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Water Line (water + line)
Kinds of Water Line Selected AbstractsStudy of mineral water resources from the Eastern Carpathians using stable isotopes,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2009Dana A. Magdas The Eastern Carpathians contain many mineral water springs that feed famous Romanian health resorts such as Borsec, Biborteni and Vatra Dornei. These waters have been used for their different therapeutic effects. In this work, mineral and spring waters from these Romanian regions were investigated by means of chemical and isotopic (,D and ,18O) analyses in order to understand the recharge mechanisms and also to determine their origins. Most of the investigated springs are of meteoric origin, having the average deuterium content of the local meteoric water. The higher 18O content with respect to the Meteoric Water Line (MWL) indicated an exchange reaction with crystalline igneous rocks at depth and with other rocks that the water encounters on its journey back to the surface. Copyright © 2009 John Wiley & Sons, Ltd. [source] Chemical and Isotopic Constraints on the Origin of Wadi El-Tarfa Ground Water, Eastern Desert, EgyptGROUND WATER, Issue 5 2000M. Sultan We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River. Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L. Values of ,D and ,18O range from -10 to +34 %o and -2 to +5.2 %o, respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about ,D = -15 %o on a plot of 8D versus ,18O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River water. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium unite), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation. [source] ,Distribution of oxygen-18 and deuterium in river waters across the United StatesHYDROLOGICAL PROCESSES, Issue 7 2001Carol Kendall Abstract Reconstruction of continental palaeoclimate and palaeohydrology is currently hampered by limited information about isotopic patterns in the modern hydrologic cycle. To remedy this situation and to provide baseline data for other isotope hydrology studies, more than 4800, depth- and width-integrated, stream samples from 391 selected sites within the USGS National Stream Quality Accounting Network (NASQAN) and Hydrologic Benchmark Network (HBN) were analysed for ,18O and ,2H (http://water.usgs.gov/pubs/ofr/ofr00-160/pdf/ofr00-160.pdf). Each site was sampled bimonthly or quarterly for 2·5 to 3 years between 1984 and 1987. The ability of this dataset to serve as a proxy for the isotopic composition of modern precipitation in the USA is supported by the excellent agreement between the river dataset and the isotopic compositions of adjacent precipitation monitoring sites, the strong spatial coherence of the distributions of ,18O and ,2H, the good correlations of the isotopic compositions with climatic parameters, and the good agreement between the ,national' meteoric water line (MWL) generated from unweighted analyses of samples from the 48 contiguous states of ,2H=8·11,18O+8·99 (r2=0·98) and the unweighted global MWL of sites from the Global Network for Isotopes in Precipitation (GNIP) of the International Atomic Energy Agency and the World Meteorological Organization (WMO) of ,2H=8·17,18O+10·35. The national MWL is composed of water samples that arise in diverse local conditions where the local meteoric water lines (LMWLs) usually have much lower slopes. Adjacent sites often have similar LMWLs, allowing the datasets to be combined into regional MWLs. The slopes of regional MWLs probably reflect the humidity of the local air mass, which imparts a distinctive evaporative isotopic signature to rainfall and hence to stream samples. Deuterium excess values range from 6 to 15, in the eastern half of the USA, along the northwest coast and on the Colorado Plateau. In the rest of the USA, these values range from ,2 to 6,, with strong spatial correlations with regional aridity. The river samples have successfully integrated the spatial variability in the meteorological cycle and provide the best available dataset on the spatial distributions of ,18O and ,2H values of meteoric waters in the USA. Published in 2001 by John Wiley & Sons, Ltd. [source] Stable water isotope simulation in different reservoirs of Manaus, Brazil, by Community Land Model incorporating stable isotopic effectINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 5 2009Xin-Ping Zhang Abstract The daily and monthly variations of stable water isotopes in different reservoirs at Manaus, Brazil, are simulated and inter-compared in an equilibrium year, using the Community Land Model (CLM) involving the stable isotopic effects as a diagnostic tool for an in-depth understanding of the hydrometeorological processes. On the daily scale, the ,18O in precipitation, vapour and surface runoff have clear seasonality, with marked negative correlations with the corresponding water amount. However, the ,18O in surface dew displays marked positive correlation with dew amount. On the diurnal time scale, the ,18O in precipitation displays an unclear diurnal variation and an unmarked correlation with the precipitation amount. However, the ,18O in vapour keeps consistency with specific humidity. On the monthly time scale, the ,18O in precipitation and surface runoff displays distinct bimodal seasonality, with two maxima in January and in July, and two minima in April and in October; Vapor displays a similar bimodal pattern, two maxima appear in January and August, and two minima in April and November. The amount effect simulated on the monthly time scale has consistency with the actual survey result at the Manaus station, from 1965 to 1990, set up by International Atomic Energy Agency (IAEA)/World Meteorological Organization (WMO). In addition, the slope (7.49) and the intercept (6.25) of the simulated meteoric water line (MWL) are all smaller than those of the actual mean MWL. However, compared with the annual MWL, the simulated MWL lies within the variation range of actual MWLs. Copyright © 2008 Royal Meteorological Society [source] Survival of Salmonella in bathrooms and toilets in domestic homes following salmonellosisJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2000J. Barker The survival and environmental spread of Salmonella bacteria from domestic toilets was examined in homes, where a family member had recently suffered an attack of salmonellosis. In four out of six households tested, Salmonella bacteria persisted in the biofilm material found under the recess of the toilet bowl rim which was difficult to remove with household toilet cleaners. In two homes Salmonella bacteria became incorporated into the scaly biofilm adhering to the toilet bowl surface below the water line. Salmonella enteritidis persisted in one toilet for 4 weeks after the diarrhoea had stopped, despite the use of cleaning fluids. Salmonellas were not isolated from normally dry areas such as, the toilet seat, the flush handle and door handle. Toilet seeding experiments were set up with Salmonella enteritidis PT4 to mimic environmental conditions associated with acute diarrhoea. Flushing the toilet resulted in contamination of the toilet seat and the toilet seat lid. In one out of three seedings, Salmonella bacteria were also isolated from an air sample taken immediately after flushing, indicating that airborne spread of the organism could contaminate surfaces in the bathroom. In the seeded toilet Salmonella bacteria were isolated from the biofilm in the toilet bowl below the waterline for up to 50 d after seeding, and also on one occasion from the bowl water. The results suggest that during diarrhoeal illness, there is considerable risk of spread of Salmonella infection to other family members via the environment, including contaminated hands and surfaces in the toilet area. [source] Species richness,standing crop relationship in stream bryophyte communities: patterns across multiple scalesJOURNAL OF ECOLOGY, Issue 1 2001Risto Virtanen Summary 1,We tested for a unimodal (,hump-backed') relationship between species richness and standing crop at various spatial scales in stream bryophyte communities. Bryophyte species and their biomasses were determined from 20 to 25 quadrats in eight river and six stream sites in northern Finland. 2,Regression analyses revealed a quadratic relationship between richness and biomass in only two of the river sites and a positive correlation in one other. A quadratic relationship was detected in three stream sites and richness increased linearly with biomass in another. 3,We also tested for the hump-shaped pattern across individual stream boulders, representing an elevational gradient from continuously submerged to permanently dry conditions, with an intermediate zone with fluctuating water level. 4,Species richness-standing crop relationship conformed to the hump-backed model only when samples from all three microhabitats were included in the analysis. A significant positive correlation occurred in the exposed low biomass end of the gradient which is characterized by semi-aquatic species, whereas the relationship tended to be negative in permanently submerged areas with high biomass of large canopy-forming species. Quadrats close to the water level had intermediate standing crop and highest species richness. 5,Species dominant at either end of the gradient appeared unable to monopolize space in the intermediate zone where disturbances (e.g. scouring by ice) detach mosses from the substratum, creating vacant gaps for colonization. The unimodal relationship between richness and biomass is likely to occur only in streams that contain large boulders protruding above the water line, thus providing scope for community diversification along very short vertical distances. [source] The hydrological response of heavy clay grassland soils to rainfall in south-west England using ,2H,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2010Steven J. Granger Stable isotopes of water have been previously used in catchment studies to separate rain-event water from pre-event groundwater. However, there are a lack of studies at the smaller scale looking at the separation of event water from pre-event water. This is particularly relevant for heavy clay soil systems through which the movement of water is uncertain but is thought to be rainwater-dominated. The data presented here were collected at a rural site in the south-west of England. The historic rainfall at the site was isotopically varied but similar to the global meteoric water line, with annual weighted means of ,37, for ,2H and ,5.7, for ,18O and with no seasonal variation. Drainage was sampled from the inter-flow (surface runoff,+,lateral through-flow) and drain-flow (55,cm deep mole drains) pathways of two 1,ha lysimeters during two rainfall events, which had ,2H values of ,68, and ,92,, respectively. The ,2H values of the lysimeter drainage water suggest that there was no contribution of event water during the first, small discharge (Q) event; however, the second larger event did show isotopic variation in ,2H values negatively related to Q indicating that rainwater was contributing to Q. A hydrograph separation indicated that only 49,58% of the inter-flow and 18,25% of the drain-flow consisted of event water. This was surprising given that these soil types are considered retentive of soil water. More work is needed on heavy clay soils to understand better the nature of water movement from these systems. Copyright © 2010 John Wiley & Sons, Ltd. [source] Lecithin requirements of juvenile Australian red claw crayfish Cherax quadricarinatusAQUACULTURE NUTRITION, Issue 4 2003K.R. Thompson Abstract Australian red claw crayfish Cherax quadricarinatus is considered a popular crustacean species in several countries around the world because of its large size potential and resemblance to high-priced American lobsters. However, little is currently known of the nutrient requirements and practical diet formulations for red claw. Lecithin has been shown to be required in the diets of several crustacean species, but there are no reports of dietary lecithin requirements for red claw. A 10-week feeding trial was conducted in an effort to evaluate lecithin requirements for juvenile red claw. Juvenile red claw (mean individual weight of 1.6 ± 0.91 g) were individually stocked in a recirculating system at random into 80 plastic-mesh culture units, each containing its own individual water line. There were 20 red claw per treatment (diet). Water was recirculated through biological and mechanical filters. Four semi-purified diets were formulated to contain increasing percentages of commercial soya bean lecithin (0, 0.5, 1.0 and 2.0%). Diet ingredients included solvent-extracted menhaden fish meal (FM), casein, dextrin, wheat flour, pellet binder, vitamin and mineral mix, cod liver oil, and corn oil. Semi-purified diets were formulated to contain 40% protein using casein, menhaden FM, and wheat flour as protein sources. After 10 weeks, no significant differences (P > 0.05) were found in final weight, percentage weight gain and specific growth rate with average values of 13.0 g, 934%, and 3.14% day,1, respectively. Percentage survival was high during the 10-week period (100, 95, 100 and 95%) as only two individuals died during the study; one of these, because of an escape from the culture unit. There was also no significant differences (P > 0.05) in percentage moisture, protein, fat and ash in whole-body red claw carcasses (wet-weight basis) among any treatment (diet) and averaged 77.1, 12.6, 1.3 and 6.2%, respectively. Based upon the present study, these results indicate that a diet containing 5% cod liver oil and 1% corn oil, and having no supplemental lecithin, may be sufficient for growth and survival of juvenile red claw crayfish. [source] Oxygen and Hydrogen Isotopes of Waters in the Ordos Basin, China: Implications for Recharge of Groundwater in the North of Cretaceous Groundwater BasinACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2009Yuncheng YANG Abstract: Hundreds of precipitation samples collected from meteorological stations in the Ordos Basin from January 1988 to December 2005 were used to set up a local meteoric water line and to calculate weighted average isotopic compositions of modern precipitation. Oxygen and hydrogen isotopes, with averages of ,7.8, and ,53.0, for ,18O and ,D, respectively, are depleted in winter and rich in spring, and gradually decrease in summer and fall, illustrating that the seasonal effect is considerable. They also show that the isotopic difference between south portion and north portion of the Ordos Basin are not obvious, and the isotope in the middle portion is normally depleted. The isotope compositions of 32 samples collected from shallow groundwater (less than a depth of 150 m) in desert plateau range from ,10.6, to ,6.0, with an average of ,8.4, for ,18O and from ,85, to ,46, with an average of ,63, for ,D. Most of them are identical with modern precipitation. The isotope compositions of 22 middle and deep groundwaters (greater than a depth of 275 m) fall in ranges from ,11.6, to ,8.8, with an average of ,10.2, for ,18O and from ,89, to ,63, with an average of ,76, for ,D. The average values are significantly less than those of modern precipitation, illustrating that the middle and deep groundwaters were recharged at comparatively lower air temperatures. Primary analysis of 14C shows that the recharge of the middle and deep groundwaters started at late Pleistocene. The isotopes of 13 lake water samples collected from eight lakes define a local evaporation trend, with a relatively flat slope of 3.77, and show that the lake waters were mainly fed by modern precipitation and shallow groundwater. [source] ,Distribution of oxygen-18 and deuterium in river waters across the United StatesHYDROLOGICAL PROCESSES, Issue 7 2001Carol Kendall Abstract Reconstruction of continental palaeoclimate and palaeohydrology is currently hampered by limited information about isotopic patterns in the modern hydrologic cycle. To remedy this situation and to provide baseline data for other isotope hydrology studies, more than 4800, depth- and width-integrated, stream samples from 391 selected sites within the USGS National Stream Quality Accounting Network (NASQAN) and Hydrologic Benchmark Network (HBN) were analysed for ,18O and ,2H (http://water.usgs.gov/pubs/ofr/ofr00-160/pdf/ofr00-160.pdf). Each site was sampled bimonthly or quarterly for 2·5 to 3 years between 1984 and 1987. The ability of this dataset to serve as a proxy for the isotopic composition of modern precipitation in the USA is supported by the excellent agreement between the river dataset and the isotopic compositions of adjacent precipitation monitoring sites, the strong spatial coherence of the distributions of ,18O and ,2H, the good correlations of the isotopic compositions with climatic parameters, and the good agreement between the ,national' meteoric water line (MWL) generated from unweighted analyses of samples from the 48 contiguous states of ,2H=8·11,18O+8·99 (r2=0·98) and the unweighted global MWL of sites from the Global Network for Isotopes in Precipitation (GNIP) of the International Atomic Energy Agency and the World Meteorological Organization (WMO) of ,2H=8·17,18O+10·35. The national MWL is composed of water samples that arise in diverse local conditions where the local meteoric water lines (LMWLs) usually have much lower slopes. Adjacent sites often have similar LMWLs, allowing the datasets to be combined into regional MWLs. The slopes of regional MWLs probably reflect the humidity of the local air mass, which imparts a distinctive evaporative isotopic signature to rainfall and hence to stream samples. Deuterium excess values range from 6 to 15, in the eastern half of the USA, along the northwest coast and on the Colorado Plateau. In the rest of the USA, these values range from ,2 to 6,, with strong spatial correlations with regional aridity. The river samples have successfully integrated the spatial variability in the meteorological cycle and provide the best available dataset on the spatial distributions of ,18O and ,2H values of meteoric waters in the USA. Published in 2001 by John Wiley & Sons, Ltd. [source] Automated concentration and recovery of micro-organisms from drinking water using dead-end ultrafiltrationJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2008E.A. Kearns Abstract Aims:, Concentration of pathogens diluted in large volumes of water is necessary for their detection. An automated concentration system placed online in drinking water distribution systems would facilitate detection and mitigate the risk to public health. Methods and Results:, A prototype concentrator based on dead-end hollow fibre ultrafiltration was used to concentrate Bacillus atrophaeus spores directly from tap water. Backflush was used to recover accumulated particulates for analysis. In field tests conducted on a water utility distribution system, 3·2 × 104,1·4 × 106 CFU ml,1 (6·1 × 106,3·0 × 108 CFU) were recovered from the filter when 2·9 × 107,1·0 × 109 CFU were spiked into the system. Per cent recovery ranged from 21% to 68% for flow volumes of 15,21 l. Tests using spore influent levels <10 CFU l,1 (spike < 1000 CFU) yielded 23,40% recovery for volumes >100 l. Conclusions:,B. atrophaeus spores at levels <10 CFU l,1 were concentrated directly from tap water using an automated dead-end hollow-fibre ultrafiltration system. Significance and Impact of the Study:, The prototype concentrator represents a critical step towards an autonomous system that could be installed in drinking water distribution lines or other critical water lines to facilitate monitoring. Recovered samples can be analysed using standard or rapid biosensor methods. [source] Protecting the Nation's Critical Infrastructure: The Vulnerability of U.S. Water Supply SystemsJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2000Robert M. Clark Terrorism in the United States was not considered a serious threat until the second half of the 1990s. However, recent attacks both at home and abroad have forced government planners to consider the possibility that critical elements of the U.S. infrastructure might in fact be vulnerable to terrorism. The potential for chemical or biological contamination of water supply systems exists along with the possibility that such systems might be sabotaged. This article reviews the threat of biological and chemical compounds in relation to the characteristics of water supply systems. Vulnerability of such systems to terrorist attacks is examined, as well as possible physical and chemical countermeasures that could be applied. A case study is presented of an accidental contamination event that illustrates the difficulty of tracking such events in a drinking water system. It can be concluded that municipal water supplies are vulnerable. However, appropriate physical planning of such systems, including contingency back-up with separate water lines for emergencies, coupled with proactive monitoring, will significantly increase security in the face of possible terrorist attacks. [source] | ||||||||||||||||