Modeling decadal timescale interactions between surface water and ground water in the central Everglades, Florida, USA

Science.gov (United States)

Harvey, Judson W.; Newlin, Jessica T.; Krupa, Steven L.

2006-04-01

calculated recharge and discharge) is much less sensitive to vertical mixing compared with residence time alone. We conclude that a small but potentially significant component of flow through the Everglades is recharged to the aquifer and stored there for years to decades before discharged back to surface water. Long-term storage of water and solutes in the ground-water system beneath the wetlands has implications for restoration of Everglades water quality.

Solar water heating at Ikea's Montreal store; Chauffage solaire de l'eau courante au magasin Ikea de Montreal

Energy Technology Data Exchange (ETDEWEB)

Lagana, A.; Sonmor, K. [Ecovision experts-conseils inc., Montreal, PQ (Canada)

2010-01-01

The Ikea store in Montreal has integrated an energy efficient solar water heater into its building infrastructure. In June 2010, 30 fixed solar panels were installed on the roof to recuperate energy from the sun for hot water use in the restaurant and store facilities. Prior to this installation, the store was using natural gas for water heating purposes. During a sunny summer day, the solar water heater can provide 100 percent of the hot water needs of the store, even though it was designed to provide only one-third of the heating requirements. The panels are made of copper and painted with black titanium paint. A solution of water and antifreeze circulates in the panels. Digital controls are used at the pumps to control the temperature. The Ikea store uses approximately 3,100 gallons of water per day. The panels provide more than 60 MWh of energy, and represent a savings of 8440 cubic metres of natural gas, and a savings of 19.7 tons of carbon dioxide. The panels cost $1,300 and the return on investment is estimated to be 15.6 years. 3 figs.

Comparison of boiling and chlorination on the quality of stored drinking water and childhood diarrhoea in Indonesian households.

Science.gov (United States)

Fagerli, K; Trivedi, K K; Sodha, S V; Blanton, E; Ati, A; Nguyen, T; Delea, K C; Ainslie, R; Figueroa, M E; Kim, S; Quick, R

2017-11-01

We compared the impact of a commercial chlorination product (brand name Air RahMat) in stored drinking water to traditional boiling practices in Indonesia. We conducted a baseline survey of all households with children 1000 MPN/100 ml (RR 1·86, 95% CI 1·09-3·19) in stored water than in households without detectable E. coli. Although results suggested that Air RahMat water treatment was associated with lower E. coli contamination and diarrhoeal rates among children water treatment by boiling, Air RahMat use remained low.

Context of surveillance of underground and surface waters; Contexte de la surveillance des eaux souterraines et superficielles

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

This document briefly describes the evolutions of regulations on site liquid effluents and of guideline values concerning radioactive wastes, briefly presents the surveillance of underground and surface waters of CEA sites, comments the guideline values of the radiological quality of waters aimed at human consumption, and gives an overview of information which are brought to public's attention. Then, for different CEA sites (Cadarache, Marcoule, Saclay, Grenoble, Fontenay-aux-Roses, Valduc, DIF), this document proposes a presentation of the hydrological context, regulatory context, the surface and underground water surveillance process and values, the storing zones of old wastes.

Gamma irradiation, hot water and imazalil treatments on decay organisms and physical quality of stored netted muskmelon fruit

International Nuclear Information System (INIS)

Lester, G.

1989-01-01

Nonchemical treatments of gamma irradiation (2 Kilograys) and hot water (57°C) and the fungicide imazalil (1000 ppm) were compared with and without shrink-film wrap for effects on decay and physical quality of netted muskmelon fruit stored at 4°C for 0 through 60 days. Gamma irradiation was ineffective in controlling decay and surface molds, and injurious to physical quality by decreasing firmness, increasing fresh weight loss, membrane leakage and vein track browning. Hot water treatment coupled with shrink-film wrap was effective in controlling decay activity and maintaining physical quality up to 20 days storage. Imazalil coupled with shrink-film wrap controlled the incidence and severity of decay and maintained fruit firmness, moisture loss, membrane permeability and vein track browning for almost 60 days storage. (author)

Surface Water & Surface Drainage

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

Performance assessment of a single-layer moisture store-and-release cover system at a mine waste rock pile in a seasonally humid region (Nova Scotia, Canada).

Science.gov (United States)

Power, Christopher; Ramasamy, Murugan; Mkandawire, Martin

2018-03-03

Cover systems are commonly applied to mine waste rock piles (WRPs) to control acid mine drainage (AMD). Single-layer covers utilize the moisture "store-and-release" concept to first store and then release moisture back to the atmosphere via evapotranspiration. Although more commonly used in semi-arid and arid climates, store-and-release covers remain an attractive option in humid climates due to the low cost and relative simplicity of installation. However, knowledge of their performance in these climates is limited. The objective of this study was to assess the performance of moisture store-and-release covers at full-scale WRPs located in humid climates. This cover type was installed at a WRP in Nova Scotia, Canada, alongside state-of-the-art monitoring instrumentation. Field monitoring was conducted over 5 years to assess key components such as meteorological conditions, cover material water dynamics, net percolation, surface runoff, pore-gas, environmental receptor water quality, landform stability and vegetation. Water balances indicate small reductions in water influx to the waste rock (i.e., 34 to 28% of precipitation) with the diminished AMD release also apparent by small improvements in groundwater quality (increase in pH, decrease in sulfate/metals). Surface water quality analysis and field observations of vegetative/aquatic life demonstrate significant improvements in the surface water receptor. The WRP landform is stable and the vegetative cover is thriving. This study has shown that while a simple store-and-release cover may not be a highly effective barrier to water infiltration in humid climates, it can be used to (i) eliminate contaminated surface water runoff, (ii) minimize AMD impacts to surface water receptor(s), (iii) maintain a stable landform, and (iv) provide a sustainable vegetative canopy.

An inventory and estimate of water stored in firn fields, glaciers, debris-covered glaciers, and rock glaciers in the Aconcagua River Basin, Chile

Science.gov (United States)

Janke, Jason R.; Ng, Sam; Bellisario, Antonio

2017-11-01

An inventory of firn fields, glaciers, debris-covered glaciers, and rock glaciers was conducted in the Aconcagua River Basin of the semiarid Andes of central Chile. A total of 916 landforms were identified, of which rock glaciers were the most abundant (669) and occupied the most total area. Glaciers and debris-covered glaciers were less numerous, but were about five times larger in comparison. The total area occupied by glaciers and debris-covered glaciers was roughly equivalent to the total area of rock glaciers. Debris-covered glaciers and rock glaciers were subcategorized into six ice-content classes based on interpretation of surface morphology with high-resolution satellite imagery. Over 50% of rock glaciers fell within a transitional stage; 85% of debris-covered glaciers were either fully covered or buried. Most landforms occupied elevations between 3500 and 4500 m. Glaciers and firn occurred at higher elevations compared to rock glaciers and debris-covered glaciers. Rock glaciers had a greater frequency in the northern part of the study area where arid climate conditions exist. Firn and glaciers were oriented south, debris-covered glaciers west, and rock glaciers southwest. An analysis of water contribution of each landform in the upper Andes of the Aconcagua River Basin was conducted using formulas that associate the size of the landforms to estimates of water stored. Minimum and maximum water storage was calculated based on a range of debris to ice content ratios for debris-covered glaciers and rock glaciers. In the Aconcagua River Basin, rock glaciers accounted for 48 to 64% of the water stored within the landforms analyzed; glaciers accounted for 15 to 25%; debris-covered glaciers were estimated at 15 to 19%; firn fields contained only about 5 to 8% of the water stored. Expansion of agriculture, prolonged drought, and removal of ice-rich landforms for mining have put additional pressure on already scarce water resources. To develop long

Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: An integrative model perspective using stable isotopes and acesulfame

Energy Technology Data Exchange (ETDEWEB)

Engelhardt, I., E-mail: i.engelhardt@fz-juelich.de [Forschungszentrum Jülich, Institute of Bio- and Geosciences, Agrosphere — IBG-3 (Germany); Technical University of Darmstadt, Institute of Applied Geosciences (Germany); Barth, J.A.C. [GeoZentrum Nordbayern, University of Erlangen-Nuremberg (Germany); Bol, R. [Forschungszentrum Jülich, Institute of Bio- and Geosciences, Agrosphere — IBG-3 (Germany); Schulz, M.; Ternes, T.A. [Federal Institute of Hydrology (BfG) (Germany); Schüth, C. [Technical University of Darmstadt, Institute of Applied Geosciences (Germany); van Geldern, R. [GeoZentrum Nordbayern, University of Erlangen-Nuremberg (Germany)

2014-01-01

The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ{sup 18}O or δ{sup 2}H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5 months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153 day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water–groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended

Enteric pathogens in stored drinking water and on caregiver's hands in Tanzanian households with and without reported cases of child diarrhea.

Directory of Open Access Journals (Sweden)

Mia Catharine Mattioli

Full Text Available BACKGROUND: Diarrhea is one of the leading causes of mortality in young children. Diarrheal pathogens are transmitted via the fecal-oral route, and for children the majority of this transmission is thought to occur within the home. However, very few studies have documented enteric pathogens within households of low-income countries. METHODS AND FINDINGS: The presence of molecular markers for three enteric viruses (enterovirus, adenovirus, and rotavirus, seven Escherichia coli virulence genes (ECVG, and human-specific Bacteroidales was assessed in hand rinses and household stored drinking water in Bagamoyo, Tanzania. Using a matched case-control study design, we examined the relationship between contamination of hands and water with these markers and child diarrhea. We found that the presence of ECVG in household stored water was associated with a significant decrease in the odds of a child within the home having diarrhea (OR = 0.51; 95% confidence interval 0.27-0.93. We also evaluated water management and hygiene behaviors. Recent hand contact with water or food was positively associated with detection of enteric pathogen markers on hands, as was relatively lower volumes of water reportedly used for daily hand washing. Enteropathogen markers in stored drinking water were more likely found among households in which the markers were also detected on hands, as well as in households with unimproved water supply and sanitation infrastructure. CONCLUSIONS: The prevalence of enteric pathogen genes and the human-specific Bacteroidales fecal marker in stored water and on hands suggests extensive environmental contamination within homes both with and without reported child diarrhea. Better stored water quality among households with diarrhea indicates caregivers with sick children may be more likely to ensure safe drinking water in the home. Interventions to increase the quantity of water available for hand washing, and to improve food hygiene, may

Surface-water surveillance

Energy Technology Data Exchange (ETDEWEB)

Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

1995-06-01

This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995).

Surface-water surveillance

International Nuclear Information System (INIS)

Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

1995-01-01

This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995)

Water at surfaces with tunable surface chemistries

Science.gov (United States)

Sanders, Stephanie E.; Vanselous, Heather; Petersen, Poul B.

2018-03-01

Aqueous interfaces are ubiquitous in natural environments, spanning atmospheric, geological, oceanographic, and biological systems, as well as in technical applications, such as fuel cells and membrane filtration. Where liquid water terminates at a surface, an interfacial region is formed, which exhibits distinct properties from the bulk aqueous phase. The unique properties of water are governed by the hydrogen-bonded network. The chemical and physical properties of the surface dictate the boundary conditions of the bulk hydrogen-bonded network and thus the interfacial properties of the water and any molecules in that region. Understanding the properties of interfacial water requires systematically characterizing the structure and dynamics of interfacial water as a function of the surface chemistry. In this review, we focus on the use of experimental surface-specific spectroscopic methods to understand the properties of interfacial water as a function of surface chemistry. Investigations of the air-water interface, as well as efforts in tuning the properties of the air-water interface by adding solutes or surfactants, are briefly discussed. Buried aqueous interfaces can be accessed with careful selection of spectroscopic technique and sample configuration, further expanding the range of chemical environments that can be probed, including solid inorganic materials, polymers, and water immiscible liquids. Solid substrates can be finely tuned by functionalization with self-assembled monolayers, polymers, or biomolecules. These variables provide a platform for systematically tuning the chemical nature of the interface and examining the resulting water structure. Finally, time-resolved methods to probe the dynamics of interfacial water are briefly summarized before discussing the current status and future directions in studying the structure and dynamics of interfacial water.

Surface freezing of water

OpenAIRE

P?rez-D?az, J. L.; ?lvarez-Valenzuela, M. A.; Rodr?guez-Celis, F.

2016-01-01

Freezing, melting, evaporation and condensation of water are essential ingredients for climate and eventually life on Earth. In the present work, we show how surface freezing of supercooled water in an open container is conditioned and triggered?exclusively?by humidity in air. Additionally, a change of phase is demonstrated to be triggered on the water surface forming surface ice crystals prior to freezing of bulk. The symmetry of the surface crystal, as well as the freezing point, depend on ...

Surface freezing of water.

Science.gov (United States)

Pérez-Díaz, J L; Álvarez-Valenzuela, M A; Rodríguez-Celis, F

2016-01-01

Freezing, melting, evaporation and condensation of water are essential ingredients for climate and eventually life on Earth. In the present work, we show how surface freezing of supercooled water in an open container is conditioned and triggered-exclusively-by humidity in air. Additionally, a change of phase is demonstrated to be triggered on the water surface forming surface ice crystals prior to freezing of bulk. The symmetry of the surface crystal, as well as the freezing point, depend on humidity, presenting at least three different types of surface crystals. Humidity triggers surface freezing as soon as it overpasses a defined value for a given temperature, generating a plurality of nucleation nodes. An evidence of simultaneous nucleation of surface ice crystals is also provided.

Potential for formation of disinfection by-products from storage of chlorinated surface water in the Basalt aquifer near Fallon, Nevada

Science.gov (United States)

Fram, Miranda S.; Maurer, Douglas K.; Lico, Michael S.

2005-01-01

that the amount of organic carbon released from the rocks during successive cycles of recharge, storage, and recovery of chlorinated surface water may be relatively small. The chlorine demand of the rocks is so large that all of the free chlorine in the entire volume of recharged water likely would be consumed by only a very small volume of the aquifer surrounding an injection well, or beneath an infiltration bed. The majority of the volume of the aquifer filled by the stored water likely would never come in contact with free chlorine, and the increases in concentration of DOC observed in these experiments likely would occur in a very small volume of the stored water. For this reason, increases in concentration of THMs for the entire volume of water stored also likely would be considerably less than those measured in these experiments. To test this hypothesis, additional laboratory experiments using varying levels of chlorination, varying lengths of reaction periods, and repeated cycles of chlorination would be useful. A field experiment made at a small scale in an isolated part of the basalt aquifer would aid in the design of an operational system.

Sustaining dry surfaces under water

DEFF Research Database (Denmark)

Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.

2015-01-01

Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional...... mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have...... not been investigated, and are critically important to maintain surfaces dry under water.In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys – thus keeping the immersed surface dry. Theoretical...

Ultrasonic-energy enhance the ionic liquid-based dual microextraction to preconcentrate the lead in ground and stored rain water samples as compared to conventional shaking method.

Science.gov (United States)

Nizamani, Sooraj; Kazi, Tasneem G; Afridi, Hassan I

2018-01-01

An efficient preconcentration technique based on ultrasonic-assisted ionic liquid-based dual microextraction (UA-ILDµE) method has been developed to preconcentrate the lead (Pb +2 ) in ground and stored rain water. In the current proposed method, Pb +2 was complexed with a chelating agent (dithizone), whereas an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was used for extraction purpose. The ultrasonic irradiation and electrical shaking system were applied to enhance the dispersion and extraction of Pb +2 complex in aqueous samples. For second phase, dual microextraction (DµE phase), the enriched Pb +2 complex in ionic liquid, extracted back into the acidic aqueous solution and finally determined by flame atomic absorption spectrometry. Some major analytical parameters that influenced the extraction efficiency of developed method, such as pH, concentration of ligand, volume of ionic liquid and samples, time of shaking in thermostatic electrical shaker and ultrasonic bath, effect of back extracting HNO 3 volume, matrix effect, centrifugation time and rate were optimized. At the sample volume of 25mL, the calculated preconcentration factor was 62.2. The limit of detection of proposed procedure for Pb +2 ions was found to be 0.54μgL -1 . The validation of developed method was performed by the analysis of certified sample of water SRM 1643e and standard addition method in a real water sample. The extraction recovery of Pb +2 was enhanced≥2% with shaking time of 80s in ultrasonic bath as compared to used thermostatic electrical shaker, where for optimum recovery up to 10min was required. The developed procedure was successfully used for the enrichment of Pb +2 in ground and stored rain water (surface water) samples of an endemic region of Pakistan. The resulted data indicated that the ground water samples were highly contaminated with Pb +2 , while some of the surface water samples were also have higher values of Pb +2 than permissible limit of

Surface Water in Hawaii

Science.gov (United States)

Oki, Delwyn S.

2003-01-01

Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.

When Big Ice Turns Into Water It Matters For Houses, Stores And Schools All Over

Science.gov (United States)

Bell, R. E.

2017-12-01

When ice in my glass turns to water it is not bad but when the big ice at the top and bottom of the world turns into water it is not good. This new water makes many houses, stores and schools wet. It is really bad during when the wind is strong and the rain is hard. New old ice water gets all over the place. We can not get to work or school or home. We go to the big ice at the top and bottom of the world to see if it will turn to water soon and make more houses wet. We fly over the big ice to see how it is doing. Most of the big ice sits on rock. Around the edge of the big sitting on rock ice, is really low ice that rides on top of the water. This really low ice slows down the big rock ice turning into water. If the really low ice cracks up and turns into little pieces of ice, the big rock ice will make more houses wet. We look to see if there is new water in the cracks. Water in the cracks is bad as it hurts the big rock ice. Water in the cracks on the really low ice will turn the low ice into many little pieces of ice. Then the big rock ice will turn to water. That is water in cracks is bad for the houses, schools and businesses. If water moves off the really low ice, it does not stay in the cracks. This is better for the really low ice. This is better for the big rock ice. We took pictures of the really low ice and saw water leaving. The water was not staying in the cracks. Water leaving the really low ice might be good for houses, schools and stores.

Magnitude of [14C] DDT residues in stored dried fish and pre-cooking processing effect on their removal

International Nuclear Information System (INIS)

Rahman, M.; Khatoon, J.; Matin, M.A.; Main, A.J.

1998-01-01

Residues of 14 C-DDT in stored dried fish was determined under ambient conditions for a 6 month period. Immediately after treatment, about 40% of the applied DDT was eliminated from surface of the dried fish with water washing. However, such removal was reduced to about 26% on storage for 6 months. Boiling of dried fish in water resulted in further removal of about 16% residues. In boiled dried fish, about 14% residues might remain and this could be removed by Soxhlet extraction. Surface extraction with hexane yielded about 80% of the residues immediately after treatment and the extractable residues decreased to about half the initial value of 6 months' storage. Dried fish residues, on surface extraction with water or hexane, when subjected to exhaustive Soxhlet extraction with methanol was found to result in further recovery of about 39-49% and 17-32%, respectively. Bound DDT residues were found to be about 5% in water washed dried fish samples and about 1.5% in case of hexane-extracted samples. Degradation of parent DDT to DDE and DDD was found. Maximum values of 16.58% DDE and 21.6% DDD were found in dried fish stored for 6 months. (author)

Water, vapour and heat transport in concrete cells for storing radioactive waste

Science.gov (United States)

Carme Chaparro, M.; W. Saaltink, Maarten

2016-08-01

Water is collected from a drain situated at the centre of a concrete cell that stores radioactive waste at 'El Cabril', which is the low and intermediate level radioactive waste disposal facility of Spain. This indicates flow of water within the cell. 2D numerical models have been made in order to reproduce and understand the processes that take place inside the cell. Temperature and relative humidity measured by sensors in the cells and thermo-hydraulic parameters from laboratory test have been used. Results show that this phenomenon is caused by capillary rise from the phreatic level, evaporation and condensation within the cell produced by temperature gradients caused by seasonal temperature fluctuations outside. At the centre of the cell, flow of gas and convection also play a role. Three remedial actions have been studied that may avoid the leakage of water from the drain.

Water on a Hydrophobic surface

Science.gov (United States)

Scruggs, Ryan; Zhu, Mengjue; Poynor, Adele

2012-02-01

Hydrophobicity, meaning literally fear of water, is exhibited on the surfaces of non-stick cooking pans and water resistant clothing, on the leaves of the lotus plan, or even during the protein folding process in our bodies. Hydrophobicity is directly measured by determining a contact angle between water and an objects surface. Associated with a hydrophobic surface is the depletion layer, a low density region approximately 0.2 nm thick. We study this region by comparing data found in lab using surface plasmon resonance techniques to theoretical calculations. Experiments use gold slides coated in ODT and Mercapto solutions to model both hydrophobic and hydrophilic surfaces respectively.

Productivity of Stored Water in Some Selected Multiple Use Small Reservoirs in the Upper East Region of Ghana

Science.gov (United States)

Annor, F. O.; Yamoah-Antwi, D.; Odai, S. N.; Adjei, K. A.; van de Giesen, N. C.

2009-04-01

The Upper East Region (UER) of Ghana is a water stressed area with agriculture as the main occupation of the inhabitants. The importance of small reservoirs for the sustenance of the livelihood of the people in this part of the country during the dry season cannot be over emphasized. Most of these small reservoirs were constructed, in the 1960s, mainly with the aim of providing water for domestic use and livestock watering during the dry periods of the year. Over the years, however, these small reservoirs have been put to a variety of uses, some of which accelerate the depletion of the stored water. The reservoirs are therefore most times, unable to serve the purposes for which they were constructed. To address this situation, a study was conducted to determine the productivity of stored water in small reservoirs to better inform policy makers and water managers in the allocation of water especially in the dry season. Water productivity can be thought of as the output (product) that can be obtained per unit volume of water used or applied for either crop or livestock production. Data on crops and livestock were obtained through questionnaire administration, interviews, focus group discussions, physical measurements as well as field observations from nine reservoirs in the UER. The research findings show that donkeys have the highest productivity of about US90 followed by cattle with US70. These high productivity values are as a result of the variety of products and services rendered by donkeys and cattle. For crop, tomatoes have the highest productivity value compared with pepper and leafy vegetables. Despite the fact that donkeys had the highest productivity and hence priority over all uses, it is prudent to note that, inhabitants of the study area aside the sale of livestock for money (income) keep livestock for prestige. Therefore in the allocation of stored water in small multiple use reservoirs, the allocation criteria should consider the views, values and

Near-Surface Profiles of Water Stable Isotope Components and Indicated Transitional History of Ice-Wedge Polygons Near Barrow

Science.gov (United States)

Iwahana, G.; Wilson, C.; Newman, B. D.; Heikoop, J. M.; Busey, R.

2017-12-01

Wetlands associated with ice-wedge polygons are commonly distributed across the Arctic Coastal Plain of northern Alaska, a region underlain by continuous permafrost. Micro-topography of the ice-wedge polygons controls local hydrology, and the micro-topography could be altered due to factors such like surface vegetation, wetness, freeze-thaw cycles, and permafrost degradation/aggradation under climate change. Understanding status of the wetlands in the near future is important because it determines biogeochemical cycle, which drives release of greenhouse gases from the ground. However, transitional regime of the ice-wedge polygons under the changing climate is not fully understood. In this study, we analyzed geochemistry of water extracted from frozen soil cores sampled down to about 1m depth in 2014 March at NGEE-Arctic sites in the Barrow Environmental Observatory. The cores were sampled from troughs/rims/centers of five different low-centered or flat-centered polygons. The frozen cores are divided into 5-10cm cores for each location, thawed in sealed plastic bags, and then extracted water was stored in vials. Comparison between the profiles of geochemistry indicated connection of soil water in the active layer at different location in a polygon, while it revealed that distinctly different water has been stored in permafrost layer at troughs/rims/centers of some polygons. Profiles of volumetric water content (VWC) showed clear signals of freeze-up desiccation in the middle of saturated active layers as low VWC anomalies at most sampling points. Water in the active layer and near-surface permafrost was classified into four categories: ice wedge / fresh meteoric / transitional / highly fractionated water. The overall results suggested prolonged separation of water in the active layer at the center of low-centered polygons without lateral connection in water path in the past.

Procedure for permanently storing radioactive material

International Nuclear Information System (INIS)

Canevall, J.

1987-01-01

This patent describes a method of storing radioactive material in a hollow construction having an access opening. The construction is located below the surface of the ground within a rock chamber. The chamber has walls, a floor, and a ceiling. The construction is completely spaced from the walls, floor, and ceiling of the rock chamber to form an outer spacing, and the construction is made of material impervious to water. The construction comprises a capsule storage area and a capsule handling passageway adjacent thereto having a track and being connected to a lift-shaft running to the surface. The method includes the steps of: completely filling the outer spacing between the walls, ceiling, and floor of the rock chamber and the construction with material not impervious to water; placing capsules containing the radioactive waste in encapsulated form into the capsule storage area; filling the storage area around the loaded capsule with a sealing material to enclose the capsules; repeating the placing and filling steps until the storage area has been completely filled in with the capsules and sealing material; loading the passageway adjacent the storage area with a removable material different than the sealing material; closing the construction and sealing the lift-shaft at least at the construction level and at ground level; and providing means for collecting any water penetrating into the outer spacing

The Assessment of Instruments for Detecting Surface Water Spills Associated with Oil and Gas Operations

Energy Technology Data Exchange (ETDEWEB)

Harris, Aubrey E. [West Virginia Univ., Morgantown, WV (United States); National Energy Technology Lab. (NETL), Morgantown, WV (United States); U.S. Bureau of Reclamation, Albuquerque, NM (United States); Hopkinson, Leslie [West Virginia Univ., Morgantown, WV (United States); Soeder, Daniel [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

2016-12-02

Surface water and groundwater risks associated with unconventional oil and gas development result from potential spills of the large volumes of chemicals stored on-site during drilling and hydraulic fracturing operations, and the return to the surface of significant quantities of saline water produced during oil or gas well production. To better identify and mitigate risks, watershed models and tools are needed to evaluate the dispersion of pollutants in possible spill scenarios. This information may be used to determine the placement of in-stream water-quality monitoring instruments and to develop early-warning systems and emergency plans. A chemical dispersion model has been used to estimate the contaminant signal for in-stream measurements. Spills associated with oil and gas operations were identified within the Susquehanna River Basin Commission’s Remote Water Quality Monitoring Network. The volume of some contaminants was found to be sufficient to affect the water quality of certain drainage areas. The most commonly spilled compounds and expected peak concentrations at monitoring stations were used in laboratory experiments to determine if a signal could be detected and positively identified using standard water-quality monitoring equipment. The results were compared to historical data and baseline observations of water quality parameters, and showed that the chemicals tested do commonly affect water quality parameters. This work is an effort to demonstrate that hydrologic and water quality models may be applied to improve the placement of in-stream water quality monitoring devices. This information may increase the capability of early-warning systems to alert community health and environmental agencies of surface water spills associated with unconventional oil and gas operations.

XML-BSPM: an XML format for storing Body Surface Potential Map recordings.

Science.gov (United States)

Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George

2010-05-14

The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual solutions and inspire existing formats

Identifying Financially Sustainable Pricing Interventions to Promote Healthier Beverage Purchases in Small Neighborhood Stores.

Science.gov (United States)

Nau, Claudia; Kumanyika, Shiriki; Gittelsohn, Joel; Adam, Atif; Wong, Michelle S; Mui, Yeeli; Lee, Bruce Y

2018-01-25

Residents of low-income communities often purchase sugar-sweetened beverages (SSBs) at small, neighborhood "corner" stores. Lowering water prices and increasing SSB prices are potentially complementary public health strategies to promote more healthful beverage purchasing patterns in these stores. Sustainability, however, depends on financial feasibility. Because in-store pricing experiments are complex and require retailers to take business risks, we used a simulation approach to identify profitable pricing combinations for corner stores. The analytic approach was based on inventory models, which are suitable for modeling business operations. We used discrete-event simulation to build inventory models that use data representing beverage inventory, wholesale costs, changes in retail prices, and consumer demand for 2 corner stores in Baltimore, Maryland. Model outputs yielded ranges for water and SSB prices that increased water demand without loss of profit from combined water and SSB sales. A 20% SSB price increase allowed lowering water prices by up to 20% while maintaining profit and increased water demand by 9% and 14%, for stores selling SSBs in 12-oz cans and 16- to 20-oz bottles, respectively. Without changing water prices, profits could increase by 4% and 6%, respectively. Sensitivity analysis showed that stores with a higher volume of SSB sales could reduce water prices the most without loss of profit. Various combinations of SSB and water prices could encourage water consumption while maintaining or increasing store owners' profits. This model is a first step in designing and implementing profitable pricing strategies in collaboration with store owners.

Controllability of Surface Water Networks

Science.gov (United States)

Riasi, M. Sadegh; Yeghiazarian, Lilit

2017-12-01

To sustainably manage water resources, we must understand how to control complex networked systems. In this paper, we study surface water networks from the perspective of structural controllability, a concept that integrates classical control theory with graph-theoretic formalism. We present structural controllability theory and compute four metrics: full and target controllability, control centrality and control profile (FTCP) that collectively determine the structural boundaries of the system's control space. We use these metrics to answer the following questions: How does the structure of a surface water network affect its controllability? How to efficiently control a preselected subset of the network? Which nodes have the highest control power? What types of topological structures dominate controllability? Finally, we demonstrate the structural controllability theory in the analysis of a wide range of surface water networks, such as tributary, deltaic, and braided river systems.

The importance of store windows in creating store identity and store attractiveness

Directory of Open Access Journals (Sweden)

Renko Sanda

2012-01-01

Full Text Available While choosing the store, customer first notices the store window and it plays an important role in retailing strategy. Store's window is what customers see first in meeting with the store. Store window design can lead customer to enter the store, and can give a lot of information about store brands and products. Besides the analysis of the way how specific elements of the window design affect customers and their perception, the explanation of their attraction and rejection to customers is given. If we consider the importance of the topics, we can point out the lack of literature about store windows as the communication tool which allow store to communicate with its customers and to create its retailing strategy as well. There is the scientific contribution of this paper. The paper gives theoretical comprehensions completed with the results of the study about the importance of store windows for retailers as well as for customers. Therefore, for the purpose of this paper, a two-phase research study, including a qualitative and a quantitative approach, was used: 1 the qualitative study among retailers which indicated the most important elements of store windows, the level of financial sources invested in the window design, the basis for the decisions about store window design, etc.; 2 the quantitative study on the sample of consumers conducted with on-line questionnaire. Findings suggest that store window attractiveness is the main motif for store visits. The results of the research confirm that by means of store window and its elements (with special emphasis on price and pricing actions retail store sends messages to its consumers.

Groundwater–Surface Water Exchange

DEFF Research Database (Denmark)

Karan, Sachin

The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: an integrative model perspective using stable isotopes and acesulfame.

Science.gov (United States)

Engelhardt, I; Barth, J A C; Bol, R; Schulz, M; Ternes, T A; Schüth, C; van Geldern, R

2014-01-01

The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ(18)O or δ(2)H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water-groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended. © 2013 Elsevier

Impact of Water Withdrawals from Groundwater and Surface Water on Continental Water Storage Variations

Science.gov (United States)

Doell, Petra; Hoffmann-Dobrev, Heike; Portmann, Felix T.; Siebert, Stefan; Eicker, Annette; Rodell, Matthew; Strassberg, Gil

2011-01-01

Humans have strongly impacted the global water cycle, not only water flows but also water storage. We have performed a first global-scale analysis of the impact of water withdrawals on water storage variations, using the global water resources and use model WaterGAP. This required estimation of fractions of total water withdrawals from groundwater, considering five water use sectors. According to our assessment, the source of 35% of the water withdrawn worldwide (4300 cubic km/yr during 1998-2002) is groundwater. Groundwater contributes 42%, 36% and 27% of water used for irrigation, households and manufacturing, respectively, while we assume that only surface water is used for livestock and for cooling of thermal power plants. Consumptive water use was 1400 cubic km/yr during 1998-2002. It is the sum of the net abstraction of 250 cubic km/yr of groundwater (taking into account evapotranspiration and return flows of withdrawn surface water and groundwater) and the net abstraction of 1150 km3/yr of surface water. Computed net abstractions indicate, for the first time at the global scale, where and when human water withdrawals decrease or increase groundwater or surface water storage. In regions with extensive surface water irrigation, such as Southern China, net abstractions from groundwater are negative, i.e. groundwater is recharged by irrigation. The opposite is true for areas dominated by groundwater irrigation, such as in the High Plains aquifer of the central USA, where net abstraction of surface water is negative because return flow of withdrawn groundwater recharges the surface water compartments. In intensively irrigated areas, the amplitude of seasonal total water storage variations is generally increased due to human water use; however, in some areas, it is decreased. For the High Plains aquifer and the whole Mississippi basin, modeled groundwater and total water storage variations were compared with estimates of groundwater storage variations based on

Surface composition and surface properties of water hyacinth ...

African Journals Online (AJOL)

Surface composition and surface properties of water hyacinth ( Eichhornia ... (2/1, v/v) followed by ethanol, using Fourier Transform Infra-red (FT-IR) spectroscopy, ... polar organic solvents and non-polar n-alkane hydrocarbons is discussed.

Infiltration of pesticides in surface water into nearby drinking water supply wells

DEFF Research Database (Denmark)

Malaguerra, Flavio; Albrechtsen, Hans-Jørgen; Binning, Philip John

Drinking water wells are often placed near streams because streams often overly permeable sediments and the water table is near the surface in valleys, and so pumping costs are reduced. The lowering of the water table by pumping wells can reverse the natural flow from the groundwater to the stream......, inducing infiltration of surface water to groundwater and consequently to the drinking water well. Many attenuation processes can take place in the riparian zone, mainly due to mixing, biodegradation and sorption. However, if the water travel time from the surface water to the pumping well is too short......, or if the compounds are poorly degradable, contaminants can reach the drinking water well at high concentrations, jeopardizing drinking water quality. Here we developed a reactive transport model to evaluate the risk of contamination of drinking water wells by surface water pollution. The model was validated using...

Storage fee analysis for a retrievable surface storage facility

International Nuclear Information System (INIS)

Field, B.B.; Rosnick, C.K.

1973-12-01

Conceptual design studies are in progress for a Water Basin Concept (WBC) and an alternative Sealed Storage Cask Concept (SSCC) of a Retrievable Surface Storage Facility (RSSF) intended as a Federal government facility for storing high-level radioactive wastes until a permanent disposal method is established. The RSSF will be a man-made facility with a design life of at least 100 y, and will have capacity to store all of the high-level waste from the reprocessing of nuclear power plant spent fuels generated by the industry through the year 2000. This report is a basic version of ARH-2746, ''Retrievable Surface Storage Facility, Water Basin Concept, User Charge Analysis.'' It is concerned with the issue of establishing a fee to cover the cost of storing nuclear wastes both in the RSSF and at the subsequent disposal facility. (U.S.)

Waste water treatment in surface mines

Energy Technology Data Exchange (ETDEWEB)

Navasardyants, M A; Esipov, V Z; Ryzhkov, Yu A

1981-01-01

This paper evaluates problems associated with waste water from coal surface mines of the Kemerovougol' association in the Kuzbass. Waste water treatment in the Kuzbass is of major importance as the region is supplied with water from only one river, the Tom river. Water influx to Kemerovougol' surface mines in a year amounts to 136 million m/sup 3/. The water is used during technological processes, for fire fighting, and spraying to prevent dusting; the rest, about 82.1 million m/sup 3/, is discharged into surface waters. Of this amount, 25.1 million m/sup 3/ is heavily polluted water, 46.6 million m3 are polluted but within limits, and 10.4 million m/sup 3/ are characterized as relatively clean. Waste water is polluted with: suspended matters, oils and oil products, nitrates, nitrides and chlorides. Suspended matter content sometimes reaches 4,000 and 5,000 mg/l, and oil product content in water amounts to 2.17 mg/l. Water treatment in surface mines is two-staged: sumps and sedimentation tanks are used. Water with suspended matter content of 50 to 100 mg/l in winter and summer, and 200 to 250 mg/l in spring and autumn is reduced in sumps to 25 to 30 mg/l in summer and winter and to 40 to 50 mg/l in autumn and spring. During the first stage water treatment efficiency ranges from 50 to 80%. During the second stage water is collected in sedimentation tanks. It is noted that so-called secondary pollution is one of the causes of the relatively high level of suspended matter in discharged water. Water discharged from sedimentation tanks carries clay and loam particles from the bottom and walls of water tanks and channels.

Environmental geochemistry of surface and subsurface water from Dera Ismail Khan Division, Khyber Pakhtunkhwa, Pakistan

International Nuclear Information System (INIS)

Shah, M.T.; Alizai, A.H.; Khan, S.D.

2012-01-01

The Dera Ismail Khan division is situated in the southern most part of the Khyber-Pakhtunkhwa province in Pakistan. Majority of population in this region obtain domestic water from tube wells, dug wells, ponds, stored run off of the Indus and Gomal rivers and perennial streams. This study is aimed to determine the physio-chemical contaminants in the surface and subsurface water which could cause environmental problem. For this purpose, representative water sample were collected from tube wells, dug wells, streams and rivers. These analyses were performed using Hach DR/2000 spectrophotometer and graphite furnace atomic absorption spectrometer. Chemically both surface and subsurface water samples of the area were classified as alkaline fresh water. The comparison of the data with standard limits set by Word Health Organization (WHO) for drinking water suggested that in certain areas of the division, the drinking water samples have high concentrations of Total Dissolved Solids, NO/sub 3//sup 2-/, SO/sub 4//sup 2-/, F-, Cl-, Fe/sup 2+/, Ca/sup 2+/, Mg/sup 2+/, Pb/sup 2+/, Ni/sup 2+/ and Cd/sup 2+/ while pH, EC, HCO/sub 3/-, PO/sub 4//sup 3-/, Na/sup +/, Mn/sup 2+/, K/sup +/, Cr/sup 3+/ and Zn/sup 2+/ were within the permissible limits. These contaminations could be attributed to the geogenic sources which might be responsible for the health related problems in certain areas of the division. (author)

Volume de água armazenado no tanque de bromélias, em restingas da costa brasileira Water volume stored in bromeliad tanks in Brazilian restinga habitats

Directory of Open Access Journals (Sweden)

Luciana Cogliatti-Carvalho

2010-03-01

Full Text Available Muitas espécies de bromélias armazenam água da chuva em seu interior, sendo esta característica resultado da distribuição espiralada de suas folhas, que formam pequenos tanques. O objetivo deste estudo foi avaliar e comparar o volume de água efetivamente armazenado e o volume máximo que pode ser armazenado no tanque de diferentes espécies de bromélias de 13 restingas brasileiras. Em cada restinga, em 100 plots de 100 m² cada, registramos as espécies de bromélias-tanque, os parâmetros morfométricos e o volume efetivo e máximo em 20 indivíduos de cada espécie. Encontramos 32 espécies de bromélias-tanque, para as quais medimos o volume máximo e o volume efetivo de água armazenado. Em 59.007 rosetas, estimamos o volume máximo em 44.388 litros e medimos 17.000 litros de água efetivamente armazenados. Encontramos diferenças interespecíficas nos volumes máximo e efetivamente reservado de água, na biomassa, no número de folhas e no volume do cone da planta. Aechmea aquilega, A. blanchetiana e Hohenbergia castelanosii tiveram os maiores volumes efetivos. Somente A. nudicaulis e Billbergia amoena diferiram entre suas populações em todos os parâmetros analisados. As restingas de Maricá, Prado, Trancoso e Jurubatiba tiveram os maiores volumes de água.ha-1 armazenada nas bromélias-tanque. O volume máximo de água estimado para as bromélias-tanque variou entre espécies devido a diferenças na forma e no tamanho das bromélias.Many bromeliad species store rain water in tanks, as a result of the spiraled distribution of their leaves. The aim of this study was to evaluate how much water is stored and what is the maximum volume of water possible to be stored in different tank-bromeliad species in 13 different Brazilian restingas. The species were recorded in 100 plots of 100 m2, in each restinga habitat. For each bromeliad species, the effective and the maximum water stored in the tanks were measured. We found 32 tank

Indices of quality surface water bodies in the planning of water resources

Directory of Open Access Journals (Sweden)

Rodríguez-Miranda, Juan Pablo

2016-12-01

Full Text Available This paper considers a review of the literature major and significant methods of quality indices of water applied in surface water bodies, used and proposed for assessing the significance of parameters of water quality in the assessment of surface water currents and they are usually used in making decisions for intervention and strategic prevention measures for those responsible for the conservation and preservation of watersheds where these water bodies belong. An exploratory methodology was applied to realize the conceptualization of each water quality index. As a result, it is observed that there are several important methods for determining the water quality index applied in surface water bodies.

How does subsurface retain and release stored water? An explicit estimation of young water fraction and mean transit time

Science.gov (United States)

Ameli, Ali; McDonnell, Jeffrey; Laudon, Hjalmar; Bishop, Kevin

2017-04-01

The stable isotopes of water have served science well as hydrological tracers which have demonstrated that there is often a large component of "old" water in stream runoff. It has been more problematic to define the full transit time distribution of that stream water. Non-linear mixing of previous precipitation signals that is stored for extended periods and slowly travel through the subsurface before reaching the stream results in a large range of possible transit times. It difficult to find tracers can represent this, especially if all that one has is data on the precipitation input and the stream runoff. In this paper, we explicitly characterize this "old water" displacement using a novel quasi-steady physically-based flow and transport model in the well-studied S-Transect hillslope in Sweden where the concentration of hydrological tracers in the subsurface and stream has been measured. We explore how subsurface conductivity profile impacts the characteristics of old water displacement, and then test these scenarios against the observed dynamics of conservative hydrological tracers in both the stream and subsurface. This work explores the efficiency of convolution-based approaches in the estimation of stream "young water" fraction and time-variant mean transit times. We also suggest how celerity and velocity differ with landscape structure

Insight into Chemistry on Cloud/Aerosol Water Surfaces.

Science.gov (United States)

Zhong, Jie; Kumar, Manoj; Francisco, Joseph S; Zeng, Xiao Cheng

2018-05-15

Cloud/aerosol water surfaces exert significant influence over atmospheric chemical processes. Atmospheric processes at the water surface are observed to follow mechanisms that are quite different from those in the gas phase. This Account summarizes our recent findings of new reaction pathways on the water surface. We have studied these surface reactions using Born-Oppenheimer molecular dynamics simulations. These studies provide useful information on the reaction time scale, the underlying mechanism of surface reactions, and the dynamic behavior of the product formed on the aqueous surface. According to these studies, the aerosol water surfaces confine the atmospheric species into a specific orientation depending on the hydrophilicity of atmospheric species or the hydrogen-bonding interactions between atmospheric species and interfacial water. As a result, atmospheric species are activated toward a particular reaction on the aerosol water surface. For example, the simplest Criegee intermediate (CH 2 OO) exhibits high reactivity toward the interfacial water and hydrogen sulfide, with the reaction times being a few picoseconds, 2-3 orders of magnitude faster than that in the gas phase. The presence of interfacial water molecules induces proton-transfer-based stepwise pathways for these reactions, which are not possible in the gas phase. The strong hydrophobicity of methyl substituents in larger Criegee intermediates (>C1), such as CH 3 CHOO and (CH 3 ) 2 COO, blocks the formation of the necessary prereaction complexes for the Criegee-water reaction to occur at the water droplet surface, which lowers their proton-transfer ability and hampers the reaction. The aerosol water surface provides a solvent medium for acids (e.g., HNO 3 and HCOOH) to participate in reactions via mechanisms that are different from those in the gas and bulk aqueous phases. For example, the anti-CH 3 CHOO-HNO 3 reaction in the gas phase follows a direct reaction between anti-CH 3 CHOO and HNO 3

Convergent surface water distributions in U.S. cities

Science.gov (United States)

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

2014-01-01

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

Monitoring of Water and Contaminant Migration at the Groundwater-Surface Water Interface

Science.gov (United States)

2008-08-01

seepage is occurring in a freshwater lake environment and to map the lateral extent of any subsurface contamination at the groundwater –surface water ...and Contaminant Migration at the Groundwater -Surface Water Interface August 2008 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...4. TITLE AND SUBTITLE Monitoring of Water and Contaminant Migration at the Groundwater -Surface Water Interface 5a. CONTRACT NUMBER 5b. GRANT NUMBER

Underground coal mine subsidence impacts on surface water

International Nuclear Information System (INIS)

Stump, D.E. Jr.

1992-01-01

This paper reports that subsidence from underground coal mining alters surface water discharge and availability. The magnitude and areal extent of these impacts are dependent on many factors, including the amount of subsidence, topography, geology, climate, surface water - ground water interactions, and fractures in the overburden. There alterations may have positive and/or negative impacts. One of the most significant surface water impacts occurred in July 1957 near West Pittston, Pennsylvania. Subsidence in the Knox Mine under the Coxton Yards of the Lehigh Valley Railroad allowed part of the discharge in the Susquehanna River to flow into the mine and create a crater 200 feet in diameter and 300 feet deep. Fourteen railroad gondola cars fell into the hole which was eventually filled with rock, sand, and gravel. Other surface water impacts from subsidence may include the loss of water to the ground water system, the gaining of water from the ground water system, the creation of flooded subsidence troughs, the increasing of impoundment storage capacity, the relocation of water sources (springs), and the alteration of surface drainage patterns

Quick Detection of Contaminants Leaching from Polypropylene Centrifuge Tube with Surface Enhanced Raman Spectroscopy and Ultra Violet Absorption Spectroscopy

OpenAIRE

Xu, Zhida; Liu, Logan

2014-01-01

Anomalous surface enhanced Raman scattering (SERS) peaks are identified for liquid sample stored in polypropylene centrifuge tubes (PP tube) for months. We observed the unexpected Raman peaks during experiments for Thiamine Hydrochloride aqueous solution stored in PP tube for two months. In order to identify the contaminants we have performed SERS experiments for de-ionized water (DI water) stored in polypropylene centrifuge tube for two months and compared them with fresh DI water sample. We...

Oxide/water interfaces: how the surface chemistry modifies interfacial water properties

International Nuclear Information System (INIS)

Gaigeot, Marie-Pierre; Sprik, Michiel; Sulpizi, Marialore

2012-01-01

The organization of water at the interface with silica and alumina oxides is analysed using density functional theory-based molecular dynamics simulation (DFT-MD). The interfacial hydrogen bonding is investigated in detail and related to the chemistry of the oxide surfaces by computing the surface charge density and acidity. We find that water molecules hydrogen-bonded to the surface have different orientations depending on the strength of the hydrogen bonds and use this observation to explain the features in the surface vibrational spectra measured by sum frequency generation spectroscopy. In particular, ‘ice-like’ and ‘liquid-like’ features in these spectra are interpreted as the result of hydrogen bonds of different strengths between surface silanols/aluminols and water. (paper)

Water's Interfacial Hydrogen Bonding Structure Reveals the Effective Strength of Surface-Water Interactions.

Science.gov (United States)

Shin, Sucheol; Willard, Adam P

2018-06-05

We combine all-atom molecular dynamics simulations with a mean field model of interfacial hydrogen bonding to analyze the effect of surface-water interactions on the structural and energetic properties of the liquid water interface. We show that the molecular structure of water at a weakly interacting ( i.e., hydrophobic) surface is resistant to change unless the strength of surface-water interactions are above a certain threshold. We find that below this threshold water's interfacial structure is homogeneous and insensitive to the details of the disordered surface, however, above this threshold water's interfacial structure is heterogeneous. Despite this heterogeneity, we demonstrate that the equilibrium distribution of molecular orientations can be used to quantify the energetic component of the surface-water interactions that contribute specifically to modifying the interfacial hydrogen bonding network. We identify this specific energetic component as a new measure of hydrophilicity, which we refer to as the intrinsic hydropathy.

Factors affecting the longevity of interim ILW stores, monitoring methods and techniques supporting store life extension - 59151

International Nuclear Information System (INIS)

Morris, Jenny; Wickham, Stephen; Hicks, Tim; Richardson, Phil; McKinney, James; Morris, Darrell; Brownridge, Melanie; Tearle, Mark

2012-01-01

Life-limiting features of stores (i.e. components of a typical Intermediate Level Waste (ILW) store that are vulnerable to failure) can be separated into those related to store design, the continuing operation of the store and equipment and store management. Environmental factors, including temperature, humidity, atmospheric pollutants and radiation fields also affect the longevity of ILW storage buildings and the integrity of the waste packages within the store. The current condition of the store and the causes and rates of any observed deterioration need to be determined to estimate the current operating life of the store and to analyse the costs and benefits associated with life extension. Suitable monitoring techniques and methods for extending the operating life of stores, either by remediation or replacement of identified life-limiting features, have also been assessed. Techniques including visual inspection (directly or by use of CCTV or inspection cells), corrosion coupons, crane monitoring and a wide range of indirect measurement methods can be used to monitor the condition of life-limiting features and the store environment. Methods for extending store life include the application of paint or coatings to retard degradation, use of electro-chemical treatments and repair of the concrete structure or replacement of components. Life-limiting features and environmental factors that affect the longevity of facilities for the interim storage of ILW have been identified through a literature review and Expert Workshop. Monitoring techniques are available for the key life-limiting feature of structural integrity of reinforced concrete, and for the atmospheric or surface concentration of corrosion-accelerating substances. Methods for remediating the reinforced concrete structure or crane rails to increase the expected lifetime of the store are also reviewed. Many of these techniques have previously been used at radioactive waste stores or other nuclear facilities in

An ontology design pattern for surface water features

Science.gov (United States)

Sinha, Gaurav; Mark, David; Kolas, Dave; Varanka, Dalia; Romero, Boleslo E.; Feng, Chen-Chieh; Usery, E. Lynn; Liebermann, Joshua; Sorokine, Alexandre

2014-01-01

Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities exist due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology for other more context-dependent ontologies. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex or specialized surface water ontologies. A fundamental distinction is made in this ontology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is implemented in OWL, but Description Logic axioms and a detailed explanation is provided in this paper. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. Also provided is a discussion of why there is a need to complement the pattern with other ontologies, especially the previously developed Surface Network pattern. Finally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through an annotated geospatial dataset and sample queries using the classes of the Surface Water pattern.

How to repel hot water from a superhydrophobic surface?

KAUST Repository

Yu, Zhejun

2014-01-01

Superhydrophobic surfaces, with water contact angles greater than 150° and slide angles less than 10°, have attracted a great deal of attention due to their self-cleaning ability and excellent water-repellency. It is commonly accepted that a superhydrophobic surface loses its superhydrophobicity in contact with water hotter than 50 °C. Such a phenomenon was recently demonstrated by Liu et al. [J. Mater. Chem., 2009, 19, 5602], using both natural lotus leaf and artificial leaf-like surfaces. However, our work has shown that superhydrophobic surfaces maintained their superhydrophobicity, even in water at 80 °C, provided that the leaf temperature is greater than that of the water droplet. In this paper, we report on the wettability of water droplets on superhydrophobic thin films, as a function of both their temperatures. The results have shown that both the water contact and slide angles on the surfaces will remain unchanged when the temperature of the water droplet is greater than that of the surface. The water contact angle, or the slide angle, will decrease or increase, however, with droplet temperatures increasingly greater than that of the surfaces. We propose that, in such cases, the loss of superhydrophobicity of the surfaces is caused by evaporation of the hot water molecules and their condensation on the cooler surface. © 2014 the Partner Organisations.

Surface freshwater storage and dynamics in the Amazon basin during the 2005 exceptional drought

International Nuclear Information System (INIS)

Frappart, Frédéric; Ramillien, Guillaume; Papa, Fabrice; Calmant, Stéphane; Santos da Silva, Joecila; Prigent, Catherine; Seyler, Frédérique

2012-01-01

The Amazon river basin has been recently affected by extreme climatic events, such as the exceptional drought of 2005, with significant impacts on human activities and ecosystems. In spite of the importance of monitoring freshwater stored and moving in such large river basins, only scarce measurements of river stages and discharges are available and the signatures of extreme drought conditions on surface freshwater dynamics at the basin scale are still poorly known. Here we use continuous multisatellite observations of inundation extent and water levels between 2003 and 2007 to monitor monthly variations of surface water storage at the basin scale. During the 2005 drought, the amount of water stored in the river and floodplains of the Amazon basin was ∼130 km 3 (∼70%) below its 2003–7 average. This represents almost a half of the anomaly of minimum terrestrial water stored in the basin as estimated using the Gravity Recovery and Climate Experiment (GRACE) data. (letter)

Adsorption of surface functionalized silica nanoparticles onto mineral surfaces and decane/water interface

International Nuclear Information System (INIS)

Metin, Cigdem O.; Baran, Jimmie R.; Nguyen, Quoc P.

2012-01-01

The adsorption of silica nanoparticles onto representative mineral surfaces and at the decane/water interface was studied. The effects of particle size (the mean diameters from 5 to 75 nm), concentration and surface type on the adsorption were studied in detail. Silica nanoparticles with four different surfaces [unmodified, surface modified with anionic (sulfonate), cationic (quaternary ammonium (quat)) or nonionic (polyethylene glycol (PEG)) surfactant] were used. The zeta potential of these silica nanoparticles ranges from −79.8 to 15.3 mV. The shape of silica particles examined by a Hitachi-S5500 scanning transmission electron microscope (STEM) is quite spherical. The adsorption of all the nanoparticles (unmodified or surface modified) on quartz and calcite surfaces was found to be insignificant. We used interfacial tension (IFT) measurements to investigate the adsorption of silica nanoparticles at the decane/water interface. Unmodified nanoparticles or surface modified ones with sulfonate or quat do not significantly affect the IFT of the decane/water interface. It also does not appear that the particle size or concentration influences the IFT. However, the presence of PEG as a surface modifying material significantly reduces the IFT. The PEG surface modifier alone in an aqueous solution, without the nanoparticles, yields the same IFT reduction for an equivalent PEG concentration as that used for modifying the surface of nanoparticles. Contact angle measurements of a decane droplet on quartz or calcite plate immersed in water (or aqueous nanoparticle dispersion) showed a slight change in the contact angle in the presence of the studied nanoparticles. The results of contact angle measurements are in good agreement with experiments of adsorption of nanoparticles on mineral surfaces or decane/water interface. This study brings new insights into the understanding and modeling of the adsorption of surface-modified silica nanoparticles onto mineral surfaces and

Radioactivity in surface waters and its effects

International Nuclear Information System (INIS)

Stoeber, I.

1987-01-01

In consequence of the reactor accident in Chernobyl, the State Office for Water and Waste Disposal of North-Rhine Westphalia implemented immediate programmes for monitoring radioactivity in surface waters, including their sediments and organisms. Of the initially-measured radionuclides, only cesium-137, with its long half-life of 30 years, is of interest. Only trace amounts of the almost equally long-lived strontium 90 (half-life 28 years) were present in rainfall. Cs-137 is a non-natural-radionuclide, occurring solely as a by-product of nuclear installations and atomic bomb tests. Following the ban on surface testing of nuclear weapons, the Cs-137 content of surface waters had fallen significantly up to April 1986. The load due to the reactor disaster is of the same order of magnitude as that produced by atomic testing at the end of the nineteen-sixties. The paper surveys radioactive pollution of surface waters in North-Rhine Westphalia and its effects on water use, especially in regard to potable water supplies and the fish population. (orig./HSCH) [de

Ion exchange-based treatment of "6"0Co contaminated well-water for storing γ irradiation source

International Nuclear Information System (INIS)

Bi Meng; Miao Shilin; Zhang Xiaolu; Zhang Youjiu

2014-01-01

Objective: To select an efficient ion exchange resin to purify the "6"0Co contaminated well-water for storing radioactive source and to ensure the radioactivity of "6"0Co in treated well-water below 10 Bq/L. Methods: The radioactivity of "6"0Co in the water samples was measured by using the potassium cobaltinitrite coprecipitation-β counting method. The treatment efficiencies of two different ion exchange resins for the simulated "6"0Co-bearing waste water were compared to select a better one to dispose of the "6"0Co contaminated well-water. Results: The treatment efficiency of MBD-15-SC mixed ion exchange resin was about 5.8 times higher than ZGCNR50 strong-acid cation exchange resin. The radioactivity of "6"0Co in the contaminated well-water could be reduced from 4.16 × 10"5 Bq/L to 1.16 Bq/L by two-stage sorption of MBD-15-SC mixed ion exchange resin. Conclusions: Using several times of two-stage MBD-15-SC mixed ion exchange resin could effectively purify the "6"0Co contaminated well-water. The quality of the treated well-water could meet the sewage discharge standards. (authors)

Surface-Water Data, Georgia, Water Year 1999

Science.gov (United States)

Alhadeff, S. Jack; Landers, Mark N.; McCallum, Brian E.

1999-01-01

Water resources data for the 1999 water year for Georgia consists of records of stage, discharge, and water quality of streams; and the stage and contents of lakes and reservoirs published in one volume in a digital format on a CD-ROM. This volume contains discharge records of 121 gaging stations; stage for 13 gaging stations; stage and contents for 18 lakes and reservoirs; continuous water quality records for 10 stations; and the annual peak stage and annual peak discharge for 75 crest-stage partial-record stations. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Georgia. Records of discharge and stage of streams, and contents or stage of lakes and reservoirs were first published in a series of U.S. Geological water-supply papers entitled, 'Surface-Water Supply of the United States.' Through September 30, 1960, these water-supply papers were in an annual series and then in a 5-year series for 1961-65 and 1966-70. Records of chemical quality, water temperature, and suspended sediment were published from 1941 to 1970 in an annual series of water-supply papers entitled, 'Quality of Surface Waters of the United States.' Records of ground-water levels were published from 1935 to 1974 in a series of water-supply papers entitled, 'Ground-Water Levels in the United States.' Water-supply papers may be consulted in the libraries of the principal cities in the United States or may be purchased from the U.S. Geological Survey, Branch of Information Services, Federal Center, Box 25286, Denver, CO 80225. For water years 1961 through 1970, streamflow data were released by the U.S. Geological Survey in annual reports on a State-boundary basis prior to the two 5-year series water-supply papers, which cover this period. The data contained in the water-supply papers are considered the official record. Water-quality records for water years 1964 through 1970 were similarly released

Store manager performance and satisfaction: effects on store employee performance and satisfaction, store customer satisfaction, and store customer spending growth.

Science.gov (United States)

Netemeyer, Richard G; Maxham, James G; Lichtenstein, Donald R

2010-05-01

Based on emotional contagion theory and the value-profit chain literatures, the present study posits a number of hypotheses that show how managers in the small store, small number of employees retail context may affect store employees, customers, and potentially store performance. With data from 306 store managers, 1,615 store customer-contact employees, and 57,656 customers of a single retail chain, the authors examined relationships among store manager job satisfaction and job performance, store customer-contact employee job satisfaction and job performance, customer satisfaction with the retailer, and a customer-spending-based store performance metric (customer spending growth over a 2-year period). Via path analysis, several hypothesized direct and interaction relations among these constructs are supported. The results suggest implications for academic researchers and retail managers. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Antarctic Ice Shelf Potentially Stabilized by Export of Meltwater in Surface River

Science.gov (United States)

Bell, Robin E.; Chu, Winnie; Kingslake, Jonathan; Das, Indrani; Tedesco, Marco; Tinto, Kirsty J.; Zappa, Christopher J.; Frezzotti, Massimo; Boghosian, Alexandra; Lee, Won Sang

2017-01-01

Meltwater stored in ponds and crevasses can weaken and fracture ice shelves, triggering their rapid disintegration. This ice-shelf collapse results in an increased flux of ice from adjacent glaciers and ice streams, thereby raising sea level globally. However, surface rivers forming on ice shelves could potentially export stored meltwater and prevent its destructive effects. Here we present evidence for persistent active drainage networks-interconnected streams, ponds and rivers-on the Nansen Ice Shelf in Antarctica that export a large fraction of the ice shelf's meltwater into the ocean. We find that active drainage has exported water off the ice surface through waterfalls and dolines for more than a century. The surface river terminates in a 130-metre-wide waterfall that can export the entire annual surface melt over the course of seven days. During warmer melt seasons, these drainage networks adapt to changing environmental conditions by remaining active for longer and exporting more water. Similar networks are present on the ice shelf in front of Petermann Glacier, Greenland, but other systems, such as on the Larsen C and Amery Ice Shelves, retain surface water at present. The underlying reasons for export versus retention remain unclear. Nonetheless our results suggest that, in a future warming climate, surface rivers could export melt off the large ice shelves surrounding Antarctica-contrary to present Antarctic ice-sheet models, which assume that meltwater is stored on the ice surface where it triggers ice-shelf disintegration.

Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

OpenAIRE

Kostik, Vesna; Bauer, Biljana; Kavrakovski, Zoran

2014-01-01

The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupl...

Presence and risk assessment of pharmaceuticals in surface water and drinking water

DEFF Research Database (Denmark)

Sanderson, Hans

2011-01-01

Trace amounts of pharmaceuticals have been detected in surface waters in the nano- to microgram per liter range, and in drinking water in the nanogram/L range. The environmental risks of pharmaceuticals in surface waters have been evaluated and generally found to be low if the wastewater is treated...

Anomalous water dynamics at surfaces and interfaces: synergistic effects of confinement and surface interactions

Science.gov (United States)

Biswas, Rajib; Bagchi, Biman

2018-01-01

In nature, water is often found in contact with surfaces that are extended on the scale of molecule size but small on a macroscopic scale. Examples include lipid bilayers and reverse micelles as well as biomolecules like proteins, DNA and zeolites, to name a few. While the presence of surfaces and interfaces interrupts the continuous hydrogen bond network of liquid water, confinement on a mesoscopic scale introduces new features. Even when extended on a molecular scale, natural and biological surfaces often have features (like charge, hydrophobicity) that vary on the scale of the molecular diameter of water. As a result, many new and exotic features, which are not seen in the bulk, appear in the dynamics of water close to the surface. These different behaviors bear the signature of both water-surface interactions and of confinement. In other words, the altered properties are the result of the synergistic effects of surface-water interactions and confinement. Ultrafast spectroscopy, theoretical modeling and computer simulations together form powerful synergistic approaches towards an understanding of the properties of confined water in such systems as nanocavities, reverse micelles (RMs), water inside and outside biomolecules like proteins and DNA, and also between two hydrophobic walls. We shall review the experimental results and place them in the context of theory and simulations. For water confined within RMs, we discuss the possible interference effects propagating from opposite surfaces. Similar interference is found to give rise to an effective attractive force between two hydrophobic surfaces immersed and kept fixed at a separation of d, with the force showing an exponential dependence on this distance. For protein and DNA hydration, we shall examine a multitude of timescales that arise from frustration effects due to the inherent heterogeneity of these surfaces. We pay particular attention to the role of orientational correlations and modification of the

40 CFR 257.3-3 - Surface water.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Surface water. 257.3-3 Section 257.3-3... and Practices § 257.3-3 Surface water. (a) For purposes of section 4004(a) of the Act, a facility... Water Act, as amended. (b) For purposes of section 4004(a) of the Act, a facility shall not cause a...

Atmospheric Water Harvesting: Role of Surface Wettability and Edge Effect

KAUST Repository

Jin, Yong

2017-06-23

Atmospheric water is emerging as an important potable water source. The present work experimentally and theoretically investigates water condensation and collection on flat surfaces with contrasting contact angles and contact angle hysteresis (CAH) to elucidate their roles on water mass collection efficiency. The experimental results indicate that a hydrophilic surface promotes nucleation and individual droplets growth, and a surface with a low CAH tends to let a smaller droplet to slide down, but the overall water mass collection efficiency is independent of both surface contact angle and CAH. The experimental results agree well with our theoretical calculations. During water condensation, a balance has to be struck between single droplet growth and droplet density on a surface so as to maintain a constant water droplet surface coverage ratio, which renders the role of both surface wettability and hysteresis insignificant to the ultimate water mass collection. Moreover, water droplets on the edges of a surface grow much faster than those on the non-edge areas and thus dominate the contribution to the water mass collection by the entire surface, directly pointing out the very important role of edge effect on water condensation and collection.

Microbiological and Chemical Quality of Packaged Sachet Water and Household Stored Drinking Water in Freetown, Sierra Leone.

Science.gov (United States)

Fisher, Michael B; Williams, Ashley R; Jalloh, Mohamed F; Saquee, George; Bain, Robert E S; Bartram, Jamie K

2015-01-01

Packaged drinking water (PW) sold in bottles and plastic bags/sachets is widely consumed in low- and middle-income countries (LMICs), and many urban users in sub-Saharan Africa (SSA) rely on packaged sachet water (PSW) as their primary source of water for consumption. However, few rigorous studies have investigated PSW quality in SSA, and none have compared PSW to stored household water for consumption (HWC). A clearer understanding of PSW quality in the context of alternative sources is needed to inform policy and regulation. As elsewhere in SSA, PSW is widely consumed in Sierra Leone, but government oversight is nearly nonexistent. This study examined the microbiological and chemical quality of a representative sample of PSW products in Freetown, Sierra Leone at packaged water manufacturing facilities (PWMFs) and at points of sale (POSs). Samples of HWC were also analyzed for comparison. The study did not find evidence of serious chemical contamination among the parameters studied. However, 19% of 45 PSW products sampled at the PWMF contained detectable Escherichia coli (EC), although only two samples exceeded 10 CFU/100 mL. Concentrations of total coliforms (TC) in PSW (but not EC) increased along the supply chain. Samples of HWC from 60 households in Freetown were significantly more likely to contain EC and TC than PSW at the point of production (p<0.01), and had significantly higher concentrations of both bacterial indicators (p<0.01). These results highlight the need for additional PSW regulation and surveillance, while demonstrating the need to prioritize the safety of HWC. At present, PSW may be the least unsafe option for many households.

Storing Hydrogen, by Enhancing Diamond Powder Properties under Hydrogen Plasma with CaF2 and KF for Use in Fuel Cells

International Nuclear Information System (INIS)

Ochoa, Franklyn E. Colmenares

2006-01-01

A fuel cell is like a battery that instead of using electricity to recharge itself, it uses hydrogen. In the fuel cell industry, one of the main problems is storing hydrogen in a safe way and extracting it economically. Gaseous hydrogen requires high pressures which could be very dangerous in case of a collision. The success of hydrogen use depends largely on the development of an efficient storage and release method. In an effort to develop a better hydrogen storage system for fuel cells technology this research investigates the use of 99% pure diamond powder for storing hydrogen. Mixing this powder with a calcium fluoride and potassium fluoride compound in its solid form and treating the surface of the powder with hydrogen plasma, modifies the surface of the diamond. After some filtration through distilled water and drying, the modified diamond is treated with hydrogen. We expect hydrogen to be attracted to the diamond powder surface in higher quantities due to the CaF2 and KF treatment. Due to the large surface area of diamond nanopowder and the electronegative terminal bonds of the fluorine particles on the structure's surface, to the method shows promise in storing high densities of hydrogen

Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions.

Directory of Open Access Journals (Sweden)

Maryna Kapustina

2016-03-01

Full Text Available Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs, whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model "learns" from the thin section transmission electron micrograph image (2D or the "seed and growth" model image (3D. Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts.

Modelling global fresh surface water temperature

NARCIS (Netherlands)

Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

2011-01-01

Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

An Ontology Design Pattern for Surface Water Features

Energy Technology Data Exchange (ETDEWEB)

Sinha, Gaurav [Ohio University; Mark, David [University at Buffalo (SUNY); Kolas, Dave [Raytheon BBN Technologies; Varanka, Dalia [U.S. Geological Survey, Rolla, MO; Romero, Boleslo E [University of California, Santa Barbara; Feng, Chen-Chieh [National University of Singapore; Usery, Lynn [U.S. Geological Survey, Rolla, MO; Liebermann, Joshua [Tumbling Walls, LLC; Sorokine, Alexandre [ORNL

2014-01-01

Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities can be found due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology. It can then be used to systematically incor-porate concepts that are specific to a culture, language, or scientific domain. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex surface water ontologies. A fundamental distinction is made in this on-tology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is imple-mented in OWL, but Description Logic axioms and a detailed explanation is provided. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. A discussion about why there is a need to complement the pattern with other ontologies, es-pecially the previously developed Surface Network pattern is also provided. Fi-nally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through a few queries and annotated geospatial datasets.

Surface-Water Conditions in Georgia, Water Year 2005

Science.gov (United States)

Painter, Jaime A.; Landers, Mark N.

2007-01-01

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

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

African Journals Online (AJOL)

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

Surface water quality assessment using factor analysis

African Journals Online (AJOL)

2006-01-16

Jan 16, 2006 ... Surface water, groundwater quality assessment and environ- .... Urbanisation influences the water cycle through changes in flow and water ..... tion of aquatic life, CCME water quality Index 1, 0. User`s ... Water, Air Soil Pollut.

Rapid surface-water volume estimations in beaver ponds

Science.gov (United States)

Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

2017-02-01

Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

Global modelling of Cryptosporidium in surface water

Science.gov (United States)

Vermeulen, Lucie; Hofstra, Nynke

2016-04-01

Introduction Waterborne pathogens that cause diarrhoea, such as Cryptosporidium, pose a health risk all over the world. In many regions quantitative information on pathogens in surface water is unavailable. Our main objective is to model Cryptosporidium concentrations in surface waters worldwide. We present the GloWPa-Crypto model and use the model in a scenario analysis. A first exploration of global Cryptosporidium emissions to surface waters has been published by Hofstra et al. (2013). Further work has focused on modelling emissions of Cryptosporidium and Rotavirus to surface waters from human sources (Vermeulen et al 2015, Kiulia et al 2015). A global waterborne pathogen model can provide valuable insights by (1) providing quantitative information on pathogen levels in data-sparse regions, (2) identifying pathogen hotspots, (3) enabling future projections under global change scenarios and (4) supporting decision making. Material and Methods GloWPa-Crypto runs on a monthly time step and represents conditions for approximately the year 2010. The spatial resolution is a 0.5 x 0.5 degree latitude x longitude grid for the world. We use livestock maps (http://livestock.geo-wiki.org/) combined with literature estimates to calculate spatially explicit livestock Cryptosporidium emissions. For human Cryptosporidium emissions, we use UN population estimates, the WHO/UNICEF JMP sanitation country data and literature estimates of wastewater treatment. We combine our emissions model with a river routing model and data from the VIC hydrological model (http://vic.readthedocs.org/en/master/) to calculate concentrations in surface water. Cryptosporidium survival during transport depends on UV radiation and water temperature. We explore pathogen emissions and concentrations in 2050 with the new Shared Socio-economic Pathways (SSPs) 1 and 3. These scenarios describe plausible future trends in demographics, economic development and the degree of global integration. Results and

Assessing Near-surface Heat, Water Vapor and Carbon Dioxide Exchange Over a Coastal Salt-marsh

Science.gov (United States)

Bogoev, I.; O'Halloran, T. L.; LeMoine, J.

2017-12-01

Coastal ecosystems play an important role in mitigating the effects of climate change by storing significant quantities of carbon. A growing number of studies suggest that vegetated estuarine habitats, specifically salt marshes, have high long-term rates of carbon sequestration, perhaps even higher than mature tropical and temperate forests. Large amounts of carbon, accumulated over thousands of years, are stored in the plant materials and sediment. Improved understanding of the factors that control energy and carbon exchange is needed to better guide restoration and conservation management practices. To that end, we recently established an observation system to study marsh-atmosphere interactions within the North Inlet-Winyah Bay National Estuarine Research Reserve. Near-surface fluxes of heat, water vapor (H2O) and carbon dioxide (CO2) were measured by an eddy-covariance system consisting of an aerodynamic open-path H2O / CO2 gas analyzer with a spatially integrated 3D sonic anemometer/thermometer (IRGASON). The IRGASON instrument provides co-located and highly synchronized, fast response H2O, CO2 and air- temperature measurements, which eliminates the need for spectral corrections associated with the separation between the sonic anemometer and the gas analyzer. This facilitates calculating the instantaneous CO2 molar mixing ratio relative to dry air. Fluxes computed from CO2 and H2O mixing ratios, which are conserved quantities, do not require post-processing corrections for air-density changes associated with temperature and water vapor fluctuations. These corrections are particularly important for CO2, because they could be even larger than the measured flux. Here we present the normalized frequency spectra of air temperature, water vapor and CO2, as well as their co-spectra with the co-located vertical wind. We also show mean daily cycles of sensible, latent and CO2 fluxes and analyze correlations with air/water temperature, wind speed and light availability.

Desert Beetle-Inspired Superwettable Patterned Surfaces for Water Harvesting.

Science.gov (United States)

Yu, Zhenwei; Yun, Frank F; Wang, Yanqin; Yao, Li; Dou, Shixue; Liu, Kesong; Jiang, Lei; Wang, Xiaolin

2017-09-01

With the impacts of climate change and impending crisis of clean drinking water, designing functional materials for water harvesting from fog with large water capacity has received much attention in recent years. Nature has evolved different strategies for surviving dry, arid, and xeric conditions. Nature is a school for human beings. In this contribution, inspired by the Stenocara beetle, superhydrophilic/superhydrophobic patterned surfaces are fabricated on the silica poly(dimethylsiloxane) (PDMS)-coated superhydrophobic surfaces using a pulsed laser deposition approach with masks. The resultant samples with patterned wettability demonstrate water-harvesting efficiency in comparison with the silica PDMS-coated superhydrophobic surface and the Pt nanoparticles-coated superhydrophilic surface. The maximum water-harvesting efficiency can reach about 5.3 g cm -2 h -1 . Both the size and the percentage of the Pt-coated superhydrophilic square regions on the patterned surface affect the condensation and coalescence of the water droplet, as well as the final water-harvesting efficiency. The present water-harvesting strategy should provide an avenue to alleviate the water crisis facing mankind in certain arid regions of the world. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

chemical and microbiological assessment of surface water samples

African Journals Online (AJOL)

PROF EKWUEME

concentrations and bacteriological content. Evaluation of the results ... and Aninri local government areas of Enugu state. Surface water ... surface water bodies are prone to impacts from ... Coal Measures (Akamigbo, 1987). The geologic map ...

Walmart Experimental Store Performance Stories: Preprint

Energy Technology Data Exchange (ETDEWEB)

Deru, M.; Kozubal, E.; Norton, P.

2010-08-01

Walmart opened two experimental stores--one in Colorado and one in Texas--in 2005 to serve as test beds for several advanced building systems. Each embodied more than 50 experiments covering materials, water systems, energy systems, and renewable energy production. Walmart worked for three years with the National Renewable Energy Laboratory for the Colorado Store and Oak Ridge National Laboratory for the Texas store to monitor, analyze, and report on their performance. HVAC experiments included waste oil boilers, a microturbine/absorption chiller combined heat and power system, evaporative cooling, and a transpired solar collector. The refrigeration systems integrated a medium-temperature secondary loop, evaporatively cooled condenser, doors on medium-temperature cases, and light-emitting diodes on cases. Experiments in the lighting systems included a redesigned roof for clerestory daylighting and T-5 fluorescent lamps. Three photovoltaic systems for a total of 135 kW and a 50-kW wind turbine are also included. The energy system performance was compared to the measured performance of a prototypical Walmart store and to other benchmarks.

A deformable surface model for real-time water drop animation.

Science.gov (United States)

Zhang, Yizhong; Wang, Huamin; Wang, Shuai; Tong, Yiying; Zhou, Kun

2012-08-01

A water drop behaves differently from a large water body because of its strong viscosity and surface tension under the small scale. Surface tension causes the motion of a water drop to be largely determined by its boundary surface. Meanwhile, viscosity makes the interior of a water drop less relevant to its motion, as the smooth velocity field can be well approximated by an interpolation of the velocity on the boundary. Consequently, we propose a fast deformable surface model to realistically animate water drops and their flowing behaviors on solid surfaces. Our system efficiently simulates water drop motions in a Lagrangian fashion, by reducing 3D fluid dynamics over the whole liquid volume to a deformable surface model. In each time step, the model uses an implicit mean curvature flow operator to produce surface tension effects, a contact angle operator to change droplet shapes on solid surfaces, and a set of mesh connectivity updates to handle topological changes and improve mesh quality over time. Our numerical experiments demonstrate a variety of physically plausible water drop phenomena at a real-time rate, including capillary waves when water drops collide, pinch-off of water jets, and droplets flowing over solid materials. The whole system performs orders-of-magnitude faster than existing simulation approaches that generate comparable water drop effects.

Created mangrove wetlands store belowground carbon and surface elevation change enables them to adjust to sea-level rise

Science.gov (United States)

Krauss, Ken W.; Cormier, Nicole; Osland, Michael J.; Kirwan, Matthew L.; Stagg, Camille L.; Nestlerode, Janet A.; Russell, Marc J.; From, Andrew; Spivak, Amanda C.; Dantin, Darrin D.; Harvey, James E.; Almario, Alejandro E.

2017-01-01

Mangrove wetlands provide ecosystem services for millions of people, most prominently by providing storm protection, food and fodder. Mangrove wetlands are also valuable ecosystems for promoting carbon (C) sequestration and storage. However, loss of mangrove wetlands and these ecosystem services are a global concern, prompting the restoration and creation of mangrove wetlands as a potential solution. Here, we investigate soil surface elevation change, and its components, in created mangrove wetlands over a 25 year developmental gradient. All created mangrove wetlands were exceeding current relative sea-level rise rates (2.6 mm yr−1), with surface elevation change of 4.2–11.0 mm yr−1 compared with 1.5–7.2 mm yr−1 for nearby reference mangroves. While mangrove wetlands store C persistently in roots/soils, storage capacity is most valuable if maintained with future sea-level rise. Through empirical modeling, we discovered that properly designed creation projects may not only yield enhanced C storage, but also can facilitate wetland persistence perennially under current rates of sea-level rise and, for most sites, for over a century with projected medium accelerations in sea-level rise (IPCC RCP 6.0). Only the fastest projected accelerations in sea-level rise (IPCC RCP 8.5) led to widespread submergence and potential loss of stored C for created mangrove wetlands before 2100.

Created mangrove wetlands store belowground carbon and surface elevation change enables them to adjust to sea-level rise.

Science.gov (United States)

Krauss, Ken W; Cormier, Nicole; Osland, Michael J; Kirwan, Matthew L; Stagg, Camille L; Nestlerode, Janet A; Russell, Marc J; From, Andrew S; Spivak, Amanda C; Dantin, Darrin D; Harvey, James E; Almario, Alejandro E

2017-04-21

Mangrove wetlands provide ecosystem services for millions of people, most prominently by providing storm protection, food and fodder. Mangrove wetlands are also valuable ecosystems for promoting carbon (C) sequestration and storage. However, loss of mangrove wetlands and these ecosystem services are a global concern, prompting the restoration and creation of mangrove wetlands as a potential solution. Here, we investigate soil surface elevation change, and its components, in created mangrove wetlands over a 25 year developmental gradient. All created mangrove wetlands were exceeding current relative sea-level rise rates (2.6 mm yr -1 ), with surface elevation change of 4.2-11.0 mm yr -1 compared with 1.5-7.2 mm yr -1 for nearby reference mangroves. While mangrove wetlands store C persistently in roots/soils, storage capacity is most valuable if maintained with future sea-level rise. Through empirical modeling, we discovered that properly designed creation projects may not only yield enhanced C storage, but also can facilitate wetland persistence perennially under current rates of sea-level rise and, for most sites, for over a century with projected medium accelerations in sea-level rise (IPCC RCP 6.0). Only the fastest projected accelerations in sea-level rise (IPCC RCP 8.5) led to widespread submergence and potential loss of stored C for created mangrove wetlands before 2100.

Wetlands inform how climate extremes influence surface water expansion and contraction

Science.gov (United States)

Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.

2018-03-01

Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage

Wetlands inform how climate extremes influence surface water expansion and contraction

Science.gov (United States)

Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.

2018-01-01

Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic

Wetlands inform how climate extremes influence surface water expansion and contraction

Directory of Open Access Journals (Sweden)

M. K. Vanderhoof

2018-03-01

Full Text Available Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1 quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR and adjacent Northern Prairie (NP in the United States, and (2 explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015. The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density. To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less

Potentially hazardous substances in surface waters. II. Cholinesterase inhibitors in Dutch surface waters

NARCIS (Netherlands)

Greve, P.A.; Freudenthal, J.; Wit, S.L.

1972-01-01

Several analytical methods were employed to determine the concentrations of cholinesterase inhibitors in several Dutch surface waters. An Auto-Analyzer method was used for screening purposes; thin-layer chromatography and gas-liquid chromatography-mass spectrometry were used for identification and

Cooperativity in Surface Bonding and Hydrogen Bonding of Water and Hydroxyl at Metal Surfaces

DEFF Research Database (Denmark)

Schiros, T.; Ogasawara, H.; Naslund, L. A.

2010-01-01

of the mixed phase at metal surfaces. The surface bonding can be considered to be similar to accepting a hydrogen bond, and we can thereby apply general cooperativity rules developed for hydrogen-bonded systems. This provides a simple understanding of why water molecules become more strongly bonded...... to the surface upon hydrogen bonding to OH and why the OH surface bonding is instead weakened through hydrogen bonding to water. We extend the application of this simple model to other observed cooperativity effects for pure water adsorption systems and H3O+ on metal surfaces.......We examine the balance of surface bonding and hydrogen bonding in the mixed OH + H2O overlayer on Pt(111), Cu(111), and Cu(110) via density functional theory calculations. We find that there is a cooperativity effect between surface bonding and hydrogen bonding that underlies the stability...

Surface wastewater in Samara and their impact on water basins as water supply sources

Science.gov (United States)

Strelkov, Alexander; Shuvalov, Mikhail; Gridneva, Marina

2017-10-01

The paper gives an overview of surface wastewater outlets in Samara through the rainwater sewer system into the Saratov water reservoir and the Samara river. The rainwater sewer system in Samara is designed and executed according to a separate scheme, except for the old part of the city, where surface run-off is dumped into the sewer system through siphoned drain. The rainwater system disposes of surface, drainage, industrial clean-contamined waters, emergency and technology discharges from the city’s heat supply and water supply systems. The effluent discharge is carried out by means of separate wastewater outlets into ravines or directly into the Samara river and the Saratov water reservoir without cleaning. The effluent discharge is carried out through the rainwater sewer system with 17 wastewater outlets into the Saratov water reservoir. In the Samara river, surface runoff drainage and clean-contamined water of industrial enterprises is carried out through 14 wastewater outlets. This study emphasizes the demand to arrange effluent discharge and construction of sewage treatment plants to prevent contamination of water objects by surface run-off from residential areas and industrial territories.

Escape jumping by three age-classes of water striders from smooth, wavy and bubbling water surfaces.

Science.gov (United States)

Ortega-Jimenez, Victor Manuel; von Rabenau, Lisa; Dudley, Robert

2017-08-01

Surface roughness is a ubiquitous phenomenon in both oceanic and terrestrial waters. For insects that live at the air-water interface, such as water striders, non-linear and multi-scale perturbations produce dynamic surface deformations which may impair locomotion. We studied escape jumps of adults, juveniles and first-instar larvae of the water strider Aquarius remigis on smooth, wave-dominated and bubble-dominated water surfaces. Effects of substrate on takeoff jumps were substantial, with significant reductions in takeoff angles, peak translational speeds, attained heights and power expenditure on more perturbed water surfaces. Age effects were similarly pronounced, with the first-instar larvae experiencing the greatest degradation in performance; age-by-treatment effects were also significant for many kinematic variables. Although commonplace in nature, perturbed water surfaces thus have significant and age-dependent effects on water strider locomotion, and on behavior more generally of surface-dwelling insects. © 2017. Published by The Company of Biologists Ltd.

Partitioning of water between surface and mantle on terrestrial exoplanets: effect of surface-mantle water exchange parameterizations on ocean depth

Science.gov (United States)

Komacek, T. D.; Abbot, D. S.

2016-12-01

Terrestrial exoplanets in the canonical habitable zone may have a variety of initial water fractions due to their volatile delivery rate via planetesimals. If the total planetary water complement is high, the entire surface may be covered in water, forming a "waterworld". The habitable zone for waterworlds is likely smaller than that for planets with partial land coverage because waterworlds lack the stabilizing silicate-weathering feedback. On a planet with active tectonics, competing mechanisms act to regulate the abundance of water on the surface by determining the partitioning of water between interior and surface. We have explored how the incorporation of different mechanisms for the outgassing and regassing of water changes the volatile evolution of a planet. Specifically, we have examined three models for volatile cycling: a model with degassing and regassing both determined by the seafloor pressure, one with mantle temperature-dependent degassing and regassing rates, and a hybrid model that has the degassing rate driven by seafloor pressure and the regassing rate determined by the mantle temperature. We find that the volatile cycling in all three of these scenarios reaches a steady-state after a few billion years. Using these steady-states, we can make predictions from each model for how much water is needed to flood the surface and make a waterworld. We find that if volatile cycling is either solely temperature-dependent or pressure-dependent, exoplanets require a high abundance (more than 0.3% by mass) of water to have fully inundated surfaces. This is because the waterworld boundary for these models is regulated by how much water can be stuffed into the mantle. However, if degassing is more dependent on the seafloor pressure and regassing mainly dependent on mantle temperature, super-Earth mass planets with a total water fraction similar to that of the Earth (approximately 0.05% by mass) can become waterworlds. As a result, further understanding of the

A GPU-based mipmapping method for water surface visualization

Science.gov (United States)

Li, Hua; Quan, Wei; Xu, Chao; Wu, Yan

2018-03-01

Visualization of water surface is a hot topic in computer graphics. In this paper, we presented a fast method to generate wide range of water surface with good image quality both near and far from the viewpoint. This method utilized uniform mesh and Fractal Perlin noise to model water surface. Mipmapping technology was enforced to the surface textures, which adjust the resolution with respect to the distance from the viewpoint and reduce the computing cost. Lighting effect was computed based on shadow mapping technology, Snell's law and Fresnel term. The render pipeline utilizes a CPU-GPU shared memory structure, which improves the rendering efficiency. Experiment results show that our approach visualizes water surface with good image quality at real-time frame rates performance.

Specialty Store and Multi-Brand Store loyalty: An Indian consumer perspective

Directory of Open Access Journals (Sweden)

Sarabjot Singh

2013-12-01

Full Text Available In the competitive era of retailing, retailers need to understand the importance of store format preferences. The study aimed to understand consumer store loyalty; in-depth interview was conducted to examine consumer store loyalty antecedents for two retail formats: specialty stores and multi brand stores. The study conceptualizes store loyalty factors like program loyalty, trust and brand commitment. Trust and brand commitment act as mediating factors between store image and store loyalty formats, and also between brand image and store loyalty formats. The findings highlight how consumer store loyalty preference differ for these two formats.

Water surface coverage effects on reactivity of plasma oxidized Ti films

International Nuclear Information System (INIS)

Pranevicius, L.; Pranevicius, L.L.; Vilkinis, P.; Baltaragis, S.; Gedvilas, K.

2014-01-01

Highlights: • The reactivity of Ti films immersed in water vapor plasma depends on the surface water coverage. • The adsorbed water monolayers are disintegrated into atomic constituents on the hydrophilic TiO 2 under plasma radiation. • The TiO 2 surface covered by water multilayer loses its ability to split adsorbed water molecules under plasma radiation. - Abstract: The behavior of the adsorbed water on the surface of thin sputter deposited Ti films maintained at room temperature was investigated in dependence on the thickness of the resulting adsorbed water layer, controllably injecting water vapor into plasma. The surface morphology and microstructure were used to characterize the surfaces of plasma treated titanium films. Presented experimental results showed that titanium films immersed in water vapor plasma at pressure of 10–100 Pa promoted the photocatalytic activity of overall water splitting. The surfaces of plasma oxidized titanium covered by an adsorbed hydroxyl-rich island structure water layer and activated by plasma radiation became highly chemically reactive. As water vapor pressure increased up to 300–500 Pa, the formed water multilayer diminished the water oxidation and, consequently, water splitting efficiency decreased. Analysis of the experimental results gave important insights into the role an adsorbed water layer on surface of titanium exposed to water vapor plasma on its chemical activity and plasma activated electrochemical processes, and elucidated the surface reactions that could lead to the split of water molecules

Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

Science.gov (United States)

Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

2004-01-01

Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and 'bomb-pulse' tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the

Water vapor retrieval over many surface types

Energy Technology Data Exchange (ETDEWEB)

Borel, C.C.; Clodius, W.C.; Johnson, J.

1996-04-01

In this paper we present a study of of the water vapor retrieval for many natural surface types which would be valuable for multi-spectral instruments using the existing Continuum Interpolated Band Ratio (CIBR) for the 940 nm water vapor absorption feature. An atmospheric code (6S) and 562 spectra were used to compute the top of the atmosphere radiance near the 940 nm water vapor absorption feature in steps of 2.5 nm as a function of precipitable water (PW). We derive a novel technique called ``Atmospheric Pre-corrected Differential Absorption`` (APDA) and show that APDA performs better than the CIBR over many surface types.

Thermodynamic properties of water solvating biomolecular surfaces

Science.gov (United States)

Heyden, Matthias

Changes in the potential energy and entropy of water molecules hydrating biomolecular interfaces play a significant role for biomolecular solubility and association. Free energy perturbation and thermodynamic integration methods allow calculations of free energy differences between two states from simulations. However, these methods are computationally demanding and do not provide insights into individual thermodynamic contributions, i.e. changes in the solvent energy or entropy. Here, we employ methods to spatially resolve distributions of hydration water thermodynamic properties in the vicinity of biomolecular surfaces. This allows direct insights into thermodynamic signatures of the hydration of hydrophobic and hydrophilic solvent accessible sites of proteins and small molecules and comparisons to ideal model surfaces. We correlate dynamic properties of hydration water molecules, i.e. translational and rotational mobility, to their thermodynamics. The latter can be used as a guide to extract thermodynamic information from experimental measurements of site-resolved water dynamics. Further, we study energy-entropy compensations of water at different hydration sites of biomolecular surfaces. This work is supported by the Cluster of Excellence RESOLV (EXC 1069) funded by the Deutsche Forschungsgemeinschaft.

Nanofiltration in Transforming Surface Water into Healthy Water: Comparison with Reverse Osmosis

Directory of Open Access Journals (Sweden)

L. D. Naidu

2015-01-01

Full Text Available The natural surface water, especially available through rivers, is the main source of healthy water for the living beings throughout the world from ancient days as it consists of all essential minerals. With the advent of industrialization, gradually even the most prominent rivers have been polluted in all parts of the world. Although there are lots of technologies, nanofiltration (NF has been chosen to transform river water into healthy water due to its unique advantages of retaining optimum TDS (with essential minerals required for human body, consuming of lower energy, and no usage of any chemicals. The prominent parameters of surface water and macro/microminerals of treated water have been analyzed. It is shown that NF is better in producing healthy water with high flux by consuming low energy.

Surface water acidification and critical loads: exploring the F-factor

Directory of Open Access Journals (Sweden)

K. Bishop

2009-11-01

Full Text Available As acid deposition decreases, uncertainties in methods for calculating critical loads become more important when judgements have to be made about whether or not further emission reductions are needed. An important aspect of one type of model that has been used to calculate surface water critical loads is the empirical F-factor which estimates the degree to which acid deposition is neutralised before it reaches a lake at any particular point in time relative to the pre-industrial, steady-state water chemistry conditions.

In this paper we will examine how well the empirical F-functions are able to estimate pre-industrial lake chemistry as lake chemistry changes during different phases of acidification and recovery. To accomplish this, we use the dynamic, process-oriented biogeochemical model SAFE to generate a plausible time series of annual runoff chemistry for ca. 140 Swedish catchments between 1800 and 2100. These annual hydrochemistry data are then used to generate empirical F-factors that are compared to the "actual" F-factor seen in the SAFE data for each lake and year in the time series. The dynamics of the F-factor as catchments acidify, and then recover are not widely recognised.

Our results suggest that the F-factor approach worked best during the acidification phase when soil processes buffer incoming acidity. However, the empirical functions for estimating F from contemporary lake chemistry are not well suited to the recovery phase when the F-factor turns negative due to recovery processes in the soil. This happens when acid deposition has depleted the soil store of BC, and then acid deposition declines, reducing the leaching of base cations to levels below those in the pre-industrial era. An estimate of critical load from water chemistry during recovery and empirical F functions would therefore result in critical loads that are too low. Therefore, the empirical estimates of the F-factor are a significant source of

Dynamics of ice nucleation on water repellent surfaces.

Science.gov (United States)

Alizadeh, Azar; Yamada, Masako; Li, Ri; Shang, Wen; Otta, Shourya; Zhong, Sheng; Ge, Liehui; Dhinojwala, Ali; Conway, Ken R; Bahadur, Vaibhav; Vinciquerra, A Joseph; Stephens, Brian; Blohm, Margaret L

2012-02-14

Prevention of ice accretion and adhesion on surfaces is relevant to many applications, leading to improved operation safety, increased energy efficiency, and cost reduction. Development of passive nonicing coatings is highly desirable, since current antiicing strategies are energy and cost intensive. Superhydrophobicity has been proposed as a lead passive nonicing strategy, yet the exact mechanism of delayed icing on these surfaces is not clearly understood. In this work, we present an in-depth analysis of ice formation dynamics upon water droplet impact on surfaces with different wettabilities. We experimentally demonstrate that ice nucleation under low-humidity conditions can be delayed through control of surface chemistry and texture. Combining infrared (IR) thermometry and high-speed photography, we observe that the reduction of water-surface contact area on superhydrophobic surfaces plays a dual role in delaying nucleation: first by reducing heat transfer and second by reducing the probability of heterogeneous nucleation at the water-substrate interface. This work also includes an analysis (based on classical nucleation theory) to estimate various homogeneous and heterogeneous nucleation rates in icing situations. The key finding is that ice nucleation delay on superhydrophobic surfaces is more prominent at moderate degrees of supercooling, while closer to the homogeneous nucleation temperature, bulk and air-water interface nucleation effects become equally important. The study presented here offers a comprehensive perspective on the efficacy of textured surfaces for nonicing applications.

Roles of surface water areas for water and solute cycle in Hanoi city, Viet Nam

Science.gov (United States)

Hayashi, Takeshi; Kuroda, Keisuke; Do Thuan, An; Tran Thi Viet, Nga; Takizawa, Satoshi

2013-04-01

Hanoi city, the capital of Viet Nam, has developed beside the Red river. Recent rapid urbanization of this city has reduced a large number of natural water areas such as lakes, ponds and canals not only in the central area but the suburban area. Contrary, the urbanization has increased artificial water areas such as pond for fish cultivation and landscaping. On the other hand, the urbanization has induced the inflow of waste water from households and various kinds of factories to these water areas because of delay of sewerage system development. Inflow of the waste water has induced eutrophication and pollution of these water areas. Also, there is a possibility of groundwater pollution by infiltration of polluted surface water. However, the role of these water areas for water cycle and solute transport is not clarified. Therefore, this study focuses on the interaction between surface water areas and groundwater in Hanoi city to evaluate appropriate land development and groundwater resource management. We are carrying out three approaches: a) understanding of geochemical characteristics of surface water and groundwater, b) monitoring of water levels of pond and groundwater, c) sampling of soil and pond sediment. Correlation between d18O and dD of precipitation (after GNIP), the Red River (after GNIR) and the water samples of this study showed that the groundwater is composed of precipitation, the Red River and surface water that has evaporation process. Contribution of the surface water with evaporation process was widely found in the study area. As for groundwater monitoring, the Holocene aquifers at two sites were in unconfined condition in dry season and the groundwater levels in the aquifer continued to increase through rainy season. The results of isotopic analysis and groundwater level monitoring showed that the surface water areas are one of the major groundwater sources. On the other hand, concentrations of dissolved Arsenic (filtered by 0.45um) in the pore

Total Nitrogen in Surface Water

Data.gov (United States)

U.S. Environmental Protection Agency — Excess nitrogen in surface water can result in eutrophication. TOTALN is reported in kilograms/hectare/year. More information about these resources, including the...

Total Phosphorus in Surface Water

Data.gov (United States)

U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...

Characteristics of pulse corona discharge over water surface

Science.gov (United States)

Fujii, Tomio; Arao, Yasushi; Rea, Massimo

2008-12-01

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

Characteristics of pulse corona discharge over water surface

International Nuclear Information System (INIS)

Fujii, Tomio; Arao, Yasushi; Rea, Massimo

2008-01-01

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO 2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

Ultra-Pure Water and Extremophilic Bacteria interactions with Germanium Surfaces

Science.gov (United States)

Sah, Vasu R.

Supported by a consortium of semiconductor industry sponsors, an international "TIE" project among 5 National Science Foundation (NSF) Industry/university Cooperative Research Centers discovered that a particular extremophilic microbe, Pseudomonas syzygii, persists in the UltraPure Water (UPW) supplies of chip fabrication facilities (FABs) and can bio-corrode germanium wafers to produce microbe-encased optically transparent crystals. Considered as potentially functional "biochips", this investigation explored mechanisms for the efficient and deliberate production of such microbe-germania adducts as a step toward later testing of their properties as sensors or switches in bioelectronic or biophotonic circuits. Recirculating UPW (Ultra-Pure Water) and other purified water, laminar-flow loops were developed across 50X20x1mm germanium (Ge) prisms, followed by subsequent examination of the prism surfaces using Multiple Attenuated Internal Reflection InfraRed (MAIR-IR) spectroscopy, Contact Potential measurements, Differential Interference Contrast Light Microscopy (DICLM), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDS), and Electron Spectroscopy for Chemical Analysis (ESCA; XPS). P. syzygii cultures originally obtained from a working FAB at University of Arizona were successfully grown on R2A minimal nutrient media. They were found to be identical to the microbes in stored UPW from the same facility, such microbes routinely capable of nucleation and entrapment within GeO2 crystals on the Ge flow surfaces. Optimum flow rates and exposure times were 1 ml/minute (3.2 s-1 shear rate) for 4 days at room temperature, producing densest crystal arrays at the prism central zones 2-3 cm from the flow inlets. Other flow rates and exposure times have higher shear rate which induces a different nucleation mechanism and saturation of crystal formation. Nucleation events began with square and circular oxide deposits surrounding active attached bacteria

Thermophoretically driven water droplets on graphene and boron nitride surfaces

Science.gov (United States)

Rajegowda, Rakesh; Kannam, Sridhar Kumar; Hartkamp, Remco; Sathian, Sarith P.

2018-05-01

We investigate thermally driven water droplet transport on graphene and hexagonal boron nitride (h-BN) surfaces using molecular dynamics simulations. The two surfaces considered here have different wettabilities with a significant difference in the mode of droplet transport. The water droplet travels along a straighter path on the h-BN sheet than on graphene. The h-BN surface produced a higher driving force on the droplet than the graphene surface. The water droplet is found to move faster on h-BN surface compared to graphene surface. The instantaneous contact angle was monitored as a measure of droplet deformation during thermal transport. The characteristics of the droplet motion on both surfaces is determined through the moment scaling spectrum. The water droplet on h-BN surface showed the attributes of the super-diffusive process, whereas it was sub-diffusive on the graphene surface.

Radionuclide transfer onto ground surface in surface water flow, 1

International Nuclear Information System (INIS)

Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu; Kamiyama, Hideo

1991-07-01

Radionuclides migration in ground surface water flow is considered to be one of the important path way in the scenario for environmental migration of radionuclides leaked from low level radioactive waste repository. Simulating the slightly sloped surface on which contaminated solution is flowing downward, testing for radionuclide migration on ground surface had been started. As it's first step, an experiment was carried out under the condition of restricted infiltration in order to elucidate the adsorption behavior of radionuclides onto the loamy soil surface in related with hydraulic conditions. Radionuclides concentration change in effluent solution with time and a concentration distribution of radionuclides adsorbed on the ground surface were obtained from several experimental conditions combining the rate and the duration time of the water flow. The radionuclides concentration in the effluent solution was nearly constant during each experimental period, and was reduced under the condition of lower flow rate. The surface distribution of radionuclides concentration showed two distinctive regions. The one was near the inlet vessel where the concentration was promptly reducing, and the other was following the former where the concentration was nearly constant. The characteristic surface distribution of radionuclides concentration can be explained by a two dimensional diffusion model with a first order adsorption reaction, based on the advection of flow rate distribution in perpendicular direction. (author)

Occurrence of Surface Water Contaminations: An Overview

Science.gov (United States)

Shahabudin, M. M.; Musa, S.

2018-04-01

Water is a part of our life and needed by all organisms. As time goes by, the needs by human increased transforming water quality into bad conditions. Surface water contaminated in various ways which is pointed sources and non-pointed sources. Pointed sources means the source are distinguished from the source such from drains or factory but the non-pointed always occurred in mixed of elements of pollutants. This paper is reviewing the occurrence of the contaminations with effects that occurred around us. Pollutant factors from natural or anthropology factors such nutrients, pathogens, and chemical elements contributed to contaminations. Most of the effects from contaminated surface water contributed to the public health effects also to the environments.

Reducing phosphorus loading of surface water using iron-coated sand

NARCIS (Netherlands)

Groenenberg, J.E.; Chardon, W.J.; Koopmans, G.F.

2013-01-01

Phosphorus losses from agricultural soils is an important source of P in surface waters leading to surface water quality impairment. In addition to reducing P inputs, mitigation measures are needed to reduce P enrichment of surface waters. Because drainage of agricultural land by pipe drainage is an

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-15

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

Leak testing fuel stored in the ICPP fuel storage basin

International Nuclear Information System (INIS)

Lee, J.L.; Rhodes, D.W.

1977-06-01

Irradiated fuel to be processed at the Idaho Chemical Processing Plant is stored under water at the CPP-603 Fuel Storage Facility. Leakage of radionuclides through breaks in the cladding of some of the stored fuels contaminates the water with radionuclides resulting in radiation exposure to personnel during fuel handling operations and contamination of the shipping casks. A leak test vessel was fabricated to test individual fuel assemblies which were suspected to be leaking. The test equipment and procedures are described. Test results demonstrated that a leaking fuel element could be identified by this method; of the eleven fuel assemblies tested, six were estimated to be releasing greater than 0.5 Ci total radionuclides/day to the basin water

Free Surface Water Tunnel (FSWT)

Data.gov (United States)

Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

Instability of confined water films between elastic surfaces

NARCIS (Netherlands)

de Beer, Sissi; 't Mannetje, Dieter; Zantema, Sietske; Mugele, Friedrich

2010-01-01

We investigated the dynamics of nanometer thin water films at controlled ambient humidity adsorbed onto two atomically smooth mica sheets upon rapidly bringing the surfaces into contact. Using a surface forces apparatus (SFA) in imaging mode, we found that the water films break up into a

Turbulent flow over an interactive alternating land-water surface

Science.gov (United States)

Van Heerwaarden, C.; Mellado, J. P.

2014-12-01

The alternating land-water surface is a challenging surface to represent accurately in weather and climate models, but it is of great importance for the surface energy balance in polar regions. The complexity of this surface lies in the fact that secondary circulations, which form at the boundary of water and land, interact strongly with the surface energy balance. Due to its large heat capacity, the water temperature adapts slowly to the flow, thus the properties of the atmosphere determine the uptake of energy from the water. In order to study this complex system in a simpler way, retaining only the most essential physics, we have simplified the full surface energy balance including radiation. We have derived a boundary condition that mimics the full balance and can be formulated as a so-called Robin boundary condition: a linear combination of Dirichlet (fixed temperature) and Neumann (fixed temperature gradient) ones. By spatially varying the coefficients, we are able to express land and water using this boundary condition. We have done a series of direct numerical simulations in which we generate artificial land-water patterns from noise created from a Gaussian spectrum centered around a dominant wave number. This method creates realistic random patterns, but we are still in control of the length scales. We show that the system can manifest itself in three regimes: micro-, meso- and macro-scale. In the micro-scale, we find perfect mixing of the near-surface atmosphere that results in identical air properties over water and land. In the meso-scale, secondary circulations alter the heat exchange considerably by advecting air between land and water. In addition, they bring the surface temperature of the land closer to that of the air, thereby modulating the energy loss due to outgoing longwave radiation. In the macro-scale regime, the flow over land and water become independent of each other and only the large scale forcings determine the energy balance.

Documentation of the Surface-Water Routing (SWR1) Process for modeling surface-water flow with the U.S. Geological Survey Modular Ground-Water Model (MODFLOW-2005)

Science.gov (United States)

Hughes, Joseph D.; Langevin, Christian D.; Chartier, Kevin L.; White, Jeremy T.

2012-01-01

A flexible Surface-Water Routing (SWR1) Process that solves the continuity equation for one-dimensional and two-dimensional surface-water flow routing has been developed for the U.S. Geological Survey three-dimensional groundwater model, MODFLOW-2005. Simple level- and tilted-pool reservoir routing and a diffusive-wave approximation of the Saint-Venant equations have been implemented. Both methods can be implemented in the same model and the solution method can be simplified to represent constant-stage elements that are functionally equivalent to the standard MODFLOW River or Drain Package boundary conditions. A generic approach has been used to represent surface-water features (reaches) and allows implementation of a variety of geometric forms. One-dimensional geometric forms include rectangular, trapezoidal, and irregular cross section reaches to simulate one-dimensional surface-water features, such as canals and streams. Two-dimensional geometric forms include reaches defined using specified stage-volume-area-perimeter (SVAP) tables and reaches covering entire finite-difference grid cells to simulate two-dimensional surface-water features, such as wetlands and lakes. Specified SVAP tables can be used to represent reaches that are smaller than the finite-difference grid cell (for example, isolated lakes), or reaches that cannot be represented accurately using the defined top of the model. Specified lateral flows (which can represent point and distributed flows) and stage-dependent rainfall and evaporation can be applied to each reach. The SWR1 Process can be used with the MODFLOW Unsaturated Zone Flow (UZF1) Package to permit dynamic simulation of runoff from the land surface to specified reaches. Surface-water/groundwater interactions in the SWR1 Process are mathematically defined to be a function of the difference between simulated stages and groundwater levels, and the specific form of the reach conductance equation used in each reach. Conductance can be

Looking at anything that is green when hearing "frog": how object surface colour and stored object colour knowledge influence language-mediated overt attention.

Science.gov (United States)

Huettig, Falk; Altmann, Gerry T M

2011-01-01

Three eye-tracking experiments investigated the influence of stored colour knowledge, perceived surface colour, and conceptual category of visual objects on language-mediated overt attention. Participants heard spoken target words whose concepts are associated with a diagnostic colour (e.g., "spinach"; spinach is typically green) while their eye movements were monitored to (a) objects associated with a diagnostic colour but presented in black and white (e.g., a black-and-white line drawing of a frog), (b) objects associated with a diagnostic colour but presented in an appropriate but atypical colour (e.g., a colour photograph of a yellow frog), and (c) objects not associated with a diagnostic colour but presented in the diagnostic colour of the target concept (e.g., a green blouse; blouses are not typically green). We observed that colour-mediated shifts in overt attention are primarily due to the perceived surface attributes of the visual objects rather than stored knowledge about the typical colour of the object. In addition our data reveal that conceptual category information is the primary determinant of overt attention if both conceptual category and surface colour competitors are copresent in the visual environment.

Modelling surface-water depression storage in a Prairie Pothole Region

Science.gov (United States)

Hay, Lauren E.; Norton, Parker A.; Viger, Roland; Markstrom, Steven; Regan, R. Steven; Vanderhoof, Melanie

2018-01-01

In this study, the Precipitation-Runoff Modelling System (PRMS) was used to simulate changes in surface-water depression storage in the 1,126-km2 Upper Pipestem Creek basin located within the Prairie Pothole Region of North Dakota, USA. The Prairie Pothole Region is characterized by millions of small water bodies (or surface-water depressions) that provide numerous ecosystem services and are considered an important contribution to the hydrologic cycle. The Upper Pipestem PRMS model was extracted from the U.S. Geological Survey's (USGS) National Hydrologic Model (NHM), developed to support consistent hydrologic modelling across the conterminous United States. The Geospatial Fabric database, created for the USGS NHM, contains hydrologic model parameter values derived from datasets that characterize the physical features of the entire conterminous United States for 109,951 hydrologic response units. Each hydrologic response unit in the Geospatial Fabric was parameterized using aggregated surface-water depression area derived from the National Hydrography Dataset Plus, an integrated suite of application-ready geospatial datasets. This paper presents a calibration strategy for the Upper Pipestem PRMS model that uses normalized lake elevation measurements to calibrate the parameters influencing simulated fractional surface-water depression storage. Results indicate that inclusion of measurements that give an indication of the change in surface-water depression storage in the calibration procedure resulted in accurate changes in surface-water depression storage in the water balance. Regionalized parameterization of the USGS NHM will require a proxy for change in surface-storage to accurately parameterize surface-water depression storage within the USGS NHM.

Electrodialysis and nanofiltration of surface water for subsequent use as infiltration water.

Science.gov (United States)

Van der Bruggen, B; Milis, R; Vandecasteele, C; Bielen, P; Van San, E; Huysman, K

2003-09-01

In order to achieve stable groundwater levels, an equilibrium between the use of groundwater for drinking water production and natural or artificial groundwater recharge by infiltration is needed. Local governments usually require that the composition of the water used for artificial recharge is similar to the surface water that is naturally present in the specific recharge area. In this paper, electrodialysis (ED) and nanofiltration were evaluated as possible treatment technologies for surface water from a canal in Flanders, the North of Belgium, in view of infiltration at critical places on heathlands. Both methods were evaluated on the basis of a comparison between the water composition after treatment and the composition of local surface waters. The treatment generally consists of a tuning of pH and the removal of contaminants originating from industrial and agricultural activity, e.g., nitrates and pesticides. Further evaluation of the influence of the composition of the water on the characteristics of the artificial recharge, however, was not envisaged. In a case study of water from the canal Schoten-Dessel, satisfactory concentration reductions of Cl(-), SO(4)(2-), NO(3)(-), HCO(3)(-), Na(+), Mg(2+), K(+) and Ca(2+) were obtained by ultrafiltration pretreatment followed by ED. Nanofiltration with UTC-20, N30F, Desal 51 HL, UTC-60 and Desal 5 DL membranes resulted in an insufficient removal level, especially for the monovalent ions.

Water reactivity with mixed oxide (U,Pu)O2 surfaces

International Nuclear Information System (INIS)

Gaillard, Jeremy

2013-01-01

The interaction of water with actinides oxide surfaces remains poorly understood. The adsorption of water on PuO 2 surface and (U,Pu)O 2 surface leads to hydrogen generation through radiolysis but also surface evolution. The study of water interaction with mixed oxide (U,Pu)O 2 and PuO 2 surfaces requires the implementation of non intrusive techniques. The study of the hydration of CeO 2 surface is used to study the effectiveness of different techniques. The results show that the water adsorption leads to the surface evolution through the formation of a hydroxide superficial layer. The reactivity of water on the surface depends on the calcination temperature of the oxide precursor. The thermal treatment of hydrated surfaces can regenerate the surface. The study on CeO 2 hydration emphasizes the relevancies of these techniques in studying the hydration of surfaces. The hydrogen generation through water radiolysis is studied with an experimental methodology based on constant relative humidity in the radiolysis cell. The hydrogen accumulation is linear for the first hours and then tends to a steady state content. A mechanism of hydrogen consumption is proposed to explain the existence of the steady state of hydrogen content. This mechanism enables to explain also the evolution of the oxide surface during hydrogen generation experiments as shown by the evolution of hydrogen accumulation kinetics. The accumulation kinetics depends on the dose rate, specific surface area and the relative humidity but also on the oxide aging. The plutonium percentage appears to be a crucial parameter in hydrogen accumulation kinetics. (author) [fr

Surface Water Protection by Productive Buffers

DEFF Research Database (Denmark)

Christen, Benjamin

Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... designed for local conditions could be a way of protecting water quality attractive to many stakeholders....

A conceptual model of daily water balance following partial clearing from forest to pasture

Directory of Open Access Journals (Sweden)

M. A. Bari

2006-01-01

Full Text Available A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii a transient Stream zone Store (iii a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important components of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a downward approach by analysing data from Ernies (control and Lemon (53% cleared catchments in Western Australia and elaborating a monthly model. The daily model performed very well in simulating daily flow generation processes for both catchments. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.

Foulant characteristics comparison in recycling cooling water system makeup by municipal reclaimed water and surface water in power plant.

Science.gov (United States)

Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

2015-01-01

Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.

How well Can We Classify SWOT-derived Water Surface Profiles?

Science.gov (United States)

Frasson, R. P. M.; Wei, R.; Picamilh, C.; Durand, M. T.

2015-12-01

The upcoming Surface Water Ocean Topography (SWOT) mission will detect water bodies and measure water surface elevation throughout the globe. Within its continental high resolution mask, SWOT is expected to deliver measurements of river width, water elevation and slope of rivers wider than ~50 m. The definition of river reaches is an integral step of the computation of discharge based on SWOT's observables. As poorly defined reaches can negatively affect the accuracy of discharge estimations, we seek strategies to break up rivers into physically meaningful sections. In the present work, we investigate how accurately we can classify water surface profiles based on simulated SWOT observations. We assume that most river sections can be classified as either M1 (mild slope, with depth larger than the normal depth), or A1 (adverse slope with depth larger than the critical depth). This assumption allows the classification to be based solely on the second derivative of water surface profiles, with convex profiles being classified as A1 and concave profiles as M1. We consider a HEC-RAS model of the Sacramento River as a representation of the true state of the river. We employ the SWOT instrument simulator to generate a synthetic pass of the river, which includes our best estimates of height measurement noise and geolocation errors. We process the resulting point cloud of water surface heights with the RiverObs package, which delineates the river center line and draws the water surface profile. Next, we identify inflection points in the water surface profile and classify the sections between the inflection points. Finally, we compare our limited classification of simulated SWOT-derived water surface profile to the "exact" classification of the modeled Sacramento River. With this exercise, we expect to determine if SWOT observations can be used to find inflection points in water surface profiles, which would bring knowledge of flow regimes into the definition of river reaches.

Apparatus and process for recovering petroleum spread on the surface of water

Energy Technology Data Exchange (ETDEWEB)

Sourdis, P

1968-05-06

A flexible suction tube is towed by means of 2 or more cables in a direction substantially perpendicular to the axis of the tube. The tube is made of light plastic and has a longitudinal slot over its entire length; the width of the slot can be made adjustable. The interior of the suction tube is connected through tubes with a discharge tube in which the liquid level can vary between certain limits. The discharge tube is equipped with floats and steering surfaces to maintain its position in the water; its ends are connected to the pumps on a ship. This assembly is used in conjunction with a flexible, ballasted barrier filled with air to insure its buoyancy. The barrier may consist of a flat plastic tube, or of sheet plastic wound on a core of foamed or expanded plastic. The barrier is stored aboard a tanker or aboard the pumping ship, and when in use, it is towed by one or several speedboats.

STORE IN STORE FRANCHISING STRATEGY: THE TREND IN FRANCHISING NEGOTIATION

OpenAIRE

Rosado-Serrano, Alexander; Universidad de Puerto Rico

2016-01-01

The literature on franchising has traditionally focused on the effects and transformation it has promoted in the service sector, retailing, restaurants, hotels and other service-related industries. Store within a store research has been focused on the perspective of the manufacturer entering department stores. To date, little research has been carried out for the store in store strategy from the franchising perspective. This paper explores why big box retailers such as Walmart are adopting th...

Effective use of surface-water management to control saltwater intrusion

Science.gov (United States)

Hughes, J. D.; White, J.

2012-12-01

The Biscayne aquifer in southeast Florida is susceptible to saltwater intrusion and inundation from rising sea-level as a result of high groundwater withdrawal rates and low topographic relief. Groundwater levels in the Biscayne aquifer are managed by an extensive canal system that is designed to control flooding, supply recharge to municipal well fields, and control saltwater intrusion. We present results from an integrated surface-water/groundwater model of a portion of the Biscayne aquifer to evaluate the ability of the existing managed surface-water control network to control saltwater intrusion. Surface-water stage and flow are simulated using a hydrodynamic model that solves the diffusive-wave approximation of the depth-integrated shallow surface-water equations. Variable-density groundwater flow and fluid density are solved using the Oberbeck--Boussinesq approximation of the three-dimensional variable-density groundwater flow equation and a sharp interface approximation, respectively. The surface-water and variable-density groundwater domains are implicitly coupled during each Picard iteration. The Biscayne aquifer is discretized into a multi-layer model having a 500-m square horizontal grid spacing. All primary and secondary surface-water features in the active model domain are discretized into segments using the 500-m square horizontal grid. A 15-year period of time is simulated and the model includes 66 operable surface-water control structures, 127 municipal production wells, and spatially-distributed daily internal and external hydrologic stresses. Numerical results indicate that the existing surface-water system can be effectively used in many locations to control saltwater intrusion in the Biscayne aquifer resulting from increases in groundwater withdrawals or sea-level rise expected to occur over the next 25 years. In other locations, numerical results indicate surface-water control structures and/or operations may need to be modified to control

Water Adsorption on Clean and Defective Anatase TiO2 (001) Nanotube Surfaces: A Surface Science Approach.

Science.gov (United States)

Kenmoe, Stephane; Lisovski, Oleg; Piskunov, Sergei; Bocharov, Dmitry; Zhukovskii, Yuri F; Spohr, Eckhard

2018-04-11

We use ab initio molecular dynamics simulations to study the adsorption of thin water films with 1 and 2 ML coverage on anatase TiO 2 (001) nanotubes. The nanotubes are modeled as 2D slabs, which consist of partially constrained and partially relaxed structural motifs from nanotubes. The effect of anion doping on the adsorption is investigated by substituting O atoms with N and S impurities on the nanotube slab surface. Due to strain-induced curvature effects, water adsorbs molecularly on defect-free surfaces via weak bonds on Ti sites and H bonds to surface oxygens. While the introduction of an S atom weakens the interaction of the surface with water, which adsorbs molecularly, the presence of an N impurity renders the surface more reactive to water, with a proton transfer from the water film and the formation of an NH group at the N site. At 2 ML coverage, a further surface-assisted proton transfer takes place in the water film, resulting in the formation of an OH - group and an NH 2 + cationic site on the surface.

Quantifying Organic Matter in Surface Waters of the United States and Delivery to the Coastal Zone

Science.gov (United States)

Boyer, E. W.; Alexander, R. B.; Smith, R. A.; Shih, J.

2012-12-01

Organic carbon (OC) is a critical water quality characteristic in surface waters. It is an important component of the energy balance and food chains in freshwater and estuarine aquatic ecosystems, is significant in the mobilization and transport of contaminants along flow paths, and is associated with the formation of known carcinogens in drinking water supplies. The importance of OC dynamics on water quality has been recognized, but challenges remain in quantitatively addressing processes controlling OC fluxes over broad spatial scales in a hydrological context, and considering upstream-downstream linkages along flow paths. Here, we: 1) quantified lateral OC fluxes in rivers, streams, and reservoirs across the nation from headwaters to the coasts; 2) partitioned how much organic carbon that is stored in lakes, rivers and streams comes from allochthonous sources (produced in the terrestrial landscape) versus autochthonous sources (produced in-stream by primary production); 3) estimated the delivery of dissolved and total forms of organic carbon to coastal estuaries and embayments; and 4) considered seasonal factors affecting the temporal variation in OC responses. To accomplish this, we developed national-scale models of organic carbon in U.S. surface waters using the spatially referenced regression on watersheds (SPARROW) technique. The modeling approach uses mechanistic formulations, imposes mass balance constraints, and provides a formal parameter estimation structure to statistically estimate sources and fate of OC in terrestrial and aquatic ecosystems. We calibrated and evaluated the model with statistical estimates of OC loads that were observed at a network of monitoring stations across the nation, and further explored factors controlling seasonal dynamics of OC based on these long term monitoring data. Our results illustrate spatial patterns and magnitudes OC loadings in rivers, highlighting hot spots and suggesting origins of the OC to each location

Groundwater and surface water pollution

Energy Technology Data Exchange (ETDEWEB)

Chae, Y.S.; Hamidi, A. [eds.

2000-07-01

This book contains almost all the technical know-how that is required to clean up the water supply. It provides a survey of up-to-date technologies for remediation, as well as a step-by-step guide to pollution assessment for both ground and surface waters. In addition to focusing on causes, effects, and remedies, the book stresses reuse, recycling, and recovery of resources. The authors suggest that through total recycling wastes can become resources.

Characterisation of the inorganic chemistry of surface waters in ...

African Journals Online (AJOL)

The main purpose of this study was to determine a simple inorganic chemistry index that can be used for all surface waters in South Africa, in order to characterise the inorganic chemistry of surface waters. Water quality data collected up until 1999 from all sample monitoring stations (2 068 monitoring stations, 364 659 ...

Store tobacco policies: a survey of store managers, California, 1996-1997.

Science.gov (United States)

Weinbaum, Z; Quinn, V; Rogers, T; Roeseler, A

1999-01-01

To identify store tobacco policies and retailer perception and beliefs that may have contributed to changes in compliance with youth access laws in California. In the winter of 1996-7, a cross sectional, follow up telephone survey was conducted of California store managers whose stores were anonymously surveyed for illegal tobacco sales in the summer of 1996 (that is, 1996 Youth Tobacco Purchase Survey, YTPS). A simple random sample of stores from a list of California stores likely to sell tobacco, used in the 1996 YTPS. 334 managers (77%) of the 434 stores surveyed in 1996 responded to the survey. After eliminating stores that stopped selling tobacco or were under new management or ownership, 320 responses of store managers were included in the analysis. The stores were analysed by type of ownership: chain, which included corporate managed (n = 61); franchise owned (n = 56); and independent (n = 203). Responses of store managers were linked with the 1996 YTPS outcomes. Manager responses were compared by chi2 tests. Logistic regression analyses were conducted to identify store factors associated with illegal tobacco sales. A lower likelihood of illegal sales rate was associated with the chain stores when compared with the independent stores (odds ratio (OR) = 0.4, 95% confidence interval (CI) 0.2 to 0.9). A lower likelihood of illegal tobacco sales was found in stores that implemented tobacco related activities in the previous year such as changing tobacco displays (OR = 0.5, 95% CI 0.2 to 0.9) or adding new warning signs (OR = 0.7, 95% CI 0.4 to 1.2). Store managers' beliefs that youth were sent to their stores to do compliance checks also resulted in a lower likelihood of illegal sales (OR = 0.7, 95% CI 0.4 to 1.1). Store tobacco youth access policies, and managers' beliefs about the extent of youth access enforcement in the community, are important in reducing illegal tobacco sales to minors.

Eco-hydrological process simulations within an integrated surface water-groundwater model

DEFF Research Database (Denmark)

Butts, Michael; Loinaz, Maria Christina; Bauer-Gottwein, Peter

2014-01-01

Integrated water resources management requires tools that can quantify changes in groundwater, surface water, water quality and ecosystem health, as a result of changes in catchment management. To address these requirements we have developed an integrated eco-hydrological modelling framework...... that allows hydrologists and ecologists to represent the complex and dynamic interactions occurring between surface water, ground water, water quality and freshwater ecosystems within a catchment. We demonstrate here the practical application of this tool to two case studies where the interaction of surface...... water and ground water are important for the ecosystem. In the first, simulations are performed to understand the importance of surface water-groundwater interactions for a restored riparian wetland on the Odense River in Denmark as part of a larger investigation of water quality and nitrate retention...

Stores

CERN Multimedia

2004-01-01

Following the introduction of Condensators, resistors and potentiometers from the Farnell electronic-catalogue into CERN Stores' catalogue, following products are now available: PRODUCT FAMILY GROUP SCEM Oscillators and quartz crystals 07.94.10 / 07.94.12 Diodes 08.51.14 / 08.51.54 Thyristors 08.51.60 / 08.51.66 Opto-electronics 08.52 Transistors 08.53 Integrated circuits 08.54 / 08.55 These articles can be procured in the same way as any other stores item, by completing a Material Request. N.B. Individual Farnell order codes can be used as keywords to facilitate searches in the CERN Stores Catalogue.

Technical Note: Stored grain volume measurement using a low density point cloud

Science.gov (United States)

The mass of stored grain is often determined from volume measurements by crop insurers, government auditors, and stored grain managers conducting inventories. Recent increases in bin size have accentuated the difficulty of accounting for irregularities and variations in surface conditions in calcula...

A robust Multi-Band Water Index (MBWI) for automated extraction of surface water from Landsat 8 OLI imagery

Science.gov (United States)

Wang, Xiaobiao; Xie, Shunping; Zhang, Xueliang; Chen, Cheng; Guo, Hao; Du, Jinkang; Duan, Zheng

2018-06-01

Surface water is vital resources for terrestrial life, while the rapid development of urbanization results in diverse changes in sizes, amounts, and quality of surface water. To accurately extract surface water from remote sensing imagery is very important for water environment conservations and water resource management. In this study, a new Multi-Band Water Index (MBWI) for Landsat 8 Operational Land Imager (OLI) images is proposed by maximizing the spectral difference between water and non-water surfaces using pure pixels. Based on the MBWI map, the K-means cluster method is applied to automatically extract surface water. The performance of MBWI is validated and compared with six widely used water indices in 29 sites of China. Results show that our proposed MBWI performs best with the highest accuracy in 26 out of the 29 test sites. Compared with other water indices, the MBWI results in lower mean water total errors by a range of 9.31%-25.99%, and higher mean overall accuracies and kappa coefficients by 0.87%-3.73% and 0.06-0.18, respectively. It is also demonstrated for MBWI in terms of robustly discriminating surface water from confused backgrounds that are usually sources of surface water extraction errors, e.g., mountainous shadows and dark built-up areas. In addition, the new index is validated to be able to mitigate the seasonal and daily influences resulting from the variations of the solar condition. MBWI holds the potential to be a useful surface water extraction technology for water resource studies and applications.

Surface Freshwater Storage and Variability in the Amazon Basin from Multi-Satellite Observations, 1993-2007

Science.gov (United States)

Papa, Fabrice; Frappart, Frederic; Guntner, Andreas; Prigent, Catherine; Aires, Filipe; Getirana, Augusto; Maurer, Raffael

2013-01-01

The amount of water stored and moving through the surface water bodies of large river basins (river, floodplains, wetlands) plays a major role in the global water and biochemical cycles and is a critical parameter for water resources management. However, the spatio-temporal variations of these freshwater reservoirs are still widely unknown at the global scale. Here, we propose a hypsographic curve approach to estimate surface freshwater storage variations over the Amazon basin combining surface water extent from a multi-satellite-technique with topographic data from the Global Digital Elevation Model (GDEM) from Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Monthly surface water storage variations for 1993-2007 are presented, showing a strong seasonal and interannual variability, and are evaluated against in situ river discharge and precipitation. The basin-scale mean annual amplitude of approx. 1200 cu km is in the range of previous estimates and contributes to about half of the Gravity Recovery And Climate Experiment (GRACE) total water storage variations. For the first time, we map the surface water volume anomaly during the extreme droughts of 1997 (October-November) and 2005 (September-October) and found that during these dry events the water stored in the river and flood-plains of the Amazon basin was, respectively, approx. 230 (approx. 40%) and 210 (approx. 50%) cu km below the 1993-2007 average. This new 15year data set of surface water volume represents an unprecedented source of information for future hydrological or climate modeling of the Amazon. It is also a first step toward the development of such database at the global scale.

WATER SURFACE RECONSTRUCTION IN AIRBORNE LASER BATHYMETRY FROM REDUNDANT BED OBSERVATIONS

Directory of Open Access Journals (Sweden)

G. Mandlburger

2017-09-01

Full Text Available In airborne laser bathymetry knowledge of exact water level heights is a precondition for applying run-time and refraction correction of the raw laser beam travel path in the medium water. However, due to specular reflection especially at very smooth water surfaces often no echoes from the water surface itself are recorded (drop outs. In this paper, we first discuss the feasibility of reconstructing the water surface from redundant observations of the water bottom in theory. Furthermore, we provide a first practical approach for solving this problem, suitable for static and locally planar water surfaces. It minimizes the bottom surface deviations of point clouds from individual flight strips after refraction correction. Both theoretical estimations and practical results confirm the potential of the presented method to reconstruct water level heights in dm precision. Achieving good results requires enough morphological details in the scene and that the water bottom topography is captured from different directions.

The study of dynamic force acted on water strider leg departing from water surface

Science.gov (United States)

Sun, Peiyuan; Zhao, Meirong; Jiang, Jile; Zheng, Yelong

2018-01-01

Water-walking insects such as water striders can skate on the water surface easily with the help of the hierarchical structure on legs. Numerous theoretical and experimental studies show that the hierarchical structure would help water strider in quasi-static case such as load-bearing capacity. However, the advantage of the hierarchical structure in the dynamic stage has not been reported yet. In this paper, the function of super hydrophobicity and the hierarchical structure was investigated by measuring the adhesion force of legs departing from the water surface at different lifting speed by a dynamic force sensor. The results show that the adhesion force decreased with the increase of lifting speed from 0.02 m/s to 0.4 m/s, whose mechanic is investigated by Energy analysis. In addition, it can be found that the needle shape setae on water strider leg can help them depart from water surface easily. Thus, it can serve as a starting point to understand how the hierarchical structure on the legs help water-walking insects to jump upward rapidly to avoid preying by other insects.

Effect of water table dynamics on land surface hydrologic memory

Science.gov (United States)

Lo, Min-Hui; Famiglietti, James S.

2010-11-01

The representation of groundwater dynamics in land surface models has received considerable attention in recent years. Most studies have found that soil moisture increases after adding a groundwater component because of the additional supply of water to the root zone. However, the effect of groundwater on land surface hydrologic memory (persistence) has not been explored thoroughly. In this study we investigate the effect of water table dynamics on National Center for Atmospheric Research Community Land Model hydrologic simulations in terms of land surface hydrologic memory. Unlike soil water or evapotranspiration, results show that land surface hydrologic memory does not always increase after adding a groundwater component. In regions where the water table level is intermediate, land surface hydrologic memory can even decrease, which occurs when soil moisture and capillary rise from groundwater are not in phase with each other. Further, we explore the hypothesis that in addition to atmospheric forcing, groundwater variations may also play an important role in affecting land surface hydrologic memory. Analyses show that feedbacks of groundwater on land surface hydrologic memory can be positive, negative, or neutral, depending on water table dynamics. In regions where the water table is shallow, the damping process of soil moisture variations by groundwater is not significant, and soil moisture variations are mostly controlled by random noise from atmospheric forcing. In contrast, in regions where the water table is very deep, capillary fluxes from groundwater are small, having limited potential to affect soil moisture variations. Therefore, a positive feedback of groundwater to land surface hydrologic memory is observed in a transition zone between deep and shallow water tables, where capillary fluxes act as a buffer by reducing high-frequency soil moisture variations resulting in longer land surface hydrologic memory.

Salinization and arsenic contamination of surface water in southwest Bangladesh.

Science.gov (United States)

Ayers, John C; George, Gregory; Fry, David; Benneyworth, Laura; Wilson, Carol; Auerbach, Leslie; Roy, Kushal; Karim, Md Rezaul; Akter, Farjana; Goodbred, Steven

2017-09-11

To identify the causes of salinization and arsenic contamination of surface water on an embanked island (i.e., polder) in the tidal delta plain of SW Bangladesh we collected and analyzed water samples in the dry (May) and wet (October) seasons in 2012-2013. Samples were collected from rice paddies (wet season), saltwater ponds used for brine shrimp aquaculture (dry season), freshwater ponds and tidal channels (both wet and dry season), and rainwater collectors. Continuous measurements of salinity from March 2012 to February 2013 show that tidal channel water increases from ~0.15 ppt in the wet season up to ~20 ppt in the dry season. On the polder, surface water exceeds the World Health Organization drinking water guideline of 10 μg As/L in 78% of shrimp ponds and 27% of rice paddies, raising concerns that produced shrimp and rice could have unsafe levels of As. Drinking water sources also often have unsafe As levels, with 83% of tubewell and 43% of freshwater pond samples having >10 μg As/L. Water compositions and field observations are consistent with shrimp pond water being sourced from tidal channels during the dry season, rather than the locally saline groundwater from tubewells. Irrigation water for rice paddies is also obtained from the tidal channels, but during the wet season when surface waters are fresh. Salts become concentrated in irrigation water through evaporation, with average salinity increasing from 0.43 ppt in the tidal channel source to 0.91 ppt in the rice paddies. Our observations suggest that the practice of seasonally alternating rice and shrimp farming in a field has a negligible effect on rice paddy water salinity. Also, shrimp ponds do not significantly affect the salinity of adjacent surface water bodies or subjacent groundwater because impermeable shallow surface deposits of silt and clay mostly isolate surface water bodies from each other and from the shallow groundwater aquifer. Bivariate plots of conservative element

Water Transport and Removal in PEMFC Gas Flow Channel with Various Water Droplet Locations and Channel Surface Wettability

Directory of Open Access Journals (Sweden)

Yanzhou Qin

2018-04-01

Full Text Available Water transport and removal in the proton exchange membrane fuel cell (PEMFC is critically important to fuel cell performance, stability, and durability. Water emerging locations on the membrane-electrode assembly (MEA surface and the channel surface wettability significantly influence the water transport and removal in PEMFC. In most simulations of water transport and removal in the PEMFC flow channel, liquid water is usually introduced at the center of the MEA surface, which is fortuitous, since water droplet can emerge randomly on the MEA surface in PEMFC. In addition, the commonly used no-slip wall boundary condition greatly confines the water sliding features on hydrophobic MEA/channel surfaces, degrading the simulation accuracy. In this study, water droplet is introduced with various locations along the channel width direction on the MEA surface, and water transport and removal is investigated numerically using an improved model incorporating the sliding flow property by using the shear wall boundary condition. It is found that the water droplet can be driven to the channel sidewall by aerodynamics when the initial water location deviates from the MEA center to a certain amount, forming the water corner flow in the flow channel. The channel surface wettability on the water transport is also studied and is shown to have a significant impact on the water corner flow in the flow channel.

Organizational choices and financial performance: the case of company-owned stores, franchisee-owned stores and stores-within-a-store among French fashion retailers

OpenAIRE

Paul Amadieu; Karine Picot-Coupey; Jean-Laurent Viviani

2013-01-01

This paper deals with the governance and financial performance issues in the context of French Fashion retail companies. In this study, we analyze the influence of the organizational choices on the financial performance at the network level. We consider three forms used in isolation (company-owned stores, franchisee-owned stores and stores-within-a-store), three dually-organized forms (dual forms mixing two of the three forms) as well as a combined form associating the three ones. We study a ...

Basin scale management of surface and ground water

International Nuclear Information System (INIS)

Tracy, J.C.; Al-Sharif, M.

1993-01-01

An important element in the economic development of many regions of the Great Plains is the availability of a reliable water supply. Due to the highly variable nature of the climate through out much of the Great Plains region, non-controlled stream flow rates tend to be highly variable from year to year. Thus, the primary water supply has tended towards developing ground water aquifers. However, in regions where shallow ground water is extracted for use, there exists the potential for over drafting aquifers to the point of depleting hydraulically connected stream flows, which could adversely affect the water supply of downstream users. To prevent the potential conflict that can arise when a basin's water supply is being developed or to control the water extractions within a developed basin requires the ability to predict the effect that water extractions in one region will have on water extractions from either surface or ground water supplies else where in the basin. This requires the ability to simulate ground water levels and stream flows on a basin scale as affected by changes in water use, land use practices and climatic changes within the basin. The outline for such a basin scale surface water-ground water model has been presented in Tracy (1991) and Tracy and Koelliker (1992), and the outline for the mathematical programming statement to aid in determining the optimal allocation of water on a basin scale has been presented in Tracy and Al-Sharif (1992). This previous work has been combined into a computer based model with graphical output referred to as the LINOSA model and was developed as a decision support system for basin managers. This paper will present the application of the LINOSA surface-ground water management model to the Rattlesnake watershed basin that resides within Ground Water Management District Number 5 in south central Kansas

TO STORES USERS

CERN Multimedia

SPL Division

2001-01-01

Stores users are informed that the Stores (Central, Emergency window, Raw materials, Chemical products and Prévessin Self service stores) will be closed on Friday, 7 December owing to migration of the Stores computers to Windows 2000. Thank you for your understanding.

Water use and quality of fresh surface-water resources in the Barataria-Terrebonne Basins, Louisiana

Science.gov (United States)

Johnson-Thibaut, Penny M.; Demcheck, Dennis K.; Swarzenski, Christopher M.; Ensminger, Paul A.

1998-01-01

Approximately 170 Mgal/d (million gallons per day) of ground- and surface-water was withdrawn from the Barataria-Terrebonne Basins in 1995. Of this amount, surface water accounted for 64 percent ( 110 MgaVd) of the total withdrawal rates in the basins. The largest surface-water withdrawal rates were from Bayou Lafourche ( 40 Mgal/d), Bayou Boeuf ( 14 MgaVd), and the Gulf Intracoastal Waterway (4.2 Mgal/d). The largest ground-water withdrawal rates were from the Mississippi River alluvial aquifer (29 Mgal/d), the Gonzales-New Orleans aquifer (9.5 Mgal/d), and the Norco aquifer (3.6 MgaVd). The amounts of water withdrawn in the basins in 1995 differed by category of use. Public water suppliers within the basins withdrew 41 Mgal/d of water. The five largest public water suppliers in the basins withdrew 30 Mgal/d of surface water: Terrebonne Waterworks District 1 withdrew the largest amount, almost 15 MgaVd. Industrial facilities withdrew 88 Mgal/d, fossil-fuel plants withdrew 4.7 MgaVd, and commercial facilities withdrew 0.67 MgaVd. Aggregate water-withdrawal rates, compiled by parish for aquaculture (37 Mgal/d), livestock (0.56 Mgal/d), rural domestic (0.44 MgaVd), and irrigation uses (0.54 MgaVd), totaled about 38 MgaVd in the basins. Ninety-five percent of aquaculture withdrawal rates, primarily for crawfish and alligator farming, were from surface-water sources. >br> Total water-withdrawal rates increased 221 percent from 1960–95. Surface-water withdrawal rates have increased by 310 percent, and ground-water withdrawal rates have increased by 133 percent. The projection for the total water-withdrawal rates in 2020 is 220 MgaVd, an increase of 30 percent from 1995. Surface-water withdrawal rates would account for 59 percent of the total, or 130 Mgal/d. Surface-water withdrawal rates are projected to increase by 20 percent from 1995 to 2020. Analysis of water-quality data from the Mississippi River indicates that the main threats to surface water resources are

Liquid Water may Stick on Hydrophobic Surfaces

Indian Academy of Sciences (India)

IAS Admin

Common Perception. A surface can be classified as. > Wetting. > Non-wetting. Depending on the spreading characteristics of a droplet of water that splashes on the surface. The behavior of fluid on a solid surface under static and dynamic ..... color of the number density profile. Ions at the interface tend to form pinning zones ...

Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

Energy Technology Data Exchange (ETDEWEB)

Apfelbaum, Steven L. [Applied Ecological Services Inc., Brodhead, WI (United States); Duvall, Kenneth W. [Sterling Energy Services, LLC, Atlanta, GA (United States); Nelson, Theresa M. [Applied Ecological Services Inc., Brodhead, WI (United States); Mensing, Douglas M. [Applied Ecological Services Inc., Brodhead, WI (United States); Bengtson, Harlan H. [Sterling Energy Services, LLC, Atlanta, GA (United States); Eppich, John [Waterflow Consultants, Champaign, IL (United States); Penhallegon, Clayton [Sterling Energy Services, LLC, Atlanta, GA (United States); Thompson, Ry L. [Applied Ecological Services Inc., Brodhead, WI (United States)

2013-12-01

Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive

Studies Concerning Water-Surface Deposits in Recovery Boilers

Energy Technology Data Exchange (ETDEWEB)

Strandberg, O; Arvesen, J; Dahl, L

1971-11-15

The Feed-water Committee of the Stiftelsen Svensk Cellulosaforskning (Foundation for Swedish Cellulose Research) has initiated research and investigations which aim to increase knowledge about water-surface deposits in boiler tubes, and the resulting risks of gas-surface corrosion in chemical recovery boilers (sulphate pulp industry). The Committee has arranged with AB Atomenergi, Studsvik, for investigations into the water-surface deposits on tubes from six Scandinavian boilers. These investigations have included direct measurements of the thermal conductivity of the deposits, and determinations of their quantity, thickness and structure have been carried out. Previous investigations have shown that gas-surface corrosion can occur at tube temperatures above 330 deg C. The measured values for the thermal conductivity of the deposits indicate that even with small quantities of deposit (c. 1 g/dm2 ) and a moderate boiler pressure (40 atm), certain types of deposit can give rise to the above-mentioned surface temperature, at which the risk of gas-surface corrosion becomes appreciable. For higher boiler pressures the risk is great even with a minimal layer of deposit. The critical deposit thickness can be as low as 0.1 mm

Sampling procedure for lake or stream surface water chemistry

Science.gov (United States)

Robert Musselman

2012-01-01

Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

Surface tension of normal and heavy water

International Nuclear Information System (INIS)

Straub, J.; Rosner, N.; Grigull, V.

1980-01-01

A Skeleton Table and simple interpolation equation for the surface tension of light water was developed by the Working Group III of the International Association for the Properties of Steam and is recommended as an International Standard. The Skeleton Table is based on all known measurements of the surface tension and individual data were weighted corresponding to the accuracy of the measurements. The form of the interpolation equation is based on a physical concept. It represents an extension of van der Waals-equation, where the exponent conforms to the 'Scaling Laws'. In addition for application purposes simple relations for the Laplace-coefficient and for the density difference between the liquid and gaseous phases of light water are given. The same form of interpolation equation for the surface tension can be used for heavy water, for which the coefficients are given. However, this equation is based only on a single set of data. (orig.) [de

Bulk water freezing dynamics on superhydrophobic surfaces

Science.gov (United States)

Chavan, S.; Carpenter, J.; Nallapaneni, M.; Chen, J. Y.; Miljkovic, N.

2017-01-01

In this study, we elucidate the mechanisms governing the heat-transfer mediated, non-thermodynamic limited, freezing delay on non-wetting surfaces for a variety of characteristic length scales, Lc (volume/surface area, 3 mm commercial superhydrophobic spray coatings, showing a monotonic increase in freezing time with coating thickness. The added thermal resistance of thicker coatings was much larger than that of the nanoscale superhydrophobic features, which reduced the droplet heat transfer and increased the total freezing time. Transient finite element method heat transfer simulations of the water slab freezing process were performed to calculate the overall heat transfer coefficient at the substrate-water/ice interface during freezing, and shown to be in the range of 1-2.5 kW/m2K for these experiments. The results shown here suggest that in order to exploit the heat-transfer mediated freezing delay, thicker superhydrophobic coatings must be deposited on the surface, where the coating resistance is comparable to the bulk water/ice conduction resistance.

Surface water, particulate matter, and sediments of inland waters

International Nuclear Information System (INIS)

Mundschenk, H.

1985-01-01

The Bundesanstalt fuer Gewaesserkunde (BfG) since 1958 runs a system for monitoring the surface water and sediments of Federal German waterways in its capacity as a directing water monitoring centre. The data recorded over the years show that the radioactivity released by the various emission sources leads to radionuclide concentrations in water, particulate matter, or sediments that generally are below the detection limits defined in the relevant legal provisions governing monitoring and surveillance of nuclear facilities effluents. Representative examples of measuring methods and results (as for e.g. for H-3) are given. (DG) [de

RISK ASSESSMENT OF SURFACE WATERS ASSOCIATED WITH WATER CIRCULATION TECHNOLOGIES ON TROUT FARMS

Directory of Open Access Journals (Sweden)

Marcin Sidoruk

2014-07-01

Full Text Available Dynamic development of aquaculture has led to an increasing impact on the status of surface waters. Fish production generates wastes that, at high concentrations, may present a serious risk to the aquatic environment. Studies on the assessment of the impact of water management technologies in trout production on the quality of surface waters were conducted in 2011. Six farms were selected for the studies and were divided into two groups based on water management solutions (n = 3: farms with a flow through system (FTS and farms with a recirculation aquaculture system (RAS. On all farms, water measurement points were set and they depicted the quality of inflow water, the quality of water in ponds and the quality of outflow water. The studies did not demonstrate any impact of applied technology on electrolyte conductivity or calcium and magnesium concentrations in outflow water from a trout operation. In addition, it was found that the use of water for production purposes resulted in a slight increase in phosphorus and total nitrogen concentrations in waste waters.

A Facile All-Solution-Processed Surface with High Water Contact Angle and High Water Adhesive Force.

Science.gov (United States)

Chen, Mei; Hu, Wei; Liang, Xiao; Zou, Cheng; Li, Fasheng; Zhang, Lanying; Chen, Feiwu; Yang, Huai

2017-07-12

A series of sticky superhydrophobicity surfaces with high water contact angle and high water adhesive force is facilely prepared via an all-solution-processed method based on polymerization-induced phase separation between liquid crystals (LCs) and epoxy resin, which produces layers of epoxy microspheres (EMSs) with nanofolds on the surface of a substrate. The morphologies and size distributions of EMSs are confirmed by scanning electron microscopy. Results reveal that the obtained EMS coated-surface exhibits high apparent contact angle of 152.0° and high water adhesive force up to 117.6 μN. By varying the composition of the sample or preparing conditions, the sizes of the produced EMSs can be artificially regulated and, thus, control the wetting properties and water adhesive behaviors. Also, the sticky superhydrophobic surface exhibits excellent chemical stability, as well as long-term durability. Water droplet transportation experiments further prove that the as-made surface can be effectively used as a mechanical hand for water transportation applications. Based on this, it is believed that the simple method proposed in this paper will pave a new way for producing a sticky superhydrophobic surface and obtain a wide range of use.

Occurrence of estrogenic activities in second-grade surface water and ground water in the Yangtze River Delta, China

International Nuclear Information System (INIS)

Shi, Wei; Hu, Guanjiu; Chen, Sulan; Wei, Si; Cai, Xi; Chen, Bo; Feng, Jianfang; Hu, Xinxin; Wang, Xinru; Yu, Hongxia

2013-01-01

Second-grade surface water and ground water are considered as the commonly used cleanest water in the Yangtze River Delta, which supplies centralized drinking water and contains rare species. However, some synthetic chemicals with estrogenic disrupting activities are detectable. Estrogenic activities in the second-grade surface water and ground water were surveyed by a green monkey kidney fibroblast (CV-1) cell line based ER reporter gene assay. Qualitative and quantitative analysis were further conducted to identify the responsible compounds. Estrogen receptor (ER) agonist activities were present in 7 out of 16 surface water and all the ground water samples. Huaihe River and Yangtze River posed the highest toxicity potential. The highest equivalent (2.2 ng E 2 /L) is higher than the predicted no-effect-concentration (PNEC). Bisphenol A (BPA) contributes to greater than 50% of the total derived equivalents in surface water, and the risk potential in this region deserves more attention and further research. -- Highlights: •Estrogenic activities were present in second-grade surface water and ground water. •Most of the detected equivalents were higher than the predicted no-effect-concentration of E 2 . •ER-EQ 20–80 ranges showed that samples in Huaihe River and Yangtze River posed the highest toxicity. •Bisphenol A contributes to most of the instrumentally derived equivalents in surface water. -- Estrogenic activities were observed in second-grade surface water and ground water in Yangtze River Delta, and BPA was the responsible contaminant

Water Reclamation Using a Ceramic Nanofiltration Membrane and Surface Flushing with Ozonated Water

Science.gov (United States)

Hoang, Anh T.; Okuda, Tetsuji; Takeuchi, Haruka; Tanaka, Hiroaki; Nghiem, Long D.

2018-01-01

A new membrane fouling control technique using ozonated water flushing was evaluated for direct nanofiltration (NF) of secondary wastewater effluent using a ceramic NF membrane. Experiments were conducted at a permeate flux of 44 L/m2h to evaluate the ozonated water flushing technique for fouling mitigation. Surface flushing with clean water did not effectively remove foulants from the NF membrane. In contrast, surface flushing with ozonated water (4 mg/L dissolved ozone) could effectively remove most foulants to restore the membrane permeability. This surface flushing technique using ozonated water was able to limit the progression of fouling to 35% in transmembrane pressure increase over five filtration cycles. Results from this study also heighten the need for further development of ceramic NF membrane to ensure adequate removal of pharmaceuticals and personal care products (PPCPs) for water recycling applications. The ceramic NF membrane used in this study showed approximately 40% TOC rejection, and the rejection of PPCPs was generally low and highly variable. It is expected that the fouling mitigation technique developed here is even more important for ceramic NF membranes with smaller pore size and thus better PPCP rejection. PMID:29671797

Water Reclamation Using a Ceramic Nanofiltration Membrane and Surface Flushing with Ozonated Water

Directory of Open Access Journals (Sweden)

Takahiro Fujioka

2018-04-01

Full Text Available A new membrane fouling control technique using ozonated water flushing was evaluated for direct nanofiltration (NF of secondary wastewater effluent using a ceramic NF membrane. Experiments were conducted at a permeate flux of 44 L/m2h to evaluate the ozonated water flushing technique for fouling mitigation. Surface flushing with clean water did not effectively remove foulants from the NF membrane. In contrast, surface flushing with ozonated water (4 mg/L dissolved ozone could effectively remove most foulants to restore the membrane permeability. This surface flushing technique using ozonated water was able to limit the progression of fouling to 35% in transmembrane pressure increase over five filtration cycles. Results from this study also heighten the need for further development of ceramic NF membrane to ensure adequate removal of pharmaceuticals and personal care products (PPCPs for water recycling applications. The ceramic NF membrane used in this study showed approximately 40% TOC rejection, and the rejection of PPCPs was generally low and highly variable. It is expected that the fouling mitigation technique developed here is even more important for ceramic NF membranes with smaller pore size and thus better PPCP rejection.

Evaporation of tiny water aggregation on solid surfaces with different wetting properties.

Science.gov (United States)

Wang, Shen; Tu, Yusong; Wan, Rongzheng; Fang, Haiping

2012-11-29

The evaporation of a tiny amount of water on the solid surface with different wettabilities has been studied by molecular dynamics simulations. From nonequilibrium MD simulations, we found that, as the surface changed from hydrophobic to hydrophilic, the evaporation speed did not show a monotonic decrease as intuitively expected, but increased first, and then decreased after it reached a maximum value. The analysis of the simulation trajectory and calculation of the surface water interaction illustrate that the competition between the number of water molecules on the water-gas surface from where the water molecules can evaporate and the potential barrier to prevent those water molecules from evaporating results in the unexpected behavior of the evaporation. This finding is helpful in understanding the evaporation on biological surfaces, designing artificial surfaces of ultrafast water evaporating, or preserving water in soil.

Stormwater Priority Pollutants Versus Surface Water Quality Criteria

DEFF Research Database (Denmark)

Eriksson, Eva; Ledin, Anna; Baun, Anders

2011-01-01

Stormwater in urban areas comprises of a substantial part of the urban water cycle, dominating the flow in many small urban streams, and the pollution levels are sizeable. No stormwater quality criteria were found here and no European or national emission limit values exist. Stormwater pollutants...... however are present in levels exceeding most of the regulated surface water quality criteria and environmental quality standards. Therefore catchment characterisation is needed to chose suitable treatment prior to discharge into receiving surface waters, as the mixing may be insufficient in small streams....

Radiolysis of water in the vicinity of passive surfaces

International Nuclear Information System (INIS)

Moreau, S.; Fenart, M.; Renault, J.P.

2014-01-01

Highlights: • HO° production through water radiolysis is enhanced near metal surfaces. • Hastelloy and Stainless steel surfaces can also produce HO° radicals through hydrogen peroxide activation. • There is a deficit in solvated electron production compared to hydroxyl radicals near metal surfaces. - Abstract: Porous metals were used to describe the water radiolysis in the vicinity of metal surfaces. The hydroxyl radical production under gamma irradiation was measured by benzoate scavenging in water confined in a 200 nm porous Ni base alloy or in Stainless steel. The presence of the metallic surfaces changed drastically the HO° production level and lifetime. The solvated electron production was measured via glycylglycine scavenging for Stainless steel and was found to be significantly smaller than hydroxyl production. These observations imply that interfacial radiolysis may deeply impact the corrosion behavior of the SS and Ni based alloys

The study of dynamic force acted on water strider leg departing from water surface

Directory of Open Access Journals (Sweden)

Peiyuan Sun

2018-01-01

Full Text Available Water-walking insects such as water striders can skate on the water surface easily with the help of the hierarchical structure on legs. Numerous theoretical and experimental studies show that the hierarchical structure would help water strider in quasi-static case such as load-bearing capacity. However, the advantage of the hierarchical structure in the dynamic stage has not been reported yet. In this paper, the function of super hydrophobicity and the hierarchical structure was investigated by measuring the adhesion force of legs departing from the water surface at different lifting speed by a dynamic force sensor. The results show that the adhesion force decreased with the increase of lifting speed from 0.02 m/s to 0.4 m/s, whose mechanic is investigated by Energy analysis. In addition, it can be found that the needle shape setae on water strider leg can help them depart from water surface easily. Thus, it can serve as a starting point to understand how the hierarchical structure on the legs help water-walking insects to jump upward rapidly to avoid preying by other insects.

Chlorine stress mediates microbial surface attachment in drinking water systems.

Science.gov (United States)

Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

2015-03-01

Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

A Probabilistic Analysis of Surface Water Flood Risk in London.

Science.gov (United States)

Jenkins, Katie; Hall, Jim; Glenis, Vassilis; Kilsby, Chris

2017-10-30

Flooding in urban areas during heavy rainfall, often characterized by short duration and high-intensity events, is known as "surface water flooding." Analyzing surface water flood risk is complex as it requires understanding of biophysical and human factors, such as the localized scale and nature of heavy precipitation events, characteristics of the urban area affected (including detailed topography and drainage networks), and the spatial distribution of economic and social vulnerability. Climate change is recognized as having the potential to enhance the intensity and frequency of heavy rainfall events. This study develops a methodology to link high spatial resolution probabilistic projections of hourly precipitation with detailed surface water flood depth maps and characterization of urban vulnerability to estimate surface water flood risk. It incorporates probabilistic information on the range of uncertainties in future precipitation in a changing climate. The method is applied to a case study of Greater London and highlights that both the frequency and spatial extent of surface water flood events are set to increase under future climate change. The expected annual damage from surface water flooding is estimated to be to be £171 million, £343 million, and £390 million/year under the baseline, 2030 high, and 2050 high climate change scenarios, respectively. © 2017 Society for Risk Analysis.

IMPROVING CYANOBACTERIA AND CYANOTOXIN MONITORING IN SURFACE WATERS FOR DRINKING WATER SUPPLY

Directory of Open Access Journals (Sweden)

Jing Li

2017-06-01

Full Text Available Cyanobacteria in fresh water can cause serious threats to drinking water supplies. Managing cyanobacterial blooms particularly at small drinking water treatment plants is challenging. Because large amount of cyanobacteria may cause clogging in the treatment process and various cyanotoxins are hard to remove, while they may cause severe health problems. There is lack of instructions of what cyanobacteria/toxin amount should trigger what kind of actions for drinking water management except for Microcystins. This demands a Cyanobacteria Management Tool (CMT to help regulators/operators to improve cyanobacteria/cyanotoxin monitoring in surface waters for drinking water supply. This project proposes a CMT tool, including selecting proper indicators for quick cyanobacteria monitoring and verifying quick analysis methods for cyanobacteria and cyanotoxin. This tool is suggested for raw water management regarding cyanobacteria monitoring in lakes, especially in boreal forest climate. In addition, it applies to regions that apply international WHO standards for water management. In Swedish context, drinking water producers which use raw water from lakes that experience cyanobacterial blooms, need to create a monitoring routine for cyanobacteria/cyanotoxin and to monitor beyond such as Anatoxins, Cylindrospermopsins and Saxitoxins. Using the proposed CMT tool will increase water safety at surface water treatment plants substantially by introducing three alerting points for actions. CMT design for each local condition should integrate adaptive monitoring program.

Quality-assurance and data-management plan for water-quality activities in the Kansas Water Science Center, 2014

Science.gov (United States)

Rasmussen, Teresa J.; Bennett, Trudy J.; Foster, Guy M.; Graham, Jennifer L.; Putnam, James E.

2014-01-01

As the Nation’s largest water, earth, and biological science and civilian mapping information agency, the U.S. Geological Survey is relied on to collect high-quality data, and produce factual and impartial interpretive reports. This quality-assurance and data-management plan provides guidance for water-quality activities conducted by the Kansas Water Science Center. Policies and procedures are documented for activities related to planning, collecting, storing, documenting, tracking, verifying, approving, archiving, and disseminating water-quality data. The policies and procedures described in this plan complement quality-assurance plans for continuous water-quality monitoring, surface-water, and groundwater activities in Kansas.

Part 2: Surface water quality

International Nuclear Information System (INIS)

1997-01-01

In 1996 the surface water quality measurements were performed, according to the Agreement, at 8 profiles on the Hungarian territory and at 15 profiles on the Slovak territory. Basic physical and chemical parameters (as water temperature, pH values, conductivity, suspended solids, cations and anions (nitrates, ammonium ion, nitrites, total nitrogen, phosphates, total phosphorus, oxygen and organic carbon regime parameters), metals (iron, manganese and heavy metals), biological and microbiological parameters (coliform bacteria, chlorophyll-a, saprobity index and other biological parameters) and quality of sediment were measured

Electrolysis of water on (oxidized) metal surfaces

DEFF Research Database (Denmark)

Rossmeisl, Jan; Logadottir, Ashildur; Nørskov, Jens Kehlet

2005-01-01

Density functional theory calculations are used as the basis for an analysis of the electrochemical process, where by water is split to form molecular oxygen and hydrogen. We develop a method for obtaining the thermochemistry of the electrochemical water splitting process as a function of the bias...... directly from the electronic structure calculations. We consider electrodes of Pt(111) and Au(111) in detail and then discuss trends for a series of different metals. We show that the difficult step in the water splitting process is the formation of superoxy-type (OOH) species on the surface...... by the splitting of a water molecule on top an adsorbed oxygen atom. One conclusion is that this is only possible on metal surfaces that are (partly) oxidized. We show that the binding energies of the different intermediates are linearly correlated for a number of metals. In a simple analysis, where the linear...

Iron oxidation kinetics and phosphorus immobilization at the groundwater-surface water interface

NARCIS (Netherlands)

van der Grift, Bas; Rozemeijer, Joachim; Griffioen, Jasper; van der Velde, Ype

2014-01-01

Eutrophication of freshwater environments following diffuse nutrient loads is a widely recognized water quality problem in catchments. Fluxes of non-point P sources to surface waters originate from surface runoff and flow from soil water and groundwater into surface water. The availability of P in

Economic Evaluation of a Solar Charged Thermal Energy Store for Space Heating

OpenAIRE

Melo, Manuel

2013-01-01

A thermal energy store corrects the misalignment of heating demand in the winter relative to solar thermal energy gathered in the summer. This thesis reviews the viability of a solar charged hot water tank thermal energy store for a school at latitude 56.25N, longitude -120.85W

Summary of Surface-Water Quality Data from the Illinois River Basin in Northeast Oklahoma, 1970-2007

Science.gov (United States)

Andrews, William J.; Becker, Mark F.; Smith, S. Jerrod; Tortorelli, Robert L.

2009-01-01

periods. Concentrations of nitrogen, phosphorus, and sediment, and counts of bacteria generally increased with streamflow at the five sites, probably due to runoff from the land surface and re-suspension of streambed sediments. Phosphorus concentrations typically exceeded the Oklahoma standard of 0.037 milligrams per liter for Scenic Rivers. Concentrations of chlorophyll-a in phytoplankton in water samples collected at the five sites were not well correlated with streamflow, nor to concentrations of the nutrients nitrogen and phosphorus, probably because much of the algae growing in these streams are periphyton attached to streambed cobbles and other debris, rather than phytoplankton in the water column. Sediment concentrations correlated with phosphorus concentrations in water samples collected at the sites, probably due to sorption of phosphorus to soil particles and streambed sediments and runoff of soils and animal wastes at the land surface and resuspension of streambed sediments and phosphorus during wet, high-flow periods. Fecal coliform bacteria counts at the five sites sometimes exceeded the Oklahoma Primary Body Contact Standard of 400 colonies per 100 milliliters when streamflows were greater than 1000 cubic feet per second. Ultimately, Lake Tenkiller, an important ecological and economic resource for the region, receives the compounds that runoff the land surface or seep to local streams from groundwater in the basin. Because of eutrophication from increased nutrient loading, Lake Tenkiller is listed for impairment by diminished dissolved oxygen concentrations, phosphorus, and chlorophyll-a by the State of Oklahoma in evaluation of surface-water quality required by section 303d of the Clean Water Act. Stored phosphorus in soils and streambed and lakebed sediments may continue to provide phosphorus to local streams and lakes for decades to come. Steps are being made to reduce local sources of phosphorus, including upgrades in capacity and effective

Disagreement between Hydrological and Land Surface models on the water budgets in the Arctic: why is this and which of them is right?

Science.gov (United States)

Blyth, E.; Martinez-de la Torre, A.; Ellis, R.; Robinson, E.

2017-12-01

The fresh-water budget of the Artic region has a diverse range of impacts: the ecosystems of the region, ocean circulation response to Arctic freshwater, methane emissions through changing wetland extent as well as the available fresh water for human consumption. But there are many processes that control the budget including a seasonal snow packs building and thawing, freezing soils and permafrost, extensive organic soils and large wetland systems. All these processes interact to create a complex hydrological system. In this study we examine a suite of 10 models that bring all those processes together in a 25 year reanalysis of the global water budget. We assess their performance in the Arctic region. There are two approaches to modelling fresh-water flows at large scales, referred to here as `Hydrological' and `Land Surface' models. While both approaches include a physically based model of the water stores and fluxes, the Land Surface models links the water flows to an energy-based model for processes such as snow melt and soil freezing. This study will analyse the impact of that basic difference on the regional patterns of evapotranspiration, runoff generation and terrestrial water storage. For the evapotranspiration, the Hydrological models tend to have a bigger spatial range in the model bias (difference to observations), implying greater errors compared to the Land-Surface models. For instance, some regions such as Eastern Siberia have consistently lower Evaporation in the Hydrological models than the Land Surface models. For the Runoff however, the results are the other way round with a slightly higher spatial range in bias for the Land Surface models implying greater errors than the Hydrological models. A simple analysis would suggest that Hydrological models are designed to get the runoff right, while Land Surface models designed to get the evapotranspiration right. Tracing the source of the difference suggests that the difference comes from the treatment

Hydraulics and drones: observations of water level, bathymetry and water surface velocity from Unmanned Aerial Vehicles

DEFF Research Database (Denmark)

Bandini, Filippo

-navigable rivers and overpass obstacles (e.g. river structures). Computer vision, autopilot system and beyond visual line-of-sight (BVLOS) flights will ensure the possibility to retrieve hyper-spatial observations of water depth, without requiring the operator to access the area. Surface water speed can......The planet faces several water-related threats, including water scarcity, floods, and pollution. Satellite and airborne sensing technology is rapidly evolving to improve the observation and prediction of surface water and thus prevent natural disasters. While technological developments require....... Although UAV-borne measurements of surface water speed have already been documented in the literature, a novel approach was developed to avoid GCPs. This research is the first demonstration that orthometric water level can be measured from UAVs with a radar system and a GNSS (Global Navigation Satellite...

Effect of solid waste landfill on underground and surface water ...

African Journals Online (AJOL)

Effect of solid waste landfill on underground and surface water quality at ring road, Ibadan, Nigeria. ... parameters showed increased concentrations over those from control sites. ... Keywords: Landfill, groundwater, surface-water, pollution.

Surface water classification and monitoring using polarimetric synthetic aperture radar

Science.gov (United States)

Irwin, Katherine Elizabeth

Surface water classification using synthetic aperture radar (SAR) is an established practice for monitoring flood hazards due to the high temporal and spatial resolution it provides. Surface water change is a dynamic process that varies both spatially and temporally, and can occur on various scales resulting in significant impacts on affected areas. Small-scale flooding hazards, caused by beaver dam failure, is an example of surface water change, which can impact nearby infrastructure and ecosystems. Assessing these hazards is essential to transportation and infrastructure maintenance. With current satellite missions operating in multiple polarizations, spatio-temporal resolutions, and frequencies, a comprehensive comparison between SAR products for surface water monitoring is necessary. In this thesis, surface water extent models derived from high resolution single-polarization TerraSAR-X (TSX) data, medium resolution dual-polarization TSX data and low resolution quad-polarization RADARSAT-2 (RS-2) data are compared. There exists a compromise between acquiring SAR data with a high resolution or high information content. Multi-polarization data provides additional phase and intensity information, which makes it possible to better classify areas of flooded vegetation and wetlands. These locations are often where fluctuations in surface water occur and are essential for understanding dynamic underlying processes. However, often multi-polarized data is acquired at a low resolution, which cannot image these zones effectively. High spatial resolution, single-polarization TSX data provides the best model of open water. However, these single-polarization observations have limited information content and are affected by shadow and layover errors. This often hinders the classification of other land cover types. The dual-polarization TSX data allows for the classification of flooded vegetation, but classification is less accurate compared to the quad-polarization RS-2 data

Water slip and friction at a solid surface

Energy Technology Data Exchange (ETDEWEB)

Brigo, L; Pierno, M; Mammano, F; Sada, C; Fois, G; Pozzato, A; Zilio, S dal; Mistura, G [Dipartimento di Fisica G Galilei, Universita degli Studi di Padova, via Marzolo 8, 35131 Padova (Italy); Natali, M [Istituto di Chimica Inorganica e delle Superfici (ICIS), CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Tormen, M [TASC-INFM, CNR, S S 14 km 163.5 Area Science Park, 34012 Basovizza, Trieste (Italy)], E-mail: mistura@padova.infm.it

2008-09-03

A versatile micro-particle imaging velocimetry ({mu}-PIV) recording system is described, which allows us to make fluid velocity measurements in a wide range of flow conditions both inside microchannels and at liquid-solid interfaces by using epifluorescence and total internal reflection fluorescence excitation. This set-up has been applied to study the slippage of water over flat surfaces characterized by different degrees of hydrophobicity and the effects that a grooved surface has on the fluid flow inside a microchannel. Preliminary measurements of the slip length of water past various flat surfaces show no significant dependence on the contact angle.

The Proposed Surface Water and Ocean Topography (SWOT) Mission

Science.gov (United States)

Fu, Lee-Lueng; Alsdorf, Douglas; Rodriguez, Ernesto; Morrow, Rosemary; Mognard, Nelly; Vaze, Parag; Lafon, Thierry

2012-01-01

A new space mission concept called Surface Water and Ocean Topography (SWOT) is being developed jointly by a collaborative effort of the international oceanographic and hydrological communities for making high-resolution measurement of the water elevation of both the ocean and land surface water to answer the questions about the oceanic submesoscale processes and the storage and discharge of land surface water. The key instrument payload would be a Ka-band radar interferometer capable of making high-resolution wide-swath altimetry measurement. This paper describes the proposed science objectives and requirements as well as the measurement approach of SWOT, which is baselined to be launched in 2019. SWOT would demonstrate this new approach to advancing both oceanography and land hydrology and set a standard for future altimetry missions.

Presence of active pharmaceutical ingredients in the continuum of surface and ground water used in drinking water production.

Science.gov (United States)

Ahkola, Heidi; Tuominen, Sirkku; Karlsson, Sanja; Perkola, Noora; Huttula, Timo; Saraperä, Sami; Artimo, Aki; Korpiharju, Taina; Äystö, Lauri; Fjäder, Päivi; Assmuth, Timo; Rosendahl, Kirsi; Nysten, Taina

2017-12-01

Anthropogenic chemicals in surface water and groundwater cause concern especially when the water is used in drinking water production. Due to their continuous release or spill-over at waste water treatment plants, active pharmaceutical ingredients (APIs) are constantly present in aquatic environment and despite their low concentrations, APIs can still cause effects on the organisms. In the present study, Chemcatcher passive sampling was applied in surface water, surface water intake site, and groundwater observation wells to estimate whether the selected APIs are able to end up in drinking water supply through an artificial groundwater recharge system. The API concentrations measured in conventional wastewater, surface water, and groundwater grab samples were assessed with the results obtained with passive samplers. Out of the 25 APIs studied with passive sampling, four were observed in groundwater and 21 in surface water. This suggests that many anthropogenic APIs released to waste water proceed downstream and can be detectable in groundwater recharge. Chemcatcher passive samplers have previously been used in monitoring several harmful chemicals in surface and wastewaters, but the path of chemicals to groundwater has not been studied. This study provides novel information on the suitability of the Chemcatcher passive samplers for detecting APIs in groundwater wells.

Surface Waters Information Management System (SWIMS)

Data.gov (United States)

Kansas Data Access and Support Center — The Surface Waters Information Management System (SWIMS) has been designed to meet multi-agency hydrologic database needs for Kansas. The SWIMS project was supported...

Fabrication of Superhydrophobic Surfaces with Controllable Electrical Conductivity and Water Adhesion.

Science.gov (United States)

Ye, Lijun; Guan, Jipeng; Li, Zhixiang; Zhao, Jingxin; Ye, Cuicui; You, Jichun; Li, Yongjin

2017-02-14

A facile and versatile strategy for fabricating superhydrophobic surfaces with controllable electrical conductivity and water adhesion is reported. "Vine-on-fence"-structured and cerebral cortex-like superhydrophobic surfaces are constructed by filtering a suspension of multiwalled carbon nanotubes (MWCNTs), using polyoxymethylene nonwovens as the filter paper. The nonwovens with micro- and nanoporous two-tier structures act as the skeleton, introducing a microscale structure. The MWCNTs act as nanoscale structures, creating hierarchical surface roughness. The surface topography and the electrical conductivity of the superhydrophobic surfaces are controlled by varying the MWCNT loading. The vine-on-fence-structured surfaces exhibit "sticky" superhydrophobicity with high water adhesion. The cerebral cortex-like surfaces exhibit self-cleaning properties with low water adhesion. The as-prepared superhydrophobic surfaces are chemically resistant to acidic and alkaline environments of pH 2-12. They therefore have potential in applications such as droplet-based microreactors and thin-film microextraction. These findings aid our understanding of the role that surface topography plays in the design and fabrication of superhydrophobic surfaces with different water-adhesion properties.

Wind turbine tower for storing hydrogen and energy

Science.gov (United States)

Fingersh, Lee Jay [Westminster, CO

2008-12-30

A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

The significant surface-water connectivity of "geographically isolated wetlands"

Science.gov (United States)

Calhoun, Aram J.K.; Mushet, David M.; Alexander, Laurie C.; DeKeyser, Edward S.; Fowler, Laurie; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Richter, Stephen; Walls, Susan

2017-01-01

We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “geographically isolated” shows the difficulties in grouping an ecological resource that does not reliably indicate lack of surface water connectivity in order to meet legal, regulatory, or scientific needs. Additionally, the practice of identifying “geographically isolated wetlands” based on distance from a stream can result in gross overestimates of the number of wetlands lacking ecologically important surface-water connections. Our findings do not support use of the overly simplistic label of “geographically isolated wetlands”. Wetlands surrounded by uplands vary in function and surface-water connections based on wetland landscape setting, context, climate, and geographic region and should be evaluated as such. We found that the “geographically isolated” grouping does not reflect our understanding of the hydrologic variability of these wetlands and hence does not benefit conservation of the Nation’s diverse wetland resources. Therefore, we strongly discourage use of categorizations that provide overly simplistic views of surface-water connectivity of wetlands fully embedded in upland landscapes.

Quality-control design for surface-water sampling in the National Water-Quality Network

Science.gov (United States)

Riskin, Melissa L.; Reutter, David C.; Martin, Jeffrey D.; Mueller, David K.

2018-04-10

The data-quality objectives for samples collected at surface-water sites in the National Water-Quality Network include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of environmental conditions. Quality-control samples provide insight into how well the samples collected at surface-water sites represent the true environmental conditions. Quality-control samples used in this program include field blanks, replicates, and field matrix spikes. This report describes the design for collection of these quality-control samples and the data management needed to properly identify these samples in the U.S. Geological Survey’s national database.

Strategic Evaluation Tool for Surface Water Quality Management Remedies in Drinking Water Catchments

Directory of Open Access Journals (Sweden)

Huda Almaaofi

2017-09-01

Full Text Available Drinking water catchments (DWC are under pressure from point and nonpoint source pollution due to the growing human activities. This worldwide challenge is causing number of adverse effects, such as degradation in water quality, ecosystem health, and other economic and social pressures. Different evaluation tools have been developed to achieve sustainable and healthy drinking water catchments. However, a holistic and strategic framework is still required to adequately consider the uncertainty associated with feasible management remedies of surface water quality in drinking water catchments. A strategic framework was developed to adequately consider the uncertainty associated with management remedies for surface water quality in drinking water catchments. A Fuzzy Multiple Criteria Decision Analysis (FMCDA approach was embedded into a strategic decision support framework to evaluate and rank water quality remediation options within a typical fixed budget constraint faced by bulk water providers. The evaluation framework consists of four core aspects; namely, water quality, environmental, economic and social, and number of associated quantitative and qualitative criteria and sub-criteria. Final remediation strategy ranking was achieved through the application of the Euclidean Distance by the In-center of Centroids (EDIC.

Manufacturing and characterisation of water repellent surfaces

DEFF Research Database (Denmark)

De Grave, Arnaud; Botija, Pablo; Hansen, Hans Nørgaard

2006-01-01

design criteria for such surfaces. The problem of adapting this behaviour to artificially roughened surfaces is addressed by providing design criteria for superhydrophobic, water-repellent and self-cleaning surfaces according to the concrete performance desired for them. Different kind of manufacturing...... techniques are investigated and the production of patterned micro structured surfaces following two different manufacturing techniques is reported. The first is a combination of laser manufacturing and hot embossing on polystyrene. To compare geometry and functionality a non-silicon based lithography...

Effect of water storage and surface treatments on the tensile bond strength of IPS Empress 2 ceramic.

Science.gov (United States)

Salvio, Luciana A; Correr-Sobrinho, Lourenço; Consani, Simonides; Sinhoreti, Mário A C; de Goes, Mario F; Knowles, Jonathan C

2007-01-01

The aim of this study was to evaluate the effect of water storage (24 hours and 1 year) on the tensile bond strength between the IPS Empress 2 ceramic and Variolink II resin cement under different superficial treatments. One hundred and eighty disks with diameters of 5.3 mm at the top and 7.0 mm at the bottom, and a thickness of 2.5 mm were made, embedded in resin, and randomly divided into six groups: Groups 1 and 4 = 10% hydrofluoric acid for 20 seconds; Groups 2 and 5 = sandblasting for 5 seconds with 50 microm aluminum oxide; and Groups 3 and 6 = sandblasting for 5 seconds with 100 microm aluminum oxide. Silane was applied on the treated ceramic surfaces, and the disks were bonded into pairs with adhesive resin cement. The samples of Groups 1 to 3 were stored in distilled water at 37 degrees C for 24 hours, and Groups 4 to 6 were stored for 1 year. The samples were subjected to a tensile strength test in an Instron universal testing machine at a crosshead speed of 1.0 mm/min, until failure. The data were submitted to analysis of variance and Tukey's test (5%). The means of the tensile bond strength of Groups 1, 2, and 3 (15.54 +/- 4.53, 10.60 +/- 3.32, and 7.87 +/- 2.26 MPa) for 24-hour storage time were significantly higher than those observed for the 1-year storage (Groups 4, 5, and 6: 10.10 +/- 3.17, 6.34 +/- 1.06, and 2.60 +/- 0.41 MPa). The surface treatments with 10% hydrofluoric acid (15.54 +/- 4.53 and 10.10 +/- 3.17 MPa) showed statistically higher tensile bond strengths compared with sandblasting with 50 microm(10.60 +/- 3.32 and 6.34 +/- 1.06 MPa) and 100 microm (7.87 +/- 2.26 and 2.60 +/- 0.41 MPa) aluminum oxide for the storage time 24 hours and 1 year. Storage time significantly decreased the tensile bond strength for both ceramic surface treatments. The application of 10% hydrofluoric acid resulted in stronger tensile bond strength values than those achieved with aluminum oxide.

Aspects of radiation exposure amongst the population after release of radionuclides from terminal stores

International Nuclear Information System (INIS)

Proehl, G.; Mueller, H.; Paretzke, H.G.

1989-08-01

The release of radionuclides from terminal stores may lead to the contamination of ground water lying close to the surface, after the radionuclides have migrated within the covering rock. Use of this water can result in radiation exposure for human beings along many exposure pathways. In order to assess the radiation exposure from these exposure pathways the model ECOSYS-87-B was developed, as an extension of ECOSYS (Jacobi et al. 1985). On the basis of a standardized contamination of the ground water, the potential radiation exposure of a one-year-old and an adult are calculated, under the assumption that the entire food supply of these persons was produced using radioactively contaminated water. Special questions on the transfer of radionuclides in food chains are discussed, and, in particular, the mineral content of the water and the influence of the chemical form of the radionuclides dissolved in the ground water on their transfer within the food chain are explained. There is also a study of the extent to which various physiologically-based nutritional habits influence the radiation exposure of a human being. Various criteria for the evaluation of radiation exposure are discussed. (orig./HP) [de

Near-field Oblique Remote Sensing of Stream Water-surface Elevation, Slope, and Surface Velocity

Science.gov (United States)

Minear, J. T.; Kinzel, P. J.; Nelson, J. M.; McDonald, R.; Wright, S. A.

2014-12-01

A major challenge for estimating discharges during flood events or in steep channels is the difficulty and hazard inherent in obtaining in-stream measurements. One possible solution is to use near-field remote sensing to obtain simultaneous water-surface elevations, slope, and surface velocities. In this test case, we utilized Terrestrial Laser Scanning (TLS) to remotely measure water-surface elevations and slope in combination with surface velocities estimated from particle image velocimetry (PIV) obtained by video-camera and/or infrared camera. We tested this method at several sites in New Mexico and Colorado using independent validation data consisting of in-channel measurements from survey-grade GPS and Acoustic Doppler Current Profiler (ADCP) instruments. Preliminary results indicate that for relatively turbid or steep streams, TLS collects tens of thousands of water-surface elevations and slopes in minutes, much faster than conventional means and at relatively high precision, at least as good as continuous survey-grade GPS measurements. Estimated surface velocities from this technique are within 15% of measured velocity magnitudes and within 10 degrees from the measured velocity direction (using extrapolation from the shallowest bin of the ADCP measurements). Accurately aligning the PIV results into Cartesian coordinates appears to be one of the main sources of error, primarily due to the sensitivity at these shallow oblique look angles and the low numbers of stationary objects for rectification. Combining remotely-sensed water-surface elevations, slope, and surface velocities produces simultaneous velocity measurements from a large number of locations in the channel and is more spatially extensive than traditional velocity measurements. These factors make this technique useful for improving estimates of flow measurements during flood flows and in steep channels while also decreasing the difficulty and hazard associated with making measurements in these

Water evaporation from substrate tooth surface during dentin treatments.

Science.gov (United States)

Kusunoki, Mizuho; Itoh, Kazuo; Gokan, Yuka; Nagai, Yoshitaka; Tani, Chihiro; Hisamitsu, Hisashi

2011-01-01

The purpose of this study was to evaluate changes in the quantity of water evaporation from tooth surfaces. The amount of water evaporation was measured using Multi probe adapter MPA5 and Tewameter TM300 (Courage+Khazaka Electric GmbH, Köln, Germany) after acid etching and GM priming of enamel; and after EDTA conditioning and GM priming of dentin. The results indicated that the amount of water evaporation from the enamel surface was significantly less than that from the dentin. Acid etching did not affect the water evaporation from enamel, though GM priming significantly decreased the evaporation (83.48 ± 15.14% of that before priming). The evaporation from dentin was significantly increased by EDTA conditioning (131.38 ± 42.08% of that before conditioning) and significantly reduced by GM priming (80.26 ± 7.43% of that before priming). It was concluded that dentin priming reduced water evaporation from the dentin surface.

Evaluation of human enamel surfaces treated with theobromine: a pilot study.

Science.gov (United States)

Kargul, Betul; Özcan, Mutlu; Peker, Sertac; Nakamoto, Tetsuo; Simmons, William B; Falster, Alexander U

2012-01-01

The objectives of this in-vitro study were to investigate the effect of theobromine, which is the principle xanthine species in Theobroma cacao, at two concentrations on the surface hardness and topography of human enamel. Twenty-four freshly extracted human third molars were collected and stored in distilled water with 0.1% thymol solution at room temperature prior to the experiments. The enamel specimens were treated with one coat of theobromine at two concentrations (100 mg/l or 200 mg/l in distilled water) for 5 min. Enamel surfaces in the control group received no theobromine. They were then kept in distilled water for 1 week and subjected to SEM analysis. The specimens were demineralised by storing them in acidic hydroxyethylcellulose for three days. After baseline microhardness measurements, they were incubated either in 100 or 200 mg/l theobromine for 5 min. The control group was kept in distilled water. After washing the specimens under distilled water, they were kept in a remineralising solution for 18 h. Microhardness of the enamel surface was initially determined for each specimen before artificial demineralisation. After demineralisation, the experimental groups were incubated in 100 mg or 200 mg theobromine and control-group specimens were placed in remineralising solution. Enamel surfaces of the untreated control group presented a generally smooth and slightly hummocky surface with small lines of pits. Specimens treated with theobromine showed differences between the two concentrations. The group treated with 200 mg/l solution for 5 min showed a greater quantity of globules on enamel than did specimens treated with 100 mg/l solution. As shown by the microhardness values, a consistent and remarkable protection of the enamel surface was found with the application of theobromine.

Lake Chad Total Surface Water Area as Derived from Land Surface Temperature and Radar Remote Sensing Data

Directory of Open Access Journals (Sweden)

Frederick Policelli

2018-02-01

Full Text Available Lake Chad, located in the middle of the African Sahel belt, underwent dramatic decreases in the 1970s and 1980s leaving less than ten percent of its 1960s surface water extent as open water. In this paper, we present an extended record (dry seasons 1988–2016 of the total surface water area of the lake (including both open water and flooded vegetation derived using Land Surface Temperature (LST data (dry seasons 2000–2016 from the NASA Terra MODIS sensor and EUMETSAT Meteosat-based LST measurements (dry seasons 1988–2001 from an earlier study. We also examine the total surface water area for Lake Chad using radar data (dry seasons 2015–2016 from the ESA Sentinel-1a mission. For the limited number of radar data sets available to us (18 data sets, we find on average a close match between the estimates from these data and the corresponding estimates from LST, though we find spatial differences in the estimates using the two types of data. We use these spatial differences to adjust the record (dry seasons 2000–2016 from MODIS LST. Then we use the adjusted record to remove the bias of the existing LST record (dry seasons 1988–2001 derived from Meteosat measurements and combine the two records. From this composite, extended record, we plot the total surface water area of the lake for the dry seasons of 1988–1989 through 2016–2017. We find for the dry seasons of 1988–1989 to 2016–2017 that the maximum total surface water area of the lake was approximately 16,800 sq. km (February and May, 2000, the minimum total surface water area of the lake was approximately 6400 sq. km (November, 1990, and the average was approximately 12,700 sq. km. Further, we find the total surface water area of the lake to be highly variable during this period, with an average rate of increase of approximately 143 km2 per year.

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.

Analysis of water microdroplet condensation on silicon surfaces

Science.gov (United States)

Honda, Takuya; Fujimoto, Kenya; Yoshimoto, Yuta; Mogi, Katsuo; Kinefuchi, Ikuya; Sugii, Yasuhiko; Takagi, Shu; Univ. of Tokyo Team; Tokyo Inst. of Tech. Team

2016-11-01

We observed the condensation process of water microdroplets on flat silicon (100) surfaces by means of the sequential visualization of the droplets using an environmental scanning electron microscope. As previously reported for nanostructured surfaces, the condensation process of water microdroplets on the flat silicon surfaces also exhibits two modes: the constant base (CB) area mode and the constant contact angle (CCA) mode. In the CB mode, the contact angle increases with time while the base diameter is constant. Subsequently, in the CCA mode, the base diameter increases with time while the contact angle remains constant. The dropwise condensation model regulated by subcooling temperature does not reproduce the experimental results. Because the subcooling temperature is not constant in the case of a slow condensation rate, this model is not applicable to the condensation of the long time scale ( several tens of minutes). The contact angle of water microdroplets ( several μm) tended to be smaller than the macro contact angle. Two hypotheses are proposed as the cause of small contact angles: electrowetting and the coalescence of sub- μm water droplets.

Modification of surface properties of LLDPE by water plasma discharge

International Nuclear Information System (INIS)

Chantara Thevy Ratnam; Hill, D.J.T.; Firas Rasoul; Whittaker, A.K.; Imelda Keen

2007-01-01

Linear low density polyethylene (LLDPE) surface was modified by water plasma treatment. The LLDPE surface was treated at 10 and 20 W discharge power at various exposure times. A laboratory scale Megatherm radio frequency (RF) plasma apparatus that operates at 27 MHz was used to generate the water plasmas. The changes in chemical structure of the LLDPE polymeric chain upon plasma treatment were characterized by FTIR and XPS techniques. The selectivity of trifluoroacetic anhydride (TFAA) toward hydroxyl groups is used to quantify the hydroxyl groups formed on the polymer surface upon plasma treatment. After exposition to the plasma discharge a decline in water contact angle were observed. FTIR and XPS measurements indicate an oxidation of degraded polymeric chains and creation of hydroxyl, carbonyl, ether, ester and carboxyl groups. Chemical derivatization with TFAA of water plasma treated polymer surfaces has shown that under the conditions employed, a very small (less than 5%) of the oxygen introduced by the water plasma treatment was present as hydroxyl group. (Author)

The influence of lithology on surface water sources | Science ...

Science.gov (United States)

Understanding the temporal and spatial variability of surface water sources within a basin is vital to our ability to manage the impacts of climate variability and land cover change. Water stable isotopes can be used as a tool to determine geographic and seasonal sources of water at the basin scale. Previous studies in the Coastal Range of Oregon reported that the variation in the isotopic signatures of surface water does not conform to the commonly observed “rainout effect”, which exhibits a trend of increasing isotopic depletion with rising elevation. The primary purpose of this research is to investigate the mechanisms governing seasonal and spatial variations in the isotopic signature of surface waters within the Marys River Basin, located in the leeward side of the Oregon Coastal Range. Surface water and precipitation samples were collected every 2-3 weeks for isotopic analysis of δ18O and δ2H for one year. Results indicate a significant difference in isotopic signature between watersheds underlain by basalt and sandstone. The degree of separation was the most distinct during the summer when low flows reflect deeper groundwater sources, whereas isotopic signatures during the rainy season (fall and winter) showed a greater degree of similarity between the two lithologies. This indicates that baseflow within streams drained by sandstone versus basalt is being supplied from two distinctly separate water sources. In addition, Marys River flow at the outle

Contamination levels of human pharmaceutical compounds in French surface and drinking water.

Science.gov (United States)

Mompelat, S; Thomas, O; Le Bot, B

2011-10-01

The occurrence of 20 human pharmaceutical compounds and metabolites from 10 representative therapeutic classes was analysed from resource and drinking water in two catchment basins located in north-west France. 98 samples were analysed from 63 stations (surface water and drinking water produced from surface water). Of the 20 human pharmaceutical compounds selected, 16 were quantified in both the surface water and drinking water, with 22% of the values above the limit of quantification for surface water and 14% for drinking water). Psychostimulants, non-steroidal anti-inflammatory drugs, iodinated contrast media and anxiolytic drugs were the main therapeutic classes of human pharmaceutical compounds detected in the surface water and drinking water. The results for surface water were close to results from previous studies in spite of differences in prescription rates of human pharmaceutical compounds in different countries. The removal rate of human pharmaceutical compounds at 11 water treatment units was also determined. Only caffeine proved to be resistant to drinking water treatment processes (with a minimum rate of 5%). Other human pharmaceutical compounds seemed to be removed more efficiently (average elimination rate of over 50%) by adsorption onto activated carbon and oxidation/disinfection with ozone or chlorine (not taking account of the disinfection by-products). These results add to the increasing evidence of the occurrence of human pharmaceutical compounds in drinking water that may represent a threat to human beings exposed to a cocktail of human pharmaceutical compounds and related metabolites and by-products in drinking water.

Lawrence Livermore National Laboratory Surface Water Protection: A Watershed Approach

Energy Technology Data Exchange (ETDEWEB)

Coty, J

2009-03-16

This surface water protection plan (plan) provides an overview of the management efforts implemented at Lawrence Livermore National Laboratory (LLNL) that support a watershed approach to protect surface water. This plan fulfills a requirement in the Department of Energy (DOE) Order 450.1A to demonstrate a watershed approach for surface water protection that protects the environment and public health. This plan describes the use of a watershed approach within which the Laboratory's current surface water management and protections efforts have been structured and coordinated. With more than 800 million acres of land in the U.S. under federal management and stewardship, a unified approach across agencies provides enhanced resource protection and cost-effectiveness. The DOE adopted, along with other federal agencies, the Unified Federal Policy for a Watershed Approach to Federal Land and Resource Management (UFP) with a goal to protect water quality and aquatic ecosystems on federal lands. This policy intends to prevent and/or reduce water pollution from federal activities while fostering a cost-effective watershed approach to federal land and resource management. The UFP also intends to enhance the implementation of existing laws (e.g., the Clean Water Act [CWA] and National Environmental Policy Act [NEPA]) and regulations. In addition, this provides an opportunity for the federal government to serve as a model for water quality stewardship using a watershed approach for federal land and resource activities that potentially impact surface water and its uses. As a federal land manager, the Laboratory is responsible for a small but important part of those 800 million acres of land. Diverse land uses are required to support the Laboratory's mission and provide an appropriate work environment for its staff. The Laboratory comprises two sites: its main site in Livermore, California, and the Experimental Test Site (Site 300), near Tracy, California. The main site

Surface Water Connectivity, Flow Pathways and Water Level Fluctuation in a Cold Region Deltaic Ecosystem

Science.gov (United States)

Peters, D. L.; Niemann, O.; Skelly, R.; Monk, W. A.; Baird, D. J.

2017-12-01

The Peace-Athabasca Delta (PAD) is a 6000 km2 deltaic floodplain ecosystem of international importance (Wood Buffalo National Park, Ramsar Convention, UNESCO World Heritage, and SWOT satellite water level calibration/validation site). The low-relief floodplain formed at the confluence of the Peace, Athabasca and Birch rivers with Lake Athabasca. More than 1000 wetland and lake basins have varying degrees of connectivity to the main flow system. Hydroperiod and water storage is influenced by ice-jam and open-water inundations and prevailing semi-arid climate that control water drawdown. Prior studies have identified pathways of river-to-wetland floodwater connection and historical water level fluctuation/trends as a key knowledge gaps, limiting our knowledge of deltaic ecosystem status and potential hydroecological responses to climate change and upstream water alterations to flow contributions. To address this knowledge gap, surface elevation mapping of the PAD has been conducted since 2012 using aerial remote sensing Light Detection and Ranging (LiDAR), plus thousands of ground based surface and bathymetric survey points tied to Global Positioning System (GPS) were obtained. The elevation information was used to develop a high resolution digital terrain model to simulate and investigate surface water connectivity. Importantly, the surveyed areas contain a set of wetland monitoring sites where ground-based surface water connectivity, water level/depth, water quality, and aquatic ecology (eg, vegetation, macroinvertebrate and muskrat) have been examined. The goal of this presentation is to present an assessment of: i) surface water fluctuation and connectivity for PAD wetland sites; ii) 40+ year inter-annual hydroperiod reconstruction for a perched basin using a combination of field measurements, remote sensing estimates, and historical documents; and iii) outline an approach to integrate newly available hydro-bio-geophysical information into a novel, multi

Drinking Water Sources with Surface Intakes from LDHH source data, Geographic NAD83, LOSCO (1999) [drinking_water_surface_intakes_LDHH_1999

Data.gov (United States)

Louisiana Geographic Information Center — This is a point dataset for 87 public drinking water sources with surface intakes. It was derived from a larger statewide general drinking water source dataset...

The interaction between surface water and groundwater and its ...

Indian Academy of Sciences (India)

Surface water; groundwater; stable isotopes; water quality; Second Songhua River basin. .... The total dissolved solid (TDS) was calculated by the con- centrations of major ions in ...... evaluating water quality management effectiveness; J.

Surface Water Data at Los Alamos National Laboratory 2006 Water Year

Energy Technology Data Exchange (ETDEWEB)

R.P. Romero, D. Ortiz, G. Kuyumjian

2007-08-01

The principal investigators collected and computed surface water discharge data from 44 stream-gaging stations that cover most of Los Alamos National Laboratory and one at Bandelier National Monument. Also included are discharge data from three springs--two that flow into Canon de Valle and one that flows into Water Canyon--and peak flow data for 44 stations.

Modelling of flow and settling in storm water sedimentation tanks

OpenAIRE

Kluck, J.

1994-01-01

In the near future in the Netherlands many reservoirs will have to be built to abate the pollution of the surface water by overflowing storm water from combined sewer systems [Kluck, 1992-a]. These reservoirs, called storm water sedimentation tanks, reduce the pollution in two ways. The most important is by simply storing a part of the sewage (waste water and storm water) and thus reducing the quantity of overflowing water. The second is by providing flow conditions in which particles can set...

Impinging Water Droplets on Inclined Glass Surfaces

Energy Technology Data Exchange (ETDEWEB)

Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lance, Blake [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ho, Clifford K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

Multiphase computational models and tests of falling water droplets on inclined glass surfaces were developed to investigate the physics of impingement and potential of these droplets to self-clean glass surfaces for photovoltaic modules and heliostats. A multiphase volume-of-fluid model was developed in ANSYS Fluent to simulate the impinging droplets. The simulations considered different droplet sizes (1 mm and 3 mm), tilt angles (0°, 10°, and 45°), droplet velocities (1 m/s and 3 m/s), and wetting characteristics (wetting=47° contact angle and non-wetting = 93° contact angle). Results showed that the spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) decreased with increasing inclination angle due to the reduced normal force on the surface. The hydrophilic surface yielded greater spread factors than the hydrophobic surface in all cases. With regard to impact forces, the greater surface tilt angles yielded lower normal forces, but higher shear forces. Experiments showed that the experimentally observed spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) was significantly larger than the simulated spread factor. Observed spread factors were on the order of 5 - 6 for droplet velocities of ~3 m/s, whereas the simulated spread factors were on the order of 2. Droplets were observed to be mobile following impact only for the cases with 45° tilt angle, which matched the simulations. An interesting phenomenon that was observed was that shortly after being released from the nozzle, the water droplet oscillated (like a trampoline) due to the "snapback" caused by the surface tension of the water droplet being released from the nozzle. This oscillation impacted the velocity immediately after the release. Future work should evaluate the impact of parameters such as tilt angle and surface wettability on the impact of particle/soiling uptake and removal to investigate ways that

Africa-wide monitoring of small surface water bodies using multisource satellite data: a monitoring system for FEWS NET: chapter 5

Science.gov (United States)

Velpuri, Naga Manohar; Senay, Gabriel B.; Rowland, James; Verdin, James P.; Alemu, Henok; Melesse, Assefa M.; Abtew, Wossenu; Setegn, Shimelis G.

2014-01-01

Continental Africa has the highest volume of water stored in wetlands, large lakes, reservoirs, and rivers, yet it suffers from problems such as water availability and access. With climate change intensifying the hydrologic cycle and altering the distribution and frequency of rainfall, the problem of water availability and access will increase further. Famine Early Warning Systems Network (FEWS NET) funded by the United States Agency for International Development (USAID) has initiated a large-scale project to monitor small to medium surface water points in Africa. Under this project, multisource satellite data and hydrologic modeling techniques are integrated to monitor several hundreds of small to medium surface water points in Africa. This approach has been already tested to operationally monitor 41 water points in East Africa. The validation of modeled scaled depths with field-installed gauge data demonstrated the ability of the model to capture both the spatial patterns and seasonal variations. Modeled scaled estimates captured up to 60 % of the observed gauge variability with a mean root-mean-square error (RMSE) of 22 %. The data on relative water level, precipitation, and evapotranspiration (ETo) for water points in East and West Africa were modeled since 1998 and current information is being made available in near-real time. This chapter presents the approach, results from the East African study, and the first phase of expansion activities in the West Africa region. The water point monitoring network will be further expanded to cover much of sub-Saharan Africa. The goal of this study is to provide timely information on the water availability that would support already established FEWS NET activities in Africa. This chapter also presents the potential improvements in modeling approach to be implemented during future expansion in Africa.

Subcellular location of astrocytic calcium stores favors extrasynaptic neuron-astrocyte communication.

Science.gov (United States)

Patrushev, Ilya; Gavrilov, Nikolay; Turlapov, Vadim; Semyanov, Alexey

2013-11-01

Neuron-astrocyte interactions are important for brain computations and synaptic plasticity. Perisynaptic astrocytic processes (PAPs) contain a high density of transporters that are responsible for neurotransmitter clearance. Metabotropic glutamate receptors are thought to trigger Ca(2+) release from Ca(2+) stores in PAPs in response to synaptic activity. Our ultrastructural study revealed that PAPs are actually devoid of Ca(2+) stores and have a high surface-to-volume ratio favorable for uptake. Astrocytic processes containing Ca(2+) stores were located further away from the synapses and could therefore respond to changes in ambient glutamate. Thus, the anatomic data do not support communication involving Ca(2+) stores in tripartite synapses, but rather point to extrasynaptic communication. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular dynamics study of room temperature ionic liquids with water at mica surface

Directory of Open Access Journals (Sweden)

Huanhuan Zhang

2018-04-01

Full Text Available Water in room temperature ionic liquids (RTILs could impose significant effects on their interfacial properties at a charged surface. Although the interfaces between RTILs and mica surfaces exhibit rich microstructure, the influence of water content on such interfaces is little understood, in particular, considering the fact that RTILs are always associated with water due to their hygroscopicity. In this work, we studied how different types of RTILs and different amounts of water molecules affect the RTIL-mica interfaces, especially the water distribution at mica surfaces, using molecular dynamics (MD simulation. MD results showed that (1 there is more water and a thicker water layer adsorbed on the mica surface as the water content increases, and correspondingly the average location of K+ ions is farther from mica surface; (2 more water accumulated at the interface with the hydrophobic [Emim][TFSI] than in case of the hydrophilic [Emim][BF4] due to the respective RTIL hydrophobicity and ion size. A similar trend was also observed in the hydrogen bonds formed between water molecules. Moreover, the 2D number density map of adsorbed water revealed that the high-density areas of water seem to be related to K+ ions and silicon/aluminum atoms on mica surface. These results are of great importance to understand the effects of hydrophobicity/hydrophicility of RTIL and water on the interfacial microstructure at electrified surfaces. Keywords: Room temperature ionic liquids, Hydrophobicity/hydrophicility, Water content, Electrical double layer, Mica surface

Surface WAter Scenario Help (SWASH) version 5.3 : technical description

NARCIS (Netherlands)

Roller, te J.A.; Berg, van den F.; Adriaanse, P.I.; Jong, de A.; Beltman, W.H.J.

2015-01-01

The user-friendly shell SWASH, acronym for Surface WAter Scenarios Help, assists the user in calculating pesticide exposure concentrations in the EU FOCUS surface water scenarios. SWASH encompasses five separate tools and models: (i) FOCUS Drift Calculator, calculating pesticide entries through

Water, gravity and trees: Relationship of tree-ring widths and total water storage dynamics

Science.gov (United States)

Creutzfeldt, B.; Heinrich, I.; Merz, B.; Blume, T.; Güntner, A.

2012-04-01

Water stored in the subsurface as groundwater or soil moisture is the main fresh water source not only for drinking water and food production but also for the natural vegetation. In a changing environment water availability becomes a critical issue in many different regions. Long-term observations of the past are needed to improve the understanding of the hydrological system and the prediction of future developments. Tree ring data have repeatedly proved to be valuable sources for reconstructing long-term climate dynamics, e.g. temperature, precipitation and different hydrological variables. In water-limited environments, tree growth is primarily influenced by total water stored in the subsurface and hence, tree-ring records usually contain information about subsurface water storage. The challenge is to retrieve the information on total water storage from tree rings, because a training dataset of water stored in the sub-surface is required for calibration against the tree-ring series. However, measuring water stored in the subsurface is notoriously difficult. We here present high-precision temporal gravimeter measurements which allow for the depth-integrated quantification of total water storage dynamics at the field scale. In this study, we evaluate the relationship of total water storage change and tree ring growth also in the context of the complex interactions of other meteorological forcing factors. A tree-ring chronology was derived from a Norway spruce stand in the Bavarian Forest, Germany. Total water storage dynamics were measured directly by the superconducting gravimeter of the Geodetic Observatory Wettzell for a 9-years period. Time series were extended to 63-years period by a hydrological model using gravity data as the only calibration constrain. Finally, water storage changes were reconstructed based on the relationship between the hydrological model and the tree-ring chronology. Measurement results indicate that tree-ring growth is primarily

Boron content of South African surface waters: prelimenary assessment for irrigation

International Nuclear Information System (INIS)

Reid, P.C.; Davies, E.

1989-01-01

Boron, a naturally occuring constituent of surface and ground water, is an essential plant nutrient. However, at relatively low concentrations, boron becomes toxic to plant growth. In order to assess the boron status in South African surface waters, the Department of Water Affairs launched a long-term boron water quality assessment programme in 1985, encompassing the analysis of water samples taken at 91 sites throughout South Africa. Results to date indicate that the boron concentration in South African surface waters varies between 0,02 to 0,33 mg l -1 . At these concentrations even the most boron sensitive crops can be grown without fear of boron toxicity. 3 refs., 1 fig., 2 tabs

Radionuclide transfer onto ground surface in surface water flow. 2. Undisturbed tuff rock

International Nuclear Information System (INIS)

Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu

1994-09-01

Radionuclide migration with ground surface water flow is considered to be one of path ways in the scenario for environmental migration of the radionuclide leaked from LLRW depository. To study the radionuclide migration demonstratively, a ground surface radionuclide migration test was carried out by simulating radioactive solution flowing on the sloped tuff rock surface. Tuff rock sample of 240 cm in length taken from the Shimokita district was used to test the transfer of 60 Co, 85 Sr and 137 Cs onto the sample surface from the flowing radioactive solution under restricted infiltration condition at flow rates of 25, 80, 160ml/min and duration of 56h. The concentration change of the radionuclides in effluent was nearly constant as a function of elapsed time during the experimental period, but decreased with lower flow rates. Among the three radionuclides, 137 Cs was greatly decreased its concentration to 30% of the inflow. Adsorbed distribution of the radionuclides concentration on the ground surface decreased gradually with the distance from the inlet, and showed greater gradient at lower flow rate. Analyzing the result by the migration model, where a vertical advection distribution and two-dimensional diffusion in surface water are adopted with a first order adsorption reaction, value of migration parameters was obtained relating to the radionuclide adsorption and the surface water flow, and the measured distribution could be well simulated by adopting the value to the model. By comparing the values with the case of loamy soil layer, all values of the migration parameters showed not so great difference between two samples for 60 Co and 85 Sr. For 137 Cs, reflecting a few larger value of adsorption to the tuff rock, larger ability to reduce the concentration of flowing radioactive solution could be indicated than that to the loamy soil surface by estimation for long flowed distance. (author)

Hydrologic Science and Satellite Measurements of Surface Water (Invited)

Science.gov (United States)

Alsdorf, D. E.; Mognard, N. M.; Lettenmaier, D. P.

2010-12-01

While significant advances continue to be made for satellite measurements of surface waters, important science and application opportunities remain. Examples include the following: (1) Our current methods of measuring floodwater dynamics are either sparsely distributed or temporally inadequate. As an example, flood depths are measured by using high water marks, which capture only the peak of the flood wave, not its temporal variability. (2) Discharge is well measured at individual points along stream networks using in-situ gauges, but these do not capture within-reach hydraulic variability such as the water surface slope changes on the rising and falling limbs of flood waves. (3) Just a 1.0 mm/day error in ET over the Congo Basin translates to a 35,000 m3/s discharge error. Knowing the discharge of the Congo River and its many tributaries should significantly improve our understanding of the water balance throughout the basin. The Congo is exemplary of many other basins around the globe. (4) Arctic hydrology is punctuated by millions of unmeasured lakes. Globally, there might be as many as 30 million lakes larger than a hectare. Storage changes in these lakes are nearly unknown, but in the Arctic such changes are likely an indication of global warming. (5) Well over 100 rivers cross international boundaries, yet the sharing of water data is poor. Overcoming this helps to better manage the entire river basin while also providing a better assessment of potential water related disasters. The Surface Water and Ocean Topography (SWOT, http://swot.jpl.nasa.gov/) mission is designed to meet these needs by providing global measurements of surface water hydrodynamics. SWOT will allow estimates of discharge in rivers wider than 100m (50m goal) and storage changes in water bodies larger than 250m by 250m (and likely as small as one hectare).

33 CFR 106.270 - Security measures for delivery of stores and industrial supplies.

Science.gov (United States)

2010-07-01

... stores and industrial supplies. (a) General. The OCS facility owner or operator must ensure that security...). These additional security measures may include: (1) Intensifying inspection of the stores or industrial... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Security measures for delivery of...

Surface water management at a mixed waste remediation site

International Nuclear Information System (INIS)

Schlotzhauer, D.S.; Warbritton, K.R.

1991-01-01

The Weldon Spring Remedial Action Project (WSSRAP) deals with chemical and radiological contaminants. MK-Ferguson Company is managing the project under contract with the US Department of Energy. Remedial activities include demolishing buildings, constructing material storage and staging areas, excavating and consolidating waste materials, and treating and disposing of the materials in a land disposal facility. Due to the excavation and construction required during remediation, a well-planned surface water management system is essential. Planning involves characterization of source areas and surface water transport mechanisms and identification of applicable regulations. System components include: erosion control sediment control, flow attenuation, and management of contaminated water. Combinations of these components may be utilized during actual construction and remediation to obtain optimum control. Monitoring is performed during implementation in order to assess the effectiveness of control measures. This management scheme provides for comprehensive management of surface water at this site by providing control and/or treatment to appropriate standards. Although some treatment methodologies for contaminated water are specific to site contaminants, this comprehensive program provides a management approach which is applicable to many remedial projects in order to minimize contaminant release and meet Clean Water Act requirements

Observation of dynamic water microadsorption on Au surface

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiaokang, E-mail: xiaokang.huang@tqs.com; Gupta, Gaurav; Gao, Weixiang; Tran, Van; Nguyen, Bang; McCormick, Eric; Cui, Yongjie; Yang, Yinbao; Hall, Craig; Isom, Harold [TriQuint Semiconductor, Inc., 500 W Renner Road, Richardson, Texas 75080 (United States)

2014-05-15

Experimental and theoretical research on water wettability, adsorption, and condensation on solid surfaces has been ongoing for many decades because of the availability of new materials, new detection and measurement techniques, novel applications, and different scales of dimensions. Au is a metal of special interest because it is chemically inert, has a high surface energy, is highly conductive, and has a relatively high melting point. It has wide applications in semiconductor integrated circuitry, microelectromechanical systems, microfluidics, biochips, jewelry, coinage, and even dental restoration. Therefore, its surface condition, wettability, wear resistance, lubrication, and friction attract a lot of attention from both scientists and engineers. In this paper, the authors experimentally investigated Au{sub 2}O{sub 3} growth, wettability, roughness, and adsorption utilizing atomic force microscopy, scanning electron microscopy, reflectance spectrometry, and contact angle measurement. Samples were made using a GaAs substrate. Utilizing a super-hydrophilic Au surface and the proper surface conditions of the surrounding GaAs, dynamic microadsorption of water on the Au surface was observed in a clean room environment. The Au surface area can be as small as 12 μm{sup 2}. The adsorbed water was collected by the GaAs groove structure and then redistributed around the structure. A model was developed to qualitatively describe the dynamic microadsorption process. The effective adsorption rate was estimated by modeling and experimental data. Devices for moisture collection and a liquid channel can be made by properly arranging the wettabilities or contact angles of different materials. These novel devices will be very useful in microfluid applications or biochips.

Economic Impacts of Surface Mining on Household Drinking Water Supplies

Science.gov (United States)

This report provides information on the economic and social impacts of contaminated surface and ground water supplies on residents and households near surface mining operations. The focus is on coal slurry contamination of water supplies in Mingo County, West Virginia, and descr...

Geologic Water Storage in Pre-Columbian Peru

Energy Technology Data Exchange (ETDEWEB)

Fairley Jr., Jerry P.

1997-07-14

Agriculture in the arid and semi-arid regions that comprise much of present-day Peru, Bolivia, and Northern Chile is heavily dependent on irrigation; however, obtaining a dependable water supply in these areas is often difficult. The precolumbian peoples of Andean South America adapted to this situation by devising many strategies for transporting, storing, and retrieving water to insure consistent supply. I propose that the ''elaborated springs'' found at several Inka sites near Cuzco, Peru, are the visible expression of a simple and effective system of groundwater control and storage. I call this system ''geologic water storage'' because the water is stored in the pore spaces of sands, soils, and other near-surface geologic materials. I present two examples of sites in the Cuzco area that use this technology (Tambomachay and Tipon) and discuss the potential for identification of similar systems developed by other ancient Latin American cultures.

Effect of Surface-mantle Water Exchange Parameterizations on Exoplanet Ocean Depths

Science.gov (United States)

Komacek, Thaddeus D.; Abbot, Dorian S.

2016-11-01

Terrestrial exoplanets in the canonical habitable zone may have a variety of initial water fractions due to random volatile delivery by planetesimals. If the total planetary water complement is high, the entire surface may be covered in water, forming a “waterworld.” On a planet with active tectonics, competing mechanisms act to regulate the abundance of water on the surface by determining the partitioning of water between interior and surface. Here we explore how the incorporation of different mechanisms for the degassing and regassing of water changes the volatile evolution of a planet. For all of the models considered, volatile cycling reaches an approximate steady state after ∼ 2 {Gyr}. Using these steady states, we find that if volatile cycling is either solely dependent on temperature or seafloor pressure, exoplanets require a high abundance (≳ 0.3 % of total mass) of water to have fully inundated surfaces. However, if degassing is more dependent on seafloor pressure and regassing mainly dependent on mantle temperature, the degassing rate is relatively large at late times and a steady state between degassing and regassing is reached with a substantial surface water fraction. If this hybrid model is physical, super-Earths with a total water fraction similar to that of the Earth can become waterworlds. As a result, further understanding of the processes that drive volatile cycling on terrestrial planets is needed to determine the water fraction at which they are likely to become waterworlds.

New test techniques to evaluate near field effects for supersonic store carriage and separation

Science.gov (United States)

Sawyer, Wallace C.; Stallings, Robert L., Jr.; Wilcox, Floyd J., Jr.; Blair, A. B., Jr.; Monta, William J.; Plentovich, Elizabeth B.

1989-01-01

Store separation and store carriage drag studies were conducted. A primary purpose is to develop new experimental methods to evaluate near field effects of store separation and levels of store carriage drag associated with a variety of carriage techniques for different store shapes and arrangements. Flow field measurements consisting of surface pressure distributions and vapor screen photographs are used to analyze the variations of the store separation characteristics with cavity geometry. Store carriage drag measurements representative of tangent, semi-submerged, and internal carriage installations are presented and discussed. Results are included from both fully metric models and models with only metric segments (metric pallets) and the relative merits of the two are discussed. Carriage drag measurements for store installations on an aircraft parent body are compared both with prediction methods and with installations on a generic parent body.

Water on graphene surfaces

Energy Technology Data Exchange (ETDEWEB)

Gordillo, M C [Departamento de Sistemas Fisicos, Quimicos y Naturales, Facultad de Ciencias Experimentales, Universidad Pablo de Olavide, Carretera de Utrera, km 1, E-41013 Sevilla (Spain); Marti, J, E-mail: cgorbar@upo.e, E-mail: jordi.marti@upc.ed [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, B4-B5 Campus Nord, E-08034 Barcelona, Catalonia (Spain)

2010-07-21

In this paper, we summarize the main results obtained in our group about the behavior of water confined inside or close to different graphene surfaces by means of molecular dynamics simulations. These include the inside and outside of carbon nanotubes, and the confinement inside a slit pore or a single graphene sheet. We paid special attention to some thermodynamical (binding energies), structural (hydrogen-bond distributions) and dynamic (infrared spectra) properties, and their comparison to their bulk counterparts.

Concentration data for anthropogenic organic compounds in ground water, surface water, and finished water of selected community water systems in the United States, 2002-05

Science.gov (United States)

Carter, Janet M.; Delzer, Gregory C.; Kingsbury, James A.; Hopple, Jessica A.

2007-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey began implementing Source Water-Quality Assessments (SWQAs) in 2001 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems (CWSs) in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water), and finished water is the water that is treated and ready to be delivered to consumers. Finished water is collected before entering the distribution system. SWQA studies are conducted in two phases, and the objectives of SWQA studies are twofold: (1) to determine the occurrence and, for rivers, seasonal changes in concentrations of a broad list of anthropogenic organic compounds (AOCs) in aquifers and rivers that have some of the largest withdrawals for drinking-water supply (phase 1), and (2) for those AOCs found to occur most frequently in source water, characterize the extent to which these compounds are present in finished water (phase 2). These objectives were met for SWQA studies by collecting ground-water and surface-water (source) samples and analyzing these samples for 258 AOCs during phase 1. Samples from a subset of wells and surface-water sites located in areas with substantial agricultural production in the watershed were analyzed for 19 additional AOCs, for a total of 277 compounds analyzed for SWQA studies. The 277 compounds were classified according to the following 13 primary use or source groups: (1) disinfection by-products; (2) fumigant-related compounds; (3) fungicides; (4) gasoline hydrocarbons, oxygenates, and oxygenate degradates; (5) herbicides and herbicide degradates; (6) insecticides and insecticide degradates; (7) manufacturing additives; (8) organic synthesis compounds; (9) pavement- and

Sensory aspects and water quality impacts of chlorinated and chloraminated drinking water in contact with HDPE and cPVC pipe.

Science.gov (United States)

Heim, Timothy H; Dietrich, Andrea M

2007-02-01

Pipes constructed with high-density polyethylene (HDPE) or chlorinated polyvinyl chloride (cPVC) are commonly used in drinking water distribution systems and premise plumbing. In this comprehensive investigation, the effects on odor, organic chemical release, trihalomethane (THM) formation, free chlorine demand and monochloramine demand were determined for water exposed to HDPE and cPVC pipes. The study was conducted in accordance with the Utility Quick Test (UQT), a migration/leaching protocol for analysis of materials in contact with drinking water. The sensory panel consistently attributed a weak to moderate intensity of a "waxy/plastic/citrus" odor to the water from the HDPE pipes but not the cPVC-contacted water samples. The odor intensity generated by the HDPE pipe remained relatively constant for multiple water flushes, and the odor descriptors were affected by disinfectant type. Water samples stored in both types of pipe showed a significant increase in the leaching of organic compounds when compared to glass controls, with HDPE producing 0.14 microgTOC/cm(2) pipe surface, which was significantly greater than the TOC release from cPVC. Water stored in both types of pipe showed disinfectant demands of 0.1-0.9 microg disinfectant/cm(2) pipe surface, with HDPE exerting more demand than cPVC. No THMs were detected in chlorinated water exposed to the pipes. The results demonstrate the impact that synthetic plumbing materials can have on sensory and chemical water quality, as well as the significant variations in drinking water quality generated from different materials.

Perfluoroalkyl substances in the Maltese Environment - (I) Surface water and rain water

NARCIS (Netherlands)

Sammut, G.; Sinagra, E.; Helmus, R.; de Voogt, P.

2017-01-01

The presence of perfluoroalkyl substances (PFASs) in rain water on the Maltese Islands is reported here for the first time and an extensive survey of these substances in surface water also reported. The Maltese archipelago lies at the centre of the Mediterranean Sea and consists of three main

Novel Americium Treatment Process for Surface Water and Dust Suppression Water

International Nuclear Information System (INIS)

Tiepel, E.W.; Pigeon, P.; Nesta, S.; Anderson, J.

2006-01-01

The Rocky Flats Environmental Technology Site (RFETS), a former nuclear weapons production plant, has been remediated under CERCLA and decommissioned to become a National Wildlife Refuge. The site conducted this cleanup effort under the Rocky Flats Cleanup Agreement (RFCA) that established limits for the discharge of surface and process waters from the site. At the end of 2004, while a number of process buildings were undergoing decommissioning, routine monitoring of a discharge pond (Pond A-4) containing approximately 28 million gallons of water was discovered to have been contaminated with a trace amount of Americium-241 (Am-241). While the amount of Am-241 in the pond waters was very low (0.5 - 0.7 pCi/l), it was above the established Colorado stream standard of 0.15 pCi/l for release to off site drainage waters. The rapid successful treatment of these waters to the regulatory limit was important to the site for two reasons. The first was that the pond was approaching its hold-up limit. Without rapid treatment and release of the Pond A-4 water, typical spring run-off would require water management actions to other drainages onsite or a mass shuttling of water for disposal. The second reason was that this type of contaminated water had not been treated to the stringent stream standard at Rocky Flats before. Technical challenges in treatment could translate to impacts on water and secondary waste management, and ultimately, cost impacts. All of the technical challenges and specific site criteria led to the conclusion that a different approach to the treatment of this problem was necessary and a crash treatability program to identify applicable treatment techniques was undertaken. The goal of this program was to develop treatment options that could be implemented very quickly and would result in the generation of no high volume secondary waste that would be costly to dispose. A novel chemical treatment system was developed and implemented at the RFETS to treat Am

Inductive energy store (IES) technology for multi-terrawatt generators

International Nuclear Information System (INIS)

Sincerny, P.S.; Ashby, S.R.; Childers, F.K.; Deeney, C.; Kortbawi, D.; Goyer, J.R.; Riordan, J.C.; Roth, I.S.; Stallings, C.; Schlitt, L.

1993-01-01

An IES pulsed power machine has been built at Physics International Company that serves as a prototype demonstration of IES technology that is scaleable to very large TW generators. The prototype module utilizes inductive store opening switch technology for the final stage of pulse compression and is capable of driving both electron beam Bremsstrahlung loads or imploding plasma loads. Each module consists of a fast discharge Marx driving a water dielectric transfer capacitor which is command triggered to drive the inductive store section of the machine. The inductive store is discharged into the load using a plasma erosion opening switch. Data demonstrating 22% efficient operation into an electron beam diode load are presented. The system issues addressing the combining of these modules into a very large pulsed power machine are discussed

Enhanced load-carrying capacity of hairy surfaces floating on water.

Science.gov (United States)

Xue, Yahui; Yuan, Huijing; Su, Weidong; Shi, Yipeng; Duan, Huiling

2014-05-08

Water repellency of hairy surfaces depends on the geometric arrangement of these hairs and enables different applications in both nature and engineering. We investigate the mechanism and optimization of a hairy surface floating on water to obtain its maximum load-carrying capacity by the free energy and force analyses. It is demonstrated that there is an optimum cylinder spacing, as a result of the compromise between the vertical capillary force and the gravity, so that the hairy surface has both high load-carrying capacity and mechanical stability. Our analysis makes it clear that the setae on water striders' legs or some insects' wings are in such an optimized geometry. Moreover, it is shown that surface hydrophobicity can further increase the capacity of a hairy surface with thick cylinders, while the influence is negligible when the cylinders are thin.

Evaluation of Major Dike-Impounded Ground-Water Reservoirs, Island of Oahu

Science.gov (United States)

Takasaki, Kiyoshi J.; Mink, John Francis

1985-01-01

Ground-water reservoirs impounded by volcanic dikes receive a substantial part of the total recharge to ground water on the island of Oahu because they generally underlie the rainiest areas. These reservoirs accumulate the infiltration from rainfall, store it temporarily, and steadily leak it to abutting basal reservoirs or to streams cutting into them. The dike reservoirs have high hydraulic heads and are mostly isolated from saline water. The most important and productive of the dike-impounded reservoirs are in an area of about 135 square miles in the main fissure zone of the Koolau volcano where the top of the dike-impounded water reaches an altitude of at least 1,000 feet. Water is impounded and stored both above and below sea level. The water stored above sea level in the 135 square mile area has been roughly estimated at 560 billion gallons. In comparison, the water stored above sea level in reservoirs underlying a dike-intruded area of about 53 square miles in the Waianae Range has been roughly estimated at 100 billion gallons. Storage below sea level is indeterminable, owing to uncertainties about the ability of the rock to store water as dike density increases and porosity decreases. Tunnels, by breaching dike controls, have reduced the water stored above sea level by at least 50 billion gallons in the Koolau Range and by 5 1/2 billion gallons in the Waianae Range, only a small part of the total water stored. Total leakage from storage in the Koolau Range has been estimated at about 280 Mgal/d (million gallons per day). This estimated leakage from the dike-impounded reservoirs makes up a significant part of the ground-water yield of the Koolau Range, which has been estimated to range from 450 to 580 Mgal/d. The largest unused surface leakage is in the Kaneohe, Kahana, and Punaluu areas, and the largest unused underflow occurs in the Waialee, Hauula-Laie, Punaluu, and Kahana areas. The unused underflow leakage is small in areas near and east of Waialae, but

CORPORATE REBRANDING OF GRAMEDIA STORE (CORPORATE REBRANDING DI GRAMEDIA STORE

Directory of Open Access Journals (Sweden)

Natasha Helena Kairupan

2016-10-01

Full Text Available Abstract. The purposes of this research are to determine the stages of analysis, planning, and evaluation of corporate rebranding process of Gramedia Book Store to be Gramedia Store to rise stakeholder’s awareness. The method used is descriptive qualitative with positivism paradigm. The technique of collecting data through in-depth interview, observation, and literature study. The result of this research showed the analysis stage by analyzing the market through insights and foresights, brand audit through SWOT analysis, and identifying opportunities. The planning stage is by determine the purpose of the planning process and then determine the target audience, consist of external and internal customer. The planning of external customer by renaming and change of corporate identity, and marketing planning using communication channel (above the line and below the line. The planning of internal customer by Brand Induction, training, inspiration briefing at store, and innovation competition. The evaluation of rebranding process of Gramedia Store is having a focus group discussion with customer, media monitoring, and presentation to BOD. Keywords : Process, Corporate Rebranding, Stakeholder Awareness, Corporate Identity, Gramedia Store Abstrak.Tujuan penelitian ini adalah untuk mengetahui bagaimana tahapan analisis, perencanaan, dan evaluasi proses corporate rebranding Gramedia Book Store menjadi Gramedia Store untuk meningkatkan stakeholder awareness. Pendekatan yang digunakan adalah kualitatif dengan paradigma positivisme dan jenis studi deksriptif. Teknik pengumpulan data yang dilakukan melalui wawancara mendalam, observasi, dan studi pustaka. Berdasarkan hasil penelitian, tahapan analisis dilakukan dengan menganalisis pasar melalui insights dan foresights, audit merek dengan analisis SWOT, dan mengidentifikasi peluang. Dalam tahapan perencanaan dengan menentukan tujuan kemudian menentukan target audiens, yaitu eksternal dan internal. Perencanaan

Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

Science.gov (United States)

Juckem, Paul F.

2009-01-01

A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

Polyfluorinated chemicals in European surface waters, ground- and drinking waters

NARCIS (Netherlands)

Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

2012-01-01

Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during

Surface Freshwater Storage Variations in the Orinoco Floodplains Using Multi-Satellite Observations

Directory of Open Access Journals (Sweden)

Frédéric Frappart

2014-12-01

Full Text Available Variations in surface water extent and storage are poorly characterized from regional to global scales. In this study, a multi-satellite approach is proposed to estimate the water stored in the floodplains of the Orinoco Basin at a monthly time-scale using remotely-sensed observations of surface water from the Global Inundation Extent Multi-Satellite (GIEMS and stages from Envisat radar altimetry. Surface water storage variations over 2003–2007 exhibit large interannual variability and a strong seasonal signal, peaking during summer, and associated with the flood pulse. The volume of surface water storage in the Orinoco Basin was highly correlated with the river discharge at Ciudad Bolivar (R = 0.95, the closest station to the mouth where discharge was estimated, although discharge lagged one month behind storage. The correlation remained high (R = 0.73 after removing seasonal effects. Mean annual variations in surface water volume represented ~170 km3, contributing to ~45% of the Gravity Recovery and Climate Experiment (GRACE-derived total water storage variations and representing ~13% of the total volume of water that flowed out of the Orinoco Basin to the Atlantic Ocean.

Effect of high-extraction coal mining on surface and ground waters

International Nuclear Information System (INIS)

Kendorski, F.S.

1993-01-01

Since first quantified around 1979, much new data have become available. In examining the sources of data and the methods and intents of the researchers of over 65 case histories, it became apparent that the strata behaviors were being confused with overlapping vertical extents reported for the fractured zones and aquiclude zones depending on whether the researcher was interested in water intrusion into the mine or in water loss from surface or ground waters. These more recent data, and critical examination of existing data, have led to the realization that the former Aquiclude Zone defined for its ability to prevent or minimize the intrusion of ground or surface waters into mines has another important character in increasing storage of surface and shallow ground waters in response to mining with no permanent loss of waters. This zone is here named the Dilated Zone. Surface and ground waters can drain into this zone, but seldom into the mine, and can eventually be recovered through closing of dilations by mine subsidence progression away from the area, or filling of the additional void space created, or both. A revised model has been developed which accommodates the available data, by modifying the zones as follows: collapse and disaggregation extending 6 to 10 times the mined thickness above the panel; continuous fracturing extending approximately 24 times the mined thickness above the panel, allowing temporary drainage of intersected surface and ground waters; development of a zone of dilated, increased storativity, and leaky strata with little enhanced vertical permeability from 24 to 60 times the mined thickness above the panel above the continuous fracturing zone, and below the constrained or surface effects zones; maintenance of a constrained but leaky zone above the dilated zone and below the surface effects zone; and limited surface fracturing in areas of extension extending up to 50 ft or so beneath the ground surface. 119 ref., 5 figs., 2 tabs

Using IR Imaging of Water Surfaces for Estimating Piston Velocities

Science.gov (United States)

Gålfalk, M.; Bastviken, D.; Arneborg, L.

2013-12-01

The transport of gasses dissolved in surface waters across the water-atmosphere interface is controlled by the piston velocity (k). This coefficient has large implications for, e.g., greenhouse gas fluxes but is challenging to quantify in situ. At present, empirical k-wind speed relationships from a small number of studies and systems are often extrapolated without knowledge of model performance. It is therefore of interest to search for new methods for estimating k, and to compare the pros and cons of existing and new methods. Wind speeds in such models are often measured at a height of 10 meters. In smaller bodies of water such as lakes, wind speeds can vary dramatically across the surface through varying degrees of wind shadow from e.g. trees at the shoreline. More local measurements of the water surface, through wave heights or surface motion mapping, could give improved k-estimates over a surface, also taking into account wind fetch. At thermal infrared (IR) wavelengths water has very low reflectivity (depending on viewing angle) than can go below 1%, meaning that more than 99% is heat radiation giving a direct measurement of surface temperature variations. Using an IR camera at about 100 frames/s one could map surface temperature structures at a fraction of a mm depth even with waves present. In this presentation I will focus on IR imaging as a possible tool for estimating piston velocities. Results will be presented from IR field measurements, relating the motions of surface temperature structures to k calculated from other simultaneous measurements (flux chamber and ADV-Based Dissipation Rate), but also attempting to calculate k directly from the IR surface divergence. A relation between wave height and k will also be presented.

Polarization Patterns of Transmitted Celestial Light under Wavy Water Surfaces

Directory of Open Access Journals (Sweden)

Guanhua Zhou

2017-03-01

Full Text Available This paper presents a model to describe the polarization patterns of celestial light, which includes sunlight and skylight, when refracted by wavy water surfaces. The polarization patterns and intensity distribution of refracted light through the wave water surface were calculated. The model was validated by underwater experimental measurements. The experimental and theoretical values agree well qualitatively. This work provides a quantitative description of the repolarization and transmittance of celestial light transmitted through wave water surfaces. The effects of wind speed and incident sources on the underwater refraction polarization patterns are discussed. Scattering skylight dominates the polarization patterns while direct solar light is the dominant source of the intensity of the underwater light field. Wind speed has an influence on disturbing the patterns under water.

Calcium carbonate nucleation in an alkaline lake surface water, Pyramid Lake, Nevada, USA

Science.gov (United States)

Reddy, Michael M.; Hoch, Anthony

2012-01-01

Calcium concentration and calcite supersaturation (Ω) needed for calcium carbonate nucleation and crystal growth in Pyramid Lake (PL) surface water were determined during August of 1997, 2000, and 2001. PL surface water has Ω values of 10-16. Notwithstanding high Ω, calcium carbonate growth did not occur on aragonite single crystals suspended PL surface water for several months. However, calcium solution addition to PL surface-water samples caused reproducible calcium carbonate mineral nucleation and crystal growth. Mean PL surface-water calcium concentration at nucleation was 2.33 mM (n = 10), a value about nine times higher than the ambient PL surface-water calcium concentration (0.26 mM); mean Ω at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water Ω. Calcium concentration and Ω regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower Ω than filtered samples. Calcium concentration and Ω at nucleation for experiments in the presence of added particles were within one standard deviation of the mean for all samples. Calcium carbonate formation rates followed a simple rate expression of the form, rate (mM/min) = A (Ω) + B. The best fit rate equation "Rate (Δ mM/Δ min) = -0.0026 Ω + 0.0175 (r = 0.904, n = 10)" was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, Ω at zero rate of 6.7. Nucleation in PL surface water and morphology of calcium carbonate particles formed in PL nucleation experiments and in PL surface-water samples suggest crystal growth inhibition by multiple substances present in PL surface water mediates PL calcium carbonate formation, but there is insufficient information to determine the chemical nature of all inhibitors.

The oxidative corrosion of carbide inclusions at the surface of uranium metal during exposure to water vapour

International Nuclear Information System (INIS)

Scott, T.B.; Petherbridge, J.R.; Harker, N.J.; Ball, R.J.; Heard, P.J.; Glascott, J.; Allen, G.C.

2011-01-01

Highlights: → High resolution imagery (FIB, SEM and SIMS) of carbide inclusions in uranium metal. → Real time images following the reaction of the carbide inclusions with water vapour. → Shown preferential consumption of carbide over that of the bulk metal. → Quantity of impurities in the metal therefore seriously influence reaction rate. → Metal purity must be considered when storing uranium in air or moist conditions. - Abstract: The reaction between uranium and water vapour has been well investigated, however discrepancies exist between the described kinetic laws, pressure dependence of the reaction rate constant and activation energies. Here this problem is looked at by examining the influence of impurities in the form of carbide inclusions on the reaction. Samples of uranium containing 600 ppm carbon were analysed during and after exposure to water vapour at 19 mbar pressure, in an environmental scanning electron microscope (ESEM) system. After water exposure, samples were analysed using secondary ion mass spectrometry (SIMS), focused ion beam (FIB) imaging and sectioning and transmission electron microscopy (TEM) with X-ray diffraction (micro-XRD). The results of the current study indicate that carbide particles on the surface of uranium readily react with water vapour to form voluminous UO 3 .xH 2 O growths at rates significantly faster than that of the metal. The observation may also have implications for previous experimental studies of uranium-water interactions, where the presence of differing levels of undetected carbide may partly account for the discrepancies observed between datasets.

The impact of uncontrolled waste disposal on surface water quality ...

African Journals Online (AJOL)

The main threat to the surface water quality in Addis Ababa is environmental pollution derived from domestic and industrial activities. Due to the inadequacy of controlled waste management strategies and waste treatment plants, people are forced to discharge wastes both on open surface and within water bodies.

Water surface deformation in strong electrical fields and its influence on electrical breakdown in a metal pin-water electrode system

International Nuclear Information System (INIS)

Bruggeman, Peter; Graham, Leigh; Groote, Joris de; Vierendeels, Jan; Leys, Christophe

2007-01-01

Electrical breakdown and water surface deformation in a metal pin-water electrode system with dc applied voltages is studied for small inter-electrode distances (2-12 mm). The radius of curvature of the metal pin is 0.5 cm to exclude corona before breakdown at these small inter-electrode spacings. Calculations of the water surface deformation as a function of the applied voltage and initial inter-electrode spacing are compared with measurements of the water elevation. For distances smaller than 7 mm the calculated stability limit of the water surface corresponds with the experimentally obtained breakdown voltage. It is proved with fast CCD images and calculations of the electrical field distribution that the water surface instability triggers the electrical breakdown in this case. The images show that at breakdown the water surface has a Taylor cone-like shape. At inter-electrode distance of 7 mm and larger the breakdown voltage is well below the water stability limit and the conductive channel at breakdown is formed between the pin electrode and the static water surface. Both cases are discussed and compared

A global, 30-m resolution land-surface water body dataset for 2000

Science.gov (United States)

Feng, M.; Sexton, J. O.; Huang, C.; Song, D. X.; Song, X. P.; Channan, S.; Townshend, J. R.

2014-12-01

Inland surface water is essential to terrestrial ecosystems and human civilization. The distribution of surface water in space and its change over time are related to many agricultural, environmental and ecological issues, and are important factors that must be considered in human socioeconomic development. Accurate mapping of surface water is essential for both scientific research and policy-driven applications. Satellite-based remote sensing provides snapshots of Earth's surface and can be used as the main input for water mapping, especially in large areas. Global water areas have been mapped with coarse resolution remotely sensed data (e.g., the Moderate Resolution Imaging Spectroradiometer (MODIS)). However, most inland rivers and water bodies, as well as their changes, are too small to map at such coarse resolutions. Landsat TM (Thematic Mapper) and ETM+ (Enhanced Thematic Mapper Plus) imagery has a 30m spatial resolution and provides decades of records (~40 years). Since 2008, the opening of the Landsat archive, coupled with relatively lower costs associated with computing and data storage, has made comprehensive study of the dynamic changes of surface water over large even global areas more feasible. Although Landsat images have been used for regional and even global water mapping, the method can hardly be automated due to the difficulties on distinguishing inland surface water with variant degrees of impurities and mixing of soil background with only Landsat data. The spectral similarities to other land cover types, e.g., shadow and glacier remnants, also cause misidentification. We have developed a probabilistic based automatic approach for mapping inland surface water bodies. Landsat surface reflectance in multiple bands, derived water indices, and data from other sources are integrated to maximize the ability of identifying water without human interference. The approach has been implemented with open-source libraries to facilitate processing large

Water redistribution at the soil surface : ponding and surface runoff in flat areas

NARCIS (Netherlands)

Appels, W.M.

2013-01-01

In The Netherlands, one of the most important targets for the improvement of surface water quality as aimed for in the European Water Framework Directive, is the reduction of nutrient concentrations (both nitrogen and phosphorus). To identify the most suitable and effective measures for reducing the

UV sensitivity of planktonic net community production in ocean surface waters

OpenAIRE

Regaudie de Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

2014-01-01

The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we tes...

Surface Water Quality Assessment and Prioritize the Factors Pollute This Water Using Topsis Fuzzy Hierarchical Analysis

Directory of Open Access Journals (Sweden)

Mehdi Komasi

2017-03-01

Full Text Available Background & Objective: Nowadays, according to growth of industry and increasing population, water resources are seriousely shortened. This lack of water resources will require special management to be considered in industry and agriculture. Among the various sources of water, surface waters are more susceptible to infection. The most important of these sources of pollution are industrial pollution, detergent, pesticides, radioactive materials, heat and salt concentration.  Materials & methods: In this article, at first the importance of each pollutant will be evaluated base on the effects and its results and then quality evaluation of surface water will be studied. In order to assess the relative importance of these pollutants primarily using TOPSIS software, prioritize these factors as one of the hierarchical analysis and then is modeled with decision tree method using Weka software, the importance of each factor is evaluated and if it does not meet the minimal importance of the decision tree will be removed. Results: The results obtained from the Topsis fuzzy analysis indicate that surface water and groundwater are exposed to pollution about 74% and 26% respectively among the six pollutants examined in this study. In addition, results obtaned from the hierarchical tree in software Weka has shown that the heat factor, soluble salts and industrial pollutants give impac factor or purity about 0.1338, 0.0523 and 1.2694 respectively. Conclusion: Surface water is at greater risk of being polluted compared with groundwater. The heat factor and low concentration of dissolved salts have the low impact and industrial pollutants are considered as the most influential factors in surface water pollution.

Food and beverage purchases in corner stores, gas-marts, pharmacies and dollar stores.

Science.gov (United States)

Caspi, Caitlin E; Lenk, Kathleen; Pelletier, Jennifer E; Barnes, Timothy L; Harnack, Lisa; Erickson, Darin J; Laska, Melissa N

2017-10-01

Little is known about customer purchases of foods and beverages from small and non-traditional food retailers (i.e. corner stores, gas-marts, dollar stores and pharmacies). The present study aimed to: (i) describe customer characteristics, shopping frequency and reasons for shopping at small and non-traditional food retailers; and (ii) describe food/beverage purchases and their nutritional quality, including differences across store type. Data were collected through customer intercept interviews. Nutritional quality of food/beverage purchases was analysed; a Healthy Eating Index-2010 (HEI-2010) score for purchases was created by aggregating participant purchases at each store. Small and non-traditional food stores that were not WIC-authorized in Minneapolis and St. Paul, MN, USA. Customers (n 661) from 105 food retailers. Among participants, 29 % shopped at the store at least once daily; an additional 44 % shopped there at least once weekly. Most participants (74 %) cited convenient location as the primary draw to the store. Customers purchased a median of 2262 kJ (540 kcal), which varied by store type (P=0·04). The amount of added sugar far surpassed national dietary recommendations. At dollar stores, participants purchased a median of 5302 kJ (1266 kcal) for a median value of $US 2·89. Sugar-sweetened beverages were the most common purchase. The mean HEI-2010 score across all stores was 36·4. Small and non-traditional food stores contribute to the urban food environment. Given the poor nutritional quality of purchases, findings support the need for interventions that address customer decision making in these stores.

Persistence of pirimiphos methyl residues in stored wheat

International Nuclear Information System (INIS)

Zennouche, B.; Bennaceur, M.

1991-03-01

The persistence of 14C pirimiphos methyl in stored wheat was investigated under local conditions during a storage period of 6 months. Surface, methanol extractable and bound residues were quantified. There was a gradual increase in the surface residues over the storage period. 27,97% of the applied amount was found in the surface residues and 54,16% in the extractable and bound residues one month after treatment. After 6 months storage, about 17,8% of the total quantity of the applied pirimiphos methyl remained on the surface and about 58,6% was present in the grains (extractable and bound residues). During cooking 10,91% of the extractable and bound residues were lost

Multi-objective analysis of the conjunctive use of surface water and groundwater in a multisource water supply system

Science.gov (United States)

Vieira, João; da Conceição Cunha, Maria

2017-04-01

A multi-objective decision model has been developed to identify the Pareto-optimal set of management alternatives for the conjunctive use of surface water and groundwater of a multisource urban water supply system. A multi-objective evolutionary algorithm, Borg MOEA, is used to solve the multi-objective decision model. The multiple solutions can be shown to stakeholders allowing them to choose their own solutions depending on their preferences. The multisource urban water supply system studied here is dependent on surface water and groundwater and located in the Algarve region, southernmost province of Portugal, with a typical warm Mediterranean climate. The rainfall is low, intermittent and concentrated in a short winter, followed by a long and dry period. A base population of 450 000 inhabitants and visits by more than 13 million tourists per year, mostly in summertime, turns water management critical and challenging. Previous studies on single objective optimization after aggregating multiple objectives together have already concluded that only an integrated and interannual water resources management perspective can be efficient for water resource allocation in this drought prone region. A simulation model of the multisource urban water supply system using mathematical functions to represent the water balance in the surface reservoirs, the groundwater flow in the aquifers, and the water transport in the distribution network with explicit representation of water quality is coupled with Borg MOEA. The multi-objective problem formulation includes five objectives. Two objective evaluate separately the water quantity and the water quality supplied for the urban use in a finite time horizon, one objective calculates the operating costs, and two objectives appraise the state of the two water sources - the storage in the surface reservoir and the piezometric levels in aquifer - at the end of the time horizon. The decision variables are the volume of withdrawals from

Water surface modeling from a single viewpoint video.

Science.gov (United States)

Li, Chuan; Pickup, David; Saunders, Thomas; Cosker, Darren; Marshall, David; Hall, Peter; Willis, Philip

2013-07-01

We introduce a video-based approach for producing water surface models. Recent advances in this field output high-quality results but require dedicated capturing devices and only work in limited conditions. In contrast, our method achieves a good tradeoff between the visual quality and the production cost: It automatically produces a visually plausible animation using a single viewpoint video as the input. Our approach is based on two discoveries: first, shape from shading (SFS) is adequate to capture the appearance and dynamic behavior of the example water; second, shallow water model can be used to estimate a velocity field that produces complex surface dynamics. We will provide qualitative evaluation of our method and demonstrate its good performance across a wide range of scenes.

Surface Water Quality Trends from EPA's LTM Network

Science.gov (United States)

Funk, C.; Lynch, J. A.

2013-12-01

Surface water chemistry provides direct indicators of the potential effects of anthropogenic impacts, such as acid deposition and climate change, on the overall health of aquatic ecosystems. Long-term surface water monitoring networks provide a host of environmental data that can be used, in conjunction with other networks, to assess how water bodies respond to stressors and if they are potentially at risk (e.g., receiving pollutant deposition beyond its critical load). Two EPA-administered monitoring programs provide information on the effects of acidic deposition on headwater aquatic systems: the Long Term Monitoring (LTM) program and the Temporally Integrated Monitoring of Ecosystems (TIME) program, designed to track the effectiveness of the 1990 Clean Air Act Amendments (CAAA) in reducing the acidity of surface waters in acid sensitive ecoregions of the Northeast and Mid-Atlantic. Here we present regional variability of long term trends in surface water quality in response to substantial reductions in atmospheric deposition. Water quality trends at acid sensitive LTM sites exhibit decreasing concentrations of sulfate at 100% of monitored sites in the Adirondack Mountains and New England, 80% of Northern Appalachian Plateau sites, and yet only 15% of sites in the Ridge and Blue Ridge Provinces over the 1990-2011 period of record. Across all regions, most LTM sites exhibited constant or only slightly declining nitrate concentrations over the same time period. Acid Neutralizing Capacity (ANC) levels improved at 68% and 45% of LTM sites in the Adirondacks and Northern Appalachian Plateau, respectively, but few sites showed increases in New England or the Ridge and Blue Ridge Provinces due to lagging improvements in base cation concentration. The ANC of northeastern TIME lakes was also evaluated from 1991 to 1994 and 2008 to 2011. The percentage of lakes with ANC values below 50 μeq/L, lakes of acute or elevated concern, dropped by about 7%, indicating improvement

Association between store food environment and customer purchases in small grocery stores, gas-marts, pharmacies and dollar stores.

Science.gov (United States)

Caspi, Caitlin E; Lenk, Kathleen; Pelletier, Jennifer E; Barnes, Timothy L; Harnack, Lisa; Erickson, Darin J; Laska, Melissa N

2017-06-05

Purchases at small/non-traditional food stores tend to have poor nutritional quality, and have been associated with poor health outcomes, including increased obesity risk The purpose of this study was to examine whether customers who shop at small/non-traditional food stores with more health promoting features make healthier purchases. In a cross-sectional design, data collectors assessed store features in a sample of 99 small and non-traditional food stores not participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Minneapolis/St. Paul, MN in 2014. Customer intercept interviews (n = 594) collected purchase data from a bag check and demographics from a survey. Store measures included fruit/vegetable and whole grain availability, an overall Healthy Food Supply Score (HFSS), healthy food advertisements and in-store placement, and shelf space of key items. Customer nutritional measures were analyzed using Nutrient Databases System for Research (NDSR), and included the purchase of ≥1 serving of fruits/vegetables; ≥1 serving of whole grains; and overall Healthy Eating Index-2010 (HEI-2010) score for foods/beverages purchased. Associations between store and customer measures were estimated in multilevel linear and logistic regression models, controlling for customer characteristics and store type. Few customers purchased fruits and vegetables (8%) or whole grains (8%). In fully adjusted models, purchase HEI-2010 scores were associated with fruit/vegetable shelf space (p = 0.002) and the ratio of shelf space devoted to healthy vs. less healthy items (p = 0.0002). Offering ≥14 varieties of fruit/vegetables was associated with produce purchases (OR 3.9, 95% CI 1.2-12.3), as was having produce visible from the store entrance (OR 2.3 95% CI 1.0 to 5.8), but whole grain availability measures were not associated with whole grain purchases. Strategies addressing both customer demand and the availability of healthy food

Cholesterol enhances surface water diffusion of phospholipid bilayers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Chi-Yuan; Kausik, Ravinath; Han, Songi, E-mail: songi@chem.ucsb.edu [Department of Chemistry and Biochemistry and Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Olijve, Luuk L. C. [Laboratory of Macromolecular and Organic Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven (Netherlands)

2014-12-14

Elucidating the physical effect of cholesterol (Chol) on biological membranes is necessary towards rationalizing their structural and functional role in cell membranes. One of the debated questions is the role of hydration water in Chol-embedding lipid membranes, for which only little direct experimental data are available. Here, we study the hydration dynamics in a series of Chol-rich and depleted bilayer systems using an approach termed {sup 1}H Overhauser dynamic nuclear polarization (ODNP) NMR relaxometry that enables the sensitive and selective determination of water diffusion within 5–10 Å of a nitroxide-based spin label, positioned off the surface of the polar headgroups or within the nonpolar core of lipid membranes. The Chol-rich membrane systems were prepared from mixtures of Chol, dipalmitoyl phosphatidylcholine and/or dioctadecyl phosphatidylcholine lipid that are known to form liquid-ordered, raft-like, domains. Our data reveal that the translational diffusion of local water on the surface and within the hydrocarbon volume of the bilayer is significantly altered, but in opposite directions: accelerated on the membrane surface and dramatically slowed in the bilayer interior with increasing Chol content. Electron paramagnetic resonance (EPR) lineshape analysis shows looser packing of lipid headgroups and concurrently tighter packing in the bilayer core with increasing Chol content, with the effects peaking at lipid compositions reported to form lipid rafts. The complementary capability of ODNP and EPR to site-specifically probe the hydration dynamics and lipid ordering in lipid membrane systems extends the current understanding of how Chol may regulate biological processes. One possible role of Chol is the facilitation of interactions between biological constituents and the lipid membrane through the weakening or disruption of strong hydrogen-bond networks of the surface hydration layers that otherwise exert stronger repulsive forces, as reflected in

Issues of the presence of parasitic protozoa in surface waters

Directory of Open Access Journals (Sweden)

Hawrylik Eliza

2018-01-01

This paper focuses on the problem of the presence of parasitic protozoa in surface waters. Characteristics of the most frequently recognized pathogens responsible for water-borne outbreaks were described, as well as sources of contamination and surface waters contamination due to protozoa of the genus Cryptosporidium and Giardia were presented. The methods of destroying the cysts and oocysts of parasitic protozoa used nowadays in the world were also presented in a review.

Water droplet evaporation from sticky superhydrophobic surfaces

Science.gov (United States)

Lee, Moonchan; Kim, Wuseok; Lee, Sanghee; Baek, Seunghyeon; Yong, Kijung; Jeon, Sangmin

2017-07-01

The evaporation dynamics of water from sticky superhydrophobic surfaces was investigated using a quartz crystal microresonator and an optical microscope. Anodic aluminum oxide (AAO) layers with different pore sizes were directly fabricated onto quartz crystal substrates and hydrophobized via chemical modification. The resulting AAO layers exhibited hydrophobic or superhydrophobic characteristics with strong adhesion to water due to the presence of sealed air pockets inside the nanopores. After placing a water droplet on the AAO membranes, variations in the resonance frequency and Q-factor were measured throughout the evaporation process, which were related to changes in mass and viscous damping, respectively. It was found that droplet evaporation from a sticky superhydrophobic surface followed a constant contact radius (CCR) mode in the early stage of evaporation and a combination of CCR and constant contact angle modes without a Cassie-Wenzel transition in the final stage. Furthermore, AAO membranes with larger pore sizes exhibited longer evaporation times, which were attributed to evaporative cooling at the droplet interface.

Using a Virtual Store As a Research Tool to Investigate Consumer In-store Behavior.

Science.gov (United States)

Ploydanai, Kunalai; van den Puttelaar, Jos; van Herpen, Erica; van Trijp, Hans

2017-07-24

People's responses to products and/or choice environments are crucial to understanding in-store consumer behaviors. Currently, there are various approaches (e.g., surveys or laboratory settings) to study in-store behaviors, but the external validity of these is limited by their poor capability to resemble realistic choice environments. In addition, building a real store to meet experimental conditions while controlling for undesirable effects is costly and highly difficult. A virtual store developed by virtual reality techniques potentially transcends these limitations by offering the simulation of a 3D virtual store environment in a realistic, flexible, and cost-efficient way. In particular, a virtual store interactively allows consumers (participants) to experience and interact with objects in a tightly controlled yet realistic setting. This paper presents the key elements of using a desktop virtual store to study in-store consumer behavior. Descriptions of the protocol steps to: 1) build the experimental store, 2) prepare the data management program, 3) run the virtual store experiment, and 4) organize and export data from the data management program are presented. The virtual store enables participants to navigate through the store, choose a product from alternatives, and select or return products. Moreover, consumer-related shopping behaviors (e.g., shopping time, walking speed, and number and type of products examined and bought) can also be collected. The protocol is illustrated with an example of a store layout experiment showing that shelf length and shelf orientation influence shopping- and movement-related behaviors. This demonstrates that the use of a virtual store facilitates the study of consumer responses. The virtual store can be especially helpful when examining factors that are costly or difficult to change in real life (e.g., overall store layout), products that are not presently available in the market, and routinized behaviors in familiar

Characterizing water-metal interfaces and machine learning potential energy surfaces

Science.gov (United States)

Ryczko, Kevin

In this thesis, we first discuss the fundamentals of ab initio electronic structure theory and density functional theory (DFT). We also discuss statistics related to computing thermodynamic averages of molecular dynamics (MD). We then use this theory to analyze and compare the structural, dynamical, and electronic properties of liquid water next to prototypical metals including platinum, graphite, and graphene. Our results are built on Born-Oppenheimer molecular dynamics (BOMD) generated using density functional theory (DFT) which explicitly include van der Waals (vdW) interactions within a first principles approach. All calculations reported use large simulation cells, allowing for an accurate treatment of the water-electrode interfaces. We have included vdW interactions through the use of the optB86b-vdW exchange correlation functional. Comparisons with the Perdew-Burke-Ernzerhof (PBE) exchange correlation functional are also shown. We find an initial peak, due to chemisorption, in the density profile of the liquid water-Pt interface not seen in the liquid water-graphite interface, liquid watergraphene interface, nor interfaces studied previously. To further investigate this chemisorption peak, we also report differences in the electronic structure of single water molecules on both Pt and graphite surfaces. We find that a covalent bond forms between the single water molecule and the platinum surface, but not between the single water molecule and the graphite surface. We also discuss the effects that defects and dopants in the graphite and graphene surfaces have on the structure and dynamics of liquid water. Lastly, we introduce artificial neural networks (ANNs), and demonstrate how they can be used to machine learn electronic structure calculations. As a proof of principle, we show the success of an ANN potential energy surfaces for a dimer molecule with a Lennard-Jones potential.

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.…

Emissivity Measurements of Foam-Covered Water Surface at L-Band for Low Water Temperatures

Directory of Open Access Journals (Sweden)

En-Bo Wei

2014-11-01

Full Text Available For a foam-covered sea surface, it is difficult to retrieve sea surface salinity (SSS with L-band brightness temperature (1.4 GHz because of the effect of a foam layer with wind speeds stronger than 7 m/s, especially at low sea surface temperature (SST. With foam-controlled experiments, emissivities of a foam-covered water surface at low SST (−1.4 °C to 1.7 °C are measured for varying SSS, foam thickness, incidence angle, and polarization. Furthermore, a theoretical model of emissivity is introduced by combining wave approach theory with the effective medium approximation method. Good agreement is obtained upon comparing theoretical emissivities with those of experiments. The results indicate that foam parameters have a strong influence on increasing emissivity of a foam-covered water surface. Increments of experimental emissivities caused by foam thickness of 1 cm increase from about 0.014 to 0.131 for horizontal polarization and 0.022 to 0.150 for vertical polarization with SSS increase and SST decrease. Contributions of the interface between the foam layer and water surface to the foam layer emissivity increments are discussed for frequencies between 1 and 37 GHz.

Quality of surface water and ground water in the proposed artificial-recharge project area, Rillito Creek basin, Tucson, Arizona, 1994

Science.gov (United States)

Tadayon, Saeid

1995-01-01

Controlled artificial recharge of surface runoff is being considered as a water-management technique to address the problem of ground-water overdraft. The planned use of recharge facilities in urban areas has caused concern about the quality of urban runoff to be recharged and the potential for ground-water contamination. The proposed recharge facility in Rillito Creek will utilize runoff entering a 1-mile reach of the Rillito Creek between Craycroft Road and Swan Road for infiltration and recharge purposes within the channel and excavated overbank areas. Physical and chemical data were collected from two surface-water and two ground-water sites in the study area in 1994. Analyses of surface-water samples were done to determine the occurrence and concentration of potential contaminants and to determine changes in quality since samples were collected during 1987-93. Analyses of ground-water samples were done to determine the variability of ground-water quality at the monitoring wells throughout the year and to determine changes in quality since samples were collected in 1989 and 1993. Surface-water samples were collected from Tanque Verde Creek at Sabino Canyon Road (streamflow-gaging station Tanque Verde Creek at Tucson, 09484500) and from Alamo Wash at Fort Lowell Road in September and May 1994, respectively. Ground-water samples were collected from monitoring wells (D- 13-14)26cbb2 and (D-13-14)26dcb2 in January, May, July, and October 1994. In surface water, calcium was the dominant cation, and bicarbonate was the dominant anion. In ground water, calcium and sodium were the dominant cations and bicarbonate was the dominant anion. Surface water in the area is soft, and ground water is moderately hard to hard. In surface water and ground water, nitrogen was found predominantly as nitrate. Concentrations of manganese in ground-water samples ranged from 60 to 230 micrograms per liter and exceeded the U.S. Environmental Protection Agency secondary maximum contaminant

Bio-inspired water repellent surfaces produced by ultrafast laser structuring of silicon

International Nuclear Information System (INIS)

Barberoglou, M.; Zorba, V.; Stratakis, E.; Spanakis, E.; Tzanetakis, P.; Anastasiadis, S.H.; Fotakis, C.

2009-01-01

We report here an efficient method for preparing stable superhydrophobic and highly water repellent surfaces by irradiating silicon wafers with femtosecond laser pulses and subsequently coating them with chloroalkylsilane monolayers. By varying the laser pulse fluence on the surface one can successfully control its wetting properties via a systematic and reproducible variation of roughness at micro- and nano-scale, which mimics the topology of natural superhydrophobic surfaces. The self-cleaning and water repellent properties of these artificial surfaces are investigated. It is found that the processed surfaces are among the most water repellent surfaces ever reported. These results may pave the way for the implementation of laser surface microstructuring techniques for the fabrication of superhydrophobic and self-cleaning surfaces in different kinds of materials as well

Hydrological analysis relevant to surface water storage at Jabiluka. Supervising Scientist report 142

International Nuclear Information System (INIS)

Chiew, F.H.S.; Wang, Q.J.

1999-01-01

The report is prepared for the Supervising Scientist at Jabiru. It describes part of an investigation into hydrological issues relating to the water management system proposed for the Jabiluka project. Specifically, the objective is to estimate the water storage capacity required to store surface runoff and other water within the total containment zone (TCZ) of the Jabiluka project. The water storage volume is calculated for a range of probabilities up to 0.002% that the pond design volume would be exceeded over a 30-year mine life. In this study, 50 000 sets of 30 years of daily rainfall and monthly pan evaporation data are stochastically generated to simulate the storage water balance. The approach used by Kinhill and Energy Resources of Australia (ERA) is reviewed and the pond design compared with the estimates derived here. The Kinhill-ERA approach is described in the Jabiluka Mill Alternative Public Environment Report and the Jabiluka Mill Alternative Public Environment Report Technical Appendices (hereon referred to as Jabiluka PER Appendices) (1998). The two reports also provide background to many other issues. The structural design of the storage and other features of the mine site are not considered here. This study also assumes that the bunds and other drainage diversion structures will prevent all water outside the TCZ from entering the TCZ and vice versa. The storage water balance components are discussed in section 2. Some of the water inflows into the storage and losses from the storage are discussed in detail, while elsewhere, the values used by Kinhill-ERA are adopted. Section 3 describes the selection of the climate stations used here, the rainfall and pan evaporation characteristics in the area and the stochastic generation of 1.5 million years of daily rainfall and monthly pan evaporation data. Section 4 describes the approach used to estimate the storage capacity, and presents the storage capacity estimates for various probabilities of

Properties of water surface discharge at different pulse repetition rates

International Nuclear Information System (INIS)

Ruma,; Yoshihara, K.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.; Akiyama, M.; Lukeš, P.

2014-01-01

The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H 2 O 2 ) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H 2 O 2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

Prediction of water droplet evaporation on zircaloy surface

International Nuclear Information System (INIS)

Lee, Chi Young; In, Wang Kee

2014-01-01

In the present experimental study, the prediction of water droplet evaporation on a zircaloy surface was investigated using various initial droplet sizes. To the best of our knowledge, this may be the first valuable effort for understanding the details of water droplet evaporation on a zircaloy surface. The initial contact diameters of the water droplets tested ranged from 1.76 to 3.41 mm. The behavior (i.e., time-dependent droplet volume, contact angle, droplet height, and contact diameter) and mode-transition time of the water droplet evaporation were strongly influenced by the initial droplet size. Using the normalized contact angle (θ*) and contact diameter (d*), the transitions between evaporation modes were successfully expressed by a single curve, and their criteria were proposed. To predict the temporal droplet volume change and evaporation rate, the range of θ* > 0.25 and d* > 0.9, which mostly covered the whole evaporation period and the initial contact diameter remained almost constant during evaporation, was targeted. In this range, the previous contact angle functions for the evaporation model underpredicted the experimental data. A new contact angle function of a zircaloy surface was empirically proposed, which represented the present experimental data within a reasonable degree of accuracy. (author)

Biphilic Surfaces for Enhanced Water Collection from Humid Air

Science.gov (United States)

Benkoski, Jason; Gerasopoulos, Konstantinos; Luedeman, William

Surface wettability plays an important role in water recovery, distillation, dehumidification, and heat transfer. The efficiency of each process depends on the rate of droplet nucleation, droplet growth, and mass transfer. Unfortunately, hydrophilic surfaces are good at nucleation but poor at shedding. Hydrophobic surfaces are the reverse. Many plants and animals overcome this tradeoff through biphilic surfaces with patterned wettability. For example, the Stenocara beetle uses hydrophilic patches on a superhydrophobic background to collect fog from air. Cribellate spiders similarly collect fog on their webs through periodic spindle-knot structures. In this study, we investigate the effects of wettability patterns on the rate of water collection from humid air. The steady state rate of water collection per unit area is measured as a function of undercooling, angle of inclination, water contact angle, hydrophilic patch size, patch spacing, area fraction, and patch height relative to the hydrophobic background. We then model each pattern by comparing the potential and kinetic energy of a droplet as it rolls downwards at a fixed angle. The results indicate that the design rules for collecting fog differ from those for condensation from humid air. The authors gratefully acknowledge the Office of Naval Research for financial support through Grant Number N00014-15-1-2107.

Water and Regolith Shielding for Surface Reactor Missions

Science.gov (United States)

Poston, David I.; Ade, Brian J.; Sadasivan, Pratap; Leichliter, Katrina J.; Dixon, David D.

2006-01-01

This paper investigates potential shielding options for surface power fission reactors. The majority of work is focused on a lunar shield that uses a combination of water in stainless-steel cans and lunar regolith. The major advantage of a water-based shield is that development, testing, and deployment should be relatively inexpensive. This shielding approach is used for three surface reactor concepts: (1) a moderated spectrum, NaK cooled, Hastalloy/UZrH reactor, (2) a fast-spectrum, NaK-cooled, SS/UO2 reactor, and (3) a fast-spectrum, K-heat-pipe-cooled, SS/UO2 reactor. For this study, each of these reactors is coupled to a 25-kWt Stirling power system, designed for 5 year life. The shields are designed to limit the dose both to the Stirling alternators and potential astronauts on the surface. The general configuration used is to bury the reactor, but several other options exist as well. Dose calculations are presented as a function of distance from reactor, depth of buried hole, water boron concentration (if any), and regolith repacked density.

Water and Regolith Shielding for Surface Reactor Missions

International Nuclear Information System (INIS)

Poston, David I.; Sadasivan, Pratap; Dixon, David D.; Ade, Brian J.; Leichliter, Katrina J.

2006-01-01

This paper investigates potential shielding options for surface power fission reactors. The majority of work is focused on a lunar shield that uses a combination of water in stainless-steel cans and lunar regolith. The major advantage of a water-based shield is that development, testing, and deployment should be relatively inexpensive. This shielding approach is used for three surface reactor concepts: (1) a moderated spectrum, NaK cooled, Hastalloy/UZrH reactor, (2) a fast-spectrum, NaK-cooled, SS/UO2 reactor, and (3) a fast-spectrum, K-heat-pipe-cooled, SS/UO2 reactor. For this study, each of these reactors is coupled to a 25-kWt Stirling power system, designed for 5 year life. The shields are designed to limit the dose both to the Stirling alternators and potential astronauts on the surface. The general configuration used is to bury the reactor, but several other options exist as well. Dose calculations are presented as a function of distance from reactor, depth of buried hole, water boron concentration (if any), and regolith repacked density

Integrated modeling of groundwater–surface water interactions in a tile-drained agricultural field

NARCIS (Netherlands)

Rosemeijer, J.C.; Velde, van der Y.; McLaren, R.G.; Geer, van F.C.; Broers, H.P.; Bierkens, M.F.P.

2010-01-01

Understanding the dynamics of groundwater–surface water interaction is needed to evaluate and simulate water and solute transport in catchments. However, direct measurements of the contributions of different flow routes from specific surfaces within a catchment toward the surface water are rarely

UV sensitivity of planktonic net community production in ocean surface waters

Science.gov (United States)

Regaudie-de-Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

2014-05-01

The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we test the sensitivity of net community production (NCP) to UVB of planktonic communities in surface waters across contrasting regions of the ocean. We observed here that UVB radiation affects net plankton community production at the ocean surface, imposing a shift in NCP by, on average, 50% relative to the values measured when excluding partly UVB. Our results show that under full solar radiation, the metabolic balance shows the prevalence of net heterotrophic community production. The demonstration of an important effect of UVB radiation on NCP in surface waters presented here is of particular relevance in relation to the increased UVB radiation derived from the erosion of the stratospheric ozone layer. Our results encourage design future research to further our understanding of UVB effects on the metabolic balance of plankton communities.

Protocol for quantitative tracing of surface water with synthetic DNA

Science.gov (United States)

Foppen, J. W.; Bogaard, T. A.

2012-04-01

, the field tests were performed with salt and deuterium as tracer. To study possible decay by sunlight and/or microbial activity for synthetic DNA, immediately in the field and for the duration of the entire experiment, we carried out batch experiments. All samples were stored in a 1.5 ml Eppendorf vial in a cool-box in dry ice (-80°C). Quantitative PCR on a Mini Opticon (Bio Rad, Hercules, CA, USA) was carried out to determine DNA concentrations in the samples. Results showed the importance of a strict protocol for working with ssDNA as a tracer for quantitative tracing, since ssDNA interacts with surface areas of glass and plastic, depending on water quality and ionic strength. Interaction with the sediment and decay due to sunlight and/or microbial activity was negligible in most cases. The ssDNA protocol was then tested in natural streams. Promising results were obtained using ssDNA as quantitative tracer. The breakthrough curves using ssDNA were similar to the ones of salt or deuterium. We will present the revised protocol to use ssDNA for multi-tracing experiments in natural streams and discuss the opportunities and limitations.

Short Communication: Conductivity as an indicator of surface water ...

African Journals Online (AJOL)

Various water- soluble species are present in FeCr waste materials and in process water. Considering the size of the South African FeCr industry and its global importance, it is essential to assess the extent of potential surface water pollution in the proximity of FeCr smelters by such watersoluble species. In this study water ...

Modeling global distribution of agricultural insecticides in surface waters

International Nuclear Information System (INIS)

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

2015-01-01

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. - Highlights: • First global map on insecticide runoff through modelling. • Model predicts upper limit of insecticide exposure when compared to field data. • Water bodies in 40% of global land surface may be at risk of adverse effects. • Insecticide application rate, terrain slope and rainfall main drivers of exposure. - We provide the first global map on insecticide runoff to surface water predicting that water bodies in 40% of global land surface may be at risk of adverse effects

Water Surface Overgrowing of the Tatra’s Lakes

Directory of Open Access Journals (Sweden)

Kapusta Juraj

2018-03-01

Full Text Available Tatra’s lakes are vulnerable ecosystems and an important element of the alpine landscape. Mainly some shallow lake basins succumb to intense detritus sedimentation, fine fractions of material from the catchment area or to the overgrowing of water level by vegetation. In this paper, changes and dynamics of the 12 Tatra’s lake shorelines that were selected based on the detailed mapping of their extent are pointed out. Changes were assessed by accurate comparisons of historical and current orthophoto maps from the years 1949, 1955 and 2015 – and therefore, based on the oldest and the latest relevant materials. Due to the overgrowing of lakes caused by vegetation, their water surface decreased from −0.9% up to −47.9%, during the examined period. Losses were caused by the overgrowing of open water surface by the communities of sedges and peat bogs. The most significant dynamics of the shorelines during the last decades were reached by those lakes, into which fine sediments were simultaneously deposited by means of mountain water coarse. These sediments made the marginal parts of the lake basins shallower and accelerated rapid expansion of vegetation to the detriment of the open water surface. The overgrowing of shallow moraine lakes lying in the vegetation zone is a significant phenomenon of the High Tatras alpine landscape. It leads to their gradual extinction, turn into peat bogs and wet alpine meadows.

77 FR 12227 - Long Term 2 Enhanced Surface Water Treatment Rule: Uncovered Finished Water Reservoirs; Public...

Science.gov (United States)

2012-02-29

... Water Treatment Rule: Uncovered Finished Water Reservoirs; Public Meeting AGENCY: Environmental... review of the uncovered finished water reservoir requirement in the Long Term 2 Enhanced Surface Water... uncovered finished water reservoir requirement and the agency's Six Year Review process. EPA also plans to...

Adaptable bioinspired special wetting surface for multifunctional oil/water separation

Science.gov (United States)

Kavalenka, Maryna N.; Vüllers, Felix; Kumberg, Jana; Zeiger, Claudia; Trouillet, Vanessa; Stein, Sebastian; Ava, Tanzila T.; Li, Chunyan; Worgull, Matthias; Hölscher, Hendrik

2017-01-01

Inspired by the multifunctionality of biological surfaces necessary for the survival of an organism in its specific environment, we developed an artificial special wetting nanofur surface which can be adapted to perform different functionalities necessary to efficiently separate oil and water for cleaning accidental oil spills or separating industrial oily wastewater. Initial superhydrophobic nanofur surface is fabricated using a hot pulling method, in which nano- and microhairs are drawn out of the polymer surface during separation from a heated sandblasted steel plate. By using a set of simple modification techniques, which include microperforation, plasma treatment and subsequent control of storage environment, we achieved selective separation of either water or oil, variable oil absorption and continuous gravity driven separation of oil/water mixtures by filtration. Furthermore, these functions can be performed using special wetting nanofur made from various thermoplastics, including biodegradable and recyclable polymers. Additionally, nanofur can be reused after washing it with organic solvents, thus, further helping to reduce the environmental impacts of oil/water separation processes. PMID:28051163

Inhibition of biofilm formation on the surface of water storage containers using biosand zeolite silver-impregnated clay granular and silver impregnated porous pot filtration systems.

Science.gov (United States)

Budeli, Phumudzo; Moropeng, Resoketswe Charlotte; Mpenyana-Monyatsi, Lizzy; Momba, Maggie Ndombo Benteke

2018-01-01

containing drinking water treated with the BSZ-SICG filter between 3 and 14 days. The attachment of target bacteria on the surface of the coupons inoculated in storage containers ranged from (0.07 CFU/cm2-227.8 CFU/cm2). To effectively prevent the development of biofilms on the surface of container-stored water, which can lead to the recontamination of treated water, plastic storage containers should be washed within 14 days for water treated with the SIPP filter and within 3 days for water treated with the BSZ-SICG filter.

Inhibition of biofilm formation on the surface of water storage containers using biosand zeolite silver-impregnated clay granular and silver impregnated porous pot filtration systems

Science.gov (United States)

Moropeng, Resoketswe Charlotte; Mpenyana-Monyatsi, Lizzy; Momba, Maggie Ndombo Benteke

2018-01-01

those containing drinking water treated with the BSZ-SICG filter between 3 and 14 days. The attachment of target bacteria on the surface of the coupons inoculated in storage containers ranged from (0.07 CFU/cm2–227.8 CFU/cm2). To effectively prevent the development of biofilms on the surface of container-stored water, which can lead to the recontamination of treated water, plastic storage containers should be washed within 14 days for water treated with the SIPP filter and within 3 days for water treated with the BSZ-SICG filter. PMID:29621296

Numerical Simulation of the Effects of Water Surface in Building Environment

Science.gov (United States)

Li, Guangyao; Pan, Yuqing; Yang, Li

2018-03-01

Water body could affect the thermal environment and airflow field in the building districts, because of its special thermal characteristics, evaporation and flat surface. The thermal influence of water body in Tongji University Jiading Campus front area was evaluated. First, a suitable evaporation model was selected and then was applied to calculate the boundary conditions of the water surface in the Fluent software. Next, the computational fluid dynamics (CFD) simulations were conducted on the models both with and without water, following the CFD practices guidelines. Finally, the outputs of the two simulations were compared with each other. Results showed that the effect of evaporative cooling from water surface strongly depends on the wind direction and temperature decrease was about 2∼5°C. The relative humidity within the enclosing area was affected by both the building arrangement and surrounding water. An increase of about 0.1∼0.2m/s of wind speed induced by the water evaporation was observed in the open space.

Macroelements in the surface microlayer of water of urban ponds

Directory of Open Access Journals (Sweden)

Antonowicz Józef Piotr

2016-03-01

Full Text Available Analyses were conducted concerning the accumulation of four metals representing the group of macroelements, i.e. sodium, potassium, calcium and magnesium in two ponds located in the city of Słupsk. Water samples for chemical analyses were collected from the surface microlayer using a Garrett net. At the same time subsurface water samples were collected. Concentrations of metals were determined using a mass spectrometer. Generally, amounts of sodium, potassium, calcium and magnesium were similar in surface microlayer and subsurface water. Only in the case of potassium and calcium was low enrichment observed in the surface microlayer in one pond, while the greatest extent for magnesium enrichment was observed in the spring period.

Sulphur dioxide removal by turbulent transfer over grass, snow, and water surfaces

Energy Technology Data Exchange (ETDEWEB)

Whelpdale, D M; Shaw, R W

1974-01-01

Vertical gradients of sulphur dioxide concentration have been measured over grass, snow, and water surfaces in order to assess the importance of these surfaces as SO/sub 2/ sinks. Concentrations were usually found to be lower near the surface indicating that removal occurs there. Vertical concentration gradients, normalized with repect to the concentration at 8 m, were generally greatest over water and least over snow, independent of meteorological conditions, suggesting that a water surface is the strongest SO/sub 2/ sink, with grass next, and snow weakest. The turbulent transfer of SO/sub 2/ to the interface is discussed in relation to stability of the lower atmosphere and physical and chemical properties of the surfaces. Using a bulk aerodynamic transfer approach similar to that for water vapour, values of SO/sub 2/ flux averaged over periods of from one to several hours were found to be of the order of 1 microgram/M/sup 2//S to the water and grass surfaces, and an order of magnitude smaller to the snow surface. Deposition velocities were found to be of the order of 1 cm/s.

Methane oxidation and methane fluxes in the ocean surface layer and deep anoxic waters

Science.gov (United States)

Ward, B. B.; Kilpatrick, K. A.; Novelli, P. C.; Scranton, M. I.

1987-01-01

Measured biological oxidation rates of methane in near-surface waters of the Cariaco Basin are compared with the diffusional fluxes computed from concentration gradients of methane in the surface layer. Methane fluxes and oxidation rates were investigated in surface waters, at the oxic/anoxic interface, and in deep anoxic waters. It is shown that the surface-waters oxidation of methane is a mechanism which modulates the flux of methane from marine waters to the atmosphere.

Viability of sublethally injured coliform bacteria on fresh-cut cabbage stored in high CO2 atmospheres following rinsing with electrolyzed water.

Science.gov (United States)

Izumi, Hidemi; Inoue, Ayano

2018-02-02

The extent of sublethally injured coliform bacteria on shredded cabbage, either rinsed or not rinsed with electrolyzed water, was evaluated during storage in air and high CO 2 controlled atmospheres (5%, 10%, and 15%) at 5°C and 10°C using the thin agar layer (TAL) method. Sublethally injured coliform bacteria on nonrinsed shredded cabbage were either absent or they were injured at a 64-65% level when present. Rinsing of shredded cabbage with electrolyzed water containing 25ppm available chlorine reduced the coliform counts by 0.4 to 1.1 log and caused sublethal injury ranging from 42 to 77%. Pantoea ananatis was one of the species injured by chlorine stress. When shredded cabbage, nonrinsed or rinsed with electrolyzed water, was stored in air and high CO 2 atmospheres at 5°C for 7days and 10°C for 5days, coliform counts on TAL plates increased from 3.3-4.5 to 6.5-9.0 log CFU/g during storage, with the increase being greater at 10°C than at 5°C. High CO 2 of 10% and 15% reduced the bacterial growth on shredded cabbage during storage at 5°C. Although injured coliform bacteria were not found on nonrinsed shredded cabbage on the initial day, injured coliforms at a range of 49-84% were detected on samples stored in air and high CO 2 atmospheres at 5°C and 10°C. Injured cells were detected more frequently during storage at both temperatures irrespective of the CO 2 atmosphere when shredded cabbage was rinsed with electrolyzed water. These results indicated that injured coliform bacteria on shredded cabbage, either rinsed or not rinsed with electrolyzed water, exhibited different degrees of injury during storage regardless of the CO 2 atmosphere and temperature tested. Copyright © 2017 Elsevier B.V. All rights reserved.

Treating mine water

Energy Technology Data Exchange (ETDEWEB)

Matlak, E S; Kochegarova, L V; Zaslavskaya, I Yu

1980-10-01

Taking into account the negative influence of mine waters with suspended matter on the natural environment on the surface, the maximum treatment of mine water underground, is proposed. It is noted that full treatment of mine water, using conventional filtration methods, would be rather expensive, but a limited treatment of mine water is possible. Such treated mine water can be used in dust suppression and fire fighting systems. Mine water treated underground should be free of any odor, with pH level ranging from 6 to 9.5, with suspended matter content not exceeding 50 mg/l and coli-titre not less than 300 cm$SUP$3. It is suggested that water treatment to produce water characterized by these parameters is possible and economical. Recommendations on construction of underground sedimentation tanks and channels, and a hydraulic system of cleaning sedimentation tanks are proposed. The settling would be stored underground in abandoned workings. (2 refs.) (In Russian)

Ground Water and Climate Change

Science.gov (United States)

Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike;

Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles.

Science.gov (United States)

Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

2014-10-01

To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

Atmospheric Water Harvesting: Role of Surface Wettability and Edge Effect

KAUST Repository

Jin, Yong; Zhang, Lianbin; Wang, Peng

2017-01-01

Atmospheric water is emerging as an important potable water source. The present work experimentally and theoretically investigates water condensation and collection on flat surfaces with contrasting contact angles and contact angle hysteresis (CAH

Evaluation of Human Enteric Viruses in Surface Water and Drinking Water Resources in Southern Ghana

Science.gov (United States)

Gibson, Kristen E.; Opryszko, Melissa C.; Schissler, James T.; Guo, Yayi; Schwab, Kellogg J.

2011-01-01

An estimated 884 million people worldwide do not have access to an improved drinking water source, and the microbial quality of these sources is often unknown. In this study, a combined tangential flow, hollow fiber ultrafiltration (UF), and real-time PCR method was applied to large volume (100 L) groundwater (N = 4), surface water (N = 9), and finished (i.e., receiving treatment) drinking water (N = 6) samples for the evaluation of human enteric viruses and bacterial indicators. Human enteric viruses including norovirus GI and GII, adenovirus, and polyomavirus were detected in five different samples including one groundwater, three surface water, and one drinking water sample. Total coliforms and Escherichia coli assessed for each sample before and after UF revealed a lack of correlation between bacterial indicators and the presence of human enteric viruses. PMID:21212196

Surface Water Data at Los Alamos National Laboratory 1998 Water Year

International Nuclear Information System (INIS)

Shaull, D.A.; Alexander, M.R.; Reynolds, R.P.; McLean, C.T.; Romero, R.P.

1999-01-01

The principal investigators collected and computed surface water discharge data from 19 stream-gaging stations that cover most of Los Alamos National Laboratory. Also included are discharge data from three springs that flow into Caiion de Vane

Safety assessment of greenhouse hydroponic tomatoes irrigated with reclaimed and surface water.

Science.gov (United States)

Lopez-Galvez, Francisco; Allende, Ana; Pedrero-Salcedo, Francisco; Alarcon, Juan Jose; Gil, Maria Isabel

2014-11-17

The impact of reclaimed and surface water on the microbiological safety of hydroponic tomatoes was assessed. Greenhouse tomatoes were irrigated with reclaimed and surface water and grown on two hydroponic substrates (coconut fiber and rock wool). Water samples (n=208) were taken from irrigation water, with and without the addition of fertilizers and drainage water, and hydroponic tomatoes (n=72). Samples were analyzed for indicator microorganisms, generic Escherichia coli and Listeria spp., and pathogenic bacteria such as Salmonella spp. and Shiga-toxigenic E. coli (STEC), using multiplex real-time PCR (RT-PCR) after enrichment. The correlation between climatological parameters such as temperature and the levels of microorganisms in water samples was also determined. In irrigation water, generic E. coli counts were higher in reclaimed than in surface water whereas Listeria spp. numbers increased after adding the fertilizers in both water sources. In drainage water, no clear differences in E. coli and Listeria numbers were observed between reclaimed and surface water. No positive samples for STEC were found in irrigation water. Presumptive positives for Salmonella spp. were found in 7.7% of the water samples and 62.5% of these samples were reclaimed water. Salmonella-positive samples by RT-PCR could not be confirmed by conventional methods. Higher concentrations of E. coli were associated with Salmonella-presumptive positive samples. Climatological parameters, such as temperature, were not correlated with the E. coli and Listeria spp. counts. Tomato samples were negative for bacterial pathogens, while generic E. coli and Listeria spp. counts were below the detection limit. The prevalence of presumptive Salmonella spp. found in irrigation water (reclaimed and surface water) was high, which might present a risk of contamination. The absence of pathogens on greenhouse hydroponic tomatoes indicates that good agricultural practices (GAP) were in place, avoiding the

Heterogeneous Ice Nucleation: Interplay of Surface Properties and Their Impact on Water Orientations.

Science.gov (United States)

Glatz, Brittany; Sarupria, Sapna

2018-01-23

Ice is ubiquitous in nature, and heterogeneous ice nucleation is the most common pathway of ice formation. How surface properties affect the propensity to observe ice nucleation on that surface remains an open question. We present results of molecular dynamics studies of heterogeneous ice nucleation on model surfaces. The models surfaces considered emulate the chemistry of kaolinite, an abundant component of mineral dust. We investigate the interplay of surface lattice and hydrogen bonding properties in affecting ice nucleation. We find that lattice matching and hydrogen bonding are necessary but not sufficient conditions for observing ice nucleation at these surfaces. We correlate this behavior to the orientations sampled by the metastable supercooled water in contact with the surfaces. We find that ice is observed in cases where water molecules not only sample orientations favorable for bilayer formation but also do not sample unfavorable orientations. This distribution depends on both surface-water and water-water interactions and can change with subtle modifications to the surface properties. Our results provide insights into the diverse behavior of ice nucleation observed at different surfaces and highlight the complexity in elucidating heterogeneous ice nucleation.

Wavefront modulation of water surface wave by a metasurface

International Nuclear Information System (INIS)

Sun Hai-Tao; Cheng Ying; Liu Xiao-Jun; Wang Jing-Shi

2015-01-01

We design a planar metasurface to modulate the wavefront of a water surface wave (WSW) on a deep sub-wavelength scale. The metasurface is composed of an array of coiling-up-space units with specially designed parameters, and can take on the work of steering the wavefront when it is pierced into water. Like their acoustic counterparts, the modulation of WSW is ascribed to the gradient phase shift of the coiling-up-space units, which can be perfectly tuned by changing the coiling plate length and channel number inside the units. According to the generalized Snell’s law, negative refraction and ‘driven’ surface mode of WSW are also demonstrated at certain incidences. Specially, the transmitted WSW could be efficiently guided out by linking a symmetrically-corrugated channel in ‘driven’ surface mode. This work may have potential applications in water wave energy extraction and coastal protection. (paper)

Treatability of South African surface waters by enhanced coagulation

African Journals Online (AJOL)

The majority of South African inland surface water sources are compromised due to a long-standing national policy of mandatory return flows. With renewed emphasis on the removal of organic carbon in the latest SANS 241 water quality standard, many South African water treatment managers may need to consider ...

Environmental impact of by pass channel of surface waters

International Nuclear Information System (INIS)

Vismara, R.; Renoldi, M.; Torretta, V.

1996-01-01

In this paper are analyzed the impacts generated by surface waters drawing on river course. This impacts are generated also by reduction of water flow. This effect is most important for the presence of biological community: algae, fiches, micro invertebrates. Are also reported regional laws, water master plan of Lombardia region

Surface properties and water treatment capacity of surface engineered silica coated with 3-(2-aminoethyl) aminopropyltrimethoxysilane

Energy Technology Data Exchange (ETDEWEB)

Majewski, Peter, E-mail: peter.majewski@unisa.edu.au [School of Advanced Manufacturing and Mechanical Engineering, Mawson Institute, University of South Australia, Adelaide (Australia); Keegan, Alexandra [Microbiology Research, Australian Water Quality Centre, South Australian Water Corporation, Adelaide (Australia)

2012-01-15

This study's focus was on the water-based, one-pot preparation and characterisation of silica particles coated with 3-(2-aminoethyl)aminopropyltrimethoxysilane (Diamo) and the efficiency of the material in removing the pathogens Escherichia coli, Pseudomonas aeruginosa, Mycobacterium immunogenum, Vibrio cholerae, poliovirus, and Cryptosporidium parvum. The water-based processing resulted in Diamo coated silica particles with significantly increased positive surface charge as determined by zeta potential measurements. In addition, X-ray photoelectron spectrometry of pure and Diamo coated silica confirmed the presence of Diamo on the surface of the particles. Thermogravimetric measurements and chemical analysis of the silica indicated a surface concentration of amine groups of about 1 mmol/g{sub silica}. Water treatment tests with the pathogens showed that a dose of about 10 g appeared to be sufficient to remove pathogens from pure water samples which were spiked with pathogen concentrations between about 10{sup 2} and 10{sup 4} cfu/mL.

Surface properties and water treatment capacity of surface engineered silica coated with 3-(2-aminoethyl) aminopropyltrimethoxysilane

International Nuclear Information System (INIS)

Majewski, Peter; Keegan, Alexandra

2012-01-01

This study's focus was on the water-based, one-pot preparation and characterisation of silica particles coated with 3-(2-aminoethyl)aminopropyltrimethoxysilane (Diamo) and the efficiency of the material in removing the pathogens Escherichia coli, Pseudomonas aeruginosa, Mycobacterium immunogenum, Vibrio cholerae, poliovirus, and Cryptosporidium parvum. The water-based processing resulted in Diamo coated silica particles with significantly increased positive surface charge as determined by zeta potential measurements. In addition, X-ray photoelectron spectrometry of pure and Diamo coated silica confirmed the presence of Diamo on the surface of the particles. Thermogravimetric measurements and chemical analysis of the silica indicated a surface concentration of amine groups of about 1 mmol/g silica . Water treatment tests with the pathogens showed that a dose of about 10 g appeared to be sufficient to remove pathogens from pure water samples which were spiked with pathogen concentrations between about 10 2 and 10 4 cfu/mL.

Iron oxidation kinetics and phosphorus immobilization at the groundwater-surface water interface

Science.gov (United States)

van der Grift, Bas; Rozemeijer, Joachim; Griffioen, Jasper; van der Velde, Ype

2014-05-01

Eutrophication of freshwater environments following diffuse nutrient loads is a widely recognized water quality problem in catchments. Fluxes of non-point P sources to surface waters originate from surface runoff and flow from soil water and groundwater into surface water. The availability of P in surface waters is controlled strongly by biogeochemical nutrient cycling processes at the soil-water interface. The mechanisms and rates of the iron oxidation process with associated binding of phosphate during exfiltration of anaerobic Fe(II) bearing groundwater are among the key unknowns in P retention processes in surface waters in delta areas where the shallow groundwater is typically pH-neutral to slightly acid, anoxic, iron-rich. We developed an experimental field set-up to study the dynamics in Fe(II) oxidation and mechanisms of P immobilization at the groundwater-surface water interface in an agricultural experimental catchment of a small lowland river. We physically separated tube drain effluent from groundwater discharge before it entered a ditch in an agricultural field. The exfiltrating groundwater was captured in in-stream reservoirs constructed in the ditch. Through continuous discharge measurements and weekly water quality sampling of groundwater, tube drain water, exfiltrated groundwater, and ditch water, we quantified Fe(II) oxidation kinetics and P immobilization processes across the seasons. This study showed that seasonal changes in climatic conditions affect the Fe(II) oxidation process. In winter time the dissolved iron concentrations in the in-stream reservoirs reached the levels of the anaerobic groundwater. In summer time, the dissolved iron concentrations of the water in the reservoirs are low, indicating that dissolved Fe(II) is completely oxidized prior to inflow into the reservoirs. Higher discharges, lower temperatures and lower pH of the exfiltrated groundwater in winter compared to summer shifts the location of the redox transition zone

Tracer experiment by using radioisotope in surface water environment

International Nuclear Information System (INIS)

Suh, K.S.; Kim, K.C.; Chun, I.Y.; Jung, S.H.; Lee, C.W.

2007-01-01

Complete text of publication follows. 1. Objective An expansion of industrial activities and urbanization result in still increasing amount of pollutants discharged into surface water. Discharged pollutants in surface water have harmful effects on the ecology of a river system and human beings. Pollutants discharged into surface water is transported and dispersed under conditions characteristic to particular natural water receiver. Radiotracer method is a useful tool for monitoring the pollutant dispersion and description of mixing process taking place in natural streams. A tracer experiment using radioisotope was carried out to investigate the characteristics of a pollutant transport and a determination of the diffusion coefficients in a river system. 2. Methods The upper area of the Keum river was selected for the tracer experiment, which is located in a mid west of Korea. The measurements of the velocity and bathymetry before a tracer experiment were performed to select the sampling lines for a detection of the radioisotope. The radioisotope was instantaneously injected into a flow as a point source by an underwater glass-vial crusher. The detection was made with 60 2inch NaI(Tl) scintillation detectors at 3 transverse lines at a downstream position. The multi-channel data acquisition systems were used to collect and process the signals transmitted from the detectors. Two-dimensional numerical models were used to simulate the hydraulic parameters and the concentration distributions of the radioisotope injected into the river. 3. Results and Conclusion The calculated results such as velocity and concentrations were compared with the measured ones. The dispersion characteristics of the radioisotope were analyzed according to a variation of the flow rate, water level and diffusion coefficients. Also, the diffusion coefficients were calculated by using the measured concentrations and the coefficients obtained from the field experiment were compared with the ones

Radioactivity in the Dutch surface waters after Chernobylsk

International Nuclear Information System (INIS)

Kroesbergen, J.; Ballegooijen, L. van; Uunk, E.J.B.

1988-12-01

A survey is given of the impact of the nuclear accident in Chernobylsk upon the Dutch surface waters. With this the measurements, which have been performed in the various compartments (water, suspended matter, bottom, biota) are presented. Since the investigation is still going, the period from May 1986 - December 1987 has been chosen. This period is long enough in order to obtain an impression of the long-term effects. In chapter 2 a description is given of the measuring program performed and the analyzing methods employed. In chapter 3 the activation measurements in the surface waters, the suspended matter and the bottom are considered. Also the contamination of biologic matter and the purification mud is discussed. Chapter 4 gives a survey of the amount of radionuclides, which have been accumulated in the Dutch surface waters as a result of the Chernobylsk accident. The investigation of the processes are discussed in chapter 5. Since the study of the effects of radionuclides in the aquatic environment is still going, only some aspects are treated. Chapter 6 gives a general discussion of the results. Also an estimation is presented towards the future development of the contamination of the aquatic environment. Finally in chapter 7 the most important conclusions are summarized. Also some recommendations are made with regard to future measurements to be taken. (author). 72 refs.; 36 figs.; 26 tabs

Surface-water, water-quality, and ground-water assessment of the Municipio of Carolina, Puerto Rico, 1997-99

Science.gov (United States)

Rodríguez-Martínez, Jesús; Gómez-Gómez, Fernando; Santiago-Rivera, Luis; Oliveras-Feliciano, M. L.

2001-01-01

To meet the increasing need for a safe and adequate supply of water in the municipio of Carolina, an integrated surface-water, water-quality, and ground-water assessment of the area was conducted. The major results of this study and other important hydrologic and water-quality features were compiled in a Geographic Information System and are presented in two 1:30,000-scale map plates to facilitate interpretation and use of the diverse water-resources data. Because the supply of safe drinking water was a critical issue during recent dry periods, the surface-water assessment portion of this study focused on analysis of low-flow characteristics in local streams and rivers. Low-flow characteristics were evaluated for one continuous-record gaging station, based on graphical curve-fitting techniques and log-Pearson Type III frequency analysis. Estimates of low-flow characteristics for seven partial-record stations were generated using graphical-correlation techniques. Flow-duration characteristics were computed for the one continuous-record gaging station and were estimated for the partial-record stations using the relation curves developed from the low-flow study. Stream low-flow statistics document the general hydrology under current land and water use. Low-flow statistics may substantially change as a result of streamflow diversions for public supply, and an increase in ground-water development, waste-water discharges, and flood-control measures; the current analysis provides baseline information to evaluate these impacts and develop water budgets. A sanitary quality survey of streams utilized 29 sampling stations to evaluate the sanitary quality of about 87 miles of stream channels. River and stream samples were collected on two occasions during base-flow conditions and were analyzed for fecal coliform and fecal streptococcus. Bacteriological analyses indicate that a significant portion of the stream reaches within the municipio of Carolina may have fecal coliform

Field Evaluation Of Arsenic Transport Across The Ground-Water/Surface Water Interface: Ground-Water Discharge And Iron Oxide Precipitation

Science.gov (United States)

A field investigation was conducted to examine the distribution of arsenic in ground water, surface water, and sediments at a Superfund Site in the northeastern United States (see companion presentation by K. G. Scheckel et al). Ground-water discharge into the study area was cha...

Microcystin-LR in surface water of Ponjavica river

Directory of Open Access Journals (Sweden)

Natić Dejan

2012-01-01

Full Text Available Background/Aim. Cyanobacterial toxins befall a group of various compounds according to chemical structure and health effects on people and animals. The most significant in this large group of compounds are microcystins. Their presence in water used for human consumption causes serious health problems, liver beeing the target organ. Microcystins are spread all over the world. Waterblooms of cyanobacterias and their cyanotoxins are also common in the majority of surface waters in Serbia. The aim of this study was to propose HPLC method for determination of mikrocystin-LR, to validate the method and to use it for determination of microcystin-LR in the surface water of the river Ponjavica. The Ponjavica is very eutrophic water and has ideal conditions for the cyanobacterial growth. Methods. Sample of water form the Ponjavica river were collected during the summer 2008. Coupled columns (HLB, Sep-Pak, were used for sample preparation and HPLC/PDA method was used for quantification of microcystin- LR. Results. Parameters of validation show that the proposed method is simple, fast, sensitive (0.1 mg/L and selective with the yield of 89%-92%. The measuring uncertainty of

Review: Impacts of permafrost degradation on inorganic chemistry of surface fresh water

Science.gov (United States)

Colombo, Nicola; Salerno, Franco; Gruber, Stephan; Freppaz, Michele; Williams, Mark; Fratianni, Simona; Giardino, Marco

2018-03-01

Recent studies have shown that climate change is impacting the inorganic chemical characteristics of surface fresh water in permafrost areas and affecting aquatic ecosystems. Concentrations of major ions (e.g., Ca2 +, Mg2 +, SO42 -, NO3-) can increase following permafrost degradation with associated deepening of flow pathways and increased contributions of deep groundwater. In addition, thickening of the active layer and melting of near-surface ground ice can influence inorganic chemical fluxes from permafrost into surface water. Permafrost degradation has also the capability to modify trace element (e.g., Ni, Mn, Al, Hg, Pb) contents in surface water. Although several local and regional modifications of inorganic chemistry of surface fresh water have been attributed to permafrost degradation, a comprehensive review of the observed changes is lacking. The goal of this paper is to distil insight gained across differing permafrost settings through the identification of common patterns in previous studies, at global scale. In this review we focus on three typical permafrost configurations (pervasive permafrost degradation, thermokarst, and thawing rock glaciers) as examples and distinguish impacts on (i) major ions and (ii) trace elements. Consequences of warming climate have caused spatially-distributed progressive increases of major ion and trace element delivery to surface fresh water in both polar and mountain areas following pervasive permafrost degradation. Moreover, localised releases of major ions and trace elements to surface water due to the liberation of soluble materials sequestered in permafrost and ground ice have been found in ice-rich terrains both at high latitude (thermokarst features) and high elevation (rock glaciers). Further release of solutes and related transport to surface fresh water can be expected under warming climatic conditions. However, complex interactions among several factors able to influence the timing and magnitude of the impacts

[Occurrence of bacteria of the Yersinia genus in surface water].

Science.gov (United States)

Krogulska, B; Maleszewska, J

1992-01-01

The aim of the study was determination of the frequency of occurrence of Yersinia genus bacteria in surface waters polluted to various degrees with bacteria of the coliform and of fecal coli. For detection of Yersinia rods the previously elaborated medium Endo MLCe and the membrane filter method were applied. Samples of 42 surface waters were examined, including 26 from rivers and 16 from lakes, ponds and clay-pits. On the basis of sanitary bacteriological analysis 16 surface waters were classified to class I purity, 10 to class II, the remaining ones to class III or beyond classification. Yersinia rods were detected in 15 water bodies that is 35.7% of the examined waters. A total of 27 Yersinia strains were identified with dominance of Y. intermedia (14 strains) and Y. enterocolitica (10 strains). Three strains represented by the species Yersinia frederiksenii. Most of the Y. enterocolitica strains belonged to biotype 1, the particular strains being represented by various serotypes. Hence their different origin may be concluded. The pathogenic serotypes 0:3 and 0:9 of Yersinia enterocolitica were not detected.

Screening and human health risk assessment of pharmaceuticals and their transformation products in Dutch surface waters and drinking water

NARCIS (Netherlands)

de Jongh, C.M.; Kooij, P.J.F.; de Voogt, P.; ter Laak, T.L.

2012-01-01

Numerous studies describe the presence of pharmaceuticals in the water cycle, while their transformation products are usually not included. In the current study 17 common pharmaceuticals and 9 transformation products were monitored in the Dutch waters, including surface waters, pre-treated surface

Water and nutrient budgets at field and regional scale : travel times of drainage water and nutrient loads to surface water

NARCIS (Netherlands)

Eertwegh, van den G.A.P.H.

2002-01-01

Keywords : water and nutrient budget, travel time of drainage water, dual-porosity concept, agricultural nutrient losses, loads to surface water, field-scale experiments, regional-scale