WorldWideScience

Sample records for models determining water

  1. Determining extreme parameter correlation in ground water models

    DEFF Research Database (Denmark)

    Hill, Mary Cole; Østerby, Ole

    2003-01-01

    In ground water flow system models with hydraulic-head observations but without significant imposed or observed flows, extreme parameter correlation generally exists. As a result, hydraulic conductivity and recharge parameters cannot be uniquely estimated. In complicated problems, such correlation...... correlation coefficients with absolute values that round to 1.00 were good indicators of extreme parameter correlation, but smaller values were not necessarily good indicators of lack of correlation and resulting unique parameter estimates; (2) the SVD may be more difficult to interpret than parameter...

  2. A Model for Determining Leakage in Water Distribution Systems

    OpenAIRE

    Stathis, Jonathan Alexander

    1998-01-01

    Leaks in pipe networks cause significant problems for utilities and water users in terms of lost revenue and interrupted service. In many cities the leakage is as high as forty percent. A water audit is carried out to assess system-wide leakage. However, to detect leakage at the level of a pipeline, a physical measurement technique is generally employed. For large cities the distribution piping length amounts to a few thousand miles. Therefore, the physical measurements can become tediou...

  3. Determination of water flushing characteristics and their influencing factors on the Dahuofang Reservoir in China using an improved ECOMSED model

    Science.gov (United States)

    Zhang, Ming; Shen, Yongming

    2015-09-01

    A three-dimensional hydrodynamic model with the capability to deal with changing land water boundaries was developed based on ECOMSED in this study. The model was configured to numerically study the water flushing characteristics of Dahuofang Reservoir in China through the determination of spatially distributed residence times. The model successfully reproduced the intra-annual water level variations, as well as the temporal evolution and spatial distribution of water temperature. Through a series of numerical experiments, it can be concluded that (1) the water flushing of the reservoir is both temporally and spatially variable; and (2) inflows and withdrawals are the decisive factors influencing the water flushing characteristics. Heat fluxes are the controlling factors of the water flushing of a strong stratified reservoir. Wind has the weakest effect, but it still should be considered in determination of reservoir water flushing characteristics.

  4. Determining TOC in Waters

    Science.gov (United States)

    Kehoe, Thomas J.

    1977-01-01

    The instrumental method for detecting total organic carbon (TOC) in water samples is detailed. The method's limitations are discussed and certain precautions that must be taken are emphasized. The subject of TOC versus COD and BOD is investigated and TOC is determined to be a valid indication of biological demand. (BT)

  5. Uranium determination in water

    International Nuclear Information System (INIS)

    Prudenzo, E.J.; Puga, Maria J.; Cerchietti, Maria L.R.; Arguelles, Maria G.

    2005-01-01

    In our laboratory, a procedure has been assessed to determine uranium content of water in normal situations. The method proposed without sample pre-treatment, is simple and rapid. Uranium mass is measured by fluorimetry. For calculation of detection limit (Ld) and quantification level (Lq) we used blank samples and the results were analyzed for different statistical test. The calculation of total propagated uncertainty and sources contribution on real samples are presented. (author)

  6. A modelling approach to determine the origin of urban ground water

    Science.gov (United States)

    Trowsdale, Sam A.; Lerner, David N.

    2007-04-01

    A simple modelling approach was developed to link patterns of urban land-use with ground water flow and chemistry in three dimensions and was applied to characterize the origin of recharge in the aquifer beneath the old industrial city of Nottingham, UK. The approach involved dividing land uses into types, and times into periods, and assigning the recharge from each an individual tracer-solute with a unit concentration. The computer code MT3DMS was used to track the multiple tracer-solutes in transient, three-dimensional simulations of the important urban aquifer. A depth-specific hydrochemical dataset collected in parallel supported the model predictions. At depth under the industrial area studied, a large component of ground water originated of older agricultural origin, with relatively low nitrate concentrations. Shallower ground water originated mainly from residential and industrial areas, with higher nitrate concentrations probably arising from leaking sewers and contaminated land. The results highlighted the spectrum of ground water from different origins that amalgamate even at short well screens in a non-pumped borehole and remind us that the non-point-source pollution of ground water from anthropogenic activities will involve more years of slow degradation of quality.

  7. Application of a lake-watershed model for the determination of water balance

    Science.gov (United States)

    Crowe, Allan S.; Schwartz, Franklin W.

    1985-10-01

    A lumped-parameter, lake-watershed response model has been developed for the Wabamun Lake system and used to assess the role of groundwater in the water balance of the lake. Wabamun Lake, located in central Alberta, Canada, has a surface area of 78 km 2. The surrounding watershed has an area of 263 km 2 and is covered by a thin layer (0-15 m) of glacial sediments, which in turn overlie bedrock deposits of sandstone, siltstone, shale and coal. Good agreement has been achieved between the monthly observed and the monthly predicted lake stages for a 26 yr record, with a maximum difference of less than 0.25 m. In addition, the simulation of lake chemistry, including specific conductance, Cl - and K +, is in good agreement with the observed data. On the basis on the simulations, the main hydrologic components contributing water to Wabamun Lake are direct precipitation (43.1-59.8%) and surface-water inflow (36.8-48.3%). Outflow from the lake occurs primarily through evaporation (46.5-57.5%) and the groundwater system (35.0-43.5%). Groundwater discharging to Wabamun Lake (1.3-8.6%) and surface water draining from the lake (0.0-18.5%) are minor components in the water balance of Wabamun Lake.

  8. Solubility Determination and Modeling and Dissolution Thermodynamic Properties of Raspberry Ketone in Binary Solvent Mixtures of Ethanol and Water

    Science.gov (United States)

    Shu, Min; Zhu, Liang; Wang, Yan-fei; Yang, Jing; Wang, Liyu; Yang, Libin; Zhao, Xiaoyu; Du, Wei

    2018-01-01

    The solubility and dissolution thermodynamic properties of raspberry ketone in a set of binary solvent mixtures (ethanol + water) with different compositions were experimentally determined by static gravimetrical method in the temperature range of 283.15-313.15 K at 0.10 MPa. The solubility of raspberry ketone in this series of ethanol/water binary solvent mixtures was found to increase with a rise in temperature and the rising mole fraction of ethanol in binary solvent mixtures. The van't Hoff, modified Apelblat and 3D Jouyban-Acree-van't Hoff equations were increasingly applied to correlate the solubility in ethanol/water binary solvent mixtures. The former two models could reach better fitting results with the solubility data, while the 3D model can be comprehensively used to estimate the solubility data in all the ratios of ethanol and water in binary solvent mixtures at random temperature. Furthermore, the changes of dissolution thermodynamic properties of raspberry ketone in experimental ethanol/water solvent mixtures were obtained by van't Hoff equation. For all the above experiments, these dissolution processes of raspberry ketone in experimental ethanol/water binary solvent mixtures were estimated to be endothermic and enthalpy-driven.

  9. Determinants of Household Water Conservation Retrofit Activity: A Discrete Choice Model Using Survey Data

    Science.gov (United States)

    Cameron, T. A.; Wright, M. B.

    1990-02-01

    Economic analyses of residential water demand have typically concentrated on price and income elasticities. In the short run a substantial change in water prices might induce only small changes in consumption levels. As time passes, however, households will have the opportunity to "retrofit" existing water-using equipment to make it less water-intensive. This produces medium- to long-run demand elasticities that are higher than short-run studies suggest. We examine responses to water conservation questions appearing on the Los Angeles Department of Water and Power's 1983 residential energy survey. We find that households' decisions to install shower retrofit devices are influenced by the potential to save money on water heating bills. We attribute toilet retrofit decisions more to noneconomic factors which might be characterized as "general conservation mindedness." The endogeneity of these retrofit decisions casts some doubt on the results of studies of individual households that treat voluntary retrofits as exogenous.

  10. Preliminary simulation model to determine ground-water flow and ages within the Palo Duro Basin hydrogeologic province

    International Nuclear Information System (INIS)

    Atwood, H.; Picking, L.

    1986-01-01

    Ground-water flow through the Palo Duro and Tucumcari Basins is simulated by developing a hydrogeolgic profile and applying a cross-sectional, finite-element, numerical model to the profile. The profile is 350 miles long and 2 miles deep and extends from east-central New Mexico to the Texas-Oklahoma border. It is comprised of hydrogeologic units that are identified from geophysical well logs, sample logs, and core descriptions. A hydrogeologic unit as used in this profile is a physically continuous rock sequence with hydrologic properties that are relatively consistent throughout and distinct from surrounding units. The resulting hydrogeologic profile, with the exception of the Ogallala Formation and the Dockum Group, is discretized into a 6000-element mesh and a 22,000-element mesh. Permeability values assigned to hydrogeologic units were, in part, calculated from drill stem tests conducted throughout the Palo Duro Basin. Ground-water age and travel paths are determined by applying Darcy's equation to selected flow lines. The 170 million-year age determined from ground-water at points within the Wolfcamp Series compares favorably with the geochemical data for this region. An age of 188 million years is determined for the Pennsylvanian granite wash

  11. Economic Time Series Modeling to Determine the Feasibility of Incorporating Drinking Water Treatment in Water Quality Trading

    Science.gov (United States)

    The critical steps required to evaluating the feasiblity of establishing a water quality trading market in a testbed watershed is described. Focus is given toward describing the problem of thin markets as a specifi barrier to successful trading. Economic theory for considering an...

  12. Liquid chromatographic determination of water

    Science.gov (United States)

    Fortier, N.E.; Fritz, J.S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present. 1 fig.

  13. Physiological water model development

    Science.gov (United States)

    Doty, Susan

    1993-01-01

    The water of the human body can be categorized as existing in two main compartments: intracellular water and extracellular water. The intracellular water consists of all the water within the cells and constitutes over half of the total body water. Since red blood cells are surrounded by plasma, and all other cells are surrounded by interstitial fluid, the intracellular compartment has been subdivided to represent these two cell types. The extracellular water, which includes all of the fluid outside of the cells, can be further subdivided into compartments which represent the interstitial fluid, circulating blood plasma, lymph, and transcellular water. The interstitial fluid surrounds cells outside of the vascular system whereas plasma is contained within the blood vessels. Avascular tissues such as dense connective tissue and cartilage contain interstitial water which slowly equilibrates with tracers used to determine extracellular fluid volume. For this reason, additional compartments are sometimes used to represent these avascular tissues. The average size of each compartment, in terms of percent body weight, has been determined for adult males and females. These compartments and the forces which cause flow between them are presented. The kidneys, a main compartment, receive about 25 percent of the cardiac output and filters out a fluid similar to plasma. The composition of this filtered fluid changes as it flows through the kidney tubules since compounds are continually being secreted and reabsorbed. Through this mechanism, the kidneys eliminate wastes while conserving body water, electrolytes, and metabolites. Since sodium accounts for over 90 percent of the cations in the extracellular fluid, and the number of cations is balanced by the number of anions, considering the renal handling sodium and water only should sufficiently describe the relationship between the plasma compartment and kidneys. A kidney function model is presented which has been adapted from a

  14. Determining the Threshold Value of Basil Yield Reduction and Evaluation of Water Uptake Models under Salinity Stress Condition

    OpenAIRE

    M. Sarai Tabrizi; H. Babazadeh; M. Homaee; F. Kaveh Kaveh; M. Parsinejad

    2016-01-01

    Introduction: Several mathematical models are being used for assessing the plant response to the salinity of the root zone. The salinity of the soil and water resources is a major challenge for agricultural sector in Iran. Several mathematical models have been developed for plant responses to the salinity stress. However, these models are often applicable in particular conditions. The objectives of this study were to evaluate the threshold value of Basil yield reduction, modeling Basil respon...

  15. Determining water storage depletion within Iran by assimilating GRACE data into the W3RA hydrological model

    Science.gov (United States)

    Khaki, M.; Forootan, E.; Kuhn, M.; Awange, J.; van Dijk, A. I. J. M.; Schumacher, M.; Sharifi, M. A.

    2018-04-01

    Groundwater depletion, due to both unsustainable water use and a decrease in precipitation, has been reported in many parts of Iran. In order to analyze these changes during the recent decade, in this study, we assimilate Terrestrial Water Storage (TWS) data from the Gravity Recovery And Climate Experiment (GRACE) into the World-Wide Water Resources Assessment (W3RA) model. This assimilation improves model derived water storage simulations by introducing missing trends and correcting the amplitude and phase of seasonal water storage variations. The Ensemble Square-Root Filter (EnSRF) technique is applied, which showed stable performance in propagating errors during the assimilation period (2002-2012). Our focus is on sub-surface water storage changes including groundwater and soil moisture variations within six major drainage divisions covering the whole Iran including its eastern part (East), Caspian Sea, Centre, Sarakhs, Persian Gulf and Oman Sea, and Lake Urmia. Results indicate an average of -8.9 mm/year groundwater reduction within Iran during the period 2002 to 2012. A similar decrease is also observed in soil moisture storage especially after 2005. We further apply the canonical correlation analysis (CCA) technique to relate sub-surface water storage changes to climate (e.g., precipitation) and anthropogenic (e.g., farming) impacts. Results indicate an average correlation of 0.81 between rainfall and groundwater variations and also a large impact of anthropogenic activities (mainly for irrigations) on Iran's water storage depletions.

  16. Determining sources of elevated salinity in pre-hydraulic fracturing water quality data using a multivariate discriminant analysis model

    Science.gov (United States)

    Lautz, L. K.; Hoke, G. D.; Lu, Z.; Siegel, D. I.

    2013-12-01

    Hydraulic fracturing has the potential to introduce saline water into the environment due to migration of deep formation water to shallow aquifers and/or discharge of flowback water to the environment during transport and disposal. It is challenging to definitively identify whether elevated salinity is associated with hydraulic fracturing, in part, due to the real possibility of other anthropogenic sources of salinity in the human-impacted watersheds in which drilling is taking place and some formation water present naturally in shallow groundwater aquifers. We combined new and published chemistry data for private drinking water wells sampled across five southern New York (NY) counties overlying the Marcellus Shale (Broome, Chemung, Chenango, Steuben, and Tioga). Measurements include Cl, Na, Br, I, Ca, Mg, Ba, SO4, and Sr. We compared this baseline groundwater quality data in NY, now under a moratorium on hydraulic fracturing, with published chemistry data for 6 different potential sources of elevated salinity in shallow groundwater, including Appalachian Basin formation water, road salt runoff, septic effluent, landfill leachate, animal waste, and water softeners. A multivariate random number generator was used to create a synthetic, low salinity ( 20 mg/L Cl) as being affected by formation water, road salt, septic effluent, landfill leachate, animal waste, or water softeners. Single elements or pairs of elements (e.g. Cl and Br) were not effective at discriminating between sources of salinity, indicating multivariate methods are needed. The discriminant analysis model classified most accurately samples affected by formation water and landfill leachate, whereas those contaminated by road salt, animal waste, and water softeners were more likely to be discriminated as contaminated by a different source. Using this approach, no shallow groundwater samples from NY appear to be affected by formation water, suggesting the source of salinity pre-hydraulic fracturing is

  17. Mathematical modeling of systemic factors determining the risk of deterioration of drinking water supply and development of allergic diseases of population

    Science.gov (United States)

    Bespalov, Yurii G.; Nosov, Konstantin V.; Vysotska, Olena V.; Porvan, Andrii P.; Omiotek, Zbigniew; Burlibay, Aron; Assembay, Azat; Szatkowska, Małgorzata

    2017-08-01

    This study aims at mathematical modeling of systemic factors threatening the sanitary and hygienic state of sources of water supply. It is well-known, that this state affects health of population consuming water from different water sources (lakes, reservoirs, rivers). In particular, water quality problem may cause allergic reactions that are the important problem of health care. In the paper, the authors present the mathematical model, that enables on the basis of observations of a natural system to predict the system's behavior and determine the risks related to deterioration of drinking water resources. As a case study, we uses supply of drinking water from Lake Sevan, but the approach developed in the study can be applied to wide area of adjacent problems.

  18. Determining the terrain characteristics related to the surface expression of subsurface water pressurization in permafrost landscapes using susceptibility modelling

    Science.gov (United States)

    Holloway, Jean E.; Rudy, Ashley C. A.; Lamoureux, Scott F.; Treitz, Paul M.

    2017-06-01

    Warming of the Arctic in recent years has led to changes in the active layer and uppermost permafrost. In particular, thick active layer formation results in more frequent thaw of the ice-rich transient layer. This addition of moisture, as well as infiltration from late season precipitation, results in high pore-water pressures (PWPs) at the base of the active layer and can potentially result in landscape degradation. To predict areas that have the potential for subsurface pressurization, we use susceptibility maps generated using a generalized additive model (GAM). As model response variables, we used active layer detachments (ALDs) and mud ejections (MEs), both formed by high PWP conditions at the Cape Bounty Arctic Watershed Observatory, Melville Island, Canada. As explanatory variables, we used the terrain characteristics elevation, slope, distance to water, topographic position index (TPI), potential incoming solar radiation (PISR), distance to water, normalized difference vegetation index (NDVI; ME model only), geology, and topographic wetness index (TWI). ALDs and MEs were accurately modelled in terms of susceptibility to disturbance across the study area. The susceptibility models demonstrate that ALDs are most probable on hill slopes with gradual to steep slopes and relatively low PISR, whereas MEs are associated with higher elevation areas, lower slope angles, and areas relatively far from water. Based on these results, this method identifies areas that may be sensitive to high PWPs and helps improve our understanding of geomorphic sensitivity to permafrost degradation.

  19. Determining the terrain characteristics related to the surface expression of subsurface water pressurization in permafrost landscapes using susceptibility modelling

    Directory of Open Access Journals (Sweden)

    J. E. Holloway

    2017-06-01

    Full Text Available Warming of the Arctic in recent years has led to changes in the active layer and uppermost permafrost. In particular, thick active layer formation results in more frequent thaw of the ice-rich transient layer. This addition of moisture, as well as infiltration from late season precipitation, results in high pore-water pressures (PWPs at the base of the active layer and can potentially result in landscape degradation. To predict areas that have the potential for subsurface pressurization, we use susceptibility maps generated using a generalized additive model (GAM. As model response variables, we used active layer detachments (ALDs and mud ejections (MEs, both formed by high PWP conditions at the Cape Bounty Arctic Watershed Observatory, Melville Island, Canada. As explanatory variables, we used the terrain characteristics elevation, slope, distance to water, topographic position index (TPI, potential incoming solar radiation (PISR, distance to water, normalized difference vegetation index (NDVI; ME model only, geology, and topographic wetness index (TWI. ALDs and MEs were accurately modelled in terms of susceptibility to disturbance across the study area. The susceptibility models demonstrate that ALDs are most probable on hill slopes with gradual to steep slopes and relatively low PISR, whereas MEs are associated with higher elevation areas, lower slope angles, and areas relatively far from water. Based on these results, this method identifies areas that may be sensitive to high PWPs and helps improve our understanding of geomorphic sensitivity to permafrost degradation.

  20. Determination of radium in water

    International Nuclear Information System (INIS)

    Hohorst, F.A.; Huntley, M.W.; Hartenstein, S.D.

    1995-10-01

    These detailed work instructions (DWIs) are tailored for the analysis of radium-226 and radium-228 in drinking water supplies from ground water and surface water sources and composites derived from them. The instructions have been adapted from several sources, including a draft EPA method. One objective was to minimize the generation of mixed wastes. Quantitative determinations of actinium-228 are made at 911 keV. The minimum detection level (MDL) for the gamma spectrometric measurements at this energy vary with matrix, volume, geometry, detector, background, and counting statistics. The range of MDL's for current detectors is 0.07 to 0.5 Bq/sample. Quantitative determinations of radium-226 are made by counting the high energy alpha particles which radium-226 progeny emit using liquid scintillation counting (LSC). The minimum detectable activity (MDA) is 3.8 E-3 Bq/sample. The maximum concentration which may be counted on available instruments without dilution is about 2 E + 5 Bq/sample. Typically, this determination of radium in a 2 L sample has a yield of 80%. If radium-228 is determined using a 16 h count after 50 h grow-in, the typical MDL is 1 E-9 to 8 E-9 μCi/mL (1 to 8 pCi/L). If radium-226 is determined using a 2.5 h count after 150 h grow-in, the typical MDA is about 1 E-10 μCi/mL (0. 1 pCi/L)

  1. Determination of radium in water

    Energy Technology Data Exchange (ETDEWEB)

    Hohorst, F.A.; Huntley, M.W.; Hartenstein, S.D.

    1995-10-01

    These detailed work instructions (DWIs) are tailored for the analysis of radium-226 and radium-228 in drinking water supplies from ground water and surface water sources and composites derived from them. The instructions have been adapted from several sources, including a draft EPA method. One objective was to minimize the generation of mixed wastes. Quantitative determinations of actinium-228 are made at 911 keV. The minimum detection level (MDL) for the gamma spectrometric measurements at this energy vary with matrix, volume, geometry, detector, background, and counting statistics. The range of MDL`s for current detectors is 0.07 to 0.5 Bq/sample. Quantitative determinations of radium-226 are made by counting the high energy alpha particles which radium-226 progeny emit using liquid scintillation counting (LSC). The minimum detectable activity (MDA) is 3.8 E-3 Bq/sample. The maximum concentration which may be counted on available instruments without dilution is about 2 E + 5 Bq/sample. Typically, this determination of radium in a 2 L sample has a yield of 80%. If radium-228 is determined using a 16 h count after 50 h grow-in, the typical MDL is 1 E-9 to 8 E-9 {mu}Ci/mL (1 to 8 pCi/L). If radium-226 is determined using a 2.5 h count after 150 h grow-in, the typical MDA is about 1 E-10 {mu}Ci/mL (0. 1 pCi/L).

  2. How hydrology determines seasonal and interannual variations in water table depth, surface energy exchange, and water stress in a tropical peatland: Modeling versus measurements

    Science.gov (United States)

    Mezbahuddin, M.; Grant, R. F.; Hirano, T.

    2015-11-01

    Soil carbon stocks in tropical peatlands have declined recently from water table depth (WTD) drawdown caused by increased frequency and intensity of climate extremes like El Niño and by artificial drainage. Restoration of these carbon stocks under these climatic and anthropogenic disturbances requires improved predictive capacity for hydrological feedbacks to ecological processes. Process-based modeling of tropical peatland ecohydrology could provide us with such capacity, but such modeling has thus far been limited. We aimed at using basic processes for water and O2 transport and their effects on ecosystem water, carbon, and nitrogen cycling to model seasonal and interannual variations of WTD and surface energy exchange. We tested these processes in a process-based model ecosys in a drained tropical Indonesian peatland from an El Niño year 2002 to a wetter year 2005. WTD was modeled from hydraulically driven water transfers controlled vertically by precipitation versus evapotranspiration (ET) and laterally by discharge versus recharge to or from an external reference WTD. These transfers caused WTD drawdown and soil drying to be modeled during dry seasons, which reduced ET and increased Bowen ratio by lowering stomatal conductance. More pronounced dry seasons in drier years 2002-2004 versus wetter year 2005 caused deeper WTD, more intense peat drying, and greater plant water stress. These modeled trends were well corroborated by site measurements as apparent in regression statistics of modeled versus observed WTD (R2 > 0.8), latent heat (R2 > 0.8), and sensible heat (R2 > 0.7) fluxes. Insights gained from this modeling would aid in predicting the fate of tropical peatlands under future drier climates.

  3. Determining the Threshold Value of Basil Yield Reduction and Evaluation of Water Uptake Models under Salinity Stress Condition

    Directory of Open Access Journals (Sweden)

    M. Sarai Tabrizi

    2016-10-01

    Full Text Available Introduction: Several mathematical models are being used for assessing the plant response to the salinity of the root zone. The salinity of the soil and water resources is a major challenge for agricultural sector in Iran. Several mathematical models have been developed for plant responses to the salinity stress. However, these models are often applicable in particular conditions. The objectives of this study were to evaluate the threshold value of Basil yield reduction, modeling Basil response to salinity and to evaluate the effectiveness of available mathematical models for the yield estimation of the Basil . Materials and Methods: The extensive experiments were conducted with 13 natural saline water treatments including 1.2, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.5, 4, 5, 6, 8, and 10 dSm-1. Water salinity treatments were prepared by mixing Shoor River water with fresh water. In order to quantify the salinity effect on Basil yield, seven mathematical models including Maas and Hoffman (1977, van Genuchten and Hoffman (1984, Dirksen and Augustijn (1988, and Homaee et al., (2002 were used. One of the relatively recent methods for soil water content measurements is theta probes instrument. Theta probes instrument consists of four probes with 60 mm long and 3 mm diameter, a water proof container (probe structure, and a cable that links input and output signals to the data logger display. The advantages that have been attributed to this method are high precision and direct and rapid measurements in the field and greenhouse. The range of measurements is not limited like tensiometer and is from saturation to wilting point. In this study, Theta probes instrument was calibrated by weighing method for exact irrigation scheduling. Relative transpiration was calculated using daily soil water content changes. A coarse sand layer with 2 centimeters thick was used to decrease evaporation from the surface soil of the pots. Quantity comparison of the used models was done

  4. DETERMINATION OF ACTIVATED SLUDGE MODEL ASDM PARAMETERS FOR WASTE WATER TREATMENT PLANT OPERATING IN THE SEQUENTIAL–FLOW TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-01-01

    Full Text Available This paper presents a method for calibration of activated sludge model with the use of computer program BioWin. Computer scheme has been developed on the basis of waste water treatment plant operating in the sequential – flow technology. For calibration of the activated sludge model data of influent and treated effluent from the existing object were used. As a result of conducted analysis was a change in biokinetic model and kinetic parameters parameters of wastewater treatment facilities. The presented method of study of the selected parameters impact on the activated sludge biokinetic model (including autotrophs maximum growth rate, the share of organic slurry in suspension general operational, efficiency secondary settling tanks can be used for conducting simulation studies of other treatment plants.

  5. Determining lake surface water temperatures worldwide using a tuned one-dimensional lake model (FLake, v1)

    Science.gov (United States)

    Layden, Aisling; MacCallum, Stuart N.; Merchant, Christopher J.

    2016-06-01

    A tuning method for FLake, a one-dimensional (1-D) freshwater lake model, is applied for the individual tuning of 244 globally distributed large lakes using observed lake surface water temperatures (LSWTs) derived from along-track scanning radiometers (ATSRs). The model, which was tuned using only three lake properties (lake depth, snow and ice albedo and light extinction coefficient), substantially improves the measured mean differences in various features of the LSWT annual cycle, including the LSWTs of saline and high altitude lakes, when compared to the observed LSWTs. Lakes whose lake-mean LSWT persists below 1 °C for part of the annual cycle are considered to be seasonally ice-covered. For trial seasonally ice-covered lakes (21 lakes), the daily mean and standard deviation (2σ) of absolute differences between the modelled and observed LSWTs are reduced from 3.07 °C ± 2.25 °C to 0.84 °C ± 0.51 °C by tuning the model. For all other trial lakes (14 non-ice-covered lakes), the improvement is from 3.55 °C ± 3.20 °C to 0.96 °C ± 0.63 °C. The post tuning results for the 35 trial lakes (21 seasonally ice-covered lakes and 14 non-ice-covered lakes) are highly representative of the post-tuning results of the 244 lakes. For the 21 seasonally ice-covered lakes, the modelled response of the summer LSWTs to changes in snow and ice albedo is found to be statistically related to lake depth and latitude, which together explain 0.50 (R2adj, p = 0.001) of the inter-lake variance in summer LSWTs. Lake depth alone explains 0.35 (p = 0.003) of the variance. Lake characteristic information (snow and ice albedo and light extinction coefficient) is not available for many lakes. The approach taken to tune the model, bypasses the need to acquire detailed lake characteristic values. Furthermore, the tuned values for lake depth, snow and ice albedo and light extinction coefficient for the 244 lakes provide some guidance on improving FLake LSWT modelling.

  6. Bioregional Assessments: Determining the Impacts of Coal Resource Development on Water Resources in Australia through Groundwater, Surface Water and Ecological Modelling

    Science.gov (United States)

    Peeters, L. J.; Post, D. A.; Crosbie, R.; Holland, K.

    2017-12-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed `coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. The Australian Federal Government commissioned a multi-disciplinary programme of bioregional assessments to improve understanding of the potential impacts of coal seam gas and large coal mining activities on water resources and water-dependent assets across six bioregions Australia. A bioregional assessment is a transparent scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. The first step in the analysis is to establish the most likely scenario for coal development in each region and establish a causal pathway linking coal development to impacts to the social, economic and ecological functioning of water resources. This forms the basis for a sequence of probabilistic geological, hydrogeological, hydrological and ecological models to quantify the probability of potential impacts. This suite of models is developed independent of the proponents and regulators of coal resource developments and so can provide unbiased information to all stakeholders. To demonstrate transparency of the modelling, all inputs, outputs and executables will be available from http://www.bioregionalassessments.gov.au. The analysis delineated a zone of potential hydrological change for each region, outside of which impacts

  7. A model of water and sediment balance as determinants of relative sea level rise in contemporary and future deltas

    Science.gov (United States)

    Tessler, Zachary D.; Vörösmarty, Charles J.; Overeem, Irina; Syvitski, James P. M.

    2018-03-01

    Modern deltas are dependent on human-mediated freshwater and sediment fluxes. Changes to these fluxes impact delta biogeophysical functioning and affect the long-term sustainability of these landscapes for human and for natural systems. Here we present contemporary estimates of long-term mean sediment balance and relative sea level rise across 46 global deltas. We model scenarios of contemporary and future water resource management schemes and hydropower infrastructure in upstream river basins to explore how changing sediment fluxes impact relative sea level rise in delta systems. Model results show that contemporary sediment fluxes, anthropogenic drivers of land subsidence, and sea level rise result in delta relative sea level rise rates that average 6.8 mm/y. Assessment of impacts of planned and under-construction dams on relative sea level rise rates suggests increases on the order of 1 mm/y in deltas with new upstream construction. Sediment fluxes are estimated to decrease by up to 60% in the Danube and 21% in the Ganges-Brahmaputra-Meghna if all currently planned dams are constructed. Reduced sediment retention on deltas caused by increased river channelization and management has a larger impact, increasing relative sea level rise on average by nearly 2 mm/y. Long-term delta sustainability requires a more complete understanding of how geophysical and anthropogenic change impact delta geomorphology. Local and regional strategies for sustainable delta management that focus on local and regional drivers of change, especially groundwater and hydrocarbon extraction and upstream dam construction, can be highly impactful even in the context of global climate-induced sea level rise.

  8. Comparison of MRI techniques and modelling with R-SWMS for determining solute distribution patterns and root water uptake of a white lupine plant (Lupinus Albus L.).

    Science.gov (United States)

    Koch, Axelle; Schröder, Natalie; Pohlmeier, Andreas; Garré, Sarah; Vanderborght, Jan; Javaux, Mathieu

    2017-04-01

    Measuring water extraction by plant would allow us to better understand root water uptake processes and how soil and plant properties affect them. Yet, direct measurement of root water uptake is still challenging and determining its distribution requires coupling experimentation and modelling. In this study, we investigated how the 3D monitoring of a tracer movement in a sand container with a lupine plant could inform us about root water uptake process. A sand column (10 cm height, 5 cm inner diameter) planted with an 18-day-old white lupine was subject to a tracer experiment with a chemically inert tracer (1 mmol/L Gd-DTPA2-) applied for 6 days. Then the tracer and water fluxes were stopped. The plume was monitored in 3-D for 7 days by Magnetic Resonance Imaging (Haber-Pohlmeier et al, unp). In addition the breakthrough curve at the outlet was also measured. We used a biophysical 3-D soil-plant model: R-SWMS (Javaux et al, 2008) to extract information from this experiment. First, we ran a virtual experiment to check the assumption that Gd concentration increase around roots is proportional to the extracted soil water during the same period. We also investigated whether this type of experiment helps discriminate different root hydraulic properties with a sensitivity analysis. Then, we compared the experimental and simulated Gd concentration patterns. A preliminary (qualitative) assessment showed that measured Gd distribution patterns were better represented by the model at day 7, where the main driver of the concentration distribution was root and not soil heterogeneity (which is not taken into account in the model). The main spatial and temporal features of the transport where adequately reproduced by the model in particular during the last day. The distribution of the tracer was shown to be sensitive to the root hydraulic properties. To conclude, information about root water uptake distributions and so about root hydraulic properties could be deduced from Gd

  9. Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface. Long contact time experiments

    International Nuclear Information System (INIS)

    We report on the last experimental and modelling results of a research programme that started in 1995, corresponding in that case to the long contact time experiments. The aim of this programme has been to understand the processes that control the radiolytic generation of oxidants and reductants at the spent fuel water interface and their consequences for spent fuel stability and radionuclide release. The results of this work have been reported in different papers and technical reports during the last decade. In this series, well controlled dissolution experiments of PWR Ringhals spent fuel fragments in an initially anoxic closed system and by using different solution compositions have been carried out, the experiments have been opened after a long time period (between 1.5 and 3 years), samples have been taken and gas and solution analyses have been performed. The results indicate the following: Hydrogen and oxygen concentrations follow the same trend, an initial increase of the concentration of both compounds with time until they reach a steady state that indicates an overall balance of all the radiolytic species generated in the system. Hydrogen peroxide data show in general an initial decrease with time until it reaches a steady state for a given solution composition. This confirms the overall balance of the generated radiolytic species. The experimental data shows that uranium dissolution is controlled by the oxidation of the UO 2 matrix in 10 mM bicarbonate solutions while in the rest of the tests carried out at lower or in the absence of carbonate, uranium in the aqueous phase is governed by the precipitation of schoepite. These processes control the co-dissolution of most of the analysed radionuclides, including Sr, Cs, Mo, Tc and Np while not a clear dependency is found for Pu, Y, and Nd suggesting that other processes are governing the concentration of these radionuclides in the aqueous phase. Kinetic modelling has been performed with data from experiments

  10. WATER DIVERSION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Case

    1999-12-21

    The distribution of seepage in the proposed repository will be highly variable due in part to variations in the spatial distribution of percolations. The performance of the drip shield and the backfill system may divert the water flux around the waste packages to the invert. Diversion will occur along the drift surface, within the backfill, at the drip shield, and at the Waste Package (WP) surface, even after the drip shield and WP have been breached by corrosion. The purpose and objective of this Analysis and Modeling Report (AMR) are to develop a conceptual model and constitutive properties for bounding the volume and rate of seepage water that flows around the drip shield (CRWMS M&O 1999c). This analysis model is to be compatible with the selected repository conceptual design (Wilkins and Heath, 1999) and will be used to evaluate the performance of the Engineered Barrier System (EBS), and to provide input to the EBS Water Distribution and Removal Model. This model supports the Engineered Barrier System (EBS) postclosure performance assessment for the Site Recommendation (SR). This document characterizes the hydrological constitutive properties of the backfill and invert materials (Section 6.2) and a third material that represents a mixture of the two. These include the Overton Sand which is selected as a backfill (Section 5.2), crushed tuff which is selected as the invert (Section 5.1), and a combined material (Sections 5.9 and 5.10) which has retention and hydraulic conductivity properties intermediate to the selected materials for the backfill and the invert. The properties include the grain size distribution, the dry bulk density and porosity, the moisture retention, the intrinsic permeability, the relative permeability, and the material thermal properties. The van Genuchten relationships with curve fit parameters are used to define the basic retention relationship of moisture potential to volumetric moisture content, and the basic relationship of unsaturated

  11. WATER DIVERSION MODEL

    International Nuclear Information System (INIS)

    J.B. Case

    1999-01-01

    The distribution of seepage in the proposed repository will be highly variable due in part to variations in the spatial distribution of percolations. The performance of the drip shield and the backfill system may divert the water flux around the waste packages to the invert. Diversion will occur along the drift surface, within the backfill, at the drip shield, and at the Waste Package (WP) surface, even after the drip shield and WP have been breached by corrosion. The purpose and objective of this Analysis and Modeling Report (AMR) are to develop a conceptual model and constitutive properties for bounding the volume and rate of seepage water that flows around the drip shield (CRWMS MandO 1999c). This analysis model is to be compatible with the selected repository conceptual design (Wilkins and Heath, 1999) and will be used to evaluate the performance of the Engineered Barrier System (EBS), and to provide input to the EBS Water Distribution and Removal Model. This model supports the Engineered Barrier System (EBS) postclosure performance assessment for the Site Recommendation (SR). This document characterizes the hydrological constitutive properties of the backfill and invert materials (Section 6.2) and a third material that represents a mixture of the two. These include the Overton Sand which is selected as a backfill (Section 5.2), crushed tuff which is selected as the invert (Section 5.1), and a combined material (Sections 5.9 and 5.10) which has retention and hydraulic conductivity properties intermediate to the selected materials for the backfill and the invert. The properties include the grain size distribution, the dry bulk density and porosity, the moisture retention, the intrinsic permeability, the relative permeability, and the material thermal properties. The van Genuchten relationships with curve fit parameters are used to define the basic retention relationship of moisture potential to volumetric moisture content, and the basic relationship of

  12. Polyelectrolyte determination in drinking water

    African Journals Online (AJOL)

    include: colloidal titration, extraction-spectrophotometry, chro- matography, fluorometry and potentiometry. Methods that are simple to perform and that allow water- works operators to achieve precise results are desirable as quick. TABLE 1. List of contaminants found in polyelectrolyte products. Contaminant. Polyelectrolyte.

  13. Radon determination in ground water

    International Nuclear Information System (INIS)

    Segovia A, N.; Bulbulian G, S.

    1991-08-01

    Studies on natural radioactivity in ground water were started in Mexico in San Luis Potosi state followed by samplings from deep wells and springs in the states of Mexico and Michoacan. The samples were analyzed for solubilized and 226 Ra- supported 222 Rn. Some of them were also studied for 234 U/ 238 U activity ratio. In this paper we discuss the activities obtained and their relationship with the geologic characteristics of the studied zones. (Author)

  14. Radon determination in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Segovia A, N.; Bulbulian G, S

    1991-08-15

    Studies on natural radioactivity in ground water were started in Mexico in San Luis Potosi state followed by samplings from deep wells and springs in the states of Mexico and Michoacan. The samples were analyzed for solubilized and {sup 226} Ra- supported {sup 222} Rn. Some of them were also studied for {sup 234} U/ {sup 238} U activity ratio. In this paper we discuss the activities obtained and their relationship with the geologic characteristics of the studied zones. (Author)

  15. A calorimetric method to determine water activity.

    Science.gov (United States)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

    A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg(-1) to 3 mol kg(-1) and seven saturated aqueous salt solutions (LiCl, MgCl(2), NaBr, NaCl, KCl, KNO(3), and K(2)SO(4)) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities. © 2011 American Institute of Physics

  16. Fluorimetric determination of uranium in water

    International Nuclear Information System (INIS)

    Acosta L, E.

    1992-02-01

    The fluorimetric method for the determination of microquantities of uranium in water is described. This method covers the determination of uranium in water in the interval from 0.2 to 50 ppm on 50 ml. of radioactive base sample. These limits can be variable if the volume of the aliquot one of the base sample is changed, as well as the volume of the used aliquot one for to the final determination of uranium. (Author)

  17. CREDIT RISK. DETERMINATION MODELS

    Directory of Open Access Journals (Sweden)

    MIHAELA GRUIESCU

    2012-01-01

    Full Text Available The internationalization of financial flows and banking and the rapid development of markets have changed the financial sector, causing him to respond with force and imagination. Under these conditions, the concerns of financial and banking institutions, rating institutions are increasingly turning to find the best solutions to hedge risks and maximize profits. This paper aims to present a number of advantages, but also limits the Merton model, the first structural model for modeling credit risk. Also, some are extensions of the model, some empirical research and performance known, others such as state-dependent models (SDM, which together with the liquidation process models (LPM, are two recent efforts in the structural models, show different phenomena in real life.

  18. Sr90 determination in calcareous water

    International Nuclear Information System (INIS)

    Cohen, P.; Pardo, G.; Wormser, G.

    1958-01-01

    The Straub method (ref. 2) for determination of radioactive strontium in water containing calcium is valid within very wide limits, and particularly in the case of residual water from the chemical purification treatment of the radioactive liquid effluent at the C.E.N. Saclay. (author) [fr

  19. A method to determine plant water source using transpired water

    Science.gov (United States)

    Menchaca, L. B.; Smith, B. M.; Connolly, J.; Conrad, M.; Emmett, B.

    2007-04-01

    A method to determine the stable isotope ratio of a plant's water source using the plant's transpired water is proposed as an alternative to standard xylem extraction methods. The method consists of periodically sampling transpired waters from shoots or leaves enclosed in sealed, transparent bags which create a saturated environment, preclude further evaporation and allow the progressive mixing of evaporated transpired water and un-evaporated xylem water. The method was applied on trees and shrubs coexisting in a non-irrigated area where stable isotope ratios of local environmental waters are well characterized. The results show Eucalyptus globulus (tree) and Genista monspessulana (shrub) using water sources of different isotopic ratios congruent with groundwater and soil water respectively. In addition, tritium concentrations indicate that pine trees (Pinus sylvestris) switch water source from soil water in the winter to groundwater in the summer. The method proposed is particularly useful in remote or protected areas and in large scale studies related to water management, environmental compliance and surveillance, because it eliminates the need for destructive sampling and greatly reduces costs associated with laboratory extraction of xylem waters from plant tissues for isotopic analyses.

  20. Lotic Water Hydrodynamic Model

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tasseff, Byron Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-23

    Water-related natural disasters, for example, floods and droughts, are among the most frequent and costly natural hazards, both socially and economically. Many of these floods are a result of excess rainfall collecting in streams and rivers, and subsequently overtopping banks and flowing overland into urban environments. Floods can cause physical damage to critical infrastructure and present health risks through the spread of waterborne diseases. Los Alamos National Laboratory (LANL) has developed Lotic, a state-of-the-art surface water hydrodynamic model, to simulate propagation of flood waves originating from a variety of events. Lotic is a two-dimensional (2D) flood model that has been used primarily for simulations in which overland water flows are characterized by movement in two dimensions, such as flood waves expected from rainfall-runoff events, storm surge, and tsunamis. In 2013, LANL developers enhanced Lotic through several development efforts. These developments included enhancements to the 2D simulation engine, including numerical formulation, computational efficiency developments, and visualization. Stakeholders can use simulation results to estimate infrastructure damage and cascading consequences within other sets of infrastructure, as well as to inform the development of flood mitigation strategies.

  1. Determinants of virtual water flows in the Mediterranean.

    Science.gov (United States)

    Fracasso, Andrea; Sartori, Martina; Schiavo, Stefano

    2016-02-01

    The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a "refined" version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger 'export' of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water 'exports' ('imports'). Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Use of remotely-sensed observations and a data assimilating marine biogeochemical model to determine water quality on the Great Barrier Reef.

    Science.gov (United States)

    Baird, Mark; Jones, Emlyn; Wozniak, Monika; Mongin, Mathieu; Skerratt, Jennifer; Margvelashvilli, Nugzar; Wild-Allen, Karen; Robson, Barbara; Rizwi, Farhan; Schroeder, Thomas; Steven, Andy

    2017-04-01

    The health of the Great Barrier Reef is presently assessed using the water column concentration of chlorophyll and suspended solids, and measured light penetration. Quantifying these water column properties over 2,000 km of often cloud-covered, sparsely sampled, and highly variable coastal waters is problematic. To provide the best estimate of water quality, we assimilating satellite remote-sensing reflectance (the ratio of water-leaving radiance versus water-entering irradiance) using an in-water optical model to produce an equivalent simulated remote-sensing reflectance, and calculate the mis-match between the observed and simulated quantities to constrain a complex biogeochemical model (eReefs) with a Deterministic Ensemble Kalman Filter (DEnKF). We compare the water quality properties of the data assimilating model with in-situ observations, as well as with withheld remote-sensed observations. As a final step, we consider whether withheld observations can be combined with the data-assimilation generated chlorophyll fields to provide the best estimate of the chlorophyll concentration given all the available information.

  3. Estimating the Determinants of Residential Water Demand in Italy

    Directory of Open Access Journals (Sweden)

    Giulia Romano

    2014-09-01

    Full Text Available The aim of this study was to estimate the determinants of residential water demand for chief towns of every Italian province, in the period 2007–2009, using the linear mixed-effects model estimated with the restricted-maximum-likelihood method. Results confirmed that the applied tariff had a negative effect on residential water consumption and that it was a relevant driver of domestic water consumption. Moreover, income per capita had a positive effect on water consumption. Among measured climatic and geographical features, precipitation and altitude exerted a strongly significant negative effect on water consumption, while temperature did not influence water demand. Further, data show that small towns in terms of population served were characterized by lower levels of consumption. Water utilities ownership itself did not have a significant effect on water consumption but tariffs were significantly lower and residential water consumption was higher in towns where the water service was managed by publicly owned water utilities. However, further research is needed to gain a better understanding of the connection between ownership of water utilities and water prices and water consumption.

  4. Absorbed dose determination in water. I

    International Nuclear Information System (INIS)

    Novotny, J.

    1991-01-01

    The use of new values of physical parameters as recommended by international organizations has consequences in radiotherapy, e.g. in the determination of absorbed doses in water based on ionometric measurements. A procedure is proposed for the determination of the conversion factor K w,u between kerma in air and absorbed dose in water, and of the factor C w,u between exposure measured and absorbed dose in water, for ionization chambers and high-energy photon beams. The conversion factors depend not only on the radiation quality but also on the dimensions and composition of the chamber and of the cup used in the calibrations. Numerical values are given for conventional kinds of ionization chambers. (author). 3 tabs., 16 refs

  5. Absorbed dose determination in water. II

    International Nuclear Information System (INIS)

    Novotny, J.; Hobzova, L.; Kindlova, A.

    1991-01-01

    The use of new values of physical parameters as recommended by international organizations has consequences in radiotherapy, e.g. in the determination of absorbed doses in water based on ionometric measurements. A procedure is proposed for the determination of the conversion factor K w,e from kerma in air to absorbed dose in water, and of the conversion factor C w,e from exposure measured to dose absorbed in water, this for ionization chambers and high-energy electron beams. The conversion factors depend not only on the radiation quality and measurement depth in the phantom but also on the dimensions and composition of the chamber and of the cup used in the calibrations. Numerical values are given for two conventional kinds of ionization chambers. (author). 3 tabs., 9 refs

  6. DETERMINANTS OF RESIDENTIAL PER CAPITA WATER ...

    African Journals Online (AJOL)

    This report presents the findings of the study on the determinants of residential per capita water demand of Makurdi metropolis in Benue State, Nigeria. Data for the study was obtained by the use of questionnaires, oral interviews and observations. The data was analyzed using SPSS. Twenty variables were considered in ...

  7. Underground water stress release models

    Science.gov (United States)

    Li, Yong; Dang, Shenjun; Lü, Shaochuan

    2011-08-01

    The accumulation of tectonic stress may cause earthquakes at some epochs. However, in most cases, it leads to crustal deformations. Underground water level is a sensitive indication of the crustal deformations. We incorporate the information of the underground water level into the stress release models (SRM), and obtain the underground water stress release model (USRM). We apply USRM to the earthquakes occurred at Tangshan region. The analysis shows that the underground water stress release model outperforms both Poisson model and stress release model. Monte Carlo simulation shows that the simulated seismicity by USRM is very close to the real seismicity.

  8. Preliminary ECLSS waste water model

    Science.gov (United States)

    Carter, Donald L.; Holder, Donald W., Jr.; Alexander, Kevin; Shaw, R. G.; Hayase, John K.

    1991-01-01

    A preliminary waste water model for input to the Space Station Freedom (SSF) Environmental Control and Life Support System (ECLSS) Water Processor (WP) has been generated for design purposes. Data have been compiled from various ECLSS tests and flight sample analyses. A discussion of the characterization of the waste streams comprising the model is presented, along with a discussion of the waste water model and the rationale for the inclusion of contaminants in their respective concentrations. The major objective is to establish a methodology for the development of a waste water model and to present the current state of that model.

  9. Determination of mercury in drinking water

    International Nuclear Information System (INIS)

    Anand, S.J.S.

    1976-01-01

    Determination of mercury in drinking water samples have been carried out by neutron activation followed by chemical separation. The chemical analysis is necessary as the levels of mercury in these samples are quite low and activities of sodium, copper etc. interfere in its determination by direct spectroscopy. Solvent extraction separation offers speed and complete separation from interfering activities. Some of drinking water samples collected at Trombay have been analysed and their result are given in this paper. The procedure was checked with 197 Hg tracer and the reproducibility of the procedure is within 5%. It was free from contamination due to the activities of Cu, Na etc. The time of analysis was 15 minutes, and upto 5 samples could be analysed conveniently at a time. The average chemical yield was 72%. (T.I.)

  10. Studies of the kinetics and mechanism of the oxidation of uranium by dry and moist air A model for determining the oxidation rate over a wide range of temperatures and water vapour pressures

    Science.gov (United States)

    McGillivray, G. W.; Geeson, D. A.; Greenwood, R. C.

    1994-01-01

    The rate of oxidation of uranium metal by moist air has been measured at temperatures from 115 to 350°C and water vapour pressures from 0 to 47 kPa (350 Torr). From this and from previously reported data, a model has been developed which allows the rate of uranium oxidation to be calculated at any particular combination of temperature and water vapour pressure of interest, in the range 0-350°C and 0-101.3 kPa (760 Torr). The model is based on the assumption that the surface concentration of water determines the rate of reaction and that the adsorption of water onto the oxide follows a Langmuir type isotherm. Theoretical plots of rate as a function of water vapour pressure and Arrhenius plots derived from the model have been shown to be in good agreement with experimental data. The model assumes separate contributions to the overall observed rate from oxygen and water vapour. Surface studies have been carried out using SIMS (secondary ion mass spectrometry). Depth profiling of the oxide produced by isotopically labelled reagents ( 18O 2 and H 218O), has shown that oxygen from both reactants is incorporated into the oxide layer in the ratio predicted by the kinetic model. This supports a mechanism in which oxygen and water vapour produce separate diffusing species (possibly O 2- and OH -).

  11. Modelling water temperature in TOXSWA

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Deneer, J.W.; Adriaanse, P.I.

    2010-01-01

    A reasonably accurate estimate of the water temperature is necessary for a good description of the degradation of plant protection products in water which is used in the surface water model TOXSWA. Based on a consideration of basic physical processes that describe the influence of weather on the

  12. Development Smart Water Aquaponics Model

    Directory of Open Access Journals (Sweden)

    Gheorghe Adrian ZUGRAVU

    2017-06-01

    Full Text Available The present paper contributes to the modeling aquaculture. The paper main objectives are to identify an analysis smart water aquaponics. The purpose is to add more value to end aquaponics products. Aquaculture production depends on physical, chemical and biological qualities of pond water to a greater extent. The successful pond management requires an understanding of water quality. Intensification of pond makes the water quality undesirable with a number of water quality parameters. The objective of this model is to test and predicts plant and fish growth and net ammonium and nitrate concentrations in water in an aquaponic system. This is done by comparing the model outputs with measurements under controlled conditions in order to assess the accuracy of the tool to simulate nutrient concentrations in water and fish and plant biomass production of the system.

  13. Catalytic determination of vanadium in water

    Science.gov (United States)

    Fishman, M. J.; Skougstad, M.W.

    1964-01-01

    A rapid, accurate, and sensitive spectrophotometric method for the quantitative determination of trace amounts of vanadium in water is based on the catalytic effect of vanadium on the rate of oxidation of gallic acid by persulfate in acid solution. Under given conditions of concentrations of reactants, temperature, and reaction time, the extent of oxidation of gallic acid is proportional to the concentration of vanadium present. Vanadium is determined by measuring the absorbance of the sample at 415 m?? and comparison with standard solutions treated in an identical manner. Concentrations in the range of from 0.1 to 8.0 ??g. per liter may be determined with a standard deviation of 0.2 or less. By reducing the reaction time, the method may be extended to cover the range from 1 to 100 ??g. with a standard deviation of 0.8 or less. Several substances interfere, including chloride above 100 p.p.m., and bromide and iodide in much lower concentrations. Interference from the halides is eliminated or minimized by the addition of mercuric nitrate solution. Most other substances do not interfere at the concentration levels at which they commonly occur in natural waters.

  14. Modelling Ballast Water Transport

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Babu, M.T.; Vethamony, P.

    water in the marine environment. The bathymetry of the region has been taken from the CMAP data and augmented by data from hydrographic charts and bathymetry data available at NIO Data Center, Goa. Tides along the open boundary were generated...

  15. Flood Water Crossing: Laboratory Model Investigations for Water Velocity Reductions

    Directory of Open Access Journals (Sweden)

    Kasnon N.

    2014-01-01

    Full Text Available The occurrence of floods may give a negative impact towards road traffic in terms of difficulties in mobilizing traffic as well as causing damage to the vehicles, which later cause them to be stuck in the traffic and trigger traffic problems. The high velocity of water flows occur when there is no existence of objects capable of diffusing the water velocity on the road surface. The shape, orientation and size of the object to be placed beside the road as a diffuser are important for the effective flow attenuation of water. In order to investigate the water flow, a laboratory experiment was set up and models were constructed to study the flow velocity reduction. The velocity of water before and after passing through the diffuser objects was investigated. This paper focuses on laboratory experiments to determine the flow velocity of the water using sensors before and after passing through two best diffuser objects chosen from a previous flow pattern experiment.

  16. Empirical model for chlorophyll-a determination in inland waters from the forthcoming Sentinel-2 and 3. Validation from HICO images

    Directory of Open Access Journals (Sweden)

    J. Delegido

    2014-06-01

    Full Text Available Chlorophyll-a concentration is one of the main indicators of inland waters quality. Using CHRIS/PROBA images and in situ data obtained in four lakes in Colombia and Spain, we obtained empirical models for the estimation of chlorophyll-a concentration, which can be directly applied to future images of MSI Sentinel-2 and OLCI Sentinel-3 sensors. The models, based on spectral band indices, were validated with data from the hyperspectral sensor HICO, onboard of the International Space Station.

  17. Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

    Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

  18. Determination of trace elements in ground drinking water in Norway

    OpenAIRE

    Abiyos, Beka

    2017-01-01

    Drinking water is essential for life. However, unless standard quality of drinking water is maintained, water can be associated with health risks. The present study was conducted to determine primarily inorganic elements in Norwegian ground drinking water in a nationwide investigation including 201 well works. In addition, indicators of water quality such as pH, conductivity, alkalinity, turbidity, and color were also determined. Water samples were collected from the source (raw water) and fr...

  19. Determining the phase diagram of water from direct coexistence simulations: the phase diagram of the TIP4P/2005 model revisited.

    Science.gov (United States)

    Conde, M M; Gonzalez, M A; Abascal, J L F; Vega, C

    2013-10-21

    Direct coexistence simulations between the fluid and solid phases are performed for several ices. For ices Ih and VII it has already been shown that the methodology is successful and the melting point is in agreement with that obtained from free energy calculations. In this work the methodology is applied to ices II, III, V, and VI. The lengths of the direct coexistence runs for the high pressure polymorphs are not too long and last less than 20 ns for all ices except for ice II where longer runs (of about 150 ns) are needed. For ices II, V, and VI the results obtained are completely consistent with those obtained from free energy calculations. However, for ice III it is found that the melting point from direct coexistence simulations is higher than that obtained from free energy calculations, the difference being greater than the statistical error. Since ice III presents partial proton orientational disorder, the departure is attributed to differences in the partial proton order in the water model with respect to that found in the experiment. The phase diagram of the TIP4P/2005 model is recalculated using the melting points obtained from direct coexistence simulations. The new phase diagram is similar to the previous one except for the coexistence lines where ice III is involved. The range of stability of ice III on the p-T plot of the phase diagram increases significantly. It is seen that the model qualitatively describes the phase diagram of water. In this work it is shown that the complete phase diagram of water including ices Ih, II, III, V, VI, VII, and the fluid phase can be obtained from direct coexistence simulations without the need of free energy calculations.

  20. Ground water modelling

    International Nuclear Information System (INIS)

    Leino-Forsman, H.; Olin, M.

    1991-01-01

    The first Seminar on Groundwater Modelling was arranged by VTT (Reactor Laboratory) in Espoo Finland in May 1991. The one day seminar dealt both with modelling of geochemistry and transport of groundwater, as well as mathematical methods for modelling. The seminar concentrated on giving a broad picture of the applications of groundwater modelling e.g. nuclear waste, groundwater resources including artificial groundwater and pollution. The participants came from research institutes and universities as well as engineering companies. Articles are published in Finnish with English abstracts

  1. Stochastic Still Water Response Model

    DEFF Research Database (Denmark)

    Friis-Hansen, Peter; Ditlevsen, Ove Dalager

    2002-01-01

    water bending moment is compared to statistics from available regression formulas. It is found that the suggested model predicts a coefficient of variation of the maximum still water bending moment that is a factor of two to three times lower than that obtained by use of the regression formula. It turns......In this study a stochastic field model for the still water loading is formulated where the statistics (mean value, standard deviation, and correlation) of the sectional forces are obtained by integration of the load field over the relevant part of the ship structure. The objective of the model...

  2. Modeling Water Filtration

    Science.gov (United States)

    Parks, Melissa

    2014-01-01

    Model-eliciting activities (MEAs) are not new to those in engineering or mathematics, but they were new to Melissa Parks. Model-eliciting activities are simulated real-world problems that integrate engineering, mathematical, and scientific thinking as students find solutions for specific scenarios. During this process, students generate solutions…

  3. WATER QUALITY MODELS: A REVIEW

    OpenAIRE

    Nair Sumita; Bhatia Sukhpreet Kaur

    2017-01-01

    Maintaining water quality and predicting the fate of water pollutants are one of the important tasks of present environmental problems. The best tool for predicting different pollution scenarios are the simulation of mathematical models which can provide a basis and technical support for environmental management.

  4. Water Stress Projection Modeling

    Science.gov (United States)

    2016-09-01

    www.eia.gov/ forecasts /aeo/tables_ref.cfm U.S. Geological Survey (USGS). 2014. National land cover database (NLCD). Multi - Resolution Land...Engineers Washington, DC 20314-1000 ERDC/CERL TR-16-32 ii Abstract U.S. Army stationing is a constant multi -scale process. Large scale station- ing, which...20 4.6 Model output

  5. Modelling reveals endogenous osmotic adaptation of storage tissue water potential as an important driver determining different stem diameter variation patterns in the mangrove species Avicennia marina and Rhizophora stylosa.

    Science.gov (United States)

    Vandegehuchte, Maurits W; Guyot, Adrien; Hubeau, Michiel; De Swaef, Tom; Lockington, David A; Steppe, Kathy

    2014-09-01

    Stem diameter variations are mainly determined by the radial water transport between xylem and storage tissues. This radial transport results from the water potential difference between these tissues, which is influenced by both hydraulic and carbon related processes. Measurements have shown that when subjected to the same environmental conditions, the co-occurring mangrove species Avicennia marina and Rhizophora stylosa unexpectedly show a totally different pattern in daily stem diameter variation. Using in situ measurements of stem diameter variation, stem water potential and sap flow, a mechanistic flow and storage model based on the cohesion-tension theory was applied to assess the differences in osmotic storage water potential between Avicennia marina and Rhizophora stylosa. Both species, subjected to the same environmental conditions, showed a resembling daily pattern in simulated osmotic storage water potential. However, the osmotic storage water potential of R. stylosa started to decrease slightly after that of A. marina in the morning and increased again slightly later in the evening. This small shift in osmotic storage water potential likely underlaid the marked differences in daily stem diameter variation pattern between the two species. The results show that in addition to environmental dynamics, endogenous changes in the osmotic storage water potential must be taken into account in order to accurately predict stem diameter variations, and hence growth.

  6. River water quality modelling: II

    DEFF Research Database (Denmark)

    Shanahan, P.; Henze, Mogens; Koncsos, L.

    1998-01-01

    The U.S. EPA QUAL2E model is currently the standard for river water quality modelling. While QUAL2E is adequate for the regulatory situation for which it was developed (the U.S. wasteload allocation process), there is a need for a more comprehensive framework for research and teaching. Moreover......, and to achieve robust model calibration. Mass balance problems arise from failure to account for mass in the sediment as well as in the water column and due to the fundamental imprecision of BOD as a state variable. (C) 1998 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  7. Determining water management training needs through stakeholder ...

    African Journals Online (AJOL)

    South Africa is a water-stressed country and the efficient management of the demand for and frugal use of water is a topic that can no longer be avoided. Community-based natural resource management is an alternative approach to government stewardship of natural resources, and in the instance of water management it is ...

  8. Integrated Water Resources Simulation Model for Rural Community

    Science.gov (United States)

    Li, Y.-H.; Liao, W.-T.; Tung, C.-P.

    2012-04-01

    The purpose of this study is to develop several water resources simulation models for residence houses, constructed wetlands and farms and then integrate these models for a rural community. Domestic and irrigation water uses are the major water demand in rural community. To build up a model estimating domestic water demand for residence houses, the average water use per person per day should be accounted first, including water uses of kitchen, bathroom, toilet and laundry. On the other hand, rice is the major crop in the study region, and its productive efficiency sometimes depends on the quantity of irrigation water. The water demand can be estimated by crop water use, field leakage and water distribution loss. Irrigation water comes from rainfall, water supply system and reclaimed water which treated by constructed wetland. In recent years, constructed wetlands play an important role in water resources recycle. They can purify domestic wastewater for water recycling and reuse. After treating from constructed wetlands, the reclaimed water can be reused in washing toilets, watering gardens and irrigating farms. Constructed wetland is one of highly economic benefits for treating wastewater through imitating the processing mechanism of natural wetlands. In general, the treatment efficiency of constructed wetlands is determined by evapotranspiration, inflow, and water temperature. This study uses system dynamics modeling to develop models for different water resource components in a rural community. Furthermore, these models are integrated into a whole system. The model not only is utilized to simulate how water moves through different components, including residence houses, constructed wetlands and farms, but also evaluates the efficiency of water use. By analyzing the flow of water, the water resource simulation model can optimizes water resource distribution under different scenarios, and the result can provide suggestions for designing water resource system of a

  9. Mathematical model for water quality (portable water): a case study ...

    African Journals Online (AJOL)

    A water quality model for water-use-goal is proposed. The model is tested with a treatment schedule at a water works for portable water. It was observed that at least a 25 per cent savings can be achieved if the model is employed. Mathematics Connection Vol. 4 2004: 27-30 ...

  10. Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface. Experiments carried out in carbonate solutions in absence and presence of chloride

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Jordi; Cera, Esther; Grive, Mireia; Duro, Lara [Enviros Spain SL (Spain); Eriksen, Trygve [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear Chemistry

    2003-01-01

    We report on the recent experimental and modelling results of a research programme that started in 1995. The aim has been to understand the kinetic and thermodynamic processes that control the radiolytic generation of oxidants and reductants at the spent fuel water interface and their consequences for spent fuel matrix stability and radionuclide release. This has been done by carrying out well-controlled dissolution experiments of PWR Ringhals spent fuel fragments in an initially anoxic closed system and by using different solution compositions. Experimental series started with several tests carried out with deionised water as solvent, in a second phase experiments were conducted with 10 mM bicarbonate solutions. New experimental series were set up during the last two years by using the same bicarbonate content in solutions with varying NaCl concentrations in order to ascertain the role of this ligand on the radiolytic products and its consequence for radionuclide release. The selected NaCl concentrations are in the range of 0.1 to 10 mM. Experimental data shows that uranium dissolution at early contact times is controlled by the oxidation of the UO{sub 2} matrix. This process controls the co-dissolution of most of the analysed radionuclides, including Sr, Mo, Tc, Np and surprisingly enough, Cs. In the overall the release rates for U and the matrix associated radionuclides are in the range of 10{sup -6} moles/day with a clear decreasing trend with exposure time and after 2 years the initial release rates have decreased down to 3x10{sup -8} moles/day. The solubility of the released actinides appears to be limited by the formation of An(IV) hydroxide phases, although Np concentrations in solution did not reach solubility levels during the time intervals of the present tests. No secondary solid phase appears to control the solubility of the rest of the elements.

  11. Spectrophotometric determination of silica in water with Hach equipment

    International Nuclear Information System (INIS)

    Acosta L, E.

    1992-06-01

    The method for the determination of the silica element in water, demineralized water, raw waters, laundry waters, waters treated with ion exchange resins and sea waters using the indicated technique in the operation manual of the Hach equipment with a DR/3 spectrophotometer is described. This method covers the determination of the silica element in the interval from 0 to 1.5 mg/l on 50 ml. of base sample. These limits its can be variable if the size of the used aliquot one is changed for the final determination of the silica element. (Author)

  12. Water Distribution and Removal Model

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-08-26

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

  13. Water Distribution and Removal Model

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  14. COMPILATION OF GROUND WATER MODELS

    Science.gov (United States)

    The full report presents an overview of currently available computer-based simulation models for ground-water flow, solute and heat transport, and hydrogeochemistry in both porous media and fractured rock. Separate sections address multiphase flow and related chemical species tra...

  15. Remote sensing inputs to water demand modeling

    Science.gov (United States)

    Estes, J. E.; Jensen, J. R.; Tinney, L. R.; Rector, M.

    1975-01-01

    In an attempt to determine the ability of remote sensing techniques to economically generate data required by water demand models, the Geography Remote Sensing Unit, in conjunction with the Kern County Water Agency of California, developed an analysis model. As a result it was determined that agricultural cropland inventories utilizing both high altitude photography and LANDSAT imagery can be conducted cost effectively. In addition, by using average irrigation application rates in conjunction with cropland data, estimates of agricultural water demand can be generated. However, more accurate estimates are possible if crop type, acreage, and crop specific application rates are employed. An analysis of the effect of saline-alkali soils on water demand in the study area is also examined. Finally, reference is made to the detection and delineation of water tables that are perched near the surface by semi-permeable clay layers. Soil salinity prediction, automated crop identification on a by-field basis, and a potential input to the determination of zones of equal benefit taxation are briefly touched upon.

  16. Determination of 40K in water samples

    International Nuclear Information System (INIS)

    Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R.

    2014-10-01

    The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of 40 K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the 40 K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the 40 K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of 137 Cs, diameter 22 Na and 7.62 cm of height, using containers Marinelli and 60 Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the 40 K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of 40 K deposits an effective dose which contributes to annual dose received by people. (Author)

  17. Quantitative Determination of Spring Water Quality Parameters via Electronic Tongue

    Directory of Open Access Journals (Sweden)

    Noèlia Carbó

    2017-12-01

    Full Text Available The use of a voltammetric electronic tongue for the quantitative analysis of quality parameters in spring water is proposed here. The electronic voltammetric tongue consisted of a set of four noble electrodes (iridium, rhodium, platinum, and gold housed inside a stainless steel cylinder. These noble metals have a high durability and are not demanding for maintenance, features required for the development of future automated equipment. A pulse voltammetry study was conducted in 83 spring water samples to determine concentrations of nitrate (range: 6.9–115 mg/L, sulfate (32–472 mg/L, fluoride (0.08–0.26 mg/L, chloride (17–190 mg/L, and sodium (11–94 mg/L as well as pH (7.3–7.8. These parameters were also determined by routine analytical methods in spring water samples. A partial least squares (PLS analysis was run to obtain a model to predict these parameter. Orthogonal signal correction (OSC was applied in the preprocessing step. Calibration (67% and validation (33% sets were selected randomly. The electronic tongue showed good predictive power to determine the concentrations of nitrate, sulfate, chloride, and sodium as well as pH and displayed a lower R2 and slope in the validation set for fluoride. Nitrate and fluoride concentrations were estimated with errors lower than 15%, whereas chloride, sulfate, and sodium concentrations as well as pH were estimated with errors below 10%.

  18. Spectrophotometric Determination of Boron in Environmental Water Samples

    International Nuclear Information System (INIS)

    San San; Khin Win Kyi; Kwaw Naing

    2002-02-01

    The present paper deals with the study on the methods for the determination of boron in the environmental water samples. The standard methods which are useful for this determination are discussed thoroughly in this work. Among the standard methods approved by American Public Health Association, the carmine method was selected for this study. Prior to the determination of boron in the water samples, the precision and accuracy of the methods of choice were examined by using standard boron solutions. The determination of Boron was carried out by using water samples, waste water from Aquaculture Research Centre, University of Yangon, the Ayeyarwady River water near Magway Myathalon Pagoda in Magway Division, ground water from Sanchaung Township, and tap water from Universities' Research Centre, University of Yangon. Analyses of these water samples were done and statistical treatment of the results was carried out. (author)

  19. Spectrophotometric determination of fluoride in drinking water using ...

    African Journals Online (AJOL)

    2011-03-14

    Mar 14, 2011 ... A sensitive spectrophotometric determination of fluoride in drinking water has been developed using aluminium complexes ... Keywords: Fluoride analysis, spectrophotometric method, drinking water, aluminium triphenylmethane dye ..... mechanism at the mercury electrode in neutral and alkaline aque-.

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

    International Nuclear Information System (INIS)

    Zimmer, U.

    1998-01-01

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

  1. Optimisation of ATP determination in drinking water

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    and an Advance Coupe luminometer. The investigations showed a 60 times higher response of the PCP-kit, making it more suitable for measurement of samples with low ATP content. ATP-standard dilutions prepared in tap water were stable for at least 15 months when stored frozen at -80ºC, and storage of large...... aliquots of standards increase quality control and ease daily operation. The medium (Lumin(PM) buffer, tap water or MilliQ water) for preparation of ATP-standard dilution significantly affected the rlu response of the ATP-standard dilutions (20% difference). The effect of dilution media and of sample...... characteristics can be eliminated by use of internal standard. In strongly coloured biofilm samples the measuring efficiency can be reduced with up to 85%. Extra cellular ATP made up a significant part of the total ATP (>50%) in some samples, so when only intra cellular ATP is of interest the cells need...

  2. Determination of carbofuran in water by radioimmunoassay

    International Nuclear Information System (INIS)

    Zhu Guonian; Wu Huiming; Yang Ting; Hu Xiuqing

    2004-01-01

    A competitive radioimmunoassay (RIA) method was established to detect carbofuran in water samples. Compared with traditional analytical methods RIA provided a easy procedure with higher sensitivity. The detective limitation of RIA for carbofuran was proved to be 0.175 ng/ml. A study was performed to test validation of the RIA. In this study carbofuran residues in water samples were detected simultaneously by RIA and by high performance liquid chromatograph (HPLC). The linear correlation coefficient of the test results was measure to be 0.9985. (authors)

  3. Spectrophotometric determination of fluorides in water with Hach equipment

    International Nuclear Information System (INIS)

    Acosta L, E.

    1994-11-01

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  4. Preconcentration NAA for simultaneous multielemental determination in water sample

    International Nuclear Information System (INIS)

    Chatt, A.

    1999-01-01

    Full text: Environment concerns with water, air, land and their interrelationship viz., human beings, fauna and flora. One of the important environmental compartments is water. Elements present in water might face a whole lot of physico-chemical conditions. This poses challenges to measure their total concentrations as well as different species. Preconcentration of the elements present in water samples is a necessary requisites in water analysis. For multi elements concentration measurements, Neutron Activation Analysis (NAA) is one of the preferred analytical techniques due to its sensitivity and selectivity. In this talk preconcentration NAA for multielemental determination in water sample determination will be discussed

  5. Methods for Determining Organic Matter and Colour in Water

    Directory of Open Access Journals (Sweden)

    Ramunė Albrektienė

    2011-02-01

    Full Text Available The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.Article in Lithuanian

  6. Polyelectrolyte determination in drinking water | Majam | Water SA

    African Journals Online (AJOL)

    Chemical contaminants that occur in drinking water are not usually associated with acute health effects when compared to microbial contaminants and are usually given a lower priority. Those that are of concern have cumulative toxic properties such as metals and substances that are carcinogenic. Some of these potentially ...

  7. Modeling Water Pollution of Soil

    Directory of Open Access Journals (Sweden)

    V. Doležel

    2008-01-01

    depth of 220–300 m below the terrain. As an alternative, thinner stoppers were considered, but this option was discarded.The aim of this paper is to describe the design of the stoppers applied to separate the two types of water along the contact horizon using Desai’s DSC theory (Distinct State Concept, and generalized plane strain in the multiphase problem of water flow in a porous medium. In addition, a comparison of some results from scale experimental models with numerical solutions was carried out. The intrinsic material properties of stoppers for numerical computations were obtained from physical and chemical laboratory tests. The models were evaluated for the complete underground work, particularly in its final stage of construction. 

  8. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  9. Determination of the Level of Contamination of Underground Water ...

    African Journals Online (AJOL)

    The aim of this study is to determine the level of contamination of hand-dug well which is one of the major source of water supply for the population. Water samples were taken from a total of fifteen wells at the vicinity of three major refuse dumpsite taking measurement of depth of the well, diameter, volume of water, distance ...

  10. Accounting for Water Insecurity in Modeling Domestic Water Demand

    Science.gov (United States)

    Galaitsis, S. E.; Huber-lee, A. T.; Vogel, R. M.; Naumova, E.

    2013-12-01

    Water demand management uses price elasticity estimates to predict consumer demand in relation to water pricing changes, but studies have shown that many additional factors effect water consumption. Development scholars document the need for water security, however, much of the water security literature focuses on broad policies which can influence water demand. Previous domestic water demand studies have not considered how water security can affect a population's consumption behavior. This study is the first to model the influence of water insecurity on water demand. A subjective indicator scale measuring water insecurity among consumers in the Palestinian West Bank is developed and included as a variable to explore how perceptions of control, or lack thereof, impact consumption behavior and resulting estimates of price elasticity. A multivariate regression model demonstrates the significance of a water insecurity variable for data sets encompassing disparate water access. When accounting for insecurity, the R-squaed value improves and the marginal price a household is willing to pay becomes a significant predictor for the household quantity consumption. The model denotes that, with all other variables held equal, a household will buy more water when the users are more water insecure. Though the reasons behind this trend require further study, the findings suggest broad policy implications by demonstrating that water distribution practices in scarcity conditions can promote consumer welfare and efficient water use.

  11. Spent nuclear fuel/water interface behavior: Alpha dose rate profile determination for model surfaces and microcracks by using Monte-Carlo methods

    Science.gov (United States)

    Tribet, M.; Mougnaud, S.; Jégou, C.

    2017-05-01

    This work aims to better understand the nature and evolution of energy deposits at the UO2/water reactional interface subjected to alpha irradiation, through an original approach based on Monte-Carlo-type simulations, using the MCNPX code. Such an approach has the advantage of describing the energy deposit profiles on both sides of the interface (UO2 and water). The calculations have been performed on simple geometries, with data from an irradiated UOX fuel (burnup of 47 GWd.tHM-1 and 15 years of alpha decay). The influence of geometric parameters such as the diameter and the calculation steps at the reactional interface are discussed, and the exponential laws to be used in practice are suggested. The case of cracks with various different apertures (from 5 to 35 μm) has also been examined and these calculations have also enabled new information on the mean range of radiolytic species in cracks, and thus on the local chemistry.

  12. 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

  13. Modeling of Water Quality 'Almendares River'

    International Nuclear Information System (INIS)

    Domínguez Catasús, Judith

    2005-01-01

    The river Almendares, one of the most important water bodies of the Havana City, is very polluted. The analysis of parameters as dissolved oxygen and biochemical oxygen demand is very helpful for the studies aimed to the recovery of the river. There is a growing recognition around the word that the water quality models are very useful tools to plan sanitary strategies for the handling of the contamination. In the present work, the advective, steady- state Streeter and Phelps model was validated to simulate the effect of the multiple-point and distributed sources on the carbonaceous oxygen demand, NH4 and dissolved oxygen. For modeling purposes the section of the river located between the point where the waste water treatment station Maria del Carmen discharges to the river and the Bridge El Bosque, was divided in 11 segments. The use of the 99mTc and the Rodamine WT as tracers allowed determining the hydrodynamic parameters necessary for modeling purposes. The validated model allows to predict the effect of the sanitary strategies on the water quality of the river. The main conclusions are: 1. The model Streeter and Phelps calibrated and validated in the Almendares between the confluence of the channel 'María del Carmen' and bridge the Forest of Havana, described in more than 90% The behavior of the dissolved oxygen and BODn (in terms of ammonia), and more than 85%, the carbonaceous demand oxygen, which characterizes the process of purification. 2. Model validation Streeter and Phelps, indicates that implicit conceptual model is appropriate. This refers primarily to the considerations relating to the calculation of the kinetic constants and the DOS, the segmentation used, to the location of the discharges and the Standing been about them, to the river morphology and hydrodynamic parameters . 3. The calibration procedure Streeter and Phelps model that determines the least-squares Kr-Kd pair that best fits the OD and uses this Kr to model BOD gets four% increase in

  14. Drinking Water Temperature Modelling in Domestic Systems

    OpenAIRE

    Moerman, A.; Blokker, M.; Vreeburg, J.; van der Hoek, J.P.

    2014-01-01

    Domestic water supply systems are the final stage of the transport process to deliver potable water to the customers’ tap. Under the influence of temperature, residence time and pipe materials the drinking water quality can change while the water passes the domestic drinking water system. According to the Dutch Drinking Water Act the drinking water temperature may not exceed the 25 °C threshold at point-of-use level. This paper provides a mathematical approach to model the heating of drinking...

  15. Streamer model for high voltage water switches

    International Nuclear Information System (INIS)

    Sazama, F.J.; Kenyon, V.L. III

    1979-01-01

    An electrical switch model for high voltage water switches has been developed which predicts streamer-switching effects that correlate well with water-switch data from Casino over the past four years and with switch data from recent Aurora/AMP experiments. Preclosure rounding and postclosure resistive damping of pulseforming line voltage waveforms are explained in terms of spatially-extensive, capacitive-coupling of the conducting streamers as they propagate across the gap and in terms of time-dependent streamer resistance and inductance. The arc resistance of the Casino water switch and of a gas switch under test on Casino was determined by computer fit to be 0.5 +- 0.1 ohms and 0.3 +- 0.06 ohms respectively, during the time of peak current in the power pulse. Energy lost in the water switch during the first pulse is 18% of that stored in the pulseforming line while similar energy lost in the gas switch is 11%. The model is described, computer transient analyses are compared with observed water and gas switch data and the results - switch resistance, inductance and energy loss during the primary power pulse - are presented

  16. Review of Watershed Water Quality Models

    National Research Council Canada - National Science Library

    Deliman, Patrick

    1999-01-01

    .... Several available watershed water quality models were reviewed and rated with regard to their potential in being utilized as the building block for the development of a Corps of Engineers watershed water quality model...

  17. Water quality modelling and optimisation of wastewater treatment ...

    African Journals Online (AJOL)

    Instream water quality management encompasses field monitoring and utilisation of mathematical models. These models can be coupled with optimisation techniques to determine more efficient water quality management alternatives. Among these activities, wastewater treatment plays a crucial role. In this work, a ...

  18. Molecular Determinants of Dissolved Organic Matter Reactivity in Lake Water

    Directory of Open Access Journals (Sweden)

    Alina Mostovaya

    2017-12-01

    Full Text Available Lakes in the boreal region have been recognized as the biogeochemical hotspots, yet many questions regarding the regulators of organic matter processing in these systems remain open. Molecular composition can be an important determinant of dissolved organic matter (DOM fate in freshwater systems, but many aspects of this relationship remain unclear due to the complexity of DOM and its interactions in the natural environment. Here, we combine ultrahigh resolution mass spectrometry (FT-ICR-MS with kinetic modeling of decay of >1,300 individual DOM molecular formulae identified by mass spectrometry, to evaluate the role of specific molecular characteristics in decomposition of lake water DOM. Our data is derived from a 4 months microbial decomposition experiment, carried out on water from three Swedish lakes, with the set-up including natural lake water, as well as the lake water pretreated with UV light. The relative decay rate of every molecular formula was estimated by fitting a single exponential model to the change in FT-ICR-MS signal intensities over decomposition time. We found a continuous range of exponential decay coefficients (kexp within different groups of compounds and show that for highly unsaturated and phenolic compounds the distribution of kexp was shifted toward the lowest values. Contrary to this general trend, plant-derived polyphenols and polycondensed aromatics were on average more reactive than compounds with an intermediate aromaticity. The decay rate of aromatic compounds increased with increasing nominal oxidation state of carbon, and molecular mass in some cases showed an inverse relationship with kexp in the UV-manipulated treatment. Further, we observe an increase in formulae-specific kexp as a result of the UV pretreatment. General trends in reactivity identified among major compound groups emphasize the importance of the intrinsic controllers of lake water DOM decay. However, we additionally indicate that each

  19. Modern Modeling of Water Hammer

    Directory of Open Access Journals (Sweden)

    Urbanowicz Kamil

    2017-09-01

    Full Text Available Hydraulic equipment on board ships is common. It assists in the work of: steering gear, pitch propellers, watertight doors, cargo hatch covers, cargo and mooring winches, deck cranes, stern ramps etc. The damage caused by transient flows (which include among others water hammer are often impossible to repair at sea. Hence, it is very important to estimate the correct pressure runs and associated side effects during their design. The presented study compares the results of research on the impact of a simplified way of modeling the hydraulic resistance and simplified effective weighting functions build of two and three-terms on the estimated results of the pressure changes. As it turns out, simple effective two-terms weighting functions are able to accurately model the analyzed transients. The implementation of the presented method will soon allow current automatic protection of hydraulic systems of the adverse effects associated with frequent elevated and reduced pressures.

  20. On the determination of the mean excitation energy of water

    DEFF Research Database (Denmark)

    Sabin, John R.; Oddershede, Jens; Sauer, Stephan P. A.

    2013-01-01

    Water is a ubiquitous substance in nature, and thus the mean excitation energy of water is an important quantity for understanding and prediction of the details of many fast ion/molecule collision processes such as those involved in external beam radiotherapy of tumors. There are several methods...... for determining numerical values for a mean excitation energy for water, both theoretical and experimental. Here the factors affecting the determination of the value of the mean excitation energy of water, especially from experiment, are discussed....

  1. Global modelling of Cryptosporidium in surface water

    Science.gov (United States)

    Vermeulen, Lucie; Hofstra, Nynke

    2016-04-01

    Conclusions GloWPa-Crypto is the first global model that can be used to analyse dynamics in surface water pathogen concentrations worldwide. Global human Cryptosporidium emissions are estimated at 1 x 10^17 oocysts/ year for the year 2010.We estimated future emissions for SSP1 and SSP3. Preliminary results show that for SSP1human emissions are approximately halved by 2050. The SSP3 human emissions are 1.5 times higher than the 2010 emissions due to increased population growth and urbanisation. Livestock Cryptosporidium emissions are expected to increase under both SSP1 and SSP3, as meat consumption continues to rise. We conclude that population growth, urbanization, changes in sanitation systems and treatment, and changes in livestock consumption and production systems are important processes that determine future Cryptosporidium emissions to surface water. References Hofstra N, Bouwman A F, Beusen A H W and Medema G J 2013 Exploring global Cryptosporidium emissions to surface water Sci. Total Environ. 442 10-9 Kiulia N M, Hofstra N, Vermeulen L C, Obara M A, Medema G J and Rose J B 2015 Global occurrence and emission of rotaviruses to surface waters Pathogens 4 229-55 Vermeulen L C, De Kraker J, Hofstra N, Kroeze C and Medema G J 2015 Modelling the impact of sanitation, population and urbanization estimates on human emissions of Cryptosporidium to surface waters - a case study for Bangladesh and India Environ. Res. Lett. 10

  2. APLIKASI MODEL QUAL2Kw UNTUK MENENTUKAN STRATEGI PENANGGULANGAN PENCEMARAN AIR SUNGAI GAJAHWONG YANG DISEBABKAN OLEH BAHAN ORGANIK (Aplication of Qual2Kw Model to Determine the Strategy in Solving Gajahwong River Water Pollution Caused by Organic Matter

    Directory of Open Access Journals (Sweden)

    Agnes Dyah Novitasari Lestari

    2013-11-01

    Full Text Available ABSTRAK Telah dilakukan pemodelan kualitas air terhadap Sungai Gajahwong menggunakan model QUAL2Kw untuk parameter DO-BOD. Diselidiki dinamika DO-BOD sungai tersebut pada kondisi eksisting tahun 2011. Oleh karena beban pencemar pada kondisi hujan dan tanpa hujan berbeda, maka prediksi dilakukan pada kedua kondisi tersebut. Hasil pemodelan QUAL2Kw untuk kondisi eksisting Sungai Gajahwong tahun 2011 menunjukkan bahwa pada kondisi hujan dan tanpa hujan, konsentrasi BOD sungai telah melebihi bakumutu air kelas II. Hasil simulasi menunjukkan bahwa (1 Pembangunan perumahan yang membuang limbah cairnya ke Sungai Gajahwong pada debit total 0,1 m3/s dengan konsentrasi BOD 10 mg/L dapat meningkatkan BOD serta menurunkan DO Sungai Gajahwong, dan (2 Pengelolaan kualitas air dan penanggulangan pencemaran air oleh bahan organik pada Sungai Gajahwong dapat dilakukan dengan strategi pembuatan IPAL komunal di setiap kabupaten dengan penurunan konsentrasi BOD hulu hingga 2 mg/L.   ABSTRACT Water quality modelling of Gajahwong River has been done using QUAL2Kw model for DO-BOD parameters. The dynamics of DO-BOD of the river on the existing conditions in 2011 has been investigated. Because of  the load of pollutants in the rainy condition and no rain condition was different, then the predictions made on both conditions. QUAL2Kw modelling results for Gajahwong River in year 2011 showed that the BOD concentration of the river on both conditions has exceeded water quality standards class II. The simulation results showed that: (1 Housing construction that discharge its liquid waste into Gajahwong River on total discharge 0,1 m3/s with concentration of BOD 10 mg/L, increased the BOD and decreased the DO of Gajahwong River, and (2 Water quality management and organic pollution control of Gajahwong River can be done by a strategy of making communal WWTP in each district with reduction of the upstream BOD concentration to 2 mg /L.

  3. The methods of cesium-137 determination in sea water

    International Nuclear Information System (INIS)

    Gedeonov, L.I.; Krylov, V.N.; Stepanov, A.V.

    1978-01-01

    New express procedures of Cs-137 determination in sea water using selective sorbents are described. One of them is based on the use of natural radioactive potassium-40 as internal standard. Another one allows to perform Cs-137 determination without use of any standards, by pumping a certain amount of water through several successive identical cells filled with sorbent. The positive feature of the procedures consists in that it is no longer necessary chemical treatment of samples in Cs-133 determination in the sorbent and sea water. The danger of polution of samples by alkali metals which can be introduced with reactive agents in the process of chemical treatment is reduced to minimum

  4. Modeling water demand when households have multiple sources of water

    Science.gov (United States)

    Coulibaly, Lassina; Jakus, Paul M.; Keith, John E.

    2014-07-01

    A significant portion of the world's population lives in areas where public water delivery systems are unreliable and/or deliver poor quality water. In response, people have developed important alternatives to publicly supplied water. To date, most water demand research has been based on single-equation models for a single source of water, with very few studies that have examined water demand from two sources of water (where all nonpublic system water sources have been aggregated into a single demand). This modeling approach leads to two outcomes. First, the demand models do not capture the full range of alternatives, so the true economic relationship among the alternatives is obscured. Second, and more seriously, economic theory predicts that demand for a good becomes more price-elastic as the number of close substitutes increases. If researchers artificially limit the number of alternatives studied to something less than the true number, the price elasticity estimate may be biased downward. This paper examines water demand in a region with near universal access to piped water, but where system reliability and quality is such that many alternative sources of water exist. In extending the demand analysis to four sources of water, we are able to (i) demonstrate why households choose the water sources they do, (ii) provide a richer description of the demand relationships among sources, and (iii) calculate own-price elasticity estimates that are more elastic than those generally found in the literature.

  5. Determination of selected heavy metals in inland fresh water of ...

    African Journals Online (AJOL)

    ... heavy metals were determined in freshwater from River Niger. Water samples were collected from both upstream and downstream along the mainstream drainage channel, traversing past the steel production industry Ajaokuta between 2003 and 2005. The water samples were digested according to standard methods and ...

  6. Trace elements determination in municpal water supply in Damaturu ...

    African Journals Online (AJOL)

    This study examines the presence of trace elements in the municipal water supplies of Damaturu Metropolis, Yobe state. The trace elements were determined using standard methods for the examination of water and wastewater from the US Environmental Protection Agency (USEPA). The result of the analysis shows that ...

  7. Formation water resistivity (R w )determination: The SP method ...

    African Journals Online (AJOL)

    uncontaminated by drilling mud) that saturates the porous formation. It is also referred to as connate water or interstitial water. Its resistivity can be determined by a number of methods, one of which is by the SP curve discussed in this work. Analysis of ...

  8. Determining pomegranate water and nitrogen requirements with drip irrigation

    Science.gov (United States)

    Despite being an ancient crop there is limited knowledge on the water and nitrogen (N) requirements of pomegranate. We conducted research at the University of California, Kearney Agricultural Research and Extension Center (KARE) to determine the water and nitrogen requirements of a developing pomegr...

  9. Determination of heavy metals and genotoxicity of water from an ...

    African Journals Online (AJOL)

    The mineral processing and geochemical processes may determine high concentrations of heavy metals in water intended for human consumption. Thus, the present study aimed to quantify and evaluate the heavy metal genotoxicity of artesian water in the city by Atomic absorption spectrophotometer analysis and testing ...

  10. Ground Water Quality Determination of former Lake Haramaya ...

    African Journals Online (AJOL)

    Michael Horsfall

    ml, 250ml and 10.52 L, measuring cylinders and stopwatch were also used. RESULT AND DISCUSSION. Source Inventory in Haramaya University and inside the area of the former lake: Groundwater water inventory had been done in Haramaya University with the objective of determining the location of the water points ...

  11. Determination of Phenols in Water Samples using a Supported ...

    African Journals Online (AJOL)

    The sample preparation method was tested for the determination of phenols in river water samples and landfill leachate. Concentrations of phenols in river water were found to be in the range 4.2 μg L–1 for 2-chlorophenol to 50 μg L–1 for 4-chlorophenol. In landfill leachate, 4-chlorophenol was detected at a concentration ...

  12. Determination of radium 226 and 228 in water

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Willemot, J.M.; Verry, M.

    1989-01-01

    Usually, only radium 226 is measured in water since determination of radium 228 is not easy at the natural levels. A technique has therefore been developed to measure, at the same time and at low radioactivity levels, two radionuclides most often associated in water and with similar toxicity. Computer data processing brings significant improvements though calculation can be manually done [fr

  13. Nationwide water availability data for energy-water modeling

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent Carroll [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zemlick, Katie M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-11-01

    The purpose of this effort is to explore where the availability of water could be a limiting factor in the siting of new electric power generation. To support this analysis, water availability is mapped at the county level for the conterminous United States (3109 counties). Five water sources are individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water (western U.S. only), municipal wastewater and brackish groundwater. Also mapped is projected growth in non-thermoelectric consumptive water demand to 2035. Finally, the water availability metrics are accompanied by estimated costs associated with utilizing that particular supply of water. Ultimately these data sets are being developed for use in the National Renewable Energy Laboratories' (NREL) Regional Energy Deployment System (ReEDS) model, designed to investigate the likely deployment of new energy installations in the U.S., subject to a number of constraints, particularly water.

  14. Determination of Heavy Metal Levels in Various Industrial Waste Waters

    Directory of Open Access Journals (Sweden)

    Mustafa Şahin Dündar

    2012-06-01

    Full Text Available Important part of the environmetal pollution consists of waste water and water pollution. The water polluted by anthropogenical, industrial, and agricultural originated sources are defined as waste waters which are the main pollution sources for reservoirs, rivers, lakes, and seas. In this work, waste waters of leather, textile, automotive side, and metal plating industries were used to determine the levels of Cu, Zn, Cr, Pb and Ni by using Flame Atomic Absorption Spectrometer. As a result, highest mean levels of copper in supernatants of plating and textile industries were observed as 377,18 ng ml-1, respectively 103 ng ml-1 lead and 963,6 ng ml-1 nickel in plating industry, 1068,2 ng ml-1 zinc and 14557,1 ng ml-1 chromium in plating and leather industries were determined.

  15. Spectroscopic determination of leaf water content using linear ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-02-02

    Feb 2, 2012 ... Linear regression and backpropagation artificial neural network methods were used to establish peach tree leaf water content ... Key words: Spectroscopy, crop water, linear regression, artificial neural network. INTRODUCTION .... Simple linear regression is the most basic modeling approach; because the ...

  16. Spectrophotometric determination of fluoride in drinking water using ...

    African Journals Online (AJOL)

    A sensitive spectrophotometric determination of fluoride in drinking water has been developed using aluminium complexes of triphenylmethane dyes (chrome azurol B and malachite green) as spectrophotometric reagents. The method allowed a reliable determination of fluoride in the range of 0.5–4.0 mg·l-1 for chrome ...

  17. Determination of the radioactive concentration of 137Cs in water

    International Nuclear Information System (INIS)

    1986-01-01

    The recently accepted standard method to determine the radioactive concentration of 137 Cs in water is based on the selective retention of cesium ions on ammonium-phosphorous-molybdate followed by the dissolution of the sorbent and the selective precipitation of cesium-hexa-chloro-platinate. The radioactive concentration is determined by the measurement of β disintegration rate of the preparate. (V.N.)

  18. Spectrophotometric determination of iron (III) in tap water using 8 ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... Atomic absorption spectro- metry and inductively coupled with plasma spectrometry have also been applied for the determination of iron in water and other cations (Abollino et al., 1995). Iron has been separated by capillary isotachophoresis as an. EDTA complex for the simultaneous determination of.

  19. Determination of water quality index by fuzzy logic approach: a case of ground water in an Indian town.

    Science.gov (United States)

    Jinturkar, A M; Deshmukh, S S; Agarkar, S V; Chavhan, G R

    2010-01-01

    The paper proposes fuzzy logic model that deals with the physico-chemical water analysis of ground water of Chikhli town for determination of Water Quality Index (WQI). The study was carried by collection of ground water samples from about eleven hand pumps located in this town. Ground water quality is studied by systematic collection and analysis of samples. The fuzzy logic is used for the deciding the water quality index on the basis of which, water quality rankings are given to determine the quality of water. The Water Quality Index presented here is a unitless number ranging from 1 to 10. A higher number is indicative of better water quality. Around 81% of samples were found suitable for drinking purpose. It is also observed that all the parameters fall within the permissible limits laid by WHO, ISI, and ICMR, except Total Hardness, Calcium and Magnesium. The quality parameters were compared with standards laid by the World Health Organization (WHO), Indian Standards Institute (ISI) and Indian Council of Medical Research (ICMR) for drinking water quality.

  20. Flame Spectrophotometric Determination of Strontium in Water and Biological Material

    International Nuclear Information System (INIS)

    Joensson, G.

    1964-10-01

    A flame spectrophotometric method has been developed for the determination of strontium in biological material and water samples. Strontium is determined in the presence of calcium at a wavelength of 4607 A. The intensity of the strontium emission from the sample is increased if n-butanol is added to a solution of the sample in water. With a 6 vol% solution of n-butanol in water, an optimum intensity of 3.5 times that obtained with pure water solution is obtained. Anions and alkali metals which might interfere with the flame spectrophotometric determination are separated from the sample by a simple ion exchange operation. The method allows determination of strontium in solutions down to 0.1μg/ml. In this case the standard deviation is 3.1 % and with a strontium concentration of 1 μg/ml the deviation is 0.9 %. This method has been used for the determination of strontium in samples of varying composition such as bone, meat and skin from fishes, samples of human bones, shell-fish, milk, and water, in which case Sr quantities of 5μg were determined with an analytical error of less than 5 % and Sr q uantities greater than 10 μg with an error of less than 3 %

  1. A Possibility of Determining the Optical Peoperties of Water from the Snell-Window Image

    Science.gov (United States)

    Dolin, L. S.; Molkov, A. A.

    2017-06-01

    We develop an analytical model of the Snell window, which allows for the effects of absorption and multiple scattering of light in water. The effect of an abnormally weak dependence of the visual brightness of the Snell-window boundary on the water turbidity is revealed. This effect, along with the effect of the Snell-window boundary "blurring" because of the light scattering in water can be used to determine the absorption and scattering coefficients of water using the corresponding processing of the Snell window images. We propose and experimentally check the algorithms for determining the inherent hydrooptical characteristics from the Snell-window images using the empirical correlations between various characteristics.

  2. Tagging Water Sources in Atmospheric Models

    Science.gov (United States)

    Bosilovich, M.

    2003-01-01

    Tagging of water sources in atmospheric models allows for quantitative diagnostics of how water is transported from its source region to its sink region. In this presentation, we review how this methodology is applied to global atmospheric models. We will present several applications of the methodology. In one example, the regional sources of water for the North American Monsoon system are evaluated by tagging the surface evaporation. In another example, the tagged water is used to quantify the global water cycling rate and residence time. We will also discuss the need for more research and the importance of these diagnostics in water cycle studies.

  3. Fuzzy pricing for urban water resources: model construction and application.

    Science.gov (United States)

    Zhao, Ranhang; Chen, Shouyu

    2008-08-01

    A rational water price system plays a crucial role in the optimal allocation of water resources. In this paper, a fuzzy pricing model for urban water resources is presented, which consists of a multi-criteria fuzzy evaluation model and a water resources price (WRP) computation model. Various factors affecting WRP are comprehensively evaluated with multiple levels and objectives in the multi-criteria fuzzy evaluation model, while the price vectors of water resources are constructed in the WRP computation model according to the definition of the bearing water price index, and then WRP is calculated. With the incorporation of an operator's knowledge, it considers iterative weights and subjective preference of operators for weight-assessment. The weights determined are more rational and the evaluation results are more realistic. Particularly, dual water supply is considered in the study. Different prices being fixed for water resources with different qualities conforms to the law of water resources value (WRV) itself. A high-quality groundwater price computation model is also proposed to provide optimal water allocation and to meet higher living standards. The developed model is applied in Jinan for evaluating its validity. The method presented in this paper offers some new directions in the research of WRP.

  4. Urban-Water Harmony model to evaluate the urban water management.

    Science.gov (United States)

    Ding, Yifan; Tang, Deshan; Wei, Yuhang; Yin, Sun

    2014-01-01

    Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water-society coordination, and water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social-economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes.

  5. Applying the WEAP Model to Water Resource

    DEFF Research Database (Denmark)

    Gao, Jingjing; Christensen, Per; Li, Wei

    Water resources assessment is a tool to provide decision makers with an appropriate basis to make informed judgments regarding the objectives and targets to be addressed during the Strategic Environmental Assessment (SEA) process. The study shows how water resources assessment can be applied in SEA...... in assessing the effects on water resources using a case study on a Coal Industry Development Plan in an arid region in North Western China. In the case the WEAP model (Water Evaluation And Planning System) were used to simulate various scenarios using a diversity of technological instruments like irrigation...... efficiency, treatment and reuse of water. The WEAP model was applied to the Ordos catchment where it was used for the first time in China. The changes in water resource utilization in Ordos basin were assessed with the model. It was found that the WEAP model is a useful tool for water resource assessment...

  6. Modelo para a determinação do espaçamento entre desaguadouros em estradas não pavimentadas A model to determine the spacing between water outlets in unpaved roads

    Directory of Open Access Journals (Sweden)

    Nori Paulo Griebeler

    2005-06-01

    Full Text Available As estradas não pavimentadas são de fundamental importância para o desenvolvimento social e econômico do Brasil, sendo a erosão provocada pela água no leito e nas margens destas estradas um dos principais fatores para sua degradação. Neste artigo, apresenta-se um novo modelo para a determinação do espaçamento entre desaguadouros em estradas não pavimentadas e, conseqüentemente, para a redução dos problemas associados à erosão hídrica. Utilizando o modelo de ondas cinemáticas, determina-se o hidrograma de escoamento superficial no canal de drenagem da estrada e, a partir deste, é calculada a tensão provocada pelo escoamento. Sempre que a tensão cisalhante causada pelo escoamento supera a tensão crítica para cisalhamento do solo ocorre o seu desprendimento. A diferença entre essas tensões cisalhantes é multiplicada pela erodibilidade do solo e pela área em que ocorre a aplicação da tensão cisalhante para estimar a perda de solo provocada pelo escoamento. O espaçamento máximo entre desaguadouros é obtido, comparando-se a perda de solo provocada pelo escoamento com a perda de solo tolerável. O comprimento máximo do canal é aquele para o qual a perda tolerável é atingida. O modelo permite determinar o espaçamento entre desaguadouros considerando as características das áreas que contribuem para o escoamento e a resistência do solo. As simulações realizadas mostraram que o modelo é sensível às alterações na erodibilidade e na tensão crítica de cisalhamento do solo, bem como à declividade do canal, permitindo ainda que, por meio da alteração no aprofundamento tolerável para o canal, os espaçamentos possam ser ampliados ou reduzidos.Unpaved roads are essential for the economic and social development in Brazil. Water erosion is one of the key factors causing their degradation. This study developed a new model of determination of spacing between water outlets in unpaved roads. The surface runoff

  7. Neutron fluence determination for light water reactor pressure vessels

    International Nuclear Information System (INIS)

    Gold, R.

    1994-01-01

    A general description of limitations that exist in pressure vessel neutron fluence determinations for commercial light water reactors is presented. Complexity factors that arise in light water reactor pressure vessel neutron fluence calculations are identified and used to analyze calculational limitations. Two broad categories of calculational limitations are introduced, namely benchmark field limitations and deep penetration limitations. Explicit examples of limitations that can arise in each of these two broad categories are presented. These limitations are used to show that the recent draft regulatory guide for the determination of pressure vessel neutron fluence, developed by the Nuclear Regulatory Commission, is based upon procedures and assumptions that are not valid. To eliminate the complexity and limitations of calculational methods, it is recommended that the determination of light water reactor pressure vessel neutron fluence be based upon experiment. Recommendations for improved methods of pressure vessel surveillance neutron dosimetry are advanced

  8. Coulometric Karl Fischer determination of trace amounts of water

    Energy Technology Data Exchange (ETDEWEB)

    Nichugovskii, G.F.

    1986-06-01

    The authors maintain that it is convenient to determine small amounts of water by coulometric titration in spent Fischer reagent because this method is highly sensitive and provides an absolute measurement. The water content of the sample is calculated from the amount of electricity consumed in the electrochemical production of enough molecular iodine to bond completely with the water. This paper attempts to correct for the effect of various factors on the indicator current in the coulometric titration of trace quantities of water by the Karl Fischer reagent. The paper discusses the sources of error by biamperometric indication of the titration endpoint. When the water content is lower than 0.001%, it is absolutely necessary according to the authors, to correct for the effect of the analytical sample. Analytical and graphical methods of calculating the correction are suggested.

  9. Modeling water transport in liquid feed direct methanol fuel cells

    Science.gov (United States)

    Liu, Wenpeng; Wang, Chao-Yang

    Proper water management in direct methanol fuel cells (DMFCs) is very critical and complicated because of many interacting physicochemical phenomena. Among these, the liquid saturation in the cathode side is believed to have a very strong effect on water crossover through the membrane, a key parameter to determine water balance between the anode and cathode. In this paper, based on an interfacial liquid coverage model implemented in a three-dimensional (3D) two-phase DMFC model, the liquid saturation variations in the cathode are examined in detail and their effects on the net water transport coefficient through the membrane discussed.

  10. Trihalomethane concentrations in tap water as determinant of bottled water use in the city of Barcelona.

    Science.gov (United States)

    Font-Ribera, Laia; Cotta, Jordi Colomer; Gómez-Gutiérrez, Anna; Villanueva, Cristina M

    2017-08-01

    Bottled water consumption is increasing worldwide, despite its huge economic and environmental cost. We aim to describe personal and tap water quality determinants of bottled water use in the city of Barcelona. This cross-sectional study used data from the Health Survey of Barcelona in 2006 (N=5417 adults). The use of bottled water to drink and to cook was evaluated in relation to age, gender, educational level, district and levels of trihalomethanes (THMs), free chlorine, conductivity, chloride, sodium, pH, nitrate and aluminium in municipal tap water using Robust Poisson Regression. The prevalence of bottled water use to drink and cook was 53.9% and 6.7%, respectively. Chemical parameters in water had a large variability (interquartile range of THMs concentrations: 83.2-200.8μg/L) and were correlated between them, except aluminium. Drinking bottled water increased with educational level, while cooking with bottled water was higher among men than among women and decreased with age. After adjusting by these personal determinants, a dose-response relationship was found between concentrations of all chemicals except aluminium in tap water and bottled water use. The highest association was found for THMs, with a Prevalence Ratio of 2.00 (95%CI=1.86, 2.15) for drinking bottled water and 2.80 (95%CI=1.72, 4.58) for cooking with bottled water, among those with >150μg/L vs. tap water. More than half of Barcelona residents regularly drank bottled water, and the main determinant was the chemical composition of tap water, particularly THM level. Copyright © 2017. Published by Elsevier B.V.

  11. Multi-Phase Modeling of Rainbird Water Injection

    Science.gov (United States)

    Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

    2014-01-01

    This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.

  12. Nambe Pueblo Water Budget and Forecasting model.

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, James Robert

    2009-10-01

    This report documents The Nambe Pueblo Water Budget and Water Forecasting model. The model has been constructed using Powersim Studio (PS), a software package designed to investigate complex systems where flows and accumulations are central to the system. Here PS has been used as a platform for modeling various aspects of Nambe Pueblo's current and future water use. The model contains three major components, the Water Forecast Component, Irrigation Scheduling Component, and the Reservoir Model Component. In each of the components, the user can change variables to investigate the impacts of water management scenarios on future water use. The Water Forecast Component includes forecasting for industrial, commercial, and livestock use. Domestic demand is also forecasted based on user specified current population, population growth rates, and per capita water consumption. Irrigation efficiencies are quantified in the Irrigated Agriculture component using critical information concerning diversion rates, acreages, ditch dimensions and seepage rates. Results from this section are used in the Water Demand Forecast, Irrigation Scheduling, and the Reservoir Model components. The Reservoir Component contains two sections, (1) Storage and Inflow Accumulations by Categories and (2) Release, Diversion and Shortages. Results from both sections are derived from the calibrated Nambe Reservoir model where historic, pre-dam or above dam USGS stream flow data is fed into the model and releases are calculated.

  13. WATER LAW AND MODEL OF RESPONSIBLE WATER USAGE

    Directory of Open Access Journals (Sweden)

    Dmitri Olegovitch Sivakov

    2017-03-01

    Full Text Available As it is known, the water law regulates dynamic social relationships concerning study, usage and protection of water objects, as well as their transformation. The water law explicitly regulates water economic activities. The regulatory method of the water law has a mixed nature and thus is not distinctive. It predetermines in some cases equality and independence of subjects of relationships (water usage agreement and in other – power and submission (permissive nature of water usage. The aim of the publication is to promote scientific ideas about the fate of the water law in order to make a further polygonal and productive discussion in which the reader is invited to participate. Scientific novelty. In 2016 the monograph of D.O. Sivakov “Water law: dynamics, problems, perspectives: monograph” (second edition, reviewed and updated. Moscow: Stolitsa, 2016. 540 p. was published. In 2017 the author reconsidered some conclusions of his monograph and applied scientific achievements of theory of state and law in water sphere. In accordance with this, it is important to mention research of Petrov D.E. related to issues of differentiation and integration of structural formations of Russian legal system. The scientific novelty of the article includes the synthesis of ideas of the monograph and some achievements of theory of state and law. Methods of research. The author of the article relies on some collective and individual monographic studies in the sphere of theory of state and law, natural resource law, arctic law, financial law. Basic results of research. The author promotes the model of responsible water usage. This model shall be based not on the unstable balance of economic and environmental interests (which shall practically lead to the domination of economic interests, but on the obligatory combination of economic activities with technologies, ensuring maximal preservation of water resources. Responsible water usage shall mean a system of

  14. An empirical method to determine inadequacy of dietary water.

    Science.gov (United States)

    Armstrong, Lawrence E; Johnson, Evan C; McKenzie, Amy L; Muñoz, Colleen X

    2016-01-01

    The physiological regulation of total body water and fluid concentrations is complex and dynamic. The human daily water requirement varies because of differences in body size, dietary solute load, exercise, and activities. Although chronically concentrated urine increases the risk of renal diseases, an empirical method to determine inadequate daily water consumption has not been described for any demographic group; instead, statistical analyses are applied to estimate nutritional guidelines (i.e., adequate intake). This investigation describes a novel empirical method to determine the 24-h total fluid intake (TFI; TFI = water + beverages + moisture in food) and 24-h urine volume, which correspond to inadequate 24-h water intake (defined as urine osmolality of 800 mOsm/kg; U800). Healthy young women (mean ± standard deviation; age, 20 ± 2 y, mass, 60.8 ± 11.7 kg; n = 28) were observed for 7 consecutive days. A 24-h urine sample was analyzed for volume and osmolality. Diet records were analyzed to determine 24-h TFI. For these 28 healthy young women, the U800 corresponded to a TFI ≥2.4 L/d (≥39 mL/kg/d) and a urine volume ≥1.3 L/d. The U800 method could be employed to empirically determine 24-h TFI and 24-h urine volumes that correspond to inadequate water intake in diverse demographic groups, residents of specific geographic regions, and individuals who consume specialized diets or experience large daily water turnover. Because laboratory expertise and instrumentation are required, this technique provides greatest value in research and clinical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. A theoretical model of water and trade

    Science.gov (United States)

    Dang, Qian; Konar, Megan; Reimer, Jeffrey J.; Di Baldassarre, Giuliano; Lin, Xiaowen; Zeng, Ruijie

    2016-03-01

    Water is an essential input for agricultural production. Agriculture, in turn, is globalized through the trade of agricultural commodities. In this paper, we develop a theoretical model that emphasizes four tradeoffs involving water-use decision-making that are important yet not always considered in a consistent framework. One tradeoff focuses on competition for water among different economic sectors. A second tradeoff examines the possibility that certain types of agricultural investments can offset water use. A third tradeoff explores the possibility that the rest of the world can be a source of supply or demand for a country's water-using commodities. The fourth tradeoff concerns how variability in water supplies influences farmer decision-making. We show conditions under which trade liberalization affect water use. Two policy scenarios to reduce water use are evaluated. First, we derive a target tax that reduces water use without offsetting the gains from trade liberalization, although important tradeoffs exist between economic performance and resource use. Second, we show how subsidization of water-saving technologies can allow producers to use less water without reducing agricultural production, making such subsidization an indirect means of influencing water use decision-making. Finally, we outline conditions under which riskiness of water availability affects water use. These theoretical model results generate hypotheses that can be tested empirically in future work.

  16. Cokriging model for estimation of water table elevation

    International Nuclear Information System (INIS)

    Hoeksema, R.J.; Clapp, R.B.; Thomas, A.L.; Hunley, A.E.; Farrow, N.D.; Dearstone, K.C.

    1989-01-01

    In geological settings where the water table is a subdued replica of the ground surface, cokriging can be used to estimate the water table elevation at unsampled locations on the basis of values of water table elevation and ground surface elevation measured at wells and at points along flowing streams. The ground surface elevation at the estimation point must also be determined. In the proposed method, separate models are generated for the spatial variability of the water table and ground surface elevation and for the dependence between these variables. After the models have been validated, cokriging or minimum variance unbiased estimation is used to obtain the estimated water table elevations and their estimation variances. For the Pits and Trenches area (formerly a liquid radioactive waste disposal facility) near Oak Ridge National Laboratory, water table estimation along a linear section, both with and without the inclusion of ground surface elevation as a statistical predictor, illustrate the advantages of the cokriging model

  17. Comparative Assessment of Physical and Social Determinants of Water Quantity and Water Quality Concerns

    Science.gov (United States)

    Gunda, T.; Hornberger, G. M.

    2017-12-01

    Concerns over water resources have evolved over time, from physical availability to economic access and recently, to a more comprehensive study of "water security," which is inherently interdisciplinary because a secure water system is influenced by and affects both physical and social components. The concept of water security carries connotations of both an adequate supply of water as well as water that meets certain quality standards. Although the term "water security" has many interpretations in the literature, the research field has not yet developed a synthetic analysis of water security as both a quantity (availability) and quality (contamination) issue. Using qualitative comparative and multi-regression analyses, we evaluate the primary physical and social factors influencing U.S. states' water security from a quantity perspective and from a quality perspective. Water system characteristics are collated from academic and government sources and include access/use, governance, and sociodemographic, and ecosystem metrics. Our analysis indicates differences in variables driving availability and contamination concerns; for example, climate is a more significant determinant in water quantity-based security analyses than in water quality-based security analyses. We will also discuss coevolution of system traits and the merits of constructing a robust water security index based on the relative importance of metrics from our analyses. These insights will improve understanding of the complex interactions between quantity and quality aspects and thus, overall security of water systems.

  18. Water quality modelling and optimisation of wastewater treatment network using mixed integer programming

    CSIR Research Space (South Africa)

    Mahlathi, Christopher

    2016-10-01

    Full Text Available Instream water quality management encompasses field monitoring and utilisation of mathematical models. These models can be coupled with optimisation techniques to determine more efficient water quality management alternatives. Among these activities...

  19. Calculation method of water injection forward modeling and inversion process in oilfield water injection network

    Science.gov (United States)

    Liu, Long; Liu, Wei

    2018-04-01

    A forward modeling and inversion algorithm is adopted in order to determine the water injection plan in the oilfield water injection network. The main idea of the algorithm is shown as follows: firstly, the oilfield water injection network is inversely calculated. The pumping station demand flow is calculated. Then, forward modeling calculation is carried out for judging whether all water injection wells meet the requirements of injection allocation or not. If all water injection wells meet the requirements of injection allocation, calculation is stopped, otherwise the demand injection allocation flow rate of certain step size is reduced aiming at water injection wells which do not meet requirements, and next iterative operation is started. It is not necessary to list the algorithm into water injection network system algorithm, which can be realized easily. Iterative method is used, which is suitable for computer programming. Experimental result shows that the algorithm is fast and accurate.

  20. Integrated water resources modelling for assessing sustainable water governance

    Science.gov (United States)

    Skoulikaris, Charalampos; Ganoulis, Jacques; Tsoukalas, Ioannis; Makropoulos, Christos; Gkatzogianni, Eleni; Michas, Spyros

    2015-04-01

    Climatic variations and resulting future uncertainties, increasing anthropogenic pressures, changes in political boundaries, ineffective or dysfunctional governance of natural resources and environmental degradation are some of the most fundamental challenges with which worldwide initiatives fostering the "think globally, act locally" concept are concerned. Different initiatives target the protection of the environment through sustainable development; Integrated Water Resources Management (IWRM) and Transboundary Water Resources Management (TWRM) in the case of internationally shared waters are frameworks that have gained wide political acceptance at international level and form part of water resources management planning and implementation on a global scale. Both concepts contribute in promoting economic efficiency, social equity and environmental sustainability. Inspired by these holistic management approaches, the present work describes an effort that uses integrated water resources modelling for the development of an integrated, coherent and flexible water governance tool. This work in which a sequence of computer based models and tools are linked together, aims at the evaluation of the sustainable operation of projects generating renewable energy from water as well as the sustainability of agricultural demands and environmental security in terms of environmental flow under various climatic and operational conditions. More specifically, catchment hydrological modelling is coupled with dams' simulation models and thereafter with models dedicated to water resources management and planning,while the bridging of models is conducted through geographic information systems and custom programming tools. For the case of Mesta/Nestos river basin different priority rules in the dams' operational schedule (e.g. priority given to power production as opposed to irrigation needs and vice versa), as well as different irrigation demands, e.g. current water demands as opposed to

  1. Model for radionuclide transport in running waters

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Karin; Elert, Mark [Kemakta Konsult AB, Stockholm (Sweden)

    2005-11-15

    Two sites in Sweden are currently under investigation by SKB for their suitability as places for deep repository of radioactive waste, the Forsmark and Simpevarp/Laxemar area. As a part of the safety assessment, SKB has formulated a biosphere model with different sub-models for different parts of the ecosystem in order to be able to predict the dose to humans following a possible radionuclide discharge from a future deep repository. In this report, a new model concept describing radionuclide transport in streams is presented. The main difference from the previous model for running water used by SKB, where only dilution of the inflow of radionuclides was considered, is that the new model includes parameterizations also of the exchange processes present along the stream. This is done in order to be able to investigate the effect of the retention on the transport and to be able to estimate the resulting concentrations in the different parts of the system. The concentrations determined with this new model could later be used for order of magnitude predictions of the dose to humans. The presented model concept is divided in two parts, one hydraulic and one radionuclide transport model. The hydraulic model is used to determine the flow conditions in the stream channel and is based on the assumption of uniform flow and quasi-stationary conditions. The results from the hydraulic model are used in the radionuclide transport model where the concentration is determined in the different parts of the stream ecosystem. The exchange processes considered are exchange with the sediments due to diffusion, advective transport and sedimentation/resuspension and uptake of radionuclides in biota. Transport of both dissolved radionuclides and sorbed onto particulates is considered. Sorption kinetics in the stream water phase is implemented as the time scale of the residence time in the stream water probably is short in comparison to the time scale of the kinetic sorption. In the sediment

  2. A Theoretical Model of Water and Trade

    Science.gov (United States)

    Dang, Q.; Konar, M.; Reimer, J.; Di Baldassarre, G.; Lin, X.; Zeng, R.

    2015-12-01

    Water is an essential factor of agricultural production. Agriculture, in turn, is globalized through the trade of food commodities. In this paper, we develop a theoretical model of a small open economy that explicitly incorporates water resources. The model emphasizes three tradeoffs involving water decision-making that are important yet not always considered within the existing literature. One tradeoff focuses on competition for water among different sectors when there is a shock to one of the sectors only, such as trade liberalization and consequent higher demand for the product. A second tradeoff concerns the possibility that there may or may not be substitutes for water, such as increased use of sophisticated irrigation technology as a means to increase crop output in the absence of higher water availability. A third tradeoff explores the possibility that the rest of the world can be a source of supply or demand for a country's water-using products. A number of propositions are proven. For example, while trade liberalization tends to increase water use, increased pressure on water supplies can be moderated by way of a tax that is derivable with observable economic phenomena. Another example is that increased riskiness of water availability tends to cause water users to use less water than would be the case under profit maximization. These theoretical model results generate hypotheses that can be tested empirically in future work.

  3. Determination of radium-226 in fresh water, using alpha spectroscopy

    International Nuclear Information System (INIS)

    Byrakdar, M. E.

    2006-12-01

    Four radium isotopes are present in nature, i.e. Ra-223, Ra-224, Ra-226, and Ra-228. The first three are alpha emitters while the last is a beta emitter. Because of the importance of the determination of Alpha isotope emitters in pure water (drinking water), this work focuses on the determination of radium-226 as it has the longest half-life (1600 years, in comparison to 11.4 day, 3.66 days for Ra-223 and Ra-224, respectively) using Alpha spectroscopy. This method has the capability to be applied in sampling fields and low detection limit which in turn makes the analysis of low-level radioactive environmental water samples, with hardness does not exceed 40 French Degree, satisfying for health and environment control programmes. However, counting the samples using Alpha spectroscopy has to be immediate (or within 48 hours). (author)

  4. determination of thiobencarb in water samples by gas

    African Journals Online (AJOL)

    Preferred Customer

    ... liquid-liquid microextraction via flotation assistance (HLLME-FA) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent ...

  5. Determination of thiobencarb in water samples by gas ...

    African Journals Online (AJOL)

    ... liquid-liquid microextraction via flotation assistance (HLLME-FA) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent ...

  6. Source determination of polynuclear aromatic hydrocarbons in water ...

    African Journals Online (AJOL)

    SERVER

    2008-02-05

    Feb 5, 2008 ... Polynuclear aromatic hydrocarbons in surface water and sediment of Ekpan Creek of the Warri River were determined with GC Perkin-Elmer/Clarius 500. Compositional patterns of the PAHs were used to distinguish their sources in the aquatic system. The three diagnostic selected concentration ratios of.

  7. Determination of the Level of Contamination of Underground Water ...

    African Journals Online (AJOL)

    Misrak

    Determination of the Level of Contamination of. Underground Water (hand- dug well) by Organic Waste: A case Study of Ado-Ekiti, Nigeria. O.S. Omotoyinbo *. Abstract. The recent increase in urbanization has lead to increase in city population, spatial size, and generation of waste. This is a common phenomenon in Nigeria ...

  8. Determination of lead at nanogram level in water samples by ...

    African Journals Online (AJOL)

    A novel method of chemistry applicable to the determination of trace lead in water samples based on the resonance light scattering (RLS) technique has been developed. In dilute phosphoric acid medium, in the presence of a large excess of I-, Pb(II) can form [PbI4]2-, which further reacts with tetrabutyl ammonium bromide ...

  9. Determination of the Concentration of Total Cyanide in Waste Water ...

    African Journals Online (AJOL)

    Cyanide has been listed as one of the toxic pollutants that is usually released into the environment. Cyanide is said to be released during the processing of cyanogenic plant parts which tobacco plant is one of them. This work determines the concentration of total cyanide in waste water collected in and around a tobacco ...

  10. Determination of radionuclides in discharged water from gold ...

    African Journals Online (AJOL)

    The levels of radionuclides concentrations in discharged water from gold processing into the environment of Bogoso (Ghana) were determined using radioanalytical techniques. Radioactivity screening was first carried out to identify physical and chemical processing stages that might be concentrating the radionuclides.

  11. Fluorescent sensing and determination of mercury (II) ions in water ...

    African Journals Online (AJOL)

    In this study we report on a fluorescent sensing probe based on a naphthyl azo dye modified dibenzo-18-crown-6-ether (DB18C6) for the detection and determination of mercury (II) ions in water. The probe showed high sensitivity and selectivity towards the mercury (II) ion among various alkali, alkaline earth, and transition ...

  12. Determining the Field Capacity, Wilting point and Available Water ...

    African Journals Online (AJOL)

    Prof. Ogunji

    determination of this moisture constants (fc, pwp) using tension tables and pressure plate apparatus is time consuming and tedious and in many developing countries the pressure plate apparatus in unavailable. Van Genuchen (1980) and Clapp and Hornberger ( 1978) observed that other approaches for estimating water ...

  13. Quality Determination of Pipe-Borne Water in Sokoto Metropolis ...

    African Journals Online (AJOL)

    The quality of the pipe-borne water supplied to Sokoto metropolis was determined in this study. The total bacterial count was carried out using surface plating method of inoculation. The coliforms were enumerated using multiple tube fermentation technique (Most Probable Number Method). Some physicochemical ...

  14. An improved shallow water equation model for water animation

    Science.gov (United States)

    Ai, Mingjing; Du, Anding; Xu, Han; Niu, Jianwei

    2017-03-01

    In this paper, we proposed a new scheme for simulating water flows under shallow water assumption. The method is an extension of traditional shallow water equations. In contrast to traditional methods, we design a dynamic coordinate system for modeling in order to efficiently simulate water flows. Within this system, we derive our specialized shallow water equations directly from the Navier-Stockes equation. At the same time, we develop an implicit mechanism for solving the advection term and a vector projection operator for solving the external forces acting on water. We also present a two-way coupling method for simulating the interaction between water and rigid solid. The experimental results show that the proposed scheme can achieve a more realistic and accurate water model compared with the traditional methods, especially when the solid surfaces are too steep. Also we demonstrate the efficiency of our method in several scenes, all run at least 50 frames per second on average which allows real-time simulation.

  15. 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

  16. A system model for water management.

    Science.gov (United States)

    Schenk, Colin; Roquier, Bastien; Soutter, Marc; Mermoud, André

    2009-03-01

    Although generally accepted as a necessary step to improve water management and planning, integrated water resources management (IWRM) methodology does not provide a clear definition of what should be integrated. The various water-related issues that IWRM might encompass are well documented in the literature, but they are generally addressed separately. Therefore, water management lacks a holistic, systems-based description, with a special emphasis on the interrelations between issues. This article presents such a system model for water management, including a graphical representation and textual descriptions of the various water issues, their components, and their interactions. This model is seen as an aide-memoire and a generic reference, providing background knowledge helping to elicit actual system definitions, in possible combination with other participatory systems approaches. The applicability of the model is demonstrated through its application to two test case studies.

  17. Dynamic modelling of Industrial Heavy Water Plant

    International Nuclear Information System (INIS)

    Teruel, F.E.

    1997-01-01

    The dynamic behavior of the isotopic enrichment unites of the Industrial Heavy Water Plant, located in Arroyito, Neuquen, Argentina, was modeled and simulated in the present work. Dynamic models of the chemical and isotopic interchange processes existent in the plant, were developed. This served as a base to obtain representative models of the different unit and control systems. The developed models were represented in a modular code for each unit. Each simulator consists of approximately one hundred non-linear-first-order differential equations and some other algebraic equation, which are time resolved by the code. The different simulators allow to change a big number of boundary conditions and the control systems set point for each simulation, so that the program become very versatile. The output of the code allows to see the evolution through time of the variables of interest. An interface which facilitates the use of the first enrichment stage simulator was developed. This interface allows an easy access to generate wished events during the simulation and includes the possibility to plot evolution of the variables involved. The obtained results agree with the expected tendencies. The calculated nominal steady state matches by the manufacturer. The different steady states obtained, agree with previous works. The times and tendencies involved in the transients generated by the program, are in good agreement with the experience obtained at the plant. Based in the obtained results, it is concluded that the characteristic times of the plant are determined by the masses involved in the process. Different characteristics in the system dynamic behavior were generated with the different simulators, and were validated by plant personnel. This work allowed to understand the different process involved in the heavy water manufacture, and to develop a very useful tool for the personnel of the plant. (author). 14 refs., figs., tabs. plant. (author). 14 refs., figs., tabs

  18. Determining the Utility Value of Water-Supply Interconnections.

    Science.gov (United States)

    Hardman, James L.; Cheremisinoff, Paul N.

    1979-01-01

    This article is the third in a series which discusses a mathematical methodology for evaluating interconnections of water supply systems. The model can be used to analyze the carrying capacity of proposed links or predict the impact of abandoning interconnections. (AS)

  19. Determination of cognitive development: postnonclassical theoretical model

    Directory of Open Access Journals (Sweden)

    Irina N. Pogozhina

    2015-09-01

    Full Text Available The aim of this research is to develop a postnonclassical cognitive processes content determination model in which mental processes are considered as open selfdeveloping, self-organizing systems. Three types of systems (dynamic, statistical, developing were analysed and compared on the basis of the description of the external and internal characteristics of causation, types of causal chains (dependent, independent and their interactions, as well as the nature of the relationship between the elements of the system (hard, probabilistic, mixed. Mechanisms of open non-equilibrium nonlinear systems (dissipative and four dissipative structures emergence conditions are described. Determination models of mental and behaviour formation and development that were developed under various theoretical approaches (associationism, behaviorism, gestaltism, psychology of intelligence by Piaget, Vygotsky culture historical approach, activity approach and others are mapped on each other as the models that describe behaviour of the three system types mentioned above. The development models of the mental sphere are shown to be different by the following criteria: 1 allocated determinants amount; 2 presence or absence of the system own activity that results in selecting the model not only external, but also internal determinants; 3 types of causal chains (dependent-independent-blended; 4 types of relationships between the causal chain that ultimately determines the subsequent system determination type as decisive (a tough dynamic pattern or stochastic (statistical regularity. The continuity of postnonclassical, classical and non-classical models of mental development determination are described. The process of gradual refinement, complexity, «absorption» of the mental determination by the latter models is characterized. The human mental can be deemed as the functioning of the open developing non-equilibrium nonlinear system (dissipative. The mental sphere is

  20. A Water Temperature Simulation Model for Rice Paddies With Variable Water Depths

    Science.gov (United States)

    Maruyama, Atsushi; Nemoto, Manabu; Hamasaki, Takahiro; Ishida, Sachinobu; Kuwagata, Tsuneo

    2017-12-01

    A water temperature simulation model was developed to estimate the effects of water management on the thermal environment in rice paddies. The model was based on two energy balance equations: for the ground and for the vegetation, and considered the water layer and changes in the aerodynamic properties of its surface with water depth. The model was examined with field experiments for water depths of 0 mm (drained conditions) and 100 mm (flooded condition) at two locations. Daily mean water temperatures in the flooded condition were mostly higher than in the drained condition in both locations, and the maximum difference reached 2.6°C. This difference was mainly caused by the difference in surface roughness of the ground. Heat exchange by free convection played an important role in determining water temperature. From the model simulation, the temperature difference between drained and flooded conditions was more apparent under low air temperature and small leaf area index conditions; the maximum difference reached 3°C. Most of this difference occurred when the range of water depth was lower than 50 mm. The season-long variation in modeled water temperature showed good agreement with an observation data set from rice paddies with various rice-growing seasons, for a diverse range of water depths (root mean square error of 0.8-1.0°C). The proposed model can estimate water temperature for a given water depth, irrigation, and drainage conditions, which will improve our understanding of the effect of water management on plant growth and greenhouse gas emissions through the thermal environment of rice paddies.

  1. Experimental determination of cavitation thresholds in liquid water and mercury

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.; West, C.D.; Moraga, F.

    1998-01-01

    An overview is provided on cavitation threshold measurement experiments for water and mercury. Various aspects to be considered that affect onset determination are discussed along with design specifications developed for construction of appropriate apparatus types. Both static and transient-cavitation effects were studied using radically different apparatus designs. Preliminary data are presented for cavitation thresholds for water and mercury over a range of temperatures in static and high-frequency environments. Implications and issues related to spallation neutron source target designs and operation are discussed

  2. National Water Model: Providing the Nation with Actionable Water Intelligence

    Science.gov (United States)

    Aggett, G. R.; Bates, B.

    2017-12-01

    The National Water Model (NWM) provides national, street-level detail of water movement through time and space. Operating hourly, this flood of information offers enormous benefits in the form of water resource management, natural disaster preparedness, and the protection of life and property. The Geo-Intelligence Division at the NOAA National Water Center supplies forecasters and decision-makers with timely, actionable water intelligence through the processing of billions of NWM data points every hour. These datasets include current streamflow estimates, short and medium range streamflow forecasts, and many other ancillary datasets. The sheer amount of NWM data produced yields a dataset too large to allow for direct human comprehension. As such, it is necessary to undergo model data post-processing, filtering, and data ingestion by visualization web apps that make use of cartographic techniques to bring attention to the areas of highest urgency. This poster illustrates NWM output post-processing and cartographic visualization techniques being developed and employed by the Geo-Intelligence Division at the NOAA National Water Center to provide national actionable water intelligence.

  3. Imaging and modelling root water uptake

    Science.gov (United States)

    Zarebanadkouki, M.; Meunier, F.; Javaux, M.; Kaestner, A.; Carminati, A.

    2017-12-01

    Spatially resolved measurement and modelling of root water uptake is urgently needed to identify root traits that can improve capture of water from the soil. However, measuring water fluxes into roots of transpiring plants growing in soil remains challenging. Here, we describe an in-situ technique to measure local fluxes of water into roots. The technique consists of tracing the transport of deuterated water (D2O) in soil and roots using time series neutron radiography and tomography. A diffusion-convection model was used to model the transport of D2O in roots. The model includes root features such as the endodermis, xylem and the composite flow of water in the apoplastic and symplastic pathways. Diffusion permeability of root cells and of the endodermis were estimated by fitting the experiment during the night, when transpiration was negligible. The water fluxes at different position of the root system were obtained by fitting the experiments at daytime. The results showed that root water uptake was not uniform along root system and varied among different root types. The measured profiles of root water uptake into roots were used to estimate the radial and axial hydraulic of the roots. A three-dimensional model of root water uptake was used to fit the measured water fluxes by adjusting the root radial and axial hydraulic conductivities. We found that the estimated radial conductivities decreased with root age, while the axial conducances increased, and they are different among root types. The significance of this study is the development of a method to estimate 1) water uptake and 2) the radial and axial hydraulic conductivities of roots of transpiring plants growing in the soil.

  4. Predicting water main failures using Bayesian model averaging and survival modelling approach

    International Nuclear Information System (INIS)

    Kabir, Golam; Tesfamariam, Solomon; Sadiq, Rehan

    2015-01-01

    To develop an effective preventive or proactive repair and replacement action plan, water utilities often rely on water main failure prediction models. However, in predicting the failure of water mains, uncertainty is inherent regardless of the quality and quantity of data used in the model. To improve the understanding of water main failure, a Bayesian framework is developed for predicting the failure of water mains considering uncertainties. In this study, Bayesian model averaging method (BMA) is presented to identify the influential pipe-dependent and time-dependent covariates considering model uncertainties whereas Bayesian Weibull Proportional Hazard Model (BWPHM) is applied to develop the survival curves and to predict the failure rates of water mains. To accredit the proposed framework, it is implemented to predict the failure of cast iron (CI) and ductile iron (DI) pipes of the water distribution network of the City of Calgary, Alberta, Canada. Results indicate that the predicted 95% uncertainty bounds of the proposed BWPHMs capture effectively the observed breaks for both CI and DI water mains. Moreover, the performance of the proposed BWPHMs are better compare to the Cox-Proportional Hazard Model (Cox-PHM) for considering Weibull distribution for the baseline hazard function and model uncertainties. - Highlights: • Prioritize rehabilitation and replacements (R/R) strategies of water mains. • Consider the uncertainties for the failure prediction. • Improve the prediction capability of the water mains failure models. • Identify the influential and appropriate covariates for different models. • Determine the effects of the covariates on failure

  5. Determination of water use in Rockford and Kankakee areas, Illinois

    Science.gov (United States)

    LaTour, John K.

    1991-01-01

    Amounts of water withdrawn, delivered, consumed, released, returned, and lost or gained during conveyance were determined for six communities--Rockford, Loves Park, North Park, Kankakee, Bourbonnais, and Bradley--served by the public-water systems in the Rockford and the Kankakee areas of Illinois. Water-use categories studied were commercial, industrial, domestic, and municipal uses; public supply; and sewage treatment. The availability and accuracy of water-use data are described, and water-use coefficients and methods of estimating water use are provided to improve the collection and the analysis of water-use information. Water-use data were obtained from all the water utilities and from 30 major water users in the Rockford and the Kankakee areas. Data were available for water withdrawals by water suppliers; deliveries by water suppliers to water users; returns by sewage-treatment plants and water users; releases by water users to sewers; and sewer-conveyance losses. Accuracy of the water-use data was determined from discharge measurements or reliability tests of water meters, or was estimated according to the completeness of the data. Accuracy of withdrawal and sewage-treatment-return data for the Rockford area and of withdrawal, delivery, industrial release, and sewage-treatment-return data for the Kankakee area was considered to be at least 90 percent. Where water-use data were inadequate or unavailable, various methods were used to estimate consumptive uses; releases; returns by commercial, domestic, and municipal users; and conveyance losses and gains. The methods focused on water budgeting to assure that water uses balanced. Consumptive uses were estimated by use of the consumption-budget method, the types-of-use method, consumptive-use ratios, the winter base-rate method, and the maximum lawn-watering method. The winter base-rate method provided the best domestic consumptive-use estimates, whose ratios (consumptive use from the winter base-rate method

  6. Qualitative and quantitative determination of water in airborne particulate matter

    Directory of Open Access Journals (Sweden)

    S. Canepari

    2013-02-01

    Full Text Available This paper describes the optimization and validation of a new simple method for the quantitative determination of water in atmospheric particulate matter (PM. The analyses are performed by using a coulometric Karl-Fisher system equipped with a controlled heating device; different water contributions are separated by the application of an optimized thermal ramp (three heating steps: 50–120 °C, 120–180 °C, 180–250 °C.

    The analytical performance of the method was verified by using standard materials containing 5.55% and 1% by weight of water. The recovery was greater than 95%; the detection limit was about 20 μg. The method was then applied to NIST Reference Materials (NIST1649a, urban particulate matter and to real PM10 samples collected in different geographical areas. In all cases the repeatability was satisfactory (10–15%.

    When analyzing the Reference Material, the separation of four different types of water was obtained. In real PM10 samples the amount of water and its thermal profile differed as a function of the chemical composition of the dust. Mass percentages of 3–4% of water were obtained in most samples, but values up to about 15% were reached in areas where the chemical composition of PM is dominated by secondary inorganic ions and organic matter. High percentages of water were also observed in areas where PM is characterized by the presence of desert dust.

    A possible identification of the quality of water released from the samples was tried by applying the method to some hygroscopic compounds that are likely contained in PM (pure SiO2, Al2O3, ammonium salts, carbohydrates and dicarboxylic acids and by comparing the results with those obtained from field samples.

  7. Modelling stable water isotopes: Status and perspectives

    Directory of Open Access Journals (Sweden)

    Werner M.

    2010-12-01

    Full Text Available Modelling of stable water isotopes H2 18O and HDO within various parts of the Earth’s hydrological cycle has clearly improved our understanding of the interplay between climatic variations and related isotope fractionation processes. In this article key principles and major research results of stable water isotope modelling studies are described. Emphasis is put on research work using explicit isotope diagnostics within general circulation models as this highly complex model setup bears many resemblances with studies using simpler isotope modelling approaches.

  8. Tree tomato water requirements determined by neutron probe

    International Nuclear Information System (INIS)

    1994-01-01

    The dynamics of water was studied at ''La Tola'', experimental teaching center of the Central University of Ecuador, in a sandy-loan, typic durustoll soil in which trees tomato were growing. All the components of the crop water balance were determined. Real evapotranspiration (ETR) was estimated through the mass balance method, using every 5-10 days a neutron probe to access the volumetric humidity of the soil. The real evapotranspiration was in direct relation with the growth of the crop, reaching its maximum value of 3,8 mm day-1, at vegetative stage. The soil layer supplying most of the water for the consumptive use of the crop was between 0-40 cm being the root activity also greater in that layer

  9. 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.)

  10. Spectroscopic determination of gas-water interactions in clathrate hydrates

    International Nuclear Information System (INIS)

    Richardson, H.H. Jr.

    1985-01-01

    The technique of forming clathrate hydrates by first forming the amorphous deposits of gas-water mixture and, secondly, annealing this deposit was used to form the clathrate hydrates of ethylene oxide, hydrogen sulfide and sulfur dioxide. Once the clathrate hydrate formed as a thin film on the CsI substrate, the infrared spectrum of these hydrates could be obtained. The clathrate hydrates could be irradiated with 1.7 MeV electrons to promote high proton concentrations in the clathrate hydrate lattice at low temperatures (approx.30K) where the Bjerrum defects in the lattice are not mobile. The ring breathing model of ethylene oxide in the clathrate hydrate can be assigned. It was possible to incorporate D 2 O into the hydrogen bonded lattice of the ethylene oxide clathrate hydrate by growing the clathrate hydrate epitaxially on a thin film of clathrate hydrate at 100 K. The half-life of the D 2 O molecules in the ethylene oxide clathrate hydrate was only 9 minutes at 120 K. The activation energy determined from the hopping rate constant in ethylene oxide clathrate hydrate was 4.5 +/- 1.8 Kcal/mole. Irradiation of the ethylene oxide clathrate hydrate with 1.7 MeV electrons transformed some of the ethylene oxide molecules in the cages to (a) CH 2 = CH 2 , (b) CH 2 = C = O, (c) CH 3 -CH 2 -OH, (d) CO 2 , and (e) CO. A steady state concentration of coupled HOD was maintained in irradiated samples of ethylene oxide clathrate hydrates at a temperature around 80 K. The enclathrated H 2 S molecule in the small cages had a different infrared spectrum (broad band complex centered at 2600 cm -1 ) from the H 2 S molecules which had been enclathrated in the large cages (broad band complex centered at 2550 cm -1 )

  11. Multielement determination in water by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Naeem, A.

    1987-01-01

    INAA technique was applied to a water sample to determine the elemental concentrations. The sample was irradiated with a neutron flux of 1.2x10 12 n cm -2 s -1 for two different decay times, using two coaxial type high-resolution Ge(Li) detectors. The dominant elements determined in the water sample are Ca, Cl, Na, Mg and K present in ppm-level, while Co, I, Mn, Sm, and Sb are present in smaller amounts, approx. on the average 0.01 ppm. Only traces of other elements such as the rare-earths Ag, As, Ba, Cu, Cd, Fe, Sr, W, Zn, seem to be present. (author)

  12. 222Rn determination in mineral waters from the Pocos de Caldas Plateau in Brazil

    International Nuclear Information System (INIS)

    Taddei, M.H.T.; Silva, N.C.; Cipriani, M.

    2002-01-01

    It is estimated that 50% of the radioactive effective dose equivalent to man comes from radon and its radioactivity daughters. The main 222 Rn sources are the soils, building materials and potable waters. There is an especial interest in spas waters with high natural radioactivity. It's considered that the use of these waters as drinking waters is a significant radiation exposure factor, and it is worthwhile to assess the consequent dose. Such estimation has been made for the Pocos de Caldas Plateau, which is a region of high natural radioactivity, from volcanic origin, containing several spas (Aguas da Prata, Caldas, Pocos de Caldas and Andradas). The 222 Rn content was determined in 23 spring waters in Pocos de Caldas and neighboring cities. In water sampling, modified Marinelli flasks were used. The determinations were effected with a high resolution gamma ray spectrometer. High concentration variations were observed in the collected mineral waters, the highest values having been found in Fonte Villela's waters, in Aguas da Prata town (926 Bq/l); Grande Hotel's in Caldas Town (420 Bq/l) and COLAB's in Pocos de Caldas region (289 Bq/l). The annual whole body effective dose equivalent estimate for adult due to water ingestion, using the Crowford-Brown's biokinetic model's adult dose conversion factors, was higher than 1 mSv/year in 61% of the analyzed waters. (author)

  13. Recent Experimental Advances to Determine (noble) Gases in Waters

    Science.gov (United States)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (doi:10:4319/lom.2011.9.42. [2] Vogel et al. (2013) Geochem. Geophys. Geosyst., 14, doi:10.1002/ggge.20164. [3] Brennwald et al. (2013) Environ. Sci. Technol., Article ASAP, DOI: 10.1021/es401698p. [4] Mächler et al. (2012) Environ. Sci. Technol., 47, 7060-7066. [5] Huxol et al. Environ. Sci. Technol., in revision.

  14. 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)

  15. Specific determination of ferbam residues in fog-water.

    Science.gov (United States)

    Agarwal, Smita; Aggarwal, Shankar G; Singh, Pahup

    2003-12-23

    A specific method for the determination of a fungicide, i.e. iron(III) dimethyldithiocarbamate (ferbam) in fog-water samples is described. The method is based on the releasing of equivalent amount of iron from the fungicide and subsequently determination by spectrophotometrically or by flame-atomic absorption spectrometrically (flame-AAS). The fungicide was extracted with chloroform/toluene from the samples and digested with nitric acid. For spectrophotometric determination, the solution was then treated with ammonium thiocyanate solution in presence of the surfactants and absorbance was measured at 475 nm. Whereas, the digested solution was directly applied for flame-AAS determination of ferbam. The molar absorptivity in terms of ferbam was determined to be (3.49)x10(4) l mol(-1) cm(-1). The detection limits for spectrophotometric and flame-AAS methods were calculated to be 62 and 111 ppb ferbam (R.S.D. fog-water. The methods have been successfully applied to fog samples collected from agriculture sites of Raipur (central India).

  16. Determination of radionuclides in discharged water from gold ...

    African Journals Online (AJOL)

    Long-lived radionuclides from the Uranium-, Thorium- and Actinium-decay chains in the discharged water into the environment were radiochemically separated and the activity concentrations determined for 238U-series ranged from 3.8 ± 1.5 to 178 ± 19 mBqL-1, 232Th-series ranged from < 2.0 to 47.8 ± 7.3 mBqL-1 and ...

  17. Spectrophotometric determination of thorium using arsenazo III in water

    International Nuclear Information System (INIS)

    Rio, M.A.P. do; Godoy, J.M. de.

    1985-01-01

    A spectrophotometric determination of thorium with arsenazo III (1,8 dihidroxynaphtaline - 3,6 sulfanic acid - 2,7 bis (azo-2) - phenil argonic acid) was carried out aiming to analyse this element in water. In order to eliminate possible interferences, a coprecipitation with lantanium fluoride was used followed by an extration with 0,2 M TTA (tenoil-trifluor - aceton) / Benzen. The results showed a good agreement with the ones obtained by alfa-spectrometry. (Author) [pt

  18. Modelling anisotropic water transport in polymer composite

    Indian Academy of Sciences (India)

    This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were ...

  19. A dual model approach to ground water recovery trench design

    International Nuclear Information System (INIS)

    Clodfelter, C.L.; Crouch, M.S.

    1992-01-01

    The design of trenches for contaminated ground water recovery must consider several variables. This paper presents a dual-model approach for effectively recovering contaminated ground water migrating toward a trench by advection. The approach involves an analytical model to determine the vertical influence of the trench and a numerical flow model to determine the capture zone within the trench and the surrounding aquifer. The analytical model is utilized by varying trench dimensions and head values to design a trench which meets the remediation criteria. The numerical flow model is utilized to select the type of backfill and location of sumps within the trench. The dual-model approach can be used to design a recovery trench which effectively captures advective migration of contaminants in the vertical and horizontal planes

  20. Modelling transitions in urban water systems.

    Science.gov (United States)

    Rauch, W; Urich, C; Bach, P M; Rogers, B C; de Haan, F J; Brown, R R; Mair, M; McCarthy, D T; Kleidorfer, M; Sitzenfrei, R; Deletic, A

    2017-12-01

    Long term planning of urban water infrastructure requires acknowledgement that transitions in the water system are driven by changes in the urban environment, as well as societal dynamics. Inherent to the complexity of these underlying processes is that the dynamics of a system's evolution cannot be explained by linear cause-effect relationships and cannot be predicted under narrow sets of assumptions. Planning therefore needs to consider the functional behaviour and performance of integrated flexible infrastructure systems under a wide range of future conditions. This paper presents the first step towards a new generation of integrated planning tools that take such an exploratory planning approach. The spatially explicit model, denoted DAnCE4Water, integrates urban development patterns, water infrastructure changes and the dynamics of socio-institutional changes. While the individual components of the DAnCE4Water model (i.e. modules for simulation of urban development, societal dynamics and evolution/performance of water infrastructure) have been developed elsewhere, this paper presents their integration into a single model. We explain the modelling framework of DAnCE4Water, its potential utility and its software implementation. The integrated model is validated for the case study of an urban catchment located in Melbourne, Australia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. What Determines Water Temperature Dynamics in the San Francisco Bay-Delta System?

    Science.gov (United States)

    Vroom, J.; van der Wegen, M.; Martyr-Koller, R. C.; Lucas, L. V.

    2017-11-01

    Water temperature is an important factor determining estuarine species habitat conditions. Water temperature is mainly governed by advection (e.g., from rivers) and atmospheric exchange processes varying strongly over time (day-night, seasonally) and the spatial domain. On a long time scale, climate change will impact water temperature in estuarine systems due to changes in river flow regimes, air temperature, and sea level rise. To determine which factors govern estuarine water temperature and its sensitivity to changes in its forcing, we developed a process-based numerical model (Delft3D Flexible Mesh) and applied it to a well-monitored estuarine system (the San Francisco Estuary) for validation. The process-based approach allows for detailed process description and a physics-based analysis of governing processes. The model was calibrated for water year 2011 and incorporated 3-D hydrodynamics, salinity intrusion, water temperature dynamics, and atmospheric coupling. Results show significant skill in reproducing temperature observations on daily, seasonal, and yearly time scales. In North San Francisco Bay, thermal stratification is present, enhanced by salinity stratification. The temperature of the upstream, fresh water Delta area is captured well in 2-D mode, although locally—on a small scale—vertical processes (e.g., stratification) may be important. The impact of upstream river temperature and discharge and atmospheric forcing on water temperatures differs throughout the Delta, possibly depending on dispersion and residence times. Our modeling effort provides a sound basis for future modeling studies including climate change impact on water temperature and associated ecological modeling, e.g., clam and fish habitat and phytoplankton dynamics.

  2. Determination of coefficient matrices for ARMA model

    International Nuclear Information System (INIS)

    Tran Dinh Tri.

    1990-10-01

    A new recursive algorithm for determining coefficient matrices of ARMA model from measured data is presented. The Yule-Walker equations for the case of ARMA model are derived from the ARMA innovation equation. The recursive algorithm is based on choosing appropriate form of the operator functions and suitable representation of the (n+1)-th order operator functions according to ones with the lower order. Two cases, when the order of the AR part is equal to one of the MA part, and the optimal case, were considered. (author) 5 refs

  3. Development of Ensemble Model Based Water Demand Forecasting Model

    Science.gov (United States)

    Kwon, Hyun-Han; So, Byung-Jin; Kim, Seong-Hyeon; Kim, Byung-Seop

    2014-05-01

    In recent years, Smart Water Grid (SWG) concept has globally emerged over the last decade and also gained significant recognition in South Korea. Especially, there has been growing interest in water demand forecast and optimal pump operation and this has led to various studies regarding energy saving and improvement of water supply reliability. Existing water demand forecasting models are categorized into two groups in view of modeling and predicting their behavior in time series. One is to consider embedded patterns such as seasonality, periodicity and trends, and the other one is an autoregressive model that is using short memory Markovian processes (Emmanuel et al., 2012). The main disadvantage of the abovementioned model is that there is a limit to predictability of water demands of about sub-daily scale because the system is nonlinear. In this regard, this study aims to develop a nonlinear ensemble model for hourly water demand forecasting which allow us to estimate uncertainties across different model classes. The proposed model is consist of two parts. One is a multi-model scheme that is based on combination of independent prediction model. The other one is a cross validation scheme named Bagging approach introduced by Brieman (1996) to derive weighting factors corresponding to individual models. Individual forecasting models that used in this study are linear regression analysis model, polynomial regression, multivariate adaptive regression splines(MARS), SVM(support vector machine). The concepts are demonstrated through application to observed from water plant at several locations in the South Korea. Keywords: water demand, non-linear model, the ensemble forecasting model, uncertainty. Acknowledgements This subject is supported by Korea Ministry of Environment as "Projects for Developing Eco-Innovation Technologies (GT-11-G-02-001-6)

  4. Development of neutron measurement techniques in reactor diagnostics and determination of water content and water flow

    International Nuclear Information System (INIS)

    Avdic, Senada

    2000-09-01

    The present thesis deals with three comparatively different topics in neutron physics research. These topics are as follows: construction and experimental investigation of a new detector, capable of measuring the neutron current, and investigation of the possibility to use it for the localisation of a neutron source in a simple experimental arrangement; execution of neutron transmission measurements based on a stationary neutron generator, and the study of their suitability for determining the volume porosity of geological samples; study of the possibility for improving the accuracy of water flow measurements based on the pulsed neutron activation technique. The first subject of this thesis concerns the measurement of the neutron current by a newly constructed detector. The motivation for this work stems from a recent suggestion that the performance of core monitoring methods could be enhanced if, in addition to the scalar neutron flux, also the neutron current was measured. To this end, a current detector was based on a scintillator mounted on a fibre and a Cd layer on one side of the detector. The measurements of the 2-D neutron current were performed in an experimental system by using this detector. The efficiency of the detector in reactor diagnostics was illustrated by demonstrating that the position of a neutron source can be determined by measuring the scalar neutron flux and the neutron current in one spatial point. The results of measurement and calculation show both the suitability of the detector construction for the measurement of the neutron current vector and the use of the current in diagnostics and monitoring. The second subject of this thesis concerns fast neutron transmission measurements, based on a stationary neutron generator, for determining the volume porosity of a sample in a model experiment. Such a technique could be used in field measurements with obvious advantages in comparison with thermal neutron transmission techniques, which can

  5. Building better water models using the shape of the charge distribution of a water molecule

    Science.gov (United States)

    Dharmawardhana, Chamila Chathuranga; Ichiye, Toshiko

    2017-11-01

    The unique properties of liquid water apparently arise from more than just the tetrahedral bond angle between the nuclei of a water molecule since simple three-site models of water are poor at mimicking these properties in computer simulations. Four- and five-site models add partial charges on dummy sites and are better at modeling these properties, which suggests that the shape of charge distribution is important. Since a multipole expansion of the electrostatic potential describes a charge distribution in an orthogonal basis set that is exact in the limit of infinite order, multipoles may be an even better way to model the charge distribution. In particular, molecular multipoles up to the octupole centered on the oxygen appear to describe the electrostatic potential from electronic structure calculations better than four- and five-site models, and molecular multipole models give better agreement with the temperature and pressure dependence of many liquid state properties of water while retaining the computational efficiency of three-site models. Here, the influence of the shape of the molecular charge distribution on liquid state properties is examined by correlating multipoles of non-polarizable water models with their liquid state properties in computer simulations. This will aid in the development of accurate water models for classical simulations as well as in determining the accuracy needed in quantum mechanical/molecular mechanical studies and ab initio molecular dynamics simulations of water. More fundamentally, this will lead to a greater understanding of how the charge distribution of a water molecule leads to the unique properties of liquid water. In particular, these studies indicate that p-orbital charge out of the molecular plane is important.

  6. The water kefir grain inoculum determines the characteristics of the resulting water kefir fermentation process.

    Science.gov (United States)

    Laureys, D; De Vuyst, L

    2017-03-01

    To investigate the influence of the water kefir grain inoculum on the characteristics of the water kefir fermentation process. Three water kefir fermentation processes were started with different water kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile and metabolite production course. The inoculum determined the water kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these micro-organisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii and Saccharomyces cerevisiae were always present and may be the key micro-organisms during water kefir fermentation. Low water kefir grain growth was associated with small grains with high viable counts of micro-organisms, fast fermentation and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. The water kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key micro-organisms was always present during fermentation. This study allows a rational selection of a water kefir grain inoculum. © 2016 The Society for Applied Microbiology.

  7. Cold water extraction (CWE). Procedure for the determination of the alkali content and pore solution composition

    OpenAIRE

    Plusquellec, Gilles; De Weerdt, Klaartje

    2017-01-01

    This document describes the cold water extraction (CWE) procedure which allows to determine the free alkali content of hydrated cement paste, mortar or concrete. The calculation of the pH using the thermodynamic modelling software PhreeqC is presented in the appendix

  8. Determining Reduced Order Models for Optimal Stochastic Reduced Order Models

    Energy Technology Data Exchange (ETDEWEB)

    Bonney, Matthew S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Brake, Matthew R.W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-08-01

    The use of parameterized reduced order models(PROMs) within the stochastic reduced order model (SROM) framework is a logical progression for both methods. In this report, five different parameterized reduced order models are selected and critiqued against the other models along with truth model for the example of the Brake-Reuss beam. The models are: a Taylor series using finite difference, a proper orthogonal decomposition of the the output, a Craig-Bampton representation of the model, a method that uses Hyper-Dual numbers to determine the sensitivities, and a Meta-Model method that uses the Hyper-Dual results and constructs a polynomial curve to better represent the output data. The methods are compared against a parameter sweep and a distribution propagation where the first four statistical moments are used as a comparison. Each method produces very accurate results with the Craig-Bampton reduction having the least accurate results. The models are also compared based on time requirements for the evaluation of each model where the Meta- Model requires the least amount of time for computation by a significant amount. Each of the five models provided accurate results in a reasonable time frame. The determination of which model to use is dependent on the availability of the high-fidelity model and how many evaluations can be performed. Analysis of the output distribution is examined by using a large Monte-Carlo simulation along with a reduced simulation using Latin Hypercube and the stochastic reduced order model sampling technique. Both techniques produced accurate results. The stochastic reduced order modeling technique produced less error when compared to an exhaustive sampling for the majority of methods.

  9. DETERMINATION OF PHTHALATES FROM BOTTLED WATER BY GC-MS

    Directory of Open Access Journals (Sweden)

    IRINA DUMITRAȘCU

    2012-03-01

    Full Text Available Determination of phthalates from bottled water by GC-MS. Phthalates are ubiquitous pollutants in the environment, due to their widespread use in the last years. These compounds are used principally as plasticizers, to impact flexibility, workability and durability to polymers but they can also be found in products such as paints, adhesives, inks and cosmetics. Phthalates are not chemically bounded to polymers; hence they are easily released and migrate into foods, beverages and drinking water from the packaging or bottling materials or manufacturing processes. This process accelerates as plastic products age and break down. With respect to their endocrine disrupting potential, phthalates such as benzyl butyl phthalate (BBP, di-butyl phthalate (DBP and di-isobutyl phthalate (DIBP have been found to elicit estrogenic responses in in vitro assays. It is possible that phthalates are a contributory factor to endocrine-mediated adverse effects observed in wildlife and humans over the past few decades. In this experiment we have analyzed the phthalates from different bottled waters purchased from the market. Determination by gas chromatography in combination with mass spectrometry detector (GC–MS in electronic ionization mode (EI with selected-ion monitoring (SIM acquisition method (GC–MS (EI–SIM has been carried out. Methods have been developed for both qualitative and quantitative analysis of phthalates. The base peak (m/z = 149 of all the phthalates was selected for the screening studies. The characteristic ions of each compound were chosen for quantitative studies.

  10. Kinetic modelization of water-rock interaction processes

    International Nuclear Information System (INIS)

    Pena, J.; Gimeno, M.J.

    1994-01-01

    A review of basic concepts in kinetics of low temperature natural systems is given: elementary and overall reactions, steady state and reaction mechanism, sequential reactions, parallel reactions and rate-determining step, temperature dependence of rate constant and principle of detailed balancing. The current status of kinetics modeling of water/rock interaction is treated. The comparison of the mean life of the processes with the residence time of the water in the system is very useful to decide the application or not of the kinetics treatment to the water/rock interaction processes. The right application of the kinetics treatment to the water/rock interaction needs the knowledge of the magnitude of the surface through which the water/rock reaction take place and its variation with time. Two ways to treat kinetically the water/rock interaction are the Mass Transfer method and the quasi-stationary state method

  11. Spectrophotometric determination of acidity constants of Alizarine Red S in water, water-Brij-35 and water-SDS micellar media solutions

    Science.gov (United States)

    Niazi, Ali; Ghalie, Mohammad; Yazdanipour, Ateesa; Ghasemi, Jahanbakhsh

    2006-06-01

    The acidity constants of Alizarine Red S in water, water-Brij-35 and water-SDS micellar media solutions at 25 °C and an ionic strength of 0.1 M have been determined spectrophotometrically. To evaluate the pH-absorbance data, a resolution method based on the combination of soft- and hard-modeling is applied. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program applied for determination of acidity constants. Results show that the p Ka values of Alizarine Red S are influenced as the percentages of a neutral and an anionic surfactant such as Brij-35 and SDS, respectively, added to the solution of this reagent. Effect of surfactant on acidity constants and pure spectrum of each component are also discussed.

  12. Fluoroquinolone antibiotics in environmental waters: sample preparation and determination.

    Science.gov (United States)

    Speltini, Andrea; Sturini, Michela; Maraschi, Federica; Profumo, Antonella

    2010-04-01

    The aim of this review is to provide a general overview on the analytical methods proposed in the last decade for trace fluoroquinolone (FQ) determination in environmental waters. A large number of studies have been developed on this topic in reason of the importance of their monitoring in the studies of environmental mobility and potential degradation pathways. Every step of the analysis has been carefully considered, with a particular attention to sample preparation, in relationship with the problems involved in the analysis of real matrices. The different strategies to minimise interference from organic matter and to achieve optimal sensitivity, especially important in those samples with lower FQ concentrations, were also highlighted. Results and progress in this field have been described and critically commented. Moreover, a worldwide overview on the presence of FQs in the environmental waters has been reported.

  13. Determination of isotopic uranium in food and water

    International Nuclear Information System (INIS)

    Baratta, E.J.; Mackill, P.

    2001-01-01

    The U.S. Food and Drug Administration (FDA) conducts surveys of foods both domestic and imported for the presence of radioactivity. It does not routinely analyze for the actinides, specifically uranium, as it has been shown by previously by studies as reported by WELFORD and others that the concentration in food is very low. This was the result of a 'Tri-City' study. However, at specific sites, the FDA has been requested to analyze for uranium. The concern is that either 'enriched' or 'depleted' uranium has been introduced into the environment and possibly contaminated the food supply. In addition some concern has been raised that water from wells or other sources used for processing food may contain uranium, both natural, depleted or enriched. Methodology for the determination of isotopic uranium, specifically for uranium-238 (depleted) and/or uranium-235 (enriched) in the analyses of food and water samples and the results of these surveys are discussed. (author)

  14. Microwave Determination of Water Mole Fraction in Humid Gas Mixtures

    Science.gov (United States)

    Cuccaro, R.; Gavioso, R. M.; Benedetto, G.; Madonna Ripa, D.; Fernicola, V.; Guianvarc'h, C.

    2012-09-01

    A small volume (65 cm3) gold-plated quasi-spherical microwave resonator has been used to measure the water vapor mole fraction x w of H2O/N2 and H2O/air mixtures. This experimental technique exploits the high precision achievable in the determination of the cavity microwave resonance frequencies and is particularly sensitive to the presence of small concentrations of water vapor as a result of the high polarizability of this substance. The mixtures were prepared using the INRIM standard humidity generator for frost-point temperatures T fp in the range between 241 K and 270 K and a commercial two-pressure humidity generator operated at a dew-point temperature between 272 K and 291 K. The experimental measurements compare favorably with the calculated molar fractions of the mixture supplied by the humidity generators, showing a normalized error lower than 0.8.

  15. STREAMFLOW AND WATER QUALITY REGRESSION MODELING ...

    African Journals Online (AJOL)

    Journal of Modeling, Design and Management of Engineering Systems ... Consistency tests, trend analyses and mathematical modeling of water quality constituents and riverflow characteristics at upstream Nekede station and downstream Obigbo station show: consistent time-trends in degree of contamination; linear and ...

  16. Robustness of river basin water quality models

    NARCIS (Netherlands)

    de Blois, Chris; Wind, H.G.; de Kok, Jean-Luc; Koppeschaar, K.

    2003-01-01

    In this paper the concept of robustness is introduced and applied to a model for the analysis of the impacts of spatially distributed policy measures on the surface water quality on a river basin scale. In this model the influence of precipitation on emissions and resuspension of pollutants in the

  17. Modeling climate change impacts on water trading.

    Science.gov (United States)

    Luo, Bin; Maqsood, Imran; Gong, Yazhen

    2010-04-01

    This paper presents a new method of evaluating the impacts of climate change on the long-term performance of water trading programs, through designing an indicator to measure the mean of periodic water volume that can be released by trading through a water-use system. The indicator is computed with a stochastic optimization model which can reflect the random uncertainty of water availability. The developed method was demonstrated in the Swift Current Creek watershed of Prairie Canada under two future scenarios simulated by a Canadian Regional Climate Model, in which total water availabilities under future scenarios were estimated using a monthly water balance model. Frequency analysis was performed to obtain the best probability distributions for both observed and simulated water quantity data. Results from the case study indicate that the performance of a trading system is highly scenario-dependent in future climate, with trading effectiveness highly optimistic or undesirable under different future scenarios. Trading effectiveness also largely depends on trading costs, with high costs resulting in failure of the trading program. (c) 2010 Elsevier B.V. All rights reserved.

  18. High purity heavy water production: need for total organic carbon determination in process water streams

    International Nuclear Information System (INIS)

    Ayushi; Kumar, Sangita D.; Reddy, A.V.R.; Vithal, G.K.

    2009-01-01

    In recent times, demand for high purity heavy water (99.98% pure) in industries and laboratories has grown by manifold. Its application started in nuclear industry with the design of CANDU reactor, which uses natural uranium as fuel. In this reactor the purest grade of heavy water is used as the moderator and the primary coolant. Diverse industrial applications like fibre optics, medicine, semiconductors etc. use high purity heavy water extensively to achieve better performance of the specific material. In all these applications there is a stringent requirement that the total organic carbon content (TOC) of high purity heavy water should be very low. This is because the presence of TOC can lead to adverse interactions in different applications. To minimize the TOC content in the final product there is a need to monitor and control the TOC content at each and every stage of heavy water production. Hence a simple, rapid and accurate method was developed for the determination of TOC content in process water samples. The paper summarizes the results obtained for the TOC content in the water samples collected from process streams of heavy water production plant. (author)

  19. Using an inverse modelling approach to evaluate the water retention in a simple water harvesting technique

    Directory of Open Access Journals (Sweden)

    K. Verbist

    2009-10-01

    Full Text Available In arid and semi-arid zones, runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Nevertheless, few efforts were observed to quantify the water harvesting processes of these techniques and to evaluate their efficiency. In this study, a combination of detailed field measurements and modelling with the HYDRUS-2D software package was used to visualize the effect of an infiltration trench on the soil water content of a bare slope in northern Chile. Rainfall simulations were combined with high spatial and temporal resolution water content monitoring in order to construct a useful dataset for inverse modelling purposes. Initial estimates of model parameters were provided by detailed infiltration and soil water retention measurements. Four different measurement techniques were used to determine the saturated hydraulic conductivity (Ksat independently. The tension infiltrometer measurements proved a good estimator of the Ksat value and a proxy for those measured under simulated rainfall, whereas the pressure and constant head well infiltrometer measurements showed larger variability. Six different parameter optimization functions were tested as a combination of soil-water content, water retention and cumulative infiltration data. Infiltration data alone proved insufficient to obtain high model accuracy, due to large scatter on the data set, and water content data were needed to obtain optimized effective parameter sets with small confidence intervals. Correlation between the observed soil water content and the simulated values was as high as R2=0.93 for ten selected observation points used in the model calibration phase, with overall correlation for the 22 observation points equal to 0.85. The model results indicate that the infiltration trench has a

  20. Modelling water uptake efficiency of root systems

    Science.gov (United States)

    Leitner, Daniel; Tron, Stefania; Schröder, Natalie; Bodner, Gernot; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry; Schnepf, Andrea

    2016-04-01

    Water uptake is crucial for plant productivity. Trait based breeding for more water efficient crops will enable a sustainable agricultural management under specific pedoclimatic conditions, and can increase drought resistance of plants. Mathematical modelling can be used to find suitable root system traits for better water uptake efficiency defined as amount of water taken up per unit of root biomass. This approach requires large simulation times and large number of simulation runs, since we test different root systems under different pedoclimatic conditions. In this work, we model water movement by the 1-dimensional Richards equation with the soil hydraulic properties described according to the van Genuchten model. Climatic conditions serve as the upper boundary condition. The root system grows during the simulation period and water uptake is calculated via a sink term (after Tron et al. 2015). The goal of this work is to compare different free software tools based on different numerical schemes to solve the model. We compare implementations using DUMUX (based on finite volumes), Hydrus 1D (based on finite elements), and a Matlab implementation of Van Dam, J. C., & Feddes 2000 (based on finite differences). We analyse the methods for accuracy, speed and flexibility. Using this model case study, we can clearly show the impact of various root system traits on water uptake efficiency. Furthermore, we can quantify frequent simplifications that are introduced in the modelling step like considering a static root system instead of a growing one, or considering a sink term based on root density instead of considering the full root hydraulic model (Javaux et al. 2008). References Tron, S., Bodner, G., Laio, F., Ridolfi, L., & Leitner, D. (2015). Can diversity in root architecture explain plant water use efficiency? A modeling study. Ecological modelling, 312, 200-210. Van Dam, J. C., & Feddes, R. A. (2000). Numerical simulation of infiltration, evaporation and shallow

  1. Determination of organic compounds in water using ultraviolet LED

    Science.gov (United States)

    Kim, Chihoon; Ji, Taeksoo; Eom, Joo Beom

    2018-04-01

    This paper describes a method of detecting organic compounds in water using an ultraviolet LED (280 nm) spectroscopy system and a photodetector. The LED spectroscopy system showed a high correlation between the concentration of the prepared potassium hydrogen phthalate and that calculated by multiple linear regression, indicating an adjusted coefficient of determination ranging from 0.953-0.993. In addition, a comparison between the performance of the spectroscopy system and the total organic carbon analyzer indicated that the difference in concentration was small. Based on the close correlation between the spectroscopy and photodetector absorbance values, organic measurement with a photodetector could be configured for monitoring.

  2. Modelling soil-water dynamics in the rootzone of structured and water-repellent soils

    Science.gov (United States)

    Brown, Hamish; Carrick, Sam; Müller, Karin; Thomas, Steve; Sharp, Joanna; Cichota, Rogerio; Holzworth, Dean; Clothier, Brent

    2018-04-01

    In modelling the hydrology of Earth's critical zone, there are two major challenges. The first is to understand and model the processes of infiltration, runoff, redistribution and root-water uptake in structured soils that exhibit preferential flows through macropore networks. The other challenge is to parametrise and model the impact of ephemeral hydrophobicity of water-repellent soils. Here we have developed a soil-water model, which is based on physical principles, yet possesses simple functionality to enable easier parameterisation, so as to predict soil-water dynamics in structured soils displaying time-varying degrees of hydrophobicity. Our model, WEIRDO (Water Evapotranspiration Infiltration Redistribution Drainage runOff), has been developed in the APSIM Next Generation platform (Agricultural Production Systems sIMulation). The model operates on an hourly time-step. The repository for this open-source code is https://github.com/APSIMInitiative/ApsimX. We have carried out sensitivity tests to show how WEIRDO predicts infiltration, drainage, redistribution, transpiration and soil-water evaporation for three distinctly different soil textures displaying differing hydraulic properties. These three soils were drawn from the UNSODA (Unsaturated SOil hydraulic Database) soils database of the United States Department of Agriculture (USDA). We show how preferential flow process and hydrophobicity determine the spatio-temporal pattern of soil-water dynamics. Finally, we have validated WEIRDO by comparing its predictions against three years of soil-water content measurements made under an irrigated alfalfa (Medicago sativa L.) trial. The results provide validation of the model's ability to simulate soil-water dynamics in structured soils.

  3. Computer modeling of lime-soda softening of cooling waters

    International Nuclear Information System (INIS)

    Chen, J.C.Y.

    1986-01-01

    A computer model is developed to fully describe the lime soda ash softening process. This process has a long history of being used to remove calcium and magnesium hardness from cooling waters in order to prevent scaling on heat exchangers. Softening of makeup water and/or a sidestream from the recirculating water will allow a reduction in blowdown. In the extreme case, zero blowdown may be accomplished to conserve cooling waters and to save the costs of disposing of blowdown. Cooling waters differ from most natural waters in having higher temperature and higher concentration of dissolved solids, and, therefore, a higher ionic strength. These factors plus the effects of complex formation are taken into consideration in the development of the computer model. To determine the composition of a softened water, the model assumes that an equilibrium state is reached in a reactor, and employs the equations of mass action and mass balance. The resulting nonlinear simultaneous equations are then linearized by Taylor series expansion and solved by the multidimensional Newton-Raphson method. The computer predictions are compared to the results of laboratory studies using synthetic waters

  4. The Community Water Model (CWATM) / Development of a community driven global water model

    Science.gov (United States)

    Burek, Peter; Satoh, Yusuke; Greve, Peter; Kahil, Taher; Wada, Yoshihide

    2017-04-01

    With a growing population and economic development, it is expected that water demands will increase significantly in the future, especially in developing regions. At the same time, climate change is expected to alter spatial patterns of hydrological cycle and will have global, regional and local impacts on water availability. Thus, it is important to assess water supply, water demand and environmental needs over time to identify the populations and locations that will be most affected by these changes linked to water scarcity, droughts and floods. The Community Water Model (CWATM) will be designed for this purpose in that it includes an accounting of how future water demands will evolve in response to socioeconomic change and how water availability will change in response to climate. CWATM represents one of the new key elements of IIASA's Water program. It has been developed to work flexibly at both global and regional level at different spatial resolutions. The model is open source and community-driven to promote our work amongst the wider water community worldwide and is flexible enough linking to further planned developments such as water quality and hydro-economic modules. CWATM will be a basis to develop a next-generation global hydro-economic modeling framework that represents the economic trade-offs among different water management options over a basin looking at water supply infrastructure and demand managements. The integrated modeling framework will consider water demand from agriculture, domestic, energy, industry and environment, investment needs to alleviate future water scarcity, and will provide a portfolio of economically optimal solutions for achieving future water management options under the Sustainable Development Goals (SDG) for example. In addition, it will be able to track the energy requirements associated with the water supply system e.g., pumping, desalination and interbasin transfer to realize the linkage with the water-energy economy. In

  5. Tests to determine water uptake behaviour of tunnel backfill

    International Nuclear Information System (INIS)

    Dixon, David; Anttila, S.; Viitanen, M.; Keto, Paula

    2008-12-01

    likely that the backfill can handle somewhat higher inflow rates and provide a longer time period before exiting the backfill. This would provide more capacity to handle interruptions in backfilling operations before remedial actions will be necessary to ensure backfill competence. Based on preliminary data the quantity of material removed by water flowing into and past the backfill in the first 48 hours after inflow begins will range from 0 to 35 g/l. Beyond 48 hours the erosion rate drops to 5 to 15 g per litre of water through-flow. It is flow amount rather than rate that will determine the amount of material removed by water movement along the rock-pellet interfaces. These data provide guidance to the planning and conduct of larger (1/2 scale) tests that will quantify the effects of scale, time, flow path length and flow rate on backfill performance

  6. Tests to determine water uptake behaviour of tunnel backfill

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (AECL) (Canada)); Anttila, S.; Viitanen, M. (Poeyry InfRa Oy (Finland)); Keto, Paula (Saanio and Riekkola Oy, Helsinki (Finland))

    2008-12-15

    is likely that the backfill can handle somewhat higher inflow rates and provide a longer time period before exiting the backfill. This would provide more capacity to handle interruptions in backfilling operations before remedial actions will be necessary to ensure backfill competence. Based on preliminary data the quantity of material removed by water flowing into and past the backfill in the first 48 hours after inflow begins will range from 0 to 35 g/l. Beyond 48 hours the erosion rate drops to 5 to 15 g per litre of water through-flow. It is flow amount rather than rate that will determine the amount of material removed by water movement along the rock-pellet interfaces. These data provide guidance to the planning and conduct of larger (1/2 scale) tests that will quantify the effects of scale, time, flow path length and flow rate on backfill performance

  7. Determinants of single family residential water use across scales in four western US cities.

    Science.gov (United States)

    Chang, Heejun; Bonnette, Matthew Ryan; Stoker, Philip; Crow-Miller, Britt; Wentz, Elizabeth

    2017-10-15

    A growing body of literature examines urban water sustainability with increasing evidence that locally-based physical and social spatial interactions contribute to water use. These studies however are based on single-city analysis and often fail to consider whether these interactions occur more generally. We examine a multi-city comparison using a common set of spatially-explicit water, socioeconomic, and biophysical data. We investigate the relative importance of variables for explaining the variations of single family residential (SFR) water uses at Census Block Group (CBG) and Census Tract (CT) scales in four representative western US cities - Austin, Phoenix, Portland, and Salt Lake City, - which cover a wide range of climate and development density. We used both ordinary least squares regression and spatial error regression models to identify the influence of spatial dependence on water use patterns. Our results show that older downtown areas show lower water use than newer suburban areas in all four cities. Tax assessed value and building age are the main determinants of SFR water use across the four cities regardless of the scale. Impervious surface area becomes an important variable for summer water use in all cities, and it is important in all seasons for arid environments such as Phoenix. CT level analysis shows better model predictability than CBG analysis. In all cities, seasons, and spatial scales, spatial error regression models better explain the variations of SFR water use. Such a spatially-varying relationship of urban water consumption provides additional evidence for the need to integrate urban land use planning and municipal water planning. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Modeling of the Global Water Cycle - Analytical Models

    Science.gov (United States)

    Yongqiang Liu; Roni Avissar

    2005-01-01

    Both numerical and analytical models of coupled atmosphere and its underlying ground components (land, ocean, ice) are useful tools for modeling the global and regional water cycle. Unlike complex three-dimensional climate models, which need very large computing resources and involve a large number of complicated interactions often difficult to interpret, analytical...

  9. An elemental mercury diffusion coefficient for natural waters determined by molecular dynamics simulation.

    Science.gov (United States)

    Kuss, Joachim; Holzmann, Jörg; Ludwig, Ralf

    2009-05-01

    Mercury is a priority pollutant as its mobility between the hydrosphere and the atmosphere threatens the biosphere globally. The air-water gas transfer of elemental mercury (Hg0) is controlled by its diffusion through the water-side boundary layer and thus by its diffusion coefficient, D(Hg), the value of which, however, has not been established. Here, the diffusion of Hg0 in water was modeled by molecular dynamics (MD) simulation and the diffusion coefficient subsequently determined. Therefore the movement of either Hg(0) or xenon and 1000 model water molecules (TIP4P-Ew) were traced for time spans of 50 ns. The modeled D(Xe) of the monatomic noble gas agreed well with measured data; thus, MD simulation was assumed to be a reliable approach to determine D(Hg) for monatomic Hg(0) as well. Accordingly, Hg(0) diffusion was then simulated for freshwater and seawater, and the data were well-described by the equation of Eyring. The activation energies for the diffusion of Hg0 in freshwater was 17.0 kJ mol(-1) and in seawater 17.8 kJ mol(-1). The newly determined D(Hg) is clearly lower than the one previously used for an oceanic mercury budget. Thus, its incorporation into the model should lead to lower estimates of global ocean mercury emissions.

  10. Spectrophotometric determination of microamounts of boron in water

    International Nuclear Information System (INIS)

    Weber de D'Alessio, Ana; Guido, O.O.; Bandin, N.A.

    1980-01-01

    A fast method of boron in water determination has been studied for the 0.5 .- 2 μg ml -1 concentration range. The procedure is based on the formation of a coloured complex of the tetrafluoroborate of a thionine derivate cation, its extraction by an organic solvent and the further absorptiometric measurement in such media. Methylene blue and azur C were comparatively tested as organic reagents, with 1.2-dichloroethane as the extractant. The absorbance was measured at the maximum (658 nm). The tetrafluoroboric acid formation was reached in 20 min on a water-bath kept at 60 deg C. The sensitivity with methylene blue was higher than with azur C. The molar absorptivities were 65,000 and 38,000 (l mol -1 cm -1 ) respectively. For a boron concentration of 0.1 μg ml -1 the relative standard deviation was 9% for methylene blue and 7% for azur C. The procedure is applicable to the control of boron traces in heavy water of nuclear reactors refrigerating loops. (author) [es

  11. A Water Management Model for Toshka Depression

    Directory of Open Access Journals (Sweden)

    K. M. Fassieh

    2014-01-01

    Full Text Available Toshka Depression (TD, located about 250 km south west of the High Aswan Dam (HAD, consists of four deep-cut basins connected by natural sills. It is required to assess the contribution of TD as a spillway, in enhancing the effectiveness of Lake Nasser in flood control and water availability. However, most related previous works are descriptive and use qualitative methods. In order to provide the required assessment quantitatively, we developed a numerical model which computes TD mass balance and interbasin water movements. The model computes the variation of water volume, surface area, and water level in each one of the four basins (subdepressions, thus depicting their filling sequence, for the past 130 years. This TD response to realistic time series of water inflow gains and evaporation losses is analyzed to compute the TD overflow time series. This response helps assess water availability for agricultural use and effectiveness in alleviating flood risks. Furthermore, the developed model compares between three TD configurations to help the decision maker and recommends (i building a dam—height 10 m—at the end of the fourth subdepression near Kharga Oasis and/or (ii incorporating the third subdepression into TD by digging a canal through the hill that blocks it from the first subdepression.

  12. Determination of substraces of alpha emitter elements in water

    International Nuclear Information System (INIS)

    Gascon, J.L.

    1990-01-01

    To determine alpha emitter elements in water by alpha spectrometry, it is necessary to use large volumes of samples, concentration techniq-ues and to separate the elements of interest. In this report a study is presented about two concentration techniques and the process of analysis. Firstly, the stages of concentration method by iron hydroxide coprecipitation were studied in order to improve the results. The combination of liquid-liquid extraction and ion exchange techniques was the best way. Secondly, the technique by adsorption on manganese dioxide was studied. To apply this technique it was necessary to develop analysis methods to separate uranium, thorium, plutonium, americium and radium. These methods were designed combining several techniques of separation: liquid-liquid extraction, liquid-solid extraction, ionic exchange and coprecipitation. After the analysis methods were developped the adsorption on manganese dioxide with artificial samples was studied in the laboratory. Finally, the method of adsorption on manganese dioxide was studied to determine uranium, thorium and radium in the drinking water of Madrid. (Author)

  13. Determinants of water and sodium intake and output.

    Science.gov (United States)

    Stanhewicz, Anna E; Kenney, W Larry

    2015-09-01

    Physiological regulation of sodium and water intake and output is required for the maintenance of homeostasis. The behavioral and neuroendocrine mechanisms that govern fluid and salt balance are highly interdependent, with acute and chronic alterations in renal output tightly balanced by appropriate changes in thirst and, to a lesser extent in humans, sodium appetite. In healthy individuals, these tightly coupled mechanisms maintain extracellular fluid volume and body tonicity within a narrow homeostatic range by initiating ingestive behaviors and the release of hormones necessary to conserve water and sodium within the body. In this review, the factors that determine output of sodium and fluid and those that determine "normal" input (i.e., matched to output) are addressed. For output, individual variability accompanied by dysregulation of homeostatic mechanisms may contribute to acute and/or chronic disease. To illustrate that point, the specific condition of salt-sensitive hypertension is discussed. For input, physical characteristics, physiological phenotypes, genetic and developmental influences, and cultural and environmental factors combine to result in a wide range of individual variability that, in humans, is compensated for by alterations in excretion. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Transport Models for Inland and Coastal Waters

    Science.gov (United States)

    Hamilton, Peter

    This proceedings volume originates from a symposium held at Berkeley, California, in August 1980. The purpose of the symposium was to assess the ability of models to predict surface water flow and the transport of dissolved substances in natural systems. The authors were invited, after an initial call for papers, by a Scientific Committee of the International Association for Hydraulic Research.In this context, predictive modeling is limited to hydrodynamic and transport models as applied to rivers, estuaries, shallow coastal waters, lakes, and reservoirs. This is a large subject, though evidently not the whole story on predictive techniques applied to natural water bodies, and many different models are described with applications to a wide variety of natural systems. There is relatively little overlap of material between chapters. It is noteworthy that 21 out of 24 authors of the chapters are affiliated with institutions outside the United States, and many of these are from large European hydraulic laboratories. A number of the chapters summarize numerical modeling studies undertaken by these institutions and so provide the U.S. reader with valuable references to the European open literature and laboratory technical reports. The latter are not usually readily available in the United States. This bias reflects a greater willingness of European engineers to employ sophisticated hydrodynamic numerical models as tools for the solution of engineering and environmental problems of natural water bodies.

  15. Determination of total metal pollutants in water with optical detection

    Science.gov (United States)

    Chudy, Michal; Prokaryn, Piotr; Dybko, Artur; Wroblewski, Wojciech; Brzozka, Zbigniew

    2003-09-01

    The total concentration of heavy metal ions was measured with the use of a highly sensitive reagent (4-(2-pyridylzo)-resorcinol (PAR)). Because of PAR chelates are slightly soluble in water and their forming is not selective, the analytical procedure for Cd, Cu, Hg, Pb, Zn determination was developed to perform the analysis in an aqueous environment without the need of inconvenient and time-consuming extraction. A proposed analysis method is more useful in comparison with classical FIA analysis what is crucial during fast classification of various natural water samples. To minimize the chemicals consumption such a classification can be performed in a specially designed microsystem. The Y- shape microchannel structure with a mixing area was made by fine engraving in PMMA plate and sealed with the PDMS one. The M2+-PAR complex forming conditions were determined for each of the chosen metal ions. The solubility of formed complexes was better when a micellar environment was created by the addition of a non-ionic surfactant (Triton X100). Next the synthetic mixtures of Cd, Cu, Hg, Pb, Zn ions were prepared to obtain total molar metal ions concentration in the range from 10-6 to 10-4 M and measured after on-chip reaction. A tap water and HAC-sample (Highest Allowable Concentration, ΣMe=1,2•10-5 M) were also measured. The detection was performed in a special flow cuvette and spectra measurements were carried out using diode array spectrophotometer and CCD detector.

  16. Determinants of tree water use across a floodplain in arid, subtropical northwest Australia

    Science.gov (United States)

    Grierson, Pauline; McLean, Elizabeth; Iles, Jordan; Skrzypek, Grzegorz; Brand, Melinda; O'Donnell, Alison; Siebers, Andre; Dogramaci, Shawan

    2017-04-01

    Riparian zones of ephemeral streams in hot arid regions are subject to unpredictable and generally short-lived flood periods. However, droughts tend to be longer and more severe than floods in their ecological impact as low water availability in surficial alluvium and on the floodplain results in hydrological stress. Resolving how riparian and floodplain vegetation respond to highly variable flow regimes remains a fundamental challenge for estimating water budgets in arid regions, particularly where water tables are subject to groundwater abstraction. Here, we investigated patterns of water use by a range of tree species (Eucalyptus camaldulensis, E. victrix, Acacia citrinoviridis, A. coriacea, Hakea lorea, Atalaya hemiglauca) across a floodplain in the Pilbara region of northwest Australia and assessed vegetation responsiveness to both temporal and spatial variation in water supply. We sought to disentangle the varying contributions of soil water, groundwater and surface water to tree water use to determine the ecological implications of changes in hydrologic connectivity resulting from both seasonal water deficits and anthropogenic management. Diurnal and seasonal dynamics of water use were assessed using sapflux measurements coupled with observations of changing source availability. Source utilization was examined using water stable isotope compositions of xylem, soil, rain, surface water and groundwater. Depending on distance from the stream channel and time since last rainfall, we found that small trees were primarily accessing shallow soil water of meteoric origin while larger eucalypts accessed water deeper in the profile (either stored soil water or groundwater), especially as surface soils dried out. However, tree species were highly variable in their diurnal patterns of water use,including some evidence of nocturnal sapflux in A. coriacea adjacent to streams. Sapflux rates also varied almost four-fold among species but generally declined with increasing

  17. Modelling Approach to Assess Future Agricultural Water Demand

    Science.gov (United States)

    Spano, D.; Mancosu, N.; Orang, M.; Sarreshteh, S.; Snyder, R. L.

    2013-12-01

    The combination of long-term climate changes (e.g., warmer average temperatures) and extremes events (e.g., droughts) can have decisive impacts on water demand, with further implications on the ecosystems. In countries already affected by water scarcity, water management problems are becoming increasingly serious. The sustainable management of available water resources at the global, regional, and site-specific level is necessary. In agriculture, the first step is to compute how much water is needed by crops in regards to climate conditions. Modelling approach can be a way to compute crop water requirement (CWR). In this study, the improved version of the SIMETAW model was used. The model is a user friendly soil water balance model, developed by the University of California, Davis, the California Department of Water Resource, and the University of Sassari. The SIMETAW# model assesses CWR and generates hypothetical irrigation scheduling for a wide range of irrigated crops experiencing full, deficit, or no irrigation. The model computes the evapotranspiration of the applied water (ETaw), which is the sum of the net amount of irrigation water needed to match losses due to the crop evapotranspiration (ETc). ETaw is determined by first computing reference evapotranspiration (ETo) using the daily standardized Reference Evapotranspiration equation. ETaw is computed as ETaw = CETc - CEr, where CETc and CE are the cumulative total crop ET and effective rainfall values, respectively. Crop evapotranspiration is estimated as ETc = ETo x Kc, where Kc is the corrected midseason tabular crop coefficient, adjusted for climate conditions. The net irrigation amounts are determined from a daily soil water balance, using an integrated approach that considers soil and crop management information, and the daily ETc estimates. Using input information on irrigation system distribution uniformity and runoff, when appropriate, the model estimates the applied water to the low quarter of the

  18. Connectivity between surface and deep waters determines prokaryotic diversity in the North Atlantic Deep Water.

    Science.gov (United States)

    Frank, Alexander H; Garcia, Juan A L; Herndl, Gerhard J; Reinthaler, Thomas

    2016-06-01

    To decipher the influence of depth stratification and surface provincialism on the dark ocean prokaryotic community composition, we sampled the major deep-water masses in the eastern North Atlantic covering three biogeographic provinces. Their diversity was evaluated using ordination and canonical analysis of 454 pyrotag sequences. Variance partitioning suggested that 16% of the variation in the bacterial community composition was based on depth stratification while 9% of the variation was due to geographic location. General linear mixed effect models showed that the community of the subsurface waters was connected to the dark ocean prokaryotic communities in different biogeographic provinces. Cluster analysis indicated that some prokaryotic taxa are specific to distinct regions in bathypelagic water masses. Taken together, our data suggest that the dark ocean prokaryotic community composition of the eastern North Atlantic is primed by the formation and the horizontal transport of water masses. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Klang River water quality modelling using music

    Science.gov (United States)

    Zahari, Nazirul Mubin; Zawawi, Mohd Hafiz; Muda, Zakaria Che; Sidek, Lariyah Mohd; Fauzi, Nurfazila Mohd; Othman, Mohd Edzham Fareez; Ahmad, Zulkepply

    2017-09-01

    Water is an essential resource that sustains life on earth; changes in the natural quality and distribution of water have ecological impacts that can sometimes be devastating. Recently, Malaysia is facing many environmental issues regarding water pollution. The main causes of river pollution are rapid urbanization, arising from the development of residential, commercial, industrial sites, infrastructural facilities and others. The purpose of the study was to predict the water quality of the Connaught Bridge Power Station (CBPS), Klang River. Besides that, affects to the low tide and high tide and. to forecast the pollutant concentrations of the Biochemical Oxygen Demand (BOD) and Total Suspended Solid (TSS) for existing land use of the catchment area through water quality modeling (by using the MUSIC software). Besides that, to identifying an integrated urban stormwater treatment system (Best Management Practice or BMPs) to achieve optimal performance in improving the water quality of the catchment using the MUSIC software in catchment areas having tropical climates. Result from MUSIC Model such as BOD5 at station 1 can be reduce the concentration from Class IV to become Class III. Whereas, for TSS concentration from Class III to become Class II at the station 1. The model predicted a mean TSS reduction of 0.17%, TP reduction of 0.14%, TN reduction of 0.48% and BOD5 reduction of 0.31% for Station 1 Thus, from the result after purposed BMPs the water quality is safe to use because basically water quality monitoring is important due to threat such as activities are harmful to aquatic organisms and public health.

  20. Spectrophotometric determination of silica in water. Low range; Determinacion espectrofotometrica de silicio en aguas. Rango bajo

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1992-07-15

    The spectrophotometric method for the determination of the silica element in water, demineralized water, raw waters, laundry waters, waters treated with ion exchange resins and sea waters is described. This method covers the determination of the silica element in the interval from 20 to 1000 {mu}g/l on 50 ml. of base sample. These limits its can be variable if the size of the used aliquot one is changed for the final determination of the silica element. (Author)

  1. [Water environmental capacity calculation model for the rivers in drinking water source conservation area].

    Science.gov (United States)

    Chen, Ding-jiang; Lü, Jun; Shen, Ye-na; Jin, Shu-quan; Shi, Yi-ming

    2008-09-01

    Based on the one-dimension model for water environmental capacity (WEC) in river, a new model for the WEC estimation in river-reservoir system was developed in drinking water source conservation area (DWSCA). In the new model, the concept was introduced that the water quality target of the rivers in DWSCA was determined by the water quality demand of reservoir for drinking water source. It implied that the WEC of the reservoir could be used as the water quality control target at the reach-end of the upstream rivers in DWSCA so that the problems for WEC estimation might be avoided that the differences of the standards for a water quality control target between in river and in reservoir, such as the criterions differences for total phosphorus (TP)/total nitrogen (TN) between in reservoir and in river according to the National Surface Water Quality Standard of China (GB 3838-2002), and the difference of designed hydrology conditions for WEC estimation between in reservoir and in river. The new model described the quantitative relationship between the WEC of drinking water source and of the river, and it factually expressed the continuity and interplay of these low water areas. As a case study, WEC for the rivers in DWSCA of Laohutan reservoir located in southeast China was estimated using the new model. Results indicated that the WEC for TN and TP was 65.05 t x a(-1) and 5.05 t x a(-1) in the rivers of the DWSCA, respectively. According to the WEC of Laohutan reservoir and current TN and TP quantity that entered into the rivers, about 33.86 t x a(-1) of current TN quantity should be reduced in the DWSCA, while there was 2.23 t x a(-1) of residual WEC of TP in the rivers. The modeling method was also widely applicable for the continuous water bodies with different water quality targets, especially for the situation of higher water quality control target in downstream water body than that in upstream.

  2. Ultraviolet multiwavelength absorptiometry (UVMA) for the examination of natural waters and waste waters. Pt. 2. Determination of nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, O.; Mazas, N. (Chambery Univ., 73 (France). Dept. de Chimie et Ingenierie de l' Environnement); Gallot, S. (Ecole Polytechnique, 91 - Palaiseau (France). Centre de Mathematiques)

    1990-10-01

    A new method for nitrate determination in natural waters and waste waters based on ultraviolet multiwavelength absorptiometry (UVMA) is proposed. After acquisition of spectral data for a sample, without added reagent or pretreatment at 1 nanometer intervals between 205 and 250 nm, a computational procedure gives in a few seconds the concentration of nitrate. The principle is to use a polynomial correction function to cancel numerically the interferences from suspended and organic matters, and to resolve the system formed by the sum of the proper absorbance of nitrate and the previous function. Matrix calculation is made with the least squares method, which minimizes the error between the measured absorbances and the model. The characteristics of the UVMA method and the residual interferences have been evaluated and a comparison with reference methods for different samples has shown that nitrate UVMA is a valuable tool for fast determination and/or continuous monitoring. (orig.).

  3. [Weight parameters of water quality impact and risk grade determination of water environmental sensitive spots in Jiashan].

    Science.gov (United States)

    Xie, Rong-Rong; Pang, Yong; Zhang, Qian; Chen, Ke; Sun, Ming-Yuan

    2012-07-01

    For the safety of the water environment in Jiashan county in Zhejiang Province, one-dimensional hydrodynamic and water quality models are established based on three large-scale monitoring of hydrology and water quality in Jiashan county, three water environmental sensitive spots including Hongqitang dam Chijia hydrological station and Luxie pond are selected to investigate weight parameters of water quality impact and risk grade determination. Results indicate as follows (1) Internal pollution impact in Jiashan areas was greater than the external, the average weight parameters of internal chemical oxygen demand (COD) pollution is 55.3%, internal ammonia nitrogen (NH(4+)-N) is 67.4%, internal total phosphor (TP) is 63.1%. Non-point pollution impact in Jiashan areas was greater than point pollution impact, the average weight parameters of non-point COD pollutions is 53.7%, non-point NH(4+)-N is 65.9%, non-point TP is 57.8%. (2) The risk of Hongqitang dam and Chijia hydrological station are in the middle risk. The risk of Luxie pond is also in the middle risk in August, and in April and December the risk of Luxie pond is low. The strategic decision will be suggested to guarantee water environment security and social and economic security in the study.

  4. Data-driven behavioural modelling of residential water consumption to inform water demand management strategies

    Science.gov (United States)

    Giuliani, Matteo; Cominola, Andrea; Alshaf, Ahmad; Castelletti, Andrea; Anda, Martin

    2016-04-01

    The continuous expansion of urban areas worldwide is expected to highly increase residential water demand over the next few years, ultimately challenging the distribution and supply of drinking water. Several studies have recently demonstrated that actions focused only on the water supply side of the problem (e.g., augmenting existing water supply infrastructure) will likely fail to meet future demands, thus calling for the concurrent deployment of effective water demand management strategies (WDMS) to pursue water savings and conservation. However, to be effective WDMS do require a substantial understanding of water consumers' behaviors and consumption patterns at different spatial and temporal resolutions. Retrieving information on users' behaviors, as well as their explanatory and/or causal factors, is key to spot potential areas for targeting water saving efforts and to design user-tailored WDMS, such as education campaigns and personalized recommendations. In this work, we contribute a data-driven approach to identify household water users' consumption behavioural profiles and model their water use habits. State-of-the-art clustering methods are coupled with big data machine learning techniques with the aim of extracting dominant behaviors from a set of water consumption data collected at the household scale. This allows identifying heterogeneous groups of consumers from the studied sample and characterizing them with respect to several consumption features. Our approach is validated onto a real-world household water consumption dataset associated with a variety of demographic and psychographic user data and household attributes, collected in nine towns of the Pilbara and Kimberley Regions of Western Australia. Results show the effectiveness of the proposed method in capturing the influence of candidate determinants on residential water consumption profiles and in attaining sufficiently accurate predictions of users' consumption behaviors, ultimately providing

  5. Modelling of water potential and water uptake rate of tomato plants in the greenhouse: preliminary results.

    NARCIS (Netherlands)

    Bruggink, G.T.; Schouwink, H.E.; Gieling, Th.H.

    1988-01-01

    A dynamic model is presented which predicts water potential and water uptake rate of greenhouse tomato plants using transpiration rate as input. The model assumes that water uptake is the resultant of water potential and hydraulic resistance, and that water potential is linearly related to water

  6. Putting people into water quality modelling.

    Science.gov (United States)

    Strickert, G. E.; Hassanzadeh, E.; Noble, B.; Baulch, H. M.; Morales-Marin, L. A.; Lindenschmidt, K. E.

    2017-12-01

    Water quality in the Qu'Appelle River Basin, Saskatchewan is under pressure due to nutrient pollution entering the river system from major cities, industrial zones and agricultural areas. Among these stressors, agricultural activities are basin-wide; therefore, they are the largest non-point source of water pollution in this region. The dynamics of agricultural impacts on water quality are complex and stem from decisions and activities of two distinct stakeholder groups, namely grain farmers and cattle producers, which have different business plans, values, and attitudes towards water quality. As a result, improving water quality in this basin requires engaging with stakeholders to: (1) understand their perspectives regarding a range of agricultural Beneficial Management Practices (BMPs) that can improve water quality in the region, (2) show them the potential consequences of their selected BMPs, and (3) work with stakeholders to better understand the barriers and incentives to implement the effective BMPs. In this line, we held a series of workshops in the Qu'Appelle River Basin with both groups of stakeholders to understand stakeholders' viewpoints about alternative agricultural BMPs and their impact on water quality. Workshop participants were involved in the statement sorting activity (Q-sorts), group discussions, as well as mapping activity. The workshop outcomes show that stakeholder had four distinct viewpoints about the BMPs that can improve water quality, i.e., flow and erosion control, fertilizer management, cattle site management, as well as mixed cattle and wetland management. Accordingly, to simulate the consequences of stakeholder selected BMPs, a conceptual water quality model was developed using System Dynamics (SD). The model estimates potential changes in water quality at the farm, tributary and regional scale in the Qu'Appelle River Basin under each and/or combination of stakeholder selected BMPs. The SD model was then used for real

  7. Mathematical modeling of water radiolysis in the Syrian MNSR reactor

    International Nuclear Information System (INIS)

    Soukieh, M.

    2009-11-01

    Because it is difficult to measure the concentration of the radiolytic species in reactors under operating conduction, they must be estimated by computer simulation techniques. This study discusses the mathematical modeling of water radiolysis modeling of the MNSR nuclear reactor cooling water. The mathematical model comprising of 13 differential equations describe 55 chemical reactions of radiolytic species e - a q H + , OH - , H, H 2 , OH, HO 2 , O 2 , HO - 2 , O - , O - 2 , O - 3 . The mathematical model have been tested and it shows a good agreement of the computed values in this work with the results cited in references [1,18] in case of only γray irradiation of pure water with dose rate of 1.18x10 19 eV/L s. The neutron fluxes and dose rates at the interface of cladding-water for the different fuel rings in the MNSR core are determined using MCNP-4C code. In addition, the time dependent of the radiolytic specie concentrations were estimated for max. and min. dose rates and at temperature of 20 degree centigrade in the MNSR. The radiolytic specie concentrations reach the steady sate after about 200-400 s. The radiolytic specie concentrations order of H 2 , O 2 , H 2 O 2 were about ppb. Also this study shows the possibility of suppressed the water radiolysis reactions by adding hydrogen to the MNSR reactor cooling water. (author)

  8. Environmental Modeling of Storm Water Channels

    OpenAIRE

    L. Grinis

    2014-01-01

    Turbulent flow in complex geometries receives considerable attention due to its importance in many engineering applications. It has been the subject of interest for many researchers. Some of these interests include the design of storm water channels. The design of these channels requires testing through physical models. The main practical limitation of physical models is the so called “scale effect”, that is, the fact that in many cases only primary physical mechanisms can be correctly repres...

  9. Determination and correlation of solubility and solution thermodynamics of oxiracetam in three (alcohol + water) binary solvents

    International Nuclear Information System (INIS)

    Li, Kangli; Du, Shichao; Wu, Songgu; Cai, Dongchen; Wang, Jinxu; Zhang, Dejiang; Zhao, Kaifei; Yang, Peng; Yu, Bo; Guo, Baisong; Li, Daixi; Gong, Junbo

    2016-01-01

    Highlights: • The solubility of racemic oxiracetam in three binary solvents were determined. • The experimental solubility of racemic oxiracetam were correlated by four models. • The dissolution thermodynamic properties of racemic oxiracetam were calculated. - Abstract: In this paper, we proposed a static analysis method to experimentally determine the (solid + liquid) equilibrium of racemic oxiracetam in (methanol + water), (ethanol + water) and (isopropanol + water) binary solvents with alcohol mole fraction ranging from 0.30 to 0.90 at atmosphere pressure (p = 0.1 MPa). For the experiments, the temperatures range from (283.15 to 308.15) K. The results showed that the solubility of oxiracetam increased with the increasing temperature, while decreased with the increasing organic solvent fraction in all three tested binary solvent systems. The modified Apelblat model, the CNIBS/Redlich–Kister model, the combined version of Jouyban–Acree model and the NRTL model were employed to correlate the measured solubility values, respectively. Additionally, some of the thermodynamic properties which can help to evaluate its dissolution behavior were obtained based on the NRTL model.

  10. Installed water resource modelling systems for catchment ...

    African Journals Online (AJOL)

    Following international trends there are a growing number of modelling systems being installed for integrated water resource management, in Southern Africa. Such systems are likely to be installed for operational use in ongoing learning, research, strategic planning and consensus-building amongst stakeholders in the ...

  11. A generic hydroeconomic model to assess future water scarcity

    Science.gov (United States)

    Neverre, Noémie; Dumas, Patrice

    2015-04-01

    We developed a generic hydroeconomic model able to confront future water supply and demand on a large scale, taking into account man-made reservoirs. The assessment is done at the scale of river basins, using only globally available data; the methodology can thus be generalized. On the supply side, we evaluate the impacts of climate change on water resources. The available quantity of water at each site is computed using the following information: runoff is taken from the outputs of CNRM climate model (Dubois et al., 2010), reservoirs are located using Aquastat, and the sub-basin flow-accumulation area of each reservoir is determined based on a Digital Elevation Model (HYDRO1k). On the demand side, agricultural and domestic demands are projected in terms of both quantity and economic value. For the agricultural sector, globally available data on irrigated areas and crops are combined in order to determine irrigated crops localization. Then, crops irrigation requirements are computed for the different stages of the growing season using Allen (1998) method with Hargreaves potential evapotranspiration. Irrigation water economic value is based on a yield comparison approach between rainfed and irrigated crops. Potential irrigated and rainfed yields are taken from LPJmL (Blondeau et al., 2007), or from FAOSTAT by making simple assumptions on yield ratios. For the domestic sector, we project the combined effects of demographic growth, economic development and water cost evolution on future demands. The method consists in building three-blocks inverse demand functions where volume limits of the blocks evolve with the level of GDP per capita. The value of water along the demand curve is determined from price-elasticity, price and demand data from the literature, using the point-expansion method, and from water costs data. Then projected demands are confronted to future water availability. Operating rules of the reservoirs and water allocation between demands are based on

  12. Determination of metals in water from Billings dam, Sao Paulo

    International Nuclear Information System (INIS)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante; Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile

    2013-01-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  13. Determination of metals in water from Billings dam, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante, E-mail: taoliveira@ipen.br, E-mail: jesarkis@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile, E-mail: lcbm@usp.br [Instituto de Pesca, (IP/SAA-SP), Sao Paulo, SP (Brazil). Secretaria da Agricultura e Abastecimento do Estado de Sao Paulo

    2013-07-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  14. Model independent spin determination at hadron colliders

    International Nuclear Information System (INIS)

    Edelhaeuser, Lisa

    2012-01-01

    By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s ff of the adjacent particles. In this thesis we

  15. Model independent spin determination at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Edelhaeuser, Lisa

    2012-04-25

    By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s{sub ff} of the adjacent particles. In this thesis

  16. Model Based Vision for Aircraft Position Determination

    Science.gov (United States)

    Sridhar, Banavar; Chatterji, Gano B.; Soni, Tarun; Showman, Robert D. (Technical Monitor)

    1994-01-01

    This paper investigates the use of imaging sensors to estimate the position of an aircraft with respect to the runway during landing. Passive vision techniques to estimate aircraft position during landing rely on the known runway model, images acquired by onboard imaging sensor, orientation information provided by the inertial navigation system and the position estimate provided by devices such as the global positioning system. Point features in the runway model are compared with the onboard sensor images of the features and the difference between the two is used to correct the aircraft position and orientation. In this paper the sensitivity of point features is examined as a means of determining the accuracy of such position estimation techniques. Expressions are derived for the sensitivity of image point to errors in the position and orientation of the sensor. Using these, the sensitivity of the image to aircraft position and orientation errors along a typical landing glide path is studied. A least squares technique based on this sensitivity analysis is described for the correction of position and orientation estimates. The final version of the paper will include results from the application of this analysis to real image sequences collected in flight.

  17. Modelling raster-based monthly water balance components for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ulmen, C.

    2000-11-01

    The terrestrial runoff component is a comparatively small but sensitive and thus significant quantity in the global energy and water cycle at the interface between landmass and atmosphere. As opposed to soil moisture and evapotranspiration which critically determine water vapour fluxes and thus water and energy transport, it can be measured as an integrated quantity over a large area, i.e. the river basin. This peculiarity makes terrestrial runoff ideally suited for the calibration, verification and validation of general circulation models (GCMs). Gauging stations are not homogeneously distributed in space. Moreover, time series are not necessarily continuously measured nor do they in general have overlapping time periods. To overcome this problems with regard to regular grid spacing used in GCMs, different methods can be applied to transform irregular data to regular so called gridded runoff fields. The present work aims to directly compute the gridded components of the monthly water balance (including gridded runoff fields) for Europe by application of the well-established raster-based macro-scale water balance model WABIMON used at the Federal Institute of Hydrology, Germany. Model calibration and validation is performed by separated examination of 29 representative European catchments. Results indicate a general applicability of the model delivering reliable overall patterns and integrated quantities on a monthly basis. For time steps less then too weeks further research and structural improvements of the model are suggested. (orig.)

  18. Determination of Leaf Water Content by Visible and Near-Infrared Spectrometry and Multivariate Calibration in Miscanthus

    Directory of Open Access Journals (Sweden)

    Xiaoli Jin

    2017-05-01

    Full Text Available Leaf water content is one of the most common physiological parameters limiting efficiency of photosynthesis and biomass productivity in plants including Miscanthus. Therefore, it is of great significance to determine or predict the water content quickly and non-destructively. In this study, we explored the relationship between leaf water content and diffuse reflectance spectra in Miscanthus. Three multivariate calibrations including partial least squares (PLS, least squares support vector machine regression (LSSVR, and radial basis function (RBF neural network (NN were developed for the models of leaf water content determination. The non-linear models including RBF_LSSVR and RBF_NN showed higher accuracy than the PLS and Lin_LSSVR models. Moreover, 75 sensitive wavelengths were identified to be closely associated with the leaf water content in Miscanthus. The RBF_LSSVR and RBF_NN models for predicting leaf water content, based on 75 characteristic wavelengths, obtained the high determination coefficients of 0.9838 and 0.9899, respectively. The results indicated the non-linear models were more accurate than the linear models using both wavelength intervals. These results demonstrated that visible and near-infrared (VIS/NIR spectroscopy combined with RBF_LSSVR or RBF_NN is a useful, non-destructive tool for determinations of the leaf water content in Miscanthus, and thus very helpful for development of drought-resistant varieties in Miscanthus.

  19. Instream water use in the United States: water laws and methods for determining flow requirements

    Science.gov (United States)

    Lamb, Berton L.; Doerksen, Harvey R.

    1987-01-01

    the conterminous United States consists of about 12,000 miles of maintained waterways, over which about 500 million tons of cargo is carried each year (U.S. Army Corps of Engineers, 1988, p. 16). Although not so widely practiced in recent years, streams have been used to dispose of raw waste products from homes, communities, and factories. This use has been discouraged by law and public policy because of public health concerns and the damage it causes to the environment. Beginning in the mid-1960's, other instream uses gained new prominence in the water-resources arena-the assertion of a legal right to a free-flowing stream for biological, recreational, and esthetic purposes. These uses themselves, however, are not new. Riverine habitat always has produced fish, and the beauty of flowing water always has evoked a strong sense of esthetic appreciation. What is new is the emerging legitimacy and awareness of these noneconomic uses under State and Federal laws and regulations. In the past, environmental uses of flowing water were ignored, for the most part, under a long-standing legal tradition that favored offstream uses and certain instream uses that had a strong economic basis. The history of instream-flow policy debate really concerns those recently recognized types of interim uses. Although the more transitional water uses have been protected by law, the recognition of other in stream uses has resulted in substantial changes in State water laws. Although methods for determining the volume of water needed for most traditional water uses are relatively straight-forward and well-established, methods for determining water requirements for the in stream uses have been developed only recently and are continuing to evolve. Water laws that have favored the more traditional water uses, the inherent nature of conflict between instream and offstream water uses, and the special kinds of technological and philosophical problems posed by the "newer" types of instream uses are

  20. Modelling anisotropic water transport in polymer composite ...

    Indian Academy of Sciences (India)

    and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were determined by least-square curve fitting to the experimental data. Diffusion parameters of epoxy and vinyl ester resin were used as input during development of finite element (FE) model of polymer composite.

  1. Water-Air Volatilization Factors to Determine Volatile Organic Compound (VOC Reference Levels in Water

    Directory of Open Access Journals (Sweden)

    Vicenç Martí

    2014-06-01

    Full Text Available The goal of this work is the modeling and calculation of volatilization factors (VFs from water to air for volatile organic compounds (VOCs in order to perform human health risk-based reference levels (RLs for the safe use of water. The VF models have been developed starting from the overall mass-transfer coefficients (Koverall concept from air to water for two interaction geometries (flat surface and spherical droplets in indoor and outdoor scenarios. For a case study with five groups of risk scenarios and thirty VOCs, theoretical VFs have been calculated by using the developed models. Results showed that Koverall values for flat and spherical surface geometries were close to the mass transfer coefficient for water (KL when Henry’s law constant (KH was high. In the case of spherical drop geometry, the fraction of volatilization (fV was asymptotical when increasing KH with fV values also limited due to Koverall. VFs for flat surfaces were calculated from the emission flux of VOCs, and results showed values close to 1000KH for the most conservative indoor scenarios and almost constant values for outdoor scenarios. VFs for spherical geometry in indoor scenarios followed also constant VFs and were far from 1000KH. The highest calculated VF values corresponded to the E2A, E2B, E3A and E5A scenarios and were compared with experimental and real results in order to check the goodness of flat and sphere geometry models. Results showed an overestimation of calculated values for the E2A and E2B scenarios and an underestimation for the E3A and E5A scenarios. In both cases, most of the calculated VFs were from 0.1- to 10-times higher than experimental/real values.

  2. A Provenance Model for Real-Time Water Information Systems

    Science.gov (United States)

    Liu, Q.; Bai, Q.; Zednik, S.; Taylor, P.; Fox, P. A.; Taylor, K.; Kloppers, C.; Peters, C.; Terhorst, A.; West, P.; Compton, M.; Shu, Y.; Provenance Management Team

    2010-12-01

    Generating hydrological data products, such as flow forecasts, involves complex interactions among instruments, data simulation models, computational facilities and data providers. Correct interpretation of the data produced at various stages requires good understanding of how data was generated or processed. Provenance describes the lineage of a data product. Making provenance information accessible to hydrologists and decision makers not only helps to determine the data’s value, accuracy and authorship, but also enables users to determine the trustworthiness of the data product. In the water domain, WaterML2 [1] is an emerging standard which describes an information model and format for the publication of water observations data in XML. The W3C semantic sensor network incubator group (SSN-XG) [3] is producing ontologies for the description of sensor configurations. By integrating domain knowledge of this kind into the provenance information model, the integrated information model will enable water domain researchers and water resource managers to better analyse how observations and derived data products were generated. We first introduce the Proof Mark Language (PML2) [2], WaterML2 and the SSN-XG sensor ontology as the proposed provenance representation formalism. Then we describe some initial implementations how these standards could be integrated to represent the lineage of water information products. Finally we will highlight how the provenance model for a distributed real-time water information system assists the interpretation of the data product and establishing trust. Reference [1] Taylor, P., Walker, G., Valentine, D., Cox, Simon: WaterML2.0: Harmonising standards for water observation data. Geophysical Research Abstracts. Vol. 12. [2] da Silva, P.P., McGuinness, D.L., Fikes, R.: A proof markup language for semantic web services. Inf. Syst. 31(4) (2006), 381-395. [3] W3C Semantic Sensor Network Incubator Group http://www.w3.org/2005/Incubator

  3. A Data Mining Approach to Modelling of Water Supply Assets

    DEFF Research Database (Denmark)

    Babovic, V.; Drecourt, J.; Keijzer, M.

    2002-01-01

    The economic and social costs associated with pipe bursts and associated leakage problems in modern water supply systems are rapidly rising to unacceptable high levels. Pipe burst risks depend on a number of factors which are extremely difficult to characterise. A part of the problem is that water...... with the choice of pipes to be replaced, the outlined approach opens completely new avenues in asset modelling. The condition of an asset such as a water supply network deteriorates with age. With reliable risk models, addressing the evolution of risk with aging asset, it is now possible to plan optimal...... supply assets are mainly situated underground, and therefore not visible and under the influence of various highly unpredictable forces. This paper proposes the use of advanced data mining methods in order to determine the risks of pipe bursts. For example, analysis of the database of already occurred...

  4. A Data Mining Approach to Modelling of Water Supply Assets

    DEFF Research Database (Denmark)

    Babovic, V.; Drecourt, J.; Keijzer, M.

    2002-01-01

    The economic and social costs associated with pipe bursts and associated leakage problems in modern water supply systems are rapidly rising to unacceptable high levels. Pipe burst risks depend on a number of factors which are extremely difficult to characterise. A part of the problem is that water...... supply assets are mainly situated underground, and therefore not visible and under the influence of various highly unpredictable forces. This paper proposes the use of advanced data mining methods in order to determine the risks of pipe bursts. For example, analysis of the database of already occurred...... with the choice of pipes to be replaced, the outlined approach opens completely new avenues in asset modelling. The condition of an asset such as a water supply network deteriorates with age. With reliable risk models, addressing the evolution of risk with aging asset, it is now possible to plan optimal...

  5. Laser based water equilibration method for d18O determination of water samples

    Science.gov (United States)

    Mandic, Magda; Smajgl, Danijela; Stoebener, Nils

    2017-04-01

    Determination of d18O with water equilibration method using mass spectrometers equipped with equilibration unit or Gas Bench is known already for many years. Now, with development of laser spectrometers this extends methods and possibilities to apply different technologies in laboratory but also in the field. The Thermo Scientific™ Delta Ray™ Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect and Teledyne Cetac ASX-7100 offers high precision and throughput of samples. It employs optical spectroscopy for continuous measurement of isotope ratio values and concentration of carbon dioxide in ambient air, and also for analysis of discrete samples from vials, syringes, bags, or other user-provided sample containers. Test measurements and conformation of precision and accuracy of method determination d18O in water samples were done in Thermo Fisher application laboratory with three lab standards, namely ANST, Ocean II and HBW. All laboratory standards were previously calibrated with international reference material VSMOW2 and SLAP2 to assure accuracy of the isotopic values of the water. With method that we present in this work achieved repeatability and accuracy are 0.16‰ and 0.71‰, respectively, which fulfill requirements of regulatory method for wine and must after equilibration with CO2.

  6. Behavioural modelling of irrigation decision making under water scarcity

    Science.gov (United States)

    Foster, T.; Brozovic, N.; Butler, A. P.

    2013-12-01

    Providing effective policy solutions to aquifer depletion caused by abstraction for irrigation is a key challenge for socio-hydrology. However, most crop production functions used in hydrological models do not capture the intraseasonal nature of irrigation planning, or the importance of well yield in land and water use decisions. Here we develop a method for determining stochastic intraseasonal water use that is based on observed farmer behaviour but is also theoretically consistent with dynamically optimal decision making. We use the model to (i) analyse the joint land and water use decision by farmers; (ii) to assess changes in behaviour and production risk in response to water scarcity; and (iii) to understand the limits of applicability of current methods in policy design. We develop a biophysical model of water-limited crop yield building on the AquaCrop model. The model is calibrated and applied to case studies of irrigated corn production in Nebraska and Texas. We run the model iteratively, using long-term climate records, to define two formulations of the crop-water production function: (i) the aggregate relationship between total seasonal irrigation and yield (typical of current approaches); and (ii) the stochastic response of yield and total seasonal irrigation to the choice of an intraseasonal soil moisture target and irrigated area. Irrigated area (the extensive margin decision) and per-area irrigation intensity (the intensive margin decision) are then calculated for different seasonal water restrictions (corresponding to regulatory policies) and well yield constraints on intraseasonal abstraction rates (corresponding to aquifer system limits). Profit- and utility-maximising decisions are determined assuming risk neutrality and varying degrees of risk aversion, respectively. Our results demonstrate that the formulation of the production function has a significant impact on the response to water scarcity. For low well yields, which are the major concern

  7. Ares I Scale Model Acoustic Test Above Deck Water Sound Suppression Results

    Science.gov (United States)

    Counter, Douglas D.; Houston, Janice D.

    2011-01-01

    The Ares I Scale Model Acoustic Test (ASMAT) program test matrix was designed to determine the acoustic reduction for the Liftoff acoustics (LOA) environment with an above deck water sound suppression system. The scale model test can be used to quantify the effectiveness of the water suppression system as well as optimize the systems necessary for the LOA noise reduction. Several water flow rates were tested to determine which rate provides the greatest acoustic reductions. Preliminary results are presented.

  8. Geochemical Modeling of ILAW Lysimeter Water Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-22

    Geochemical modeling results of water extracts from simulated immobilized low-activity waste (ILAW) glasses, placed in lysimeters for eight years suggest that the secondary phase reaction network developed using product consistency test (PCT) results at 90°C may need to be modified for field conditions. For sediment samples that had been collected from near the glass samples, the impact of glass corrosion could be readily observed based upon the pH of their water extracts. For unimpacted sediments the pH ranged from 7.88 to 8.11 with an average of 8.04. Sediments that had observable impacts from glass corrosion exhibited elevated pH values (as high as 9.97). For lysimeter sediment samples that appear to have been impacted by glass corrosion to the greatest extent, saturation indices determined for analcime, calcite, and chalcedony in the 1:1 water extracts were near equilibrium and were consistent with the secondary phase reaction network developed using PCT results at 90°C. Fe(OH)3(s) also appears to be essentially at equilibrium in extracts impacted by glass corrosion, but with a solubility product (log Ksp) that is approximately 2.13 units lower than that used in the secondary phase reaction network developed using PCT results at 90°C. The solubilities of TiO2(am) and ZrO2(am) also appear to be much lower than that assumed in the secondary phase reaction network developed using PCT results at 90°C. The extent that the solubility of TiO2(am) and ZrO2(am) were reduced relative to that assumed in the secondary phase reaction network developed using PCT results at 90°C could not be quantified because the concentrations of Ti and Zr in the extracts were below the estimated quantification limit. Gibbsite was consistently highly oversaturated in the extract while dawsonite was at or near equilibrium. This suggests that dawsonite might be a more suitable phase for the secondary phase reaction network

  9. Modeling global distribution of agricultural insecticides in surface waters.

    Science.gov (United States)

    Ippolito, Alessio; Kattwinkel, Mira; Rasmussen, Jes J; Schäfer, Ralf B; Fornaroli, Riccardo; Liess, Matthias

    2015-03-01

    Agricultural insecticides constitute a major driver of animal biodiversity loss in freshwater ecosystems. However, the global extent of their effects and the spatial extent of exposure remain largely unknown. We applied a spatially explicit model to estimate the potential for agricultural insecticide runoff into streams. Water bodies within 40% of the global land surface were at risk of insecticide runoff. We separated the influence of natural factors and variables under human control determining insecticide runoff. In the northern hemisphere, insecticide runoff presented a latitudinal gradient mainly driven by insecticide application rate; in the southern hemisphere, a combination of daily rainfall intensity, terrain slope, agricultural intensity and insecticide application rate determined the process. The model predicted the upper limit of observed insecticide exposure measured in water bodies (n = 82) in five different countries reasonably well. The study provides a global map of hotspots for insecticide contamination guiding future freshwater management and conservation efforts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. A new method for the determination of water quality

    African Journals Online (AJOL)

    2010-12-13

    Dec 13, 2010 ... each measures a specific parameter of water, and methods differ in precision, speed, and cost. Frequently, water quality determi- nation is expensive and complicated. In this paper a new screen- ing method that can provide a preliminary test of water quality is proposed. It is based on measuring the ...

  11. trace element determination in municipal water supply of Damaturu

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. Groundwater is the only source of drinking water for residents of Damaturu Metropolis. This is ... result of the analysis shows that metals such as Lead, Cadmium, Zinc and Copper were not found in all the water samples, ... Key words: Contamination, Trace elements, Toxic, underground water. INTRODUCTION.

  12. Gas-Chromatographic Determination Of Water In Freon PCA

    Science.gov (United States)

    Melton, Donald M.

    1994-01-01

    Gas-chromatographic apparatus measures small concentrations of water in specimens of Freon PCA. Testing by use of apparatus faster and provides greater protection against accidental contamination of specimens by water in testing environment. Automated for unattended operation. Also used to measure water contents of materials, other than Freon PCA. Innovation extended to development of purgeable sampling accessory for gas chromatographs.

  13. determinants of residential per capita water demand of makurdi

    African Journals Online (AJOL)

    user

    the demand. Rapid development has also brought about increase in the uses of water as houses are now with gardens, increased number of cars and water using home appliances. This rapid growth in water demand has to be accompanied by regular review and adjustment in planning, designing and management of.

  14. Determination of oestrogen hormones in raw and treated water ...

    African Journals Online (AJOL)

    Hormones in water samples have been classified as 'emerging pollutants' and may pose a potential risk for humans. Hormones can be found in both surface and ground water at low concentrations. These compounds enter water streams through wastewater treatment plants (WWTP) and may elicit endocrine disruption to ...

  15. Modeling Water Flux through Crops based on the Optimum Water Use Hypothesis

    Science.gov (United States)

    Hosseini, Atefeh; Gayler, Sebastian; Konrad, Wilfried; Streck, Thilo

    2014-05-01

    Vegetation models can be used to predict plants response to altering climate conditions. Stomatal conductance (gs) controls diffusion of CO2 from the atmosphere to the leaf and water loss through transpiration and allows plants to adjust themselves to fluctuating environmental conditions. The hypothesis that stomata adapt optimally to its environment to maximize assimilation (A) for a given amount of water loss through transpiration (E) was introduced by Cowan and Farquhar (1977). This theory provides a framework for modeling the interactions between vegetation dynamics and soil moisture that does not rely on empirical calibration as long as photosynthetic canopy properties and total amount of water available for transpiration are known. The current study introduces a new approach to implement optimization theory of stomatal conductance into a canopy gas exchange model. The adequacy of the new approach was tested in a real case study by comparing predicted diurnal cycles of assimilation and transpiration rates as well as variability of soil moisture with observations at a winter wheat (Triticum aestivum cv.Cubus) field in southwest Germany. For analyzing the impact of soil texture on stomata regulation, three soil types were compared in a drying soil simulation scenario. Soil water balance was calculated from measured precipitation and simulated transpiration using a single bucket model, where the soil within the root zone was assumed to be homogeneous. Since the model focused on fully developed vegetation canopies, soil evaporation is considered negligible. Marginal water use efficiency can be expressed as partial derivative of assimilation with respect to transpiration (δA/δE =Λ). Daily values of Λ were determined using the formalism of Lagrangian multipliers. Potential evapotranspiration (Penman-Monteith) and effective reduction factor of root water uptake under unfavorable soil moisture conditions were used to estimate amounts of plant available water per

  16. Modeling regulated water utility investment incentives

    Science.gov (United States)

    Padula, S.; Harou, J. J.

    2014-12-01

    This work attempts to model the infrastructure investment choices of privatized water utilities subject to rate of return and price cap regulation. The goal is to understand how regulation influences water companies' investment decisions such as their desire to engage in transfers with neighbouring companies. We formulate a profit maximization capacity expansion model that finds the schedule of new supply, demand management and transfer schemes that maintain the annual supply-demand balance and maximize a companies' profit under the 2010-15 price control process in England. Regulatory incentives for costs savings are also represented in the model. These include: the CIS scheme for the capital expenditure (capex) and incentive allowance schemes for the operating expenditure (opex) . The profit-maximizing investment program (what to build, when and what size) is compared with the least cost program (social optimum). We apply this formulation to several water companies in South East England to model performance and sensitivity to water network particulars. Results show that if companies' are able to outperform the regulatory assumption on the cost of capital, a capital bias can be generated, due to the fact that the capital expenditure, contrarily to opex, can be remunerated through the companies' regulatory capital value (RCV). The occurrence of the 'capital bias' or its entity depends on the extent to which a company can finance its investments at a rate below the allowed cost of capital. The bias can be reduced by the regulatory penalties for underperformances on the capital expenditure (CIS scheme); Sensitivity analysis can be applied by varying the CIS penalty to see how and to which extent this impacts the capital bias effect. We show how regulatory changes could potentially be devised to partially remove the 'capital bias' effect. Solutions potentially include allowing for incentives on total expenditure rather than separately for capex and opex and allowing

  17. Vegetation cover-another dominant factor in determining global water resources in forested regions.

    Science.gov (United States)

    Wei, Xiaohua; Li, Qiang; Zhang, Mingfang; Giles-Hansen, Krysta; Liu, Wenfei; Fan, Houbao; Wang, Yi; Zhou, Guoyi; Piao, Shilong; Liu, Shirong

    2018-02-01

    Forested catchments provide critically important water resources. Due to dramatic global forest change over the past decades, the importance of including forest or vegetation change in the assessment of water resources under climate change has been highly recognized by Intergovernmental Panel on Climate Change (IPCC); however, this importance has not yet been examined quantitatively across the globe. Here, we used four remote sensing-based indices to represent changes in vegetation cover in forest-dominated regions, and then applied them to widely used models: the Fuh model and the Choudhury-Yang model to assess relative contributions of vegetation and climate change to annual runoff variations from 2000 to 2011 in forested landscape (forest coverage >30%) across the globe. Our simulations show that the global average variation in annual runoff due to change in vegetation cover is 30.7% ± 22.5% with the rest attributed to climate change. Large annual runoff variation in response to vegetation change is found in tropical and boreal forests due to greater forest losses. Our simulations also demonstrate both offsetting and additive effects of vegetation cover and climate in determining water resource change. We conclude that vegetation cover change must be included in any global models for assessing global water resource change under climate change in forest-dominant areas. © 2017 John Wiley & Sons Ltd.

  18. Determination of trihalomethanes in water samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Perez Pavon, Jose Luis [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias Quimicas, Universidad de Salamanca, 37008 Salamanca (Spain)], E-mail: jlpp@usal.es; Herrero Martin, Sara; Garcia Pinto, Carmelo; Moreno Cordero, Bernardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias Quimicas, Universidad de Salamanca, 37008 Salamanca (Spain)

    2008-11-23

    This article reviews the most recent literature addressing the analytical methods applied for trihalomethanes (THMs) determination in water samples. This analysis is usually performed with gas chromatography (GC) combined with a preconcentration step. The detectors most widely used in this type of analyses are mass spectrometers (MS) and electron capture detectors (ECD). Here, we review the analytical characteristics, the time required for analysis, and the simplicity of the optimised methods. The main difference between these methods lies in the sample pretreatment step; therefore, special emphasis is placed on this aspect. The techniques covered are direct aqueous injection (DAI), liquid-liquid extraction (LLE), headspace (HS), and membrane-based techniques. We also review the main chromatographic columns employed and consider novel aspects of chromatographic analysis, such as the use of fast gas chromatography (FGC). Concerning the detection step, besides the common techniques, the use of uncommon detectors such as fluorescence detector, pulsed discharge photoionization detector (PDPID), dry electrolytic conductivity detector (DELCD), atomic emission detector (AED) and inductively coupled plasma-mass spectrometry (ICP-MS) for this type of analysis is described.

  19. Modeling of Revitalization of Atmospheric Water

    Science.gov (United States)

    Coker, Robert; Knox, Jim

    2014-01-01

    The Atmosphere Revitalization Recovery and Environmental Monitoring (ARREM) project was initiated in September of 2011 as part of the Advanced Exploration Systems (AES) program. Under the ARREM project, testing of sub-scale and full-scale systems has been combined with multiphysics computer simulations for evaluation and optimization of subsystem approaches. In particular, this paper describes the testing and modeling of the water desiccant subsystem of the carbon dioxide removal assembly (CDRA). The goal is a full system predictive model of CDRA to guide system optimization and development.

  20. Determination of absorption coefficient of Chlorella vulgaris and Arthrospira maxima in water

    Science.gov (United States)

    Tekiner, Murat; Kurt, Mustafa; Ak, Ilknur; Kurt, Arzu

    2018-02-01

    Safe drinking water is crucial for human healthy, nowadays all drinking and irrigation water in developed country commonly come from dams. The water is transported to our usage area by several type of pipe or water-trench. The water can be infected some bacteria such as Chlorella vulgaris, Arthrospira maxima, during this transportation. In this study, we determine which wavelength effect to these green algae and cyanobacteria. For different concentration of these microorganisms in water, we determined uv-vis spectrum. By analyzing these spectrums, we determined absorption coefficient of these microorganisms for selected wavelength. The results show which wavelength can be used for destroy these microorganisms in affected water.

  1. CrowdWater - Can people observe what models need?

    Science.gov (United States)

    van Meerveld, I. H. J.; Seibert, J.; Vis, M.; Etter, S.; Strobl, B.

    2017-12-01

    CrowdWater (www.crowdwater.ch) is a citizen science project that explores the usefulness of crowd-sourced data for hydrological model calibration and prediction. Hydrological models are usually calibrated based on observed streamflow data but it is likely easier for people to estimate relative stream water levels, such as the water level above or below a rock, than streamflow. Relative stream water levels may, therefore, be a more suitable variable for citizen science projects than streamflow. In order to test this assumption, we held surveys near seven different sized rivers in Switzerland and asked more than 450 volunteers to estimate the water level class based on a picture with a virtual staff gauge. The results show that people can generally estimate the relative water level well, although there were also a few outliers. We also asked the volunteers to estimate streamflow based on the stick method. The median estimated streamflow was close to the observed streamflow but the spread in the streamflow estimates was large and there were very large outliers, suggesting that crowd-based streamflow data is highly uncertain. In order to determine the potential value of water level class data for model calibration, we converted streamflow time series for 100 catchments in the US to stream level class time series and used these to calibrate the HBV model. The model was then validated using the streamflow data. The results of this modeling exercise show that stream level class data are useful for constraining a simple runoff model. Time series of only two stream level classes, e.g. above or below a rock in the stream, were already informative, especially when the class boundary was chosen towards the highest stream levels. There was hardly any improvement in model performance when more than five water level classes were used. This suggests that if crowd-sourced stream level observations are available for otherwise ungauged catchments, these data can be used to constrain

  2. Evaluation of the Current State of Integrated Water Quality Modelling

    Science.gov (United States)

    Arhonditsis, G. B.; Wellen, C. C.; Ecological Modelling Laboratory

    2010-12-01

    Environmental policy and management implementation require robust methods for assessing the contribution of various point and non-point pollution sources to water quality problems as well as methods for estimating the expected and achieved compliance with the water quality goals. Water quality models have been widely used for creating the scientific basis for management decisions by providing a predictive link between restoration actions and ecosystem response. Modelling water quality and nutrient transport is challenging due a number of constraints associated with the input data and existing knowledge gaps related to the mathematical description of landscape and in-stream biogeochemical processes. While enormous effort has been invested to make watershed models process-based and spatially-distributed, there has not been a comprehensive meta-analysis of model credibility in watershed modelling literature. In this study, we evaluate the current state of integrated water quality modeling across the range of temporal and spatial scales typically utilized. We address several common modeling questions by providing a quantitative assessment of model performance and by assessing how model performance depends on model development. The data compiled represent a heterogeneous group of modeling studies, especially with respect to complexity, spatial and temporal scales and model development objectives. Beginning from 1992, the year when Beven and Binley published their seminal paper on uncertainty analysis in hydrological modelling, and ending in 2009, we selected over 150 papers fitting a number of criteria. These criteria involved publications that: (i) employed distributed or semi-distributed modelling approaches; (ii) provided predictions on flow and nutrient concentration state variables; and (iii) reported fit to measured data. Model performance was quantified with the Nash-Sutcliffe Efficiency, the relative error, and the coefficient of determination. Further, our

  3. Community Based Educational Model on Water Conservation Program

    Science.gov (United States)

    Sudiajeng, L.; Parwita, I. G. L.; Wiraga, I. W.; Mudhina, M.

    2018-01-01

    The previous research showed that there were indicators of water crisis in the northern and eastern part of Denpasar city and most of coastal area experienced on seawater intrusion. The recommended water conservation programs were rainwater harvesting and educate the community to develop a water saving and environmentally conscious culture. This research was conducted to built the community based educational model on water conservation program through ergonomics SHIP approach which placed the human aspect as the first consideration, besides the economic and technically aspects. The stakeholders involved in the program started from the problem analyses to the implementation and the maintenance as well. The model was built through three main steps, included determination of accepted design; building the recharge wells by involving local communities; guidance and assistance in developing a water saving and environmentally conscious culture for early childhood, elementary and junior high school students, community and industry. The program was implemented based on the “TRIHITA KARANA” concept, which means the relationship between human to God, human-to-human, and human to environment. Through the development of the model, it is expected to grow a sense of belonging and awareness from the community to maintain the sustainability of the program.

  4. Maneuver Estimation Model for Relative Orbit Determination

    National Research Council Canada - National Science Library

    Storch, Tara R

    2005-01-01

    While the use of relative orbit determination has reduced the difficulties inherent in tracking geosynchronous satellites that are in close proximity, the problem is often compounded by stationkeeping...

  5. Determination of paraquat in water samples using a sensitive fluorescent probe titration method.

    Science.gov (United States)

    Yao, Feihu; Liu, Hailong; Wang, Guangquan; Du, Liming; Yin, Xiaofen; Fu, Yunlong

    2013-06-01

    Paraquat (PQ), a nonselective herbicide, is non-fluorescent in aqueous solutions. Thus, its determination through direct fluorescent methods is not feasible. The supramolecular inclusion interaction of PQ with cucurbit[7]uril was studied by a fluorescent probe titration method. Significant quenching of the fluorescence intensity of the cucurbit[7]uril-coptisine fluorescent probe was observed with the addition of PQ. A new fluorescent probe titration method with high selectivity and sensitivity at the ng/mL level was developed to determine PQ in aqueous solutions with good precision and accuracy based on the significant quenching of the supramolecular complex fluorescence intensity. The proposed method was successfully used in the determination of PQ in lake water, tap water, well water, and ditch water in an agricultural area, with recoveries of 96.73% to 105.77%. The fluorescence quenching values (deltaF) showed a good linear relationship with PQ concentrations from 1.0 x 10(-8) to 1.2 x 10(-5) mol/L with a detection limit of 3.35 x 10(-9) mol/L. In addition, the interaction models of the supramolecular complexes formed between the host and the guest were established using theoretical calculations. The interaction mechanism between the cucurbit[7]uril and PQ was confirmed by 1H NMR spectroscopy.

  6. Determination of the IGRF 2000 model

    DEFF Research Database (Denmark)

    Olsen, Nils; Sabaka, T.J.; Tøffner-Clausen, Lars

    2000-01-01

    The IGRF 2000 has been estimated from magnetic measurements taken by the Orsted sattelite in summer 1999. For this purpose, three models have been derived: The first two models were estimated using a few geomagnetic quiet days in May and September 1999, respectively. The third model, called Oerst...

  7. Shell model in-water frequencies of the core barrel

    International Nuclear Information System (INIS)

    Takeuchi, K.; De Santo, D.F.

    1980-01-01

    Natural frequencies of a 1/24th-scale core barrel/vessel model in air and in water are measured by determining frequency responses to applied forces. The measured data are analyzed by the use of the one-dimensional fluid-structure computer code, MULTIFLEX, developed to calculate the hydraulic force. The fluid-structure interaction in the downcomer annulus is computed with a one-dimensional network model formed to be equivalent to two-dimensional fluid-structure interaction. The structural model incorporated in MULTIFLEX is substantially simpler than that necessary for structural analyses. Proposed for computation of structural dynamics is the projector method than can deal with the beam mode by modal analysis and the other shell modes by a direct integration method. Computed in-air and in-water frequencies agree fairly well with the experimental data, verifying the above MULTIFLEX technique

  8. The Role of Riparian Vegetation Density, Channel Orientation and Water Velocity in Determining River Water Temperature Dynamics

    Science.gov (United States)

    Garner, G.; Malcolm, I.; Sadler, J. P.; Hannah, D. M.

    2015-12-01

    There is substantial scientific and practical interest in the potential of riparian shading to mitigate climate change impacts on river temperature extremes. However, there is limited process-based evidence to determine the density and spatial extent of riparian tree planting required to obtain temperature targets under differing environmental conditions. A simulation experiment was used to understand the importance of riparian vegetation density, channel orientation and flow velocity for stream energy budgets and river temperature dynamics. Water temperature and meteorological observations were obtained in addition to hemispherical photographs along a ~1 km reach of the Girnock Burn, a tributary of the Aberdeenshire Dee, Scotland. Nine hemispherical images (representing different uniform canopy density scenarios) were used to parameterise a deterministic net radiation model and simulate radiative fluxes. For each vegetation scenario, the effects of eight channel orientations were investigated by changing the position of north at 45° intervals in each hemispheric image. Simulated radiative fluxes and observed turbulent fluxes drove a high-resolution water temperature model for the reach. Simulations were performed under low and high water velocity scenarios. Both velocity scenarios yielded decreases in mean (≥ 1.7 °C) and maximum (≥ 3.0 °C) temperature as canopy density increased. Slow-flowing water resided longer within the reach, which enhanced heat accumulation and dissipation and drove higher maximum and lower minimum temperatures. Intermediate levels of shade produced highly variable energy flux and water temperature dynamics depending on the channel orientation and thus the time of day when the channel was shaded. We demonstrate that in many reaches relatively sparse but strategically located vegetation could produce substantial reductions in maximum temperature and suggest that these criteria are used to inform future river management.

  9. Determination of kinetic isotopic fractionation of water during bare soil evaporation

    Science.gov (United States)

    Quade, Maria; Brüggemann, Nicolas; Graf, Alexander; Rothfuss, Youri

    2017-04-01

    A process-based understanding of the water cycle in the atmosphere is important for improving meteorological and hydrological forecasting models. Usually only net fluxes of evapotranspiration - ET are measured, while land-surface models compute their raw components evaporation -E and transpiration -T. Isotopologues can be used as tracers to partition ET, but this requires knowledge of the isotopic kinetic fractionation factor (αK) which impacts the stable isotopic composition of water pools (e.g., soil and plant waters) during phase change and vapor transport by soil evaporation and plant transpiration. It is defined as a function of the ratio of the transport resistances in air of the less to the most abundant isotopologue. Previous studies determined αK for free evaporating water (Merlivat, 1978) or bare soil evaporation (Braud et al. 2009) at only low temporal resolution. The goal of this study is to provide estimates at higher temporal resolution. We performed a soil evaporation laboratory experiment to determine the αK by applying the Craig and Gordon (1965) model. A 0.7 m high column (0.48 m i.d.) was filled with silt loam (20.1 % sand, 14.9 % loam, 65 % silt) and saturated with water of known isotopic composition. Soil volumetric water content, temperature and the isotopic composition (δ) of the soil water vapor were measured at six different depths. At each depth microporous polypropylene tubing allowed the sampling of soil water vapor and the measurement of its δ in a non-destructive manner with high precision and accuracy as detailed in Rothfuss et al. (2013). In addition, atmospheric water vapor was sampled at seven different heights up to one meter above the surface for isotopic analysis. Results showed that soil and atmospheric δ profiles could be monitored at high temporal and vertical resolutions during the course of the experiment. αK could be calculated by using an inverse modeling approach and the Keeling (1958) plot method at high temporal

  10. Modeling Water Quality Parameters Using Data-driven Methods

    Directory of Open Access Journals (Sweden)

    Shima Soleimani

    2017-02-01

    model water quality parameters such as Na+, K+, Mg2+, So42-, Cl-, pH, Electric conductivity (EC and total dissolved solids (TDS in the Sefidrood River. For comparison the selected input variable methods coefficient of determination (R2, root mean square error (RMSE, and Nash-Sutcliff (NS are applied. Results and Discussion: According to Table 5, the results of the GA-LSSVR algorithm by using correlation coefficient and PCA methods approximately show similar results. About pH, EC, and TDS quality parameters, the results of PCA method have, the more accuracy, but the difference of RMSE between the PCA method and correlation coefficient method is not significant. The PCA method cause improvement in NS values to 22 and 0.1 percentages in pH and TDS water quality parameters to the correlation coefficient method, respectively,and NS criteria value for EC water quality parameter did not change in both methods. As a result, according to positive values of NS criteria in both PCA and correlation methods, it is clear that GA-LSSVR has a high ability for modeling of water quality parameters. Because of summation of NS criteria for PCA method is 5.53 and for correlation coefficient is 5.62, we can say that the correlation coefficient method has more applicable as a data processing method, but both methods have a high ability. Orouji et all. (18 used assumed models to model Na+, K+, Mg2+, So42- , Cl- , pH, EC, and TDS by Genetic programming (GP method. The RMSE criteria of the better models for testing data are 2.1, 0.02, 0.85, 0.93, 2.18, 0.33, 404.15, and 246.15, respectively. For comparison the orouji et al. (18 and table (5, the Results show using the correlation coefficient method as a data processing method can improve the results to 5.5 times. The results indicate the superiority of developingalgorithm increases the modeling accuracy. It is worth mentioning that according to NS criteria both selected inputs variable methods (correlation coefficient and PCA are capable to

  11. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2011-10-01

    Full Text Available Estimates of surface actual evapotranspiration (ET can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  12. Water adsorption on goethite: Application of multilayer adsorption models

    Science.gov (United States)

    Hatch, C. D.; Tumminello, R.; Meredith, R.

    2016-12-01

    Adsorbed water on the surface of atmospheric mineral dust has recently been shown to significantly affect the ability of mineral dust aerosol to act as cloud condensation nuclei. We have studied water adsorption as a function of relative humidity (RH) on goethite (α-FeO(OH)), a common component of atmospheric mineral dust. The goethite surface area and particle size was determined using BET analysis and with N2 as an adsorbate and scanning electron microscopy, respectively. Water adsorption on the sample was monitored using horizontal attenuated total reflectance Fourier transform infrared (HATR-FTIR) spectroscopy equipped with a flow cell. Water content was determined using Beer's law and the optical constants for bulk water. The results were analyzed using Type II adsorption isotherms to model multilayer adsorption, including BET (Brunauer, Emmet and Teller), FHH (Frenkel, Halsey and Hill) and Freundlich. BET fits to experimental data provide parameters of monolayer coverage, while the FHH and Freundlich isotherms provide insights into multilayer adsorption mechanisms. Results indicate that goethite contains 5% H2O by mass at 50% RH, which increases to 12% by mass at 90% RH. Adsorption parameters and experimental results will be presented.

  13. Spectroscopic determination of leaf water content using linear ...

    African Journals Online (AJOL)

    In order to detect crop water status with fast, non-destructive monitoring based on its spectral characteristics, this study measured 33 groups of peach tree leaf reflectance spectra (350 to 1075 nm). Linear regression and backpropagation artificial neural network methods were used to establish peach tree leaf water content ...

  14. determination of lead at nanogram level in water samples

    African Journals Online (AJOL)

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    As is well known, heavy metal pollution has been a focus of attention all over the world. Metal ions frequently contained in industrial and municipal wastewater can be harmful to aquatic ... an urgent need to develop a simple and sensitive conventional method for measuring lead ion in ..... 5 Drinking water, sea water sample.

  15. Determination of radionuclide levels in soil and water around ...

    African Journals Online (AJOL)

    The study of the radionuclide concentration levels in soil and water samples in Eagle, Atlas and rock cement companies in Port Harcourt was carried out. Soil and water samples collected from the respective premises were analyzed using the gamma -ray spectrometry. The average absorbed dose rates of the soil samples ...

  16. water quality determination of rainwater harvesting birkas in harshin

    African Journals Online (AJOL)

    Osondu

    2012-03-14

    Mar 14, 2012 ... In an effort to address the problems of recurrent drought, famine and food insecurity, attempts were made to harvest run-off water in cisterns ... In Ethiopia, safe water coverage for urban areas in 2000 was estimated to be 72% ..... kitchen utensils and adverse health effects are not expected (WHO, 2009).

  17. Determination of water quality index and portability of Iguedo stream ...

    African Journals Online (AJOL)

    The parameters that most influenced the WQI as depicted by quality rating values include pH, Mn, Ni, Cd and Pb. Application of WQI in this study has been found functional in assessing the water quality of this stream based on the selected parameters. Key words: Water quality index, physicochemical parameters, Iguedo ...

  18. Water density and polarizability deduced from the refractive index determined by interferometric measurements up to 250 MPa.

    Science.gov (United States)

    Weiss, L; Tazibt, A; Tidu, A; Aillerie, M

    2012-03-28

    The refractive index of water is precisely determined in the visible light range as a function of the pressure until 250 MPa by means of a new measurement device that uses a special pipe tee included in an interferometer set. This technique allows revisiting the Bradley-Tait and Sellmeier equations to make them dependent on the wavelength and the pressure, respectively. The Bradley-Tait equation for the pressure dependence of the water refractive index is completed by a wavelength-dependent factor. Also, in the considered pressure and wavelength ranges, it is shown that the Sellmeier coefficients can be straightforwardly linked to the pressure, allowing the determination of the refractive index of water for either any wavelength or pressure. A new simple model allows the determination of the density of water as a function of the measured refractive index. Finally, the polarizability of water as function of pressure and wavelength is calculated by means of the Lorentz-Lorenz equation.

  19. Simultaneous determination of aerosol optical thickness and water-leaving radiance from multispectral measurements in coastal waters

    Science.gov (United States)

    Shi, Chong; Nakajima, Teruyuki

    2018-03-01

    Retrieval of aerosol optical properties and water-leaving radiance over ocean is challenging since the latter mostly accounts for ˜ 10 % of the satellite-observed signal and can be easily influenced by the atmospheric scattering. Such an effort would be more difficult in turbid coastal waters due to the existence of optically complex oceanic substances or high aerosol loading. In an effort to solve such problems, we present an optimization approach for the simultaneous determination of aerosol optical thickness (AOT) and normalized water-leaving radiance (nLw) from multispectral satellite measurements. In this algorithm, a coupled atmosphere-ocean radiative transfer model combined with a comprehensive bio-optical oceanic module is used to jointly simulate the satellite-observed reflectance at the top of atmosphere and water-leaving radiance just above the ocean surface. Then, an optimal estimation method is adopted to retrieve AOT and nLw iteratively. The algorithm is validated using Aerosol Robotic Network - Ocean Color (AERONET-OC) products selected from eight OC sites distributed over different waters, consisting of observations that covered glint and non-glint conditions from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. Results show a good consistency between retrieved and in situ measurements at each site. It is demonstrated that more accurate AOTs are determined based on the simultaneous retrieval method, particularly in shorter wavelengths and sunglint conditions, where the averaged percentage difference (APD) of retrieved AOT is generally reduced by approximate 10 % in visible bands compared with those derived from the standard atmospheric correction (AC) scheme, since all the spectral measurements can be used jointly to increase the information content in the inversion of AOT, and the wind speed is also simultaneously retrieved to compensate the specular reflectance error estimated from the rough ocean surface model. For the

  20. [Determination of the redox potential of water saturated with hydrogen].

    Science.gov (United States)

    Piskarev, I M; Ushkanov, V A; Aristova, N A; Likhachev, P P; Myslivets, T C

    2010-01-01

    It has been shown that the redox potential of water saturated with hydrogen is -500--700 mV. The time of the establishment of the potential is 24 h. The potential somewhat increases with increasing volume of hydrogen introduced to a reservoir with water and practically does not depend on the presence of additions in water, provided these additions are not reduced by hydrogen. The pH value of water does not change after the addition of water. In a glass vessel with a metallic cover resting on the side, no decrease in potential during the 2.5-month storage was observed. In plastic bottles, the content of hydrogen decreased; on storage for more than two weeks, it disappeared almost completely, and as a result, the potential increased after storage for three to four weeks to a level near zero. In an open vessel, the potential remained negative for two days.

  1. Ocean modelling for aquaculture and fisheries in Irish waters

    Science.gov (United States)

    Dabrowski, T.; Lyons, K.; Cusack, C.; Casal, G.; Berry, A.; Nolan, G. D.

    2016-01-01

    The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. The authors give an overview of a shellfish model developed in-house and that was designed to predict the growth, the physiological interactions with the ecosystem, and the level of coliform contamination of the blue mussel. As such, this model is applicable in studies on the carrying capacity of embayments, assessment of the impacts of pollution on aquaculture grounds, and the determination of shellfish water classes. Further services include the assimilation of the model-predicted shelf water movement into a new harmful algal bloom alert system used to inform end users of potential toxic shellfish events and high biomass blooms that include fish-killing species. Models are also used to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish, and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the resources of marine fisheries. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries.

  2. Ground-water transport model selection and evaluation guidelines

    International Nuclear Information System (INIS)

    Simmons, C.S.; Cole, C.R.

    1983-01-01

    Guidelines are being developed to assist potential users with selecting appropriate computer codes for ground-water contaminant transport modeling. The guidelines are meant to assist managers with selecting appropriate predictive models for evaluating either arid or humid low-level radioactive waste burial sites. Evaluation test cases in the form of analytical solutions to fundamental equations and experimental data sets have been identified and recommended to ensure adequate code selection, based on accurate simulation of relevant physical processes. The recommended evaluation procedures will consider certain technical issues related to the present limitations in transport modeling capabilities. A code-selection plan will depend on identifying problem objectives, determining the extent of collectible site-specific data, and developing a site-specific conceptual model for the involved hydrology. Code selection will be predicated on steps for developing an appropriate systems model. This paper will review the progress in developing those guidelines. 12 references

  3. Determination of hydraulic properties of unsaturated soil via inverse modeling

    International Nuclear Information System (INIS)

    Kodesova, R.

    2004-01-01

    The method for determining the hydraulic properties of unsaturated soil with inverse modeling is presented. A modified cone penetrometer has been designed to inject water into the soil through a screen, and measure the progress of the wetting front with two tensiometer rings positioned above the screen. Cumulative inflow and pressure head readings are analyzed to obtain estimates of the hydraulic parameters describing K(h) and θ(h). Optimization results for tests at one side are used to demonstrate the possibility to evaluate either the wetting branches of the soil hydraulic properties, or the wetting and drying curves simultaneously, via analysis of different parts of the experiment. The optimization results are compared to the results of standard laboratory and field methods. (author)

  4. Integrated modeling of ozonation for optimization of drinking water treatment

    NARCIS (Netherlands)

    van der Helm, A.W.C.

    2007-01-01

    Drinking water treatment plants automation becomes more sophisticated, more on-line monitoring systems become available and integration of modeling environments with control systems becomes easier. This gives possibilities for model-based optimization. In operation of drinking water treatment

  5. Modeling Surface Water Flow in the Atchafalaya Basin

    Science.gov (United States)

    Liu, K.; Simard, M.

    2017-12-01

    While most of the Mississippi River Delta is sinking due to insufficient sediment supply and subsidence, the stable wetlands and the prograding delta systems in the Atchafalaya Basin provide a unique opportunity to study the constructive interactions between riverine and marine forcings and their impacts upon coastal morphology. To better understand the hydrodynamics in this region, we developed a numerical modeling system for the water flow through the river channel - deltas - wetlands networks in the Atchafalaya Basin. Determining spatially varying model parameters for a large area composed of such diverse land cover types poses a challenge to developing an accurate numerical model. For example, the bottom friction coefficient can not be measured directly and the available elevation maps for the wetlands in the basin are inaccurate. To overcome these obstacles, we developed the modeling system in three steps. Firstly, we modeled river bathymetry based on in situ sonar transects and developed a simplified 1D model for the Wax Lake Outlet using HEC-RAS. Secondly, we used a Bayesian approach to calibrate the model automatically and infer important unknown parameters such as riverbank elevation and bottom friction coefficient through Markov Chain Monte Carlo (MCMC) simulations. We also estimated the wetland elevation based on the distribution of different vegetation species in the basin. Thirdly, with the lessons learnt from the 1D model, we developed a depth-averaged 2D model for the whole Atchafalaya Basin using Delft3D. After calibrations, the model successfully reproduced the water levels measured at five gauges in the Wax Lake Outlet and the modeled water surface profile along the channel agreed reasonably well with our LIDAR measurements. In addition, the model predicted a one-hour delay in tidal phase from the Wax Lake Delta to the upstream gauge. In summary, this project presents a procedure to initialize hydrology model parameters that integrates field

  6. Modelling of bio-optical parameters of open ocean waters

    Directory of Open Access Journals (Sweden)

    Vadim N. Pelevin

    2001-12-01

    Full Text Available An original method for estimating the concentration of chlorophyll pigments, absorption of yellow substance and absorption of suspended matter without pigments and yellow substance in detritus using spectral diffuse attenuation coefficient for downwelling irradiance and irradiance reflectance data has been applied to sea waters of different types in the open ocean (case 1. Using the effective numerical single parameter classification with the water type optical index m as a parameter over the whole range of the open ocean waters, the calculations have been carried out and the light absorption spectra of sea waters tabulated. These spectra are used to optimize the absorption models and thus to estimate the concentrations of the main admixtures in sea water. The value of m can be determined from direct measurements of the downward irradiance attenuation coefficient at 500 nm or calculated from remote sensing data using the regressions given in the article. The sea water composition can then be readily estimated from the tables given for any open ocean area if that one parameter m characterizing the basin is known.

  7. Informal household water market and determinants of price: Evidence from an Indian hill city

    Science.gov (United States)

    Pal, Manoranjan; De, Utpal Kumar

    2015-02-01

    Pricing of water in the hill cities in India is different from that of plain lands, because water is a scarce resource in most of the hill cities. The supply of water by the municipalities is inadequate. The private vendors come into picture and they put the prices according to the difficulties faced in supplying to the specific locations. Thus prices become variables and are also based on the economic demand-supply mechanism in which the households try to maximise their satisfaction subject to budget and other constraints, while the vendors try to extract as much benefit as possible from the buyers. This paper tries to examine the pricing of household water use in Shillong urban area, India and the impact of various factors including income, house rent, seasonal scarcity of water, capacity of municipal supply, household size on the price-quantity determination. The analysis is made in terms of a simultaneous equation framework and the model is applied to a data collected by stratified random sampling technique across the municipal wards and non-municipal segments of greater Shillong urban Agglomeration. The result of three stage least squares reveals significant positive impacts of income, scarcity of water on the demand price while significantly negative impacts of quantity purchased, extent of municipal supply, house rent paid on the demand price. But the household size does not have any significant impact on the demand price though large household is expected to require more water. The supply of water on the other hand is not significantly affected by price, extent of municipal supply and deficiency though the coefficients are in the expected line.

  8. Maneuver Estimation Model for Geostationary Orbit Determination

    National Research Council Canada - National Science Library

    Hirsch, Brian J

    2006-01-01

    .... The Clohessy-Wiltshire equations were used to model the relative motion of a geostationary satellite about its intended location, and a nonlinear least squares algorithm was developed to estimate the satellite trajectories.

  9. The effect of hydraulic roughness on design water levels in river models

    NARCIS (Netherlands)

    Warmink, Jord Jurriaan; Straatsma, M.; Huthoff, Freek; Klijn, F.; Schweckendiek, T.

    2013-01-01

    Accurate estimates of design water levels are essential, because they determine the required dimensions of the flood defences. Hydrodynamic models are used for the prediction of flood water levels to support flood safety and are often applied in a deterministic way. However, the modelling of river

  10. Bio-economic modeling of water quality improvements using a dynamic applied general equilibrium approach

    NARCIS (Netherlands)

    Dellink, R.; Brouwer, R.; Linderhof, V.G.M.; Stone, K.

    2011-01-01

    An integrated bio-economic model is developed to assess the impacts of pollution reduction policies on water quality and the economy. Emission levels of economic activities to water are determined based on existing environmental accounts. These emission levels are built into a dynamic economic model

  11. Dosimetry Modeling for Predicting Radiolytic Production at the Spent Fuel - Water Interface

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William H.; Kline, Amanda J.; Hanson, Brady D.

    2006-04-30

    Modeling of the alpha, beta, and gamma dose from spent fuel as a function of particle size and fuel to water ratio was examined. These doses will be combined with modeling of G values and interactions to determine the concentration of various species formed at the fuel water interface and their affect on dissolution rates.

  12. Soil water availability and rooting depth as determinants of hydraulic architecture of Patagonian woody species

    Science.gov (United States)

    Sandra J. Bucci; Fabian G. Scholz; Guillermo Goldstein; Frederick C. Meinzer; Maria E. Arce

    2009-01-01

    We studied the water economy of nine woody species differing in rooting depth in a Patagonian shrub steppe from southern Argentina to understand how soil water availability and rooting depth determine their hydraulic architecture. Soil water content and potentials, leaf water potentials (Leaf) hydraulic conductivity, wood density (Pw), rooting depth, and specific leaf...

  13. Ground-water pollution determined by boron isotope systematics

    International Nuclear Information System (INIS)

    Vengosh, A.; Kolodny, Y.; Spivack, A.J.

    1998-01-01

    Boron isotopic systematics as related to ground-water pollution is reviewed. We report isotopic results of contaminated ground water from the coastal aquifers of the Mediterranean in Israel, Cornia River in north-western Italy, and Salinas Valley, California. In addition, the B isotopic composition of synthetic B compounds used for detergents and fertilizers was investigated. Isotopic analyses were carried out by negative thermal ionization mass spectrometry. The investigated ground water revealed different contamination sources; underlying saline water of a marine origin in saline plumes in the Mediterranean coastal aquifer of Israel (δ 11 B=31.7 per mille to 49.9 per mille, B/Cl ratio ∼1.5x10 -3 ), mixing of fresh and sea water (25 per mille to 38 per mille, B/Cl∼7x10 -3 ) in saline water associated with salt-water intrusion to Salinas Valley, California, and a hydrothermal contribution (high B/Cl of ∼0.03, δ 11 B=2.4 per mille to 9.3 per mille) in ground water from Cornia River, Italy. The δ 11 B values of synthetic Na-borate products (-0.4 per mille to 7.5 per mille) overlap with those of natural Na-borate minerals (-0.9 per mille to 10.2 per mille). In contrast, the δ 11 B values of synthetic Ca-borate and Na/Ca borate products are significantly lower (-15 per mille to -12.1 per mille) and overlap with those of the natural Ca-borate minerals. We suggest that the original isotopic signature of the natural borate minerals is not modified during the manufacturing process of the synthetic products, and it is controlled by the crystal chemistry of borate minerals. The B concentrations in pristine ground-waters are generally low ( 11 B=39 per mille), salt-water intrusion and marine-derived brines (40 per mille to 60 per mille) are sharply different from hydrothermal fluids (δ 11 B=10 per mille to 10 per mille) and anthropogenic sources (sewage effluent: δ 11 B=0 per mille to 10 per mille; boron-fertilizer: δ 11 B=-15 per mille to 7 per mille). some

  14. Modeling terahertz heating effects on water

    DEFF Research Database (Denmark)

    Kristensen, Torben T.L.; Withayachumnankul, Withawat; Jepsen, Peter Uhd

    2010-01-01

    down to a spot with a diameter of 0.5 mm, we find that the steadystate temperature increase per milliwatt of transmitted power is 1.8◦C/mW. A quantum cascade laser can produce a CW beam in the order of several milliwatts and this motivates the need to estimate the effect of beam power on the sample...... temperature. For THz time domain systems, we indicate how to use our model as a worst-case approximation based on the beam average power. It turns out that THz pulses created from photoconductive antennas give a negligible increase in temperature. As biotissue contains a high water content, this leads...... to a discussion of worst-case predictions for THz heating of the human body in order to motivate future detailed study. An open source Matlab implementation of our model is freely available for at www.eleceng.adelaide.edu.au/thz...

  15. Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications.

    Science.gov (United States)

    Hajigholizadeh, Mohammad; Melesse, Assefa M; Fuentes, Hector R

    2018-03-14

    The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability.

  16. Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications

    Science.gov (United States)

    Fuentes, Hector R.

    2018-01-01

    The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability. PMID:29538335

  17. Effect of Model Selection on Computed Water Balance Components

    NARCIS (Netherlands)

    Jhorar, R.K.; Smit, A.A.M.F.R.; Roest, C.W.J.

    2009-01-01

    Soil water flow modelling approaches as used in four selected on-farm water management models, namely CROPWAT. FAIDS, CERES and SWAP, are compared through numerical experiments. The soil water simulation approaches used in the first three models are reformulated to incorporate ail evapotranspiration

  18. A novel dual soil sensor for simultaneous water content and water potential determination in irrigation scheduling and environmental monitoring

    Science.gov (United States)

    Hübner, Christof; Spohrer, Klaus; Karaj, Shkelqim; Müller, Joachim

    2013-04-01

    Due to the climate change and decreasing water availability in many parts of the world, water efficient irrigation becomes more and more important to stabilize or even increase agricultural productivity. An efficient irrigation scheduling relies on soil water potential information in order to define the optimal irrigation start as well as on soil water content data to quantify the amount of soil water and thus to properly define irrigation depth. Furthermore, nutrient leaching and groundwater contamination will be reduced by controlled irrigation. Therefore, a novel dual soil sensor was developed which allows for simultaneous determination of water content and water potential at low costs suitable for distributed sensing. The soil water content measurement is realized with a dielectric measurement approach. Sensor elements are arranged on a printed circuit board, which can easily be inserted into the soil. Soil water potential data is deduced from water content measurements in porous matrices with known retention characteristics. The matrices are placed on the printed circuit board above a water content sensitive dielectric measuring area. In contrast to common granular matrix sensors, the matrices are characterized by a narrow pore size ranges by which the accuracy of soil water potential determination can be improved and a threshold characteristic suitable for irrigation is achieved. Sensor principle and laboratory experiments will be presented. For application in irrigation scheduling, the dual sensor is connected to off-the-shelf irrigation controllers by an additional interface controller. The interface controller activates moisture measurements of the sensor and compares the actual measurements with set-points of water content or water potential. The running time-based programme of the irrigation controller will be interrupted if measured soil water contents are above a predefined water content threshold or soil water potential measurements are below a

  19. Underwater light field determined by water constituents in highly turbid water: the case of Taihu lake

    Directory of Open Access Journals (Sweden)

    Chang-Chun Huang

    2013-02-01

    . Overall, the knowledge of the bio-optical properties obtained in this study extends our understanding of water optics and can be used to predict the optical properties via water constituent concentration, regardless of measurement type (in situ or simulated by hydrodynamic model.

  20. Hysteresis of Soil Point Water Retention Functions Determined by Neutron Radiography

    Science.gov (United States)

    Perfect, E.; Kang, M.; Bilheux, H.; Willis, K. J.; Horita, J.; Warren, J.; Cheng, C.

    2010-12-01

    Soil point water retention functions are needed for modeling flow and transport in partially-saturated porous media. Such functions are usually determined by inverse modeling of average water retention data measured experimentally on columns of finite length. However, the resulting functions are subject to the appropriateness of the chosen model, as well as the initial and boundary condition assumptions employed. Soil point water retention functions are rarely measured directly and when they are the focus is invariably on the main drying branch. Previous direct measurement methods include time domain reflectometry and gamma beam attenuation. Here we report direct measurements of the main wetting and drying branches of the point water retention function using neutron radiography. The measurements were performed on a coarse sand (Flint #13) packed into 2.6 cm diameter x 4 cm long aluminum cylinders at the NIST BT-2 (50 μm resolution) and ORNL-HFIR CG1D (70 μm resolution) imaging beamlines. The sand columns were saturated with water and then drained and rewetted under quasi-equilibrium conditions using a hanging water column setup. 2048 x 2048 pixel images of the transmitted flux of neutrons through the column were acquired at each imposed suction (~10-15 suction values per experiment). Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert’s law in conjunction with beam hardening and geometric corrections. The pixel rows were averaged and combined with information on the known distribution of suctions within the column to give 2048 point drying and wetting functions for each experiment. The point functions exhibited pronounced hysteresis and varied with column height, possibly due to differences in porosity caused by the packing procedure employed. Predicted point functions, extracted from the hanging water column volumetric data using the TrueCell inverse modeling procedure, showed very good agreement with the range of point

  1. Leaf anatomical traits determine the 18O enrichment of leaf water in coastal halophytes

    Science.gov (United States)

    Liang, J.; Lin, G., Sr.; Sternberg, L. O.

    2017-12-01

    Foliar anatomical adaptations to high-salinity environment in mangroves may be recorded by leaf water isotopes. Recent studies observed that a few mangrove species have lower 18O enrichment of leaf water (ΔL) relative to source water than the adjacent terrestrial trees, but what factors actually control this phenomenon is still disputable at present. To resolve this issue, we collected 15 species of true mangrove plants, 14 species of adjacent freshwater trees and 4 species of semi-mangrove plants at five study sites on the southeastern coast of China. Leaf stomatal density and pore size, water content, ΔL and other related leaf physiological traits were determined for the selected leaves of these plants. Our results confirmed that ΔL values of mangroves were generally 3 4 ‰ lower than those of the adjacent freshwater or semi-mangrove species. Higher leaf water per area (LWC) and lower leaf stomatal density (LS) of mangroves played co-dominant roles in lowering ΔL through elongating effective leaf mixing length by about 20%. The Péclet model incorporated by LWC and LS performed well in predicting ΔL. The demonstrated general law between leaf anatomy and ΔL in this paper based on a large pool of species bridges the gap between leaf functional traits and metabolic proxies derived ΔL, which will have considerable potential applications in vegetation succession and reconstruction of paleoclimate research.

  2. Drinking behavior in nursery pigs: determining the accuracy between an automatic water meter versus human observers.

    Science.gov (United States)

    Meiszberg, A M; Johnson, A K; Sadler, L J; Carroll, J A; Dailey, J W; Krebs, N

    2009-12-01

    Assimilating accurate behavioral events over a long period can be labor-intensive and relatively expensive. If an automatic device could accurately record the duration and frequency for a given behavioral event, it would be a valuable alternative to the traditional use of human observers for behavioral studies. Therefore, the objective of this study was to determine the accuracy in the time spent at the waterer and the number of visits to the waterer by individually housed nursery pigs between human observers scoring video files using Observer software (OBS) and an automatic water meter Hobo (WM, control) affixed onto the waterline. Eleven PIC USA genotype gilts (22 +/- 2 d of age; 6.5 +/- 1.4 kg of BW) were housed individually in pens with ad libitum access to a corn-based starter ration and one nipple waterer. Behavior was collected on d 0 (day of weaning), 7, and 14 of the trial using 1 color camera positioned over 4 attached pens and a RECO-204 DVR at 1 frame per second. For the OBS method, 2 experienced observers recorded drinking behavior from the video files, which was defined as when the gilt placed her mouth over the nipple waterer. Data were analyzed using nonparametric methods and the general linear model and regression procedures in SAS. The experimental unit was the individual pen housing 1 gilt. The GLM model included the method of observation (WM vs. OBS) and time (24 h) as variables, and the gilt nested within method was used as the error term. Gilts consumed more water (P = 0.04) on d 14 than on d 0. The time of day affected (P < 0.001) the number of visits and the time spent at the waterer regardless of the method. However, the OBS method underestimated (P < 0.001) the number of visits to the waterer (3.48 +/- 0.33 visits/h for OBS vs. 4.94 +/- 0.33 for WM) and overestimated (P < 0.001) the time spent at the waterer (22.6 +/- 1.46 s/h for OBS vs. 13.9 +/- 1.43 for WM) compared with WM. The relationship between the 2 methods for prediction of time

  3. Drinking Water Temperature Modelling in Domestic Systems

    NARCIS (Netherlands)

    Moerman, A.; Blokker, M.; Vreeburg, J.; Van der Hoek, J.P.

    2014-01-01

    Domestic water supply systems are the final stage of the transport process to deliver potable water to the customers’ tap. Under the influence of temperature, residence time and pipe materials the drinking water quality can change while the water passes the domestic drinking water system. According

  4. The determinants of domestic water demand. Empirical evidence from Emilia-Romagna municipal data

    International Nuclear Information System (INIS)

    Mazzanti, Massimiliano; Montini, Anna

    2004-01-01

    This paper presents empirical evidence on the determinants of water demand for domestic use in one Italian region, the Emilia Romagna, by using municipal data. Two main stems in urban/domestic demand analysis cab be found in the empirical literature. The first deals with the estimation of price or income demand elasticities in the short and the long run. The price demand elasticities can be used for water demand managements purpose while the income price elasticities can be useful in the forecasting process of the water requirements. The second one deals with the estimate of customer willingness to pay increasing in water service quality in holistic sense or concerning single characteristics of the service: safety, flavour, continuity, appearance, pollution rate and cost. The aim of the analysis in this case the elicitation of the direct use, indirect use and non-use values associated to the water resource consumption, by means of direct or indirect techniques. In this paper we focused the analysis in the first stem of the empirical literature in which a cross section data set is required. The paper explores the topic problems of the estimating process whit the analysis of the empirical literature (with particular regard to investigations that use municipal data) and with the analysis of the econometric problems related to the demand estimate. The theoretical model for the water demand analysis is also presented and discussed. Two datasets have been implemented: one with 125 municipalities and four years, the other with 40 municipalities and eleven years. Both the databases bring together municipal water consumption and tariffs data provided by local water utilities and other municipal data (inhabitants, surface, household, income, etc.) stemming from official sources. The econometric analysis is based on both fixed effects, performing better than random effects models, and dynamic panel models. The estimated coefficient of the tariff variable arises always

  5. Dissolved oxygen - A target indicator in determining use of the Gulf of Kachchh waters

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.; Zingde, M.D.; Vethamony, P.; Babu, M.T.; DeSousa, S.N.; Verlecar, X.N.

    sensitivity to effluent load. Based on the DO analysis, BOD assimilation capacity of coastal waters around the Marine National Park (MNP) and Marine Sanctuary (MS) in the Gulf is determined. DO available for utilization for various categories of water use...

  6. Modelling price determination in South Africa

    Directory of Open Access Journals (Sweden)

    E Moolman

    2004-07-01

    Full Text Available South Africa has been faced with high inflation rates since the early 1970s. Despite continued monetary discipline the inflation target has not yet been met, highlighting South Africa’s price-vulnerability as a small open emerging economy and raising questions about the efficiency of monetary policy. The objectives of this paper are: (i to analyse the influence of monetary policy on inflation in the small open emerging economy of South Africa, (ii to highlight the channels other than monetary policy through which inflation can be influenced (iii to analyse the influence of international prices and the exchange rate on inflation, (iv to determine the role of the labour market on inflation, especially through wage-push dynamics and (v to determine the role of demand-pull factors on inflation.

  7. Water institutions and governance models for the funding, financing ...

    African Journals Online (AJOL)

    ... Model 3: SPV housing dedicated water infrastructure cash-flows, Model 4: stand-alone water institution with strong balance sheet, Model 5: public-private partnership (PPP) with equity, Model 6: private concession, and Model 7: private development. Various institutional options for consideration for the future management ...

  8. Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

    Energy Technology Data Exchange (ETDEWEB)

    Werner, F.L., E-mail: fernanda.werner@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Alves, A.S.M., E-mail: asergi@eletronuclear.gov.br [Eletrobras Termonuclear (Eletronuclear), Rio de Janeiro, RJ (Brazil); Frutuoso e Melo, P.F., E-mail: frutuoso@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

  9. Modeling the Determinants of Internet Use

    Science.gov (United States)

    Chen, Y. L.

    2008-01-01

    The purpose of the study is to build a model that predicts the level of Internet use by teachers of English as a foreign language in the northern Taiwanese higher education institutions. It examines interactional relationships among variables associated with barriers and issues of technology application as a means of analyzing the extent and the…

  10. Determinants of cyanuric acid and melamine assembly in water.

    Science.gov (United States)

    Ma, Mingming; Bong, Dennis

    2011-07-19

    While the recognition of cyanuric acid (CA) by melamine (M) and their derivatives has been known to occur in both water and organic solvents for some time, analysis of CA/M assembly in water has not been reported (Ranganathan, A.; Pedireddi, V. R.; Rao, C. N. R. J. Am. Chem. Soc.1999, 121, 1752-1753; Mathias, J. P.; Simanek, E. E.; Seto, C. T.; Whitesides, G. M. Macromol. Symp.1994, 77, 157-166; Zerkowski, J. A.; MacDonald, J. C.; Seto, C. T.; Wierda, D. A.; Whitesides, G. M. J. Am. Chem. Soc.1994, 116, 2382-2391; Mathias, J. P.; Seto, C. T.; Whitesides, G. M. Polym. Prepr.1993, 34, 92-93; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1993, 115, 905-916; Zerkowski, J. A.; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1992, 114, 5473-5475; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1990, 112, 6409-6411; Wang, Y.; Wei, B.; Wang, Q. J. Chem. Cryst.1990, 20, 79-84; ten Cate, M. G. J.; Huskens, J.; Crego-Calama, M.; Reinhoudt, D. N. Chem.-Eur. J.2004, 10, 3632-3639). We have examined assembly of CA/M, as well as assembly of soluble trivalent CA and M derivatives (TCA/TM), in aqueous solvent, using a combination of solution phase NMR, isothermal titration and differential scanning calorimetry (ITC/DSC), cryo-transmission electron microscopy (cryo-TEM), and synthetic chemistry. While the parent heterocycles coprecipitate in water, the trivalent system displays more controlled and cooperative assembly that occurs at lower concentrations than the parent and yields a stable nanoparticle suspension. The assembly of both parent and trivalent systems is rigorously 1:1 and proceeds as an exothermic, proton-transfer coupled process in neutral pH water. Though CA and M are considered canonical hydrogen-bonding motifs in organic solvents, we find that their assembly in water is driven in large part by enthalpically favorable surface-area burial, similar to what is observed with nucleic acid recognition. There are currently few synthetic systems capable of robust molecular

  11. Determination of estrogenic potential in waste water without sample extraction.

    Science.gov (United States)

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Uranjek-Ževart, Nataša; Heath, Ester

    2013-09-15

    This study describes the modification of the ER-Calux assay for testing water samples without sample extraction (NE-(ER-Calux) assay). The results are compared to those obtained with ER-Calux assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux) to "real" influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux) assay gave higher values compared to ER-Calux assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was

  12. Climate change, livelihoods and the multiple determinants of water adequacy: two approaches at regional to global scale

    Science.gov (United States)

    Lissner, Tabea; Reusser, Dominik

    2015-04-01

    Inadequate access to water is already a problem in many regions of the world and processes of global change are expected to further exacerbate the situation. Many aspects determine the adequacy of water resources: beside actual physical water stress, where the resource itself is limited, economic and social water stress can be experienced if access to resource is limited by inadequate infrastructure, political or financial constraints. To assess the adequacy of water availability for human use, integrated approaches are needed that allow to view the multiple determinants in conjunction and provide sound results as a basis for informed decisions. This contribution proposes two parts of an integrated approach to look at the multiple dimensions of water scarcity at regional to global scale. These were developed in a joint project with the German Development Agency (GIZ). It first outlines the AHEAD approach to measure Adequate Human livelihood conditions for wEll-being And Development, implemented at global scale and at national resolution. This first approach allows viewing impacts of climate change, e.g. changes in water availability, within the wider context of AHEAD conditions. A specific focus lies on the uncertainties in projections of climate change and future water availability. As adequate water access is not determined by water availability alone, in a second step we develop an approach to assess the water requirements for different sectors in more detail, including aspects of quantity, quality as well as access, in an integrated way. This more detailed approach is exemplified at region-scale in Indonesia and South Africa. Our results show that in many regions of the world, water scarcity is a limitation to AHEAD conditions in many countries, regardless of differing modelling output. The more detailed assessments highlight the relevance of additional aspects to assess the adequacy of water for human use, showing that in many regions, quality and

  13. Modeling soil water content for vegetation modeling improvement

    Science.gov (United States)

    Cianfrani, Carmen; Buri, Aline; Zingg, Barbara; Vittoz, Pascal; Verrecchia, Eric; Guisan, Antoine

    2016-04-01

    Soil water content (SWC) is known to be important for plants as it affects the physiological processes regulating plant growth. Therefore, SWC controls plant distribution over the Earth surface, ranging from deserts and grassland to rain forests. Unfortunately, only a few data on SWC are available as its measurement is very time consuming and costly and needs specific laboratory tools. The scarcity of SWC measurements in geographic space makes it difficult to model and spatially project SWC over larger areas. In particular, it prevents its inclusion in plant species distribution model (SDMs) as predictor. The aims of this study were, first, to test a new methodology allowing problems of the scarcity of SWC measurements to be overpassed and second, to model and spatially project SWC in order to improve plant SDMs with the inclusion of SWC parameter. The study was developed in four steps. First, SWC was modeled by measuring it at 10 different pressures (expressed in pF and ranging from pF=0 to pF=4.2). The different pF represent different degrees of soil water availability for plants. An ensemble of bivariate models was built to overpass the problem of having only a few SWC measurements (n = 24) but several predictors to include in the model. Soil texture (clay, silt, sand), organic matter (OM), topographic variables (elevation, aspect, convexity), climatic variables (precipitation) and hydrological variables (river distance, NDWI) were used as predictors. Weighted ensemble models were built using only bivariate models with adjusted-R2 > 0.5 for each SWC at different pF. The second step consisted in running plant SDMs including modeled SWC jointly with the conventional topo-climatic variable used for plant SDMs. Third, SDMs were only run using the conventional topo-climatic variables. Finally, comparing the models obtained in the second and third steps allowed assessing the additional predictive power of SWC in plant SDMs. SWC ensemble models remained very good, with

  14. River water quality model no. 1 (RWQM1): I. Modelling approach

    DEFF Research Database (Denmark)

    Shanahan, P.; Borchardt, D.; Henze, Mogens

    2001-01-01

    Successful river water quality modelling requires the specification of an appropriate model structure and process formulation. Both must be related to the compartment structure of running water ecosystems including their longitudinal, vertical, and lateral zonation patterns. Furthermore......, the temporal variability of abiotic boundary conditions may be important and must be incorporated by an appropriate choice of model parameters. A six-step decision procedure is proposed to achieve these objectives. The steps address the determination of the following model features: (1) temporal representation...... (dynamic or steady-state); (2) model dimensionality; (3) mixing; (4) advection; (5) reaction terms; and (6) boundary conditions. Numerical criteria based on process time constants and length scales provide a basis for these decisions....

  15. Determining and modeling the dispersion of non point source ...

    African Journals Online (AJOL)

    EJIRO

    mathematical model which can be used to predict the nutrient (ammonia, nitrite, nitrate, and phosphate) ... The ecological health of Lake Victoria ... Modeling approach. The modeling approach used is based on the fundamental principle of conservation of mass for managing surface water quality. (Biswas, 1976), as ...

  16. An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs

    Science.gov (United States)

    Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai

    2017-12-01

    Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

  17. METHOD FOR NITRATE DETERMINATION IN WATER IN THE PRESENCE OF NITRITE

    Directory of Open Access Journals (Sweden)

    Maria Sandu

    2014-12-01

    Full Text Available The study relates to determination of nitrate in presence of nitrite in water and can be used in the quality monitoring of natural water (surface and groundwater, drinking water, water from fish farms and public aquaria where autonomous filters is used. The nature and quantity of reagents used have insignificant impact on natural waters and sewages. According to the investigation, the method includes the removal of nitrite from the solution/water with sulfaminic acid, the nitrate ion reduction to nitrite using a reducing mixture that contains Na2SO4 and zinc dust in ratio of 100:5 and determining the nitrite with the Griess reagent.

  18. Definition and experimental determination of a soil-water retention surface

    OpenAIRE

    Salager, S.; El Youssoufi, M. S.; Saix, C.

    2010-01-01

    International audience; This paper deals with the definition and determination methods of the soil-water retention surface (SWRS), which is the tool used to present the hydromechanical behaviour of soils to highlight both the effect of suction on the change in water and total volumes and the effect of deformation with respect to the water retention capability. An experimental method is introduced to determine the SWRS and applied to a clayey silty sand. The determination of this surface is ba...

  19. Shallow Water Measurements Using a Single Green Laser Corrected by Building a Near Water Surface Penetration Model

    Directory of Open Access Journals (Sweden)

    Jianhu Zhao

    2017-04-01

    Full Text Available To reduce the size and cost of an integrated infrared (IR and green airborne LiDAR bathymetry (ALB system, and improve the accuracy of the green ALB system, this study proposes a method to accurately determine water surface and water bottom heights using a single green laser corrected by the near water surface penetration (NWSP model. The factors that influence the NWSP of green laser are likewise analyzed. In addition, an NWSP modeling method is proposed to determine the relationship between NWSP and the suspended sediment concentration (SSC of the surface layer, scanning angle of a laser beam and sensor height. The water surface and water bottom height models are deduced by considering NWSP and using only green laser based on the measurement principle of the IR laser and green laser, as well as employing the relationship between NWSP and the time delay of the surface return of the green laser. Lastly, these methods and models are applied to a practical ALB measurement. Standard deviations of 3.0, 5.3, and 1.3 cm are obtained by the NWSP, water-surface height, and water-bottom height models, respectively. Several beneficial conclusions and recommendations are drawn through the experiments and discussions.

  20. Extraction and determination of organosulfur compounds in water

    African Journals Online (AJOL)

    Preferred Customer

    Liquid-liquid extraction is time consuming or requires large amounts of toxic solvents. Solid-phase microextraction and headspace sorptive extraction are time consuming. The main disadvantage of DLLME is that the extraction solvent is generally limited to solvents of density higher than water in order to be sedimented by ...

  1. Determination of nitrate in water by flow-injection analysis

    Czech Academy of Sciences Publication Activity Database

    Mikuška, Pavel; Večeřa, Zbyněk

    2001-01-01

    Roč. 8, č. 1 (2001), s. 115-120 ISSN 1231-7098 R&D Projects: GA ČR GA203/98/0943 Grant - others:COPERNICUS(BE) SUB-AERO EVK2-1999-000327 Institutional research plan: CEZ:AV0Z4031919 Keywords : nitrate * chemiluminescence * water Subject RIV: CB - Analytical Chemistry, Separation

  2. DETERMINING HOW VAPOR PHASE MTBE REACHES GROUND WATER

    Science.gov (United States)

    EPA Region 2 and ORD have funded a RARE project for FY 2005/2006 to evaluate the prospects that MTBE (and other fuel components) in vapors that escape from an underground storage tank (UST) can find its way to ground water produced by monitoring wells at a gasoline filling statio...

  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. Determining the Field Capacity, Wilting point and Available Water ...

    African Journals Online (AJOL)

    Water is a unique material resource which plays a vital role in nature and in agriculture. The objective of this study was to find out the applicability of saturation percentage (SP) to estimate field capacity (FC) and permanent wilting point (PWP) of soils across different texture in southeast Nigeria. Top 0-20 cm soil sample were ...

  5. Determination of Perchlorate in Bottled Water from Italy

    Directory of Open Access Journals (Sweden)

    Patrizia Iannece

    2013-06-01

    Full Text Available Perchlorate is regarded as an emerging persistent inorganic contaminant. It is widely known that perchlorate is an endocrine disruptor as it competitively inhibits iodide transport in the thyroid gland. As drinking water is the major source of human exposure to perchlorate, its occurrence in commercially available bottled waters purchased in different regions of Italy was investigated. Perchlorate was measured using the rapid, sensitive, and selective LC-ESI-MS/MS (liquid chromatography-electrospray tandem mass spectrometry method by multiple reaction monitoring (MRM of the transition 98.8→82.8, which corresponds to the loss of one oxygen atom in the perchlorate ion (ClO4−→ClO3−. The chlorine isotope ratio (35Cl/37Cl was used as a confirmation tool. The limit of quantification (LOQ for this method was 5 ng/L, and the recovery ranged from 94% to 108%. Perchlorate was detected in 44 of the 62 drinking waters tested, with concentrations ranging from <5 to 75 ng/L. These values are similar in magnitude to those reported in drinking water from the USA and do not pose an immediate health concern.

  6. A rapid method for determining chlorobenzenes in dam water systems

    African Journals Online (AJOL)

    A method using direct immersion solid phase microextraction (DI-SPME) coupled to gas chromatography equipped with a flame ionisation detector (GC-FID) was developed for the analysis of 7 chlorinated benzenes in dam water. The main parameters affecting the DI-SPME process were optimised. The optimised method ...

  7. Determination of water quality, and trace metals in endemic ...

    African Journals Online (AJOL)

    ICP-MS and ICP-OES analyses of trace metals based on total concentration of unfiltered lake water samples showed the presence of trace metals. All fish species accumulated Al, Mn and Sr in the highest concentrations in their gills, with Cu, Cd, Co, Cr, Pb and U highest in the liver. Pungu maclareni accumulated Al, Cr, Co, ...

  8. Experimental partition determination of octanol-water coefficients of ...

    African Journals Online (AJOL)

    An electrochemical method based on square wave voltammetry was developed for the measurement of octanol-water partition coefficient, LogP, for ten ferrocene derivatives. Measured LogP values ranged over two orders of magnitude, between 2.18 for 1- ferrocenylethanol and 4.38 for ferrocenyl-2-nitrophenyl.

  9. Determinants of domestic water consumption in a growing urban ...

    African Journals Online (AJOL)

    cinthia

    in result-oriented water demand planning and designing. MATERIALS AND METHODS. This study was carried out in Iwo Township (Figure 1). Iwo is one of the 30 Local Government Areas in Osun State, Nigeria. The town has an area of 245 km2 with a population of 191,348 according to. (National Population census, 2006) ...

  10. DETERMINATION OF ZINC AND LEAD IN SURROUNDING WATER ...

    African Journals Online (AJOL)

    userpc

    Zinc (Zn) and Lead (Pb) ions in pond water and gill samples of Tilapia zilli. These were achieved .... between the various parameters. RESULTS .... from wastewater treatment plants effluents to the Seine River. Physics and Chemistry of the Earth, 36, 500–. 505. Censi, P., Spoto, S. E., Saiano, F., Sprovieri,. M., Mazzola, S.

  11. A rapid method for determining chlorobenzenes in dam water systems

    African Journals Online (AJOL)

    2012-04-16

    Apr 16, 2012 ... A method using direct immersion solid phase microextraction (DI-SPME) coupled to gas chromatography equipped with a flame ionisation detector (GC-FID) was developed for the analysis of 7 chlorinated benzenes in dam water. The main parameters affecting the DI-SPME process were optimised.

  12. Determination of Carboxylic Acids and Water-soluble Inorganic Ions ...

    African Journals Online (AJOL)

    NICO

    Atmospheric aerosol samples of PM2.5 and PM10 were collected in April–May 2011 from a rural site in Tanzania and analyzed for water-soluble inorganic ions and low molecular weight carboxylic acids using ion chromatography. PM2.5 and PM10 low-volume samplers with quartz fibre filters were deployed and aerosol ...

  13. Determination of heavy metals in water sediments and Tilapia zilli ...

    African Journals Online (AJOL)

    The study investigated the heavy metal concentration in Tilapia zilli and water sediments along Kolo Creek in Ogbia Local Government Area, Bayelsa State. Tilapia fish and sediment samples were collected from 5 stations, and analyzed for heavy metals following standard procedures. Four metals (Copper, Lead. Cadmium ...

  14. Determination of Carboxylic Acids and Water-soluble Inorganic Ions ...

    African Journals Online (AJOL)

    Oxalate and malonate inPM2.5 and acetate in PM10 were most abundant carboxylates accounting for 64% and 62 % of total acids, respectively. Mg2+ was most important cation in PM2.5 and PM10 accounting for 44 % and 24 % of total water-soluble ions, respectively, whereas SO4 2- was the main anionic component ...

  15. Spectroscopic determination of leaf water content using linear ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-02-02

    Feb 2, 2012 ... In order to detect crop water status with fast, non-destructive monitoring based on its spectral characteristics, this study measured 33 groups of peach tree leaf reflectance spectra (350 to 1075 nm). Linear regression and backpropagation artificial neural network methods were used to establish peach.

  16. Titrimetric determination of arsenic concentration in water samples ...

    African Journals Online (AJOL)

    This research is aimed at titrimetric determination of Arsenic concentration in samples collected from boreholes and irrigation channels of Hadejia Emirate council, Jigawa State, Nigeria. Twenty three samples were randomly collected using standard techniques. The pH of the samples was determined immediately at the ...

  17. Modeling water quality in distribution systems

    National Research Council Canada - National Science Library

    Clark, Robert Maurice

    2012-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Effects of Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Organization of Water Supplies in the United...

  18. Determination of arsenic concentration in drinking water from tubewell

    International Nuclear Information System (INIS)

    Molla, N.I.; Basunia, S.; Zaman, Laila; Hossain, S.M.; Miah, R.U.; Rahman, M.

    1998-01-01

    Arsenic contamination in drinking water from tubewells in the north-western and south-western region of Bangladesh has posed a great risk to public health. Most of the affected districts are primarily reported to have arsenic concentration in drinking water more than the permissible level, set by WHO, of 0.01 mg/L. Therefore, use of a reliable analytical technique like instrumental neutron activation analysis (INAA) for bulk sample analysis, covering a wide sampling area, has become an essential task. In this work the analytical results of forty tubewell water samples from two districts, namely Chapainawabganj and Faridpur, are reported. The concentration level of arsenic are found to be 28 to 378 μg/L. The detection limit is 3 μg/L. Tubewell samples, collected from different locations of Chapainawabganj and Faridpur municipal areas, and standard reference material NIST 1643d (water) together with primary standard of arsenic (100 μg/L) were irradiated at the TRIGA Mark-II research reactor, AERE, Savar with a nominal neutron flux about 10 12 cm -2 s -1 for one hour using the Lazy Susan facility. After irradiation, allowing a cooling time of 50-70 hours, radioactivity of the 76 As radionuclide was measured with a high resolution HPGe detector in combination with a PC based S-100 MCA master board packages. The detector was previously calibrated with a set of standard gamma ray sources. The gamma ray spectra were analyzed using gamma-software Peakgr-10 and GANAAS and manually. It has been possible to minimize the contribution of interfering 82 Br and 122 Sb radionuclides and the background of 24Na by optimizing irradiation time, cooling period and counting time. The quality of the analysis has been crossed-checked by analyzing the NIST SRM-1643b with respect to the primary standard of arsenic (100 μg/L). It is concluded that that arsenic concentration level is much higher in underground water of some areas posing serious threat to public health. However, hundred

  19. Determining The Water Quality of Maruf Dam (Boyabat–Sinop

    Directory of Open Access Journals (Sweden)

    Ekrem MUTLU

    2017-06-01

    Full Text Available In this study, the preliminary findings obtained from 3 sampling points, which represent the whole, on Maruf Irrigation Dam, which is located in Boyabat district of Sinop province, for 12 months between September 2015 and August 2016 were examined. The parameters monitored are temperature, dissolved oxygen, pH, electrical conductivity, total hardness, total alkalinity, chemical oxygen demand, biological oxygen demand, and dissolved anions and cations (sodium, potassium, calcium, magnesium, ammonium, nitrate, phosphate, chloride, sulfate, and sulfite. Because of its low dissolved ionic matter content, Maruf Dam was characterized as an alkali dam with mid-hard water and low electrical conductivity. In terms of parameters A and B of Surface Water Quality Management Regulation, the dam is considered “high-quality” and “unpolluted”. Besides the irrigation purposes, for which the barrage was constructed, the dam can also be used for aquaculture, animal breeding, and farming needs.

  20. Rigorous determination of stratospheric water vapor trends from MIPAS observations.

    Science.gov (United States)

    Ceccherini, Simone; Carli, Bruno; Raspollini, Piera; Ridolfi, Marco

    2011-05-09

    The trend of stratospheric water vapor as a function of latitude is estimated by the MIPAS measurements by means of a new method that uses the measurement space solution. The method uses all the information provided by the observations avoiding the artifacts introduced by the a priori information and by the interpolation to different vertical grids. The analysis provides very precise values of the trends that, however, are limited by a relatively large systematic error induced by the radiometric calibration error of the instrument. The results show in the five years from 2005 to 2009 a dependence on latitude of the stratospheric (from 37 to 53 km) water vapor trend with a positive value of (0.41 ± 0.16)%yr-1 in the northern hemisphere and less than 0.16%yr-1 in the southern hemisphere.

  1. Determining surface water and bed sediment quality of Lake Kopa

    Directory of Open Access Journals (Sweden)

    Nurgul Kazangapovaa

    2016-10-01

    Full Text Available In this research, the results of a hydro-chemical study of Lake Kopa in Kazakhstan are described, in the context of the regional geography and aggravating ecological problems of the lake. Besides analyzing the concentrations of all major ions, heavy-metal ions and other pollutants, their vertical and horizontal distribution were also assessed. Moreover, water pollution indices (WPI were calculated for individual ions, classes of pollutants, and total pollution, revealing serious overload of human- induced pollution within the lake’s ecosystem. Concentrations of major ions and WPI were monitored over 2009-2013 period, revealing a distinct seasonal pattern and a multi-year periodicity in respect to the measured parameters. In addition, studying ion exchange between lake water and bottom sediment showed complex non-equilibrium processes besides leaching out Ca2+ and its exchange for Na+.

  2. The optimation of radon-222 determination in water by Lucas cell technique

    International Nuclear Information System (INIS)

    Andrejkovicova, S.; Kuruc, J.; Kovacsova, A.; Mackova, J.; Rajec, P.

    2003-01-01

    The aim of this work was to determine detection efficiency ε, volume activity a v , low detection limit, minimal detection activity for radon. There were collecting several samples of water: water from tap water, mineral water, thermal water, water from wells and bottled drinking water. As we expected, the lowest values of volume activities of radon were reached in bottled drinking water (0.1 - 4.9 Bq/dm 3 ). Higher values were reached in water from tap water and natural mineral water (2.5 - 14.9 Bq/dm 3 ). The highest volume activities of radon were obtained in thermal water and water from wells (17.2 - 107.9 Bq/dm 3 ). Method for determination of radon in water was verified at Institute of Preventive and Clinical Medicine, Bratislava, Slovakia. Results of radon concentration in waters are in accordance with an uppermost - accepted value of radon in water. The volume activity of radon in our samples has never been higher as a limit value has allowed (300 Bq/dm 3 ). (authors)

  3. Application of Water Evaluation and Planning Model for Integrated Water Resources Management: Case Study of Langat River Basin, Malaysia

    Science.gov (United States)

    Leong, W. K.; Lai, S. H.

    2017-06-01

    Due to the effects of climate change and the increasing demand on water, sustainable development in term of water resources management has become a major challenge. In this context, the application of simulation models is useful to duel with the uncertainty and complexity of water system by providing stakeholders with the best solution. This paper outlines an integrated management planning network is developed based on Water Evaluation and Planning (WEAP) to evaluate current and future water management system of Langat River Basin, Malaysia under various scenarios. The WEAP model is known as an integrated decision support system investigate major stresses on demand and supply in terms of water availability in catchment scale. In fact, WEAP is applicable to simulate complex systems including various sectors within a single catchment or transboundary river system. To construct the model, by taking account of the Langat catchment and the corresponding demand points, we defined the hydrological model into 10 sub-hydrological catchments and 17 demand points included the export of treated water to the major cities outside the catchment. The model is calibrated and verified by several quantitative statistics (coefficient of determination, R2; Nash-Sutcliffe efficiency, NSE and Percent bias, PBIAS). The trend of supply and demand in the catchment is evaluated under three scenarios to 2050, 1: Population growth rate, 2: Demand side management (DSM) and 3: Combination of DSM and reduce non-revenue water (NRW). Results show that by reducing NRW and proper DSM, unmet demand able to reduce significantly.

  4. Determination of antibiotic residues in manure, soil, and surface waters

    Science.gov (United States)

    Christian, T.; Schneider, R.J.; Farber, H.A.; Skutlarek, D.; Meyer, M.T.; Goldbach, H.E.

    2003-01-01

    In the last years more and more often detections of antimicrobially active compounds ("antibiotics") in surface waters have been reported. As a possible input pathway in most cases municipal sewage has been discussed. But as an input from the realm of agriculture is conceivable as well, in this study it should be investigated if an input can occur via the pathway application of liquid manure on fields with the subsequent mechanisms surface run-off/interflow, leaching, and drift. For this purpose a series of surface waters, soils, and liquid manures from North Rhine-Westphalia (Northwestern Germany) were sampled and analyzed for up to 29 compounds by HPLC-MS/MS. In each of the surface waters antibiotics could be detected. The highest concentrations were found in samples from spring (300 ng/L of erythromycin). Some of the substances detected (e.g., tylosin), as well as characteristics in the landscape suggest an input from agriculture in some particular cases. In the investigation of different liquid manure samples by a fast immunoassay method sulfadimidine could be detected in the range of 1...2 mg/kg. Soil that had been fertilized with this liquid manure showed a content of sulfadimidine extractable by accelerated solvent extraction (ASE) of 15 ??g/kg dry weight even 7 months after the application. This indicates the high stability of some antibiotics in manure and soil.

  5. Rapid determination of radionuclide activity concentrations in contaminated drinking water

    International Nuclear Information System (INIS)

    Medley, P.; Ryan, B.; Bollhofer, A.; Martin, P.; International Atomic Energy Agency, Vienna

    2007-01-01

    As a result of an incident at the Ranger Uranium mine in which drinking water was contaminated with process water, it was necessary to perform quick analysis for naturally occurring uranium and thorium series radionuclide activity concentrations, including 226Ra, 210Pb, 210Po, U and Th isotopes. The methods which were subsequently used are presented here. The techniques used were high-resolution gamma spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICPMS) and high-resolution alpha spectrometry. Routine methods were modified to allow for rapid analyses on priority samples in 1-2 days, with some results for highest priority samples available in less than 1 day. Comparison of initial results obtained through standard procedures, is discussed. An emphasis is placed on high-resolution alpha spectrometry of major alpha-emitting nuclides, specifically 226Ra, 230Th and 238U. The range of uranium concentrations in the samples investigated was from background levels to 6.6ppm. Implications for radiological dose assessment in contamination incidents involving process water are presented. The worst-case scenario for the incident at Ranger Uranium Mine indicates that the maximum committed effective dose to workers was well below the ICRP limit for worker-related dose and below the dose limit for a member of the public, with 230Th being the highest contributor

  6. Validation of a spatial–temporal soil water movement and plant water uptake model

    KAUST Repository

    HEPPELL, J.

    2014-06-01

    © 2014, (publisher). All rights reserved. Management and irrigation of plants increasingly relies on accurate mathematical models for the movement of water within unsaturated soils. Current models often use values for water content and soil parameters that are averaged over the soil profile. However, many applications require models to more accurately represent the soil–plant–atmosphere continuum, in particular, water movement and saturation within specific parts of the soil profile. In this paper a mathematical model for water uptake by a plant root system from unsaturated soil is presented. The model provides an estimate of the water content level within the soil at different depths, and the uptake of water by the root system. The model was validated using field data, which include hourly water content values at five different soil depths under a grass/herb cover over 1 year, to obtain a fully calibrated system for plant water uptake with respect to climate conditions. When compared quantitatively to a simple water balance model, the proposed model achieves a better fit to the experimental data due to its ability to vary water content with depth. To accurately model the water content in the soil profile, the soil water retention curve and saturated hydraulic conductivity needed to vary with depth.

  7. Determining water content of fresh concrete by microwave reflection or transmission measurement.

    Science.gov (United States)

    1987-01-01

    In search of a rapid and accurate method for determining the water content of fresh concrete mixes, the microwave reflection and transmission properties of fresh concrete mixes were studied to determine the extent of correlation between each of these...

  8. A method for the determination of residual beta activity in drinking water samples

    Energy Technology Data Exchange (ETDEWEB)

    Idoeta, R. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)], E-mail: raquel.idoeta@ehu.es; Herranz, M.; Abelairas, A.; Legarda, F. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)

    2007-09-15

    The determination of residual beta activity in drinking water is usually needed in most monitoring programs. In this work a procedure for its determination is described and expressions for the calculations of detection limits and uncertainties are proposed.

  9. A method for the determination of residual beta activity in drinking water samples

    International Nuclear Information System (INIS)

    Idoeta, R.; Herranz, M.; Abelairas, A.; Legarda, F.

    2007-01-01

    The determination of residual beta activity in drinking water is usually needed in most monitoring programs. In this work a procedure for its determination is described and expressions for the calculations of detection limits and uncertainties are proposed

  10. Determination of soil parameters during the water horizontal infiltration and redistribution by gamma ray attenuation method and tensiometry

    International Nuclear Information System (INIS)

    Oliveira, J.C.M. de.

    1991-04-01

    The present work studies the water diffusivity and hydraulic conductivity in a Latossolo Roxo distrofico soil, during the water infiltration and redistribution processes. Variation water flow equations were utilized for the calculations. The data of wetting front positions and of soil water content profiles were obtained through the gamma ray attenuation from a 241-Am source, with 100 mCi activity detected by a standard electronic equipment of gamma spectrometry, with NaI CTD scintillation detector. From the soil water content data in function of space and time and from analytic models, the properties of soil water diffusivity and soil hydraulic conductivity were determined in the laboratory for the 0-10 cm and 10-25 soil layers. (author)

  11. Development of an optochemical sensor for continuous reversible determination of nitrate in drinking water and ground water

    International Nuclear Information System (INIS)

    Lumpp, R.

    1993-09-01

    An optochemical sensor has been developed for continuous reversible determination of nitrate in drinking water and ground water. The sensor is based on the combination of the anion selective liquid ion exchanger Ni(II[bathophenanthroline] 3 2+ with phenolsulfonephtalein dyes in a polyvinylchloride membrane. (orig.) [de

  12. Modeling of water treatment plant using timed continuous Petri nets

    Science.gov (United States)

    Nurul Fuady Adhalia, H.; Subiono, Adzkiya, Dieky

    2017-08-01

    Petri nets represent graphically certain conditions and rules. In this paper, we construct a model of the Water Treatment Plant (WTP) using timed continuous Petri nets. Specifically, we consider that (1) the water pump always active and (2) the water source is always available. After obtaining the model, the flow through the transitions and token conservation laws are calculated.

  13. Experimental determination of viscosity of water based magnetite nanofluid for application in heating and cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Toghraie, Davood; Alempour, Seyed Mohammadbagher [Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Afrand, Masoud, E-mail: masoud.afrand@pmc.iaun.ac.ir [Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of)

    2016-11-01

    In this paper, experimental determination of dynamic viscosity of water based magnetite nanofluid (Fe{sub 3}O{sub 4}/water) was performed. The viscosity was measured in the temperature range of 20–55 °C for various samples with solid volume fractions of 0.1%, 0.2%, 0.4%, 1%, 2% and 3%. The results showed that the viscosity considerably decreases with increasing temperature. Moreover, the viscosity enhances with an increase in the solid volume fraction, remarkably. The calculated viscosity ratios showed that the maximum viscosity enhancement was 129.7%. Using experimental data, a new correlation has been proposed to predict the viscosity of magnetite nanofluid (Fe{sub 3}O{sub 4}/water). A comparison between the experimental results and the correlation outputs showed that the proposed model has a suitable accuracy. - Highlights: • Preparing Magnetite nanofluids with solid volume fractions up to 3%. • Measuring viscosity in temperature range of 20–55 °C using Brookfield Viscometer. • Maximum viscosity enhancement occurred at volume fraction of 3% and was 129.7%. • Proposing new correlation to predict the viscosity of Fe3O4/water nanofluid.

  14. Asian water futures - Multi scenarios, models and criteria assessment -

    Science.gov (United States)

    Satoh, Yusuke; Burek, Peter; Wada, Yoshihide; Flrörke, Martina; Eisner, Stephanie; Hanasaki, Naota; Kahil, Taher; Tramberend, Sylvia; Fischer, Günther; Wiberg, David

    2016-04-01

    A better understanding of the current and future availability of water resources is essential for the implementation of the recently agreed Sustainable Development Goals (SDGs). Long-term/efficient strategies for coping with current and potential future water-related challenges are urgently required. Although Representative Concentration Pathways (RCPs) and Shared Socioeconomic Pathways (SSPs) were develop for the impact assessment of climate change, very few assessments have yet used the SSPs to assess water resources. Then the IIASA Water Futures and Solutions Initiative (WFaS), developed a set of water use scenarios consistent with RCPs and SSPs and applying the latest climate changes scenarios. Here this study focuses on results for Asian countries for the period 2010-2050. We present three conceivable future pathways of Asian water resources, determined by feasible combinations of two RCPs and three SSPs. Such a scenario approach provides valuable insights towards identifying appropriate strategies as gaps between a "scenario world" and reality. In addition, for the assessment of future water resources a multi-criteria analysis is applied. A classification system for countries and watershed that consists of two broad dimensions: (i) economic and institutional adaptive capacity, (ii) hydrological complexity. The latter is composed of several sub-indexes including total renewable water resources per capita, the ratio of water demand to renewable water resource, variability of runoff and dependency ratio to external. Furthermore, this analysis uses a multi-model approach to estimate runoff and discharge using 5 GCMs and 5 global hydrological models (GHMs). Three of these GHMs calculate water use based on a consistent set of scenarios in addition to water availability. As a result, we have projected hot spots of water scarcity in Asia and their spatial and temporal change. For example, in a scenario based on SSP2 and RCP6.0, by 2050, in total 2.1 billion people

  15. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Science.gov (United States)

    2010-04-01

    ... protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water Resources... Determination of protected areas and restriction on water use. In consideration of the foregoing facts and for... a protected area within the meaning and for the purpose of Article 10 of the Delaware River Basin...

  16. Technical note: A new method for the determination of water quality ...

    African Journals Online (AJOL)

    The aim of this study was to develop and test a novel screening method for determining water quality. We hypothesised that L-ascorbic acid would be a good indicator of water quality, due to its sensitivity to pollutants. We investigated the absorption spectra of L‑ascorbic acid dissolved at different concentrations in water from ...

  17. Using genetic algorithms to calibrate a water quality model.

    Science.gov (United States)

    Liu, Shuming; Butler, David; Brazier, Richard; Heathwaite, Louise; Khu, Soon-Thiam

    2007-03-15

    With the increasing concern over the impact of diffuse pollution on water bodies, many diffuse pollution models have been developed in the last two decades. A common obstacle in using such models is how to determine the values of the model parameters. This is especially true when a model has a large number of parameters, which makes a full range of calibration expensive in terms of computing time. Compared with conventional optimisation approaches, soft computing techniques often have a faster convergence speed and are more efficient for global optimum searches. This paper presents an attempt to calibrate a diffuse pollution model using a genetic algorithm (GA). Designed to simulate the export of phosphorus from diffuse sources (agricultural land) and point sources (human), the Phosphorus Indicators Tool (PIT) version 1.1, on which this paper is based, consisted of 78 parameters. Previous studies have indicated the difficulty of full range model calibration due to the number of parameters involved. In this paper, a GA was employed to carry out the model calibration in which all parameters were involved. A sensitivity analysis was also performed to investigate the impact of operators in the GA on its effectiveness in optimum searching. The calibration yielded satisfactory results and required reasonable computing time. The application of the PIT model to the Windrush catchment with optimum parameter values was demonstrated. The annual P loss was predicted as 4.4 kg P/ha/yr, which showed a good fitness to the observed value.

  18. Thorium determination in water and biological materials by fission track

    International Nuclear Information System (INIS)

    Melo Ferreira, A.C. de.

    1989-01-01

    As a segment of a research programme on the study of bioaccumulation of radionuclides, in animals and vegetables from Morro do Ferro, Pocos de Caldas, MG, a fission track method for the determination of low levels of thorium in environmental samples was developed as an alternative for alpha spectroscopy. The study was carried out in early alpha spectroscopy samples, containing high levels of 228 Th activity, which makes difficult the 232 Th determination. A dry way method for thorium evaluation was developed. Pieces of membrane filters, containing La F 3 (Th), coupled to Makrofol detectors, were irradiated in the core of a research reactor, IEA-R1 (IPEN). (author)

  19. GPR-Based Water Leak Models in Water Distribution Systems

    Science.gov (United States)

    Ayala-Cabrera, David; Herrera, Manuel; Izquierdo, Joaquín; Ocaña-Levario, Silvia J.; Pérez-García, Rafael

    2013-01-01

    This paper addresses the problem of leakage in water distribution systems through the use of ground penetrating radar (GPR) as a nondestructive method. Laboratory tests are performed to extract features of water leakage from the obtained GPR images. Moreover, a test in a real-world urban system under real conditions is performed. Feature extraction is performed by interpreting GPR images with the support of a pre-processing methodology based on an appropriate combination of statistical methods and multi-agent systems. The results of these tests are presented, interpreted, analyzed and discussed in this paper.

  20. GPR-Based Water Leak Models in Water Distribution Systems

    Directory of Open Access Journals (Sweden)

    David Ayala–Cabrera

    2013-11-01

    Full Text Available This paper addresses the problem of leakage in water distribution systems through the use of ground penetrating radar (GPR as a nondestructive method. Laboratory tests are performed to extract features of water leakage from the obtained GPR images. Moreover, a test in a real-world urban system under real conditions is performed. Feature extraction is performed by interpreting GPR images with the support of a pre-processing methodology based on an appropriate combination of statistical methods and multi-agent systems. The results of these tests are presented, interpreted, analyzed and discussed in this paper.

  1. The Determination of Trace Metals in Saline Waters and Biological Tissues Using the Heated Graphite Atomizer

    Science.gov (United States)

    Segar, D. A.

    1971-01-01

    A selective, volatalization technique utilizing the heated graphite atomizer atomic absorption technique has been developed for the analysis of iron in sea water. A similar technique may be used to determine vanadium, copper, nickel and cobalt in saline waters when their concentrations are higher than those normally encountered'in unpolluted sea waters. A preliminary solvent extraction using ammonium pyrolidine dithiocarbamate and methyl iso-butyl ketone permits the determination of a number of elements including iron, copper, zinc, nickel, cobalt and lead in sea water. The heated graphite atomized technique has also been applied to the determination of a range of trace transition elements in marine plant and animal tissues.

  2. Determination of boron in sea water by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Horta, A.M.T.C.; Curtius, A.J.

    1978-01-01

    The chelation-extraction of boric acid with are acid solution of 2-ethyl-1,3 hexanediol in methy1-isobutye-ketone is studied. By this way a simple, quick and precise method for boron determination can be obtained [pt

  3. Determination of the Concentration of Total Cyanide in Waste Water ...

    African Journals Online (AJOL)

    Michael Horsfall

    compound that can be determined as the cyanide ion,. CN- . Many chemical forms of ... used when dealing with HCN include titration of cyanides with silver nitrate , spectrophotometry methods, ion-selective electrodes, ion chromatography (Bradbury et al., 2009) etc. .... glycosides: a case study for evolution and application.

  4. Determination of oestrogen hormones in raw and treated water ...

    African Journals Online (AJOL)

    (E2β) and 17-α-ethinylestradiol (EE2) hormones using reverse phase ultra-fast liquid chromatography mass spectrometry. (RP-UFLC). Using the .... has become a reliable standard technique in clinical application fields like therapeutic drug .... they determine the prevalence of the ionic and neutral forms of compounds as a ...

  5. The use of material balanced equation to determine the oil water ...

    African Journals Online (AJOL)

    The oil water contact of an oil reservoir can be determined using some geophysical well logs. However, some of the methods might not be accurate. Therefore the material balanced equation which is an accurate means of formation evaluation is critically analysed in this study and then used to determine the oil water contact ...

  6. Generalization of Water Pricing Model in Agriculture and Domestic Groundwater for Water Sustainability and Conservation

    Science.gov (United States)

    Hek, Tan Kim; Fadzli Ramli, Mohammad; Iryanto; Rohana Goh, Siti; Zaki, Mohd Faiz M.

    2018-03-01

    The water requirement greatly increased due to population growth, increased agricultural areas and industrial development, thus causing high water demand. The complex problems facing by country is water pricing is not designed optimally as a staple of human needs and on the other hand also cannot guarantee the maintenance and distribution of water effectively. The cheap water pricing caused increase of water use and unmanageable water resource. Therefore, the more optimal water pricing as an effective control of water policy is needed for the sake of ensuring water resources conservation and sustainability. This paper presents the review on problems, issues and mathematical modelling of water pricing based on agriculture and domestic groundwater for water sustainability and conservation.

  7. Modeling water clarity in oceans and coasts

    Science.gov (United States)

    In oceans and coastal waters, phytoplankton is the primary producer of organic compounds which form the base for the food chain. The concentration of phytoplankton is a major factor controlling water clarity and the depth to which light penetrates in the water column. The light i...

  8. Model predictive control on open water systems

    NARCIS (Netherlands)

    Van Overloop, P.J.

    2006-01-01

    Human life depends on water daily, especially for drinking and food production. Also, human life needs to be protected against excess of water caused by heavy precipitation and floods. People have formed water management organizations to guarantee these necessities of life for communities. These

  9. Determinants of willingness to pay for improved water supply services in rural Kazakhstan

    Science.gov (United States)

    Tussupova, Kamshat

    2017-04-01

    The UN Sustainable development goals declare to provide water, sanitation and hygiene for all. The supply of affordable and safe water is a global priority and there is thus a requirement for a safe drinking water management and management of excreta disposal and wastewater. The current paper assesses the determinants of consumers' willingness to connect and pay (WTP) for the piped water in rural Kazakhstan. The results show that local villagers use water from different sources and at least three quarters of the respondents are willing to connect and use water from the piped water supply. The general defined determinants for WTP should be carefully considered among the different water users. Perceived water quality is a variable that is relevant for all water users. Other variables such as perceived reliability and the time-spent to collect water from the source, in-household treatment of water, and income perception are also significant but differently correlated with the WTP among different water users. Although, piped water is considered to be a safe system if properly managed, still some water users are reluctant to pay for the system and are satisfied with their current water supply and sanitation services. In this case, a proper management for the drinking water and wastewater and safe management of the excreta disposal should be supplied. It is recommended to include local water userś opinion as regard the willingness to connect and pay for the piped water system. The findings are of particular importance for policy-makers, water managers, engineers, and public health specialists.

  10. Using System Dynamic Model and Neural Network Model to Analyse Water Scarcity in Sudan

    Science.gov (United States)

    Li, Y.; Tang, C.; Xu, L.; Ye, S.

    2017-07-01

    Many parts of the world are facing the problem of Water Scarcity. Analysing Water Scarcity quantitatively is an important step to solve the problem. Water scarcity in a region is gauged by WSI (water scarcity index), which incorporate water supply and water demand. To get the WSI, Neural Network Model and SDM (System Dynamic Model) that depict how environmental and social factors affect water supply and demand are developed to depict how environmental and social factors affect water supply and demand. The uneven distribution of water resource and water demand across a region leads to an uneven distribution of WSI within this region. To predict WSI for the future, logistic model, Grey Prediction, and statistics are applied in predicting variables. Sudan suffers from severe water scarcity problem with WSI of 1 in 2014, water resource unevenly distributed. According to the result of modified model, after the intervention, Sudan’s water situation will become better.

  11. Techniques for determining total body water using deuterium oxide

    Science.gov (United States)

    Bishop, Phillip A.

    1990-01-01

    The measurement of total body water (TBW) is fundamental to the study of body fluid changes consequent to microgravity exposure or treatment with microgravity countermeasures. Often, the use of radioactive isotopes is prohibited for safety or other reasons. It was selected and implemented for use by some Johnson Space Center (JCS) laboratories, which permitted serial measurements over a 14 day period which was accurate enough to serve as a criterion method for validating new techniques. These requirements resulted in the selection of deuterium oxide dilution as the method of choice for TBW measurement. The development of this technique at JSC is reviewed. The recommended dosage, body fluid sampling techniques, and deuterium assay options are described.

  12. The determination of radiocaesium in sea and fresh waters

    International Nuclear Information System (INIS)

    Baker, C.W.

    1975-10-01

    The caesium is adsorbed on to a cartridge of silica gel impregnated with ammonium molybdophosphate from 50 litres of filtered water, adjusted to pH 2 with nitric acid. The cartridge is then placed in a well crystal detector and gamma counted. An additional separation step is required if zirconium-95/niobium-95 contamination has occurred, as shown by gamma spectrometric analysis of the cartridge. The measurement of caesium-137 and caesium-134 is by conventional γ-spectrometry. The output of the analysing system is ASCII paper tape, and a PDP-8 computer is used to convert this spectral information to activity of caesium-137 and -134 in pCi l -1 at the time of sample collection. (U.K.)

  13. DETERMINATION OF WATER CONTENT IN PYROLYTIC TARS USING COULOMETRIC KARL-FISHER TITRATION

    Directory of Open Access Journals (Sweden)

    Lenka Jílková

    2017-02-01

    Full Text Available The liquid organic fraction of pyrolytic tar has a high energy value which makes possible its utilization as an energy source. However, before utilization, it is crucial to remove water from the liquid fraction. The presence of water reduces the energy value of pyrolytic tars. Water separation from the organic tar fraction is a complex process, since an emulsion can be readily formed. Therefore, after phase separation, it is important to know the residual water content in the organic phase and whether it is necessary to further dry it. The results presented in this manuscript focus on a water determination in liquid products from coal and biomass pyrolysis by a coulometric Karl‑Fischer titration. The Coulometric Karl‑Fischer titration is often used for a water content determination in gaseous, liquid and solid samples. However, to date, this titration method has not been used for a water determination in tars. A new water determination method, which has been tested on different types of tar, has been developed. The Coulometric Karl‑Fischer titration is suitable for tar samples with a water content not greater than 5 wt. %. The obtained experimental results indicate that the new introduced method can be used with a very good repeatability for a water content determination in tars.

  14. Predicted impacts of future water level decline on monitoring wells using a ground-water model of the Hanford Site

    International Nuclear Information System (INIS)

    Wurstner, S.K.; Freshley, M.D.

    1994-12-01

    A ground-water flow model was used to predict water level decline in selected wells in the operating areas (100, 200, 300, and 400 Areas) and the 600 Area. To predict future water levels, the unconfined aquifer system was stimulated with the two-dimensional version of a ground-water model of the Hanford Site, which is based on the Coupled Fluid, Energy, and Solute Transport (CFEST) Code in conjunction with the Geographic Information Systems (GIS) software package. The model was developed using the assumption that artificial recharge to the unconfined aquifer system from Site operations was much greater than any natural recharge from precipitation or from the basalt aquifers below. However, artificial recharge is presently decreasing and projected to decrease even more in the future. Wells currently used for monitoring at the Hanford Site are beginning to go dry or are difficult to sample, and as the water table declines over the next 5 to 10 years, a larger number of wells is expected to be impacted. The water levels predicted by the ground-water model were compared with monitoring well completion intervals to determine which wells will become dry in the future. Predictions of wells that will go dry within the next 5 years have less uncertainty than predictions for wells that will become dry within 5 to 10 years. Each prediction is an estimate based on assumed future Hanford Site operating conditions and model assumptions

  15. Developing a particle tracking surrogate model to improve inversion of ground water - Surface water models

    Science.gov (United States)

    Cousquer, Yohann; Pryet, Alexandre; Atteia, Olivier; Ferré, Ty P. A.; Delbart, Célestine; Valois, Rémi; Dupuy, Alain

    2018-03-01

    The inverse problem of groundwater models is often ill-posed and model parameters are likely to be poorly constrained. Identifiability is improved if diverse data types are used for parameter estimation. However, some models, including detailed solute transport models, are further limited by prohibitive computation times. This often precludes the use of concentration data for parameter estimation, even if those data are available. In the case of surface water-groundwater (SW-GW) models, concentration data can provide SW-GW mixing ratios, which efficiently constrain the estimate of exchange flow, but are rarely used. We propose to reduce computational limits by simulating SW-GW exchange at a sink (well or drain) based on particle tracking under steady state flow conditions. Particle tracking is used to simulate advective transport. A comparison between the particle tracking surrogate model and an advective-dispersive model shows that dispersion can often be neglected when the mixing ratio is computed for a sink, allowing for use of the particle tracking surrogate model. The surrogate model was implemented to solve the inverse problem for a real SW-GW transport problem with heads and concentrations combined in a weighted hybrid objective function. The resulting inversion showed markedly reduced uncertainty in the transmissivity field compared to calibration on head data alone.

  16. Determination of water table using electrical sounding technique: A ...

    African Journals Online (AJOL)

    Models were generated for computer iterative technique and Borehole data were also collected using spontaneous potential logging method as well as driller's log in some selected sites within the study area so as to correlate surface measurement with borehole records. Analysis based on three depth related resistivity ...

  17. 76 FR 7762 - Drinking Water: Regulatory Determination on Perchlorate

    Science.gov (United States)

    2011-02-11

    ... across life stages in the human: Using PBPK models to predict dosimetry and thyroid inhibition and... developing children as additional life stages, EPA derived potential alternative HRLs for 14 life stages (age groups) using the RfD and life stage-specific exposure information in the August 9, 2009, notice (74 FR...

  18. Water Level Flux in Household Containers in Vietnam - A Key Determinant of Aedes aegypti Population Dynamics

    Science.gov (United States)

    Jeffery, Jason A. L.; Clements, Archie C. A.; Nguyen, Yen Thi; Nguyen, Le Hoang; Tran, Son Hai; Le, Nghia Trung; Vu, Nam Sinh; Ryan, Peter A.; Kay, Brian H.

    2012-01-01

    We examined changes in the abundance of immature Aedes aegypti at the household and water storage container level during the dry-season (June-July, 2008) in Tri Nguyen village, central Vietnam. We conducted quantitative immature mosquito surveys of 171 containers in the same 41 households, with replacement of samples, every two days during a 29-day period. We developed multi-level mixed effects regression models to investigate container and household variability in pupal abundance. The percentage of houses that were positive for I/II instars, III/IV instars and pupae during any one survey ranged from 19.5–43.9%, 48.8–75.6% and 17.1–53.7%, respectively. The mean numbers of Ae. aegypti pupae per house ranged between 1.9–12.6 over the study period. Estimates of absolute pupal abundance were highly variable over the 29-day period despite relatively stable weather conditions. Most variability in pupal abundance occurred at the container rather than the household level. A key determinant of Ae. aegypti production was the frequent filling of the containers with water, which caused asynchronous hatching of Ae. aegypti eggs and development of cohorts of immatures. We calculated the probability of the water volume of a large container (>500L) increasing or decreasing by ≥20% to be 0.05 and 0.07 per day, respectively, and for small containers (<500L) to be 0.11 and 0.13 per day, respectively. These human water-management behaviors are important determinants of Ae. aegypti production during the dry season. This has implications for choosing a suitable Wolbachia strain for release as it appears that prolonged egg desiccation does not occur in this village. PMID:22911683

  19. Total Body Water Determination: Have We To Adapt Its Determination To The Patient Clinical Status?

    Directory of Open Access Journals (Sweden)

    Almudena Pérez Torres

    2012-06-01

    Conclusion: There is a good concordance between both methods in the determination of the TBW. The Watson formula overestimates the TBW in patients with high %FM and underestimates in those with high FFM. In the clinical practice, it is necessary to adapt the determination of TBW to the patient situation.

  20. Modelling Soil Water Retention for Weed Seed Germination Sensitivity to Water Potential

    Directory of Open Access Journals (Sweden)

    W. John Bullied

    2012-01-01

    Full Text Available Soil water retention is important for the study of water availability to germinating weed seeds. Six soil water retention models (Campbell, Brooks-Corey, four- and five-parameter van Genuchten, Tani, and Russo with residual soil water parameter derivations were evaluated to describe water retention for weed seed germination at minimum threshold soil water potential for three hillslope positions. The Campbell, Brooks-Corey, and four-parameter van Genuchten model with modified or estimated forms of the residual parameter had superior but similar data fit. The Campbell model underestimated water retention at a potential less than −0.5 MPa for the upper hillslope that could result in underestimating seed germination. The Tani and Russo models overestimated water retention at a potential less than −0.1 MPa for all hillslope positions. Model selection and residual parameter specification are important for weed seed germination by representing water retention at the level of minimum threshold water potential for germination. Weed seed germination models driven by the hydrothermal soil environment rely on the best-fitting soil water retention model to produce dynamic predictions of seed germination.

  1. Determination of the cavity mode in the water

    Directory of Open Access Journals (Sweden)

    Vikulin Pavel

    2018-01-01

    Full Text Available Ultrasonic oscillations find their wide application in various sectors and industries: metallurgy, chemical and food industries, in engineering, in medicine. This is due to physical and chemical changes when exposed to the sound field. Cavitation in ultrasonic field causes the dispersion and emulsification of certain substances and promotes coagulation and degassing affects of crystallization and dissolution. It is known that ultrasonic vibrations also cause a variety of chemical transformations of substances such as oxidation, recovery, polymerization, and depolymerization. Researchers of cavitation action on the matter find the explanation of these phenomena: shock waves and, consequently, acoustic wind. The experiments were conducted in liquid environment (non-distilled water. The volume of the experimental sample amounted to 10 dm3. Method of the magnetostriction was applied to receive ultrasonic vibration, the principle of which consists in transforming electrical oscillations into mechanical. The level of cavitation was checked in two stages to evaluate the cavitation mode according to the degree of erosion of the artificial barriers and to measure the intensity of cavitation noise in the volume.

  2. Rapid determination of actinides and (90)Sr in river water.

    Science.gov (United States)

    Habibi, A; Boulet, B; Gleizes, M; Larivière, D; Cote, G

    2015-07-09

    Nuclear accidents occurred in latest years highlighted the difficulty to achieve, in a short time, the quantification of alpha and beta emitters. Indeed, most of the existing methods, though displaying excellent performances, can be very long, taking up to several weeks for some radioisotopes, such as (90)Sr. This study focuses on alpha and beta radioisotopes which could be accidentally released from nuclear installations and which could be measured by inductively coupled plasma mass spectrometer (ICP-MS). Indeed, a new and rapid separation method was developed for (234,235,236,238)U, (230,232)Th, (239,240)Pu, (237)Np, (241)Am and (90)Sr. The main objective was to minimize the duration of the separation protocol by the development of a unique radiochemical procedure with elution media compatible with ICP-MS measurements. Excellent performances were obtained with spiked river water samples. These performances are characterized by total yields exceeding 80% for all monitored radionuclides, as well as good reproducibility (RSD≤10%, n=12). The proposed radiochemical separation (including counting time) required less than 7h for a batch of 8 samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Determination of water in NIST reference material for mineral oils

    Science.gov (United States)

    Cedergren; Nordmark

    2000-07-15

    The accuracy of the reference concentrations of moisture in electrical insulating oil RM 8506 and lubricating oil RM 8507 (both of mineral type) and specified by the National Institute of Standards and Technology (NIST) as containing 39.7 and 76.8 ppm (w/w) water, respectively, has recently been the subject of debate in this journal. To shed some further light on this controversy, we report in this correspondence results for these oils obtained by two additional methods, one based on specially designed reagents for diaphragm-free Karl Fischer (KF) coulometry and the other based on the concept of stripping at elevated temperature/continuous KF coulometry. A positive interference effect was shown to take place for RM 8506 when the direct coulometric method was used. If the results are corrected for this, the values including six different procedures varied in the range 13.5-15.6 ppm (w/w). For RM 8507, all values were between 42.5 and 47.2 ppm (w/w), which means that the values recommended by NIST for both reference oils using volumetric titration are about twice as high as those obtained with the other techniques. A possible explanation for this discrepancy is presented.

  4. Water level determination for transportation projects : mean high water manual, final report, November 2009.

    Science.gov (United States)

    2009-11-01

    To ensure proficient network management and safe usage of navigable waterways especially in waters that are : subject to tides, it is essential that the height of the water at various tidal phases be known. This knowledge is also : essential for prop...

  5. [Watershed water environment pollution models and their applications: a review].

    Science.gov (United States)

    Zhu, Yao; Liang, Zhi-Wei; Li, Wei; Yang, Yi; Yang, Mu-Yi; Mao, Wei; Xu, Han-Li; Wu, Wei-Xiang

    2013-10-01

    Watershed water environment pollution model is the important tool for studying watershed environmental problems. Through the quantitative description of the complicated pollution processes of whole watershed system and its parts, the model can identify the main sources and migration pathways of pollutants, estimate the pollutant loadings, and evaluate their impacts on water environment, providing a basis for watershed planning and management. This paper reviewed the watershed water environment models widely applied at home and abroad, with the focuses on the models of pollutants loading (GWLF and PLOAD), water quality of received water bodies (QUAL2E and WASP), and the watershed models integrated pollutant loadings and water quality (HSPF, SWAT, AGNPS, AnnAGNPS, and SWMM), and introduced the structures, principles, and main characteristics as well as the limitations in practical applications of these models. The other models of water quality (CE-QUAL-W2, EFDC, and AQUATOX) and watershed models (GLEAMS and MIKE SHE) were also briefly introduced. Through the case analysis on the applications of single model and integrated models, the development trend and application prospect of the watershed water environment pollution models were discussed.

  6. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann

    2006-01-01

    The movement of connate water spiked with gamma emitting 22Na was studied during laboratory water flooding of oil saturated chalk from a North Sea oil reservoir. Using a one dimensional gamma monitoring technique is was observed that connate water is piled-up at the front of the injection water...... and forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined...

  7. Kinetic model of water vapour adsorption by gluten-free starch

    Science.gov (United States)

    Ocieczek, Aneta; Kostek, Robert; Ruszkowska, Millena

    2015-01-01

    This study evaluated the kinetics of water vapour adsorption on the surface of starch molecules derived from wheat. The aim of the study was to determine an equation that would allow estimation of water content in tested material in any timepoint of the adsorption process aimed at settling a balance with the environment. An adsorption isotherm of water vapour on starch granules was drawn. The parameters of the Guggenheim, Anderson, and De Boer equation were determined by characterizing the tested product and adsorption process. The equation of kinetics of water vapour adsorption on the surface of starch was determined based on the Guggenheim, Anderson, and De Boer model describing the state of equilibrium and on the model of a first-order linear inert element describing the changes in water content over time.

  8. The effects of hard water consumption on kidney function: Insights from mathematical modelling

    Science.gov (United States)

    Tambaru, David; Djahi, Bertha S.; Ndii, Meksianis Z.

    2018-03-01

    Most water sources in Nusa Tenggara Timur contain higher concentration of calcium and magnesium ions, which is known as hard water. Long-term consumption of hard water can cause kidney dysfunction, which may lead to the other diseases such as cerebrovascular disease, diabetes and others. Therefore, understanding the effects of hard water consumption on kidney function is of importance. This paper studies the transmission dynamics of kidney dysfunction due to the consumption of hard water using a mathematical model. We propose a new deterministic mathematical model comprising human and water compartments and conduct a global sensitivity analysis to determine the most influential parameters of the model. The Routh-Hurwitz criterion is used to examine the stability of the steady states. The results shows that the model has two steady states, which are locally stable. Moreover, we found that the most influential parameters are the maximum concentration of magnesium and calcium in the water, the increase rate of calcium and magnesium concentration in the water and the rate of effectiveness of water treatment. The results suggest that better water treatments are required to reduce the concentration of magnesium and calcium in the water. This aid in minimizing the probability of humans to attract kidney dysfunction. Furthermore, water-related data need to be collected for further investigation.

  9. Human-water interface in hydrological modelling

    OpenAIRE

    Wada, Yoshihide; Bierkens, Marc F.P.; Roo, de, Ad; Dirmeyer, Paul A.; Famiglietti, James S.; Hanasaki, Naota; Konar, Megan; Liu, Junguo; Schmied, Hannes Möller; Oki, Taikan; Pokhrel, Yadu; Sivapalan, Murugesu; Troy, Tara J.; Dijk, Van, Albert I.J.M.; Emmerik, Van, Tim

    2017-01-01

    Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion) and at various scales (from a watershed to the globe). During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global wate...

  10. Surface water pesticide modelling for decision support in drinking water production

    Science.gov (United States)

    Desmet, Nele; Dams, Jef; Bronders, Jan; Peleman, Gisèle; Verdickt, Liesbeth

    2015-04-01

    The occurrence of pesticides and other contaminants in river systems may compromise the use of surface water for drinking water production. To reduce the cost of removal of pesticides from the raw water, drinking water companies can: search for other raw water sources, invest in water storage capacity to overcome periods with high pesticide concentrations (often related to the application period), or impose measures to reduce the emission of pesticides to surface water (i.e. sustainable application strategies or use restrictions). To select the most appropriate water management options, the costs and effects of the aforementioned actions need to be evaluated. This evaluation requires knowledge on the concentrations and loads of pesticides at the point of drinking water abstraction, as well as insight in the contribution and the temporal variability of different sources or subbasins. In such a case, a modelling approach can assist in generating measurement-based datasets and to compare different scenarios for water management. We illustrate how a modelling approach can provide decision support for water management related to drinking water abstraction from surface water in a catchment that suffers from elevated pesticide concentrations. The study area is a water production center (WPC) located in northwestern Belgium. The WPC abstracts raw water from the river IJzer or from a natural pond and its connected streams. The available quantities as well as the quality of the water vary throughout the year. The WPC uses a reservoir of 3 million m³ to capture and store raw water to overcome periods with limited water availability and/or poor water quality. However, the pressure on water increases and in the future this buffering capacity might be no longer sufficient to fulfill the drinking water production demand. A surface water quality model for the area is set up using InfoWorks RS. The model is applied to obtain insight in the concentrations and loads at the different

  11. Determination of the Corona model parameters with artificial neural networks

    International Nuclear Information System (INIS)

    Ahmet, Nayir; Bekir, Karlik; Arif, Hashimov

    2005-01-01

    Full text : The aim of this study is to calculate new model parameters taking into account the corona of electrical transmission line wires. For this purpose, a neural network modeling proposed for the corona frequent characteristics modeling. Then this model was compared with the other model developed at the Polytechnic Institute of Saint Petersburg. The results of development of the specified corona model for calculation of its influence on the wave processes in multi-wires line and determination of its parameters are submitted. Results of obtained calculation equations are brought for electrical transmission line with allowance for superficial effect in the ground and wires with reference to developed corona model

  12. Determination of Water Quality Parameters in Sivas - Kurugöl Lake

    Directory of Open Access Journals (Sweden)

    Ekrem Mutlu

    2013-12-01

    Full Text Available Kurugöl Lake; Sivas province Hafik county Kurugöl village located within the boundaries of Sivas province, 54 km, Hafik the town 24 miles away, an area of 8.9 ha altitude of 1362 m, an average depth of 3.4 - 4 m with gypsum plateau on the bottom of the boiling water along with rainfall and snowmelt with the lake is fed naturally. Kurugöl (Hafik - Sivas waters of Lake of the physical and chemical properties during the year changes occurring determining water quality characteristics to reveal the pollution levels are determined, living life in terms of the availability of the detection, water pollution and control regulations by the lake water classification and fishing activities, compliance with were identified. The inland lake in Kurugöl (SKKY according to the classification of water resources in accordance with the parameters measured I-III water quality varies from class.

  13. Determination of Trichloroethylene in Water by Liquid–Liquid Microextraction Assisted Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Mengliang Zhang

    2015-02-01

    Full Text Available A method for the determination of trichloroethylene (TCE in water using portable gas chromatography/mass spectrometry (GC/MS was developed. A novel sample preparation method, liquid–liquid microextraction assisted solid phase microextraction (LLME–SPME, is introduced. In this method, 20 µL of hexane was added to 10 mL of TCE contaminated aqueous samples to assist headspace SPME. The extraction efficiency of SPME was significantly improved with the addition of minute amounts of organic solvents (i.e., 20 µL hexane. The absolute recoveries of TCE at different concentrations were increased from 11%–17% for the samples extracted by SPME to 29%–41% for the samples extracted by LLME–SPME. The method was demonstrated to be linear from 10 to 1000 ng mL−1 for TCE in water. The improvements on extraction efficiencies were also observed for toluene and 1, 2, 4-trichlorobenzene in water by using LLME–SPME method. The LLME–SPME method was optimized by using response surface modeling (RSM.

  14. Model of urban water management towards water sensitive city: a literature review

    Science.gov (United States)

    Maftuhah, D. I.; Anityasari, M.; Sholihah, M.

    2018-04-01

    Nowadays, many cities are facing with complex issues such as climate change, social, economic, culture, and environmental problems, especially urban water. In other words, the city has to struggle with the challenge to make sure its sustainability in all aspects. This research focuses on how to ensure the city sustainability and resilience on urban water management. Many research were not only conducted in urban water management, but also in sustainability itself. Moreover, water sustainability shifts from urban water management into water sensitive city. This transition needs comprehensive aspects such as social, institutional dynamics, technical innovation, and local contents. Some literatures about model of urban water management and the transition towards water sensitivity had been reviewed in this study. This study proposed discussion about model of urban water management and the transition towards water sensitive city. Research findings suggest that there are many different models developed in urban water management, but they are not comprehensive yet and only few studies discuss about the transition towards water sensitive and resilience city. The drawbacks of previous research can identify and fulfill the gap of this study. Therefore, the paper contributes a general framework for the urban water management modelling studies.

  15. COMPUTER MODELING OF SELECTED WATER QUALITY PARAMETERS IN WATER DISTRIBUTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Wojciech Kruszyński

    2016-06-01

    Full Text Available The paper presents the results of computer modeling of flowsand the age of the water in two rural communi-ties province Podlasie - Rutka and Jeleniewo. The model is made using Epanet. In the study, a series of variants of models simulating the behavior of existing distribution systems and water analyzes were performed century. Analysis of the age of the water in water works modeled showed areas where standing water is aging, not having the estuary and not giving way to fresh. Age of water in the pipes is an important indicator of its quality and shelf life. The longer standing water in the aqueduct, the more likely that it will develop dangerous bacteria and produce deposits which remain on the walls of the ducts.

  16. The Performance of Equalization Model of Water Allocation Inter Irrigation Areas in River System

    Directory of Open Access Journals (Sweden)

    Farriansyah Anang M.

    2018-01-01

    Full Text Available In Indonesia, water is public goods so it is necessary to control water allocation. Inequity of water allocation between water users is expanding largely, including irrigation as the largest user, while the density of headworks in the river are getting higher. Considering that water is limited, the practice of irrigation water allocation needs to be refined, from the traditional equity to volumetric equity. MEQAA (Model Equalisasi Alokasi Air/Equalization Model of Water Allocation plays a role in determining water sharing between headworks in order to meet the maximum-equal K-factor in river. MEQAA-Generic is a calculation machine with: analog-deterministic dynamic model; network equation according to mass balance and linear optimization; independent-based system; sustainability-efficiency-equity constraints; Ms. Excel-VBA. The inputs are: scheme system, local inflow, and irrigation demand. The outputs are: K-factor, release and ecosystem quote. The model performance is identified by comparing the output to the class of K-factor based on treatment of water distribution. The model test is performed in an uncontrolled and complicated system in Kukusan Tanggek watershed with 24 headworks in Lombok river basin. As long as it is adequate for water sharing, MEQAA-G can always produce maximum-equal K-factor. The output model is used to operation control.

  17. Monte Carlo modeling of 60 Co HDR brachytherapy source in water and in different solid water phantom materials

    Directory of Open Access Journals (Sweden)

    Sahoo S

    2010-01-01

    Full Text Available The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source-detector distance. A solid phantom can be precisely machined and hence source-detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA, polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG 60 Co brachytherapy source. The calculated dose rate constant is 1.086 ± 0.06% cGy h−1 U−1 for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom.

  18. Standard method for the determination of activity concentration of 90Sr in water

    International Nuclear Information System (INIS)

    1987-01-01

    The subject of the standard is the determination of the radioactive concentration of 90 Sr in surface waters, in ground water and in drinking water, by measuring the radioactivity of the daughter isotope 90 Y that was previously separated by a selective radiochemical method. Yttrium ions are extracted from alkaline earth metal cations by tributil-phosphate equilibrated with concentrated nitric acid. The ions are then reextracted into distilled water and precipitated in the form of yttrium-oxalate. Radioactivity of the precipitate is determined based on the measurement of the β-disintegration rate using a low-background nuclear instrument. (V.N.)

  19. A new breed of innovative ground water modeling

    International Nuclear Information System (INIS)

    Gelinas, R.J.; Doss, S.K.; Ziagos, J.; McKereghan, P.; Vogele, T.; Nelson, R.G.

    1995-07-01

    Sparse data is a critical obstacle in every ground water remediation project. Lack of data necessitates non-unique interpolations that can distort modeled distributions of contaminants and essential physical properties (e.g., permeability, porosity). These properties largely determine the rates and paths that contaminants may take in migrating from sources to receptor locations. We apply both forward and inverse model estimates to resolve this problem because coupled modeling provides the only way to obtain constitutive property distributions that simultaneously simulate the flow and transport behavior observed in borehole measurements. Innovations in multidimensional modeling are a key to achieving more effective subsurface characterizations, remedial designs, risk assessments, and compliance monitoring in efforts to accelerate cleanup and reduce costs in national environmental remediations. Fundamentally new modeling concepts and novel software have emerged recently from two decades of research on self-adaptive solvers of partial differential equations (PDEs). We have tested a revolutionary software product, PDEase, applying it to coupled forward and inverse flow problems. In the Superfund cleanup effort at Lawrence Livermore National Laboratory's (LLNL) Livermore Site, the new modeling paradigm of PDEase enables ground water professionals to simply provide the flow equations, site geometry, sources, sinks, constitutive parameters, and boundary conditions. Its symbolic processors then construct the actual numerical solution code and solve it automatically. Powerful grid refinements that conform adaptively to evolving flow features are executed dynamically with iterative finite-element solutions that minimize numerical errors to user-specified limits. Numerical solution accuracy can be tested easily with the diagnostic information and interactive graphical displays that appear as the solutions are generated

  20. Integrating the simulation of domestic water demand behaviour to an urban water model using agent based modelling

    Science.gov (United States)

    Koutiva, Ifigeneia; Makropoulos, Christos

    2015-04-01

    The urban water system's sustainable evolution requires tools that can analyse and simulate the complete cycle including both physical and cultural environments. One of the main challenges, in this regard, is the design and development of tools that are able to simulate the society's water demand behaviour and the way policy measures affect it. The effects of these policy measures are a function of personal opinions that subsequently lead to the formation of people's attitudes. These attitudes will eventually form behaviours. This work presents the design of an ABM tool for addressing the social dimension of the urban water system. The created tool, called Urban Water Agents' Behaviour (UWAB) model, was implemented, using the NetLogo agent programming language. The main aim of the UWAB model is to capture the effects of policies and environmental pressures to water conservation behaviour of urban households. The model consists of agents representing urban households that are linked to each other creating a social network that influences the water conservation behaviour of its members. Household agents are influenced as well by policies and environmental pressures, such as drought. The UWAB model simulates behaviour resulting in the evolution of water conservation within an urban population. The final outcome of the model is the evolution of the distribution of different conservation levels (no, low, high) to the selected urban population. In addition, UWAB is implemented in combination with an existing urban water management simulation tool, the Urban Water Optioneering Tool (UWOT) in order to create a modelling platform aiming to facilitate an adaptive approach of water resources management. For the purposes of this proposed modelling platform, UWOT is used in a twofold manner: (1) to simulate domestic water demand evolution and (2) to simulate the response of the water system to the domestic water demand evolution. The main advantage of the UWAB - UWOT model

  1. Modelling anisotropic water transport in polymer composite ...

    Indian Academy of Sciences (India)

    Abstract. This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation ...

  2. Effects of spatially distributed sectoral water management on the redistribution of water resources in an integrated water model

    Science.gov (United States)

    Voisin, Nathalie; Hejazi, Mohamad I.; Leung, L. Ruby; Liu, Lu; Huang, Maoyi; Li, Hong-Yi; Tesfa, Teklu

    2017-05-01

    Realistic representations of sectoral water withdrawals and consumptive demands and their allocation to surface and groundwater sources are important for improving modeling of the integrated water cycle. To inform future model development, we enhance the representation of water management in a regional Earth system (ES) model with a spatially distributed allocation of sectoral water demands simulated by a regional integrated assessment (IA) model to surface and groundwater systems. The integrated modeling framework (IA-ES) is evaluated by analyzing the simulated regulated flow and sectoral supply deficit in major hydrologic regions of the conterminous U.S, which differ from ES studies looking at water storage variations. Decreases in historical supply deficit are used as metrics to evaluate IA-ES model improvement in representating the complex sectoral human activities for assessing future adaptation and mitigation strategies. We also assess the spatial changes in both regulated flow and unmet demands, for irrigation and nonirrigation sectors, resulting from the individual and combined additions of groundwater and return flow modules. Results show that groundwater use has a pronounced regional and sectoral effect by reducing water supply deficit. The effects of sectoral return flow exhibit a clear east-west contrast in the hydrologic patterns, so the return flow component combined with the IA sectoral demands is a major driver for spatial redistribution of water resources and water deficits in the US. Our analysis highlights the need for spatially distributed sectoral representation of water management to capture the regional differences in interbasin redistribution of water resources and deficits.

  3. A novel water poverty index model for evaluation of Chinese regional water security

    Science.gov (United States)

    Gong, L.; Jin, C. L.; Li, Y. X.; Zhou, Z. L.

    2017-08-01

    This study proposed an improved Water Poverty Index (WPI) model employed in evaluating Chinese regional water security. Firstly, the Chinese WPI index system was constructed, in which the indicators were obtained according to China River reality. A new mathematical model was then established for WPI values calculation on the basis of Center for Ecology and Hydrology (CEH) model. Furthermore, this new model was applied in Shiyanghe River (located in western China). It turned out that the Chinese index system could clearly reflect the indicators threatening security of river water and the Chinese WPI model is feasible. This work has also developed a Water Security Degree (WSD) standard which is able to be regarded as a scientific basis for further water resources utilization and water security warning mechanism formulation.

  4. Determination of methanol concentrations in traditional herbal waters of different brands in iran.

    Science.gov (United States)

    Mousavi, Seyed Reza; Namaei-Ghassemi, Mohssen; Layegh, Massomeh; Afzalaghaee, Monavar; Vafaee, Manssoreh; Zare, Gholamali; Moghiman, Toktam; Mood, Mahdi Balali

    2011-07-01

    Herbal waters are extensively used in most parts of including . Visiting a patient with total blindness due to daily ingestion of around 200 ml of herbal water (Plant forty water) per day for six months was the rational for methanol determination in all herbal waters available in markets. A total of two hundred and nineteen bottles of herbal waters were randomly bought from market. Methanol concentration was determined by gas chromatography, using a Flame Ionized Detector. Benzene (1000 mg/l) was applied as the internal standard. Collected data was analyzed by SPSS software (version 11.5), using appropriate descriptive statistical tests. Forty six different herbal waters from three main producing factories (A, B and C) were tested. Highest methanol concentration was measured in dill water of A (1208±202.74 mg/l), concentrated rose water of A (1017.41±59.68 mg/l) and concentrated rose water of B (978.52±92.81 mg/l). Lowest methanol concentration was determined in Trachyspermum copticum water of B (18.93±1.04 mg/l), cinnamon and ginger water of B (29.64±10.88 mg/l) and rice skin water of A (41.33±7.85 mg/l). Mean methanol concentrations of herbal waters including ginger, cinnamon, dill, peppermint, alfalfa, and plant forty from A, B and C were 374.69, 209.81 and 280.12 mg/l, respectively (P< 0.001). Methanol concentration in all herbal waters, especially rose water of the three producers was very high that may induce toxicity in people taking these products regularly for a long time.

  5. National Water Model assessment for water management needs over the Western United States.

    Science.gov (United States)

    Viterbo, F.; Thorstensen, A.; Cifelli, R.; Hughes, M.; Johnson, L.; Gochis, D.; Wood, A.; Nowak, K.; Dahm, K.

    2017-12-01

    The NOAA National Water Model (NWM) became operational in August 2016, providing the first ever, real-time distributed high-resolution forecasts for the continental United States. Since the model predictions occur at the CONUS scale, there is a need to evaluate the NWM in different regions to assess the wide variety and heterogeneity of hydrological processes that are included (e.g., snow melting, ice freezing, flash flooding events). In particular, to address water management needs in the western U.S., a collaborative project between the Bureau of Reclamation, NOAA, and NCAR is ongoing to assess the NWM performance for reservoir inflow forecasting needs and water management operations. In this work, the NWM is evaluated using different forecast ranges (short to medium) and retrospective historical runs forced by North American Land Data Assimilation System (NLDAS) analysis to assess the NWM skills over key headwaters watersheds in the western U.S. that are of interest to the Bureau of Reclamation. The streamflow results are analyzed and compared with the available observations at the gauge sites, evaluating different NWM operational versions together with the already existing local River Forecast Center forecasts. The NWM uncertainty is also considered, evaluating the propagation of the precipitation forcing uncertainties in the resulting hydrograph. In addition, the possible advantages of high-resolution distributed output variables (such as soil moisture, evapotranspiration fluxes) are investigated, to determine the utility of such information for water managers in terms of watershed characteristics in areas that traditionally have not had any forecast information. The results highlight the NWM's ability to provide high-resolution forecast information in space and time. As anticipated, the performance is best in regions that are dominated by natural flows and where the model has benefited from efforts toward parameter calibration. In highly regulated basins, the

  6. Flood modeling using WMS model for determining peak flood discharge in southwest Iran case study: Simili basin in Khuzestan Province

    Science.gov (United States)

    Hoseini, Yaser; Azari, Arash; Pilpayeh, Alireza

    2017-10-01

    It is of high importance to determine the flood discharge of different basins, in studies on water resources. However, it is necessary to use new models to determine flood hydrograph parameters. Therefore, it will be beneficial to conduct studies to calibrate the models, keeping in mind the local conditions of different regions. Therefore, this study was carried out to determine the peak flood discharge of a basin located in Southwest Iran, using the TR-20, TR55, and HEC-1 methods of the WMS model (watershed modeling system). The obtained results were compared with empirical values, as well as those of the soil conservation service (SCS) approach. Based on the results obtained, the TR55 method of the WMS model recorded the highest agreement with empirical values in Southwest Iran.

  7. Anion-exchange enrichment and spectrophotometric determination of uranium in sea-water

    International Nuclear Information System (INIS)

    Kuroda, Rokuro; Oguma, Koichi; Mukai, Noriko; Iwamoto, Masatoshi

    1987-01-01

    A method is proposed for the determination of uranium in sea-water. The uranium is strongly sorbed on a strongly basic anion-exchange resin (Cl - form) from acidified sea-water containing sodium azide (0.3M) and is easily eluted with 1M hydrochloric acid. Uranium in the effluent can be determined spectrophotometrically with Arsenazo III. The combined method allows easy and selective determination of uranium in sea-water without using a sophisticated adsorbent. The overall recovery and precision are satisfactory at the 3 μg/1. level. (author)

  8. Speciative determination of phosphorus in environmental water by the isotope exchange method

    International Nuclear Information System (INIS)

    Ikeda, N.; Yoshikawa, M.; Murakami, S.; Kunika, J.

    1988-01-01

    An isotope exchage method for the speciative determination of phosphorus (PO 4 3- ,PO 3 3- and total P) in natural water samples is proposed by using the exchange system of molybdophosphate in the aqueous phase and tetraphenylarsonium molybdophosphate in the organic phase. In this exchange system, only PO 4 3- exchanges and is determined. When the sample water is treated with Br 2 water in advance, the amount of PO 4 3- +PO 3 3- can be obtained. When the sample is treated with H 2 SO 4 and HNO 3 , the amount of total P can be determined. (author) 4 refs.; 5 tabs

  9. Suitability of a Coupled Hydrodynamic Water Quality Model to Predict Changes in Water Quality from Altered Meteorological Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Leon van der Linden

    2015-01-01

    Full Text Available Downscaled climate scenarios can be used to inform management decisions on investment in infrastructure or alternative water sources within water supply systems. Appropriate models of the system components, such as catchments, rivers, lakes and reservoirs, are required. The climatic sensitivity of the coupled hydrodynamic water quality model ELCOM-CAEDYM was investigated, by incrementally altering boundary conditions, to determine its suitability for evaluating climate change impacts. A series of simulations were run with altered boundary condition inputs for the reservoir. Air and inflowing water temperature (TEMP, wind speed (WIND and reservoir inflow and outflow volumes (FLOW were altered to investigate the sensitivity of these key drivers over relevant domains. The simulated water quality variables responded in broadly plausible ways to the altered boundary conditions; sensitivity of the simulated cyanobacteria population to increases in temperature was similar to published values. However the negative response of total chlorophyll-a suggested by the model was not supported by an empirical analysis of climatic sensitivity. This study demonstrated that ELCOM-CAEDYM is sensitive to climate drivers and may be suitable for use in climate impact studies. It is recommended that the influence of structural and parameter derived uncertainty on the results be evaluated. Important factors in determining phytoplankton growth were identified and the importance of inflowing water quality was emphasized.

  10. Determination of dew absorption by coffee plant through deuterium concentrations in leaf water

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Salati, E.; Matsui, E.

    1975-01-01

    The effect of dew falling on leaves on the water metabolism of the coffee plant (Coffea arabica) is examined. The use of natural stable isotopes variations in plant physiological studies is demonstrated. Water extracted from leaf samples is analysed by mass spectrometry. Analyses of deuterium concentrations in water extracted from plant leaves, dew and nutrient solutions are made. Determination of changes in deuterium concentration in the water of leaves from plants exposed to dew, compared with leaves not exposed to dew, is carried out. Results show that during daytime there is an enrichment in deuterium in water contained in the leaves, while at night the opposite occurs [pt

  11. Determination of moisture content and water activity in algae and fish by thermoanalytical techniques

    Directory of Open Access Journals (Sweden)

    Vilma Mota da Silva

    2008-01-01

    Full Text Available The water content in seafoods is very important since it affects their sensorial quality, microbiological stability, physical characteristics and shelf life. In this study, thermoanalytical techniques were employed to develop a simple and accurate method to determine water content (moisture by thermogravimetry (TG and water activity from moisture content values and freezing point depression using differential scanning calorimetry (DSC. The precision of the results suggests that TG is a suitable technique to determine moisture content in biological samples. The average water content values for fish samples of Lutjanus synagris and Ocyurus chrysurus species were 76.4 ± 5.7% and 63.3 ± 3.9%, respectively, while that of Ulva lactuca marine algae species was 76.0 ± 4.4%. The method presented here was also successfully applied to determine water activity in two species of fish and six species of marine algae collected in the Atlantic coastal waters of Bahia, in Brazil. Water activity determined in fish samples ranged from 0.946 - 0.960 and was consistent with values reported in the literature, i.e., 0.9 - 1.0. The water activity values determined in marine algae samples lay within the interval of 0.974 - 0.979.

  12. Insights on the energy-water nexus through modeling of the integrated water cycle

    Science.gov (United States)

    Leung, L. R.; Li, H. Y.; Zhang, X.; Wan, W.; Voisin, N.; Leng, G.

    2016-12-01

    For sustainable energy planning, understanding the impacts of climate change, land use change, and water management is essential as they all exert notable controls on streamflow and stream temperature that influence energy production. An integrated water model representing river processes, irrigation water use and water management has been developed and coupled to a land surface model to investigate the energy-water nexus. Simulations driven by two climate change projections with the RCP 4.5 and RCP 8.5 emissions scenarios, with and without water management, are analyzed to evaluate the individual and combined effects of climate change and water management on streamflow and stream temperature. The simulations revealed important impacts of climate change and water management on both floods and droughts. The simulations also revealed the dynamics of competition between changes in water demand and water availability in the climate mitigation (RCP 4.5) and business as usual (RCP 8.5) scenarios that influence streamflow and stream temperature, with important consequences to energy production. The integrated water model is being implemented to the Accelerated Climate Modeling for Energy (ACME) to enable investigation of the energy-water nexus in the fully coupled Earth system.

  13. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann

    2006-01-01

    and forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined...

  14. A model to assess water tariffs as part of water demand management

    African Journals Online (AJOL)

    Keywords: water demand management, price elasticity, change in water tariff, block tariff, WC/WDM model. INTRODUCTION ... ever developed for a 6-block pricing structure and allows for limited available input data from ..... Payment Strategies and Price Elasticity of Demand for Water for. Different revenue Groups in Three ...

  15. River water quality model no. 1 (RWQM1): I. Modelling approach

    DEFF Research Database (Denmark)

    Shanahan, P.; Borchardt, D.; Henze, Mogens

    2001-01-01

    Successful river water quality modelling requires the specification of an appropriate model structure and process formulation. Both must be related to the compartment structure of running water ecosystems including their longitudinal, vertical, and lateral zonation patterns. Furthermore...

  16. Determination of strontium in drinking water and consequences of radioactive elements present in drinking water for human health

    OpenAIRE

    Rajković Miloš B.; Stojanović Mirjana D.; Pantelić Gordana K.; Vuletić Vedrana V.

    2006-01-01

    In this paper the analysis of strontium and uranium content in drinking water has been done, indirectly, according to the scale which originates from drinking water in water-supply system of the city of Belgrade. Gamaspectrometric analysis showed the presence of free natural radionuclide in low activities. The activity of 90Sr in scale which is 0.72±0.11 Bq/kg was determined by radiochemical. Because of the small quantities of fur in the house heater this activity can be considered as irrelev...

  17. Water balance modelling of a uranium mill effluent management system

    Science.gov (United States)

    Plagnes, Valérie; Schmid, Brad; Mitchell, Brett; Judd-Henrey, Ian

    2017-06-01

    A water balance model was developed to forecast the management strategy of a uranium mill effluent system, located in northern Saskatchewan, Canada. Mining and milling operations, such as pit dewatering or treated effluent release, can potentially influence the hydrology and the water quality downstream of the operations. This study presents the methodology used to predict water volumes and water quality discharging downstream in surface water bodies. A compartment model representing the three subsequent lakes included in the management system was set up using the software GoldSim®. The water balance allows predicting lake volumes at the daily time step. A mass balance model developed for conservative elements was also developed and allows validating the proportions of inputs and outputs issued from the water balance model. This model was then used as predictive tool to evaluate the impact of different scenarios of effluents management on volumes and chemistry of surface water for short and longer time periods. An additional significant benefit of this model is that it can be used as an input for geochemical modelling to predict the concentrations of all constituents of concern in the receiving surface water.

  18. Water-Tree Modelling and Detection for Underground Cables

    Science.gov (United States)

    Chen, Qi

    is used to model water-tree in large system. Both empirical measurements and the mathematical model show that the impedance of early-stage water-tree is extremely large. As the result, traditional detection methods such Tan-Delta or Partial Discharge are not effective due to the excessively high accuracy requirement. A high-frequency pulse detection method is developed instead. The water-tree impedance is capacitive in nature and it can be reduced to manageable level by high-frequency inputs. The method is able to determine the location of early-stage water-tree in long-distance cables using economically feasible equipment. A pattern recognition method is developed to estimate the severity of water-tree using its pulse response from the high-frequency test method. The early-warning system for water-tree appearance is a tool developed to assist the practical implementation of the high-frequency pulse detection method. Although the equipment used by the detection method is economically feasible, it is still a specialized test and not designed for constant monitoring of the system. The test also place heavy stress on the cable and it is most effective when the cable is taken offline. As the result, utilities need a method to estimate the likelihood of water-tree presence before subjecting the cable to the specialized test. The early-warning system takes advantage of naturally occurring high-frequency events in the system and uses a deviation-comparison method to estimate the probability of water-tree presence on the cable. If the likelihood is high, then the utility can use the high-frequency pulse detection method to obtain accurate results. Specific pulse response patterns can be used to calculate the capacitance of water-tree. The calculated result, however, is subjected to margins of error due to limitations from the real system. There are both long-term and short-term methods to improve the accuracy. Computation algorithm improvement allows immediate improvement on

  19. Determination of Soil and Plant Water Balance and Its Critical Stages for Rainfed Wheat Using Crop Water Stress Index (CWSI

    Directory of Open Access Journals (Sweden)

    V. Feiziasl

    2014-12-01

    Full Text Available In order to determination of water stress threshold and dryland wheat genotypes water status in different nitrogen managements, this experiment was carried out in split split plot RCBD design in three replications in 2010-2011 cropping year. Treatments included: N application time (whole fertilization of N at planting time , and its split fertilization as 2/3 at planting time and 1/3 in early spring, N rates (0, 30, 60 and 90 kg ha-1 and 7 wheat genotypes. Also these genotypes were grown in supplemental irrigation condition for calculation of crop water stress index (CWSI parameters. Canopy temperature (Tc was measured in flowering and early milking stages. Crop water stress index (CWSI was calculated. A non-water stressed baseline (lower baseline were fitted as Tc-Ta=4.523-3.761×VPD; R2=0.92 and non-transpiring baseline (upper baseline determined 6 ºC for rainfed wheat genotypes. Water stress threshold was 0.4 and crossing of that occurred 8 days before heading stage. In water stress threshold boundary, was depleted 60 mm available water from 0 to 50 cm soil depth. There was negative significant relationship (p >0.01 between CWSI and grain yield in all treatments and different nitrogen rates. Nitrogen application reduced water stress and increased grain yield of rainfed wheat genotypes. Ohadi and Rasad genotypes showed highest resistance to water stress and high grain yield production for N30 in split and planting time application, respectively. Cereal4 and Rasad genotypes were suitable for N60 application in split and planting time application, respectively.

  20. Determination of the number of water molecules in the proton pathway of bacteriorhodopsin using neutron diffraction data.

    Science.gov (United States)

    Papadopoulos, Georgios; Hauss, Thomas

    2003-07-01

    It has been shown that water molecules participate in the proton pathway of bacteriorhodopsin. Large efforts have been made to determine with various biophysical methods the number of water molecules involved. Neutron diffraction H2O/D2O exchange experiments have been often used to reveal the position of water even with low-resolution diffraction data. With this technique, care must be taken with the limitations of the difference Fourier method which are commonly applied to analyze the data. In this paper we compare the results of the difference Fourier method applied to measured diffraction data (not presented here) and models with those from alternative methods introduced here: (1) a computer model calculation procedure to determine a label's scattering length density based on a comparison of intensity differences derived from models and intensity differences from our measurements; (2) a method based on the Parseval formula. Both alternative methods have been evaluated and tested using results of neutron diffraction experiments on purple membranes (Hauss et al. 1994). Our findings indicate that the difference Fourier method applied to low-resolution diffraction data can successfully determine the position of localized water molecules but underestimates their integrated scattering length density in the presence of labels in other positions. Furthermore, we present the results of neutron diffraction experiments on purple membranes performed to determine the number of water molecules in the projected area of the Schiff base at 86%, 75% and 57% relative humidity (r.h.). We found 19 +/- 2 exchangeable protons at 75% r.h., which means at least 8-9 water molecules are indispensable for normal pump function.

  1. Validation of Storm Water Management Model Storm Control Measures Modules

    Science.gov (United States)

    Simon, M. A.; Platz, M. C.

    2017-12-01

    EPA's Storm Water Management Model (SWMM) is a computational code heavily relied upon by industry for the simulation of wastewater and stormwater infrastructure performance. Many municipalities are relying on SWMM results to design multi-billion-dollar, multi-decade infrastructure upgrades. Since the 1970's, EPA and others have developed five major releases, the most recent ones containing storm control measures modules for green infrastructure. The main objective of this study was to quantify the accuracy with which SWMM v5.1.10 simulates the hydrologic activity of previously monitored low impact developments. Model performance was evaluated with a mathematical comparison of outflow hydrographs and total outflow volumes, using empirical data and a multi-event, multi-objective calibration method. The calibration methodology utilized PEST++ Version 3, a parameter estimation tool, which aided in the selection of unmeasured hydrologic parameters. From the validation study and sensitivity analysis, several model improvements were identified to advance SWMM LID Module performance for permeable pavements, infiltration units and green roofs, and these were performed and reported herein. Overall, it was determined that SWMM can successfully simulate low impact development controls given accurate model confirmation, parameter measurement, and model calibration.

  2. Water Quality Model of Florida Bay

    National Research Council Canada - National Science Library

    Cerco, Carl

    2000-01-01

    .... Application consists of calibrating the model to the two-year period 1996-1997, testing model sensitivity for the two year period, and simulating the ten-year period 1988-1997 to evaluate model long-term performance...

  3. Health Belief Model and Reasoned Action Theory in Predicting Water Saving Behaviors in Yazd, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Ghaneian

    2012-12-01

    Full Text Available Background: People's behaviors and intentions about healthy behaviors depend on their beliefs, values, and knowledge about the issue. Various models of health education are used in deter-mining predictors of different healthy behaviors but their efficacy in cultural behaviors, such as water saving behaviors, are not studied. The study was conducted to explain water saving beha-viors in Yazd, Iran on the basis of Health Belief Model and Reasoned Action Theory. Methods: The cross-sectional study used random cluster sampling to recruit 200 heads of households to collect the data. The survey questionnaire was tested for its content validity and reliability. Analysis of data included descriptive statistics, simple correlation, hierarchical multiple regression. Results: Simple correlations between water saving behaviors and Reasoned Action Theory and Health Belief Model constructs were statistically significant. Health Belief Model and Reasoned Action Theory constructs explained 20.80% and 8.40% of the variances in water saving beha-viors, respectively. Perceived barriers were the strongest Predictor. Additionally, there was a sta-tistically positive correlation between water saving behaviors and intention. Conclusion: In designing interventions aimed at water waste prevention, barriers of water saving behaviors should be addressed first, followed by people's attitude towards water saving. Health Belief Model constructs, with the exception of perceived severity and benefits, is more powerful than is Reasoned Action Theory in predicting water saving behavior and may be used as a framework for educational interventions aimed at improving water saving behaviors.

  4. Contemporary changes of water resources, water and land use in Central Asia based on observations and modeling.

    Science.gov (United States)

    Shiklomanov, A. I.; Prousevitch, A.; Sokolik, I. N.; Lammers, R. B.

    2015-12-01

    Water is a key agent in Central Asia ultimately determining human well-being, food security, and economic development. There are complex interplays among the natural and anthropogenic drivers effecting the regional hydrological processes and water availability. Analysis of the data combined from regional censuses and remote sensing shows a decline in areas of arable and irrigated lands and a significant decrease in availability of arable and irrigated lands per capita across all Central Asian countries since the middle of 1990thas the result of post-Soviet transformation processes. This change could lead to considerable deterioration in food security and human system sustainability. The change of political situation in the region has also resulted in the escalated problems of water demand between countries in international river basins. We applied the University of New Hampshire - Water Balance Model - Transport from Anthropogenic and Natural Systems (WBM-TrANS) to understand the consequences of changes in climate, water and land use on regional hydrological processes and water availability. The model accounts for sub-pixel land cover types, glacier and snow-pack accumulation/melt across sub-pixel elevation bands, anthropogenic water use (e.g. domestic and industrial consumption, and irrigation for most of existing crop types), hydro-infrastructure for inter-basin water transfer and reservoir/dam regulations. A suite of historical climate re-analysis and temporal extrapolation of MIRCA-2000 crop structure datasets has been used in WBM-TrANS for this project. A preliminary analysis of the model simulations over the last 30 years has shown significant spatial and temporal changes in hydrology and water availability for crops and human across the region due to climatic and anthropogenic causes. We found that regional water availability is mostly impacted by changes in extents and efficiency of crop filed irrigation, especially in highly arid areas of Central Asia

  5. Numerical and Qualitative Contrasts of Two Statistical Models for Water Quality Change in Tidal Waters

    Science.gov (United States)

    Two statistical approaches, weighted regression on time, discharge, and season and generalized additive models, have recently been used to evaluate water quality trends in estuaries. Both models have been used in similar contexts despite differences in statistical foundations and...

  6. Determination of 131I in water environment by β counting method

    International Nuclear Information System (INIS)

    Peng Anyin; Xiao Jingshui; Zhao Zhiwei; Zhou Peng; Zhao Li

    2012-01-01

    131 I is a very important nuclide applied in nuclear medicine;also it is one of the most important fission nuclides released from nuclear leak accidents,so accurate determination of 131 I is very important for environment protection. First, we described β counting method in detail for 131 I in different water environment; Second, we determined 131 I in ocean water and radioactive waste water by this method. The experimental results showed that 1) The full chemical recovery rates of iodine varied from 85.39% to 94.47% and the average is 90.90%; 2) The volume activities of 131 I in four parallel samples of ocean water were 0.673 4-0.735 1 Bq/m 3 , while in radioactive waste water, the volume activities of 131 I were 16.80-17.43 Bq/m 3 ; the results of parallel sample determination suggested that reproducibility was good for this method. (authors)

  7. [Rapid determination of COD in aquaculture water based on LS-SVM with ultraviolet/visible spectroscopy].

    Science.gov (United States)

    Liu, Xue-Mei; Zhang, Hai-Liang

    2014-10-01

    Ultraviolet/visible (UV/Vis) spectroscopy was studied for the rapid determination of chemical oxygen demand (COD), which was an indicator to measure the concentration of organic matter in aquaculture water. In order to reduce the influence of the absolute noises of the spectra, the extracted 135 absorbance spectra were preprocessed by Savitzky-Golay smoothing (SG), EMD, and wavelet transform (WT) methods. The preprocessed spectra were then used to select latent variables (LVs) by partial least squares (PLS) methods. Partial least squares (PLS) was used to build models with the full spectra, and back- propagation neural network (BPNN) and least square support vector machine (LS-SVM) were applied to build models with the selected LVs. The overall results showed that BPNN and LS-SVM models performed better than PLS models, and the LS-SVM models with LVs based on WT preprocessed spectra obtained the best results with the determination coefficient (r2) and RMSE being 0. 83 and 14. 78 mg · L(-1) for calibration set, and 0.82 and 14.82 mg · L(-1) for the prediction set respectively. The method showed the best performance in LS-SVM model. The results indicated that it was feasible to use UV/Vis with LVs which were obtained by PLS method, combined with LS-SVM calibration could be applied to the rapid and accurate determination of COD in aquaculture water. Moreover, this study laid the foundation for further implementation of online analysis of aquaculture water and rapid determination of other water quality parameters.

  8. Determination of Aluminium and Physicochemical Parameters in the Palm Oil Estates Water Supply at Johor, Malaysia

    Directory of Open Access Journals (Sweden)

    M. R. Siti Farizwana

    2010-01-01

    Full Text Available The study was to determine the concentration of aluminium (Al and study the physicochemical parameters (pH, total dissolved solids (TDS, turbidity, and residual chlorine in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S, the treatment plant outlet (TPO, and at the nearest houses (H1 and the furthest houses (H2 from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90. The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU. Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L. Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems.

  9. Determination of Aluminium and Physicochemical Parameters in the Palm Oil Estates Water Supply at Johor, Malaysia

    Science.gov (United States)

    Siti Farizwana, M. R.; Mazrura, S.; Zurahanim Fasha, A.; Ahmad Rohi, G.

    2010-01-01

    The study was to determine the concentration of aluminium (Al) and study the physicochemical parameters (pH, total dissolved solids (TDS), turbidity, and residual chlorine) in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S), the treatment plant outlet (TPO), and at the nearest houses (H1) and the furthest houses (H2) from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90). The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU). Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L). Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems. PMID:21461348

  10. Determination of aluminium and physicochemical parameters in the palm oil estates water supply at Johor, Malaysia.

    Science.gov (United States)

    Siti Farizwana, M R; Mazrura, S; Zurahanim Fasha, A; Ahmad Rohi, G

    2010-01-01

    The study was to determine the concentration of aluminium (Al) and study the physicochemical parameters (pH, total dissolved solids (TDS), turbidity, and residual chlorine) in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S), the treatment plant outlet (TPO), and at the nearest houses (H1) and the furthest houses (H2) from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90). The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU). Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L). Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems.

  11. Relationships between water table and model simulated ET

    Science.gov (United States)

    Prem B. Parajuli; Gretchen F. Sassenrath; Ying Ouyang

    2013-01-01

    This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km2) within the Yazoo River Basin...

  12. Model for predicting the quantity of water evaporated during oven ...

    African Journals Online (AJOL)

    Model for calculating the quantity of water that evaporated during oven drying of Otamiri clay has been derived. The model; j = exp ((In1/2.9206)18) showed that the quantity of water that evaporated during the drying process was dependent on the drying time, the evaporation surface being constant. It was found that the ...

  13. A review of mathematical programming models of irrigation water ...

    African Journals Online (AJOL)

    Crops modelled influence water values, but there is no apparent relationship between objective function specification and average value. Nor does the number of irrigation options seem to influence water value either. The policy implication is that while similar models for the same region produce consistent estimates, each ...

  14. TAPWAT: Definition structure and applications for modelling drinking water treatment

    NARCIS (Netherlands)

    Versteegh JFM; Gaalen FW van; Rietveld LC; Evers EG; Aldenberg TA; Cleij P; Technische Universiteit Delft; LWD

    2001-01-01

    The 'Tool for the Analysis of the Production of drinking WATer' (TAPWAT) model has been developed for describing drinking-water quality in integral studies in the context of the Environmental Policy Assessment of the RIVM. The model consists of modules that represent individual steps in a treatment

  15. A stochastic dynamic programming model for stream water quality ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    1. Introduction. River water quality management problems are characterized by various uncertainties at differ- ... model to achieve the maximum economic benefits without violating water quality standards. This model ..... for aquatic life, for example, would be a useful application of the methodology presented in the paper.

  16. The role of eutrophication models in water management

    NARCIS (Netherlands)

    Molen, van der D.

    1999-01-01

    In this thesis the role of eutrophication models in water management is analysed. The thesis consists of an extended introduction followed by five Appendices with papers describing different mathematical models dealing with eutrophication in surface waters. At first systems analysis is

  17. Modelling the economic tradeoffs between allocating water for crop ...

    African Journals Online (AJOL)

    2009-06-05

    Jun 5, 2009 ... typically evaluated with an optimisation model. Critical to the analysis is the modelling of the non-linear relationship between the increasing leaching requirement, resulting from soil water salinity, and final crop yield as affected by soil water salinity. Within a South African context, Armour and Viljoen (2002;.

  18. WATER QUALITY MODELING IN THE RIO CHONE ESTUARY

    Science.gov (United States)

    Water quality in the Rio Chone Estuary, a seasonally inverse, tropical estuary, in Ecuador was characterized by modeling the distribution of biochemical oxygen demand (BOD) and dissolved inorganic nitrogen (DIN) within the water column. These two variables are modeled using modif...

  19. Using stable isotopes to determine seasonal variations in water uptake of summer maize under different fertilization treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ying, E-mail: maying@igsnrr.ac.cn [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing (China); State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing (China); Song, Xianfang [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing (China)

    2016-04-15

    Fertilization and water both affect root water uptake in the nutrient and water cycle of the Soil-Plant-Atmosphere-Continuum (SPAC). In this study, dual stable isotopes (D and {sup 18}O) were used to determine seasonal variations in water uptake patterns of summer maize under different fertilization treatments in Beijing, China during 2013–2014. The contributions of soil water at different depths to water uptake were quantified by the MixSIAR Bayesian mixing model. Water uptake was mainly sourced from soil water in the 0–20 cm depth at the seeding (67.7%), jointing (60.5%), tasseling (47.5%), dough (41.4%), and harvest (43.9%) stages, and the 20–50 cm depth at the milk stage (32.8%). Different levels of fertilization application led to considerable differences in the proportional contribution of soil water at 0–20 cm (6.0–58.5%) and 20–50 cm (6.1–26.3%). There was little difference of contributions in the deep layers (50–200 cm) among treatments in 2013, whereas differences were observed in 50–90 cm at the milk stage and 50–200 cm at the dough stage during 2014. The main water uptake depth was concentrated in the upper soil layers (0–50 cm) during the wet season (2013), whereas a seasonal drought in 2014 promoted the contribution of soil water in deep layers. The contribution of soil water was significantly and positively correlated with the proportions of root length (r = 0.753, p < 0.01). The changes of soil water distribution were consistent with the seasonal variation in water uptake patterns. The present study identified water sources for summer maize under varying fertilization treatments and provided scientific implications for fertilization and irrigation management. - Highlights: • Dual stable isotopes and MixSIAR were coupled to quantify water uptake of maize. • Maize mainly used soil water in 20–50 cm at milk stage and 0–20 cm at other stages. • Fertilization treatments led to distinct water uptake pattern at 0–50 cm

  20. Using stable isotopes to determine seasonal variations in water uptake of summer maize under different fertilization treatments

    International Nuclear Information System (INIS)

    Ma, Ying; Song, Xianfang

    2016-01-01

    Fertilization and water both affect root water uptake in the nutrient and water cycle of the Soil-Plant-Atmosphere-Continuum (SPAC). In this study, dual stable isotopes (D and 18 O) were used to determine seasonal variations in water uptake patterns of summer maize under different fertilization treatments in Beijing, China during 2013–2014. The contributions of soil water at different depths to water uptake were quantified by the MixSIAR Bayesian mixing model. Water uptake was mainly sourced from soil water in the 0–20 cm depth at the seeding (67.7%), jointing (60.5%), tasseling (47.5%), dough (41.4%), and harvest (43.9%) stages, and the 20–50 cm depth at the milk stage (32.8%). Different levels of fertilization application led to considerable differences in the proportional contribution of soil water at 0–20 cm (6.0–58.5%) and 20–50 cm (6.1–26.3%). There was little difference of contributions in the deep layers (50–200 cm) among treatments in 2013, whereas differences were observed in 50–90 cm at the milk stage and 50–200 cm at the dough stage during 2014. The main water uptake depth was concentrated in the upper soil layers (0–50 cm) during the wet season (2013), whereas a seasonal drought in 2014 promoted the contribution of soil water in deep layers. The contribution of soil water was significantly and positively correlated with the proportions of root length (r = 0.753, p < 0.01). The changes of soil water distribution were consistent with the seasonal variation in water uptake patterns. The present study identified water sources for summer maize under varying fertilization treatments and provided scientific implications for fertilization and irrigation management. - Highlights: • Dual stable isotopes and MixSIAR were coupled to quantify water uptake of maize. • Maize mainly used soil water in 20–50 cm at milk stage and 0–20 cm at other stages. • Fertilization treatments led to distinct water uptake pattern at 0–50 cm depth.

  1. Chromatographic determination of the rate and extent of absorption of air pollutants by sea water

    International Nuclear Information System (INIS)

    Nikolakaki, S.; Vassilakos, C.; Katsanos, N.A.

    1994-01-01

    A simple chromatographic method is developed to determine the rate constant for expulsion of an air pollutant from water or its diffusion parameter in the liquid, the rate constant for chemical reaction of the pollutant with water, its mass transfer coefficient in the liquid, and the partition coefficient between liquid water and air. From these physicochemical parameters, the absorption rate by sea water and, therefore, the depletion rate of a polluting substance from the air can be calculated, together with the equilibrium state of this absorption. The method has been applied to nitrogen dioxide being absorbed by triple-distilled water and by sea water, at various temperatures. From the temperature variation of the reaction rate constant and of the partition coefficient, the activation energy for the reaction and the differential heat of solution were determined. (orig.)

  2. Comparing National Water Model Inundation Predictions with Hydrodynamic Modeling

    Science.gov (United States)

    Egbert, R. J.; Shastry, A.; Aristizabal, F.; Luo, C.

    2017-12-01

    The National Water Model (NWM) simulates the hydrologic cycle and produces streamflow forecasts, runoff, and other variables for 2.7 million reaches along the National Hydrography Dataset for the continental United States. NWM applies Muskingum-Cunge channel routing which is based on the continuity equation. However, the momentum equation also needs to be considered to obtain better estimates of streamflow and stage in rivers especially for applications such as flood inundation mapping. Simulation Program for River NeTworks (SPRNT) is a fully dynamic model for large scale river networks that solves the full nonlinear Saint-Venant equations for 1D flow and stage height in river channel networks with non-uniform bathymetry. For the current work, the steady-state version of the SPRNT model was leveraged. An evaluation on SPRNT's and NWM's abilities to predict inundation was conducted for the record flood of Hurricane Matthew in October 2016 along the Neuse River in North Carolina. This event was known to have been influenced by backwater effects from the Hurricane's storm surge. Retrospective NWM discharge predictions were converted to stage using synthetic rating curves. The stages from both models were utilized to produce flood inundation maps using the Height Above Nearest Drainage (HAND) method which uses the local relative heights to provide a spatial representation of inundation depths. In order to validate the inundation produced by the models, Sentinel-1A synthetic aperture radar data in the VV and VH polarizations along with auxiliary data was used to produce a reference inundation map. A preliminary, binary comparison of the inundation maps to the reference, limited to the five HUC-12 areas of Goldsboro, NC, yielded that the flood inundation accuracies for NWM and SPRNT were 74.68% and 78.37%, respectively. The differences for all the relevant test statistics including accuracy, true positive rate, true negative rate, and positive predictive value were found

  3. Immobilized enzymes in organic media: Determinants of water dependence. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, S.; DeFilippi, I.; Bedwell, B.; Zemel, H.

    1993-06-01

    The overall goals of our DOE-funded project are to investigate the critical factors that limit commercial scale applications of enzymes in organic solvents, and to scale-up a process for the production of a precursor to optically active polymers. Initially, we are attempting to quantify the effect of intra-particle dynamics on overall process performance. This involves examination of coupled enzyme kinetics, solubility, wetting and mass transfer effects toward support selection, reactor design/scheme and scale-up. For this study we selected a pure enzyme preparation: a lipase from C. Viscosum. The enzyme has been immobilized on celite and the catalyzed interesterification kinetics in petroleum ether and its dependence on water concentration have been determined. The results are very similar to those obtained in the past with crude Pseudomonas Cepacia. So far we have formulated a model for tripalmitin depletion, based on taking mass balances. A parameter has been included which accounts for the effect of water content inside the celite particle. The initial rate of depletion can be described by Monod-like kinetics. Our experimental data, at 0.003 mg H{sub 2}O per cm{sup 2}, fit a model and parameters presented in the literature. Because of the small size of the support, the relatively low amount of water, and the low reaction rates, our calculations predict that the lipase system at 0.003-0.01 mgH{sub 2}O/cm{sup 2} is reaction rate limited. The mass transfer through the organic phase within the support particles is not limiting. In order to test the dense particles with varying diameter but the same total surface area have been tested and compared to the porous celite.

  4. Optimal Decision-making Model of Integrated Water Resources Management - A Case of Hsinchu Water Resources Management

    Science.gov (United States)

    Wang, S. Y.; Ho, C. C.; Chang, L. C.

    2017-12-01

    The public use water in Hsinchu are mainly supplied from Baoshan Reservoir, Second Baoshan Reservoir, Yongheshan Reservoir and Longen Weir. However, the increasing water demand, caused by development of the Hsinchu Science and Industrial Park, results in supply stable water getting more difficult. For stabilize water supply in Hsinchu, the study applies long-term and short-term plans to fulfill the water shortage. Developing an efficient methodology to define a cost-effective action portfolio is an important task. Hence, the study develops a novel decision model, the Stochastic Programming with Recourse Decision Model (SPRDM), to estimate a cost-effective action portfolio. The first-stage of SPRDM determine the long-term action portfolio and the portfolio accompany recourse information (the probability for water shortage event). The second-stage of SPRDM optimize the cost-effective action portfolio in response to the recourse information. In order to consider the uncertainty of reservoir sediment and demand growth, the study set 9 scenarios comprise optimistic, most likely, and pessimistic reservoir sediment and demand growth. The results show the optimal action portfolio consist of FengTain Lake and Panlon Weir, Hsinchu Desalination Plant, Domestic and Industrial Water long-term plans, and Emergency Backup Well, Irrigation Water Transference, Preliminary Water Rationing, Advanced Water Rationing and Water Transport from Other Districts short-term plans. The minimum expected cost of optimal action portfolio is NT$1.1002 billion. The results can be used as a reference for decision making because the results have considered the uncertainty of varied hydrology, reservoir sediment, and water demand growth.

  5. Development and validation of a drinking water temperature model in domestic drinking water supply systems

    OpenAIRE

    Zlatanovic, Ljiljana; Moerman, Andreas; Hoek, van der, Jan Peter; Vreeburg, Jan; Blokker, Mirjam

    2017-01-01

    Domestic drinking water supply systems (DDWSs) are the final step in the delivery of drinking water to consumers. Temperature is one of the rate-controlling parameters for many chemical and microbiological processes and is, therefore, considered as a surrogate parameter for water quality processes. In this study, a mathematical model is presented that predicts temperature dynamics of the drinking water in DDWSs. A full-scale DDWS resembling a conventional system was built and run according to...

  6. Determination of water environment standards based on water quality criteria in China: Limitations and feasibilities.

    Science.gov (United States)

    Wang, Tieyu; Zhou, Yunqiao; Bi, Cencen; Lu, Yonglong; He, Guizhen; Giesy, John P

    2017-07-01

    There is a need to formulate water environment standards (WESs) from the current water quality criteria (WQC) in China. To this end, we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs, and three limitations to formulating WESs in China were identified. After analyzing the feasibility factors including economic development, scientific support capability and environmental policies, we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system. Thus, we proposed a framework for transformation from WQC to WESs in China. The framework consists of three parts, including responsibilities, processes and policies. The responsibilities include research authorization, development of guidelines, and collection of information, at both national and local levels; the processes include four steps and an impact factor system to establish water quality standards; and the policies include seven specific proposals. Copyright © 2016. Published by Elsevier B.V.

  7. How processing digital elevation models can affect simulated water budgets

    Science.gov (United States)

    Kuniansky, E.L.; Lowery, M.A.; Campbell, B.G.

    2009-01-01

    For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation of the water table used in model cells is estimated via a two-step process. First, a regression equation is developed using existing land and water table elevations from wells in the area. This equation is then used to predict the water table surface for each model cell using land surface elevation available from digital elevation models (DEM). Two methods of processing DEM for estimating the land surface for each cell are commonly used (value nearest the cell centroid or mean value in the cell). This article demonstrates how these two methods of DEM processing can affect the simulated water budget. For the example presented, approximately 20% more total flow through the aquifer system is simulated if the centroid value rather than the mean value is used. This is due to the one-third greater average ground water gradients associated with the centroid value than the mean value. The results will vary depending on the particular model area topography and cell size. The use of the mean DEM value in each model cell will result in a more conservative water budget and is more appropriate because the model cell water table value should be representative of the entire cell area, not the centroid of the model cell.

  8. Headspace Volumetric Karl Fischer Titration for the Determination of Water Content in Finished Tobacco Products

    OpenAIRE

    Aydin N; Chardonnens F; Rotach M

    2014-01-01

    Because many physicochemical properties of tobacco are highly sensitive to its moisture content, the determination of water level is an important parameter for tobacco characterization. A headspace volumetric Karl Fischer titration (HS-V-KFT) method is presented for the quantification of water content in different finished tobacco materials. The parameters affecting the extraction of water from the tobacco materials were the sample size and the oven temperature which have been optimized. The ...

  9. Determination of malachite green in trout tissue and effluent water from fish farms

    OpenAIRE

    Abbas Khodabakhshi; Mohammad Mehdi Amin

    2012-01-01

    Aims: The objective of this study was to determine the malachite green (MG) concentration in trout tissue and the effluent water of fish farms, at one of the largest trout fishery industries in Iran. Materiels and Methods: Twelve samples of water and fish tissue were collected from fish farms placed at the upstream ends of two large rivers in the study area. The samples, after extraction, were analyzed with liquid chromatography-mass spectrometry (LC-MS). The effluent water samples were ...

  10. Preliminary results of an algorithm to determine the total absorption coefficient of water

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Talaulikar, M.; Desa, E.J.; Lotlikar, A.

    An algorithm to determine the spectral total absorption coefficient of water is presented. The algorithm is based on the Gershun’s equation of alfa = micro KE. The spectral underwater average cosine, micro and vertical attenuation...

  11. An Agent Based Model of Household Water Use

    Directory of Open Access Journals (Sweden)

    Clinton J. Andrews

    2013-07-01

    Full Text Available Households consume a significant fraction of total potable water production. Strategies to improve the efficiency of water use tend to emphasize technological interventions to reduce or shift water demand. Behavioral water use reduction strategies can also play an important role, but a flexible framework for exploring the “what-ifs” has not been available. This paper introduces such a framework, presenting an agent-based model of household water-consuming behavior. The model simulates hourly water-using activities of household members within a rich technological and behavioral context, calibrated with appropriate data. Illustrative experiments compare the resulting water usage of U.S. and Dutch households and their associated water-using technologies, different household types (singles, families with children, and retired couples, different water metering regimes, and educational campaigns. All else equal, Dutch and metered households use less water. Retired households use more water because they are more often at home. Water-saving educational campaigns are effective for the part of the population that is receptive. Important interactions among these factors, both technological and behavioral, highlight the value of this framework for integrated analysis of the human-technology-water system.

  12. Mathematical model for water quality impact assessment and its computer application in coal mine water

    International Nuclear Information System (INIS)

    Sundararajan, M.; Chakraborty, M.K.; Gupta, J.P.; Saxena, N.C.; Dhar, B.B.

    1994-01-01

    This paper presents a mathematical model to assess the Water Quality Impact in coal mine or in river system by accurate and rational method. Algorithm, flowchart and computer programme have been developed upon this model to assess the quality of coal mine water. 3 refs., 2 figs., 2 tabs

  13. A model to assess water tariffs as part of water demand management

    African Journals Online (AJOL)

    ... that was developed for municipalities to calculate the predicted change in water use and the associated income. The model takes into account variation in price elasticity per tariff block. The effectiveness of the model as a planning tool is illustrated through an appropriate example. Keywords: water demand management, ...

  14. Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate Scale Water Quality Model

    Energy Technology Data Exchange (ETDEWEB)

    Khangaonkar, Tarang; Sackmann, Brandon S.; Long, Wen; Mohamedali, Teizeen; Roberts, Mindy

    2012-10-01

    The Salish Sea, including Puget Sound, is a large estuarine system bounded by over seven thousand miles of complex shorelines, consists of several subbasins and many large inlets with distinct properties of their own. Pacific Ocean water enters Puget Sound through the Strait of Juan de Fuca at depth over the Admiralty Inlet sill. Ocean water mixed with freshwater discharges from runoff, rivers, and wastewater outfalls exits Puget Sound through the brackish surface outflow layer. Nutrient pollution is considered one of the largest threats to Puget Sound. There is considerable interest in understanding the effect of nutrient loads on the water quality and ecological health of Puget Sound in particular and the Salish Sea as a whole. The Washington State Department of Ecology (Ecology) contracted with Pacific Northwest National Laboratory (PNNL) to develop a coupled hydrodynamic and water quality model. The water quality model simulates algae growth, dissolved oxygen, (DO) and nutrient dynamics in Puget Sound to inform potential Puget Sound-wide nutrient management strategies. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or control human impacts to DO levels in the sensitive areas. The project did not include any additional data collection but instead relied on currently available information. This report describes model development effort conducted during the period 2009 to 2012 under a U.S. Environmental Protection Agency (EPA) cooperative agreement with PNNL, Ecology, and the University of Washington awarded under the National Estuary Program

  15. Determination of water diffusion coefficient by gamma radiation and thermal shock

    International Nuclear Information System (INIS)

    Crausse, P.; Lemarchand, D.

    1985-01-01

    Mass transfer coefficient of water in a porous material (baked clay) is determined by gamma ray attenuation (from a Cs135 source) and thermal shock. Water content is found higher by thermal shock, difference obtained between the two methods is discussed. 7 refs [fr

  16. Water contentwater of determination of cationic polystyrene sulfonate resins by infrared spectrophotometry

    International Nuclear Information System (INIS)

    Noki, V.

    1987-01-01

    A method of the determination of water content in polystyrene sulfonate ion-exchange resins in the presence of alkaline earth counter-ions by I.R. spectrophotometry is proposed. This method does not hold in the case of transition metal due to the formation of coordinated complexes with water molecules.

  17. Temperature effects in soil water content determined with time domain reflectometry

    NARCIS (Netherlands)

    Halbertsma, J.; Elsen, van den E.; Bohl, H.; Skierucha, W.

    1996-01-01

    The relative permittivity of water decreases with increasing temperature. Therefore, it is likely that the soil water content determined with time domain reflectometry is influenced by temperature. This study showed that significant temperature effects may occur. The magnitude of these effects is a

  18. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  19. Optimization and comparison of three different methods for the determination of Rn-222 in water

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, P.; Ingrao, G. [ENEA CRE, Casaccia AMB-BIO, Roma (Italy); Cavaioli, M.; Notaro, M.; Torri, G.; Vasselli, R. [ANPA, National Environmental Protection Agency, DISP ARA MET, Roma (Italy); Mancini, C. [Nuclear Engineering Department, University `La Sapienza, Roma (Italy); Santaroni, P. [National Institute of Nutrition, Roma (Italy)

    1995-10-19

    Three different systems for the determination of radon in water have been examined: liquid scintillation counting (LSC), degassification followed by Lucas cell counting (LCC) and gamma counting (GC). Particular care has been devoted to the sampling methodologies of the water. Comparative results for several environmental samples are given. A critical evaluation is also given on the basis of the final aim of the measurements.

  20. Optimization and comparison of three different methods for the determination of Rn-222 in water

    International Nuclear Information System (INIS)

    Belloni, P.; Ingrao, G.; Cavaioli, M.; Notaro, M.; Torri, G.; Vasselli, R.; Mancini, C.; Santaroni, P.

    1995-01-01

    Three different systems for the determination of radon in water have been examined: liquid scintillation counting (LSC), degassification followed by Lucas cell counting (LCC) and gamma counting (GC). Particular care has been devoted to the sampling methodologies of the water. Comparative results for several environmental samples are given. A critical evaluation is also given on the basis of the final aim of the measurements

  1. Dynamic modelling of water demand, water availability and adaptation strategies for power plants to global change

    International Nuclear Information System (INIS)

    Koch, Hagen; Voegele, Stefan

    2009-01-01

    According to the latest IPCC reports, the frequency of hot and dry periods will increase in many regions of the world in the future. For power plant operators, the increasing possibility of water shortages is an important challenge that they have to face. Shortages of electricity due to water shortages could have an influence on industries as well as on private households. Climate change impact analyses must analyse the climate effects on power plants and possible adaptation strategies for the power generation sector. Power plants have lifetimes of several decades. Their water demand changes with climate parameters in the short- and medium-term. In the long-term, the water demand will change as old units are phased out and new generating units appear in their place. In this paper, we describe the integration of functions for the calculation of the water demand of power plants into a water resources management model. Also included are both short-term reactive and long-term planned adaptation. This integration allows us to simulate the interconnection between the water demand of power plants and water resources management, i.e. water availability. Economic evaluation functions for water shortages are also integrated into the water resources management model. This coupled model enables us to analyse scenarios of socio-economic and climate change, as well as the effects of water management actions. (author)

  2. Modeling Determinants of Discriminatory Attitude towards HIV/AIDS ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    Modeling Determinants of Discriminatory Attitude towards HIV/AIDS. Patients in Zambia: A Generalized Additive Mixed Model. Oluwayemisi Oyeronke ALABA. Department of Statistics, University of Ibadan, Nigeria and Department of Statistics, University of South Africa, oluwayemisioyeronke@yahoo.com. Abstract. The 2007 ...

  3. 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

  4. Improving Water Resources Management on Global and Region Scales - Evaluating Strategies for Water Futures with the IIASA's Community Water Model

    Science.gov (United States)

    Burek, P.; Kahil, T.; Satoh, Y.; Greve, P.; Byers, E.; Langan, S.; Wada, Y.

    2017-12-01

    Half of the planet's population is severely impacted by severe water issues including absent or unreliable water supply, sanitation, poor water quality, unmitigated floods and droughts, and degraded water environments. In recent years, global water security has been highlighted not only by the science community but also by business leaders as one of the greatest threats to sustainable human development for different generations. How can we ensure the well-being of people and ecosystems with limited water, technology and financial resources? To evaluate this, IIASA's Water Futures and Solutions Initiative (WFaS) is identifying a portfolios of robust and cost-effective options across different economic sectors including agriculture, energy, manufacturing, households, and environment and ecosystems. Options to increase water supply and accessibility are evaluated together with water demand management and water governance options. To test these solution-portfolios in order to obtain a clear picture of the opportunities but also of the risks and the trade-offs we have developed the Community Water Model (CWATM) which joins IIASA's integrated assessment modeling framework, coupling hydrology with hydro-economics (ECHO model), energy (MESSAGE model) and land use (GLOBIOM model). CWATM has been developed to work flexibly with varying spatial resolutions from global to regional levels. The model is open source and community-driven to promote our work amongst the wider water and other science community worldwide, with flexibility to link to other models and integrate newly developed modules such as water quality. In order to identify the solution portfolios, we present a global hotspots assessment of water-related risks with the ability to zoom in at regional scale using the example of the Lake Victoria basin in E. Africa. We show how socio-economic and climate change will alter spatial patterns of the hydrological cycle and have regional impacts on water availability. At

  5. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    Science.gov (United States)

    Wada, Y.; van Beek, L. P. H.; Bierkens, M. F. P.

    2011-12-01

    During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate variability but also growing water demand, desalinated water use and non-renewable groundwater abstraction over the period 1960-2001 at a spatial resolution of 0.5°. Agricultural water demand is estimated based on past extents of irrigated areas and livestock densities. We approximate past economic development based on GDP, energy and household consumption and electricity production, which are subsequently used together with population numbers to estimate industrial and domestic water demand. Climate variability is expressed by simulated blue water availability defined by freshwater in rivers, lakes, wetlands and reservoirs by means of the global hydrological model PCR-GLOBWB. We thus define blue water stress by comparing blue water availability with corresponding net total blue water demand by means of the commonly used, Water Scarcity Index. The results show a drastic increase in the global population living under water-stressed conditions (i.e. moderate to high water stress) due to growing water demand, primarily for irrigation, which has more than doubled from 1708/818 to 3708/1832 km3 yr-1 (gross/net) over the period 1960-2000. We estimate that 800 million people or 27% of the global population were living under water-stressed conditions for 1960. This number is eventually increased to 2.6 billion or 43% for 2000. Our results indicate that increased water demand is a decisive factor for heightened water stress in various regions such as India and North China, enhancing the intensity of water stress up to 200%, while climate variability is often a main determinant of extreme events. However, our results also suggest that in several emerging and developing economies

  6. Development of the heat and mass transfer model for the study of the temperature traces water droplets in a flame

    Directory of Open Access Journals (Sweden)

    Antonov Dmitry

    2017-01-01

    Full Text Available The heat and mass transfer model is developed with using Ansys Fluent. The typical temperature of gases in the trace of water droplets is determined (initial temperature of gases 1170 К. Several types for the location of water droplets are studied: two successive water droplets; two parallel water droplets; five water droplets in checkerboard order. The hypothesis about gas temperature reduction in the trace of a moving liquid is confirmed.

  7. Development of the heat and mass transfer model for the study of the temperature traces water droplets in a flame

    OpenAIRE

    Antonov Dmitry; Kostomarov Petr

    2017-01-01

    The heat and mass transfer model is developed with using Ansys Fluent. The typical temperature of gases in the trace of water droplets is determined (initial temperature of gases 1170 К). Several types for the location of water droplets are studied: two successive water droplets; two parallel water droplets; five water droplets in checkerboard order. The hypothesis about gas temperature reduction in the trace of a moving liquid is confirmed.

  8. Oscillatory water sorption test for determining water uptake behavior in bread crust

    NARCIS (Netherlands)

    Nieuwenhuijzen, N.H. van; Tromp, R.H.; Hamer, R.J.; Vliet, T. van

    2007-01-01

    In this work, water sorption kinetics of bread crust are described using an oscillatory sorption test in combination with a Langmuir type equation. Both kinetic and thermodynamic information could be obtained at the same time. An advantage of applying a Langmuir type equation for a quantitative

  9. Automatic Relevance Determination for multi-way models

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai

    2009-01-01

    Estimating the adequate number of components is an important yet difficult problem in multi-way modelling. We demonstrate how a Bayesian framework for model selection based on Automatic Relevance Determination (ARD) can be adapted to the Tucker and CP models. By assigning priors for the model...... parameters and learning the hyperparameters of these priors the method is able to turn off excess components and simplify the core structure at a computational cost of fitting the conventional Tucker/CP model. To investigate the impact of the choice of priors we based the ARD on both Laplace and Gaussian...

  10. Multisample conversion of water to hydrogen by zinc for stable isotope determination

    Science.gov (United States)

    Kendall, C.; Coplen, T.B.

    1985-01-01

    Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

  11. A review of hydrological/water-quality models

    Directory of Open Access Journals (Sweden)

    Liangliang GAO,Daoliang LI

    2014-12-01

    Full Text Available Water quality models are important in predicting the changes in surface water quality for environmental management. A range of water quality models are wildly used, but every model has its advantages and limitations for specific situations. The aim of this review is to provide a guide to researcher for selecting a suitable water quality model. Eight well known water quality models were selected for this review: SWAT, WASP, QUALs, MIKE 11, HSPF, CE-QUAL-W2, ELCOM-CAEDYM and EFDC. Each model is described according to its intended use, development, simulation elements, basic principles and applicability (e.g., for rivers, lakes, and reservoirs and estuaries. Currently, the most important trends for future model development are: (1 combination models─individual models cannot completely solve the complex situations so combined models are needed to obtain the most appropriate results, (2 application of artificial intelligence and mechanistic models combined with non-mechanistic models will provide more accurate results because of the realistic parameters derived from non-mechanistic models, and (3 integration with remote sensing, geographical information and global position systems (3S ─3S can solve problems requiring large amounts of data.

  12. A methodology to support multidisciplinary model-based water management

    NARCIS (Netherlands)

    Scholten, H.; Kassahun, A.; Refsgaard, J.C.; Kargas, Th.; Gavardinas, C.; Beulens, A.J.M.

    2007-01-01

    Quality assurance in model based water management is needed because of some frequently perceived shortcomings, e.g. a lack of mutual understanding between modelling team members, malpractice and a tendency of modellers to oversell model capabilities. Initiatives to support quality assurance focus on

  13. Thermodynamic Model for the Ammonia-Water System

    DEFF Research Database (Denmark)

    Thomsen, Kaj; Rasmussen, Peter

    2000-01-01

    The ammonia-water system is described by the Extended UNIQUAC model, which is an electrolyte model, formed by combining the original UNIQUAC model, the Debye-Hückel law and the Soave-Redlich-Kwong equation of state. The model is limited to temperatures below the critical temperature of ammonia. V...

  14. Concentration and determination of trace organic pollutants in water. [Phenols; organics; halomethanes

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.C.Y.

    1976-10-01

    A method was developed for determining phenols in natural water, treated drinking water, and wastewater. They are determined by selective sorption on a macroreticular anion-exchange resin, elution with acetone-water, concentration by evaporation after extraction with methylene chloride, and measurement by gas chromatography. Techniques are given for preventing phenol loss. Common inorganic ions and many organic substances cause no interference; neutral organics that are retained by the resin can be removed by a methanol wash. The method gives accurate results for phenol, alkyl- and chloro-substituted phenols in the ppB to ppM range. Volatile compounds, as well as less volatile gas chromatographable compounds can also be determined. Resin purification, sorption columns preparation, thermal desorptions, the mini-sampler, method for analysis of real water for organics and development of analytical method are presented. Finally, a rapid method was developed for concentrating and determining halomethanes in drinking water. The halomethanes are determined by sorption on mini-samplers of macroreticular resin. The halomethanes sorbed on resin are eluted with two milliliters of methanol. Halomethanes are separated on a Tenax-GC column and determined by electron capture gas chromatography. Storage of halomethanes on the mini-sampler was studied. Real water samples were analyzed. (DLC)

  15. DRAINMOD-GIS: a lumped parameter watershed scale drainage and water quality model

    Science.gov (United States)

    G.P. Fernandez; G.M. Chescheir; R.W. Skaggs; D.M. Amatya

    2006-01-01

    A watershed scale lumped parameter hydrology and water quality model that includes an uncertainty analysis component was developed and tested on a lower coastal plain watershed in North Carolina. Uncertainty analysis was used to determine the impacts of uncertainty in field and network parameters of the model on the predicted outflows and nitrate-nitrogen loads at the...

  16. A Budyko-type Model for Human Water Consumption

    Science.gov (United States)

    Lei, X.; Zhao, J.; Wang, D.; Sivapalan, M.

    2017-12-01

    With the expansion of human water footprint, water crisis is no longer only a conflict or competition for water between different economic sectors, but also increasingly between human and the environment. In order to describe the emergent dynamics and patterns of the interaction, a theoretical framework that encapsulates the physical and societal controls impacting human water consumption is needed. In traditional hydrology, Budyko-type models are simple but efficient descriptions of vegetation-mediated hydrologic cycle in catchments, i.e., the partitioning of mean annual precipitation into runoff and evapotranspiration. Plant water consumption plays a crucial role in the process. Hypothesized similarities between human-water and vegetation-water interactions, including water demand, constraints and system functioning, give the idea of corresponding Budyko-type framework for human water consumption at the catchment scale. Analogous to variables of Budyko-type models for hydrologic cycle, water demand, water consumption, environmental water use and available water are corresponding to potential evaporation, actual evaporation, runoff and precipitation respectively. Human water consumption data, economic and hydro-meteorological data for 51 human-impacted catchments and 10 major river basins in China are assembled to look for the existence of a Budyko-type relationship for human water consumption, and to seek explanations for the spread in the observed relationship. Guided by this, a Budyko-type analytical model is derived based on application of an optimality principle, that of maximum water benefit. The model derived has the same functional form and mathematical features as those that apply for the original Budyko model. Parameters of the new Budyko-type model for human consumption are linked to economic and social factors. The results of this paper suggest that the functioning of both social and hydrologic subsystems within catchment systems can be explored within

  17. The use of stable isotopes in quantitative determinations of exogenous water and added ethanol in wines

    Science.gov (United States)

    Magdas, D. A.; Moldovan, Z.; Cristea, G.

    2012-02-01

    The application of oxygen isotope ratios analysis to wine water according to EU regulation no. 822/97 to determine wine's origin and also, the possible water addition to wines, gained great importance in wines authenticity control. In the natural cycle of water isotopic fractionation, during water evaporation process, the water vapors are depleted in heavy isotopes. On the other hand inside the plants take place an isotope enrichment of heavy stable isotopes of water compared with meteoric water due to photosynthesis and plants transpiration. This process makes possible the detection of exogenous water from wines 18O/16O ratios. Carbon isotopic ratios were used to estimate the supplementary addition of ethanol obtained from C4 plants (sugar cane or corn). This work presents the way in which the isotopic fingerprints (δ13C and δ18O) were used to determine the content of exogenous water from wines and the added supplementary ethanol coming from C4 plants. By using this method, the calculated values obtained for the degree of wine adulteration were in a good agreement with the real exogenous percent of water and ethanol from investigated samples.

  18. DETERMINATION OF ORGANOCHLORINE PESTICIDES IN DRINKING WATERS SAMPLED FROM CLUJ AND HUNEDOARA COUNTIES

    Directory of Open Access Journals (Sweden)

    MARIA-ELISABETA LOVÁSZ

    2011-03-01

    Full Text Available Determination of organochlorine pesticides in drinking waterssampled from Cluj and Hunedoara counties. Pesticides are found scattered indifferent environmental factors (water, air, soil wherefrom they are drawn off byvegetal and animal organisms. Water pollution by pesticides results from the plantprotection products industry and also from massive application of these resourcesin agriculture and other branches of economy. Pesticides can reach surface wateralong with dripping waters and by infiltration may reach the groundwater layers,organochlorine pesticides are most often found in the water sources (dieldrin,endrin, DDT, aldrin, lindane, heptachlor, etc. due to their increased persistence inthe external environment. This study followed up the determination oforganochlorine pesticides in 14 drinking water samples collected from the outputof water treatment plants in Cluj and Hunedoara counties that process surfacewater and deep-water sources. For identification of organochlorine pesticides, thegas chromatographic method after liquid-liquid extraction was used, by a gascromatograph Shimadzu GC 2010 with detector ECD (Electron CaptureDetection. There were not detected higher values than the method detection limit(0.01 μg/l in the drinking water samples collected and analyzed for both totalorganochlorine pesticides and components, which were well below the maximumconcentration admitted by Law 452/2002 regarding drinking water quality. Resultsare correlated with the sanitary protection areas for water sources and with the useof agricultural lands in the area. The solution to reduce risk of pesticides use isecological agriculture , which gains increasingly more ground in Romania too.

  19. A computerized coal-water slurry transportation model

    Energy Technology Data Exchange (ETDEWEB)

    Ljubicic, B.R.; Trostad, B. [Univ. of North Dakota, Grand Forks, ND (United States); Bukurov, Z.; Cvijanovic, P. [Univ. of Novi Sad (Yugoslavia)

    1995-12-01

    Coal-water fuel (CWF) technology has been developed to the point where full-scale commercialization is just a matter of gaining sufficient market confidence in the price stability of alternate fossil fuels. In order to generalize alternative fuel cost estimates for the desired combinations of processing and/or transportation, a great deal of flexibility is required owing to the understood lack of precision in many of the newly emerging coal technologies. Previously, decisions regarding the sequential and spatial arrangement of the various process steps were made strictly on the basis of experience, simplified analysis, and intuition. Over the last decade, computer modeling has progressed from empirically based correlation to that of intricate mechanistic analysis. Nomograms, charts, tables, and many simple rules of thumb have been made obsolete by the availability of complex computer models. Given the ability to view results graphically in real or near real time, the engineer can immediately verify, from a practical standpoint, whether the initial assumptions and inputs were indeed valid. If the feasibility of a project is being determined in the context of a lack of specific data, the ability to provide a dynamic software-based solution is crucial. Furthermore, the resulting model can be used to establish preliminary operating procedures, test control logic, and train plant/process operators. Presented in this paper is a computerized model capable of estimating the delivered cost of CWF. The model uses coal-specific values, process and transport requirements, terrain factors, and input costs to determine the final operating configuration, bill of materials, and, ultimately, the capital, operating, and unit costs.

  20. Calibrating an optimal condition model for solar water disinfection in peri-urban household water treatment in Kampala, Uganda.

    Science.gov (United States)

    Okurut, Kenan; Wozei, Eleanor; Kulabako, Robinah; Nabasirye, Lillian; Kinobe, Joel

    2013-03-01

    In low income settlements where the quality of drinking water is highly contaminated due to poor hygienic practices at community and household levels, there is need for appropriate, simple, affordable and environmentally sustainable household water treatment technology. Solar water disinfection (SODIS) that utilizes both the thermal and ultra-violet effect of solar radiation to disinfect water can be used to treat small quantities of water at household level to improve its bacteriological quality for drinking purposes. This study investigated the efficacy of the SODIS treatment method in Uganda and determined the optimal condition for effective disinfection. Results of raw water samples from the study area showed deterioration in bacteriological quality of water moved from source to the household; from 3 to 36 cfu/100 mL for tap water and 75 to 126 cfu/100 mL for spring water, using thermotolerant coliforms (TTCs) as indicator microorganisms. SODIS experiments showed over 99.9% inactivation of TTCs in 6 h of exposure, with a threshold temperature of 39.5 ± 0.7°C at about 12:00 noon, in the sun during a clear sunny day. A mathematical optimal condition model for effective disinfection has been calibrated to predict the decline of the number of viable microorganisms over time.

  1. Global modelling of river water quality under climate change

    Science.gov (United States)

    van Vliet, Michelle T. H.; Franssen, Wietse H. P.; Yearsley, John R.

    2017-04-01

    Climate change will pose challenges on the quality of freshwater resources for human use and ecosystems for instance by changing the dilution capacity and by affecting the rate of chemical processes in rivers. Here we assess the impacts of climate change and induced streamflow changes on a selection of water quality parameters for river basins globally. We used the Variable Infiltration Capacity (VIC) model and a newly developed global water quality module for salinity, temperature, dissolved oxygen and biochemical oxygen demand. The modelling framework was validated using observed records of streamflow, water temperature, chloride, electrical conductivity, dissolved oxygen and biochemical oxygen demand for 1981-2010. VIC and the water quality module were then forced with an ensemble of bias-corrected General Circulation Model (GCM) output for the representative concentration pathways RCP2.6 and RCP8.5 to study water quality trends and identify critical regions (hotspots) of water quality deterioration for the 21st century.

  2. Application of HEC-RAS water quality model to estimate contaminant spreading in small stream

    International Nuclear Information System (INIS)

    Halaj, Peter; Bárek, Viliam; Halajová, Anna Báreková; Halajová, Denisa

    2013-01-01

    The paper presents study of some aspects of HEC-RAS water quality model connected to simulation of contaminant transport in small stream. Authors mainly focused on one of the key tasks in process of pollutant transport modelling in streams - determination of the dispersion characteristics represented by longitudinal dispersion coefficient D. Different theoretical and empirical formulas have been proposed for D value determination and they have revealed that the coefficient is variable parameter that depends on hydraulic and morphometric characteristics of the stream reaches. Authors compare the results of several methods of coefficient D assessment, assuming experimental data obtained by tracer studies and compare them with results optimized by HEC-RAS water quality model. The analyses of tracer study and computation outputs allow us to outline the important aspects of longitudinal dispersion coefficient set up in process of the HEC-RAS model use. Key words: longitudinal dispersion coefficient, HEC-RAS, water quality modeling

  3. Modeling of Microwave Reflection from the Surface of Water Basins with Spills of Water-Cut Oil

    Science.gov (United States)

    Krotikov, V. D.; Pelushenko, S. A.; Rakut', I. V.; Savelyev, V. Yu.

    2015-06-01

    We consider specific features of reflection of microwaves from the surface of a water basin for the two-layer model of oil spills, which are determined by a water-cut-oil film. Within the spill model, the dielectric properties of water were allowed for in accordance with the Debye theory, and the dielectric properties of the water-cut oil, in accordance with the theory developed for binary systems. The data about variations in the values of reflection coefficients depending on the frequency, viewing angle, thickness of the oil film, and moisture content in the film are obtained. The dependences of reflection coefficients on the film thickness are determined for various values of volume content of the water fraction in oil. Complex values of the dielectric permittivity of oil-water emulsions with preset volume moisture content are found. Describing the obtained dependences of the complex dielectric permittivity of the emulsion on the volume moisture content requires application of asymmetrical formulas for the mixture of polar and nonpolar fluids.

  4. Use Of Stable Isotope To Determine Time of Red River Water Recharging To Production Groundwater Wells In Hanoi

    International Nuclear Information System (INIS)

    Trinh Van Giap; Dang Anh Minh

    2011-01-01

    Stable isotope O-18 and lump parameter models has been used to determine time of Red River water recharging to some production groundwater wells at Yen Phu station in Ha noi. Composition of stable isotope O-18 in Red River water changed on time in a year has been used as a tracer with lump parameter models to study flow of groundwater. Composition of stable isotope O-18 in production groundwater wells was measured on months in a year and the fitting of measured data and calculation data with selected flow models was carried out by lumped parameter models. The results of fitting shows resident time or time of Red River water recharging to production groundwater wells. At 4 production groundwater wells of Yen Phu station selected in this study, the time of Red River water recharging to wells H26 and H29 is following 3.5 months and 11 months. Composition of stable isotope O-18 at wells H12 and H27 do not change on time, but proportions of Red River water in production groundwater at these wells were calculated of following 99% and 97%. (author)

  5. Revised Parameters for the AMOEBA Polarizable Atomic Multipole Water Model.

    Science.gov (United States)

    Laury, Marie L; Wang, Lee-Ping; Pande, Vijay S; Head-Gordon, Teresa; Ponder, Jay W

    2015-07-23

    A set of improved parameters for the AMOEBA polarizable atomic multipole water model is developed. An automated procedure, ForceBalance, is used to adjust model parameters to enforce agreement with ab initio-derived results for water clusters and experimental data for a variety of liquid phase properties across a broad temperature range. The values reported here for the new AMOEBA14 water model represent a substantial improvement over the previous AMOEBA03 model. The AMOEBA14 model accurately predicts the temperature of maximum density and qualitatively matches the experimental density curve across temperatures from 249 to 373 K. Excellent agreement is observed for the AMOEBA14 model in comparison to experimental properties as a function of temperature, including the second virial coefficient, enthalpy of vaporization, isothermal compressibility, thermal expansion coefficient, and dielectric constant. The viscosity, self-diffusion constant, and surface tension are also well reproduced. In comparison to high-level ab initio results for clusters of 2-20 water molecules, the AMOEBA14 model yields results similar to AMOEBA03 and the direct polarization iAMOEBA models. With advances in computing power, calibration data, and optimization techniques, we recommend the use of the AMOEBA14 water model for future studies employing a polarizable water model.

  6. Fuzzy logic applied to the modeling of water dynamics in an Oxisol in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Antônio Cláudio Marques Afonso

    2014-04-01

    Full Text Available Modeling of water movement in non-saturated soil usually requires a large number of parameters and variables, such as initial soil water content, saturated water content and saturated hydraulic conductivity, which can be assessed relatively easily. Dimensional flow of water in the soil is usually modeled by a nonlinear partial differential equation, known as the Richards equation. Since this equation cannot be solved analytically in certain cases, one way to approach its solution is by numerical algorithms. The success of numerical models in describing the dynamics of water in the soil is closely related to the accuracy with which the water-physical parameters are determined. That has been a big challenge in the use of numerical models because these parameters are generally difficult to determine since they present great spatial variability in the soil. Therefore, it is necessary to develop and use methods that properly incorporate the uncertainties inherent to water displacement in soils. In this paper, a model based on fuzzy logic is used as an alternative to describe water flow in the vadose zone. This fuzzy model was developed to simulate the displacement of water in a non-vegetated crop soil during the period called the emergency phase. The principle of this model consists of a Mamdani fuzzy rule-based system in which the rules are based on the moisture content of adjacent soil layers. The performances of the results modeled by the fuzzy system were evaluated by the evolution of moisture profiles over time as compared to those obtained in the field. The results obtained through use of the fuzzy model provided satisfactory reproduction of soil moisture profiles.

  7. Wireless model predictive control: Application to water-level system

    Directory of Open Access Journals (Sweden)

    Ramdane Hedjar

    2016-04-01

    Full Text Available This article deals with wireless model predictive control of a water-level control system. The objective of the model predictive control algorithm is to constrain the control signal inside saturation limits and maintain the water level around the desired level. Linear modeling of any nonlinear plant leads to parameter uncertainties and non-modeled dynamics in the linearized mathematical model. These uncertainties induce a steady-state error in the output response of the water level. To eliminate this steady-state error and increase the robustness of the control algorithm, an integral action is included in the closed loop. To control the water-level system remotely, the communication between the controller and the process is performed using radio channel. To validate the proposed scheme, simulation and real-time implementation of the algorithm have been conducted, and the results show the effectiveness of wireless model predictive control with integral action.

  8. Development of an Integrated Water and Wind Erosion Model

    Science.gov (United States)

    Flanagan, D. C.; Ascough, J. C.; Wagner, L. E.; Geter, W. F.

    2006-12-01

    Prediction technologies for soil erosion by the forces of wind or water have largely been developed independently from one another, especially within the United States. Much of this has been due to the initial creation of equations and models which were empirical in nature (i.e., Universal Soil Loss Equation, Wind Erosion Equation) and based upon separate water erosion or wind erosion plot and field measurements. Additionally, institutional organizations in place typically divided research efforts and funding to unique wind or water erosion research and modeling projects. However, during the past 20 years computer technologies and erosion modeling have progressed to the point where it is now possible to merge physical process-based computer simulation models into an integrated water and wind erosion prediction system. In a physically- based model, many of the processes which must be simulated for wind and water erosion computations are the same, e.g., climate, water balance, runoff, plant growth, etc. Model components which specifically deal with the wind or water detachment, transport and deposition processes are those that must differ, as well as any necessary parameterization of input variables (e.g., adjusted soil erodibilities, critical shear stresses, etc.) for those components. This presentation describes current efforts towards development of a combined wind and water erosion model, based in part upon technologies present in the Water Erosion Prediction Project (WEPP) and the Wind Erosion Prediction System (WEPS) models. Initial efforts during the past two years have resulted in modular modeling components that allow for prediction of infiltration, surface runoff, and water erosion at a hillslope scale within an Object Modeling System. Additional components currently in development include wind detachment at a single field point, continuous water balance, and unified plant growth. Challenges in this project are many, and include adequate field

  9. Determination of strontium in drinking water and consequences of radioactive elements present in drinking water for human health

    International Nuclear Information System (INIS)

    Rajkovic, M.B.; Stojanovic, M.D.; Pantelic, G.K.; Vuletic, V.V.

    2006-01-01

    In this paper the analysis of strontium and uranium content in drinking water has been done, indirectly, according to the scale which originates from drinking water in water-supply system of the city of Belgrade. Gamaspectrometric analysis showed the presence of free natural radionuclide in low activities. The activity of 90Sr in scale which is 0.72±0.11 Bq/kg was determined by radiochemical. Because of the small quantities of fur in the house heater this activity can be considered as irrelevant, but the accumulation of scale can have intensified influence. In this paper, the analysis of effects of the radioactive isotopes presence (first of all 238U and 235U) in drinking water on human health has been done

  10. Decay of Bacteroidales genetic markers in relation to traditional fecal indicators for water quality modeling of drinking water sources.

    Science.gov (United States)

    Sokolova, Ekaterina; Aström, Johan; Pettersson, Thomas J R; Bergstedt, Olof; Hermansson, Malte

    2012-01-17

    The implementation of microbial fecal source tracking (MST) methods in drinking water management is limited by the lack of knowledge on the transport and decay of host-specific genetic markers in water sources. To address these limitations, the decay and transport of human (BacH) and ruminant (BacR) fecal Bacteroidales 16S rRNA genetic markers in a drinking water source (Lake Rådasjön in Sweden) were simulated using a microbiological model coupled to a three-dimensional hydrodynamic model. The microbiological model was calibrated using data from outdoor microcosm trials performed in March, August, and November 2010 to determine the decay of BacH and BacR markers in relation to traditional fecal indicators. The microcosm trials indicated that the persistence of BacH and BacR in the microcosms was not significantly different from the persistence of traditional fecal indicators. The modeling of BacH and BacR transport within the lake illustrated that the highest levels of genetic markers at the raw water intakes were associated with human fecal sources (on-site sewers and emergency sewer overflow). This novel modeling approach improves the interpretation of MST data, especially when fecal pollution from the same host group is released into the water source from different sites in the catchment.

  11. Modeling the electrochemistry of the primary circuits of light water reactors

    International Nuclear Information System (INIS)

    Bertuch, A.; Macdonald, D.D.; Pang, J.; Kriksunov, L.; Arioka, K.

    1994-01-01

    To model the corrosion behaviors of the heat transport circuits of light water reactors, a mixed potential model (NTM) has been developed and applied to both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Using the data generated by the GE/UKEA-Harwell radiolysis model, electrochemical potentials (ECPs) have been calculated for the heat transport circuits of eight BWRs operating under hydrogen water chemistry (HWC). By modeling the corrosion behaviors of these reactors, the effectiveness of HWC at limiting IGSCC and IASCC can be determined. For simulating PWR primary circuits, a chemical-radiolysis model (developed by the authors) was used to generate input parameters for the MPM. Corrosion potentials of Type 304 and 316 SSs in PWR primary environments were calculated using the NTM and were found to be in good agreement with the corrosion potentials measured in the laboratory for simulated PWR primary environments

  12. Water uptake profile in a model ion-exchange membrane: Conditions for water-rich channels

    Science.gov (United States)

    Herbst, Daniel C.; Witten, Thomas A.; Tsai, Tsung-Han; Coughlin, E. Bryan; Maes, Ashley M.; Herring, Andrew M.

    2015-03-01

    Ionic conductivity in a polymeric fuel cell requires water uptake. Previous theoretical studies of water uptake used idealized parameters. We report a parameter-free prediction of the water-swelling behavior of a model fuel cell membrane. The model polymers, poly(methyl-butylene)-block-poly(vinylbenzyl-trimethylamine), form lamellar domains that absorb water in humid air. We use the Scheutjens-Fleer methodology to predict the resulting change in lamellar structure and compare with x-ray scattering. The results suggest locally uniform water distributions. However, under conditions where a PVBTMA and water mixture phase-separate, the two phases arrange into stripes with a dilute stripe sandwiched between two concentrated stripes. A small amount of water enhances conductivity most when it is partitioned into such channels, improving fuel-cell performance.

  13. Determination of trace elements in bottled water in Greece by instrumental and radiochemical neutron activation analyses

    International Nuclear Information System (INIS)

    Soupioni, M.J.; Symeopoulos, B.D.; Papaefthymiou, H.V.

    2006-01-01

    Four different bottled water brands sold in Greece in the winter of 2001-2002 were analyzed for a wide range of chemical elements, using neutron activation analysis (NAA). The elements Na and Br were determined instrumentally (INAA), whereas the other metals and trace elements radiochemically (RNAA). The results indicated that the mean level of all the elements determined in the samples were well within the European Union (EU) directive on drinking water and accomplish the drinking water standards of the World Health Organisation (WHO) as well as of the Food and Drug Administration (FDA). (author)

  14. Novel method for the determination of water content and higher heating value of pyrolysis

    OpenAIRE

    Mohammed, Isah; Kabir, Feroz Kazi; Abakr, Yousif; Yusuf, Suzana; Razzaque, Abdur

    2015-01-01

    This research provides a novel approach for the determination of water content and higher heating value of pyrolysis oil. Pyrolysis oil from Napier grass was used in this study. Water content was determined with pH adjustment using a Karl Fisher titration unit. An equation for actual water in the oil was developed and used, and the results were compared with the traditional Karl Fisher method. The oil was found to have between 42 and 64% moisture under the same pyrolysis condition depending o...

  15. A holistic water depth simulation model for small ponds

    Science.gov (United States)

    Ali, Shakir; Ghosh, Narayan C.; Mishra, P. K.; Singh, R. K.

    2015-10-01

    Estimation of time varying water depth and time to empty of a pond is prerequisite for comprehensive and coordinated planning of water resource for its effective utilization. A holistic water depth simulation (HWDS) and time to empty (TE) model for small, shallow ephemeral ponds have been derived by employing the generalized model based on the Green-Ampt equation in the basic water balance equation. The HWDS model includes time varying rainfall, runoff, surface water evaporation, outflow and advancement of wetting front length as external inputs. The TE model includes two external inputs; surface water evaporation and advancement of wetting front length. Both the models also consider saturated hydraulic conductivity and fillable porosity of the pond's bed material as their parameters. The solution of the HWDS model involved numerical iteration in successive time intervals. The HWDS model has successfully evaluated with 3 years of field data from two small ponds located within a watershed in a semi-arid region in western India. The HWDS model simulated time varying water depth in the ponds with high accuracy as shown by correlation coefficient (R2 ⩾ 0.9765), index of agreement (d ⩾ 0.9878), root mean square errors (RMSE ⩽ 0.20 m) and percent bias (PB ⩽ 6.23%) for the pooled data sets of the measured and simulated water depth. The statistical F and t-tests also confirmed the reliability of the HWDS model at probability level, p ⩽ 0.0001. The response of the TE model showed its ability to estimate the time to empty the ponds. An additional field calibration and validation of the HWDS and TE models with observed field data in varied hydro-climatic conditions could be conducted to increase the applicability and credibility of the models.

  16. Determination of velocity and flow direction of ground water by using nuclear techniques

    International Nuclear Information System (INIS)

    Santos Ferreira, L. dos.

    1976-06-01

    The dynamics of water in an aquifer with the purpose of determining the filtration velocity and the direction of groundwater flow with radioactive tracers was studied. Field equipment for the purposes of the study was built in the Laboratory of Tracers in Hydrology in collaboration with the Institute of Nuclear Engineering (IEN/NUCLEBRAS). The equipment was designed to minimize the possible vertical flows, loss and molecular diffusion of the tracer out of the studied region. The performance of the nuclear detectors and the constructional details of the field equipament were examined. The selection of the radioactive tracers was made taking into account its availibility and radiation facilities, cost of the inactive material and their physical and chemical properties. The tracers used were 82 Br and 198 Au. The results are discussed with the help of auxiliary informations such as plots of water levels in time and space, profiles and grain analysis. In order to obtain a physical explanation of the results, a qualitative model of the flow in the aquifer is also presented. (Author) [pt

  17. Electrodialytic desalination of brackish water: determination of optimal experimental parameters using full factorial design

    Science.gov (United States)

    Gmar, Soumaya; Helali, Nawel; Boubakri, Ali; Sayadi, Ilhem Ben Salah; Tlili, Mohamed; Amor, Mohamed Ben

    2017-12-01

    The aim of this work is to study the desalination of brackish water by electrodialysis (ED). A two level-three factor (23) full factorial design methodology was used to investigate the influence of different physicochemical parameters on the demineralization rate (DR) and the specific power consumption (SPC). Statistical design determines factors which have the important effects on ED performance and studies all interactions between the considered parameters. Three significant factors were used including applied potential, salt concentration and flow rate. The experimental results and statistical analysis show that applied potential and salt concentration are the main effect for DR as well as for SPC. The effect of interaction between applied potential and salt concentration was observed for SPC. A maximum value of 82.24% was obtained for DR under optimum conditions and the best value of SPC obtained was 5.64 Wh L-1. Empirical regression models were also obtained and used to predict the DR and the SPC profiles with satisfactory results. The process was applied for the treatment of real brackish water using the optimal parameters.

  18. Human-water interface in hydrological modelling

    NARCIS (Netherlands)

    Wada, Yoshihide; Bierkens, Marc F.P.; Roo, de Ad; Dirmeyer, Paul A.; Famiglietti, James S.; Hanasaki, Naota; Konar, Megan; Liu, Junguo; Schmied, Hannes Möller; Oki, Taikan; Pokhrel, Yadu; Sivapalan, Murugesu; Troy, Tara J.; Dijk, Van Albert I.J.M.; Emmerik, Van Tim; Huijgevoort, Van Marjolein H.J.; Lanen, van Henny A.J.; Vörösmarty, Charles J.; Wanders, Niko; Wheater, Howard

    2017-01-01

    Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial

  19. Determination of total alpha index in samples of see water by coprecipitation method

    International Nuclear Information System (INIS)

    Suarez-Navarro, J.A.; Pujol, L.; Pozuelo, M.; Pablo, A. de

    1998-01-01

    An environmental radiological monitoring network in the Spanish sea waters was set up by CEDEX in 1993. Water radioactivity is determined quarterly in eleven sampling points along the Spanish coast. The gross alpha activity is one of the parameters to be determined. The usual method for monitoring the gross alpha activity includes sample evaporation to dryness on a disk and counting using ZnS(Ag) scintillation detector. Nevertheless, the gross alpha activity determination in saline waters, such as sea waters, is troublesome, because mass attenuation is high and a very small of water is needed (0.2 ml). The coprecipitation method allows to analyze 500 ml water samples, so the detection limit is reduced and sensitivity is improved. In this work, the coprecipitation method was used to determine the gross alpha activity in the radiological network of the Spanish coast sea waters during 1996 and 1997. Gross alpha activity was very homogenous. It averaged 0.0844±0.0086 Bq.1''1 and ranged from 0.062 to 0.102 Bq.1''1. In collaboration with CIEMAT a set of samples was analyzed, they averaged 0.0689±0.0074 Bq.1''1 and ranged from 0.056 to 0.082 Bq.1''1. (Author) 5 refs

  20. Models of Fate and Transport of Pollutants in Surface Waters

    Science.gov (United States)

    Okome, Gloria Eloho

    2013-01-01

    There is the need to answer very crucial questions of "what happens to pollutants in surface waters?" This question must be answered to determine the factors controlling fate and transport of chemicals and their evolutionary state in surface waters. Monitoring and experimental methods are used in establishing the environmental states.…