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

NASA Astrophysics Data System (ADS)

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.

A Water Rich Mars Surface Mission Scenario

NASA Technical Reports Server (NTRS)

Hoffman, Stephen J.; Andrews, Alida; Joosten, B. Kent; Watts, Kevin

2017-01-01

In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial Polar Regions are reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable

A Water Rich Mars Surface Mission Scenario

NASA Technical Reports Server (NTRS)

Hoffman, Stephen J.; Andrews, Alida; Joosten, B. Kent; Watts, Kevin

2017-01-01

In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial polar regions is reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable

21 CFR 173.310 - Boiler water additives.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Boiler water additives. 173.310 Section 173.310... Boiler water additives. Boiler water additives may be safely used in the preparation of steam that will... Total not to exceed 1.5 parts per million in boiler feed water. Copolymer contains not more than 0.5...

Uncertainties in selected surface water quality data

NASA Astrophysics Data System (ADS)

Rode, M.; Suhr, U.

2006-09-01

Monitoring of surface waters is primarily done to detect the status and trends in water quality and to identify whether observed trends arise form natural or anthropogenic causes. Empirical quality of surface water quality data is rarely certain and knowledge of their uncertainties is essential to assess the reliability of water quality models and their predictions. The objective of this paper is to assess the uncertainties in selected surface water quality data, i.e. suspended sediment, nitrogen fraction, phosphorus fraction, heavy metals and biological compounds. The methodology used to structure the uncertainty is based on the empirical quality of data and the sources of uncertainty in data (van Loon et al., 2006). A literature review was carried out including additional experimental data of the Elbe river. All data of compounds associated with suspended particulate matter have considerable higher sampling uncertainties than soluble concentrations. This is due to high variability's within the cross section of a given river. This variability is positively correlated with total suspended particulate matter concentrations. Sampling location has also considerable effect on the representativeness of a water sample. These sampling uncertainties are highly site specific. The estimation of uncertainty in sampling can only be achieved by taking at least a proportion of samples in duplicates. Compared to sampling uncertainties measurement and analytical uncertainties are much lower. Instrument quality can be stated well suited for field and laboratory situations for all considered constituents. Analytical errors can contribute considerable to the overall uncertainty of surface water quality data. Temporal autocorrelation of surface water quality data is present but literature on general behaviour of water quality compounds is rare. For meso scale river catchments reasonable yearly dissolved load calculations can be achieved using biweekly sample frequencies. For suspended

An all-water-based system for robust superhydrophobic surfaces.

PubMed

Liu, Mingming; Hou, Yuanyuan; Li, Jing; Tie, Lu; Guo, Zhiguang

2018-06-01

Superhydrophobic surfaces with micro-/nanohierarchical structures are mechanically weak. Generally, organic solvents are used to dissolve or disperse organic adhesives and modifiers to enhance the mechanical strength of superhydrophobic surfaces. In this work, an all-water-based spraying solution is developed for the preparation of robust superhydrophobic surfaces, which contains ZnO nanoparticles, aluminum phosphate as an inorganic adhesive, and polytetrafluoroethylene with low surface energy. The all-water-based system is appreciated for low price and less pollution. Importantly, the prepared superhydrophobic surfaces are durable enough against various harsh conditions (such as UV irradiation for 12 h, pH values from 1 to 13, and temperatures from -10 to 300 °C for 12 h) and physical damages (including sandpaper abrasion and sand impact tests for 50 cycles). In addition, the obtained interfacial materials show promise for practical applications such as anti-icing and oil-water separation. Copyright © 2018 Elsevier Inc. All rights reserved.

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

USGS Publications Warehouse

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

The utility of surface temperature measurements for the remote sensing of surface soil water status

NASA Technical Reports Server (NTRS)

Idso, S. B.; Jackson, R. D.; Reginato, R. J.; Schmugge, T. J.

1975-01-01

Experiments carried out on an Avondale loam soil indicated that the thermal inertia concept of soil water content detection is reasonably sound. The volumetric water contents of surface soil layers between 2 and 4 cm thick were found to be linear functions of the amplitude of the diurnal surface soil temperature wave for clear day-night periods. They were also found to be linear functions of the daily maximum value of the surface soil-air-temperature differential. Tests on three additional soils ranging from sandy loam to clay indicated that the relations determined for Avondale loam could not be accurately applied to these other soil types. When the moisture characteristic curves of each soil were used to transform water contents into pressure potentials, however, it was found that soil water pressure potential could be determined without prior knowledge of soil type, and thus its value as a potential soil water status survey tool was significantly enhanced.

THE PERSISTENCE OF MYCOBACTERIUM AVIUM IN A DRINKING WATER SYSTEM AFTER THE ADDITION OF FILTRATION

EPA Science Inventory

Drinking water is increasingly recognized as a major source of pathogenic nontuberculous mycobacteria (NTM) associated with human infection. Our goal was to determine if the prevalence of NTM would decrease after the addition of filtration treatment to an unfiltered surface water...

Surface Water in Hawaii

USGS Publications Warehouse

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.

Surface water risk assessment of pesticides in Ethiopia.

PubMed

Teklu, Berhan M; Adriaanse, Paulien I; Ter Horst, Mechteld M S; Deneer, John W; Van den Brink, Paul J

2015-03-01

Scenarios for future use in the pesticide registration procedure in Ethiopia were designed for 3 separate Ethiopian locations, which are aimed to be protective for the whole of Ethiopia. The scenarios estimate concentrations in surface water resulting from agricultural use of pesticides for a small stream and for two types of small ponds. Seven selected pesticides were selected since they were estimated to bear the highest risk to humans on the basis of volume of use, application rate and acute and chronic human toxicity, assuming exposure as a result of the consumption of surface water. Potential ecotoxicological risks were not considered as a selection criterion at this stage. Estimates of exposure concentrations in surface water were established using modelling software also applied in the EU registration procedure (PRZM and TOXSWA). Input variables included physico-chemical properties, and data such as crop calendars, irrigation schedules, meteorological information and detailed application data which were specifically tailored to the Ethiopian situation. The results indicate that for all the pesticides investigated the acute human risk resulting from the consumption of surface water is low to negligible, whereas agricultural use of chlorothalonil, deltamethrin, endosulfan and malathion in some crops may result in medium to high risk to aquatic species. The predicted environmental concentration estimates are based on procedures similar to procedures used at the EU level and in the USA. Addition of aquatic macrophytes as an ecotoxicological endpoint may constitute a welcome future addition to the risk assessment procedure. Implementation of the methods used for risk characterization constitutes a good step forward in the pesticide registration procedure in Ethiopia. Copyright © 2014 Elsevier B.V. All rights reserved.

Enthalpic Breakdown of Water Structure on Protein Active-Site Surfaces

PubMed Central

Haider, Kamran; Wickstrom, Lauren; Ramsey, Steven; Gilson, Michael K.; Kurtzman, Tom

2016-01-01

The principles underlying water reorganization around simple non-polar solutes are well understood and provide the framework for classical hydrophobic effect, whereby water molecules structure themselves around solutes so that they maintain favorable energetic contacts with both the solute and with other water molecules. However, for certain solute surface topographies, water molecules, due to their geometry and size, are unable to simultaneously maintain favorable energetic contacts with both the surface and neighboring water molecules. In this study, we analyze the solvation of ligand-binding sites for six structurally diverse proteins using hydration site analysis and measures of local water structure, in order to identify surfaces at which water molecules are unable to structure themselves in a way that maintains favorable enthalpy relative to bulk water. These surfaces are characterized by a high degree of enclosure, weak solute-water interactions, and surface constraints that induce unfavorable pair interactions between neighboring water molecules. Additionally, we find that the solvation of charged side-chains in an active site generally results in favorable enthalpy but can also lead to pair interactions between neighboring water molecules that are significantly unfavorable relative to bulk water. We find that frustrated local structure can occur not only in apolar and weakly polar pockets, where overall enthalpy tends to be unfavorable, but also in charged pockets, where overall water enthalpy tends to be favorable. The characterization of local water structure in these terms may prove useful for evaluating the displacement of water from diverse protein active-site environments. PMID:27169482

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

NASA Astrophysics Data System (ADS)

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.

Adsorption of benzyldimethylhexadecylammonium chloride at the hydrophobic silica-water interface studied by total internal reflection Raman spectroscopy: effects of silica surface properties and metal salt addition.

PubMed

Grenoble, Zlata; Baldelli, Steven

2013-08-29

The adsorption of the cationic surfactant benzyldimethylhexadecylammonium (BDMHA(+)) chloride was studied at an octadecyltrichlorosilane (OTS)-monolayer-modified silica-water interface by Raman spectroscopy in total internal reflection (TIR) geometry. The present study demonstrates the capabilities of this spectroscopic technique to evaluate thermodynamic and kinetic BDMHA(+)Cl(-) adsorption properties at the hydrophobic silica surface. The surface coverage of BDMHA(+) decreased by 50% at the hydrophobic OTS-silica surface relative to the surface coverage on bare silica; the dominating driving mechanisms for surfactant adsorption were identified as hydrophobic effects and head group charge screening by the electrolyte counterions. Addition of magnesium metal salt (MgCl2) to the aqueous solution (∼ neutral pH) lowered the surface coverage and moderately increased the Langmuir adsorption constants relative to those of the pure surfactant. These trends were previously observed at the hydrophilic, negatively charged silica surface but with a smaller change in the Gibbs free energy of adsorption at the hydrophobic silica surface. The hydrophobic OTS-silica surface properties resulted in shorter times for the surfactant to reach steady-state adsorption conditions compared to the slow adsorption kinetics previously seen with the surfactant at the hydrophilic surface. Adsorption isotherms, based on Raman signal intensities from spectral analysis, were developed according to the Langmuir adsorption model for the pure surfactant at the OTS-silica-water interface; the modified Langmuir model was applied to the surfactant adsorption in the presence of 5, 10, 50, and 100 mM magnesium chloride. Spectral analysis of the Raman scattering intensities and geometric considerations suggests a hemimicelle-type surface aggregate as the most likely surfactant structure at the OTS-silica surface. The different kinetics observed at the hydrophilic versus the hydrophobic silica surface

Adaptable bioinspired special wetting surface for multifunctional oil/water separation

NASA Astrophysics Data System (ADS)

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.

Surface Tension Mediated Under-Water Adhesion of Rigid Spheres on Soft, Charged Surfaces

NASA Astrophysics Data System (ADS)

Sinha, Shayandev; Das, Siddhartha

2015-11-01

Understanding the phenomenon of surface-tension-mediated under-water adhesion is necessary for studying a plethora of physiological and technical phenomena, such as the uptake of bacteria or nanoparticle by cells, attachment of virus on bacterial surfaces, biofouling on large ocean vessels and marine devices, etc. This adhesion phenomenon becomes highly non-trivial in case the soft surface where the adhesion occurs is also charged. Here we propose a theory for analyzing such an under-water adhesion of a rigid sphere on a soft, charged surface, represented by a grafted polyelectrolyte layer (PEL). We develop a model based on the minimization of free energy that, in addition to considering the elastic and the surface-tension-mediated adhesion energies, also accounts for the PEL electric double layer (EDL) induced electrostatic energies. We show that in the presence of surface charges, adhesion gets enhanced. This can be explained by the fact that the increase in the elastic energy is better balanced by the lowering of the EDL energy associated with the adhesion process. The entire behaviour is further dictated by the surface tension components that govern the adhesion energy.

Roles of additives and surface control in slurry atomization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, S.C.

1992-01-01

This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy atmore » 25[degrees]C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.« less

Surface-specific additive manufacturing test artefacts

NASA Astrophysics Data System (ADS)

Townsend, Andrew; Racasan, Radu; Blunt, Liam

2018-06-01

Many test artefact designs have been proposed for use with additive manufacturing (AM) systems. These test artefacts have primarily been designed for the evaluation of AM form and dimensional performance. A series of surface-specific measurement test artefacts designed for use in the verification of AM manufacturing processes are proposed here. Surface-specific test artefacts can be made more compact because they do not require the large dimensions needed for accurate dimensional and form measurements. The series of three test artefacts are designed to provide comprehensive information pertaining to the manufactured surface. Measurement possibilities include deviation analysis, surface texture parameter data generation, sub-surface analysis, layer step analysis and build resolution comparison. The test artefacts are designed to provide easy access for measurement using conventional surface measurement techniques, for example, focus variation microscopy, stylus profilometry, confocal microscopy and scanning electron microscopy. Additionally, the test artefacts may be simply visually inspected as a comparative tool, giving a fast indication of process variation between builds. The three test artefacts are small enough to be included in every build and include built-in manufacturing traceability information, making them a convenient physical record of the build.

Surface texture measurement for additive manufacturing

NASA Astrophysics Data System (ADS)

Triantaphyllou, Andrew; Giusca, Claudiu L.; Macaulay, Gavin D.; Roerig, Felix; Hoebel, Matthias; Leach, Richard K.; Tomita, Ben; Milne, Katherine A.

2015-06-01

The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

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

USGS Publications Warehouse

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.

Field Techniques for Estimating Water Fluxes Between Surface Water and Ground Water

USGS Publications Warehouse

Rosenberry, Donald O.; LaBaugh, James W.

2008-01-01

This report focuses on measuring the flow of water across the interface between surface water and ground water, rather than the hydrogeological or geochemical processes that occur at or near this interface. The methods, however, that use hydrogeological and geochemical evidence to quantify water fluxes are described herein. This material is presented as a guide for those who have to examine the interaction of surface water and ground water. The intent here is that both the overview of the many available methods and the in-depth presentation of specific methods will enable the reader to choose those study approaches that will best meet the requirements of the environments and processes they are investigating, as well as to recognize the merits of using more than one approach. This report is designed to make the reader aware of the breadth of approaches available for the study of the exchange between surface and ground water. To accomplish this, the report is divided into four chapters. Chapter 1 describes many well-documented approaches for defining the flow between surface and ground waters. Subsequent chapters provide an in-depth presentation of particular methods. Chapter 2 focuses on three of the most commonly used methods to either calculate or directly measure flow of water between surface-water bodies and the ground-water domain: (1) measurement of water levels in well networks in combination with measurement of water level in nearby surface water to determine water-level gradients and flow; (2) use of portable piezometers (wells) or hydraulic potentiomanometers to measure hydraulic gradients; and (3) use of seepage meters to measure flow directly. Chapter 3 focuses on describing the techniques involved in conducting water-tracer tests using fluorescent dyes, a method commonly used in the hydrogeologic investigation and characterization of karst aquifers, and in the study of water fluxes in karst terranes. Chapter 4 focuses on heat as a tracer in hydrological

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

NASA Astrophysics Data System (ADS)

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/gsilica. 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 102 and 104 cfu/mL.

Versatile antifouling polyethersulfone filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive.

PubMed

Zhao, Yi-Fan; Zhang, Pei-Bin; Sun, Jian; Liu, Cui-Jing; Yi, Zhuan; Zhu, Li-Ping; Xu, You-Yi

2015-06-15

Here we describe the development of versatile antifouling polyethersulfone (PES) filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive. Amphiphilic polyethersulfone-block-poly(2-hydroxyethyl methacrylate) (PES-b-PHEMA) was beforehand designed and used as the blending additive of PES membranes prepared by phase inversion technique. The surface enriched PHEMA blocks on membrane surface acted as an anchor to immobilize the initiating site. Poly(sulfobetaine methacrylate) (PSBMA) were subsequently grafted onto the PES blend membranes by surface-initiated atom transfer radical polymerization (SI-ATRP). The analysis of surface chemistry confirmed the successful grafting of zwitterionic PSBMA brushes on PES membrane surface. The resulted PES-g-PSBMA membranes were capable of separating proteins from protein solution and oil from oil/water emulsion efficiently. Furthermore, the modified membranes showed high hydrophilicity and strongly antifouling properties due to the incorporation of well-defined PSBMA layer. In addition, the PES-g-PSBMA membranes exhibited excellent blood compatibility and durability during the washing process. The developed antifouling PES membranes are versatile and can find their applications in protein filtration, blood purification and oil/water separation, etc. Copyright © 2015 Elsevier Inc. All rights reserved.

Water based drilling mud additive

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrary, J.L.

1983-12-13

A water based fluid additive useful in drilling mud used during drilling of an oil or gas well is disclosed, produced by reacting water at temperatures between 210/sup 0/-280/sup 0/ F. with a mixture comprising in percent by weight: gilsonite 25-30%, tannin 7-15%, lignite 25-35%, sulfonating compound 15-25%, water soluble base compound 5-15%, methylene-yielding compound 1-5%, and then removing substantially all of the remaining water to produce a dried product.

Interactions between groundwater and surface water: The state of the science

USGS Publications Warehouse

Sophocleous, M.

2002-01-01

The interactions between groundwater and surface water are complex. To understand these interactions in relation to climate, landform, geology, and biotic factors, a sound hydrogeoecological framework is needed. All these aspects are synthesized and exemplified in this overview. In addition, the mechanisms of interactions between groundwater and surface water (GW-SW) as they affect recharge-discharge processes are comprehensively outlined, and the ecological significance and the human impacts of such interactions are emphasized. Surface-water and groundwater ecosystems are viewed as linked components of a hydrologic continuum leading to related sustainability issues. This overview concludes with a discussion of research needs and challenges facting this evolving field. The biogeochemical processes within the upper few centimeters of sediments beneath nearly all surface-water bodies (hyporheic zone) have a profound effect on the chemistry of the water interchange, and here is where most of the recent research has been focusing. However, to advance conceptual and other modeling of GW-SW systems, a broader perspective of such interactions across and between surface-water bodies is needed, including multidimensional analyses, interface hydraulic characterization and spatial variability, site-to-region regionalization approaches, as well as cross-disciplinary collaborations.

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

EPA Pesticide Factsheets

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

Water and Carbon Dioxide Adsorption at Olivine Surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerisit, Sebastien N.; Bylaska, Eric J.; Felmy, Andrew R.

2013-11-14

Plane-wave density functional theory (DFT) calculations were performed to simulate water and carbon dioxide adsorption at the (010) surface of five olivine minerals, namely, forsterite (Mg2SiO4), calcio-olivine (Ca2SiO4), tephroite (Mn2SiO4), fayalite (Fe2SiO4), and Co-olivine (Co2SiO4). Adsorption energies per water molecule obtained from energy minimizations varied from -78 kJ mol-1 for fayalite to -128 kJ mol-1 for calcio-olivine at sub-monolayer coverage and became less exothermic as coverage increased. In contrast, carbon dioxide adsorption energies at sub-monolayer coverage ranged from -20 kJ mol-1 for fayalite to -59 kJ mol-1 for calcio-olivine. Therefore, the DFT calculations show a strong driving force for carbonmore » dioxide displacement by water at the surface of all olivine minerals in a competitive adsorption scenario. Additionally, adsorption energies for both water and carbon dioxide were found to be more exothermic for the alkaline-earth (AE) olivines than for the transition-metal (TM) olivines and to not correlate with the solvation enthalpies of the corresponding divalent cations. However, a correlation was obtained with the charge of the surface divalent cation indicating that the more ionic character of the AE cations in the olivine structure relative to the TM cations leads to greater interactions with adsorbed water and carbon dioxide molecules at the surface and thus more exothermic adsorption energies for the AE olivines. For calcio-olivine, which exhibits the highest divalent cation charge of the five olivines, ab initio molecular dynamics simulations showed that this effect leads both water and carbon dioxide to react with the surface and form hydroxyl groups and a carbonate-like species, respectively.« less

Water resources data, New Jersey, water year 2005. Volume 1 - surface-water data

USGS Publications Warehouse

White, B.T.; Hoppe, H.L.; Centinaro, G.L.; Dudek, J.F.; Painter, B.S.; Protz, A.R.; Reed, T.J.; Shvanda, J.C.; Watson, A.F.

2006-01-01

Water-resources data for the 2005 water year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water-quality of streams; stage and contents of lakes and reservoirs; and water levels and water-quality of ground water. Volume 1 contains discharge records for 103 gaging stations; tide summaries at 28 tidal gaging stations; stage and contents at 34 lakes and reservoirs; and diversions from 50 surface-water sources. Also included are stage and discharge for 116 crest-stage partial-record stations, stage-only at 33 tidal crest-stage gages, and discharge for 155 low-flow partial-record stations. Locations of these sites are shown in figures 8-11. Additional discharge measurements were made at 222 miscellaneous sites that are not part of the systematic data-collection program. Discontinued station tables for gaging stations, crest-stage gages, tidal crest-stage and tidal gaging stations show historical coverage. The data in this report represent that part of the National Water Information System (NWIS) data collected by the United States Geological Survey (USGS). Hydrologic conditions are also described for this water year, including stream-flow, precipitation, reservoir conditions, and air temperatures.

Water resources data, New Jersey, water year 2004-volume 1. surface-water data

USGS Publications Warehouse

Centinaro, G.L.; White, B.T.; Hoppe, H.L.; Dudek, J.F.; Protz, A.R.; Reed, T.J.; Shvanda, J.C.; Watson, A.F.

2005-01-01

Water-resources data for the 2004 water year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water-quality of streams; stage and contents of lakes and reservoirs; and water levels and water-quality of ground water. Volume 1 contains discharge records for 105 gaging stations; tide summaries at 27 tidal gaging stations; stage and contents at 39 lakes and reservoirs; and diversions from 51 surface-water sources. Also included are stage and discharge for 108 crest-stage partial-record stations, stage-only at 34 tidal crest-stage gages, and discharge for 124 low-flow partial-record stations. Locations of these sites are shown in figures 8-11. Additional discharge measurements were made at 131 miscellaneous sites that are not part of the systematic data-collection program. Discontinued station tables for gaging stations, crest-stage gages, tidal crest-stage and tidal gaging stations show historical coverage. The data in this report represent that part of the National Water Information System (NWIS) data collected by the United States Geological Survey (USGS). Hydrologic conditions are also described for this water year, including stream-flow, precipitation, reservoir conditions, and air temperatures.

Adaptable bioinspired special wetting surface for multifunctional oil/water separation

PubMed Central

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

Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe

PubMed Central

Zhai, Penghui; Huang, Jianhui; Zhao, Xiang; Dong, Kuanhu

2018-01-01

Water use efficiency (WUE) is an important indicator of ecosystem functioning but how ecosystem WUE responds to climate change including precipitation and nitrogen (N) deposition increases is still unknown. To investigate such responses, an experiment with a randomized block design with water (spring snowfall or summer water addition) and nitrogen addition was conducted in a temperate steppe of northern China. We investigated net ecosystem CO2 production (NEP), gross ecosystem production (GEP) and evapotranspiration (ET) to calculate ecosystem WUE (WUEnep = NEP/ET or WUEgep = GEP/ET) under spring snow and summer water addition with or without N addition from 2011 to 2013. The results showed that spring snow addition only had significant effect on ecosystem WUE in 2013 and summer water addition showed positive effect on ecosystem WUE in 2011 and 2013, as their effects on NEP and GEP is stronger than ET. N addition increased ecosystem WUE in 2012 and 2013 both in spring snow addition and summer water addition for its increasing effects on NEP and GEP but no effect on ET. Summer water addition had less but N addition had greater increasing effects on ecosystem WUE as natural precipitation increase indicating that natural precipitation regulates ecosystem WUE responses to water and N addition. Moreover, WUE was tightly related with atmospheric vapor-pressure deficit (VPD), photosynthetic active radiation (PAR), precipitation and soil moisture indicating the regulation of climate drivers on ecosystem WUE. In addition, it also was affected by aboveground net primary production (ANPP). The study suggests that ecosystem WUE responses to water and N addition is determined by the change in carbon process rather than that in water process, which are regulated by climate change in the temperate steppe of northern China. PMID:29529082

Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe.

PubMed

Zhang, Xiaolin; Zhai, Penghui; Huang, Jianhui; Zhao, Xiang; Dong, Kuanhu

2018-01-01

Water use efficiency (WUE) is an important indicator of ecosystem functioning but how ecosystem WUE responds to climate change including precipitation and nitrogen (N) deposition increases is still unknown. To investigate such responses, an experiment with a randomized block design with water (spring snowfall or summer water addition) and nitrogen addition was conducted in a temperate steppe of northern China. We investigated net ecosystem CO2 production (NEP), gross ecosystem production (GEP) and evapotranspiration (ET) to calculate ecosystem WUE (WUEnep = NEP/ET or WUEgep = GEP/ET) under spring snow and summer water addition with or without N addition from 2011 to 2013. The results showed that spring snow addition only had significant effect on ecosystem WUE in 2013 and summer water addition showed positive effect on ecosystem WUE in 2011 and 2013, as their effects on NEP and GEP is stronger than ET. N addition increased ecosystem WUE in 2012 and 2013 both in spring snow addition and summer water addition for its increasing effects on NEP and GEP but no effect on ET. Summer water addition had less but N addition had greater increasing effects on ecosystem WUE as natural precipitation increase indicating that natural precipitation regulates ecosystem WUE responses to water and N addition. Moreover, WUE was tightly related with atmospheric vapor-pressure deficit (VPD), photosynthetic active radiation (PAR), precipitation and soil moisture indicating the regulation of climate drivers on ecosystem WUE. In addition, it also was affected by aboveground net primary production (ANPP). The study suggests that ecosystem WUE responses to water and N addition is determined by the change in carbon process rather than that in water process, which are regulated by climate change in the temperate steppe of northern China.

Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces.

PubMed

Amorim, Patrícia M; Ferraria, Ana M; Colaço, Rogério; Branco, Luís C; Saramago, Benilde

2017-01-01

In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl)-3-methylimidazolium [C 2 OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO 4 ] were added to dry PEG. All additives (2 wt %) led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO]) and improved the Si wettability. The additives based on the anion [EtSO 4 ] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.

Surface Water Records of Colorado

USGS Publications Warehouse

U.S. Geological Survey, Water Resources Division

1962-01-01

The surface-water records for the 1962 water year for gaging stations and miscellaneous sites within the State of Colorado are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of J. W. Odell, district engineer, Surface Water Branch.

Assessing metaldehyde concentrations in surface water catchments and implications for drinking water abstraction

NASA Astrophysics Data System (ADS)

Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; Cherry, Katherine

2015-04-01

Metaldehyde is an active ingredient in agricultural pesticides such as slug pellets, which are heavily applied to UK farmland during the autumn application season. There is current concern that existing drinking water treatment processes may be inadequate in reducing potentially high levels of metaldehyde in surface waters to below the UK drinking water quality regulation limit of 0.1 µg/l. In addition, current water quality monitoring methods can miss short term fluctuations in metaldehyde concentration caused by rainfall driven runoff, hampering prediction of the potential risk of exposure. Datasets describing levels, fate and transport of metaldehyde in river catchments are currently very scarce. This work presents results from an ongoing study to quantify the presence of metaldehyde in surface waters within a UK catchment used for drinking water abstraction. High resolution water quality data from auto-samplers installed in rivers are coupled with radar rainfall, catchment characteristics and land use data to i) understand which hydro-meteorological characteristics of the catchment trigger the peak migration of metaldehyde to surface waters; ii) assess the relationship between measured metaldehyde levels and catchment characteristics such as land use, topographic index, proximity to water bodies and runoff generation area; iii) describe the current risks to drinking water supply and discuss mitigation options based on modelling and real-time control of water abstraction. Identifying the correlation between catchment attributes and metaldehyde generation will help in the development of effective catchment management strategies, which can help to significantly reduce the amount of metaldehyde finding its way into river water. Furthermore, the effectiveness of current water quality monitoring strategy in accurately quantifying the generation of metaldehyde from the catchment and its ability to benefit the development of effective catchment management practices

Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces

PubMed Central

Amorim, Patrícia M; Ferraria, Ana M; Colaço, Rogério; Branco, Luís C

2017-01-01

In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl)-3-methylimidazolium [C2OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO4] were added to dry PEG. All additives (2 wt %) led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO]) and improved the Si wettability. The additives based on the anion [EtSO4] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces. PMID:29046844

Additional boundary conditions and surface exciton dispersion relations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimbey, P.R.

1977-01-15

The surface-exciton dispersion curves in ZnO are derived from the surface impedances developed by Fuchs and Kliewer (FK) and Rimbey and Mahan (RM) including retardation. There exists a distinctive splitting between the two dispersions, the FK additional boundary conditions having longitudinal character, the RM additional boundary conditions being transverse. Surface-mode attenuation due to spatial dispersion is more pronouced in the RM formalism, although inclusion of a phenomenological damping parameter does not alter either dispersion curve. (AIP)

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

USGS Publications Warehouse

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

Groundwater and surface-water utilisation using a bank infiltration technique in Malaysia

NASA Astrophysics Data System (ADS)

Shamsuddin, Mohd Khairul Nizar; Sulaiman, Wan Nor Azmin; Suratman, Saim; Zakaria, Mohamad Pauzi; Samuding, Kamarudin

2014-05-01

Bank infiltration (BI) is one of the solutions to providing raw water for public supply in tropical countries. This study in Malaysia explores the use of BI to supplement a polluted surface-water resource with groundwater. Three major factors were investigated: (1) contribution of surface water through BI to the resulting abstraction, (2) input of local groundwater, and (3) water-quality characteristics of the resulting water supply. A geophysical method was employed to define the subsurface geology and hydrogeology, and isotope techniques were performed to identify the source of groundwater recharge and the interaction between surface water and groundwater. The physicochemical and microbiological parameters of the local surface-water bodies and groundwater were analyzed before and during water abstraction. Extracted water revealed a 5-98 % decrease in turbidity, as well as reductions in HCO3 -, Cl-, SO4 2-, NO3 -, Ca2+, Al3+ and As concentrations compared with those of Langat River water. In addition, amounts of E. coli, total coliform and Giardia were significantly reduced (99.9 %). However, water samples from test wells during pumping showed high concentrations of Fe2+ and Mn2+. Pumping test results indicate that the two wells used in the study were able to sustain yields.

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

USGS Publications Warehouse

Harvey, J.W.; Newlin, J.T.; Krupa, S.L.

2006-01-01

Surface-water and ground-water flow are coupled in the central Everglades, although the remoteness of this system has hindered many previous attempts to quantify interactions between surface water and ground water. We modeled flow through a 43,000 ha basin in the central Everglades called Water Conservation Area 2A. The purpose of the model was to quantify recharge and discharge in the basin's vast interior areas. The presence and distribution of tritium in ground water was the principal constraint on the modeling, based on measurements in 25 research wells ranging in depth from 2 to 37 m. In addition to average characteristics of surface-water flow, the model parameters included depth of the layer of 'interactive' ground water that is actively exchanged with surface water, average residence time of interactive ground water, and the associated recharge and discharge fluxes across the wetland ground surface. Results indicated that only a relatively thin (8 m) layer of the 60 m deep surfical aquifer actively exchanges surface water and ground water on a decadal timescale. The calculated storage depth of interactive ground water was 3.1 m after adjustment for the porosity of peat and sandy limestone. Modeling of the tritium data yielded an average residence time of 90 years in interactive ground water, with associated recharge and discharge fluxes equal to 0.01 cm d -1. 3H/3He isotopic ratio measurements (which correct for effects of vertical mixing in the aquifer with deeper, tritium-dead water) were available from several wells, and these indicated an average residence time of 25 years, suggesting that residence time was overestimated using tritium measurements alone. Indeed, both residence time and storage depth would be expected to be overestimated due to vertical mixing. The estimate of recharge and discharge (0.01 cm d-1) that resulted from tritium modeling therefore is still considered reliable, because the ratio of residence time and storage depth (used to

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

NASA Astrophysics Data System (ADS)

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

2006-04-01

Surface-water and ground-water flow are coupled in the central Everglades, although the remoteness of this system has hindered many previous attempts to quantify interactions between surface water and ground water. We modeled flow through a 43,000 ha basin in the central Everglades called Water Conservation Area 2A. The purpose of the model was to quantify recharge and discharge in the basin's vast interior areas. The presence and distribution of tritium in ground water was the principal constraint on the modeling, based on measurements in 25 research wells ranging in depth from 2 to 37 m. In addition to average characteristics of surface-water flow, the model parameters included depth of the layer of 'interactive' ground water that is actively exchanged with surface water, average residence time of interactive ground water, and the associated recharge and discharge fluxes across the wetland ground surface. Results indicated that only a relatively thin (8 m) layer of the 60 m deep surfical aquifer actively exchanges surface water and ground water on a decadal timescale. The calculated storage depth of interactive ground water was 3.1 m after adjustment for the porosity of peat and sandy limestone. Modeling of the tritium data yielded an average residence time of 90 years in interactive ground water, with associated recharge and discharge fluxes equal to 0.01 cm d -1. 3H/ 3He isotopic ratio measurements (which correct for effects of vertical mixing in the aquifer with deeper, tritium-dead water) were available from several wells, and these indicated an average residence time of 25 years, suggesting that residence time was overestimated using tritium measurements alone. Indeed, both residence time and storage depth would be expected to be overestimated due to vertical mixing. The estimate of recharge and discharge (0.01 cm d -1) that resulted from tritium modeling therefore is still considered reliable, because the ratio of residence time and storage depth (used to

CONNECTICUT SURFACE WATER QUALITY CLASSIFICATIONS

EPA Science Inventory

This is a 1:24,000-scale datalayer of Surface Water Quality Classifications for Connecticut. It is comprised of two 0Shapefiles with line and polygon features. Both Shapefiles must be used together with the Hydrography datalayer. The polygon Shapefile includes surface water qual...

Surface water classification and monitoring using polarimetric synthetic aperture radar

NASA Astrophysics Data System (ADS)

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

Effect of Surface Oxidation on Interfacial Water Structure at a Pyrite (100) Surface as Studied by Molecular Dynamics Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2015-06-01

In the first part of this paper, a Scanning Electron Microscopy and contact angle study of a pyrite surface (100) is reported describing the relationship between surface oxidation and the hydrophilic surface state. In addition to these experimental results, the following simulated surface states were examined using Molecular Dynamics Simulation (MDS): fresh unoxidized (100) surface; polysulfide at the (100) surface; elemental sulfur at the (100) surface. Crystal structures for the polysulfide and elemental sulfur at the (100) surface were simulated using Density Functional Theory (DFT) quantum chemical calculations. The well known oxidation mechanism which involves formation of a metal deficientmore » layer was also described with DFT. Our MDS results of the behavior of interfacial water at the fresh and oxidized pyrite (100) surfaces without/with the presence of ferric hydroxide include simulated contact angles, number density distribution for water, water dipole orientation, water residence time, and hydrogen-bonding considerations. The significance of the formation of ferric hydroxide islands in accounting for the corresponding hydrophilic surface state is revealed not only from experimental contact angle measurements but also from simulated contact angle measurements using MDS. The hydrophilic surface state developed at oxidized pyrite surfaces has been described by MDS, on which basis the surface state is explained based on interfacial water structure. The Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (BES), of the DOE funded work performed by Liem X. Dang. Battelle operates the Pacific Northwest National Laboratory for DOE. The calculations were carried out using computer resources provided by BES.« less

Field and laboratory determination of water-surface elevation and velocity using noncontact measurements

USGS Publications Warehouse

Nelson, Jonathan M.; Kinzel, Paul J.; Schmeeckle, Mark Walter; McDonald, Richard R.; Minear, Justin T.

2016-01-01

Noncontact methods for measuring water-surface elevation and velocity in laboratory flumes and rivers are presented with examples. Water-surface elevations are measured using an array of acoustic transducers in the laboratory and using laser scanning in field situations. Water-surface velocities are based on using particle image velocimetry or other machine vision techniques on infrared video of the water surface. Using spatial and temporal averaging, results from these methods provide information that can be used to develop estimates of discharge for flows over known bathymetry. Making such estimates requires relating water-surface velocities to vertically averaged velocities; the methods here use standard relations. To examine where these relations break down, laboratory data for flows over simple bumps of three amplitudes are evaluated. As anticipated, discharges determined from surface information can have large errors where nonhydrostatic effects are large. In addition to investigating and characterizing this potential error in estimating discharge, a simple method for correction of the issue is presented. With a simple correction based on bed gradient along the flow direction, remotely sensed estimates of discharge appear to be viable.

Map showing general chemical quality of surface water in the Richfield Quadrangle, Utah

USGS Publications Warehouse

Price, Don

1980-01-01

This is one of a series of maps that describe the geology and related natural resources of the Richfield 2° quadrangle, Utah. The purpose of this map is to show the general chemical quality of surface water in the area by ranges of dissolved-solids concentrations.Data used to compile this map were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights. In those areas where little or no surface-water-quality data are available, ranges of dissolved-solids concentrations of the water are inferred on the basis of such factors as geology (Stokes, 1964), precipitation, topography, known ground-water quality, and water uses – all of which affect the chemical quality of surface water.Additional information about the chemical quality of surface water in various parts of the Richfield 2° quadrangle may be found in the following reports: Hahl and Cabell (1965), Hahl and Mundorff (1968), Stephens (1974, 1976), Cruff and Mower (1976), and Cruff(1977)

Modulators of heterogeneous protein surface water dynamics

NASA Astrophysics Data System (ADS)

Han, Songi

The hydration water that solvates proteins is a major factor in driving or enabling biological events, including protein-protein and protein-ligand interactions. We investigate the role of the protein surface in modulating the hydration water fluctuations on both the picosecond and nanosecond timescale with an emerging experimental NMR technique known as Overhauser Dynamic Nuclear Polarization (ODNP). We carry out site-specific ODNP measurements of the hydration water fluctuations along the surface of Chemotaxis Y (CheY), and correlate the measured fluctuations to hydropathic and topological properties of the CheY surface as derived from molecular dynamics (MD) simulation. Furthermore, we compare hydration water fluctuations measured on the CheY surface to that of other globular proteins, as well as intrinsically disordered proteins, peptides, and liposome surfaces to systematically test characteristic effects of the biomolecular surface on the hydration water dynamics. Our results suggest that the labile (ps) hydration water fluctuations are modulated by the chemical nature of the surface, while the bound (ns) water fluctuations are present on surfaces that feature a rough topology and chemical heterogeneity such as the surface of a folded and structured protein. In collaboration with: Ryan Barnes, Dept of Chemistry and Biochemistry, University of California Santa Barbara

Water surface capturing by image processing

USDA-ARS?s Scientific Manuscript database

An alternative means of measuring the water surface interface during laboratory experiments is processing a series of sequentially captured images. Image processing can provide a continuous, non-intrusive record of the water surface profile whose accuracy is not dependent on water depth. More trad...

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

USGS Publications Warehouse

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.

Calcium Carbonate Nucleation in an Alkaline Lake Surface Water, Pyramid Lake, Nevada, USA

USGS Publications Warehouse

Reddy, M.M.; Hoch, A.

2012-01-01

Calcium concentration and calcite supersaturation (??) 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 ?? values of 10-16. Notwithstanding high ??, 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 ?? at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water ??. Calcium concentration and ?? regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower ?? than filtered samples. Calcium concentration and ?? 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 (??) + B. The best fit rate equation "Rate (?? mM/?? min) = -0.0026 ?? + 0.0175 (r = 0.904, n = 10)" was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, ?? 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. ?? 2011 U.S. Government.

Summary of surface-water hydrologic data for the Houston metropolitan area, Texas, water years 1964-89

USGS Publications Warehouse

Liscum, Fred; Brown, D.W.; Kasmarek, M.C.

1997-01-01

The study area, a metropolitan area in southeast Texas about 45 miles north of the Gulf of Mexico, has been undergoing extensive urban development since the 1950s. The Houston Urban Runoff Program was begun by the U.S. Geological Survey in water year 1964 to define the magnitude and frequency of flood peaks, to determine the impact of continuing urban development on surface-water hydrologic responses, and to determine variations in stream water quality for different flow conditions, seasons, and urban development. An extensive data base has been developed.During water years 1964-89, the Houston Urban Runoff Program collected information from a total of 54 U.S. Geological Survey streamflow-gaging stations, 30 U.S. Geological Survey water-quality sampling sites, and 102 rain gages (operated by the U.S. Geological Survey, the National Weather Service, and local agencies). In addition, basin characteristics were developed to aid in understanding the effects of urban development on surface-water hydrologic responses.Surface-water hydrologic data on diskettes describe the 54 U.S. Geological Survey streamflow-gaging stations, list annual peaks (and where available, peaks above an arbitrary base) for 50 streamflow sites, tabulate 1,125 storm hydrographs from 43 sites, and document 102 waterquality parameters determined from 3,242 available samples.

Icephobicity and the effect of water condensation on the superhydrophobic low-density polyethylene surface

NASA Astrophysics Data System (ADS)

Yuan, Zhiqing; Wang, Menglei; Huang, Juan; Wang, Xian; Bin, Jiping; Peng, Chaoyi; Xing, Suli; Xiao, Jiayu; Zeng, Jingcheng; Xiao, Ximei; Fu, Xin; Gong, Huifang; Zhao, Dejian; Chen, Hong

2015-06-01

A superhydrophobic surface was obtained on a low-density polyethylene (LDPE) substrate using a facile method. The water contact angle and the sliding angle of the superhydrophobic LDPE surface were 155 ± 2° and 4°, respectively. The ice shear stress of the superhydrophobic LDPE surface was 2.08 times smaller than that of the flat LDPE surface. The superhydrophobic surface still showed excellent icephobicity and superhydrophobicity after undergoing a circulatory icing/deicing procedure five times. In addition, water condensation and its effect on the icephobicity of the as-prepared superhydrophobic surface were also studied.

The differences in crown formation during the splash on the thin water layers formed on the saturated soil surface and model surface

PubMed Central

Mazur, Rafał; Polakowski, Cezary; Bieganowski, Andrzej

2017-01-01

Splash is the first stage of a negative phenomenon–soil erosion. The aim of this work was to describe the crown formation quantitatively (as part of the splash erosion) and compare the course of this phenomenon on the thin water film formed on a smooth glass surface and on the surface of saturated soil. The height of the falling water drop was 1.5 m. The observation of the crowns was carried out by high-speed cameras. The static and dynamic parameters of crown formation were analysed. It was found that the crowns formed on the water film covering the saturated soil surface were smaller and the time intervals of their existence were shorter. In addition, the shapes of the crowns were different from those created on the water layer covering the glass surface. These differences can be explained by the slightly different values of surface tension and viscosity of the soil solution, the greater roughness of the soil surface and the lower thickness of the water film on the soil surface. PMID:28750072

The differences in crown formation during the splash on the thin water layers formed on the saturated soil surface and model surface.

PubMed

Beczek, Michał; Ryżak, Magdalena; Sochan, Agata; Mazur, Rafał; Polakowski, Cezary; Bieganowski, Andrzej

2017-01-01

Splash is the first stage of a negative phenomenon-soil erosion. The aim of this work was to describe the crown formation quantitatively (as part of the splash erosion) and compare the course of this phenomenon on the thin water film formed on a smooth glass surface and on the surface of saturated soil. The height of the falling water drop was 1.5 m. The observation of the crowns was carried out by high-speed cameras. The static and dynamic parameters of crown formation were analysed. It was found that the crowns formed on the water film covering the saturated soil surface were smaller and the time intervals of their existence were shorter. In addition, the shapes of the crowns were different from those created on the water layer covering the glass surface. These differences can be explained by the slightly different values of surface tension and viscosity of the soil solution, the greater roughness of the soil surface and the lower thickness of the water film on the soil surface.

Precise determination of water exchanges on a mineral surface

DOE PAGES

Stack, Andrew G.; Borreguero, Jose M.; Prisk, Timothy R.; ...

2016-10-03

Solvent exchanges on solid surfaces and dissolved ions are a fundamental property important for understanding chemical reactions, but the rates of fast exchanges are poorly constrained. In this paper, we probed the diffusional motions of water adsorbed onto nanoparticles of the mineral barite (BaSO 4) using quasi-elastic neutron scattering (QENS) and classical molecular dynamics (MD) to reveal the complex dynamics of water exchange along mineral surfaces. QENS data as a function of temperature and momentum transfer (Q) were fit using scattering functions derived from MD trajectories. The simulations reproduce the dynamics measured in the experiments at ambient temperatures, but asmore » temperature is lowered the simulations overestimate slower motions. Decomposition of the MD-computed QENS intensity into contributions from adsorbed and unbound water shows that the majority of the signal arises from adsorbed species, although the dynamics of unbound water cannot be dismissed. The mean residence times of water on each of the four surface sites present on the barite {001} were calculated using MD: at room temperature the low barium site is 194 ps, whereas the high barium site contains two distributions of motions at 84 and 2.5 ps. These contrast to 13 ps residence time on both sulfate sites, with an additional surface diffusion exchange of 66 ps. Surface exchanges are similar to those of the aqueous ions calculated using the same force field: Ba aq 2+ is 208 ps and SO 4aq 2- is 5.8 ps. Finally, this work demonstrates how MD can be a reliable method to deconvolute solvent exchange reactions when quantitatively validated by QENS measurements.« less

Ground-water/surface-water relations along Honey Creek, Washtenaw County, Michigan, 2003

USGS Publications Warehouse

Healy, Denis F.

2005-01-01

The U.S. Geological Survey (USGS), in cooperation with the city of Ann Arbor, Mich., investigated the ground-water/ surface-water relations along the lower reaches of Honey Creek, Washtenaw County, Mich., and an unnamed tributary to Honey Creek (the discharge tributary) from June through October 2003. Streamflow in these reaches was artificially high during a naturally low-flow period due to an anthropogenic discharge. Ground-water/surface-water relations were examined by seepage runs (series of streamflow measurements for the computation of streams gains or losses) and measurements of the difference in head between the stream surface and shallow aquifer. Specific conductance and water-temperature measurements were used as ancillary data to help identify gaining and losing reaches. Three seepage runs and four runs in which hydraulic-head differences between the stream and shallow aquifer were measured (piezometer runs) were made during periods of base flow. Streamflow measurements were made at 18 sites for the seepage runs. Instream piezometers were installed at 16 sites and bank piezometers were installed at 2 sites. Two deeper instream piezometers were installed at site 13 on September 4, 2003 to collect additional data on the ground-water/surface-water relations at that site. The seepage runs indicate that the main stem of Honey Creek and the discharge tributary in the study area are overall gaining reaches. The seepage runs also indicate that smaller reaches of Honey Creek and the discharge tributary may be losing reaches and that this relation may change over time with changing hydraulic conditions. The piezometer-run measurements support the seepage-run results on the main stem, whereas piezometer-run measurements both support and conflict with seepage-run measurements on the discharge tributary. Seepage runs give an average for the reach, whereas piezometer head-difference measurements are for a specific area around the piezometer. Data that may appear to be

Influence of ethanol vapor addition on the surface modification of polyethylene in a dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Van Deynse, Annick; Morent, Rino; Leys, Christophe; De Geyter, Nathalie

2017-10-01

In this paper, ethanol vapor up to 50% is added to an argon, air or nitrogen dielectric barrier discharge at medium pressure to profoundly investigate the effect of ethanol addition on the surface modification of low density polyethylene (LDPE). Water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) measurements show that the ethanol vapor addition effect on the LDPE surface depends on the used carrier gas. Adding ethanol to an argon plasma has no significant effect on the wettability nor on the chemical composition of LDPE compared to a pure argon plasma treatment. Ethanol addition does however slightly increase the LDPE surface roughness. Addition of small amounts of ethanol vapor to an air plasma makes it possible to incorporate additional nitrogen and oxygen groups on the LDPE surface, resulting in an extra decrease of 11% in WCA value. Moreover, the LDPE surface roughness is slightly increased due to the ethanol vapor addition. The most significant effect of ethanol addition is however observed when nitrogen is used as carrier gas. After an N2/2% ethanol plasma treatment, an 85% reduction in WCA value to 8.5° is found compared to a pure N2 plasma treatment. This very hydrophilic LDPE surface is obtained due to a significantly high incorporation of oxygen and nitrogen groups on the surface with an O/C and N/C ratio reaching 32% and 53% respectively. FTIR measurements also reveal that the observed extremely high wettability of LDPE is not the result of plasma activation but is due to plasma polymerization effects occurring on the surface resulting into the deposition of a plasma polymer containing ketones, amides as well as Cdbnd N groups. In addition, ageing studies have also been conducted and these studies reveal that for all carrier gases, ethanol addition to the discharge gas significantly suppresses the ageing effect. All the above mentioned conclusions therefore indicate that ethanol vapor based plasmas can be an excellent tool to increase

Aflatoxin Toxicity Reduction in Feed by Enhanced Binding to Surface-Modified Clay Additives

PubMed Central

Jaynes, William F.; Zartman, Richard E.

2011-01-01

Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (Kd = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (Kd = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (Kd = 13,800) and carnitine (Kd = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (Kd = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (Kd = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (Kd = 1340) or the untreated montmorillonite (Kd = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity. PMID:22069725

Planetary-scale surface water detection from space

NASA Astrophysics Data System (ADS)

Donchyts, G.; Baart, F.; Winsemius, H.; Gorelick, N.

2017-12-01

Accurate, efficient and high-resolution methods of surface water detection are needed for a better water management. Datasets on surface water extent and dynamics are crucial for a better understanding of natural and human-made processes, and as an input data for hydrological and hydraulic models. In spite of considerable progress in the harmonization of freely available satellite data, producing accurate and efficient higher-level surface water data products remains very challenging. This presentation will provide an overview of existing methods for surface water extent and change detection from multitemporal and multi-sensor satellite imagery. An algorithm to detect surface water changes from multi-temporal satellite imagery will be demonstrated as well as its open-source implementation (http://aqua-monitor.deltares.nl). This algorithm was used to estimate global surface water changes at high spatial resolution. These changes include climate change, land reclamation, reservoir construction/decommissioning, erosion/accretion, and many other. This presentation will demonstrate how open satellite data and open platforms such as Google Earth Engine have helped with this research.

Controllability of Surface Water Networks

NASA Astrophysics Data System (ADS)

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.

Isotopic Tracers for Delineating Non-Point Source Pollutants in Surface Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davisson, M L

2001-03-01

This study tested whether isotope measurements of surface water and dissolved constituents in surface water could be used as tracers of non-point source pollution. Oxygen-18 was used as a water tracer, while carbon-14, carbon-13, and deuterium were tested as tracers of DOC. Carbon-14 and carbon-13 were also used as tracers of dissolved inorganic carbon, and chlorine-36 and uranium isotopes were tested as tracers of other dissolved salts. In addition, large databases of water quality measurements were assembled for the Missouri River at St. Louis and the Sacramento-San Joaquin Delta in California to enhance interpretive results of the isotope measurements. Muchmore » of the water quality data has been under-interpreted and provides a valuable resource to investigative research, for which this report exploits and integrates with the isotope measurements.« less

The effect of switchable water additives on clay settling.

PubMed

Chen, Chien-Shun; Lau, Ying Yin; Mercer, Sean M; Robert, Tobias; Horton, J Hugh; Jessop, Philip G

2013-01-01

The recycling of process water from strip mining extractions is a very relevant task both industrially and environmentally. The sedimentation of fine tailings during such processes, however, can often require long periods of time and/or the addition of flocculants which make later water recycling difficult. We propose the use of switchable water additives as reversible flocculants for clay/water suspensions. Switchable water additives are compounds such as diamines that make it possible to reversibly control the ionic strength of an aqueous solution. Addition of CO(2) to such an aqueous solution causes the ionic strength to rise dramatically, and the change is reversed upon removal of the CO(2). These additives, while in the presence of CO(2), promote the aggregation of clay tailings, reduce settling times, and greatly increase the clarity of the liberated water. The removal of CO(2) from the liberated water regenerates a low ionic strength solution that does not promote clay aggregation and settling until CO(2) is added again. Such reversible behavior would be useful in applications such as oil sands separations in which the recycled water must not promote aggregation. When added to kaolinite and montmorillonite clay suspensions, switchable water provided process waters of lower turbidity than those additives from inorganic salts or by CO(2)-treatment alone. When recollected, the switchable water supernatant was shown to be recyclable over three cycles for enhanced settling of kaolinite. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vitro genotoxicity of chlorinated drinking water processed from humus-rich surface water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liimatainen, A.; Grummt, T.

Chlorination by-products of drinking waters are capable of inducing sister chromatid exchanges (SCE) and chromosome aberrations (CA) in vitro, in addition to their mutagenic activity in the Ames test. Finnish drinking waters, processed from humus-rich surface water using chlorine disinfection, have been found to be highly mutagenic in the Ames' test. The highest activities have been found in the acidic, non-volatile fraction of the water concentrates using tester strain TA100 without metabolic activation by S9mix. The mutagenicities have varied between 500 and 14,000 induced revertants per liter. These figures are one to two magnitudes higher than those reported elsewhere. Themore » authors studied five Finnish drinking water samples for their potency to exert genotoxic effects, SCEs and CAs, in mammalian cells in vitro (human peripheral lymphocytes and Chinese hamster lung fibroblasts).« less

Input dynamics of pesticide transformation products into surface water

NASA Astrophysics Data System (ADS)

Kern, Susanne; Singer, Heinz; Hollender, Juliane; Schwarzenbach, René P.; Fenner, Kathrin

2010-05-01

Some pesticide transformation products have been observed to occur in higher concentrations and more frequently than the parent active pesticide in surface water and groundwater. These products are often more mobile and sometimes more stable than the parent pesticide. If they also represent the major product into which the parent substance is transformed, these transformation products may dominate observed pesticide occurrences in surface water and groundwater. Their potential contribution to the overall risk to the aquatic environment caused by the use of the parent pesticide should therefore not be neglected in chemical risk and water quality assessments. The same is true for transformation products of other compound classes that might reach the soil environment, such as veterinary pharmaceuticals. However, the fate and input pathways of transformation products of soil-applied chemicals into surface water are not yet well understood, which largely prevents their appropriate inclusion into chemical risk and water quality assessments. Here, we studied whether prioritization methods based on available environmental fate data from pesticide registration dossiers in combination with basic fate models could help identify transformation products which can be found in relevant concentrations in surface and groundwater and which should therefore be included into monitoring programs. A three-box steady state model containing air, soil, and surface water compartments was used to predict relative inputs of pesticide transformation products into surface waters based on their physico-chemical and environmental fate properties. The model predictions were compared to monitoring data from a small Swiss river located in an intensely agricultural catchment (90 km2) which was flow-proportionally sampled from May to October 2008 and screened for 74 pesticides as well as 50 corresponding transformation products. Sampling mainly occurred during high discharge, but additional samples

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

NASA Technical Reports Server (NTRS)

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

Contamination of surface, ground, and drinking water from pharmaceutical production.

PubMed

Fick, Jerker; Söderström, Hanna; Lindberg, Richard H; Phan, Chau; Tysklind, Mats; Larsson, D G Joakim

2009-12-01

Low levels of pharmaceuticals are detected in surface, ground, and drinking water worldwide. Usage and incorrect disposal have been considered the major environmental sources of these microcontaminants. Recent publications, however, suggest that wastewater from drug production can potentially be a source of much higher concentrations in certain locations. The present study investigated the environmental fate of active pharmaceutical ingredients in a major production area for the global bulk drug market. Water samples were taken from a common effluent treatment plant near Hyderabad, India, which receives process water from approximately 90 bulk drug manufacturers. Surface water was analyzed from the recipient stream and from two lakes that are not contaminated by the treatment plant. Water samples were also taken from wells in six nearby villages. The samples were analyzed for the presence of 12 pharmaceuticals with liquid chromatography-mass spectrometry. All wells were determined to be contaminated with drugs. Ciprofloxacin, enoxacin, cetirizine, terbinafine, and citalopram were detected at more than 1 microg/L in several wells. Very high concentrations of ciprofloxacin (14 mg/L) and cetirizine (2.1 mg/L) were found in the effluent of the treatment plant, together with high concentrations of seven additional pharmaceuticals. Very high concentrations of ciprofloxacin (up to 6.5 mg/L), cetirizine (up to 1.2 mg/L), norfloxacin (up to 0.52 mg/L), and enoxacin (up to 0.16 mg/L) were also detected in the two lakes, which clearly shows that the investigated area has additional environmental sources of insufficiently treated industrial waste. Thus, insufficient wastewater management in one of the world's largest centers for bulk drug production leads to unprecedented drug contamination of surface, ground, and drinking water. This raises serious concerns regarding the development of antibiotic resistance, and it creates a major challenge for producers and regulatory

Surface restructuring behavior of various types of poly(dimethylsiloxane) in water detected by SFG.

PubMed

Chen, Chunyan; Wang, Jie; Chen, Zhan

2004-11-09

Surface structures of several different poly(dimethylsiloxane) (PDMS) materials, tetraethoxysilane-cured hydroxy-terminated PDMS (TEOS-PDMS), platinum-cured vinyl-terminated PDMS (Pt-PDMS), platinum-cured vinyl-terminated poly(diphenylsiloxane)-co-poly(dimethylsiloxane) (PDPS-co-PDMS), and PDMS-co-polystyrene (PDMS-co-PS) copolymer in air and water have been investigated by sum frequency generation (SFG) vibrational spectroscopy. The SFG spectra collected from all PDMS surfaces in both air and water are dominated by methyl group stretches, indicating that all the surfaces are mainly covered by methyl groups. Other than surface-dominating methyl groups, some -Si-CH2-CH2- moieties on the Pt-PDMS surface have also been detected in air, which are present at cross-linking points. Information about the average orientation angle and angle distribution of the methyl groups on the PDMS surface has been evaluated. Surface restructuring of the methyl groups has been observed for all PDMS surfaces in water. Upon contacting water, the methyl groups on all PDMS surfaces tilt more toward the surface. The detailed restructuring behaviors of several PDMS surfaces in water and the effects of molecular weight on restructuring behaviors have been investigated. For comparison, in addition to air and water, surface structures of PDMS materials mentioned above in a nonpolar solvent, FC-75, have also been studied. By comparing the different response of phenyl groups to water on both PDPS-co-PDMS and PS-co-PDMS surfaces, we have demonstrated how the restructuring behaviors of surface phenyl groups are affected by the structural flexibility of the molecular chains where they are attached.

Surface water records of New Mexico, water year 1961

USGS Publications Warehouse

,

1962-01-01

The surface-water records for the 1961 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of New Mexico are given in this report. For convenience there are also included for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey, under the direction of W. L. Heckler, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water supply papers entitled "Surface Water Supply of the United States." Since 1951 there has been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports On a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey watersupply paper at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Surface water records of Colorado, 1961

USGS Publications Warehouse

U.S. Geological Survey, Water Resources Division

1961-01-01

The surface-water records for the 1961 water year for gaging stations and miscellaneous sites within the State of Colorado are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of W. T. Miller, district engineer, Surface Water Branch, succeeded by J. W. Odell.

Effect of water depth and water velocity upon the surfacing frequency of the bimodally respiring freshwater turtle, Rheodytes leukops.

PubMed

Gordos, Matthew A; Franklin, Craig E; Limpus, Colin J

2004-08-01

This study examines the effect of increasing water depth and water velocity upon the surfacing behaviour of the bimodally respiring turtle, Rheodytes leukops. Surfacing frequency was recorded for R. leukops at varying water depths (50, 100, 150 cm) and water velocities (5, 15, 30 cm s(-1)) during independent trials to provide an indirect cost-benefit analysis of aquatic versus pulmonary respiration. With increasing water velocity, R. leukops decreased its surfacing frequency twentyfold, thus suggesting a heightened reliance upon aquatic gas exchange. An elevated reliance upon aquatic respiration, which presumably translates into a decreased air-breathing frequency, may be metabolically more efficient for R. leukops compared to the expenditure (i.e. time and energy) associated with air-breathing within fast-flowing riffle zones. Additionally, R. leukops at higher water velocities preferentially selected low-velocity microhabitats, presumably to avoid the metabolic expenditure associated with high water flow. Alternatively, increasing water depth had no effect upon the surfacing frequency of R. leukops, suggesting little to no change in the respiratory partitioning of the species across treatment settings. Routinely long dives (>90 min) recorded for R. leukops indicate a high reliance upon aquatic O2 uptake regardless of water depth. Moreover, metabolic and temporal costs attributed to pulmonary gas exchange within a pool-like environment were likely minimal for R. leukops, irrespective of water depth.

Laser-assisted surface modification of Ti-implant in air and water environment

NASA Astrophysics Data System (ADS)

Trtica, M.; Stasic, J.; Batani, D.; Benocci, R.; Narayanan, V.; Ciganovic, J.

2018-01-01

A study of the surface modification of titanium CP grade 2 implant/target with high intensity picosecond (Nd:YAG) laser, operating at 1064 nm wavelength and pulse duration of 40 ps, in gaseous (air) and liquid (water) medium, is presented. The exposure of Ti to a laser pulse energy of 17 mJ in both media - gaseous and liquid, induced specific surface features and phenomena: (i) enhancement of the implant surface roughness (higher in water). In this context, the damage depth is more prominent in water (as high as ∼40 μm) vs. air (∼14 μm). Also, the appearance of laser induced periodic surface structures (LIPSS) is recorded in both media, at periphery area, while in water they are registered at lower pulse count; (ii) variation of chemical surface content depending on the applied medium. Thus, in the central irradiation region, the oxygen was absent in air while its concentration was relatively high (6.44 wt%) in case of water; (iii) possibility of direct collection of synthesized titanium based nanoparticles in water environment, and (iv) formation of the plasma above the sample in both mediums, more volumetrically confined in water. These investigations showed that surface structuring and observed phenomena are in strong correlation with the medium used. The liquid - water seems like the medium of choice in regard to titanium implant biocompatibility and bio-activity (the water is a favorable medium for build-up of the oxide layer which affects bioactivity). The process of laser interaction with titanium implant targets was accompanied by the formation of plasma plume, which provides the additional sterilizing effect facilitating contaminant-free conditions.

Water adsorption on the Fe3O4(111) surface: dissociation and network formation.

PubMed

Zaki, Eman; Mirabella, Francesca; Ivars-Barceló, Francisco; Seifert, Jan; Carey, Spencer; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Li, Xiaoke; Paier, Joachim; Sauer, Joachim

2018-06-13

We monitored adsorption of water on a well-defined Fe3O4(111) film surface at different temperatures as a function of coverage using infrared reflection-absorption spectroscopy, temperature programmed desorption, and single crystal adsorption calorimetry. Additionally, density functional theory was employed using a Fe3O4(111)-(2 × 2) slab model to generate 15 energy minimum structures for various coverages. Corresponding vibrational properties of the adsorbed water species were also computed. The results show that water molecules readily dissociate on regular surface Fetet1-O ion pairs to form "monomers", i.e., terminal Fe-OH and surface OH groups. Further water molecules adsorb on the hydroxyl covered surface non-dissociatively and form "dimers" and larger oligomers, which ultimately assemble into an ordered (2 × 2) hydrogen-bonded network structure with increasing coverage prior to the formation of a solid water film.

Aflatoxin toxicity reduction in feed by enhanced binding to surface-modified clay additives.

PubMed

Jaynes, William F; Zartman, Richard E

2011-06-01

Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (K(d) = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (K(d) = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (K(d) = 13,800) and carnitine (K(d) = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (K(d) = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (K(d) = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (K(d) = 1340) or the untreated montmorillonite (K(d) = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity.

Ions, metabolites, and cells: Water as a reporter of surface conditions during bacterial growth.

PubMed

Jarisz, Tasha A; Lane, Sarah; Gozdzialski, Lea; Hore, Dennis K

2018-06-14

Surface-specific nonlinear vibrational spectroscopy, combined with bulk solution measurements and imaging, is used to study the surface conditions during the growth of E. coli. As a result of the silica high surface charge density, the water structure at the silica-aqueous interface is known to be especially sensitive to pH and ionic strength, and surface concentration profiles develop that can be appreciably different from the bulk solution conditions. We illustrate that, in the presence of growing cells, a unique surface micro-environment is established as a result of metabolites accumulating on the silica surface. Even in the subsequent absence of the cells, this surface layer works to reduce the interfacial ionic strength as revealed by the enhanced signal from surface water molecules. In the presence of growing cells, an additional boost in surface water signal is attributed to a local pH that is higher than that of the bulk solution.

Ions, metabolites, and cells: Water as a reporter of surface conditions during bacterial growth

NASA Astrophysics Data System (ADS)

Jarisz, Tasha A.; Lane, Sarah; Gozdzialski, Lea; Hore, Dennis K.

2018-06-01

Surface-specific nonlinear vibrational spectroscopy, combined with bulk solution measurements and imaging, is used to study the surface conditions during the growth of E. coli. As a result of the silica high surface charge density, the water structure at the silica-aqueous interface is known to be especially sensitive to pH and ionic strength, and surface concentration profiles develop that can be appreciably different from the bulk solution conditions. We illustrate that, in the presence of growing cells, a unique surface micro-environment is established as a result of metabolites accumulating on the silica surface. Even in the subsequent absence of the cells, this surface layer works to reduce the interfacial ionic strength as revealed by the enhanced signal from surface water molecules. In the presence of growing cells, an additional boost in surface water signal is attributed to a local pH that is higher than that of the bulk solution.

Compositions of surface layers formed on amalgams in air, water, and saline.

PubMed

Hanawa, T; Gnade, B E; Ferracane, J L; Okabe, T; Watari, F

1993-12-01

The surface layers formed on both a zinc-free and a zinc-containing dental amalgam after polishing and aging in air, water, or saline, were characterized using x-ray photoelectron spectroscopy (XPS) to determine the compositions of the surface layers which might govern the release of mercury from amalgam. The XPS data revealed that the formation of the surface layer on the zinc-containing amalgam was affected by the environment in which the amalgam was polished and aged, whereas that on the zinc-free amalgam was not affected. In addition, among the elements contained in amalgam, zinc was the most reactive with the environment, and was preferentially dissolved from amalgam into water or saline. Mercury atoms existed in the metallic state in the surface layer.

Insight into Chemistry on Cloud/Aerosol Water Surfaces.

PubMed

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

Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions.

PubMed

Borchardt, Mark A; Haas, Nathaniel L; Hunt, Randall J

2004-10-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. (18)O/(16)O and (2)H/(1)H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.

Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions

USGS Publications Warehouse

Borchardt, M. A.; Haas, N.L.; Hunt, R.J.

2004-01-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/ 16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.

Investigating surface water-well interaction using stable isotope ratios of water

USGS Publications Warehouse

Hunt, R.J.; Coplen, T.B.; Haas, N.L.; Saad, D.A.; Borchardt, M. A.

2005-01-01

Because surface water can be a source of undesirable water quality in a drinking water well, an understanding of the amount of surface water and its travel time to the well is needed to assess a well's vulnerability. Stable isotope ratios of oxygen in river water at the City of La Crosse, Wisconsin, show peak-to-peak seasonal variation greater than 4??? in 2001 and 2002. This seasonal signal was identified in 7 of 13 city municipal wells, indicating that these 7 wells have appreciable surface water contributions and are potentially vulnerable to contaminants in the surface water. When looking at wells with more than 6 sampling events, a larger variation in ??18O compositions correlated with a larger fraction of surface water, suggesting that samples collected for oxygen isotopic composition over time may be useful for identifying the vulnerability to surface water influence even if a local meteoric water line is not available. A time series of ??18O from one of the municipal wells and from a piezometer located between the river and the municipal well showed that the travel time of flood water to the municipal well was approximately 2 months; non-flood arrival times were on the order of 9 months. Four independent methods were also used to assess time of travel. Three methods (groundwater temperature arrival times at the intermediate piezometer, virus-culture results, and particle tracking using a numerical groundwater-flow model) yielded flood and non-flood travel times of less than 1 year for this site. Age dating of one groundwater sample using 3H-3He methods estimated an age longer than 1 year, but was likely confounded by deviations from piston flow as noted by others. Chlorofluorocarbons and SF6 analyses were not useful at this site due to degradation and contamination, respectively. This work illustrates the utility of stable hydrogen and oxygen isotope ratios of water to determine the contribution and travel time of surface water in groundwater, and

Convergent surface water distributions in U.S. cities

Treesearch

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

DTIC Science & Technology

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

Simulation of ground-water flow, surface-water flow, and a deep sewer tunnel system in the Menomonee Valley, Milwaukee, Wisconsin

USGS Publications Warehouse

Dunning, C.P.; Feinstein, D.T.; Hunt, R.J.; Krohelski, J.T.

2004-01-01

Numerical models were constructed for simulation of ground-water flow in the Menomonee Valley Brownfield, in Milwaukee, Wisconsin. An understanding of ground-water flow is necessary to develop an efficient program to sample ground water for contaminants. Models were constructed in a stepwise fashion, beginning with a regional, single-layer, analytic-element model (GFLOW code) that provided boundary conditions for a local, eight layer, finite-difference model (MODFLOW code) centered on the Menomonee Valley Brownfield. The primary source of ground water to the models is recharge over the model domains; primary sinks for ground water within the models are surface-water features and the Milwaukee Metropolitan Sewerage District Inline Storage System (ISS). Calibration targets were hydraulic heads, surface-water fluxes, vertical gradients, and ground-water infiltration to the ISS. Simulation of ground-water flow by use of the MODFLOW model indicates that about 73 percent of recharge within the MODFLOW domain circulates to the ISS and 27 percent discharges to gaining surface-water bodies. In addition, infiltration to the ISS comes from the following sources: 36 percent from recharge within the model domain, 45 percent from lateral flow into the domain, 15 percent from Lake Michigan, and 4 percent from other surface-water bodies. Particle tracking reveals that the median traveltime from the recharge point to surface-water features is 8 years; the median time to the ISS is 255 years. The traveltimes to the ISS are least over the northern part of the valley, where dolomite is near the land surface. The distribution of traveltimes in the MODFLOW simulation is greatly influenced by the effective porosity values assigned to the various lithologies.

Interpreting contact angle results under air, water and oil for the same surfaces

NASA Astrophysics Data System (ADS)

Ozkan, Orkun; Yildirim Erbil, H.

2017-06-01

Under-water and under-oil superhydropobicity and superhydrophilicity have gained significant attention over the last few years. In this study, contact angles on five flat surfaces (polypropylene, poly(methyl methacrylate), polycarbonate, TEFLON-FEP and glass slide) were measured in water drop-in-air, air bubble-under-water, oil drop-in-air, air bubble-under-oil, oil drop-under-water and water drop-under-oil conditions. Heptane, octane, nonane, decane, dodecane, and hexadecane hydrocarbons were used as oils. Immiscible water/oil pairs were previously mutually saturated to provide thermodynamical equilibrium conditions and their surface and interfacial tensions were determined experimentally. These pairs were used in the two-liquid contact angle measurements. Surface free energies of the solid surfaces in air were determined independently by using the van Oss-Good method, using the contact angle results of pure water, ethylene glycol, formamide, methylene iodide and α-bromonaphalene. In addition, Zisman’s ‘critical surface tension’ values were also determined for comparison. In theory, the summation of contact angle results in a complementary case would give a total of 180° for ideal surfaces. However, it was determined that there are large deviations from this rule in practical cases and these deviations depend on surface free energies of solids. Three complementary cases of (water-in-air with air bubble-under-water); (oil-in-air with air bubble-under-oil); and (oil-under-water with water-under-oil) were investigated in particular to determine the deviations from ideality. A novel approach, named ‘complementary hysteresis’ [γ WA(cosθ 1  -  cosθ 2) and γ OW(cosθ 6  -  cosθ 5)] was developed where γ WA and γ OW represent the interfacial tensions of water/air and oil/water, and θ 1, θ 2, θ 5, and θ 6 were the contact angles of water/air, air bubble/water, oil/water and water/oil respectively. It was experimentally determined that

Surface-wave-sustained plasma torch for water treatment

NASA Astrophysics Data System (ADS)

Marinova, P.; Benova, E.; Todorova, Y.; Topalova, Y.; Yotinov, I.; Atanasova, M.; Krcma, F.

2018-02-01

In this study the effects of water treatment by surface-wave-sustained plasma torch at 2.45 GHz are studied. Changes in two directions are obtained: (i) changes of the plasma characteristics during the interaction with the water; (ii) water physical and chemical characteristics modification as a result of the plasma treatment. In addition, deactivation of Gram positive and Gram negative bacteria in suspension are registered. A number of charged and excited particles from the plasma interact with the water. As a result the water chemical and physical characteristics such as the water conductivity, pH, H2O2 concentration are modified. It is observed that the effect depends on the treatment time, wave power, and volume of the treated liquid. At specific discharge conditions determined by the wave power, gas flow, discharge tube radius, thickness and permittivity, the surface-wave-sustained discharge (SWD) operating at atmospheric pressure in argon is strongly non-equilibrium with electron temperature T e much higher than the temperature of the heavy particles (gas temperature T g). It has been observed that SWD argon plasma with T g close to the room temperature is able to produce H2O2 in the water with high efficiency at short exposure times (less than 60 sec). The H2O2 decomposition is strongly dependant on the temperature thus the low operating gas temperature is crucial for the H2O2 production efficiency. After scaling up the device, the observed effects can be applied for the waste water treatment in different facilities. The innovation will be useful especially for the treatment of waters and materials for medical application.

Geophysical characterisation of the groundwater-surface water interface

NASA Astrophysics Data System (ADS)

McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.

2017-11-01

Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.

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

NASA Astrophysics Data System (ADS)

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

Influence of mineral oil and additives on microhardness and surface chemistry of magnesium oxide (001) surface

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Shigaki, H.; Buckley, D. H.

1982-01-01

X-ray photoelectron spectroscopy analyses and hardness experiments were conducted with cleaved magnesium oxide /001/ surfaces. The magnesium oxide bulk crystals were cleaved into specimens along the /001/ surface, and indentations were made on the cleaved surface in laboratory air, in nitrogen gas, or in degassed mineral oil with and without an additive while not exposing specimen surface to any other environment. The various additives examined contained sulfur, phosphorus, chlorine, or oleic acid. The sulfur-containing additive exhibited the highest hardness and smallest dislocation patterns evidencing plastic deformation; the chlorine-containing additive exhibited the lowest hardness and largest dislocation patterns evidencing plastic deformation. Hydrocarbon and chloride (MgCl2) films formed on the magnesium oxide surface. A chloride film was responsible for the lowest measured hardness.

Water balance model for mean annual hydrogen and oxygen isotope distributions in surface waters of the contiguous United States

NASA Astrophysics Data System (ADS)

Bowen, Gabriel J.; Kennedy, Casey D.; Liu, Zhongfang; Stalker, Jeremy

2011-12-01

The stable H and O isotope composition of river and stream water records information on runoff sources and land-atmosphere water fluxes within the catchment and is a potentially powerful tool for network-based monitoring of ecohydrological systems. Process-based hydrological models, however, have thus far shown limited power to replicate observed large-scale variation in U.S. surface water isotope ratios. Here we develop a geographic information system-based model to predict long-term annual average surface water isotope ratios across the contiguous United States. We use elevation-explicit, gridded precipitation isotope maps as model input and data from a U.S. Geological Survey monitoring program for validation. We find that models incorporating monthly variation in precipitation-evapotranspiration (P-E) amounts account for the majority (>89%) of isotopic variation and have reduced regional bias relative to models that do not consider intra-annual P-E effects on catchment water balance. Residuals from the water balance model exhibit strong spatial patterning and correlations that suggest model residuals isolate additional hydrological signal. We use interpolated model residuals to generate optimized prediction maps for U.S. surface water δ2H and δ18O values. We show that the modeled surface water values represent a relatively accurate and unbiased proxy for drinking water isotope ratios across the United States, making these data products useful in ecological and criminal forensics applications that require estimates of the local environmental water isotope variation across large geographic regions.

Understanding surface-water availability in the Central Valley as a means to projecting future groundwater storage with climate variability

NASA Astrophysics Data System (ADS)

Goodrich, J. P.; Cayan, D. R.

2017-12-01

California's Central Valley (CV) relies heavily on diverted surface water and groundwater pumping to supply irrigated agriculture. However, understanding the spatiotemporal character of water availability in the CV is difficult because of the number of individual farms and local, state, and federal agencies involved in using and managing water. Here we use the Central Valley Hydrologic Model (CVHM), developed by the USGS, to understand the relationships between climatic variability, surface water inputs, and resulting groundwater use over the historical period 1970-2013. We analyzed monthly surface water diversion data from >500 CV locations. Principle components analyses were applied to drivers constructed from meteorological data, surface reservoir storage, ET, land use cover, and upstream inflows, to feed multiple regressions and identify factors most important in predicting surface water diversions. Two thirds of the diversion locations ( 80% of total diverted water) can be predicted to within 15%. Along with monthly inputs, representations of cumulative precipitation over the previous 3 to 36 months can explain an additional 10% of variance, depending on location, compared to results that excluded this information. Diversions in the southern CV are highly sensitive to inter-annual variability in precipitation (R2 = 0.8), whereby more surface water is used during wet years. Until recently, this was not the case in the northern and mid-CV, where diversions were relatively constant annually, suggesting relative insensitivity to drought. In contrast, this has important implications for drought response in southern regions (eg. Tulare Basin) where extended dry conditions can severely limit surface water supplies and lead to excess groundwater pumping, storage loss, and subsidence. In addition to fueling our understanding of spatiotemporal variability in diversions, our ability to predict these water balance components allows us to update CVHM predictions before

Synthesis, Surface Parameters, and Biodegradability of Water-soluble Surfactants for Various Applications.

PubMed

El-Sayed, Refat; Alotaibi, Hawazin H; Elhady, Heba A

2018-01-01

The synthesis of water-soluble heterocyclic compounds was verified on the basis of nonionic surfactants for use as surface-active agents. Surface characteristics such as surface and interfacial tensions, cloud point, wetting time, emulsion stability, foaming height and foaming stability were measured for these surface factors in aqueous solutions. In addition, the critical micelle concentration (CMC), the surface pressure at CMC (π cmc ), the effectiveness of surface tension reduction (pC 20 ), the maximum surface concentration (Γ ma. ) and the minimum area/molecule at the aqueous solution/air interface (A min ) were calculated. Moreover, the biodegradability for these nonionic surfactants has been investigated. Furthermore, the antimicrobial evaluation has been evaluated with some surfactants that have demonstrated a potent cytotoxicity as antibacterial, antifungal and anticancer. These surfactants have a good water solubility, low toxicity, environmentally friendly environment, high foam, good emulsifier and easy production that will be used them in various fields such as medical drugs, insecticides, detergents, emulsifiers, cosmetics, inks clothing, leather industry and oil recovery.

A molecular catalyst for water oxidation that binds to metal oxide surfaces

PubMed Central

Sheehan, Stafford W.; Thomsen, Julianne M.; Hintermair, Ulrich; Crabtree, Robert H.; Brudvig, Gary W.; Schmuttenmaer, Charles A.

2015-01-01

Molecular catalysts are known for their high activity and tunability, but their solubility and limited stability often restrict their use in practical applications. Here we describe how a molecular iridium catalyst for water oxidation directly and robustly binds to oxide surfaces without the need for any external stimulus or additional linking groups. On conductive electrode surfaces, this heterogenized molecular catalyst oxidizes water with low overpotential, high turnover frequency and minimal degradation. Spectroscopic and electrochemical studies show that it does not decompose into iridium oxide, thus preserving its molecular identity, and that it is capable of sustaining high activity towards water oxidation with stability comparable to state-of-the-art bulk metal oxide catalysts. PMID:25757425

The Dynamic Surface Tension of Water

PubMed Central

2017-01-01

The surface tension of water is an important parameter for many biological or industrial processes, and roughly a factor of 3 higher than that of nonpolar liquids such as oils, which is usually attributed to hydrogen bonding and dipolar interactions. Here we show by studying the formation of water drops that the surface tension of a freshly created water surface is even higher (∼90 mN m–1) than under equilibrium conditions (∼72 mN m–1) with a relaxation process occurring on a long time scale (∼1 ms). Dynamic adsorption effects of protons or hydroxides may be at the origin of this dynamic surface tension. However, changing the pH does not significantly change the dynamic surface tension. It also seems unlikely that hydrogen bonding or dipole orientation effects play any role at the relatively long time scale probed in the experiments. PMID:28301160

The Dynamic Surface Tension of Water.

PubMed

Hauner, Ines M; Deblais, Antoine; Beattie, James K; Kellay, Hamid; Bonn, Daniel

2017-04-06

The surface tension of water is an important parameter for many biological or industrial processes, and roughly a factor of 3 higher than that of nonpolar liquids such as oils, which is usually attributed to hydrogen bonding and dipolar interactions. Here we show by studying the formation of water drops that the surface tension of a freshly created water surface is even higher (∼90 mN m -1 ) than under equilibrium conditions (∼72 mN m -1 ) with a relaxation process occurring on a long time scale (∼1 ms). Dynamic adsorption effects of protons or hydroxides may be at the origin of this dynamic surface tension. However, changing the pH does not significantly change the dynamic surface tension. It also seems unlikely that hydrogen bonding or dipole orientation effects play any role at the relatively long time scale probed in the experiments.

Additively Manufactured and Surface Biofunctionalized Porous Nitinol.

PubMed

Gorgin Karaji, Z; Speirs, M; Dadbakhsh, S; Kruth, J-P; Weinans, H; Zadpoor, A A; Amin Yavari, S

2017-01-18

Enhanced bone tissue regeneration and improved osseointegration are among the most important goals in design of multifunctional orthopedic biomaterials. In this study, we used additive manufacturing (selective laser melting) to develop multifunctional porous nitinol that combines superelasticity with a rationally designed microarchitecture and biofunctionalized surface. The rational design based on triply periodic minimal surfaces aimed to properly adjust the pore size, increase the surface area (thereby amplifying the effects of surface biofunctionalization), and resemble the curvature characteristics of trabecular bone. The surface of additively manufactured (AM) porous nitinol was biofunctionalized using polydopamine-immobilized rhBMP2 for better control of the release kinetics. The actual morphological properties of porous nitinol measured by microcomputed tomography (e.g., open/close porosity, and surface area) closely matched the design values. The superelasticity originated from the austenite phase formed in the nitinol porous structure at room temperature. Polydopamine and rhBMP2 signature peaks were confirmed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy tests. The release of rhBMP2 continued until 28 days. The early time and long-term release profiles were found to be adjustable independent of each other. In vitro cell culture showed improved cell attachment, cell proliferation, cell morphology (spreading, spindle-like shape), and cell coverage as well as elevated levels of ALP activity and increased calcium content for biofunctionalized surfaces as compared to as-manufactured specimens. The demonstrated functionalities of porous nitinol could be used as a basis for deployable orthopedic implants with rationally designed microarchitectures that maximize bone tissue regeneration performance by release of biomolecules with adjustable and well-controlled release profiles.

Oil Contact Angles in a Water-Decane-Silicon Dioxide System: Effects of Surface Charge

NASA Astrophysics Data System (ADS)

Xu, Shijing; Wang, Jingyao; Wu, Jiazhong; Liu, Qingjie; Sun, Chengzhen; Bai, Bofeng

2018-04-01

Oil wettability in the water-oil-rock systems is very sensitive to the evolution of surface charges on the rock surfaces induced by the adsorption of ions and other chemical agents in water flooding. Through a set of large-scale molecular dynamics simulations, we reveal the effects of surface charge on the oil contact angles in an ideal water-decane-silicon dioxide system. The results show that the contact angles of oil nano-droplets have a great dependence on the surface charges. As the surface charge density exceeds a critical value of 0.992 e/nm2, the contact angle reaches up to 78.8° and the water-wet state is very apparent. The variation of contact angles can be confirmed from the number density distributions of oil molecules. With increasing the surface charge density, the adsorption of oil molecules weakens and the contact areas between nano-droplets and silicon dioxide surface are reduced. In addition, the number density distributions, RDF distributions, and molecular orientations indicate that the oil molecules are adsorbed on the silicon dioxide surface layer-by-layer with an orientation parallel to the surface. However, the layered structure of oil molecules near the silicon dioxide surface becomes more and more obscure at higher surface charge densities.

Oil Contact Angles in a Water-Decane-Silicon Dioxide System: Effects of Surface Charge.

PubMed

Xu, Shijing; Wang, Jingyao; Wu, Jiazhong; Liu, Qingjie; Sun, Chengzhen; Bai, Bofeng

2018-04-19

Oil wettability in the water-oil-rock systems is very sensitive to the evolution of surface charges on the rock surfaces induced by the adsorption of ions and other chemical agents in water flooding. Through a set of large-scale molecular dynamics simulations, we reveal the effects of surface charge on the oil contact angles in an ideal water-decane-silicon dioxide system. The results show that the contact angles of oil nano-droplets have a great dependence on the surface charges. As the surface charge density exceeds a critical value of 0.992 e/nm 2 , the contact angle reaches up to 78.8° and the water-wet state is very apparent. The variation of contact angles can be confirmed from the number density distributions of oil molecules. With increasing the surface charge density, the adsorption of oil molecules weakens and the contact areas between nano-droplets and silicon dioxide surface are reduced. In addition, the number density distributions, RDF distributions, and molecular orientations indicate that the oil molecules are adsorbed on the silicon dioxide surface layer-by-layer with an orientation parallel to the surface. However, the layered structure of oil molecules near the silicon dioxide surface becomes more and more obscure at higher surface charge densities.

First-principles study of water desorption from montmorillonite surface.

PubMed

Zhang, Yao; Meng, Yingfeng; Liu, Houbin; Yang, Mingli

2016-05-01

Knowledge about water desorption is important to give a full picture of water diffusion in montmorillonites (MMT), which is a driving factor in MMT swelling. The desorption paths and energetics of water molecules from the surface of MMT with trapped Li(+), Na(+) or K(+) counterions were studied using periodic density functional theory calculations. Two paths--surface and vacuum desorption--were designed for water desorption starting from a stationary structure in which water bonds with both the counterion and the MMT surface. Surface desorption is energetically more favorable than vacuum desorption due to water-surface hydrogen bonds that help stabilize the intermediate structure of water released from the counterion. The energy barriers of water desorption are in the order of Li(+) > Na(+) > K(+), which can be attributed to the short ionic radius of Li(+), which favors strong binding with the water molecule. The temperature dependence of water adsorption and desorption rates were compared based on the computed activation energies. Our calculations reveal that the water desorption on the MMT surface has a different mechanism from water adsorption, which results from surface effects favoring stabilization of water conformers during the desorption process.

40 CFR 258.27 - Surface water requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Surface water requirements. 258.27... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF... wetlands, that violates any requirements of the Clean Water Act, including, but not limited to, the...

40 CFR 258.27 - Surface water requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Surface water requirements. 258.27... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF... wetlands, that violates any requirements of the Clean Water Act, including, but not limited to, the...

40 CFR 258.27 - Surface water requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Surface water requirements. 258.27... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF... wetlands, that violates any requirements of the Clean Water Act, including, but not limited to, the...

Surface water records of Indiana, 1962

USGS Publications Warehouse

,

1962-01-01

The surface-water records for the 1962 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1963

USGS Publications Warehouse

,

1963-01-01

The surface-water records for the 1963 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1964

USGS Publications Warehouse

,

1964-01-01

The surface-water records for the 1964 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1961

USGS Publications Warehouse

,

1961-01-01

The surface-water records for the 1961 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Water structuring and collagen adsorption at hydrophilic and hydrophobic silicon surfaces.

PubMed

Cole, Daniel J; Payne, Mike C; Ciacchi, Lucio Colombi

2009-12-28

The adsorption of a collagen fragment on both a hydrophobic, hydrogen-terminated and a hydrophilic, natively oxidised Si surface is investigated using all-atom molecular dynamics. While favourable direct protein-surface interactions via localised contact points characterise adhesion to the hydrophilic surface, evenly spread surface/molecule contacts and stabilisation of the helical structure occurs upon adsorption on the hydrophobic surface. In the latter case, we find that adhesion is accompanied by a mutual fit between the hydrophilic/hydrophobic pattern within the protein and the layered water structure at the solid/liquid interface, which may provide an additional driving force to the classic hydrophobic effect.

High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.

PubMed

Steyer, Andrej; Torkar, Karmen Godič; Gutiérrez-Aguirre, Ion; Poljšak-Prijatelj, Mateja

2011-09-01

Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks

Vulnerability of Drinking-Water Wells in La Crosse, Wisconsin, to Enteric-Virus Contamination from Surface Water Contributions

PubMed Central

Borchardt, Mark A.; Haas, Nathaniel L.; Hunt, Randall J.

2004-01-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination. PMID:15466536

UHF RiverSonde observations of water surface velocity at Threemile Slough, California

USGS Publications Warehouse

Teague, C.C.; Barrick, D.E.; Lilleboe, P.M.; Cheng, R.T.; Ruhl, C.A.

2005-01-01

A UHF RiverSonde system, operating near 350 MHz, has been in operation at Threemile Slough in central California, USA since September 2004. The water in the slough is dominated by tidal effects, with flow reversals four times a day and a peak velocity of about 0.8 m/s in each direction. Water level and water velocity are continually measured by the U. S. Geological Survey at the experiment site. The velocity is measured every 15 minutes by an ultrasonic velocity meter (UVM) which determines the water velocity from two-way acoustic propagation time-difference measurements made across the channel. The RiverSonde also measures surface velocity every 15 minutes using radar resonant backscatter techniques. Velocity and water level data are retrieved through a radio data link and a wideband internet connection. Over a period of several months, the radar-derived mean surface velocity has been very highly correlated with the UVM index velocity several meters below the surface, with a coefficient of determination R2 of 0.976 and an RMS difference of less than 10 cm/s. The wind has a small but measurable effect on the velocities measured by both instruments. In addition to the mean surface velocity across the channel, the RiverSonde system provides an estimate of the cross-channel variation of the surface velocity. ?? 2005 IEEE.

Integrated Water Flow Model (IWFM), A Tool For Numerically Simulating Linked Groundwater, Surface Water And Land-Surface Hydrologic Processes

NASA Astrophysics Data System (ADS)

Dogrul, E. C.; Brush, C. F.; Kadir, T. N.

2006-12-01

The Integrated Water Flow Model (IWFM) is a comprehensive input-driven application for simulating groundwater flow, surface water flow and land-surface hydrologic processes, and interactions between these processes, developed by the California Department of Water Resources (DWR). IWFM couples a 3-D finite element groundwater flow process and 1-D land surface, lake, stream flow and vertical unsaturated-zone flow processes which are solved simultaneously at each time step. The groundwater flow system is simulated as a multilayer aquifer system with a mixture of confined and unconfined aquifers separated by semiconfining layers. The groundwater flow process can simulate changing aquifer conditions (confined to unconfined and vice versa), subsidence, tile drains, injection wells and pumping wells. The land surface process calculates elemental water budgets for agricultural, urban, riparian and native vegetation classes. Crop water demands are dynamically calculated using distributed soil properties, land use and crop data, and precipitation and evapotranspiration rates. The crop mix can also be automatically modified as a function of pumping lift using logit functions. Surface water diversions and groundwater pumping can each be specified, or can be automatically adjusted at run time to balance water supply with water demand. The land-surface process also routes runoff to streams and deep percolation to the unsaturated zone. Surface water networks are specified as a series of stream nodes (coincident with groundwater nodes) with specified bed elevation, conductance and stage-flow relationships. Stream nodes are linked to form stream reaches. Stream inflows at the model boundary, surface water diversion locations, and one or more surface water deliveries per location are specified. IWFM routes stream flows through the network, calculating groundwater-surface water interactions, accumulating inflows from runoff, and allocating available stream flows to meet specified or

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

PubMed

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.

Synopsis of ground-water and surface-water resources of North Dakota

USGS Publications Warehouse

Winter, T.C.; Benson, R.D.; Engberg, R.A.; Wiche, G.J.; Emerson, D.G.; Crosby, O.A.; Miller, J.E.

1984-01-01

This report describes the surface- and ground-water resources of North Dakota and the limitations of our understanding of these resources. Ground water and surface water are actually one resource, because they are often hydraulically interconnected. They are discussed separately for convenience. In general, the surface-water resources of the mainstem of the Missouri river are abundant and suitable for most uses. Other rivers may be important locally as water-supply sources, but the quantities of flow are small, quite variable in time, and generally of an unsuitable quality for most uses. Streamflow characteristics of North Dakota reflect its arid to semiarid climate (annual precipitation varies from 13 to 20 inches from west to east across the State), cold winters (usually including a significant snowpack available for spring snowmelt runoff), and the seasonal distribution of annual precipitation (almost 50 percent falls from Nky to July).Significant volumes of shallow ground water, of variable quality are found in the glacial-drift aquifers in parts of central, northern, and eastern North Dakota. Existing information provides only a limited capability to assess the long-term reliability of these scattered aquifers. There are significant indications, however, of water-quality problems related to sustained production of wells if long-term utilization of these aquifers is planned. A summary of the general suitability for use of surface water and ground water is given in Table E1.

On the merging of optical and SAR satellite imagery for surface water mapping applications

NASA Astrophysics Data System (ADS)

Markert, Kel N.; Chishtie, Farrukh; Anderson, Eric R.; Saah, David; Griffin, Robert E.

2018-06-01

Optical and Synthetic Aperture Radar (SAR) imagery from satellite platforms provide a means to discretely map surface water; however, the application of the two data sources in tandem has been inhibited by inconsistent data availability, the distinct physical properties that optical and SAR instruments sense, and dissimilar data delivery platforms. In this paper, we describe a preliminary methodology for merging optical and SAR data into a common data space. We apply our approach over a portion of the Mekong Basin, a region with highly variable surface water cover and persistent cloud cover, for surface water applications requiring dense time series analysis. The methods include the derivation of a representative index from both sensors that transforms data from disparate physical units (reflectance and backscatter) to a comparable dimensionless space applying a consistent water extraction approach to both datasets. The merging of optical and SAR data allows for increased observations in cloud prone regions that can be used to gain additional insight into surface water dynamics or flood mapping applications. This preliminary methodology shows promise for a common optical-SAR water extraction; however, data ranges and thresholding values can vary depending on data source, yielding classification errors in the resulting surface water maps. We discuss some potential future approaches to address these inconsistencies.

Water addition, evaporation and water holding capacity of poultry litter.

PubMed

Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

2015-12-15

Litter moisture content has been related to ammonia, dust and odour emissions as well as bird health and welfare. Improved understanding of the water holding properties of poultry litter as well as water additions to litter and evaporation from litter will contribute to improved litter moisture management during the meat chicken grow-out. The purpose of this paper is to demonstrate how management and environmental conditions over the course of a grow-out affect the volume of water A) applied to litter, B) able to be stored in litter, and C) evaporated from litter on a daily basis. The same unit of measurement has been used to enable direct comparison-litres of water per square metre of poultry shed floor area, L/m(2), assuming a litter depth of 5cm. An equation was developed to estimate the amount of water added to litter from bird excretion and drinking spillage, which are sources of regular water application to the litter. Using this equation showed that water applied to litter from these sources changes over the course of a grow-out, and can be as much as 3.2L/m(2)/day. Over a 56day grow-out, the total quantity of water added to the litter was estimated to be 104L/m(2). Litter porosity, water holding capacity and water evaporation rates from litter were measured experimentally. Litter porosity decreased and water holding capacity increased over the course of a grow-out due to manure addition. Water evaporation rates at 25°C and 50% relative humidity ranged from 0.5 to 10L/m(2)/day. Evaporation rates increased with litter moisture content and air speed. Maintaining dry litter at the peak of a grow-out is likely to be challenging because evaporation rates from dry litter may be insufficient to remove the quantity of water added to the litter on a daily basis. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Water adsorption on surface-modified cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Wei, Zonghui; Sinko, Robert; Keten, Sinan; Luijten, Erik

Cellulose nanocrystals (CNCs) have attracted much attention as a filler phase for polymer nanocomposites due to their impressive mechanical properties, low cost, and environmental sustainability. Despite their promise for this application, there are still numerous obstacles that prevent optimal performance of CNC-polymer nanocomposites, such as poor filler dispersion and high levels of water absorption. One way to mitigate these negative effects is to modify CNC surfaces. Computational approaches can be utilized to obtain direct insight into the properties of modified CNC surfaces and probe the interactions of CNCs with other materials to facilitate the experimental design of nanocomposites. We use atomistic grand-canonical Monte Carlo simulations to study how surface modification of ion-exchanged sulfated cellulose nanocrystals (Na-CNCs) impacts water adsorption. We find that methyl(triphenyl)phosphonium-exchanged CNCs adsorb less water than Na-CNCs at the same relative humidity, supporting recent experimental dynamic vapor sorption measurements. By characterizing the distribution and configuration of water molecules near the modified CNC surfaces we determine how surface modifications disrupt CNC-water interactions.

An ontology design pattern for surface water features

USGS Publications Warehouse

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.

Interaction of poly(ethylene-glycols) with air-water interfaces and lipid monolayers: investigations on surface pressure and surface potential.

PubMed Central

Winterhalter, M; Bürner, H; Marzinka, S; Benz, R; Kasianowicz, J J

1995-01-01

We have characterized the surface activity of different-sized poly(ethylene-glycols) (PEG; M(r) 200-100,000 Da) in the presence or absence of lipid monolayers and over a wide range of bulk PEG concentrations (10(-8)-10% w/v). Measurements of the surface potential and surface pressure demonstrate that PEGs interact with the air-water and lipid-water interfaces. Without lipid, PEG added either to the subphase or to the air-water interface forms relatively stable monolayers. Except for very low molecular weight polymers (PEGs < 1000 Da), low concentrations of PEG in the subphase (between 10(-5) and 10(-4)% w/v) increase the surface potential from zero (with respect to the potential of a pure air-water interface) to a plateau value of approximately 440 mV. At much higher polymer concentrations, > 10(-1)% (w/v), depending on the molecular weight of the PEG and corresponding to the concentration at which the polymers in solution are likely to overlap, the surface potential decreases. High concentrations of PEG in the subphase cause a similar decrease in the surface potential of densely packed lipid monolayers spread from either diphytanoyl phosphatidylcholine (DPhPC), dipalmitoyl phosphatidylcholine (DPPC), or dioleoyl phosphatidylserine (DOPS). Adding PEG as a monolayer at the air-water interface also affects the surface activity of DPhPC or DPPC monolayers. At low lipid concentration, the surface pressure and potential are determined by the polymer. For intermediate lipid concentrations, the surface pressure-area and surface potential-area isotherms show that the effects due to lipid and PEG are not always additive and that the polymer's effect is distinct for the two lipids. When PEG-lipid-mixed monolayers are compressed to surface pressures greater than the collapse pressure for a PEG monolayer, the surface pressure-area and surface potential-area isotherms approach that of the lipid alone, suggesting that for this experimental condition PEG is expelled from the

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

PubMed

de Jongh, Cindy M; Kooij, Pascal J F; de Voogt, Pim; ter Laak, Thomas L

2012-06-15

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 waters, river bank filtrates, two groundwater samples affected by surface water and drinking waters. In these samples, 12 pharmaceuticals and 7 transformation products were present. Concentrations were generally highest in surface waters, intermediate in treated surface waters and river bank filtrates and lowest or not detected in produced drinking water. However, the concentrations of phenazone and its environmental transformation product AMPH were significantly higher in river bank filtrates, which is likely due to historical contamination. Fairly constant ratios were observed between concentrations of transformation products and parent pharmaceuticals. This might enable prediction of concentrations of transformation products from concentrations of parent pharmaceuticals. The toxicological relevance of the observed pharmaceuticals and transformation products was assessed by deriving (i) a substance specific provisional guideline value (pGLV) and (ii) a group pGLV for groups of related compounds were under the assumption of additivity of effects within each group. A substantial margin exists between the maximum summed concentrations of these compounds present in different water types and the derived (group) pGLVs. Based on the results of this limited screening campaign no adverse health effects of the studied compounds are expected in (sources of) drinking water in the Netherlands. The presence of transformation products with similar pharmacological activities and concentration levels as their parents illustrates the relevance of monitoring transformation products, and including these in risk assessment. More thorough monitoring yielding information on statistical

Toward a mechanistic understanding of the effect of biochar addition on soil water retention

NASA Astrophysics Data System (ADS)

Yi, S.; Chang, N.; Guo, M.; Imhoff, P. T.

2014-12-01

Biochar (BC) is a carbon-rich product produced by thermal degradation of biomass in an oxygen-free environment, whose application to sediment is said to improve water retention. However, BC produced from different feedstocks and pyrolyzed at different temperatures have distinct properties, which may alter water retention in ways difficult to predict a priori. Our goal is to develop a mechanistic understanding of BC addition on water retention by examining the impact of BC from two feedstocks, poultry litter (PL) and hardwood (HW), on the soil-water retention curves (SWRC) of a uniform sand and a sandy loam (SL). For experiments with sand, BC and sand were sieved to the same particle size (~ 0.547 mm) to minimize effects of BC addition on particle size distribution. Experiments with SL contained the same sieved BC. PL and HW bicohars were added at 2 and 7% (w/w), and water retention was measured from 0 to -4.38 × 106 cm-H2O. Both BCs increased porosities for sand and SL, up to 39 and 13% for sand and SL, respectively, with 7% HW BC addition. The primary cause for these increases was the internal porosity of BC particles. While the matric potential for air-entry was unchanged with BC addition, BC amendment increased water retention for sand and SL in the capillary region (0 to -15,000 cm-H2O) by an average of 26 and 33 % for 7% PL and HW BC in sand, respectively, but only 7 and 14 % for 7% PL and HW BC in SL. The most dramatic influence of BC amendment on water retention occurred in the adsorption region (< -15,000 cm-H2O), where water retention increased by a factor of 11 and 22 for 7% PL and HW BC in sand, respectively, but by 140 and 190 % for 7% PL and HW BC in SL, respectively. The impact of BC on water retention in these sediments is explained primarily by the additional surface area and internal porosity of PL and HW BC particles. van Genuchten (VG) models were fitted to the water retention data. For SL where the impact of BC addition on water retention was

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

NASA Astrophysics Data System (ADS)

Malaguerra, F.; Albrechtsen, H.; Binning, P. J.

2010-12-01

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 data of a tracer experiment in a riparian zone. Three compounds were considered: an older pesticide MCPP (Mecoprop) which is mobile and persistent, glyphosate (Roundup), a new biodegradable and strongly sorbed pesticide, and its degradation product AMPA. Global sensitivity analysis using the method of Morris was employed to identify the dominant model parameters. Results showed that the presence of an aquitard and its characteristics (degree of fracturing and thickness), pollutant properties and well depth are the crucial factors affecting the risk of drinking water well contamination from surface water. Global sensitivity analysis results were compared with rank correlation statistics between pesticide concentrations and geological parameters derived from a comprehensive database of Danish drinking water wells. Aquitard thickness and well depth are the most critical parameters in both the model and observed data.

Mechanically durable underwater superoleophobic surfaces based on hydrophilic bulk metals for oil/water separation

NASA Astrophysics Data System (ADS)

Yu, Huadong; Lian, Zhongxu; Xu, Jinkai; Wan, Yanling; Wang, Zuobin; Li, Yiquan; Yu, Zhanjiang; Weng, Zhankun

2018-04-01

Despite the success of previous methods for fabricating underwater superoleophobic surfaces, most of the surfaces based on soft materials are prone to collapse and deformation due to their mechanically fragile nature, and they fail to perform their designed functions after the surface materials are damaged in water. In this work, the nanosecond laser-induced oxide coatings on hydrophilic bulk metals are reported which overcomes the limitation and shows the robust underwater superoleophobicity to a mechanical challenge encountered by surfaces deployed in water environment. The results show that the surface materials have the advantage that the underwater superoleophobicity is still preserved after the surfaces are scratched by knife or sandpaper and even completely destroyed because of the hydrophilic property of damaged materials in water. It is important that the results provide a guide for the design of durable underwater superoleophobic surfaces, and the development of superoleophobic materials in many potential applications such as the oil-repellent and the oil/water separation. Additionally, the nanosecond laser technology is simple, cost-effective and suitable for the large-area and mass fabrication of mechanically durable underwater superoleophobic metal materials.

Surface-Water Quality-Assurance Plan for the USGS Wisconsin Water Science Center

USGS Publications Warehouse

Garn, H.S.

2007-01-01

This surface-water quality-assurance plan documents the standards, policies, and procedures used by the Wisconsin Water Science Center of the U.S. Geological Survey, Water Resources Discipline, for activities related to the collection, processing, storage, analysis, management, and publication of surface-water data. The roles and responsibilities of Water Science Center personnel in following these policies and procedures including those related to safety and training are presented.

Roles of additives and surface control in slurry atomization. Final project report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, S.C.

1992-12-31

This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy atmore » 25{degrees}C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.« less

Surface-Water Data, Georgia, Water Year 1999

USGS Publications Warehouse

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

MODFLOW-based coupled surface water routing and groundwater-flow simulation

USGS Publications Warehouse

Hughes, Joseph D.; Langevin, Christian D.; White, Jeremy T.

2015-01-01

In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a simplified level-pool approach. SWR can account for surface water flow controlled by backwater conditions caused by small water-surface gradients or surface water control structures. A number of typical surface water control structures, such as culverts, weirs, and gates, can be represented, and it is possible to implement operational rules to manage surface water stages and streamflow. The nonlinear system of surface water flow equations formulated in SWR is solved by using Newton methods and direct or iterative solvers. SWR was tested by simulating the (1) Lal axisymmetric overland flow, (2) V-catchment, and (3) modified Pinder-Sauer problems. Simulated results for these problems compare well with other published results and indicate that SWR provides accurate results for surface water-only and coupled surface water/groundwater problems. Results for an application of SWR and MODFLOW to the Snapper Creek area of Miami-Dade County, Florida, USA are also presented and demonstrate the value of coupled surface water and groundwater simulation in managed, low-relief coastal settings.

A new device for collecting time-integrated water samples from springs and surface water bodies

USGS Publications Warehouse

Panno, S.V.; Krapac, I.G.; Keefer, D.A.

1998-01-01

A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.

Modeling surface-water flow and sediment mobility with the Multi-Dimensional Surface-Water Modeling System (MD_SWMS)

USGS Publications Warehouse

McDonald, Richard; Nelson, Jonathan; Kinzel, Paul; Conaway, Jeffrey S.

2006-01-01

The Multi-Dimensional Surface-Water Modeling System (MD_SWMS) is a Graphical User Interface for surface-water flow and sediment-transport models. The capabilities of MD_SWMS for developing models include: importing raw topography and other ancillary data; building the numerical grid and defining initial and boundary conditions; running simulations; visualizing results; and comparing results with measured data.

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

NASA Astrophysics Data System (ADS)

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

Water at protein surfaces studied with femtosecond nonlinear spectroscopy

NASA Astrophysics Data System (ADS)

Bakker, Huib J.

We report on an investigation of the structure and dynamics of water molecules near protein surfaces with femtosecond nonlinear spectroscopic techniques. We measured the reorientation dynamics of water molecules near the surface of several globular protein surfaces, using polarization-resolved femtosecond infrared spectroscopy. We found that water molecules near the protein surface have a much slower reorientation than water molecules in bulk liquid water. The number of slow water molecules scales scales with the size of the hydrophobic surface of the protein. When we denature the proteins by adding an increasing amount of urea to the protein solution, we observe that the water-exposed surface increases by 50% before the secondary structure of the proteins changes. This finding indicates that protein unfolding starts with the protein structure becoming less tight, thereby allowing water to enter. With surface vibrational sum frequency generation (VSFG) spectroscopy, we studied the structure of water at the surface of antifreeze protein III. The measured VSFG spectra showed the presence of ice-like water layers at the ice-binding site of the protein in aqueous solution, at temperatures well above the freezing point. This ordered ice-like hydration layers at the protein surface likely plays an important role in the specific recognition and binding of anti-freeze protein III to nascent ice crystallites, and thus in its anti-freeze mechanism. This research is supported by the ''Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO).

MODFLOW-Based Coupled Surface Water Routing and Groundwater-Flow Simulation.

PubMed

Hughes, J D; Langevin, C D; White, J T

2015-01-01

In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a simplified level-pool approach. SWR can account for surface water flow controlled by backwater conditions caused by small water-surface gradients or surface water control structures. A number of typical surface water control structures, such as culverts, weirs, and gates, can be represented, and it is possible to implement operational rules to manage surface water stages and streamflow. The nonlinear system of surface water flow equations formulated in SWR is solved by using Newton methods and direct or iterative solvers. SWR was tested by simulating the (1) Lal axisymmetric overland flow, (2) V-catchment, and (3) modified Pinder-Sauer problems. Simulated results for these problems compare well with other published results and indicate that SWR provides accurate results for surface water-only and coupled surface water/groundwater problems. Results for an application of SWR and MODFLOW to the Snapper Creek area of Miami-Dade County, Florida, USA are also presented and demonstrate the value of coupled surface water and groundwater simulation in managed, low-relief coastal settings. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

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

USGS Publications Warehouse

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

40 CFR 257.3-3 - Surface water.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 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...

40 CFR 257.3-3 - Surface water.

Code of Federal Regulations, 2010 CFR

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...

40 CFR 257.3-3 - Surface water.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true 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...

40 CFR 257.3-3 - Surface water.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 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...

40 CFR 257.3-3 - Surface water.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 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...

A Water Rich Mars Surface Mission Scenario

NASA Technical Reports Server (NTRS)

Hoffman, Stephen; Andrews, Alida; Joosten, Kent; Watts, Kevin

2017-01-01

The surface of Mars once had abundant water flowing on its surface, but now there is a general perception that this surface is completely dry. Several lines of research have shown that there are sources of potentially large quantities of water at many locations on the surface, including regions considered as candidates for future human missions. Traditionally, system designs for these human missions are constrained to tightly recycle water and oxygen, and current resource utilization strategies involve ascent vehicle oxidizer production only. But the assumption of relatively abundant extant water may change this. Several scenarios were constructed to evaluate water requirements for human Mars expeditions to assess the impact to system design if locally produced water is available. Specifically, we have assessed water resources needed for 1) ascent vehicle oxidizer and fuel production, 2) open-loop water and oxygen life support requirements along with more robust usage scenarios, and 3) crew radiation protection augmentation. In this assessment, production techniques and the associated chemistry to transform Martian water and atmosphere into these useful commodities are identified, but production mass and power requirements are left to future analyses. The figure below illustrates the type of water need assessment performed and that will be discussed. There have been several sources of feedstock material discussed in recent literature that could be used to produce these quantities of water. This paper will focus on Mars surface features that resemble glacier-like forms on Earth. Several lines of evidence indicate that some of these features are in fact buried ice, likely remnants from an earlier ice age on Mars. This paper examines techniques and hardware systems used in the polar regions of Earth to access this buried ice and withdraw water from it. These techniques and systems will be described to illustrate options available. A technique known as a Rodriguez Well

Estimating variations in global surface water storage

NASA Astrophysics Data System (ADS)

Lettenmaier, D. P.

2016-12-01

Arguably, the most dramatic advances attributable to remote sensing in the hydrologic sciences have involved the extension of knowledge about processes and state variables from the scale of field experiments to regions, continents, and the entire Earth. However, despite the availability of information about total terrestrial water storage over large areas provided by the Gravity Recovery and Climate Experiment (GRACE) mission, we still have remarkably little knowledge of the magnitude of freshwater stored at and near the land surface, and its temporal scales of variation. This is especially true with respect to freshwater storage in natural lakes and manmade reservoirs. Estimates of the amount of water that could be stored in artificial reservoirs are in the neighborhood of 15% of the mean annual runoff from the continents or around 7-8000 km3. However, while global reservoir storage was increasing through about 1980 due to filling of new reservoirs constructed in the second half of the 20th century, it is not even known whether aggregate usable reservoir storage is increasing or decreasing, due to sedimentation effects. With the advent of satellite altimeters (mostly intended to measure ocean surface topography and or the surface elevation of glaciers and ice sheets), along with improved methods for estimating space-time variations in the extent of surface waters, new opportunities have arisen to piece together estimates of storage variations of fractions approaching one-half of the global surface water storage, for periods approaching two decades in some cases. Although this ability is nascent, it offers encouragement that, with the launch of the planned Surface Water and Ocean Topography (SWOT) satellite mission in 2020, which has as a specific objective the measurement of surface water variations, climate-scale understanding of this source of variability in Earth's surface water balance may be at hand. I discuss specific examples of the technology and resulting

Ground- and Surface-Water Chemistry of Handcart Gulch, Park County, Colorado, 2003-2006

USGS Publications Warehouse

Verplanck, Philip L.; Manning, Andrew H.; Kimball, Briant A.; McCleskey, R. Blaine; Runkel, Robert L.; Caine, Jonathan S.; Adams, Monique; Gemery-Hill, Pamela A.; Fey, David L.

2008-01-01

As part of a multidisciplinary project to determine the processes that control ground-water chemistry and flow in mineralized alpine environments, ground- and surface-water samples from Handcart Gulch, Colorado were collected for analysis of inorganic solutes and water and dissolved sulfate stable isotopes in selected samples. The primary aim of this study was to document variations in ground-water chemistry in Handcart Gulch and to identify changes in water chemistry along the receiving stream of Handcart Gulch. Water analyses are reported for ground-water samples collected from 12 wells in Handcart Gulch, Colorado. Samples were collected between August 2003 and October 2005. Water analyses for surface-water samples are reported for 50 samples collected from Handcart Gulch and its inflows during a low-flow tracer injection on August 6, 2003. In addition, water analyses are reported for three other Handcart Gulch stream samples collected in September 2005 and March 2006. Reported analyses include field parameters (pH, specific conductance, temperature, dissolved oxygen, and Eh), major and trace constituents, oxygen and hydrogen isotopic composition of water and oxygen and sulfur isotopic composition of dissolved sulfate. Ground-water samples from this study are Ca-SO4 type and range in pH from 2.5 to 6.8. Most of the samples (75 percent) have pH values between 3.3 and 4.3. Surface water samples are also Ca-SO4 type and have a narrower range in pH (2.7?4.0). Ground- and surface-water samples vary from relatively dilute (specific conductance of 68 ?S/cm) to concentrated (specific conductance of 2,000 ?S/cm).

Water resources data for Kansas, water year 1972; Part 1, Surface water records

USGS Publications Warehouse

Thompson, M.L.; Curtis, R. E.

1973-01-01

Surface-water records for the 1972 water year for Kansas, including records of streamflow or reservoir storage at gaging stations and partial-record stations, are given in this report. The locations of the stations are on figures 1 and 2. Records for a few pertinent gaging stations in bordering States also are included. 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 Kansas. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey under the direction of C. W. Lane, district chief. Kansas district personnel who contributed significantly to the collection and preparation of data included in this report were: J. L. Ebling, C. 0. Geiger, K. D. Medina, L. E. Stuliken, C. 0. Peek, J. D. Craig, L. L. Jones, A. T. Klamm, J. P. Marshall, C. W. Kennedy, W. J. Carswell, D. L. Lacock, G. G. Quy II, J. T. Religa, R. D. Thomas, S. V. Bond, S. T. Green, C. G. Sauer, A. B. Evans, A. F. Browning, M. J. Goetz, M. L. Penny, and M. Pabst.Through September 30, 1960, the records of discharge and stage of streams and canals and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States."Beginning with the 1961 water year, surface-water records have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these reports is limited; they are designed primarily for rapid release of data shortly after the end of the water year to meet local needs. The discharge and reservoir storage records for 1961-65 also have been published in a Geological Survey water-supply paper series entitled "Surface Water Supply of the United States 1961-65."

Water resources data for Kansas, water year 1973; Part 1, Surface water records

USGS Publications Warehouse

Thompson, M.L.; Curtis, R. E.

1974-01-01

Surface-water records for the 1973 water year for Kansas, including records of streamflow or reservoir storage at gaging stations and partial-record stations, are given in this report. The locations of the stations are on figures 1 and 2. Records for a few pertinent gaging stations in bordering States also are included. 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 Kansas. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey under the direction of C. W. Lane, district chief. Kansas district personnel who contributed significantly to the collection and preparation of data included in this report were: J. L. Ebling, C. 0. Geiger, K. D. Medina, C. 0. Peek, J. D. Craig, L. L. Jones, J. P. Marshall, W. J. Carswell, D. L. Lacock, G. G. Quy II, J. T. Religa, R. D. Thomas, S. V. Bond, S. T. Green, C. G. Sauer, L. M. Pope, F. D. Toepfer, A. F. Browning, M. L. Penny, M. Pabst, and L. R. Stringer.Through September 30, 1960, the records of discharge and stage of streams and canals and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States."Beginning with the 1961 water year, surface-water records have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these reports is limited; they are designed primarily for rapid release of data shortly after the end of the water year to meet local needs. The discharge and reservoir storage records for 1961-65 also have been published in a Geological Survey water-supply paper series entitled "Surface Water Supply of the United States 1961-65."

Hydrochemical and environmental isotope analysis of groundwater and surface water in a dry mountain region in Northern Chile.

PubMed

Zang, Carina; Dame, Juliane; Nüsser, Marcus

2018-05-08

This case study examines the geological imprint and land use practices on water quality in the arid Huasco Valley against the backdrop of ongoing water conflicts surrounding competing demands for agriculture and mining. The study is based on a detailed analysis of spatial and temporal variations of monthly surface and bi-monthly groundwater quality samples measured during the Chilean summer of 2015/16. Additional information on source regions and river-groundwater interactions were collected using stable water isotopes. Regarding the geological impact on water quality, high concentrations of Ca 2+ , SO 4 2- and HCO 3 - indicate a strong influence of magmatic rocks, which constitute this high mountain basin, on the hydrochemistry. Piper and Gibbs-diagrams revealed that all samples show a homogenous distribution dominated by rock-water interactions. Measured NO 3 - concentrations in surface water are generally low. However, groundwater aquifers exhibit higher concentrations. Mn is the only heavy metal with elevated concentrations in surface water, which are possibly related to mining activities. The results illustrate that both surface and groundwater can be classified as suitable for irrigation. In addition, groundwater has been found to be suitable as drinking water. High similarities in isotopic signatures indicate a strong connection between surface and groundwater. Isotopic analyses suggest a strong influence of evaporation. This combined approach of hydrogeochemical and isotopic analysis proved to be a helpful tool in characterizing the catchment and can serve as a basis for future sustainable water management.

The glass-liquid transition of water on hydrophobic surfaces

NASA Astrophysics Data System (ADS)

Souda, Ryutaro

2008-09-01

Interactions of thin water films with surfaces of graphite and vitrified room-temperature ionic liquid [1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6])] were investigated using time-of-flight secondary ion mass spectrometry as a function of temperature and annealing time to elucidate the glass-liquid transition of water at the molecular level. Surface diffusion of water occurs at temperatures higher than 120K, thereby forming three-dimensional clusters (a two-dimensional layer) on the [bmim][PF6] (graphite) surface. The hydrophobic effect of the surface decreases with increasing coverage of water; the bulklike properties evolve up to 40 ML, as evidenced by the occurrence of film dewetting at around the conventional glass transition temperature (140K). Results also showed that aging is necessary for the water monolayer (a 40 ML water film) to dewet the graphite ([bmim][PF6]) surface. The occurrence of aging is explainable by the successive evolution of two distinct liquids during the glass-liquid transition: low density liquid is followed by supercooled liquid water. The water monolayer on graphite is characterized by the preferred orientation of unpaired OH groups toward the surface; this structure is arrested during the aging time despite the occurrence of surface diffusion. However, the water monolayer formed on the [bmim][PF6] surface agglomerates immediately after the commencement of surface diffusion. The structure of low density liquid tends to be arrested by the attractive interaction with the neighbors.

Water resources data, Idaho, 2004; Volume 2. Surface water records for Upper Columbia River basin and Great Basin below King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2005-01-01

Water resources data for the 2004 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 209 stream-gaging stations and 8 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 39 stream-gaging stations and partial record sites, 3 lakes sites, and 395 groundwater wells; and water levels for 425 observation network wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Phoebe: A Surface Dominated by Water

NASA Astrophysics Data System (ADS)

Fraser, Wesley C.; Brown, Michael E.

2018-07-01

The Saturnian irregular satellite, Phoebe, can be broadly described as a water-rich rock. This object, which presumably originated from the same primordial population shared by the dynamically excited Kuiper Belt Objects (KBOs), has received high-resolution spectral imaging during the Cassini flyby. We present a new analysis of the Visual Infrared Mapping Spectrometer observations of Phoebe, which critically, includes a geometry correction routine that enables pixel-by-pixel mapping of visible and infrared spectral cubes directly onto the Phoebe shape model, even when an image exhibits significant trailing errors. The result of our re-analysis is a successful match of 46 images, producing spectral maps covering the majority of Phoebe’s surface, roughly a third of which is imaged by high-resolution observations (<22 km per pixel resolution). There is no spot on Phoebe’s surface that is absent of water absorption. The regions richest in water are clearly associated with the Jason and south pole impact basins. Phoebe exhibits only three spectral types, and a water–ice concentration that correlates with physical depth and visible albedo. The water-rich and water-poor regions exhibit significantly different crater size frequency distributions and different large crater morphologies. We propose that Phoebe once had a water-poor surface whose water–ice concentration was enhanced by basin-forming impacts that exposed richer subsurface layers. The range of Phoebe’s water–ice absorption spans the same range exhibited by dynamically excited KBOs. The common water–ice absorption depths and primordial origins, and the association of Phoebe’s water-rich regions with its impact basins, suggests the plausible idea that KBOs also originated with water-poor surfaces that were enhanced through stochastic collisional modification.

Innovative Technique for High-Accuracy Remote Monitoring of Surface Water

NASA Astrophysics Data System (ADS)

Gisler, A.; Barton-Grimley, R. A.; Thayer, J. P.; Crowley, G.

2016-12-01

Lidar (light detection and ranging) provides absolute depth and topographic mapping capability compared to other remote sensing methods, which is useful for mapping rapidly changing environments such as riverine systems and agricultural waterways. Effectiveness of current lidar bathymetric systems is limited by the difficulty in unambiguously identifying backscattered lidar signals from the water surface versus the bottom, limiting their depth resolution to 0.3-0.5 m. Additionally these are large, bulky systems that are constrained to expensive aircraft-mounted platforms and use waveform-processing techniques requiring substantial computation time. These restrictions are prohibitive for many potential users. A novel lidar device has been developed that allows for non-contact measurements of water depth down to 1 cm with an accuracy and precision of < 1 cm by exploiting the polarization properties of the light-surface interaction. This system can transition seamlessly from ranging over land to shallow to deep water allowing for shoreline charting, measuring water volume, mapping bottom topology, and identifying submerged objects. The scalability of the technique opens up the ability for handheld or UAS-mounted lidar bathymetric systems, which provides for potential applications currently unavailable to the community. The high laser pulse repetition rate allows for very fine horizontal resolution while the photon-counting technique permits real-time depth measurement and object detection. The enhanced measurement capability, portability, scalability, and relatively low-cost creates the opportunity to perform frequent high-accuracy monitoring and measuring of aquatic environments which is crucial for monitoring water resources on fast timescales. Results from recent campaigns measuring water depth in flowing creeks and murky ponds will be presented which demonstrate that the method is not limited by rough water surfaces and can map underwater topology through

Water resources data, Idaho, 2003; Volume 1. Surface water records for Great Basin and Snake River basin above King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2004-01-01

Water resources data for the 2003 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 208 stream-gaging stations and 14 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 50 stream-gaging stations and partial record sites, 3 lakes sites, and 398 groundwater wells; and water levels for 427 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Water resources data, Idaho, 2004; Volume 1. Surface water records for Great Basin and Snake River basin above King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2005-01-01

Water resources data for the 2004 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 209 stream-gaging stations and 8 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 39 stream-gaging stations and partial record sites, 3 lakes sites, and 395 groundwater wells; and water levels for 425 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

40 CFR 258.27 - Surface water requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Surface water requirements. 258.27 Section 258.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF...

A Review of Surface Water Quality Models

PubMed Central

Li, Shibei; Jia, Peng; Qi, Changjun; Ding, Feng

2013-01-01

Surface water quality models can be useful tools to simulate and predict the levels, distributions, and risks of chemical pollutants in a given water body. The modeling results from these models under different pollution scenarios are very important components of environmental impact assessment and can provide a basis and technique support for environmental management agencies to make right decisions. Whether the model results are right or not can impact the reasonability and scientificity of the authorized construct projects and the availability of pollution control measures. We reviewed the development of surface water quality models at three stages and analyzed the suitability, precisions, and methods among different models. Standardization of water quality models can help environmental management agencies guarantee the consistency in application of water quality models for regulatory purposes. We concluded the status of standardization of these models in developed countries and put forward available measures for the standardization of these surface water quality models, especially in developing countries. PMID:23853533

Water Resources Data, Florida, Water Year 2003 Volume 2A: South Florida Surface Water

USGS Publications Warehouse

Price, C.; Woolverton, J.; Overton, K.

2004-01-01

Water resources data for 2003 water year in Florida consists of continuous or daily discharge for 385 streams, periodic discharge for 13 streams, continuous or daily stage for 255 streams, periodic stage for 13 stream, peak discharge for 36 streams, and peak stage for 36 streams, continuous or daily elevations for 13 lakes, periodic elevations for 46 lakes, continuous ground-water levels for 441 wells, periodic ground-water levels for 1227 wells, quality of water data for 133 surface-water sites, and 308 wells. The data for South Florida included continuous or daily discharge for 72 streams, continuous or daily stage for 50 streams, no peak stage discharge for streams, 1 continuous elevation for lake, continuous ground-water levels for 237 wells, periodic ground-water levels for 248 wells, water quality for 25 surface-water sites, and 161 wells. These data represent the National Water Data System records collected by the U.S. Geological Survey and cooperation with local, state, and federal agencies in Florida.

Membrane bioreactor for the drinking water treatment of polluted surface water supplies.

PubMed

Li, Xiao-yan; Chu, Hiu Ping

2003-11-01

A laboratory membrane bioreactor (MBR) using a submerged polyethylene hollow-fibre membrane module with a pore size of 0.4 microm and a total surface area of 0.2 m2 was used for treating a raw water supply slightly polluted by domestic sewage. The feeding influent had a total organic carbon (TOC) level of 3-5 mg/L and an ammonia nitrogen (NH(3)-N) concentration of 3-4 mg/L. The MBR ran continuously for more than 500 days, with a hydraulic retention time (HRT) as short as 1h or less. Sufficient organic degradation and complete nitrification were achieved in the MBR effluent, which normally had a TOC of less than 2 mg/L and a NH(3)-N of lower than 0.2 mg/L. The process was also highly effective for eliminating conventional water impurities, as demonstrated by decreases in turbidity from 4.50+/-1.11 to 0.08+/-0.03 NTU, in total coliforms from 10(5)/mL to less than 5/mL and in UV(254) absorbance from 0.098+/-0.019 to 0.036+/-0.007 cm(-1). With the MBR treatment, the 3-day trihalomethane formation potential (THMFP) was significantly reduced from 239.5+/-43.8 to 60.4+/-23.1 microg/L. The initial chlorine demand for disinfection decreased from 22.3+/-5.1 to 0.5+/-0. 1mg/L. The biostability of the effluent improved considerably as the assimilable organic carbon (AOC) decreased from 134.5+/-52.7 to 25.3+/-19.9 microg/L. All of these water quality parameters show the superior quality of the MBR-treated water, which was comparable to or even better than the local tap water. Molecular size distribution analysis and the hydrophobic characterisation of the MBR effluent, in comparison to the filtered liquor from the bioreactor, suggest that the MBR had an enhanced filtration mechanism. A sludge layer on the membrane surface could have functioned as an additional barrier to the passage of typical THM precursors, such as large organic molecules and hydrophobic compounds. These results indicate that the MBR with a short HRT could be developed as an effective biological water

Global modelling of Cryptosporidium in surface water

NASA Astrophysics Data System (ADS)

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

The physics of water droplets on surfaces: exploring the effects of roughness and surface chemistry

NASA Astrophysics Data System (ADS)

Eid, K. F.; Panth, M.; Sommers, A. D.

2018-03-01

This paper explores the fluid property commonly called surface tension, its effect on droplet shape and contact angle, and the major influences of contact angle behaviour (i.e. surface roughness and surface chemistry). Images of water droplets placed on treated copper surfaces are used to measure the contact angles between the droplets and the surface. The surface wettability is manipulated either by growing a self-assembled monolayer on the surface to make it hydrophobic or by changing the surface roughness. The main activities in this experiment, then, are (1) preparing and studying surfaces with different surface wettability and roughness; (2) determining the shape and contact angles of water droplets on these surfaces; and (3) demonstrating the spontaneous motion of water droplets using surface tension gradients.

Surface water records of New Mexico, water year 1963

USGS Publications Warehouse

,

1964-01-01

This report is the third in a series presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States". Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5- year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Streaks Of Colored Water Indicate Surface Airflows

NASA Technical Reports Server (NTRS)

Wilcox, Floyd J., Jr.

1994-01-01

Response faster and contamination less than in oil-flow technique. Flowing colored water provides accurate and clean way to reveal flows of air on surfaces of models in wind tunnels. Colored water flows from small orifices in model, forming streak lines under influence of air streaming over surface of model.

Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid

PubMed Central

Van Dijk, Tessa C.; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

2013-01-01

Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001) between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l−1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l−1 (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. PMID:23650513

The influence of compost addition on the water repellency of brownfield soils

NASA Astrophysics Data System (ADS)

Whelan, Amii; Kechavarzi, Cedric; Sakrabani, Ruben; Coulon, Frederic; Simmons, Robert; Wu, Guozhong

2010-05-01

Compost application to brownfield sites, which can facilitate the stabilisation and remediation of contaminants whilst providing adequate conditions for plant growth, is seen as an opportunity to divert biodegradable wastes from landfill and put degraded land back into productive use. However, although compost application is thought to improve soil hydraulic functioning, there is a lack of information on the impact of large amounts of compost on soil water repellency. Water repellency in soils is attributed to the accumulation of hydrophobic organic compounds released as root exudates, fungal and microbial by-products and decomposition of organic matter. It has also been shown that brownfield soils contaminated with petroleum-derived organic contaminants can exhibit strong water repellency, preventing the rapid infiltration of water and leading potentially to surface run off and erosion of contaminated soil. However, hydrophobic organic contaminants are known to become sequestrated by partitioning into organic matter or diffusing into nano- and micropores, making them less available over time (ageing). The effect of large amounts of organic matter addition through compost application on the water repellency of soils contaminated with petroleum-derived organic contaminants requires further investigation. We characterised the influence of compost addition on water repellency in the laboratory by measuring the Water Drop Penetration Time (WDPT), sorptivity and water repellency index through infiltration experiments on soil samples amended with two composts made with contrasting feedstocks (green waste and predominantly meat waste). The treatments consisted of a sandy loam, a clay loam and a sandy loam contaminated with diesel fuel and aged for 3 years, which were amended with the two composts at a rate equivalent to 750t/ha. In addition core samples collected from a brownfield site, amended with compost at three different rates (250, 500 and 750t/ha) in 2007, were

Emission of dimers from a free surface of heated water

NASA Astrophysics Data System (ADS)

Bochkarev, A. A.; Polyakova, V. I.

2014-09-01

The emission rate of water dimers from a free surface and a wetted solid surface in various cases was calculated by a simplified Monte Carlo method with the use of the binding energy of water molecules. The binding energy of water molecules obtained numerically assuming equilibrium between the free surface of water and vapor in the temperature range of 298-438 K corresponds to the coordination number for liquid water equal to 4.956 and is close to the reference value. The calculation results show that as the water temperature increases, the free surface of water and the wetted solid surface become sources of free water dimers. At a temperature of 438 K, the proportion of dimers in the total flow of water molecules on its surface reaches 1%. It is found that in the film boiling mode, the emission rate of dimers decreases with decreasing saturation vapor. Two mechanisms of the emission are described.

Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting.

PubMed

Varadhan, Purushothaman; Fu, Hui-Chun; Priante, Davide; Retamal, Jose Ramon Duran; Zhao, Chao; Ebaid, Mohamed; Ng, Tien Khee; Ajia, Idirs; Mitra, Somak; Roqan, Iman S; Ooi, Boon S; He, Jr-Hau

2017-03-08

Hydrogen production via photoelectrochemical water-splitting is a key source of clean and sustainable energy. The use of one-dimensional nanostructures as photoelectrodes is desirable for photoelectrochemical water-splitting applications due to the ultralarge surface areas, lateral carrier extraction schemes, and superior light-harvesting capabilities. However, the unavoidable surface states of nanostructured materials create additional charge carrier trapping centers and energy barriers at the semiconductor-electrolyte interface, which severely reduce the solar-to-hydrogen conversion efficiency. In this work, we address the issue of surface states in GaN nanowire photoelectrodes by employing a simple and low-cost surface treatment method, which utilizes an organic thiol compound (i.e., 1,2-ethanedithiol). The surface-treated photocathode showed an enhanced photocurrent density of -31 mA/cm 2 at -0.2 V versus RHE with an incident photon-to-current conversion efficiency of 18.3%, whereas untreated nanowires yielded only 8.1% efficiency. Furthermore, the surface passivation provides enhanced photoelectrochemical stability as surface-treated nanowires retained ∼80% of their initial photocurrent value and produced 8000 μmol of gas molecules over 55 h at acidic conditions (pH ∼ 0), whereas the untreated nanowires demonstrated only <4 h of photoelectrochemical stability. These findings shed new light on the importance of surface passivation of nanostructured photoelectrodes for photoelectrochemical applications.

40 CFR 258.27 - Surface water requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Surface water requirements. 258.27 Section 258.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF units shall not: (a) Cause a discharge of...

Structure and stability of pyrophyllite edge surfaces: Effect of temperature and water chemical potential

NASA Astrophysics Data System (ADS)

Kwon, Kideok D.; Newton, Aric G.

2016-10-01

regardless of the water chemical potential. The equilibrium morphology of pyrophyllite crystals is also expected to be dependent on these two environmental variables. Surface defects may impact the surface reactivity. We discuss the thermodynamic stability of a possible Si cation vacancy defect which provides additional hydroxyl group on the surface.

Water resources data, Idaho, 2003; Volume 2. Surface water records for Upper Columbia River basin and Great Basin below King Hill

USGS Publications Warehouse

Brennan, T.S.; Lehmann, A.K.; O'Dell, I.

2004-01-01

Water resources data for the 2003 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 208 stream-gaging stations and 14 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 50 stream-gaging stations and partial record sites, 3 lakes sites, and 398 groundwater wells; and water levels for 427 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

Desert Beetle-Inspired Superwettable Patterned Surfaces for Water Harvesting.

PubMed

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.

Leaching of additives from construction materials to urban storm water runoff.

PubMed

Burkhardt, M; Zuleeg, S; Vonbank, R; Schmid, P; Hean, S; Lamani, X; Bester, K; Boller, M

2011-01-01

Urban water management requires further clarification about pollutants in storm water. Little is known about the release of organic additives used in construction materials and the impact of these compounds to storm water runoff. We investigated sources and pathways of additives used in construction materials, i.e., biocides in facades' render as well as root protection products in bitumen membranes for rooftops. Under wet-weather conditions, the concentrations of diuron, terbutryn, carbendazim, irgarol 1051 (all from facades) and mecoprop in storm water and receiving water exceeded the predicted no-effect concentrations values and the Swiss water quality standard of 0.1 microg/L. Under laboratory conditions maximum concentrations of additives were in the range of a few milligrams and a few hundred micrograms per litre in runoff of facades and bitumen membranes. Runoff from aged materials shows approximately one to two orders of magnitude lower concentrations. Concentrations decreased also during individual runoff events. In storm water and receiving water the occurrence of additives did not follow the typical first flush model. This can be explained by the release lasting over the time of rainfall and the complexity of the drainage network. Beside the amounts used, the impact of construction materials containing hazardous additives on water quality is related clearly to the age of the buildings and the separated sewer network. The development of improved products regarding release of hazardous additives is the most efficient way of reducing the pollutant load from construction materials in storm water runoff.

Effect of polymerization technique and glass fiber addition on the surface roughness and hardness of PMMA denture base material.

PubMed

Gad, Mohammed M; Rahoma, Ahmed; Al-Thobity, Ahmad M

2018-06-20

The current study evaluated the effects of autoclave polymerization both with and without glass fiber (GF) reinforcement on the surface roughness and hardness of acrylic denture base material. Ninety disc specimens (30×2.5 mm) were prepared from Vertex resin and divided according to polymerization techniques into a water bath, short and long autoclave polymerization groups. Tested groups were divided into three subgroups according to the GF concentration (0, 2.5, and 5 wt%). Profilometer and Vickers hardness tests were performed to measure surface roughness and hardness. ANOVA and Tukey-Kramer multiple comparison tests analyzed the results, and p≤0.05 was considered statistically significant. Autoclave polymerization significantly decreased the surface roughness and increased the hardness of acrylic resin without GF reinforcement (p<0.05). However, 5 wt% GF addition significantly increased surface roughness and decreased hardness of the autoclave polymerized denture base resin (p<0.05). Surface properties of Polymethyl methacrylate (PMMA) denture base material improved with autoclave polymerization and negatively affected with GFs addition.

Pharmaceuticals and personal care products (PPCPs) in surface and treated waters of Louisiana, USA and Ontario, Canada.

PubMed

Boyd, Glen R; Reemtsma, Helge; Grimm, Deborah A; Mitra, Siddhartha

2003-07-20

A newly developed analytical method was used to measure concentrations of nine pharmaceuticals and personal care products (PPCPs) in samples from two surface water bodies, a sewage treatment plant effluent and various stages of a drinking water treatment plant in Louisiana, USA, and from one surface water body, a drinking water treatment plant and a pilot plant in Ontario, Canada. The analytical method provides for simultaneous extraction and quantification of the following broad range of PPCPs and endocrine-disrupting chemicals: naproxen; ibuprofen; estrone; 17beta-estradiol; bisphenol A; clorophene; triclosan; fluoxetine; and clofibric acid. Naproxen was detected in Louisiana sewage treatment plant effluent at 81-106 ng/l and Louisiana and Ontario surface waters at 22-107 ng/l. Triclosan was detected in Louisiana sewage treatment plant effluent at 10-21 ng/l. Of the three surface waters sampled, clofibric acid was detected in Detroit River water at 103 ng/l, but not in Mississippi River or Lake Pontchartrain waters. None of the other target analytes were detected above their method detection limits. Based on results at various stages of treatment, conventional drinking-water treatment processes (coagulation, flocculation and sedimentation) plus continuous addition of powdered activated carbon at a dosage of 2 mg/l did not remove naproxen from Mississippi River waters. However, chlorination, ozonation and dual media filtration processes reduced the concentration of naproxen below detection in Mississippi River and Detroit River waters and reduced clofibric acid in Detroit River waters. Results of this study demonstrate that existing water treatment technologies can effectively remove certain PPCPs. In addition, our study demonstrates the importance of obtaining data on removal mechanisms and byproducts associated with PPCPs and other endocrine-disrupting chemicals in drinking water and sewage treatment processes.

Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives

PubMed Central

Wang, Hongdong; Liu, Yuhong; Chen, Zhe; Wu, Bibo; Xu, Sailong; Luo, Jianbin

2016-01-01

High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application. PMID:26951794

Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives.

PubMed

Wang, Hongdong; Liu, Yuhong; Chen, Zhe; Wu, Bibo; Xu, Sailong; Luo, Jianbin

2016-03-08

High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application.

Water Resources Data, Florida, Water Year 2003, Volume 1A: Northeast Florida Surface Water

USGS Publications Warehouse

,

2004-01-01

Water resources data for the 2003 water year in Florida consist of continuous or daily discharge for 385 streams, periodic discharge for 13 streams, continuous or daily stage for 255 streams, periodic stage for 13 streams, peak stage and discharge for 36 streams; continuous or daily elevations for 13 lakes, periodic elevations for 46 lakes; continuous ground-water levels for 441 wells, periodic ground-water levels for 1,227 wells; quality-of-water data for 133 surface-water sites and 308 wells. The data for northeast Florida include continuous or daily discharge for 138 streams, periodic discharge for 3 streams, continuous or daily stage for 61 streams, periodic stage for 0 streams; peak stage and discharge for 0 streams; continuous or daily elevations for 9 lakes, periodic elevations for 20 lakes; continuous ground water levels for 73 wells, periodic groundwater levels for 543 wells; quality-of-water data for 43 surface-water sites and 115 wells. These data represent the National Water Data System records collected by the U.S. Geological Survey and cooperating local, State and Federal agencies in Florida.

Sectoral contributions to surface water stress in the coterminous United States

NASA Astrophysics Data System (ADS)

Averyt, K.; Meldrum, J.; Caldwell, P.; Sun, G.; McNulty, S.; Huber-Lee, A.; Madden, N.

2013-09-01

Here, we assess current stress in the freshwater system based on the best available data in order to understand possible risks and vulnerabilities to regional water resources and the sectors dependent on freshwater. We present watershed-scale measures of surface water supply stress for the coterminous United States (US) using the water supply stress index (WaSSI) model which considers regional trends in both water supply and demand. A snapshot of contemporary annual water demand is compared against different water supply regimes, including current average supplies, current extreme-year supplies, and projected future average surface water flows under a changing climate. In addition, we investigate the contributions of different water demand sectors to current water stress. On average, water supplies are stressed, meaning that demands for water outstrip natural supplies in over 9% of the 2103 watersheds examined. These watersheds rely on reservoir storage, conveyance systems, and groundwater to meet current water demands. Overall, agriculture is the major demand-side driver of water stress in the US, whereas municipal stress is isolated to southern California. Water stress introduced by cooling water demands for power plants is punctuated across the US, indicating that a single power plant has the potential to stress water supplies at the watershed scale. On the supply side, watersheds in the western US are particularly sensitive to low flow events and projected long-term shifts in flow driven by climate change. The WaSSI results imply that not only are water resources in the southwest in particular at risk, but that there are also potential vulnerabilities to specific sectors, even in the ‘water-rich’ southeast.

Hydrophilic directional slippery rough surfaces for water harvesting

PubMed Central

Sun, Nan; Nielsen, Steven O.; Wang, Jing

2018-01-01

Multifunctional surfaces that are favorable for both droplet nucleation and removal are highly desirable for water harvesting applications but are rare. Inspired by the unique functions of pitcher plants and rice leaves, we present a hydrophilic directional slippery rough surface (SRS) that is capable of rapidly nucleating and removing water droplets. Our surfaces consist of nanotextured directional microgrooves in which the nanotextures alone are infused with hydrophilic liquid lubricant. We have shown through molecular dynamics simulations that the physical origin of the efficient droplet nucleation is attributed to the hydrophilic surface functional groups, whereas the rapid droplet removal is due to the significantly reduced droplet pinning of the directional surface structures and slippery interface. We have further demonstrated that the SRS, owing to its large surface area, hydrophilic slippery interface, and directional liquid repellency, outperforms conventional liquid-repellent surfaces in water harvesting applications. PMID:29670942

The Interaction of Water with Solid Surfaces: Fundamental Aspects Revisited

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, Michael A.

2002-05-01

Water is perhaps the most important and most pervasive chemical on our planet. The influence of water permeates virtually all areas of biochemical, chemical and physical importance, and is especially evident in phenomena occurring at the interfaces of solid surfaces. Since 1987, when Thiel and Madey (TM) published their review titled "The Interaction of Water with Solid Surfaces: Fundamental Aspects" in Surface Science Reports, there has been considerable progress made in further understanding the fundamental interactions of water with solid surfaces. In the decade and a half, the increased capability of surface scientists to probe at the molecular-level has resultedmore » in more detailed information of the properties of water on progressively more complicated materials and under more stringent conditions. This progress in understanding the properties of water on solid surfaces is evident both in areas for which surface science methodology has traditionally been strong (catalysis and electronic materials) and also in new areas not traditionally studied by surface scientists, such as electrochemistry, photoconversion, mineralogy, adhesion, sensors, atmospheric chemistry, and tribology. Researchers in all these fields grapple with very basic questions regarding the interactions of water with solid surfaces, such as how is water adsorbed, what are the chemical and electrostatic forces that constitute the adsorbed layer, how is water thermally or non-thermally activated, and how do coadsorbates influence these properties of water. The attention paid to these and other fundamental questions in the past decade and a half has been immense. In this review, experimental studies published since the TM review are assimilated with those covered by TM to provide a current picture of the fundamental interactions of water with solid surfaces.« less

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

PubMed

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.

A framework for modeling connections between hydraulics, water surface roughness, and surface reflectance in open channel flows

USGS Publications Warehouse

Legleiter, Carl; Mobley, Curtis D.; Overstreet, Brandon

2017-01-01

This paper introduces a framework for examining connections between the flow field, the texture of the air-water interface, and the reflectance of the water surface and thus evaluating the potential to infer hydraulic information from remotely sensed observations of surface reflectance. We used a spatial correlation model describing water surface topography to illustrate the application of our framework. Nondimensional relations between model parameters and flow intensity were established based on a prior flume study. Expressing the model in the spatial frequency domain allowed us to use an efficient Fourier transform-based algorithm for simulating water surfaces. Realizations for both flume and field settings had water surface slope distributions positively correlated with velocity and water surface roughness. However, most surface facets were gently sloped and thus unlikely to yield strong specular reflections; the model exaggerated the extent of water surface features, leading to underestimation of facet slopes. A ray tracing algorithm indicated that reflectance was greatest when solar and view zenith angles were equal and the sensor scanned toward the Sun to capture specular reflections of the solar beam. Reflected energy was concentrated in a small portion of the sky, but rougher water surfaces reflected rays into a broader range of directions. Our framework facilitates flight planning to avoid surface-reflected radiance while mapping other river attributes, or to maximize this component to exploit relationships between hydraulics and surface reflectance. This initial analysis also highlighted the need for improved models of water surface topography in natural rivers.

Influence of water on the surface of graphene

NASA Astrophysics Data System (ADS)

Kaya, Yunus; Kalkan, Yalçin; Veenhof, Rob

2018-02-01

We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT) with the B3LYP hybrid functional combined with the 6-31G(d) basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

Summary of surface-water quality, ground-water quality, and water withdrawals for the Spirit Lake Reservation, North Dakota

USGS Publications Warehouse

Vining, Kevin C.; Cates, Steven W.

2006-01-01

Available surface-water quality, ground-water quality, and water-withdrawal data for the Spirit Lake Reservation were summarized. The data were collected intermittently from 1948 through 2004 and were compiled from U.S. Geological Survey databases, North Dakota State Water Commission databases, and Spirit Lake Nation tribal agencies. Although the quality of surface water on the reservation generally is satisfactory, no surface-water sources are used for consumable water supplies. Ground water on the reservation is of sufficient quality for most uses. The Tokio and Warwick aquifers have better overall water quality than the Spiritwood aquifer. Water from the Spiritwood aquifer is used mostly for irrigation. The Warwick aquifer provides most of the consumable water for the reservation and for the city of Devils Lake. Annual water withdrawals from the Warwick aquifer by the Spirit Lake Nation ranged from 71 million gallons to 122 million gallons during 2000-04.

Wetlands inform how climate extremes influence surface water expansion and contraction

USGS Publications Warehouse

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

NASA Astrophysics Data System (ADS)

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

The impact of land use on microbial surface water pollution.

PubMed

Schreiber, Christiane; Rechenburg, Andrea; Rind, Esther; Kistemann, Thomas

2015-03-01

Our knowledge relating to water contamination from point and diffuse sources has increased in recent years and there have been many studies undertaken focusing on effluent from sewage plants or combined sewer overflows. However, there is still only a limited amount of microbial data on non-point sources leading to diffuse pollution of surface waters. In this study, the concentrations of several indicator micro-organisms and pathogens in the upper reaches of a river system were examined over a period of 16 months. In addition to bacteria, diffuse pollution caused by Giardia lamblia and Cryptosporidium spp. was analysed. A single land use type predestined to cause high concentrations of all microbial parameters could not be identified. The influence of different land use types varies between microbial species. The microbial concentration in river water cannot be explained by stable non-point effluent concentrations from different land use types. There is variation in the ranking of the potential of different land use types resulting in surface water contamination with regard to minimum, median and maximum effects. These differences between median and maximum impact indicate that small-scale events like spreading manure substantially influence the general contamination potential of a land use type and may cause increasing micro-organism concentrations in the river water by mobilisation during the next rainfall event. Copyright © 2014 Elsevier GmbH. All rights reserved.

Methylmercury photodegradation in surface water of the Florida Everglades: importance of dissolved organic matter-methylmercury complexation.

PubMed

Tai, Chao; Li, Yanbin; Yin, Yongguang; Scinto, Leonard J; Jiang, Guibin; Cai, Yong

2014-07-01

Photodegradation is the major pathway of methylmercury (MeHg) degradation in many surface waters. However, the mechanism of MeHg photodegradation is still not completely understood. Dissolved organic matter (DOM) is expected to play a critical role in MeHg photodegradation. By using several techniques, including N2/O2 purging and the addition of stable isotope (Me(201)Hg), scavengers, competing ligands, and a singlet oxygen ((1)O2) generator, the role played by MeHg-DOM complexation in MeHg photodegradation of Everglades surface water was investigated. DOM appeared to be involved in MeHg photodegradation via the formation MeHg-DOM complexes based on three findings: (1) MeHg was quickly photodegraded in solutions containing DOM extracts; (2) degradation of MeHg did not occur in deionized water; and (3) addition of competing complexation reagents (dithiothreitol-DTT) dramatically prohibited the photodegradation of MeHg in Everglades water. Further experiments indicated that free radicals/reactive oxygen species, including hydroxyl radical (·OH), (1)O2, triplet excited state of DOM ((3)DOM*), and hydrated electron (e(-)aq), played a minor role in MeHg photodegradation in Everglades water, based on the results of scavenger addition, (1)O2 generator addition and N2/O2 purging. A pathway, involving direct photodegradation of MeHg-DOM complexes via intramolecular electron transfer, is proposed as the dominant mechanism for MeHg photodegradation in Everglades water.

Impact of surface water withdrawals on water storage variations under a changing climate

NASA Astrophysics Data System (ADS)

Ashraf, B.; AghaKouchak, A.; Mousavi Baygi, M.; Alizadeh, A.; Moftakhari, H.; Miao, C.; Arab, D. R.; Anjileli, H.

2016-12-01

Quantitative evaluation of water storage variations in large river basins is an important element of water management, especially in a climate change. In addition, human water use has developed into another strong driver of water storage changes especially in densely populated semiarid and arid areas. In this study, we estimate the normalized human outflow of the thirty main basins in Iran during the past three decades. Then, we investigate the individual and combined effects of climate variability and human water withdrawals on surface water storage in the 21st century in four major basins (Urmia, Karkheh, Karun and Jarrahi) located in semi-arid areas of Iran. These basins are selected because they experienced medium to high human-induced water demand in last decades. We use bias-corrected historical simulations and future projections from 26 General Circulation Models (GCMs) and three climate change scenarios RCP2.6, RCP4.5, RCP8.5). The results show that humans have strongly impacted the water balances of most basins in Iran, dominating potential climate change impacts in the historical period. In fact, the main reason for water scarcity in these regions appears to be due to the increased anthropogenic water demand resulting from substantial socio-economic growth in the past three decades. Furthermore, by the end of the 21st century, the compounding effects of increased irrigation water demand and precipitation variability may lead to severe local water scarcity in these basins. Our study highlights the need to improve our understanding of the hydrologic responses to anthropogenic perturbations, and local water resource management decisions.

Intermittent Surface Water Connectivity: Fill and Spill vs. Fill ...

EPA Pesticide Factsheets

Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

Intermittent Surface Water Connectivity: Fill and Spill Vs. Fill ...

EPA Pesticide Factsheets

Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

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

NASA Astrophysics Data System (ADS)

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.

Surface Water and Energy Budgets for Sub-Saharan Africa in GFDL Coupled Climate Model

NASA Astrophysics Data System (ADS)

Tian, D.; Wood, E. F.; Vecchi, G. A.; Jia, L.; Pan, M.

2015-12-01

This study compare surface water and energy budget variables from the Geophysical Fluid Dynamics Laboratory (GFDL) FLOR models with the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR), Princeton University Global Meteorological Forcing Dataset (PGF), and PGF-driven Variable Infiltration Capacity (VIC) model outputs, as well as available observations over the sub-Saharan Africa. The comparison was made for four configurations of the FLOR models that included FLOR phase 1 (FLOR-p1) and phase 2 (FLOR-p2) and two phases of flux adjusted versions (FLOR-FA-p1 and FLOR-FA-p2). Compared to p1, simulated atmospheric states in p2 were nudged to the Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. The seasonal cycle and annual mean of major surface water (precipitation, evapotranspiration, runoff, and change of storage) and energy variables (sensible heat, ground heat, latent heat, net solar radiation, net longwave radiation, and skin temperature) over a 34-yr period during 1981-2014 were compared in different regions in sub-Saharan Africa (West Africa, East Africa, and Southern Africa). In addition to evaluating the means in three sub-regions, empirical orthogonal functions (EOFs) analyses were conducted to compare both spatial and temporal characteristics of water and energy budget variables from four versions of GFDL FLOR, NCEP CFSR, PGF, and VIC outputs. This presentation will show how well each coupled climate model represented land surface physics and reproduced spatiotemporal characteristics of surface water and energy budget variables. We discuss what caused differences in surface water and energy budgets in land surface components of coupled climate model, climate reanalysis, and reanalysis driven land surface model. The comparisons will reveal whether flux adjustment and nudging would improve depiction of the surface water and energy budgets in coupled climate models.

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

PubMed

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.

Water Resources Data, Florida, Water Year 2003, Volume 3A: Southwest Florida Surface Water

USGS Publications Warehouse

Kane, R.L.; Fletcher, W.L.

2004-01-01

Water resources data for the 2003 water year in Florida consist of continuous or daily discharges for 385 streams, periodic discharge for 13 streams, continuous daily stage for 255 streams, periodic stage for 13 streams, peak stage for 36 streams and peak discharge for 36 streams, continuous or daily elevations for 13 lakes, periodic elevations for 46 lakes; continuous ground-water levels for 441 wells, periodic ground-water levels for 1,227 wells, and quality-of-water data for 133 surface-water sites and 308 wells. The data for Southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 103 streams, periodic discharge for 7 streams, continuous or daily stage for 67 streams, periodic stage for 13 streams, peak stage and discharge for 8 streams, continuous or daily elevations for 2 lakes, periodic elevations for 26 lakes, and quality-of-water data for 62 surface-water sites. These data represent the national Water Data System records collected by the U.S. Geological Survey and cooperating local, state, and federal agencies in Florida.

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

NASA Astrophysics Data System (ADS)

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

Assesment of pesticide fluxes to surface water using Uranine in Colombia

NASA Astrophysics Data System (ADS)

Garcia-Santos, G.; Scheiben, D.; Diaz, J.; Leuenberger, F.; Binder, C. R.

2009-04-01

In the highlands of Colombia, potato farmers maximize their yields by the application of pesticides. Properly applied pesticides can significantly reduce yield loss and improve product quality; however their misuse leads to human health and environmental problems, i.e. water bodies contaminated with pesticides. Due to the lack of control regarding local pesticide use, unmeasured hydrological parameters and use of local water runoff as a drinking water supply, an assessment of the impact of agricultural practice on water quality is mandatory as first stage. In order to accomplish this, our study assesses pesticide fluxes to surface water using the tracer Uranine. The experimental area La Hoya main basin (3 km2) contains the Pantano Verde river which flows into the Teatinos river in the Boyaca region (Colombia). Some facts such as the deep soils in the area and the importance of the unsaturated zone for the sorption and degradation of pesticides suggest a lack of contaminants in groundwater. However, due to the humid conditions, steep slopes and an intensive agricultural with high pesticide use, we expect surface water to be highly contaminated. In order to assess pesticide pathways, a tracer (Uranine), detectable at very low amount was used. Four local farmers applied the tracer instead of the pesticide mixture covering a total surface of 1.2 10-2 km2. Meteorological data were measured every 15 min with one compact meteorological station installed within the basin and water flow and water sampling were obtained using an ISCO-6700 water sampler, during one week every 10 min in the outlet of Pantano Verde River. In addition, three pairs of membranes were installed down the river and collected 1 week, one month and 4 months after the experiment to measure tracer accumulation. The tracer in water was analysed using a fluorescent spectrometer. Results of this study show first variations of tracer concentration in water in La Hoya basin and constitute an initial steep in

Water resources data, Iowa, water year 2001, Volume 2. surface water--Missouri River basin, and ground water

USGS Publications Warehouse

Nalley, G.M.; Gorman, J.G.; Goodrich, R.D.; Miller, V.E.; Turco, M.J.; Linhart, S.M.

2002-01-01

The Water Resources Division of the U.S. Geological Survey, in cooperation with State, county, municipal, and other Federal agencies, obtains a large amount of data pertaining to the water resources of Iowa each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make this data readily available to interested parties outside of the Geological Survey, the data is published annually in this report series entitled “Water Resources Data - Iowa” as part of the National Water Data System. Water resources data for water year 2001 for Iowa consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water quality of ground water. This report, in two volumes, contains stage or discharge records for 132 gaging stations; stage records for 9 lakes and reservoirs; water-quality records for 4 gaging stations; sediment records for 13 gaging stations; and water levels for 163 ground-water observation wells. Also included are peak-flow data for 92 crest-stage partial-record stations, water-quality data from 86 municipal wells, and precipitation data collected at 6 gaging stations and 2 precipitation sites. Additional water data were collected at various sites not included in the systematic data-collection program, and are published here as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating local, State, and Federal agencies in Iowa.Records of discharge or stage of streams, and contents or stage of lakes and reservoirs were first published in a series of U.S. Geological Survey water-supply papers entitled “Surface Water Supply of the United States.” Through September 30, 1960, these water-supply papers were published in an annual series; during 1961-65 and 1966-70, they

The Role of Surface Water Flow in Gas Fluxes from a Subtropical Rice Field

NASA Astrophysics Data System (ADS)

Huynh, K. T.; Suvocarev, K.; Reavis, C.; Runkle, B.; Variano, E. A.

2016-12-01

Wetlands are the single largest source of methane emissions, but the underlying processes behind this flux are not yet fully understood. Typically, methane fluxes from wetlands have been attributed to ebullition (bubbling) and to transport through vegetation. However, a third major pathway-hydrodynamic transport-has been seen in a temperate wetland in the Sacramento-San Joaquin Delta. We wish to explore whether this additional pathway is also important to a subtropical rice paddy site where the diel thermal cycle is less pronounced than in the temperate site. Measurements in the surface water of a rice field were collected over two weeks. Specific measurements collected included dissolved and atmospheric methane concentration, surface water velocity, and air and water temperature. These were used to augment a long-term dataset of micrometeorology and gas fluxes. Together, these data demonstrate the role that surface water motions play in the fluxes between soil and atmosphere. Data are analyzed to reveal the fraction of total methane flux that is governed by advective/diffusive transport through surface water, and daily cycles in this behavior. Results will be used to advance predictions of atmospheric methane gas concentrations and could be foundational for developing methane management solutions. Closing this gap in knowledge is key to improving calculations of current global greenhouse gas emissions.

High-Frequency Focused Water-Coupled Ultrasound Used for Three-Dimensional Surface Depression Profiling

NASA Technical Reports Server (NTRS)

Roth, Don J.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

2001-01-01

To interface with other solids, many surfaces are engineered via methods such as plating, coating, and machining to produce a functional surface ensuring successful end products. In addition, subsurface properties such as hardness, residual stress, deformation, chemical composition, and microstructure are often linked to surface characteristics. Surface topography, therefore, contains the signatures of the surface and possibly links to volumetric properties, and as a result serves as a vital link between surface design, manufacturing, and performance. Hence, surface topography can be used to diagnose, monitor, and control fabrication methods. At the NASA Glenn Research Center, the measurement of surface topography is important in developing high-temperature structural materials and for profiling the surface changes of materials during microgravity combustion experiments. A prior study demonstrated that focused air-coupled ultrasound at 1 MHz could profile surfaces with a 25-m depth resolution and a 400-m lateral resolution over a 1.4-mm depth range. In this work, we address the question of whether higher frequency focused water-coupled ultrasound can improve on these specifications. To this end, we employed 10- and 25-MHz focused ultrasonic transducers in the water-coupled mode. The surface profile results seen in this investigation for 25-MHz water-coupled ultrasound, in comparison to those for 1-MHz air-coupled ultrasound, represent an 8 times improvement in depth resolution (3 vs. 25 m seen in practice), an improvement of at least 2 times in lateral resolution (180 vs. 400 m calculated and observed in practice), and an improvement in vertical depth range of 4 times (calculated).

A GPU-based mipmapping method for water surface visualization

NASA Astrophysics Data System (ADS)

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.

Thermodynamic properties of water solvating biomolecular surfaces

NASA Astrophysics Data System (ADS)

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.

Evaluation of automated urban surface water extraction from Sentinel-2A imagery using different water indices

NASA Astrophysics Data System (ADS)

Yang, Xiucheng; Chen, Li

2017-04-01

Urban surface water is characterized by complex surface continents and small size of water bodies, and the mapping of urban surface water is currently a challenging task. The moderate-resolution remote sensing satellites provide effective ways of monitoring surface water. This study conducts an exploratory evaluation on the performance of the newly available Sentinel-2A multispectral instrument (MSI) imagery for detecting urban surface water. An automatic framework that integrates pixel-level threshold adjustment and object-oriented segmentation is proposed. Based on the automated workflow, different combinations of visible, near infrared, and short-wave infrared bands in Sentinel-2 image via different water indices are first compared. Results show that object-level modified normalized difference water index (MNDWI with band 11) and automated water extraction index are feasible in urban surface water mapping for Sentinel-2 MSI imagery. Moreover, comparative results are obtained utilizing optimal MNDWI from Sentinel-2 and Landsat 8 images, respectively. Consequently, Sentinel-2 MSI achieves the kappa coefficient of 0.92, compared with that of 0.83 from Landsat 8 operational land imager.

Water surface locomotion in tropical canopy ants.

PubMed

Yanoviak, S P; Frederick, D N

2014-06-15

Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants. © 2014. Published by The Company of Biologists Ltd.

Surface nanobubble nucleation dynamics during water-ethanol exchange

NASA Astrophysics Data System (ADS)

Chan, Chon U.; Ohl, Claus-Dieter

2015-11-01

Water-ethanol exchange has been a promising nucleation method for surface attached nanobubbles since their discovery. In this process, water and ethanol displace each other sequentially on a substrate. As the gas solubility is 36 times higher in ethanol than water, it was suggested that the exchange process leads to transient supersaturation and is responsible for the nanobubble nucleation. In this work, we visualize the nucleation dynamics by controllably mixing water and ethanol. It depicts the temporal evolution of the conventional exchange in a single field of view, detailing the conditions for surface nanobubble nucleation and the flow field that influences their spatial organization. This technique can also pattern surface nanobubbles with variable size distribution.

Water surface elevation from the upcoming SWOT mission under different flows conditions

NASA Astrophysics Data System (ADS)

Domeneghetti, Alessio; Schumann, Guy J. P.; Wei, Rui; Frasson, Renato P. M.; Durand, Michael; Pavelsky, Tamlin; Castellarin, Attilio; Brath, Armando

2017-04-01

The upcoming SWOT (Surface Water and Ocean Topography) satellite mission will provide unprecedented bi-dimensional observations of terrestrial water surface heights along rivers wider than 100m. Despite the literature reports several activities showing possible uses of SWOT products, potential and limitations of satellite observations still remain poorly understood and investigated. We present one of the first analyses regarding the spatial observation of water surface elevation expected from SWOT for a 140 km reach of the middle-lower portion of the Po River, in Northern Italy. The river stretch is characterized by a main channel varying from 100-500 m in width and a floodplain delimited by a system of major embankments that can be as wide as 5 km. The reconstruction of the hydraulic behavior of the Po River is performed by means of a quasi-2D model built with detailed topographic and bathymetric information (LiDAR, 2m resolution), while the simulation of remotely sensed hydrometric data is performed with a SWOT simulator that mimics the satellite sensor characteristics. Referring to water surface elevations associated with different flow conditions (maximum, minimum and average flow) this work characterizes the spatial observations provided by SWOT and highlights the strengths and limitations of the expected products. The analysis provides a robust reference for spatial water observations that will be available from SWOT and assesses possible effects of river embankments, river width and river topography under different hydraulic conditions. Results of the study characterize the expected accuracy of the upcoming SWOT mission and provide additional insights towards the appropriate exploitation of future hydrological observations.

Surface water records of Texas, 1964

USGS Publications Warehouse

,

1965-01-01

The surface-water records for the 1964 water year for gaging stations, partial-record stations, miscellaneous sites, and base-flow studies within the State of Texas are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey, under the direction of Trigg Twichell, district chief, Water Resources Division. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water supply papers, entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Texas were contained in Parts 7 and 8 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs. Records will be published in Geological Survey water-supply papers at 5-year intervals.

Hydrogen generation due to water splitting on Si - terminated 4H-Sic(0001) surfaces

NASA Astrophysics Data System (ADS)

Li, Qingfang; Li, Qiqi; Yang, Cuihong; Rao, Weifeng

2018-02-01

The chemical reactions of hydrogen gas generation via water splitting on Si-terminated 4H-SiC surfaces with or without C/Si vacancies were studied by using first-principles. We studied the reaction mechanisms of hydrogen generation on the 4H-SiC(0001) surface. Our calculations demonstrate that there are major rearrangements in surface when H2O approaches the SiC(0001) surface. The first H splitting from water can occur with ground-state electronic structures. The second H splitting involves an energy barrier of 0.65 eV. However, the energy barrier for two H atoms desorbing from the Si-face and forming H2 gas is 3.04 eV. In addition, it is found that C and Si vacancies can form easier in SiC(0001)surfaces than in SiC bulk and nanoribbons. The C/Si vacancies introduced can enhance photocatalytic activities. It is easier to split OH on SiC(0001) surface with vacancies compared to the case of clean SiC surface. H2 can form on the 4H-SiC(0001) surface with C and Si vacancies if the energy barriers of 1.02 and 2.28 eV are surmounted, respectively. Therefore, SiC(0001) surface with C vacancy has potential applications in photocatalytic water-splitting.

Synthesis of DHA/EPA-rich phosphatidylcholine by immobilized phospholipase A1: effect of water addition and vacuum condition.

PubMed

Li, Daoming; Qin, Xiaoli; Wang, Weifei; Li, Zhigang; Yang, Bo; Wang, Yonghua

2016-08-01

DHA/EPA-rich phosphatidylcholine (PC) was successfully synthesized by immobilized phospholipase A1 (PLA1)-catalyzed transesterification of PC and DHA/EPA-rich ethyl esters in a solvent-free system. Effects of reaction temperature, water addition and substrate mass ratio on the incorporation of DHA/EPA were evaluated using response surface methods (RSM). Water addition had most significant effect on the incorporation. Reaction temperature and substrate mass ratio, however, had no significant effect on the incorporation. The maximal incorporation was 19.09 % (24 h) under the following conditions: temperature 55.7 °C, water addition 1.1 wt % and substrate mass ratio (ethyl esters/PC) 6.8:1. Furthermore, effects of water addition (from 0 to 1.25 wt %) on DHA/EPA incorporation and the composition of products were further investigated. The immobilized PLA1 was more active when water addition was above 0.5 wt %. By monitoring the reaction processes with different water addition, a possible reaction scheme was proposed for transesterification of PC with DHA/EPA-rich ethyl esters. In summary, PC and sn2-lysophosphatidylocholine (LPC) were predominant in the mixtures at early stages of reaction, whereas sn1-LPC and glycerophosphocholine (GPC) predominant at later stages. The vacuum employed after 24 h significantly increased the incorporation of DHA/EPA and the composition of PC, and the highest incorporation (30.31 %) of DHA/EPA was obtained at 72 h and the yield of PC was 47.2 %.

Dynamics of ice nucleation on water repellent surfaces.

PubMed

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

NASA Astrophysics Data System (ADS)

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

Water resources data for New Mexico, water year 1965; Part 1. Surface water records

USGS Publications Warehouse

,

1966-01-01

The surface-water records for the 1965 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of New Mexico are given in this report. For convenience there are also Included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of W. E. Hale, District Chief, Water Resources Division. This report is the fifth In a series presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled Surface Water Supply of the United States. Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8 and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5~year intervals. These 5-year water-supply papers will show daily discharge and will be compi led On the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Langmuir circulation inhibits near-surface water turbulence

NASA Astrophysics Data System (ADS)

Schultz, Colin

2012-07-01

In the surface ocean, breaking waves are a major source of air bubbles and turbulent kinetic energy. During the presence of a consistent surface wind, these wave-generated bubbles, along with other surface material like seaweed or foam, can be drawn into long rows along the surface. Driving this organization is Langmuir circulation, a phenomenon in which the wind and waves cause surface waters to rotate helically, moving like a wire wrapped around a pole in the windward direction. These spiral currents oscillate between clockwise and counterclockwise rotations, such that in some places the surface waters are pushed together and in others they are pulled apart. Researchers have previously found that at sites of convergence the bubbles produced by breaking waves are pushed to depths of 15 meters or more, with important implications for air-sea gas mixing and other processes.

Modelling surface runoff and water fluxes over contrasted soils in pastoral Sahel: evaluation of the ALMIP2 land surface models over the Gourma region in Mali

USDA-ARS?s Scientific Manuscript database

Land surface processes play an important role in West African monsoon variability and land –atmosphere coupling has been shown to be particularly important in the Sahel. In addition, the evolution of hydrological systems in this region, and particularly the increase of surface water and runoff coeff...

Characteristics of pulse corona discharge over water surface

NASA Astrophysics Data System (ADS)

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.

Thermophoretically driven water droplets on graphene and boron nitride surfaces.

PubMed

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

2018-05-25

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.

Thermophoretically driven water droplets on graphene and boron nitride surfaces

NASA Astrophysics Data System (ADS)

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.

Surface-water quality-assurance plan for the U.S. Geological Survey Washington Water Science Center

USGS Publications Warehouse

Mastin, Mark C.

2016-02-19

This Surface-Water Quality-Assurance Plan documents the standards, policies, and procedures used by the U.S. Geological Survey Washington Water Science Center (WAWSC) for activities related to the collection, processing, storage, analysis, and publication of surface-water data. This plan serves as a guide to all WAWSC personnel involved in surface-water data activities, and changes as the needs and requirements of the WAWSC change. Regular updates to this plan represent an integral part of the quality-assurance process. In the WAWSC, direct oversight and responsibility by the hydrographer(s) assigned to a surface-water station, combined with team approaches in all work efforts, assure highquality data, analyses, reviews, and reports for cooperating agencies and the public.

Occurrence of Surface Water Contaminations: An Overview

NASA Astrophysics Data System (ADS)

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.

Data on dissolved pesticides and volatile organic compounds in surface and ground waters in the San Joaquin-Tulare basins, California, water years 1992-1995

USGS Publications Warehouse

Kinsey, Willie B.; Johnson, Mark V.; Gronberg, JoAnn M.

2005-01-01

This report contains pesticide, volatile organic compound, major ion, nutrient, tritium, stable isotope, organic carbon, and trace-metal data collected from 149 ground-water wells, and pesticide data collected from 39 surface-water stream sites in the San Joaquin Valley of California. Included with the ground-water data are field measurements of pH, specific conductance, alkalinity, temperature, and dissolved oxygen. This report describes data collection procedures, analytical methods, quality assurance, and quality controls used by the National Water-Quality Assessment Program to ensure data reliability. Data contained in this report were collected during a four year period by the San Joaquin?Tulare Basins Study Unit of the United States Geological Survey's National Water-Quality Assessment Program. Surface-water-quality data collection began in April 1992, with sampling done three times a week at three sites as part of a pilot study conducted to provide background information for the surface-water-study design. Monthly samples were collected at 10 sites for major ions and nutrients from January 1993 to March 1995. Additional samples were collected at four of these sites, from January to December 1993, to study spatial and temporal variability in dissolved pesticide concentrations. Samples for several synoptic studies were collected from 1993 to 1995. Ground-water-quality data collection was restricted to the eastern alluvial fans subarea of the San Joaquin Valley. Data collection began in 1993 with the sampling of 21 wells in vineyard land-use settings. In 1994, 29 wells were sampled in almond land-use settings and 9 in vineyard land-use settings; an additional 11 wells were sampled along a flow path in the eastern Fresno County vineyard land-use area. Among the 79 wells sampled in 1995, 30 wells were in the corn, alfalfa, and vegetable land-use setting, and 1 well was in the vineyard land-use setting; an additional 20 were flow-path wells. Also sampled in 1995

Total Nitrogen Concentrations in Surface Water of Typical Agro- and Forest Ecosystems in China, 2004-2009

PubMed Central

Xu, Zhiwei; Zhang, Xinyu; Xie, Juan; Yuan, Guofu; Tang, Xinzhai; Sun, Xiaomin; Yu, Guirui

2014-01-01

We assessed the total nitrogen (N) concentrations of 28 still surface water (lake and pond), and 42 flowing surface water (river), monitoring sites under 29 typical terrestrial ecosystems of the Chinese Ecosystem Research Network (CERN) using monitoring data collected between 2004 and 2009. The results showed that the median total N concentrations of still surface water were significantly higher in the agro- (1.5 mg·L−1) and oasis agro- ecosystems (1.8 mg·L−1) than in the forest ecosystems (1.0 mg·L−1). This was also the case for flowing surface water, with total N concentrations of 2.4 mg·L−1, 1.8 mg·L−1 and 0.5 mg·L−1 for the agro-, oasis agro- and forest ecosystems, respectively. In addition, more than 50% of the samples in agro- and oasis agro- ecosystems were seriously polluted (>1.0 mg·L−1) by N. Spatial analysis showed that the total N concentrations in northern and northwestern regions were higher than those in the southern region for both still and flowing surface waters under agro- and oasis agro- ecosystems, with more than 50% of samples exceeding 1.0 mg·L−1 (the Class III limit of the Chinese National Quality Standards for Surface Waters) in surface water in the northern region. Nitrogen pollution in agro- ecosystems is mainly due to fertilizer applications, while the combination of fertilizer and irrigation exacerbates nitrogen pollution in oasis agro- ecosystems. PMID:24667701

Water resources data for New Mexico, water year 1964; Part I. Surface water records

USGS Publications Warehouse

,

1965-01-01

The surface-water records for the 1964 water year for gaging stations, partialrecord stations, and miscellaneous sites within the State of New Mexico are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey, under the direction of W. L. Heckler, district engineer, Surface Water Branch. This report is the fourth in a series presenting, annually, basic data on surfacewater records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Impact of Water Recovery from Wastes on the Lunar Surface Mission Water Balance

NASA Technical Reports Server (NTRS)

Fisher, John W.; Hogan, John Andrew; Wignarajah, Kanapathipi; Pace, Gregory S.

2010-01-01

Future extended lunar surface missions will require extensive recovery of resources to reduce mission costs and enable self-sufficiency. Water is of particular importance due to its potential use for human consumption and hygiene, general cleaning, clothes washing, radiation shielding, cooling for extravehicular activity suits, and oxygen and hydrogen production. Various water sources are inherently present or are generated in lunar surface missions, and subject to recovery. They include: initial water stores, water contained in food, human and other solid wastes, wastewaters and associated brines, ISRU water, and scavenging from residual propellant in landers. This paper presents the results of an analysis of the contribution of water recovery from life support wastes on the overall water balance for lunar surface missions. Water in human wastes, metabolic activity and survival needs are well characterized and dependable figures are available. A detailed life support waste model was developed that summarizes the composition of life support wastes and their water content. Waste processing technologies were reviewed for their potential to recover that water. The recoverable water in waste is a significant contribution to the overall water balance. The value of this contribution is discussed in the context of the other major sources and loses of water. Combined with other analyses these results provide guidance for research and technology development and down-selection.

Quality-control results for ground-water and surface-water data, Sacramento River Basin, California, National Water-Quality Assessment, 1996-1998

USGS Publications Warehouse

Munday, Cathy; Domagalski, Joseph L.

2003-01-01

Evaluating the extent that bias and variability affect the interpretation of ground- and surface-water data is necessary to meet the objectives of the National Water-Quality Assessment (NAWQA) Program. Quality-control samples used to evaluate the bias and variability include annual equipment blanks, field blanks, field matrix spikes, surrogates, and replicates. This report contains quality-control results for the constituents critical to the ground- and surface-water components of the Sacramento River Basin study unit of the NAWQA Program. A critical constituent is one that was detected frequently (more than 50 percent of the time in blank samples), was detected at amounts exceeding water-quality standards or goals, or was important for the interpretation of water-quality data. Quality-control samples were collected along with ground- and surface-water samples during the high intensity phase (cycle 1) of the Sacramento River Basin NAWQA beginning early in 1996 and ending in 1998. Ground-water field blanks indicated contamination of varying levels of significance when compared with concentrations detected in environmental ground-water samples for ammonia, dissolved organic carbon, aluminum, and copper. Concentrations of aluminum in surface-water field blanks were significant when compared with environmental samples. Field blank samples collected for pesticide and volatile organic compound analyses revealed no contamination in either ground- or surface-water samples that would effect the interpretation of environmental data, with the possible exception of the volatile organic compound trichloromethane (chloroform) in ground water. Replicate samples for ground water and surface water indicate that variability resulting from sample collection, processing, and analysis was generally low. Some of the larger maximum relative percentage differences calculated for replicate samples occurred between samples having lowest absolute concentration differences and(or) values near

Photocatalytic inactivation of E. coli in surface water using immobilised nanoparticle TiO2 films.

PubMed

Alrousan, Dheaya M A; Dunlop, Patrick S M; McMurray, Trudy A; Byrne, J Anthony

2009-01-01

Photocatalysis is a promising method for the disinfection of potable water in developing countries where solar irradiation can be employed, thus reducing the cost of treatment. In addition to microbial contamination, water normally contains suspended solids, dissolved inorganic ions and organic compounds (mainly humic substances) which may affect the efficacy of solar photocatalysis. In this work the photocatalytic and photolytic inactivation rates of Escherichia coli using immobilised nanoparticle TiO2 films were found to be significantly lower in surface water samples in comparison to distilled water. The presence of nitrate and sulphate anions spiked into distilled water resulted in a decrease in the rate of photocatalytic disinfection. The presence of humic acid, at the concentration found in the surface water, was found to have a more pronounced affect, significantly decreasing the rate of disinfection. Adjusting the initial pH of the water did not markedly affect the photocatalytic disinfection rate, within the narrow range studied.

The methods of receiving coal water suspension and its use as the modifying additive in concrete

NASA Astrophysics Data System (ADS)

Buyantuyev, S. L.; Urkhanova, L. A.; Lkhasaranov, S. A.; Stebenkova, Y. Y.; Khmelev, A. B.; Kondratenko, A. S.

2017-01-01

Results of research of the coal water suspension (CWS) from a cake received in the electrodigit ways in the fluid environment and gas are given in article and also the possibilities of its use as the modifying additive in concrete are considered. Use of a coal cake is perspective as it is a withdrawal of the coal and concentrating enterprises and has extremely low cost. Methods of receiving CWS and possibility of formation of carbon nanomaterials (CNM) are given in their structure. Research and the analysis of a microstructure of a surface of exemplars before electrodigit processing, their element structure, dependence of durability of a cement stone on a look and quantity of an additive of CWS is conducted. For modification of cement the carbon nanomaterials received from the following exemplars of water coal suspensions were used: foams from a cake from a scrubber of the plasma modular reactor, coal water suspension from a cake from electrodigit installation. The product which can find further application for a power engineering as fuel for combustion, and also in structural materials science, in particular, as the modifying additive in concrete allows to receive these methods.

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)

USGS Publications Warehouse

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

Impact of water chemistry on surface charge and aggregation of polystyrene microspheres suspensions.

PubMed

Lu, Songhua; Zhu, Kairuo; Song, Wencheng; Song, Gang; Chen, Diyun; Hayat, Tasawar; Alharbi, Njud S; Chen, Changlun; Sun, Yubing

2018-07-15

The discharge of microplastics into aquatic environment poses the potential threat to the hydrocoles and human health. The fate and transport of microplastics in aqueous solutions are significantly influenced by water chemistry. In this study, the effect of water chemistry (i.e., pH, foreign salts and humic acid) on the surface charge and aggregation of polystyrene microsphere in aqueous solutions was conducted by batch, zeta potentials, hydrodynamic diameters, FT-IR and XPS analysis. Compared to Na + and K + , the lower negative zeta potentials and larger hydrodynamic diameters of polystyrene microspheres after introduction of Mg 2+ were observed within a wide range of pH (2.0-11.0) and ionic strength (IS, 0.01-500mmol/L). No effect of Cl - , HCO 3 - and SO 4 2- on the zeta potentials and hydrodynamic diameters of polystyrene microspheres was observed at low IS concentrations (<5mmol/L), whereas the zeta potentials and hydrodynamic diameters of polystyrene microspheres after addition of SO 4 2- were higher than that of Cl - and HCO 3 - at high IS concentrations (>10mmol/L). The zeta potentials of polystyrene microspheres after HA addition were decreased at pH2.0-11.0, whereas the lower hydrodynamic diameters were observed at pH<4.0. According to FT-IR and XPS analysis, the change in surface properties of polystyrene microspheres after addition of hydrated Mg 2+ and HA was attributed to surface electrostatic and/or steric repulsions. These investigations are crucial for understanding the effect of water chemistry on colloidal stability of microplastics in aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Water transport mechanism through open capillaries analyzed by direct surface modifications on biological surfaces

NASA Astrophysics Data System (ADS)

Ishii, Daisuke; Horiguchi, Hiroko; Hirai, Yuji; Yabu, Hiroshi; Matsuo, Yasutaka; Ijiro, Kuniharu; Tsujii, Kaoru; Shimozawa, Tateo; Hariyama, Takahiko; Shimomura, Masatsugu

2013-10-01

Some small animals only use water transport mechanisms passively driven by surface energies. However, little is known about passive water transport mechanisms because it is difficult to measure the wettability of microstructures in small areas and determine the chemistry of biological surfaces. Herein, we developed to directly analyse the structural effects of wettability of chemically modified biological surfaces by using a nanoliter volume water droplet and a hi-speed video system. The wharf roach Ligia exotica transports water only by using open capillaries in its legs containing hair- and paddle-like microstructures. The structural effects of legs chemically modified with a self-assembled monolayer were analysed, so that the wharf roach has a smart water transport system passively driven by differences of wettability between the microstructures. We anticipate that this passive water transport mechanism may inspire novel biomimetic fluid manipulations with or without a gravitational field.

Surface modification of biomaterials and biomedical devices using additive manufacturing.

PubMed

Bose, Susmita; Robertson, Samuel Ford; Bandyopadhyay, Amit

2018-01-15

The demand for synthetic biomaterials in medical devices, pharmaceutical products and, tissue replacement applications are growing steadily due to aging population worldwide. The use for patient matched devices is also increasing due to availability and integration of new technologies. Applications of additive manufacturing (AM) or 3D printing (3DP) in biomaterials have also increased significantly over the past decade towards traditional as well as innovative next generation Class I, II and III devices. In this review, we have focused our attention towards the use of AM in surface modified biomaterials to enhance their in vitro and in vivo performances. Specifically, we have discussed the use of AM to deliberately modify the surfaces of different classes of biomaterials with spatial specificity in a single manufacturing process as well as commented on the future outlook towards surface modification using AM. It is widely understood that the success of implanted medical devices depends largely on favorable material-tissue interactions. Additive manufacturing has gained traction as a viable and unique approach to engineered biomaterials, for both bulk and surface properties that improve implant outcomes. This review explores how additive manufacturing techniques have been and can be used to augment the surfaces of biomedical devices for direct clinical applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Modelling surface-water depression storage in a Prairie Pothole Region

USGS Publications Warehouse

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.

Concentration data for anthropogenic organic compounds in groundwater, surface water, and finished water of selected community water systems in the United States, 2002-10

USGS Publications Warehouse

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

2010-01-01

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 in the United States. As used in SWQA studies, source water is the raw (ambient) water collected at the supply well before water treatment (for groundwater) or the raw (ambient) water collected from the river near the intake (for surface water), and finished water is the water that has been treated and is ready to be delivered to consumers. Finished-water samples are collected before the water enters the distribution system. The primary objective of SWQAs is to determine the occurrence of more than 250 anthropogenic organic compounds in source water used by community water systems, many of which currently are unregulated in drinking water by the U.S. Environmental Protection Agency. A secondary objective is to understand recurrence patterns in source water and determine if these patterns also occur in finished water before distribution. SWQA studies were conducted in two phases for most studies completed by 2005, and in one phase for most studies completed since 2005. Analytical results are reported for a total of 295 different anthropogenic organic compounds monitored in source-water and finished-water samples collected during 2002-10. The 295 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 combustion-derived compounds; (10) personal-care and domestic-use products; (11) plant- or animal-derived biochemicals; (12) refrigerants and

Benefits of neutral electrolyzed oxidizing water as a drinking water additive for broiler chickens.

PubMed

Bügener, E; Kump, A Wilms-Schulze; Casteel, M; Klein, G

2014-09-01

In the wake of discussion about the use of drugs in food-producing farms, it seems to be more and more important to search for alternatives and supportive measures to improve health. In this field trial, the influence of electrolyzed oxidizing (EO) water on water quality, drug consumption, mortality, and performance parameters such as BW and feed conversion rate was investigated on 2 broiler farms. At each farm, 3 rearing periods were included in the study. With EO water as the water additive, the total viable cell count and the number of Escherichia coli in drinking water samples were reduced compared with the respective control group. The frequency of treatment days was represented by the number of used daily doses per population and showed lower values in EO-water-treated groups at both farms. Furthermore, the addition of EO water resulted in a lower mortality rate. In terms of analyzed performance parameters, no significant differences were determined. In this study, the use of EO water improved drinking water quality and seemed to reduce the drug use without showing negative effects on performance parameters and mortality rates. © 2014 Poultry Science Association Inc.

CCQM-K126: low polarity organic in water: carbamazepine in surface water

NASA Astrophysics Data System (ADS)

Wai-mei Sin, Della; Wong, Yiu-chung; Lehmann, Andreas; Schneider, Rudolf J.; Kakoulides, Elias; Tang Lin, Teo; Qinde, Liu; Cabillic, Julie; Lardy-fontan, Sophie; Nammoonnoy, Jintana; Prevoo-Franzsen, Désirée; López, Eduardo Emilio; Alberti, Cecilia; Su, Fuhai

2017-01-01

The key comparison CCQM-K126 low polarity organic in water: carbamazepine in surface water was coordinated by Government Laboratory Hong Kong under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Eight National Metrology institutes or Designated Institutes participated and participants were requested to report the mass fraction of carbamazepine in surface water study material. The surface water sample was collected in Hong Kong and was gravimetrically spiked with standard solution. This study provided the means for assessing measurement capabilities for determination of low molecular weight analytes (mass range 100-500) and low polarity (pKOW<= -2) in aqueous matrix. Nine NMIs/DIs registered for the KC and one withdrew before results were submitted. Nine results were submitted by the eight participants. Eight results applied the LC-MS/MS method and Isotope Dilution Mass Spectrometry approach for quantification. BAM additionally submitted a result from ELISA that was not included in the key comparison reference values (KCRV) calculation as is provided in the report for information. One further result was not included as the participant withdrew their result from the calculation after further analysis. The assigned KCRV was the median of the seven results and was assigned a KCRV of 250.2 ng/kg with a combined standard uncertainty of 3.6 ng/kg, The k-factor for the estimation of the expanded uncertainty of the KCRVs was chosen as k = 2. The degree of equivalence (with the KCRV) and its uncertainty was calculated for each result. Seven of the participants were able to demonstrate the ability to quantitatively determine low-polarity analyte in aqueous matrix by applying LC-MS/MS technique at a very low level. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final

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

PubMed

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.

Modeling Water Redistribution in a Near-Surface Arid Soil

NASA Astrophysics Data System (ADS)

Luo, Y.; Ghezzehei, T. A.; Berli, M.; Dijkema, J.; Koonce, J.

2017-12-01

Desert soils cover about one third of the Earth's land surface and play an important role in the ecology and hydrology of arid environments. Despite their large extend, relatively little is known about their near-surface (top centimeters to meter) water dynamics. Recent studies by Koonce (2016) and Dijkema et al. (2017) shed light on the water dynamics of near-surface arid soil but also revealed some of the challenges to simulate the water redistribution in arid soils. The goal of this study was to improve water redistribution simulations in near-surface arid soils by employing more advanced hydraulic conductivity functions. Expanding on the work by Dijkema et al. (2017), we used a HYDRUS-1D model with different hydraulic conductivity functions to simulate water redistribution within the soil as a function of precipitation, evaporation and drainage. Model calculations were compared with measured data from the SEPHAS weighing lysimeters in Boulder City, NV. Preliminary results indicate that water redistribution simulations of near-surface arid soils can be improved by using hydraulic conductivity functions that can capture capillary, film and vapor flow, like for example the Peter-Durner-Iden (PDI) model.

Interaction between ground water and surface water in the northern Everglades and relation to water budget and mercury cycling; study methods and appendixes

USGS Publications Warehouse

Harvey, Judson W.; Krupa, S.L.; Gefvert, C.J.; Choi, Jungyill; Mooney, R.H.; Giddings, J.B.

2000-01-01

(since at least the mid- 1970s), but the number of sites and data- collection frequency is much less. Very little prior ground water data were available in WCA-2A. Given the availability of prior information, the present study emphasized the collection of ground water field data, particularly in the interior wetland areas of ENR and WCA- 2A. New wells were emplaced to permit the geologic, hydraulic, and chemical sampling that was needed to characterize interactions between surface water and ground water. In particular, lithology and hydraulic properties of the Surficial aquifer were determined, ground water flow paths and velocities were delineated, hydrologic fluxes between surface water and ground water were measured, and water budgets and surface- subsurface fluxes of mercury were determined. The purpose of this report is to compile under one cover all of the data collected in this investigation. In addition, the report contains a detailed description of the study methods and information about study sites, borehole drilling, well construction, seepage meter installation, and hydraulic and geochemical chemical sampling. Data interpretations are the subject of a companion report.

Coastal surface water suitability analysis for irrigation in Bangladesh

NASA Astrophysics Data System (ADS)

Mahtab, Mohammad Hossain; Zahid, Anwar

2018-03-01

Water with adequate quality and quantity is very important for irrigation to ensure the crop yields. Salinity is common problem in the coastal waters in Bangladesh. The intensity of salinity in the coastal zone in Bangladesh is not same. It fluctuates over the year. Sodium is another hazard which may hamper permeability and ultimately affects the fertility. It can reduce the crop yields. Although surface water is available in the coastal zone of Bangladesh, but its quality for irrigation needs to be monitored over the year. This paper will investigate the overall quality of coastal surface waters. Thirty-three water samples from different rivers were collected both in wet period (October-December) and in dry period (February-April). Different physical and chemical parameters are considered for investigation of the adequacy of water with respect to international irrigation water quality standards and Bangladesh standards. A comparison between the dry and wet period coastal surface water quality in Bangladesh will also be drawn here. The analysis shows that coastal surface water in Bangladesh is overall suitable for irrigation during wet period, while it needs treatment (which will increase the irrigation cost) for using for irrigation during dry period. Adaptation to this situation can improve the scenario. An integrated plan should be taken to increase the water storing capacity in the coastal area to harvest water during wet period.

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

PubMed

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.

Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant

PubMed Central

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. PMID:25893132

Influence of the Institutional Structure of Surface Water Rights on Agricultural Production in the Central Valley

NASA Astrophysics Data System (ADS)

Nelson, K.; Burchfield, E. K.

2017-12-01

California's Central Valley region is one of the most productive agricultural systems on the planet. The high levels of agricultural production in this region require large amounts of fresh water for irrigation. However, the long-term availability of water required to sustain such levels of agricultural production has been questioned following the latest drought in California. In this study, we use Bayesian multilevel spatiotemporal modeling techniques to examine the influence of the institutional structure of surface water rights in the Central Valley on agricultural production during the recent drought. The R-INLA package is employed to account for spatial processes that have the potential to influence the effects of water right structures on crop productivity as well as on extent of cultivation. Model results suggest that seniority in surface water access significantly improves crop productivity on cultivated lands, but does not directly affect the ability to maintain cultivated extent. In addition, results suggest that areas with more junior surface water rights tend to reduce extent of cultivation, but maintain crop productivity, as cumulative drought stress increases.

Water resources data for Michigan, water year 1972; Part 1, Surface water records

USGS Publications Warehouse

,

1973-01-01

Surface-water records for the 1972 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Michigan are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of T. R. Cummings, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Michigan. Records of discharge and stage of streams, and contents and stage of lakes or reservoirs are published in a series of U.S. Geological Survey 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 since then are in a 5-year series. Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Michigan were contained in Part 4 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs.

Water resources data for Michigan, water year 1971; Part 1, Surface water records

USGS Publications Warehouse

,

1972-01-01

Surface-water records for the 1971 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Michigan are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of T. R. Cummings, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Michigan. Records of discharge and stage of streams, and contents and stage of lakes or reservoirs are published in a series of U.S. Geological Survey 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 since then are in a 5-year series. Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Michigan were contained in Part 4 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs.

Water resources data for Michigan, water year 1973; Part 1, Surface water records

USGS Publications Warehouse

,

1974-01-01

Surface-water records for the 1973 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Michigan are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of T.R. Cummings, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Michigan. Records of discharge and stage of streams, and contents and stage of lakes or reservoirs are published in a series of U.S. Geological Survey 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 since then are in a 5-year series. Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Michigan are contained in Part 4 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs.

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

NASA Astrophysics Data System (ADS)

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.

Characterization of Surface Water and Groundwater Quality in the Lower Tano River Basin Using Statistical and Isotopic Approach.

NASA Astrophysics Data System (ADS)

Edjah, Adwoba; Stenni, Barbara; Cozzi, Giulio; Turetta, Clara; Dreossi, Giuliano; Tetteh Akiti, Thomas; Yidana, Sandow

2017-04-01

Adwoba Kua- Manza Edjaha, Barbara Stennib,c,Giuliano Dreossib, Giulio Cozzic, Clara Turetta c,T.T Akitid ,Sandow Yidanae a,eDepartment of Earth Science, University of Ghana Legon, Ghana West Africa bDepartment of Enviromental Sciences, Informatics and Statistics, Ca Foscari University of Venice, Italy cInstitute for the Dynamics of Environmental Processes, CNR, Venice, Italy dDepartment of Nuclear Application and Techniques, Graduate School of Nuclear and Allied Sciences University of Ghana Legon This research is part of a PhD research work "Hydrogeological Assessment of the Lower Tano river basin for sustainable economic usage, Ghana, West - Africa". In this study, the researcher investigated surface water and groundwater quality in the Lower Tano river basin. This assessment was based on some selected sampling sites associated with mining activities, and the development of oil and gas. Statistical approach was applied to characterize the quality of surface water and groundwater. Also, water stable isotopes, which is a natural tracer of the hydrological cycle was used to investigate the origin of groundwater recharge in the basin. The study revealed that Pb and Ni values of the surface water and groundwater samples exceeded the WHO standards for drinking water. In addition, water quality index (WQI), based on physicochemical parameters(EC, TDS, pH) and major ions(Ca2+, Na+, Mg2+, HCO3-,NO3-, CL-, SO42-, K+) exhibited good quality water for 60% of the sampled surface water and groundwater. Other statistical techniques, such as Heavy metal pollution index (HPI), degree of contamination (Cd), and heavy metal evaluation index (HEI), based on trace element parameters in the water samples, reveal that 90% of the surface water and groundwater samples belong to high level of pollution. Principal component analysis (PCA) also suggests that the water quality in the basin is likely affected by rock - water interaction and anthropogenic activities (sea water intrusion). This

Effective use of surface-water management to control saltwater intrusion

NASA Astrophysics Data System (ADS)

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 Resources Data: New Jersey, Water Year 1998, Volume 1, Surface-Water Data

USGS Publications Warehouse

Reed, T.J.; Centinaro, G.L.; Dudek, J.F.; Corcino, V.; Stekroadt, G.C.; McTigure, R.C.

1999-01-01

This volume of the annual hydrologic data report of New Jersey is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and water quality provide the hydrologic information needed by state, local and federal agencies, and the private sector for developing and managing our Nation's land and water resources.

Polydimethylsiloxane-Based Superhydrophobic Surfaces on Steel Substrate: Fabrication, Reversibly Extreme Wettability and Oil-Water Separation.

PubMed

Su, Xiaojing; Li, Hongqiang; Lai, Xuejun; Zhang, Lin; Liang, Tao; Feng, Yuchun; Zeng, Xingrong

2017-01-25

Functional surfaces for reversibly switchable wettability and oil-water separation have attracted much interest with pushing forward an immense influence on fundamental research and industrial application in recent years. This article proposed a facile method to fabricate superhydrophobic surfaces on steel substrates via electroless replacement deposition of copper sulfate (CuSO 4 ) and UV curing of vinyl-terminated polydimethylsiloxane (PDMS). PDMS-based superhydrophobic surfaces exhibited water contact angle (WCA) close to 160° and water sliding angle (WSA) lower than 5°, preserving outstanding chemical stability that maintained superhydrophobicity immersing in different aqueous solutions with pH values from 1 to 13 for 12 h. Interestingly, the superhydrophobic surface could dramatically switch to the superhydrophilic state under UV irradiation and then gradually recover to the highly hydrophobic state with WCA at 140° after dark storage. The underlying mechanism was also investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Additionally, the PDMS-based steel mesh possessed high separation efficiency and excellent reusability in oil-water separation. Our studies provide a simple, fast, and economical fabrication method for wettability-transformable superhydrophobic surfaces and have the potential applications in microfluidics, the biomedical field, and oil spill cleanup.

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

PubMed

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

2018-05-31

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.

Water resources data for Michigan, water year 1974; Part 1, Surface water records

USGS Publications Warehouse

,

1975-01-01

Surface-water records for the 1974 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Michigan are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of T.R. Cummings, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Michigan.Records of discharge and stage of streams, and contents and stage of lakes or reservoirs are published in a series of U.S. Geological Survey 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 since then are in a 5-year series. Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Michigan are contained in Part 4 of that series.Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and they are designed primarily for rapid release of data shortly after the end of the water year.

Water Resources Data, Wyoming, Water Year 2001, Volume 1. Surface Water

USGS Publications Warehouse

Swanson, R.B.; Woodruff, R.E.; Laidlaw, G.A.; Watson, K.R.; Clark, M.L.

2002-01-01

Water resources data for the 2001 water year for Wyoming consists of records of stage, discharge and water quality of streams; stage and contents of lakes and reservoirs, and water levels and water quality of ground water. Volume 1 of this report contains discharge records for 151 gaging stations, stage and contents for 12 lakes and reservoirs, and water quality for 33 gaging stations and 32 ungaged stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data together with the data in Volume 2 represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Wyoming.

Experimental Observation of Dark Solitons on Water Surface

DTIC Science & Technology

2016-06-13

Experimental observation of dark solitons on water surface A. Chabchoub1,∗, O. Kimmoun2, H. Branger3, N. Hoffmann1, D. Proment4, M. Onorato4,5, and N...The shape and width of the soliton depend on the water depth, carrier frequency and the amplitude of the background wave. The experimental data...partic- ular, the governing equation describing the dynamics of weakly nonlinear and quasi -monochromatic waves prop- agating on the surface of water with

One-step fabrication of robust superhydrophobic and superoleophilic surfaces with self-cleaning and oil/water separation function.

PubMed

Zhang, Zhi-Hui; Wang, Hu-Jun; Liang, Yun-Hong; Li, Xiu-Juan; Ren, Lu-Quan; Cui, Zhen-Quan; Luo, Cheng

2018-03-01

Superhydrophobic surfaces have great potential for application in self-cleaning and oil/water separation. However, the large-scale practical applications of superhydrophobic coating surfaces are impeded by many factors, such as complicated fabrication processes, the use of fluorinated reagents and noxious organic solvents and poor mechanical stability. Herein, we describe the successful preparation of a fluorine-free multifunctional coating without noxious organic solvents that was brushed, dipped or sprayed onto glass slides and stainless-steel meshes as substrates. The obtained multifunctional superhydrophobic and superoleophilic surfaces (MSHOs) demonstrated self-cleaning abilities even when contaminated with or immersed in oil. The superhydrophobic surfaces were robust and maintained their water repellency after being scratched with a knife or abraded with sandpaper for 50 cycles. In addition, stainless-steel meshes sprayed with the coating quickly separated various oil/water mixtures with a high separation efficiency (>93%). Furthermore, the coated mesh maintained a high separation efficiency above 95% over 20 cycles of separation. This simple and effective strategy will inspire the large-scale fabrication of multifunctional surfaces for practical applications in self-cleaning and oil/water separation.

Pesticide mitigation strategies for surface water quality

USDA-ARS?s Scientific Manuscript database

Pesticide residues are being increasingly detected in surface water in agricultural and urban areas. In some cases water bodies are being listed under the Clean Water Act 303(d) as impaired and Total Maximum Daily Loads are required to address the impairments in agricultural areas. Pesticides in sur...

Water resources data, Wyoming, water year 2004; Volume 1. Surface water; with List of discontinued and active surface-water, water-quality, sediment, and biological stations

USGS Publications Warehouse

Watson, K.R.; Woodruff, R.E.; Laidlaw, G.A.; Clark, M.L.; Miller, K.A.

2005-01-01

Water resources data for the 2004 water year for Wyoming consist of records of stage, discharge and water quality of streams; stage and contents of lakes and reservoirs, and water levels and water quality of ground water. Volume 1 of this report contains discharge records for 164 gaging stations; water quality for 43 gaging stations and 45 ungaged stations, and stage and contents for one reservoir. Volume 2 of this report contains water levels records for 64 wells. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent part of the National Water Information System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Wyoming.

Effect of Periodic Water Addition on Citric Acid Production in Solid State Fermentation

NASA Astrophysics Data System (ADS)

Utpat, Shraddha S.; Kinnige, Pallavi T.; Dhamole, Pradip B.

2013-09-01

Water addition is one of the methods used to control the moisture loss in solid state fermentation (SSF). However, none of the studies report the timing of water addition and amount of water to be added in SSF. Therefore, this work was undertaken with an objective to evaluate the performance of periodic water addition on citric acid production in SSF. Experiments were conducted at different moistures (50-80 %) and temperatures (30-40 °C) to simulate the conditions in a fermenter. Citric acid production by Aspergillus niger (ATCC 9029) using sugarcane baggase was chosen as a model system. Based on the moisture profile, citric acid and sugar data, a strategy was designed for periodic addition of water. Water addition at 48, 96, 144 and 192 h enhanced the citric acid production by 62 % whereas water addition at 72, 120, and 168 h increased the citric acid production by just 17 %.

Numerical simulation of hydrodynamic processes beneath a wind-driven water surface

NASA Astrophysics Data System (ADS)

Tsai, Wu-ting

Turbulent flow driven by a constant wind stress acting at the water surface was simulated numerically to gain a better understanding of the hydrodynamic processes governing the transfer of slightly soluble gases across the atmosphere-water interfaces. Simulation results show that two distinct flow features, attributed to subsurface surface renewal eddies, appear at the water surface. The first characteristic feature is surface streaming, which consists of high-speed streaks aligned with the wind stress. Floating Lagrangian particles, which are distributed uniformly at the water surface, merge to the predominantly high-speed streaks and form elongated streets immediately after they are released. The second characteristic surface signatures are localized low-speed spots which emerge randomly at the water surface. A high-speed streak bifurcates and forms a dividing flow when it encounters a low-speed surface spot. These coherent surface flow structures are qualitatively identical to those observed in the experiment of Melville et al. [1998]. The persistence of these surface features also suggests that there must exist organized subsurface vortical structures that undergo autonomous generation cycles maintained by self-sustaining mechanisms. These coherent vortical flows serve as the renewal eddies that pump the submerged fluids toward the water surface and bring down the upper fluids, and therefore enhance the scalar exchange between the atmosphere and the water body.

Shallow Alluvial Aquifer Ground Water System and Surface Water/Ground Water Interaction, Boulder Creek, Boulder, Colorado

NASA Astrophysics Data System (ADS)

Babcock, K. P.; Ge, S.; Crifasi, R. R.

2006-12-01

Water chemistry in Boulder Creek, Colorado, shows significant variation as the Creek flows through the City of Boulder [Barber et al., 2006]. This variation is partially due to ground water inputs, which are not quantitatively understood. The purpose of this study is (1) to understand ground water movement in a shallow alluvial aquifer system and (2) to assess surface water/ground water interaction. The study area, encompassing an area of 1 mi2, is located at the Sawhill and Walden Ponds area in Boulder. This area was reclaimed by the City of Boulder and Boulder County after gravel mining operations ceased in the 1970's. Consequently, ground water has filled in the numerous gravel pits allowing riparian vegetation regrowth and replanting. An integrated approach is used to examine the shallow ground water and surface water of the study area through field measurements, water table mapping, graphical data analysis, and numerical modeling. Collected field data suggest that lateral heterogeneity exists throughout the unconsolidated sediment. Alluvial hydraulic conductivities range from 1 to 24 ft/day and flow rates range from 0.01 to 2 ft/day. Preliminary data analysis suggests that ground water movement parallels surface topography and does not noticeably vary with season. Recharge via infiltrating precipitation is dependent on evapotranspiration (ET) demands and is influenced by preferential flow paths. During the growing season when ET demand exceeds precipitation rates, there is little recharge; however recharge occurs during cooler months when ET demand is insignificant. Preliminary data suggest that the Boulder Creek is gaining ground water as it traverses the study area. Stream flow influences the water table for distances up to 400 feet. The influence of stream flow is reflected in the zones relatively low total dissolved solids concentration. A modeling study is being conducted to synthesize aquifer test data, ground water levels, and stream flow data. The

Modeling diffuse sources of surface water contamination with plant protection products

NASA Astrophysics Data System (ADS)

Wendland, Sandra; Bock, Michael; Böhner, Jürgen; Lembrich, David

2015-04-01

Entries of chemical pollutants in surface waters are a serious environmental problem. Among water pollutants plant protection products (ppp) from farming practice are of major concern not only for water suppliers and environmental agencies, but also for farmers and industrial manufacturers. Lost chemicals no longer fulfill their original purpose on the field, but lead to severe damage of the environment and surface waters. Besides point-source inputs of chemical pollutants, the diffuse-source inputs from agricultural procedures play an important and not yet sufficiently studied role concerning water quality. The two most important factors for diffuse inputs are erosion and runoff. The latter usually occurs before erosion begins, and is thus often not visible in hindsight. Only if it has come to erosion, it is obvious to expect runoff in foresight at this area, too. In addition to numerous erosion models, there are also few applications to model runoff processes available. However, these conventional models utilize approximations of catchment parameters based on long-term average values or theoretically calculated concentration peaks which can only provide indications to relative amounts. Our study aims to develop and validate a simplified spatially-explicit dynamic model with high spatiotemporal resolution that enables to measure current and forecast runoff potential not only at catchment scale but field-differentiated. This method allows very precise estimations of runoff risks and supports risk reduction measures to be targeted before fields are treated. By focusing on water pathways occurring on arable land, targeted risk reduction measures like buffer strips at certain points and adapted ppp use can be taken early and pollution of rivers and other surface waters through transported pesticides, fertilizers and their products could be nearly avoided or largely minimized. Using a SAGA-based physical-parametric modeling approach, major factors influencing runoff

Uncertainty in surface water flood risk modelling

NASA Astrophysics Data System (ADS)

Butler, J. B.; Martin, D. N.; Roberts, E.; Domuah, R.

2009-04-01

Two thirds of the flooding that occurred in the UK during summer 2007 was as a result of surface water (otherwise known as ‘pluvial') rather than river or coastal flooding. In response, the Environment Agency and Interim Pitt Reviews have highlighted the need for surface water risk mapping and warning tools to identify, and prepare for, flooding induced by heavy rainfall events. This need is compounded by the likely increase in rainfall intensities due to climate change. The Association of British Insurers has called for the Environment Agency to commission nationwide flood risk maps showing the relative risk of flooding from all sources. At the wider European scale, the recently-published EC Directive on the assessment and management of flood risks will require Member States to evaluate, map and model flood risk from a variety of sources. As such, there is now a clear and immediate requirement for the development of techniques for assessing and managing surface water flood risk across large areas. This paper describes an approach for integrating rainfall, drainage network and high-resolution topographic data using Flowroute™, a high-resolution flood mapping and modelling platform, to produce deterministic surface water flood risk maps. Information is provided from UK case studies to enable assessment and validation of modelled results using historical flood information and insurance claims data. Flowroute was co-developed with flood scientists at Cambridge University specifically to simulate river dynamics and floodplain inundation in complex, congested urban areas in a highly computationally efficient manner. It utilises high-resolution topographic information to route flows around individual buildings so as to enable the prediction of flood depths, extents, durations and velocities. As such, the model forms an ideal platform for the development of surface water flood risk modelling and mapping capabilities. The 2-dimensional component of Flowroute employs

Salinization and arsenic contamination of surface water in southwest Bangladesh.

PubMed

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

Isotopic Estimation of Water Balance and Groundwater-Surface Water Interactions of Tropical Wetland Lakes in the Pantanal, Brazil

NASA Astrophysics Data System (ADS)

Schwerdtfeger, J.; Johnson, M. S.; Weiler, M.; Couto, E. G.

2009-12-01

The Pantanal is the largest and most pristine wetland of the world, yet hydrological research there is still in its infancy. In particular the water balance of the millions of lakes and ponds and their interaction with the groundwater and the rivers are not known. The aim of this study was to assess the hydrological behaviour between different water bodies in the dry season of the northern Pantanal wetland, Brazil, to provide a more general understanding of the hydrological functioning of tropical floodplain lakes and surface water-groundwater interactions of wetlands. In the field 6-9 water sample of seven different lakes were taken during 3 months and were analyzed for stable water isotopes and chloride. In addition meteorological data from a nearby station was used to estimate daily evaporation from the water surface. This information was then used to predict the hydrological dynamics to determine whether the lakes are evaporation-controlled or throughflow-dominated systems. A chloride mass balance served to evaluate whether Cl- enrichment took place due to evaporation only, or whether the system has significant inflow and/or outflow rates. The results of those methods showed that for all lakes the water budget in the dry season, output was controlled by strong evaporation while significant inflow rates were also apparent. Inflow rates and their specific concentrations in stable isotopes and chloride were successfully estimated using the simple mass balance model MINA TrêS. This approach enabled us to calculate the water balance for the lakes as well as providing an information on source water flowing into the lakes.

Transfer of Materials from Water to Solid Surfaces Using Liquid Marbles.

PubMed

Kawashima, Hisato; Paven, Maxime; Mayama, Hiroyuki; Butt, Hans-Jürgen; Nakamura, Yoshinobu; Fujii, Syuji

2017-09-27

Remotely controlling the movement of small objects is desirable, especially for the transportation and selection of materials. Transfer of objects between liquid and solid surfaces and triggering their release would allow for development of novel material transportation technology. Here, we describe the remote transport of a material from a water film surface to a solid surface using quasispherical liquid marbles (LMs). A light-induced Marangoni flow or an air stream is used to propel the LMs on water. As the LMs approach the rim of the water film, gravity forces them to slide down the water rim and roll onto the solid surface. Through this method, LMs can be efficiently moved on water and placed on a solid surface. The materials encapsulated within LMs can be released at a specific time by an external stimulus. We analyzed the velocity, acceleration, and force of the LMs on the liquid and solid surfaces. On water, the sliding friction due to the drag force resists the movement of the LMs. On a solid surface, the rolling distance is affected by the surface roughness of the LMs.

Surface Water Treatment Rules State Implementation Guidance

EPA Pesticide Factsheets

These documents provide guidance to states, tribes and U.S. EPA Regions exercising primary enforcement responsibility under the Safe Drinking Water Act. The documents contain EPA’s recommendations for implementation of the Surface Water Treatment Rules.

Assessing the Impact of Sublimation on the Stable Water Isotope Signal of Surface Ice

NASA Astrophysics Data System (ADS)

Dennis, D. P.; Ehrenfeucht, S.; Marchant, D. R.

2017-12-01

Sublimation is often a significant, if not the dominant, mechanism for ablation in polar and high elevation glacial systems. Previous field studies on firn and ice have suggested that sublimation can enrich the stable water isotope (δD and δ18O) signatures of these exposed materials. Several additional studies have attempted to replicate this effect through laboratory experiments. However, neither the magnitude of alteration caused by sublimation nor the maximum depth at which ice is affected are well-constrained. The effect of sublimation-induced alteration on the original meteoric signal relative to other post-depositional processes is additionally unknown. Here, we present the results of an experimental study on the effect of sublimation on stable water isotope ratios in surface ice. Using high-resolution data, we attempt to assess the suitability of δD and δ18O in near-surface and exposed ice for use as paleoclimate proxies. This type of analysis is particularly useful for future studies of ice from hyper-arid polar regions like the Antarctic McMurdo Dry Valleys, and may be extended to icy planetary bodies, including surface ice on Mars.

Water chemistry of surface waters affected by the Fourmile Canyon wildfire, Colorado, 2010-2011

USGS Publications Warehouse

McCleskey, R. Blaine; Writer, Jeffrey H.; Murphy, Sheila F.

2012-01-01

In September 2010, the Fourmile Canyon fire burned about 23 percent of the Fourmile Creek watershed in Boulder County, Colo. Water-quality sampling of Fourmile Creek began within a month after the wildfire to assess its effects on surface-water chemistry. Water samples were collected from five sites along Fourmile Creek (above, within, and below the burned area) monthly during base flow, twice weekly during snowmelt runoff, and at higher frequencies during storm events. Stream discharge was also monitored. Water-quality samples were collected less frequently from an additional 6 sites on Fourmile Creek, from 11 tributaries or other inputs, and from 3 sites along Boulder Creek. The pH, electrical conductivity, temperature, specific ultraviolet absorbance, total suspended solids, and concentrations (dissolved and total) of major cations (calcium, magnesium, sodium, and potassium), anions (chloride, sulfate, alkalinity, fluoride, and bromide), nutrients (nitrate, ammonium, and phosphorus), trace metals (aluminum, arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, iron, mercury, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, strontium, vanadium, and zinc), and dissolved organic carbon are here reported for 436 samples collected during 2010 and 2011.

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

USGS Publications Warehouse

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

Surface, Water and Air Biocharacterization (SWAB)

NASA Image and Video Library

2009-08-18

ISS020-E-031558 (18 Aug. 2009) --- NASA astronaut Michael Barratt, Expedition 20 flight engineer, conducts a Surface, Water and Air Biocharacterization (SWAB) water sampling from the Potable Water Dispenser (PWD) in the Destiny laboratory of the International Space Station. SWAB uses advanced molecular techniques to comprehensively evaluate microbes onboard the space station, including pathogens (organisms that may cause disease). This study will allow an assessment of the risk of microbes to the crew and the spacecraft.

Transforming Surface Water Hydrology Through SWOT Altimetry

NASA Astrophysics Data System (ADS)

Alsdorf, Douglas; Mognard, Nelly; Rodriguez, Ernesto

2013-09-01

SWOT will measure water surface elevations across rivers, lakes, wetlands, and reservoirs with a 120km wide swath using decimeter-scale pixels having centimetric-scale height accuracies. Nothing like this "water surface topography" has been collected on a consistent basis from any method. Thus, SWOT will provide a transformative measurement for global hydrology. Storage change measurements from SWOT are expected to have an error of 10% or better for 250m2 and larger water bodies. Discharge estimation is complicated by the lack of channel bathymetric knowledge. Nevertheless, two model-based studies of the Ohio River suggest SWOT discharge errors will be 10%. Important questions will be addressed via SWOT measurements, e.g., (1) What is the water balance of the Congo Basin and indeed of any basin? (2) Where does a wetland receive its water: from upland runoff or from an adjacent river? (3) What are the implications for transboundary rivers?

Sampling procedure for lake or stream surface water chemistry

Treesearch

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.

Fast Transport of Water Droplets over a Thermo-Switchable Surface Using Rewritable Wettability Gradient.

PubMed

Banuprasad, Theneyur Narayanaswamy; Vinay, Thamarasseril Vijayan; Subash, Cherumannil Karumuthil; Varghese, Soney; George, Sajan D; Varanakkottu, Subramanyan Namboodiri

2017-08-23

In spite of the reported temperature dependent tunability in wettability of poly(N-isopropylacrylamide) (PNIPAAm) surfaces for below and above lower critical solution temperature (32 °C), the transport of water droplets is inhibited by the large contact angle hysteresis. Herein, for the first time, we report on-demand, fast, and reconfigurable droplet manipulation over a PNIPAAm grafted structured polymer surface using temperature-induced wettability gradient. Our study reveals that the PNIPAAm grafted on intrinsically superhydrophobic surfaces exhibit hydrophilic nature with high contact angle hysteresis below 30 °C and superhydrophobic nature with ultralow contact angle hysteresis above 36 °C. The transition region between 30 and 36 °C is characterized by a large change in water contact angle (∼100°) with a concomitant change in contact angle hysteresis. By utilizing this "transport zone" wherein driving forces overcome the frictional forces, we demonstrate macroscopic transport of water drops with a maximum transport velocity of approximately 40 cm/s. The theoretical calculations on the force measurements concur with dominating behavior of driving forces across the transport zone. The tunability in transport velocity by varying the temperature gradient along the surface or the inclination angle of the surface (maximum angle of 15° with a reduced velocity 0.4 mm/s) is also elucidated. In addition, as a practical application, coalescence of water droplets is demonstrated by using the temperature controlled wettability gradient. The presented results are expected to provide new insights on the design and fabrication of smart multifunctional surfaces for applications such as biochemical analysis, self-cleaning, and microfluidics.

Temperature Dependence of Cryogenic Ammonia-Water Ice Mixtures and Implications for Icy Satellite Surfaces

NASA Technical Reports Server (NTRS)

Dalton, J. B., III; Curchin, J. M.; Clark, R. N.

2001-01-01

Infrared spectra of ammonia-water ice mixtures reveal temperature-dependent absorption bands due to ammonia. These features, at 1.04, 2.0, and 2.25 microns, may shed light on the surface compositions of the Galilean and Saturnian satellites. Additional information is contained in the original extended abstract.

Pathways of upwelling deep waters to the surface of the Southern Ocean

NASA Astrophysics Data System (ADS)

Tamsitt, Veronica; Drake, Henri; Morrison, Adele; Talley, Lynne; Dufour, Carolina; Gray, Alison; Griffies, Stephen; Mazloff, Matthew; Sarmiento, Jorge; Wang, Jinbo; Weijer, Wilbert

2017-04-01

Upwelling of Atlantic, Indian and Pacific deep waters to the sea surface in the Southern Ocean closes the global overturning circulation and is fundamentally important for oceanic uptake of anthropogenic carbon and heat, nutrient resupply for sustaining oceanic biological production, and the melt rate of ice shelves. Here we go beyond the two-dimensional view of Southern Ocean upwelling, to show detailed Southern Ocean upwelling pathways in three dimensions, using hydrographic observations and particle tracking in high-resolution ocean and climate models. The northern deep waters enter the Antarctic Circumpolar Current (ACC) via narrow southward currents along the boundaries of the three ocean basins, before spiraling southeastward and upward through the ACC. Upwelling is greatly enhanced at five major topographic features, associated with vigorous mesoscale eddy activity. Deep water reaches the upper ocean predominantly south of the southern ACC boundary, with a spatially nonuniform distribution, regionalizing warm water supply to Antarctic ice shelves and the delivery of nutrient and carbon-rich water to the sea surface. The timescale for half of the deep water to upwell from 30°S to the mixed layer is on the order of 60-90 years, which has important implications for the timescale for signals to propagate through the deep ocean. In addition, we quantify the diabatic transformation along particle trajectories, to identify where diabatic processes are important along the upwelling pathways.

Bubble formation in water with addition of a hydrophobic solute.

PubMed

Okamoto, Ryuichi; Onuki, Akira

2015-07-01

We show that phase separation can occur in a one-component liquid outside its coexistence curve (CX) with addition of a small amount of a solute. The solute concentration at the transition decreases with increasing the difference of the solvation chemical potential between liquid and gas. As a typical bubble-forming solute, we consider O2 in ambient liquid water, which exhibits mild hydrophobicity and its critical temperature is lower than that of water. Such a solute can be expelled from the liquid to form gaseous domains while the surrounding liquid pressure is higher than the saturated vapor pressure p cx. This solute-induced bubble formation is a first-order transition in bulk and on a partially dried wall, while a gas film grows continuously on a completely dried wall. We set up a bubble free energy ΔG for bulk and surface bubbles with a small volume fraction ϕ. It becomes a function of the bubble radius R under the Laplace pressure balance. Then, for sufficiently large solute densities above a threshold, ΔG exhibits a local maximum at a critical radius and a minimum at an equilibrium radius. We also examine solute-induced nucleation taking place outside CX, where bubbles larger than the critical radius grow until attainment of equilibrium.

Fabrication of superhydrophobic copper surface on various substrates for roll-off, self-cleaning, and water/oil separation.

PubMed

Sasmal, Anup Kumar; Mondal, Chanchal; Sinha, Arun Kumar; Gauri, Samiran Sona; Pal, Jaya; Aditya, Teresa; Ganguly, Mainak; Dey, Satyahari; Pal, Tarasankar

2014-12-24

Superhydrophobic surfaces prevent percolation of water droplets and thus render roll-off, self-cleaning, corrosion protection, etc., which find day-to-day and industrial applications. In this work, we developed a facile, cost-effective, and free-standing method for direct fabrication of copper nanoparticles to engender superhydrophobicity for various flat and irregular surfaces such as glass, transparency sheet (plastic), cotton wool, textile, and silicon substrates. The fabrication of as-prepared superhydrophobic surfaces was accomplished using a simple chemical reduction of copper acetate by hydrazine hydrate at room temperature. The surface morphological studies demonstrate that the as-prepared surfaces are rough and display superhydrophobic character on wetting due to generation of air pockets (The Cassie-Baxter state). Because of the low adhesion of water droplets on the as-prepared surfaces, the surfaces exhibited not only high water contact angle (164 ± 2°, 5 μL droplets) but also superb roll-off and self-cleaning properties. Superhydrophobic copper nanoparticle coated glass surface uniquely withstands water (10 min), mild alkali (5 min in saturated aqueous NaHCO3 of pH ≈ 9), acids (10 s in dilute HNO3, H2SO4 of pH ≈ 5) and thiol (10 s in neat 1-octanethiol) at room temperature (25-35 °C). Again as-prepared surface (cotton wool) was also found to be very effective for water-kerosene separation due to its superhydrophobic and oleophilic character. Additionally, the superhydrophobic copper nanoparticle (deposited on glass surface) was found to exhibit antibacterial activity against both Gram-negative and Gram-positive bacteria.

Evaluation of Surface Quality of Silicone Impression Materials after Disinfection with Ozone Water: An In vitro Study.

PubMed

Abinaya, K; Muthu Kumar, B; Ahila, S C

2018-01-01

To compare and evaluate the surface quality of silicone impression materials after ozone water disinfection. A total of 60 samples were prepared on a stainless steel die (American Dental Association specification no. 19 and International Standard of Organization - 4823). The samples were divided into four groups; each group contains 15 samples. Group A as control, Group B, C, and D disinfected with 2% glutaraldehyde, 5.25% sodium hypochlorite, and ozone water, respectively. The samples were made according to the manufacturer's instructions, and the samples were allowed to set in a thermostatically controlled water bath at 35°C ± 1°C and retrieved after 10 min. The surface qualities of the samples were measured in stereomicroscope with ×20 magnification. The data obtained were analyzed using Chi-square test, and the " P " value was calculated. The results showed that there were no differences in the surface quality among the Groups A, C, and D for addition silicone putty and light body and medium body impression materials than the Group B. This study concluded that ozone water disinfection showed least changes when compared to 5.25%sodium hypochloride and 2% glutaraldehyde disinfection for addition silicone putty , light body and medium body impression materials.

Methods and energy storage devices utilizing electrolytes having surface-smoothing additives

DOEpatents

Xu, Wu; Zhang, Jiguang; Graff, Gordon L; Chen, Xilin; Ding, Fei

2015-11-12

Electrodeposition and energy storage devices utilizing an electrolyte having a surface-smoothing additive can result in self-healing, instead of self-amplification, of initial protuberant tips that give rise to roughness and/or dendrite formation on the substrate and anode surface. For electrodeposition of a first metal (M1) on a substrate or anode from one or more cations of M1 in an electrolyte solution, the electrolyte solution is characterized by a surface-smoothing additive containing cations of a second metal (M2), wherein cations of M2 have an effective electrochemical reduction potential in the solution lower than that of the cations of M1.

Hydrogeology and ground-water/surface water interactions in the Des Moines River valley, southwestern Minnesota, 1997-2001

USGS Publications Warehouse

Cowdery, Timothy K.

2005-01-01

Long-term withdrawals of water for public supplies may cause a net decrease in ground-water discharge to surface water. Water that does not evaporate, or that is not exported, is discharged to the Des Moines River but with changed water quality. Because ground-water and surface-water qualities in the study area are similar, the ground-water discharge probably has little effect on river water quality.

The Role of Surface Water for the Branching Geometry of Mars' Channel Networks

NASA Astrophysics Data System (ADS)

Seybold, H. F.; Rothman, D.; Kirchner, J. W.

2016-12-01

The controversy over the origin of Mars' channel networks is almost as old as their discovery 150 years ago. In recent decades, new Mars probe missions have revealed detailed network structures, and new studies suggest that Mars once had an active hydrologic cycle. But how this water flowed and how it could have carved these huge channel networks remains unclear. A recent analysis of high-resolution data for the Continental United States suggests that climate leaves a characteristic imprint in the branching geometry of stream networks: arid regions dominated by overland or near-surface flows have much narrower branching angles than humid regions with greater groundwater recharge. Based on this result we analyze the channel networks of Mars, and find that their geometry resembles those created by near-surface and overland flows on Earth. This result gives additional support to the hypothesis that Mars once had a more active hydrologic cycle, with liquid water flowing over its surface.

Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

USGS Publications Warehouse

Hanson, R.T.; Li, Zhen; Faunt, C.C.

2004-01-01

The Santa Clara Valley is a long, narrow trough extending about 35 miles southeast from the southern end of San Francisco Bay where the regional alluvial-aquifer system has been a major source of water. Intensive agricultural and urban development throughout the 20th century and related ground-water development resulted in ground-water-level declines of more than 200 feet and land subsidence of as much as 12.7 feet between the early 1900s and the mid-1960s. Since the 1960s, Santa Clara Valley Water District has imported surface water to meet growing demands and reduce dependence on ground-water supplies. This importation of water has resulted in a sustained recovery of the ground-water flow system. To help support effective management of the ground-water resources, a regional ground-water/surface-water flow model was developed. This model simulates the flow of ground water and surface water, changes in ground-water storage, and related effects such as land subsidence. A numerical ground-water/surface-water flow model of the Santa Clara Valley subbasin of the Santa Clara Valley was developed as part of a cooperative investigation with the Santa Clara Valley Water District. The model better defines the geohydrologic framework of the regional flow system and better delineates the supply and demand components that affect the inflows to and outflows from the regional ground-water flow system. Development of the model includes revisions to the previous ground-water flow model that upgraded the temporal and spatial discretization, added source-specific inflows and outflows, simulated additional flow features such as land subsidence and multi-aquifer wellbore flow, and extended the period of simulation through September 1999. The transient-state model was calibrated to historical surface-water and ground-water data for the period 197099 and to historical subsidence for the period 198399. The regional ground-water flow system consists of multiple aquifers that are grouped

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

PubMed

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.

The Influence of Climate Change on Irrigated Water Demands and Surface Water Availability of the Yellow River Basin

NASA Astrophysics Data System (ADS)

Troy, T. J.; Zhang, J.

2017-12-01

Balancing irrigated water demands and surface water availability is critical for sustainable water resources management. In China, irrigation is the largest water user, and there is concern that irrigated water demands will be affected by climate change. If the relationship between climate change, irrigated water demands and surface water availability is quantified, then effective measures can be developed to maintain food production while ensuring water sustainability. This research focuses on the Yellow River, the second longest in China, and analyzes the impact of historical and projected climate change on agricultural water demands and surface water availability. Corn and wheat are selected as representative crops to estimate the effect of temperature and precipitin changes on irrigated water demands. The VIC model is used to simulate daily streamflow throughout the Yellow River, providing estimates of surface water availability. Overall, results indicate the irrigated water need and surface water availability are impacted by climate change, with spatially varying impacts depending on spatial patterns of climate trends and river network position. This research provides insight into water security in the Yellow River basin, indicating where water efficiency measures are needed and where they are not.

DETECTION OF A GROUND-WATER/SURFACE-WATER INTERFACE WITH DIRECT-PUSH EQUIPMENT

EPA Science Inventory

A ground-water/surface-water interface (GSI) was documented at the Thermo Chem CERCLA Site in Muskegon, MI via direct-push (DP) sampling. At that time, contaminated ground water flowed from the upland area of the site into the Black Creek floodplain. DP rods equipped with a 1.5...

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

PubMed Central

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.

PubMed

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

2018-04-19

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.

Herbicide Metabolites in Surface Water and Groundwater: Introduction and Overview

USGS Publications Warehouse

Thurman, E.M.; Meyer, M.T.

1996-01-01

Several future research topics for herbicide metabolites in surface and ground water are outlined in this chapter. They are herbicide usage, chemical analysis of metabolites, and fate and transport of metabolites in surface and ground water. These three ideas follow the themes in this book, which are the summary of a symposium of the American Chemical Society on herbicide metabolites in surface and ground water. First, geographic information systems allow the spatial distribution of herbicide-use data to be combined with geochemical information on fate and transport of herbicides. Next these two types of information are useful in predicting the kinds of metabolites present and their probable distribution in surface and ground water. Finally, methods development efforts may be focused on these specific target analytes. This chapter discusses these three concepts and provides an introduction to this book on the analysis, chemistry, and fate and transport of herbicide metabolites in surface and ground water.

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

PubMed

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.

Spatial and Temporal Scales of Surface Water-Groundwater Interactions

NASA Astrophysics Data System (ADS)

Boano, F.

2016-12-01

The interfaces between surface water and groundwater (i.e., river and lake sediments) represent hotspots for nutrient transformation in watersheds. This intense biochemical activity stems from the peculiar physicochemical properties of these interface areas. Here, the exchange of water and nutrients between surface and subsurface environments creates an ecotone region that can support the presence of different microbial species responsible for nutrient transformation. Previous studies have elucidated that water exchange between rivers and aquifers is organized in a complex system of nested flow cells. Each cell entails a range of residence timescales spanning multiple order of magnitudes, providing opportunities for different biochemical reactions to occur. Physically-bases models represent useful tools to deal with the wide range of spatial and temporal scales that characterize surface-subsurface water exchange. This contribution will present insights about how hydrodynamic processes control scale organization for surface water - groundwater interactions. The specific focus will be the influence of exchange processes on microbial activity and nutrient transformation, discussing how groundwater flow at watershed scale controls flow conditions and hence constrain microbial reactions at much smaller scales.

Water Surface Impact and Ricochet of Deformable Elastomeric Spheres

NASA Astrophysics Data System (ADS)

Hurd, Randy C.

Soft and deformable silicone rubber spheres ricochet from a water surface when rigid spheres and disks (or skipping stones) cannot. This dissertation investigates why these objects are able to skip so successfully. High speed cameras allow us to see that these unique spheres deform significantly as they impact the water surface, flattening into pancake-like shapes with greater area. Though the water entry behavior of deformable spheres deviates from that of rigid spheres, our research shows that if this deformation is accounted for, their behavior can be predicted from previously established methods. Soft spheres skip more easily because they deform significantly when impacting the water surface. We present a diagram which enables the prediction of a ricochet from sphere impact conditions such as speed and angle. Experiments and mathematical representations of the sphere skipping both show that these deformable spheres skip more readily because deformation momentarily increases sphere area and produces an attack angle with the water which is favorable to skipping. Predictions from our mathematical representation of sphere skipping agree strongly with observations from experiments. Even when a sphere was allowed to skip multiple times in the laboratory, the mathematical predictions show good agreement with measured impact conditions through subsequent skipping events. While studying multiple impact events in an outdoor setting, we discovered a previously unidentified means of skipping, which is unique to deformable spheres. This new skipping occurs when a relatively soft sphere first hits the water at a high speed and low impact angle and the sphere begins to rotate very quickly. This quick rotation causes the sphere to stretch into a shape similar to an American football and maintain this shape while it spins. The sphere is observed to move nearly parallel with the water surface with the tips of this "football" dipping into the water as it rotates and the sides

Storm water contamination and its effect on the quality of urban surface waters.

PubMed

Barałkiewicz, Danuta; Chudzińska, Maria; Szpakowska, Barbara; Świerk, Dariusz; Gołdyn, Ryszard; Dondajewska, Renata

2014-10-01

We studied the effect of storm water drained by the sewerage system and discharged into a river and a small reservoir, on the example of five catchments located within the boundaries of the city of Poznań (Poland). These catchments differed both in terms of their surface area and land use (single- and multi-family housing, industrial areas). The aim of the analyses was to explain to what extent pollutants found in storm water runoff from the studied catchments affected the quality of surface waters and whether it threatened the aquatic organisms. Only some of the 14 studied variables and 22 chemical elements were important for the water quality of the river, i.e., pH, TSS, rain intensity, temperature, conductivity, dissolved oxygen, organic matter content, Al, Cu, Pb, Zn, Fe, Cd, Ni, Se, and Tl. The most serious threat to biota in the receiver came from the copper contamination of storm water runoff. Of all samples below the sewerage outflow, 74% exceeded the mean acute value for Daphnia species. Some of them exceeded safe concentrations for other aquatic organisms. Only the outlet from the industrial area with the highest impervious surface had a substantial influence on the water quality of the river. A reservoir situated in the river course had an important influence on the elimination of storm water pollution, despite the very short residence time of its water.

Occurrence and Distribution of Organophosphate Flame Retardants/Plasticizers in Surface Waters, Tap Water, and Rainwater: Implications for Human Exposure.

PubMed

Kim, Un-Jung; Kannan, Kurunthachalam

2018-04-27

The occurrence and profiles of 14 triester organophosphate flame retardants (OPFRs) and plasticizers were investigated in surface water, tap water, rainwater, and seawater collected from New York State. In total, 150 samples collected from rivers ( n = 35), lakes ( n = 39), tap water ( n = 58), precipitation/rainwater ( n = 15), and seawater ( n = 3) were analyzed for 14 organophosphate esters (OPEs). An additional nine Hudson River water samples were collected periodically to delineate seasonal trends in OPE levels. The total concentrations of OPEs were found at part-per-trillion ranges, with average concentrations that ranged from 0.01 ng/L for tripropyl phosphate (TPP) in river water to 689 ng/L for tris(2-butoxyethyl)phosphate (TBOEP) in lake water. Tris(1-chloro-2-propyl)phosphate (TCIPP) was the most abundant compound among the investigated OPEs in all types of water. The concentrations of OPEs in river-, lake-, and rainwater were similar but >3 times higher than those found in tap water. Chlorinated alkyl OPFRs accounted for a major proportion of total concentrations. TCIPP, TBOEP, and triethyl phosphate (TEP) were found in >90% of the samples analyzed. Wet deposition fluxes for 14 OPFRs were estimated, on the basis of the concentrations measured in rainwater in Albany, New York, and the values were between 440 and 5250 ng/m 2 . Among several surface water bodies analyzed, samples from the Hudson River and Onondaga Lake contained elevated concentrations of OPEs. Estimated daily intake of OPEs via the ingestion of drinking water was up to 9.65 ng/kg body weight/day.

A Probabilistic Analysis of Surface Water Flood Risk in London.

PubMed

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

2018-06-01

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.

Chlorine stress mediates microbial surface attachment in drinking water systems.

PubMed

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.

Effects of Dimethyl Sulfoxide on Surface Water near Phospholipid Bilayers.

PubMed

Lee, Yuno; Pincus, Philip A; Hyeon, Changbong

2016-12-06

Despite much effort to probe the properties of dimethyl sulfoxide (DMSO) solution, the effects of DMSO on water, especially near plasma membrane surfaces, still remain elusive. By performing molecular dynamics simulations at varying DMSO concentrations (X DMSO ), we study how DMSO affects structural and dynamical properties of water in the vicinity of phospholipid bilayers. As proposed by a number of experiments, our simulations confirm that DMSO induces dehydration from bilayer surfaces and disrupts the H-bond structure of water. However, DMSO-enhanced water diffusivity at solvent-bilayer interfaces, an intriguing discovery reported by a spin-label measurement, is not confirmed in our simulations. To resolve this discrepancy, we examine the location of the spin label (Tempo) relative to the solvent-bilayer interface. In accord with the evidence in the literature, our simulations, which explicitly model Tempo-phosphatidylcholine, find that the Tempo moiety is equilibrated at ∼8-10 Å below the bilayer surface. Furthermore, the DMSO-enhanced surface-water diffusion is confirmed only when water diffusion is analyzed around the Tempo moiety that is immersed below the bilayer surface, which implies that the experimentally detected signal of water using Tempo stems from the interior of bilayers, not from the interface. Our analysis finds that the increase of water diffusion below the bilayer surface is coupled to the increase of area per lipid with an increasing X DMSO (≲10mol%). Underscoring the hydrophobic nature of the Tempo moiety, our study calls for careful re-evaluation of the use of Tempo in measurements on lipid bilayer surfaces. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Surface tension isotherms of the dioxane-acetone-water and glycerol-ethanol-water ternary systems

NASA Astrophysics Data System (ADS)

Dzhambulatov, R. S.; Dadashev, R. Kh.; Elimkhanov, D. Z.; Dadashev, I. N.

2016-10-01

The results of the experimental and theoretical studies of the concentration dependence of surface tension of aqueous solutions of the 1,4-dioxane-acetone-water and glycerol-ethanol-water ternary systems were given. The studies were performed by the hanging-drop method on a DSA100 tensiometer. The maximum error of surface tension was 1%. The theoretical models for calculating the surface tension of the ternary systems of organic solutions were analyzed.

Coupling surface water (Delft3D) to groundwater (MODFLOW) in the Bay-Delta community model: the effect of major abstractions in the Delta

NASA Astrophysics Data System (ADS)

Hendriks, D.; Ball, S. M.; Van der Wegen, M.; Verkaik, J.; van Dam, A.

2016-12-01

We present a coupled groundwater-surface water model for the San Francisco Bay and Sacramento Valley that consists of a combination of a spatially-distributed groundwater model (Modflow) based on the USGS Central Valley model(1) and the Flexible Mesh (FM) surface water model of the Bay Area(2). With this coupled groundwater-surface water model, we assessed effects of climate, surface water abstractions and groundwater pumping on surface water and groundwater levels, groundwater-surface water interaction and infiltration/seepage fluxes. Results show that the effect of climate (high flow and low flow) on surface water and groundwater is significant and most prominent in upstream areas. The surface water abstractions cause significant local surface water levels decrease (over 2 m), which may cause inflow of bay water during low flow periods, resulting in salinization of surface water in more upstream areas. Groundwater level drawdown due to surface water withdrawal is moderate and limited to the area of the withdrawals. The groundwater pumping causes large groundwater level drawdowns (up to 0.8 m) and significant changes in seepage/infiltration fluxes in the model. However, the effect on groundwater-surface water exchange is relatively small. The presented model instrument gives a sound first impression of the effects of climate and water abstraction on both surface water and groundwater. The combination of Modflow and Flexible Mesh has potential for modelling of groundwater-surface water exchange in deltaic areas, also in other parts of the world. However, various improvements need to be made in order to make the simulation results useful in practice. In addition, a water quality aspect could be added to assess salinization processes as well as groundwater-surface water aspects of water and soil pollution. (1) http://ca.water.usgs.gov/projects/central-valley/central-valley-hydrologic-model.html (2) www.d3d-baydelta.org

Suppression of polymethyl methacrylate dust explosion by ultrafine water mist/additives.

PubMed

Gan, Bo; Li, Bei; Jiang, Haipeng; Bi, Mingshu; Gao, Wei

2018-06-05

The suppressions of ultrafine water mists containing additives (NaCl and NaHCO 3 ) on 100 nm, 5 μm, and 30 μm polymethyl methacrylate (PMMA) dust explosions were experimentally studied in a dust-explosion apparatus. High-speed photography showed that maximum vertical positions and flame propagation velocities were significantly decreased by suppression with ultrafine water mist/additives. Flame propagation velocities in 100 nm, 5 μm, and 30 μm dust explosions suppressed by the ultrafine pure water mist were reduced by 48.2%, 27.7%, and 15.3%, respectively. Maximum temperatures and temperature rising rates measured by a fine thermocouple in nano- and micro-PMMA dust explosions were also significantly decreased. It was proved that the addition of NaCl and NaHCO 3 improved the suppression effects of the ultrafine pure water mist. The improvement of explosion suppression by an 8% NaHCO 3 mist was superior to that of a 16% NaCl mist. The suppression mechanisms of ultrafine water mist/additives are further discussed by analyzing the physical and chemical effects. Copyright © 2018 Elsevier B.V. All rights reserved.

Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface

PubMed Central

2014-01-01

The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties. PMID:25243045

Roles of additives and surface control in slurry atomization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, S.C.

1990-01-01

This report focuses on the effects of interparticle forces on the rheology and airblast atomization of micronized coal water slurry (CWS). We found that the CWS flow behavior index is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The former intensifies as the Hamaker constant increases and the interparticle distance reduces while the latter increases as the particle surface charge density increases. The interparticle attraction causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior. In contrast, the interparticle repulsion prevents particle aggregation andmore » thus leads to Newtonian behavior. Both atomized at low atomizing air pressures (less than 270 kPa) using twin-fluid jet atomizers of various distributor designs. We found that the atomized drop sizes of micronized coal water slurries substantially decrease as the atomizing air pressure exceeds a threshold value. The effects of coal volume fraction, coal particle surface charge, liquid composition and liquid viscosity on slurry atomization can be accounted for by their effects on slurry rheology. 26 refs.« less

Recent advances in understanding the interaction of groundwater and surface water

USGS Publications Warehouse

Winter, Thomas C.

1995-01-01

The most common image of the interaction of groundwater and surface water is that of the interaction of streams with a contiguous alluvial aquifer. This type of system has been the focus of study for more than 100 years, from the work of Boussinesq (1877) to the present, and stream-aquifer interaction continues to be the most common topic of papers discussing the interaction of groundwater and surface water. However, groundwater and surface water interact in a wide variety of landscapes from alpine to coastal. Within these landscapes, ground-water systems range in scale from local to regional, and the types of surface water include streams, lakes, wetlands, and oceans. Given the broad spectrum of the topic of groundwater and surface water interaction, an overview of studies of this topic could be organized according to surface water type, landscape type, scale of hydrologic systems, or field and analytical methods. All these factors are discussed, but this paper is organized according to landscape type because of the great increase in studies of the interaction of groundwater and surface water in landscapes other than riverine systems in the last 15 years. Furthermore, discussing studies by landscape type facilitates comparison of methods and results from different geologic and climatic settings. The general landscapes discussed are mountain terrane, riverine systems, coastal terrane, hummocky terrane, and karst terrane.

Coastal groundwater/surface-water interactions: a Great Lakes case study