for sea water cooled condensers

    International Nuclear Information System (INIS)

    Singh, Umesh Pratap; Kain, Vivekanand; Chandra, Kamlesh

    2011-01-01

    The sea water cooled condensers have to resist severe corrosion as marine environment is the most corrosive natural environment. Copper alloys are being phased out due to difficulties in water chemistry control and Titanium base alloys are extremely expensive. Austenitic stainless steels (SS) remain prone to localized corrosion in marine environments hence not suitable. These heat exchangers operate at temperatures not exceeding 50 deg C and at very low pressures. The tubes of these heat exchangers are joined to the carbon steel tube sheets by roll expansion or by roll expansion followed by seam welding. These conditions are expected to affect the localized corrosion resistance of the tube in roll joined region due to cold working and in the tube-tube sheet welded joint due to thermal effects of welding. In this study, the localized corrosion behaviour of a Hyper Duplex Stainless Steel (HDSS) has been evaluated, and compared with other materials e.g. types 304L SS, 316L SS, Duplex SS 2205, Titanium grade - 2, and Al Brass. The evaluation is done in three metallurgical conditions (a) as received, (b) cold rolled and (c) welded condition in synthetic sea water at room temperature and at 50 deg C to assess the resistance to crevice, pitting and stress corrosion cracking using standard ASTM exposure and electrochemical techniques. The results provide comparative assessment of these alloys and show their susceptibility in the three metallurgical conditions as encountered in condensers. Hyper-duplex SS has been shown to be highly resistant in sea water for the condenser tubing application. (author)

  7. Working regime identification for natural circulation loops by comparative thermalhydraulic analyses with three fluids under identical operating conditions

    International Nuclear Information System (INIS)

    Sarkar, Milan K.S.; Basu, Dipankar N.

    2015-01-01

    Highlights: • Thermalhydraulic analyses of NCL to justify the use of supercritical condition. • Mass flow rate of supercritical loop increases with heater power till a maxima. • Supercritical loop suffer from HTD beyond the maxima with jump in fluid temperature. • HTD is pronounced at higher sink temperatures and pressures just above critical. • Supercritical CO_2 is preferred fluid till the HTD and single-phase water afterwards. - Abstract: Computational investigation for comparative thermalhydraulic analyses of rectangular natural circulation loops is performed to propose a guideline for selecting the working fluid and nature of the loop, subcritical or supercritical, under identical levels of operating parameters like pressure, heating power and coolant temperature. A 3-d uniform-diameter loop geometry is developed with horizontal heating and cooling. Heating is provided in constant heat flux mode, whereas cooling is through a constant temperature sink. Due to favourable thermophysical properties and environmental conformity, water, CO_2 and R134a are selected as possible working fluids. Operational parameters are set so as to have sub- to supercritical condition for CO_2, supercritical for R134a and single-phase liquid for water. Mass flow rate for supercritical fluid rapidly increases with heater power, when the fluid is allowed to cross the pseudocritical point during its passage through the heater, and exhibits a maxima. Drastic fall in mass flow rate can be observed beyond the maxima, accompanied by a jump in maximum fluid temperature and a rapid decline in sink-side heat transfer coefficient. That can be identified as heat transfer deterioration in supercritical natural circulation loops, a highly undesirable situation from loop safety point of view. Allowable working range of heater power can be enhanced by increasing system pressure and decreasing sink temperature. For any specified set of operating conditions, CO_2-based supercritical loops

  8. Working regime identification for natural circulation loops by comparative thermalhydraulic analyses with three fluids under identical operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Milan K.S.; Basu, Dipankar N., E-mail: dipankar.n.basu@gmail.com

    2015-11-15

    Highlights: • Thermalhydraulic analyses of NCL to justify the use of supercritical condition. • Mass flow rate of supercritical loop increases with heater power till a maxima. • Supercritical loop suffer from HTD beyond the maxima with jump in fluid temperature. • HTD is pronounced at higher sink temperatures and pressures just above critical. • Supercritical CO{sub 2} is preferred fluid till the HTD and single-phase water afterwards. - Abstract: Computational investigation for comparative thermalhydraulic analyses of rectangular natural circulation loops is performed to propose a guideline for selecting the working fluid and nature of the loop, subcritical or supercritical, under identical levels of operating parameters like pressure, heating power and coolant temperature. A 3-d uniform-diameter loop geometry is developed with horizontal heating and cooling. Heating is provided in constant heat flux mode, whereas cooling is through a constant temperature sink. Due to favourable thermophysical properties and environmental conformity, water, CO{sub 2} and R134a are selected as possible working fluids. Operational parameters are set so as to have sub- to supercritical condition for CO{sub 2}, supercritical for R134a and single-phase liquid for water. Mass flow rate for supercritical fluid rapidly increases with heater power, when the fluid is allowed to cross the pseudocritical point during its passage through the heater, and exhibits a maxima. Drastic fall in mass flow rate can be observed beyond the maxima, accompanied by a jump in maximum fluid temperature and a rapid decline in sink-side heat transfer coefficient. That can be identified as heat transfer deterioration in supercritical natural circulation loops, a highly undesirable situation from loop safety point of view. Allowable working range of heater power can be enhanced by increasing system pressure and decreasing sink temperature. For any specified set of operating conditions, CO{sub 2}-based

  9. Explicit formulation for natural frequencies of double-beam system with arbitrary boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mirzabeigy, Alborz; Madoliat, Reza [Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Dabbagh, Vahid [University of Malaya, Kuala Lumpur (Malaysia)

    2017-02-15

    In this paper, free transverse vibration of two parallel beams connected through Winkler type elastic layer is investigated. Euler- Bernoulli beam hypothesis has been applied and it is assumed that boundary conditions of upper and lower beams are similar while arbitrary without any limitation even for non-ideal boundary conditions. Material properties and cross-section geometry of beams could be different from each other. The motion of the system is described by a homogeneous set of two partial differential equations, which is solved by using the classical Bernoulli-Fourier method. Explicit expressions are derived for the natural frequencies. In order to verify accuracy of results, the problem once again solved using modified Adomian decomposition method. Comparison between results indicates excellent accuracy of proposed formulation for any arbitrary boundary conditions. Derived explicit formulation is simplest method to determine natural frequencies of double-beam systems with high level of accuracy in comparison with other methods in literature.

  10. Moment-based boundary conditions for lattice Boltzmann simulations of natural convection in cavities

    KAUST Repository

    Allen, Rebecca

    2016-06-29

    We study a multiple relaxation time lattice Boltzmann model for natural convection with moment-based boundary conditions. The unknown primary variables of the algorithm at a boundary are found by imposing conditions directly upon hydrodynamic moments, which are then translated into conditions for the discrete velocity distribution functions. The method is formulated so that it is consistent with the second order implementation of the discrete velocity Boltzmann equations for fluid flow and temperature. Natural convection in square cavities is studied for Rayleigh numbers ranging from 103 to 108. An excellent agreement with benchmark data is observed and the flow fields are shown to converge with second order accuracy. Copyright © 2016 Inderscience Enterprises Ltd.

  11. Shallow ground-water conditions, Tom Green County, Texas

    Science.gov (United States)

    Lee, J.N.

    1986-01-01

    Most of the water needs of Tom Green County, Texas, are supplied by ground water; however, the city of San Angelo is supplied by surface water. Groundwater withdrawals during 1980 (latest year for which data are available) in Tom Green County totaled about 15,300 acre-feet, all derived from shallow aquifers. Shallow aquifers in this report refer to the ground-water system generally less than 400 feet deep that contains water with less than a 10,000 milligrams per liter concentration of dissolved solids; aquifers comprising this system include: The Leona, Comanche Peak, Trinity, Blaine, San Angelo, Choza, Bullwagon, Vale, Standpipe, and Arroyo aquifers.

  12. Natural convection heat transfer of water in a horizontal circular gap

    Institute of Scientific and Technical Information of China (English)

    SU Guanghui; Kenichiro Sugiyama; WU Yingwei

    2007-01-01

    An experimental study on the natural convection heat transfer on a horizontal downward facing heated surface in a water gap was carried out under atmospheric pressure conditions. A total of 700 experimental data points were correlated using Rayleigh versus Nusselt number in various forms, based on different independent variables. The effects of different characteristic lengths and film temperatures were discussed. The results show that the buoyancy force acts as a resistance force for natural convecti on beat transfer ona downward facing horizontal heated surface in a confined space. For the estimation of the natural convection heat transfer under the present conditions, empirical correlations in which Nusselt number is expressed as a function of the Rayleigh number, or both Rayleigh and Prandtl numbers, may be used. When it is accurately predicted, the Nusselt number is expressed as a function of the Rayleigh and Prandtl numbers, as well as the gap width-to-heated surface diameter ratio; and uses the temperature difference between the heated surface and the ambient fluid in the definition of Rayleigh number. The characteristic length is the gap size and the film temperature is the average fluid temperature.

  13. Development of reactor water level sensor for extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K; Ogasawara, T [Sukegawa Electric Co., Ltd., Hitachi, Ibaraki (Japan); Shibata, Akira; Nakamura, Jinichi; Saito, Takashi; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    In the Fukushima accident, measurement failure of water level was one of the most important factors which caused serious situation. The differential pressure type water level indicators are widely used in various place of nuclear power plant but after the accident of TMI-2, the need of other reliable method has been required. The BICOTH type and the TRICOTH type water level indicator for light water power reactors had been developed for in-pile water level indicator but currently those are not adopted to nuclear power plant. In this study, the development of new type water level indicator composed of thermocouple and heater is described. Demonstration test and characteristic evaluation of the water level indicator were performed and we had obtained satisfactory results. (author)

  14. Integrated treatment process using a natural Wyoming clinoptilolite for remediating produced waters from coalbed natural gas operations

    Science.gov (United States)

    Zhao, H.; Vance, G.F.; Urynowicz, M.A.; Gregory, R.W.

    2009-01-01

    Coalbed natural gas (CBNG) development in western U.S. states has resulted in an increase in an essential energy resource, but has also resulted in environmental impacts and additional regulatory needs. A concern associated with CBNG development relates to the production of the copious quantities of potentially saline-sodic groundwater required to recover the natural gas, hereafter referred to as CBNG water. Management of CBNG water is a major environmental challenge because of its quantity and quality. In this study, a locally available Na-rich natural zeolite (clinoptilolite) from Wyoming (WY) was examined for its potential to treat CBNG water to remove Na+ and lower the sodium adsorption ratio (SAR, mmol1/2 L- 1/2). The zeolite material was Ca-modified before being used in column experiments. Column breakthrough studies indicated that a metric tonne (1000??kg) of Ca-WY-zeolite could be used to treat 60,000??L of CBNG water in order to lower SAR of the CBNG water from 30 to an acceptable level of 10??mmol1/2 L- 1/2. An integrated treatment process using Na-WY-zeolite for alternately treating hard water and CBNG water was also examined for its potential to treat problematic waters in the region. Based on the results of this study, use of WY-zeolite appears to be a cost-effective water treatment technology for maximizing the beneficial use of poor-quality CBNG water. Ongoing studies are evaluating water treatment techniques involving infiltration ponds lined with zeolite. ?? 2008 Elsevier B.V. All rights reserved.

  15. Improved Management of Water and Natural Resources Requires Open, Cognizant, Adaptive Science and Policy

    Science.gov (United States)

    Glynn, P. D.; Voinov, A. A.; Shapiro, C. D.; Jenni, K. E.

    2017-12-01

    Water issues impact the availability and use of other natural resources as well as environmental conditions. In an increasingly populated hyper-connected world, water issues are increasingly "wicked problems": complex problems with high uncertainties and no independent observers. Water is essential to life, and life affects water quality and availability. Scientists, managers, decision-makers, and the greater public all have a stake in improving the management of water resources. In turn, they are part of the systems that they are studying, deciding on, affecting, or trying to improve. Governance of water issues requires greater accessibility, traceability, and accountability (ATA) in science and policy. Water-related studies and decision-making need transdisciplinary science, inclusive participatory processes, and consideration and acceptance of multiple perspectives. Biases, Beliefs, Heuristics, and Values (BBHV) shape much of our perceptions and knowledge, and inevitably, affect both science and policy. Understanding the role of BBHV is critical to (1) understanding individual and group judgments and choices, (2) recognizing potential differences between societal "wants" and societal "needs", and (3) identifying "winners" and "losers" of policy decisions. Societal acceptance of proposed policies and actions can be fostered by enhancing participatory processes and by providing greater ATA in science, in policy, and in development of the laws, rules, and traditions that constrain decision-making. An adaptive science-infused governance framework is proposed that seeks greater cognizance of the role of BBHV in shaping science and policy choices and decisions, and that also seeks "Open Traceable Accountable Policy" to complement "Open Science". We discuss the limitations of the governance that we suggest, as well as tools and approaches to help implementation.

  16. Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach

    Science.gov (United States)

    Cutshall, N. H.; Gilmore, T.; Looney, B. B.; Vangelas, K. M.; Adams, K. M.; Sink, C. H.

    2006-05-01

    Like many US industries and businesses, the Department of Energy (DOE) is responsible for remediation and restoration of soils and ground water contaminated with chlorinated ethenes. Monitored Natural Attenuation (MNA) is an attractive remediation approach and is probably the universal end-stage technology for removing such contamination. Since 2003 we have carried out a multifaceted program at the Savannah River Site designed to advance the state of the art for MNA of chlorinated ethenes in soils and groundwater. Three lines of effort were originally planned: 1) Improving the fundamental science for MNA, 2) Promoting better characterization and monitoring (CM) techniques, and 3) Advancing the regulatory aspects of MNA management. A fourth line, developing enhanced attenuation methods based on sustainable natural processes, was added in order to deal with sites where the initial natural attenuation capacity cannot offset contaminant loading rates. These four lines have been pursued in an integrated and mutually supportive fashion. Many DOE site-cleanup program managers view CM as major expenses, especially for natural attenuation where measuring attenuation is complex and the most critical attenuation mechanisms cannot be determined directly. We have reviewed new and developing approaches to CM for potential application in support of natural attenuation of chlorinated hydrocarbons in ground water at DOE sites (Gilmore, Tyler, et al., 2006 WSRC-TR- 2005-00199). Although our project is focused on chlorinated ethenes, many of the concepts and strategies are also applicable to a wider range of contaminants including radionuclides and metals. The greatest savings in CM are likely to come from new management approaches. New approaches can be based, for example, on conceptual models of attenuation capacity, the ability of a formation to reduce risks caused by contaminants. Using the mass balance concept as a guide, the integrated mass flux of contaminant is compared to

  17. The nature and causes of the global water crisis: Syndromes from a meta-analysis of coupled human-water studies

    Science.gov (United States)

    Srinivasan, V.; Lambin, E. F.; Gorelick, S. M.; Thompson, B. H.; Rozelle, S.

    2012-10-01

    Freshwater scarcity has been cited as the major crisis of the 21st century, but it is surprisingly hard to describe the nature of the global water crisis. We conducted a meta-analysis of 22 coupled human-water system case studies, using qualitative comparison analysis (QCA) to identify water resource system outcomes and the factors that drive them. The cases exhibited different outcomes for human wellbeing that could be grouped into a six "syndromes": groundwater depletion, ecological destruction, drought-driven conflicts, unmet subsistence needs, resource capture by elite, and water reallocation to nature. For syndromes that were not successful adaptations, three characteristics gave cause for concern: (1) unsustainability—a decline in the water stock or ecosystem function that could result in a long-term steep decline in future human wellbeing; (2) vulnerability—high variability in water resource availability combined with inadequate coping capacity, leading to temporary drops in human wellbeing; (3) chronic scarcity—persistent inadequate access and hence low conditions of human wellbeing. All syndromes could be explained by a limited set of causal factors that fell into four categories: demand changes, supply changes, governance systems, and infrastructure/technology. By considering basins as members of syndrome classes and tracing common causal pathways of water crises, water resource analysts and planners might develop improved water policies aimed at reducing vulnerability, inequity, and unsustainability of freshwater systems.

  18. Experimental study on convective heat transfer of water flow in a heated tube under natural circulation

    International Nuclear Information System (INIS)

    Yang Ruichang; Liu Ruolei; Zhong Yong; Liu Tao

    2006-01-01

    This paper reports on an experimental study on transitional heat transfer of water flow in a heated vertical tube under natural circulation conditions. In the experiments the local and average heat transfer coefficients were obtained. The experimental data were compared with the predictions by a forced flow correlation available in the literature. The comparisons show that the Nusselt number value in the fully developed region is about 30% lower than the predictions by the forced flow correlation due to flow laminarization in the layer induced by co-current bulk natural circulation and free convection. By using the Rayleigh number Ra to represent the influence of free convection on heat transfer, the empirical correlations for the calculation of local and average heat transfer behavior in the tube at natural circulation have been developed. The empirical correlations are in good agreement with the experimental data. Based on the experimental results, the effect of the thermal entry-length behavior on heat transfer design in the tube under natural circulation was evaluated

  19. Evaluation of the process of coagulation/flocculation of produced water using Moringa oleifera Lam. as natural coagulant

    Energy Technology Data Exchange (ETDEWEB)

    Santana, C.R.; Pereira, D.F.; Sousa, S.C S N.; Silva, G.F. [Universidade Federal de Sergipe (UFSE), Sao Cristovao, SE (Brazil). Dept. de Engenharia Quimica], e-mail: claudia@ufs.br; Cavalcanti, E.B. [Universidade Tiradentes (UNIT), SE (Brazil). Inst. de Tecnologia e Pesquisa

    2010-07-15

    In the lifetime of an oil well, there comes a moment when a lot of water begins to be produced along with oil, either by the conditions of the reservoir, or as a result of water injection in the secondary recovery of the well. An important step in such process involves the treatment of the produced water by means of coagulation techniques. Therefore, the use of environmentally correct coagulants is presented as a viable alternative and has demonstrated advantages over the use of chemical coagulants. The plant of the genus Moringa, whose species is oleifera Lam, stands out as one of the most promising natural coagulants. The present study investigated the evaluation of the coagulation/flocculation of produced water, using seeds of Moringa oleifera Lam. as coagulant. The results were very significant, demonstrating that Moringa oleifera Lam. can be used as a natural coagulant in this type of treatment. (author)

  20. Evaluating Thermal Comfort in a Naturally Conditioned Office in a Temperate Climate Zone

    Directory of Open Access Journals (Sweden)

    Andrés Gallardo

    2016-07-01

    Full Text Available This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation, and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort.

  1. Interaction between Soil Physicochemical Parameters and Earthworm Communities in Irrigated Areas with Natural Water and Wastewaters

    Directory of Open Access Journals (Sweden)

    Kourtel Ghanem Nadra

    2017-01-01

    Full Text Available Our objective is to study interaction between physical and chemical properties of soils and their earthworm community characteristics in different areas irrigated by wastewaters and well waters. The fields have different topography and agricultural practices conditions and are located in two regions of Batna department (Eastern Algeria. Both regions are characterized by a semiarid climate with cold winters and Calcisol soils. Nine fields were subject of this study. Three of these fields are located in Ouled Si Slimane region whose irrigation is effectuated by natural waters of Kochbi effluent. The other six fields are located at edges of Wed El Gourzi, effluent from Batna city, and partially treated through water treatment station. The best rates of water saturation and infiltration as well as abundance of earthworms were recorded at sites characterized by irrigation with wastewaters downstream of El Gourzi effluent. PCA characterizes two major groups: a group of hydrodynamic infiltration parameters and structural index stability of soil, explained by fields irrigated with wastewaters downstream of El Gourzi effluent. This group includes chemical characteristics: pH and electric conductivity. The second group is the characteristics of earthworms and includes organic matter content, active limestone levels, and Shannon Biodiversity Index.

  2. Marginal value of natural water in agriculture: a study in the suburbs of Mekelle City, Ethiopia

    NARCIS (Netherlands)

    Gezahegn, T.W.; Xueqin Zhu, Xueqin

    2015-01-01

    In areas where markets for natural water are lacking, information on its marginal value can be an important tool for proper pricing to achieve efficient allocation of the resource. This article investigates the marginal value of natural water (rainwater used as a proxy) in agricultural crop

  3. Investigation of natural radioactivity level of the waters in the tibet autonomous region

    International Nuclear Information System (INIS)

    Zhang Tianhua; Li Yankun; Yao Ke; Pan Chengchang

    1995-01-01

    The investigation results of natural radioactivity level in river, lake, spring, well and tap water in the Tibet Autonomous Region is reported. There were totally 46 samples collected from 53 measuring points. The results show that the radioactivity level of water bodies of the Tibet Autonomous region was within normal natural background

  4. Investigation of natural radioactivity level of the waters in Inner Mongolia

    International Nuclear Information System (INIS)

    Du Xuelin; Li Wenyuan; Fu Su

    1993-01-01

    The authors reports the investigation results of natural radioactivity level in rivers, lakes, reservoirs, springs, wells and tap water in Inner Mongolia Autonomous Region. There were totally 326 samples collected from 178 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  5. Investigation of natural radioactivity level of the waters in Guangxi Zhuangzu Autonomous Region

    International Nuclear Information System (INIS)

    Yang Mingshen; Ming Chuanbao; Dai Guozhi; Liang Runping; Chen Xiuyu; Yang Gang; Jin Mei

    1993-01-01

    This paper reports the investigation results of natural radioactivity level in river, lake reservoir, spring, well and tap water in Guangxi Zhuangzu Autonomous Region. There were totally 194 samples collected from 143 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  6. Investigation of natural radioactivity level of the waters in the Ningxia Hui Autonomous Region

    International Nuclear Information System (INIS)

    Jing Yupei; Wang Li; Tian Yi; Ai Xianyuan; Liang Ningbu

    1995-01-01

    This paper reports the investigation results of natural radioactivity level in river, lake, reservoir, spring, well and tap water in the Ningxia Hui Autonomous Region. There were totally 117 samples collected from 84 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  7. Comparative Hydrology, Water Quality, and Ecology of Selected Natural and Augmented Freshwater Wetlands in West-Central Florida

    Science.gov (United States)

    Lee, T.M.; Haag, K.H.; Metz, P.A.; Sacks, L.A.

    2009-01-01

    rates increased as the size of the flooded area decreased and as the downward head difference between the wetland and the underlying Upper Floridan aquifer increased. Allowing one of the augmented wetlands to dry up for about 2.5 months in the spring of 2004, and then refilling it, generated a net savings of augmentation water despite the amount of water required to recreate the water-table mound beneath the wetland. Runoff from the surrounding uplands was an important component of the water budget in all of the unaugmented wetlands and two of the augmented wetlands. At a minimum, runoff contributed from half (45 percent) to twice (182 percent) as much water as direct rainfall at individual wetlands. Wetland flooded areas, derived using wetland water levels and bathymetric data and presented as a percentage of total wetland area, were used to compare and contrast hydrologic conditions among the 10 wetlands. The percentages of the natural wetland areas that flooded during the study were comparable, despite differences in the sizes of the wetlands. The percent flooded area in each wetland was calculated daily over the study period and monthly for up to 16 years using historical water-level data. Historical flooding in the natural wetlands spanned a greater range in area and had more pronounced seasonality than historical flooding at either the impaired or augmented wetlands. Flooding in the impaired and natural wetlands was similar, however, during 2 years of the study with substantially reduced well-field pumping and above average rainfall. Comparisons indicated several hydrologic differences between the marsh and cypress wetlands in this study. The natural and impaired marshes leaked at about half the rate of the natural and impaired cypress wetlands, and the marshes collectively were underlain by geologic material with lower vertical leakance values than the cypress wetlands. The natural marshes had higher evaporation rates compared to cypress

  8. Natural circulation cooling in US pressurized water reactors

    International Nuclear Information System (INIS)

    Berta, V.T.; Wilson, G.E.; Boyack, B.E.

    1989-01-01

    The research into the modes of, and heat removed by, natural circulation in PWR systems is reviewed for the purpose of determining the status of this method for off-nominal recovery procedures. The referenced information comes from all facets of the nuclear industry, both domestic and international. The information focuses on recent research (1986--1988); however, pre-1986 research is summarized and referenced. Particular attention is paid to the role of scaling in the experimental facilities and analytical tools. Three modes of natural-circulation cooling are covered: condensation. The conclusion of the review is that the new research reconfirms the pre-1986 conclusion that natural circulation is a viable means of decay heat removal. In addition, the new research sufficiently completes the acquisition of an appropriate experimental data base and the development of system codes to permit the design of valid plant recovery procedures incorporating all three modes of natural circulation. 48 refs., 1 fig., 3 tabs

  9. Design and testing of a chamber device to measure organic vapor fluxes from the unsaturated zone under natural conditions

    International Nuclear Information System (INIS)

    Tillman, F.D.; Choi, J-W.; Smith, J.A.

    2002-01-01

    As the difficulty and expense of achieving water quality standards at contaminated sites becomes more apparent, the U.S. Environmental Protection Agency is taking a closer look at natural attenuation processes for selected sites. To determine if a site has potential for natural attenuation, all natural processes affecting the fate and transport of volatile organic compounds (VOCs) in the subsurface must be identified and quantified. This research addresses the quantification of air-phase VOCs leaving the subsurface and entering the atmosphere, both through diffusion and soil-gas advection caused by barometric pumping. A simple, easy-to-use, and inexpensive device for measuring VOC flux under natural conditions was designed, constructed and tested both in a controlled laboratory environment and in a natural field setting. Design parameters for the chamber were selected using continuously stirred tank reactor (CSTR)-equation based modeling under several flux inputs. The final chamber design performs at greater than 95% efficiency for the simulated cases. Laboratory testing of the flux chamber under both diffusion and advection transport conditions was performed in a device constructed to simulate the unsaturated zone. Results indicate an average flux measurement accuracy of 83% over 3 orders of magnitude for diffusion-only fluxes and 94% for combined advection-diffusion fluxes. A field test of the chamber was performed and results compared with predictions made by a 1-dimensional unsaturated zone flow and transport model whose calibration and parameters were obtained from data collected at the site. Fluxes measured directly by the chamber were generally in good agreement with the fluxes calculated from the calibrated flow-and-transport model. (author)

  10. Plutonium - its behavior in natural-water systems and assimilation by man

    International Nuclear Information System (INIS)

    Larsen, R.P.; Nelson, D.M.; Bhattacharyya, M.H.; Oldham, R.D.

    1981-01-01

    There are a number of factors which must be considered in establishing whether or not the inadvertent intrusion of a sizable amount of plutonium-bearing material into a natural-water system may have a significant impact on the health of those individuals who use that system as a drinking-water resource. These factors include the chemical form(s) and solubility of plutonium in natural waters, its behavior in relation to natural processes (geochemical and biological), its fate in water-treatment systems, and its uptake by man from drinking water. From the results obtained of the behavior in natural-water systems, it appears that (1) the chemical forms of plutonium dissolved in natural waters are Pu(IV) and Pu(V), (2) the soluble plutonium in many waters is bound to the organic constituents which probably enhance plutonium solubility, (3) the natural process responsible for the removal of plutonium from water is adsorption onto sediments, and (4) in water-treatment systems, soluble plutonium is oxidized to the VI state and this form is not removed. From investigations of gastrointestinal absorption, it appears that the value for f 1 , the fraction transferred from the gut to blood, is greater than 1 x 10 - 3 and may be as high as 2 x 10 - 1

  11. The Nature of Family Engagement in Interventions for Children With Chronic Conditions.

    Science.gov (United States)

    Knafl, Kathleen A; Havill, Nancy L; Leeman, Jennifer; Fleming, Louise; Crandell, Jamie L; Sandelowski, Margarete

    2017-05-01

    Recognizing the bi-directional relationship between family functioning and child well-being in the context of childhood chronic conditions, researchers have tested family-focused interventions aimed at promoting both child and family well-being through improving the family's condition management capacity. Based on a sample of 70 interventions for families in which there was a child with a chronic physical condition, this analysis examined the nature of family engagement in the interventions. Data were extracted from the intervention reports using a standardized template; conventional content analysis was used to describe family engagement. Interventions varied in focus, structure, and level of family engagement. Investigators most often sought to improve condition control or management, with parent engagement focused on improving capacity to manage the treatment regimen. Few investigators addressed capacity building in the context of family functioning. Recommendations are made for reporting standards for family-focused interventions and for enhancing the family systems grounding of interventions.

  12. Adsorption of natural surfactants present in sea waters at surfaces of minerals: contact angle measurements

    Directory of Open Access Journals (Sweden)

    Katarzyna Boniewicz-Szmyt

    2009-09-01

    Full Text Available The wetting properties of solid mineral samples (by contact angles in original surfactant-containing sea water (Gulf of Gdańsk, Baltic were characterised under laboratory conditions on a large set (31 samples of well-classified stones of diverse hydrophobicity using the sessile drop (ADSA-P approach, captive bubble and inclined plate methods. An experimental relation between the static contact angle θeq and stone density ρ was obtained in the form θeq = Bρ + C, where B = 12.23 ± 0.92, C = - (19.17 ± 0.77, and r2 = 0.92. The histogram of θeq distribution for polished stone plates exhibited a multimodal feature indicating that the most abundant solid materials (hydrophilic in nature have contact angles θeq = 7.2, 10.7, 15.7 and 19.2º, which appear to be applicable to unspecified field stones as well. The contact angle, a pH-dependent quantity, appears to be a sensitive measure of stone grain size, e.g. granite. The captive bubble method gives reproducible results in studies of porous and highly hydrophilic surfaces such as stones and wood. The authors consider the adsorption of natural sea water surfactants on stone surfaces to be the process responsible for contact angle hysteresis. In the model, an equation was derived for determining the solid surface free energy from the liquid's surface tension γLV it also enabled the advancing θA and receding θR contact angles of this liquid to be calculated. Measurements of contact angle hysteresis Δθ (=θA - θR with surfactant-containing sea water and distilled water (reference on the same stone surfaces allowed the film pressure ΔΠ (1.22 to 8.80 mJ m-2, solid surface free energy ΔγS (-17.03 to -23.61 mJ m-2 and work done by spreading ΔWS (-1.23 to -11.52 mJ m-2 to be determined. The variability in these parameters is attributed to autophobing, an effect operative on a solid surface covered with an adsorptive layer of surfactants. The wetting behaviour of solid particles is of great

  13. Seasonal dynamics of 60Co uptake by freshwater algae under natural conditions

    International Nuclear Information System (INIS)

    Koulikov, N.V.; Trapeznikov, A.V.

    1988-08-01

    The data presented in the present report show that the values of 60 Co uptake coefficient in freshwater algae under naturel conditions can change 5-6 times depending on seasons, reaching maximum values in summer. Specific activity of the radionuclide in water can be essentially changed depending on the nuclear power plant operation mode. In such a nonequilibrium system it is rather questionable to use the uptake coefficient as a constant parameter for the determination of the radionuclide specific activity in water [fr

  14. Assessing maize foliar water stress levels under field conditions ...

    African Journals Online (AJOL)

    The management of spectral reflectance data to extract information of importance for plant water status has been motivated by knowledge of the availability of specific bands in the electromagnetic spectrum responsible for water absorption. The purpose of this study was to investigate the potential of using selected spectral ...

  15. Remaking "Nature". the Ecological Turn in Dutch Water Management

    NARCIS (Netherlands)

    Disco, Nil/Cornelis

    2002-01-01

    The ecological turn in water management has usually been interpreted as a political andcultural rather than technical and professional accomplishment. The dynamics of theuptake of ecological expertise into hydraulic engineering bureaucracies have not beenwell described. Focusing on the controversy

  16. Natural radionuclides in waters of the New York bight

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y H; Santschi, P H; Feely, H W [Columbia Univ., Palisades, NY (USA). Lamont-Doherty Geological Observatory; Kaufman, A; Benninger, L K [Yale Univ., New Haven, CT (USA). Dept. of Geology and Geophysics

    1981-10-01

    The half removal time of /sup 228/Th from the surface waters by settling particles, tsub(c), does not change much with season, except in the winter when regenerated /sup 228/Th as well as /sup 210/Pb and /sup 210/Po were transported back to the surface water from the bottom water and/or near-shore sediments. The removal of /sup 228/Th and /sup 210/Pb from the surface waters of New York Bight by phytoplankton-zooplankton-fecal pellet route is not important in the shelf but is important in the slope areas. The removal of /sup 210/Po is almost entirely associated with the phytoplankton-zooplankton-fecal pellet pathway throughout the New York Bight.

  17. Molecular Dynamics Simulation and Analysis of Interfacial Water at Selected Sulfide Mineral Surfaces under Anaerobic Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jiaqi; Miller, Jan D.; Dang, Liem X.

    2014-04-10

    In this paper, we report on a molecular dynamics simulation (MDS) study of the behavior of interfacial water at selected sulfide mineral surfaces under anaerobic conditions. The study revealed the interfacial water structure and wetting characteristics of the pyrite (100) surface, galena (100) surface, chalcopyrite (012) surface, sphalerite (110) surface, and molybdenite surfaces (i.e., the face, armchair-edge, and zigzag-edge surfaces), including simulated contact angles, relative number density profiles, water dipole orientations, hydrogen-bonding, and residence times. For force fields of the metal and sulfur atoms in selected sulfide minerals used in the MDS, we used the universal force field (UFF) and another set of force fields optimized by quantum chemical calculations for interactions with interfacial water molecules at selected sulfide mineral surfaces. Simulation results for the structural and dynamic properties of interfacial water molecules indicate the natural hydrophobic character for the selected sulfide mineral surfaces under anaerobic conditions as well as the relatively weak hydrophobicity for the sphalerite (110) surface and two molybdenite edge surfaces. Part of the financial support for this study was provided by the U.S. Department of Energy (DOE) under Basic Science Grant No. DE-FG-03-93ER14315. The Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (BES), of the DOE, funded work performed by Liem X. Dang. Battelle operates Pacific Northwest National Laboratory for DOE. The calculations were carried out using computer resources provided by BES. The authors are grateful to Professor Tsun-Mei Chang for valuable discussions.

  18. True Colour Classification of Natural Waters with Medium-Spectral Resolution Satellites: SeaWiFS, MODIS, MERIS and OLCI

    Directory of Open Access Journals (Sweden)

    Hendrik J. van der Woerd

    2015-10-01

    Full Text Available The colours from natural waters differ markedly over the globe, depending on the water composition and illumination conditions. The space-borne “ocean colour” instruments are operational instruments designed to retrieve important water-quality indicators, based on the measurement of water leaving radiance in a limited number (5 to 10 of narrow (≈10 nm bands. Surprisingly, the analysis of the satellite data has not yet paid attention to colour as an integral optical property that can also be retrieved from multispectral satellite data. In this paper we re-introduce colour as a valuable parameter that can be expressed mainly by the hue angle (α. Based on a set of 500 synthetic spectra covering a broad range of natural waters a simple algorithm is developed to derive the hue angle from SeaWiFS, MODIS, MERIS and OLCI data. The algorithm consists of a weighted linear sum of the remote sensing reflectance in all visual bands plus a correction term for the specific band-setting of each instrument. The algorithm is validated by a set of 603 hyperspectral measurements from inland-, coastal- and near-ocean waters. We conclude that the hue angle is a simple objective parameter of natural waters that can be retrieved uniformly for all space-borne ocean colour instruments.

  19. Evaporation and Ignition Characteristics of Water Emulsified Diesel under Conventional and Low Temperature Combustion Conditions

    Directory of Open Access Journals (Sweden)

    Zhaowen Wang

    2017-07-01

    Full Text Available The combination of emulsified diesel and low temperature combustion (LTC technology has great potential in reducing engine emissions. A visualization study on the spray and combustion characteristics of water emulsified diesel was conducted experimentally in a constant volume chamber under conventional and LTC conditions. The effects of ambient temperature on the evaporation, ignition and combustion characteristics of water emulsified diesel were studied under cold, evaporating and combustion conditions. Experimental results showed that the ambient temperature had little effect on the spray structures, in terms of the liquid core length, the spray shape and the spray area. However, higher ambient temperature slightly reduced the Sauter Mean Diameter (SMD of the spray droplets. The auto-ignition delay time increased significantly with the decrease of the ambient temperature. The ignition process always occurred at the entrainment region near the front periphery of the liquid core. This entrainment region was evolved from the early injected fuel droplets which were heated and mixed by the continuous entrainment until the local temperature and equivalence ratio reached the ignition condition. The maximum value of integrated natural flame luminosity (INFL reduced by 60% when the ambient temperature dropped from 1000 to 800 K, indicating a significant decrease of the soot emissions could be achieved by LTC combustion mode than the conventional diesel engines.

  20. Mine water pollution in Scotland. Nature, extent and preventative strategies

    Energy Technology Data Exchange (ETDEWEB)

    Younger, P.L. [Water Resource Systems Research Laboratory, Department of Civil Engineering, University of Newcastle, NE1 7RU Newcastle Upon Tyne (United Kingdom)

    2001-01-29

    Scotland was one of the world's first industrialised countries, and has therefore also been one of the first countries to experience wholesale post-industrial dereliction. Water pollution arising from abandoned mines, particularly abandoned coal mines, is second only to sewage as a source of freshwater pollution nation-wide, and in many coalfield catchments it is the pre-eminent source. Most of the pollution is due to net-alkaline ferruginous waters emerging from deep mines. Scrutiny of records from 80 deep mine discharges reveals that iron concentrations in these waters are only likely to exceed 20 mg/l, and the pH to be below 6.5, where the discharge emerges within 0.5 km of the outcrop of the shallowest mined seam. The bulk of mature near-outcrop mine water discharges in Scotland have<50 mg/l total Fe, and concentrations>100 mg/l are only likely where a marine bed lies within 25 m of the worked seam. Where the nearest marine bed is more than 80 m above or below the seam, then the total iron will be less than 4 mg/l, and in most cases less than 1 mg/l. Net-acidic mine waters are far more rare than net-alkaline waters in Scotland, and are most commonly associated with unreclaimed spoil heaps (bings). Both net-alkaline and net-acidic discharges have detrimental effects on the hydrochemistry and biological integrity of receiving waters. Scotland has recently pioneered the use of pre-emptive pump-and-treat solutions to prevent mine water pollution, and has also experienced the successful introduction of passive treatment technology for both abandoned and active workings.

  1. Physical conditions in the central region, and the nature of the engine

    International Nuclear Information System (INIS)

    Cavaliere, A.

    1983-01-01

    The phenomena associated with Active Galactic Nuclei raise three main astrophysical problems: the nature of the primary source of energy; the physical conditions within the radiation source; the nature of the population evolution over cosmological time-scales. The author outlines the links between these problems. The Prime Mover is very likely to be a converter of gravitational energy in a very compact mass configuration. The associated radiation source, if it is also very compact, is so efficient and loss-dominated as to require specific conditions for the power transport and supply to the radiating particles: collisionless, effected by electromagnetic fields coherent on scales collective or macroscopic, to the point of producing at times anisotropic bulk motions. Very compact Prime Movers working at high regimes need also a compact mass supply; the output from these compound engines undergoes a characteristic change that accounts for the type of population evolutions of the associated sources. (orig.)

  2. Theoretical analysis of effect of ocean condition on natural circulation flow

    International Nuclear Information System (INIS)

    Gong Houjun; Yang Xingtuan; Jiang Shengyao; Liu Zhiyong

    2010-01-01

    According to the simulation loop of Integrated natural circulation reactor,the mathematical model of natural circulation in non-inertial reference system is established, and the influence mechanism of ocean condition upon natural circulation is analyzed. Software is programmed to investigate the behaviors in the cases of rolling without heating power, static state with different power and rolling with heating power, and calculation results show that: the inertia force added by rolling causes the periodical fluctuating of the flow rate of channels, but it is not the direct reason of core flow fluctuation. The heave changes the driving head, and causes the same flow rate fluctuation of all channels. Inclining makes the core flow rate decrease, but the change of flow rate of different channels is different.(authors)

  3. Travel Times of Water Derived from Three Naturally Occurring Cosmogenic Radioactive Isotopes

    Science.gov (United States)

    Visser, Ate; Thaw, Melissa; Deinhart, Amanda; Bibby, Richard; Esser, Brad

    2017-04-01

    confirm a small fraction of younger (travel time responses to hydrological conditions and further characterize the catchment properties. Combined analysis of three cosmogenic tracers provides a unique insight into the functioning of the catchment and constrains the volume of subsurface water storage. Short-lived naturally occurring radioactive isotopes sulfur-35 and sodium-22 are especially useful for vulnerability assessment of springs and karst systems where a contribution of very young water is expected. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-717377

  4. Inventory of water objects for purposes of development objectives and design of natural frame of Kazan (Russia)

    Science.gov (United States)

    Mingazova, N. M.

    2018-01-01

    The article is devoted to the results of the inventory and certification of water objects in the city of Kazan in 2007-2017. Inventory of water objects contributes to the formation of the natural framework of the city, improvement of the quality of the environment, preservation of the local gene pool of flora and fauna in urban conditions. During the research, 236 small lakes, rivers and their tributaries, as well as wetlands, were identified. The environmental passports were developed for each of them. Registries of water bodies were developed for administrative regions. The inventory and certification of water objects are an effective measure in the conservation of lakes and rivers in urban conditions.

  5. How Natural is the Dissolved Inorganic Composition of Mississippi River Water?

    Science.gov (United States)

    Peucker-Ehrenbrink, B.; Johnson, S. T.; Meaux, S. J.; Brown, K.; Blum, M. J.; Allison, M. A.; Halder, J.; Wassenaar, L. I.; Cuesta, A. M.; Norris, E. S.; Wang, R. S.

    2017-12-01

    The dissolved inorganic composition of rivers provides insights into natural interactions between the hydrologic cycle and the "critical zone" of watersheds, and anthropogenic modifications thereof. For instance, major ion compositions allow us to infer how effectively weathering processes counteract increasing atmospheric CO2 concentrations. Prerequisite to such assessments is the ability to detect and correct for anthropogenic modifications of river chemistry. An observatory campaign of the Mississippi River in New Orleans from July 2015 to October 2016 with an in-situ sensor system (LOBO-SUNA) and 161 discrete water sampling events reveals systematic changes in the dissolved ion and water stable isotope compositions, nutrient loading, and physical parameters of the Mississippi River. Monthly sampling has continued since as part of the Global Rivers Observatory. We compare this high-resolution data set to long-term data generated by the USGS at St. Francisville upstream of Baton Rouge, data from the USGS Baton Rouge gaging station and in-situ sensor system, as well as other historic data. Results reveal systematic changes in major ion composition in response to hydrologic conditions. In addition to annual and interannual changes, decadal trends in concentrations of certain major ions (Na, Mg, Ca) are consistent with anthropogenic activities in the drainage basin that are reminiscent of well-known, long-term changes in nutrient fluxes that affect the northern Gulf of Mexico. Our current working hypotheses to explain observed increases in Mg and Na concentrations, for example, are contaminations from road salt, from additives used in drinking and waste water treatment, as well as from groundwater pumping, particularly in the western part of the Mississippi River basin. Uncorrected, these changes impede our abilitiy to use the current chemical composition of Mississippi River water as a quantitative indicator of natural processes in the watershed.

  6. Epigenetic Differentiation of Natural Populations of Lilium bosniacum Associated with Contrasting Habitat Conditions

    OpenAIRE

    Zoldoš, Vlatka; Biruš, Ivan; Muratović, Edina; Šatović, Zlatko; Vojta, Aleksandar; Robin, Odile; Pustahija, Fatima; Bogunić, Faruk; Vičić Bočkor, Vedrana; Siljak-Yakovlev, Sonja

    2018-01-01

    Abstract Epigenetic variation in natural populations with contrasting habitats might be an important element, in addition to the genetic variation, in plant adaptation to environmental stress. Here, we assessed genetic, epigenetic, and cytogenetic structure of the three Lilium bosniacum populations growing on distinct habitats. One population was growing under habitual ecological conditions for this species and the other two were growing under stress associated with high altitude and serpenti...

  7. Elemental concentration in fruits and leaves of chicku and mango under natural environmental conditions

    International Nuclear Information System (INIS)

    Rao, S.R.

    1979-01-01

    A knowledge of the distribution patterns of stable elements in the environment is an essential pre-requisite for understanding the problems of radioactive pollution. In this paper the data obtained under natural conditions of the environment in the case of potassium, calcium, magnesium, iron, copper, zinc, cobalt, manganese, strontium, lithium and uranium are presented. A method for elimination of the interference from phosphate in the estimation of calcium and strontium in plant materials is also described. (auth.)

  8. Evolution of nitrate level in green lettuce conventional grown under natural conditions and aquaponic system

    OpenAIRE

    Flavius Blidariu; Drasovean Alexandru; Grozea Adrian; Radulov Isidora; Lalescu Dacian

    2013-01-01

    Aquaponics integrates growing plants without soil technology with aquaculture, having an important role in recovery of nutrients from effluents. The research aimed to evaluate nitrates level in lettuce (Lactuca sativa) conventional grown under natural conditions and in integrated aquaponic system with a recirculated aquaculture system designed for pikeperch growth (Sander lucioperca). Conventional production (54 plants) has been obtained in the field without fertilizer or pesticide management...

  9. [Investigation of the distribution of water clusters in vegetables, fruits, and natural waters by flicker noise spectroscopy].

    Science.gov (United States)

    Zubov, A V; Zubov, K V; Zubov, V A

    2007-01-01

    The distribution of water clusters in fresh rain water and in rain water that was aged for 30 days (North Germany, 53 degrees 33' N, 12 degrees 47' E, 293 K, rain on 25.06.06) as well as in fresh vegetables and fruits was studied by flicker noise spectroscopy. In addition, the development of water clusters in apples and potatoes during ripening in 2006 was investigated. A different distribution of water clusters in irrigation water (river and rain) and in the biomatrix of vegetables (potatoes, onions, tomatoes, red beets) and fruits (apples, bananas) was observed. It was concluded that the cluster structure of irrigation water differs from that of water of the biomatrix of vegetables and fruits and depends on drought and the biomatrix nature. Water clusters in plants are more stable and reproducible than water clusters in natural water. The main characteristics of cluster formation in materials studied were given. The oscillation frequencies of water clusters in plants (biofield) are given at which they interact with water clusters of the Earth hydrosphere. A model of series of clusters 16(H2O)100 4(H2O)402 2(H2O)903 (H2O)1889 in the biomatrix of vegetables and fruits was discussed.

  10. Typing of the sausage-shaped bacteria forming A-type sulfur-turf according to cell length distributions of natural populations and physico-chemical conditions of hot spring waters; Saibo chobunpu to seiiku kankyo kara mita A gata io shiba shizen kotaigun ni okeru okamagata saikin no katabetsu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Aki, Y. [Iwate University, Iwate (Japan). Faculty of Humanities and Social Sciences

    1996-01-25

    In order to type the sausage-shaped bacteria forming A-type sulfur-turf, cell length distributions and physics-chemical conditions of hot spring waters were investigated on twelve samples collected from all over Japan. The frequency distributions of the cell length of eight samples were bimodal, while the other four samples were unimodal. In seven samples with bimodal distributions, two types (large and small) of the sausage-shaped bacteria could be differentiated. The cell length of the large-type was between 10.1 and 31.9{mu}m, while that of the small-type ranged 2.2 to 6.6{mu}m. The pH of seven hot spring waters were between 6 and 8, and the two types (large and small) formed together sulfur-turf. In contrast, pH of the three hot springs were over 8, and the two types of the sausage-shaped bacteria could not be detected in the sulfur-turf. Therefore, it is reasonable to set a third type of the sausage-shaped bacteria which prefers high-pH (over 8) and low calcium condition. The cell lengths of the third type were in the range of 5.5 to 8.6{mu}m, which correspond to the sausage-shaped bacteria of medium size. 20 refs., 5 figs., 2 tabs.

  11. Contributions of groundwater conditions to soil and water salinization

    Science.gov (United States)

    Salama, Ramsis B.; Otto, Claus J.; Fitzpatrick, Robert W.

    Salinization is the process whereby the concentration of dissolved salts in water and soil is increased due to natural or human-induced processes. Water is lost through one or any combination of four main mechanisms: evaporation, evapotranspiration, hydrolysis, and leakage between aquifers. Salinity increases from catchment divides to the valley floors and in the direction of groundwater flow. Salinization is explained by two main chemical models developed by the authors: weathering and deposition. These models are in agreement with the weathering and depositional geological processes that have formed soils and overburden in the catchments. Five soil-change processes in arid and semi-arid climates are associated with waterlogging and water. In all represented cases, groundwater is the main geological agent for transmitting, accumulating, and discharging salt. At a small catchment scale in South and Western Australia, water is lost through evapotranspiration and hydrolysis. Saline groundwater flows along the beds of the streams and is accumulated in paleochannels, which act as a salt repository, and finally discharges in lakes, where most of the saline groundwater is concentrated. In the hummocky terrains of the Northern Great Plains Region, Canada and USA, the localized recharge and discharge scenarios cause salinization to occur mainly in depressions, in conjunction with the formation of saline soils and seepages. On a regional scale within closed basins, this process can create playas or saline lakes. In the continental aquifers of the rift basins of Sudan, salinity increases along the groundwater flow path and forms a saline zone at the distal end. The saline zone in each rift forms a closed ridge, which coincides with the closed trough of the groundwater-level map. The saline body or bodies were formed by evaporation coupled with alkaline-earth carbonate precipitation and dissolution of capillary salts. Résumé La salinisation est le processus par lequel la

  12. A gaze-contingent display to study contrast sensitivity under natural viewing conditions

    Science.gov (United States)

    Dorr, Michael; Bex, Peter J.

    2011-03-01

    Contrast sensitivity has been extensively studied over the last decades and there are well-established models of early vision that were derived by presenting the visual system with synthetic stimuli such as sine-wave gratings near threshold contrasts. Natural scenes, however, contain a much wider distribution of orientations, spatial frequencies, and both luminance and contrast values. Furthermore, humans typically move their eyes two to three times per second under natural viewing conditions, but most laboratory experiments require subjects to maintain central fixation. We here describe a gaze-contingent display capable of performing real-time contrast modulations of video in retinal coordinates, thus allowing us to study contrast sensitivity when dynamically viewing dynamic scenes. Our system is based on a Laplacian pyramid for each frame that efficiently represents individual frequency bands. Each output pixel is then computed as a locally weighted sum of pyramid levels to introduce local contrast changes as a function of gaze. Our GPU implementation achieves real-time performance with more than 100 fps on high-resolution video (1920 by 1080 pixels) and a synthesis latency of only 1.5ms. Psychophysical data show that contrast sensitivity is greatly decreased in natural videos and under dynamic viewing conditions. Synthetic stimuli therefore only poorly characterize natural vision.

  13. WATER TRAPPING ON TIDALLY LOCKED TERRESTRIAL PLANETS REQUIRES SPECIAL CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jun; Abbot, Dorian S. [Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637 (United States); Liu, Yonggang [Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544 (United States); Hu, Yongyun, E-mail: junyang28@uchicago.edu [Laboratory for Climate and Atmosphere-Ocean Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing (China)

    2014-12-01

    Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld, we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, nightside sea ice remains O(10 m) thick and nightside water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000 m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete dayside dessiccation. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10%) of Earth's would be susceptible to complete water trapping.

  14. The CARIPANDA project: Climate change and water resources in the Adamello Natural Park of Italy

    Science.gov (United States)

    Bocchiola, D.

    2009-04-01

    The three years (2007-2009) CARIPANDA project funded by the Cariplo Foundation of Italy is aimed to evaluate scenarios for water resources in the Adamello natural Park of Italy in a window of 50 years or so (until 2050). The project is led by Ente Parco Adamello and involves Politecnico di Milano, Università Statale di Milano, Università di Brescia, and ARPA Lombardia as scientific partners, while ENEL hydropower Company of Italy joins the project as stake holder. The Adamello Natural Park is a noteworthy resource in the Italian Alps. The Adamello Group is made of several glacierized areas (c. 24 km2), of both debris covered and free ice types, including the widest Italian Glacier, named Adamello, spreading on an area of about c. 18 km2. Also the Adamello Natural Reserve, covering 217 km2 inside the Adamello Park and including the Adamello glaciers, hosts a number of high altitude safeguarded vegetal and animal species, the safety of which is a primary task of the Reserve. Project's activity involves analysis of local climate trend, field campaigns on glaciers, hydrological modelling and remote sensing of snow and ice covered areas, aimed to build a consistent model of the present hydrological conditions and of the areas. Then, properly tailored climate change projections for the area, obtained using local data driven downscaling of climate change projections from GCMs model, are used to infer the likely response to expected climate change conditions. With two years in the project now some preliminary findings can be highlighted and some preliminary trend analysis carried out. The proposed poster provides a resume of the main results of the project insofar, of interest as a benchmark for similar ongoing and foregoing projects about climate change impact on European mountainous natural areas.

  15. Experimental study on the adsorptive-distillation for dehydration of ethanol-water mixture using natural and synthetic zeolites

    Science.gov (United States)

    Megawati, Wicaksono, D.; Abdullah, M. S.

    2017-03-01

    This research studied adsorptive-distillation (AD) for dehydration of ethanol-water mixture using natural and synthetic zeolites as adsorbent for ethanol purification. Especially, the effect of purification time is recorded and studied to evaluate performance of designed AD equipment. This AD was performed in a batch condition using boiling flask covered with heating mantle and it was maintained at 78°C temperature and 1 atm pressure. The initial ethanol volume was 300 mL with 93.8% v/v concentration. The synthetic zeolite type used was zeolite 3A. The flowed vapour was condensed using water as a cooling medium. Every 5 minutes of time duration the samples were collected until the vapour could not be condensed in that condition and then be analyzed its concentration using Gas-Chromatography. Experiment shows that the designed AD equipment could increase ethanol concentration at first 5 minutes with highest ethanol concentration achieved using synthetic zeolite (97.47% v/v). However, ethanol concentration from AD process using natural zeolite only reached 96.5% v/v. Thus, synthetic zeolite as adsorbent could pass azeotropic point, but natural zeolite fail. The ratio of adsorbed water per adsorbent for natural and synthetic zeolites are about 0.023 and 0.056 gwater/gads, respectively, at 50 minutes of time. Finally, synthetic zeolite (at 55 minutes the value of C/C0 is about 0.85 and the average outlet water concentration is 4.70 mole/L) as adsorbent for AD of ethanol water is better than natural zeolite (at 55 minutes the value of C/C0 is about 0.63 and the average outlet water concentration is 6.43 mole/L).

  16. Body condition, diet and ecosystem function of red deer (Cervus elaphus in a fenced nature reserve

    Directory of Open Access Journals (Sweden)

    Camilla Fløjgaard

    2017-07-01

    Full Text Available Body condition, as a sign of animal welfare, is of management concern in rewilding projects where fenced animals are subject to winter starvation, which may conflict with animal welfare legislation. Investigating the relationship between body condition, age, sex, diet quality and diet composition is therefore relevant to increase understanding of herbivores' ecosystem function and to inform management. In this study, we focused on red deer, Cervus elaphus, in a fenced nature reserve in Denmark, where the deer are managed as ecosystem engineers to contribute to biodiversity conservation. We measured body mass and body size of 91 culled red deer, and determined diet composition using DNA metabarcoding and diet quality using fecal nitrogen on 246 fecal samples. We found that body condition was predicted by age and diet composition, but not diet quality. We also found that individuals of different body condition had different diets, i.e., the fecal samples of red deer in poorer body condition contained significantly more Ericaceae sequences than red deer in good body condition. This may imply that certain functions of red deer in ecosystems, such as regeneration of heather by grazing, may depend on variation in body condition within the population. Our findings call for the need to consider the consequences of management practices, including culling or supplemental feeding, on the outcomes of habitat restoration, and more broadly underline the importance of preserving the overall breath of herbivore ecosystem functions for effective biodiversity conservation.

  17. Theoretical investigation on the steady-state natural circulation characteristics of a new type of pressurized water reactor

    International Nuclear Information System (INIS)

    Gou Junli; Qiu Suizheng; Su Guanghui; Jia Dounan

    2006-01-01

    This article presents a theoretical investigation on the steady-state natural circulation characteristics of a new type of pressurized water reactor. Through numerically solving the one-dimensional steady-state single-phase conservative equations for the primary circuit and the steady-state two-phase drift-flux conservative equations for the secondary side of the steam generator, the natural circulation characteristics were studied. On the basis of the preliminary calculation analysis, it was found that natural circulation mass flow rate was proportional to the exponential function of the power and that the value of the exponent is related to the operating conditions of the secondary side of the steam generator. The higher the outlet pressure of the secondary side of the steam generator, the higher the primary natural circulation mass flow rate. The larger height difference between the core center and the steam generator center is favorable for the heat removal capacity of the natural circulation. (authors)

  18. Data and prediction of water content of high pressure nitrogen, methane and natural gas

    DEFF Research Database (Denmark)

    Folas, Georgios; Froyna, E.W.; Lovland, J.

    2007-01-01

    New data for the equilibrium water content of nitrogen, methane and one natural gas mixture are presented. The new binary data and existing binary sets were compared to calculated values of dew point temperature using both the CPA (Cubic-Plus-Association) EoS and the GERG-water EoS. CPA is purely...... predictive (i.e. all binary interaction parameters are set equal to 0), while GERG-water uses a temperature dependent interaction parameter fitted to published data. The GERG-water model is proposed as an ISO standard for determining the water content of natural gas. The data sets for nitrogen cover...... conclusion is that GERG-water must be used with caution outside its specified working range. For some selected natural gas mixtures the two models also perform very much alike. The water content of the mixtures decreases with increasing amount of heavier components, and it seems that both models slightly...

  19. Removal of Cu (II and Zn (II from water with natural adsorbents from cassava agroindustry residues

    Directory of Open Access Journals (Sweden)

    Daniel Schwantes

    2015-07-01

    Full Text Available Current study employs solid residues from the processing industry of the cassava (Manihot esculenta Crantz (bark, bagasse and bark + bagasse as natural adsorbents for the removal of metal ions Cu(II and Zn(II from contaminated water. The first stage comprised surface morphological characterization (SEM, determination of functional groups (IR, point of zero charge and the composition of naturally existent minerals in the biomass. Further, tests were carried out to evaluate the sorption process by kinetic, equilibrium and thermodynamic studies. The adsorbents showed a surface with favorable adsorption characteristics, with adsorption sites possibly derived from lignin, cellulose and hemicellulose. The dynamic equilibrium time for adsorption was 60 min. Results followed pseudo-second-order, Langmuir and Dubinin-Radushkevich models, suggesting a chemisorption monolayer. The thermodynamic parameters suggested that the biosorption process of Cu and Zn was endothermic, spontaneous or independent according to conditions. Results showed that the studied materials were potential biosorbents in the decontamination of water contaminated by Cu(II and Zn(II. Thus, the above practice complements the final stages of the cassava production chain of cassava, with a new disposal of solid residues from the cassava agroindustry activity.

  20. Squeezed Interstitial Water and Soil Properties in Pleistocene Blue Clays under Different Natural Environments

    Directory of Open Access Journals (Sweden)

    Maria Dolores Fidelibus

    2018-03-01

    Full Text Available Studies dating almost a century relate clay properties with the structure of the diffuse double layer (DDL, where the charged surfaces of clay crystal behave like an electric capacitor, whose dielectric is the interstitial fluid. The intensity of the inner electric field relates to the concentration and type of ions in the DDL. Other important implications of the model are less stressed: this part of the clay soil system, energetically speaking, is conservative. External contribution of energy, work of overburden or sun driven capillarity and long exposure to border low salinity waters can modify the concentration of pore-waters, thus affecting the DDL geometry, with electric field and energy storage variations. The study of clay soils coming from various natural geomorphological and hydrogeological contexts, determining a different salinity of interacting groundwater, shows how the clay interaction with freely circulating waters at the boundaries produces alterations in the native pore water salinity, and, at the nano-scale, variations of electric field and stored energy from external work. The swelling and the shrinkage of clay soil with their volumetric and geotechnical implications should be regarded as variations of the electrostatic and mechanical energy of the system. The study is based on tests on natural clay soil samples coming from a formation of stiff blue clays, widespread in southern Italy. Geotechnical identification and oedometer tests have been performed, and pore waters squeezed out from the specimens have been analyzed. Tested samples have similar grain size, clay fraction and plasticity; sorted according to the classified geomorphological/hydrogeological contexts, they highlight good correlations among dry density, mechanical work performed in selected stages of the oedometric test, swelling and non-swelling behaviour, and electrical conductivity of the squeezed pore waters. The work performed for swelling and non

  1. Toward a formal definition of water scarcity in natural human systems

    Science.gov (United States)

    W.K. Jaeger; A.J. Plantinga; H. Chang; K. Dello; G. Grant; D. Hulse; J.J. McDonnell; S. Lancaster; H. Moradkhani; A.T. Morzillo; P. Mote; A. Nolin; M. Santlemann; J. Wu

    2013-01-01

    Water scarcity may appear to be a simple concept, but it can be difficult to apply to complex natural-human systems. While aggregate scarcity indices are straightforward to compute, they do not adequately represent the spatial and temporal variations in water scarcity that arise from complex systems interactions. The uncertain effects of future climate change on water...

  2. Natural and fire-induced soil water repellency in a Portugese Shrubland

    NARCIS (Netherlands)

    Stoof, C.R.; Moore, D.; Ritsema, C.J.; Dekker, L.W.

    2011-01-01

    Post-fire land degradation is often attributed to fire-induced soil water repellency, despite the fact that soil water repellency is a natural phenomenon in many soils and is therefore not necessarily caused by fire. To improve our understanding of the role of soil water repellency in causing

  3. Theoretical research for natural circulation operational characteristic of ship nuclear machinery under ocean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yan Binghuo [Department of Nuclear Science and Engineering, Naval University of Engineering, Wuhan 430033 (China)], E-mail: yanbh1986@163.com; Yu Lei [Department of Nuclear Science and Engineering, Naval University of Engineering, Wuhan 430033 (China)], E-mail: yulei301@163.com

    2009-06-15

    Based on the two-phase drift flux model and the multi-pressure nodes matrix solving method, natural circulation thermal hydraulic analysis models for the Nuclear Machinery (NM) under ocean conditions are developed. The neutron physical activities and the responses of the reactivity control systems are described by the two-group, 3-dimensional space and time dependent neutron kinetics model. Reactivity feedback is calculated by coupling the neutron physics and thermal hydraulic codes, and is tested by comparison with experiments. Using the models developed, the natural circulation operating characteristics of NM in rolling and pitching motions and the transitions between forced circulation (FC) to natural circulation (NC) are analyzed. The results show that the influence of the rolling motion increases as the rolling amplitude is increased, and as the rolling period becomes shorter. The results also show that for this NM, with the same rolling period and rolling angle, the influence of pitching motion on natural circulation is greater than that of rolling motion. Furthermore, the oscillation period for pitching motion is the same as the pitching period, while the oscillation period for rolling is one half of the rolling period. In the ocean environment, excessive flow oscillation of the natural circulation may cause the control rods to respond so frequently that the NM would not be able to realize the transition from the FC to NC steadily. However, the influence of ocean environment on the transition from NC to FC is limited.

  4. Training of panellists for the sensory control of bottled natural mineral water in connection with water chemical properties.

    Science.gov (United States)

    Rey-Salgueiro, Ledicia; Gosálbez-García, Aitana; Pérez-Lamela, Concepción; Simal-Gándara, Jesús; Falqué-López, Elena

    2013-11-01

    As bottled mineral water market is increasing in the world (especially in emergent and developed countries), the development of a simple protocol to train a panel to evaluate sensory properties would be a useful tool for natural drinking water industry. A sensory protocol was developed to evaluate bottled natural mineral water (17 still and 10 carbonated trademarks). The tasting questionnaire included 13 attributes for still water plus overall impression and they were sorted by: colour hues, transparency and brightness, odour/aroma and taste/flavour/texture and 2 more for carbonated waters (bubbles and effervescence). The training lasted two months with, at least, 10 sessions, was adequate to evaluate bottled natural mineral water. To confirm the efficiency of the sensory training procedure two sensory groups formed the whole panel. One trained panel (6 persons) and one professional panel (6 sommeliers) and both participated simultaneously in the water tasting evaluation of 3 sample lots. Similar average scores obtained from trained and professional judges, with the same water trademarks, confirmed the usefulness of the training protocol. The differences obtained for trained panel in the first lot confirm the necessity to train always before a sensory procedure. A sensory water wheel is proposed to guide the training in bottled mineral water used for drinking, in connection with their chemical mineral content. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Using natural biomass microorganisms for drinking water denitrification.

    Science.gov (United States)

    Costa, Darleila Damasceno; Gomes, Anderson Albino; Fernandes, Mylena; Lopes da Costa Bortoluzzi, Roseli; Magalhães, Maria de Lourdes Borba; Skoronski, Everton

    2018-07-01

    Among the methods that are studied to eliminate nitrate from drinking water, biological denitrification is an attractive strategy. Although several studies report the use of denitrifying bacteria for nitrate removal, they usually involve the use of sewage sludge as biomass to obtain the microbiota. In the present study, denitrifying bacteria was isolated from bamboo, and variable parameters were controlled focusing on optimal bacterial performance followed by physicochemical analysis of water adequacy. In this way, bamboo was used as a source of denitrifying microorganisms, using either Immobilized Microorganisms (IM) or Suspended Microorganisms (SM) for nitrate removal. Denitrification parameters optimization was carried out by analysis of denitrification at different pH values, temperature, nitrate concentrations, carbon sources as well as different C/N ratios. In addition, operational stability and denitrification kinetics were evaluated. Microorganisms present in the biomass responsible for denitrification were identified as Proteus mirabilis. The denitrified water was submitted to physicochemical treatment such as coagulation and flocculation to adjust to the parameters of color and turbidity to drinking water standards. Denitrification using IM occurred with 73% efficiency in the absence of an external carbon source. The use of SM provided superior denitrification efficiency using ethanol (96.46%), glucose (98.58%) or glycerol (98.5%) as carbon source. The evaluation of the operational stability allowed 12 cycles of biomass reuse using the IM and 9 cycles using the SM. After physical-chemical treatment, only SM denitrified water remained within drinking water standards parameters of color and turbidity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Natural radioactivity of geothermal water in Beijing, China

    International Nuclear Information System (INIS)

    Shufang Wang; Chao Ye; Jiurong Liu; Pei Lin; Kai Liu; Pei Dong; Ying Sun; Yuanzhang Liu; Liya Wang; Guifang Wang

    2017-01-01

    In this work, we collected 101 geothermal water samples to investigate comprehensively the radioactivity of geothermal water in Beijing. The concentrations of gross beta, 226 Ra and 222 Rn were measured and the obtained values were in the range of 0.032-7.060, 0.023-0.363 and 0.470-29.700 Bq/L, respectively. The samples with higher concentration of 222 Rn were found to be located near large faults. The effective dose of 222 Rn in the air for three cases were calculated to be greater than radiation dose limit of 1 mSv/a. (author)

  7. Natural radiation level in drinking water in Homs city

    International Nuclear Information System (INIS)

    Shweikani, R.; Raja, Gh.

    2008-11-01

    In this study, radon concentrations were measured at the sources of drinking water and in some tap water in houses in Homs County. All measurements showed that concentrations are within the international allowed limits and there is no big difference in concentration between the sources and the houses. Also total alpha/beta and radium-226 content were measured in the samples of the sources and the houses using liquid scintillation counter. All measurements showed that concentrations are within the international allowed limits. (authors)

  8. Water uptake of clay and desert dust aerosol particles at sub- and supersaturated water vapor conditions.

    Science.gov (United States)

    Herich, Hanna; Tritscher, Torsten; Wiacek, Aldona; Gysel, Martin; Weingartner, Ernest; Lohmann, Ulrike; Baltensperger, Urs; Cziczo, Daniel J

    2009-09-28

    Airborne mineral dust particles serve as cloud condensation nuclei (CCN), thereby influencing the formation and properties of warm clouds. It is therefore of atmospheric interest how dust aerosols with different mineralogy behave when exposed to high relative humidity (RH) or supersaturation (SS) with respect to liquid water. In this study the subsaturated hygroscopic growth and the supersaturated cloud condensation nucleus activity of pure clays and real desert dust aerosols were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA) and a cloud condensation nuclei counter (CCNC), respectively. Five different illite, montmorillonite and kaolinite clay samples as well as three desert dust samples (Saharan dust (SD), Chinese dust (CD) and Arizona test dust (ATD)) were investigated. Aerosols were generated both with a wet and a dry disperser. The water uptake was parameterized via the hygroscopicity parameter kappa. The hygroscopicity of dry generated dust aerosols was found to be negligible when compared to processed atmospheric aerosols, with CCNC derived kappa values between 0.00 and 0.02 (the latter corresponds to a particle consisting of 96.7% by volume insoluble material and approximately 3.3% ammonium sulfate). Pure clay aerosols were generally found to be less hygroscopic than natural desert dust particles. The illite and montmorillonite samples had kappa approximately 0.003. The kaolinite samples were less hygroscopic and had kappa=0.001. SD (kappa=0.023) was found to be the most hygroscopic dry-generated desert dust followed by CD (kappa=0.007) and ATD (kappa=0.003). Wet-generated dust showed an increased water uptake when compared to dry-generated samples. This is considered to be an artifact introduced by redistribution of soluble material between the particles. Thus, the generation method is critically important when presenting such data. These results indicate any atmospheric processing of a fresh mineral dust particle which

  9. Quantifying the potential effects of high-volume water extractions on water resources during natural gas development: Marcellus Shale, NY

    Directory of Open Access Journals (Sweden)

    Laura C. Best

    2014-07-01

    New hydrological insights for the region: The potential effects of the withdrawal scenarios on both the water table and stream discharge were quantified. Based on these impact results, locations in the aquifer and stream networks were identified, which demonstrate particular vulnerability to increased withdrawals and their distribution. These are the locations of importance for planners and regulators who oversee water permitting, to reach a sustainable management of the water resources under changing conditions of energy and corresponding water demand.

  10. Detailed evaluation of the natural circulation mass flow rate of water propelled by using an air injection

    International Nuclear Information System (INIS)

    Park, Rae-Joon; Ha, Kwang-Soon; Kim, Jae-Cheol; Hong, Seong-Wan; Kim, Sang-Baik

    2008-01-01

    One-dimensional (1D) air-water two-phase natural circulation flow in the thermohydraulic evaluation of reactor cooling mechanism by external self-induced flow - one-dimensional' (THERMES-1D) experiment has been verified and evaluated by using the RELAP5/MOD3 computer code. Experimental results on the 1D natural circulation mass flow rate of water propelled by using an air injection have been evaluated in detail. The RELAP5 results have shown that an increase in the air injection rate to 50% of the total heat flux leads to an increase in the water circulation mass flow rate. However, an increase in the air injection rate from 50 to 100% does not affect the water circulation mass flow rate, because of the inlet area condition. As the height increases in the air injection part, the void fraction increases. However, the void fraction in the upper part of the air injector maintains a constant value. An increase in the air injection mass flow rate leads to an increase in the local void fraction, but it has no influence on the local pressure. An increase in the coolant inlet area leads to an increase in the water circulation mass flow rate. However, the water outlet area does not have an influence on the water circulation mass flow rate. As the coolant outlet moves to a lower position, the water circulation mass flow rate decreases. (author)

  11. TBA IN GROUND WATER FROM THE NATURAL BIODEGRADATION OF MTBE

    Science.gov (United States)

    At many UST spills, the concentrations of TBA in ground water are much higher than would be expected from the presence of TBA in the gasoline originally spilled. The ratio of concentrations of TBA to concentrations of MTBE in monitoring wells at gasoline spill sites was compared ...

  12. Reduction in density of suspended - sediment - laden natural waters

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desa, E.; Desa, E.; Smith, D.; Peshwe, V.B.; VijayKumar, K.; Desa, J.A.E.

    to 0.4% - 4.5%) that of the density of the same water without suspended sediment. Teh values of peff in a given site differed from one tidal cycle to another (approx equal to 1.9%). These values varied slightly (less than 0.8%) from mid-tide to slack...

  13. Enhanced Natural Convection in a Metal Layer Cooled by Boiling Water

    International Nuclear Information System (INIS)

    Cho, Jae-Seon; Suh, Kune Y.; Chung, Chang-Hyun; Park, Rae-Joon; Kim, Sang-Baik

    2004-01-01

    An experimental study is performed to investigate the natural convection heat transfer characteristics and the solidification of the molten metal pool concurrently with forced convective boiling of the overlying coolant to simulate a severe accident in a nuclear power plant. The relationship between the Nusselt number (Nu) and the Rayleigh number (Ra) in the molten metal pool region is determined and compared with the correlations in the literature and experimental data with subcooled water. Given the same Ra condition, the present experimental results for Nu of the liquid metal pool with coolant boiling are found to be higher than those predicted by the existing correlations or measured from the experiment with subcooled boiling. To quantify the observed effect of the external cooling on the natural convection heat transfer rate from the molten pool, it is proposed to include an additional dimensionless group characterizing the temperature gradients in the molten pool and in the external coolant region. Starting from the Globe and Dropkin correlation, engineering correlations are developed for the enhancement of heat transfer in the molten metal pool when cooled by an overlying coolant. The new correlations for predicting natural convection heat transfer are applicable to low-Prandtl-number (Pr) materials that are heated from below and solidified by the external coolant above. Results from this study may be used to modify the current model in severe accident analysis codes

  14. Maggie Creek Water Quality Data for Ecological Proper Functioning Condition Analysis

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data are "standard" water quality parameters collected for surface water condition analysis (for example pH, conductivity, DO, TSS). This dataset is associated...

  15. Improving the water solubility of Monascus pigments under acidic conditions with gum arabic.

    Science.gov (United States)

    Jian, Wenjie; Sun, Yuanming; Wu, Jian-Yong

    2017-07-01

    Monascus pigments (Mps) are natural food colorants and their stability in acidic solutions is important for application in the food industry. This study aimed to evaluate the use of gum arabic (GA) as a stabilizer for maintaining the solubility of Mps in an acidic aqueous solution exposed to a high temperature, and to analyze the molecular interactions between GA and Mps. Mps dispersed (0.2 g kg -1 ) in deionized water at pH 3.0-4.0 without GA formed precipitates but remained in a stable solution in the presence of GA (1 g kg -1 ). The significant improvement of Mps water solubility under acidic conditions was attributed to the formation of Mps-GA complexes, as indicated by a sharp increase in the fluorescence intensity. The results on particle size, zeta potential, and transmission electron microscopy further suggested that molecular binding of Mps to GA, electrostatic repulsion, and steric hindrance of GA were contributing factors to preventing the aggregation of Mps in acidic solutions. A mechanistic model was presented for GA-Mps interactions and complex structures. GA was proven to be an effective stabilizer of natural food colorants in acidic solutions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Non-linear time series analysis on flow instability of natural circulation under rolling motion condition

    International Nuclear Information System (INIS)

    Zhang, Wenchao; Tan, Sichao; Gao, Puzhen; Wang, Zhanwei; Zhang, Liansheng; Zhang, Hong

    2014-01-01

    Highlights: • Natural circulation flow instabilities in rolling motion are studied. • The method of non-linear time series analysis is used. • Non-linear evolution characteristic of flow instability is analyzed. • Irregular complex flow oscillations are chaotic oscillations. • The effect of rolling parameter on the threshold of chaotic oscillation is studied. - Abstract: Non-linear characteristics of natural circulation flow instabilities under rolling motion conditions were studied by the method of non-linear time series analysis. Experimental flow time series of different dimensionless power and rolling parameters were analyzed based on phase space reconstruction theory. Attractors which were reconstructed in phase space and the geometric invariants, including correlation dimension, Kolmogorov entropy and largest Lyapunov exponent, were determined. Non-linear characteristics of natural circulation flow instabilities under rolling motion conditions was studied based on the results of the geometric invariant analysis. The results indicated that the values of the geometric invariants first increase and then decrease as dimensionless power increases which indicated the non-linear characteristics of the system first enhance and then weaken. The irregular complex flow oscillation is typical chaotic oscillation because the value of geometric invariants is at maximum. The threshold of chaotic oscillation becomes larger as the rolling frequency or rolling amplitude becomes big. The main influencing factors that influence the non-linear characteristics of the natural circulation system under rolling motion are thermal driving force, flow resistance and the additional forces caused by rolling motion. The non-linear characteristics of the natural circulation system under rolling motion changes caused by the change of the feedback and coupling degree among these influencing factors when the dimensionless power or rolling parameters changes

  17. Collaborative Research for Water Resource Management under Climate Change Conditions

    Science.gov (United States)

    Brundiers, K.; Garfin, G. M.; Gober, P.; Basile, G.; Bark, R. H.

    2010-12-01

    We present an ongoing project to co-produce science and policy called Collaborative Planning for Climate Change: An Integrated Approach to Water-Planning, Climate Downscaling, and Robust Decision-Making. The project responds to motivations related to dealing with sustainability challenges in research and practice: (a) state and municipal water managers seek research that addresses their planning needs; (b) the scientific literature and funding agencies call for more meaningful engagement between science and policy communities, in ways that address user needs, while advancing basic research; and (c) empirical research contributes to methods for the design and implementation of collaborative projects. To understand how climate change might impact water resources and management in the Southwest US, our project convenes local, state, and federal water management practitioners with climate-, hydrology-, policy-, and decision scientists. Three areas of research inform this collaboration: (a) the role of paleo-hydrology in water resources scenario construction; (b) the types of uncertainties that impact decision-making beyond climate and modeling uncertainty; and (c) basin-scale statistical and dynamical downscaling of climate models to generate hydrologic projections for regional water resources planning. The project engages all participants in the research process, from research design to workshops that build capacity for understanding data generation and sources of uncertainty to the discussion of water management decision contexts. A team of “science-practice translators” facilitates the collaboration between academic and professional communities. In this presentation we contextualize the challenges and opportunities of use-inspired science-policy research collaborations by contrasting the initial project design with the process of implementation. We draw from two sources to derive lessons learned: literature on collaborative research, and evaluations provided by

  18. Field-scale water balance closure in seasonally frozen conditions

    Directory of Open Access Journals (Sweden)

    X. Pan

    2017-11-01

    Full Text Available Hydrological water balance closure is a simple concept, yet in practice it is uncommon to measure every significant term independently in the field. Here we demonstrate the degree to which the field-scale water balance can be closed using only routine field observations in a seasonally frozen prairie pasture field site in Saskatchewan, Canada. Arrays of snow and soil moisture measurements were combined with a precipitation gauge and flux tower evapotranspiration estimates. We consider three hydrologically distinct periods: the snow accumulation period over the winter, the snowmelt period in spring, and the summer growing season. In each period, we attempt to quantify the residual between net precipitation (precipitation minus evaporation and the change in field-scale storage (snow and soil moisture, while accounting for measurement uncertainties. When the residual is negligible, a simple 1-D water balance with no net drainage is adequate. When the residual is non-negligible, we must find additional processes to explain the result. We identify the hydrological fluxes which confound the 1-D water balance assumptions during different periods of the year, notably blowing snow and frozen soil moisture redistribution during the snow accumulation period, and snowmelt runoff and soil drainage during the melt period. Challenges associated with quantifying these processes, as well as uncertainties in the measurable quantities, caution against the common use of water balance residuals to estimate fluxes and constrain models in such a complex environment.

  19. Reconstruction of Redox Conditions and Productivity in Coastal Waters of the Bothnian Sea during the Holocene

    Science.gov (United States)

    Dijkstra, N.; Quintana Krupinski, N. B.; Slomp, C. P.

    2014-12-01

    Hypoxia is a growing problem in coastal waters worldwide, and is a well-known cause of benthic mortality. The semi-enclosed Baltic Sea is currently the world's largest human-induced dead zone. During the early Holocene, it experienced several periods of natural hypoxia following the intrusion of seawater into the previous freshwater lake. Recent studies suggest that at that time, the hypoxia expanded north to include the deep basin of the Bothnian Sea. In this study, we assess whether the coastal zone of the Bothnian Sea was also hypoxic during the early Holocene. We analysed a unique sediment record (0 - 30 mbsf) from the Ångermanälven estuary, which was retrieved during the International Ocean Discovery Programme (IODP) Baltic Sea Paleoenvironment Expedition 347 in 2013. Using geochemical proxies and foraminifera abundances, we reconstruct the changes in redox conditions, salinity and productivity in the estuary. Our preliminary results suggest that bottom waters in this coastal basin became anoxic upon the intrusion of brackish seawater in the early Holocene and that the productivity was elevated. The presence of benthic foraminifera in this estuary during the mid-Holocene suggests more saline conditions in the Bothnian Sea than today. Due to isostatic uplift, the estuary likely gradually became more isolated from the Bothnian Sea, which itself became more isolated from the Baltic Sea. Both factors likely explain the subsequent re-oxygenation of bottom waters and gradual refreshening of the estuary as recorded in the sediments. Interestingly, the upper meters of sediment are enriched in minerals that contain iron, phosphorus and manganese. We postulate that the refreshening of the estuary triggered the formation of these minerals, thereby increasing the phosphorus retention in these sediments and further reducing primary productivity. This enhanced retention linked to refreshening may contribute to the current oligotrophic conditions in the Bothnian Sea.

  20. Burst Speed of Wild Fishes under High-Velocity Flow Conditions Using Stamina Tunnel with Natural Guidance System in River

    Science.gov (United States)

    Izumi, Mattashi; Yamamoto, Yasuyuki; Yataya, Kenichi; Kamiyama, Kohhei

    Swimming experiments were conducted on wild fishes in a natural guidance system stamina tunnel (cylindrical pipe) installed in a fishway of a local river under high-velocity flow conditions (tunnel flow velocity : 211 to 279 cm·s-1). In this study, the swimming characteristics of fishes were observed. The results show that (1) the swimming speeds of Tribolodon hakonensis (Japanese dace), Phoxinus lagowshi steindachneri (Japanese fat-minnow), Plecoglossus altivelis (Ayu), and Zacco platypus (Pale chub) were in proportion to their body length under identical water flow velocity conditions; (2) the maximum burst speed of Japanese dace and Japanese fat-minnow (measuring 4 to 6 cm in length) was 262 to 319 cm·s-1 under high flow velocity conditions (225 to 230 cm·s-1), while the maximum burst speed of Ayu and Pale chub (measuring 5 cm to 12 cm in length) was 308 to 355 cm·s-1 under high flow velocity conditions (264 to 273 cm·s-1) ; (3) the 50cm-maximum swimming speed of swimming fishes was 1.07 times faster than the pipe-swimming speed; (4) the faster the flow velocity, the shorter the swimming distance became.

  1. MODELING THE AMBIENT CONDITION EFFECTS OF AN AIR-COOLED NATURAL CIRCULATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Rui; Lisowski, Darius D.; Bucknor, Matthew; Kraus, Adam R.; Lv, Qiuping

    2017-07-02

    The Reactor Cavity Cooling System (RCCS) is a passive safety concept under consideration for the overall safety strategy of advanced reactors such as the High Temperature Gas-Cooled Reactor (HTGR). One such variant, air-cooled RCCS, uses natural convection to drive the flow of air from outside the reactor building to remove decay heat during normal operation and accident scenarios. The Natural convection Shutdown heat removal Test Facility (NSTF) at Argonne National Laboratory (“Argonne”) is a half-scale model of the primary features of one conceptual air-cooled RCCS design. The facility was constructed to carry out highly instrumented experiments to study the performance of the RCCS concept for reactor decay heat removal that relies on natural convection cooling. Parallel modeling and simulation efforts were performed to support the design, operation, and analysis of the natural convection system. Throughout the testing program, strong influences of ambient conditions were observed in the experimental data when baseline tests were repeated under the same test procedures. Thus, significant analysis efforts were devoted to gaining a better understanding of these influences and the subsequent response of the NSTF to ambient conditions. It was determined that air humidity had negligible impacts on NSTF system performance and therefore did not warrant consideration in the models. However, temperature differences between the building exterior and interior air, along with the outside wind speed, were shown to be dominant factors. Combining the stack and wind effects together, an empirical model was developed based on theoretical considerations and using experimental data to correlate zero-power system flow rates with ambient meteorological conditions. Some coefficients in the model were obtained based on best fitting the experimental data. The predictive capability of the empirical model was demonstrated by applying it to the new set of experimental data. The

  2. A Novel Method for Culturing of Leptothrix sp. Strain OUMS1 in Natural Conditions

    Directory of Open Access Journals (Sweden)

    Tomoko Suzuki

    2012-05-01

    Full Text Available Although some strains of Leptothrix spp. isolated from aquatic environments have been characterized by culturing them in laboratory conditions, they often show morphological and chemical features distinct from those found in natural environments. To resolve this discrepancy, a novel cultivation method was devised for culturing such strains in natural groundwater. Leptothrix sp. strain OUMS1 was pre-cultured in a medium lacking Fe for 2 days, and then injected into a small dialysis tube bag and immersed in a container with continuously flowing groundwater for 1–3 and 14 days. Microscopic analysis of the initial phase of sheath formation and arbitrary comparisons with medium cultures revealed that in groundwater the surface coat of the sheath comprised much thinner fibrils, and an inner sheath wall that was much thinner and more indistinct compared with medium cultures. These differences were probably attributable to poorer secretion from the cell surface in groundwater conditions. A nutrient-rich medium likely activates cell metabolism and promotes secretion, resulting in a thicker inner sheath wall and thicker outer coat fibrils. Aqueous-phase Fe was deposited on immature sheaths in a similar manner in both cultures. These results indicate that laboratory culture of isolated microbes does not always reflect their characteristics in natural environments.

  3. Prediction of flow recirculation in a blanket assembly under worst-case natural-convection conditions

    International Nuclear Information System (INIS)

    Khan, E.U.; Rector, D.R.

    1982-01-01

    Reactor fuel and blanket assemblies within a Liquid Metal Fast Breeder Reactor (LMFBR) can be subjected to severe radial heat flux gradients. At low-flow conditions, with power-to-flow ratios of nearly the same magnitude as design conditions, buoyancy forces cause flow redistribution to the side of a bundle with the higher heat generation rate. Recirculation of fluid within a rod bundle can occur during a natural convection transient because of the combined effect of flow coastdown and buoyancy-induced redistribution. An important concern is whether recirculation leads to high coolant temperatures. For this reason, the COBRA-WC code was developed with the capability of modeling recirculating flows. Experiments have been conducted in a 2 x 6 rod bundle for flow and power transients to study recirculation in the mixed-convection (forced cooled) and natural-convection regimes. The data base developed was used to validate the recirculation module in the COBRA-WC code. COBRA-WC code calculations were made to predict flow and temperature distributions in a typical LMFBR blanket assembly for the worst-case, natural-circulation transient

  4. Monitoring the Condition of the Natural and Economic Use of Land in the Poltava Region

    Directory of Open Access Journals (Sweden)

    Shchepak Vera V.

    2017-03-01

    Full Text Available The article is aimed at monitoring the condition of the natural and economic use of land on the basis of methods for integrated evaluation as well as determining the levels of intensity of land use at the regional level. Various views on evaluation of the condition of land have been considered. As the main attributes of the intensity of land use were accepted the agro-landscape ecological stability, the anthropogenic load, the ploughness of territory, the ploughness of agricultural land, the agricultural development of territory, and the recreational capacity. On the basis of methods for integral evaluation both the subjective and the objective importance of attributes has been determined, the integral indicators of intensity of land use have been calculated. Three levels of intensity of natural and economic use of land in the districts of Poltava region have been allocated, boundaries of the quantitative values of indicators have been determined. Prospect for further research is to evaluate the intensity of natural and economic land use at the national level in order to define a strategy for the rational use and protection of land in Ukraine and to formulate the directions of development of the regional land use on the basis of system approach.

  5. Express Detection of Pentachlorophenol as Dioxins Precursor in Natural Water

    Directory of Open Access Journals (Sweden)

    Vitalia S. Krikounova

    2002-01-01

    Full Text Available A rapid detection method for the pesticide pentachlorophenol (PCP — polarization fluoroimmunoassay (PFIA — in the dynamic range of 10–9,000 ppb was developed. PCP may form polychlorinated dibenzo-p-dioxins, making environmental monitoring of this compound an issue of great importance. In order to optimize the PFIA procedure, a number of fluorescein-labeled PCP derivatives and similar compounds (tracers were synthesized, and the influence of their structure on PFIA characteristics was studied. Also, two antisera were tested in developing PFIA for PCP. The developed method is highly specific for PCP and can be used for its determination in water samples at a level down to 10 ppb. Total time of the assay for 10 samples is about 7 min. The assay provides a useful and a highly practical screening tool for the processing of large numbers of samples and for the preliminary estimation of potential dioxins contamination in water resources.

  6. REVIEW ON NATURAL METHODS FOR WASTE WATER TREATMENT

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar Dubey

    2014-01-01

    Full Text Available In Ethiopia, the most common method of disposal of waste water is by land spreading. This treatment method has numerous problems, namely high labor requirements and the potential for eutrophication of surface an d ground waters. Constructed wetlands are commonl y used for treatment of seconda ry municipal wastewaters and they have been gaining popularity for treatment of agricultural wastewaters in Ethiopia. Intermittent sand filtration may offer an alternative to traditional treatment methods. As well as providing comparable treatment performance, they also have a smaller footprint, due to the substantially higher organic loading rates that may be applied to their surfaces. Th is paper discusses the performance and design criteria of constructed wetlands for the treatment of domestic and agricultural wastewater, and sand filters for the treatment of domestic wastewater. It also proposes sand filtration as an alt ernative treatment mechanism for agricultural wa stewater and suggests design guide lines.

  7. Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters

    OpenAIRE

    Bacosa, Hernando P.; Liu, Zhanfei; Erdner, Deana L.

    2015-01-01

    Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH ...

  8. A new method for dosing rhodamine B in natural water

    International Nuclear Information System (INIS)

    Marichal, M.; Benoit, R.

    1961-01-01

    A simple and sensitive method well adapted to hydrological research. The dye is first extracted from the water sample by isoamyl alcohol and then the fluorescence of the alcoholic solution, after excitation by ultraviolet radiation, is measured spectrophotometrically. The sensitivity of the method is about 10 -12 , that is, a millionth of a milligram of dye per litre. Reprint of a paper published in 'Chimie Analytique', N. 2, Feb 1962, p. 70-72 [fr

  9. Natural groundwater recharge and water balance at the Hanford Site

    International Nuclear Information System (INIS)

    Rockhold, M.L.; Fayer, M.J.; Gee, G.W.; Kanyid, M.J.

    1990-01-01

    The purpose of this report is to present water-balance data collected in 1988 and 1989 from the 300 Area Buried Waste Test Facility and Grass Site, and the 200 East Area closed-bottom lysimeter. This report is an annual update of previous recharge status reports by Gee, Rockhold, and Downs, and Gee. Data from several other lysimeter sites are included for comparison. 43 refs., 28 figs., 7 tabs

  10. Measurements of Burnout Conditions for Flow of Boiling Water in Vertical Round Ducts (Part 2)

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Kurt M; Mathisen, R P; Eklind, O; Norman, B

    1964-01-15

    The hydrodynamic stability and the burnout conditions for flow of boiling water have been studied in a natural circulation loop in the pressure range from 10 to 70 atg. The test section was a round, duct of 20 mm inner diameter and 4890 mm heated length. The experimental results showed that within the ranges tested the stability of the flow increases with increasing pressure, increasing throttling before the test section, but decreases with increasing inlet sub-cooling and increasing throttling after the test section. The measured thresholds of instability compared well with the analytical results by Jahnberg. For an inlet sub-cooling temperature of about 2 deg C the measured burnout steam qualities were low by a factor of about 1.3 compared to forced circulation data obtained with the same test section. At higher sub-cooling temperatures the discrepancy between forced and natural circulation data increased, so that at {delta}t{sub sub} = 16 deg C, the natural circulation data were low by a factor of about 2.5. However, by applying inlet throttling of the flow the burnout values approached and finally coincided with the forced circulation data.

  11. Condition, use, and management of water resources among ...

    African Journals Online (AJOL)

    Agadaga

    2012-09-17

    Sep 17, 2012 ... Issues related to use, management and control of water resources are as ... mainly on livestock production for their livelihood while 10% of the populations are .... materials such as cement, sand and stone, mix and construct, the ... is much neglected and the people are in high risk of waterborne diseases.

  12. Public Health Risk Conditioned by Chemical Composition of Ground Water

    Science.gov (United States)

    Yankovich, E.; Osipova, N.; Yankovich, K.; Matveenko, I.

    2016-03-01

    The article studies the public health potential risk originated from water consumption and estimated on the basis of the groundwater chemical composition. We have processed the results of chemical groundwater analysis in different aquifers of Tomsk district (Tomsk Oblast, Russia). More than 8400 samples of chemical groundwater analyses were taken during long-term observation period. Human health risk assessment of exposure to contaminants in drinking water was performed in accordance with the risk assessment guidance for public health concerning chemical pollution of the environment (Russian reference number: 2.1.10.1920-04-M, 2004). Identified potential risks were estimated for consuming water of each aquifer. The comparative analysis of water quality of different aquifers was performed on the basis of the risk coefficient of the total non-carcinogenic effects. The non-carcinogenic risk for the health of the Tomsk district population due to groundwater consumption without prior sanitary treatment was admitted acceptable. A rather similar picture is observed for all aquifers, although deeper aquifers show lower hazard coefficients.

  13. Soybean response to nitrogen fertilizer under water deficit conditions

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... In order to determine the effect of water deficit and nitrogen fertilizer application on growth indices, yield and yield ... located in 39°N and 47°E longitude and has 32 m altitude. The soil ...... Stable Isotope Research (GASIR).

  14. Corrosion of aluminum cladding under optimized water conditions

    International Nuclear Information System (INIS)

    Gibbs, A.

    1992-01-01

    Experience at SRS, ORNL, BNL, and Georgia Institute of Technology involving irradiated aluminum clad fuel and target elements, as well as studies of non-irradiated aluminum indicate that some types of aluminum assemblies can be kept in a continually well-deionized water atmosphere for up to 25 years without problems. SRS experience ranges from 2.75 years for the L-1.1 charge kept in deionized D 2 O 1 to greater than 10 years for assemblies stored in the Receiving Basin for Off-site Fuel (RBOF) 2 . Experience at Georgia Institute of Technology reactor in Atlanta yielded the longest value of 25 years without problems. The common denominators in all of the reports is that the water is continually deionized to approximately 2 MΩ (2 x 10 6 ohms) resistivity and the containers for the water are stainless steel or other non-porous material. This resistivity value is equivalent to a value of 0.5 micromhos or microSiemens conductivity and is reagent grade II quality water. 3 4 tabs, 26 refs

  15. Effects of source, water conditioning and thermal treatment on ...

    African Journals Online (AJOL)

    at 15 % moisture content amounting to 61.3 MJ was the optimum thermal treatment for achieving germination of 69 %. R. heudelotii seeds soaked in water for 15 days at moisture content of 24 % over dry weight followed by thermal treatment improved germination by 22 %. The highest germination of 79 % was obtained for ...

  16. Ground-water conditions in the vicinity of Enid, Oklahoma

    Science.gov (United States)

    Schoff, Stuart L.

    1948-01-01

    This memorandum summaries matter discussed at a meeting of the City Commission of Enid, Oklahoma, on Thursday, January 15, 1948, at which the write presented a brief analysis of the ground-water resources available to the City of Enid and answered questions brought up by the commissioners.

  17. Natural analogues to the conditions around a final repository for high-level radioactive waste

    International Nuclear Information System (INIS)

    Smellie, J.A.T.

    1984-12-01

    This report documents the proceedings resulting from a Workshop held at Lake Geneva, Wisconsin, USA, from 1-3 October, 1984. The theme of the Workshop was entitled 'Natural analogues to the conditions around a final repository for high-level radioactive waste', and was restricted to ultimate disposal in a crystalline bedrock environment. The Workshop provided an important first step in co-ordinating and focussing different national and individual interests and approaches towards natural analogue studies. One of the points highlighted at the concluding forum of the meeting was the necessity to first define the geochemical processes which are assumed to occur after disposal of the radioactive waste, and then locate suitable analogue systems which can be used to test the mechanisms of one, or a simple combination of these geochemical processes. Even accepting that the choice of which geochemical process(es) to be selected for validation will be sensitive to individual national disposal strategies, farfield radionuclide retardation mechanisms in the geosphere were considered to be a central topic of importance, and should therefore be given high priority. At this early stage in the development of natural analogue studies it was not possible to cover all the important aspects. In retrospect, the role of the models should have received more attention; bridging the gap between geoscientists and the modellers was seen as being of prime importance in future meetings of this nature. (author)

  18. RECREATION MONITORING OF RESOURCE CONDITIONS IN THE KRONOTSKY STATE NATURAL BIOSPHERE PRESERVE (KAMCHATKA: AN INITIAL ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Anna Zavadskaya

    2011-01-01

    Full Text Available The paper describes assessment and monitoring program which has been designed and initiated for monitoring recreational impacts in some wildernesses areas of Kamchatka. The framework of the recreational assessment was tested through its application in a case study conducted during the summer 2008 in the Kronotsky State Natural Biosphere Preserve (the Kamchatka peninsula, Russia. The overall objective of the case study was to assess the existing campsite and trail recreation impacts and to establish a network of key sites for the subsequent long-term impact monitoring. The detailed assessment of different components of natural complexes of the Kronotsky State Natural Preserve and the obtained maps of their ecological conditions showed that some sites had been highly disturbed. The results of these works have given rise to a concern that the intensive use of these areas would make an unacceptable impact on the nature. Findings of our initial work corroborate the importance of founding wilderness management programs on knowledge about the trail and campsite impacts and emphasize the necessity of adopting the recreational assessment and monitoring framework to the practice of decision-making.

  19. Hydrochemical evidence for mixing of river water and groundwater during high-flow conditions, lower Suwannee River basin, Florida, USA

    Science.gov (United States)

    Crandall, C.A.; Katz, B.G.; Hirten, J.J.

    1999-01-01

    Karstic aquifers are highly susceptible to rapid infiltration of river water, particularly during periods of high flow. Following a period of sustained rainfall in the Suwannee River basin, Florida, USA, the stage of the Suwannee River rose from 3.0 to 5.88 m above mean sea level in April 1996 and discharge peaked at 360 m3/s. During these high-flow conditions, water from the Suwannee River migrated directly into the karstic Upper Floridan aquifer, the main source of water supply for the area. Changes in the chemical composition of groundwater were quantified using naturally occurring geochemical tracers and mass-balance modeling techniques. Mixing of river water with groundwater was indicated by a decrease in the concentrations of calcium, silica, and 222Rn; and by an increase in dissolved organic carbon (DOC), tannic acid, and chloride, compared to low-flow conditions in water from a nearby monitoring well, Wingate Sink, and Little River Springs. The proportion (fraction) of river water in groundwater ranged from 0.13 to 0.65 at Wingate Sink and from 0.5 to 0.99 at well W-17258, based on binary mixing models using various tracers. The effectiveness of a natural tracer in quantifying mixing of river water and groundwater was related to differences in tracer concentration of the two end members and how conservatively the tracer reacted in the mixed water. Solutes with similar concentrations in the two end-member waters (Na, Mg, K, Cl, SO4, SiO2) were not as effective tracers for quantifying mixing of river water and groundwater as those with larger differences in end-member concentrations (Ca, tannic acid, DOC, 222Rn, HCO3). ?? Springer-Verlag.

  20. Interdependence between natural conditions and mining in causes of landslides in the vicinity of a coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R; Rybicki, S; Palki, J

    1983-01-01

    This paper discusses effects of underground black coal mining in the Rybnik coal region in Upper Silesia on landslides. Geologic structures of a mine situated in the southern section of the Chwalowice trough are analyzed. Several landslides and events which could have influenced them are discussed. The following data on landslides are given: date, season of the year, dimensions and range of a landslide, angle of slope inclination, angle of slope inclination after a landslide, water conditions, type of soil and its mechanical properties. Investigation results are given in 7 tables. Analyses show that only some landslides were caused by underground coal mining and the remaining ones were caused by natural factors. There is a close correlation between landslide number and atmospheric precipitation (between landslides and seasons characterized by a level of atmospheric precipitation far exceeding the average). Landslides are more frequent in the case of slopes with angle of inclination exceeding 30 degrees and under conditions of soils characterized by low stability (cohesion). Underground mining is only a supplementary factor which reduces soil stability and increases water infiltration. (8 refs.)

  1. Occupants' adaptive responses and perception of thermal environment in naturally conditioned university classrooms

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Runming [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Liu, Jing [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); Li, Baizhan [The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment (Ministry of Education), Chongqing University, Chongqing 400042 (China)

    2010-03-15

    A year-long field study of the thermal environment in university classrooms was conducted from March 2005 to May 2006 in Chongqing, China. This paper presents the occupants' thermal sensation votes and discusses the occupants' adaptive response and perception of the thermal environment in a naturally conditioned space. Comparisons between the Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) have been made as well as between the Actual Percentage of Dissatisfied (APD) and Predicted Percentage of Dissatisfied (PPD). The adaptive thermal comfort zone for the naturally conditioned space for Chongqing, which has hot summer and cold winter climatic characteristics, has been proposed based on the field study results. The Chongqing adaptive comfort range is broader than that of the ASHRAE Standard 55-2004 in general, but in the extreme cold and hot months, it is narrower. The thermal conditions in classrooms in Chongqing in summer and winter are severe. Behavioural adaptation such as changing clothing, adjusting indoor air velocity, taking hot/cold drinks, etc., as well as psychological adaptation, has played a role in adapting to the thermal environment. (author)

  2. Development of a butterfly check valve model under natural circulation conditions

    International Nuclear Information System (INIS)

    Rao, Yuxian; Yu, Lei; Fu, Shengwei; Zhang, Fan

    2015-01-01

    Highlights: • Bases on Lim’s swing check valve model, a butterfly check valve model was developed. • The method to quantify the friction torque T F in Li’s model was corrected. • The developed model was implemented into the RELAP5 code and verified. - Abstract: A butterfly check valve is widely used to prevent a reverse flow in the pipe lines of a marine nuclear power plant. Under some conditions, the natural circulation conditions in particular, the fluid velocity through the butterfly check valve might become too low to hold the valve disk fully open, thereby the flow resistance of the butterfly check valve varies with the location of the valve disk and as a result the fluid flow is significantly affected by the dynamic motion of the valve disk. Simulation of a pipe line that includes some butterfly check valves, especially under natural circulation conditions, is thus complicated. This paper focuses on the development of a butterfly check valve model to enhance the capability of the thermal–hydraulic system code and the developed model is implemented into the RELAP5 code. Both steady-state calculations and transient calculations were carried out for the primary loop system of a marine nuclear power plant and the calculation results are compared with the experimental data for verification purpose. The simulation results show an agreement with the experimental data

  3. Methyl tert-butyl ether biodegradation by indigenous aquifer microorganisms under natural and artificial oxic conditions

    Science.gov (United States)

    Landmeyer, J.E.; Chapelle, F.H.; Herlong, H.H.; Bradley, P.M.

    2001-01-01

    Microbial communities indigenous to a shallow groundwater system near Beaufort, SC, degraded milligram per liter concentrations of methyl tert-butyl ether (MTBE) under natural and artificial oxic conditions. Significant MTBE biodegradation was observed where anoxic, MTBE-contaminated groundwater discharged to a concrete-lined ditch. In the anoxic groundwater adjacent to the ditch, concentrations of MTBE were > 1 mg/L. Where groundwater discharge occurs, dissolved oxygen (DO) concentrations beneath the ditch exceeded 1.0 mg/L to a depth of 1.5 m, and MTBE concentrations decreased to CO2 in laboratory liquid culture studies, with no accumulation of intermediate compounds. Upgradient of the ditch in the anoxic, MTBE and BTEX-contaminated aquifer, addition of a soluble oxygen release compound resulted in oxic conditions and rapid MTBE biodegradation by indigenous microorganisms. In an observation well located closest to the oxygen addition area, DO concentrations increased from 0.4 to 12 mg/L in <60 days and MTBE concentrations decreased from 20 to 3 mg/L. In the same time period at a downgradient observation well, DO increased from <0.2 to 2 mg/L and MTBE concentrations decreased from 30 to <5 mg/L. These results indicate that microorganisms indigenous to the groundwater system at this site can degrade milligram per liter concentrations of MTBE under natural and artificial oxic conditions.

  4. Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition

    International Nuclear Information System (INIS)

    Tollefsen, Isak; Joergensen, Ingrid K.; Woie, Leik; Fossdal, Jan E.

    2001-01-01

    Objective: In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Methods and material: Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. Conclusion: These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on

  5. Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition.

    Science.gov (United States)

    Tollefsen, I; Jørgensen, I K; Woie, L; Fossdal, J E

    2001-10-01

    In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on.

  6. Age- and Wavelength-Dependency of Drosophila Larval Phototaxis and Behavioral Responses to Natural Lighting Conditions

    Directory of Open Access Journals (Sweden)

    Simon G. Sprecher

    2017-04-01

    Full Text Available Animals use various environmental cues as key determinant for their behavioral decisions. Visual systems are hereby responsible to translate light-dependent stimuli into neuronal encoded information. Even though the larval eyes of the fruit fly Drosophila melanogaster are comparably simple, they comprise two types of photoreceptor neurons (PRs, defined by different Rhodopsin genes expressed. Recent findings support that for light avoidance Rhodopsin5 (Rh5 expressing photoreceptors are crucial, while Rhodopsin6 (Rh6 expressing photoreceptors are dispensable under laboratory conditions. However, it remains debated how animals change light preference during larval live. We show that larval negative phototaxis is age-independent as it persists in larvae from foraging to wandering developmental stages. Moreover, if spectrally different Rhodopsins are employed for the detection of different wavelength of light remains unexplored. We found that negative phototaxis can be elicit by light with wavelengths ranging from ultraviolet (UV to green. This behavior is uniquely mediated by Rh5 expressing photoreceptors, and therefore suggest that this photoreceptor-type is able to perceive UV up to green light. In contrast to laboratory our field experiments revealed that Drosophila larvae uses both types of photoreceptors under natural lighting conditions. All our results, demonstrate that Drosophila larval eyes mediate avoidance of light stimuli with a wide, ecological relevant range of quantity (intensities and quality (wavelengths. Thus, the two photoreceptor-types appear more likely to play a role in different aspects of phototaxis under natural lighting conditions, rather than color discrimination.

  7. Finding water scarcity amid abundance using human-natural system models.

    Science.gov (United States)

    Jaeger, William K; Amos, Adell; Bigelow, Daniel P; Chang, Heejun; Conklin, David R; Haggerty, Roy; Langpap, Christian; Moore, Kathleen; Mote, Philip W; Nolin, Anne W; Plantinga, Andrew J; Schwartz, Cynthia L; Tullos, Desiree; Turner, David P

    2017-11-07

    Water scarcity afflicts societies worldwide. Anticipating water shortages is vital because of water's indispensable role in social-ecological systems. But the challenge is daunting due to heterogeneity, feedbacks, and water's spatial-temporal sequencing throughout such systems. Regional system models with sufficient detail can help address this challenge. In our study, a detailed coupled human-natural system model of one such region identifies how climate change and socioeconomic growth will alter the availability and use of water in coming decades. Results demonstrate how water scarcity varies greatly across small distances and brief time periods, even in basins where water may be relatively abundant overall. Some of these results were unexpected and may appear counterintuitive to some observers. Key determinants of water scarcity are found to be the cost of transporting and storing water, society's institutions that circumscribe human choices, and the opportunity cost of water when alternative uses compete. Published under the PNAS license.

  8. Absorption of nicotine and carbon monoxide from passive smoking under natural conditions of exposure.

    Science.gov (United States)

    Jarvis, M J; Russell, M A; Feyerabend, C

    1983-01-01

    Seven non-smokers were exposed to tobacco smoke under natural conditions for two hours in a public house. Measures of nicotine and cotinine in plasma, saliva, and urine and expired air carbon monoxide all showed reliable increases. The concentrations of carbon monoxide and nicotine after exposure averaged 15.7% and 7.5% respectively of the values found in heavy smokers. Although the increase in expired air carbon monoxide of 5.9 ppm was similar to increases in smokers after a single cigarette, the amount of nicotine absorbed was between a tenth and a third of the amount taken in from one cigarette. Since this represented a relatively extreme acute natural exposure, any health risks of passive smoking probably depend less on quantitative factors than on qualitative differences between sidestream and mainstream smoke. PMID:6648864

  9. Natural organic matter interactions with polyamide and polysulfone membranes: Formation of conditioning film

    KAUST Repository

    Gutierrez, Leonardo

    2015-03-31

    A conditioning film changes the physicochemical properties of the membrane surface and strongly affects subsequent fouling behavior. Results from this Atomic Force Microscopy study indicate that Natural Organic Matter (NOM) characteristics, membrane surface properties, and solution chemistry are fundamental during conditioning film formation. Repulsive forces were observed between HUM (humic-NOM) and Polyamide (PA) or Polysulfone (PS) membranes during approach in Na+ and Ca2+ solutions. However, repulsive and attractive forces were randomly recorded during BIOP (biopolymer-NOM) approach to both membranes, possibly caused by low electrostatic repulsion, hydrogen bonding, and presence of chemically/physically heterogeneous regions on membrane surfaces. During retracting, Ca2+ ions increased HUM adhesion to PA and PS membrane, indicating cation bridging/complexation as dominant interacting mechanism for this isolate. BIOP adsorption on PS and PA membrane was stronger than HUM under similar solution conditions, where hydrogen bonding would play an important role. Additionally, irrespective of solution conditions, higher adhesion energy was recorded on PS than on PA membrane for both NOM isolates, indicating membrane hydrophobicity as an important interacting factor. Results from this research will advance our understanding of conditioning film formation for NOM isolates and membranes of different physicochemical characteristics.

  10. A Bibliography of References in Natural Water Photochemistry

    Science.gov (United States)

    1984-12-01

    Impacto ambiental do la derrama, del Pozo IXTOC-I sobre 91 zooplancton. I.P.N. Falk-Peterson, I.-B., Saethre, L. J. and LUnning, S., 1982. Toxic effects of...larvas, postlarvas, jueveniles y adultos do camaron y adultos do osti6n y pulpo por medio de biosensayos. Cientffica y Ticnica. Universidad de Sonora...spill: Flaking of surface mousse in the Gulf of Mexico . Nature 290: 235-238. Payne, J., 1984.t Physical/chemical weathering of petroleum in the marine

  11. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae in a Brazilian oligotrophic reservoir

    Directory of Open Access Journals (Sweden)

    Alejandra Filippo Gonzalez Neves dos Santos

    Full Text Available Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K and gonadosomatic index (GSI were compared according to water level (low and high. Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad development occurred in low water. Females presented higher reproductive investment than males, which allocated most of energy for somatic development. This strategy could be a mechanism to undergo the stress caused by oligotrophic characteristics of the reservoir enhanced during low water level.

  13. Mercury determination in natural waters using neutron activation analysis

    International Nuclear Information System (INIS)

    Cagnone, M.; Marques, R.O.

    1994-01-01

    Available as short communication only. An analytical method for quantitative determination of Mercury traces in river and sea water is proposed. The neutron activation method and radiochemical separation of Mercury by developing of C L 4 Hg -2 complex, and their chromatographic separation using anionic exchange resin Dowex 1 X 8 of 400 mesh is used. The quantitative determination is done by gamma spectrometric analysis. The selection limits reached with this method showed that this is an amenable procedure in routine mercury determination in the ppb level, specially useful in the environmental contamination analysis. (author). 3 refs, 2 figs, 1 tab

  14. The nature of water: Greek thought from Homer to Acusilaos.

    Science.gov (United States)

    De Santo, Rosa Maria; Bisaccia, Carmela; Cirillo, Massimo; Pollastro, Rosa Maria; Raiola, Ilaria; De Santo, Luca Salvatore

    2009-01-01

    Greek philosophy finds its roots in the myth of Homer's and Hesiod's poems and especially in Orphism which introduced the concept of a soul separated from the body with an independent principle, psiche (soul), to be rewarded or punished after death. Orphism was an important step in Greek culture. It introduced the divine into man, the soul which does not die with the body and reincarnates. From Orphism started the need of rituals capable of separating the spirit from the body. From Homer to Acusilaos, water was a very important element which connected humans and gods, long before Thales of Miletus defined it the arche.

  15. Fasting conditions: Influence of water intake on clinical chemistry analytes.

    Science.gov (United States)

    Benozzi, Silvia F; Unger, Gisela; Campion, Amparo; Pennacchiotti, Graciela L

    2018-02-15

    Currently available recommendations regarding fasting requirements before phlebotomy do not specify any maximum water intake volume permitted during the fasting period. The aim was to study the effects of 300 mL water intake 1 h before phlebotomy on specific analytes. Blood was collected from 20 women (median age (min-max): 24 (22 - 50) years) in basal state (T 0 ) and 1 h after 300 mL water intake (T 1 ). Glucose, total proteins (TP), urea, creatinine, cystatin C, total bilirubin (BT), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides (Tg), uric acid (UA), high-sensitivity C-reactive protein, gamma-glutamyl transferase (GGT), aspartate-aminotransferase (AST), alanine-aminotransferase and lactate-dehydrogenase (LD) were studied. Results were analyzed using Wilcoxon test. Mean difference (%) was calculated for each analyte and was further compared with reference change value (RCV). Only mean differences (%) higher than RCV were considered clinically significant. Significant differences (median T 0 vs median T 1 , P) were observed for TP (73 vs 74 g/L, 0.001); urea (4.08 vs 4.16 mmol/L, 0.010); BT (12 vs 13 µmol/L, 0.021); total cholesterol (4.9 vs 4.9 mmol/L, 0.042); Tg (1.05 vs 1.06 mmol/L, 0.002); UA (260 vs 270 µmol/L, 0.006); GGT (12 vs 12 U/L, 0.046); AST (22 vs 24 U/L, 0.001); and LD (364 vs 386 U/L, 0.001). Although the differences observed were statistically significant, they were not indicative of clinically significant changes. A water intake of 300 mL 1 h prior to phlebotomy does not interfere with the analytes studied in the present work.

  16. Colloid and radionuclide retention mechanisms in fractured rock under near-natural flow conditions

    International Nuclear Information System (INIS)

    Delos, A.; Schaefer, T.; Geckeis, H.; Guimera, J.; Carrera, J.; Fanghaenel, T.

    2005-01-01

    Full text of publication follows: Experiments in fractured host rock (Grimsel Test Site, GTS, Switzerland) revealed that the colloid relevance for actinide migration is high due to the specific geochemical groundwater conditions [1]. However, even under such conditions it is found that retention of colloids and colloid-borne actinides becomes significant under near-natural groundwater flow rates (1-10 m/a) [2]. Underlying mechanisms of colloid and radionuclide retention are not well understood up to now. The present study co-funded by the NoE ACTINET-6 focuses on (i) the kinetics of actinide-colloid interactions and (ii) the relevance of matrix diffusion as a competition process to other retention mechanisms which affect the actinides behavior in fractured rock systems such as the Grimsel granodiorite. Colloid migration is studied with well defined model colloids as e.g. fluorescence dyed carboxylated polystyrene particles, and natural colloids extracted from bentonite (FEBEX) and from fracture filling material (GTS). In order to study the influence of matrix porosity on actinides migration, those experiments are performed in columns of well defined geometry filled with microporous unmodified silica spheres, porous ceramic material and natural fracture filling material from the GTS. The behaviour of actinides (Pu(IV) and Am(III)) sorbed onto bentonite colloids is investigated in column and batch experiments. All experiments are performed under anoxic conditions. Colloid characterization methods used in this study include the combination of photon correlation spectroscopy (PCS), laser-induced breakdown detection (LIBD), fluorimetry and field flow fractionation (FFF). Experimental results and their application to the parametrisation of reactive colloid transport models are discussed. [1] Geckeis H, Schaefer T, Hauser W, Rabung T, Missana T, Degueldre C, Moeri A, Eikenberg J, Fierz T, Alexander WR (2004) Results of the Colloid and Radionuclide Retention experiment

  17. Bridging Mediterranean cultures in the IYS: A documentary exhibition on irrigation techniques in water scarcity conditions

    Science.gov (United States)

    Barontini, Stefano; Louki, Amina; Ben Slima, Zied; Ezzahra Ghaouch, Fatima; Labaran, Raisa; Raffelli, Giulia; Peli, Marco; Vitale, Nicola

    2015-04-01

    Brescia, an industrial city in Northern Italy, is now experiencing a crucial change in its traditional structure. In recent years in fact it has been elected as living and working seat by many foreigners and it is now one of the cities with the greatest percentage of migrants in the Country. This is an important challenge for the city and an opportunity to merge, compare and integrate different cultures to build its future. In this context some students of different Courses (engineering and medicine), belonging both to the Arabian and local community, met together and with researchers in the study team 'Al-B¯i r¯u n¯i , for culture, science and society'. The team aims at organising cultural events in which, starting from the figure of the Persian scientist Ab¯u Raih. ¯a n Al-B¯i r¯u n¯i (about 973, 1051), the contribution of the Arabian and Islamic culture to the development of the European one in the middle ages is investigated. Moving from the initial idea of the study team Al-B¯i r¯u n¯i and from the suggestions of the World Soil Day 2014 and of the International Year of Soils 2015, we built a documentary exhibition entitled 'Irrigation techniques in water scarcity conditions'. The exhibition, which stresses the importance of the irrigation techniques for the soil conservation, is focused on the idea of disseminating two main concepts, i.e. (1) the technological continuity of some water supply systems in countries, around the Mediterranean Sea, affected by similar conditions of water availability, and (2) the possibility of building environments where, due to severe or extreme climatic conditions, the sustainability is reached when the man lives in equilibrium with the nature. The exhibition, which is written in Italian and will move around in the city during all 2015, consists of about twenty posters organized into three main chapters, corresponding to three main classes of water supply systems which are common in most of the countries surrounding

  18. IMPACT OF HYDRAULIC FRACTURING ON THE QUALITY OF NATURAL WATERS

    Directory of Open Access Journals (Sweden)

    Wojciech Cel

    2017-03-01

    Full Text Available Poland, due to the estimated shale gas deposits amounting to 346-768 billion m3 has become one of the most attractive regions for shale gas exploration in Europe. Throughout the period 2010-2015, 72 exploratory drillings have been made (as of 4.01.2016 while hydraulic fracturing was carried out 25 times. Employing new drilling and shale gas prospecting technologies raises a question pertaining to their impact on the environment. The number of chemical compounds used (approximately 2000 for the production of new technological fluids may potentially pollute the environment. The fact that the composition of these fluids remains undisclosed hinders the assessment of their impact on the environment and devising optimal methods for managing this type of waste. The presented work indicates the chemical compounds which may infiltrate to groundwater, identified on the basis of technological fluids characteristics, as well as the review of studies pertaining to their impact on potable water carried out in the United States. The study focused on marking heavy metals, calcium, sodium, magnesium, potassium, chlorides and sulphates in the surface waters collected in proximity of Lewino well.

  19. THE USE OF DRINKING WATER IN THE CONDITIONS OF MAINTAINING ECOLOGICAL BALANCE

    Directory of Open Access Journals (Sweden)

    Avtandil SILAGADZE

    2016-02-01

    Full Text Available Central Caucasus is an important transit place for the "Great Silk Road"; an important role in it is assigned to the Baku-Tbilisi-Supsa and Baku-Tbilisi-Ceyhan oil pipeline, Baku-Tbilisi-Erzurum gas pipeline and the Baku-Tbilisi-Kars railway line which is at finishing stage of its construction, and others. The countries of Central Caucasus can make a meaningful contribution to the construction of the "New Silk Road" with other untapped rich natural resources. Especially attractive for investors can be the Georgian underground artesian renewable, biologically clean drinking water reserves of international importance; an effective utilization of their small part can make a significant contribution to the resolving of high quality drinking water supply problem for millions of people in Europe and Asia. After the collapse of the Soviet Union, independent post-Soviet Georgia has passed through the toughest period of reforms, conflicts and development. A significant part of its territory is still occupied, the economy is weak; the country is oriented to the European Union. In this light the country should use foreign experience and capabilities in the real sector (agriculture, mining industry .... In post-Soviet Georgia according to the current legislation, foreign investors enjoy the same rights as domestic ones. A large part of the world's population suffers from water shortages. In Georgia this resource is virtually untapped (only 0.01 is used. This resource will further rise in price on the world market of raw materials. Through the participation of foreign investors Georgia can make its contribution to the solving of the above-noted global problem in different directions: By the exploitation of freshwater resources Georgia should become a larger producer and exporter of drinking water until the problems of products transportation arise; the second part of underground water reserves should be provided to Europe and other countries through

  20. Hydrophysical conditions and periphyton in natural rivers. Analysis and predictive modelling of periphyton by changed regulations

    International Nuclear Information System (INIS)

    Stokseth, S.

    1994-10-01

    The objective of this thesis has been to examine the interaction between hydrodynamical and physical factors and the temporal and spatial dynamics of periphyton in natural steep rivers. The study strategy has been to work with quantitative system variables to be able to evaluate the potential usability of a predictive model for periphyton changes as a response to river regulations. The thesis is constituted by a theoretical and an empirical study. The theoretical study is aimed at presenting a conceptual model of the relevant factors based on an analysis of published studies. Effort has been made to evaluate and present the background material in a structured way. To concurrently handle the spatial and temporal dynamics of periphyton a new method for data collection has been developed. A procedure for quantifying the photo registrations has been developed. The simple hydrodynamical parameters were estimated from a set of standard formulas whereas the complex parameters were estimated from a three dimensional simulation model called SSIIM. The main conclusion from the analysis is that flood events are the major controlling factors wrt. periphyton biomass and that water temperature is of major importance for the periphyton resistance. Low temperature clearly increases the periphyton erosion resistance. Thus, to model or control the temporal dynamics the river periphyton, the water temperature and the frequency and size of floods should be regarded the most significant controlling factors. The data in this study has been collected from a river with a stable water quality and frequent floods. 109 refs., 41 figs., 34 tabs

  1. An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale formation.

    Science.gov (United States)

    Fontenot, Brian E; Hunt, Laura R; Hildenbrand, Zacariah L; Carlton, Doug D; Oka, Hyppolite; Walton, Jayme L; Hopkins, Dan; Osorio, Alexandra; Bjorndal, Bryan; Hu, Qinhong H; Schug, Kevin A

    2013-09-03

    Natural gas has become a leading source of alternative energy with the advent of techniques to economically extract gas reserves from deep shale formations. Here, we present an assessment of private well water quality in aquifers overlying the Barnett Shale formation of North Texas. We evaluated samples from 100 private drinking water wells using analytical chemistry techniques. Analyses revealed that arsenic, selenium, strontium and total dissolved solids (TDS) exceeded the Environmental Protection Agency's Drinking Water Maximum Contaminant Limit (MCL) in some samples from private water wells located within 3 km of active natural gas wells. Lower levels of arsenic, selenium, strontium, and barium were detected at reference sites outside the Barnett Shale region as well as sites within the Barnett Shale region located more than 3 km from active natural gas wells. Methanol and ethanol were also detected in 29% of samples. Samples exceeding MCL levels were randomly distributed within areas of active natural gas extraction, and the spatial patterns in our data suggest that elevated constituent levels could be due to a variety of factors including mobilization of natural constituents, hydrogeochemical changes from lowering of the water table, or industrial accidents such as faulty gas well casings.

  2. The natural gas air-conditioning; La climatisation au gaz naturel. Un avenir prometteur, une technique confirmee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The natural gas air-conditioning market is in growth (it will cover 10% of the market in 2002).To illustrate the possibilities of this energy source, this paper presents three examples of the natural gas air-conditioning in France. The technical aspects, the cost and the advantages of such systems are discussed. (A.L.B.)

  3. The influence of nitric oxide and mercury chloride on leaf mesophyll structure under natural drought conditions

    Directory of Open Access Journals (Sweden)

    Mykola M. Musiyenko

    2012-03-01

    Full Text Available It is established that under natural drought conditions starch was accumulated in the central part of chloroplasts of mesophyll cells and chloroplasts were localized on the periphery of cells at plasmalemma. After treatment wheat plants by nitric oxide donor the decreasing of starch deposits number and close contacts between chloroplasts were indicated, elongated nucleus was localized in the centre of cells. After treatment wheat plant by mercury chloride chloroplasts in the cells lost their oval shape and contacts, increased eventually deposition of starch, indicating the acceleration of aging tissues. Thus, nitric oxide in drought conditions reduced the destructive effect of drought on mesophyll cells, and mercury chloride caused deformation of the membrane cell.

  4. Extreme temperatures increase the deleterious consequences of inbreeding under laboratory and semi-natural conditions

    DEFF Research Database (Denmark)

    Kristensen, Torsten Nygård; Barker, J. Stuart F.; Pedersen, Kamilla Sofie

    2008-01-01

    when compared with non-inbred lines of Drosophila melanogaster under different temperature conditions. Egg-to-adult viability, developmental time and sex ratio of emerging adults are studied under low, intermediate and high temperatures under laboratory as well as semi-natural conditions. The results...... show inbreeding depression for egg-to-adult viability. The level of inbreeding depression is highly dependent on test temperature and is observed only at low and high temperatures. Inbreeding did not affect the developmental time or the sex ratio of emerging adults. However, temperature affected...... the sex ratio with more females relative to males emerging at low temperatures, suggesting that selection against males in pre-adult life stages is stronger at low temperatures. The coefficient of variation (CV) of egg-to-adult viability within and among lines is higher for inbred flies and generally...

  5. Effects of gamma radiation on the storage of domestic onions under natural conditions

    International Nuclear Information System (INIS)

    Ayyoubi, Zouhair; Sharabi, N.E.

    1993-02-01

    Local variety (red and white onions) were stored under natural conditions using gamma radiation. 30, 60, 90 and 120 Gy of doses were used in three replicates with the control. Onions were irradiated after fifteen days of harvesting. Weight reduction, internal and external sprout were recorded monthly during the storage which lasted for eight months. The results proved a positive effect of radiation in all the doses used in sprout inhibition and accepted effect statistically in limiting the loss of weight. Decrease in the occurrence and intensity of disease and insect infection have been noticed in the treatments in comparison with the control. Therefore, doses of 60 and 90 Gy have been considered to be the best in storing onions under the conditions of the experiments. (author). 5 refs., 2 figs

  6. Fate of nuclides in natural water systems. Annual progress report, April 1, 1983-March 31, 1984

    International Nuclear Information System (INIS)

    Turekian, K.K.

    1983-01-01

    This study of the behavior of nuclides in natural water systems is divided into studies of atmospheric aerosols, soils, groundwater, rivers, estuaries and coastal zones, the carbon cycle and the growth rates of marine organisms

  7. HYDROCHEMICAL CONDITIONS OF THE ŁOSOSINA RIVER WATER MANAGEMENT IN THE AREA OF TYMBARK

    OpenAIRE

    Agnieszka Policht-Latawiec; Włodzimierz Kanownik

    2015-01-01

    Sustainable use of waters requires not only determining the amount, but primarily the quality of the available water resources and developing a long-term programme of their protection. The analysis of the Łososina river water in the area of Tymbark city was presented in the paper. The water was tested in a view of the requirements as the natural fish habitat and its potential use for people supply in potable water. The river water samples were taken in 2014 at randomly selected dates, once a ...

  8. A novel start-up procedure for natural-circulation boiling water reactors

    International Nuclear Information System (INIS)

    Annalisa Manera; Frank Schaefer

    2005-01-01

    Full text of publication follows: The elimination of recirculation pumps and associated systems, as proposed for natural-circulation Boiling Water Reactors (BWRs), allow a great simplification in the design of BWRs. On the other hand, it has been shown both experimentally and analytically that such a new reactor configuration makes the system susceptible to thermal-hydraulic instabilities during the start-up phase (so-called flashing-induced instabilities). Therefore, appropriate start-up procedures have to be planned to avoid instabilities in natural-circulation BWRs. Not many proposals of start-up procedures for natural-circulation BWRs are reported in literature, but all authors agree on the fact that the system should be pressurized before the transition to two-phase circulation is allowed. Nayak [1] and Jiang and coauthors [2] proposed to externally pressurize the system by injecting in the pressure vessel respectively steam produced in a separate boiler or nitrogen. Once the pressure in the reactor vessel is high enough, the reactor power can be increased to achieve two-phase natural circulation. Unfortunately, the procedure suggested by Nayak requires an external boiler of adequate volume and power and the related connecting piping to the reactor vessel, while the procedure suggested by Jiang and coauthors requires an additional system for the nitrogen storage and the related connecting piping to the reactor vessel. The external pressurization does not accomplish to the requirements of simplicity that are at the very base of natural circulation BWRs design and it is thus not recommendable. Cheung and Rao [3] suggested a start-up procedure in which the reactor is first filled with water at 80 deg. C at a pressure of 0.55 bar. The reactor is made critical and is pressurized in conditions of single-phase circulation up to a pressure of 63 bar. At this pressure a sudden transition to two-phase operation is achieved by opening the MSIVs (Main Steam Isolation

  9. Extraction and characterisation of aqueous organic acids from natural waters

    International Nuclear Information System (INIS)

    Smith, B.; Moody, P.M.; Higgo, J.J.W.

    1993-01-01

    Humic and fulvic acids were extracted from large volumes of groundwater associated with the Broubster and Needle's Eye natural analogue sites, and the BGS research site at Drigg in Cumbria. Extractions were performed by both batchwise extraction and radial flow chromatography using DEAE-cellulose. Retained humic substances were eluted using NaOH and separated into humic and fulvic components by acidification to pH 1. After separation the humic component was purified by repetitive precipitation and dissolution whilst the fulvic component was purified by absorption chromatography. The resulting humic substances were shown to be of high purity with respect to metallic elements, with less than 1% of available sites being occupied. During elution the association of trace elements with humic substances was monitored and a high degree of association between humic substances, U and the Rare Earth Elements was noted. (author)

  10. Use of natural user interfaces in water simulations

    Science.gov (United States)

    Donchyts, G.; Baart, F.; van Dam, A.; Jagers, B.

    2013-12-01

    Conventional graphical user interfaces, used to edit input and present results of earth science models, have seen little innovation for the past two decades. In most cases model data is presented and edited using 2D projections even when working with 3D data. The emergence of 3D motion sensing technologies, such as Microsoft Kinect and LEAP Motion, opens new possibilities for user interaction by adding more degrees of freedom compared to a classical way using mouse and keyboard. Here we investigate how interaction with hydrodynamic numerical models can be improved using these new technologies. Our research hypothesis (H1) states that properly designed 3D graphical user interface paired with the 3D motion sensor can significantly reduce the time required to setup and use numerical models. In this work we have used a LEAP motion controller combined with a shallow water flow model engine D-Flow Flexible Mesh. Interacting with numerical model using hands

  11. Natural Radioactivity in Public Water supplies in Spain

    International Nuclear Information System (INIS)

    Sostoa Grodo-Pacheco, A.

    1989-01-01

    This paper present the values of the Ra-226 concentration in public water supplies from different provinces of Spain and the values of anual intake. The Ra-226 concentration is in the range of (22.31 ± 3.44) 10 5 Bq/I - (8.55 ± 0.44) 10''2 Bq/l. The annual intake is in the range of (17.80±2.75) 10''2 Bq/l- (68 ± 3.5) Bq/I. As a conclusion no health risk due to intake is expected. Also is discussed in the paper a method for determination of Ra-226 concentration. (Author) 11 ref

  12. UPLC-MS/MS determination of ptaquiloside and pterosin B in preserved natural water.

    Science.gov (United States)

    Clauson-Kaas, Frederik; Hansen, Hans Christian Bruun; Strobel, Bjarne W

    2016-11-01

    The naturally occurring carcinogen ptaquiloside and its degradation product pterosin B are found in water leaching from bracken stands. The objective of this work is to present a new sample preservation method and a fast UPLC-MS/MS method for quantification of ptaquiloside and pterosin B in environmental water samples, employing a novel internal standard. A faster, reliable, and efficient method was developed for isolation of high purity ptaquiloside and pterosin B from plant material for use as analytical standards, with purity verified by 1 H-NMR. The chemical analysis was performed by cleanup and preconcentration of samples with solid phase extraction, before analyte quantification with UPLC-MS/MS. By including gradient elution and optimizing the liquid chromatography mobile phase buffer system, a total run cycle of 5 min was achieved, with method detection limits, including preconcentration, of 8 and 4 ng/L for ptaquiloside and pterosin B, respectively. The use of loganin as internal standard improved repeatability of the determination of both analytes, though it could not be employed for sample preparation. Buffering raw water samples in situ with ammonium acetate to pH ∼5.5 decisively increased sample integrity at realistic transportation and storing conditions prior to extraction. Groundwater samples collected in November 2015 at the shallow water table below a Danish bracken stand were preserved and analyzed using the above methods, and PTA concentrations of 3.8 ± 0.24 μg/L (±sd, n = 3) were found, much higher than previously reported. Graphical abstract Workflow overview of ptaquiloside determination.

  13. Determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization

    International Nuclear Information System (INIS)

    Usenko, S.I.; Prorok, M.M.

    1992-01-01

    A method of direct determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization was developed. Concomitant elements Si, K, Mg, Na, present in natural waters in the concentration of 0.05-100 mg/cv 3 , do not produce effect on the value of boron atomic absorption. Boron determination limit constituted 0.02 mg/cm 3 for 25 ml of solution introduced

  14. Standardization of sequential separation of naturally occurring radionuclides in drinking water

    International Nuclear Information System (INIS)

    Nair, Madhu G.; Rao, D.D.; Sathyapriya, R.S.; Sarkar, P.K.

    2012-01-01

    Human are constantly exposed to radiation originating from natural or manmade sources. The main contribution for internal dose is due to radionuclides from uranium and thorium series in drinking water. The distribution of these elements varies depending on the geological and physiological characteristics of the aquifer. With increased concern for radiological safety of public, it is necessary to evaluate the naturally occurring radionuclides in the drinking water

  15. Dynamics of the near response under natural viewing conditions with an open-view sensor

    Science.gov (United States)

    Chirre, Emmanuel; Prieto, Pedro; Artal, Pablo

    2015-01-01

    We have studied the temporal dynamics of the near response (accommodation, convergence and pupil constriction) in healthy subjects when accommodation was performed under natural binocular and monocular viewing conditions. A binocular open-view multi-sensor based on an invisible infrared Hartmann-Shack sensor was used for non-invasive measurements of both eyes simultaneously in real time at 25Hz. Response times for each process under different conditions were measured. The accommodative responses for binocular vision were faster than for monocular conditions. When one eye was blocked, accommodation and convergence were triggered simultaneously and synchronized, despite the fact that no retinal disparity was available. We found that upon the onset of the near target, the unblocked eye rapidly changes its line of sight to fix it on the stimulus while the blocked eye moves in the same direction, producing the equivalent to a saccade, but then converges to the (blocked) target in synchrony with accommodation. This open-view instrument could be further used for additional experiments with other tasks and conditions. PMID:26504666

  16. Effect of boundary conditions on measured water retention behavior within soils

    Science.gov (United States)

    Galindo-torres, S.; Scheuermann, A.; Pedroso, D.; Li, L.

    2013-12-01

    The Soil Water Characteristic Curve (SWCC) is a practical representation of the behavior of soil water by relating the suction (difference between the air and water pressures to the moisture content (water saturation). The SWCC is characterized by a hysteresis loop, which is thought to be unique in that any drainage-imbibition cycle lies within a main hysteresis loop limited by two different curves for drainage and imbibition. This 'uniqueness' is the main argument for considering the SWCC as a material-intrinsic feature that characterizes the pore structure and its interaction with fluids. Models have been developed with the SWCC as input data to describe the evolution of the water saturation and the suction within soils. One example of these models is the widely used Richard's equation [1]. In this work we present a series of numerical simulations to evaluate the 'unique' nature of the SWCC. The simulations involves the use of the Lattice Boltzmann Method (LBM) [2] within a regular soil, modelling the flow behavior of two immiscible fluids: wetting and non-wetting. The soil is packed within a cubic domain to resemble the experimental setups that are commonly used for measuring the SWCC[3]. The boundary conditions ensure that the non-wetting phase enters through one cubic face and the wetting phase enters trough the opposite phase, with no flow boundary conditions in the remaining 4 cubic faces. The SWCC known features are inspected including the presence of the common limit curves for different cycles involving varying limits for the suction. For this stage of simulations, the SWCC is indeed unique. Later, different boundary conditions are applied with the two fluids each injected from 3 opposing faces into the porous medium. The effect of this boundary condition change is a net flow direction, which is different from that in the previous case. A striking result is observed when both SWCC are compared and found to be noticeable different. Further analysis is

  17. A comparison of the recruitment success of introduced and native species under natural conditions.

    Directory of Open Access Journals (Sweden)

    Habacuc Flores-Moreno

    Full Text Available It is commonly accepted that introduced species have recruitment advantages over native species. However, this idea has not been widely tested, and those studies that have compared survival of introduced and native species have produced mixed results. We compiled data from the literature on survival through germination (seed to seedling survival, early seedling survival (survival through one week from seedling emergence and survival to adulthood (survival from germination to first reproduction under natural conditions for 285 native and 63 introduced species. Contrary to expectations, we found that introduced and native species do not significantly differ in survival through germination, early seedling survival, or survival from germination to first reproduction. These comparisons remained non-significant after accounting for seed mass, longevity and when including a random effect for site. Results remained consistent after excluding naturalized species from the introduced species data set, after performing phylogenetic independent contrasts, and after accounting for the effect of life form (woody/non-woody. Although introduced species sometimes do have advantages over native species (for example, through enemy release, or greater phenotypic plasticity, our findings suggest that the overall advantage conferred by these factors is either counterbalanced by advantages of native species (such as superior adaptation to local conditions or is simply too small to be detected at a broad scale.

  18. Influences of buoyancy and thermal boundary conditions on heat transfer with naturally-induced flow

    International Nuclear Information System (INIS)

    Jackson, J.D.; Li, J.

    2002-01-01

    A fundamental study is reported of heat transfer from a vertical heated tube to air which is induced naturally upwards through it by the action of buoyancy. Measurements of local heat transfer coefficient were made using a specially designed computer-controlled power supply and measurement system for conditions of uniform wall temperature and uniform wall heat flux. The effectiveness of heat transfer proved to be much lower than for conditions of forced convection. It was found that the results could be correlated satisfactorily when presented in terms of dimensionless parameters similar to those used for free convection heat transfer from vertical surfaces provided that the heat transfer coefficients were evaluated using local fluid bulk temperature calculated utilising the measured values of flow rate induced through the system. Additional experiments were performed' with pumped flow. These covered the entire mixed convection region. It was found that the data for naturally-induced flow mapped onto the pumped flow data when presented in terms of Nusselt number ratio (mixed to forced) and buoyancy parameter. Computational simulations of the experiments were performed using an advanced computer code which incorporated a buoyancy-influenced, variable property, developing wall shear flow formulation and a low Reynolds number k-ε turbulence model. These reproduced observed behaviour quite well. (author)

  19. Alternative geometry for cylindrical natural draft cooling tower with higher cooling efficiency under crosswind condition

    International Nuclear Information System (INIS)

    Goodarzi, M.; Ramezanpour, R.

    2014-01-01

    Highlights: • Alternative cross sections for natural draft cooling tower were proposed. • Numerical solution was applied to study thermal and hydraulic performances. • Thermal and hydraulic performances were assessed by comparative parameters. • Cooling tower with elliptical cross section had better thermal performance under crosswind. • It could successfully used at the regions with invariant wind direction. - Abstract: Cooling efficiency of a natural draft dry cooling tower may significantly decrease under crosswind condition. Therefore, many researchers attempted to improve the cooling efficiency under this condition by using structural or mechanical facilities. In this article, alternative shell geometry with elliptical cross section is proposed for this type of cooling tower instead of usual shell geometry with circular cross section. Thermal performance and cooling efficiency of the two types of cooling towers are numerically investigated. Numerical simulations show that cooling tower with elliptical cross section improves the cooling efficiency compared to the usual type with circular cross section under high-speed wind moving normal to the longitudinal diameter of the elliptical cooling tower

  20. Impact of possible climate changes on river runoff under different natural conditions

    Science.gov (United States)

    Gusev, Yeugeniy M.; Nasonova, Olga N.; Kovalev, Evgeny E.; Ayzel, Georgy V.

    2018-06-01

    The present study was carried out within the framework of the International Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) for 11 large river basins located in different continents of the globe under a wide variety of natural conditions. The aim of the study was to investigate possible changes in various characteristics of annual river runoff (mean values, standard deviations, frequency of extreme annual runoff) up to 2100 on the basis of application of the land surface model SWAP and meteorological projections simulated by five General Circulation Models (GCMs) according to four RCP scenarios. Analysis of the obtained results has shown that changes in climatic runoff are different (both in magnitude and sign) for the river basins located in different regions of the planet due to differences in natural (primarily climatic) conditions. The climatic elasticities of river runoff to changes in air temperature and precipitation were estimated that makes it possible, as the first approximation, to project changes in climatic values of annual runoff, using the projected changes in mean annual air temperature and annual precipitation for the river basins. It was found that for most rivers under study, the frequency of occurrence of extreme runoff values increases. This is true both for extremely high runoff (when the projected climatic runoff increases) and for extremely low values (when the projected climatic runoff decreases).

  1. Super-emitters in natural gas infrastructure are caused by abnormal process conditions

    Science.gov (United States)

    Zavala-Araiza, Daniel; Alvarez, Ramón A.; Lyon, David R.; Allen, David T.; Marchese, Anthony J.; Zimmerle, Daniel J.; Hamburg, Steven P.

    2017-01-01

    Effectively mitigating methane emissions from the natural gas supply chain requires addressing the disproportionate influence of high-emitting sources. Here we use a Monte Carlo simulation to aggregate methane emissions from all components on natural gas production sites in the Barnett Shale production region (Texas). Our total emission estimates are two-thirds of those derived from independent site-based measurements. Although some high-emitting operations occur by design (condensate flashing and liquid unloadings), they occur more than an order of magnitude less frequently than required to explain the reported frequency at which high site-based emissions are observed. We conclude that the occurrence of abnormal process conditions (for example, malfunctions upstream of the point of emissions; equipment issues) cause additional emissions that explain the gap between component-based and site-based emissions. Such abnormal conditions can cause a substantial proportion of a site's gas production to be emitted to the atmosphere and are the defining attribute of super-emitting sites.

  2. Demonstration of the Tilting of the Gas-Water Interface under Hydrodynamic Conditions.

    Science.gov (United States)

    Gretener, P. E.

    1979-01-01

    Describes the construction of an apparatus to demonstrate the tilting of an oil-water, gas-water, or gas-oil interface when the subsurface reservoir is under hydrodynamic conditions (i.e., when conditions of lateral flow exist). The model can be constructed of readily-available materials. (RE)

  3. Experimental Observations of Natural Circulation Flow in the NSTF at Steady-State Conditions

    International Nuclear Information System (INIS)

    Lisowski, Darius D.; Farmer, Mitch T.

    2014-01-01

    A ½ scale test facility has been constructed at Argonne National Laboratory (ANL) to study the heat removal performance and natural circulation flow patterns in a Reactor Cavity Cooling System (RCCS). Our test facility, the Natural convection Shutdown heat removal Test Facility (NSTF), supports the broader goal of developing an inherently safe and fully passive ex-vessel decay heat removal for advanced reactor designs. The project, initiated in 2010 to support the Advanced Reactor Concepts (ARC), Small Modular Reactor (SMR), and Next Generation Nuclear Plant (NGNP) programs, has been conducting experimental operations since early 2014. The following paper provides a summary of some primary design features of the 26-m tall test facility along with a description of the data acquisition suite that guides our experimental practices. Specifics of the distributed fiber optic temperature measurements will be discussed, which introduces an unparalleled level of data density that has never before been implemented in a large scale natural circulation test facility. Results from our first test series will then be presented, which provide insight into the thermal hydraulic behavior at steady-state conditions for varying heat flux levels and exhaust chimney configuration states. (author)

  4. Historical metal pollution in natural gudgeon populations: Inferences from allozyme, microsatellite and condition factor analysis

    International Nuclear Information System (INIS)

    Knapen, Dries; De Wolf, Hans; Knaepkens, Guy; Bervoets, Lieven; Eens, Marcel; Blust, Ronny; Verheyen, Erik

    2009-01-01

    This study presents the results of a microsatellite and allozyme analysis on natural populations of the gudgeon (Gobio gobio) located in a pollution gradient of cadmium and zinc. Differences among contaminated and reference populations were observed at 2 allozyme loci, as well as a relationship between the fish condition factor and glucose-6-phosphate dehydrogenase genotypes, the locus that showed the largest difference in allele frequencies. The microsatellite data partly confirmed the differentiation pattern that was revealed by the allozyme survey. Our data further suggest that at least 2 microsatellite loci may be affected by natural selection. We thus illustrate that both microsatellite and allozyme loci do not necessarily behave as selectively neutral markers in polluted populations. Estimates of population differentiation can therefore be significantly different depending on which loci are being studied. Finally, these results are discussed in the light of the conservation unit concept, because microsatellites are often used to assess genetic variation in endangered natural populations and to propose measures for conservation or management.

  5. Kinetics of Natural Attenuation: Review of the Critical Chemical Conditions and Measurements at Bore Scale

    Directory of Open Access Journals (Sweden)

    O. Atteia

    2002-01-01

    Full Text Available This paper describes the chemical conditions that should favour the biodegradation of organic pollutants. Thermodynamic considerations help to define the reaction that can occur under defined chemical conditions. The BTEX (benzene, toluene, ethylbenzene, and xylene degradation is focused on benzene, as it is the most toxic oil component and also because it has the slowest degradation rate under most field conditions. Several studies on benzene degradation allow the understanding of the basic degradation mechanisms and their importance in field conditions. The use of models is needed to interpret field data when transport, retardation, and degradation occur. A detailed comparison of two existing models shows that the limits imposed by oxygen transport must be simulated precisely to reach correct plumes shapes and dimensions, and that first-order kinetic approaches may be misleading. This analysis led us to develop a technique to measure directly biodegradation in the field. The technique to recirculate water at the borehole scale and the CO2 analysis are depicted. First results of biodegradation show that this technique is able to easily detect the degradation of 1 mg/l of hydrocarbons and that, in oxic media, a fast degradation rate of mixed fuel is observed.

  6. Simulation of Two-Phase Natural Circulation Loop for Core Cather Cooling Using Air Water

    International Nuclear Information System (INIS)

    Revankar, S. T.; Huang, S. F.; Song, K. W.; Rhee, B. W.; Park, R. J.; Song, J. H.

    2012-01-01

    A closed loop natural circulation system employs thermally induced density gradients in single phase or two-phase liquid form to induce circulation of the working fluid thereby obviating the need for any mechanical moving parts such as pumps and pump controls. This increases the reliability and safety of the cooling system and reduces installation, operation and maintenance costs. That is the reason natural circulation cooling has been considered in advanced reactor core cooling and in engineered safety systems. Natural circulation cooling has been proposed to remove reactor decay heat by external vessel cooling for in-vessel core retention during sever accident scenario. Recently in APR1400 reactor core catcher design natural circulation cooling is proposed to stabilize and cool the corium ejected from the reactor vessel following core melt and breach of reactor vessel. The natural circulation flow is similar to external vessel cooling where water flows through an inclined narrow gap below hot surface and is heated to produce boiling. The two-phase natural circulation enables cooling of the corium pool collected on core catcher. Due to importance of this problem this paper focuses simulation of the two-phase natural circulation through inclined gap using air-water system. Scaling criteria for air-water loop are derived that enable simulation of the flow regimes and natural circulation flow rates in such systems using air-water system

  7. 78 FR 64905 - Carriage of Conditionally Permitted Shale Gas Extraction Waste Water in Bulk

    Science.gov (United States)

    2013-10-30

    ...-ZA31 Carriage of Conditionally Permitted Shale Gas Extraction Waste Water in Bulk AGENCY: Coast Guard... availability of a proposed policy letter concerning the carriage of shale gas extraction waste water in bulk... transport shale gas extraction waste water in bulk. The policy letter also defines the information the Coast...

  8. Subsurface Water as Natural CO{sub 2} Sink

    Energy Technology Data Exchange (ETDEWEB)

    Gillon, M. [Centre National de la Recherche Scientifique (UMR CNRS 8148-IDES), Interaction et Dynamique des Environnements de Surface, Universite Paris 11 and Centre National de la Recherche Scientifique (UMR UAPV-INRA EMMAH), Environnement Mediterraneen et Modelisation des Agro-Hydrosystemes, Universite d' Avignon et des Pays de Vaucluse, Avignon, (France); Barbecot, F.; Gibert, E.; Massault, M. [Centre National de La Recherche Scientifique (UMR CNRS 8148-IDES), Interaction et Dynamique des Environnements de Surface, Universite Paris 11 (France)

    2013-07-15

    In aquifer recharge areas, groundwater mineralization acts as an important sink for CO{sub 2} (assessed at 100 Mt{sub co2}/a on a European scale). An isotopic study of C fluxes in the unsaturated zone of a sand carbonate aquifer shows that the physical and geochemical processes controlling CO{sub 2} abstraction induce changes in the isotopic composition of both dissolved and matrix carbonates. An integrated record of these fluxes toward the aquifers is evidenced through isotopic investigation of the recharge areas. It is evidenced that the unsaturated zone represents an archive of pristine conditions, and would help to quantify downward C fluxes and environmental changes related to this CO{sub 2} abstraction process. (author)

  9. Presence and patterns of alkaline phosphatase activity and phosphorus cycling in natural riparian zones under changing nutrient conditions

    Directory of Open Access Journals (Sweden)

    Peifang Wang

    2014-08-01

    Full Text Available Phosphorus (P is an important limiting nutrient in aquatic ecosystems and knowledge of P cycling is fundamental for reducing harmful algae blooms and other negative effects in water. Despite their importance, the characteristics of P cycling under changing nutrient conditions in shallow lakes were poorly investigated. In this study, in situ incubation experiments were conducted in a natural riparian zone in the main diversion channel used for water transfer into Lake Taihu (Wangyu River. Variations in microbial biomass, dissolved P fractions (organic and inorganic, and alkaline phosphatase activity (bulk APA and specific APA were determined after incubation with and without the addition of P and nitrogen (N (4 total water treatments: +P, +N, +NP, and control. Experiments were conducted during two seasons (late spring and early fall to account for natural differences in nutrient levels that may occur in situ. Our results demonstrated that low levels of DRP may not necessarily indicate P limitation. Phytoplankton exhibited “serial N limitation with P stress” in May, such that chlorophyll a (Chl a increased significantly with N addition, while the limiting nutrient shifted to P in October and phytoplankton biomass increased with P addition. Phytoplankton contributed greatly to APA production and was significantly influenced by P bioavailability, yet high levels of bulk APA were also not necessarily indicative of P limitation. In contrast to phytoplankton, bacteria were less P stressed. As a consequence of enhanced utilization of dissolved reactive P (DRP and dissolved organic P (DOP, +N treatment elevated APA significantly. By contrast, APA could be repressed to low values and phytoplankton converted a large portion of DRP to DOP with P addition. But this was not consistent with bacteria APA (bact-APA in the absence or presence of abundant phytoplankton biomass. The correlation between bulk APA and DRP was good at separate sites and discrepant

  10. The performance of BAF using natural zeolite as filter media under conditions of low temperature and ammonium shock load

    International Nuclear Information System (INIS)

    He Shengbing; Xue Gang; Kong Hainan

    2007-01-01

    Natural zeolite and expanded clay were used as filter media for biological aerated filter (BAF) to treat municipal wastewater in parallel in whole three test stages. The stage one test results revealed that zeolite BAF and expanded clay BAF have COD and NH 3 -N removals in the range of 84.63-93.11%, 85.74-96.26%, 82.34-93.71%, and 85.06-93.2%, respectively, under the conditions of water temperature of 20-25 deg. C and hydraulic load of 2-3 m 3 /(m 2 h). At the following stage two, the influent NH 3 -N concentration was increased to about double value of the stage one, and it was investigated that the effluent NH 3 -N of expanded clay BAF increased significantly and then gradually restored to normal condition in 2 weeks, while the effluent NH 3 -N of zeolite BAF kept stable. At stage three, the low reactor temperature has also different effects on these two BAFs, under conditions of water temperature of 7-10 deg. C, hydraulic load of 2-3 m 3 /(m 2 h), zeolite BAF and expanded clay BAF have COD and NH 3 -N removals in the range of 74.5-88.47% (average of 81.57%), 71.73-88.49% (average of 81.06%), 71.91-87.76% (average of 80.49%), and 38.41-77.17% (average of 65.42%), respectively. Three stages test results indicated that the zeolite BAF has a stronger adaptability to NH 3 -N shock load and low temperature compared to expanded clay BAF. In addition, the detection of the amounts of heterobacteria and nitrobacteria of two biological aerated filters in three stages also showed the zeolite filter media was more suitable to the attached growth of nitrobacteria, which is helpful to the improvement of nitrification performance in zeolite BAF

  11. Participation of the Halogens in Photochemical Reactions in Natural and Treated Waters

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2017-10-01

    Full Text Available Halide ions are ubiquitous in natural waters and wastewaters. Halogens play an important and complex role in environmental photochemical processes and in reactions taking place during photochemical water treatment. While inert to solar wavelengths, halides can be converted into radical and non-radical reactive halogen species (RHS by sensitized photolysis and by reactions with secondary reactive oxygen species (ROS produced through sunlight-initiated reactions in water and atmospheric aerosols, such as hydroxyl radical, ozone, and nitrate radical. In photochemical advanced oxidation processes for water treatment, RHS can be generated by UV photolysis and by reactions of halides with hydroxyl radicals, sulfate radicals, ozone, and other ROS. RHS are reactive toward organic compounds, and some reactions lead to incorporation of halogen into byproducts. Recent studies indicate that halides, or the RHS derived from them, affect the concentrations of photogenerated reactive oxygen species (ROS and other reactive species; influence the photobleaching of dissolved natural organic matter (DOM; alter the rates and products of pollutant transformations; lead to covalent incorporation of halogen into small natural molecules, DOM, and pollutants; and give rise to certain halogen oxides of concern as water contaminants. The complex and colorful chemistry of halogen in waters will be summarized in detail and the implications of this chemistry for global biogeochemical cycling of halogen, contaminant fate in natural waters, and water purification technologies will be discussed.

  12. Alpha low activity determination from limitter isotopes of uranium, thorium ands radium in natural waters

    International Nuclear Information System (INIS)

    Gascon, J.L.; Crespo, M.T.; Acena, M.L.

    1989-01-01

    A method to concentrate uranium, thorium and radium in natural waters has been developed. The method, based on the adsorbing propert-ies of manganes dioxide, has been applied to determine the alpha emitter isotopes of these elements in drinking water of Madrid. In this work we present the description of the method, the analytical procedu-res and the obtained results. (Author)

  13. Steam drum level dynamics in a multiple loop natural circulation system of a pressure-tube type boiling water reactor

    International Nuclear Information System (INIS)

    Jain, Vikas; Kulkarni, P.P.; Nayak, A.K.; Vijayan, P.K.; Saha, D.; Sinha, R.K.

    2011-01-01

    Highlights: → We have highlighted the problem of drum level dynamics in a multiple loop type NC system using RELAP5 code. → The need of interconnections in steam and liquid spaces close to drum is established. → The steam space interconnections equalize pressure and liquid space interconnections equalize level. → With this scheme, the system can withstand anomalous conditions. → However, the controller is found to be inevitable for inventory balance. - Abstract: Advanced Heavy Water Reactor (AHWR) is a pressure tube type boiling water reactor employing natural circulation as the mode of heat removal under all the operating conditions. Main heat transport system (MHTS) of AHWR is essentially a multi-loop natural circulation system with all the loops connected to each other. Each loop of MHTS has a steam drum that provides for gravity based steam-water separation. Steam drum level is a very critical parameter especially in multi-loop natural circulation systems as large departures from the set point may lead to ineffective separation of steam-water or may affect the driving head. However, such a system is susceptible to steam drum level anomalies under postulated asymmetrical operating conditions among the different quadrants of the core like feedwater flow distribution anomaly among the steam drums or power anomaly among the core quadrants. Analyses were carried out to probe such scenarios and unravel the underlying dynamics of steam drum level using system code RELAP5/Mod3.2. In addition, a scheme to obviate such problem in a passive manner without dependence on level controller was examined. It was concluded that steam drums need to be connected in the liquid as well as steam space to make the system tolerant to asymmetrical operating conditions.

  14. Energy behavior of solar hot water systems under different conditions

    International Nuclear Information System (INIS)

    Fuentes Lombá, Osmanys; Torres Ten, Alonso; Arzuaga Machado, Yusnel; Hernández, Massipe J. Raúl; Cueva Gonzales, Wagner

    2017-01-01

    By means of numerical simulations in TRNSYS v14 the influence of the solar absorption area of a system for heating water with solar energy, composed by a flat solar collector and a tank thermo-accumulator, on its energy efficiency. For the study, the solar collectors EDWARDS, ISOFOTÓN 1, ISOFOTÓN 2, MADE, ROLDAN and IBERSOLAR of absorption area 2, 1,9, 1,88, 2, 1,9 and 2,3 m2 respectively were chosen. For each collector, the energy performance was simulated for one year, setting 200 L for the accumulation volume and 50 °C for the intake temperature. Despite the different characteristics of each collector, their behavior is quite similar showing a very mature technology. (author)

  15. Using reverse osmosis to remove natural organic matter from power plant makeup water

    International Nuclear Information System (INIS)

    Mattaraj, S.; Kilduff, J.E.

    2003-01-01

    A field-scale reverse osmosis (RO) system was used to remove salts and natural organic matter (NOM) from a surface water source. The RO membrane exhibited an NOM solution hydraulic permeability of 8.33 x 10 -9 m x s -1 x kPa -1 , about 6% less than the clean water value, over pressures ranging from 414 to 1 000 kPa (60 to 145 psi). The rejection of salt and NOM were greater than 98% and 99%, respectively. Under controlled laboratory conditions, greater than 99% mass recovery of NOM could be obtained. A small fraction of NOM was not recovered using hydrodynamic cleaning but could be recovered with chemical cleaning (NaOH wash solution). The mass recovered in the NaOH solution increased from 6% with increasing transmembrane pressures from 414 kPa to 1 000 kPa, respectively. This is consistent with fouling that results from an increase in solution flux, and a concomitant decrease in tangential crossflow velocity. (orig.)

  16. Time evolution simulation of heat removal in a small water tank by natural convection

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Carlos Alberto de, E-mail: carlos.freitas1950@hotmail.com [Instituto Federal do Rio de Janeiro (IFRJ), Nilopolis, RJ (Brazil); Jachic, Joao; Moreira, Maria de Lourdes, E-mail: jjachic@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    One of the cooling modes for any source of heat such as in a shutdown nuclear core is the natural convection. The design specifications of any cooling pool can only be done when the removal heat rate and the corresponding mass flow rate is reasonably established. In our simulation scheme, we assumed that the body forces acting in the cubic water cell are: the weight, the drag force and the integrated pressure forces on the horizontal surfaces, the viscosity shear forces on the vertical surfaces and also a special viscosity drag force due to the mass dislocation along a Bernoulli type current tube outside the motive region. For a suitable time step, the uprising convection velocity is determined by an implicit and also by an explicit solution algorithm. The resulting differential equation depends on updating specific mass, dynamic viscosity and constant pressure heat coefficient with the last known temperature in the cell that absorbed heat. Numerical calculation software was performed using MATLAB’s technical computing language and then applied for a heat generation plate simulating a spent fuel assembler from a shutdown nuclear core. The results show time evolution of convection, terminal velocity and water temperature distribution. Pool dimension as well as pool level decrement are also determined for various air exhausting system conditions and heat rate of the spent fuel plate being cooled. (author)

  17. Time evolution simulation of heat removal in a small water tank by natural convection

    International Nuclear Information System (INIS)

    Freitas, Carlos Alberto de; Jachic, Joao; Moreira, Maria de Lourdes

    2013-01-01

    One of the cooling modes for any source of heat such as in a shutdown nuclear core is the natural convection. The design specifications of any cooling pool can only be done when the removal heat rate and the corresponding mass flow rate is reasonably established. In our simulation scheme, we assumed that the body forces acting in the cubic water cell are: the weight, the drag force and the integrated pressure forces on the horizontal surfaces, the viscosity shear forces on the vertical surfaces and also a special viscosity drag force due to the mass dislocation along a Bernoulli type current tube outside the motive region. For a suitable time step, the uprising convection velocity is determined by an implicit and also by an explicit solution algorithm. The resulting differential equation depends on updating specific mass, dynamic viscosity and constant pressure heat coefficient with the last known temperature in the cell that absorbed heat. Numerical calculation software was performed using MATLAB’s technical computing language and then applied for a heat generation plate simulating a spent fuel assembler from a shutdown nuclear core. The results show time evolution of convection, terminal velocity and water temperature distribution. Pool dimension as well as pool level decrement are also determined for various air exhausting system conditions and heat rate of the spent fuel plate being cooled. (author)

  18. Alteration of borosilicate glass under water saturated condition

    International Nuclear Information System (INIS)

    Tsukimura, K.; Matsuhisa, Y.; Kanai, Y.; Hirai, H.

    1991-01-01

    In the long term of the high-level nuclear waste disposal, the dissolving rates of radionuclides from the waste will be controlled by crystalline phases secondarily formed in the borosilicate glass by reaction with ground water. We have determined the crystalline phases formed from borosilicate glass in a hydrothermal experiment. Borosilicate glass powder (50 mg, Si 40 B 20 Al 4 Li 12 Na 14 K 3 Ca 2 Fe 5 O 140 ) and 200 ml of water were reacted at 300degC and 300 bars for 2 weeks with a cold-seal type hydrothermal high pressure apparatus. After the reaction the liquid phase was analyzed with atomic absorption spectroscopy and the solid phases with x-ray powder diffraction and analytical electron microscopy. The liquid phase contains 58 % of Na, 14 % of Li and 11 % of K but less than 1 % of Ca and Fe. The solid phases were found to be zeolite and smectite. The zeolite is isostructural with analcime Na 2 Al 2 (SiO 3 ) 4 · 2H 2 O or wairakite CaAl 2 (SiO 3 ) 4 · 2H 2 O and contains Ca and Si as major constituents but does not contain Al. Although no direct analytical evidence is available, logical induction of the experimental results indicates that the chemical composition of the zeolite is CaB 2 (SiO 3 ) 4 . The remaining x-ray powder diffraction peaks are same as those of smectite Na 06.7 (Al 3.33 Mg 0.67 )Si 8 O 20 (OH) 4 . However, since our starting material was free of Mg, and Na was not detected by AEM, the smectite may contain Fe instead of Mg, and Li instead of Na. (author)

  19. Investigation of Natural Radioactivity in the Tap and Spring Water in Yaounde Town, Cameroon

    International Nuclear Information System (INIS)

    Lydie, R.M.; Hakam, O.K.; Choukri, A.; Lydie, R.M.; Hakam, O.K.; Choukri, A.

    2013-01-01

    The natural radionuclide concentrations in the tap and springs water in Yaounde town, capital of Cameroon with a population of 3.5 million inhabitants were estimated by gamma spectrometry, using both well calibrated Canberra NaI(Tl) and HPGe detector systems. Tap water samples were collected during the dry and the rainy seasons, respectively in December 2002 and July 2003 and spring water samples were collected in August 2010. The radionuclides observed with regularity belonged to the series decay naturally occurring radionuclides headed by 238 U and 232 Th as well as the non-series nuclide 40 K. Assuming an individual daily consumption of 1 litre of water, the average annual intake for these populations is 3821 Bq/y for tap water and 1161 Bq/y for spring water.

  20. Development of a water purifier for radioactive cesium removal from contaminated natural water by radiation-induced graft polymerization

    Science.gov (United States)

    Seko, Noriaki; Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya; Saiki, Seiichi; Ueki, Yuji

    2018-02-01

    Six years after the Fukushima-nuclear accident, the dissolved radioactive cesium (Cs) is now hardly detected in environmental natural waters. These natural waters are directly used as source of drinking and domestic waters in disaster-stricken areas in Fukushima. However, the possibility that some radioactive Cs adsorbed on soil or leaves will contaminate these natural waters during heavy rains or typhoon is always present. In order for the returning residents to live with peace of mind, it is important to demonstrate the safety of the domestic waters that they will use for their daily life. For this purpose, we have synthesized a material for selective removal of radioactive Cs by introducing ammonium 12-molybdophosphate (AMP) onto polyethylene nonwoven fabric through radiation-induced emulsion graft polymerization technique. Water purifiers filled with the grafted Cs adsorbent were installed in selected houses in Fukushima. The capability of the grafted adsorbent to remove Cs from domestic waters was evaluated for a whole year. The results showed that the tap water filtered through the developed water purifier contained no radioactive Cs, signifying the very effective adsorption performance of the developed grafted adsorbent. From several demonstrations, we have commercialized the water purifier named "KranCsair®". Furthermore, we have also developed a method for the mass production of the grafted nonwoven fabric. Using a 30 L grafting reactor, it was possible to produce the grafted nonwoven fabric with a suitable range of degree of grafting. When an irradiated roll of nonwoven trunk fabric with a length of 10 m and a width of 30 cm was set in the reactor filled with glycidyl methacrylate (GMA), AMP, Tween 80 monomer emulsion solution at 40 °C for 1 h, the difference of Dgs in the length and the width on roll of fabrics was negligible.

  1. The efficiency of macroporous polystyrene ion-exchange resins in natural organic matter removal from surface water

    Directory of Open Access Journals (Sweden)

    Urbanowska Agnieszka

    2017-01-01

    Full Text Available Natural water sources used for water treatment contains various organic and inorganic compounds. Surface waters are commonly contaminated with natural organic matter (NOM. NOM removal from water is important e.g. due to lowering the risk of disinfection by-product formation during chlorination. Ion exchange with the use of synthetic ion-exchange resins is an alternative process to typical NOM removal approach (e.g. coagulation, adsorption or oxidation as most NOM compounds have anionic character. Moreover, neutral fraction could be removed from water due to its adsorption on resin surface. In this study, applicability of two macroporous, polystyrene ion exchange resins (BD400FD and A100 in NOM removal from water was assessed including comparison of treatment efficiency in various process set-ups and conditions. Moreover, resin regeneration effectivity was determined. Obtained results shown that examined resins could be applied in NOM removal and it should be noticed that column set-up yielded better results (contrary to batch set-up. Among the examined resins A100 one possessed better properties. It was determined that increase of solution pH resulted in a slight decrease in treatment efficiency while higher temperature improved it. It was also observed that regeneration efficiency was comparable in both tested methods but batch set-up required less reagents.

  2. Evaluations of two-phase natural circulation flow induced in the reactor vessel annular gap under ERVC conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kwang Soon, E-mail: tomo@kaeri.re.kr [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Cheung, Fan-Bill [The Pennsylvania State University, University Park, PA 16802 (United States); Park, Rae Joon; Kim, Sang Baik [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Two-phase natural circulation flow induced in insulation gap was investigated. Black-Right-Pointing-Pointer Half-scaled non-heating experiments were performed to evaluate flow behavior. Black-Right-Pointing-Pointer The loop-integrated momentum equation was formulated and solved asymptotically. Black-Right-Pointing-Pointer First-order approximate solution was obtained and agreed with experimental data. - Abstract: The process of two-phase natural circulation flow induced in the annular gap between the reactor vessel and the insulation under external reactor vessel cooling conditions was investigated experimentally and analytically in this study. HERMES-HALF experiments were performed to observe and quantify the induced two-phase natural circulation flow in the annular gap. A half-scaled non-heating experimental facility was designed by utilizing the results of a scaling analysis to simulate the APR1400 reactor and its insulation system. The behavior of the boiling-induced two-phase natural circulation flow in the annular gap was observed, and the liquid mass flow rates driven by the natural circulation loop and the void fraction distribution were measured. Direct flow visualization revealed that choking would occur under certain flow conditions in the minimum gap region near the shear keys. Specifically, large recirculation flows were observed in the minimum gap region for large air injection rates and small outlet areas. Under such conditions, the injected air could not pass through the minimum gap region, resulting in the occurrence of choking near the minimum gap with a periodical air back flow being generated. Therefore, a design modification of the minimum gap region needs to be done to facilitate steam venting and to prevent choking from occurring. To complement the HERMES-HALF experimental effort, an analytical study of the dependence of the induced natural circulation mass flow rate on the inlet area and the

  3. Characterizing Pavement Surface Distress Conditions with Hyper-Spatial Resolution Natural Color Aerial Photography

    Directory of Open Access Journals (Sweden)

    Su Zhang

    2016-05-01

    Full Text Available Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS, in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application

  4. Study of Sesame (Sesame indicum L. Cultivars based on Morphological Characteristics Under Water Deficit Stress Condition Using Factor Analysis

    Directory of Open Access Journals (Sweden)

    A Asghari

    2014-03-01

    Full Text Available In order to evaluation sesame cultivars based on morphological characteristics under water deficit stress condition using factor analysis, an experiment was conducted as a split plot based on randomized complete block design with three replications during 2009 in Research Center of Agriculture and Natural Resources in Parsabad. In this experiment, irrigation as the main factor at three levels (50, 75 and 100 percent of crop water requirement and ten sesame cultivars as the sub-factor were studied. The water requirement of sesame was calculated using CROPWAT software (Penman-Monteith method according to FAO-56. Results showed significant differences between the cultivars and the irrigation levels for all studied traits. Interaction between cultivars and irrigation levels was significant for some of traits. Comparisons of means showed that in water deficit condition, yield and all of traits reduced. In all traits the greatest amounts observed in complete irrigation treatment. In 50 percent of water requirement treatment, amount of leaf chlorophyll, root length, root branches and root length/plant height ratio were greater than other treatments. The Karaj1, Ultan, Naze and IS cultivars were better than other cultivars in stress and non stress condition. In factor analysis 5 and 4 first factors in non stress and stress condition explained 91.36 and 89.52 percent of trait variance, respectively. Grouping of sesame cultivars based on first and second factors in non stress conditions showed that Karaj1, Ultan and Naze cultivars were better than other cultivars. Also, in stress conditions Karaj1 and Ultan cultivars grouped as water deficit stress and better cultivars.

  5. Environmental water requirements of groundwater dependent ecosystems: conflict between nature and man

    Science.gov (United States)

    Witczak, S.; Kania, J.; Rozanski, K.; Wachniew, P.; Zurek, A.; Dulinski, M.

    2012-04-01

    The presented study was aimed at investigating possible interactions between the porous sandy aquifer intensively exploited for drinking water purposes and the groundwater dependent ecosystem (GDE) consisting of a valuable forest stand. The investigated aquifer (Bogucice Sands) and the associated GDE (Niepolomice Forest) are located in the south of Poland. The aquifer covers the area of ca. 200 km2 and belongs to the category of medium groundwater basins in Poland. The Niepolomice Forest is a lowland forest covering around 110 km2. This relic of once vast forests is protected as a Natura 2000 Special Protection Area "Puszcza Niepolomicka" (PLB120002) that supports bird populations of European importance. Additionally, a fen in the western part of the Niepolomice Forest comprises a separate Natura 2000 area "Torfowisko Wielkie Bloto" (PLH120080), a significant habitat of endangered butterfly species associated with wet meadows. The Niepolomice Forest contains also several nature reserves and the European bison breeding centre and has an important recreational value as the largest forest complex in the vicinity of Krakow. Due to spatially variable lithologies and groundwater levels, the Niepolomice Forest is a mosaic of various forest and non-forest habitats, including wetlands, marsh forests, humid forests and fresh forests. Dependence of the Niepolomice Forest stands on groundwater is enhanced by low available water capacity and low capillary rise of soils in the area. Groundwater conditions in the Niepolomice Forest, including Wielkie Bloto fen have been affected by meliorations carried out mostly in the period 1900-1930 and after the Second World War and by forest management. Due to artesian conditions in the area and relatively thin clay layer separating Tertiary aquifer layers from shallow Quaternary aquifer, the upward leaching of deeper groundwater may contribute in a significant way to the water balance of the investigated GDE. In September 2009 a cluster of

  6. Human-Nature Relationship in Mediterranean Streams: Integrating Different Types of Knowledge to Improve Water Management

    Directory of Open Access Journals (Sweden)

    Carla Gonzalez

    2009-12-01

    Full Text Available The social and ecological systems of Mediterranean streams are intrinsically linked as a result of long human occupation. In this region, these links vary greatly across small distances due to geomorphology, resulting in great diversity across space, which poses particular challenges for understanding and managing these systems. This demands (i interdisciplinary integration of knowledge that focuses on the social-ecological interactions, while according due consideration to the whole; and also (ii transdisciplinary integration, integrating lay and expert knowledge to understand local specificities. To address these needs - a focus on interactions and local knowledge - the research presented here studies the human-nature relationship in Mediterranean streams. Its main objective is to improve understanding of Mediterranean streams, but it also provides practical inputs to enhance local-level management. The study adopts an applied approach from the perspective of natural resources management. A case study was developed conducting field work on streams within the Natura 2000 site of Monfurado, Portugal - a mainly privately owned area with conflicting land uses between conservation and farming. Rivers and streams in Portugal are considered to be in very bad condition, particularly with regard to water quality. The experimental design was based, from a critical realism perspective of inter- and trans-disciplinarity, on the complementarities between methodologies from (i the social sciences: value survey and analysis of discourse; and (ii the natural sciences: biomonitoring and integrity biotic indexes. Results characterized the connected systems from both ecological and social points of view. They also characterized the relationship between both dimensions. We concluded that well-established riparian vegetation cover of streams is a key structural element of the human-nature relationship in the Mediterranean streams of Monfurado at several levels

  7. Impacts of Embankment System on Natural Wetlands and Sustainable Water Resources Development in the Northwest Region of Bangladesh

    Science.gov (United States)

    Pervin, M.; Rahman, M. A.

    2012-12-01

    In the Northwest region of Bangladesh, the Chalan Beel is one of the largest Beel ("Beel" refers to natural wetland) in Bangladesh. Polder C (an area surrounded by embankment) of Chalan Beel area consists of 50% natural wetland of the region. Historically, the area was rich with fish, flora and fauna, and agricultural resources. Both flood and drainage congestion have been identified as major problems existing in the project area. Farmers are badly affected by the sudden onrush of floodwater through the embankment breaches, public cuts and incomplete hydraulic structures during the rainy season. The floodwater damages B. Aman and late Boro paddy by 10% and washes away housing settlements. Sometimes water gets scarce in polder C in dry season that is unfavorable for the crop. Loss of crops and fishery affects the economy strongly. The polder was not according to master plan and with lack of operation and maintenance. Instead of improving the livelihood in the study area the embankment arises detrimental effect on the people. This paper focuses mainly the impact of the embankments on hydrology, fishery, agriculture and socio-economic condition in polder C at Chalan Beel area. Present conditions are compared with the natural conditions existed in the last decades. Finally, the paper gives some recommendations for further sustainable water resources management. It is estimated that the natural wetland loss is about 10%. The analysis shows that the river or channel cross-sections are reduced by ca. 2 m and water level is increasing with time in the rivers along the polder due to confinement effect and siltation. It appears from the study that due to this confinement effect and siltation effect, flood and drainage problems are increasing and consequently, the area is affected in every year to a great extent. At present, cross sections of natural canals are not working properly and back water flow from Hurasagar River creates drainage congestion. About 20% of fish

  8. [Spectrum Variance Analysis of Tree Leaves Under the Condition of Different Leaf water Content].

    Science.gov (United States)

    Wu, Jian; Chen, Tai-sheng; Pan, Li-xin

    2015-07-01

    Leaf water content is an important factor affecting tree spectral characteristics. So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are not only the keys of hyperspectral vegetation remote sensing information identification but also the theoretical support of research on vegetation spectrum change as the differences in leaf water content. The spectrometer was used to observe six species of tree leaves, and the reflectivity and first order differential spectrum of different leaf water content were obtained. Then, the spectral characteristics of each tree species leaves under the condition of different leaf water content were analyzed, and the spectral differences of different tree species leaves under the condition of the same leaf water content were compared to explore possible bands of the leaf water content identification by hyperspectral remote sensing. Results show that the spectra of each tree leaf have changed a lot with the change of the leaf water content, but the change laws are different. Leaf spectral of different tree species has lager differences in some wavelength range under the condition of same leaf water content, and it provides some possibility for high precision identification of tree species.

  9. RADIOACTIVITY OF ROCKS, SOILS AND NATURAL WATERS OF DAGESTAN AND DUE TO THEIR EFFECTIVE DOSE

    Directory of Open Access Journals (Sweden)

    A. S. Abdulaeva

    2012-01-01

    Full Text Available The results of long-term radioecological studies in the mountainous areas of Dagestan. The data of the study of territorial exposure dose, determination of natural radioactive nuclides in rocks, soils and natural waters of Dagestan. The parameters of the correlation between alpha-and beta-activity of rocks, soil, and radon in water and indoor air. This paper discusses issues related to the formation of radiation dose from natural sources of ionizing radiation in the biosphere and as a result of this review - doses to man.

  10. Study on the Mediterranean coastal seaweed Ulva linza exposed to natural and stressed environmental conditions

    Directory of Open Access Journals (Sweden)

    Ayman Abd Elmoneim El-Gamal

    2015-10-01

    Full Text Available Objective: To study Ulva linza (U. linza as macro-alga exposed to different levels of ionizing radiation from the natural background of radioactivity. Methods: Samples of U. linza were collected from two different habitats at the two terminals of the rocky shore of Abu Qir Bay, Alexandria, Egypt. The western terminal at Abu Qir represented an area of normal background radiation while the eastern terminal at Rosetta represented an area of relatively high background radiation. Distinguishing between the algae grown in areas of relatively high and normal background radiation was investigated by using different indicators. Moreover, the ambient water quality was measured and the concentrations of natural radionuclides (238U, 232Th and 40K bio-accumulated in the tested macro-alga were detected. Results: The algae naturally exposed to radionuclides (238U series, 232Th series and 40K were investigated. Radiation dose rates in U. linza inhabiting in Rosetta and Abu Qir were calculated as 70.12 and 42.67 nGy/h, respectively. Chemical analysis of algal samples demonstrated that total pigment contents were 2.21 and 2.19 mg/g on a fresh weight basis for U. linza inhabiting in Rosetta and Abu Qir, respectively. Fatty acid compositions showed comparable profiles for both algal samples with saturated fatty acids as major component. The results of protein profiles confirmed slight differential expression in protein bands. Sequence-related randomly amplified polymorphic DNA provided evidence that both samples were strongly similar. By using transmission electron microscopy, no obvious ultra structural changes in the examined cells were observed. Conclusions: These experimental results demonstrate that radiation doses are not high enough to cause damage or manifest any significant variation in Ulva tissues.

  11. Uranium redistribution under oxidizing conditions in Oklo natural reactor zone 2, Gabon

    International Nuclear Information System (INIS)

    Isobe, H.; Ohnuki, T.; Murakami, T.; Gauthier-Lafaye, F.

    1995-01-01

    This mineralogical study was completed to elucidate the relationships between uranium distribution and alteration products of the host rock of natural reactor zone clays just below the reactor core. Uraninite is preserved without any alteration in the reactor core. Uranium minerals are found to be present in the fractures in the reactor zone clays associated with iron-mineral veins, galena and Ti-bearing minerals. Uranium, for which the phases could not be identified, occurs in iron-mineral veins and the iron-mineral rim of pyrite grains in the reactor zone clays. Uranium is not associated with granular iron minerals occurring in the illite matrix of the reactor zone clays. The degree of crystallinity and uranium content of the three iron-bearing alteration products suggest that they formed under different conditions; the granular iron minerals, under alteration conditions where uranium was not mobilized while the iron-mineral veins and the iron-mineral rim of pyrite, under conditions in which uranium is mobilized after the formation of the granular iron minerals

  12. Thermal conditions in selected urban and semi-natural habitats, important for the forensic entomology.

    Science.gov (United States)

    Michalski, Marek; Nadolski, Jerzy

    2018-06-01

    A long-term study on thermal conditions in selected urban and semi-natural habitats, where human corpses are likely to be found, was conducted in the city of Lodz (Central Poland). Thermal data were collected during two years at nine sites and compared with corresponding data from the nearest permanent meteorological station at Lodz Airport (ICAO code: EPLL). The conditions closest to those at the meteorological station prevailed in the deciduous forest, coefficient of determination R 2 for those sets of data was above 0.96. The open field was characterized by high daily amplitudes, especially during spring, while the site in the allotment gardens was characterized by relatively high winter temperatures. The conditions prevailing in all closed space sites were very diverse and only slightly similar to the external ones. The most distinct site was an unheated basement in a tenement house, where temperature was almost always above 0°C and daily amplitudes were negligible. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Natural training tools of informatics in conditions of embodied and mental approach realization

    Directory of Open Access Journals (Sweden)

    Daria A. Barkhatova

    2017-01-01

    Full Text Available Modern processes of globalization and informatization of human activity cause the necessity of change of the educational paradigm in the field of information training of a person, focused on the formation of the strong fundamental knowledge and abilities, which are necessary for person’s information activities and self-education during all life.In connection with these requirements, it is necessary to pay attention to new approaches in education, based on achievements of cognitive science and modern pedagogic. One of such approaches is embodied and mental approach. The paper is devoted to the description of a way of realization of embodied and mental approach in training of informatics through application of the natural tools, providing the fullest and deep understanding of the educational material, and development of cognitive abilities of students.In the paper the theoretical analysis of psychology-pedagogical and methodical literature on a research subject is carried out, results are generalized, natural tools are modeled and results of their partial approbation are described. Achievement of necessary quality of education is offered due to the use of modern techniques, focused on the development of cognitive abilities and improvement of quality of the knowledge. In the conditions of information education, the combination of embodied and mental approaches will allow to acquaint students with the essence of the studied subject due to activation of motor area of the memory and the kinesthetic and visual perception channels. The instrument of realization of this idea is offered to use natural tools in informatics, what is actualized by age features of cognitive abilities of students and individual requirements to ways of perception and mastering of the material, matched according to the level of their knowledge.The research results describe the models of natural tools, developed by students and lecturers of the basic Department of Informatics

  14. Effect of natural and man-made factors on mineral composition of Ardon river water

    International Nuclear Information System (INIS)

    Tyutikov, S.F.; Ermakov, V.V.; Degtyarev, A.P.; Krechetova, E.V.; Petrunina, N.S.

    2008-01-01

    The data on change of landscapes and biota (plants, algae, amphibious) are submitted as a result of natural catastrophes (mud-stream) and man-made factors (construction of a gas main and hydroelectric power station). It is shown, that the specified factors in some cases change not only structure of landscapes and a chemical compound of natural and industrial waters, but also a character of invasion of organisms. The certain influence of size of suspended matter of Ardon river waters on their general mineralization was discovered. Contents of heavy metals in waters of Ardon river is not critical and is in acceptable hygienic parameters.

  15. The protective role of ceramic filters against natural radioactivity of water

    International Nuclear Information System (INIS)

    Domanski, T.; Bakir, Y.Y.Y.; El-Zenki, S.; Bem, H.

    1992-01-01

    The paper presents results of measurements of the natural radioactivity of tap water where samples were taken in front of, and behind the ceramic filter commonly used in houses for the purification of tap water. Altogether, 289 samples were taken, processed and measured during 1985-1986 in Kuwait. Results reveal the fact that ceramic filters reduce substantially the natural radioactivity in water (the 'gross' alpha activity reduced by the factor 2.18 ± 18%; the 'gross' beta by 1.53 ± 1.6%. (author)

  16. Pu(V) as the stable form of oxidized plutonium in natural waters

    International Nuclear Information System (INIS)

    Orlandini, K.A.; Penrose, W.R.; Nelson, D.M.

    1986-01-01

    This work presents analytical evidence supporting the proposition that Pu(V) is the sole or predominant form of oxidized plutonium in natural waters. Two independent methods, the selective adsorption of Pu(VI) by silica gel, and the somewhat less selective coprecipitation of Pu(V) with calcium carbonate, were developed to separate Pu(V) from Pu(VI). Measurements of ambient plutonium in several natural waters by these methods found only Pu(V). In laboratory tracer studies, Pu(VI) was shown to be highly unstable in dilute bicarbonate solution and in Lake Michigan water, reducing in first-order fashion to Pu(V). (orig.)

  17. DESIGN OF WATER-COOLED PACKAGED AIR-CONDITIONING SYSTEMS BASED ON RELIABILITY ASSESSMENT

    OpenAIRE

    関口, 圭輔; 中尾, 正喜; 藁谷, 至誠; 植草, 常雄; 羽山, 広文

    2007-01-01

    Water-cooled packaged air-conditioning systems are reevaluated in terms of alleviating the heat island phenomenon in cities and effectively utilizing building rooftops. Up to now, such reliability assessment has been insufficient, and this has limited the use of this kind of air-conditioning system in the information and communications sectors that demand a high reliability. This work has led to the development of a model for evaluating the reliability of water-cooled package