WorldWideScience

Sample records for currents water properties

  1. Analysis of Water Properties and Geostrophic Currents in Fiji Waters Before and After Tropical Cyclone Gene

    Directory of Open Access Journals (Sweden)

    Shivneel Prasad

    2009-01-01

    Full Text Available Problem statement: Water properties influence ocean primary production and drive the ocean food chain. This study depicts changes in temperature and salinity and its effects on geostrophic currents near Fiji before and after Tropical Cyclone (TC Gene. Approach: Available Argo float data from 6 January-4 February 2008 were used for analysis since TC Gene passed the area on 28 January 2008. The dynamic height and geostrophic current data were obtained from the Aviso website. Results: The thermocline depth increased by 20 m after the cyclone. A temperature drop of approximately 3°C was also noticed in the study area. Using this drop in temperature, the heat energy removed by the cyclone was calculated to be 0.095 MWh m-2. Salinity profiles showed an increase of 0.42 psu to a depth of 35 m after the cyclone. Changes in salinity and temperature of water may also cause changes in the dynamic height and in turn the geostrophic current patterns. After plotting the geostrophic current vectors, it was observed that the current patterns changed significantly after TC gene. Seasonal changes were also evident before the cyclone. Conclusion/Recommendations: Although the lifespan of TC gene was short, its effect on the water properties near Fiji was significant as it completely changed the geostrophic current patterns and this can have a huge implication on marine life.

  2. Secondary current properties generated by wind-induced water waves in experimental conditions

    Directory of Open Access Journals (Sweden)

    Michio Sanjou

    2014-06-01

    Full Text Available Secondary currents such as the Langmuir circulation are of high interest in natural rivers and the ocean because they have striking impacts on scour, sedimentation, and mass transport. Basic characteristics have been well-studied in straight open-channel flows. However, little is known regarding secondary circulation induced by wind waves. The presented study describes the generation properties of wind waves observed in the laboratory tank. Wind-induced water waves are known to produce large scale circulations. The phenomenon is observed together with high-speed and low-speed streaks, convergence and divergence zones, respectively. Therefore, it is important to determine the hydrodynamic properties of secondary currents for wind-induced water waves within rivers and lakes. In this study, using two high-speed CMOS cameras, stereoscopic particle image velocimetry (PIV measurements were conducted in order to reveal the distribution of all three components of velocity vectors. The experiments allowed us to investigate the three-dimensional turbulent structure under water waves and the generation mechanism of large-scale circulations. Additionally, a third CMOS camera was used to measure the spanwise profile of thefree-surface elevation. The time-series of velocity components and the free-surface were obtained simultaneously. From our experiments, free-surface variations were found to influence the instantaneous velocity distributions of the cross-sectional plane. We also considered thegeneration process by the phase analysis related to gravity waves and compared the contribution of the apparent stress.

  3. Alongcoast structure and interannual variability of seasonal midshelf water properties and velocity in the Northern California Current System

    Science.gov (United States)

    Hickey, B.; Geier, S.; Kachel, N.; Ramp, S.; Kosro, P. M.; Connolly, T.

    2016-10-01

    Moored sensors were maintained for ˜5 years on the northern California Current System (CCS) midshelf. The alongcoast sensor array spanned the area of influence of the plume from the Columbia River, several submarine canyons, as well as a coastal promontory where the equatorward coastal jet frequently separates from the shelf. Upwelling-favorable wind stress magnitude decreases poleward by more than a factor of three over the latitudinal range and shelf width varies by a factor of two. In spite of the alongcoast structure in setting, both seasonal and interannual patterns in subsurface layer water properties were remarkably similar at all sites. Higher in the water column, freshwater forcing was substantial. Because of the near surface freshwater input, seasonal sea surface and subsurface temperatures were almost perfectly out of phase in the northernmost CCS, with a mid water column inversion in winter. Year to year differences in subsurface layer wintertime water properties were similar to spatial and temporal patterns of wind stress variability: little alongcoast structure except in salinity, but pronounced interannual differences strongly related to local wind stress. Summertime wind and subsurface property patterns were the opposite of those in winter: pronounced alongcoast wind stress structure, but little or no alongcoast or interannual variability in water properties, and only a weak relationship to local wind stress. Summertime interannual water property variability, including source waters, was shown to be more consistent with "remote forcing" via larger scale wind stress rather than with local wind stress, particularly in the northernmost CCS.

  4. Application of hydrographic and surface current data to describe water properties in the Porsangerfjorden, Norway

    Science.gov (United States)

    Cieszyńska, Agata; Białogrodzka, Jagoda; Yngve Børsheim, Knut; Stramska, Małgorzata; Jankowski, Andrzej

    2016-04-01

    This presentation is a part of the NORDFLUX project, and describes some of the results from experimental work carried out in 2014 in the Porsangerfjorden located in the area of the European Arctic. The fjord borders the Barents Sea. This is a region of high climatic sensitivity and our interest in the basin stemmed from this fact. One of our long-term goals is to develop an improved understanding of the undergoing changes and interactions between this fjord and the large-scale atmospheric and oceanic conditions. In present work we focus on data sets collected with High Frequency (HF) radars monitoring surface currents in the outer part of the Porsnagerfjorden. In our analysis we also use data on water salinity and temperature collected as part of the NORDFLUX experiment, and data from sea level and meteorological station located in Honningsvaag. Analysis of data sets enabled us to describe water salinity, temperature, density distributions and their variability. What is more, we have related aforementioned results to tides, meteorological conditions, and sea surface currents speed and directions. During the poster session the Author will present the schemes of water masses movement in the area of interest. This work was funded by the Norway Grants through the Polish-Norwegian Research Programme, National Centre for Research and Development (contract No. 201985). Project title: 'Application of in situ observations, high frequency radars, and ocean color, to study suspended matter, particulate carbon, and dissolved organic carbon fluxes in coastal waters of the Barents Sea'.

  5. Optimum structural properties for an anode current collector used in a polymer electrolyte membrane water electrolyzer operated at the boiling point of water

    Science.gov (United States)

    Li, Hua; Fujigaya, Tsuyohiko; Nakajima, Hironori; Inada, Akiko; Ito, Kohei

    2016-11-01

    This study attempts to optimize the properties of the anode current collector of a polymer electrolyte membrane water electrolyzer at high temperatures, particularly at the boiling point of water. Different titanium meshes (4 commercial ones and 4 modified ones) with various properties are experimentally examined by operating a cell with each mesh under different conditions. The average pore diameter, thickness, and contact angle of the anode current collector are controlled in the ranges of 10-35 μm, 0.2-0.3 mm, and 0-120°, respectively. These results showed that increasing the temperature from the conventional temperature of 80 °C to the boiling point could reduce both the open circuit voltage and the overvoltages to a large extent without notable dehydration of the membrane. These results also showed that decreasing the contact angle and the thickness suppresses the electrolysis overvoltage largely by decreasing the concentration overvoltage. The effect of the average pore diameter was not evident until the temperature reached the boiling point. Using operating conditions of 100 °C and 2 A/cm2, the electrolysis voltage is minimized to 1.69 V with a hydrophilic titanium mesh with an average pore diameter of 21 μm and a thickness of 0.2 mm.

  6. Water Current Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tidal, river and ocean current observations collected by the U.S. Coast and Geodetic Survey. Period of record is late 1800s to mid-1980s.

  7. The Savonius Water Current Meter

    Science.gov (United States)

    1960-11-03

    the author visited the David Taylor Model Basin for the purpose of calibrating five (5) Savonius water current ,meter rotors in the range of .1 to 1...Iastitution of Oceanography. Figure 1 is a block diagram of the water current meter and its associated equipment. The details of the Savonius rotor are...an amplifier. The Savonius rotor functions as a salt water switch which varies the r-. coupling of the transformer thus it awplitude modulates the 100

  8. Water Properties Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I project, Kaitech proposes to design a Water Properties Sensor (WPS) sensing system to synchronously measure the spectral inherent and apparent...

  9. Water Properties Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase II project, Kaitech proposes to develop and demonstrate a Water Properties Sensor (WPS) sensing system to synchronously measure the spectral inherent...

  10. WaterWatch -- Current Water Resources Conditions

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — WaterWatch (http://waterwatch.usgs.gov) is a U.S. Geological Survey (USGS) World Wide Web site that displays maps, graphs, and tables describing real-time, recent,...

  11. Structural features and functional properties of water in model DMPC membranes: thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) studies

    Science.gov (United States)

    Bridelli, M. G.; Capelletti, R.; Mora, C.

    2013-12-01

    Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectroscopies were employed to investigate the state of water incorporated in a model DMPC (dimyristoyl-phosphatidylcholine) membrane. The lipid multilayers, highly inhomogeneous from the dielectric point of view, originate complex TSDC spectra critically dependent on the sample water content and thermal history. Different temperature ranges were chosen to polarize the sample, i.e. 100-300 K (type I) and 100-285 K (type II). The purpose of the latter choice was to avoid any sample heating above the DMPC phase transition temperature (295 K) along the sample polarization. According to the results, water in a fully hydrated system (aw = 0.92) (1) is ordered around the hydrophilic head molecular groups, (2) is layered in the interbilayer space and (3) penetrates among the hydrocarbon chains. It can assume different local structural configurations depending on the lipid packing. Irreversible conformational transitions in the lipid array system were monitored as a consequence of different dehydration treatments. FTIR absorption measurements were performed to study the water sorption kinetics into a DMPC thin film. The water related OH band was decomposed into three components, describing three water states, with different propensity to the H-bond formation. The changes of the lipid characteristic groups (CH2/CH3, PO_{2}^{-} and C=O) absorption bands as a function of increasing hydration level were monitored and discussed.

  12. PROPERTIES OF SWIMMING WATER

    Directory of Open Access Journals (Sweden)

    Tayfun KIR

    2004-10-01

    Full Text Available Swimming waters may be hazardous on human health. So, The physicians who work in the facilities, which include swimming areas, are responsible to prevent risks. To ensure hygiene of swimming water, European Swimming Water Directive offers microbiological, physical, and chemical criteria. [TAF Prev Med Bull 2004; 3(5.000: 103-104

  13. PROPERTIES OF SWIMMING WATER

    OpenAIRE

    Tayfun KIR; Zakir COBANOÐLU

    2004-01-01

    Swimming waters may be hazardous on human health. So, The physicians who work in the facilities, which include swimming areas, are responsible to prevent risks. To ensure hygiene of swimming water, European Swimming Water Directive offers microbiological, physical, and chemical criteria. [TAF Prev Med Bull 2004; 3(5.000): 103-104

  14. Tidal power harnessing energy from water currents

    CERN Document Server

    Lyatkher, Victor

    2014-01-01

    As the global supply of conventional energy sources, such as fossil fuels, dwindles and becomes more and more expensive, unconventional and renewable sources of energy, such as power generation from water sources, is becoming more and more important.  Hydropower has been around for decades, but this book suggests new methods that are more cost-effective and less intrusive to the environment for creating power sources from rivers, the tides, and other sources of water.   The energy available from water currents is potentially much greater than society's needs.  Presenting a detailed discussi

  15. Critical current properties in HTS tapes

    Energy Technology Data Exchange (ETDEWEB)

    Kiss, T.; Inoue, M.; Kuga, T.; Ishimaru, M.; Egashira, S.; Irie, S.; Ohta, T.; Imamura, K.; Yasunaga, M.; Takeo, M.; Matsushita, T.; Iijima, Y.; Kakimoto, K.; Saitoh, T.; Awaji, S.; Watanabe, K.; Shiohara, Y

    2003-10-15

    The author's recent studies on the critical current properties in Bi-2223 multifilamentary tapes as well as YBCO coated IBAD tapes have been reviewed. Extended electric field vs. current density (E-J) characteristics were studied over wide range of temperature, T, magnetic field, B, and angle, {theta}. Based on the analysis of statistic J{sub c} distribution and scaling, we derived an analytical expression for J as a function of E, T, B, and {theta}. This method allows us to describe and extrapolate the nonlinear E-J characteristics even in extremely low E region and/or high B region based on rather simple measurements.

  16. Properties of Water in Nanovolumes

    CERN Document Server

    Górski, N I

    2003-01-01

    This small review considers results of investigations carried out at a small-angle scattering facility in Dubna (the fourth channel of the IBR-2 reactor) with the aim of studying the properties of water in small volumes. Some physical aspects of dimensional effects for water drops are discussed. Peculiarities of the micellar objects used for the studies are pointed out. It is shown that the density of water in small volumes differs severalfold from the macroscopic one. References to works on contrast variation published earlier are given.

  17. Current Water Issues Faced with Tianjin

    Institute of Scientific and Technical Information of China (English)

    刘柳

    2009-01-01

    Tianjin is the third biggest city in China,but currently facing a severe water shortage.Historically,due to Tianjin's geographic location it is a water rich city,but over the past 50 decades has become a water poor area.Over all both quality and quantity of Tianjin's water resource are declining.Recommendations arc made to resolve this water problem in different aspects.%天津作为中国的直辖市之一,目前面临着严重水资源短缺的问题.在历史上,因为它的地理位置,天津是水资源丰富的城市.然而近几十年来天津已经成为水资源极度匮乏地区.天津水资源的数量和质量都在急刷下降.在这篇文章中提出了一些建议来帮助解决这些水问题.

  18. Turbulent wind waves on a water current

    Directory of Open Access Journals (Sweden)

    M. V. Zavolgensky

    2008-05-01

    Full Text Available An analytical model of water waves generated by the wind over the water surface is presented. A simple modeling method of wind waves is described based on waves lengths diagram, azimuthal hodograph of waves velocities and others. Properties of the generated waves are described. The wave length and wave velocity are obtained as functions on azimuth of wave propagation and growth rate. Motionless waves dynamically trapped into the general picture of three dimensional waves are described. The gravitation force does not enter the three dimensional of turbulent wind waves. That is why these waves have turbulent and not gravitational nature. The Langmuir stripes are naturally modeled and existence of the rogue waves is theoretically proved.

  19. Properties of Red Sea coastal currents

    KAUST Repository

    Churchill, J.H.

    2014-02-14

    Properties of coastal flows of the central Red Sea are examined using 2 years of velocity data acquired off the coast of Saudi Arabia near 22 °N. The tidal flow is found to be very weak. The strongest tidal constituent, the M2 tide, has a magnitude of order 4 cm s−1. Energetic near-inertial and diurnal period motions are observed. These are surface-intensified currents, reaching magnitudes of >10 cm s−1. Although the diurnal currents appear to be principally wind-driven, their relationship with the surface wind stress record is complex. Less than 50% of the diurnal current variance is related to the diurnal wind stress through linear correlation. Correlation analysis reveals a classical upwelling/downwelling response to the alongshore wind stress. However, less than 30% of the overall sub-inertial variance can be accounted for by this response. The action of basin-scale eddies, impinging on the coastal zone, is implicated as a primary mechanism for driving coastal flows.

  20. Noise Properties of CMOS Current Conveyors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1996-01-01

    The definition of the current conveyor is presented and it is shown how different generations of current conveyors can all be combined into a single definition of a multiple-output second generation current conveyor (CCII). Next, noise sources are introduced into the model, and a general noise...... model for the current conveyor is established. This model is used for the analysis of selected examples of current conveyor based operational amplifier configurations and the relative merits with respect to the noise performance of these configurations are discussed. Finally, the noise model...... is developed for a CMOS current conveyor implementation, and optimization strategies for noise reduction are discussed. It is concluded that a class AB implementation provides more flexibility than does a class A configuration. In both cases it is essential to design low noise current mirrors and current...

  1. Leakage-current properties of encapsulants

    Science.gov (United States)

    Wen, L. C.

    A theoretical modeling of leakage current in ethylene vinyl acetate (EVA) and polyvinyl butyral (PVB) modules is being developed and is described. The modeling effort derives mathematical relationships for the bulk and surface conductivites of EVA and PVB, the surface conductivities of glass and polymeric films, and the EVA and PVB pottants, all as functions of environmental parameters. Results from the modeling indicate that for glass/EVA, the glass surface controls the interfacial conductivity, although EVA bulk conductivity controls total leakage current. For PVB/glass, the interface conductivity controls leakage currents for relative humidity (RH) less than 40 to 50%, but PVB bulk conductivity controls leakage current above 50% RH.

  2. Quench properties of high current superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Garber, M; Sampson, W B

    1980-01-01

    A technique has been developed which allows the simultaneous determination of most of the important parameters of a high current superconductor. The critical current, propagation velocity, normal state resistivity, magnetoresistance, and enthalpy are determined as a function of current and applied field. The measurements are made on non-inductive samples which simulate conditions in full scale magnets. For wide, braided conductors the propagation velocity was found to vary approximately quadratically with current in the 2 to 5 kA region. A number of conductors have been tested including some Nb/sub 3/Sn braids which have critical currents in excess of 10 kA at 5 T, 4.2 K.

  3. Coastal circulation and water-column properties in the War in the Pacific National Historical Park, Guam: measurements and modeling of waves, currents, temperature, salinity, and turbidity, April-August 2012

    Science.gov (United States)

    Storlazzi, Curt D.; Cheriton, Olivia M.; Lescinski, Jamie M.R.; Logan, Joshua B.

    2014-01-01

    The U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) initiated an investigation in the National Park Service’s (NPS) War in the Pacific National Historical Park (WAPA) to provide baseline scientific information on coastal circulation and water-column properties along west-central Guam, focusing on WAPA’s Agat Unit, as it relates to the transport and settlement of coral larvae, fish, and other marine organisms. The oceanographic data and numerical circulation modeling results from this study demonstrate that circulation in Agat Bay was strongly driven by winds and waves at longer (>1 day) timescales and by the tides at shorter (Turbidity was relatively low in Agat Bay and was similar to levels measured elsewhere along west-central Guam. The numerical circulation modeling results provide insight into the potential paths of buoyant material released from a series of locations along west-central Guam under summer non-trade wind forcing conditions that characterize coral spawning events. This information may be useful in evaluating the potential zones of influence/impact resulting from transport by surface currents of material released from these select locations.

  4. Water- and foodborne viruses: current developments

    African Journals Online (AJOL)

    water and lack of adequate sanitation.3 In South Africa approximately. 12 million ... are without sanitation. Food sources can .... individuals >1 year of age and watery diarrhoea in children <1 ... HAV infection include improved personal hygiene ...

  5. Gas Property Demonstrations Using Plastic Water Bottles

    Science.gov (United States)

    Campbell, Dean J.; Bannon, Stephen J.; Gunter, Molly M.

    2011-01-01

    Plastic water bottles are convenient containers for demonstrations of gas properties illustrating Boyle's law, Charles's law, and Avogadro's law. The contents of iron-based disposable hand warmer packets can be used to remove oxygen gas from the air within an unfilled plastic water bottle.

  6. Review of coastal currents in Southern African waters

    CSIR Research Space (South Africa)

    Harris, TFW

    1978-08-01

    Full Text Available A review has been made of existing knowledge of the coastal currents in Southern African waters between Pretoria to Oudtshoorn on the northeast border, and the Orange River on the west coast. These waters have been divided into five sectors...

  7. Fresh water-salt water density currents, a major cause of siltation in estuaries

    National Research Council Canada - National Science Library

    Schultz, E.A; Simmons, H.B

    1957-01-01

    ... the effects of changing the upland discharge into estuaries, rivers, and harbours where the fresh water-salt water density currents are present in some degree, and in some cases are the major cause of siltation; and 4...

  8. Optical properties of water for the Yangbajing water cherenkov detector

    Science.gov (United States)

    Gao, Shang-qi; Sun, Zhi-bin; Jiang, Yuan-da; Wang, Chao; Du, Ke-ming

    2011-08-01

    Cherenkov radiation is used to study the production of particles during collisions, cosmic rays detections and distinguishing between different types of neutrinos and electrons. The optical properties of water are very important to the research of Cherenkov Effect. Lambert-beer law is a method to study the attenuation of light through medium. In this paper, optical properties of water are investigated by use of a water attenuation performance test system. The system is composed of the light-emitting diode (LED) light source and the photon receiver models. The LED light source model provides a pulse light signal which frequency is 1 kHz and width is 100ns. In photon receiver model, a high sensitivity photomultiplier tube (PMT) is used to detect the photons across the water. Because the output voltage amplitude of PMT is weak which is from 80mv to 120mV, a low noise pre-amplifier is used to improve the detector precise. An effective detector maximum time window of PMT is 100ns for a long lifetime, so a peak holder circuit is used to hold the maximum peak amplitude of PMT for the induced photons signal before the digitalization. In order to reduce the noise of peak holder, a multi-pulse integration is used before the sampling of analog to digital converter. At last, the detector of photons from the light source to the PMT across the water is synchronized to the pulse width of the LED. In order to calculate the attenuation coefficient and attenuation length of water precisely, the attenuation properties of air-to-water boundary is considered in the calculation.

  9. Effect of current annealing on electronic properties of multilayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, S; Goto, H; Tomori, H; Kanda, A [Institute of Physics, University of Tsukuba, Tsukuba 305-8571 (Japan); Ootuka, Y [Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, Tsukuba 305-8571 (Japan); Tsukagoshi, K, E-mail: tanaka@lt.px.tsukuba.ac.j [MANA, NIMS, Namiki, Tsukuba, Ibaraki 305-0047 (Japan)

    2010-06-01

    While ideal graphene has high mobility due to the relativistic nature of carriers, it is known that the carrier transport in actual graphene samples is dominated by the influence of scattering from charged impurities, which almost conceals the intrinsic splendid properties of this novel material. The common techniques to improve the graphene mobility include the annealing in hydrogen atmosphere and the local annealing by imposing a large biasing current. Although annealing is quite important technique for the experimental study of graphene, detailed evaluation of the annealing effect is lacking at present. In this paper, we study the effect of the current annealing in multilayer graphene devices quantitatively by investigating the change in the mobility and the carrier density at the charge neutrality point. We find that the current annealing sometimes causes degradation of the transport properties.

  10. The current state of water resources of Transcarpathia

    Directory of Open Access Journals (Sweden)

    V. І. Nikolaichuk

    2015-07-01

    sanitary rules and regulations by the most of indicators of general health and specific indices. 19.0% of total water supply systems fail to meet the sanitary norms and regulations, in particular: 14.2% for the lack of sanitary protection zones; 1.9% because of unavailability of the necessary integrated treatment facilities, and 7.6% by the reason of absence of disinfecting plants. Possible ways of avoiding the depletion of water bodies are preventive water protection measures aimed at preventing or limiting pollution, water contamination and depletion; besides, it is necessary to educate people explaning them the current state and possible consequences of thoughtless water consumption.

  11. Thermodynamic properties of water solvating biomolecular surfaces

    Science.gov (United States)

    Heyden, Matthias

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

  12. Grey water impact on soil physical properties

    Directory of Open Access Journals (Sweden)

    Miguel L. Murcia-Sarmiento

    2014-01-01

    Full Text Available Due to the increasing demand for food produced by the increase in population, water as an indispensable element in the growth cycle of plants every day becomes a fundamental aspect of production. The demand for the use of this resource is necessary to search for alternatives that should be evaluated to avoid potential negative impacts. In this paper, the changes in some physical properties of soil irrigated with synthetic gray water were evaluated. The experimental design involved: one factor: home water and two treatments; without treated water (T1 and treated water (T2. The variables to consider in the soil were: electrical conductivity (EC, exchangeable sodium percentage (ESP, average weighted diameter (MWD and soil moisture retention (RHS. The water used in drip irrigation high frequency was monitored by tensiometer for producing a bean crop (Phaseolous vulgaris L. As filtration system used was employed a unit composed of a sand filter (FLA and a subsurface flow wetland artificial (HFSS. The treatments showed significant differences in the PSI and the RHS. The FLA+HFSS system is an alternative to the gray water treatment due to increased sodium retention.

  13. Transport properties of supercooled confined water

    Science.gov (United States)

    Mallamace, F.; Branca, C.; Broccio, M.; Corsaro, C.; Gonzalez-Segredo, N.; Spooren, J.; Stanley, H. E.; Chen, S.-H.

    2008-07-01

    This article presents an overview of recent experiments performed on transport properties of water in the deeply supercooled region, a temperature region of fundamental importance in the science of water. We report data of nuclear magnetic resonance, quasi-elastic neutron scattering, Fourier-transform infrared spectroscopy, and Raman spectroscopy, studying water confined in nanometer-scale environments. When contained within small pores, water does not crystallise, and can be supercooled well below its homogeneous nucleation temperature Th. On this basis it is possible to carry out a careful analysis of the well known thermodynamical anomalies of water. Studying the temperature and pressure dependencies of water dynamics, we show that the liquid-liquid phase transition (LLPT) hypothesis represents a reliable model for describing liquid water. In this model, water in the liquid state is a mixture of two different local structures, characterised by different densities, namely the low density liquid (LDL) and the high-density liquid (HDL). The LLPT line should terminate at a special transition point: a low-T liquid-liquid critical point. We discuss the following experimental findings on liquid water: (i) a crossover from non-Arrhenius behaviour at high T to Arrhenius behaviour at low T in transport parameters; (ii) a breakdown of the Stokes-Einstein relation; (iii) the existence of a Widom line, which is the locus of points corresponding to maximum correlation length in the p-T phase diagram and which ends in the liquid-liquid critical point; (iv) the direct observation of the LDL phase; (v) a minimum in the density at approximately 70 K below the temperature of the density maximum. In our opinion these results represent the experimental proofs of the validity of the LLPT hypothesis.

  14. The potential versus current state of water splitting with hematite.

    Science.gov (United States)

    Zandi, Omid; Hamann, Thomas W

    2015-09-21

    This review describes the potential of hematite as a photoanode material for photoelectrochemical (PEC) water splitting. The current understanding of key loss-mechanisms of hematite are introduced and correlated to performance enhancement strategies. The significant voltage loss associated with overcoming the competitive water oxidation and surface state recombination has recently been surmounted through a combination of high temperature annealing and surface modification with water oxidation catalysts. Substantial efforts have been made at nanostructuring electrodes to increase the charge separation efficiency without sacrificing light absorption. Even in optimized nanostructured electrodes, however, charge separation continues to be the primary barrier to achieving efficient water splitting with hematite. Specifically, significant depletion region recombination results in voltage dependant photocurrent which constrains the fill factor. Thus, future directions to enhance the efficiency of hematite electrodes are discussed with an emphasis on circumventing depletion region recombination.

  15. Index of current water-resources activities in Ohio, 1985

    Science.gov (United States)

    Eberle, Michael

    1985-01-01

    This report summarizes the U. S. Geological Survey 's Water Resources Division 's program in Ohio in 1985. The work of the Ohio District is carried out through the District office in Columbus and a field office in New Philadelphia. Collection of basic data needed for continuing determination and evaluation of the quantity, quality, and use of Ohio 's water resources is the responsibility of the District 's Hydrologic Surveillance Section. The Hydrologic Investigations Section conducts analytical and interpretive water-resource appraisals describing the occurrence, availability, and the physical, chemical, and biological characteristics of surface and groundwater. In addition to introductory material describing the structure of the Ohio District, information is presented on current projects, sites at which basic surface- and groundwater data are collected , and reports of Ohio 's water resources published by the U.S. Geological Survey and cooperating agencies. (USGS)

  16. The properties of chromium electrodeposited with programmed currents. Part II. Reversing current

    Directory of Open Access Journals (Sweden)

    TANJA M. KOSTIC

    2000-01-01

    Full Text Available The electrodeposition of chromium in programmed reversing current (RC, was investigated in the regime of high cathodic current density (77 A dm-2 and anodic current density (55 A dm-2. The ratio of the cathodic and anodic time (60 : 1 was used. Chromium was deposed on a steel substrate from a chromic-sulphuric acid solution, during one hour. Anode and cathode were suited in a system of parallel plates. Basic properties of deposits, like thickness, morphology, microhardness, brightness were examined. Surface distribution of the deposits was obtained from the measurements of the thicknesses of the deposits (between 32 and 67 µm. A ferromagnetic non-destructive method was used in the measurements. Based on the results, graphic models of deposit surface distribution were made. Two ranges of the thickness could be seen on the model (range 1 - average thickness 35.1 µm and range 2 - average thickness 57.81 µm. These results were statisticaly analysed by colums, rows and by the whole surface. For the whole specimens, the average thickness was 45.39 µm with a coefficient of variation of 0.2582. The basic properties of the deposits did not change with a variation of the thickness. Because of this, the coatings deposited with the reversing current could be much more considered reliable in wear and corrosion protection systems than ones deposited by direct current.

  17. Anthropogenic currents and shoreline water quality in Avalon Bay, California.

    Science.gov (United States)

    Ho, Lin C; Litton, Rachel M; Grant, Stanley B

    2011-03-15

    Shoreline concentrations of fecal indicator bacteria (FIB) and fecal indicator viruses (FIV) in Avalon Bay (Catalina Island, California) display a marked diurnal pattern (higher at night and lower during the day) previously attributed to the tidal flux of sewage-contaminated groundwater and the tidal washing of contaminated sediments, coupled with light and dark die-off of FIB and FIV (Boehm, et al., Environ. Sci. Technol. 2009, 43, 8046-8052). In this paper we document the existence of strong (peak velocities between 20 to 40 cm/s) transient currents in the nearshore waters of Avalon Bay that occur between 07:00 and 20:00 each day. These currents, which have a significant onshore component, are generated by anthropogenic activities in the Bay, including prop wash from local boat traffic and the docking practices of large passenger ferries. A budget analysis carried out on simultaneous measurements of FIB at two cross-shore locations indicates that anthropogenic currents contribute to the diurnal cycling of FIB concentrations along the shoreline, by transporting relatively unpolluted water from offshore toward the beach. The data and analysis presented in this paper support the idea that anthropogenic currents represent a significant, and previously overlooked, source of variability in shoreline water quality.

  18. Properties Variation of Carbon Fiber Reinforced Composite for Marine Current Turbine in Seawater

    Directory of Open Access Journals (Sweden)

    Li Jing

    2016-01-01

    Full Text Available Turbine blade which are generally made of composite is a core device among components of tidal current power generator that converts the flow of tidal current into a turning force. Recent years, damages of composite turbine blades have been reported due to reasons like seawater degradation, lake of strength, manufacture etc. In this paper, water absorption, tensile, bending, longitudinal transverse shearing properties of carbon fiber reinforced plastic (CRP composite which would be applied to fabricate the marine current turbine blade has been investigated. Furthermore, the variations of properties with seawater immersion period were studied. The results indicated that the water absorption increased almost linearly at the beginning of immersion and then became stable. Tensile strength of specimen tended to decrease firstly and then recovered slightly. However, the longitudinal transverse shearing strength showed reverse variation trend comparing to tensile strength. And the bending property of specimens was depressed significantly. The properties variations in seawater shall be referenced to design and fabrication of composite marine current turbine blade.

  19. Current perspectives in contaminant hydrology and water resources sustainability

    Science.gov (United States)

    Bradley, Paul M.

    2013-01-01

    Human society depends on liquid freshwater resources to meet drinking, sanitation and hygiene, agriculture, and industry needs. Improved resource monitoring and better understanding of the anthropogenic threats to freshwater environments are critical to efficient management of freshwater resources and ultimately to the survival and quality of life of the global human population. This book helps address the need for improved freshwater resource monitoring and threat assessment by presenting current reviews and case studies focused on the fate and transport of contaminants in the environment and on the sustainability of groundwater and surface-water resources around the world. It is intended for students and professionals working in hydrology and water resources management.

  20. [Anomalous Properties of Water and Aqueous Solutions at Low Temperatures].

    Science.gov (United States)

    Matsumoto, Masakazu

    2015-01-01

    Water has many anomalous properties below the room temperature. The temperature range overlaps with that of the Earth's atmosphere and also with that natural life forms favor. We review the origin of the anomalous properties of water and aqueous solutions in association with the hypothetical second critical point and liquid-liquid phase separation of water hidden in the supercooled state of liquid water.

  1. The Atlantic Water boundary current in the Nansen Basin: Transport and mechanisms of lateral exchange

    Science.gov (United States)

    Vâge, Kjetil; Pickart, Robert S.; Pavlov, Vladimir; Lin, Peigen; Torres, Daniel J.; Ingvaldsen, Randi; Sundfjord, Arild; Proshutinsky, Andrey

    2016-09-01

    Data from a shipboard hydrographic survey near 30°E in the Nansen Basin of the Arctic Ocean are used to investigate the structure and transport of the Atlantic Water boundary current. Two high-resolution synoptic crossings of the current indicate that it is roughly 30 km wide and weakly middepth-intensified. Using a previously determined definition of Atlantic Water, the transport of this water mass is calculated to be 1.6 ± 0.3 Sv, which is similar to the transport of Atlantic Water in the inner branch of the West Spitsbergen Current. At the time of the survey a small anticyclonic eddy of Atlantic Water was situated just offshore of the boundary current. The data suggest that the feature was recently detached from the boundary current, and, due to compensating effects of temperature and salinity on the thermal wind shear, the maximum swirl speed was situated below the hydrographic property core. Two other similar features were detected within our study domain, suggesting that these eddies are common and represent an effective means of fluxing warm and salty water from the boundary current into the interior. An atmospheric low-pressure system transiting south of our study area resulted in southeasterly winds prior to and during the field measurements. A comparison to hydrographic data from the Pacific Water boundary current in the Canada Basin under similar atmospheric forcing suggests that upwelling was taking place during the survey. This provides a second mechanism related to cross-stream exchange of heat and salt in this region of the Nansen Basin.

  2. Properties and Distribution of Current Sheets in Accretion Disk Coronae

    Science.gov (United States)

    Salvesen, Greg; Begelman, M. C.; Simon, J. B.; Beckwith, K.

    2013-04-01

    Theoretical models involving the interplay of a geometrically thin, optically thick accretion disk embedded in an extended coronal atmosphere may describe black hole X-ray binaries across all spectral states. Buoyant magnetic field generated in the accretion disk is continuously supplied to the corona by a dynamo process driven by the magnetorotational instability. This rising field leads to the formation of a magnetic pressure-dominated, low-density, geometrically thick corona where substantial accretion energy is dissipated, likely by collisionless magnetic reconnection, perhaps even generating outflows. Despite the potential importance of magnetic reconnection in shaping the energetics and kinematics of the corona, studies of multiple reconnection sites in a large volume are currently prohibited by the computational expense required to properly treat the microphysical nature of reconnection. Under the assumption that coronal structure is determined by ideal magnetohydrodynamics, we analyze local simulations of accretion disks (i.e., shearing boxes) performed with the ATHENA code, where the spatial domains are extended to capture 'mesoscale' structures that are dynamically important in accretion disk evolution. We employ a location routine to identify zones of enhanced current density, which trace likely sites of magnetic reconnection. We describe the positions, orientations, sizes, shapes, strengths, and kinematics of these regions and correlate them with the spatial distribution of numerical dissipation. Statistical distributions of these various properties of current density zones are presented to determine the heights within the corona that contribute most to the dissipation rate, the flow properties associated with reconnection sites, and representative parameters for future large volume reconnection simulations.

  3. FILM-30: A Heat Transfer Properties Code for Water Coolant

    Energy Technology Data Exchange (ETDEWEB)

    MARSHALL, THERON D.

    2001-02-01

    A FORTRAN computer code has been written to calculate the heat transfer properties at the wetted perimeter of a coolant channel when provided the bulk water conditions. This computer code is titled FILM-30 and the code calculates its heat transfer properties by using the following correlations: (1) Sieder-Tate: forced convection, (2) Bergles-Rohsenow: onset to nucleate boiling, (3) Bergles-Rohsenow: partially developed nucleate boiling, (4) Araki: fully developed nucleate boiling, (5) Tong-75: critical heat flux (CHF), and (6) Marshall-98: transition boiling. FILM-30 produces output files that provide the heat flux and heat transfer coefficient at the wetted perimeter as a function of temperature. To validate FILM-30, the calculated heat transfer properties were used in finite element analyses to predict internal temperatures for a water-cooled copper mockup under one-sided heating from a rastered electron beam. These predicted temperatures were compared with the measured temperatures from the author's 1994 and 1998 heat transfer experiments. There was excellent agreement between the predicted and experimentally measured temperatures, which confirmed the accuracy of FILM-30 within the experimental range of the tests. FILM-30 can accurately predict the CHF and transition boiling regimes, which is an important advantage over current heat transfer codes. Consequently, FILM-30 is ideal for predicting heat transfer properties for applications that feature high heat fluxes produced by one-sided heating.

  4. Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges.

    Science.gov (United States)

    Ceriotti, Michele; Fang, Wei; Kusalik, Peter G; McKenzie, Ross H; Michaelides, Angelos; Morales, Miguel A; Markland, Thomas E

    2016-07-13

    Nuclear quantum effects influence the structure and dynamics of hydrogen-bonded systems, such as water, which impacts their observed properties with widely varying magnitudes. This review highlights the recent significant developments in the experiment, theory, and simulation of nuclear quantum effects in water. Novel experimental techniques, such as deep inelastic neutron scattering, now provide a detailed view of the role of nuclear quantum effects in water's properties. These have been combined with theoretical developments such as the introduction of the principle of competing quantum effects that allows the subtle interplay of water's quantum effects and their manifestation in experimental observables to be explained. We discuss how this principle has recently been used to explain the apparent dichotomy in water's isotope effects, which can range from very large to almost nonexistent depending on the property and conditions. We then review the latest major developments in simulation algorithms and theory that have enabled the efficient inclusion of nuclear quantum effects in molecular simulations, permitting their combination with on-the-fly evaluation of the potential energy surface using electronic structure theory. Finally, we identify current challenges and future opportunities in this area of research.

  5. An empirical model for salt removal percentage in water under the effect of different current intensities of current carrying coil at different flow rates

    Directory of Open Access Journals (Sweden)

    Rameen S. AbdelHady

    2011-10-01

    Full Text Available The magnetic treatment of hard water is an alternative, simple approach by which the hard water that needs to be treated flows through a magnetic field. This field is created by inducing current in a coil wrapped around a pipe. Consequently some of its properties, such as total dissolved salts (TDS, conductivity (Ec and PH change. The primary purpose of hard water treatment is to decrease TDS in the incoming liquid stream. Using performance data from the application of different magnetic field densities on the different flow levels of water, empirical mathematical models were developed relating the salt removal percentage (SRP to operating flow rate and current of the coil. The obtained experimental results showed that the SRP increased with increasing the current at low flow rates (up to 0.75 ml/s.

  6. C++ Implementation of IAPWS Water/Steam Properties

    Energy Technology Data Exchange (ETDEWEB)

    Ling Zou; Haihua Zhao; Hongbin Zhang; Qiyue Lu

    2014-02-01

    For the calculations of water-involved systems, such as safety analysis of light water reactors, it is essential to provide accurate water properties. The International Association for the Properties of Water and Steam is an international non-profit association of national organizations concerned with the properties of water and steam. It provides internationally accepted formulations of water/steam properties for scientific and industrial applications. The purpose of this work is to provide a stand-alone software package in C++ programming language to provide accurate and efficient water/steam properties evaluation, based on the latest IAPWS releases. The discussion on related IAPWS releases, code implementations and verifications are provided in details.

  7. Monitoring dental-unit-water-line output water by current in-office test kits.

    Science.gov (United States)

    Lal, Sham; Singhrao, Sim K; Bricknell, Matt; Pearce, Mark; Morton, L H Glyn; Ahmed, Waqar; Crean, St John

    2014-08-01

    The importance of monitoring contamination levels in the output water of dental-unit-water-lines (DUWLs) is essential as they are prone to developing biofilms that may contaminate water that is used to treat patients, with opportunistic pathogens such as species of Legionella, Pseudomonas and others. Dentists and practice staff are also at risk of being infected by means of cross-infection due to aerosols generated from DUWL water. The unit of measurement for the microbial contamination of water by aerobic mesophilic heterotrophic bacteria is the colony-forming unit per millilitre (cfu/ml) of water. The UK has its own guidelines set by the Department of Health for water discharged from DUWL to be between 100 and 200 cfu/ml of water. The benchmark or accepted standard laboratory test is by microbiological culture on R2A agar plates. However, this is costly and not convenient for routine testing in dental practices. A number of commercial indicator tests are used in dental surgeries, but they were not developed for the dental market and serve only to indicate gross levels of contamination when used outside of the manufacturer's recommended incubation period. The aim of this article is to briefly review the universal problem of DUWL contamination with microbial biofilms and to update dental professionals on the availability of currently available commercial in-office monitoring systems for aerobic mesophilic heterotrophic bacteria and to discuss their limitations for testing water samples in assuring compliance with recommended guidelines.

  8. Water masses and property distribution in the EEZ of Mauritius

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Singbal, S.Y.S.; George, M.D.

    Water masses and their properties have been studied in the Mauritian during September-October, 1987. Surface water is characterizEd. by two water masses: 1) a warm (temp. 27 degrees C) and relatively saline water (salinity 35.3 x 10 sup(-3)) which...

  9. Wave-current interactions in deep water conditions: field measurements and analyses

    Science.gov (United States)

    Rougier, Gilles; Rey, Vincent; Molcard, Anne

    2015-04-01

    The study of wave - current interaction has drawn interest in oceanography, ocean engineering, maritime navigation and for tides or waves power device design. In the context of the hydrodynamics study along the French Mediterranean coast, a current profiler was deployed near Toulon at the south of the "Port Cros" island. This coastal zone is characterized by a steep slope, the water depth varying from tens meters to several thousand meters over few kilometers from the coast. An ambient current, the "Northern Current", coming from the Ligurian sea (area of Genoa, Italy) and following the coast up to Toulon, is present all over the year. Its mean surface velocity is of about 0.30 m/s, its flow rate of about 1.5 Sv. The region is exposed to two dominating winds: the Mistral, coming from North-West, and Eastern winds. Both generate swell and/or wind waves in either following or opposing current conditions with respect to the Northern Current. A current profiler equipped with a wave tracking system (ACPD workhorse from RDI) was deployed from July to October 2014 in deep water conditions (depth of about 500m). The mooring system allowed the ADCP to measure the current profile from the sea surface down to 25m depth, which corresponds more or less to the depth of influence of waves of periods up to 10s. The collected data include energetic wave conditions in either following or opposing current conditions. The current intensity and its vertical profiles have shown a significant temporal variability according to the meteorological conditions. Effects of the wave conditions on the current properties are discussed. ACKNOWLEDGEMENTS This work was supported by the program BOMBYX and the ANR grant No ANR-13-ASTR-0007.

  10. Physicochemical Properties of Biopolymer Hydrogels Treated by Direct Electric Current

    Directory of Open Access Journals (Sweden)

    Żaneta Król

    2016-07-01

    Full Text Available The objective of this study was to evaluate the changes within the physicochemical properties of gelatine (2%; 4%; 8%, carrageenan (1.5%; 2%; 2.5% and sodium alginate (0.75%; 1%; 1.25% hydrogels with different sodium chloride concentrations that were triggered by applying direct current (DC of 400 mA for a duration of five minutes. There were three types of gels prepared for the purpose of the study: C, control; H, gels on the basis of hydrosols that were treated with DC; and G, gels treated with DC. In the course of the study, the authors carried out the following analyses: Texture Profile Analysis (TPA, Fourier Transform Infrared spectroscopy (FTIR, Scanning Electron Microscopy (SEM and Swelling Ratio (SR. Furthermore, the color and pH of hydrogels were measured. The FTIR spectra showed that the structures of gelatine, carrageenan and sodium alginate do not significantly change upon applying DC. The results of TPA, SR, color and pH measurement indicate that hydrogels’ properties are significantly dependent on the type of polymer, its concentration and the type of the gel. By changing those parameters, the characteristics of such gels can be additionally tuned, which extends their applicability, e.g., in the food industry. Moreover, the analysis revealed that SR of H gel gelatine after 72 h of storage was 1.84-times higher than SR of the control sample, which indicated that this gel may be considered as a possible component for wound dressing materials.

  11. Current Computational Challenges for CMC Processes, Properties, and Structures

    Science.gov (United States)

    DiCarlo, James

    2008-01-01

    In comparison to current state-of-the-art metallic alloys, ceramic matrix composites (CMC) offer a variety of performance advantages, such as higher temperature capability (greater than the approx.2100 F capability for best metallic alloys), lower density (approx.30-50% metal density), and lower thermal expansion. In comparison to other competing high-temperature materials, CMC are also capable of providing significantly better static and dynamic toughness than un-reinforced monolithic ceramics and significantly better environmental resistance than carbon-fiber reinforced composites. Because of these advantages, NASA, the Air Force, and other U.S. government agencies and industries are currently seeking to implement these advanced materials into hot-section components of gas turbine engines for both propulsion and power generation. For applications such as these, CMC are expected to result in many important performance benefits, such as reduced component cooling air requirements, simpler component design, reduced weight, improved fuel efficiency, reduced emissions, higher blade frequencies, reduced blade clearances, and higher thrust. Although much progress has been made recently in the development of CMC constituent materials and fabrication processes, major challenges still remain for implementation of these advanced composite materials into viable engine components. The objective of this presentation is to briefly review some of those challenges that are generally related to the need to develop physics-based computational approaches to allow CMC fabricators and designers to model (1) CMC processes for fiber architecture formation and matrix infiltration, (2) CMC properties of high technical interest such as multidirectional creep, thermal conductivity, matrix cracking stress, damage accumulation, and degradation effects in aggressive environments, and (3) CMC component life times when all of these effects are interacting in a complex stress and service

  12. Contrasting optical properties of surface waters across the Fram Strait and its potential biological implications

    DEFF Research Database (Denmark)

    Pavlov, Alexey K.; Granskog, Mats A.; Stedmon, Colin A.

    2015-01-01

    radiation (PAR, 400-700nm), but does result in notable differences in ultraviolet (UV) light penetration, with higher attenuation in the EGC. Future changes in the Arctic Ocean system will likely affect EGC through diminishing sea-ice cover and potentially increasing CDOM export due to increase in river......Underwater light regime is controlled by distribution and optical properties of colored dissolved organic matter (CDOM) and particulate matter. The Fram Strait is a region where two contrasting water masses are found. Polar water in the East Greenland Current (EGC) and Atlantic water in the West...... Spitsbergen Current (WSC) differ with regards to temperature, salinity and optical properties. We present data on absorption properties of CDOM and particles across the Fram Strait (along 79° N), comparing Polar and Atlantic surface waters in September 2009 and 2010. CDOM absorption of Polar water in the EGC...

  13. CURRENT ENVIRONMENT STATE OF COASTAL MARINE WATER OF DAGESTAN

    Directory of Open Access Journals (Sweden)

    S. A. Guseinova

    2014-01-01

    Full Text Available Aim. We analysed current environmental state of the Dagestan coast of the Caspian Sea. Data on the spatial variability of contaminants in the coastal areas of the Dagestan segment of the Caspian Sea from the northern districts (Lopatin to the central (Sulak coastal land and, further, to the southern district (within Russian subsoil management confirm that it is caused by irregular contamination of the sea by above-ground sources. Location. Dagestan coastal area of the Caspian SeaMethods. Concentration analysis of background contamination of chemical agents in the Dagestan coastal water from northern districts (Lopatin to southern (Sulak coastal land during the period between 2004 and 2007.Results. Data on the spatial variability of contaminants in the coastal areas of the Dagestan segment of the Caspian Sea from the northern districts (Lopatin to the central (Sulak coastal land and, further, to the southern district (within Russian subsoil management confirm that it is caused by irregular contamination of the sea by above-ground sources.Main conclusions. The envisaged large-scale hydrocarbon resource development requires regular monitoring of sea currents on Makhachkala, Izberbash and Derbent roads.

  14. Multiple planetary systems: Properties of the current sample

    Science.gov (United States)

    Hobson, Melissa J.; Gomez, Mercedes

    2017-08-01

    We carry out analyses on stellar and planetary properties of multiple exoplanetary systems in the currently available sample. With regards to the stars, we study their temperature, distance from the Sun, and metallicity distributions, finding that the stars that harbour multiple exoplanets tend to have subsolar metallicities, in contrast to metal-rich Hot Jupiter hosts; while non-Hot Jupiter single planet hosts form an intermediate group between these two, with approximately solar metallicities. With regards to the planetary systems, we select those with four or more planets and analyse their configurations in terms of stability (via Hill radii), compactness, and size variations. We find that most planetary pairs are stable, and that the compactness correlates to the size variation: More compact systems have more similarly sized planets and vice versa. We also investigate the spectral energy distributions of the stars hosting multiple exoplanetary systems, seeking infra-red excesses that could indicate the presence of debris disks. These disks would be leftovers from the planetary formation process, and could be considered as analogues of the Solar System's Asteroid or Kuiper belts. We identify potential candidates for disks that are good targets for far infra-red follow-up observations to confirm their existence.

  15. Material properties of zooplankton and nekton from the California current

    Science.gov (United States)

    Becker, Kaylyn

    This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density

  16. Predictions of the properties of water from first principles

    NARCIS (Netherlands)

    Bukowski, R.; Szalewicz, K.; Groenenboom, G.C.; Avoird, A. van der

    2007-01-01

    A force field for water has been developed entirely from first principles, without any fitting to experimental data. It contains both pairwise and many-body interactions. This force field predicts the properties of the water dimer and of liquid water in excellent agreement with experiments, a previo

  17. Physical properties of current dental nanohybrid and nanofill light-cured resin composites.

    Science.gov (United States)

    Sideridou, Irini D; Karabela, Maria M; Vouvoudi, Evangelia Ch

    2011-06-01

    The purpose of this work was the detailed study of sorption characteristics of water or artificial saliva, the determination of flexural strength and the flexural modulus, and the study of the thermal stability of some current commercial dental light-cured nanocomposites containing nano-sized filler particles. Three nanohydrid dental composites (Tetric EvoCeram (TEC), Grandio (GR) and Protofill-nano (PR)) and two nanofill composites (Filtek Supreme Body (FSB) and the Filtek Supreme Translucent (FST)) were used in this work. The volumetric shrinkage due to polymerization was first determined. Also the sorption, solubility and volumetric increase were measured after storage of composites in water or artificial saliva for 30 days. The flexural strength and flexural modulus were measured using a three-point bending set-up according to the ISO-4049 specification, after immersion of samples in water or artificial saliva for 1 day or 30 days. Thermal analysis technique TGA method was used to investigate the thermal stability of composites. GR and TEC composites showed statistically no difference in volumetric shrinkage (%) which is lower than the other composites, which follow the order PRcomposites studied the amount of water, which is sorbed (% on composite) is not statistically different than the amount of water, which is desorbed and follows the order: GRcomposites after immersion for one day follows the order TECcomposites studied, Grandio had the lowest polymer matrix content, consisting mainly of Bis-GMA. It showed the lowest polymerization shrinkage and water sorption and the highest flexural strength and flexural modulus after immersion in water or artificial saliva for 30 days. The water and artificial saliva generally showed the same effect on physical properties of the studied composites. Thermogravimetric analysis gave good information about the structure and the amount of organic polymer matrix of composites. Copyright © 2011 Academy of Dental Materials

  18. The trade of virtual water: do property rights matter?

    Science.gov (United States)

    Xu, Ankai

    2016-04-01

    My paper examines the determinants of the virtual water trade - embodied in the trade of agriculture products - by estimating a structural gravity model. In particular, it tests the relationship between property rights and the export of water-intensive agricultural products based on water footprint data in Mekonnen and Hoekstra (2011, 2012). Using two different measures of property rights protection, I show that countries with weaker property rights have an apparent comparative advantage in the trade of water-intensive products. After controlling for the economic size, natural resource endowments, and possible effects of reverse causality, the trade flow of virtual water is negatively and significantly correlated with the property rights index of the exporting country. Holding other factors constant, one point increase in the property rights index of a country is associated with a 24% - 36% decrease in its virtual water export, whereas a 1% increase in the natural resource protection index of a country is associated with a 16% decrease in its virtual water export. This paper is the first empirical work that tests the relationship between property rights and trade of water-intensive products, offering a new perceptive in the debate of virtual water trade. The findings provide a possible explanation on the paradoxical evidence that some countries with scarce water resources export water-intensive products. The result is important not only in terms of its theoretical relevance, but also its policy implications. As prescribed by the model of trade and property rights, when countries with weaker property rights open to international trade, they are more likely to over-exploit and thus expedite the depletion of natural resources.

  19. Overview of water resource assessment in South Africa: Current ...

    African Journals Online (AJOL)

    is essential to planners and designers of water supply schemes and those ... Particular emphasis is given to the evolution of the computer as an ... we now call the historical firm yield. ..... In their article, Strategic planning for water resources in.

  20. Numerical study on water waves and wave-induced longshore currents in Obaköy coastal water

    Institute of Scientific and Technical Information of China (English)

    TANG Jun; LYU Yigang; SHEN Yongming

    2014-01-01

    In this paper, the water waves and wave-induced longshore currents in Obaköy coastal water which is lo-cated at the Mediterranean coast of Turkey were numerically studied. The numerical model is based on the parabolic mild-slope equation for coastal water waves and the nonlinear shallow water equation for the wave-induced currents. The wave transformation under the effects of shoaling, refraction, diffraction and breaking is considered, and the wave provides radiation stresses for driving currents in the model. The numerical results for the water wave-induced longshore currents were validated by the measured data to demonstrate the efficiency of the numerical model. Then the water waves and longshore currents induced by the waves from main directions were numerically simulated and analyzed based on the numerical re-sults. The numerical results show that the movement of the longshore currents was different while the wave propagated to a coastal zone from different directions.

  1. Exploiting interfacial water properties for desalination and purification applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongwu (Los Alamos National Laboratory, Los Alamos, NM); Varma, Sameer; Nyman, May Devan; Alam, Todd Michael; Thuermer, Konrad; Holland, Gregory P.; Leung, Kevin; Liu, Nanguo (University of New Mexico Albuquerque, NM); Xomeritakis, George K. (University of New Mexico Albuquerque, NM); Frankamp, Benjamin L.; Siepmann, J. Ilja (University of Minnesota, Minneapolis, MN); Cygan, Randall Timothy; Hartl, Monika A. (Los Alamos National Laboratory, Los Alamos, NM); Travesset, Alex (Iowa State University, Ames, IA); Anderson, Joshua A. (Iowa State University, Ames, IA); Huber, Dale L.; Kissel, David J. (University of New Mexico Albuquerque, NM); Bunker, Bruce Conrad; Lorenz, Christian Douglas; Major, Ryan C. (University of Minnesota, Minneapolis, MN); McGrath, Matthew J. (University of Minnesota, Minneapolis, MN); Farrow, Darcie; Cecchi, Joseph L. (University of New Mexico Albuquerque, NM); van Swol, Frank B.; Singh, Seema; Rempe, Susan B.; Brinker, C. Jeffrey; Clawson, Jacalyn S.; Feibelman, Peter Julian; Houston, Jack E.; Crozier, Paul Stewart; Criscenti, Louise Jacqueline; Chen, Zhu (University of New Mexico Albuquerque, NM); Zhu, Xiaoyang (University of Minnesota, Minneapolis, MN); Dunphy, Darren Robert (University of New Mexico Albuquerque, NM); Orendorff, Christopher J.; Pless, Jason D.; Daemen, Luke L. (Los Alamos National Laboratory, Los Alamos, NM); Gerung, Henry (University of New Mexico Albuquerque, NM); Ockwig, Nathan W.; Nenoff, Tina Maria; Jiang, Ying-Bing; Stevens, Mark Jackson

    2008-09-01

    A molecular-scale interpretation of interfacial processes is often downplayed in the analysis of traditional water treatment methods. However, such an approach is critical for the development of enhanced performance in traditional desalination and water treatments. Water confined between surfaces, within channels, or in pores is ubiquitous in technology and nature. Its physical and chemical properties in such environments are unpredictably different from bulk water. As a result, advances in water desalination and purification methods may be accomplished through an improved analysis of water behavior in these challenging environments using state-of-the-art microscopy, spectroscopy, experimental, and computational methods.

  2. Assessing the Current State of Cognitive Frailty: Measurement Properties.

    Science.gov (United States)

    Sargent, L; Brown, R

    2017-01-01

    Currently, an estimated 25-30% of people ages 85 or older have dementia, with a projected 115 million people worldwide living with dementia by 2050. With this worldwide phenomenon fast approaching, early detection of at-risk older adults and development of interventions focused on preventing loss in quality of life are increasingly important. A new construct defined by the International Consensus Group (I.A.N.A/I.A.G.G) as «cognitive frailty» combines domains of physical frailty with cognitive impairment and provides a framework for research that may provide a means to identify individuals with cognitive impairment caused by nonneurodegenerative conditions. Using the integrative review method of Whittemore and Knafl., 2005 this study examines and appraises the optimal measures for detecting cognitive frailty in clinical populations of older adults. The integrative review was conducted using PubMed, CINAHL, Web of Science, PsycInfo, and ProQuest Dissertations and Theses. From the total 185 articles retrieved, review of titles and key words were conducted. Following the initial review, 168 articles did not meet the inclusion criteria for association of frailty and cognition. Of the 18 fulltext articles reviewed, 11 articles met the inclusion criteria; these articles were reviewed in-depth to determine validity and reliability of the cognitive frailty measures. Predictive validity was established by the studies reviewed in four main areas: frailty and type of dementia MCI (OR 7.4, 95% CI 4.2-13.2), vascular dementia (OR 6.7, 95% CI 1.6-27.4) and Alzheimer's dementia (OR 3.2, 95% CI 1.7-6.2), frailty and vascular dementia (VaAD) is further supported by the rate of change in frailty x macroinfarcts (r = 0.032, p < 0.001); frailty and the individual domains of cognitive function established with the relationship of neurocognitive speed and change in cognition using regression coefficients; individual components of frailty and individual domains of cognitive function

  3. Threshold properties of a microcavity laser with submicroampere threshold current

    Energy Technology Data Exchange (ETDEWEB)

    Choquette, K.D.; Hou, H.Q.; Lear, K.L.; Chow, W.W.; Mar, A.; Geib, K.M.; Hammons, B.E.

    1996-02-01

    We report the threshold characteristics of small oxide-confined vertical-cavity surface emitting lasers. Abrupt threshold transitions 105 times the spontaneous emission background are obtained at injection currents as low as 470 nanoampere.

  4. Physico-chemical properties of perturbed water: facts and enigmas

    Directory of Open Access Journals (Sweden)

    Vittorio Elia

    2012-09-01

    , after transitioning to the solid state when bulk water is removed through the drying procedure, but would otherwise keep the new state of aggregation indefinitely. This an extraordinarily similar phenomenology to that found in the behavior of simple living systems such as multicellular organisms, molds and bacteria. When sufficient water is present, the far-from-equilibrium conditions remain (dissipative phase. Conversely, when water is no longer present, the structures linger in a quiescence condition with no dissipation taking place. When the mutated environmental conditions allow, i.e. sufficient water is available, they start to dissipate again, i.e. to “live”, in order to keep in a state far from the equilibrium. The parallel between organized water (clusters, aggregates of water molecules, aqueous nanostructures and dissipative structures and the simpler living systems might seem exaggerated at first, but actually, to an extent, the phenomenologis are very comparable. In the solid phase, instead, these nanostructures can keep their properties indefinitely without dissipation. They’re able to go back to far-from-equilibrium conditions when sufficient water is made available again though, by exploiting radiating energies from the environment (dissipative structures. The nature of these structures in the solid phase is currently under speculation and experimental scrutiny especially making use of in the IR spectroscopy technique. From data gathered so far, it is possible to state that the existence of aqueous nanostructures in the solid phase emerges as a novel and totally unexpected phenomenon, and also worth of note is the exceptional similitude between the IR and UV-Vis spectra produced by water perturbed with the three diverse preparation protocols. Though it is worth underlining that some extraordinary differences of behavior do exist among the products of the different preparation procedures, which

  5. Current status on marine litter indicators in Nordic waters

    DEFF Research Database (Denmark)

    Strand, Jakob; Tairova, Zhanna; Magnusson, Kerstin

    Status for project on Marine litter in the Nordic waters. This includes a review of Nordic studies on marine litter indicators. Various studies as part of either research or existing monitoring have provided information on occurrence of marine litter in Nordic waters from Baltic Sea to the Arctic....

  6. Semiconductor photocatalysts for water oxidation: current status and challenges.

    Science.gov (United States)

    Yang, Lingling; Zhou, Han; Fan, Tongxiang; Zhang, Di

    2014-04-21

    Artificial photosynthesis is a highly-promising strategy to convert solar energy into hydrogen energy for the relief of the global energy crisis. Water oxidation is the bottleneck for its kinetic and energetic complexity in the further enhancement of the overall efficiency of the artificial photosystem. Developing efficient and cost-effective photocatalysts for water oxidation is a growing desire, and semiconductor photocatalysts have recently attracted more attention due to their stability and simplicity. This article reviews the recent advancement of semiconductor photocatalysts with a focus on the relationship between material optimization and water oxidation efficiency. A brief introduction to artificial photosynthesis and water oxidation is given first, followed by an explanation of the basic rules and mechanisms of semiconductor particulate photocatalysts for water oxidation as theoretical references for discussions of componential, surface structure, and crystal structure modification. O2-evolving photocatalysts in Z-scheme systems are also introduced to demonstrate practical applications of water oxidation photocatalysts in artificial photosystems. The final part proposes some challenges based on the dynamics and energetics of photoholes which are fundamental to the enhancement of water oxidation efficiency, as well as on the simulation of natural water oxidation that will be a trend in future research.

  7. Mapping current and future European public water withdrawals and consumption

    Science.gov (United States)

    Vandecasteele, I.; Bianchi, A.; Silva, F. Batista e.; Lavalle, C.; Batelaan, O.

    2014-02-01

    In Europe, public water withdrawals make up on average 30% and in some cases up to 60% of total water withdrawals. These withdrawals are becoming increasingly important with growing population density; hence there is a need to understand the spatial and temporal trends involved. Pan-European public/municipal water withdrawals and consumption were mapped for 2006 and forecasted for 2030. Population and tourism density were assumed to be the main driving factors for withdrawals. Country-level statistics on public water withdrawals were disaggregated to a combined population and tourism density map (the "user" density map) computed for 2006. The methodology was validated using actual regional withdrawal statistics from France for 2006. The total absolute error (TAE) calculated was proven to be reduced by taking into account the tourism density in addition to the population density. In order to forecast the map to 2030 we considered a reference scenario where per capita withdrawals were kept constant in time. Although there are large variations from region to region, this resulted in a European average increase of water withdrawals of 16%. If we extrapolate the average reduction in per capita withdrawals seen between 2000 and 2008, we forecast a reduction in average total water withdrawals of 4%. Considering a scenario where all countries converge to an optimal water use efficiency, we see an average decrease of 28%.

  8. Thermodynamic properties of bulk and confined water

    Energy Technology Data Exchange (ETDEWEB)

    Mallamace, Francesco, E-mail: francesco.mallamace@unime.it [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Mallamace, Domenico [Dipartimento di Scienze dell' Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Vasi, Sebastiano; Vasi, Cirino [IPCF-CNR, I-98166 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

    2014-11-14

    The thermodynamic response functions of water display anomalous behaviors. We study these anomalous behaviors in bulk and confined water. We use nuclear magnetic resonance (NMR) to examine the configurational specific heat and the transport parameters in both the thermal stable and the metastable supercooled phases. The data we obtain suggest that there is a behavior common to both phases: that the dynamics of water exhibit two singular temperatures belonging to the supercooled and the stable phase, respectively. One is the dynamic fragile-to-strong crossover temperature (T{sub L} ≃ 225 K). The second, T{sup *} ∼ 315 ± 5 K, is a special locus of the isothermal compressibility K{sub T}(T, P) and the thermal expansion coefficient α{sub P}(T, P) in the P–T plane. In the case of water confined inside a protein, we observe that these two temperatures mark, respectively, the onset of protein flexibility from its low temperature glass state (T{sub L}) and the onset of the unfolding process (T{sup *})

  9. Performance of a Straight-Bladed Water-Current Turbine

    OpenAIRE

    Sule, Luther

    2014-01-01

    The most renewable energy used in Indonesia is coming from hydro energy. The hydro energy available in Indonesia is about75000-76000MW. From the whole water energy available in Indonesia there was just about 3,783MW being harnest for large scale power plants and about 220 MW for small-scale power plants. One of the small- scale hydro energy sources is from a small river which has a water speed range between 0.01 m/s to 2.8 m/s. Although having only a low water speed, the energ...

  10. The local property taxes and municipal federalism. Current and future inequity condition of Italian Property Taxation

    Directory of Open Access Journals (Sweden)

    Michele Argiolas

    2013-08-01

    Full Text Available The main purpose of this paper is to analyze and compare the current local tax on real estate and the future and assessing criticality. The tax base is calculated by applying calculation methods that differ depending on the type of property you must tax. For buildings used for residential, the tax base is calculated on the basis of the cadastral income; in the case of building land is rather used the market value of land and buildings and, for rent, rural manor. The land property values are always lower than market values, which is because some time trying to implement a revision of the class with the objective of bringing the two values. The reclass procedure has recently been adopted in the municipality of Milano where it was decided to reclass of buildings located within a few micro-climates for the most central, in which houses were originally built affordable housing to meet the housing needs of the social classes poor and that over time turned into mansions in the city center. From 1 January 2012, the Imu will come into force, only municipal tax, which replaces the current Ici; the two taxes differ in the higher fixed rate (7.6 ‰, which does not involve substantial modifications to the old system tax. In this way, the result will be to produce an increase in the tax burden without solving the inequalities of the old system but increasing the gap. The Implementation Act contains provisions which IMU when applied to allow municipalities to solve some problems present in the Ici.

  11. 46 CFR 11.713 - Requirements for maintaining current knowledge of waters to be navigated.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Requirements for maintaining current knowledge of waters... § 11.713 Requirements for maintaining current knowledge of waters to be navigated. (a) If a first class... current knowledge of the route. Persons using this method of re-familiarization shall certify,...

  12. Water-soluble cavitands - synthesis, solubilities and binding properties

    NARCIS (Netherlands)

    Middel, Oskar; Verboom, Willem; Reinhoudt, David N.

    2002-01-01

    Water-soluble cavitand receptors have been obtained by the introduction of ionizable groups (5, 21-28, 39) and neutral hydrophilic tetraethylene glycol based dendritic wedges (19, 20). The synthesis of these cavitands and a study of their water solubilities and binding properties toward neutral orga

  13. Mapping current and future European public water withdrawals and consumption

    Directory of Open Access Journals (Sweden)

    I. Vandecasteele

    2013-07-01

    Full Text Available In Europe, public water withdrawals make up on average 30%, and in some cases up to 60% of total water withdrawals. These withdrawals are becoming increasingly important with growing population density; hence there is a need to understand the spatial and temporal trends involved. Pan-European public/municipal water withdrawals and consumption were mapped for 2006 and forecasted for 2030. Population and tourism density were assumed to be the main driving factors for withdrawals. Country-level statistics on public water withdrawals were disaggregated to a combined population and tourism density map (the "user" density map computed for 2006. In order to forecast the map to 2030 we assumed the water withdrawals per user to remain constant in time, so that the future withdrawals reflected the projected population and tourism trends. The methodology was validated using actual regional withdrawal statistics from France for 2006. The Total Absolute Error (TAE calculated was proven to be reduced by taking into account the tourism density in addition to the population density. Our results show that although there are large variations from region to region, in general public water withdrawals will increase significantly over the period 2006 to 2030. The European average increase is 16%, with a maximal increase of 53% in Ireland.

  14. Thermodynamic properties of water desorption of forage turnip seeds

    OpenAIRE

    Kelly Aparecida Sousa; Osvaldo Resende; André Luis Duarte Goneli; Thaís Adriana de Souza Smaniotto; Daniel Emanuel Cabral de Oliveira

    2014-01-01

    The purpose of this study was to determine the thermodynamic properties of the process of water sorption in forage turnip  seeds. The equilibrium moisture content of forage turnip  seeds was determined by the gravimetric-dynamic method for different values of temperature and water activity. According to the results, increasing the moisture content increases the energy required for the evaporation of water in forage turnip seeds, and the values of integral isosteric heat of desorption, within ...

  15. Thermodynamic properties of water desorption of forage turnip seeds

    OpenAIRE

    Sousa,Kelly Aparecida de; Resende,Osvaldo; Goneli, André Luis Duarte; Smaniotto,Thaís Adriana de Souza; Oliveira,Daniel Emanuel Cabral de

    2015-01-01

    The purpose of this study was to determine the thermodynamic properties of the process of water sorption in forage turnip seeds. The equilibrium moisture content of forage turnip seeds was determined by the gravimetric-dynamic method for different values of temperature and water activity. According to the results, increasing the moisture content increases the energy required for the evaporation of water in forage turnip seeds, and the values of integral isosteric heat of desorption, within th...

  16. THERMOPHYSICAL PROPERTIES AND WATER ACTIVITY OF TRANSFERRED CHEESE (UF

    Directory of Open Access Journals (Sweden)

    Mohsen Dalvi Esfahan

    2015-06-01

    Full Text Available Few data are available on the thermophysical properties of cheese in the ripening process.The main objective of this work was to investigate the effects of brining and temperature on the thermophysical properties, i.e., thermal conductivity, specific heat, density and water activity of UF cheese and finally we measure surface heat transfer coefficient .Then we develop models for thermophysical properties based on physical and multiple regression concept .

  17. Particles in water properties and processes

    CERN Document Server

    Gregory, John

    2005-01-01

    INTRODUCTION Particles in the Aquatic Environment Colloidal Aspects PARTICLE SIZE AND RELATED PROPERTIES Particle Size and Shape Particle Size Distributions Particle Transport Light Scattering and Turbidity Measurement of Particle Size SURFACE CHARGE Origin of Surface Charge The Electrical Double Layer Electrokinetic Phenomena COLLOID INTERACTIONS AND COLLOID STABILITY Colloid Interactions - General Concepts van der Waals Interaction Electrical Double Layer Interaction Combined Interaction - DLVO Theory Non-DLVO Interactions AGGREGATION KINETICS Collision Frequency - Smoluchow

  18. Microbial Source Tracking: Current and Future Molecular Tools in Microbial Water Quality Forensics

    Science.gov (United States)

    Current regulations in the United States stipulate that the microbial quality of waters used for consumption and recreational activities should be determined regularly by measuring microbial indicators of fecal pollution. Hence, the microbial risk associated with these waters is...

  19. Water masses and zonal current in the Western Tropical Atlantic in October 2007 and January 2008 (AMANDES project

    Directory of Open Access Journals (Sweden)

    A. C. Silva

    2010-11-01

    Full Text Available The properties and circulation of water masses are examined using data collected from a hydrographic and Acoustic Doppler Current profiler in the Western Tropical Atlantic during two cruises of the GEOTRACES process study "AMANDES" (AMazon-ANDEans: AMANDES I (October–November 2007 and AMANDES II (January 2008. In the upper layer (from the sea surface to 150 m means of vertical sections of velocity are showing the structure of the Current (NBC and North Equatorial Countercurrent. In the lower layer (below 150 m the subsurface velocity core of the North Brazil UnderCurrent, Western Boundary Undercurrent (WBUC and northern branch of the South Equatorial Current (nSEC could be observed. In October the WBUC flows southeastward with a velocity of about 0.3 m s−1. In the studied area during October 2007, the NBUC and nSEC are transporting South Atlantic Central Water (SACW from the Southern Hemisphere whereas the WBUC transports North Atlantic Central Water (NACW southeastward. In the deep layers, the North Atlantic Deep Water (NADW is composed of three components: the Upper North Atlantic Deep Water – UNADW (between 1310 and 1650 m, the Middle North Atlantic Deep Water (between 1930 and 2400 m, the Lower North Atlantic Deep Water (centered around 3430 m.

    Off Guyana, the Antartic Intermediate Water (AAIW changes of composition between October 2007 (45.2% ACW, 32.2% AAIWsource and 22.6% UNADW and January 2008 (62.4% ACW, 23.5% AAIWsource and 14.1% UNADW.

    These intermediate waters are significantly warmer, less oxygenated and saltier than their southern source, reflecting both oxygen consumption and mixing with the Atlantic Central Water (ACW and the Upper North Atlantic Deep Water during their northward transit.

  20. Dielectric Properties of Water in Butter and Water-AOT-Heptane Systems Measured using Terahertz Time-Domain Spectroscopy

    DEFF Research Database (Denmark)

    Møller, Uffe; Folkenberg, Jacob Riis; Jepsen, Peter Uhd

    2010-01-01

    We investigate the dielectric properties of water confined in nanometer-sized inverse micelles in mixtures of water, AOT, and heptane. We show that the dielectric properties of the confined water are dependent on the water pool size and different from those of bulk water. We also discuss the diel...... the dielectric properties of different vegetable oils, lard, and butter, and use these properties to deduce the dielectric properties of water in butter, which are shown to deviate significantly from the dielectric properties of bulk water....

  1. Viscosity and electric properties of water aerosols

    Science.gov (United States)

    Shavlov, A. V.; Sokolov, I. V.; Dzhumandzhi, V. A.

    2016-09-01

    The flow of water mist in a narrow duct has been studied experimentally. The profile of the velocity of drops has been measured, and the viscosity of the mist has been calculated using the Navier-Stokes equation. It has been found that at low gradients of the rate of shear the viscosity of the mist can exceed that of clean air by tens and even hundreds of times. The electric charge of the drops has been measured. It has been found that the viscosity of the mist differs from that of clean air at gradients of the rate of shear that are less than the frequency of the establishment of electric equilibrium between the drops. A comparative analysis of the viscosities of the mist and a drop cluster has been carried out, and the dependence of the viscosity of the water aerosol on the radius and the charge of the drops has been predicted. The possible role of aerosols that contain submicron drops in the known "clear air turbulence" problem has been shown.

  2. Critical current and electronic properties of YBCO-Ag compounds

    Energy Technology Data Exchange (ETDEWEB)

    Dwir, B.; Affronte, M.; Pavuna, D. (Physics Dept., Swiss Federal Inst. of Tech., Lausanne (Switzerland))

    1989-12-01

    We have found that in YBCO-Ag ceramic compounds Ag fills the intergranular space (''holes'') without affecting Tc. Normal-state resistivity is decreased by {approx equal} x 100 when adding up to 50 wt% Ag. Percolation analysis shows that the critical indices t,s are in agreement with 3D theoretical values, but p{sub c} is higher than expected. The critical current density J{sub c} is enhanced by up to 50% in the samples containing {approx equal} 10 wt% Ag, this enhancement corresponds to a maximum YBCO compactness in the samples. (orig.).

  3. Progress in Tribological Properties of Nano-Composite Hard Coatings under Water Lubrication

    Directory of Open Access Journals (Sweden)

    Qianzhi Wang

    2017-02-01

    Full Text Available The tribological properties, under water-lubricated conditions, of three major nano-composite coatings, i.e., diamond-like carbon (DLC or a-C, amorphous carbon nitride (a-CNx and transition metallic nitride-based (TiN-based, CrN-based, coatings are reviewed. The influences of microstructure (composition and architecture and test conditions (counterparts and friction parameters on their friction and wear behavior under water lubrication are systematically elucidated. In general, DLC and a-CNx coatings exhibit superior tribological performance under water lubrication due to the formation of the hydrophilic group and the lubricating layer with low shear strength, respectively. In contrast, TiN-based and CrN-based coatings present relatively poor tribological performance in pure water, but are expected to present promising applications in sea water because of their good corrosion resistance. No matter what kind of coatings, an appropriate selection of counterpart materials would make their water-lubricated tribological properties more prominent. Currently, Si-based materials are deemed as beneficial counterparts under water lubrication due to the formation of silica gel originating from the hydration of Si. In the meantime, the tribological properties of nano-composite coatings in water could be enhanced at appropriate normal load and sliding velocity due to mixed or hydrodynamic lubrication. At the end of this article, the main research that is now being developed concerning the development of nano-composite coatings under water lubrication is described synthetically.

  4. Analysis of Mixing of Pollutants in Water Waves and Currents

    Institute of Scientific and Technical Information of China (English)

    YUAN Li-rong; SHEN Yong-ming; TANG Jun

    2007-01-01

    A vertical two-dimensional turbulence numerical model for the interaction of waves and currents is developed in the paper based on the nonlinear two-equation k-ε model with the VOF method.The one-dimensional equivalent advection velocity and equivalent mixing coefficient are defined and the solving process is introduced: The pollutant concentration field,generated by an instant source in waves and currents,is calculated with the model,and then the equivalent advection velocity and equivalent mixing coefficient are obtained by calculating the time derivative of the mean and variance of pollutant concentration probability distribution.The effects of wave period and wave height on the equivalent mixing coefficient for waves and wave-currents are also investigated.

  5. SARAL/Altika for inland water: current and potential applications

    Science.gov (United States)

    Tarpanelli, Angelica; Brocca, Luca; Barbetta, Silvia; Moramarco, Tommaso; Santos da Silva, Joécila; Calmant, Stephane

    2015-04-01

    Although representing less than 1% of the total amount of water on Earth the freshwater is essential for terrestrial life and human needs. Over one third of the world's population is not served by adequate supplies of clean water and for this reason freshwater wars are becoming one of the most pressing environmental issues exacerbating the already difficult tensions between the riparian nations. Notwithstanding the foregoing, we have surprisingly poor knowledge of the spatial and temporal dynamics of surface discharge. In-situ gauging networks quantify the instantaneous water volume in the main river channels but provide few information about the spatial dynamics of surface water extent, such as floodplain flows and the dynamics of wetlands. The growing reduction of hydrometric monitoring networks over the world, along with the inaccessibility of many remote areas and the difficulties for data sharing among developing countries feed the need to develop new procedures for river discharge estimation based on remote sensing technology. The major challenge in this case is the possibility of using Earth Observation data without ground measurements. Radar altimeters are a valuable tool to retrieve hydrological information from space such as water level of inland water. More than a decade of research on the application of radar altimetry has demonstrated its advantages also for monitoring continental water, providing global coverage and regular temporal sampling. The high accuracy of altimetry data provided by the latest spatial missions and the convincing results obtained in the previous applications suggest that these data may be employed for hydraulic/hydrological applications as well. If used in synergy with the modeling, the potential benefits of the altimetry measurements can grow significantly. The new SARAL French-Indian mission, providing improvements in terms of vertical accuracy and spatial resolution of the onboard altimeter Altika, can offer a great

  6. Biogeochemical properties of eddies in the California Current System

    Science.gov (United States)

    Chenillat, Fanny; Franks, Peter J. S.; Combes, Vincent

    2016-06-01

    The California Current System (CCS) has intense mesoscale activity that modulates and exports biological production from the coastal upwelling system. To characterize and quantify the ability of mesoscale eddies to affect the local and regional planktonic ecosystem of the CCS, we analyzed a 10 year-long physical-biological model simulation, using eddy detection and tracking to isolate the dynamics of cyclonic and anticyclonic eddies. As they propagate westward across the shelf, cyclonic eddies efficiently transport coastal planktonic organisms and maintain locally elevated production for up to 1 year (800 km offshore). Anticyclonic eddies, on the other hand, have a limited impact on local production over their ~6 month lifetime as they propagate 400 km offshore. At any given time ~8% of the model domain was covered by eddy cores. Though the eddies cover a small area, they explain ~50 and 20% of the transport of nitrate and plankton, respectively.

  7. Can a Century Old Experiment Reveal Hidden Properties of Water?

    Directory of Open Access Journals (Sweden)

    Elmar C. Fuchs

    2010-08-01

    Full Text Available In 1893 Sir William Armstrong placed a cotton thread between two wine glasses filled with chemically pure water. After applying a high voltage, a watery connection formed, and after some time, the cotton thread was pulled into one of the glasses, leaving a rope of water suspended between the two glasses. Although being a very simple experiment, it is of special interest since it comprises a number of phenomena currently tackled in modern water science like electrolysis-less charge transport and nanobubbles. This work gives some background information about water research in general and describes the water bridge phenomenon from the viewpoint of different fields such as electrohydrodynamics and quantum field theory. It is shown that the investigation of the floating water bridge led to new discoveries about water, both in the macroscopic and microscopic realm – but these were merely “hidden” in that sense that they only become evident upon application of electric fields.

  8. BAYER COUNTER CURRENT SYSTEMS IN COMPARISON WITH CONVENTIONAL CO—CURRENT SYSTEM IN THE FIELD OF WATER TREATMENT

    Institute of Scientific and Technical Information of China (English)

    Mitschker.A; RauchfuB.K

    1994-01-01

    From an economical point of view both the quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful performance.In general,two different technologies have been established on the market:The main differneces between the CO-and counter current technologes will be discussed and data concerning the requirement of chemicals for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies,developed and patented by Bayer AG,will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out .In view of stronger regulations concerning the consumption of regeneration chemicals,and waste water,and also because of the superior quality of the produced water,the market share of counter current technologies will continue to increase world-wide.

  9. Membranes with Surface-Enhanced Antifouling Properties for Water Purification

    Science.gov (United States)

    Shahkaramipour, Nima; Tran, Thien N.; Ramanan, Sankara; Lin, Haiqing

    2017-01-01

    Membrane technology has emerged as an attractive approach for water purification, while mitigation of fouling is key to lower membrane operating costs. This article reviews various materials with antifouling properties that can be coated or grafted onto the membrane surface to improve the antifouling properties of the membranes and thus, retain high water permeance. These materials can be separated into three categories, hydrophilic materials, such as poly(ethylene glycol), polydopamine and zwitterions, hydrophobic materials, such as fluoropolymers, and amphiphilic materials. The states of water in these materials and the mechanisms for the antifouling properties are discussed. The corresponding approaches to coat or graft these materials on the membrane surface are reviewed, and the materials with promising performance are highlighted. PMID:28273869

  10. Membranes with Surface-Enhanced Antifouling Properties for Water Purification

    Directory of Open Access Journals (Sweden)

    Nima Shahkaramipour

    2017-03-01

    Full Text Available Membrane technology has emerged as an attractive approach for water purification, while mitigation of fouling is key to lower membrane operating costs. This article reviews various materials with antifouling properties that can be coated or grafted onto the membrane surface to improve the antifouling properties of the membranes and thus, retain high water permeance. These materials can be separated into three categories, hydrophilic materials, such as poly(ethylene glycol, polydopamine and zwitterions, hydrophobic materials, such as fluoropolymers, and amphiphilic materials. The states of water in these materials and the mechanisms for the antifouling properties are discussed. The corresponding approaches to coat or graft these materials on the membrane surface are reviewed, and the materials with promising performance are highlighted.

  11. Biological Properties of Acidic Cosmetic Water from Seawater

    Directory of Open Access Journals (Sweden)

    Shu-Wen Hsiao

    2012-05-01

    Full Text Available This current work was to investigate the biological effects of acidic cosmetic water (ACW on various biological assays. ACW was isolated from seawater and demonstrated several bio-functions at various concentration ranges. ACW showed a satisfactory effect against Staphylococcus aureus, which reduced 90% of bacterial growth after a 5-second exposure. We used cultured human peripheral blood mononuclear cells (PBMCs to test the properties of ACW in inflammatory cytokine release, and it did not induce inflammatory cytokine release from un-stimulated, normal PBMCs. However, ACW was able to inhibit bacterial lipopolysaccharide (LPS-induced inflammatory cytokine TNF-α released from PBMCs, showing an anti-inflammation potential. Furthermore, ACW did not stimulate the rat basophilic leukemia cell (RBL-2H3 related allergy response on de-granulation. Our data presented ACW with a strong anti-oxidative ability in a superoxide anion radical scavenging assay. In mass spectrometry information, magnesium and zinc ions demonstrated bio-functional detections for anti-inflammation as well as other metal ions such as potassium and calcium were observed. ACW also had minor tyrosinase and melanin decreasing activities in human epidermal melanocytes (HEMn-MP without apparent cytotoxicity. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects of ACW on human skin melanoma cells (A375.S2 indicating that it exerted the anti-cancer potential against skin cancer. The results obtained from biological assays showed that ACW possessed multiple bioactivities, including anti-microorganism, anti-inflammation, allergy-free, antioxidant, anti-melanin and anticancer properties. To our knowledge, this was the first report presenting these bioactivities on ACW.

  12. Global properties of magnetotail current sheet flapping: THEMIS perspectives

    Directory of Open Access Journals (Sweden)

    A. Runov

    2009-01-01

    Full Text Available A sequence of magnetic field oscillations with an amplitude of up to 30 nT and a time scale of 30 min was detected by four of the five THEMIS spacecraft in the magnetotail plasma sheet. The probes P1 and P2 were at X=−15.2 and −12.7 RE and P3 and P4 were at X=−7.9 RE. All four probes were at −6.5>Y>−7.5 RE (major conjunction. Multi-point timing analysis of the magnetic field variations shows that fronts of the oscillations propagated flankward (dawnward and Earthward nearly perpendicular to the direction of the magnetic maximum variation (B1 at velocities of 20–30 km/s. These are typical characteristics of current sheet flapping motion. The observed anti-correlation between ∂B1/∂t and the Z-component of the bulk velocity make it possible to estimate a flapping amplitude of 1 to 3 RE. The cross-tail scale wave-length was found to be about 5 RE. Thus the flapping waves are steep tail-aligned structures with a lengthwise scale of >10 RE. The intermittent plasma motion with the cross-tail velocity component changing its sign, observed during flapping, indicates that the flapping waves were propagating through the ambient plasma. Simultaneous observations of the magnetic field variations by THEMIS ground-based magnetometers show that the flapping oscillations were observed during the growth phase of a substorm.

  13. Molecular properties of aqueous solutions: a focus on the collective dynamics of hydration water.

    Science.gov (United States)

    Comez, L; Paolantoni, M; Sassi, P; Corezzi, S; Morresi, A; Fioretto, D

    2016-07-07

    When a solute is dissolved in water, their mutual interactions determine the molecular properties of the solute on one hand, and the structure and dynamics of the surrounding water particles (the so-called hydration water) on the other. The very existence of soft matter and its peculiar properties are largely due to the wide variety of possible water-solute interactions. In this context, water is not an inert medium but rather an active component, and hydration water plays a crucial role in determining the structure, stability, dynamics, and function of matter. This review focuses on the collective dynamics of hydration water in terms of retardation with respect to the bulk, and of the number of molecules whose dynamics is perturbed. Since water environments are in a dynamic equilibrium, with molecules continuously exchanging from around the solute towards the bulk and vice versa, we examine the ability of different techniques to measure the water dynamics on the basis of the explored time scales and exchange rates. Special emphasis is given to the collective dynamics probed by extended depolarized light scattering and we discuss whether and to what extent the results obtained in aqueous solutions of small molecules can be extrapolated to the case of large biomacromolecules. In fact, recent experiments performed on solutions of increasing complexity clearly indicate that a reductionist approach is not adequate to describe their collective dynamics. We conclude this review by presenting current ideas that are being developed to describe the dynamics of water interacting with macromolecules.

  14. BACTERIOLOGICAL PROPERTIES OF MARINE WATER IN ADRIATIC FISH FARMS: ENUMERATION OF HETEROTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    Emin Teskeredžić

    2012-12-01

    Full Text Available Aquaculture is currently one of the fastest growing food production sectors in the world. Increase in nutrients and organic wastes lead to general deterioration of water quality. The problem of water quality is associated with both physical and chemical factors, as well as microbiological water quality. Heterotrophic bacteria play an important role in the process of decomposition of organic matter in water environment and indicate eutrophication process. Here we present our experience and knowledge on bacterial properties of marine water in the Adriatic fish farms with European sea bass (Dicentrarchus labrax L., 1758, with an emphasis on enumeration of heterotrophic bacteria in marine water. We applied two temperatures of incubation, as well as two methods for enumeration of heterotrophic bacteria: substrate SimPlate® test and spread plate method on conventional artificial media (Marine agar and Tryptic Soy agar with added NaCl. The results of analysis of bacteriological properties of marine water in the Adriatic fish farms showed that enumeration of heterotrophic bacteria in marine water depends on the applied incubation temperature and media for enumeration. At the same time, the incubation temperature of 22C favours more intense growth of marine heterotrophic bacteria, whereas a SimPlate test gives higher values of heterotrophic bacteria. Volatile values of heterotrophic bacteria during this research indicate a possible deterioration of microbiological water quality in the Adriatic fish farms and a need for regular monitoring of marine water quality.

  15. Local heat transfer properties in co- and counter-current G-L-S magnetically stabilized fluidized beds

    Institute of Scientific and Technical Information of China (English)

    Jinli Zhang; Ming Zhang; Wei Li; Xiaofang Li; Xiangkun Meng; Baoning Zong

    2011-01-01

    Heat transfer coefficients were measured by immersed probes in co- and counter-current G-L-S magnetically stabilized fluidized beds (MSFBs) using air,water and nickel-alloy particles as the gas,liquid and solid phases. Influences of major factors,including magnetic field intensity,superficial gas and liquid velocities,liquid viscosity and surface tension,on heat-transfer properties were studied experimentally,indicating that both co- and counter-current G-L-S MSFB can provide relatively uniform radial distribution of heat transfer coefficients under appropriate operation conditions,thus controlling operation temperature for highly exothermic multi-phase reaction systems. Two correlations were provided to estimate accurately heat transfer properties in both co- and counter-current G-L-S MSFB systems,with an average error of less than 10%.

  16. Mechanical, electrical and microstructural properties of cement-based materials in conditions of stray current flow

    NARCIS (Netherlands)

    Susanto, A.; Koleva, D.A.; Copuroglu, O.; Van Beek, C.; Van Breugel, K.

    2013-01-01

    This investigation presents a comparative study on mechanical properties, electrical resistivity and microstructure of mortar under DC current, compared to mortar in rest (no current) conditions. Monitoring was performed from 24h after casting until 84 days of cement hydration. A current

  17. Dielectric properties of low-water-content tissues.

    Science.gov (United States)

    Smith, S R; Foster, K R

    1985-09-01

    The dielectric properties of two low-water-content tissues, bone marrow and adipose tissue, were measured from 1 kHz to 1 GHz. From 1 kHz to 13 MHz, the measurements were performed using a parallel-plate capacitor method. From 10 MHz to 1 GHz, a reflection coefficient technique using an open-ended coaxial transmission line was employed. The tissue water contents ranged from 1 to almost 70% by weight. The dielectric properties correlate well with the values predicted by mixture theory. Comparison with previous results from high-water-content tissues suggests that bone marrow and adipose tissues contain less motionally altered water per unit dry volume than do the previously studied tissues with lower lipid fractions. The high degree of structural heterogeneity of these tissues was reflected in the large scatter of the data, a source of uncertainty that should be considered in practical applications of the present data.

  18. Thermodynamic properties and diffusion of water + methane binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Shvab, I.; Sadus, Richard J., E-mail: rsadus@swin.edu.au [Centre for Molecular Simulation, Swinburne University of Technology, PO Box 218 Hawthorn, Victoria 3122 (Australia)

    2014-03-14

    Thermodynamic and diffusion properties of water + methane mixtures in a single liquid phase are studied using NVT molecular dynamics. An extensive comparison is reported for the thermal pressure coefficient, compressibilities, expansion coefficients, heat capacities, Joule-Thomson coefficient, zero frequency speed of sound, and diffusion coefficient at methane concentrations up to 15% in the temperature range of 298–650 K. The simulations reveal a complex concentration dependence of the thermodynamic properties of water + methane mixtures. The compressibilities, heat capacities, and diffusion coefficients decrease with increasing methane concentration, whereas values of the thermal expansion coefficients and speed of sound increase. Increasing methane concentration considerably retards the self-diffusion of both water and methane in the mixture. These effects are caused by changes in hydrogen bond network, solvation shell structure, and dynamics of water molecules induced by the solvation of methane at constant volume conditions.

  19. Properties of water surface discharge at different pulse repetition rates

    Energy Technology Data Exchange (ETDEWEB)

    Ruma,; Yoshihara, K. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Hosseini, S. H. R., E-mail: hosseini@kumamoto-u.ac.jp; Sakugawa, T.; Akiyama, H. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Akiyama, M. [Department of Electrical and Electronic Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Lukeš, P. [Institute of Plasma Physics, AS CR, Prague, Prague 18200 (Czech Republic)

    2014-09-28

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H₂O₂) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H₂O₂ and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  20. Dielectric Properties of Flocculated Water-in-Oil Emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Skodvin, T.

    1995-12-31

    When an offshore oil field is near completion, water occupies a large fraction of the available pore volume. Thus, in collecting the oil and gas reserves, one has to deal with a high co-production of either formation- or injected water. This doctoral thesis focuses on the effect of water-in-oil emulsions on the dielectric properties, in particular the effect of flocculation. Various dielectric models are applied to obtain methods for qualitative and quantitative characterization of the flocculated state. Permittivity and measurement of dielectric properties are discussed as a basis for the interpretation of the dielectric properties of the emulsions. Various flocculation models are presented. It is concluded that the dielectric properties of water-in-oil emulsions are strongly influenced by continuously ongoing processes in the system. Because of flocculation and sedimentation the traditional dielectric mixture models cannot satisfactorily predict the dielectric behaviour. The experimentally obtained permittivities for the emulsions can be reproduced by including flocculation in the models and treating the floc aggregates as spheroids or subsystems with dielectric properties given by the degree of flocculation. The models discussed have difficulties reproducing the complete frequency behaviour found experimentally. This is probably because the dielectric relaxation may be influenced by processes not included in the models, such as the effects of dipolar or multipolar interactions between the droplets. For further research it is recommended that rheological and dielectric measurements be combined. 227 refs., 61 figs., 16 tabs.

  1. Properties and pathways of Mediterranean water eddies in the Atlantic

    Science.gov (United States)

    Bashmachnikov, I.; Neves, F.; Calheiros, T.; Carton, X.

    2015-09-01

    Data from ship vertical casts (NODC data-set), ARGO profiling floats (Coriolis data-set) and RAFOS-type neutral density floats (WOCE data-set) are used to study characteristics of meddies in the Northeast Atlantic. In total 241 Mediterranean water eddies (meddies) and 236 parts of float trajectories within meddies are selected for detailed analysis. The results suggest that the meddy generation rate at the southern and southwestern Iberian Peninsula (Portimao Canyon, cap St. Vincent, Estremadura Promontory, Gorringe Bank) is 3 times that at the northwestern Iberian Peninsula (Porto-Aveiro Canyons, Cape Finisterre and Galicia Bank). Meddies generated south of Estremadura Promontory (the southern meddies), as compared to those generated north of it (the northern meddies), have smaller radii, smaller vertical extension, higher aspect ratio, higher Rossby number and higher stability (stronger potential vorticity anomaly). These latter properties result from the southern meddies higher relative vorticity and stronger buoyancy frequency anomaly. Away from the generation regions, meddy drift concentrates along four main paths: three quasi-zonal paths (Northern, Central, Southern) and a path following the African coast (Coastal). The quasi-zonal paths are aligned to the isolines of the ambient potential vorticity field. Several cross-path exchanges, identified in this work, are aligned to topographic rises. Northward translation of the northern meddies within the North Atlantic Current to the subpolar gyre is detected. Within the first 600 km from the coast, meddy merger is proved to be a common event. This explains the observed difference in radii between the newly generated meddies and those away from the Iberian margin. The decay of the southern meddies proceeds mainly via the loss of their skirts and does not affect meddy cores until the latest stages. The decay of the northern meddies goes in parallel with the decay of their cores. In average meddy decay is achieved

  2. Modeling the interaction of electric current and tissue: importance of accounting for time varying electric properties.

    Science.gov (United States)

    Evans, Daniel J; Manwaring, Mark L

    2007-01-01

    Time varying computer models of the interaction of electric current and tissue are very valuable in helping to understand the complexity of the human body and biological tissue. The electrical properties of tissue, permittivity and conductivity, are vital to accurately modeling the interaction of the human tissue with electric current. Past models have represented the electric properties of the tissue as constant or temperature dependent. This paper presents time dependent electric properties that change as a result of tissue damage, temperature, blood flow, blood vessels, and tissue property. Six models are compared to emphasize the importance of accounting for these different tissue properties in the computer model. In particular, incorporating the time varying nature of the electric properties of human tissue into the model leads to a significant increase in tissue damage. An important feature of the model is the feedback loop created between the electric properties, tissue damage, and temperature.

  3. PHYSICOCHEMICAL PROPERTIES OF THE WATER DEPLETED OF HEAVY ISOTOPES

    Directory of Open Access Journals (Sweden)

    Vladislav V. Goncharuk

    2012-06-01

    Full Text Available Data on physicochemical properties of the light water (deuterium concentration is reduced to the ratio D/H = 4 ppm and that of the isotope of oxygen 18 – to the ratio 18O/16O = 750 ppm have been obtained. They include the melting and boiling points, kinematic viscosity, density, the spin-spin proton relaxation time, self-diffusion coefficients, and the small-angle laser light scattering. An explanation was proposed for the detected significant changes of the light water as compared with the high-resistivity water having geochemically ordinary isotope composition.

  4. Volumetric properties of water/AOT/isooctane microemulsions.

    Science.gov (United States)

    Du, Changfei; He, Wei; Yin, Tianxiang; Shen, Weiguo

    2014-12-23

    The densities of AOT/isooctane micelles and water/AOT/isooctane microemulsions with the molar ratios R of water to AOT being 2, 8, 10, 12, 16, 18, 20, 25, 30, and 40 were measured at 303.15 K. The apparent specific volumes of AOT and the quasi-component water/AOT at various concentrations were calculated and used to estimate the volumetric properties of AOT and water in the droplets and in the continuous oil phase, to discuss the interaction between the droplets, and to determine the critical micelle concentration and the critical microemulsion concentrations. A thermodynamic model was proposed to analysis the stability boundary of the microemulsion droplets, which confirms the maximum value of R being about 65 for the stable AOT/water/isooctane microemulsion droplets.

  5. Nonlinear Wave-Currents interactions in shallow water

    CERN Document Server

    Lannes, David

    2015-01-01

    We study here the propagation of long waves in the presence of vorticity. In the irrotational framework, the Green-Naghdi equations (also called Serre or fully nonlinear Boussinesq equations) are the standard model for the propagation of such waves. These equations couple the surface elevation to the vertically averaged horizontal velocity and are therefore independent of the vertical variable. In the presence of vorticity, the dependence on the vertical variable cannot be removed from the vorticity equation but it was however shown in [?] that the motion of the waves could be described using an extended Green-Naghdi system. In this paper we propose an analysis of these equations, and show that they can be used to get some new insight into wave-current interactions. We show in particular that solitary waves may have a drastically different behavior in the presence of vorticity and show the existence of solitary waves of maximal amplitude with a peak at their crest, whose angle depends on the vorticity. We als...

  6. Concentration polarization with monopolar ion exchange membranes: current-voltage curves and water dissociation

    NARCIS (Netherlands)

    Krol, J.J.; Wessling, M.; Strathmann, H.

    1999-01-01

    Concentration polarization is studied using a commercial anion and cation exchange membrane. Current¿voltage curves show the occurrence of an overlimiting current. The nature of this overlimiting current is investigated in more detail, especially with respect to the contribution of water dissociatio

  7. Safe access to safe water in low income countries: water fetching in current times.

    Science.gov (United States)

    Sorenson, Susan B; Morssink, Christiaan; Campos, Paola Abril

    2011-05-01

    A substantial portion of the world's population does not have ready access to safe water. Moreover, obtaining water may involve great expense of time and energy for those who have no water sources in or near home. From an historical perspective, with the invention of piped water, fetching water has only recently become largely irrelevant in many locales. In addition, in most instances, wells and clean surface water were so close by that fetching was not considered a problem. However, population growth, weather fluctuations and social upheavals have made the daily chore of carrying water highly problematic and a public health problem of great magnitude for many, especially women, in the poor regions and classes of the world. In this paper, we consider gender differences in water carrying and summarize data about water access and carrying from 44 countries that participated in the Multiple Indicator Cluster Survey (MICS) program. Women and children are the most common water carriers, and they spend considerable time (many trips take more than an hour) supplying water to their households. Time is but one measure of the cost of fetching water; caloric expenditures, particularly during droughts, and other measures that affect health and quality of life must be considered. The full costs of fetching water must be considered when measuring progress toward two Millennium Development Goals--increasing access to safe drinking water and seeking an end to poverty.

  8. Tensile properties of ADI material in water and gaseous environments

    Energy Technology Data Exchange (ETDEWEB)

    Rajnovic, Dragan, E-mail: draganr@uns.ac.rs [Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovića 6, 21000 Novi Sad (Serbia); Balos, Sebastian; Sidjanin, Leposava [Faculty of Technical Sciences, University of Novi Sad, Trg D. Obradovića 6, 21000 Novi Sad (Serbia); Eric Cekic, Olivera [Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade (Serbia); Grbovic Novakovic, Jasmina [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade (Serbia)

    2015-03-15

    Austempered ductile iron (ADI) is an advanced type of heat treated ductile iron, having comparable mechanical properties as forged steels. However, it was found that in contact with water the mechanical properties of austempered ductile irons decrease, especially their ductility. Despite considerable scientific attention, the cause of this phenomenon remains unclear. Some authors suggested that hydrogen or small atom chemisorption causes the weakening of the surface atomic bonds. To get additional reliable data of that phenomenon, in this paper, two different types of austempered ductile irons were tensile tested in various environments, such as: argon, helium, hydrogen gas and water. It was found that only the hydrogen gas and water gave a statistically significant decrease in mechanical properties, i.e. cause embrittlement. Furthermore, the fracture surface analysis revealed that the morphology of the embrittled zone near the specimen surface shares similarities to the fatigue micro-containing striation-like lines, which indicates that the morphology of the brittle zone may be caused by cyclic local-chemisorption, micro-embrittlement and local-fracture. - Highlights: • In contact with water and other liquids the ADI suddenly exhibits embrittlement. • The embrittlement is more pronounced in water than in the gaseous hydrogen. • The hydrogen chemisorption into ADI surface causes the formation of a brittle zone. • The ADI austempered at lower temperatures (300 °C) is more resistant to embrittlement.

  9. Volumetric properties of human islet amyloid polypeptide in liquid water.

    Science.gov (United States)

    Brovchenko, I; Andrews, M N; Oleinikova, A

    2010-04-28

    The volumetric properties of human islet amyloid polypeptide (hIAPP) in water were studied in a wide temperature range by computer simulations. The intrinsic density rho(p) and the intrinsic thermal expansion coefficient alpha(p) of hIAPP were evaluated by taking into account the difference between the volumetric properties of hydration and bulk water. The density of hydration water rho(h) was found to decrease almost linearly with temperature upon heating and its thermal expansion coefficient was found to be notably higher than that of bulk water. The peptide surface exposed to water is more hydrophobic and its rho(h) is smaller in conformation with a larger number of intrapeptide hydrogen bonds. The two hIAPP peptides studied (with and without disulfide bridge) show negative alpha(p), which is close to zero at 250 K and decreases to approximately -1.5 x 10(-3) K(-1) upon heating to 450 K. The analysis of various structural properties of peptides shows a correlation between the intrinsic peptide volumes and the number of intrapeptide hydrogen bonds. The obtained negative values of alpha(p) can be attributed to the shrinkage of the inner voids of the peptides upon heating.

  10. Effect of welding current and voltage on the mechanical properties of wrought (6063 aluminium alloy

    Directory of Open Access Journals (Sweden)

    Oladele Isiaka Oluwole

    2010-06-01

    Full Text Available This work was carried out to investigate the effect of welded joints on the mechanical properties of wrought (6063 aluminium alloy. The study revealed the influence of current and voltage on the welded joint as well as the mechanical properties of the alloy. The alloy samples were welded together by metal inert gas welding process at varying values of current and voltage after which mechanical tests were performed on the welded samples. The microstructural examination of the various fusion zones obtained was carried out. Appreciable variations in the properties of the welded samples were observed due to changes in the microstructural features of the alloys. It was concluded that variation of current and voltage remarkably affect the mechanical properties of the wrought 6063 Aluminium alloy. As the voltage increases from 25 to 30 V, the ultimate tensile strengths and hardness values increases while the impact strengths decreases but the current did not show such trend.

  11. Synthesis and properties of water-soluble asterisk molecules.

    Science.gov (United States)

    Menger, Fredric M; Azov, Vladimir A

    2002-09-18

    An asterisk is comprised of six semirigid arms projecting from a benzene nucleus. In the case at hand, asterisks were synthesized with one, two, or three aromatic rings (connected by sulfur atoms) in each of the six arms. A phosphomonoester at the termini of each arm solubilized the asterisks in water. The colloidal properties of these amphiphilic molecules were investigated by UV-vis and fluorescence spectroscopy, calorimetry, light scattering, surface tensiometry, and pulse-gradient spin-echo NMR. Solubility, solubilization, metal binding, and micelle "seeding" experiments were also carried out. Chain-conformation and supramolecular assembly into remarkable molecular "scrolls" were investigated by X-ray analysis and electron microscopy, respectively. One of the more interesting properties of the asterisks is that they remain monomeric in water despite having as many as 19 hydrophobic aromatic rings exposed to the water. The reasons for this behavior, and the possibility of exploiting it for constructing enzyme models free from aggregation equilibria, are discussed.

  12. Effect of Direct Electric Current on the Cell Surface Properties of Phenol-Degrading Bacteria

    OpenAIRE

    Luo, Qishi; Wang, Hui; Zhang, Xihui; Qian, Yi

    2005-01-01

    The change in cell surface properties in the presence of electric currents is of critical concern when the potential to manipulate bacterial movement with electric fields is evaluated. In this study, the effects of different direct electric currents on the cell surface properties involved in bacterial adhesion were investigated by using a mixed phenol-degrading bacterial culture in the exponential growth phase. The traits investigated were surface hydrophobicity (measured by adherence to n-oc...

  13. Investigation of radiological properties and water equivalency of PRESAGE dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Adamovics, John; Bosi, Stephen; Kim, Jung-Ha; Baldock, Clive [Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia) and Department of Radiation Oncology, Royal Prince Alfred Hospital, Sydney, New South Wales 2050 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia); Department of Chemistry and Biology, Rider University, Lawrenceville, New Jersey 08648 (United States); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia) and Department of Radiation Oncology, Prince of Wales Hospital, Randwick, New South Wales 2031 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia)

    2011-04-15

    Purpose: PRESAGE is a dosimeter made of polyurethane, which is suitable for 3D dosimetry in modern radiation treatment techniques. Since an ideal dosimeter is radiologically water equivalent, the authors investigated water equivalency and the radiological properties of three different PRESAGE formulations that differ primarily in their elemental compositions. Two of the formulations are new and have lower halogen content than the original formulation. Methods: The radiological water equivalence was assessed by comparing the densities, interaction probabilities, and radiation dosimetry properties of the three different PRESAGE formulations to the corresponding values for water. The relative depth doses were calculated using Monte Carlo methods for 50, 100, 200, and 350 kVp and 6 MV x-ray beams. Results: The mass densities of the three PRESAGE formulations varied from 5.3% higher than that of water to as much as 10% higher than that of water for the original formulation. The probability of photoelectric absorption in the three different PRESAGE formulations varied from 2.2 times greater than that of water for the new formulations to 3.5 times greater than that of water for the original formulation. The mass attenuation coefficient for the three formulations is 12%-50% higher than the value for water. These differences occur over an energy range (10-100 keV) in which the photoelectric effect is the dominant interaction. The collision mass stopping powers of the relatively lower halogen-containing PRESAGE formulations also exhibit marginally better water equivalency than the original higher halogen-containing PRESAGE formulation. Furthermore, the depth dose curves for the lower halogen-containing PRESAGE formulations are slightly closer to that of water for a 6 MV beam. In the kilovoltage energy range, the depth dose curves for the lower halogen-containing PRESAGE formulations are in better agreement with water than the original PRESAGE formulation. Conclusions: Based

  14. The effect of electrical stray current on material properties of mortar specimens

    NARCIS (Netherlands)

    Susanto, A.; Koleva, D.A.; Van Beek, C.; Van Breugel, K.

    2013-01-01

    Well known is that stray electrical current i.e. current with a spatial distribution in any conductive environment, can affect civil structures, e.g. initiate or enhance steel corrosion or affect microstructural and mechanical properties of the cement-based bulk matrix. While the former is related

  15. Incorporating core hysteresis properties in three-dimensional computations of transformer inrush current forces

    Science.gov (United States)

    Adly, A. A.; Hanafy, H. H.

    2009-04-01

    It is well known that transformer inrush currents depend upon the core properties, residual flux, switching instant, and the overall circuit parameters. Large transient inrush currents introduce abnormal electromagnetic forces which may destroy the transformer windings. This paper presents an approach through which core hysteresis may be incorporated in three-dimensional computations of transformer inrush current forces. Details of the approach, measurements, and simulations for a shell-type transformer are given in the paper.

  16. Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Nores-Pondal, Federico J.; Corti, Horacio R. [Grupo de Pilas de Combustible, Departamento de Fisica de la Materia Condensada, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), Av. General Paz 1499, B1650KNA San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Buera, M. Pilar [Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Av. Cantilo s/n, Ciudad Universitaria (1428) Buenos Aires (Argentina)

    2010-10-01

    The thermal properties of phosphoric acid-doped poly[2-2'-(m-phenylene)-5-5' bi-benzimidazole] (PBI) and poly[2,5-benzimidazole] (ABPBI) membranes, ionomeric materials with promising properties to be used as electrolytes in direct methanol and in high temperature polymer electrolyte membrane (PEM) fuel cells, were studied by means of differential scanning calorimetry (DSC) technique in the temperature range from -145 C to 200 C. The DSC scans of samples equilibrated in water at different relative humidities (RH) and in liquid water-methanol mixtures were analyzed in relation to glass transition, water crystallization/melting and solvent desorption in different temperature regions. The thermal relaxation observed in the very low temperature region could be ascribed to the glass transition of the H{sub 3}PO{sub 4}-H{sub 2}O mixture confined in the polymeric matrix. After cooling the samples up to -145 C, frozen water was detected in PBI and ABPBI at different RH, although at 100% RH less amount of water had crystallized than that observed in Nafion membranes under the same conditions. Even more important is the fact that the freezing degree of water is much lower in ABPBI membranes equilibrated in liquid water-methanol mixtures than that observed for PBI and, in a previous study, for Nafion. Thus, apart from other well known properties, acid-doped ABPBI emerges as an excellent ionomer for applications in direct methanol fuel cells working in cold environments. (author)

  17. Biological properties of water-soluble phosphorhydrazone dendrimers

    Directory of Open Access Journals (Sweden)

    Anne-Marie Caminade

    2013-01-01

    Full Text Available Dendrimers are hyperbranched and perfectly defined macromolecules, constituted of branches emanating from a central core in an iterative fashion. Phosphorhydrazone dendrimers constitute a special family of dendrimers, possessing one phosphorus atom at each branching point. The internal structure of these dendrimers is hydrophobic, but hydrophilic terminal groups can induce the solubility of the whole structure in water. Indeed, the properties of these compounds are mainly driven by the type of terminal groups their bear; this is especially true for the biological properties. For instance, positively charged terminal groups are efficient for transfection experiments, as drug carriers, as anti-prion agents, and as inhibitor of the aggregation of Alzheimer's peptides, whereas negatively charged dendrimers have anti-HIV properties and can influence the human immune system, leading to anti-inflammatory properties usable against rheumatoid arthritis. This review will give the most representative examples of the biological properties of water-soluble phosphorhydrazone dendrimers, organized depending on the type of terminal groups they bear.

  18. Evaluation of Water Resistance and Diffusion Properties of Paint Materials

    Directory of Open Access Journals (Sweden)

    J. Drchalová

    2001-01-01

    Full Text Available A simple method is presented for evaluating the water-proofness quality of paints on lining materials. The method is based on measuring the integral capillarity in dependence on time, and then comparing this value to the value determined for the basic lining material. Measurements of the effective water vapor permeability then provide information on the risk of condensation which may increase after applying the paint. A practical application of the method is performed with four Karlocolor paints on glass concrete substrates. All the Karlocolor paints are found to be very effective materials for driven rain protection. The diffusion properties of all the paints are found to be excellent.

  19. The formation, properties and impact of secondary organic aerosol: current and emerging issues

    Directory of Open Access Journals (Sweden)

    M. Hallquist

    2009-02-01

    Full Text Available Secondary organic aerosol (SOA accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with a description of the current state of knowledge on the global SOA budget and the atmospheric degradation mechanisms for SOA precursors. The topic of gas-particle partitioning theory is followed by an account of the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail; molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.

  20. The formation, properties and impact of secondary organic aerosol: current and emerging issues

    Directory of Open Access Journals (Sweden)

    J. Wildt

    2009-07-01

    Full Text Available Secondary organic aerosol (SOA accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.

  1. Water Resources and Agricultural Water Use in the North China Plain: Current Status and Management Options

    Science.gov (United States)

    Serious water deficits with deteriorating environmental quality are threatening agricultural sustainability in the North China Plain (NCP). This paper addresses spatial and temporal availability of water resources in the NCP, and identifies the effects of soil management, irrigation and crop genetic...

  2. CURRENT STATE AND PROBLEMS OF DEVELOPMENT OF THE WATER MANAGEMENT IN THE SOUTH OF RUSSIA

    Directory of Open Access Journals (Sweden)

    T. A. Shebzukhova

    2017-01-01

    Full Text Available Aim. The aim is to give a current and retrospective assessment of the state of water resources in the South of Russia and identify key problems in their use.Methods. Based on the analysis of dynamic and territorial series of data presented in government reports and the Central Statistical Database of the Federal State Statistics Service, we conducted diagnostic studies of the current and dynamic state of water resources use in the sub-federal units of the Russian Federation.Findings. The key problems in the functioning of the water sector in the southern regions are: natural water scarcity, large-scale transfers and artificial regulation of the river flows, significant loss of water during transport, large-scale discharge of contaminated sewage and poor quality of water. A significant interregional asymmetry in the water sector of the South of Russia is being tested.Conclusions. The key water-related contradiction in the South of the Russian Federation lies in the high water intensity of the meta-regional economy due to agricultural specialization, limited opportunities for the use of circulating systems, as well as significant losses of water during transportation in conditions of naturally caused scarcity and poor quality of potable waters

  3. Effects of Coal—Water Mixture Properties in Atomization

    Institute of Scientific and Technical Information of China (English)

    DavidJ.Wildman; JamesM.Ekmann

    1994-01-01

    Recent suggested CWM applications include using filter cake material and mill tailings as coal sources.Neither coal type nor particle size distribution are necessarily well suited for coal-water mixture production.Slurries were prepared with and without additives and attempts were made to characterize their rheological properties and atomize these materials,Limits of operation and the value of existing rheological instrumentation and methods were investigated.Effects of changes in particle size distribution are discussed.

  4. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  5. The effect on slurry water as a fresh water replacement in concrete properties

    Science.gov (United States)

    Kadir, Aeslina Abdul; Shahidan, Shahiron; Hai Yee, Lau; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Concrete is the most widely used engineering material in the world and one of the largest water consuming industries. Consequently, the concrete manufacturer, ready mixed concrete plant is increased dramatically due to high demand from urban development project. At the same time, slurry water was generated and leading to environmental problems. Thus, this paper is to investigate the effect of using slurry water on concrete properties in term of mechanical properties. The basic wastewater characterization was investigated according to USEPA (Method 150.1 & 300.0) while the mechanical property of concrete with slurry water was compared according to ASTM C1602 and BS EN 1008 standards. In this research, the compressive strength, modulus of elasticity and tensile strength were studied. The percentage of wastewater replaced in concrete mixing was ranging from 0% up to 50%. In addition, the resulted also suggested that the concrete with 20% replacement of slurry water was achieved the highest compressive strength and modulus of elasticity compared to other percentages. Moreover, the results also recommended that concrete with slurry water mix have better compressive strength compared to control mix concrete.

  6. [KEEPING THE ELECTRON-DONOR PROPERTIES OF DRINKING WATER].

    Science.gov (United States)

    Gibert, K K; Stekhin, A A; Iakovleva, G V; Sul'ina, Iu S

    2015-01-01

    In a study there was performed the experimental evaluation of long-term structural--physical changes of the phase of associated water in drinking water treated in hypomagnetic conditions according to the the technology providing the retention of of ortho/para isomers of water in the presence of a catalyst--triplet oxygen. According to the results of measurements ofparameters of nano-associates formed in the water there was found a series ofconsistencies, allowing to determine the mechanisms of the impact of hypomagnetic treatment on the catalytic properties ofwater and long-term stability of its activated state, that provides the long-term maintenance of high biological activity of drinking water. In particular, under hypomagnetic conditions of the treatment there is formed denser packing of amorphous ice--VI in the composition of associates peroxide, serving as a kind of "reservoir" of atmospheric gases. In such a "reservoir" there realized higher pressure, compared with normal geophysical conditions, that stimulates the gas-phase reactions with the formation of dimers and trimers of oxygen existing in the 2-electron--active configurations with binding energies of 0.3 eVand ~0.2 eV providing phase modulation, resulting in condensation of environment additional electrons on paramagnetic oxygen, which provides the long-term maintenance of the electron--donor ability of water and electrically non-equilibrium state.

  7. Local properties of countercurrent stratified steam-water flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H J

    1985-10-01

    A study of steam condensation in countercurrent stratified flow of steam and subcooled water has been carried out in a rectangular channel/flat plate geometry over a wide range of inclination angles (4/sup 0/-87/sup 0/) at several aspect ratios. Variables were inlet water and steam flow rates, and inlet water temperature. Local condensation rates and pressure gradients were measured, and local condensation heat transfer coefficients and interfacial shear stress were calculated. Contact probe traverses of the surface waves were made, which allowed a statistical analysis of the wave properties. The local condensation Nusselt number was correlated in terms of local water and steam Reynolds or Froude numbers, as well as the liquid Prandtl number. A turbulence-centered model developed by Theofanous, et al. principally for gas absorption in several geometries, was modified. A correlation for the interfacial shear stress and the pressure gradient agreed with measured values. Mean water layer thicknesses were calculated. Interfacial wave parameters, such as the mean water layer thickness, liquid fraction probability distribution, wave amplitude and wave frequency, are analyzed.

  8. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    Science.gov (United States)

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.

  9. A molecular dynamics study on surface properties of supercooled water

    Institute of Scientific and Technical Information of China (English)

    L(U) Yongjun; WEI Bingbo

    2006-01-01

    Molecular dynamics simulations were performed to study the surface properties of water in a temperature range from 228 to 293 K by using the extended simple point charge (SPC/E) and four-site TIP4P potentials. The calculated surface tension increases with the decrease of temperature, and moreover the slopes of the surface tension-temperature curves show a weak rise below 273 K, whereas no obvious anomalies appear near 228 K, which accords with the previous experiments. Compared with the measured values, the SPC/E potential shows a good agreement, and the TIP4P potential scription of the surface structure of supercooled water for the SPC/E. When simulating the orientational distributions of water molecules near the surface, the SPC/E potential produces higher ordering and larger surface potentials than the TIP4P potential.

  10. Effective modification of particle surface properties using ultrasonic water mist

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Heinämäki, Jyrki

    2009-01-01

    The goal of the present study was to design a new technique to modify particle surface properties and, through that, to improve flowability of poorly flowing drug thiamine hydrochloride and pharmaceutical sugar lactose monohydrate of two different grades. The powdered particles were supplied...... properties. It was found that rapid exposition of pharmaceutical materials by water mist resulted in the improvement of powder technical properties. The evident changes in flowability of coarser lactose were obviously due to smoothing of particle surface and decreasing in the level of fines with very slight...... increment in particle size. The changes in thiamine powder flow were mainly due to narrowing in particle size distribution where the tendency for better flow of finer lactose was related to surface and size modifications. The aqueous mist application did not cause any alteration of the crystal structures...

  11. Effective modification of particle surface properties using ultrasonic water mist

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Heinämäki, Jyrki

    2009-01-01

    increment in particle size. The changes in thiamine powder flow were mainly due to narrowing in particle size distribution where the tendency for better flow of finer lactose was related to surface and size modifications. The aqueous mist application did not cause any alteration of the crystal structures......The goal of the present study was to design a new technique to modify particle surface properties and, through that, to improve flowability of poorly flowing drug thiamine hydrochloride and pharmaceutical sugar lactose monohydrate of two different grades. The powdered particles were supplied...... properties. It was found that rapid exposition of pharmaceutical materials by water mist resulted in the improvement of powder technical properties. The evident changes in flowability of coarser lactose were obviously due to smoothing of particle surface and decreasing in the level of fines with very slight...

  12. The Indus basin in the framework of current and future water resources management

    Science.gov (United States)

    Laghari, A. N.; Vanham, D.; Rauch, W.

    2012-04-01

    The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries - Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation). Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions - and especially groundwater extractions - have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer) season (as well as sugar cane, cotton, maize and other crops) and wheat during the rabi (dry, winter) season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM) within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1) reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater) and water demands; (2) water quality conservation and investment in wastewater infrastructure; (3) the use of alternative water resources like the recycling of wastewater and desalination; (4) land use

  13. The Indus basin in the framework of current and future water resources management

    Directory of Open Access Journals (Sweden)

    A. N. Laghari

    2012-04-01

    Full Text Available The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries – Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation. Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions – and especially groundwater extractions – have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer season (as well as sugar cane, cotton, maize and other crops and wheat during the rabi (dry, winter season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1 reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater and water demands; (2 water quality conservation and investment in wastewater infrastructure; (3 the use of alternative water resources like the recycling of wastewater and desalination; (4

  14. Urban water : harvesting rainwater at household level to improve the current water metabolism in Cuenca, Ecuador

    OpenAIRE

    Godoy Gacha, Juan Diego

    2015-01-01

    With a global population about 7 billion people and their continued growth are pressuring global natural resources, in freshwater matter this pressure is altering both the river flows; timing season of water flows; and spatial patterns in order to meet human demands both in urban as rural areas. However, water stress in urban areas are increasing and expectations by 2050 are grim with a global urban development by 70 percent moreover urbanization rate expected by 2030 in Latin America is 80 p...

  15. Transient response of microbial communities in a water well field to application of an impressed current.

    Science.gov (United States)

    Medihala, P G; Lawrence, J R; Swerhone, G D W; Korber, D R

    2013-02-01

    Deterioration of water wells due to clogging and corrosion over time is a common problem where solutions may be costly and ineffective. Pilot studies have suggested that impressed current or cathodic protection may be used to reduce microbially-induced declines in water well performance. Two water wells in an alluvial aquifer close to the North Saskatchewan River were selected to study the response of subsurface microbial communities to the application of an impressed current as an anti-fouling technology. The treated well was exposed to an impressed current while the untreated well was used as a reference site. Biofilms grown on in situ coupons under the influence of the impressed current were significantly (p anti-fouling technology but actually promoted both microbial growth and physical clogging in this aquifer.

  16. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...... direction can make any direction with the current. A consistent derivation of the wave spectrum taking into account current and finite water depth is used. The numerical results show a significant effect of the water depth, the directional spreading and the current on the conditional mean wave profile...

  17. The Effect of Water on the Flow of Stress-Activated Electric Currents through Rocks

    Science.gov (United States)

    Jahoda, A. M.; Cyr, G. G.; Dahlgren, R.; Freund, F. T.

    2011-12-01

    When igneous or high-grade metamorphic rocks are subjected to deviatoric stresses, dormant defects in the matrix of common rock-forming minerals become activated. These defects consist of pairs of oxygen anions in the 1- valence state, e.g. peroxy links such as O3Si-OO-SiO3. When a peroxy bond breaks, O3Si-O:O-SiO3, an electron is transferred from a neighboring O2- causing the donor oxygen, now O-, to turn into a defect electron, also known as a positive hole, that can propagate as a highly mobile positive charge through the rocks1. The current outflow is driven by the battery potential that builds up during this process. The question is how this electric current through rocks is affected by water. When positive holes flow into bulk water, they oxidize H2O to H2O2 and are thereby consumed2. This electrochemical reaction is driven by the potential drop across the rock-water interface. However, no such potential drop occurs across water that fills pores inside the rocks along the path of the electronic charge carriers. We present evidence that the presence of water in the pore space does indeed not "kill" the current flow. This observation leads to the conclusion that stress-activated positive hole currents should be able to flow through water-saturated rocks maybe as well as, possibly even better than through dry rocks. 1 Freund, F. T., et al.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Phys. Chem. Earth, 2006, 31, 389-396. 2 Balk, M., et al.: Oxidation of water to hydrogen peroxide at the rock-water interface due to stress-activated electric currents in rocks, Earth Planet. Sci. Lett. 2009, 283, 87-92

  18. Current meter data from moored current meter casts in the Coastal Waters of California from 12 April 1981 - 01 April 1983 (NODC Accession 8400159)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of California from April 12, 1981 to April 1, 1983. Data were submitted by...

  19. Current status of materials development of nuclear fuel cladding tubes for light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Zhengang, E-mail: duan_zg@imr.tohoku.ac.jp [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Yang, Huilong [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan); Satoh, Yuhki [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Murakami, Kenta; Kano, Sho; Zhao, Zishou; Shen, Jingjie [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan); Abe, Hiroaki, E-mail: abe.hiroaki@n.t.u-tokyo.ac.jp [Department of Nuclear Engineering, School of Engineering, The University of Tokyo, Nakagun, Ibaraki 319-1188 (Japan)

    2017-05-15

    Zirconium-based (Zr-based) alloys have been widely used as materials for the key components in light water reactors (LWRs), such as fuel claddings which suffer from waterside corrosion, hydrogen uptakes and strength loss at elevated temperature, especially during accident scenarios like the lost-of-coolant accident (LOCA). For the purpose of providing a safer, nuclear leakage resistant and economically viable LWRs, three general approaches have been proposed so far to develop the accident tolerant fuel (ATF) claddings: optimization of metallurgical composition and processing of Zr-based alloys, coatings on existing Zr-based alloys and replacement of current Zr-based alloys. In this manuscript, an attempt has been made to systematically present the historic development of Zr-based cladding, including the impacts of alloying elements on the material properties. Subsequently, the research investigations on coating layer on the surface of Zr-based claddings, mainly referring coating materials and fabrication methods, have been broadly reviewed. The last section of this review provides the introduction to alternative materials (Non-Zr) to Zr-based alloys for LWRs, such as advanced steels, Mo-based, and SiC-based materials.

  20. Regulation of Isotopic Composition of Water - way of Improvement of Cosmonauts Drinking Water Functional Properties

    Science.gov (United States)

    Kulikova, Ekaterina; Utina, Dina; Vorozhtsova, Svetlana; Severyuhin, Yuri; Abrosimova, Anna; Sinyak, Yuri; Ivanov, Alexander

    The problem in providing drinking water to cosmonauts is solved - at this moment there is a task to improve the functional properties of the water. One of the perspectives of this trend is the use of light isotopic water. The animal studies have shown that long-term consumption of water with a depletion of deuterium and oxygen heavy isotopes accelerates the rise of mass non-irradiated mice, the phase fluctuations reducing or increasing hematological parameters were having adaptive nature. These fluctuations didn’t overcome values beyond the physiological norm of this type of animal. It is established that the therapeutic use of light isotopic water with 35 - 90 ppm in deuterium increases the survival of irradiated mice by an average of 30%, contributes to the preservation of irradiated animals body weight. Treatment of acute radiation sickness with light isotopic water stimulates hematopoietic recovery. At the same time, keeping mice drinking light isotopic water for 7 - 8 days before the irradiation (from 4 to 8.5 Gr) has no effect on the level of radio resistance. Longer keeping mice on light isotopic water, for 14 -21 days - reduction in life expectancy, animal mass, bone marrow cellularity and the level of white blood cells in irradiated animals is noted. It was established that keeping mice on light isotopic water for 14 days before exposure in experimental animals causes an increase in the mitotic index and the frequency of formation of aberrant mitosis after 24 hours of Co(60) gamma radiation in doses of 1 , 2, and 4 Gr. Thus, it is clear that the regulation of the isotopic composition of drinking water - way to improve its functional properties.

  1. Characteristics of the cold-water belt formed off Soya Warm Current

    Science.gov (United States)

    Ishizu, Miho; Kitade, Yujiro; Matsuyama, Masaji

    2008-12-01

    We examined the data obtained by acoustic Doppler current profiler, conductivity-temperature-depth profiler, and expendable bathythermograph observations, which were collected in the summers of 2000, 2001, and 2002, to clarify the characteristics of the cold-water belt (CWB), i.e., lower-temperature water than the surrounding water extending from the southwest coast of Sakhalin along the offshore side of Soya Warm Current (SWC) and to confirm one of the formation mechanisms of the CWB as suggested by our previous study, i.e., the upwelling due to the convergence of bottom Ekman transport off the SWC region. The CWB was observed at about 30 km off the coast, having a thickness of 14 m and a minimum temperature of 12°C at the sea surface. The CWB does not have the specific water mass, but is constituted of three representative water types off the northeast coast of Hokkaido in summer, i.e., SWC water, Fresh Surface Okhotsk Sea Water, and Okhotsk Sea Intermediate Water. In a comparison of the horizontal distributions of current and temperature, the CWB region is found to be advected to the southeast at an average of 40 ± 29% of the maximum current velocity of the SWC. The pumping speed due to the convergence of the bottom Ekman transport is estimated as (1.5-3.0) × 10-4 m s-1. We examined the mixing ratio of the CWB, and the results implied that the water mass of the CWB is advected southeastward and mixes with a water mass upwelling in a different region off SWC.

  2. Water retention curves and thermal insulating properties of Thermosand

    Science.gov (United States)

    Leibniz, Otto; Winkler, Gerfried; Birk, Steffen

    2010-05-01

    The heat loss and the efficiency of isolating material surrounding heat supply pipes are essential issues for the energy budget of heat supply pipe lines. Until now heat loss from the pipe is minimized by enlarging the polyurethane (PU) - insulation thickness around the pipe. As a new approach to minimize the heat loss a thermally insulating bedding material was developed and investigated. Conventional bedding sands cover all necessary soil mechanical properties, but have a high thermal conductivity from λ =1,5 to 1,7 W/(m K). A newly developed embedding material 'Thermosand' shows thermal properties from λ=0,18 W/(m K) (dry) up to 0,88 W/(m K) (wet). The raw material originates from the waste rock stockpiles of a coal mine near Fohnsdorf, Austria. With high temperatures up to nearly 1000 ° C and a special mineral mixture, a natural burned reddish material resembling clinker arises. The soilmechanical properties of Thermosand has been thoroughly investigated with laboratory testing and in situ investigations to determine compaction-, permeability- and shear-behaviour, stiffness and corresponding physical parameters. Test trenches along operational heat pipes with temperature-measurement along several cross-sections were constructed to compare conventional embedding materials with 'Thermosand'. To investigate the influence of varying moisture content on thermal conductivity a 1:1 large scale model test in the laboratory to simulate real insitu-conditions was established. Based on this model it is planned to develop numerical simulations concerning varying moisture contents and unsaturated soil mechanics with heat propagation, including the drying out of the soil during heat input. These simulations require the knowledge about the water retention properties of the material. Thus, water retention curves were measured using both steady-state tension and pressure techniques and the simplified evaporation method. The steady-state method employs a tension table (sand

  3. Water Utility Management Strategies in Turkey: The current situation and the challenges

    Science.gov (United States)

    Alp, E.; Aksoy, M. N.; Koçer, B.

    2013-12-01

    As the effects of climate change becomes more prominent, current challenges related to water and wastewater management is becoming more serious. Providing water that satisfies environmental and safety standards in terms of quantity and quality is needed to maintain human life without compromising the need of future generations. Besides providing safe and affordable water, necessary treatment should be achieved according to several important factors such as receiving body standards, discharge standards, water reuse options. Therefore, management of water becomes more crucial than ever that states have to provide accessibility of safe water with affordable cost to its citizens with the means of effective utility management, including water treatment facilities, wastewater treatment facilities, water supply facilities and water distribution systems. Water utilities encounter with several challenges related to cost, infrastructure, population, legislation, workforce and resource. This study aims to determine the current situation and the necessary strategies to improve utility management in Turkish municipalities in a sustainable manner. US Environment Protection Agency (EPA) has formed a tool on effective utility management that assists utilities to provide a solution for both current and future challenges. In this study, we used EPA's guidelines and developed a survey consists of 60 questions under 10 sub-topics (Product Quality, Employee & Leadership Development, Stakeholder Understanding & Support, Operational Optimization, Infrastructure Stability, Financial Viability, Community Sustainability, Customer Satisfaction, Operational Resiliency, and Water Resource Adequacy). This survey was sent to the managers of 25 metropolitan municipalities in Turkey to assess the current condition of municipalities. After the evaluation of the survey results for each topic, including the importance given by managers, facilities were rated according to their level of achievement

  4. Density currents in the Chicago River: Characterization, effects on water quality, and potential sources

    Science.gov (United States)

    Jackson, P. Ryan; Garcia, Carlos M.; Oberg, Kevin A.; Johnson, Kevin K.; Garcia, Marcelo H.

    2008-01-01

    Bidirectional flows in a river system can occur under stratified flow conditions and in addition to creating significant errors in discharge estimates, the upstream propagating currents are capable of transporting contaminants and affecting water quality. Detailed field observations of bidirectional flows were made in the Chicago River in Chicago, Illinois in the winter of 2005-06. Using multiple acoustic Doppler current profilers simultaneously with a water-quality profiler, the formation of upstream propagating density currents within the Chicago River both as an underflow and an overflow was observed on three occasions. Density differences driving the flow primarily arise from salinity differences between intersecting branches of the Chicago River, whereas water temperature is secondary in the creation of these currents. Deicing salts appear to be the primary source of salinity in the North Branch of the Chicago River, entering the waterway through direct runoff and effluent from a wastewater-treatment plant in a large metropolitan area primarily served by combined sewers. Water-quality assessments of the Chicago River may underestimate (or overestimate) the impairment of the river because standard water-quality monitoring practices do not account for density-driven underflows (or overflows). Chloride concentrations near the riverbed can significantly exceed concentrations at the river surface during underflows indicating that full-depth parameter profiles are necessary for accurate water-quality assessments in urban environments where application of deicing salt is common.

  5. Influence of temperature on the volumetric properties of ethanol + water + 1–pentanol

    Directory of Open Access Journals (Sweden)

    M. IGLESIAS

    2004-12-01

    Full Text Available Knowledge of physical properties and phase equilibria is necessary for the design and optimization of the equipment for the production of distilled alcoholic beverages. In this paper the temperature dependence of the excess molar volumes of the ternary system ethanol + water + 1-pentanol in the temperature range 228.15 – 323.15 K and atmospheric pressure, are presented, due to the importance of 1-pentanol among the flavour compounds contained in this type of beverages. The excess molar volumes are negative over the whole homogeneous composition range, but tend to positive values towards the binaries ethanol + 1-pentanol and water + 1-pentanol. Because the design of current processes is strongly computer oriented, consideration was also given to how accurate the predictions of the SRK equations of state are. Different derived properties were computed due to their importance in the study of specific molecular interactions.

  6. Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi [Hoseo University, Asan (Korea, Republic of); Choi, Ho-Sang [Kyungil University, Gyeongsan, (Korea, Republic of)

    2014-04-15

    Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm{sup 2}. The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm{sup 2} and 3.28-3.75 Ω·cm{sup 2} for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm{sup 2} and 4.71-5.49Ω·cm{sup 2} for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

  7. Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    Pankaj Chowdhury

    2017-05-01

    Full Text Available Today, global warming and green energy are important topics of discussion for every intellectual gathering all over the world. The only sustainable solution to these problems is the use of solar energy and storing it as hydrogen fuel. Photocatalytic and photo-electrochemical water splitting and sacrificial hydrogen generation show a promise for future energy generation from renewable water and sunlight. This article mainly reviews the current research progress on photocatalytic and photo-electrochemical systems focusing on dye-sensitized overall water splitting and sacrificial hydrogen generation. An overview of significant parameters including dyes, sacrificial agents, modified photocatalysts and co-catalysts are provided. Also, the significance of statistical analysis as an effective tool for a systematic investigation of the effects of different factors and their interactions are explained. Finally, different photocatalytic reactor configurations that are currently in use for water splitting application in laboratory and large scale are discussed.

  8. Low energy high current pulsed electron beam treatment for improving surface microstructure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J; Allain-Bonasso, N; Zhang, X D; Hao, S Z; Grosdider, T; Dong, C [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM, UMR-CNRS 3143), Universite Paul Verlaine-Metz, Ile du Saulcy, 57045 Metz (France); Zou, J X, E-mail: jiang.wu@univ-metz.fr, E-mail: thierry.grosdidier@univ-metz.fr [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-06-15

    Low energy high current pulsed electron beam (LEHCPEB) is a fairly new technique for surface modifications authorizing improvement in wear and corrosion properties as well as texture changes and hardening. This contribution highlights some microstructure modifications encountered at the surface of HCPEB treated steels and bulk metallic glasses taking into account the effects of surface melting and the effects of the induced stress.

  9. Thermoelectric properties of SiC/C composites from wood charcoal by pulse current sintering

    NARCIS (Netherlands)

    Fujisawa, M; Hata, T; Bronsveld, P; Castro, [No Value; Tanaka, F; Kikuchi, H; Imamura, Y

    2005-01-01

    SiC/C composites were investigated by sintering a mix of wood charcoal and SiO2 powder (32-45 mu m) at 1400, 1600 and 1800 degrees C under N-2 atmosphere with a pulse current sintering method. Thermoelectric properties of SiC/C composites were investigated by measuring the Seebeck coefficient and th

  10. Electrical transport properties of oligothiophene based molecular films studied by current sensing Atomic Force Microscopy

    NARCIS (Netherlands)

    Hendriksen, Bas L.M.; Martin, Florent; Qi, Yabing; Qi, Y.; Mauldin, Clayton; Vukmirovic, Nenad; Ren, JunFeng; Wormeester, Herbert; Katan, Allard J.; Altoe, Virginia; Aloni, Shaul; Frechet, Jean M.J.; Wang, Lin-Wang; Salmeron, Miquel

    2011-01-01

    Using conducting probe atomic force microscopy (CAFM) we have investigated the electrical conduction properties of monolayer films of a pentathiophene derivative on a SiO2/Si-p+ substrate. By a combination of current–voltage spectroscopy and current imaging we show that lateral charge transport

  11. Thermodynamic properties of water desorption of forage turnip seeds

    Directory of Open Access Journals (Sweden)

    Kelly Aparecida Sousa

    2014-11-01

    Full Text Available The purpose of this study was to determine the thermodynamic properties of the process of water sorption in forage turnip  seeds. The equilibrium moisture content of forage turnip  seeds was determined by the gravimetric-dynamic method for different values of temperature and water activity. According to the results, increasing the moisture content increases the energy required for the evaporation of water in forage turnip seeds, and the values of integral isosteric heat of desorption, within the moisture content range of 3.33 to 11.30 (% d.b., varies from 4,222.70 to 2,870.34 kJ kg-1. With the elevation in the equilibrium moisture content, there is an increase in differential entropy and Gibbs free energy, which has positive values, demonstrating non-spontaneity in the process of desorption in the seeds. The theory of enthalpy-entropy compensation can be satisfactorily applied to the sorption phenomenon, and the process of water desorption of forage turnip seeds is controlled by enthalpy.

  12. Fouling-release Property of Water-filled Porous Elastomers

    Institute of Scientific and Technical Information of China (English)

    Lai-yong Xie; Fei Hong; Chuan-xin He; Jian-hong Liu; Chi Wu

    2012-01-01

    Since the fouling-releasing ability of silicone elastomers increased as their modulus decreases,we designed and prepared composites with embedded tiny NaCl crytals that were soluble after their immersion in water,resulting in water-filled porous elastomers.The scanning electron microscope images confirmed such a designed water-filling porous structure.The existence of many micro-drops of water in these specially designed elastomers decreased the shear storage modulus and increased the loss factors.The decrease of shear modulus plays a leading role here and is directly related to a lower critical peeling-off stress of a pseudo-barnacle on them.Therefore,such a novel preparation with cheap salts instead of an expensive silicone provides a better way to make fouling-release paints with a lower modulus,a lower critical peeling-off stress and a better fouling-release property without a significant decrease of the cross-linking density.

  13. [Mutagen properties of water-soluble polysaccharides from Acorus calamus].

    Science.gov (United States)

    Gur'ev, A M; Belousov, M B; Akhmedzhanov, R R; Iusubov, M S; Voronova, O L; Karpova, G V; Churin, A A

    2010-08-01

    Mutagenic properties of water soluble polysaccharides (WSPS) extracted from Acorus calamus L. have been studied. Neither a single intravenous injection nor a course intraperitoneal introduction of WSPS in a dose of 1/2 LD50 to mice of the CBA/CaLac line increases the level of cytogenetic disorders in the bone marrow cells. The investigation of WSPS by means of the somatic mosaicism test showed that the given dose of WSPS does not increase the rate of mutant spots on Drosophila wings.

  14. Preparation and Properties of Water-soluble Conjugated Polyelectrolyte

    Institute of Scientific and Technical Information of China (English)

    BAO Xiangjun; HONG Ruibin; HU Jianhua; ZHONG Yiping; LIU Ping; DENG Wenji

    2014-01-01

    The water-soluble conjugated polyelectrolyte, poly[3-(1′-ethyloxy-2′-N- methylimidazole) thiophene] (PEOIMT), was prepared. Its photophysical and electrochemical properties, and response characteristics to the external condition (e g, temperature response, solvent response and pH response), were investigated. The results show the PEOIMT belongs to the organic semiconductor. The interaction between the PEOIMT and the bovine serum albumin (BSA) was investigated using UV-vis spectroscopy. It was found that the PEOIMT could interact with the BSA. The PEOIMT can be used as a biosensor to detect the BSA.

  15. Water permeation and electrical properties of pottants, backings, and pottant/backing composites

    Science.gov (United States)

    Orehotsky, J.

    It is reported that the interface between plastic film back covers and ethylene vinyl acetates (EVA) or polyvinyl butyral (PVB) in photovoltaic modules can influence water permeation, and electrial properties of the composites such as leakage current and dielectric constant. The interface can either be one of two dissimilar materials in physical contact with no intermixing, or the interface can constitute a thin zone which is an interphase of the two materials having a gradient composition from one material to the other. The former condition is described as a discrete interface. A discrete interface model was developed to predict water permeation, dielectric strength, and leakage current for EVA, ethylene methyl acrylate (EMA), and PVB coupled to Tedlar and mylar films. Experimental data was compared with predicted data.

  16. Structural and functional properties of hydration and confined water in membrane interfaces.

    Science.gov (United States)

    Disalvo, E A; Lairion, F; Martini, F; Tymczyszyn, E; Frías, M; Almaleck, H; Gordillo, G J

    2008-12-01

    The scope of the present review focuses on the interfacial properties of cell membranes that may establish a link between the membrane and the cytosolic components. We present evidences that the current view of the membrane as a barrier of permeability that contains an aqueous solution of macromolecules may be replaced by one in which the membrane plays a structural and functional role. Although this idea has been previously suggested, the present is the first systematic work that puts into relevance the relation water-membrane in terms of thermodynamic and structural properties of the interphases that cannot be ignored in the understanding of cell function. To pursue this aim, we introduce a new definition of interphase, in which the water is organized in different levels on the surface with different binding energies. Altogether determines the surface free energy necessary for the structural response to changes in the surrounding media. The physical chemical properties of this region are interpreted in terms of hydration water and confined water, which explain the interaction with proteins and could affect the modulation of enzyme activity. Information provided by several methodologies indicates that the organization of the hydration states is not restricted to the membrane plane albeit to a region extending into the cytoplasm, in which polar head groups play a relevant role. In addition, dynamic properties studied by cyclic voltammetry allow one to deduce the energetics of the conformational changes of the lipid head group in relation to the head-head interactions due to the presence of carbonyls and phosphates at the interphase. These groups are, apparently, surrounded by more than one layer of water molecules: a tightly bound shell, that mostly contributes to the dipole potential, and a second one that may be displaced by proteins and osmotic stress. Hydration water around carbonyl and phosphate groups may change by the presence of polyhydroxylated compounds

  17. UCP2- and non-UCP2-mediated electric current in eukaryotic cells exhibits different properties.

    Science.gov (United States)

    Wang, Ruihua; MoYung, K C; Zhang, M H; Poon, Karen

    2015-12-01

    Using live eukaryotic cells, including cancer cells, MCF-7 and HCT-116, normal hepatocytes and red blood cells in anode and potassium ferricyanide in cathode of MFC could generate bio-based electric current. Electrons and protons generated from the metabolic reaction in both cytosol and mitochondria contributing to the leaking would mediate the generation of electric current. Both resveratrol (RVT) and 2,4-dinitrophenol (DNP) used to induce proton leak in mitochondria were found to promote electric current production in all cells except red blood cells without mitochondria. Proton leak might be important for electric current production by bringing the charge balance in cells to enhance the further electron leak. The induced electric current by RVT can be blocked by Genipin, an inhibitor of UCP2-mediated proton leak, while that induced by DNP cannot. RVT could reduce reactive oxygen species (ROS) level in cells better than that of DNP. In addition, RVT increased mitochondrial membrane potential (MMP), while DNP decreased it. Results highly suggested the existence of at least two types of electric current that showed different properties. They included UCP2-mediated and non-UCP2-mediated electric current. UCP2-mediated electric current exhibited higher reactive oxygen species (ROS) reduction effect per unit electric current production than that of non-UCP2-mediated electric current. Higher UCP2-mediated electric current observed in cancer cells might contribute to the mechanism of drug resistence. Correlation could not be established between electric current production with either ROS and MMP without distinguishing the types of electric current.

  18. Water quality, agriculture and food safety in China:Current situation, trends, interdependencies, and management

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-nan; GUO Qiu-ping; SHEN Xiao-xue; YU Sheng-wen; QIU Guo-yu

    2015-01-01

    Water quality in China is becoming a severe chalenge for agriculture and food safety, and it might also impact health of populationvia agriculture and food. Thus, it is causing widespread concern. Based on extensive literatures review and data mining, current situation of water polution in China and its effects on food safety were analyzed.The 2nd National Water Resource Survey in China show that the surface water al over the country was under slight polution and about 60% of groundwater is poluted. Drinking water quality is basicaly guaranteed in urban area but it is worrisome in rural areas. In addition, China is the largest consumer of fertilizer and pesticide in the world and the amounts of application stil show increasing trends. Fertilizers and pesticides are the most important sources of polution, which affect human health as persistent organic polutants and environmental endocrine disruptors. Eutrophication of surface water and nitrate polution of groundwater are serious threats to drinking water safety. Sewage irrigation is becoming a polution source to China’s water and land because of lacking of effective regulations. Although, with the advance in technology and management level, control of nitrogen and phosphorus emissions and reducing water polution is stil a major chalenge for China.

  19. Water Sensitive Urban Design: An Investigation of Current Systems, Implementation Drivers, Community Perceptions and Potential to Supplement Urban Water Services

    Directory of Open Access Journals (Sweden)

    Ashok K. Sharma

    2016-06-01

    Full Text Available Large scale centralised water, wastewater and stormwater systems have been implemented for over 100 years. These systems have provided a safe drinking water supply, efficient collection and disposal of wastewater to protect human health, and the mitigation of urban flood risk. The sustainability of current urban water systems is under pressure from a range of challenges which include: rapid population growth and resulting urbanisation, climate change impacts, and infrastructure that is ageing and reaching capacity constraints. To address these issues, urban water services are now being implemented with Integrated Urban Water Management (IUWM and Water Sensitive Urban Design (WSUD approaches. WSUD systems can deliver multiple benefits including water conservation, stormwater quality improvement, flood control, landscape amenity and a healthy living environment. These systems can be provided as stand-alone systems or in combination with centralised systems. These systems are still novel and thus face knowledge gaps that are impeding their mainstream uptake. Knowledge gaps cover technical, economic, social, and institutional aspects of their implementation. This paper is based on the outcomes of a comprehensive study conducted in South Australia which investigated impediments for mainstream uptake of WSUD, community perceptions of WSUD and potential of WSUD to achieve water conservation through the application of alternative resources, and in flood management. The outcomes are discussed in this paper for the benefit of water professionals engaged with WSUD planning, implementation, community consultation and regulation. Although the paper is based on a study conducted in South Australia, the comprehensive framework developed to conduct this detailed study and investigation can be adopted in any part of the world.

  20. The world of water, or testing neoliberalism: Is water a common good or private property?

    Directory of Open Access Journals (Sweden)

    Lošonc Alpar

    2006-01-01

    Full Text Available The backbone of neoliberalisation is privatization of common goods from the perspective of market naturalization and creation of a specific resource regime. It is of important to emphasis that neoliberalism coexists with other societal projects and we are witnessing simultaneity amongst different projects. The naturalization of market structures and identification of market with competition produce intensified risk-related consequences for the society; actually, neoliberalism exposes the society to environmental risks with a number of concrete examples. The author analyses the importance of water resources from the economic perspective, especially with regard to the neoliberal perspectives on water resources. The modalities of market-based usage of water are presented, constituting the property-rights regime. It is argued that an unconditional, socially irresponsible privatization does not take into account community-related management of common pools and dogmatically acknowledges only state and private forms of property. Such a critical view is supported with considerations that a the ongoing form of economic globalization does not maintain the development of the green market b water is a common good embedded in cultural and political relationships and filled with symbolic meanings. The impasse concerning the status of water takes place in the context where the Washington-consensus proved to be defective. At the same there is no other coherently formulated corpus of ideas to substitute the neoliberal canon. Water as a common good needs normative engagement and ecological economy has a task to participate in determination of sustainable levels of costs and prices of water resources.

  1. Water Repellency, Infiltration and Water Retention Properties of Forest Soils Under Different Management Practices

    Science.gov (United States)

    Wahl, N. A.; Bens, O.; Schäfer, B.; Hüttl, R. F.

    For soils under both agricultural and forest use, management and tillage practice can have significant influence on the hydraulic properties. It is therefore supposed, that management practices are capable of altering surface runoff, water retention and flood- ing risk for river catchments. Soil water repellency (hydrophobicity) can adversely affect soil hydrological properties, e.g. reduce infiltration capacity and induce pref- erential flow, thus enhancing the overall risk of flooding in river catchment areas. Hydrophobic effects are especially pronounced in coniferous forest soils. Investigations were carried out on several study plots in the German Northeastern Lowlands, located app. 50 km NE of Berlin in Brandenburg. Soils found in the area are mainly of glacifluvial origin with a pronounced sandy texture (with medium sized sand dominating). The four stands investigated represent different stages of forest transfor- mation, in a sense of a SfalseT chronosequence and are made up of populations of & cedil;Pinus sylvestris and Fagus sylvatica of different ages. Infiltration was measured with hood infiltrometers, and single infiltration rings at soil surface. Water retention capacity and the influence of soil organic matter on water storage were evaluated with laboratory methods. Water repellency was quantified with the water drop penetration time (WDPT) test, for determining the persistence of water repellency, and the ethanol percentage (EP) test, for measuring the severity/degree of water repellency. Soil samples from the four forest plots and different soil depths (0U160 cm) were used for the measurements. SPotentialT water repellencies were & cedil;determined after 3-day oven-drying at 45 C. The results indicate that for sandy forest soils, the overall infiltration capacity of the plots is low due to the effects of water repellency. The inter-variability of the plots is mainly caused by changes in the textural composition of the soils. For all plots a

  2. Superhydrophobic SAM Modified Electrodes for Enhanced Current Limiting Properties in Intrinsic Conducting Polymer Surge Protection Devices.

    Science.gov (United States)

    Jabarullah, Noor H; Verrelli, Emanuele; Mauldin, Clayton; Navarro, Luis A; Golden, Josh H; Madianos, Leonidas M; Kemp, Neil T

    2015-06-09

    Surface interface engineering using superhydrophobic gold electrodes made with 1-dodecanethiol self-assembled monolayer (SAM) has been used to enhance the current limiting properties of novel surge protection devices based on the intrinsic conducting polymer, polyaniline doped with methanesulfonic acid. The resulting devices show significantly enhanced current limiting characteristics, including current saturation, foldback, and negative differential effects. We show how SAM modification changes the morphology of the polymer film directly adjacent to the electrodes, leading to the formation of an interfacial compact thin film that lowers the contact resistance at the Au-polymer interface. We attribute the enhanced current limiting properties of the devices to a combination of lower contact resistance and increased Joule heating within this interface region which during a current surge produces a current blocking resistive barrier due to a thermally induced dedoping effect caused by the rapid diffusion of moisture away from this region. The effect is exacerbated at higher applied voltages as the higher temperature leads to stronger depletion of charge carriers in this region, resulting in a negative differential resistance effect.

  3. Transitions for fipronil quant in surface water, Summary of Current Fipronil Water Data and Water Data for WWTPs

    Data.gov (United States)

    U.S. Environmental Protection Agency — Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater. This dataset is...

  4. Gore Creek watershed, Colorado : assessment of historical and current water quantity, water quality, and aquatic ecology, 1968-98

    Science.gov (United States)

    Wynn, Kirby H.; Bauch, Nancy J.; Driver, Nancy E.

    2001-01-01

    The historical and current (1998) water-quantity, water-quality, and aquatic-ecology conditions in the Gore Creek watershed are described as part of a study by the U.S. Geological Survey, done in cooperation with the Town of Vail, the Eagle River Water and Sanitation District, and the Upper Eagle Regional Water Authority. Interpretation of the available water-quantity, water-quality, and aquatic-ecology data collected by various agencies since 1968 showed that background geology and land use in the watershed influence the water quality and stream biota. Surface-water nutrient concentrations generally increased as water moved downstream through the Town of Vail, but concentrations at the mouth of Gore Creek were typical when compared with national data for urban/undeveloped sites. Nitrate concentrations in Gore Creek were highest just downstream from a wastewater-treatment plant discharge, but concentrations decreased at sites farther downstream because of dilution and nitrogen uptake by algae. Recent total phosphorus concentrations were somewhat elevated when compared to the U.S. Environmental Protection Agency recommended level of 0.10 milligram per liter for control of eutrophication in flowing water. However, total phosphorus concentrations at the mouth of Gore Creek were relatively low when compared to a national study of phosphorus in urban land-use areas. Historically, suspended sediment associated with construction of Interstate 70 in the early 1970's has been of primary concern; however, recent data indicate that streambed aggradation of sediment originating from Interstate 70 traction sanding currently is a greater concern. About 4,000 tons of coarse sand and fine gravel is washed into Black Gore Creek each year following application of traction materials to Interstate 70 during adverse winter driving conditions. Suspended-sediment concentrations were low in Black Gore Creek; however, bedload-transport rates of as much as 4 tons per day have been measured

  5. Influence of Soil Water Retention Properties on Hydrological Cycle and Water Budgeting Module Simulation

    Directory of Open Access Journals (Sweden)

    Hamid Čustović

    2011-03-01

    Full Text Available The complexity of water budgeting module as shown in this paper is represented in phases. By experimental measurement of precipitation and lysimetric measurement of percolation runoff the fi rst phase establishes monthly and annual soil-water budgets of skeletal and clayey soils, and hence the influence of soil water-retention potential on hydrologic cycle and water budget over a four year period in the area of Mostar. Then, a soil-water budget model is simulated in a simplified procedure in order to determine the corresponding soil productive water reserve (R for given soils.In this way, depending on R values, the output parameters of the simulated model may produce different results in: calculated surplus or percolation runoff, real evapotranspiration (RET and water deficit.The lysimetric measuring of the water input and output in skeletal and clayey soils determined significant differences in the water budgets of these, by physical properties, divergent soils. Such correlations indicate that there is a realistic possibility of computing new, relatively reliable and pragmatically significant agro-hydrological parameters using measured precipitation and calculated PET.Also, this paper addresses a correlative analysis between the apple and maize ET on one side, and evaporation measured by Piche and by Class A, as well as PET calculated by Thornthwaite, Turc and Penman, on the other side. The results show a reliable reaction between ET of apple and maize with E by Piche, while the same relation is even more reliable with Class A. Other methods in this correlative analysis are less reliable.

  6. Visual information about past, current and future properties of irregular target paths in isometric force tracking.

    Science.gov (United States)

    Mazich, Molly M; Studenka, Breanna E; Newell, Karl M

    2015-01-01

    In visual-motor tracking, information about past, current, and future properties of a target path can be available but, because they are typically manipulated independently, the relative contribution of these information categories to tracking performance is not well understood. The aim of the current study was to investigate the role of visual information pertaining to past, current, and future states of the target path in guiding isometric tracking performance as a function of the irregularity of the target path (sine wave, brown/pink noise, white noise). The findings from local and global properties of the force output showed that the role of visual information about the past, current, and future states of target paths is dependent on the regularity of the signal to be tracked. The brown/pink noise pathway condition was most strongly influenced by future and past-future visual information for both local error properties (lead/lag, root mean square error (RMSE)) and global properties of the force output (ApEn, cross correlation). The highly irregular white noise pathway did not benefit from past or future information and the highly regular sine wave was only influenced for the local error properties of RMSE and lead/lag. It appears that visual information about past and future tracking states is more effective with a pathway that is middling with respect to regularity/irregularity. This is consistent with the role of visual information in tracking to be dependent on the potential adaptability for change in the dimension of the motor output.

  7. EFFECTS OF WATER CHEMISTRY ON COPPER TOXICITY - WHAT'S MISSING FROM CURRENT MODELS?

    Science.gov (United States)

    Current models for the acute toxicity of cationic metals to aquatic organisms focus on the binding of free metal ions to gill surfaces. This binding, and the resultant toxicity, can be reduced by metal-complexing ligands in the exposure water, which lower the activity of the free...

  8. Gravity waves on water with non-uniform depth and current

    NARCIS (Netherlands)

    Booij, N.

    1981-01-01

    A mathematical model for the combined refraction-diffraction of linear periodic gravity waves on water is developed, in which the influence of inhomogeneities of depth and current is taken into account. The model is used to compute partial reflection of waves a gully or an undersea slope, with influ

  9. 75 FR 27926 - Notice of Availability of Interpretive Rule on the Applicability of Current Water Conservation...

    Science.gov (United States)

    2010-05-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY 10 CFR Part 430 Notice of Availability of Interpretive Rule on the Applicability of Current Water Conservation... ``showerhead'' in the DOE's regulations related to the energy conservation program for consumer products....

  10. Gravity waves on water with non-uniform depth and current

    NARCIS (Netherlands)

    Booij, N.

    1981-01-01

    A mathematical model for the combined refraction-diffraction of linear periodic gravity waves on water is developed, in which the influence of inhomogeneities of depth and current is taken into account. The model is used to compute partial reflection of waves a gully or an undersea slope, with influ

  11. Deep water bottom current deposition in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are some active bottom currents on the northern continental slope of the South China Sea (SCS). Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m,extending from the NE to the SW,leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers sug-gests that these drifts propagated southwestward,following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current,which enters the northern SCS via the Bashi Strait. Once formed,the bottom currents trans-port sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity,the deep-sea sedimentary process in the northern SCS is complex.

  12. Coal-water slurry fuel production: Its evolution and current status in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.L.; Miller, B.G.; Scaroni, A.W. [Pennsylvania State Univ., University Park, PA (United States)

    1997-12-31

    Interest in the US in utilizing bituminous coal in a slurry form has evolved substantially over the last two decades. In the mid-1970`s, technologies to utilize coal-oil mixtures (COMs) as potential fuel oil replacements for utility and industrial boilers were developed as a consequence of escalating world oil prices. To further reduce dependency on imported oil, interest shifted away from COMs to coal-water slurry fuels (CWSFs) because higher solids loadings were obtainable while eliminating the use of oil. Research which focused on the use of CWSF as a potential fuel oil replacement peaked in the mid to late-1980`s as a result of a decline in world oil prices. During the late 1980`s and early 1990`s, coal suppliers and coal-fired utilities began to evaluate the production of CWSF using bituminous coal fines from fine coal cleaning circuits in an effort to reduce dewatering/drying costs. This marked a philosophical change in the driving force behind the utilization of CWSF in the US. In an effort to broaden the supply of coal fines, The Pennsylvania State University (Penn State) and the Pennsylvania Electric Company (Penelec) surveyed a series of fine coal impoundments in western Pennsylvania to determine the quality, cleanability, and slurryability of the coal fines contained therein. The development and commercialization of recovery technologies, cleaning techniques, and CWSF reentrainment circuits, coupled with an interest by utilities to utilize low-cost fuels, has fostered the recovery of impounded coal fines. In addition to the fine coal impoundments, fine coal cleaning circuits which actively dispose of process water having suspended coal fines (e.g. centrifuge effluent) are being examined to determine if the fines can be recovered and thickened into a low solids CWSF. The paper describes required physical and chemical properties of a CWSF for boiler applications. There is a growing awareness that CWSF is a fuel form that can be cofired with coal. The

  13. Statistical research on the motion properties of the magnetotail current sheet:Cluster observations

    Institute of Scientific and Technical Information of China (English)

    H.REME; E.LUCEK

    2010-01-01

    The origin of the flapping motion of the earth’s magnetotail current sheet is one of the most important problems in the magnetotail dynamics.Using Cluster data,we make a statistical research on the motion properties of the magnetotail current sheet of 2001 and 2003.We calculate the velocities of the magnetotail current sheet using new methods and obtain the distribution of the magnetotail current sheet velocities in the X-Y plane in GSE coordinate system.Our results show that although most of the current sheets were propagating toward the tail flanks and those of the exceptions lay in dusk side,which is consistent with previous studies,the proportions of the current sheet which were propagating toward midnight (where |YGSE|=0) were higher than those in previous studies.Motions of the current sheet in the middle area (|YGSE|<8 Re) of the magnetotail are investigated.Relatively high value of the Z component of the velocity further confirms that the middle area of the magnetotail might be a source region for the motion of the current sheets which were propagating towards the tail flanks.According to our case studies,the way the current sheets propagated toward midnight area differs significantly from that toward dusk and dawn side,from which we infer that there might be two different kinds of current sheet motions originated from different sources.The statistical results of this paper may give some clues for further studies on the origin of the flapping motion of the magnetotail current sheet.

  14. Effect of Interfacial Polarization and Water Absorption on the Dielectric Properties of Epoxy-Nanocomposites

    Directory of Open Access Journals (Sweden)

    Philipp Marx

    2017-05-01

    Full Text Available Five types of nanofillers, namely, silica, surface-silylated silica, alumina, surface-silylated alumina, and boron nitride, were tested in this study. Nanocomposites composed of an epoxy/amine resin and one of the five types of nanoparticles were tested as dielectrics with a focus on (i the surface functionalization of the nanoparticles and (ii the water absorption by the materials. The dispersability of the nanoparticles in the resin correlated with the composition (OH content of their surfaces. The interfacial polarization of the thoroughly dried samples was found to increase at lowered frequencies and increased temperatures. The β relaxation, unlike the interfacial polarization, was not significantly increased at elevated temperatures (below the glass-transition temperature. Upon the absorption of water under ambient conditions, the interfacial polarization increased significantly, and the insulating properties decreased or even deteriorated. This effect was most pronounced in the nanocomposite containing silica, and occurred as well in the nanocomposites containing silylated silica or non-functionalized alumina. The alternating current (AC breakdown strength of all specimens was in the range of 30 to 35 kV·mm−1. In direct current (DC breakdown tests, the epoxy resin exhibited the lowest strength of 110 kV·mm−1; the nanocomposite containing surface-silylated alumina had a strength of 170 kV·mm−1. In summary, water absorption had the most relevant impact on the dielectric properties of nanocomposites containing nanoparticles, the surfaces of which interacted with the water molecules. Nanocomposites containing silylated alumina particles or boron nitride showed the best dielectric properties in this study.

  15. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction...... of the main wind direction can make any direction with the current. Numerical results showing the importance of the water depth, the directional spreading and the current on the conditional mean wave profile and the associated wave kinematics are presented. A discussion of the use of the conditional wave...

  16. Loss Current Analysis of Water Tree Degradation in Polyethylene using Equivalent Circuit Model

    Science.gov (United States)

    Suzuki, Masafumi; Itoh, Atsushi; Yoshimura, Noboru

    It is well known that the degradation of XLPE cable by water tree gives rise to harmonics in the loss current. Many researches by simulation and experiment have been carried out for the purpose of the elucidation of the mechanism of the harmonics in the loss current generation. In the present study, the loss current was calculated from the equivalent circuit model composed of voltage-dependent resistance and condenser. These elements are being connected with the matrix state. As a result, we were able to obtain the good agreement between the experimental value and the calculated value by appropriately choosing the characteristics of the voltage-dependent resistance. The equivalent circuit model determined in this study can consider not only the electrical characteristic of water tree but also its shape.

  17. Non-perturbative calculation of molecular magnetic properties within current-density functional theory.

    Science.gov (United States)

    Tellgren, E I; Teale, A M; Furness, J W; Lange, K K; Ekström, U; Helgaker, T

    2014-01-21

    We present a novel implementation of Kohn-Sham density-functional theory utilizing London atomic orbitals as basis functions. External magnetic fields are treated non-perturbatively, which enable the study of both magnetic response properties and the effects of strong fields, using either standard density functionals or current-density functionals-the implementation is the first fully self-consistent implementation of the latter for molecules. Pilot applications are presented for the finite-field calculation of molecular magnetizabilities, hypermagnetizabilities, and nuclear magnetic resonance shielding constants, focusing on the impact of current-density functionals on the accuracy of the results. Existing current-density functionals based on the gauge-invariant vorticity are tested and found to be sensitive to numerical details of their implementation. Furthermore, when appropriately regularized, the resulting magnetic properties show no improvement over standard density-functional results. An advantage of the present implementation is the ability to apply density-functional theory to molecules in very strong magnetic fields, where the perturbative approach breaks down. Comparison with high accuracy full-configuration-interaction results show that the inadequacies of current-density approximations are exacerbated with increasing magnetic field strength. Standard density-functionals remain well behaved but fail to deliver high accuracy. The need for improved current-dependent density-functionals, and how they may be tested using the presented implementation, is discussed in light of our findings.

  18. Non-perturbative calculation of molecular magnetic properties within current-density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Tellgren, E. I., E-mail: erik.tellgren@kjemi.uio.no; Lange, K. K.; Ekström, U.; Helgaker, T. [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway); Teale, A. M., E-mail: andrew.teale@nottingham.ac.uk [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway); School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Furness, J. W. [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2014-01-21

    We present a novel implementation of Kohn–Sham density-functional theory utilizing London atomic orbitals as basis functions. External magnetic fields are treated non-perturbatively, which enable the study of both magnetic response properties and the effects of strong fields, using either standard density functionals or current-density functionals—the implementation is the first fully self-consistent implementation of the latter for molecules. Pilot applications are presented for the finite-field calculation of molecular magnetizabilities, hypermagnetizabilities, and nuclear magnetic resonance shielding constants, focusing on the impact of current-density functionals on the accuracy of the results. Existing current-density functionals based on the gauge-invariant vorticity are tested and found to be sensitive to numerical details of their implementation. Furthermore, when appropriately regularized, the resulting magnetic properties show no improvement over standard density-functional results. An advantage of the present implementation is the ability to apply density-functional theory to molecules in very strong magnetic fields, where the perturbative approach breaks down. Comparison with high accuracy full-configuration-interaction results show that the inadequacies of current-density approximations are exacerbated with increasing magnetic field strength. Standard density-functionals remain well behaved but fail to deliver high accuracy. The need for improved current-dependent density-functionals, and how they may be tested using the presented implementation, is discussed in light of our findings.

  19. Magnetic response and critical current properties of mesoscopic-size YBCO superconducting samples

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa-Filho, P N [UNESP - Universidade Estadual Paulista, Grupo de Materiais Avancados, Departamento de Fisica, Bauru (Brazil); Deimling, C V; Ortiz, W A, E-mail: plisboa@fc.unesp.b [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos (Brazil)

    2010-01-15

    In this contribution superconducting specimens of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were synthesized by a modified polymeric precursor method, yielding a ceramic powder with particles of mesoscopic-size. Samples of this powder were then pressed into pellets and sintered under different conditions. The critical current density was analyzed by isothermal AC-susceptibility measurements as a function of the excitation field, as well as with isothermal DC-magnetization runs at different values of the applied field. Relevant features of the magnetic response could be associated to the microstructure of the specimens and, in particular, to the superconducting intra- and intergranular critical current properties.

  20. [A review on current situations of steroid estrogen in the water system].

    Science.gov (United States)

    Du, Shao-ting; Jin, Chong-wei; Liu, Yue

    2013-09-01

    Steroid estrogens are a group of biologically active endocrine disruptors. An extremely low level of steroid estrogens is sufficient to result in reproduction and behavior disorders, and larval mutation of both human being and animals. The ecological and environmental effects of steroid estrogens should be more direct on organisms in water system as compared with those in other environment systems. Therefore, in this paper we reviewed the physical and chemical properties of some frequently-used steroid estrogens, and their contamination status, origins and transfers in water system, so as to provide a theoretical basis for developing estrogen removal strategies.

  1. Apparent optical properties of the Canadian Beaufort Sea - Part 1: Observational overview and water column relationships

    Science.gov (United States)

    Antoine, D.; Hooker, S. B.; Bélanger, S.; Matsuoka, A.; Babin, M.

    2013-07-01

    A data set of radiometric measurements collected in the Beaufort Sea (Canadian Arctic) in August 2009 (Malina project) is analyzed in order to describe apparent optical properties (AOPs) in this sea, which has been subject to dramatic environmental changes for several decades. The two properties derived from the measurements are the spectral diffuse attenuation coefficient for downward irradiance, Kd, and the spectral remote sensing reflectance, Rrs. The former controls light propagation in the upper water column. The latter determines how light is backscattered out of the water and becomes eventually observable from a satellite ocean color sensor. The data set includes offshore clear waters of the Beaufort Basin as well as highly turbid waters of the Mackenzie River plumes. In the clear waters, we show Kd values that are much larger in the ultraviolet and blue parts of the spectrum than what could be anticipated considering the chlorophyll concentration. A larger contribution of absorption by colored dissolved organic matter (CDOM) is responsible for these high Kd values, as compared to other oligotrophic areas. In turbid waters, attenuation reaches extremely high values, driven by high loads of particulate materials and also by a large CDOM content. In these two extreme types of waters, current satellite chlorophyll algorithms fail. This questions the role of ocean color remote sensing in the Arctic when Rrs from only the blue and green bands are used. Therefore, other parts of the spectrum (e.g., the red) should be explored if one aims at quantifying interannual changes in chlorophyll in the Arctic from space. The very peculiar AOPs in the Beaufort Sea also advocate for developing specific light propagation models when attempting to predict light availability for photosynthesis at depth.

  2. Interfacial properties of asphaltenes at toluene-water interfaces.

    Science.gov (United States)

    Zarkar, Sharli; Pauchard, Vincent; Farooq, Umer; Couzis, Alexander; Banerjee, Sanjoy

    2015-05-05

    Asphaltenes are "n-alkane insoluble" species in crude oil that stabilize water-in-oil emulsions. To understand asphaltene adsorption mechanisms at oil-water interfaces and coalescence blockage, we first studied the behavior in aliphatic oil-water systems in which asphaltenes are almost insoluble. They adsorbed as monomers, giving a unique master curve relating interfacial tension (IFT) to interfacial coverage through a Langmuir equation of state (EoS). The long-time surface coverage was independent of asphaltene bulk concentration and asymptotically approached the 2-D packing limit for polydisperse disks. On coalescence, the surface coverage exceeded the 2-D limit and the asphaltene film appeared to become solidlike, apparently undergoing a transition to a soft glassy material and blocking further coalescence. However, real systems consist of mixtures of aliphatic and aromatic components in which asphaltenes may be quite soluble. To understand solubility effects, we focus here on how the increased bulk solubility of asphaltenes affects their interfacial properties in comparison to aliphatic oil-water systems. Unlike the "almost irreversible" adsorption of asphaltenes where the asymptotic interfacial coverage was independent of the bulk concentration, an equilibrium surface pressure, dependent on bulk concentration, was obtained for toluene-water systems because of adsorption being balanced by desorption. The equilibrium surface coverage could be obtained from the short- and long-term Ward-Tordai approximations. The behavior of the equilibrium surface pressure with the equilibrium surface coverage was then derived. These data for various asphaltene concentrations were used to determine the EoS, which for toluene-water could also be fitted by the Langmuir EoS with Γ∞ = 3.3 molecule/nm(2), the same value as that found for these asphaltenes in aliphatic media. Asphaltene solubility in the bulk phase only appears to affect the adsorption isotherm but not the Eo

  3. Offshore produced water management: A review of current practice and challenges in harsh/Arctic environments.

    Science.gov (United States)

    Zheng, Jisi; Chen, Bing; Thanyamanta, Worakanok; Hawboldt, Kelly; Zhang, Baiyu; Liu, Bo

    2016-03-15

    Increasing offshore oil and gas exploration and development in harsh/Arctic environments require more effective offshore produced water management, as these environments are much more sensitive to changes in water quality than more temperate climates. However, the number and scope of studies of offshore produced water management in harsh/Arctic environments are limited. This paper reviews the current state of offshore produced water management, impacts, and policies, as well as the vulnerability, implications and operational challenges in harsh/Arctic environments. The findings show that the primary contaminant(s) of concern are contained in both the dissolved oil and the dispersed oil. The application of emerging technologies that can tackle this issue is significantly limited by the challenges of offshore operations in harsh/Arctic environments. Therefore, there is a need to develop more efficient and suitable management systems since more stringent policies are being implemented due to the increased vulnerability of harsh/Arctic environments.

  4. Effects of alternating and direct current in electrocoagulation process on the removal of cadmium from water

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Subramanyan, E-mail: vasudevan65@gmail.com [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India); Lakshmi, Jothinathan; Sozhan, Ganapathy [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India)

    2011-08-15

    Highlights: {yields} Very high removal efficiency of cadmium was achieved by electrocoagulation. {yields} Alternating current (AC) avoids oxide layer and corrosion on anode surface. {yields} Good current transfer between anode and cathode results more removal efficiency. {yields} Compact treatment facility and complete automation. {yields} Aluminum alloy anode prevents residual aluminum in treated water. - Abstract: In practice, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of cadmium from water using aluminum alloy as anode and cathode. The results showed that the removal efficiency of 97.5 and 96.2% with the energy consumption of 0.454 and 1.002 kWh kl{sup -1} was achieved at a current density of 0.2 A/dm{sup 2} and pH of 7.0 using aluminum alloy as electrodes using AC and DC, respectively. For both AC and DC, the adsorption of cadmium was preferably fitting Langmuir adsorption isotherm, the adsorption process follows second order kinetics and the temperature studies showed that adsorption was exothermic and spontaneous in nature.

  5. The effects of replacing the water model while decoupling water-water and water-solute interactions on computed properties of simple salts

    Science.gov (United States)

    Li, Jicun; Wang, Feng

    2016-07-01

    The effects of decoupling the water-water and water-solute interactions are studied with selected mono-valent ions as the solute. Using the ion-water cross terms developed for the BLYPSP-4F water model, we replaced the water potential with WAIL, TIP4P, and TIP3P without changing the ion-water parameters. When the adaptive force matching (AFM) derived BLYPSP-4F model is replaced by the other AFM derived WAIL model, the difference in ion properties, such as hydration free energies, radial distribution functions, relative diffusion constants, is negligible, demonstrating the feasibility for combining AFM parameters from different sources. Interestingly, when the AFM-derived ion-water cross-terms are used with a non-AFM based water model, only small changes in the ion properties are observed. The final combined models with TIP3P or TIP4P water reproduce the salt hydration free energies within 6% of experiments. The feasibility of combining AFM models with other non-AFM models is of significance since such combinations allow more complex systems to be studied without specific parameterization. In addition, the study suggests an interesting prospect of reusing the cross-terms when a part of a general force field is replaced with a different model. The prevailing practice, which is to re-derive all cross-terms with combining rules, may not have been optimal.

  6. A molecular dynamics study on surface properties of supercooled water

    Institute of Scientific and Technical Information of China (English)

    Lü; Yongjun

    2006-01-01

    [1]Basu J K,Hazra S,Sanyal M K.Growth mechanism of Langmuir-Blodgett films.Phys Rev Lett,1999,82:4675-4678[2]Taylor R S,Shields R L.Molecular-dynamics simulations of the ethanol liquid-vapor interface.J Chem Phys,2003,119:12569-12576[3]Velev O D,Gurkov T D,Ivanov I B,et al.Abnormal thickness and stability of nonequilibrium liquid films.Phys Rev Lett,1995,75:264-267[4]Weng J G,Park S,Lukes J R,et al.Molecular dynamics investigation of thickness effect on liquid films.J Chem Phys,2000,113:5917-5923[5]Zakharov V V,Brodskaya E N,Laaksonen A.Surface tension of water droplets:A molecular dynamics study of model and size dependencies.J Chem Phys,1997,107:10675-10683[6]Wang J Z,Chen M,Guo Z Y.A two-dimensional molecular dynamics simulation of liquid-vapor nucleation.Chin Sci Bull,2003,48(7):623-626[7]Guissani Y,Guillot B.A computer simulation study of the liquid-vapor coexistence curve of water.J Chem Phys,1993,98:8221-8235[8]Wilson M A,Pohorille A,Pratt L R.Surface potential of the water liquid-vapor interface.J Chem Phys,1988,88:3281-3285[9]Alejandre J,Tildesley D J,Chapela G A.Molecular dynamics simulation of the orthobaric densities and surface tension of water.J Chem Phys,1995,102:4574-4583[10]Matsumoto M,Kataoka Y.Study on liquid-vapor interface of water (Ⅰ):Simulational results of thermodynamic properties and orientational structure.J Chem Phys,1988,88:3233-3245[11]Floriano M A,Angell C A.Surface tension and molar surface free energy and entropy of water to-27.2℃.J Phys Chem,1990,94:4199-4202[12]Jorgensen W L,Chandrasekhar J,Madura J D.Comparison of simple potential functions for simulating liquid water.J Chem Phys,1993,79:926-935[13]Berendsen H J C,Grigera J R,Straatsma T P.The missing term in effective pair potentials.J Phys Chem,1987,91:6269-6271[14]Arbuckle B W,Clancy P.Effects of the Ewald sum on the free energy of the extended simple point charge model for water.J Chem Phys,2002,116:5090-5098[15]Tarazona P,Chacon E,Reinaldo-Falagan M,et al

  7. Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls.

    Science.gov (United States)

    Bouaziz, Fatma; Koubaa, Mohamed; Barba, Francisco J; Roohinejad, Shahin; Chaabouni, Semia Ellouz

    2016-08-02

    Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL(-1)), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL(-1)), high reducing power capacity (RPSFG = 5 mg·mL(-1)), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg·mL(-1)). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls.

  8. Physicochemical properties of calcium polycarbophil, a water-absorbing polymer.

    Science.gov (United States)

    Yamada, T; Kitayama, M; Yamazaki, M; Nagata, O; Tamaj, I; Tsuji, A

    1996-07-01

    The physicochemical properties of calcium polycarbophil were examined. Calcium polycarbophil was decalcified rapidly under acidic conditions, affording polycarbophil. Polycarbophil absorbed about 10 times its own weight of water under acidic conditions, but the swelling ratio markedly increased at above pH 4.0 and reached 70 times the initial weight under neutral conditions. The swelling of polycarbophil was not affected by non-ionic osmolarity, but was affected by ionic strength, showing a decrease with increase of ionic strength. Monovalent metal ions such as sodium and potassium ions in gastrointestinal fluid did not reduce the equilibrium swelling of polycarbophil, but divalent ions such as calcium and magnesium ions did. However, calcium ion only slightly reduced the equilibrium swelling under sodium-rich conditions. The viscosity (as an indicator of fluidity) of polycarbophil was larger than that of CMC-Na at every shear rate and polymer content examined.

  9. Seasonal to interannual variability of water mass characteristics and currents on the Namibian shelf

    Science.gov (United States)

    Junker, Tim; Mohrholz, Volker; Siegfried, Lydia; van der Plas, Anja

    2017-01-01

    We present long-term current meter records from the Benguela system together with salinity and temperature observations gathered by a mooring on the Namibian shelf across 13 years (2002-2015). From this unique data set a climatological mean state is estimated enabling us to investigate seasonal to interannual variations of these variables on the Namibian shelf. The present study highlights the importance of the alongshore advection for the water mass characteristics in the Benguela system on a seasonal time scale. The annual cycle of the alongshore transport is characterized by a biannual flow reversal. Poleward directed currents dominate from October to April, and from May to September equatorward currents prevail. In addition, we present observational evidence for a biannual intrusion of tropical waters into the Benguela system with maxima in October and February. Based on the in situ temperature data, several anomalous events are described that affect the whole water column. During the outstanding warm event in austral fall 2011 the monthly temperature anomaly exceeds one Kelvin for five consecutive months peaking in March (2.4 K) in the upper layer of the water column. Our study suggests, that the occurrence of such extreme temperature events in the Benguela upwelling system is closely related to the strength of the alongshore advection in austral summer.

  10. Properties of sodium currents in neonatal and young adult mouse superficial dorsal horn neurons.

    Science.gov (United States)

    Tadros, Melissa A; Farrell, Kristen E; Graham, Brett A; Brichta, Alan M; Callister, Robert J

    2015-03-28

    Superficial dorsal horn (SDH) neurons process nociceptive information and their excitability is partly determined by the properties of voltage-gated sodium channels. Recently, we showed the excitability and action potential properties of mouse SDH neurons change markedly during early postnatal development. Here we compare sodium currents generated in neonate (P0-5) and young adult (≥P21) SDH neurons. Whole cell recordings were obtained from lumbar SDH neurons in transverse spinal cord slices (CsF internal, 32°C). Fast activating and inactivating TTX-sensitive inward currents were evoked by depolarization from a holding potential of -100 mV. Poorly clamped currents, based on a deflection in the IV relationship at potentials between -60 and -50 mV, were not accepted for analysis. Current density and decay time increased significantly between the first and third weeks of postnatal development, whereas time to peak was similar at both ages. This was accompanied by more subtle changes in activation range and steady state inactivation. Recovery from inactivation was slower and TTX-sensitivity was reduced in young adult neurons. Our study suggests sodium channel expression changes markedly during early postnatal development in mouse SDH neurons. The methods employed in this study can now be applied to future investigations of spinal cord sodium channel plasticity in murine pain models.

  11. The Properties of Water and their Applications for Training

    Science.gov (United States)

    Torres-Ronda, Lorena; del Alcázar, Xavi Schelling i

    2014-01-01

    The biological effects of immersion in water, which are related to the fundamental principles of hydrodynamics, may be beneficial in certain training contexts. The effects and physical properties of water, such as density, hydrostatic pressure and buoyancy are highly useful resources for training, when used as a counterbalance to gravity, resistance, a compressor and a thermal conductor. Not only does the aquatic medium enable a wider range of activities to be used in a context of low joint impact, but it also constitutes a useful tool in relation to sports rehabilitation, since it allows the athlete to return to training earlier or to continue with high-intensity exercise while ensuring both low joint impact and greater comfort for the individual concerned. Moreover, this medium enables the stimulation of metabolic and neuromuscular systems, followed by their corresponding physiological adaptations allowing both to maintain and improve athletic performance. Hydrotherapy can also play a beneficial role in an athlete’s recovery, helping to prevent as well as treat muscle damage and soreness following exercise. PMID:25713684

  12. The Properties of Water and their Applications for Training

    Directory of Open Access Journals (Sweden)

    Torres-Ronda Lorena

    2014-12-01

    Full Text Available The biological effects of immersion in water, which are related to the fundamental principles of hydrodynamics, may be beneficial in certain training contexts. The effects and physical properties of water, such as density, hydrostatic pressure and buoyancy are highly useful resources for training, when used as a counterbalance to gravity, resistance, a compressor and a thermal conductor. Not only does the aquatic medium enable a wider range of activities to be used in a context of low joint impact, but it also constitutes a useful tool in relation to sports rehabilitation, since it allows the athlete to return to training earlier or to continue with high-intensity exercise while ensuring both low joint impact and greater comfort for the individual concerned. Moreover, this medium enables the stimulation of metabolic and neuromuscular systems, followed by their corresponding physiological adaptations allowing both to maintain and improve athletic performance. Hydrotherapy can also play a beneficial role in an athlete’s recovery, helping to prevent as well as treat muscle damage and soreness following exercise.

  13. Water Quality and optical properties of Crater Lake, Oregon

    Science.gov (United States)

    Larson, Gary L.; Hoffman, Robert L.; McIntire, C.D.; Buktenica, M.W.; Girdner, Scott

    2007-01-01

    We examine observations of key limnological properties (primarily temperature, salinity, and dissolved oxygen), measured over a 14-year period in Crater Lake, Oregon, and discuss variability in the hypolimnion on time scales of days to a decade. During some years (e.g., 1994a??1995), higher-than-average wintertime deep convection and ventilation led to the removal of significant amounts of heat and salt from the hypolimnion, while dissolved oxygen concentrations increase. In other years, such as the winter of 1996a??1997, heat and salt concentrations increase throughout the year and dissolved oxygen levels drop, indicating conditions were dominated by the background geothermal inputs and dissolved oxygen consumption by bacteria (i.e., minimal deep convection). Over the entire 14 year period, no statistically significant trend was observed in the annual hypolimnetic heat and salt content. Measurements from several thermistors moored in the hypolimnion provide new insight into the time and space scales of the deep convection events. For some events, cool water intrusions are observed sequentially, from shallower depths to deeper depths, suggesting vertical mixing or advection from above. For other events, the cooling is observed first at the deepest sensors, suggesting a thin, cold water pulse that flows along the bottom and mixes more slowly upwards into the basin. In both cases, the source waters must originate from the epilimnion. Conditions during a strong ventilation year (1994a??1995) and a weak ventilation year (1996a??1997) were compared. The results suggest the major difference between these 2 years was the evolution of the stratification in the epilimnion during the first few weeks of reverse stratification such that thermobaric instabilities were easier to form during 1995 thana?#1997. Thus, the details of surface cooling and wind-driven mixing during the early stages ofa?#reverse stratification may determine the neta?#amount of ventilation possible during

  14. PETher - Physical Properties of Thermal Water under In-situ-Conditions

    Science.gov (United States)

    Herfurth, Sarah; Schröder, Elisabeth

    2016-04-01

    The objective of PETher, a research project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), is to experimentally determine thermo-physical properties (specific isobaric heat capacity, kinematic viscosity, density and thermal conductivity) of geothermal water in-situ-conditions (pressure, temperature, chemical composition including gas content of the brine) present in geothermal applications. Knowing these thermo-physical properties reduces the uncertainties with respect to estimating the thermal output and therefore the economic viability of the power plant. Up to now, only a limited number of measurements of selected physical properties have been made, usually under laboratory conditions and for individual geothermal plants. In-situ measured parameters, especially in the temperature range of 120°C and higher, at pressures of 20 bar and higher, as well as with a salinity of up to 250 g/l, are sparse to non-existing. Therefore, pure water properties are often used as reference data and for designing the power plant and its components. Currently available numerical models describing the thermo-physical properties are typically not valid for the conditions in geothermal applications and do not consider the substantial influence of the chemical composition of the thermal water. Also, actual geothermal waters have not been subject of detailed measurements systematically performed under operational conditions on a large-scale basis. Owing to the lack of reliable data, a validation of numerical models for investigating geothermal systems is not possible. In order to determine the dependency of the thermo-physical properties of geothermal water on temperature, pressure and salinity in-situ measurements are conducted. The measurements are taking place directly at several geothermal applications located in Germany's hydrogeothermal key regions. In order to do this, a mobile testing unit was developed and refined with instruments specifically

  15. Inferring inherent optical properties and water constituent profiles from apparent optical properties.

    Science.gov (United States)

    Fan, Yongzhen; Li, Wei; Calzado, Violeta Sanjuan; Trees, Charles; Stamnes, Snorre; Fournier, Georges; McKee, David; Stamnes, Knut

    2015-07-27

    The BP09 experiment conducted by the Centre for Maritime Research and Experimentation in the Ligurian Sea in March 2009 provided paired vertical profiles of nadir-viewing radiances L(u)(z) and downward irradiances E(d)(z) and inherent optical properties (IOPs, absorption, scattering and backscattering coefficients). An inversion algorithm was implemented to retrieve IOPs from apparent optical properties (AOPs, radiance reflectance R(L), irradiance reflectance R(E) and diffuse attenuation coefficient K(d)) derived from the radiometric measurements. Then another inversion algorithm was developed to infer vertical profiles of water constituent concentrations, including chlorophyll-a concentration, non-algal particle concentration, and colored dissolved organic matter from the retrieved IOPs based on a bio-optical model. The algorithm was tested on a synthetic dataset and found to give reliable results with an accuracy better than 1%. When the algorithm was applied to the BP09 dataset it was found that good retrievals of IOPs could be obtained for sufficiently deep waters, i.e. for L(u)(z) and E(d)(z) measurements conducted to depths of 50 m or more. This requirement needs to be satisfied in order to obtain a good estimation of the backscattering coefficient. For such radiometric measurements a correlation of 0.88, 0.96 and 0.93 was found between retrieved and measured absorption, scattering and backscattering coefficients, respectively. A comparison between water constituent values derived from the measured IOPs and in-situ measured values, yielded a correlation of 0.80, 0.78, and 0.73 for chlorophyll-a concentration, non-algal particle concentration, and absorption coefficient of colored dissolved organic matter at 443 nm, respectively. This comparison indicates that adjustments to the bio-optical model are needed in order to obtain a better match between inferred and measured water constituent values in the Ligurian Sea using the methodology developed in this paper.

  16. Ecological relevance of current water quality assessment unit designations in impaired rivers

    Science.gov (United States)

    Layhee, Megan J.; Sepulveda, Adam; Ray, Andrew; Mladenka, Greg; Van Every, Lynn

    2016-01-01

    Managers often nest sections of water bodies together into assessment units (AUs) to monitor and assess water quality criteria. Ideally, AUs represent an extent of waters with similar ecological, watershed, habitat and land-use conditions and no overlapping characteristics with other waters. In the United States, AUs are typically based on political or hydrologic boundaries rather than on ecologically relevant features, so it can be difficult to detect changes in impairment status. Our goals were to evaluate if current AU designation criteria of an impaired water body in southeastern Idaho, USA that, like many U.S. waters, has three-quarters of its mainstem length divided into two AUs. We focused our evaluation in southeastern Idaho's Portneuf River, an impaired river and three-quarters of the river is divided into two AUs. We described biological and environmental conditions at multiple reaches within each AU. We used these data to (1) test if variability at the reach-scale is greater within or among AUs and, (2) to evaluate alternate AU boundaries based on multivariate analyses of reach-scale data. We found that some biological conditions had greater variability within an AU than between AUs. Multivariate analyses identified alternative, 2- and 3-group, AUs that reduced this variability. Our results suggest that the current AU designations in the mainstem Portneuf River contain ecologically distinct sections of river and that the existing AU boundaries should be reconsidered in light of the ecological conditions measured at the reach scale. Variation in biological integrity within designated AUs may complicate water quality and biological assessments, influence management decisions or affect where monitoring or mitigation resources are directed.

  17. Dendritic attenuation of synaptic potentials and currents: the role of passive membrane properties.

    Science.gov (United States)

    Spruston, N; Jaffe, D B; Johnston, D

    1994-04-01

    The dendritic trees of neurons are structurally and functionally complex integrative units receiving thousands of synaptic inputs that have excitatory and inhibitory, fast and slow, and electrical and biochemical effects. The pattern of activation of these synaptic inputs determines if the neuron will fire an action potential at any given point in time and how it will respond to similar inputs in the future. Two critical factors affect the integrative function of dendrites: the distribution of voltage-gated ion channels in the dendritic tree and the passive electrical properties, or 'electrotonic structure', upon which these active channels are superimposed. The authors review recent data from patch-clamp recordings that provide new estimates of the passive membrane properties of hippocampal neurons, and show, with examples, how these properties affect the shaping and attenuation of synaptic potentials as they propagate in the dendrites, as well as how they affect the measurement of current from synapses located in the dendrites. Voltage-gated channels might influence the measurement of 'passive' membrane properties and, reciprocally, passive membrane properties might affect the activation of voltage-gated channels in dendrites.

  18. The establishment of Atlantic Water transport as a topographically trapped slope current off Scotland

    Directory of Open Access Journals (Sweden)

    Qin Zhou

    2013-05-01

    Full Text Available Atlantic Water, with its origin in the western Atlantic, enters the Nordic Seas partly as a barotropic current following the continental slope. This water mass is carried across the Atlantic by the baroclinic North Atlantic Current (NAC. When the NAC meets the continental slope at the east side of the Atlantic, some of the transport is converted to barotropic transport over the slope before continuing northward. Here, we show that this baroclinic to barotropic conversion is in agreement with geostrophic theory. Historical observations show that the transport of the slope current increases significantly from the Rockall Channel (RC to the Faroe–Shetland Channel (FSC. Geostrophy predicts that with a northward decreasing buoyancy, baroclinic currents from the west will be transferred into northward topographically steered barotropic flow. We use hydrographic data from two sections crossing the continental slope, one located in the RC and another in the FSC, to estimate baroclinic and barotropic transport changes over the slope, within the framework of geostrophic dynamics. Our results indicate that ~1 Sv of the cross-slope baroclinic flow is mainly converted to northward barotropic transport above the 200–500m isobaths, which is consistent with observed transport changes between the RC and the FSC. Similar processes are also likely to occur further south, along the eastern Atlantic margin. This shows that AW within the slope current in the FSC is derived from both the eastern and the western Atlantic, in agreement with earlier studies of AW inflow to the Nordic Seas.

  19. The representation of boundary currents in a finite element shallow water model

    CERN Document Server

    Düben, Peter D

    2015-01-01

    We evaluate the influence of local resolution, eddy viscosity, coastline structure, and boundary conditions on the numerical representation of boundary currents in a finite element shallow-water model. The use of finite element discretization methods offers a higher flexibility compared to finite difference and finite volume methods, that are mainly used in previous publications. This is true for the geometry of the coast lines and for the realization of boundary conditions. For our investigations we simulate steady separation of western boundary currents from idealized and realistic coast lines. The use of grid refinement allows a detailed investigation of boundary separation at reasonable numerical cost.

  20. Properties of a calcium-activated K(+) current on interneurons in the developing rat hippocampus.

    Science.gov (United States)

    Aoki, T; Baraban, S C

    2000-06-01

    Calcium-activated potassium currents have an essential role in regulating excitability in a variety of neurons. Although it is well established that mature CA1 pyramidal neurons possess a Ca(2+)-activated K(+) conductance (I(K(Ca))) with early and late components, modulation by various endogenous neurotransmitters, and sensitivity to K(+) channel toxins, the properties of I(K(Ca)) on hippocampal interneurons (or immature CA1 pyramidal neurons) are relatively unknown. To address this problem, whole-cell voltage-clamp recordings were made from visually identified interneurons in stratum lacunosum-moleculare (L-M) and CA1 pyramidal cells in hippocampal slices from immature rats (P3-P25). A biphasic calcium-activated K(+) tail current was elicited following a brief depolarization from the holding potential (-50 mV). Analysis of the kinetic properties of I(K(Ca)) suggests that an early current component differs between these two cell types. An early I(K(Ca)) with a large peak current amplitude (200.8 +/- 13.2 pA, mean +/- SE), slow time constant of decay (70.9 +/- 3.3 ms), and relatively rapid time to peak (within 15 ms) was observed on L-M interneurons (n = 88), whereas an early I(K(Ca)) with a small peak current amplitude (112.5 +/- 7.3 pA), a fast time constant of decay (39.4 +/- 1.6 ms), and a slower time-to-peak (within 26 ms) was observed on CA1 pyramidal neurons (n = 85). Removal of extracellular calcium or addition of inorganic Ca(2+) channel blockers (cadmium, nickel, or cobalt) was used to demonstrate the calcium dependence of these currents. Addition of norepinephrine, carbachol, and a variety of channel toxins (apamin, iberiotoxin, verruculogen, paxilline, penitrem A, and charybdotoxin) were used to further distinguish between I(K(Ca)) on these two hippocampal cell types. Verruculogen (100 nM), carbachol (100 microM), apamin (100 nM), TEA (1 mM), and iberiotoxin (50 nM) significantly reduced early I(K(Ca)) on CA1 pyramidal neurons; early I(K(Ca)) on L

  1. Patterns and properties of polarized light in air and water.

    Science.gov (United States)

    Cronin, Thomas W; Marshall, Justin

    2011-03-12

    Natural sources of light are at best weakly polarized, but polarization of light is common in natural scenes in the atmosphere, on the surface of the Earth, and underwater. We review the current state of knowledge concerning how polarization and polarization patterns are formed in nature, emphasizing linearly polarized light. Scattering of sunlight or moonlight in the sky often forms a strongly polarized, stable and predictable pattern used by many animals for orientation and navigation throughout the day, at twilight, and on moonlit nights. By contrast, polarization of light in water, while visible in most directions of view, is generally much weaker. In air, the surfaces of natural objects often reflect partially polarized light, but such reflections are rarer underwater, and multiple-path scattering degrades such polarization within metres. Because polarization in both air and water is produced by scattering, visibility through such media can be enhanced using straightforward polarization-based methods of image recovery, and some living visual systems may use similar methods to improve vision in haze or underwater. Although circularly polarized light is rare in nature, it is produced by the surfaces of some animals, where it may be used in specialized systems of communication.

  2. Optical backscattering properties of the "clearest" natural waters

    Directory of Open Access Journals (Sweden)

    M. S. Twardowski

    2007-07-01

    Full Text Available During the BIOSOPE field campaign October–December 2004, measurements of inherent optical properties from the surface to 500 m depth were made with a ship profiler at stations covering over ~8000 km through the Southeast Pacific Ocean. Data from a ~3000 km section containing the very clearest waters in the central gyre are reported here. The total volume scattering function at 117°, βt(117°, was measured with a WET Labs ECO-BB3 sensor at 462, 532, and 650 nm with estimated uncertainties of 2×10−5, 5×10−6, and 2×10−6 m−1 sr−1, respectively. These values were approximately 6%, 3%, and 3% of the scattering by pure seawater at their respective wavelengths. From a methodological perspective, there were several results:

    bbp distributions were resolvable even though some of the values from the central gyre were an order of magnitude lower than the lowest previous measurements in the literature;
    – Direct in-situ measurements of instrument dark offsets were necessary to accurately resolve backscattering at these low levels;
    – accurate pure seawater backscattering values are critical in determining particulate backscattering coefficients in the open ocean (not only in these very clear waters; the pure water scattering values determined by Buiteveld et al. (1994 with a [1 + 0.3S/37] adjustment for salinity based on Morel (1974 appear to be the most accurate estimates, with aggregate accuracies as low as a few percent; and
    – closure was demonstrated with subsurface reflectance measurements reported by Morel et al. (2007 within instrument precisions, a useful factor in validating the backscattering measurements.

    This methodology enabled several observations with respect to the hydrography and the use of backscattering as a biogeochemical proxy:

    – The clearest waters sampled were found at

  3. Optical backscattering properties of the "clearest" natural waters

    Directory of Open Access Journals (Sweden)

    M. S. Twardowski

    2007-11-01

    Full Text Available During the BIOSOPE field campaign October–December 2004, measurements of inherent optical properties from the surface to 500 m depth were made with a ship profiler at stations covering over 8000 km through the Southeast Pacific Ocean. Data from a ~3000 km section containing the very clearest waters in the central gyre are reported here. The total volume scattering function at 117°, βt(117°, was measured with a WET Labs ECO-BB3 sensor at 462, 532, and 650 nm with estimated uncertainties of 2×10-5, 5×10-6, and 2×10-6 m−1 sr−1, respectively. These values were approximately 6%, 3%, and 3% of the volume scattering by pure seawater at their respective wavelengths. From a methodological perspective, there were several results:

    – distributions were resolvable even though some of the values from the central gyre were an order of magnitude lower than the lowest previous measurements in the literature;
    – Direct in-situ measurements of instrument dark offsets were necessary to accurately resolve backscattering at these low levels;
    – accurate pure seawater backscattering values are critical in determining particulate backscattering coefficients in the open ocean (not only in these very clear waters; the pure water scattering values determined by Buiteveld et al. (1994 with a [1+0.3S/37] adjustment for salinity based on Morel (1974 appear to be the most accurate estimates, with aggregate accuracies as low as a few percent; and
    – closure was demonstrated with subsurface reflectance measurements reported by Morel et al. (2007 within instrument precisions, a useful factor in validating the backscattering measurements.

    This methodology enabled several observations with respect to the hydrography and the use of backscattering as a biogeochemical proxy:

    –The clearest waters sampled were found at depths between 300 and 350 m, from 23.5° S

  4. Measurement of the muon-neutrino charged-current cross section on water with zero pions

    CERN Document Server

    Yuan, Tianlu

    2016-01-01

    The Tokai to Kamioka (T2K) experiment is a 295-km long-baseline neutrino experiment aimed towards the measurement of neutrino oscillation parameters ${\\theta}_{13}$ and ${\\theta}_{23}$. Precise measurement of these parameters requires accurate knowledge of neutrino cross sections. We present a flux-averaged double differential measurement of the charged-current cross section on water with zero pions in the final state using the T2K off-axis near detector, ND280. A selection of $\

  5. Thermoelectric Property Dependence on Performance of Peltier Current Leads Under Overcurrent Conditions

    Science.gov (United States)

    Kawahara, Toshio; Emoto, Masahiko; Hamabe, Makoto; Watanabe, Hirofumi; Ivanov, Yury; Sun, Jian; Yamaguchi, Satarou

    2012-06-01

    Superconductivity can potentially provide a solution to the world's energy needs because superconducting transmission and distribution (T&D) systems can decrease losses and are also capable of integrating renewables into the power grid. At Chubu University we have built a 200-m-class superconducting direct-current T&D system (CASER-2). To minimize heat leakage from the current leads, we investigated thermoelectric materials. The Peltier current lead (PCL) is one of the key technologies that will enhance the performance of superconducting systems: as direct current (DC) flows through the current lead, thermoelectric elements on opposite terminations of the superconducting line can be used to decrease the heat ingress to the cryogenic environment ( n-type on one end, p-type on the opposite end). The heat leakage to the cryogenic environment depends on the properties of the thermoelectric materials. In this paper, we estimate the performance of PCLs in cryogenic operations, including the potential for overcurrent operation, through both modeling and experiments at CASER-2.

  6. Seasonal Variation in Sea Turtle Density and Abundance in the Southeast Florida Current and Surrounding Waters.

    Science.gov (United States)

    Bovery, Caitlin M; Wyneken, Jeanette

    2015-01-01

    Assessment and management of sea turtle populations is often limited by a lack of available data pertaining to at-sea distributions at appropriate spatial and temporal resolutions. Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to the turtles' highly migratory nature. Surface counts of marine turtles in waters along the southern part of Florida's east coast were made in and adjacent to the southeast portion of the Florida Current using standard aerial surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular concern for sea turtles as interest increases in offshore energy developments, specifically harnessing the power of the Florida Current. While it is understood that marine turtles use these waters, here we evaluate seasonal variation in sea turtle abundance and density over two years. Density of sea turtles observed within the study area ranged from 0.003 turtles km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. This assessment of marine turtles in the waters off southeast Florida quantifies their in-water abundance across seasons in this area to establish baselines and inform future management strategies of these protected species.

  7. Seasonal Variation in Sea Turtle Density and Abundance in the Southeast Florida Current and Surrounding Waters

    Science.gov (United States)

    Bovery, Caitlin M.; Wyneken, Jeanette

    2015-01-01

    Assessment and management of sea turtle populations is often limited by a lack of available data pertaining to at-sea distributions at appropriate spatial and temporal resolutions. Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to the turtles’ highly migratory nature. Surface counts of marine turtles in waters along the southern part of Florida’s east coast were made in and adjacent to the southeast portion of the Florida Current using standard aerial surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular concern for sea turtles as interest increases in offshore energy developments, specifically harnessing the power of the Florida Current. While it is understood that marine turtles use these waters, here we evaluate seasonal variation in sea turtle abundance and density over two years. Density of sea turtles observed within the study area ranged from 0.003 turtles km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. This assessment of marine turtles in the waters off southeast Florida quantifies their in-water abundance across seasons in this area to establish baselines and inform future management strategies of these protected species. PMID:26717520

  8. Subcellular heterogeneity of sodium current properties in adult cardiac ventricular myocytes.

    Science.gov (United States)

    Lin, Xianming; Liu, Nian; Lu, Jia; Zhang, Jie; Anumonwo, Justus M B; Isom, Lori L; Fishman, Glenn I; Delmar, Mario

    2011-12-01

    Sodium channel α-subunits in ventricular myocytes (VMs) segregate either to the intercalated disc or to lateral membranes, where they associate with region-specific molecules. To determine the functional properties of sodium channels as a function of their location in the cell. Local sodium currents were recorded from adult rodent VMs and Purkinje cells by using the cell-attached macropatch configuration. Electrodes were placed either in the cell midsection (M) or at the cell end (area originally occupied by the intercalated disc [ID]). Channels were identified as tetrodotoxin (TTX)-sensitive (TTX-S) or TTX-resistant (TTX-R) by application of 100 nM of TTX. Average peak current amplitude was larger in ID than in M and largest at the site of contact between attached cells. TTX-S channels were found only in the M region of VMs and not in Purkinje myocytes. TTX-R channels were found in both M and ID regions, but their biophysical properties differed depending on recording location. Sodium current in rat VMs was upregulated by tumor necrosis factor-alpha. The magnitude of current increase was largest in the M region, but this difference was abolished by application of 100 nM of TTX. Our data suggest that (a) a large fraction of TTX-R (likely Na(v)1.5) channels in the M region of VMs are inactivated at normal resting potential, leaving most of the burden of excitation to TTX-R channels in the ID region; (b) cell-cell adhesion increases functional channel density at the ID; and (c) TTX-S (likely non-Na(v)1.5) channels make a minimal contribution to sodium current under control conditions, but they represent a functional reserve that can be upregulated by exogenous factors. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  9. Mapping fire effects on ash and soil properties. Current knowledge and future perspectives.

    Science.gov (United States)

    Pereira, Paulo; Cerda, Artemi; Strielko, Irina

    2014-05-01

    Fire has heterogeneous impacts on ash and soil properties, depending on severity, topography of the burned area, type of soil and vegetation affected, and meteorological conditions during and post-fire. The heterogeneous impacts of fire and the complex topography of wildland environments impose the challenge of understand fire effects at diverse scales in space and time. Mapping is fundamental to identify the impacts of fire on ash and soil properties because allow us to recognize the degree of the fire impact, vulnerable areas, soil protection and distribution of ash and soil nutrients, important to landscape recuperation. Several methodologies have been used to map fire impacts on ash soil properties. Burn severity maps are very useful to understand the immediate and long-term impacts of fire on the ecosystems (Wagtendonk et al., 2004; Kokaly et al., 2007). These studies normally are carried out with remote sensing techniques and study large burned areas. On a large scale it is very important to detect the most vulnerable areas (e.g. with risk of runoff increase, flooding, erosion, sedimentation and debris flow) and propose -if necessary- immediate rehabilitation measures. Post-fire rehabilitation measures can be extremely costly. Thus the identification of the most affected areas will reduce the erosion risks and soil degradation (Miller and Yool, 2002; Robichaud et al., 2007; Robichaud, 2009), as the consequent economical, social and ecological impacts. Recently, the United States Department of Agriculture created a field guide to map post-fire burn severity, based on remote sensing and Geographical Information Systems (GIS) technologies. The map produced should reflect the effects of fire on soil properties, and identify areas where fire was more severe (Parsons et al. 2010). Remote sensing studies have made attempts to estimate soil and ash properties after the fire, as hydrophobicity (Lewis et al., 2008), water infiltration (Finnley and Glenn, 2010), forest

  10. Interfacial properties of dissolved crude oil components in produced water

    OpenAIRE

    Eftekhardadkhah, Mona

    2013-01-01

    Produced water is a mixture of water trapped in underground formations and injection water that is brought to the surface along with oil or gas. In general, produced water is a mixture of dispersed oil in water (o/w), dissolved organic compounds (including hydrocarbons), residual concentration of chemical additives from the production line, heavy metals, dissolved minerals and suspended solids.In the year 2011, 131 million m3 of produced water were discharged on the Norwegian Continental Shel...

  11. Structural and mechanical properties of diamond-like carbon films deposited by direct current magnetron sputtering

    Science.gov (United States)

    Broitman, E.; Hellgren, N.; Czigány, Zs.; Twesten, R. D.; Luning, J.; Petrov, I.; Hultman, L.; Holloway, B. C.

    2003-07-01

    The microstructure, morphology, and mechanical properties of diamond-like carbon (DLC) films deposited by direct current magnetron sputtering were investigated for microelectromechanical systems applications. Film properties were found to vary markedly with the ion energy (Eion) and ion-to-carbon flux ratio (Jion/JC). Cross-sectional high-resolution transmission electron microscopy revealed an amorphous microstructure. However, the presence of nanometer-sized domains at Eion~85 eV was detected. Film stresses, σ, which were compressive in all cases, ranged from 0.5 to 3.5 GPa and depended on the flux ratio as well as ion energy. The hardness (H), Young's moduli (ɛ), and elastic recovery (R) increased with Eion to maximum values of H=27 GPa, ɛ=250 GPa, and R=68% at Eion=85 eV and Jion/JC=4.4. However, near edge x-ray absorption fine structure and electron energy-loss spectrum analysis showed that the sp2/sp3 content of the films does not change with Eion or Jion/JC. The measured change in mechanical properties without a corresponding change in sp2/sp3 ratio is not consistent with any previously published models. We suggest that, in the ranges 5 eV <=Eion<=85 eV and 1.1 <=Jion/JC<=6.8, the presence of defective graphite formed by subplanted C and Ar atoms has the dominant influence on the mechanical properties of DLC films.

  12. Variable influx of West Greenland Current water into the Labrador Current through the last 8000 years, based on a multiproxy study from Trinity Bay, NE Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Frandsen, Paul

    2015-01-01

    . This may be explained by a weaker North Atlantic subpolar gyre, transporting less Atlantic Water from the WGC to the (outer) LC. Arctic meltwater transport was reduced as glacial melting decreased at the end of the Holocene Thermal Optimum. At ca. 3 cal kyr BP, bottom waters returned to colder, more stable...... Current (WGC) Davis Strait branch, merging into the relatively cold LC. This Atlantic water influence gradually decreased after ca. 6 cal kyr BP, reaching a minimum at 5 cal kyr BP. In contrast, surface temperatures were relatively low due to cold surface water dominated by sea ice and meltwater carried...... conditions, indicating a slight decrease in bottom-water ventilation. After ca. 2.2 cal kyr BP surface water temperatures dropped and sea ice flux increased. The seafloor of Trinity Bay saw warmer conditions, consistent with a stronger subpolar gyre and increased influx of Atlantic-sourced water....

  13. Properties of atmospheric humic-like substances – water system

    Directory of Open Access Journals (Sweden)

    G. Láng

    2008-02-01

    Full Text Available Urban-type PM2.5-fraction aerosol samples were collected and samples of pure atmospheric humic-like substances (HULIS were isolated from them. Atmospheric concentrations of organic carbon (OC, water soluble organic carbon (WSOC and HULIS were determined, and UV/Vis spectroscopic properties, solubility and conductivity of HULIS in aqueous samples were investigated. Mean atmospheric concentrations of OC and WSOC were 8.5 and 4.6 μg m−3, respectively. Hydrophilic WSOC accounted for 39% of WSOC, carbon in HULIS made up 47% of WSOC, and 14% of WSOC was retained on the separation column by irreversible adsorption. Average molecular mass and aromatic carbon abundance of HULIS were both estimated from molar absorptivity to be 556 Da and 12%, respectively. Both results are substantially smaller than for standard reference fulvic acids, which imply different mechanisms for the formation processes of atmospheric HULIS and aquatic or terrestrial humic matter. HULIS were found to be water soluble as ionic unimers with a saturation concentration of 2–3 g l−1. Their solubility increased again with total HULIS concentration being above approximately 4 g l−1, which was most likely explained by the formation of HULIS aggregates. Solubility increased linearly from approximately 5 up to 20 g l−1 of dissolved HULIS concentration. The ionic dissolution was confirmed by electrochemical conductivity in the investigated concentration interval. Limiting molar conductivity was extrapolated and this was utilized to determine the apparent dissociation degree of HULIS for different concentrations. The dissociation degree was further applied to derive the concentration dependence of the van't Hoff factor of HULIS. The van't Hoff factor decreased monotonically with HULIS concentration; the decrease was substantial for dilute solutions and the relationship became weak for rather concentrated solutions.

  14. Properties of atmospheric humic-like substances ─ water system

    Directory of Open Access Journals (Sweden)

    G. G. Láng

    2008-04-01

    Full Text Available Urban-type PM2.5-fraction aerosol samples were collected and samples of pure atmospheric humic-like substances (HULIS were isolated from them. Atmospheric concentrations of organic carbon (OC, water soluble organic carbon (WSOC and HULIS were determined, and UV/Vis spectroscopic properties, solubility and conductivity of HULIS in aqueous samples were investigated. Atmospheric concentrations of OC and WSOC were 8.5 and 4.6 μg m−3, respectively. Hydrophilic WSOC accounted for 39% of WSOC, carbon in HULIS made up 47% of WSOC, and 14% of WSOC was retained on the separation column by irreversible adsorption. Overall average molecular mass and aromatic carbon abundance of HULIS were estimated from molar absorptivity to be 556 Da and 12%, respectively. Both results are substantially smaller than for standard reference fulvic acids, which imply different mechanisms for the formation processes of atmospheric HULIS and aquatic or terrestrial humic matter. HULIS were found to be water soluble as ionic unimers with a saturation concentration of 2–3 g l−1. Their solubility increased again with total HULIS concentration being above approximately 4 g l−1, which was most likely explained by the formation of HULIS aggregates. Solubility increased linearly from approximately 5 up to 20 g l−1 of dissolved HULIS concentration. The ionic dissolution was confirmed by electrochemical conductivity in the investigated concentration interval. Limiting molar conductivity was extrapolated and this was utilized to determine the apparent dissociation degree of HULIS for different concentrations. The dissociation degree was further applied to derive the concentration dependence of the van't Hoff factor of HULIS. The van't Hoff factor decreased monotonically with HULIS concentration; the decrease was substantial for dilute solutions and the relationship became weak for rather concentrated solutions.

  15. Comparative study of electrical breakdown properties of deionized water and heavy water under pulsed power conditions

    Energy Technology Data Exchange (ETDEWEB)

    Veda Prakash, G.; Kumar, R.; Saurabh, K.; Nasir,; Anitha, V. P.; Chowdhuri, M. B.; Shyam, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2016-01-15

    A comparative study of electrical breakdown properties of deionized water (H{sub 2}O) and heavy water (D{sub 2}O) is presented with two different electrode materials (stainless steel (SS) and brass) and polarity (positive and negative) combinations. The pulsed (∼a few tens of nanoseconds) discharges are conducted by applying high voltage (∼a few hundred kV) pulse between two hemisphere electrodes of the same material, spaced 3 mm apart, at room temperature (∼26-28 °C) with the help of Tesla based pulse generator. It is observed that breakdown occurred in heavy water at lesser voltage and in short duration compared to deionized water irrespective of the electrode material and applied voltage polarity chosen. SS electrodes are seen to perform better in terms of the voltage withstanding capacity of the liquid dielectric as compared to brass electrodes. Further, discharges with negative polarity are found to give slightly enhanced discharge breakdown voltage when compared with those with positive polarity. The observations corroborate well with conductivity measurements carried out on original and post-treated liquid samples. An interpretation of the observations is attempted using Fourier transform infrared measurements on original and post-treated liquids as well as in situ emission spectra studies. A yet another important observation from the emission spectra has been that even short (nanosecond) duration discharges result in the formation of a considerable amount of ions injected into the liquid from the electrodes in a similar manner as reported for long (microseconds) discharges. The experimental observations show that deionised water is better suited for high voltage applications and also offer a comparison of the discharge behaviour with different electrodes and polarities.

  16. Thermoelectric properties of currently available Au/Pt thermocouples related to the valid reference function

    Directory of Open Access Journals (Sweden)

    Edler F.

    2015-01-01

    Full Text Available Au/Pt thermocouples are considered to be an alternative to High Temperature Standard Platinum Resistance Thermometers (HTSPRTs for realizing temperatures according to the International Temperature Scale of 1990 (ITS-90 in the temperature range between aluminium (660.323 °C and silver (961.78 °C. The original aim of this work was to develop and to validate a new reference function for Au/Pt thermocouples which reflects the properties of presently commercially available Au and Pt wires. The thermoelectric properties of 16 Au/Pt thermocouples constructed at different National Metrological Institutes by using wires from different suppliers and 4 commercially available Au/Pt thermocouples were investigated. Most of them exhibit significant deviations from the current reference function of Au/Pt thermocouples caused by the poor performance of the Au-wires available. Thermoelectric homogeneity was investigated by measuring immersion profiles during freezes at the freezing point of silver and in liquid baths. The thermoelectric inhomogeneities were found to be one order of magnitude larger than those of Au/Pt thermocouples of the Standard Reference Material® (SRM® 1749. The improvement of the annealing procedure of the gold wires is a key process to achieve thermoelectric homogeneities in the order of only about (2–3 mK, sufficient to replace the impracticable HTSPRTs as interpolation instruments of the ITS-90. Comparison measurements of some of the Au/Pt thermocouples against a HTSPRT and an absolutely calibrated radiation thermometer were performed and exhibit agreements within the expanded measurement uncertainties. It has been found that the current reference function of Au/Pt thermocouples reflects adequately the thermoelectric properties of currently available Au/Pt thermocouples.

  17. Frequency dependence of CA3 spike phase response arising from h-current properties

    Directory of Open Access Journals (Sweden)

    Melodie eBorel

    2013-12-01

    Full Text Available The phase of firing of hippocampal neurons during theta oscillations encodes spatial information. Moreover, the spike phase response to synaptic inputs in individual cells depends on the expression of the hyperpolarisation-activated mixed cation current (Ih, which differs between CA3 and CA1 pyramidal neurons. Here, we compared the phase response of these two cell types, as well as their intrinsic membrane properties. We found that both CA3 and CA1 pyramidal neurons show a voltage sag in response to negative current steps but that this voltage sag is significantly smaller in CA3 cells. Moreover, CA3 pyramidal neurons have less prominent resonance properties compared to CA1 pyramidal neurons. This is consistent with differential expression of Ih by the two cell types. Despite their distinct intrinsic membrane properties, both CA3 and CA1 pyramidal neurons displayed bidirectional spike phase control by excitatory conductance inputs during theta oscillations. In particular, excitatory inputs delivered at the descending phase of a dynamic clamp-induced membrane potential oscillation delayed the subsequent spike by nearly 50 mrad. The effect was shown to be mediated by Ih and was counteracted by increasing inhibitory conductance driving the membrane potential oscillation. Using our experimental data to feed a computational model, we showed that differences in Ih between CA3 and CA1 pyramidal neurons could predict frequency-dependent differences in phase response properties between these cell types. We confirmed experimentally such frequency-dependent spike phase control in CA3 neurons. Therefore, a decrease in theta frequency, which is observed in intact animals during novelty, might switch the CA3 spike phase response from unidirectional to bidirectional and thereby promote encoding of the new context.

  18. A review of current and possible future human-water dynamics in Myanmar's river basins

    Science.gov (United States)

    Taft, Linda; Evers, Mariele

    2016-12-01

    Rivers provide a large number of ecosystem services and riparian people depend directly and indirectly on water availability and quality and quantity of the river waters. The country's economy and the people's well-being and income, particularly in agriculturally dominated countries, are strongly determined by the availability of sufficient water. This is particularly true for the country of Myanmar in South-east Asia, where more than 65 % of the population live in rural areas, working in the agricultural sector. Only a few studies exist on river basins in Myanmar at all and detailed knowledge providing the basis for human-water research is very limited. A deeper understanding of human-water system dynamics in the country is required because Myanmar's society, economy, ecosystems and water resources are facing major challenges due to political and economic reforms and massive and rapid investments from neighbouring countries. However, not only policy and economy modify the need for water. Climate variability and change are other essential drivers within human-water systems. Myanmar's climate is influenced by the Indian Monsoon circulation which is subject to interannual and also regional variability. Particularly the central dry zone and the Ayeyarwady delta are prone to extreme events such as serious drought periods and extreme floods. On the one hand, the farmers depend on the natural fertiliser brought by regular river inundations and high groundwater levels for irrigation; on the other hand, they suffer from these water-related extreme events. It is expected that theses climatic extreme events will likely increase in frequency and magnitude in the future as a result of global climate change. Different national and international interests in the abundant water resources may provide opportunities and risks at the same time for Myanmar. Several dam projects along the main courses of the rivers are currently in the planning phase. Dams will most likely modify the

  19. Thermoelectric Property Dependence and Geometry Optimization of Peltier Current Leads Using Highly Electrically Conductive Thermoelectric Materials

    Science.gov (United States)

    Fujii, Tomohiro; Fukuda, Shinji; Emoto, Masahiko; Osada, Koudai; Kawahara, Toshio; Hamabe, Makoto; Watanabe, Hirofumi; Ivanov, Yury; Sun, Jian; Yamaguchi, Satarou

    2011-05-01

    Thermoelectric materials are promising candidates for use in energy-saving devices in many fields. They are also useful in superconducting applications such as those using Peltier current leads (PCLs) to reduce system heat loss. In the case of PCLs, consideration must be given to Joule heating. Furthermore, the performance of PCLs is intricately dependent on their thermoelectric properties. In addition to the figure of merit Z, consideration of the electrical conductivity is also important for the design of high-performance PCLs. In this paper, we discuss the resistivity dependence of the performance of PCLs using model parameters obtained from real devices.

  20. The electric properties and the current-controlled differential negative resistance of cBN crystal

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The electric properties of nonintentionally doped n-cubic boron nitride(cBN) crystal are investigated.The cBN crystal was transformed from hexagonal-boron nitride(h-BN) under high pressure(HP) and high temperature(HT) using magnesium powder as catalyst.At room temperature,the current-voltage(I-V) characteristics of cBN crystal are measured and found to be nonlinear.When the electric field is in the range of(1―1.5)×105 V/cm,the avalanche breakdown occurs inside the whole cBN crystal.At this same time,the bright blue-violet with the wavelength of 380―400 nm from the cBN crystal is observed.When measuring the I-V curve after breakdown of cBN crystal,the current-controlled differential negative resistance phenomenon is observed.The breakdown is repeatable.

  1. Assessment of the ECCO2 reanalysis on the representation of Antarctic Bottom Water properties

    Directory of Open Access Journals (Sweden)

    M. Azaneu

    2014-03-01

    Full Text Available We analyzed the ability of the Estimating the Circulation and Climate of the Ocean – Phase II (ECCO2 reanalysis to represent the hydrographic properties and variability of the Antarctic Bottom Water (AABW in the Southern Ocean. We used a twenty-year observational database to perform comparisons of hydrographic properties and reanalysis data for the same time period (1992–2011. In addition, we evaluated four case studies based on current meter data and the AABW volume transport estimates previously reported in the literature. The main Southern Ocean oceanographic features, as well as the characteristic shape of the regional potential temperature–salinity (θ–S diagrams, are adequately represented by the reanalysis. However, the opening of an oceanic polynya in the Weddell Sea Sector, which has been clearly visible since 2005, contributed to an unrealistic representation of the hydrographic properties of the Southern Ocean primarily after 2004. In this sense, our analyses focused on the period that was identified as more reliable (1992–2004. In general, the reanalysis data showed surface waters that were warmer, saltier, and denser than observations, which may have resulted from the absence of Ice Shelf Water and from the overestimation of sea ice concentrations that limit oceanic heat loss during austral winters. Intermediate waters were generally colder, fresher, and denser than observations, whereas deep waters were warmer and less dense. These differences in deep water properties were partially a result of the inability to reproduce the densest AABW variety by reanalysis for most of the analyzed period and also because of the model's relatively coarse vertical resolution. Despite differences in absolute values, the upper AABW limit (γn ≥ 28.27 kg m−3 and AABW occupied area were well represented in the WOCE repeat sections SR2 and SR4 for the studied periods. In section WOCE SR3, however, the estimates from the differences were

  2. Effects of water concentration on the structural and diffusion properties of imidazolium-based ionic liquid-water mixtures.

    Science.gov (United States)

    Niazi, Amir A; Rabideau, Brooks D; Ismail, Ahmed E

    2013-02-07

    We have used molecular dynamics simulations to study the properties of three ionic liquid (IL)-water systems: 1-butyl-3-methylimidazolium chloride ([bmim]Cl), 1-ethyl-3-methylimidazolium acetate ([emim][Ac]), and 1,3-dimethylimidazolium dimethylphosphate ([dmim][DMP]). We observe the transition of those mixtures from pure IL to aqueous solution by analyzing the changes in important bulk properties (density) and structural and bonding properties (radial distribution functions, water clustering, hydrogen bonding, and cationic stacking) as well as dynamical properties (diffusion coefficients) at 12 different concentration samplings of each mixture, ranging from 0.0 to 99.95 mol % water. Our simulations revealed across all of the different structural, bonding, and dynamical properties major structural changes consistent with a transition from IL-water mixture to aqueous solution in all three ILs at water concentrations around 75 mol %. Among the structural changes observed were rapid increase in the frequency of hydrogen bonds, both water-water and water-anion. Similarly, at these critical concentrations, the water clusters formed begin to span the entire simulation box, rather than existing as isolated networks of molecules. At the same time, there is a sudden decrease in cationic stacking at the transition point, followed by a rapid increase near 90 mol % water. Finally, the diffusion coefficients of individual cations and anions show a rapid transition from rates consistent with diffusion in IL's to rates consistent with diffusion in water beginning at 75 mol % water. The location of this transition is consistent, for [bmim]Cl and [dmim][DMP], with the water concentration limit above which the ILs are unable to dissolve cellulose.

  3. Investigation of properties of human epidermal membrane under constant conductance alternating current iontophoresis.

    Science.gov (United States)

    Zhu, Honggang; Peck, Kendall D; Miller, David J; Liddell, Mark R; Yan, Guang; Higuchi, William I; Li, S Kevin

    2003-04-14

    Previous studies in our laboratory have shown that enhanced, constant permeant fluxes across human skin can be achieved by applying an alternating current (AC) to maintain skin electrical conductance at a constant level. Relative to conventional direct current (DC) iontophoresis, for which current is maintained at a constant level, this newly developed constant conductance alternating current (CCAC) method achieves constant fluxes with less inter- and intra-sample variability. The present study focused upon further investigating the permeability properties of human skin during CCAC iontophoresis at a variety of target resistance/conductance values. A three-stage experimental protocol was used with flux measurements determined on 3 consecutive days. Stage I was an AC only protocol (symmetrical AC square-wave signal), stage II was an AC plus DC protocol (AC square-wave with DC offset voltage), and stage III was a repeat of stage I. During this three-stage protocol, the skin electrical resistance was maintained at a constant target value by manually adjusting the applied AC voltage. Radiolabeled mannitol and urea were model permeants in all experiments. Their fluxes were determined and used to characterize the permeability properties of human skin. The results from the present study established that: (i) the CCAC protocol made it possible to reduce HEM electrical resistance to different target levels as low as 0.8 kOmega cm(2) and maintain the specific resistance level throughout the flux experiment, (ii) permeant fluxes are proportional to skin electrical conductance, (iii) under the studied CCAC passive conditions, membrane pore size tends to increase as skin resistance decreases, and (iv) as the membrane breaks down, its pore sizes become larger.

  4. Global Assessment of Functioning (GAF: properties and frontier of current knowledge

    Directory of Open Access Journals (Sweden)

    Aas IH Monrad

    2010-05-01

    Full Text Available Abstract Background Global Assessment of Functioning (GAF is well known internationally and widely used for scoring the severity of illness in psychiatry. Problems with GAF show a need for its further development (for example validity and reliability problems. The aim of the present study was to identify gaps in current knowledge about properties of GAF that are of interest for further development. Properties of GAF are defined as characteristic traits or attributes that serve to define GAF (or may have a role to define a future updated GAF. Methods A thorough literature search was conducted. Results A number of gaps in knowledge about the properties of GAF were identified: for example, the current GAF has a continuous scale, but is a continuous or categorical scale better? Scoring is not performed by setting a mark directly on a visual scale, but could this improve scoring? Would new anchor points, including key words and examples, improve GAF (anchor points for symptoms, functioning, positive mental health, prognosis, improvement of generic properties, exclusion criteria for scoring in 10-point intervals, and anchor points at the endpoints of the scale? Is a change in the number of anchor points and their distribution over the total scale important? Could better instructions for scoring within 10-point intervals improve scoring? Internationally, both single and dual scales for GAF are used, but what is the advantage of having separate symptom and functioning scales? Symptom (GAF-S and functioning (GAF-F scales should score different dimensions and still be correlated, but what is the best combination of definitions for GAF-S and GAF-F? For GAF with more than two scales there is limited empirical testing, but what is gained or lost by using more than two scales? Conclusions In the history of GAF, its basic properties have undergone limited changes. Problems with GAF may, in part, be due to lack of a research programme testing the effects of

  5. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

    2014-11-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations

  6. Thermal infrared remote sensing for riverscape analysis of water temperature heterogeneity: current research and future directions

    Science.gov (United States)

    Dugdale, S.; Hannah, D. M.; Malcolm, I.; Bergeron, N.; St-Hilaire, A.

    2016-12-01

    Climate change will increase summer water temperatures in northern latitude rivers. It is likely that this will have a negative impact on fish species such as salmonids, which are sensitive to elevated temperatures. Salmonids currently avoid heat stress by opportunistically using cool water zones that arise from the spatio-temporal mosaic of thermal habitats present within rivers. However, there is a general lack of information about the processes driving this thermal habitat heterogeneity or how these spatio-temporal patterns might vary under climate change. In this paper, we document how thermal infrared imaging has previously been used to better understand the processes driving river temperature patterns. We then identify key knowledge gaps that this technology can help to address in the future. First, we demonstrate how repeat thermal imagery has revealed the role of short-term hydrometeorological variability in influencing longitudinal river temperature patterns, showing that precipitation depth is strongly correlated with the degree of longitudinal temperature heterogeneity. Second, we document how thermal infrared imagery of a large watershed in Eastern Canada has shed new light on the landscape processes driving the spatial distribution of cool water patches, revealing that the distribution of cool patches is strongly linked to channel confinement, channel curvature and the proximity of dry tributary valleys. Finally, we detail gaps in current understanding of spatio-temporal patterns of river temperature heterogeneity. We explain how advances in unmanned aerial vehicle technology and deterministic temperature modelling will be combined to address these current limitations, shedding new light on the landscape processes driving geographical variability in patterns of river temperature heterogeneity. We then detail how such advances will help to identify rivers that will be resilient to future climatic warming, improving current and future strategies for

  7. KCTD Hetero-oligomers Confer Unique Kinetic Properties on Hippocampal GABAB Receptor-Induced K+ Currents.

    Science.gov (United States)

    Fritzius, Thorsten; Turecek, Rostislav; Seddik, Riad; Kobayashi, Hiroyuki; Tiao, Jim; Rem, Pascal D; Metz, Michaela; Kralikova, Michaela; Bouvier, Michel; Gassmann, Martin; Bettler, Bernhard

    2017-02-01

    GABAB receptors are the G-protein coupled receptors for the main inhibitory neurotransmitter in the brain, GABA. GABAB receptors were shown to associate with homo-oligomers of auxiliary KCTD8, KCTD12, KCTD12b, and KCTD16 subunits (named after their T1 K(+)-channel tetramerization domain) that regulate G-protein signaling of the receptor. Here we provide evidence that GABAB receptors also associate with hetero-oligomers of KCTD subunits. Coimmunoprecipitation experiments indicate that two-thirds of the KCTD16 proteins in the hippocampus of adult mice associate with KCTD12. We show that the KCTD proteins hetero-oligomerize through self-interacting T1 and H1 homology domains. Bioluminescence resonance energy transfer measurements in live cells reveal that KCTD12/KCTD16 hetero-oligomers associate with both the receptor and the G-protein. Electrophysiological experiments demonstrate that KCTD12/KCTD16 hetero-oligomers impart unique kinetic properties on G-protein-activated Kir3 currents. During prolonged receptor activation (one min) KCTD12/KCTD16 hetero-oligomers produce moderately desensitizing fast deactivating K(+) currents, whereas KCTD12 and KCTD16 homo-oligomers produce strongly desensitizing fast deactivating currents and nondesensitizing slowly deactivating currents, respectively. During short activation (2 s) KCTD12/KCTD16 hetero-oligomers produce nondesensitizing slowly deactivating currents. Electrophysiological recordings from hippocampal neurons of KCTD knock-out mice are consistent with these findings and indicate that KCTD12/KCTD16 hetero-oligomers increase the duration of slow IPSCs. In summary, our data demonstrate that simultaneous assembly of distinct KCTDs at the receptor increases the molecular and functional repertoire of native GABAB receptors and modulates physiologically induced K(+) current responses in the hippocampus.

  8. Effects of Current on Microcosmic Properties of Catalyst and Reforming of Bio-oil

    Institute of Scientific and Technical Information of China (English)

    Li-xia Yuan; Tong-qi Ye; Fei-yan Gong; Quan-xin Li

    2009-01-01

    Highly effective production of hydrogen from bio-oil was achieved by using a low-temperature electrochemical catalytic reforming approach over the conventional Ni-based reforming cat-alyst (NiO-Al2O3), where an AC electronic current passed through the catalyst bed. The promoting effects of current on the bio-oil reforming were studied. It was found that the performance of the bio-oil reforming was remarkably enhanced by the current which passed through the catalyst. The effects of currents on the microcosmic properties of the catalyst, including the Brunauer-Emmett-Teller (BET) surface area, pore diameter, pore volume, the size of the crystallites and the reduction level of NiO into Ni, were carefully characterized by BET, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope. The desorption of the thermal electrons from the electrified catalyst was directly observed by the TOF (time of flight) measurements. The mechanism of the electrochemical catalytic reforming of bio-oil is discussed based on the above investigation.

  9. Liquid Water Cloud Properties During the Polarimeter Definition Experiment (PODEX)

    Science.gov (United States)

    Alexandrov, Mikhail D.; Cairns, Brian; Wasilewski, Andrzei P.; Ackerman, Andrew S.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Platnick, Steven; Arnold, George; Van Diedenhoven, Bastiaan; hide

    2015-01-01

    We present retrievals of water cloud properties from the measurements made by the Research Scanning Polarimeter (RSP) during the Polarimeter Definition Experiment (PODEX) held between January 14 and February 6, 2013. The RSP was onboard the high-altitude NASA ER-2 aircraft based at NASA Dryden Aircraft Operation Facility in Palmdale, California. The retrieved cloud characteristics include cloud optical thickness, effective radius and variance of cloud droplet size distribution derived using a parameter-fitting technique, as well as the complete droplet size distribution function obtained by means of Rainbow Fourier Transform. Multi-modal size distributions are decomposed into several modes and the respective effective radii and variances are computed. The methodology used to produce the retrieval dataset is illustrated on the examples of a marine stratocumulus deck off California coast and stratus/fog over California's Central Valley. In the latter case the observed bimodal droplet size distributions were attributed to two-layer cloud structure. All retrieval data are available online from NASA GISS website.

  10. Properties of Water Blown Rigid Polyurethane Foams with Different Functionality

    Institute of Scientific and Technical Information of China (English)

    LI Xiaobin; CAO Hongbin; ZHANG Yi

    2008-01-01

    Water blown rigid polyurethane foams with different functionality were prepared.The physical properties of rigid foams were measured with rotational viscometer(NDJ-1),universal testing machine(lnstron3365),scanning electron microscope(SEM)and differential scanning calorimeter(DSC).The results show that the viscosity of polyether polyol increases exponentially from 62 mPa s to 6 000 mPa s with theincrease of functionality from 2 to 5.6,respectively.The overall density of foam increases slightly from 31.7kg/m3 to 37.4 kg/m3 with increasing functionality while core density exhibited little difference.Compressive strength of foam shows the similar behavior with density except for 2-functional sample.At the same time,dimensional stability becomes better with increasing functionality except for 5.6-functional foam that has worse stability than 4.8-functional foam.From the SEM results,the functionality is not an important factor in determining distribution of cell size of foam.According to the results of thermal analysis,the glass transition temperature(T)shifts to a higher temperature from 128.9℃ to 166.3℃ for the 2 to 5.6 functional foam,respectively.

  11. Liquid Water Cloud Properties During the Polarimeter Definition Experiment (PODEX)

    Science.gov (United States)

    Alexandrov, Mikhail D.; Cairns, Brian; Wasilewski, Andrzei P.; Ackerman, Andrew S.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Platnick, Steven; Arnold, George; Van Diedenhoven, Bastiaan; Chowdhary, Jacek; Ottaviani, Matteo; Knobelspiesse, Kirk D.

    2015-01-01

    We present retrievals of water cloud properties from the measurements made by the Research Scanning Polarimeter (RSP) during the Polarimeter Definition Experiment (PODEX) held between January 14 and February 6, 2013. The RSP was onboard the high-altitude NASA ER-2 aircraft based at NASA Dryden Aircraft Operation Facility in Palmdale, California. The retrieved cloud characteristics include cloud optical thickness, effective radius and variance of cloud droplet size distribution derived using a parameter-fitting technique, as well as the complete droplet size distribution function obtained by means of Rainbow Fourier Transform. Multi-modal size distributions are decomposed into several modes and the respective effective radii and variances are computed. The methodology used to produce the retrieval dataset is illustrated on the examples of a marine stratocumulus deck off California coast and stratus/fog over California's Central Valley. In the latter case the observed bimodal droplet size distributions were attributed to two-layer cloud structure. All retrieval data are available online from NASA GISS website.

  12. Recent hydrographic measurements in the Lake Issyk Kul: Coastal currents, thermohaline structure, water quality indicators

    Science.gov (United States)

    Zavialov, Peter; Osadchiev, Alexander; Pelevin, Vadim; Konovalov, Boris; Goncharenko, Igor

    2015-04-01

    Issyk Kul is a deep (670 m) terminal lake in the northern Tian Shan mountains in eastern Kyrgyzstan. It is the tenth largest lake in the world by volume, and the second largest saline lake after the Caspian Sea. The lake is a Ramsar site of globally significant biodiversity. We report preliminary results of a field survey undertaken in the northern coastal part of the lake, off Cholpon-Ata township, on September 10-13, 2014. A fishery boat was used to carry out CTD profiling and water sampling at 16 stations. An UV fluorescent lidar working continuosly throughout the survey yielded surface concentrations of chlorophyll-a, suspended matter, and dissolved organic substances. In addition, we deployed 3 mooring stations equipped with current meters, all at approximately 15 m isobath, recording the velocity and direction of the near-bottom currents with 10 min sampling intervals. During the experiment, the coastal waters of the lake were fully mixed down to the depth of 15-20 m and nearly uniform vertically at salinity about 5 g/kg. The only exception referred to the areas adjacent to the mouths of small river and creeks, where stable salinity stratification developed at 0.01-0.03 g/kg per 1 m of depth. The temperature stratification generally followed the diurnal pattern. The dominant coastal currents were directed westward, which agrees with the established notion about the cyclonic character of the basin-scale circulation. Superimposed on this general cyclonic pattern, there was a persistent variability of currents at the periods of 17 to 24 hours, likely associated with the interplay between the inertial oscillation and signal of breeze in the wind forcing. There was an evidence of mesoscale eddies, possibly, associated with topographic features of the shoreline. The observed velocity in the near-bottom layer was about 9 cm/s on the average, with the maximum values exceeding 25 cm/s. The Issyk Kul lake is ultra-oligotrophic - the concentrations of chlorophyll-a were

  13. A study of diffuser angle effect on ducted water current turbine performance using CFD

    Directory of Open Access Journals (Sweden)

    Adun Janyalertadun

    2012-02-01

    Full Text Available The water current has used as the energy resource for long time however its velocity is very low therefore there arenot found in wide range of uses. This study purposes accelerate water velocity by installing diffuser. The problems wereanalyzed by one dimension analysis and computational fluid dynamics (CFD; the domain covers the diffuser and turbinewhich substituted by porous jump condition is install inside. The flow was identified as axisymmetric steady flow, the inletboundary is identified as uniform flow, all simulation use the same size of diffuser, only the diffuser angles are vary. The resultsshow that velocities of water current in diffuser are increase when the diffuser angle are widen. The angle of diffuser is 20°,the velocity is increase to 1.96 times, compared to free stream velocity. If the angle was about 0-20° and 50-70° the forcetoward diffuser became high instantly; where as the force toward the rotor will be still and the maximum rate of diffuseraugmentation possibly was 3.62 and rotor power coefficient was 2.14.

  14. Currents and convection cause enhanced gas exchange in the ice–water boundary layer

    Directory of Open Access Journals (Sweden)

    Brice Loose

    2016-12-01

    Full Text Available The presence of sea ice acts as a physical barrier for air–sea exchange. On the other hand it creates additional turbulence due to current shear and convection during ice formation. We present results from a laboratory study that demonstrate how shear and convection in the ice–ocean boundary layer can lead to significant gas exchange. In the absence of wind, water currents beneath the ice of 0.23 m s−1 produced a gas transfer velocity (k of 2.8 m d−1, equivalent to k produced by a wind speed of 7 m s−1 over the open ocean. Convection caused by air–sea heat exchange also increased k of as much as 131 % compared to k produced by current shear alone. When wind and currents were combined, k increased, up to 7.6 m d−1, greater than k produced by wind or currents alone, but gas exchange forcing by wind produced mixed results in these experiments. As an aggregate, these experiments indicate that using a wind speed parametrisation to estimate k in the sea ice zone may underestimate k by ca. 50 % for wind speeds <8 m s−1.

  15. Unusual properties of water at hydrophilic/hydrophobic interfaces.

    Science.gov (United States)

    Gun'ko, V M; Turov, V V; Bogatyrev, V M; Zarko, V I; Leboda, R; Goncharuk, E V; Novza, A A; Turov, A V; Chuiko, A A

    2005-12-30

    The behaviour of water at mosaic hydrophilic/hydrophobic surfaces of different silicas and in biosystems (biomacromolecules, yeast cells, wheat seeds, bone and muscular tissues) was studied in different dispersion media over wide temperature range using 1H NMR spectroscopy with layer-by-layer freezing-out of bulk water (close to 273 K) and interfacial water (180 water and water bound to hydrophilic/hydrophobic interfaces can be assigned to different structural types. There are (i) weakly associated interfacial water (1H NMR chemical shift delta(H) = 1.1-1.7 ppm) that can be assigned to high-density water (HDW) with collapsed structure (CS), representing individual molecules in hydrophobic pockets, small clusters and interstitial water with strongly distorted hydrogen bonds or without them, and (ii) strongly associated interfacial water (delta(H) = 4-5 ppm) with larger clusters, nano- and microdomains, and continuous interfacial layer with both HDW and low-density water (LDW). The molecular mobility of weakly associated bound water is higher (because hydrogen bonds are distorted and weakened and their number is smaller than that for strongly associated water) than that of strongly associated bound water (with strong hydrogen bonds but nevertheless weaker than that in ice Ih) that results in the difference in the temperature dependences of the 1H NMR spectra at T waters are also appear in changes in the IR and TSDC spectra.

  16. Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current.

    Science.gov (United States)

    Becker, Kaylyn N; Warren, Joseph D

    2015-05-01

    Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton.

  17. Pronase acutely modifies high voltage-activated calcium currents and cell properties of Lymnaea neurons.

    Science.gov (United States)

    Hermann, P M; Lukowiak, K; Wildering, W C; Bulloch, A G

    1997-12-01

    Pronase E ('pronase') is one of the proteolytic enzymes that are used in preparative procedures such as cell isolation and to soften the sheath of invertebrate ganglia. Although several effects of proteolytic enzymes on the physiology of non-neuronal tissues have been described, the effects of these enzymes on central neurons have received little attention. We examined the effects of bath-applied pronase on neurons in the Lymnaea central nervous system and in vitro. Pronase caused action potential broadening in neurons that exhibit a shoulder on the repolarization phase of their action potentials. This effect of pronase was accompanied by, although unrelated to, a depolarization and decrease in action potential interval. Some, but not all, effects of pronase in the central nervous system were reversible. For example, the decreases in membrane potential and action potential interval were both reversed after approximately 1 h of washing with saline. However, the effect of pronase on the action potential duration was not reversed after a period of 90 min. The modulation of action potential width prompted us to examine Ca2+ currents. Exposure to pronase resulted in an increase in both peak and late high voltage-activated Ca2+ currents in isolated neurons. Pronase neither changed the inactivation rate nor caused a shift in the current-voltage relationship of the current. The changes in action potential duration could be prevented by application of 0.1 mM Cd2+, indicating that the action potential broadening caused by pronase depends on Ca2+ influx. This is the first systematic study of the acute and direct actions of pronase on Ca2+ currents and cell properties both in the CNS and in vitro.

  18. Rapid determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration

    Institute of Scientific and Technical Information of China (English)

    XIAO Jun-ping; WANG Xue-feng; ZHOU Qing-xiang; FAN Xiao-yuan; SU Xian-fa; Bai Hua-hua; DUAN Hai-jing

    2007-01-01

    A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol had an excellent linear relationship over the range of 4.82×10-6 -9.65×10-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%.

  19. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...

  20. THE RESEARCH OF RHEOLOGICAL PROPERTIES OF STOWING SLURRY WITH HIGH-WATER MATERIAL SOLIDIFYING TAILINGS

    Institute of Scientific and Technical Information of China (English)

    杨本生; 刘文永

    1996-01-01

    High-water material, tailings from goldmine and water are mixed into a new slurry.Testing of rheological properties of stowing slurries A and B is made to determine type and rheo-logical parameters of the slurry. The main factors influencing rheological properties of the slurryare analyzed and the rational concentration and empirical resistance calculating formula of pipeline transportation are presented.

  1. Analysis of current transport properties in nonpolar a-plane ZnO-based Schottky diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hogyoung [Seoul National University of Science and Technology, Seoul (Korea, Republic of); Kim, Haeri; Kim, Dongwook [Ewha Womans University, Seoul (Korea, Republic of)

    2014-09-15

    Using current-voltage (I - V) measurements, we investigated the temperature-dependent transport properties in Ag/nonpolar a-plane ZnO Schottky diodes. The bias-dependent ideality factors were altered by the different temperatures and showed a hump at lower temperatures. The series resistance of the diode depended on the temperatures, which was related to the number of free carriers contributing to the series resistance. For high forward bias, the slope m obtained from the lnI - lnV curves decreased with increasing temperature, assuring the space-charge-limited-current (SCLC) model controlled by an exponential distribution of traps. The reverse-biased current transport was associated with the Schottky effect, with a thermally-assisted tunneling for lower voltages and the Poole-Frenkel effect for higher voltages. The density of localized states (N{sub t}) was obtained by applying the theory of SCLC transport, which yielded a N{sub t} value of 8.32 x 10{sup 11} eV{sup -1}cm{sup -3}.

  2. Water properties in seeds from wild species native to Spain

    Science.gov (United States)

    Temperature, water content and relative humidity are critical factors contributing to seed longevity during storage. Water sorption isotherms describe the interrelationships between these critical factors. Understanding these relationships can lead to predictions about how best to process seeds for...

  3. Stability of steady rotational water-waves of finite amplitude on arbitrary shear currents

    Science.gov (United States)

    Seez, William; Abid, Malek; Kharif, Christian

    2016-04-01

    A versatile solver for the two-dimensional Euler equations with an unknown free-surface has been developed. This code offers the possibility to calculate two-dimensional, steady rotational water-waves of finite amplitude on an arbitrary shear current. Written in PYTHON the code incorporates both pseudo-spectral and finite-difference methods in the discretisation of the equations and thus allows the user to capture waves with large steepnesses. As such it has been possible to establish that, in a counter-flowing situation, the existence of wave solutions is not guaranteed and depends on a pair of parameters representing mass flux and vorticity. This result was predicted, for linear solutions, by Constantin. Furthermore, experimental comparisons, both with and without vorticity, have proven the precision of this code. Finally, waves propagating on top of highly realistic shear currents (exponential profiles under the surface) have been calculated following current profiles such as those used by Nwogu. In addition, a stability analysis routine has been developed to study the stability regimes of base waves calculated with the two-dimensional code. This linear stability analysis is based on three dimensional perturbations of the steady situation which lead to a generalised eigenvalue problem. Common instabilities of the first and second class have been detected, while a third class of wave-instability appears due to the presence of strong vorticity. {1} Adrian Constantin and Walter Strauss. {Exact steady periodic water waves with vorticity}. Communications on Pure and Applied Mathematics, 57(4):481-527, April 2004. Okey G. Nwogu. {Interaction of finite-amplitude waves with vertically sheared current fields}. Journal of Fluid Mechanics, 627:179, May 2009.

  4. Influence of Water Content on the β-Sheet Formation, Thermal Stability, Water Removal, and Mechanical Properties of Silk Materials.

    Science.gov (United States)

    Yazawa, Kenjiro; Ishida, Kana; Masunaga, Hiroyasu; Hikima, Takaaki; Numata, Keiji

    2016-03-14

    Silk, which has excellent mechanical toughness and is lightweight, is used as a structural material in nature, for example, in silkworm cocoons and spider draglines. However, the industrial use of silk as a structural material has garnered little attention. For silk to be used as a structural material, its thermal processability and associated properties must be well understood. Although water molecules influence the glass transition of silk, the effects of water content on the other thermal properties of silks are not well understood. In this study, we prepared Bombyx mori cocoon raw fibers, degummed fibers, and films with different water contents and then investigated the effects of water content on crystallization, degradation, and water removal during thermal processing. Thermal gravimetric analyses of the silk materials showed that water content did not affect the thermal degradation temperature but did influence the water removal behavior. By increasing the water content of silk, the water molecules were removed at lower temperatures, indicating that the amount of free water in silk materials increased; additionally, the glass transition temperature decreased with increasing water plasticization. Differential scanning calorimetry and wide-angle X-ray scattering of the silk films also suggested that the water molecules in the amorphous regions of the silk films acted as a plasticizer and induced β-sheet crystallization. The plasticizing effect of water was not detected in silk fibers, owing to their lower amorphous content and mobility. The structural and mechanical characterizations of the silk films demonstrated the silk film prepared at RH 97% realized both crystallinity and ductility simultaneously. Thus, the thermal stability, mechanical, and other properties of silk materials are regulated by their water content and crystallinity.

  5. Water-waves on linear shear currents. A comparison of experimental and numerical results.

    Science.gov (United States)

    Simon, Bruno; Seez, William; Touboul, Julien; Rey, Vincent; Abid, Malek; Kharif, Christian

    2016-04-01

    Propagation of water waves can be described for uniformly sheared current conditions. Indeed, some mathematical simplifications remain applicable in the study of waves whether there is no current or a linearly sheared current. However, the widespread use of mathematical wave theories including shear has rarely been backed by experimental studies of such flows. New experimental and numerical methods were both recently developed to study wave current interactions for constant vorticity. On one hand, the numerical code can simulate, in two dimensions, arbitrary non-linear waves. On the other hand, the experimental methods can be used to generate waves with various shear conditions. Taking advantage of the simplicity of the experimental protocol and versatility of the numerical code, comparisons between experimental and numerical data are discussed and compared with linear theory for validation of the methods. ACKNOWLEDGEMENTS The DGA (Direction Générale de l'Armement, France) is acknowledged for its financial support through the ANR grant N° ANR-13-ASTR-0007.

  6. Analysis and Discussion on Property Right of Rural Drinking Water Projects

    Institute of Scientific and Technical Information of China (English)

    Zhenlu; GAO; Jianjun; ZENG

    2014-01-01

    Since rural drinking water projects have diversified investment subjects,complex form,and lacks property right system and policy at national level,there are many difficulties in determining property right of projects in many areas.This not only puzzles competent authorities and specific management institution,but also is unfavorable for long-term full play of project benefit.Combining related laws,regulations,and policies,this paper analyzed and discussed property right of rural drinking water projects.It proposed establishing usufructuary right to replace division of property right,in the hope of helping improve management of rural drinking water projects.

  7. Adaptive capacity indicators to assess sustainability of urban water systems - Current application.

    Science.gov (United States)

    Spiller, Marc

    2016-11-01

    Sustainability is commonly assessed along environmental, societal, economic and technological dimensions. A crucial aspect of sustainability is that inter-generational equality must be ensured. This requires that sustainability is attained in the here and now as well as into the future. Therefore, what is perceived as 'sustainable' changes as a function of societal opinion and technological and scientific progress. A concept that describes the ability of systems to change is adaptive capacity. Literature suggests that the ability of systems to adapt is an integral part of sustainable development. This paper demonstrates that indicators measuring adaptive capacity are underrepresented in current urban water sustainability studies. Furthermore, it is discussed under which sustainability dimensions adaptive capacity indicators are lacking and why. Of the >90 indicators analysed, only nine are adaptive capacity indicators, of which six are socio-cultural, two technological, one economical and none environmental. This infrequent use of adaptive capacity indicators in sustainability assessments led to the conclusion that the challenge of dynamic and uncertain urban water systems is, with the exception of the socio-cultural dimension, not yet sufficiently reflected in the application of urban water sustainability indicators. This raises concerns about the progress towards urban water systems that can transform as a response variation and change. Therefore, research should focus on developing methods and indicators that can define, evaluate and quantify adaptive capacity under the economic, environmental and technical dimension of sustainability. Furthermore, it should be evaluated whether sustainability frameworks that focus on the control processes of urban water systems are more suitable for measuring adaptive capacity, than the assessments along environmental, economic, socio-cultural and technological dimensions. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Influences of water properties on the aggregation and deposition of engineered titanium dioxide nanoparticles in natural waters.

    Science.gov (United States)

    Li, Ling; Sillanpää, Markus; Risto, Maarit

    2016-12-01

    With the increasing usage of titanium dioxide nanoparticles (NPs), their release into the environment makes it important to understand their transport, fate and behaviour in natural waters. In this study, aggregation and deposition of TiO2 NPs were studied during a 3-h period by using a dynamic light scattering instrument and a UV-vis spectrophotometer, respectively. TiO2 NPs were spiked in 34 lake and 5 brackish water samples at an initial concentration of 10 mg L(-1). Depending on the physicochemical properties of the natural waters, TiO2 NPs exhibited different colloidal stability. In brackish waters with high salinity, TiO2 NPs were prone to aggregate and settled rapidly. Whereas under conditions of humic and humus-poor lake waters, TiO2 NPs were suspended in water column for a longer time without remarkable change in particle size and concentration. Deposition likely occurred in nutrient-rich lakes which had high amount of nitrogen and phosphorus accompanied by high values of conductivity, alkalinity, pH and turbidity. Linear regression analysis revealed the statistically significant relationships (p ≤ 0.008) between the TiO2 NPs stability and these water properties. Our study makes a better understanding of the water properties that control the aggregation and deposition of TiO2 NPs in complex natural waters.

  9. Assessing the ability of current climate information to facilitate local climate services for the water sector.

    Science.gov (United States)

    Koutroulis, Aristeidis; Tsanis, Ioannis; Grillakis, Manolis; Jacob, Daniela

    2014-05-01

    In the frame of ECLISE EU FP6 project researchers, in close cooperation with local users of the water sector from the area of Crete, Greece, explored the ability of current climate information to develop and support local climate services water resources management and climate adaption policies. A wealth of climate modeling output ranging from event scale to decadal and centennial experiments, at temporal scales ranging from hourly to monthly, and at spatial scales from very high resolution regional climate models (2 km) to typical GCMs, were used in order to practically assess climate change impacts on water resources. Water resources availability issues analysed and facilitated within the project, focusing on estimates of the future water demands of the island, and comparing with seven "state of the art" CMIP5 simulations within COMBINE framework (under RCPs 2.6, 4.5 and 8.5) to estimate water resources availability, during 21st century. The ability of decadal GCM prediction experiments to reproduce basic hydrometeorological variables like precipitation and temperature for local impact studies, was also examined. Water availability for the whole island at basin scale until 2100 is estimated using the SAC-SMA rainfall-runoff model for a range of different scenarios of projected hydro-climatological regime, demand and supply potential. A robust signal of temperature increase and precipitation decrease is projected for all the pathways. Several messages could be extracted from this provider - user interaction such as the communication of basic concepts and uncertainties, user skepticism and feedback. The main user concern was the coarse spatial scale of climate information and in order to cope with this feedback a special case was framed in collaboration with the project modeling groups for demonstrating a high resolution climate modeling application of an extreme precipitation-flood event over the study area. This effort provided a realistic reproduction of the

  10. Current mixing and properties of vector bosons in preon model with preonic charge

    Energy Technology Data Exchange (ETDEWEB)

    Senju, Hirofumi (Nagoya Municipal Women' s Coll. (Japan))

    1994-09-01

    In the preon model with preonic charge, new vector boson which can mix with the photon exists. On the basis of the current mixing model, its properties are studied. Cross sections of e[sup +]e[sup -] [yields] U boson pair and of [iota][sub s]-nucleus scattering are given. It will be also shown that, if the new vector boson is sufficiently heavy (say [approx] 500 GeV), the success of the standard model at the LEP level is naturally reproduced. Small deviations from the standard model are predicted in a definite way, which seems to be rather supported by the data. Our model leads to lighter W boson than the standard model does and to positive [epsilon][sub b] parameter in contrast to the standard model. (author).

  11. Current Mixing and Properties of Vector Bosons in Preon Model with Preonic Charge

    Science.gov (United States)

    Senju, H.

    1994-09-01

    In the preon model with preonic charge, new vector boson which can mix with the photon exists. On the basis of the current mixing model, its properties are studied. Cross sections of e+e- --> U boson pair and of ls-nucleus scattering are given. It will be also shown that, if the new vector boson is sufficiently heavy (say ~500 GeV), the success of the standard model at the LEP level is naturally reproduced. Small deviations from the standard model are predicted in a definite way, which seems to be rather supported by the data. Our model leads to lighter W boson than the standard model does and to positive ɛb parameter in contrast to the standard model.

  12. Environmental Impacts on Spiking Properties in Hodgkin-Huxley Neuron with Direct Current Stimulus

    Institute of Scientific and Technical Information of China (English)

    YUAN Chang-Qing; ZHAO Tong-Jun; ZHAN Yong; ZHANG Su-Hua; LIU Hui; ZHANG Yu-Hong

    2009-01-01

    Based on the well accepted Hodgkin-Huxley neuron model, the neuronal intrinsic excitability is studied when the neuron is subject to varying environmental temperatures, the typical impact for its regulating ways. With computer simulation, it is found that altering environmental temperature can improve or inhibit the neuronal intrinsic excitability so as to influence the neuronal spiking properties. The impacts from environmental factors can be understood that ,the neuronal spiking threshold is essentially influenced by the fluctuations in the environ-ment. With the environmental temperature varying, burst spiking is realized for the neuronal membrane voltage because of the environment-dependent spiking threshold. This burst induced by changes in spiking threshold is different from that excited by input currents or other stimulus.

  13. [Current status and further prospects of dental resin-based materials with antibacterial properties].

    Science.gov (United States)

    Shi, X; Lu, H B; Mao, J; Gong, S Q

    2016-09-01

    The mode of dental antibacterial resin-based materials can be divided into two types, namely, single and combined antibacterial mode. With regard to single antibacterial mode, only one kind of antibacterial agent is added into the resin, which can be released or act as contacting antibacterial agent. The single mode resin has limitation in sterilization methods and effect. As for combined antibacterial mode, it is a combination of different types of biocides and thus maximizes the sterilizing effect, including the releasing antibacterial agent incorporated with the contacting antibacterial agent or antibacterial agents combined with calcium compound possessing biological mineralization function. In this paper, current status and further prospects of dental resin-based materials with antibacterial properties are reviewed from the perspectives of single and combined antibacterial modes to provide guidance for dental antibacterial resin material research.

  14. Analysis of heavy particle processes in low current dc discharge in water vapor

    Science.gov (United States)

    Sivos, Jelena; Maric, Dragana; Skoro, Nikola; Malovic, Gordana; Petrovic, Zoran Lj

    2016-09-01

    Results presented in our recent paper show that heavy particles - positive ions and fast neutrals (created in charge transfer processes) - can have significant contribution to the processes of excitation at moderate and high reduced electric fields (E / N) . In the case of water vapor, hydrogen ions and fast atoms are the most probable candidates, as the lightest products in water vapor discharges. In order to identify dominant heavy species in water vapor discharge, we analyzed discharge parameters in low current Townsend regime. Based on the model developed by Phelps and coworkers in 1993. we were able to estimate transit time of ions from experimentally determined frequency of damped oscillations and parameters of electrical circuit. Furthermore, we compared calculated transit times with transit times of hydrogen ions (H+, H2+,H3+).Initial analysis indicates that H2+is dominant ion in the range of moderate E / N ( 2 kTd). Calculations were done for the discharge initiated at electrode gap of 1.1 cm and pressure (p) x gap (d) of 0.6 Torrcm, which corresponds to the conditions of the minimum of Paschen curve. In the next step we will extend the analysis to wider range operating conditions. This work is supported by the Serbian MESTD under project numbers ON 171037 and III 41011.

  15. Absorption properties of water-in-oil emulsions in the low THz frequency range

    DEFF Research Database (Denmark)

    Møller, Uffe; Folkenberg, Jacob Riis; Jepsen, Peter Uhd

    We use transmission THz spectroscopy to investigate the absorption properties of water-in-oil emulsions with water content varying in the 0-20% range, relevant for a range of food products. We find that at low frequencies the effective absorption coefficient of the emulsion is suppressed compared...... to bulk water....

  16. Morphological and optical properties of n-type porous silicon: effect of etching current density

    Indian Academy of Sciences (India)

    M DAS; D SARKAR

    2016-12-01

    Morphological and optical properties of porous silicon (PS) layer fabricated on n-type silicon wafer have been reported in the present article. Method of PS fabrication is by photo-assisted electrochemical etching with different etching current densities ($J$). Porosity and PS layer thickness, obtained by the gravimetric method, increase with increasing $J$. Pore morphology observed by FESEM shows the presence of randomly distributed pores with mostly spherical shape. Calculated pore size is also seen to increase with increasing value of $J$. XRD gives the characteristic amorphous peak of PS along with some peaks corresponding to crystalline silicon (c-Si). Calculated crystallite size shows decreasing trend with increasing $J$ value. The optical properties of these samples have been investigated by UV–visible reflectance, Raman spectroscopy and photoluminescence (PL) spectra. Reflectance measurement shows blue-shift of the spectrum with increased reflectivity for increasing $J$. Raman spectra show remarkable blue-shift with respect to the c-Si peak. PL spectra give the luminescence energy in the orange–red region of the visible spectrum and little change with variation of $J$.

  17. Persistent sodium current properties in hippocampal CA1 pyramidal neurons of young and adult rats.

    Science.gov (United States)

    Lunko, Oleksii; Isaev, Dmytro; Maximyuk, Oleksandr; Ivanchick, Gleb; Sydorenko, Vadym; Krishtal, Oleg; Isaeva, Elena

    2014-01-24

    Persistent tetrodotoxin-sensitive sodium current (INaP) plays an important role in cellular and neuronal network excitability in physiological conditions and under different pathological circumstances. However, developmental changes in INaP properties remain largely unclear. In the present study using whole cell patch clamp technique we evaluated INaP properties in CA1 hippocampal pyramidal neurons isolated from young (postnatal day (P) 12-16) and adult (P60-75) rats. We show that the INaP density is substantially larger in the adult group. Although INaP inactivation characteristics were found to be similar in both groups, voltage dependence of INaP activation is shifted to more negative membrane potentials (young: -48.6±0.5mV vs. adult: -52.4±0.2mV, p<0.01). Our data indicates the increase of INaP contribution in the basal membrane sodium conductivity in the mature hippocampus.

  18. Preparation and Property of the Water Absorbent Hybrid Resin

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Water absorption material has been attracted much more attention for its wide use in soil and water conservation, agriculture, etc. But this material will actually apply in agriculture, soil and water conservation only when it is cheap enough. Pulp fiber and starch to prepare high absorbing-water resin is a good method for decreasing the cost [1,2]. However, it still has a long way to turn it into reality. Now the montmorillonite is widely used in preparing nanocomposites [3]. But used it in preparing absorbing-water resin has little report. In this article the water absorption hybrid resin has been prepared by one step intercalation polymerization method. In the process of intercalation the partly neutralization acrylic acid and urea have been used as intercalating reagent. Beside that, the urea also has been used as cross-linking agent.

  19. Preparation and Property of the Water Absorbent Hybrid Resin

    Institute of Scientific and Technical Information of China (English)

    WANG; YunPu

    2001-01-01

    Water absorption material has been attracted much more attention for its wide use in soil and water conservation, agriculture, etc. But this material will actually apply in agriculture, soil and water conservation only when it is cheap enough. Pulp fiber and starch to prepare high absorbing-water resin is a good method for decreasing the cost [1,2]. However, it still has a long way to turn it into reality.  Now the montmorillonite is widely used in preparing nanocomposites [3]. But used it in preparing absorbing-water resin has little report. In this article the water absorption hybrid resin has been prepared by one step intercalation polymerization method. In the process of intercalation the partly neutralization acrylic acid and urea have been used as intercalating reagent. Beside that, the urea also has been used as cross-linking agent.   ……

  20. The legacy of social conflicts over property rights in rural Brazil and Mexico : Current land struggles in historical perspective

    NARCIS (Netherlands)

    Vergara-Camus, Leandro

    2012-01-01

    This article proposes an approach to the agrarian question that focuses on the establishment of absolute private property rights over land in Brazil and Mexico. The author argues that current land struggles are conditioned by the property regimes inherited from past struggles. The author examines th

  1. The legacy of social conflicts over property rights in rural Brazil and Mexico : Current land struggles in historical perspective

    NARCIS (Netherlands)

    Vergara-Camus, Leandro

    2012-01-01

    This article proposes an approach to the agrarian question that focuses on the establishment of absolute private property rights over land in Brazil and Mexico. The author argues that current land struggles are conditioned by the property regimes inherited from past struggles. The author examines

  2. The legacy of social conflicts over property rights in rural Brazil and Mexico : Current land struggles in historical perspective

    NARCIS (Netherlands)

    Vergara-Camus, Leandro

    2012-01-01

    This article proposes an approach to the agrarian question that focuses on the establishment of absolute private property rights over land in Brazil and Mexico. The author argues that current land struggles are conditioned by the property regimes inherited from past struggles. The author examines th

  3. Current direction/velocity and other data from current meter casts in Coastal Waters of Hawaii from 1991-09-30 to 1996-04-26 (NODC Accession 9700214)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction/velocity, wind direction/velocity, and water temperature data were collected using current meter in the Coastal Waters of Hawaii from September...

  4. Physical Properties of the Current Census of Northern White Dwarfs within 40 pc of the Sun

    CERN Document Server

    Limoges, M -M; Lépine, S

    2015-01-01

    We present a detailed description of the physical properties of our current census of white dwarfs within 40 pc of the Sun, based on an exhaustive spectroscopic survey of northern hemisphere candidates from the SUPERBLINK proper motion database. Our method for selecting white dwarf candidates is based on a combination of theoretical color-magnitude relations and reduced proper motion diagrams. We reported in an earlier publication the discovery of nearly 200 new white dwarfs, and we present here the discovery of an additional 133 new white dwarfs, among which we identify 96 DA, 3 DB, 24 DC, 3 DQ, and 7 DZ stars. We further identify 178 white dwarfs that lie within 40 pc of the Sun, representing a 40% increase of the current census, which now includes 492 objects. We estimate the completeness of our survey at between 66 and 78%, allowing for uncertainties in the distance estimates. We also perform a homogeneous model atmosphere analysis of this 40 pc sample and find a large fraction of massive white dwarfs, in...

  5. RF properties of 700 MHz, = 0.42 elliptical cavity for high current proton acceleration

    Indian Academy of Sciences (India)

    Amitava Roy; J Mondal; K C Mittal

    2008-12-01

    BARC is developing a technology for the accelerator-driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator-driven subcritical system project. We have studied RF properties of 700 MHz, = 0.42 single cell elliptical cavity for possible use in high current proton acceleration. The cavity shape optimization studies have been done using SUPERFISH code. A calculation has been done to find out the velocity range over which this cavity can accelerate protons efficiently and to select the number of cells/cavity. The cavity's peak electric and magnetic fields, power dissipation c, quality factor and effective shunt impedance 2 were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameters for the inner cell of the cavity has been suggested for possible use in high current proton accelerator.

  6. Direct current effects on high-frequency properties of patterned permalloy thin films.

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Hoffmann, A.; Divan, R.; Wang, P.; Clemson Univ.

    2009-12-01

    We have investigated experimentally direct current (dc) effects on high-frequency properties of two different permalloy (Py) submicrometer patterns of 0.24 mum and 0.55 mum width, 10 mum length, and 100 nm thickness. The natural ferromagnetic resonance (FMR) frequencies for the two samples are about 8.5 and 11.5 GHz. A 50 mA dc produces a FMR frequency reduction of about 1 GHz in both samples. We extracted susceptibility spectra for the samples from the measurement data. We studied inductance variations of Py embedded transmission lines for different dc levels. With 50 mA dc, the operational frequencies of the inductances decreased by 9% and 12.5%. We also tested effects of magnetic fields generated by external magnets on the submicrometer patterns for comparison. To obtain the same magnetization rotation angle, the external magnetic field needs to be about five times larger than the Ampere field created by the direct current. This behavior is unique and may be associated with the increased thermal energy from the Joule heating effects.

  7. Phenytoin inhibits the persistent sodium current in neocortical neurons by modifying its inactivation properties.

    Directory of Open Access Journals (Sweden)

    Elisa Colombo

    Full Text Available The persistent Na⁺ current (I(NaP is important for neuronal functions and can play a role in several pathologies, although it is small compared to the transient Na⁺ current (I(NaT. Notably, I(NaP is not a real persistent current because it undergoes inactivation with kinetics in the order of tens of seconds, but this property has often been overlooked. Na⁺ channel blockers, drugs used for treating epilepsy and other diseases, can inhibit I(NaP, but the mechanism of this action and the conditions in which I(NaP can be actually inhibited have not been completely clarified yet. We evaluated the action of phenytoin (PHT, a prototype anti-epileptic Na⁺ channel blocker, on I(NaP inactivation in pyramidal neurons of rat sensorimotor cortical slices at different concentrations, from 5 to 100 µM. PHT did not modify I(NaP evoked with depolarizing voltage ramps of 50 or 100 mVs⁻¹, but decreased I(NaP evoked by slower voltage ramps (10 mVs⁻¹. However, at all of the tested concentrations, PHT decreased I(NaP evoked by faster ramps when they were preceded by inactivating pre-pulses. Moreover, PHT shifted towards negative potentials the voltage-dependence of I(NaP inactivation and accelerated its kinetics of development also at depolarized potentials (+40 mV, not consistently with a simple inactivated state stabilizer. Therefore, our study shows a prominent PHT effect on I(NaP inactivation rather than an open channel block, which is instead often implied. I(NaP is inhibited by PHT only in conditions that induce major I(NaP inactivation. These results highlight the importance of I(NaP inactivation not only for physiological functions but also as drug target, which could be shared by other therapeutic drugs. Through this action PHT can reduce I(NaP-induced long-lasting pathological depolarisations and intracellular sodium overload, whereas shorter I(NaP actions should not be modified. These properties set the conditions of efficacy and the limits

  8. Water Resource Impacts Embedded in the Western US Electrical Energy Trade; Current Patterns and Adaptation to Future Drought

    Science.gov (United States)

    Adams, E. A.; Herron, S.; Qiu, Y.; Tidwell, V. C.; Ruddell, B. L.

    2013-12-01

    Water resources are a key element in the global coupled natural-human (CNH) system, because they are tightly coupled with the world's social, environmental, and economic subsystems, and because water resources are under increasing pressure worldwide. A fundamental adaptive tool used especially by cities to overcome local water resource scarcity is the outsourcing of water resource impacts through substitutionary economic trade. This is generally understood as the indirect component of a water footprint, and as ';virtual water' trade. This work employs generalized CNH methods to reveal the trade in water resource impacts embedded in electrical energy within the Western US power grid, and utilizes a general equilibrium economic trade model combined with drought and demand growth constraints to estimate the future status of this trade. Trade in embedded water resource impacts currently increases total water used for electricity production in the Western US and shifts water use to more water-limited States. Extreme drought and large increases in electrical energy demand increase the need for embedded water resource impact trade, while motivating a shift to more water-efficient generation technologies and more water-abundant generating locations. Cities are the largest users of electrical energy, and in the 21st Century will outsource a larger fraction of their water resource impacts through trade. This trade exposes cities to risks associated with disruption of long-distance transmission and distant hydrological droughts.

  9. Correlation of average hydrophobicity, water/air interface surface rheological properties and foaming properties of proteins.

    Science.gov (United States)

    Medrano, A; Abirached, C; Araujo, A C; Panizzolo, L A; Moyna, P; Añón, M C

    2012-04-01

    A comparative study on the behavior in the air-water interface of β-lactoglobulin, α-lactoalbumin, glycinin and β-conglycinin was performed. The behavior at the interface was evaluated by equilibrium surface tension and surface rheological properties of adsorbed films. There were significant differences (α ≤ 0.05) in the values of the constants of adsorption to the interface of the four proteins. The glycinin had the slowest rate of adsorption, due to its low average hydrophobicity, low molecular flexibility and large molecular size. Smaller proteins like β-lactoglobulin and α-lactoalbumin tended to greater equilibrium pressure values than the larger proteins because of its higher rate of adsorption to the interface. The foam capacity of proteins showed a positive correlation with the average hydrophobicity; the maximal retained liquid volume or the initial rate of passage of liquid to foam were significantly lower (α ≤ 0.05) when protein was glycinin. The dilatational modulus of glycinin was the lowest, which implies lowest resistance to disruption of the film. Glycinin protein has lower proportion of gravitational drainage and higher disproportionation having perhaps a less resistant film. In conclusion, β-conglycinin and whey proteins showed a similar behavior, so β-conglycinin might be the best soybean protein to replace milk proteins in food formulations.

  10. The Influence of the Shallow Water Internal Tide on the Properties of Acoustic Signals

    Science.gov (United States)

    2016-06-07

    LONG-TERM GOAL Quantitatively relate the temporal and spatial properties of shallow water acoustic signals to the physical processes that cause the... quantitative measure of the tidally controlled water column variability on acoustic systems the response of a Bartlett matched field processor (vertical array...moved from shallow water (~ 35 m) to deeper water (~ 60 m). Shipboard ADCP data indicated the flow conditions to be caused by an ebb barotropic tide

  11. Physical characteristics of the coastal waters between Navapur and Umbharat, West coast of India. Part 1. Current pattern

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Sarma, R.V.; Suryanarayana, A.

    Surface and bottom current patterns of the coastal waters between Navapur and Umbharat (Maharashtra-Gujarat Industrial Belt) are described in relation to tides and other environmental parameters. The results of the analysis of the frequency...

  12. Microstructures and properties of the nitrided layers fabricated on titanium substrate by direct current nitrogen arc melting technique

    Institute of Scientific and Technical Information of China (English)

    Li Xin; Ren Zhenan; Sun Daqian; Wang Li; Zhao Yunqiang

    2008-01-01

    The nitrided layers mainly containing TiN dendrites were fabricated by direct current nitrogen arc melting method. The test results show that the layers are harder and more resistant to wear than the titanium substrate. Arc traveling speeds and arc currents have an effect on both the microstructures and the properties of the layers. Decreasing the arc traveling speed or increasing the arc current can obviously enhance the hardness and the wear resistance of the nitrided layers.

  13. Review of current interest and research in water hyacinth-based wastewater treatment

    Science.gov (United States)

    Markarian, R. K.; Balon, J. E.; Robinson, A. C.

    1977-01-01

    The status of activity in the user community for water hyacinth-based wastewater treatment was evaluated. The principal technique used was that of interviewing people who either (1) were known to be engaged in hyacinth research or development or (2) had made inquiry to NASA about hyacinth systems. About 40 non-research organizations and a similar number of research organizations were contacted. As a result of the interviews and a review of the relevant literature, it was concluded that hyacinth systems have the potential for providing a lower cost way for small cities to meet increasingly stringent effluent requirements. A limited amount of full-scale demonstration of hyacinth systems has been carried out during the past two years, but the yield of design data has been small. Several organizations are currently planning construction of experimental full-scale hyacinth-based wastewater treatment systems during 1977-1978.

  14. Effects of Topography and Current on Horizontal Irrotational Waves in Shallow Water

    Institute of Scientific and Technical Information of China (English)

    孙明光; 高虎山

    2000-01-01

    Based on the Boussinesq assumption, derived are couple equations of free surface elevation and horizontal velocities for horizontal irrotational flow, and analytical expressions of the corresponding pressure and vertical velocity. After the free surface elevation and horizontal velocity at a certain depth are obtained by numerical method, the pressure and vertical velocity distributions can be obtained by simple calculation. The dispersion at different depths is the same at the O (ε) approximation. The wave amplitude will decrease with increasing time due to viscosity, but it will increase due to the matching of viscosity and the bed slope, thus. flow is unstable. Numerical or analytical results show that the wave amplitude, velocity and length will increase as the current increases along the wave direction, but the amplitude will increase, and the wave velocity and length will decrease as the water depth decreases.

  15. Categorization of failed and damaged spent LWR (light-water reactor) fuel currently in storage

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.

    1987-11-01

    The results of a study that was jointly sponsored by the US Department of Energy and the Electric Power Research Institute are described in this report. The purpose of the study was to (1) estimate the number of failed fuel assemblies and damaged fuel assemblies (i.e., ones that have sustained mechanical or chemical damage but with fuel rod cladding that is not breached) in storage, (2) categorize those fuel assemblies, and (3) prepare this report as an authoritative, illustrated source of information on such fuel. Among the more than 45,975 spent light-water reactor fuel assemblies currently in storage in the United States, it appears that there are nearly 5000 failed or damaged fuel assemblies. 78 refs., 23 figs., 19 tabs.

  16. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction......For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... waves is poorly represented, as the shape of the wave spectrum does not enter the wave kinematics. To overcome this problem and still keep the simplicity of a deterministic approach, Tromans, Anaturk and Hagemeijer (1991) suggested the use of a deterministic wave, defined as the expected linear Airy...

  17. Hydrogeologic setting, hydraulic properties, and ground-water flow at the O-Field area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Banks, W.S.; Smith, B.S.; Donnelly, C.A.

    1996-01-01

    The U.S. Army disposed chemical agents, laboratory materials, and unexploded ordnance at O-Field in the Edgewood area of Aberdeen Proving Ground, Maryland, from before World War II until at least the 1950's. Soil, ground water, surface water,and wetland sediments in the O-Field area were contaminated from the disposal activity. A ground-water-flow model of the O-Field area was constructed by the U.S. Geological Survey (USGS) in 1989 to simulate flow in the central and southern part of the Gunpowder Neck. The USGS began an additional study of the contamination in the O-Field area in cooperation with the U.S. Army in 1990 to (1) further define the hydrogeologic framework of the O-Field area, (2) characterize the hydraulic properties of the aquifers and confining units, and (3) define ground-water flow paths at O-Field based on the current data and simulations of ground-water flow. A water-table aquifer, an upper confining unit, and an upper confined aquifer comprise the shallow ground-water aquifer system of the O-Field area. A lower confining unit, through which ground-water movement is negligible, is considered a lower boundary to the shallow aquifer system. These units are all part of the Pleistocene Talbot Formation. The model developed in the previous study was redesigned using the data collected during this study and emphasized New O-Field. The current steady-state model was calibrated to water levels of June 1993. The rate of ground-water flow calculated by the model was approximately 0.48 feet per day (ft/d) and the rate determined from chlorofluorocarbon dates was approximately 0.39 ft/d.

  18. Response of stream benthic macroinvertebrates to current water management in Alpine catchments massively developed for hydropower.

    Science.gov (United States)

    Quadroni, Silvia; Crosa, Giuseppe; Gentili, Gaetano; Espa, Paolo

    2017-12-31

    The present work focuses on evaluating the ecological effects of hydropower-induced streamflow alteration within four catchments in the central Italian Alps. Downstream from the water diversions, minimum flows are released as an environmental protection measure, ranging approximately from 5 to 10% of the mean annual natural flow estimated at the intake section. Benthic macroinvertebrates as well as daily averaged streamflow were monitored for five years at twenty regulated stream reaches, and possible relationships between benthos-based stream quality metrics and environmental variables were investigated. Despite the non-negligible inter-site differences in basic streamflow metrics, benthic macroinvertebrate communities were generally dominated by few highly resilient taxa. The highest level of diversity was detected at sites where upstream minimum flow exceedance is higher and further anthropogenic pressures (other than hydropower) are lower. However, according to the current Italian normative index, the ecological quality was good/high on average at all of the investigated reaches, thus complying the Water Framework Directive standards. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Interfacial friction factors for air-water co-current stratified flow in inclined channels

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ki Yong; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    The interfacial shear stress is experimentally investigated for co-current air-water stratified flow in inclined rectangular channels having a length of 1854mm, width of 120 mm and height of 40mm at almost atmospheric pressure. Experiments are carried out in several inclinations from 0 deg up to 10 deg. The local film thickness and the wave height are measured at three locations, i.e., L/H = 8,23, and 40. According to the inclination angle, the experimental data are categorized into two groups; nearly horizontal data group (0 deg {<=} {theta} {<=} 0.7 deg), and inclined channel data group (0.7 deg {<=} {theta} {<=} 10 deg ). Experimental observations for nearly horizontal data group show that the flow is not fully developed due to the water level gradient and the hydraulic jump within the channel. For the inclined channel data group, a dimensionless wave height, {Delta}h/h, is empirically correlated in terms of Re{sub G} and h/H. A modified root-mean-square wave height is proposed to consider the effects of the interfacial and wave propagation velocities. It is found that an equivalent roughness has a linear relationship with the modified root-mean-square wave height and its relationship is independent of the inclination. 10 refs., 6 figs., 1 tab. (Author)

  20. Modeling Water and Carbon Budgets in Current and Future Agricultural Land Use

    Science.gov (United States)

    Drewniak, B.; Song, J.; Prell, J.; Kotamarthi, R.; Jacob, R.

    2008-12-01

    Biofuels are a key component of renewable energy mix proposed as a substitute to fossil fuels. Biofuels are suggested as both economical and having potential for reducing atmospheric emissions of carbon from the transportation sector, by building up soil carbon levels when planted on lands where these levels have been reduced by intensive tillage. The purpose of this research is to develop a carbon-nitrogen based crop module (CNC) for the community land model (CLM) and to improve the characterization of the below and above ground carbon sequestration for bioenergy crops. The CNC simulates planting, growing, maturing and harvesting stages for three major crops: maize, soybean and wheat. In addition, dynamic root module is implemented to simulate fine root distribution and development based on relative availability of soil water and nitrogen in the root zone. Coupled CLM-CNC models is used to study crop yields, geographic locations for bioenergy crop production and soil carbon changes. Bioenergy crop cultivation is based on current crop cultivation and future land use change dataset. Soil carbon change has been simulated based on carbon input to the soil from the leaf, stem and root, and carbon emission from soil carbon decomposition. Simulated water and carbon fluxes have been compared with field observations and soil carbon content has been examined under different harvest practices.

  1. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    DEFF Research Database (Denmark)

    Holtappels, Moritz; Glud, Ronnie N.; Doris, Daphne

    2013-01-01

    -print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations...

  2. Physico-chemical properties and heavy metal content of water ...

    African Journals Online (AJOL)

    user

    L), chloride (3.64 to. 184.04mg/L) ... activities such as drinking, cooking, industrial and agricultural ..... Point Source Pollution from Keiskammahoek Sewage Treatment. Plant on the ... European Standards for Drinking Water. World Health.

  3. Some Abnormal Properties of Water in the Cluster Model

    Directory of Open Access Journals (Sweden)

    G.A. Melnikov

    2013-12-01

    Full Text Available In the framework of the cluster model developed by the structure of liquids for the anomalous dependences of the speed of sound and thermal conductivity of water temperature along the liquid-vapor equilibrium are explained.

  4. physico-chemical properties of well water samples from some ...

    African Journals Online (AJOL)

    Administrator

    Physico-Chemical Analysis: Water samples collected were analyzed by both classical and .... This and some other factors may be responsible for the ... Diatom (Bacillariophyta) diversity of an open access lagoon in. Lagos, Nigeria. Journal ...

  5. Detecting and monitoring of water inrush in tunnels and coal mines using direct current resistivity method: A review

    OpenAIRE

    Shucai Li; Bin Liu; Lichao Nie; Zhengyu Liu; Mingzhen Tian; Shirui Wang; Maoxin Su; Qian Guo

    2015-01-01

    Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current (DC) resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and...

  6. Effect of water absorption on the mechanical properties of poly(3-hydroxybutyrate)/vegetable fiber composites

    Science.gov (United States)

    Marinho, Vithória A. D.; Carvalho, Laura H.; Canedo, Eduardo L.

    2015-05-01

    The present work studies the effect of water absorption on the performance of composites of poly(3-hydroxybutyrate) (PHB) - a fully biodegradable semi-crystalline thermoplastic obtained from renewable resources through low-impact biotechnological process, biocompatible and non-toxic - and vegetable fiber from the fruit (coconut) of babassu palm tree.Water resistance is an important characteristic of structural composites, that may exposed to rain and humid environments. Both water absorption capacity (water solubility in the material) and the rate of water absorption (controlled by the diffusivity of water in the material) are important parameters. However, water absorption per se may not be the most important characteristic, insofar as the performance and applications of the compounds. It is the effect of the water content on the ultimate properties that determine the suitability of the material for applications that involve prolonged exposure to water.PHB/babassu composites with 0-20% load were prepared in an internal mixer. Two different types of babassu fibers having two different article size ranges were compounded with PHB and test specimens molded by compression. The water absorption capacity and the kinetic constant of water absorption were measured in triplicate. Mechanical properties under tension were measured for dry and moist specimens with different amounts of absorbed water.Results indicate that the performance of the composites is comparable to that of the pure matrix. Water absorption capacity increases from 0.7% (pure PHB) to 4% (PHB/20% babassu), but the water diffusivity (4.10□8 cm2/s) was found to be virtually independent of the water absorption level. Water absorption results in moderate drop in elastic modulus (10-30% at saturation, according to fiber content) but has little effect on tensile strength and elongation at break. Fiber type and initial particle size do not have a significant effect on water absorption or mechanical properties.

  7. Quantifying the Reduction in Water Demand due to Rainwater Tank Installations at Residential Properties in Sydney

    Directory of Open Access Journals (Sweden)

    Danious P. Sountharajah

    2017-06-01

    Full Text Available This paper examines data on actual reductions in consumption of water supply due to the widespread installation of rainwater tanks at residential properties in the Sydney metropolitan area and surrounding areas connected to Sydney Water Corporation water supply mains. The water consumption was based on metered potable water usage between 2002 and 2009. The number of properties in the study database totalled 962,697 single residential dwellings. Of this a total of 52,576 or 5.5% of Sydney’s households had a rainwater tank registered with Sydney Water Corporation.  The water usage consumption before and after the installation of the rainwater tank was analysed to quantify the extent to which rainwater tanks reduced mains water consumption. The average percentage of water savings by installing rainwater tanks across all 44 local government authorities was 9%. In some Sydney localities this reduction was up to 15%. On average, a household was able to save around 24 kilolitre of water annually by installing a rainwater tank even without considering other factors that affect water usage. The results were compared against socio-demographic factors using variables such as household size, educational qualifications, taxable income, rented properties, and non-English-speaking background, etc. to gain an appreciation of how these factors may have influenced the outcomes evident in the data. Among the co-relations found were that most properties within inner Sydney with a rainwater tank achieved at least a 9 to 11% additional reduction in water usage, with more than half of those local government authorities achieving more than 11%; properties with larger land area were more likely to have a rainwater tank installed; local government authorities with more people born in non-English speaking countries had lower reduction in water consumption reductions. 

  8. Factor affecting the properties of water-in-oil-in-water emulsions for encapsulation of minerals and vitamins

    Directory of Open Access Journals (Sweden)

    Nattapong Prichapan

    2014-12-01

    Full Text Available The direct fortification of minerals and vitamins into food may induce chemical degradation, change the level of bioavailability or decrease the sensory quality of food products. The strategy to solve these problems is encapsulation technology. Numerous investigations described the use of water-in-oil-in-water (W/O/W emulsions as encapsulation system. The properties and encapsulation efficiency of W/O/W emulsions are influenced by emulsion components, the emulsification processes, and environmental conditions. The recently published results of research done on the factors affecting the properties of W/O/W emulsions for encapsulation of minerals and vitamins including form and concentration of core materials, concentration of inner water phase and lipophilic emulsifier, type and concentration of oil phase, type and concentration of hydrophilic emulsifier and stabilizer and the pH of the outer water phase have been reviewed in this article.

  9. Surface Nuclear Magnetic Resonance (SNMR - A new method for exploration of ground water and aquifer properties

    Directory of Open Access Journals (Sweden)

    U. Yaramanci

    2000-06-01

    Full Text Available The Surface Nuclear Magnetic Resonance (SNMR method is a fairly new technique in geophysics to assess ground water, i.e. existence, amount and productibility by measurements at the surface. The NMR technique used in medicine, physics and lately in borehole geophysics was adopted for surface measurements in the early eighties, and commercial equipment for measurements has been available since the mid nineties. The SNMR method has been tested at sites in Northern Germany with Quaternary sand and clay layers, to examine the suitability of this new method for groundwater exploration and environmental investigations. More information is obtained by SNMR, particularly with respect to aquifer parameters, than with other geophysical techniques. SNMR measurements were carried out at three borehole locations, together with 2D and 1D direct current geoelectrics and well logging (induction log, gamma-ray log and pulsed neutron-gamma log. Permeabilities were calculated from the grain-size distributions of core material determined in the laboratory. It is demonstrated that the SNMR method is able to detect groundwater and the results are in good agreement with other geophysical and hydrogeological data. Using the SNMR method, the water content of the unsaturated and saturated zones (i.e. porosity of an aquifer can be reliably determined. This information and resistivity data permit in-situ determination of other aquifer parameters. Comparison of the SNMR results with borehole data clearly shows that the water content determined by SNMR is the free or mobile water in the pores. The permeabilities estimated from the SNMR decay times are similar to those derived from sieve analysis of core material. Thus, the combination of SNMR with geoelectric methods promises to be a powerful tool for studying aquifer properties.

  10. The Influence of Free Water Content on Dielectric Properties of Alkali Active Slag Cement Paste

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dielectric performance of alkali activated slag (AAS) cement paste was investigated in the frequency range of 1 to 1000 MHz. The experimental results showed the unstable dielectric properties of harden paste were mostly influenced by the fraction of free water in paste or absorbed water from ambient, but not including hydration water and microstructure. The free water was completely eliminated by heat treatment at 105 ℃ about 4 hours, and then its dielectric loss was depressed; but with the exposure time in air increasing,the free water adsorption in ambient air made the dielectric property of harden cement paste to be bad. The temperature and relative humidity of environment was the key factors of free water adsorption; hence, if the influence of free water on dielectric constant was measured or eliminated, the cement-based materials may be applied in humidity sensitive materials or dielectric materials domains.

  11. Effects of Vermicompost and Water Treatment Residuals on Soil Physical Properties and Wheat Yield

    Science.gov (United States)

    Ibrahim, Mahmoud M.; Mahmoud, Essawy K.; Ibrahim, Doaa A.

    2015-04-01

    The application of vermicompost and water treatment residuals to improve the physical properties in the salt affected soils is a promising technology to meet the requirements of high plant growth and cost-effective reclamation. Therefore, the aim of this study was to investigate the effect of vermicompost and its mixtures with water treatment residuals on selected physical properties of saline sodic soil and on wheat yield. The treatments were vermicompost, water treatment residuals, vermicompost + water treatment residuals (1:1 and 2:1 wet weight ratio) at levels of 5 and 10 g dry weight kg-1 dry soil. The considered physical properties included aggregate stability, mean weight diameter, pore size distribution and dry bulk density. The addition of vermicompost and water treatment residuals had significant positive effects on the studied soil physical properties, and improved the grain yield of wheat. The treatment of (2 vermicompost + 1 water treatment residuals) at level of 5 g kg-1 soil gave the best grain yield. Combination of vermicompost and water treatment residuals improved the water treatment residuals efficiency in ameliorating the soil physical properties, and could be considered as an ameliorating material for the reclamation of salt affected soils.

  12. Current and projected water demand and water availability estimates under climate change scenarios in the Weyib River basin in Bale mountainous area of Southeastern Ethiopia

    Science.gov (United States)

    Serur, Abdulkerim Bedewi; Sarma, Arup Kumar

    2017-07-01

    This study intended to estimate the spatial and temporal variation of current and projected water demand and water availability under climate change scenarios in Weyib River basin, Bale mountainous area of Southeastern Ethiopia. Future downscaled climate variables from three Earth System Models under the three RCP emission scenarios were inputted into ArcSWAT hydrological model to simulate different components of water resources of a basin whereas current and projected human and livestock population of the basin is considered to estimate the total annual water demand for various purposes. Results revealed that the current total annual water demand of the basin is found to be about 289 Mm3, and this has to increase by 83.47% after 15 years, 200.67% after 45 years, and 328.78% after 75 years by the 2020s, 2050s, and 2080s, respectively, from base period water demand mainly due to very rapid increasing population (40.81, 130.80, and 229.12% by the 2020s, 2050s, and 2080s, respectively) and climatic variability. The future average annual total water availability in the basin is observed to be increased by ranging from 15.04 to 21.61, 20.08 to 23.34, and 16.21 to 39.53% by the 2020s, 2050s, and 2080s time slice, respectively, from base period available water resources (2333.39 Mm3). The current water availability per capita per year of the basin is about 3112.23 m3 and tends to decline ranging from 11.78 to 17.49, 46.02 to 47.45, and 57.18 to 64.34% by the 2020s, 2050s, and 2080s, respectively, from base period per capita per year water availability. This indicated that there might be possibility to fall the basin under water stress condition in the long term.

  13. Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves

    Science.gov (United States)

    Charland, Jenna; Touboul, Julien; Rey, Vincent

    2013-04-01

    Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves J. Charland * **, J. Touboul **, V. Rey ** jenna.charland@univ-tln.fr * Direction Générale de l'Armement, CNRS Délégation Normandie ** Université de Toulon, 83957 La Garde, France Mediterranean Institute of Oceanography (MIO) Aix Marseille Université, 13288 Marseille, France CNRS/INSU, IRD, MIO, UM 110 In the nearshore area, both wave propagation and currents are influenced by the bathymetry. For a better understanding of wave - current interactions in the presence of a 3D bathymetry, a large scale experiment was carried out in the Ocean Basin FIRST, Toulon, France. The 3D bathymetry consisted of two symmetric underwater mounds on both sides in the mean wave direction. The water depth at the top the mounds was hm=1,5m, the slopes of the mounds were of about 1:3, the water depth was h=3 m elsewhere. For opposite current conditions (U of order 0.30m/s), a huge focusing of the wave up to twice its incident amplitude was observed in the central part of the basin for T=1.4s. Since deep water conditions are verified, the wave amplification is ascribed to the current field. The mean velocity fields at a water depth hC=0.25m was measured by the use of an electromagnetic current meter. The results have been published in Rey et al [4]. The elliptic form of the "mild slope" equation including a uniform current on the water column (Chen et al [1]) was then used for the calculations. The calculated wave amplification of factor 1.2 is significantly smaller than observed experimentally (factor 2). So, the purpose of this study is to understand the physical processes which explain this gap. As demonstrated by Kharif & Pelinovsky [2], geometrical focusing of waves is able to modify significantly the local wave amplitude. We consider this process here. Since vertical velocity profiles measured at some locations have shown significant

  14. Invasive alien plants and water resources in South Africa: current understanding, predictive ability and research challenges

    CSIR Research Space (South Africa)

    Gorgens, AHM

    2004-01-01

    Full Text Available Predictions that invasive alien Plants would use significant amounts of water were a major factor in the establishment of South Africa's Working for Water programme, which aims to protect water resources by clearing these plants. The predictions...

  15. Measurement of fragmentation properties of charmed particle production in charged-current neutrino interactions

    CERN Document Server

    Onengüt, G; De Jong, M; Konijn, J; Melzer, O; Oldeman, R G C; Pesen, E; Van der Poel, C A F J; Visschers, J L; Güler, M; Köse, U; Serin-Zeyrek, M; Kama, S; Sever, R; Tolun,, P; Zeyrek, M T; Catanesi, M G; De Serio, M; Ieva, M; Muciaccia, M T; Radicioni, E; Simone, S; Bülte, A; Winter, Klaus; Van de Vyver, B; Vilain, P; Wilquet, G; Saitta, B; Di Capua, E; Ogawa, S; Shibuya, H; Artamonov, A V; Brunner, J; Chizhov, M; Cussans, D G; Doucet, M; Fabre, Jean-Paul; Hristova, I R; Kawamura, T; Kolev, D; Litmaath, M; Meinhard, H; Panman, J; Papadopoulos, I M; Ricciardi, S; Rozanov, A; Saltzberg, D; Tsenov, R V; Uiterwijk, J W E; Zucchelli, P; Goldberg, J; Chikawa, M; Arik, E; Song, J S; Yoon, C S; Kodama, K; Ushida, N; Aoki, S; Hara, T; Delbar, T; Favart, D; Grégoire, G; Kalinin, S; Makhlyoueva, I V; Gorbunov, P; Khovanskii, V D; Shamanov, V V; Tsukerman, I; Bruski, N; Frekers, D; Rondeshagen, D; Wolff, T; Hoshino, K; Kawada, J; Komatsu, M; Miyanishi, M; Nakamura, M; Nakano, T; Narita, K; Niu, K; Niwa, K; Nonaka, N; Sato, O; Toshito, T; Buontempo, S; Cocco, A G; D'Ambrosio, N; De Lellis, G; De Rosa, G; Di Capua, F; Ereditato, A; Fiorillo, G; Marotta, A; Messina, M; Migliozzi, P; Pistillo, C; Santorelli, R; Scotto-Lavina, L; Strolin, P; Tioukov, V; Nakamura, K; Okusawa, T; Dore, U; FLoverre, P; Ludovici, L; Maslennikov, A L; Righini, P; Rosa, G; Santacesaria, R; Satta, A; Spada, F R; Barbuto, E; Bozza, C; Grella, G; Romano, G; Sirignano, C; Sorrentino, S; Sato, Y; Tezuka, I

    2004-01-01

    During the years 1994-97, the emulsion target of the CHORUS detector was exposed to the wideband neutrino beam of the CERN SPS. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. From this sample of events which was based on the data acquired by new automatic scanning systems, 1048 D0 events were selected by a pattern recognition program. They were confirmed as neutral-particle decays through visual inspection. Fragmentation properties of deep-inelastic charm production were measured using these events. Distributions of the D0 momentum, Feynman x(x_F), z and tan thetaôut, the transverse angle out of the leptonic plane defined by the muon and the neutrino, are presented. The mean value of z was measured to be (z) = 0.63 +- 0.03(stat) +- 0.01(syst). From fits to the z distribution, values for the Peterson parameter epsilon_p = 0.108 +- 0.017(stat) +- 0.013(syst) and the Collins-Spiller parameter epsilon_CS = 0.21^+0.05_-0.04(stat) +...

  16. Electrochemical Properties of Boron-Doped Diamond Electrodes Prepared by Hot Cathode Direct Current Plasma CVD

    Directory of Open Access Journals (Sweden)

    Hong Yan PENG

    2016-05-01

    Full Text Available A series of boron-doped diamond (BDD films were deposited by using a hot cathode direct current plasma chemical vapor deposition(HCDC-PCVD system with different ratios of CH4/H2/B(OCH33 (trimethylborate gas mixture. The morphology, structure and quality of BDD films were controled by SEM, XRD and Raman measurements. The electrochemical properties of the BDD films were investigated by electrochemical methods. Cyclic voltammetric performances of the BDD films indicated that the main determinant in the electrochemical characteristics of BDD films was the boron doping amount. The threshold potential for oxygen evolution increased from 1 V to 2.5 V. Meanwhile, the electrochemical potential window of BDD films was enlarged from 2.2 V to 4.5 V when the B content was increased from 1.75 × 1019cm-3 to 2.4 × 1021 cm−3. The cyclic voltammograms of BDD films in K4Fe(CN6 and K3Fe(CN6 mixed solution indicated that the behavior of Fe(CN6-3/-4 redox couple could be regarded as semi-reversible.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12926

  17. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  18. Water mobility and thermal properties of smoked soft cheese

    Directory of Open Access Journals (Sweden)

    Hanna Maria Baranowska

    2017-01-01

    Full Text Available The main goal of the present study was to characterize the functional parameters of smoked soft cheese, with the emphasis on the behavior of water and milk fat, as analyzed by DSC, which was used to directly measure the melting/freezing phase transitions in the cheese. This study was complemented by NMR measurements of the organization and distribution of the aqueous phase within the emulsions constituting the cheese. The smoked and unsmoked cheeses were characterized by similar compositions in terms of protein (19.08-19.12 g∙100 g-1, fat (18.86-19.02 g∙100 g-1, and water content (59.86-60.27 g∙100 g-1. The water activity was higher in the unsmoked cheese (aw = 0.9736 than in the smoked cheese (aw = 0.9615. This result was confirmed by DSC (higher ice melting enthalpy and NMR (higher T1 value measurements. The smoking process led to differences in the distribution and binding of water to the lipid-protein matrix of the cheese. There was more non-freezed bound water in the smoked cheese which resulted in a more fragile and loosened structure in the smoked cheese than the unsmoked, which manifested in lower values of stretching and meltability. The meltability of the mozzarella smoked cheese was 1.5 times less than that of the unsmoked cheese (tube test and Schreiber test.

  19. Training of panellists for the sensory control of bottled natural mineral water in connection with water chemical properties.

    Science.gov (United States)

    Rey-Salgueiro, Ledicia; Gosálbez-García, Aitana; Pérez-Lamela, Concepción; Simal-Gándara, Jesús; Falqué-López, Elena

    2013-11-01

    As bottled mineral water market is increasing in the world (especially in emergent and developed countries), the development of a simple protocol to train a panel to evaluate sensory properties would be a useful tool for natural drinking water industry. A sensory protocol was developed to evaluate bottled natural mineral water (17 still and 10 carbonated trademarks). The tasting questionnaire included 13 attributes for still water plus overall impression and they were sorted by: colour hues, transparency and brightness, odour/aroma and taste/flavour/texture and 2 more for carbonated waters (bubbles and effervescence). The training lasted two months with, at least, 10 sessions, was adequate to evaluate bottled natural mineral water. To confirm the efficiency of the sensory training procedure two sensory groups formed the whole panel. One trained panel (6 persons) and one professional panel (6 sommeliers) and both participated simultaneously in the water tasting evaluation of 3 sample lots. Similar average scores obtained from trained and professional judges, with the same water trademarks, confirmed the usefulness of the training protocol. The differences obtained for trained panel in the first lot confirm the necessity to train always before a sensory procedure. A sensory water wheel is proposed to guide the training in bottled mineral water used for drinking, in connection with their chemical mineral content.

  20. Exploring Techniques for Improving Retrievals of Bio-optical Properties of Coastal Waters

    Science.gov (United States)

    2013-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Exploring Techniques for Improving Retrievals of Bio ...Exploring Techniques for Improving Retrievals of Bio -optical Properties of Coastal Waters 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...retrieval of bio -optical properties, benefits from the leveraging of funding by NOAA CREST in which remote sensing of coastal waters is an important

  1. Coastal circulation and water-column properties in the National Park of American Samoa, February–July 2015

    Science.gov (United States)

    Storlazzi, Curt; Cheriton, Olivia; Rosenberger, Kurt; Logan, Joshua; Clark, Timothy B.

    2017-06-06

    There is little information on the oceanography in the National Park of American Samoa (NPSA). The transport pathways for potentially harmful constituents of land-derived runoff, as well as larvae and other planktonic organisms, are driven by nearshore circulation patterns. To evaluate the processes affecting coral reef ecosystem health, it is first necessary to understand the oceanographic processes driving nearshore circulation, residence times, exposure rates, and transport pathways. Information on how the NPSA’s natural resources may be affected by anthropogenic sources of pollution, sediment runoff, larval transport, or modifications to the marine protected areas is critical to NPSA resource managers for understanding and ultimately managing coastal and marine resources. To address this need, U.S. Geological Survey and U.S. National Park Service researchers conducted a collaborative study in 2015 to determine coastal circulation patterns and water-column properties along north-central Tutuila, American Samoa, in an area focused on NPSA’s Tutuila Unit and its coral reef ecosystem. The continuous measurements of waves, currents, tides, and water-column properties from these instrument deployments over 150 days, coupled with available meteorological measurements of wind and rainfall, provide information on nearshore circulation and the variability in these hydrodynamic properties for NPSA’s Tutuila Unit. In general, circulation was strongly driven by regional winds at longer (greater than day) timescales and by tides at shorter (less than day) timescales. Flows were primarily directed along shore, with current speeds faster offshore to the north and slower closer to shore, especially in embayments. Water-column properties exhibit strong seasonality coupled to the shift from non-trade wind season to trade wind season. During the non-trade wind season that was characterized by variable winds and larger waves in the NPSA, waters were warmer, slightly more

  2. Modeling and managing urban water demand through smart meters: Benefits and challenges from current research and emerging trends

    Science.gov (United States)

    Cominola, A.; Giuliani, M.; Castelletti, A.; Piga, D.; Rizzoli, A. E.

    2015-12-01

    Urban population growth, climate and land use change are expected to boost residential water demand in urban contexts in the next decades. In such a context, developing suitable demand-side management strategies is essential to meet future water demands, pursue water savings, and reduce the costs for water utilities. Yet, the effectiveness of water demand management strategies (WDMS) relies on our understanding of water consumers' behavior, their consumption habits, and the water use drivers. While low spatial and temporal resolution water consumption data, as traditionally gathered for billing purposes, hardly support this understanding, the advent of high-resolution, smart metering technologies allowed for quasi real-time monitoring water consumption at the single household level. This, in turn, is advancing our ability in characterizing consumers' behavior, modeling, and designing user-oriented residential water demand management strategies. Several water smart metering programs have been rolled-out in the last two decades worldwide, addressing one or more of the following water demand management phases: (i) data gathering, (ii) water end-uses characterization, (iii) user modeling, (iv) design and implementation of personalized WDMS. Moreover, the number of research studies in this domain is quickly increasing and big economic investments are currently being devoted worldwide to smart metering programs. With this work, we contribute the first comprehensive review of more than 100 experiences in the field of residential water demand modeling and management, and we propose a general framework for their classification. We revise consolidated practices, identify emerging trends and highlight the challenges and opportunities for future developments given by the use of smart meters advancing residential water demand management. Our analysis of the status quo of smart urban water demand management research and market constitutes a structured collection of information

  3. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Song, Meng; Xu, Peng; Wang, Xu; Wu, Huizhen; Wang, Miao, E-mail: peizhao@zju.edu.cn, E-mail: miaowang@css.zju.edu.cn [Department of Physics, Zhejiang University, Hangzhou 310027 (China); Song, Yenan; Li, Zhenhua; Zhao, Pei, E-mail: peizhao@zju.edu.cn, E-mail: miaowang@css.zju.edu.cn [Institute of Applied Mechanics, Zhejiang University, Hangzhou 310027 (China); Shang, Xuefu [Department of Physics, Faculty of Science, Jiangsu University, Zhenjiang 212013 (China)

    2015-09-15

    Integrating carbon nanotubes (CNTs) and graphene into hybrid structures provides a novel approach to three dimensional (3D) materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm{sup 2}, and field enhancement factor of ∼1.3 × 10{sup 4}. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  4. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Directory of Open Access Journals (Sweden)

    Meng Song

    2015-09-01

    Full Text Available Integrating carbon nanotubes (CNTs and graphene into hybrid structures provides a novel approach to three dimensional (3D materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm2, and field enhancement factor of ∼1.3 × 104. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  5. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Science.gov (United States)

    Song, Meng; Xu, Peng; Song, Yenan; Wang, Xu; Li, Zhenhua; Shang, Xuefu; Wu, Huizhen; Zhao, Pei; Wang, Miao

    2015-09-01

    Integrating carbon nanotubes (CNTs) and graphene into hybrid structures provides a novel approach to three dimensional (3D) materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm2, and field enhancement factor of ˜1.3 × 104. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  6. Saikosaponin a mediates the anticonvulsant properties in the HNC models of AE and SE by inhibiting NMDA receptor current and persistent sodium current.

    Directory of Open Access Journals (Sweden)

    Yun-Hong Yu

    Full Text Available Epilepsy is one of the most common neurological disorders, yet its treatment remains unsatisfactory. Saikosaponin a (SSa, a triterpene saponin derived from Bupleurum chinensis DC., has been demonstrated to have significant antiepileptic activity in a variety of epilepsy models in vivo. However, the electrophysiological activities and mechanisms of the antiepileptic properties of SSa remain unclear. In this study, whole-cell current-clamp recordings were used to evaluate the anticonvulsant activities of SSa in the hippocampal neuronal culture (HNC models of acquired epilepsy (AE and status epilepticus (SE. Whole-cell voltage-clamp recordings were used to evaluate the modulation effects of SSa on NMDA-evoked current and sodium currents in cultured hippocampal neurons. We found that SSa effectively terminated spontaneous recurrent epileptiform discharges (SREDs in the HNC model of AE and continuous epileptiform high-frequency bursts (SE in the HNC model of SE, in a concentration-dependent manner with an IC(50 of 0.42 µM and 0.62 µM, respectively. Furthermore, SSa significantly reduced the peak amplitude of NMDA-evoked current and the peak current amplitude of I(NaP. These results suggest for the first time that the inhibitions of NMDA receptor current and I(NaP may be the underlying mechanisms of SSa's anticonvulsant properties, including the suppression of SREDs and SE in the HNC models of AE and SE. In addition, effectively abolishing the refractory SE implies that SSa may be a potential anticonvulsant candidate for the clinical treatment of epilepsy.

  7. Influence of boron content on the microstructure and tribological properties of Cr-B-N coatings in water lubrication

    Science.gov (United States)

    Ma, Qiang; Zhou, Fei; Gao, Song; Wu, Zhiwei; Wang, Qianzhi; Chen, Kangmin; Zhou, Zhifeng; Li, Lawrence Kwok-Yan

    2016-07-01

    Cr-B-N coatings with different boron contents were deposited on Si(1 0 0) wafers and 316 L stainless steels using unbalanced magnetron sputtering system by way of adjusting the CrB2 target currents. The microstructure and mechanical properties of Cr-B-N coatings were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), white light interferometric three dimensional profilometer and nano-indentation tester, respectively. The tribological properties of Cr-B-N/SiC tribopairs in water were studied using ball-on-disk tribometer. The results showed that the Cr-B-N coatings showed a fine nanocomposite structure consisted of CrN nanograins and amorphous BN phase regardless of boron contents, and the typical columnar structure became featureless with increasing the CrB2 target current. The hardness and reduced elastic modulus first increased to 28.9 GPa and 330 GPa at the CrB2 target current of 2 A, and then decreased gradually with further increasing the CrB2 target current to 4 A. As compared with the CrN/SiC tribopairs, the lowest friction coefficient of Cr-B-N/SiC ball tribopairs in water was 0.15, and the wear resistance of Cr-B-N coatings was effectively enhanced.

  8. Water Dissociation Phenomena on a Bipolar Membrane——Current-voltage Curve in Relation with Ionic Transport and Limiting Current Density

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The water dissociation mechanism on a bipolar membrane under the electrical field was investigated and characterized in terms of ionic transport and limiting current density. It is considered that the depletion layer exists at the junction of a bipolar membrane, which is coincided with the viewpoint of the most literatures, but we also consider that the thickness and conductivity of this layer is not only related with the increase of the applied voltage but also with the limiting current density. Below the limiting current density, the thickness of the depletion layer keeps a constant and the conductivity decreases with the increase of the applied voltage;while above the limiting current density, the depletion thickness will increase with the increase of the applied voltage and the conductivity keeps a very low constant. Based on the data reported in the literatures and independent determinations, the limiting current density was calculated and the experimental curves Ⅰ- Ⅴ in the two directions were compared with the theoretical calculations. It is demonstrated that above the limiting current density, the experimental results,either in the L-H direction or in the H-L direction, are consistent with the theoretical calculations; below the limiting current density, a slight deviation exists between the experimental and the theoretical results, and between the experimental results in the two directions. The change in Donnan potential due to the asymmetry of the mono-layers and the changes of ionic composition in the two directions is possibly responsible for this deviation.

  9. A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy

    Directory of Open Access Journals (Sweden)

    Carmelo Nasello

    2016-01-01

    Full Text Available A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy. The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

  10. Adsorptive properties of natural water surfactant films. Dead Vistula catchment water studies

    Directory of Open Access Journals (Sweden)

    Stanisław J. Pogorzelski

    2003-09-01

    Full Text Available The paper contains the results of natural film experiments carried out on inland waters in the Dead Vistula (Martwa Wisła catchment area during 1999-2002 using the integrated Langmuir trough-Wilhelmy plate system, which "cuts out" an undisturbed film-covered area without any physicochemical sample processing. The static film parameters result from the generalized scaling procedures applied to the surface pressure-area isotherms. They appear to correspond well to observations of the film composition Alim, MW, Eisoth, film solubility and the miscibility of its components (via R, ΔSc and y factors, and surface concentration Πeq, Γeq. A novel approach is presented for the adsorption dynamics on the basis of the mixed kinetic-diffusion model and analyses of the dynamic surface pressure plots, which leads to the determination of the effective relative diffusion coefficient Deff / D and activation energy barrier i>Ea / RT. There is reason to believe that certain classes of film-forming components or "end-members" may dominate the static and dynamic surface properties. Some of these substances can be used as source-specific surface-active biomarkers to trace temporal and spatial changes due to environmental factors or the production of biological matter. The concept was tested for the Dead Vistula river and its tributaries. The results demonstrate that natural films are a complex mixture of biopolymeric molecules covering a wide range of solubilities, surface activities and molecular masses with an apparentstructural film architecture. Such studies could lead to the development of film structure parameters - indicators of ecosystem quality and the state of the environment.

  11. Antioxidative properties of some phototropic microalgae grown in waste water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Peter

    for the screening and selection of the species. In this study,the potential antioxidant activities of 12 micro algal sample from Chlorella., Spirulina., Euglena, Scenedesmus and Haematococcus species grown in waste water in Kalundborg micro algal facilities were evaluated using three antioxidant assays, including...

  12. Several Dynamical Properties for a Nonlinear Shallow Water Equation

    Directory of Open Access Journals (Sweden)

    Ls Yong

    2014-01-01

    Full Text Available A nonlinear third order dispersive shallow water equation including the Degasperis-Procesi model is investigated. The existence of weak solutions for the equation is proved in the space L1(R∩BV (R under certain assumptions. The Oleinik type estimate and L2N(R  (N is a natural number estimate for the solution are obtained.

  13. Influence of boron content on the microstructure and tribological properties of Cr-B-N coatings in water lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiang [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics and Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing 210016 (China); Zhou, Fei, E-mail: fzhou@nuaa.edu.cn [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics and Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing 210016 (China); Gao, Song; Wu, Zhiwei; Wang, Qianzhi [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics and Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing 210016 (China); Chen, Kangmin [Center of Analysis, Jiangsu University, Zhenjiang 212013 (China); Zhou, Zhifeng; Li, Lawrence Kwok-Yan [Advanced Coatings Applied Research Laboratory, Department of Mechanical and Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)

    2016-07-30

    Highlights: • Cr-B-N coatings were deposited via adjusting the CrB{sub 2} target current. • Cr-B-N nanocomposite coatings consisted of CrN nanograins and amorphous BN phase. • The hardness of Cr-B-N coating increased firstly, and then decreased with increasing CrB{sub 2} target current. • The frictional behavior of Cr-B-N coatings deposited at different CrB{sub 2} target currents was compared in deionized water. • In comparison to CrN coatings, Cr-B-N coatings exhibited superior tribological properties in water. - Abstract: Cr-B-N coatings with different boron contents were deposited on Si(1 0 0) wafers and 316 L stainless steels using unbalanced magnetron sputtering system by way of adjusting the CrB{sub 2} target currents. The microstructure and mechanical properties of Cr-B-N coatings were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), white light interferometric three dimensional profilometer and nano-indentation tester, respectively. The tribological properties of Cr-B-N/SiC tribopairs in water were studied using ball-on-disk tribometer. The results showed that the Cr-B-N coatings showed a fine nanocomposite structure consisted of CrN nanograins and amorphous BN phase regardless of boron contents, and the typical columnar structure became featureless with increasing the CrB{sub 2} target current. The hardness and reduced elastic modulus first increased to 28.9 GPa and 330 GPa at the CrB{sub 2} target current of 2 A, and then decreased gradually with further increasing the CrB{sub 2} target current to 4 A. As compared with the CrN/SiC tribopairs, the lowest friction coefficient of Cr-B-N/SiC ball tribopairs in water was 0.15, and the wear resistance of Cr-B-N coatings was effectively enhanced.

  14. ABOUT TRACK CIRCUIT CALCULATION METHOD DEPENDENT ON FERROMAGNET PROPERTIES IN CONDITIONS OF TRACTION CURRENT NOISE INFLUENCE

    Directory of Open Access Journals (Sweden)

    A. Yu. Zhuravlev

    2016-02-01

    Full Text Available Purpose. The work is intended to investigate the electromagnetic processes in impedance bond in order to improve noise immunity of track circuits (TC for safe railway operation. Methodology. To achieve this purpose the methods of scientific analysis, mathematical modelling, experimental study, a large-scale simulation were used. Findings. The work examined the interference affecting the normal performance of track circuits. To a large extent, part of track circuit damages account for failures in track circuit equipment. Track circuit equipment is connected directly to the track line susceptible to traction current interference, which causes changes in its electrical characteristics and electromagnetic properties. Normal operability, performance of the main operating modes of the track circuit is determined by previous calculation of its performance and compilation of regulatory tables. The classical method for determination of track circuit parameters was analysed. The classical calculation method assumes representation of individual sections of the electrical track circuit using the quadripole network with known coefficients, usually in the A-form. Determining the coefficients of linear element circuit creates no metrological or mathematical difficulties. However, in circuits containing nonlinear ferromagnets (FM, obtaining the coefficients on the entire induction change range in the cores is quite a difficult task because the classical methods of idling (I and short circuit (SC are not acceptable. This leads to complicated methods for determining both the module and the arguments of quadripole network coefficients. Instead of the classical method, the work proposed the method for calculating the track circuit dependent on nonlinear properties of ferromagnets. Originality. The article examines a new approach to the calculation of TC taking into account the losses in ferromagnets (FM, without determination of equivalent circuit quadripole

  15. Chondrule size and related physical properties: a compilation and evaluation of current data across all meteorite groups

    CERN Document Server

    Friedrich, Jon M; Ebel, Denton S; Biltz, Alison E; Corbett, Bernadette M; Iotzov, Ivan V; Khan, Wajiha S; Wolman, Matthew D

    2014-01-01

    The examination of the physical properties of chondrules has generally received less emphasis than other properties of meteorites such as their mineralogy, petrology, and chemical and isotopic compositions. Among the various physical properties of chondrules, chondrule size is especially important for the classification of chondrites into chemical groups, since each chemical group possesses a distinct size-frequency distribution of chondrules. Knowledge of the physical properties of chondrules is also vital for the development of astrophysical models for chondrule formation, and for understanding how to utilize asteroidal resources in space exploration. To examine our current knowledge of chondrule sizes, we have compiled and provide commentary on available chondrule dimension literature data. We include all chondrite chemical groups as well as the acapulcoite primitive achondrites, some of which contain relict chondrules. We also compile and review current literature data for other astrophysically-relevant p...

  16. The chemical composition and biological properties of coconut (Cocos nucifera L.) water.

    Science.gov (United States)

    Yong, Jean W H; Ge, Liya; Ng, Yan Fei; Tan, Swee Ngin

    2009-12-09

    Coconut water (coconut liquid endosperm), with its many applications, is one of the world's most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.

  17. Altimeter data assimilation in the tropical Indian Ocean using water property conserving scheme

    Indian Academy of Sciences (India)

    Bhasha M Mankad; Rashmi Sharma; Sujit Basu; P K Pal

    2012-02-01

    Altimeter data have been assimilated in an ocean general circulation model using the water property conserving scheme. Two runs of the model have been conducted for the year 2004. In one of the runs, altimeter data have been assimilated sequentially, while in another run, assimilation has been suppressed. Assimilation has been restricted to the tropical Indian Ocean. An assessment of the strength of the scheme has been carried out by comparing the sea surface temperature (SST), simulated in the two runs, with in situ derived as well as remotely sensed observations of the same quantity. It has been found that the assimilation exhibits a significant positive impact on the simulation of SST. The subsurface effect of the assimilation could be judged by comparing the model simulated depth of the 20°C isotherm (hereafter referred to as D20), as a proxy of the thermocline depth, with the same quantity estimated from ARGO observations. In this case also, the impact is noteworthy. Effect on the dynamics has been judged by comparison of simulated surface current with observed current at a moored buoy location, and finally the impact on model sea level forecast in a free run after assimilation has been quantified in a representative example.

  18. Correlative study of properties of water in biological systems using ultrasound and magnetic resonance.

    Science.gov (United States)

    Sehgal, C M; Greenleaf, J F

    1986-12-01

    Ultrasonic and nuclear magnetic resonance properties of media rich in water are investigated. The chemical shift of the water proton in pure water, aqueous solutions of tertiary butanol, and sodium chloride is shown to be linearly correlated to the reciprocal of sound speed in these media. A new method of determining the self-diffusion coefficient of water by using acoustic nonlinearity and sound speed is proposed. The method is tested on a variety of media that include pure water, aqueous solutions of glycerol, serum albumin, egg constituents, plant tissues, frog muscle and liver, and excised human tissues. In all the cases the results are found to compare closely to diffusion coefficients measured by magnetic resonance. The results presented here indicate that the acoustic and magnetic resonance modalities, though inherently different in their origin, can provide closely related information on the properties of water.

  19. Optical properties of marine waters and the development of bio-optical algorithms

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.

    This paper presents the primary optical variables used in the measurement of the optical properties of marine waters. How can in-situ measurements be used in the optical recognition of coastal and open ocean waters. We then look at bio...

  20. Interaction of water extractable pentosans with gluten protein : effect on dough properties and gluten quality

    NARCIS (Netherlands)

    Wang, M.; Hamer, R.J.; Vliet, van T.; Oudgenoeg, G.

    2002-01-01

    The effects of modified water extractable pentosans (WEP) on gluten yield, dough properties, gluten quality and composition were studied. The results show that WEP interfere with gluten formation in both a direct and an indirect way. WEP interfere indirectly by competing for water and thus changing

  1. Interaction of water extractable pentosans with gluten protein : effect on dough properties and gluten quality

    NARCIS (Netherlands)

    Wang, M.; Hamer, R.J.; Vliet, van T.; Oudgenoeg, G.

    2002-01-01

    The effects of modified water extractable pentosans (WEP) on gluten yield, dough properties, gluten quality and composition were studied. The results show that WEP interfere with gluten formation in both a direct and an indirect way. WEP interfere indirectly by competing for water and thus changing

  2. Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄故

    2001-01-01

    The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

  3. Water Property Models as Sovereignty Prerogatives: European Legal Perspectives in Comparison

    Directory of Open Access Journals (Sweden)

    Dario Casalini

    2010-08-01

    Full Text Available Water resources in European legal systems have always been vested in sovereign power, regardless of their legal nature as goods vested in State property or as res communes omnium not subject to ownership. The common legal foundation of sovereign power over water resources departed once civil law jurisdictions leveled the demesne on ownership model, by introducing public ownership in the French codification of 1804, while common law jurisdiction developed a broader legal concept of property that includes even the rights to use res communes. The models led respectively to the establishment of administrative systems of water rights and markets of water rights. According to the first, public authorities’ power to manage and preserve water resources is grounded in a derogatory regime, whereby water rights, grounded on licenses or concessions, are neither transferable nor tradeable. On the contrary, environmental and social concerns in water market schemes must be enforced by means of regulation, thus limiting private property rights on water, in compliance with the constitutional and common law constraints set out to protect the minimum content of property as a fundamental human right.

  4. The effect of water uptake on the mechanical properties of low-k organosilica glass

    Science.gov (United States)

    X. Guo; J.E. Jakes; M.T. Nichols; S. Banna; Y. Nishi; J.L. Shohet

    2013-01-01

    Water uptake in porous low-k dielectrics has become a significant challenge for both back-end-of line integration and circuit reliability. The influence of absorbed water on the mechanical properties of plasma-enhanced chemical-vapor-deposited organosilicate glasses (SiCOH) was investigated with nanoindentation. The roles of physisorbed (α-...

  5. Retrieval of liquid water cloud properties from ground-based remote sensing observations

    NARCIS (Netherlands)

    Knist, C.L.

    2014-01-01

    Accurate ground-based remotely sensed microphysical and optical properties of liquid water clouds are essential references to validate satellite-observed cloud properties and to improve cloud parameterizations in weather and climate models. This requires the evaluation of algorithms for retrieval of

  6. Water Residence Times and Their Relation to Soil and Aquifer Properties and Degree of Urbanization (Croton Water Supply Area, NY)

    Science.gov (United States)

    Vitvar, T.; Burns, D.; Kendall, C.; McDonnell, J.

    2002-05-01

    Water residence times were determined in 3 small watersheds in the Croton water supply area, NY. The watersheds (less than 1 km2 drainage area) have different amounts of urbanization (natural, semi-developed and fully developed), different mechanisms of runoff generation (quick flow on roads and slow flow through subsurface) and different watershed landscape characteristics (wetlands, hillslopes) . Measurements of the Oxygen-18 content of throughfall, stream water, soil water and groundwater in the saturated zone were performed bi-weekly over a period of 2 years. Mean water residence times of the stream water, soil water and groundwater were estimated using Oxygen-18 and Helium-3/Tritium isotopes. There are small but significant differences in the isotopic content of waters in each watershed, along with soil and aquifer properties as a function of the level of urbanization. Longer groundwater residence times (up to more than 2 years) were estimated in wetland zones without direct communication with streams in comparison to hillslope areas (up to more than 1 year). In highly urbanized areas, mixing of natural runoff generation processes with urbanization effects such as the influence of septic plumes results in a complex spectrum of residence times in soil waters and groundwaters. We illustrate the possibilities of using stable isotope measurements to describe small-scale complex runoff generation processes in watersheds.

  7. Impact of Intellectual Property in National and Business Development under the Context of the Current Globalization

    Directory of Open Access Journals (Sweden)

    Stalin Ballesteros García

    2016-12-01

    Full Text Available The objective of the document is to show the impact of the intellectual property on the national and enterprise development in the globalization context since the early twenty-first century. First, it is a historical telling of the intellectual property and its role in the international society; then outlining the arguments to infer the incidence degree of the intellectual property in the economic development of countries and then discussing the inclusion impact of concepts directly related to the intellectual property in business growth activities. It concludes with a reflection on the Colombian situation, in public and private context, in terms of intellectual property.

  8. Carbon and water cycling in a Bornean tropical rainforest under current and future climate scenarios

    Science.gov (United States)

    Kumagai, Tomo'omi; Katul, Gabriel G.; Porporato, Amilcare; Saitoh, Taku M.; Ohashi, Mizue; Ichie, Tomoaki; Suzuki, Masakazu

    2004-12-01

    We examined how the projected increase in atmospheric CO 2 and concomitant shifts in air temperature and precipitation affect water and carbon fluxes in an Asian tropical rainforest, using a combination of field measurements, simplified hydrological and carbon models, and Global Climate Model (GCM) projections. The model links the canopy photosynthetic flux with transpiration via a bulk canopy conductance and semi-empirical models of intercellular CO 2 concentration, with the transpiration rate determined from a hydrologic balance model. The primary forcing to the hydrologic model are current and projected rainfall statistics. A main novelty in this analysis is that the effect of increased air temperature on vapor pressure deficit ( D) and the effects of shifts in precipitation statistics on net radiation are explicitly considered. The model is validated against field measurements conducted in a tropical rainforest in Sarawak, Malaysia under current climate conditions. On the basis of this model and projected shifts in climatic statistics by GCM, we compute the probability distribution of soil moisture and other hydrologic fluxes. Regardless of projected and computed shifts in soil moisture, radiation and mean air temperature, transpiration was not appreciably altered. Despite increases in atmospheric CO 2 concentration ( Ca) and unchanged transpiration, canopy photosynthesis does not significantly increase if Ci/ Ca is assumed constant independent of D (where Ci is the bulk canopy intercellular CO 2 concentration). However, photosynthesis increased by a factor of 1.5 if Ci/ Ca decreased linearly with D as derived from Leuning stomatal conductance formulation [R. Leuning. Plant Cell Environ 1995;18:339-55]. How elevated atmospheric CO 2 alters the relationship between Ci/ Ca and D needs to be further investigated under elevated atmospheric CO 2 given its consequence on photosynthesis (and concomitant carbon sink) projections.

  9. Mechanical and Thermal Properties of Pulsed Electric Current Sintered (PECS) Cu-Diamond Compacts

    Science.gov (United States)

    Ritasalo, Riina; Kanerva, Ulla; Ge, Yanling; Hannula, Simo-Pekka

    2014-04-01

    In this work, dispersion strengthening of copper by diamonds is explored. In particular, the influence of 50- and 250-nm diamonds at contents of 3 and 6 vol. pct on the mechanical and thermal properties of pulsed electric current sintered (PECS) Cu composites is studied. The composite powders were prepared by mechanical alloying in argon atmosphere using a high-energy vibratory ball mill. The PECS compacts prepared had high density (>97 pct of T.D.) with quite evenly distributed diamonds. The effectiveness of dispersoids in increasing the microhardness was more pronounced at a smaller particle size and larger volume fraction, explained by Hall-Petch and Orowan strengthening models. The microhardness of Cu with 6 and 3 vol. pct nanodiamonds and pure sm-Cu (submicron-sized Cu) was 1.77, 1.46, and 1.02 GPa, respectively. In annealing experiments at 623 K to 873 K (350 °C to 600 °C), the composites with 6 vol. pct dispersoids retained their hardness better than those with less dispersoids or sm-Cu. The coefficient of thermal expansion was lowered when diamonds were added, being the lowest at about 14 × 10-6 K-1 between 473 K and 573 K (200 °C and 300 °C). Good bonding between the copper and diamond was qualitatively demonstrated by nanoindentation. In conclusion, high-quality Cu-diamond composites can be produced by PECS with improved strength and better thermal stability than for sm-Cu.

  10. Water content influence on thermal and volumetric properties of wheat starch gelatinization under 10 MPa.

    Science.gov (United States)

    Orlowska, Marta; Randzio, Stanislaw L

    2010-02-01

    A transitiometric in situ analysis of wheat starch aqueous suspensions heated over a temperature range from 285 K to 415 K under isobaric conditions of 10 MPa is presented. Measurements were performed at four selected water concentrations: 56.0%, 64.7%, 73.5%, and 82.4% weight/water. Thermal and volumetric properties and their water content dependencies have been determined for three successive starch phase transformations occurred during wheat starch gelatinization.

  11. Influence of direct bias current on the electromagnetic properties of melt-extracted microwires and their composites

    Science.gov (United States)

    Qin, F. X.; Tang, J.; Popov, V. V.; Liu, J. S.; Peng, H. X.; Brosseau, C.

    2014-01-01

    We study the influence of a direct bias current on the magnetoimpedance (MI) in melt-extracted amorphous CoFeSiB microwires and the effective electromagnetic properties of epoxy composites filled with these microwires. Our analysis reveals two remarkable features of the current dependence of MI in the range of gigahertz frequencies: a redshift of the dielectric resonance frequency and a decrease of the peak resonance of the effective permittivity as the bias current increases. Both effects are intrinsically linked to the influence of the polymer matrix on the magnetic structure and properties of the microwires. A discussion of these results is proposed in terms of two competing effects of the bias current, i.e., the induced additional effective field in the plane normal to the wire axis and the stress relief from Joule heating.

  12. Effects of Several Natural Macromolecules on the Stability and Controlled Release Properties of Water-in-Oil-in-Water Emulsions.

    Science.gov (United States)

    Li, Jinlong; Shi, Yiheng; Zhu, Yunping; Teng, Chao; Li, Xiuting

    2016-05-18

    Water-in-oil-in-water (W/O/W) emulsions are effective vehicles for embedding application of active compounds but limited by their thermodynamic instability and rapid release properties. The present study added bovine serum albumin, whey protein isolate, whey protein hydrolysate, sodium caseinate, carboxymethylcellulose sodium, fish gelatin, apple pectin, gum arabic, ι-carrageenan, and hydroxypropyl chitosan separately to the internal or external aqueous phase to investigate their effects on the physical stabilities and controlled release properties of W/O/W emulsions. The effects of the natural macromolecules in the internal and external aqueous phases were different and depended upon the macromolecule structure and its mass fraction. The addition of the natural macromolecule strengthened the interfaces of emulsions, which improved the physical stability. The natural macromolecules that improved the stability often did not improve controlled release. Therefore, the balance between these properties needs to be considered when adding natural macromolecules to a W/O/W emulsion.

  13. Transport Properties of Water and Sodium Dodecyl Sulfate (Postprint)

    Science.gov (United States)

    2013-08-01

    and boiling temperatures. Additionally, MP2f (Akin- Ojo et al., 2008, “Developing Ab Initio Quality Force Fields From Con- densed Phase Quantum...results. In the second part, we introduce the ab initio flexible water model developed by Akin- Ojo et al. [38] in 2008 using the relatively new adaptive...38] Akin- Ojo , O., Song, Y., and Wang, F., 2008, “Developing Ab Initio Quality Force Fields From Condensed Phase Quantum-Mechanics/Molecular-Mechan

  14. Vibrational properties of water under confinement: Electronic effects

    Energy Technology Data Exchange (ETDEWEB)

    Donadio, D; Cicero, G; Schwegler, E; Sharma, M; Galli, G

    2008-10-17

    We compare calculations of infrared (IR) spectra of water confined between non polar surfaces, carried out using ab initio and classical simulations. Ab-initio results show important differences between IR spectra and vibrational density of state, unlike classical simulations. These differences originate from electronic charge fluctuations at the interface, whose signature is present in IR spectra but not in the density of states. The implications of our findings for the interpretation of experimental data are discussed.

  15. Over Current Properties of HTC Superconducting Wire Cooled by Liquid Hydrogen

    Science.gov (United States)

    Shirai, Yasuyuki; Kobayashi, Hiroto; Takegami, Taiki; Hikawa, Kyosuke; Shiotsu, Masahiro; Tatsumoto, Hideki; Naruo, Yoshihiro; Kobayashi, Hiroaki; Inatani, Yoshifumi; Kinoshita, Katsuhiko

    An experimental setup which can energize superconducting wires immersed in LH2 was designed and made. Over current tests were carried out using MgB2 wire. Critical current and resistivity of a test MgB2 wire submerged in liquid hydrogen were measured for exponentially increasing heat input, while the transport current exceeded the critical current. The resistivity of the conductor was obtained as a function of current and the temperature of the conductor by using the transient heating method. The distribution ratio of the current through the superconductor and the sheath, and the resistivity of the MgB2 conductor itself were estimated.

  16. Dynamical properties of confined supercooled water: an NMR study

    Science.gov (United States)

    Mallamace, Francesco; Broccio, Matteo; Corsaro, Carmelo; Faraone, Antonio; Liu, Li; Mou, Chung-Yuan; Chen, Sow-Hsin

    2006-09-01

    We report a set of dynamical data of confined water measured in a very deeply supercooled regime (290-190 K). Water is contained in silica matrices (MCM-41-S) which consist of 1D cylindrical pores with diameters d = 14,18 and 24 Å. When confined in these tubular pores, water does not crystallize, and can be supercooled well below 200 K. We use the NMR technique to obtain the characteristic proton relaxation time-constants (the spin-lattice relaxation time-constant T1 and the spin-spin relaxation time-constant T2) and a direct measurement of the self-diffusion coefficient in the whole temperature range. We give evidence of the existence of a fragile-to-strong dynamic crossover (FSC) at TL = 225 K from the temperature dependence of the self-diffusion coefficient. A combination of the NMR self-diffusion coefficient with the average translational relaxation time, as measured by quasi-elastic neutron scattering, shows a well defined decoupling of transport coefficients, i.e. the breakdown of the Stokes-Einstein relation, on approaching the crossover temperature TL.

  17. Dynamical properties of confined supercooled water: an NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Mallamace, Francesco [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Broccio, Matteo [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Corsaro, Carmelo [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Faraone, Antonio [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Liu Li [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Mou, C-Y [Department of Chemistry, National Taiwan University, Taipei, Taiwan (China); Chen, S-H [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2006-09-13

    We report a set of dynamical data of confined water measured in a very deeply supercooled regime (290-190 K). Water is contained in silica matrices (MCM-41-S) which consist of 1D cylindrical pores with diameters d = 14,18 and 24 A. When confined in these tubular pores, water does not crystallize, and can be supercooled well below 200 K. We use the NMR technique to obtain the characteristic proton relaxation time-constants (the spin-lattice relaxation time-constant T1 and the spin-spin relaxation time-constant T2) and a direct measurement of the self-diffusion coefficient in the whole temperature range. We give evidence of the existence of a fragile-to-strong dynamic crossover (FSC) at T{sub L} = 225 K from the temperature dependence of the self-diffusion coefficient. A combination of the NMR self-diffusion coefficient with the average translational relaxation time, as measured by quasi-elastic neutron scattering, shows a well defined decoupling of transport coefficients, i.e. the breakdown of the Stokes-Einstein relation, on approaching the crossover temperature T{sub L}.

  18. Effect of filler water absorption on water swelling properties of natural rubber

    Science.gov (United States)

    Trakuldee, J.; Boonkerd, K.

    2017-07-01

    The efficient water swelling rubber can be obtained by using high hydrophilic rubber such as chloroprene rubber. However, chloroprene rubber is synthetic rubber developed from the petroleum. Recently, many researches try to replace the usage of synthetic rubber with natural rubber. This is not only due to the concerning of environment but the cost reduction as well. However, natural rubber is hydrophobic, thus not absorbing water. To develop the water swelling rubber from natural rubber, the addition of water absorption filler is needed. The study was aimed to formulate water swelling rubber from natural rubber filled with sodium polyacrylate (SA)/sodium bentonite clay (SBC) hybrid filler used to water absorbent. The filler loading was kept constantly at 150 phr. The effect of SA/SBC ratio varied from 1:0, 1:1, 1:2 and 1:3 on the water absorption of the hybrid filled natural rubber was determined. The obtained result showed that the water adsorption proportionally increased with increasing SA loading but decreased with increasing SBC loading. The effect of glycidyl methacrylate (GM) and poly ethylene glycol (PEG) on the water absorption was studied later. The result from a scanning electron microscope depicted that the presence of GM can depress the falling out of SA from the rubber matrix while the presence of PEG increased water absorption.

  19. Ice-water vortex at the edge of the East Greenland current

    Energy Technology Data Exchange (ETDEWEB)

    Wadhams, P.; Squire, V.A.

    1983-03-30

    During the Ymer-80 cruise in August 1980 we observed an ice feature of 60-km diameter having the shape of a breaking wave. It lay at the edge of the East Greenland drift ice in Fram Strait with its center at 79/sup 0/15'N, 00/sup 0/38'E, and the wave was breaking upstream relative to the East Greenland current. Two conductivity, temperature, and depth sections across the feature in N-S and E-W directions revealed warm (up to 4.3 C) water some 60 km inside the polar front, in lenses centered at 40-m depth but with an effect to beyond 600 m. The temperature anomalies were accompanied by salinity anomalies so that there was little net effect on the density profile. The form of the sections, together with the ice distribution (observed by vertical photography from a helicopter) and surface motion (observed by tracking four radar transponders) all suggest that the feature is a vortex produced by an instability in the polar front. It has similar characteristics to vortices investigated experimentally and theoretically by Griffiths and Linden (1981a, b, 1982) and observationally by Wadhams et al. (1979).

  20. An ice-water vortex at the edge of the East Greenland Current

    Science.gov (United States)

    Wadhams, P.; Squire, V. A.

    1983-03-01

    During the Y mer-80 cruise in August 1980 we observed an ice feature of 60-km diameter having the shape of a breaking wave. It lay at the edge of the East Greenland drift ice in Fram Strait with its center at 79°15'N, 00°38'E, and the wave was breaking upstream relative to the East Greenland Current. Two conductivity, temperature, and depth sections across the feature in N-S and E-W directions revealed warm (up to 4.3°C) water some 60 km inside the polar front, in lenses centered at 40-m depth but with an effect to beyond 600 m. The temperature anomalies were accompanied by salinity anomalies so that there was little net effect on the density profile. The form of the sections, together with the ice distribution (observed by vertical photography from a helicopter) and surface motion (observed by tracking four radar transponders) all suggest that the feature is a vortex produced by an instability in the polar front. It has similar characteristics to vortices investigated experimentally and theoretically by Griffiths and Linden (1981a, b, 1982) and observationally by Wadhams et al. (1979).

  1. Dynamics of turbulent western-boundary currents at low latitude in a shallow-water model

    Science.gov (United States)

    Akuetevi, C. Q. C.; Wirth, A.

    2015-06-01

    The dynamics of low latitude turbulent western-boundary currents (WBCs) crossing the Equator are considered using numerical results from integrations of a reduced-gravity shallow-water model. For viscosity values of 1000 m2 s-1 and greater, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in the form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer, VSL) and dipoles appear. Three distinct boundary layers emerge, the VSL, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity; the second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse-resolution numerical models is proposed.

  2. Advanced Steels for Accident Tolerant Fuel Cladding in Current Light Water Reactors

    Science.gov (United States)

    Rebak, Raul B.

    After the March 2011 Fukushima events, the U.S. Congress directed the Department of Energy (DOE) to focus efforts on the development of fuel cladding materials with enhanced accident tolerance. In comparison with the stand-ard UO2-Zirconium based system, the new fuels need to tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operation conditions. Advanced steels such as iron-chromium-aluminum (FeCrAl) alloys are being investigated for degradation behavior both under normal operation conditions in high temperature water (e.g. 288°C) and under accident conditions for reaction with steam up to 1400°C. Commercial and experimental alloys were tested for several periods of time in 100% superheated steam from 800°C to 1475°C. Results show that FeCrAl alloys significantly outperform the resistance in steam of the current zirconium alloys.

  3. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-11-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents crossing the equator is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and more, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  4. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-03-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents, subject to two different types of idealized wind forcing, Monsoon Wind and Trade Wind, is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and above, the boundary layer dynamics compares well to the analytical solutions of the Munk-layer and the inertial-layer, derived from quasigeostrophic theory. Modifications due to variations in the layer thickness (vortex stretching are only important close to the boundary. When the viscosity is reduced the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  5. Influence of Water Content on Mechanical Properties of Rock in Both Saturation and Drying Processes

    Science.gov (United States)

    Zhou, Zilong; Cai, Xin; Cao, Wenzhuo; Li, Xibing; Xiong, Cheng

    2016-08-01

    Water content has a pronounced influence on the properties of rock materials, which is responsible for many rock engineering hazards, such as landslides and karst collapse. Meanwhile, water injection is also used for the prevention of some engineering disasters like rock-bursts. To comprehensively investigate the effect of water content on mechanical properties of rocks, laboratory tests were carried out on sandstone specimens with different water contents in both saturation and drying processes. The Nuclear Magnetic Resonance technique was applied to study the water distribution in specimens with variation of water contents. The servo-controlled rock mechanics testing machine and Split Hopkinson Pressure Bar technique were used to conduct both compressive and tensile tests on sandstone specimens with different water contents. From the laboratory tests, reductions of the compressive and tensile strength of sandstone under static and dynamic states in different saturation processes were observed. In the drying process, all of the saturated specimens could basically regain their mechanical properties and recover its strength as in the dry state. However, for partially saturated specimens in the saturation and drying processes, the tensile strength of specimens with the same water content was different, which could be related to different water distributions in specimens.

  6. Photoelectrolysis of water at high current density - Use of ultraviolet laser excitation

    Science.gov (United States)

    Bocarsly, A. B.; Bolts, J. M.; Cummins, P. G.; Wrighton, M. S.

    1977-01-01

    The behavior of TiO2 and SrTiO3 photoanodes in cells for the photoelectrolysis of H2O has been investigated for high-intensity 351-,364-nm excitation from an Ar ion laser. Intensities up to 380 W/sq cm have been used. For TiO2 a small amount of surface decomposition is found after irradiation at high intensity, whereas SrTiO3 undergoes no detectable changes. Current-voltage properties for both electrodes are essentially independent of light intensity up to the level of 380 W/sq cm, and there is little if any change in quantum efficiency for electron flow. Photocurrent densities have been shown to exceed 5 A/sq cm for O2 evolution. Data show that the energy storage rate associated with the SrTiO3 photoelectrolysis can exceed 30 W/sq cm; this represents the highest demonstrated rate of sustained optical-to-chemical energy conversion.

  7. Water vapor permeability, mechanical properties and antioxidant effect of Mexican oregano-soy based edible films.

    Science.gov (United States)

    Pruneda, E; Peralta-Hernández, J M; Esquivel, K; Lee, S Y; Godínez, L A; Mendoza, S

    2008-08-01

    Water-soluble extracts from Mexican oregano (Lippia graveolens) were incorporated into soy protein isolate (SPI) films. Water vapor permeability, mechanical properties, and antioxidant ability were evaluated. All the extracts were capable of scavenging DPPH radicals in a concentration-dependent fashion; the IC50 values were obtained. Oregano extracts were incorporated into SPI films plasticized with sorbitol, glycerol, and glycerol-sorbitol 1:1. The addition of the extracts resulted in an increase in the water vapor permeability values and provided a dark reddish film appearance. Changes in tensile strength as well as elongation values were observed. The oregano SPI films exhibited antioxidant properties in a concentration-dependent fashion.

  8. The Properties of Confined Water and Fluid Flow at the Nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G

    2009-03-09

    This project has been focused on the development of accurate computational tools to study fluids in confined, nanoscale geometries, and the application of these techniques to probe the structural and electronic properties of water confined between hydrophilic and hydrophobic substrates, including the presence of simple ions at the interfaces. In particular, we have used a series of ab-initio molecular dynamics simulations and quantum Monte Carlo calculations to build an understanding of how hydrogen bonding and solvation are modified at the nanoscale. The properties of confined water affect a wide range of scientific and technological problems - including protein folding, cell-membrane flow, materials properties in confined media and nanofluidic devices.

  9. Contribution study of the thermodynamics properties of the ammonia-water mixtures

    Directory of Open Access Journals (Sweden)

    Kherris Sahraoui

    2013-01-01

    Full Text Available The full thermodynamic study of the absorption refrigeration units requires the knowledge of the thermodynamic properties of the used mixture. The present work deals with the mathematical modeling of the thermodynamic properties of ammonia-water mixtures using various models. The presented model covers high vapor-liquid equilibrium pressures up to 110 [bar] and temperatures from 230 to 600 [K]. Furthermore, the calculation of the thermodynamic properties of the ammonia-water mixtures and their pure components was carried out. The obtained results were compared with results given in the literature. This shows a good concordance.

  10. Effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded high strength aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, V. [Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, Tamil Nadu 608002 (India)], E-mail: visvabalu@yahoo.com; Ravisankar, V. [Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, Tamil Nadu 608002 (India); Reddy, G. Madhusudhan [Metal Joining Section, Defence Metallurgical Research Laboratory, Kanchanbag (P.O.), Hyderabad 560058 (India)

    2007-06-25

    This paper reveals the effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded AA7075 aluminium alloy. This alloy has gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. As welded joint strength is much lower than the base metal strength and hence, a simple aging treatment has been given to improve the tensile strength of the joints. Current pulsing leads to relatively finer and more equi-axed grain structure in GTA and GMA welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Post weld aging treatment is accompanied by an increase in tensile strength and tensile ductility.

  11. Structural properties of the solar flare-producing coronal current system developed in an emerging magnetic flux tube

    Science.gov (United States)

    Magara, Tetsuya

    2017-02-01

    The activity of a magnetic structure formed in the solar corona depends on a coronal current system developed in the structure, which determines how an electric current flows in the corona. To investigate structural properties of the coronal current system responsible for producing a solar flare, we perform magnetohydrodynamic simulation of an emerging magnetic flux tube which forms a coronal magnetic structure. Investigation using fractal dimensional analysis and electric current streamlines reveals that the flare-producing coronal current system relies on a specific coronal current structure of two-dimensional spatiality, which has a sub-region where a nearly anti-parallel magnetic field configuration is spontaneously generated. We discuss the role of this locally generated anti-parallel magnetic field configuration in causing the reconnection of a three-dimensional magnetic field, which is a possible mechanism for producing a flare. We also discuss how the twist of a magnetic flux tube affects structural properties of a coronal current system, showing how much volume current flux is carried into the corona by an emerging flux tube. This gives a way to evaluate the activity of a coronal magnetic structure.

  12. The Effects of Ribose on Mechanical and Physicochemical Properties of Cold Water Fish Gelatin Films

    Directory of Open Access Journals (Sweden)

    Neda Javadian

    2014-06-01

    Full Text Available Native fish gelatin has some disadvantages such as high hydrophilic, and solubility in cold water. Mixing with other biopolymers and crosslinking by sugars may improve functional properties of fish gelatin. So in this research, the effects of ribose were investigated on moisture sorption isotherm, solubility in water, and mechanical properties of cold water fish gelatin (CWFG films. Ribose sugar was incorporated into CWFG solutions at different concentrations (e.g. 0, 2, 4, and 6% w/w dried gelatin. Physicochemical properties such as water solubility, moisture sorption isotherm and mechanical properties of the films were measured according to ASTM standards. Results showed that incorporation of ribose sugar significantly improved functional properties of CWFG films. Solubility, moisture content and monolayer water content of the matrixes were decreased by increasing the ribose contents. Mechanical properties of biocomposites were improved more than 20% and moisture sorption isotherm curve significantly shifted to lower moisture contents. The results of this study could be explored for commercial use, depending on industrial needs for either production of edible films or for packaging purposes.

  13. Remote Estimation of Leaf and Canopy Water Content in Winter Wheat with Different Vertical Distribution of Water-Related Properties

    Directory of Open Access Journals (Sweden)

    Shishi Liu

    2015-04-01

    Full Text Available This study analyzed the vertical distribution of gravimetric water content (GWC, relative water content (RWC, and equivalent water thickness (EWT in winter wheat during heading and early ripening stages, and evaluated the position of leaf number at which Vegetation Indexes (VIs can best retrieve canopy water-related properties of winter wheat. Results demonstrated that the vertical distribution of these properties followed a near-bell-shaped curve with the highest values at the intermediate leaf position. GWC of the top three or four leaves during the heading stage and the top two or three leaves during the early ripening stage can represent the GWC of the whole canopy, but the RWC and EWT of the whole canopy should be calculated based on the top four leaves. At leaf level, the analysis demonstrated strong relationships between EWT and VIs for the top leaf layer, but for GWCD, GWCF, and RWC, the strongest relationships with VIs were found in the intermediate leaf layers. At canopy level, VIs provided the most accurate estimation of GWCfor the top three or four leaves. Water absorption-based VIs could estimate canopy EWT of winter wheat for the top four leaves, but the suitable bands sensitive to water absorptions should be carefully selected for the studied species.

  14. Dielectric Properties of Ice-Water Systems: Laboratory Characterization and Modeling

    Science.gov (United States)

    West, J.; Rippin, D. M.; Endres, A. L.; Murray, T.

    2005-05-01

    Glacier mechanical properties, and hence their response to climatic change, depend strongly on the proportion and distribution of unfrozen water at ice grain boundaries. Glaciologists have characterized unfrozen water content in several ways, notably via thin section microscopic analysis of ice cores to measure porewater contents, and field surveys of electromagnetic properties using radar. Water content has a very strong influence on the velocity of electromagnetic (radar) waves in ice, because of the high dielectric constant of water (~80) in comparison with ice (~3). However, there is a strong discrepancy between the two methods of measurement, with field radar surveys on glaciers giving unfrozen water contents of several volumetric percent, whereas ice-core microscopy gives values of less than one percent. This discrepancy has called into question the approach used to obtain the unfrozen water content from radar wave velocity. This approach assumes that the ice-water mixture is a lossless medium. Here, we report a laboratory and modeling based investigation of the relationship between dielectric properties and unfrozen water content of ice cores from the Glacier de Tsanfleuron, Switzerland, aimed at resolving the discrepancy. The laboratory study uses the technique of Time Domain Reflectometry to characterize the dielectric properties of ice cores from a range of ice facies. `Press on' TDR waveguides have been developed specifically for use on ice cores. Several press-on probe designs have been developed and aspects of their performance are reported. An independent estimate of unfrozen water content is determined from temperature and total pore fluid ionic strength. The results allow the establishment of relationships between the high frequency (~500MHz) dielectric properties and water content for various ice-crystal geometries. Mathematical modeling of the dependence of dielectric constant on frequency and water phase conductivity has been undertaken using

  15. Effects of acidic functional groups on dielectric properties of sodium alginates and carrageenans in water.

    Science.gov (United States)

    Tsubaki, Shuntaro; Hiraoka, Masanori; Hadano, Shingo; Okamura, Kei; Ueda, Tadaharu; Nishimura, Hiroshi; Kashimura, Keiichiro; Mitani, Tomohiko

    2015-01-22

    This study investigated the dielectric properties of sodium alginates and carrageenans in water at frequencies between 100 MHz and 20 GHz in regard to water-hydrocolloid interactions via acidic functional groups. Both sodium alginates and carrageenans showed conduction loss at lower frequencies and dielectric loss at higher frequencies. Reduction and desulfation of sodium alginates and carrageenans, which decreased the numbers of acidic functional groups, decreased their conduction loss. In addition, H(+)-form carrageenans showed the highest ionic conduction. Correlational analysis of dielectric properties and related physical parameters showed that the loss tangent (tanδ) of the hydrocolloid solution was determined by the conductivity of the aqueous solution. Especially at pH below 2, strong H(+) conduction was associated with high tanδ probably due to the Grotthuss mechanism. The molecular dynamics of free water and H(+), viscosity conditions were also suggested to be associated with dielectric property of water-hydrocolloid system.

  16. [Changes in Properties of Water during Germination of Zucchini Seed in Water Used].

    Science.gov (United States)

    Novikov, S N; Novikov, L N; Ermolaeva, A I; Timoshenkov, S P; Goryunova, E P

    2015-01-01

    In this research the changes in the supramolecular structure of distilled water during germination of the seed in this water were studied. We used three methods: gravimetry, precision thermal analysis, electron work function measurements. In the first stage of seed germination--seed swelling--the seed extracts coherent domains in the water, herewith due to the transition of coherent domains adsorbed in nanofields into a stable state the flow of electromagnetic energy appears. In the second stage of the experiment--germ growing--the flow of biophotons occurs. This is evidenced by the increased water electron work function. A hypothetical model of the process of zucchini seed germination is suggested.

  17. EFFECT OF TROUT PRODUCTION IN CONCRETE PONDS WITH A CASCADING FLOW OF WATER ON PHYSICAL AND CHEMICAL PROPERTY OF WATER

    Directory of Open Access Journals (Sweden)

    Marcin Sidoruk

    2014-10-01

    Full Text Available Fish rearing causes changes in water quality due to the use of feed, mineral and organic fertilizers, pharmaceuticals and disinfectants. Rational fishery management aims to maintain or restore the quality of water in natural ecosystems. Cultures produce a certain amount of waste and pollutants released into the environment with waters departing from ponds, but their harmfulness depends on the conditions and type of farming. Studies on the assessment of the effects of rearing trout on physical and chemical properties of surface water were carried out in 2010-2012. Were chosen trout farm located in the Pomeranian province about 36 miles southeast of Słupsk. Water samples for physical and chemical analysis were collected every two months (a total of 12 sets samples collected and labeled them: temperature [°C], dissolved oxygen [mg · dm-3], oxygen saturation [%] electrolytic conductivity [S · cm-1], pH, redox potential [mV] and BOD5 and CODCr. The study showed that the water used to supply breeding facilities meet the requirements to be met which are inland water salmonid habitat. Only periodically for BOD5 standards have been slightly exceeded. After passing through the joints deterioration of water quality did not cause a change in the quality of the class, if only temporarily BOD5 ratio were lower in its quality from the first to the third class.

  18. Water Absorption Behaviour and Its Effect on the Mechanical Properties of Flax Fibre Reinforced Bioepoxy Composites

    Directory of Open Access Journals (Sweden)

    E. Muñoz

    2015-01-01

    Full Text Available In the context of sustainable development, considerable interest is being shown in the use of natural fibres like as reinforcement in polymer composites and in the development of resins from renewable resources. This paper focuses on eco-friendly and sustainable green composites manufacturing using resin transfer moulding (RTM process. Flax fibre reinforced bioepoxy composites at different weight fractions (40 and 55 wt% were prepared in order to study the effect of water absorption on their mechanical properties. Water absorption test was carried out by immersion specimens in water bath at room temperature for a time duration. The process of water absorption of these composites was found to approach Fickian diffusion behavior. Diffusion coefficients and maximum water uptake values were evaluated; the results showed that both increased with an increase in fibre content. Tensile and flexural properties of water immersed specimens were evaluated and compared to dry composite specimens. The results suggest that swelling of flax fibres due to water absorption can have positive effects on mechanical properties of the composite material. The results of this study showed that RTM process could be used to manufacture natural fibre reinforced composites with good mechanical properties even for potential applications in a humid environment.

  19. Parameterization for narrow band optical properties of water clouds

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The equivalent radius of cloud droplets is an important microphysical parameter in determining the optical properties of clouds. But for the present schemes of parameterization with merely the equivalent radius, the role of small droplets in clouds has not been considered properly. In this paper, several parameterization schemes are pre sented, and their performances have been analyzed through comparison with Mie scattering calculations and accurate ra diative transfer computations. The results show that for the parameterization scheme, in addition to the equivalent ra dius, including also the mean radius of cloud droplets, the role of small cloud droplets might be considered more proper ly and better accuracy could be achieved.

  20. CLASSIFYING COASTAL WATERS: HISTORICAL PERSPECTIVE AND CURRENT FOCUS ON AQUATIC STRESSORS

    Science.gov (United States)

    Coastal ecosystems are ecologically and commercially productive habitats that are experiencing significant impacts associated with accelerated population growth in coastal zones. The Clean Water Act requires identification of impaired water bodies and determination of the causes ...

  1. Development of Harmonic-Noise Reduction Technology in Diagnostic Method using AC Loss Current for Water Treed XLPE Cable

    Science.gov (United States)

    Tsujimoto, Tomiyuki; Nakade, Masahiko; Yagi, Yukihiro; Ishii, Noboru

    Water tree is one of the degradation aspects of XLPE cables used for under-ground distribution or transmission lines. We have developed the loss current method using 3rd harmonic in AC loss current for cable diagnosis. Harmonic components in loss current arise as a result of the non-linear voltage-current characteristics of water trees. We confirmed that the 3rd harmonic in AC loss current had good correlation with water tree growth and break down strength. After that, we have applied this method to the actual 66kV XLPE cable lines. Up to now, the number of the application results is more than 120 lines. In this method, it is sometimes said that the degradation signal (3rd harmonic in loss current) is affected by the 3rd harmonic in the test voltage. To indicate and solve this problem, we investigated the extent of influence by 3rd harmonic in the test voltage, and found the rule of the influence. As a result, we developed a new technique of harmonic-noise reduction in loss current method that enabled a more highly accurate diagnosis and confirmed the effectiveness of this new technique by simulations and experiments with actual cables.

  2. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  3. Best urban water management practices to prevent waterborne infectious diseases under current and future scenarios

    NARCIS (Netherlands)

    de Man-van der Vliet, H.

    2014-01-01

    Water in urban areas may pose a public health risk when people are exposed to urban water, because it may contain pathogens. These pathogens may originate from fecal bird droppings, runoff from paved surfaces (including e.g. dog feces), growth of micro-organisms in water and in some cases discharges

  4. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Maarten S.; Vries, de Marjella J.; Oel, van Pieter R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  5. Static and dynamic properties of surfactant films on natural waters

    Directory of Open Access Journals (Sweden)

    Stanis³aw J. Pogorzelski

    2001-06-01

    Full Text Available The paper contains the results of natural surface film surface pressure - area experiments carried out in inland waters and shallow offshore regions of the Baltic and Mediterranean Seas during 1990-99 under calm water conditions using the Langmuir trough - Wilhelmy filter paper plate system, which "cuts out" an undisturbed film-covered sea area without any initial physico-chemical sample processing. The limiting specific area Alim (268–3157 Å2/molecule-1 and mean molecular mass (0.65-9.7 kDa of microlayer surfactants were determined from the 2D virial equation of state applied to the isotherms. Film structure signatures were derived from – A isotherm hysteresis and application of the 2D polymer scaling theory. The stress-relaxation measurements revealed a two-step relaxation process at the interface with characteristic times 1 (1.1–2.8 and 2 (5.6-25.6 seconds suggesting the presence of diffusion-controlled and structural organization relaxation phenomena. The results demonstrate that natural films are a complex mixture of biomolecules covering a wide range of solubilities, surface activity and molecular mass with an apparent structural organization exhibiting a spatial and temporal variability.

  6. Physicochemical properties of bactericidal plasma-treated water

    Science.gov (United States)

    Ikawa, Satoshi; Tani, Atsushi; Nakashima, Yoichi; Kitano, Katsuhisa

    2016-10-01

    Plasma-treated water (PTW), i.e. distilled water (DW) exposed to low-temperature atmospheric pressure helium plasma, exhibited strong bactericidal activity against Escherichia coli in suspension even within a few minutes of preparation. This effect was enhanced under acidic conditions. The bactericidal activity of PTW was attenuated according to first-order kinetics and the half-life was highly temperature dependent. The electron spin resonance (ESR) signal of an adduct of the superoxide anion radical (\\text{O}2-\\bullet ) was detected in an aqueous solution using a spin-trapping reagent mixed with PTW, and adding superoxide dismutase to the PTW resulted in a loss of the bactericidal activity and weakening of the ESR adduct signal of \\text{O}2-\\bullet in the spin-trapping. These results suggest that \\text{O}2-\\bullet plays an important role in imparting bactericidal activity to PTW. Moreover, molecular nitrogen was required both in the ambient gas and in the DW used to prepare the PTW. We, therefore, suggest that the reactive molecule in PTW with bactericidal effects is not a free reactive oxygen species but nitrogen atom(s)-containing molecules that release \\text{O}2-\\bullet , such as peroxynitrous acid (ONOOH) or peroxynitric acid (O2NOOH). Considering the activation energy for degradation of these species, we conclude that peroxynitric acid stored in PTW induces the bactericidal effect.

  7. Water-repellent cellulose fiber networks with multifunctional properties.

    Science.gov (United States)

    Bayer, Ilker S; Fragouli, Despina; Attanasio, Agnese; Sorce, Barbara; Bertoni, Giovanni; Brescia, Rosaria; Di Corato, Riccardo; Pellegrino, Teresa; Kalyva, Maria; Sabella, Stefania; Pompa, Pier Paolo; Cingolani, Roberto; Athanassiou, Athanassia

    2011-10-01

    We demonstrate a simple but highly efficient technique to introduce multifunctional properties to cellulose fiber networks by wetting them with ethyl-cyanoacrylate monomer solutions containing various suspended organic submicrometer particles or inorganic nanoparticles. Solutions can be applied on cellulosic surfaces by simple solution casting techniques or by dip coating, both being suitable for large area applications. Immediately after solvent evaporation, ethyl-cyanoacrylate starts cross-linking around cellulose fibers under ambient conditions because of naturally occurring surface hydroxyl groups and adsorbed moisture, encapsulating them with a hydrophobic polymer shell. Furthermore, by dispersing various functional particles in the monomer solutions, hydrophobic ethyl-cyanoacrylate nanocomposites with desired functionalities can be formed around the cellulose fibers. To exhibit the versatility of the method, cellulose sheets were functionalized with different ethyl-cyanoacrylate nanocomposite shells comprising submicrometer wax or polytetrafluoroethylene particles for superhydophobicity, MnFe(2)O(4) nanoparticles for magnetic activity, CdSe/ZnS quantum dots for light emission, and silver nanoparticles for antimicrobial activity. Morphological and functional properties of each system have been studied by scanning and transmission electron microscopy, detailed contact angle measurements, light emission spectra and E. coli bacterial growth measurements. A plethora of potential applications can be envisioned for this technique, such as food and industrial packaging, document protection, catalytic cellulosic membranes, textronic (electrofunctional textiles), electromagnetic devices, authentication of valuable documents, and antimicrobial wound healing products to name a few.

  8. Retrieval of aerosol properties overland and water using (A)ATSR data

    NARCIS (Netherlands)

    Leeuw, G. de; Schoemaker, R.

    2005-01-01

    The retrieval of aerosol properties using multi-spectral data provided by satellite based radiometers, has been explored by TNO since 1995. Aerosol properties that are currently retrieved using (A)ATSR data are aerosol optical depth (AOD), the variation of AOD with the wavelength expressed by the An

  9. Enclosed waters : property rights, technology and ecology in the management of water resources in Palakkad, Kerala

    NARCIS (Netherlands)

    Krishnan, J.

    2007-01-01

    This thesis is an enquiry into the persistent problem of water scarcity in the paddy growing regions in the southeastern part of Palakkad district, in the state of Kerala, in South India. It views the problem of scarcity as an outcome of the existing unsustainable and inequitable mode of water resou

  10. Water-soluble UV curable urethane methyl acrylate coating:preparation and properties

    Institute of Scientific and Technical Information of China (English)

    魏燕彦; 罗英武; 李宝芳; 李伯耿

    2004-01-01

    Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

  11. Water-soluble UV curable urethane methyl acrylate coating:preparation and properties

    Institute of Scientific and Technical Information of China (English)

    魏燕彦; 罗英武; 李宝芳; 李伯耿

    2004-01-01

    Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous solutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

  12. Mechanical and water soaking properties of medium density fiberboard with wood fiber and soybean protein adhesive.

    Science.gov (United States)

    Li, Xin; Li, Yonghui; Zhong, Zhikai; Wang, Donghai; Ratto, Jo A; Sheng, Kuichuan; Sun, Xiuzhi Susan

    2009-07-01

    Soybean protein is a renewable and abundant material that offers an alternative to formaldehyde-based resins. In this study, soybean protein was modified with sodium dodecyl sulfate (SDS) as an adhesive for wood fiber medium density fiberboard (MDF) preparation. Second-order response surface regression models were used to study the effects and interactions of initial moisture content (IMC) of coated wood fiber, press time (PT) and temperature on mechanical and water soaking properties of MDF. Results showed that IMC of coated fiber was the dominant influencing factor. Mechanical and soaking properties improved as IMC increased and reached their highest point at an IMC of 35%. Press time and temperature also had a significant effect on mechanical and water soaking properties of MDF. Second-order regression results showed that there were strong relationships between mechanical and soaking properties of MDF and processing parameters. Properties of MDF made using soybean protein adhesive are similar to those of commercial board.

  13. Property rights and water markets in Australia: An evolutionary process toward institutional reform

    Science.gov (United States)

    Pigram, John J.

    1993-04-01

    In the past decade far-reaching reforms have taken place in the Australian water industry. Extensive restructuring of water administration has been accompanied by increased evidence of willingness by public agencies to consider alternative institutional arrangements to the traditional regulatory approach to water allocation and use. In irrigated agriculture, a market-based system linked to enforceable property rights to water is seen as preferable to rule-based management of water resources. However, significant social and economic considerations and political realities constrain the unfettered operation of water markets. The challenge facing the irrigation industry in Australia is to put in place institutional arrangements which reflect the most appropriate mix of incentive-based and regulatory mechanisms for water management.

  14. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    CERN Document Server

    Gerbino, Martina; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2016-01-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the $n_s/r$ plane. We study the following neutrino properties: (i) the total neutrino mass $ M_\

  15. Discrepancies between Ideal Characteristics of a Property Tax System and Current Practice in New York.

    Science.gov (United States)

    Netzer, Dick; Berne, Robert

    1995-01-01

    Ideally, voters' and state legislatures' policy choices should underlie a property tax system that is straightforward, comprehensible, systematic, and reasonably related to policy objectives. Administration should be uniform and fair. New York State's property tax system lacks a uniform valuation standard and "circuit breaker" and has…

  16. The Current Intellectual Property Debate: A Citation-Based Analysis

    Directory of Open Access Journals (Sweden)

    Christian Linder

    2011-03-01

    Full Text Available This paper addresses the research landscape of Intellectual PropertyRights. It describes and probes the key players and the mostinfluential journal publications. While most literature reviews arequalitative, in many cases highly subjective and necessarily selective,this paper takes another course. By using Social NetworkAnalysis and the Co-Author Citation Approach it constructs aquantitative approach. The outcome is threefold. First, the workswith the most influence are identified, as are 9 sub-networks intowhich the Intellectual Property research splits. Second, the researchinstitutions and their networks are analyzed. This researchillustrates that the Intellectual Property research landscape isshaped by a handful of universities, the rest follow suit. Third, itis demonstrated that North America dominates the academic IntellectualProperty debate by far. Regions such as South Americaand Africa do not even appear in the body of knowledge. This papergives an overview of Intellectual Property research. Based onthe quantitative output further research questions can be formulated.

  17. Apparent optical properties of the Canadian Beaufort Sea – Part 1: Observational overview and water column relationships

    Directory of Open Access Journals (Sweden)

    D. Antoine

    2013-07-01

    Full Text Available A data set of radiometric measurements collected in the Beaufort Sea (Canadian Arctic in August 2009 (Malina project is analyzed in order to describe apparent optical properties (AOPs in this sea, which has been subject to dramatic environmental changes for several decades. The two properties derived from the measurements are the spectral diffuse attenuation coefficient for downward irradiance, Kd, and the spectral remote sensing reflectance, Rrs. The former controls light propagation in the upper water column. The latter determines how light is backscattered out of the water and becomes eventually observable from a satellite ocean color sensor. The data set includes offshore clear waters of the Beaufort Basin as well as highly turbid waters of the Mackenzie River plumes. In the clear waters, we show Kd values that are much larger in the ultraviolet and blue parts of the spectrum than what could be anticipated considering the chlorophyll concentration. A larger contribution of absorption by colored dissolved organic matter (CDOM is responsible for these high Kd values, as compared to other oligotrophic areas. In turbid waters, attenuation reaches extremely high values, driven by high loads of particulate materials and also by a large CDOM content. In these two extreme types of waters, current satellite chlorophyll algorithms fail. This questions the role of ocean color remote sensing in the Arctic when Rrs from only the blue and green bands are used. Therefore, other parts of the spectrum (e.g., the red should be explored if one aims at quantifying interannual changes in chlorophyll in the Arctic from space. The very peculiar AOPs in the Beaufort Sea also advocate for developing specific light propagation models when attempting to predict light availability for photosynthesis at depth.

  18. Apparent optical properties of the Canadian Beaufort Sea – Part 1: Observational overview and water column relationships

    Directory of Open Access Journals (Sweden)

    D. Antoine

    2013-03-01

    Full Text Available A data set of radiometric measurements collected in the Beaufort Sea (Canadian Arctic in August 2009 (MALINA project is analysed in order to describe apparent optical properties (AOPs in this sea, which is subject to dramatic environmental changes for several decades. The two properties derived from the measurements are the spectral diffuse attenuation coefficient for downward irradiance, Kd, and the spectral remote sensing reflectance, Rrs. The former controls light propagation in the upper water column. The latter determines how light is backscattered out of the water and becomes eventually observable from a satellite ocean colour sensor. The data set includes offshore clear waters of the Beaufort basin as well as highly turbid waters of the Mackenzie River plumes. In the clear waters, we show Kd values that are much larger in the ultraviolet and blue parts of the spectrum than what could be anticipated considering the chlorophyll concentration. A larger contribution of absorption by coloured dissolved organic matter (CDOM is responsible for this high Kd values, as compared to other oligotrophic areas. In turbid waters, attenuation reaches extremely high values, driven by high loads of particulate materials and also by a large CDOM content. In these two extreme types of waters, current satellite chlorophyll algorithms fail. This is questioning the role of ocean colour remote sensing in the Arctic when Rrs from only the blue and green bands are used. Therefore, other parts of the spectrum (e.g. the red should be explored if one aims at quantifying interannual changes in chlorophyll in the Arctic from space. The very peculiar AOPs in the Beaufort Sea also advocate for developing specific light propagation models when attempting to predict light availability for photosynthesis at depth.

  19. Effects of pulse current on properties of electrodeposited RE-Ni-W-P-SiC composite coating

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-cheng; ZHU Xiao-yun; XU Rui-dong

    2004-01-01

    Effects of pulse current on properties of electrodeposited RE-Ni-W-P-SiC composite coating were studied. The results show that hardness of the pulse current electrodeposited composite coatings is higher than that of the direct current electrodeposited composite coatings while other parameters are the same. Otherwise, the deposited velocity is higher, and wear resistance and corrosion resistance of the pulse current electrodeposited composite coatings are also improved when the average current density is 10 A/dm2 , pulse frequency is 800 Hz and duty ratio is 1: 5. The hardness of the coating as-deposited is HV500 - 700, and it reaches HV1300 after heat treatment at 400 ℃ for 1 h.

  20. Sterically stabilized water based magnetic fluids: Synthesis, structure and properties

    Science.gov (United States)

    Bica, Doina; Vékás, Ladislau; Avdeev, Mikhail V.; Marinică, Oana; Socoliuc, Vlad; Bălăsoiu, Maria; Garamus, Vasil M.

    2007-04-01

    Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

  1. Sterically stabilized water based magnetic fluids: Synthesis, structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Bica, Doina [Laboratory of Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division, Bd. Mihai Viteazul 24, 300223 Timisoara (Romania); Vekas, Ladislau [Laboratory of Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division, Bd. Mihai Viteazul 24, 300223 Timisoara (Romania) and National Centre for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Bd. Mihai Viteazul 1, 300222 Timisoara (Romania)]. E-mail: vekas@acad-tim.tm.edu.ro; Avdeev, Mikhail V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Marinica, Oana [National Centre for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Bd. Mihai Viteazul 1, 300222 Timisoara (Romania); Socoliuc, Vlad [National Institute R and D for Electrochemistry and Condensed Matter, Str. Diaconu Coressi 144, 300588 Timisoara (Romania); Balasoiu, Maria [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Garamus, Vasil M. [GKSS Research Centre, Geesthacht (Germany)

    2007-04-15

    Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

  2. Comparison of absorption properties of colored dissolved organic matter in six different case 2 water bodies

    Science.gov (United States)

    Nima, Ciren; Frette, Øyvind; Hamre, Børge; Erga, Svein Rune; Chen, Yi-Chun; Zhao, Lu; Muyimbwa, Dennis; Ssenyonga, Taddeo; Ssebiyonga, Nicolausi; Okullo, Willy; Stamnes, Knut; Stamnes, Jakob J.

    2017-02-01

    Colored Dissolved Organic Matter (CDOM) is one of the main factors controlling the penetration of solar radiation in Case 2 water and affecting satellite-based estimation of ocean color. We present absorption properties of CDOM sampled in 6 water bodies including three in Norway (Røst coastal water, Samnangerfjord, Lysefjord), two in China (Bohai Sea, Lake Namtso), and one in Africa (Lake Victoria). These locations, which range from near the equator to subarctic regions, include water types from oligotrophic to eutrophic, and altitudes from sea level to 4,700 m above sea level.

  3. The pharmacological properties of K+ currents from rabbit isolated aortic smooth muscle cells.

    OpenAIRE

    Halliday, F. C.; Aaronson, P. I.; Evans, A. M.; Gurney, A M

    1995-01-01

    1. Using the whole-cell patch-clamp technique, the effects of several K+ channel blocking drugs on K+ current recorded from rabbit isolated aortic smooth muscle cells were investigated. 2. Upon depolarization from -80 mV, outward K+ current composed of several distinct components were observed: a transient, 4-aminopyridine (4-AP)-sensitive component (I1) and a sustained component (Isus), comprising a 4-AP-sensitive delayed rectifier current (IK(V)), and a noisy current which was sensitive to ...

  4. Human-water interface in hydrological modelling: current status and future directions

    Science.gov (United States)

    Wada, Yoshihide; Bierkens, Marc F. P.; de Roo, Ad; Dirmeyer, Paul A.; Famiglietti, James S.; Hanasaki, Naota; Konar, Megan; Liu, Junguo; Müller Schmied, Hannes; Oki, Taikan; Pokhrel, Yadu; Sivapalan, Murugesu; Troy, Tara J.; van Dijk, Albert I. J. M.; van Emmerik, Tim; Van Huijgevoort, Marjolein H. J.; Van Lanen, Henny A. J.; Vörösmarty, Charles J.; Wanders, Niko; Wheater, Howard

    2017-08-01

    Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion) and at various scales (from a watershed to the globe). During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global water resource assessments. Shortly thereafter, in order to analyse the human perturbation on terrestrial water resources, the first generation of large-scale hydrological models (LHMs) was produced. However, at this early stage few models considered the interaction between terrestrial water fluxes and human activities, including water use and reservoir regulation, and even fewer models distinguished water use from surface water and groundwater resources. Since the early 2000s, a growing number of LHMs have incorporated human impacts on the hydrological cycle, yet the representation of human activities in hydrological models remains challenging. In this paper we provide a synthesis of progress in the development and application of human impact modelling in LHMs. We highlight a number of key challenges and discuss possible improvements in order to better represent the human-water interface in hydrological models.

  5. Human–water interface in hydrological modelling: current status and future directions

    Directory of Open Access Journals (Sweden)

    Y. Wada

    2017-08-01

    Full Text Available Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion and at various scales (from a watershed to the globe. During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global water resource assessments. Shortly thereafter, in order to analyse the human perturbation on terrestrial water resources, the first generation of large-scale hydrological models (LHMs was produced. However, at this early stage few models considered the interaction between terrestrial water fluxes and human activities, including water use and reservoir regulation, and even fewer models distinguished water use from surface water and groundwater resources. Since the early 2000s, a growing number of LHMs have incorporated human impacts on the hydrological cycle, yet the representation of human activities in hydrological models remains challenging. In this paper we provide a synthesis of progress in the development and application of human impact modelling in LHMs. We highlight a number of key challenges and discuss possible improvements in order to better represent the human–water interface in hydrological models.

  6. Electric pulse current stimulation increases electrophysiological properties of If current reconstructed in mHCN4-transfected canine mesenchymal stem cells.

    Science.gov (United States)

    Feng, Yuanyuan; Luo, Shouming; Yang, Pan; Song, Zhiyuan

    2016-04-01

    The 'funny' current, also known as the If current, play a crucial role in the spontaneous diastolic depolarization of sinoatrial node cells. The If current is primarily induced by the protein encoded by the hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) gene. The functional If channel can be reconstructed in canine mesenchymal stem cells (cMSCs) transfected with mouse HCN4 (mHCN4). Biomimetic studies have shown that electric pulse current stimulation (EPCS) can promote cardiogenesis in cMSCs. However, whether EPCS is able to influence the properties of the If current reconstructed in mHCN4-transfected cMSCs remains unclear. The present study aimed to investigate the effects of EPCS on the If current reconstructed in mHCN4-transfected cMSCs. The cMSCs were transfected with the lentiviral vector pLentis-mHCN4-GFP. Following transfection, these cells were divided into two groups: mHCN4-transfected cMSCs (group A), and mHCN4-transfected cMSCs induced by EPCS (group B). Using a whole cell patch-clamp technique, the If current was recorded, and group A cMSCs showed significant time and voltage dependencies and sensitivity to extracellular Cs+. The half-maximal activation (V1/2) value was -101.2±4.6 mV and the time constant of activation was 324±41 msec under -160 mV. In the group B cells the If current increased obviously and activation curve moved to right. The absolute value of V1/2 increased significantly to -92.4±4.8 mV (P<0.05), and the time constant of activation diminished under the same command voltage (251±44 vs. 324±41, P<0.05). In addition, the mRNA and protein expression levels of HCN4, connexin 43 (Cx43) and Cx45 were upregulated in group B compared with group A, as determined by reverse transcription-quantitative polymerase chain reaction and western blot analyses. Transmission electron micrographs also confirmed the increased gap junctions in group B. Collectively, these results indicated that reconstructed If channels may have a

  7. Structure/property relationships in polymer membranes for water purification and energy applications

    Science.gov (United States)

    Geise, Geoffrey

    Providing sustainable supplies of purified water and energy is a critical global challenge for the future, and polymer membranes will play a key role in addressing these clear and pressing global needs for water and energy. Polymer membrane-based processes dominate the desalination market, and polymer membranes are crucial components in several rapidly developing power generation and storage applications that rely on membranes to control rates of water and/or ion transport. Much remains unknown about the influence of polymer structure on intrinsic water and ion transport properties, and these relationships must be developed to design next generation polymer membrane materials. For desalination applications, polymers with simultaneously high water permeability and low salt permeability are desirable in order to prepare selective membranes that can efficiently desalinate water, and a tradeoff relationship between water/salt selectivity and water permeability suggests that attempts to prepare such materials should rely on approaches that do more than simply vary polymer free volume. One strategy is to functionalize hydrocarbon polymers with fixed charge groups that can ionize upon exposure to water, and the presence of charged groups in the polymer influences transport properties. Additionally, in many emerging energy applications, charged polymers are exposed to ions that are very different from sodium and chloride. Specific ion effects have been observed in charged polymers, and these effects must be understood to prepare charged polymers that will enable emerging energy technologies. This presentation discusses research aimed at further understanding fundamental structure/property relationships that govern water and ion transport in charged polymer films considered for desalination and electric potential field-driven applications that can help address global needs for clean water and energy.

  8. Bleaching Susceptibility and Recovery of Colombian Caribbean Corals in Response to Water Current Exposure and Seasonal Upwelling

    Science.gov (United States)

    Bayraktarov, Elisa; Pizarro, Valeria; Eidens, Corvin; Wilke, Thomas; Wild, Christian

    2013-01-01

    Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs. PMID:24282551

  9. Bleaching susceptibility and recovery of Colombian Caribbean corals in response to water current exposure and seasonal upwelling.

    Science.gov (United States)

    Bayraktarov, Elisa; Pizarro, Valeria; Eidens, Corvin; Wilke, Thomas; Wild, Christian

    2013-01-01

    Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs.

  10. Bleaching susceptibility and recovery of Colombian Caribbean corals in response to water current exposure and seasonal upwelling.

    Directory of Open Access Journals (Sweden)

    Elisa Bayraktarov

    Full Text Available Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34% compared to the exposed site (8%. Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (<10% at both sites was observed, but corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs.

  11. Molecular dynamics simulation of liquid water confined inside graphite channels: dielectric and dynamical properties.

    Science.gov (United States)

    Martí, J; Nagy, G; Guàrdia, E; Gordillo, M C

    2006-11-30

    Electric and dielectric properties and microscopic dynamics of liquid water confined between graphite slabs are analyzed by means of molecular dynamics simulations for several graphite-graphite separations at ambient conditions. The electric potential across the interface shows oscillations due to water layering, and the overall potential drop is about -0.28 V. The total dielectric constant is larger than the corresponding value for the bulklike internal region of the system. This is mainly due to the preferential orientations of water nearest the graphite walls. Estimation of the capacitance of the system is reported, indicating large variations for the different adsorption layers. The main trend observed concerning water diffusion is 2-fold: on one hand, the overall diffusion of water is markedly smaller for the closest graphite-graphite separations, and on the other hand, water molecules diffuse in interfaces slightly slower than those in the bulklike internal areas. Molecular reorientational times are generally larger than those corresponding to those of unconstrained bulk water. The analysis of spectral densities revealed significant spectral shifts, compared to the bands in unconstrained water, in different frequency regions, and associated to confinement effects. These findings are important because of the scarce information available from experimental, theoretical, and computer simulation research into the dielectric and dynamical properties of confined water.

  12. Densities, Viscosities and Derived Thermophysical Properties of Water-Saturated Imidazolium-Based Ionic Liquids

    Science.gov (United States)

    Martins, Mónia A. R.; Neves, Catarina M. S. S.; Kurnia, Kiki A.; Carvalho, Pedro J.; Rocha, Marisa A. A.; Santos, Luís M. N. B. F.; Pinho, Simão P.; Freire, Mara G.

    2016-01-01

    In order to evaluate the impact of the alkyl side chain length and symmetry of the cation on the thermophysical properties of water-saturated ionic liquids (ILs), densities and viscosities as a function of temperature were measured at atmospheric pressure and in the (298.15 to 363.15) K temperature range, for systems containing two series of bis(trifluoromethylsulfonyl)imide-based compounds: the symmetric [CnCnim][NTf2] (with n = 1-8 and 10) and asymmetric [CnC1im][NTf2] (with n = 2-5, 7, 9 and 11) ILs. For water-saturated ILs, the density decreases with the increase of the alkyl side chain length while the viscosity increases with the size of the aliphatic tails. The saturation water solubility in each IL was further estimated with a reasonable agreement based on the densities of water-saturated ILs, further confirming that for the ILs investigated the volumetric mixing properties of ILs and water follow a near ideal behaviour. The water-saturated symmetric ILs generally present lower densities and viscosities than their asymmetric counterparts. From the experimental data, the isobaric thermal expansion coefficient and energy barrier were also estimated. A close correlation between the difference in the energy barrier values between the water-saturated and pure ILs and the water content in each IL was found, supporting that the decrease in the viscosity of ILs in presence of water is directly related with the decrease of the energy barrier. PMID:27642223

  13. Variations of optic properties of water under action of static magnetic field

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Effects of static magnetic field on optic properties of water are investigated by infrared spectroscopy, ultraviolet spectroscopy and X-ray diffraction, respectively. The ultraviolet spectroscopy experiments show the changes of properties of water under action of static magnetic field, in the region of 191 to 400 nm. The infrared experiment shows that the water exposed in a magnetic field had saturation and memory effects. The magnetized effects increased with increasing exposed time, but were weakened with increasing of time when the magnetic field was removed. In the X-ray experiment, the strength of diffraction increased also, after the water was exposed in magnetic field. Meanwhile, the shift of peak and increase of strength of X-ray diffraction of magnetized water added with nanoFe3O4 occurred as compared with that of pure water added with nano Fe3O4. This result suggests that the magnetized water has certain magnetism. Finally, these phenomena are simply explained by the molecular structure of water and the theory of magnetization of water.

  14. Which properties of a spanning network of hydration water enable biological functions?

    Science.gov (United States)

    Brovchenko, Ivan; Oleinikova, Alla

    2008-12-22

    The central role of water in biological functions is well-recognized, but numerous questions concerning the physical mechanisms behind the importance of water for life remain unanswered. Water in biosystems exists mainly as hydration water. Analysis of the phase diagram of hydration water shows that biological functions are possible only when the surfaces of biomolecules are covered by spanning hydrogen-bonded networks of hydration water. The comparative studies of the various properties of hydrated biosystems in the presence and in the absence of a spanning water network should clarify its specific physical properties, which are crucial for biological functions. Herein, we summarize the recent progress in these studies. The biological activity of the living organisms is maximal in a narrow temperature interval, where the spanning network of hydration water breaks up with heating via a percolation transition. The entropy of the hydration water related to the diversity of cluster size diverges at this percolation threshold. The possible role of this phenomenon in life processes is discussed.

  15. Water scarcity in the Spanish part of the Douro basin: current status and future scenarios

    Science.gov (United States)

    Jesús Vicente, David; Rodriguez-Sinobas, Leonor

    2016-04-01

    In general in Europe only 5 % of renewable freshwater resources is abstracted each year however, water availability and populations are unevenly distributed. Except in some northern and sparsely-populated areas that possess abundant resources, water scarcity occurs in many areas of Europe, particularly in the Mediterranean countries. It has been accentuated in the past decades by the increase of drought periods due to climate change. In this regard, the European Policy has addressed both drought (related to natural processes) and water scarcity (influenced by human activity) through several Directives and Communications. These have considered a common water stress indicators such as the Water Exploitation Index (WEI) and its upgraded version WEI+. They quantify the percentage of total freshwater used compared to the total renewable freshwater resources available. Their estimations help the stakeholders identify territories vulnerable to human activity pressure on water resources, and hence prone to suffer problems of water stress. The index WEI+ estimates better than WEI the actual balance between renewable water resources and water consumption, since it include the returns from water uses in its calculation. In addition, the European Community is still working on issues dealing with the temporal and spatial scaling and have suggested to adopt the river basin and monthly temporal resolution instead of the national scale and annual basis considered in the former documents. Within this context, this study assesses the water scarcity in the Spanish part of the Douro basin estimated by the WEI+ index. According to previous studies and depending on the specific period selected, this basin is near 'water stress'. In order to clarify this issue, the WEI+ index has been estimated. A detailed methodology for its calculation is presented which uses information from the water resources management model 'Aquatool' and its simulation module SIMGES which is widely applied in

  16. Next-generation sequencing (NGS) for assessment of microbial water quality: current progress, challenges, and future opportunities.

    Science.gov (United States)

    Tan, BoonFei; Ng, Charmaine; Nshimyimana, Jean Pierre; Loh, Lay Leng; Gin, Karina Y-H; Thompson, Janelle R

    2015-01-01

    Water quality is an emergent property of a complex system comprised of interacting microbial populations and introduced microbial and chemical contaminants. Studies leveraging next-generation sequencing (NGS) technologies are providing new insights into the ecology of microbially mediated processes that influence fresh water quality such as algal blooms, contaminant biodegradation, and pathogen dissemination. In addition, sequencing methods targeting small subunit (SSU) rRNA hypervariable regions have allowed identification of signature microbial species that serve as bioindicators for sewage contamination in these environments. Beyond amplicon sequencing, metagenomic and metatranscriptomic analyses of microbial communities in fresh water environments reveal the genetic capabilities and interplay of waterborne microorganisms, shedding light on the mechanisms for production and biodegradation of toxins and other contaminants. This review discusses the challenges and benefits of applying NGS-based methods to water quality research and assessment. We will consider the suitability and biases inherent in the application of NGS as a screening tool for assessment of biological risks and discuss the potential and limitations for direct quantitative interpretation of NGS data. Secondly, we will examine case studies from recent literature where NGS based methods have been applied to topics in water quality assessment, including development of bioindicators for sewage pollution and microbial source tracking, characterizing the distribution of toxin and antibiotic resistance genes in water samples, and investigating mechanisms of biodegradation of harmful pollutants that threaten water quality. Finally, we provide a short review of emerging NGS platforms and their potential applications to the next generation of water quality assessment tools.

  17. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    Science.gov (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  18. Analysis of the Current Water Environment Quality of Xiaoquan Tributary in Ba’nan District

    Institute of Scientific and Technical Information of China (English)

    Shuang; HU

    2015-01-01

    With the class V water standards of Surface Water Quality Standards( GB3838-2002) as a basis for evaluation,this paper monitors the water quality of Hongqi Village and Hongxing Village monitoring sections in Xiaoquan tributary of Huaxi River,and uses the single factor index method for evaluation.The monitoring results show that the water quality of the two sections falls within inferior class V,and Xiaoquan tributary can not meet the water functional requirements.The main reason for pollution lies in the pollution from the upstream sewage,and it is recommended to strengthen inter-regional water pollution control coordination mechanism and effectively address river pollution problems.

  19. Properties of current sheet thinning at x ˜- 10 to -12 RE

    Science.gov (United States)

    Artemyev, A. V.; Angelopoulos, V.; Runov, A.; Petrokovich, A. A.

    2016-07-01

    We report on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations of current sheet thinning in Earth's magnetotail at around x =- 10 to -12 Earth radii. The THEMIS spacecraft configuration in October-December 2015 allows us to construct both gradients that contribute to the cross-tail current density jy=μ0-1(∂Bx/∂z-∂Bz/∂x) (GSM coordinates). For 17 events when the spacecraft observed a gradual Bz decrease and jy increase, we find the following average scaling relations: for the current density jy˜Bz-7/4, for the lobe magnetic field BL˜Bz-1/4, and for the plasma density ni˜Bz-3/4. We show that the temperature of ions and electrons decreases and the plasma pressure gradient ∂p/∂x rapidly increases during current sheet thinning. The scale Lx=(∂lnp/∂x)-1 decreases a few thousand kilometers. We also consider current carriers in thinning current sheets: both ion and electron current-dominated current sheets, preferentially located near dusk and midnight, respectively, are found.

  20. Characterization of dynamic change of Fan-delta reservoir properties in water-drive development

    Energy Technology Data Exchange (ETDEWEB)

    Wu Shenghe; Xiong Qihua; Liu Yuhong [Univ. of Petroleum Changping, Beijing (China)

    1997-08-01

    Fan-delta reservoir in Huzhuangji oil field of east China, is a typical highly heterogeneous reservoir. The oil field has been developed by water-drive for 10 years, but the oil recovery is less than 12%, and water cut is over 90%, resulting from high heterogeneity and serious dynamic change of reservoir properties. This paper aims at the study of dynamic change of reservoir properties in water-drive development. Through quantitative imaging analysis and mercury injection analysis of cores from inspection wells, the dynamic change of reservoir pore structure in water-drive development was studied. The results show that the {open_quotes}large pore channels{close_quotes} develop in distributary channel sandstone and become larger in water-drive development, resulting in more serious pore heterogeneity. Through reservoir sensitivity experiments, the rock-fluid reaction in water-drive development is studied. The results show the permeability of some distal bar sandstone and deserted channel sandstone becomes lower due to swelling of I/S clay minerals in pore throats. OD the other hand, the permeability of distributary channel and mouth bar sandstone become larger because the authigenic Koalinites in pore throats are flushed away with the increase of flow rate of injection water. Well-logging analysis of flooded reservoirs are used to study the dynamic change of reservoir properties in various flow units. The distribution of remaining oil is closely related to the types and distribution of flow units.

  1. Analysis of (unsustainability of the current water: Supply strategy in Serbia

    Directory of Open Access Journals (Sweden)

    Dokmanović Petar B.

    2015-01-01

    Full Text Available Planned construction of more than 30 dams, lake-reservoirs and regional water-supply systems, are the basis of long-term water-supply strategy of the Republic of Serbia. The strategy was adopted in the 1970s and some experiences so far indicate the necessity of revision and rationalization, because of the following: - Quantity and effects of realized works are far lower than planned. The main reasons is the lack of finance as well as some systemic weaknesses shown in the processes of construction and management of the water systems. - Forecasted demographic growth as well as water consumption rates, dating back to 1970s-80s, are significantly oversized. -Global and domestic experiences in the field of construction and management of artificial lake- reservoirs indicate numerous techno-economic and environmental risks and negative consequences. - So far results of hydrogeological researches and groundwater capturing in Serbia show that this resource is a very good basis for municipal water-supply in the most part of the territory. - Water pipe lines are, on average, in very poor condition. Water supply deficits are recorded frequently because of enormous losses in distribution. The rationalization means an approach suited to the real water-supply need as well as to the financial and organizational capabilities. Orientation to the available groundwater resources is the basic guideline. One of the priorities is repairing of water pipe networks. This approach allows: - Much faster solving of water-supply problems - Big financial savings in the construction of dams, reservoirs, regional pipelines, raw water treatment plants as well as in the space adaptation and maintenance of regional water-supply systems.

  2. Deriving optical properties of Mahakam Delta coastal waters, Indonesia using in situ measurements and ocean color model inversion

    NARCIS (Netherlands)

    Budhiman, S.; Salama, M.S.; Vekerdy, Z.; Verhoef, W.

    2012-01-01

    The development of an operational water quality monitoring method based on remote sensing data requires information on the apparent and inherent optical properties of water (AOP and IOP respectively). This study was performed to determine the apparent and inherent optical properties of coastal water

  3. Deriving optical properties of Mahakam Delta coastal waters, Indonesia using in situ measurements and ocean color model inversion

    NARCIS (Netherlands)

    Budhiman, S.; Salama, M.S.; Vekerdy, Z.; Verhoef, W.

    2012-01-01

    The development of an operational water quality monitoring method based on remote sensing data requires information on the apparent and inherent optical properties of water (AOP and IOP respectively). This study was performed to determine the apparent and inherent optical properties of coastal water

  4. Current meter data from moored current meter casts in the Coastal Waters of Washington/Oregon as part of the Land-Margin Ecosystem Research (LEML) project, 06 May 1997 - 19 October 1997 (NODC Accession 9800193)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of Washington/Oregon from May 6, 1997 to October 19, 1997. Data were...

  5. Current meter data from moored current meter casts in the Coastal Waters of SE Alaska/Brit.Colum. as part of the Long-Range Effects Program Puget Sound project from 15 March 1983 - 01 November 1983 (NODC Accession 8600321)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of SE Alaska/Brit.Colum. from March 15, 1983 to November 1, 1983. Data were...

  6. Current meter data from moored current meter casts in the Coastal Waters of Hawaii as part of the Ocean Thermal Energy Conversion (OTEC) project from 23 September 1980 - 01 December 1980 (NODC Accession 8100469)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of Hawaii from September 23, 1980 to December 1, 1980. Data were submitted...

  7. Current meter data from moored current meter casts in the Coastal Waters of S. Alaska as part of the Fisheries-Oceanography Cooperative Investigations (FOCI) project from 21 August 1984 - 01 July 1985 (NCEI Accession 8700053)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of S. Alaska from August 21, 1984 to July 1, 1985. Data were submitted by...

  8. Pharmacological analysis of the activation and receptor properties of the tonic GABA(CR current in retinal bipolar cell terminals.

    Directory of Open Access Journals (Sweden)

    Stefanie M Jones

    Full Text Available GABAergic inhibition in the central nervous system (CNS can occur via rapid, transient postsynaptic currents and via a tonic increase in membrane conductance, mediated by synaptic and extrasynaptic GABA(A receptors (GABA(ARs respectively. Retinal bipolar cells (BCs exhibit a tonic current mediated by GABA(CRs in their axon terminal, in addition to synaptic GABA(AR and GABA(CR currents, which strongly regulate BC output. The tonic GABA(CR current in BC terminals (BCTs is not dependent on vesicular GABA release, but properties such as the alternative source of GABA and the identity of the GABA(CRs remain unknown. Following a recent report that tonic GABA release from cerebellar glial cells is mediated by Bestrophin 1 anion channels, we have investigated their role in non-vesicular GABA release in the retina. Using patch-clamp recordings from BCTs in goldfish retinal slices, we find that the tonic GABA(CR current is not reduced by the anion channel inhibitors NPPB or flufenamic acid but is reduced by DIDS, which decreases the tonic current without directly affecting GABA(CRs. All three drugs also exhibit non-specific effects including inhibition of GABA transporters. GABA(CR ρ subunits can form homomeric and heteromeric receptors that differ in their properties, but BC GABA(CRs are thought to be ρ1-ρ2 heteromers. To investigate whether GABA(CRs mediating tonic and synaptic currents may differ in their subunit composition, as is the case for GABA(ARs, we have examined the effects of two antagonists that show partial ρ subunit selectivity: picrotoxin and cyclothiazide. Tonic and synaptic GABA(CR currents were differentially affected by both drugs, suggesting that a population of homomeric ρ1 receptors contributes to the tonic current. These results extend our understanding of the multiple forms of GABAergic inhibition that exist in the CNS and contribute to visual signal processing in the retina.

  9. Photophysical Properties and Singlet Oxygen Generation Efficiencies of Water-Soluble Fullerene Nanoparticles

    Science.gov (United States)

    Stasheuski, Alexander S; Galievsky, Victor A; Stupak, Alexander P; Dzhagarov, Boris M; Choi, Mi Jin; Chung, Bong Hyun; Jeong, Jin Young

    2014-01-01

    As various fullerene derivatives have been developed, it is necessary to explore their photophysical properties for potential use in photoelectronics and medicine. Here, we address the photophysical properties of newly synthesized water-soluble fullerene-based nanoparticles and polyhydroxylated fullerene as a representative water-soluble fullerene derivative. They show broad emission band arising from a wide-range of excitation energies. It is attributed to the optical transitions from disorder-induced states, which decay in the nanosecond time range. We determine the kinetic properties of the singlet oxygen (1O2) luminescence generated by the fullerene nanoparticles and polyhydroxylated fullerene to consider the potential as photodynamic agents. Triplet state decay of the nanoparticles was longer than 1O2 lifetime in water. Singlet oxygen quantum yield of a series of the fullerene nanoparticles is comparably higher ranging from 0.15 to 0.2 than that of polyhydroxylated fullerene, which is about 0.06. PMID:24893622

  10. Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

    Directory of Open Access Journals (Sweden)

    David D’Melo

    2012-07-01

    Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

  11. Some Considerations on an Underwater Robotic Manipulator Subjected to the Environmental Disturbances Caused by Water Current

    Directory of Open Access Journals (Sweden)

    Kołodziejczyk Waldemar

    2016-03-01

    Full Text Available The objective of this paper is to discuss some of the issues associated with environmental load on the three-link serial manipulator caused by underwater current. We have conducted CFD simulations to investigate hydrodynamic effects induced by changing current direction and changing with time current speed in order to better understand the physics of the problem. The results are presented in terms of moments of hydrodynamic forces plotted against relative position of the current and the robotic arm. Time history of hydrodynamic loads according to periodically changing current speed is presented and discussed.

  12. Characterization and electrical properties of chitosan for waste water treatment

    Science.gov (United States)

    Saengkaew, Phannee; Chantanachai, Kanittha; Cheewajaroen, Kulthawat; Nimsiri, Woraporn

    2016-05-01

    Chitosan extracted from shrimp shell waste was characterized in order to use for the industrial wastewater treatment. By XRF technique, the qualitative and semi-quantitative analyses of pure chitosan were performed with the relative compositions of Ca, Mg, Si, Fe, Al, and Na of 0.321%, 0.738%, 0.713%, 0.363%, 0.338%, and 3.858%, respectively. In the case of two types of the contaminated chitosan from the wastewater treatment before and after a process of a primary H2O2-treatment, the relative compositions of Ca, Mg, Si and Fe were obtained with an increasing of 0.356%, 1.321%, 1.536%, 0.451% and 0.406%, 1.105%, 1.178%, 0.591%, respectively. This shows that the suspended materials in the wastewater were absorbed by chitosan. By I-V Measurements, the across-through voltage of the pure chitosan disc was 0.245V±0.053 at the applied voltage of 17V, and resistance of 53.9MΩ ±10.3 at the applied voltage of 590V. After the utilization for the wastewater treatment, the across voltage of chitosan discs from two cases were 0.133V±0.047 and 0.223V±0.063, and the resistance of 122.8MΩ ±16.1 and 24.8MΩ ±5.1. The used chitosan has a lower conductivity because of a decreasing in the chitosan's electrical dipoles by combining with the suspended ions in the wastewater. Moreover, the adsorption efficiencies of chitosan for formaldehyde in the wastewater of two cases were 31.08% and 25.40%. In summary, chitosan is efficiently utilized in the wastewater treatment by absorption of the suspended materials and formaldehyde due to its molecular structure providing a good electrical property.

  13. Influence of Composite Phosphate Inorganic Antibacterial Materials Containing Rare Earth on Activated Water Property of Ceramics

    Institute of Scientific and Technical Information of China (English)

    梁金生; 梁广川; 祁洪飞; 吴子钊; 冀志江; 金宗哲

    2004-01-01

    Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of 17O-NMR for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate.

  14. Ion current behaviors of mesoporous zeolite-polymer composite nanochannels prepared by water-assisted self-assembly.

    Science.gov (United States)

    Zhang, Wenjuan; Meng, Zheyi; Zhai, Jin; Heng, Liping

    2014-04-07

    Inspired by the asymmetry of biological ion channels in structure and composition, we designed a novel type of artificial asymmetric nanochannels based on mesoporous zeolite (MCM-41) and polyimide (PI) by water-assisted self-assembly. Meanwhile, we studied ionic current behaviors and rectifying characteristics of the mesoporous zeolite-polymer composite nanochannels.

  15. Miscibility of eudragit/chitosan polymer blend in water determined by physical property measurements.

    Science.gov (United States)

    Haque, Sk Ershadul; Sheela, A

    2013-01-30

    The interest in the preparation and application of polymeric blends is growing since they can exhibit properties of great industrial interest. The current study focuses on the preparation of polymeric blends of varying compositions of eudragit and chitosan and their miscibility studies. The preparation was carried out by using ethanol and 1% acetic acid in water. FT-IR spectra reveal the possibilities of chemical interactions between eudragit/chitosan. The miscibility of polymeric blend at different composition has been investigated by viscosity, ultrasonic velocity, density, refractive index and adiabatic compressibility values measured at two different temperatures 30 °C and 40 °C. The interaction parameters ΔB, μ and α, were determined from viscosity data. From the values observed, it is found that the blend is miscible in all compositions at 30 °C whereas at 40 °C, it seems to be immiscible in certain compositions. It is found that the blend is miscible, when the chitosan concentration is more than 70% (v/v) at both the temperatures and also observed that variation of temperature has no effect on the miscibility of eudragit/chitosan blend.

  16. [Impact of reclaimed water irrigation on soil chemical properties and culturable microorganisms ].

    Science.gov (United States)

    Gong, Xue; Wang, Ji-hua; Guan, Jian-fei; Yang, Xue-chen; Chen, Dai-ci

    2014-09-01

    This research used batch soil column experiment to study the effects of irrigating with reclaimed water and tap water on the soil chemical properties and culturable microorganisms. The results indicated that reclaimed water could markedly increase the soil organic material (OM) and total nitrogen (TN) content, but it had no obvious effect on total phosphorus (TP), available phosphorus (AP) and pH value. Reclaimed water irrigation could significantly enhance the amounts of surface soil bacteria and actinomycetes at a depth of 0-20 cm, but it had little effect on the biomass of 20-40 cm and 40-60 cm soil layers. The dominant bacteria in tap water irrigation area was the genus Bacillus whereas that of reclaimed water irrigation area was the genus Acinetobacter. Tap water irrigation area had four endemic genera and reclaimed water irrigation area had six endemic genera. Reclaimed water had no obvious effect on the microbial community Shannon diversity of 0-20 cm soil layer, while it decreased Pielou evenness index, and improved Margalef richness index. Through SPSS 17. 0 correlation analysis between soil microbes quantity and soil chemical properties, it was shown that the soil microbes quantity was positively correlated with OM, TN, TP and AP, but negatively correlated with soil water content (SWC) and pH value. Based on CANOCO 4.5 detrended correspondence analysis (DCA) and redundancy analysis (RDA) between soil microbes species and soil chemical properties, it was shown that AP had the strongest correlation with the microbial community (P = 0.002). TN and TP had larger impact on Streptococcus, Aeromonas and Neisseria. OM and AP had larger impact on Aerococcus, Planococcus and Halobacterium.

  17. Diffusive and quantum effects of water properties in different states of matter.

    Science.gov (United States)

    Yeh, Kuan-Yu; Huang, Shao-Nung; Chen, Li-Jen; Lin, Shiang-Tai

    2014-07-28

    The enthalpy, entropy, and free energy of water are important physical quantities for understanding many interesting phenomena in biological systems. However, conventional approaches require different treatments to incorporate quantum and diffusive effects of water in different states of matter. In this work, we demonstrate the use of the two-phase thermodynamic (2PT) model as a unified approach to obtain the properties of water over the whole phase region of water from short (∼20 ps) classical molecular dynamics trajectories. The 2PT model provides an effective way to separate the diffusive modes (gas-like component) from the harmonic vibrational modes (solid-like component) in the vibrational density of states (DoS). Therefore, both diffusive and quantum effect can be properly accounted for water by applying suitable statistical mechanical weighting functions to the DoS components. We applied the 2PT model to systematically examine the enthalpy, entropy, and their temperature dependence of five commonly used rigid water models. The 2PT results are found to be consistent with those obtained from more sophisticated calculations. While the thermodynamic properties determined from different water models are largely similar, the phase boundary determined from the equality of free energy is very sensitive to the small inaccuracy in the values of enthalpy and absolute entropy. The enthalpy, entropy, and diffusivity of water are strongly interrelated, which challenge further improvement of rigid water model via parameter fitting. Our results show that the 2PT is an efficient method for studying the properties of water under various chemical and biological environments.

  18. WETLANDS AND WATER QUALITY TRADING: REVIEW OF CURRENT SCIENCE AND ECONOMIC PRACTICES WITH SELECTED CASE STUDIES

    Science.gov (United States)

    The study evaluates the technical, economic, and administrative aspects of establishing water quality trading (WQT) programs where the nutrient removal capacity of wetlands is used to improve water quality. WQT is a potentially viable approach for wastewater dischargers to cost-e...

  19. Cooling of Water in a Flask: Convection Currents in a Fluid with a Density Maximum

    Science.gov (United States)

    Velasco, S.; White, J. A.; Roman, F. L.

    2010-01-01

    The effect of density inversion on the convective flow of water in a spherical glass flask cooled with the help of an ice-water bath is shown. The experiment was carried out by temperature measurements (cooling curves) taken at three different heights along the vertical diameter of the flask. Flows inside the flask are visualized by seeding the…

  20. Current and future water issues in the Oldman River Basin of Alberta, Canada.

    Science.gov (United States)

    Byrne, J; Kienzle, S; Johnson, D; Duke, G; Gannon, V; Selinger, B; Thomas, J

    2006-01-01

    Long-term trends in alpine and prairie snow pack accumulation and melt are affecting streamflow within the Oldman River Basin in southern Alberta, Canada. Unchecked rural and urban development also has contributed to changes in water quality, including enhanced microbial populations and increased waterborne pathogen occurrence. In this study we look at changing environment within the Oldman River Basin and its impact on water quality and quantity. The cumulative effects include a decline in net water supplies, and declining quality resulting in increased risk of disease. Our data indicates that decreases in the rate of flow of water can result in sedimentation of bacterial contaminants within the water column. Water for ecosystems, urban consumption, recreation and distribution through irrigation is often drawn from waterholding facilities such as dams and weirs, and concern must be expressed over the potential for contaminate build-up and disproportionate potential of these structures to pose a risk to human and animal health. With disruption of natural flow rates for water resulting from environmental change such as global warming and/or human intervention, increased attention needs to be paid to use of best management practices to protect source water supplies.

  1. Cooling of Water in a Flask: Convection Currents in a Fluid with a Density Maximum

    Science.gov (United States)

    Velasco, S.; White, J. A.; Roman, F. L.

    2010-01-01

    The effect of density inversion on the convective flow of water in a spherical glass flask cooled with the help of an ice-water bath is shown. The experiment was carried out by temperature measurements (cooling curves) taken at three different heights along the vertical diameter of the flask. Flows inside the flask are visualized by seeding the…

  2. WETLANDS AND WATER QUALITY TRADING: REVIEW OF CURRENT SCIENCE AND ECONOMIC PRACTICES WITH SELECTED CASE STUDIES

    Science.gov (United States)

    The study evaluates the technical, economic, and administrative aspects of establishing water quality trading (WQT) programs where the nutrient removal capacity of wetlands is used to improve water quality. WQT is a potentially viable approach for wastewater dischargers to cost-e...

  3. A TECHNICAL ASSESSMENT OF THE CURRENT WATER POLICY BOUNDARY AT U.S. DEPARTMENT OF ENERGY, PADUCAH GASEOUS DIFFUSION PLANT, PADUCAH, KENTUCKY

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-13

    In 1988, groundwater contaminated with trichloroethene (TCE) and technetium-99 (Tc-99) was identified in samples collected from residential water wells withdrawing groundwater from the Regional Gravel Aquifer (RGA) north of the Paducah Gaseous Diffusion Plant (PGDP) facility. In response, the U.S. Department of Energy (DOE) provided temporary drinking water supplies to approximately 100 potentially affected residents by initially supplying bottled water, water tanks, and water-treatment systems, and then by extending municipal water lines, all at no cost, to those persons whose wells could be affected by contaminated groundwater. The Water Policy boundary was established in 1993. In the Policy, DOE agreed to pay the reasonable monthly cost of water for homes and businesses and, in exchange, many of the land owners signed license agreements committing to cease using the groundwater via rural water wells. In 2012, DOE requested that Oak Ridge Associated Universities (ORAU), managing contractor of Oak Ridge Institute for Science and Education (ORISE), provide an independent assessment of the quality and quantity of the existing groundwater monitoring data and determine if there is sufficient information to support a modification to the boundary of the current Water Policy. As a result of the assessment, ORAU concludes that sufficient groundwater monitoring data exists to determine that a shrinkage and/or shift of the plume(s) responsible for the initial development of this policy has occurred. Specifically, there is compelling evidence that the TCE plume is undergoing shrinkage due to natural attenuation and associated degradation. The plume shrinkage (and migration) has also been augmented in local areas where large volumes of groundwater were recovered by pump-and treat remedial systems along the eastern and western boundaries of the Northwest Plume, and in other areas where pump-and-treat systems have been deployed by DOE to remove source contaminants. The

  4. Effects of supercritical water and mechanochemical grinding treatments on physicochemical properties of chitin.

    Science.gov (United States)

    Osada, Mitsumasa; Miura, Chika; Nakagawa, Yuko S; Kaihara, Mikio; Nikaido, Mitsuru; Totani, Kazuhide

    2013-02-15

    This study examined the effects of a combined pretreatment with supercritical water and mechanochemical grinding with a ball mill on the physicochemical properties of chitin and its enzymatic degradation. Following pretreatment with a combination of supercritical water and grinding, chitin had a lower mean molecular weight, a lower crystallinity index, a lower crystallite size, greater d-spacing, weaker hydrogen bonds, and the amide group was more exposed compared with untreated chitin. These properties increased the hydrophilicity of the chitin and enhanced its enzymatic degradation. The N,N'-diacetylchitobiose (GlcNAc)(2) yield after enzymatic degradation of chitin following pretreatment with supercritical water (400 °C, 1 min) and grinding (800 rpm, 10 min) was 93%, compared with 5% without any treatment, 37% with supercritical water pretreatment alone (400 °C, 1 min), and 60% with grinding alone (800 rpm, 30 min).

  5. STUDY OF PHYSICO-CHEMICAL PROPERTIES OF THE SURFACE AND GROUND WATER

    Directory of Open Access Journals (Sweden)

    A. Y. Al-Ghamdi

    2014-01-01

    Full Text Available Of all the natural resources, water is unarguably the most essential and precious. Life began in water and life is nurtured by water. Ninety seven percent of the world’s water is found in oceans. Only 2.5% of the world’s water are non-saline fresh water. Saudi Arabia is a desert country with no permanent rivers or lakes and very little rainfall. Water is scarce and extremely valuable and with the country’s rapid growth, the demand for water is increasing. Seven samples of water are collected, six samples from Wells (1-6 and the last sample from Al-Mallah Valley Dam, Mukhwa (7, Al-Mukhwah, in order to find impurities and pollutants and found some suitable solution. Some physical properties of water are measured such as turbidity, conductivity, pH and also, some pollutants such as iron, manganese, nitrate, nitrite fluoride, phosphate as well as calcium, magnesium, sulfate and chloride as well as detection of some microorganisms. The results shown that, the water of Al-Mallah Valley Dam has a high percentage of turbidity as a result of contamination of water with clay, plant residues and also some dead animals. On the other hand, the samples of ground water have high conductivity and high value of fluoride, nitrite, nitrate contents as well as Mn and Fe. Also the result of microorganisms showed the presence of some the water of Al-Mallah Valley Dam can be treated with a very simple method and become suitable for drinking. Also ground water can be treated with a suitable method to reduce the total hardness and some pollutants. But its content of fluoride is higher than that of gulf specifications so it must be treated before used.

  6. The Silica-Water Interface: How the Silanols Determine the Surface Acidity and Modulate the Water Properties.

    Science.gov (United States)

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

    2012-03-13

    Silica is the most abundant metal oxide and the main component of the Earth's crust. Its behavior in contact with water plays a critical role in a variety of geochemical and environmental processes. Despite its key role, the details of the aqueous silica interface at the microscopic molecular level are still elusive. Here we provide such a detailed understanding of the molecular behavior of the silica-water interface, using density functional theory based molecular dynamics (DFTMD) simulations, where a consistent treatment of the electronic structure of solvent and surface is provided. We have calculated the acidity of the silanol groups at the interface directly from the DFTMD simulations, without any fitting of parameters to the experimental data. We find two types of silanol groups at the surface of quartz: out-of-plane silanols with a strong acidic character (pKa = 5.6), which consequently results in the formation of strong and short hydrogen bonds with water molecules at the interface, and in-plane silanols with a pKa of 8.5, forming weak hydrogen bonds with the interfacial water molecules. Our estimate of the quartz point of zero charge (1.0) is found in good agreement with the experimental value of 1.9. We have also shown how the silanols orientation and their hydrogen bond properties are responsible for an amphoteric behavior of the surface. A detailed analysis has identified two species of adsorbed water molecules at the solid-liquid interface, which using the language of vibrational spectroscopy can be identified as "liquid-like" and "ice-like" water or, in other words, water molecules forming respectively weak and strong H-bonds with the oxide surface. These two populations of water are in turn responsible for two distinct peaks in the infrared spectrum of interfacial water and thus provide a molecular explanation of the experimental sum frequency generation spectrum recorded in the literature. In the specific case of quartz, we show that the liquid

  7. Effects of waxy wheat flour and water on frozen dough and bread properties.

    Science.gov (United States)

    Yi, Jinhee; Kerr, William L; Johnson, Jerry W

    2009-06-01

    The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation (T(2)) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T(2). Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.

  8. Improving the Performance and Antifouling Properties of Thin-Film Composite Membranes for Water Separation Technologies

    Science.gov (United States)

    Tiraferri, Alberto

    Membrane-based water separation processes utilize semi-permeable membranes to retain dissolved solids and contaminants. Deployment of these technologies for desalination and wastewater reuse has the potential to sustainably increase the supply of potable, agricultural, and industrial water. Despite considerable development of semi-permeable membranes in the last decades, several design obstacles hampering their progress have yet to be overcome. Specifically, major membrane improvements are currently sought with respect to their performance and productivity, as well as their resistance to fouling. This dissertation research aims at the advancement of semi-permeable membranes by rational optimization of their design to: (i) understand and improve their transport properties and (ii) reduce fouling by organic molecules and delay biofouling by microorganisms. In particular, thin-film composite polyamide membranes for both reverse osmosis and forward osmosis processes are the main target of the investigation. The structural and physicochemical properties of thin-film composite membranes are both characterized and tailored through implementation of original techniques and novel functionalization protocols. The membrane structure and morphology are rationally modified to enhance the mass transport within the support layer. The influence of fabrication conditions on support layer formation and on its final structure is elucidated. The intricate interrelationship among the performance of the different layers of the composite membrane is highlighted and a new protocol is developed to characterize the transport properties of membranes deployed in forward osmosis processes. Novel approaches to impart targeted properties to the active surface of thin-film composite membranes are also proposed. The functionalization is achieved by exploiting the inherent moieties of the polyamide layer to irreversibly bind nanomaterials with desired properties. An experimental method to determine

  9. The importance of water for the mechanical properties of insect cuticle

    Science.gov (United States)

    Klocke, D.; Schmitz, H.

    2011-04-01

    Insect cuticle has a broad range of mechanical properties. As it has to provide a very efficient and lightweight skeleton, cuticle is a highly interesting composite-material and may serve as a natural model for new biomimetic materials. However, the water content of insect cuticle is of great importance for its material properties. Here, we present a new method to perform nano-indentation experiments in cuticle which has its full water content. Parts of the exoskeleton of Locusta migratoria were investigated to determine the elastic modulus (Er) and hardness (H) of the cuticle. Cuticle sections were measured in air and then submerged and measured in water. As insect cuticle is an anisotropic material, we performed nano-indentation in the normal as well as in the transverse direction and also tested different cuticle layers within each sample (exo-, meso- and endo-cuticle). It turned out that a change of the water content has a dramatic impact on the material properties of the cuticle. For example, the Er of submerged endo-cuticle turned out to be 75% lower than of endo-cuticle samples measured in air. Further, the proportion of material property values between different cuticle layers within a sample change dramatically after addition of water.

  10. Sectoral Vulnerabilities to Changing Water Resources: Current and Future Tradeoffs between Supply and Demand in the Conterminous U.S

    Science.gov (United States)

    Meldrum, J.; Averyt, K.; Caldwell, P.; Sun, G.; Huber-lee, A. T.; McNulty, S.

    2012-12-01

    Assessing the sustainability of human activities depends, in part, on the availability of water supplies to meet the demands of those activities. Thermoelectric cooling, agriculture, and municipal uses all compete for water supplies, but each sector differs in its characteristic ratio of water consumption versus withdrawals. This creates different implications for contributing to water supply stress and, conversely, vulnerabilities within each sector to changing water supplies. In this study, we use two measures of water stress, relating to water withdrawals and to water consumption, and calculate the role of each of these three sectors in contributing to the two different measures. We estimate water stress with an enhanced version of the Water Supply Stress Index (WaSSI), calculating the ratio of water demand to water supply at the 8-digit Hydrologic Unit Code (HUC) scale (Sun et al. 2008, 2011; Caldwell et al. 2011). Current water supplies are based on an integrated water balance and flow routing model of the conterminous United States, which accounts for surface water supply, groundwater supply, and major return flows. Future supplies are based on simulated regional changes in streamflow in 2050 from an ensemble of 12 climate models (Milly et al. 2005). We estimate water demands separately for agriculture, municipal uses, and thermoelectric cooling, with the first two based on Kenny et al. (2005) and the last on the approach of Averyt et al. (2011). We find substantial regional variation not only in the overall WaSSI for withdrawals and consumption but also in contribution of the three water use sectors to that total. Results suggest that the relative vulnerabilities of different sectors of human activity to water supply stress vary spatially and that policies for alleviating that stress must consider the specific, regional context of the tradeoffs between competing water demands. Ref's: Averyt, K., Fisher, J., Huber-Lee, A., Lewis, A., Macknick, J., Madden, N

  11. Structural Insights into Water-Based Spider Silk Protein-Nanoclay Composites with Excellent Gas and Water Vapor Barrier Properties.

    Science.gov (United States)

    Doblhofer, Elena; Schmid, Jasmin; Rieß, Martin; Daab, Matthias; Suntinger, Magdalena; Habel, Christoph; Bargel, Hendrik; Hugenschmidt, Christoph; Rosenfeldt, Sabine; Breu, Josef; Scheibel, Thomas

    2016-09-28

    Nature reveals a great variety of inorganic-organic composite materials exhibiting good mechanical properties, high thermal and chemical stability, and good barrier properties. One class of natural bio-nanocomposites, e.g. found in mussel shells, comprises protein matrices with layered inorganic fillers. Inspired by such natural bio-nanocomposites, the cationic recombinant spider silk protein eADF4(κ16) was processed together with the synthetic layered silicate sodium hectorite in an all-aqueous setup. Drop-casting of this bio-nanocomposite resulted in a thermally and chemically stable film reflecting a one-dimensional crystal. Surprisingly, this bio-nanocomposite coating was, though produced in an all-aqueous process, completely water insoluble. Analyzing the structural details showed a low inner free volume due to the well-oriented self-assembly/alignment of the spider silk proteins on the nanoclay surface, yielding high oxygen and water vapor barrier properties. The here demonstrated properties in combination with good biocompatibility qualify this new bio-nanocomposite to be used in packaging applications.

  12. Mechanical and thermal properties of water glass coated sisal fibre-reinforced polypropylene composite

    CSIR Research Space (South Africa)

    Phiri, G

    2012-10-01

    Full Text Available ?C). Figure 1 shows the processing steps followed to produce composite samples. Up to 15% fibre loading could be achieved and the sisal fibres were coated with water glass to improve fire resistance. In order to improve the adhesion between sisal... preparation process: (A) WG coated fibre, (B) High speed granulator, (C) Composite granules, (D) Single screw extruder, (E) Injection moulder and (F) Composite samples (dumbbells) Mechanical and thermal properties of water glass coated sisal fi bre...

  13. Optical Properties of Mineral Particles and Their Effect on Remote-Sensing Reflectance in Coastal Waters

    Science.gov (United States)

    2001-09-30

    1997. Photometric immersion refractometry : A method for determining the refractive index of marine microbial particles from beam attenuation...light is collected by the absorption meter due to geometry of instrument. In the previous report we described our effort to develop a method for...bulk optical properties in coastal waters, (2) develop reliable remote sensing algorithms for coastal waters, (3) develop improved methods for optical

  14. Properties of waste stillage from shochu distillery and waste water occurred sosei paper production process

    OpenAIRE

    山内, 正仁; 平田, 登基男; 前野, 祐二; 三原, めぐみ; 松藤, 康司

    1999-01-01

    As an effective utilization of waste stillage, which will be banned from being dumped into sea from the year of 2001, authors have been studied and succeeded to make the sosei paper by using waste stillage form shochu distillery. This research is tried to consider the property of waste stillage from shochu distillery ( sweet potato waste stillage and barley waste stillage) and the weight and property of waste water in compressing samples added some amount of old newspaper to waste stillage. F...

  15. Properties of waste stillage from shochu distillery and waste water occurred sosei paper production process

    OpenAIRE

    山内, 正仁; 平田, 登基男; 前野, 祐二; 三原, めぐみ; 松藤, 康司

    1999-01-01

    As an effective utilization of waste stillage, which will be banned from being dumped into sea from the year of 2001, authors have been studied and succeeded to make the sosei paper by using waste stillage form shochu distillery. This research is tried to consider the property of waste stillage from shochu distillery ( sweet potato waste stillage and barley waste stillage) and the weight and property of waste water in compressing samples added some amount of old newspaper to waste stillage. F...

  16. Sub-hourly changes in biogeochemical properties in surface waters of Zuari estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, S.S.; Anju, K.J.; Mathew, D.; DileepKumar, M.

    and biogeochemical processes and consequent variability in properties. 2.2 Sampling Strategies Experiments were conducted twice; Experiment 1 during flood phase of neap tide on 13 June 2012 and Experiment 2 during ebb phase of the spring tide on 21 June 2012. 2... (Experiment 2) than the flood phase of the neap tide (Experiment 1). Higher deviations in Experiment 2 seem associated with higher turbidity of the estuarine waters than in Experiment 1. Table 2 contains the ranges of biogeochemical properties observed...

  17. Experimentally determined mechanical properties of, and models for, the periodontal ligament: critical review of current literature.

    Science.gov (United States)

    Fill, Ted S; Carey, Jason P; Toogood, Roger W; Major, Paul W

    2011-01-01

    Introduction. This review is intended to highlight and discuss discrepancies in the literature of the periodontal ligament's (PDL) mechanical properties and the various experimental approaches used to measure them. Methods. Searches were performed on biomechanical and orthodontic publications (in databases: Compendex, EMBASE, MEDLINE, PubMed, ScienceDirect, and Scopus). Results. The review revealed that significant variations exist, some on the order of six orders of magnitude, in the PDL's elastic constants and mechanical properties. Possible explanations may be attributable to different experimental approaches and assumptions. Conclusions. The discrepancies highlight the need for further research into PDL properties under various clinical and experimental loading conditions. Better understanding of the PDL's biomechanical behavior under physiologic and traumatic loading conditions might enhance the understanding of the PDL's biologic reaction in health and disease. Providing a greater insight into the response of the PDL would be instrumental to orthodontists and engineers for designing more predictable, and therefore more efficacious, orthodontic appliances.

  18. Comparison of Pore Water Chemical Extracted by Different Forces with In-situ Properties

    Science.gov (United States)

    Ito, N.; Machida, I.; Marui, A.; Scheytt, T.; Hebig, K. H.

    2010-12-01

    Due to the difficulty involved for in-situ sampling of groundwater, pore water was extracted from rock core samples for chemical analysis. Available literature indicated that, the chemical constituents of pore water are affected by large extraction force. This study is therefore aimed at discussing the reason behind the change in pore water chemistry when samples are subjected to different extraction forces. The process involved extraction of pore water from sandstone core samples at different pF values by centrifuge method. The pF expresses the tension of water, retained in soil. It is the base 10 logarithm of tension, which is measured as a head of water head in centimeters. The samples of lengths 100 m each were obtained from three locations. Tracer test using Iodine was also conducted to remove pore water polluted by drilling water. Pore water was extracted from a total of 63 samples at three different values of pF (low: up to pF 2.3, medium: pF 2.3 - 3.9, high: pF 3.9 - 4.3). For each pF range the pore water was analyzed for major anions and cations. Results showed variation of ionic concentrations with pF and depth. The average concentrations rose with increase of pF in all ions except for potassium. Based on the concentration distribution of Ca2+, three zones could be defined: (1) Ca2+ concentration, which does not depend on pF, (2) Ca2+ concentration, which increases with the value of pF and (3) Ca2+ showing the same value for medium and high pF values. It is thus concluded that, water chemistry of deep pore water is likely to have reached equilibrium due to almost stagnant flow conditions, whereas shallow water is likely to participate in chemical interactions due to the relatively high flow velocity. The depths of the interfaces of these three zones are almost consistent with geological boundaries of weathered and fine sandstone and there is evidence of a relationship between pore water chemistry and physical rock properties. Using this knowledge, we

  19. Analytical description of thermodynamic properties of steam, water and the phase interface for use in CFD

    Directory of Open Access Journals (Sweden)

    Hrubý Jan

    2014-03-01

    Full Text Available We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.

  20. Analytical description of thermodynamic properties of steam, water and the phase interface for use in CFD

    Science.gov (United States)

    Hrubý, Jan; Duška, Michal

    2014-03-01

    We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated) and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation) properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.

  1. Drinking water quality in household supply infrastructure--A survey of the current situation in Germany.

    Science.gov (United States)

    Völker, Sebastian; Schreiber, Christiane; Kistemann, Thomas

    2010-06-01

    As a result of the amendment to the German Drinking Water Ordinance in 2001, local public health authorities are obliged to monitor the water supply in installations providing water for public use (Section 18 German Drinking Water Ordinance). With a systematic and nationwide survey of locally available data relating to hygienic drinking water quality and the existing drinking water infrastructure in buildings, the extent of microbial contamination of in-building distribution systems in Germany is intended to be assessed. To gain an overview of the microbial contamination of drinking water in public buildings all 419 local public health authorities in Germany were contacted in 2007. In a detailed study with a representative cooperation level of 5% of these local public health authorities, the available data relating to microbiological, chemical, physical and technical parameters gained from in-building distribution systems were collected. Drinking water parameters were combined with regard to the total number of analyses and the absolute number as well as the percentage of limit compliance failures (n=108,288). Limits exceeded were classified as the failure to comply with the German Drinking Water Ordinance, DVGW technical regulations and Federal Environment Agency recommended limits. The highest rates of samples exceeding these limits were found for the parameter Legionella sp. which contaminated 12.8% of all samples (n=22,786; limit: 100 CFU/100ml), followed by heterotrophic plate count at 36 degrees C (3.5%, n=10,928; limit: 100 CFU/1 ml) and Pseudomonas sp. (2.9%, n=3468; limit: 0 CFU/100ml). Legionella sp. and Pseudomonas sp. pose a direct health risk to immunosuppressed users. Additionally, for some chemical parameters, such as nickel, iron and lead, a potential risk for the health of consumers was detected. Further data analysis may reveal whether this contamination is related to stagnation where there is only sporadic use or whether other factors are

  2. Technical review and evaluation of the economics of water desalination: Current and future challenges for better water supply sustainability

    KAUST Repository

    Ghaffour, Noreddine

    2013-01-01

    Desalination capacity has rapidly increased in the last decade because of the increase in water demand and a significant reduction in desalination cost as a result of significant technological advances, especially in the reverse osmosis process. The cost of desalinated seawater has fallen below US$0.50/m3 for a large scale seawater reverse osmosis plant at a specific location and conditions while in other locations the cost is 50% higher (US$1.00/m3) for a similar facility. In addition to capital and operating costs, other parameters such as local incentives or subsidies may also contribute to the large difference in desalted water cost between regions and facilities. Plant suppliers and consultants have their own cost calculation methodologies, but they are confidential and provide water costs with different accuracies. The few existing costing methodologies and software packages such as WTCost© and DEEP provide an estimated cost with different accuracies and their applications are limited to specific conditions. Most of the available cost estimation tools are of the black box type, which provide few details concerning the parameters and methodologies applied for local conditions. Many desalination plants built recently have greater desalinated water delivery costs caused by special circumstances, such as plant remediation or upgrades, local variation in energy costs, and site-specific issues in raw materials costs (e.g., tariffs and transportation). Therefore, the availability of a more transparent and unique methodology for estimating the cost will help in selecting an appropriate desalination technology suitable for specific locations with consideration of all the parameters influencing the cost. A techno-economic evaluation and review of the costing aspects and the main parameters influencing the total water cost produced by different desalination technologies are herein presented in detail. Some recent developments, such as the increase of unit capacity

  3. Groundwater science in water-utility operations: global reflections on current status and future needs

    Science.gov (United States)

    Foster, Stephen; Sage, Rob

    2017-08-01

    The relevance of groundwater science to water-utility operations is analysed from a broad international perspective, identifying key concerns and specific opportunities for the future. The strategic importance worldwide of water utilities assuming the role of lead stakeholders for integrated groundwater resource management, recognizing their often considerable technical know-how and highly significant data holdings, is emphasized. Concurrently, the utilities themselves will need an ever-closer appreciation of groundwater-system behaviour if they are to manage efficiently their water-supply and wastewater operations.

  4. Numerical simulations of the current state of waters and sea ice in the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    E. N. Golubeva

    2015-01-01

    Full Text Available The paper presents results of numerical simulation of variability of the sea ice area and water circulation in the Arctic Ocean performed with use of the atmosphere reanalysis data for the period from middle of the last century to the present time. The model results reflect the ocean responses to changes of the atmosphere circulation regimes that manifests in changes of trajectories of waters coming into the Arctic Ocean from the Pacific and Atlantic oceans. The model results show influence of the Pacific and Atlantic waters on distribution and thickness of the Arctic ice. 

  5. Current Progress of Mechanical Properties of Metals with Nano-scale Twins

    Institute of Scientific and Technical Information of China (English)

    Lei LU

    2008-01-01

    Focus on face-centered cubic (fcc) metals with nano-scale twins lamellar structure, this paper presents a brief overview of the recent progress made in improving mechanical properties, including strength, ductility, work hardening, strain rate sensitivities, and in mechanistically understanding the underling deformation mechanisms. Significant developments have been achieved in nano-twinned fcc metals with a combination of high strength and considerable ductility at the same time, enhanced work hardening ability and enhanced rate sensitivity. The findings elucidate the role of interactions between dislocations and twin boundaries (TBs) and their contribution to the origin of outstanding properties. The computer simulation analysis accounts for high plastic anisotropy and rate sensitivity anisotropy by treating TBs as internal interfaces and allowing special slip geometry arrangements that involve soft and hard modes of deformation. Parallel to the novel mechanical behaviors of the nano-twinned materials, the investigation and developments of nanocrystalline materials are also discussed in this overview for comparing the contribution of grain boundaries/TBs and grain size/twin lamellar spacing to the properties. The recent advances in the experimental and computational studies of plastic deformation of the fcc metals with nano-scale twin lamellar structures provide insights into the possible means of optimizing comprehensive mechanical properties through interfacial engineering.

  6. Eddies on the boundary between the Kuroshio current and coastal waters observed by HF ocean surface radar

    Science.gov (United States)

    Nadai, A.

    2016-02-01

    The HF ocean surface radar (HFOSR) is one of the powerful tools to measure the ocean current parameters like surface currents. Three observations of the Kuroshio current in the Tokara straight using HFOSR had done by the National Institute of Information and Comunications Technology (NICT: the former name is the Communications Research Laboratory). The first-order echoes on Doppler spectra of HFOSR shows broaden and splitting shape in the region of the border between the Kuroshio currents and coastal waters. The surface velocity maps show the existence of eddy on the border. The investigation of the mechanism of broadening first order-echoes by Nadai (2006) revealed that the modulation of wave fields from surface currents like eddy is the cause of broadening and the measured current fields also influenced the modulated wave fields. Moreover, Nadai (2006) also suggested that the influence is able to reduce using the average of two radial velocities extracted by the first-order echoes. In this paper, the results of current field observation around the border between the Kuroshio current and coastal waters are presented. Many small scale eddies are observed at the border of the Kuroshio current and coastal waters. The typical radius of the eddies is about 10km. Usury the observation of such a small scale eddy is difficult, but the eddies with same scale are observed by airborne synthetic aperture radar in the same area at different time. The eddies shows strong rotation as the typical tangential speed is about 1m/s. While the typical speed of the Kuroshio current is about 1.5m/s, the typical speed of the eddy movements is about 0.7m/s. No eddies generated in the radar coverage, but one or two eddies entered in the radar coverage a day. Therefore the origin of these eddies will exist in the upstream area of the radar coverage. Using the compensation method for the influence of the modulated wave field suggested by Nadai (2006), the eddies shows weak divergence. It is

  7. Physical and Chemical Properties of Water Treatment Residue and the Characteristics of Red Pepper Growth by Using it

    OpenAIRE

    Park, Seok-Gon; Yahata, Hisashi; Kurosawa, Kiyoshi; Shin, Hyun-Tak

    2010-01-01

    Physical and chemical properties of the water treatment residue (WTR) and the WTR_, which contained compost (CP), were measured, and the effect of the properties on growth of the red pepper (Capsicum annuum‘Takanotsume’) was studied to reuse the WTR as an alternative material for decomposed granite soil (DGS). The physical properties of relative gas diffusivity (D/D_0), saturated hydraulic conductivity (K_s), water retention curve, porosity and plant-available water, and the chemical propert...

  8. Characterization of the critical current and physical properties of superconducting epitaxial NbTiN sub-micron structures

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A., E-mail: aklimov@ite.waw.pl [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Słysz, W.; Guziewicz, M. [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Kolkovsky, V.; Zaytseva, I.; Malinowski, A. [Institute of Physics Polish Academy of Science, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-05-15

    Highlights: • This manuscript presents investigation of the critical current dependence of Nb(Ti)N nanostructured superconducting single photon detectors (SNSPD) in function of temperature and applied magnetic field. • Presented results are complimentary and compared with the same data received for submicron-wide single bridge Nb(Ti)N structures. • Our data demonstrate significant influence of local constrictions on physical properties of our SNSPD detectors. - Abstract: Measurements of critical current in NbTiN as a function of applied magnetic field and temperature are reported for two samples: 700-nm-wide bridge and 100-nm-wide meander. In 700-nm-wide NbTiN bridge we pinpointed the limiting factors for the critical current density to be current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature. In 100-nm-wide NbTiN meander we found phase slips activation, accompanied by hotspots formation at all measured temperatures. These two types of structures demonstrate different dependence of the critical current on the applied magnetic field. Although our NbTiN meander structures has high de-pairing critical current densities ∼10{sup 7} A/cm{sup 2} at low temperatures, the real critical currents are smaller due to the presence of the local constrictions.

  9. Effects of electrolyte concentration and current density on the properties of electro-deposited NiFeW alloy coatings

    Indian Academy of Sciences (India)

    J K YU; H SUN; L L ZHAO; Y H WANG; M Q YU; H L LUO; Z F XU; KAZUHIRO MATSUGI

    2017-06-01

    NiWP alloy coatings were prepared by electrodeposition, and the effects of ferrous chloride (FeCl$_2$), sodium tungstate (Na$_2$WO$_4$) and current density ($D_K$) on the properties of the coatings were studied. The results show that upon increasing the concentration of FeCl$_2$, initially the Fe content of the coating increased and then tended to be stable; the deposition rate and microhardness of coating decreased when the cathodic current efficiency ($\\eta$) initially increased and then decreased; and for a FeCl$_2$ concentration of 3.6 gl$^{−1}, the cathodic current efficiency reached its maximum of 74.23%. Upon increasing the concentration of Na$_2$WO$_4$, the W content and microhardness of the coatings increased; the deposition rate andthe cathode current efficiency initially increased and then decreased. The cathodic current efficiency reached the maximum value of 70.33% with a Na$_2$WO$_4$ concentration of 50 gl$^{−1}$, whereas the deposition rate is maximum at 8.67 $\\mu$mh$^{−1}$ with a Na$_2$WO$_4$ concentration of 40 gl$^{−1}$. Upon increasing the $D_K$, the deposition rate, microhardness, Fe and W content of the coatings increased, the cathodic current efficiency increases first increased and then decreased. When $D_K$ was 4 A dm$^{−2}$,the current efficiency reached the maximum of 73.64%.

  10. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    Science.gov (United States)

    Gerbino, Martina; Freese, Katherine; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2017-02-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the ns/r plane, where ns is the scalar spectral index and r is the tensor-to-scalar ratio. We study the following neutrino properties: (i) the total neutrino mass Mν=∑i mi (where the index i =1 , 2, 3 runs over the three neutrino mass eigenstates); (ii) the number of relativistic degrees of freedom Neff at the time of recombination; and (iii) the neutrino hierarchy. Whereas previous literature assumed three degenerate neutrino masses or two massless neutrino species (approximations that clearly do not match neutrino oscillation data), we study the cases of normal and inverted hierarchy. Our basic result is that these three neutrino properties induce measurements are included, the standard contours in the ns/r plane are basically reproduced. Larger shifts of the contours in the ns/r plane (up to 0.8 σ ) arise for nonstandard values of Neff. We also provide forecasts for the future CMB experiments Cosmic Origins Explorer (COrE, satellite) and Stage-IV (ground-based) and show that the incomplete knowledge of neutrino properties, taken into account by a marginalization over Mν, could induce a shift of ˜0.4 σ toward lower values in the determination of ns (or a ˜0.8 σ shift if one marginalizes over Neff). Comparison to specific inflationary models is shown. Imperfect knowledge of neutrino properties must be taken into account properly, given the desired precision in determining whether or not inflationary models match the future data.

  11. Eddy Surface properties and propagation at Southern Hemisphere western boundary current systems

    Directory of Open Access Journals (Sweden)

    G. S. Pilo

    2015-02-01

    Full Text Available Oceanic eddies occur in all world oceans, but are more energetic when associated to western boundary currents (WBC systems. In these regions, eddies play an important role on mixing and energy exchange. Therefore, it is important to quantify and qualify eddies occurring within these systems. Previous studies performed eddy censuses in Southern Hemisphere WBC systems. However, important aspects of local eddy population are still unknown. Main questions to be answered relate to eddies' spatial distribution, propagation and lifetime within each system. Here, we use a global eddy dataset to qualify eddies based on their surface characteristics at the Agulhas Current (AC, the Brazil Current (BC and the East Australian Current (EAC Systems. We show that eddy propagation within each system is highly forced by the local mean flow and bathymetry. In the AC System, eddy polarity dictates its propagation distance. BC system eddies do not propagate beyond the Argentine Basin, and are advected by the local ocean circulation. EAC System eddies from both polarities cross south of Tasmania, but only anticyclonics reach the Great Australian Bight. Eddies in all systems and from both polarities presented a geographical segregation according to size. Large eddies occur along the Agulhas Retroflection, the Agulhas Return Current, the Brazil-Malvinas Confluence and the Coral Sea. Small eddies occur in the systems southernmost domains. Understanding eddies' propagation helps to establish monitoring programs, and to better understand how these features would affect local mixing.

  12. Effect of Applied Current Density on Morphological and Structural Properties of Electrodeposited Fe-Cu Films

    Institute of Scientific and Technical Information of China (English)

    Umut Sarac; M. Celalettin Baykul

    2012-01-01

    A detailed study has been carried out to investigate the effect of applied current density on the composition, crystallographic structure, grain size, and surface morphology of Fe-Cu films. X-ray diffraction (XRD) results show that the films consist of a mixture of face-centered cubic (fcc) Cu and body centered cubic (bcc) ~-Fe phases. The average crystalline size of both Fe and Cu particles decreases as the applied current density becomes more negative. Compositional analysis of Fe-Cu films indicates that the Fe content within the films increases with decreasing current density towards more negative values. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to investigate the surface morphology of Fe-Cu films. It is observed that the surface morphology of the films changes from dendritic structure to a cauliflower structure as the applied current density becomes more negative. The surface roughness and grain size of the Fe-Cu films decrease with decreasing applied current density towards more negative values.

  13. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro-osmotic...... drag (EOD) with counter diffusion and/or hydraulic permeation is flawed, and that any net transport of water through the membrane is caused by diffusion. Depending on the effective drag the cathode side of the membrane may experience a lower hydration than the anode side. The effect of a water......-uptake layer on the net water transport will also be pictured. Finally, the effect of EOD is visualized using “Newton’s cradle”....

  14. Water characteristics and transport of the Antarctic circumpolar current in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Mathew, B.

    Geostrophic velocities are computed across meridians 37 degrees E and 105 degrees E using hydrographic data. The estimated mass transport is represented on a temperature - salinity diagram. The characteristics of the water within the Antarctic...

  15. Current status of bacteriological parameters and DOC/POC in Xiamen coastal waters

    Institute of Scientific and Technical Information of China (English)

    Khalid Maskaoui; Tianling Zheng; Huasheng Hong; Zhiming Yu; Zhong Hu; Yun Tian; Lizhe Cai

    2003-01-01

    The surface and bottom waters samples were collected from six locations in Xiamen west-em sea. The quantified estimation of bacterial production (3H-thymidine method) and observation ofbacterial heterotrophic activity (14C-glucose method) have been made in order to have a better under-standing of the role of marine bacteria and their activities. The results showed that the mean value ofbacterial heterotrophic activity was 9 × 108 cells/(L. h) in the surface waters and 2.6 × 108 cells/( L. h)in the bottom waters. The mean value of bacterial production was 38 × 108 cells/( L. h) in the surfacewaters and 7.1 × 108 cells/(L.h) in the bottom waters. The relationship between bacterial production,heterotrophic activity, POC and DOC measured during this survey were discussed. The good under-standing of the relationship between bacteria activity and total coliform was addressed.

  16. Influence of Water Absorption on Volume Resistivity and the Dielectric Properties of Neat Epoxy Material

    KAUST Repository

    Sulaimani, Anwar Ali

    2014-07-15

    Influence of Water Absorption on the Dielectric Properties and Volume Resistivity of Neat Epoxy Material Anwar Ali Sulaimani Epoxy resins are widely used materials in the industry as electrical insulators, adhesives and in aircrafts structural components because of their high mechanical sti ness, strength and high temperature and chemical resistance properties. But still, the in uence of water uptake due to moisture adsorption is not fully understood as it detrimentally modi es the electrical and chemical properties of the material. Here, we investigate the in uence of water moisture uptake on the neat epoxy material by monitoring the change in the volume resistivity and dielectric properties of epoxy material at three di erent thickness con gurations: 0.250 mm, 0.50 mm and 1 mm thicknesses. Gravimetric analysis was done to monitor the mass uptake behaviour, Volume Resistivity was measured to monitor the change in conductivity of the material, and the dielectric properties were mapped to characterise the type of water mechanism available within the material during two ageing processes of sorption and desorption. Two-stage behaviours of di usion and reaction have been identi ed by the mass uptake analysis. Moreover, the plot of volume resistivity versus mass uptake has indi- cated a non-uniform relationship between the two quantities. However, the analysis of the dielectric spectrum at medium range of frequency and time has showed a change 5 in the dipolar activities and also showed the extent to which the water molecules can be segregated between bounding to the resin or existing as free water.

  17. E. coli Surface Properties Differ between Stream Water and Sediment Environments

    Directory of Open Access Journals (Sweden)

    Xiao Liang

    2016-11-01

    Full Text Available The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10mM and 22˚C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity and extracellular polymeric substance (EPS composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli. Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli.

  18. E. coli Surface Properties Differ between Stream Water and Sediment Environments.

    Science.gov (United States)

    Liang, Xiao; Liao, Chunyu; Thompson, Michael L; Soupir, Michelle L; Jarboe, Laura R; Dixon, Philip M

    2016-01-01

    The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water) under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10 mM and 22°C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity, and extracellular polymeric substance (EPS) composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli. Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG)5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli.

  19. Technologies for Arsenic Removal from Water: Current Status and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Nina Ricci Nicomel

    2015-12-01

    Full Text Available This review paper presents an overview of the available technologies used nowadays for the removal of arsenic species from water. Conventionally applied techniques to remove arsenic species include oxidation, coagulation-flocculation, and membrane techniques. Besides, progress has recently been made on the utility of various nanoparticles for the remediation of contaminated water. A critical analysis of the most widely investigated nanoparticles is presented and promising future research on novel porous materials, such as metal organic frameworks, is suggested.

  20. Technologies for Arsenic Removal from Water: Current Status and Future Perspectives

    Science.gov (United States)

    Nicomel, Nina Ricci; Leus, Karen; Folens, Karel; Van Der Voort, Pascal; Du Laing, Gijs

    2015-01-01

    This review paper presents an overview of the available technologies used nowadays for the removal of arsenic species from water. Conventionally applied techniques to remove arsenic species include oxidation, coagulation-flocculation, and membrane techniques. Besides, progress has recently been made on the utility of various nanoparticles for the remediation of contaminated water. A critical analysis of the most widely investigated nanoparticles is presented and promising future research on novel porous materials, such as metal organic frameworks, is suggested. PMID:26703687

  1. Objective mapping of Argo data in the Weddell Gyre: a gridded dataset of upper ocean water properties

    Directory of Open Access Journals (Sweden)

    K. A. Reeve

    2015-06-01

    Full Text Available The Weddell Gyre plays a crucial role in the modification of climate by advecting heat poleward to the Antarctic ice shelves and by regulating the density of water masses that feed the lowest limb of the global ocean overturning circulation. However, our understanding of Weddell Gyre water mass properties is limited to regions of data availability, primarily along the Prime Meridian. The aim of this paper is to provide a dataset of the upper water column properties of the entire Weddell Gyre. Objective mapping was applied to Argo float data in order to produce spatially gridded, time composite maps of temperature and salinity for fixed pressure levels ranging from 50 to 2000 dbar, as well as temperature, salinity and pressure at the level of the sub-surface temperature maximum. While the data are currently too limited to incorporate time into the gridded structure, the data are extensive enough to produce maps of the entire region across three time composite periods (2002–2005, 2006–2009 and 2010–2013, which can be used to determine how representative conclusions drawn from data collected along general RV transect lines are on a gyre scale perspective. The work presented here represents the technical prerequisite in addressing climatological research questions in forthcoming studies. These data sets are available in netCDF format at doi:10.1594/PANGAEA.842876.

  2. The current-voltage and noise properties of high temperature superconductor SNS and grain boundary junctions

    CERN Document Server

    McGordon, A

    1999-01-01

    transport that was dominated by the interlayer material, but supercurrent transport that could be due to pinhole shorts. In addition, both geometries, especially the sandwich junction, showed large amounts of normal state noise making these junctions unsuitable for device applications. The effect of shining laser light onto a junction was investigated. The effects on the I-V characteristic were unobservable with the experimental resolution available. The effect of the light on the critical current noise of the junction was to reduce the noise peak slightly when compared to the unilluminated case- the reduction was of the order of 10%, comparable with experimental resolution. The study of the noise from Josephson Junctions is an intense field of research. Despite this, no clear picture of the current transport in these devices has emerged. Without the detailed understanding of the mechanisms of current transport in High Temperature Superconductor junctions, the design of superconducting electronics will not mo...

  3. The effects of steam on the surface properties of palygorskite: Implications for palygorskite-water interactions

    Science.gov (United States)

    Kadakia, Abhy

    Early studies on the effects of steam on montmorillonite reported a loss of osmotic swelling capacity and gelling ability of montmorillonite (Bish et al., 1997; Couture, 1985; Oscarson and Dixon, 1989; Zhu, 2009). However, the crystal structure, cation-exchange capacity, and hydration/dehydration behavior of montmorillonite were preserved. Similar steaming experiments were conducted in the current studies on palygorskite (PFl-1) at 225°C for six days in Teflon-lined Parr vessels. All untreated and steam-treated materials were examined by X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), ζ-potential, and rheological measurements. XRD and TGA data show that the crystal structure, mineralogy, and dehydration behavior of steamed palygorskites were unchanged after steam treatment. XPS revealed no changes in binding-energy peak positions of the surface Si, Mg, and O ions (XPS provides no information on the chemical state of H atoms). Rheological measurements showed that suspensions of steam-treated palygorskite in deionized H2O (5% w/w) are unstable, and the suspensions are Newtonian in nature. The flow curves also revealed a significant reduction in yield stresses after steam treatment, indicating collapse of the clay particle network in water. The ζ-potential decreased after steam treatment, with untreated palygorskite having a value of -26.1 mV and steam-treated material having a value of -18.3 mV. The reduction of surface charge may be sufficient to reduce the electrostatic repulsion between the clay particles, thereby allowing van der Waal attractive forces to dominate. Hence, steam-treated palygorskite flocculates and settles quickly in water. The decreased ζ-potentials are likely associated with decreased Lewis basicity, which can render the clay particles less hydrophilic or even moderately hydrophobic. Both N 2 (BET) and ethylene glycol monoethyl ether (EGME) adsorption surface areas of palygorskite

  4. INFLUENCE OF WATER-SOLUBLE COMPOUNDS OF RESTORED SULFUR ONTO TOXIC PROPERTIES OF NATURAL AND WASTE WATERS

    Directory of Open Access Journals (Sweden)

    Frog Boris Nikolaevich

    2012-10-01

    Full Text Available Whenever environmental pollution by sulphur compounds is under discussion, the latter contemplate those compounds that may be subjected to consideration through the employment of methods of analytical control. First of all, sulphates and volatile compounds of partially or completely restored sulphur, such as SO2, H2S, methyl sulphur compounds (merkaptans, dimethyl sulphide, dimethyl disulphide and others may be subjected to control. Elementary sulphur that is contained in the water is difficult to analyze. At the same time, an extensive group of water-soluble compounds of restored sulphur is not considered by numerous nature protection organizations. As a rule, they do not possess distinct analytical properties. The latter include any organic and inorganic thio-acids and their combinations with ions of transitive metals, in particular, with ions of monovalent copper. Microcolloidal (nano- particles of FeS may also be included into this group of compounds. The objective of the article is to generate the awareness of those compounds of reduced sulphur that are out of control. By virtue of this article, the authors apply to specialists in water treatment, water conditioning and water quality regulation.

  5. Effects of surface pressure on the properties of Langmuir monolayers and interfacial water at the air-water interface.

    Science.gov (United States)

    Lin, Wei; Clark, Anthony J; Paesani, Francesco

    2015-02-24

    The effects of surface pressure on the physical properties of Langmuir monolayers of palmitic acid (PA) and dipalmitoylphosphatidic acid (DPPA) at the air/water interface are investigated through molecular dynamics simulations with atomistic force fields. The structure and dynamics of both monolayers and interfacial water are compared across the range of surface pressures at which stable monolayers can form. For PA monolayers at T = 300 K, the untilted condensed phase with a hexagonal lattice structure is found at high surface pressure, while the uniformly tilted condensed phase with a centered rectangular lattice structure is observed at low surface pressure, in agreement with the available experimental data. A state with uniform chain tilt but no periodic spatial ordering is observed for DPPA monolayers on a Na(+)/water subphase at both high and low surface pressures. The hydrophobic acyl chains of both monolayers pack efficiently at all surface pressures, resulting in a very small number of gauche defects. The analysis of the hydrogen-bonding structure/dynamics at the monolayer/water interface indicates that water molecules hydrogen-bonded to the DPPA head groups reorient more slowly than those hydrogen-bonded to the PA head groups, with the orientational dynamics becoming significantly slower at high surface pressure. Possible implications for physicochemical processes taking place on marine aerosols in the atmosphere are discussed.

  6. Microstructure and Properties of Ni and Ni/Al2O3 Coatings Electrodeposited at Various Current Densities

    Directory of Open Access Journals (Sweden)

    Góral A.

    2016-03-01

    Full Text Available The study presents investigations of an influence of various direct current densities on microstructure, residual stresses, texture, microhardness and corrosion resistance of the nickel coatings electrodeposited from modified Watt’s baths. The properties of obtained coatings were compared to the nano-crystalline composite Ni/Al2O3 coatings prepared under the same plating conditions. The similarities and differences of the obtained coatings microstructures visible on both their surfaces and cross sections and determined properties were presented. The differences in the growth character of the Ni matrix and in the microstructural properties were observed. All electrodeposited Ni and Ni/Al2O3 coatings were compact and well adhering to the steel substrates. The thickness and the microhardness of the Ni and Ni/Al2O3 deposits increased significantly with the current density in the range 2 - 6 A/dm2. Residual stresses are tensile and they reduced as the current density increased. The composite coatings revealed better protection from the corrosion of steel substrate than pure nickel in solution 1 M NaCl.

  7. Fabrication of Bi2223 bulks with high critical current properties sintered in Ag tubes

    Science.gov (United States)

    Takeda, Yasuaki; Shimoyama, Jun-ichi; Motoki, Takanori; Kishio, Kohji; Nakashima, Takayoshi; Kagiyama, Tomohiro; Kobayashi, Shin-ichi; Hayashi, Kazuhiko

    2017-03-01

    Randomly grain oriented Bi2223 sintered bulks are one of the representative superconducting materials having weak-link problem due to very short coherence length particularly along the c-axis, resulting in poor intergrain Jc properties. In our previous studies, sintering and/or post-annealing under moderately reducing atmospheres were found to be effective for improving grain coupling in Bi2223 sintered bulks. Further optimizations of the synthesis process for Bi2223 sintered bulks were attempted in the present study to enhance their intergrain Jc. Effects of applied pressure of uniaxial pressing and sintering conditions on microstructure and superconducting properties have been systematically investigated. The best sample showed intergrain Jc of 2.0 kA cm-2 at 77 K and 8.2 kA cm-2 at 20 K, while its relative density was low ∼65%. These values are quite high as for a randomly oriented sintered bulk of cuprate superconductors.

  8. Identifying the Physical Properties of Showers That Influence User Satisfaction to Aid in Developing Water-Saving Showers

    Directory of Open Access Journals (Sweden)

    Minami Okamoto

    2015-07-01

    Full Text Available This research was conducted with the goal of clarifying the required conditions of water-saving showerheads. In order to this, the research analyzes the mutual relationship between water usage flow, the level of satisfaction and the physical properties of spray of showerheads. The physical properties of spray were measured using physical properties test apparatus of standard or scheme for water-saving showerheads issued in several water-saving countries, and satisfaction evaluation data was acquired through bathing experiments. The evaluated showerheads were separated into three groups according to usage water flow and the level of satisfaction. The relationships between usage water flow, the level of satisfaction and physical properties were compared. The results identified that Spray Force and Spray Force-per-Hole were physical properties that influence usage water flow. Spray force-per-hole, water volume ratio in Spray Patterns within φ 100 and φ 150, Temperature Drop and Spray Angle were identified as physical properties that influenced the level of satisfaction. The level of satisfaction and usage water flow has a spurious correlation through the physical properties of Spray Force-per-Hole and Temperature Drop. It is possible to improve the level of satisfaction independent of amount of water usage through designs that set an appropriate value for water volume ratio and Spray Angle for Spray Patterns within φ 100 and φ 150.

  9. Investigation of scaling properties of a thin current sheet by means of particle trajectories study

    CERN Document Server

    Sasunov, Yu L; Alexeev, I I; Belenkaya, E S; Semenov, V S; Kubyshkin, I V; Mingalev, O V

    2015-01-01

    A thin current sheet (TCS), with the width of an order of thermal proton gyroradius, appears a fundamental physical object which plays an important role in structuring of major magnetospheric current systems (magnetotail, magnetodisk, etc.). The TCSs are nowadays under extensive study by means of space missions and theoretical models. We consider a simple model of the TCS separating two half-spaces occupied by a homogenous magnetic field of opposite sign tangential to the TCS; a small normal component of the magnetic field is prescribed. An analytical solution for the electric current and plasma density in the close vicinity of the TCS has been obtained and compared with numerical simulation. The number density and the electric current profiles have two maxima each. The characteristic spatial scale $z_S$ of the maxima location was investigated as a function of initial pitch-angle of an incoming charge particle. The effect of the thermal dispersion of the incoming proton beam have been taken into consideration...

  10. Water uptake, ionic conductivity and swelling properties of anion-exchange membrane

    Energy Technology Data Exchange (ETDEWEB)

    Duan, QJ; Ge, SH; Wang, CY

    2013-12-01

    Water uptake, ionic conductivity and dimensional change of the anion-exchange membrane made by Tokuyama Corporation (A201 membrane) are investigated at different temperatures and water activities. Specifically, the amount of water taken up by membranes exposed to water vapor and membranes soaked in liquid water is determined. The water uptake of the A201 membrane increases with water content as well as temperature. In addition, water sorption data shows Schroeder's paradox for the AEMs investigated. The swelling properties of the A201 membrane exhibit improved dimensional stability compared with Nafion membrane. Water sorption of the A201 membrane occurs with a substantial negative excess volume of mixing. The threshold value of hydrophilic fraction in the A201 membrane for ionic conductivity is around 0.34, above which, the conductivity begins to rise quickly. This indicates that a change in the connectivity of the hydrophilic domains occurs when hydrophilic fraction approaches 0.34. (C) 2013 Elsevier B.V. All rights reserved.

  11. Biochar particle size, shape, and porosity act together to influence soil water properties.

    Science.gov (United States)

    Liu, Zuolin; Dugan, Brandon; Masiello, Caroline A; Gonnermann, Helge M

    2017-01-01

    Many studies report that, under some circumstances, amending soil with biochar can improve field capacity and plant-available water. However, little is known about the mechanisms that control these improvements, making it challenging to predict when biochar will improve soil water properties. To develop a conceptual model explaining biochar's effects on soil hydrologic processes, we conducted a series of well constrained laboratory experiments using a sand matrix to test the effects of biochar particle size and porosity on soil water retention curves. We showed that biochar particle size affects soil water storage through changing pore space between particles (interpores) and by adding pores that are part of the biochar (intrapores). We used these experimental results to better understand how biochar intrapores and biochar particle shape control the observed changes in water retention when capillary pressure is the main component of soil water potential. We propose that biochar's intrapores increase water content of biochar-sand mixtures when soils are drier. When biochar-sand mixtures are wetter, biochar particles' elongated shape disrupts the packing of grains in the sandy matrix, increasing the volume between grains (interpores) available for water storage. These results imply that biochars with a high intraporosity and irregular shapes will most effectively increase water storage in coarse soils.

  12. Water sorption properties of HM-pectin and liposomes intended to alleviate dry mouth.

    Science.gov (United States)

    Adamczak, Małgorzata I; Martinsen, Ørjan G; Smistad, Gro; Hiorth, Marianne

    2016-06-15

    Pharmaceutical formulations intended for treatment of xerostomia (dry mouth) should be able to keep the oral mucosa hydrated for a prolonged period of time. The products already existing on the market contain water-soluble polymers, however their ability to moisturize the oral mucosa for a longer period of time seems limited. In this paper the sorption properties of water vapor of high-methoxylated pectin (HM-pectin, a hydrophilic biopolymer) and phosphatidylcholine-based (Soya-PC) liposomes have been studied and compared using a gravimetric method. The kinetics of water desorption and sorption have been recorded over the relative humidity range RH=95-0-95%, at 35°C. The obtained isotherms were found to be well described by the n-layer Brunauer-Emmet-Teller (BET) adsorption model. The water isotherms on HM-pectin were Type II (IUPAC), while water isotherms on liposomes were Type III. The maximum water sorption capacity of liposomes (1.2mg water per mg of adsorbent at 95% RH) was found to be twice as high as for pectin. Due to the slower water release from the liposomes, as well as their high water sorption capacity, they seem to have great potential in relieving the symptoms of dry mouth syndrome.

  13. Prediction of water content at different potentials from soil property data in Jazan region

    Science.gov (United States)

    Alturki, Ali; Ibrahim, Hesham

    2016-04-01

    In dry regions effective irrigation management is crucial to maintain crop production and sustain limited water resources. Effective irrigation requires good knowledge of soil water content in the root zone. However, measurement of soil water in the root zone over time is extremely expensive and time consuming. On the other hand, weather and basic soil property data are more available, either from existing databases or by direct measurement in the field. Simulation models can be used to efficiently and accurately estimate soil water content and subsequent irrigation requirements based on the available weather and soil data. In this study we investigated three hierarchical approaches to predict water content at variable potentials (0, 10, 33, 60, 100, 300, 500, 800, 1000, and 1500 kPa) using the Rosetta model: soil texture class (STC); percent of sand, silt, and clay (SSC); bulk density, percent of sand, silt, and clay, and water content measurements at 33 and 1500 kPa (SSC+WC). Estimation of soil water content at 43 locations in Jazan region using the three hierarchical approaches was compared with gravimetric water content. Results showed that the three approaches failed to describe water content accurately at saturation conditions (achieve effective irrigation scheduling especially in locations where only limited weather and soil date are available.

  14. Tribological properties and lubricating mechanism of SiO2 nanoparticles in water-based fluid

    Science.gov (United States)

    Bao, Y. Y.; Sun, J. L.; Kong, L. H.

    2017-03-01

    The tribological properties of surface modified SiO2 nanoparticles suspension in water-based lubricant have been studied. SiO2 (30 nm) nanoparticles were dispersed through surface modification with polyethylene glycol-200. Transmission electron microscope (TEM) and infrared (IR) spectroscopy show that SiO2 nanoparticles disperse well and stably in the water-based lubricant. The diameter of the nanoparticles is about 60 nm. Tribological properties of the water-based lubricant were evaluated using four-ball wear test machine and pin-on-disk tester under different loads and different concentrations of SiO2 nanoparticles. Wear surface morphology, element chemistry configuration of steel balls and steel rings were studied by means of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Results show that the tribological properties of the water-based fluid have been improved by addition of nanoparticles ranging from 0.1% to 0.3% concentrations. SiO2 nanoparticles deposited onto the wear surface during the sliding, which helped to reduce the friction coefficients and increase the anti-wear properties due to the miniature ball bearing effect and self-repairing performance of nanoparticles between the friction pairs. With the increase of test load, the friction coefficients decrease but the wear of the surface increase.

  15. Effect of water unextractable solids on gluten formation and properties: Mechanistic considerations

    NARCIS (Netherlands)

    Wang, M.; Hamer, R.J.; Vliet, T. van; Gruppen, H.; Marseille, H.; Weegels, P.L.

    2003-01-01

    A miniaturised set-up for gluten-starch separation was used to systematically study the effect of water unextractable solids (WUS) on the formation and properties of gluten. The results showed that WUS not only have a negative effect on gluten yield, but also affect gluten and glutenin macropolymer

  16. Effect of water unextractable solids on gluten formation and properties: Mechanistic considerations

    NARCIS (Netherlands)

    Wang, M.; Hamer, R.J.; Vliet, T. van; Gruppen, H.; Marseille, H.; Weegels, P.L.

    2003-01-01

    A miniaturised set-up for gluten-starch separation was used to systematically study the effect of water unextractable solids (WUS) on the formation and properties of gluten. The results showed that WUS not only have a negative effect on gluten yield, but also affect gluten and glutenin macropolymer

  17. Water vapor permeability, mechanical, optical and sensorial properties of plasticized guar gumedible films

    Science.gov (United States)

    Edible films were prepared by casting method using guar gum and glycerol in different ratios. The concentration of guar gum was 1.0, 1.5 and 2.0% whereas glycerol concentration was 20, 30 and 40% (w/v). The water vapor permeability (WVP), mechanical properties (tensile strength and elongation), thic...

  18. Effects of Water Intrusion on Mechanical Properties of and Crack Propagation in Coal

    Science.gov (United States)

    Yao, Qiangling; Chen, Tian; Ju, Minghe; Liang, Shun; Liu, Yapeng; Li, Xuehua

    2016-12-01

    Studying the mechanical properties of and crack propagation in coal after water intrusion is necessary to tackle a number of geological engineering problems such as those associated with underground water storage in collieries and support for underground roadways in coal mines. To study the mechanical properties and crack development, 12 coal samples with moisture contents of 0, 2.37, 3.78 and 5.29 % were prepared for acoustic emission tests under uniaxial compression. Over about 6 days, the coal samples absorbed moisture from a humidifier in three different phases. In this period, uniaxial tests show that the peak stress, elastic modulus, strain softening modulus and post-peak modulus decreased with rising moisture content in the samples while the peak strain increased. It was further found that, by analysing the relationship between the stiffness and stress and the accumulated acoustic emission counts, all the phases of crack development can be evaluated. This is useful for studying the effect of water intrusion on crack propagation and for calculating the mechanical properties of the coal such as the elastic modulus. This investigation also quantifies the percentage of the stress thresholds for crack closure, crack initiation, and crack damage that constitutes the peak stress. These stress thresholds do not change with moisture content. Our results are of great significance for water storage in coal mines, for determination of pillar dimensions in coal mines, and for expanding the knowledge base of the mechanical properties of coal and the characteristics of crack propagation.

  19. Effect of water unextractable solids on gluten formation and properties: mechanistic consideration.

    NARCIS (Netherlands)

    Wang, M.; Hamer, R.J.; Vliet, van T.; Gruppen, H.; Marseille, H.; Weegels, P.L.

    2003-01-01

    A miniaturised set-up for gluten-starch separation was used to systematically study the effect of water unextractable solids (WUS) on the formation and properties of gluten. The results showed that WUS not only have a negative effect on gluten yield, but also affect gluten and glutenin macropolymer

  20. ANTI-CORROSION PROPERTIES OF CARBOXYLIC ACID IN WATER-GLYCOL SOLUTIONS

    Directory of Open Access Journals (Sweden)

    BASHKIRCEVA N.Y.

    2012-01-01

    Full Text Available Sodium salts of carboxylic acids were investigated to evaluate the corrosion properties of the water-glycol solutions. Corrosion tests were performed by methods of gravimetry and galvanostatic dissolution with metals used in cooling systems. The compositions of anticorrosion systems and their concentration that provide the most effective inhibition of metals were determined.

  1. Phytoplankton community structure and nitrogen nutrition in Leeuwin Current and coastal waters off the Gascoyne region of Western Australia

    Science.gov (United States)

    Hanson, Christine E.; Waite, Anya M.; Thompson, Peter A.; Pattiaratchi, Charitha B.

    2007-04-01

    Within the coastal waters of the eastern Indian Ocean adjacent to Western Australia, we tested the hypothesis that regenerated production (and, by inference, the microbial food web) would predominate in oligotrophic Leeuwin Current (LC) and offshore (OS) surface waters. Conversely, we expected that new production would be more important within the ˜5 times more productive shelf countercurrents (Ningaloo and Capes Currents; NC&CC) and the LC&OS deep chlorophyll maximum (DCM). Phytoplankton species composition and abundance were assessed using both light microscopy and chemotaxonomic methods, and isotopic nitrogen uptake experiments ( 15NO 3-, 15NH 4+) were performed at trace (0.05 μM) and saturating (5.0 μM) levels. Phytoplankton community structure was statistically distinct between LC&OS and countercurrent regions. Picoplankton (unicellular cyanobacteria and prochlorophytes) accounted for a mean of 55-65% of pigment biomass in LC&OS waters, with haptophytes as the other primary contributor (21-32%). Conversely, within countercurrent and shelf regions, diatoms (up to 22%) and haptophytes (up to 57%) were more abundant, although cyanobacteria still played an important role (up to 40% of pigment biomass). Absolute NO 3- uptake rates for all samples ranged between 0.5 and 7.1 nmol L -1 h -1, and in countercurrent waters were not significantly different at the surface (3.0±2.1 nmol L -1 h -1; mean±SD) compared to the DCM (2.7±2.3 nmol L -1 h -1). However, in LC&OS waters, rates were significantly lower at the surface (1.2±0.7 nmol L -1 h -1) than the DCM (3.9±2.5 nmol L -1 h -1; p=0.05). These values represent conservative estimates for the region due to methodological difficulties encountered with nitrogen uptake experiments in these oligotrophic waters. In contrast with the distinct community composition between different water types, mean estimates of the f-ratio were similar across sampling depths and water types: 0.17±0.07 at the surface and 0.16±0.06 at

  2. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang

    2014-01-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori.

  3. Current and foreseeable applications of supercritical water for energy and the environment.

    Science.gov (United States)

    Loppinet-Serani, Anne; Aymonier, Cyril; Cansell, François

    2008-01-01

    It is crucial to develop economical and energy-efficient processes for the sustainable transformation of biomass into fuels and chemicals. In this context, supercritical water biomass valorization (SCBV) processes are an alternative way to produce biogas, biofuels, and valuable chemicals. Supercritical water technology has seen much progress over the last fifteen years and an industrial application has merged: the supercritical water oxidation of wastes. The evolution from lab-scale to pilot-scale facilities has provided data on reaction mechanisms, kinetics, modeling, and reactor technology as well as an important know-how, which can now be exploited to use the reactivity in supercritical water to transform biomass into gases (CO, H(2), CO(2), CH(4), and N(2)) or into liquids (liquid fuel and valuable chemicals) with the supercritical water biomass gasification and liquefaction processes, respectively. This Review highlights the potential of SCBV processes to transform biomass into gas and liquid energy sources and highlights the developments that are still necessary to push this technology onto the market.

  4. Physical and water properties of selected Polish heavy soils of various origins

    Directory of Open Access Journals (Sweden)

    Kaczmarek Zbigniew

    2015-12-01

    Full Text Available The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.

  5. The influence of microwave curing time and water glass kind on the properties of molding sands

    Directory of Open Access Journals (Sweden)

    K. Granat

    2007-12-01

    Full Text Available This work presents results of research on the influence of microwave heating time on the process of hardening of water glass molding sands. Essential influence of this drying process on basic properties such as: compression, bending and tensile strength as well as permeability and wear resistance, has been found. It has been proved, that all the investigated sorts of sodium water glass could be used as binding material of molding sands intended for curing with the microwave process heating. It has been found, while analyzing the results of property studies of microwave heated molding sands with 2.5% addition of water glass, that all available on the market kinds of this binding agent (including the most frequently used in foundry 145 and 149 kinds after microwave heating guarantee very good compression, bending and tensile strength as well as permeability and wear resistance. Moreover, it has been determined that the optimal curing time of molding sands containing various kinds of water glass is 240 seconds. After this time, all basic properties of molding sands are stable. The use of microwave curing of water glass molding sands results in a significant decrease of hardening process time, full stabilization of molding sands as well as much lower energy consumption.

  6. Estimating water and nitrate leaching in tree crops using inverse modelled plant and soil hydraulic properties

    Science.gov (United States)

    Couvreur, Valentin; Kandelous, Maziar; Mairesse, Harmony; Baram, Shahar; Moradi, Ahmad; Pope, Katrin; Hopmans, Jan

    2015-04-01

    Groundwater quality is specifically vulnerable in irrigated agricultural lands in California and many other (semi-)arid regions of the world. The routine application of nitrogen fertilizers with irrigation water in California is likely responsible for the high nitrate concentrations in groundwater, underlying much of its main agricultural areas. To optimize irrigation/fertigation practices, it is essential that irrigation and fertilizers are applied at the optimal concentration, place, and time to ensure maximum root uptake and minimize leaching losses to the groundwater. The applied irrigation water and dissolved fertilizer, root nitrate and water uptake interact with soil and root properties in a complex manner that cannot easily be resolved. It is therefore that coupled experimental-modelling studies are required to allow for unravelling of the relevant complexities that result from typical variations of crop properties, soil texture and layering across farmer-managed fields. A combined field monitoring and modelling approach was developed to quantify from simple measurements the leaching of water and nitrate below the root zone. The monitored state variables are soil water content within the root zone, soil matric potential below the root zone, and nitrate concentration in the soil solution. Plant and soil properties of incremented complexity are optimized with the software HYDRUS in an inverse modelling scheme, which allows estimating leaching under constraint of hydraulic principles. Questions of optimal irrigation and fertilization timing can then be addressed using predictive results and global optimization algorithms.

  7. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Directory of Open Access Journals (Sweden)

    Javier Valdes-Abellan

    2015-03-01

    Full Text Available Abstract Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i non-automatic and more time-consuming; ii automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic. Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm. Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.

  8. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Valdes-Abellan, J.; Jiménez-Martínez, J.; Candela, L.; Tamoh, K.

    2015-07-01

    Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i) non-automatic and more time-consuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher. (Author)

  9. Friction Properties of OTS SAMs and Silicon Surface under Water Lubrication

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHANG Xiangjun; AHMED Imad; LIU Ying; WEN Shizhu

    2009-01-01

    The friction and wear properties of silicon surface covered with octadecyltrichloro-silane (OTS) self-assembled monolayers (SAMs) were investigated by a UMT-2 microtribometer with and without water as lubricant, and then compared with that of bare silicon surface. Dry friction measurement results show that OTS SAMs have a very low friction coefficient compared to bare silicon surface under lower sliding velocity and normal contact load. However, heavy wear occurs on OTS SAMs under higher contact stress and sliding velocity. Under water lubrication, OTS SAMs can prevent wear obviously and meanwhile present low coefficient of friction even under high velocities.The improved frictional and anti-wear property on OTS SAMs surface is attributed to the hydrophobic property of OTS and hydrodynamic effect of water. Furthermore, a wear critical phase diagram for OTS SAMs with and without water was proposed, which indicates that OTS SAMs working under water lubrication owns a wider range of available load and velocity to reduce friction and prevent wear.

  10. Spectroscopic characterization of changes of DOM deprotonation-protonation properties in water treatment processes.

    Science.gov (United States)

    Yan, Mingquan; Dryer, Deborah; Korshin, Gregory V

    2016-04-01

    The deprotonation-protonation properties of dissolved organic matter (DOM) in drinking water produced at critical treatment points were quantified using absorbance spectra in combination with DOM fractionation data. Analysis of differential spectra of DOM present in inlet, settled and filtered waters from two large treatment plants and their fractions were obtained. The data demonstrated the presence of six Gaussian bands largely associated with carboxylic and phenolic DOM functionalities. Properties of the protonation-active groups of DOM in raw and treated waters were further examined based on data of potentiometric titrations at pH from 2.5 to 10. Interpretation of the differential log-transformed absorbance at wavelength 350 nm (DlnA350) based on the NICA-Donnan model showed that the normalized concentrations of low- and high-affinity protonation-active groups in residual DOMs increases as a result of water treatment. This was consistent with the results of DOM fractionation. This study demonstrates that changes of the composition and reactivity of DOM found in drinking water treatment sequences can be quantified based on the examination of their optical properties.

  11. The effect of lake water quality and wind turbines on Rhode Island property sales price

    Science.gov (United States)

    Gorelick, Susan Shim

    This dissertation uses the hedonic pricing model to study the impact of lake water quality and wind turbines on Rhode Island house sales prices. The first two manuscripts are on lake water quality and use RI house sales transactions from 1988--2012. The third studies wind turbines using RI house sales transactions from 2000--2013. The first study shows that good lake water quality increases lakefront property price premium. It also shows that environmental amenities, such as forests, substitute for lake amenity as the property's distance from the lake increases. The second lake water quality study incorporates time variables to examine how environmental amenity values change over time. The results show that property price premium associated with good lake water quality does not change as it is constant in proportion to housing prices with short term economic fluctuations. The third study shows that wind turbines have a negative and significant impact on housing prices. However, this is highly location specific and varies with neighborhood demographics. All three studies have policy implications which are discussed in detail in the manuscripts below.

  12. New direct estimates of Iceland-Scotland Overflow Water transport through the Charlie-Gibbs Fracture Zone and its relationship to the North Atlantic Current

    Science.gov (United States)

    Bower, Amy; Furey, Heather; Xu, Xiaobiao

    2015-04-01

    Detailed observations of the pathways, transports and water properties of dense overflows associated with the Atlantic Meridional Overturning Circulation (AMOC) provide critical benchmarks for climate models and mixing parameterizations. A recent two-year time series from eight moorings offers the first long-term simultaneous observations of the hydrographic properties and transport of Iceland-Scotland Overflow Water (ISOW) flowing westward through the Charlie-Gibbs Fracture Zone (CGFZ), a major deep gap in the Mid-Atlantic Ridge (MAR) connecting the eastern and western basins of the North Atlantic. In addition, current meters up to 500-m depth and satellite altimetry allow us to investigate the overlying North Atlantic Current (NAC) as a source of ISOW transport variability. Using the isohaline 34.94 to define the ISOW layer, the two year mean and standard deviation of ISOW transport was -1.7 ± 1.5 Sv, compared to -2.4 ± 3.0 Sv reported by Saunders for a 13-month period in 1988-1989 using the same isohaline. Differences in the two estimates are partly explained by limitations of the Saunders array, but more importantly reflect the strong low-frequency variability in ISOW transport through CGFZ (which includes complete reversals). Both the observations and output from a multi-decadal simulation of the North Atlantic using the Hybrid Coordinate Ocean Model (HYCOM) forced with interannually varying wind and buoyancy fields indicate a strong positive correlation between ISOW transport and the strength of the NAC through the CGFZ. This result raises new questions regarding the interaction of the upper and lower limbs of the AMOC, downstream propagation of ISOW transport variability in the Deep Western Boundary Current and alternative pathways of ISOW across the MAR.

  13. Effects of "natural" water and "added" water on prediction of moisture content and bulk density of shelled corn from microwave dielectric properties.

    Science.gov (United States)

    Trabelsi, Samir; Nelson, Stuart O; Lewis, Micah A

    2010-01-01

    Dielectric properties of samples of shelled corn of "natural" water content and those prepared by adding water were measured in free space at microwave frequencies and 23 degrees C. Results of measurements of attenuation, phase shift and dielectric constant and loss factor at 9 GHz show no difference between the samples with "natural" water and those in which water was added artificially. Bulk densities and moisture contents predicted from calibration equations expressed in terms of dielectric properties of both natural and added water samples agreed closely, and standard errors were less than 1% for moisture content and relative error for bulk density was less than 5%.

  14. Effect of Current Density on Thermodynamic Properties of Nanocrystalline Palladium Capped Samarium Hydride Thin Film Switchable Mirrors

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar

    2007-01-01

    Full Text Available A 55 nm samarium film capped with a 10 nm palladium overlayer switched from a metallic reflecting to a semiconducting, transparent in visible state during ex-situ hydrogen loading via electrochemical means in 1 M KOH electrolytic aqueous solution at room temperature. The switching between metal to semiconductor was accompanied by measurement of transmittance during hydrogen loading/unloading. The effect of current density on switching and thermodynamic properties was studied between dihydride state (FCC phase and trihydride state (hexagonal phase. From the plateau of partial pressure of hydrogen at x=2.6, enthalpy of formation was calculated at different current densities. The diffusion coefficients and switching kinetics are shown to depend on applied current density.

  15. Subthreshold membrane currents confer distinct tuning properties that enable neurons to encode the integral or derivative of their input

    Directory of Open Access Journals (Sweden)

    Stephanie eRatté

    2015-01-01

    Full Text Available Neurons rely on action potentials, or spikes, to encode information. But spikes can encode different stimulus features in different neurons. We show here through simulations and experiments how neurons encode the integral or derivative of their input based on the distinct tuning properties conferred upon them by subthreshold currents. Slow-activating subthreshold inward (depolarizing current mediates positive feedback control of subthreshold voltage, sustaining depolarization and allowing the neuron to spike on the basis of its integrated stimulus waveform. Slow-activating subthreshold outward (hyperpolarizing current mediates negative feedback control of subthreshold voltage, truncating depolarization and forcing the neuron to spike on the basis of its differentiated stimulus waveform. Depending on its direction, slow-activating subthreshold current cooperates or competes with fast-activating inward current during spike initiation. This explanation predicts that sensitivity to the rate of change of stimulus intensity differs qualitatively between integrators and differentiators. This was confirmed experimentally in spinal sensory neurons that naturally behave as specialized integrators or differentiators. Predicted sensitivity to different stimulus features was confirmed by covariance analysis. Integration and differentiation, which are themselves inverse operations, are thus shown to be implemented by the slow feedback mediated by oppositely directed subthreshold currents expressed in different neurons.

  16. Pharmacological and physiological properties of the after-hyperpolarization current of bullfrog ganglion neurones.

    Science.gov (United States)

    Goh, J W; Pennefather, P S

    1987-12-01

    1. The slowly decaying, calcium-dependent after-hyperpolarization (a.h.p.) that follows action potentials in bullfrog ganglion B cells has previously been shown to be generated by a potassium current called IAHP. We have recorded IAHP using a switched, single-electrode hybrid clamp where current-clamp mode was changed to voltage-clamp mode immediately after repolarization of a spike or the last spike of a train. 2. Reduction of extracellular calcium reduced the decay time of IAHP following a single spike. At all levels of extracellular calcium tested (0.5-4 mM), the decay time of IAHP was longer following a train of action potentials than following a single action potential. Thus, the time course of IAHP evoked by action potentials is a function of the calcium load induced by the action potentials. Conversely, agents that reduce the amount of IAHP activated without affecting its rate of decay, probably do not affect calcium influx. 3. Muscarine (2 or 10 microM) inhibits IAHP following an action potential by at most 30% and has no effect on decay rate of IAHP. These results suggest that muscarine has little or no effect on either calcium influx or sequestration. Decay of the a.h.p. is accelerated by muscarine but this effect is due to an increased leak conductance. 4. Charybdotoxin (CTX) between 4 and 20 nM, prolongs ac