WorldWideScience

Sample records for water depth influence

  1. Influence of water vapour and permanent gases on the atmospheric optical depths and transmittance

    Science.gov (United States)

    Badescu, V.

    1991-05-01

    The influence of the atmospheric state on the extinction of direct solar radiation has been studied by using a four layer atmospheric model. Simple analytical formulae are established for the spectral optical depths of permanent gases and water vapour. These formulae use the ground level values of air pressure, temperature and relative huniidity. An additional parameter, related to the vertical distribution of the hunmidity content, is used for a better estimation of the water vapour optical depth. Good agreement between theory and measurements is found. The paper shows the dependence of the atmospheric spectral transmittance on the above mentioned parameters. L'influence de l'état atmosphérique sur l'extinction de la radiation solaire directe a été étudiée à l'aide d'un modèle atmosphérique développé antérieurement par l'auteur. Des formules simples ont été établies pour l'épaisseur optique spectrale des gaz et de la vapeur d'eau. Ces formules utilisent les valeurs de la pression atmosphérique, de la température et de l'humidité relative, mesurées au niveau du sol. Un paramètre supplémentaire, lié à la distribution verticale du contenu d'humidité, est utilisé pour calculer l'épaisseur optique due à la vapeur d'eau. La théorie est en bon accord avec les résultats des mesures. Le travail montre la dépendance de la transmittance atmosphérique spectrale en fonction des paramètres spécifiés ci-dessus.

  2. Influence of water depth on the carbon sequestration capacity of seagrasses

    Science.gov (United States)

    Serrano, Oscar; Lavery, Paul S.; Rozaimi, Mohammad; Mateo, Miguel Ángel

    2014-09-01

    The actual estimates of carbon stocks beneath seagrass meadows worldwide are derived from few data, resulting in a tendency to generalize global carbon stocks from a very limited number of seagrass habitats. We surveyed Posidonia oceanica and Posidonia sinuosa meadows along depth-induced gradients of light availability to assess the variability in their sedimentary organic carbon (Corg) stocks and accretion rates. This study showed a fourfold decrease in Corg stocks from 2-4 m to 6-8 m depth P. sinuosa meadows (averaging 7.0 and 1.8 kg m-2, respectively; top meter of sediment) and a fourteenfold to sixteenfold decrease from shallow (2 m) to deep (32 m) P. oceanica meadows (200 and 19 kg m-2 average, respectively; top 2.7 m of sediment). The average Corg accretion rates in shallow P. sinuosa meadows were higher (10.5 g m-2 yr-1) than in deeper meadows (2.1 g m-2 yr-1). The reduction of sedimentary Corg stocks and accretion rates along depth-related gradients of light reduction suggests that irradiance, controlling plant productivity, meadow density, and sediment accretion rates, is a key environmental factor affecting Corg storage potential of seagrasses. The results obtained highlighted the exceptional carbon storage capacity of P. oceanica meadows at Balearic Islands (Spain), containing the highest areal Corg stocks of all seagrasses (estimated in up to 691-770 kg m-2 in 8-13 m thick deposits). Seagrass communities are experiencing worldwide decline, and reduced irradiance (following e.g., eutrophication or sediment regime alterations) will lead to photoacclimation responses (i.e., reduced plant productivity and shoot density), which may impact the carbon sequestration capacity of seagrasses.

  3. Chemical composition, water vapor permeability, and mechanical properties of yuba film influenced by soymilk depth and concentration.

    Science.gov (United States)

    Zhang, Siran; Lee, Jaesang; Kim, Yookyung

    2017-09-01

    Yuba is a soy protein-lipid film formed during heating of soymilk. This study described yuba as an edible film by analyzing its chemical composition, water vapor permeability (WVP), and mechanical properties. Three yuba films were prepared by using different concentrations and depths of soymilk: HS (86 g kg-1 and 2.3 cm), LS (70 g kg-1 and 2.3 cm), and LD (70 g kg-1 and 3.0 cm). As yuba was successively skimmed, the protein, lipid, and SH content decreased, but carbohydrate and SS content increased. Though both the initial concentration and the depth of soymilk affect the properties of the films, the depth of soymilk influences WVP and tensile strength (TS) more. The WVP of the HS and LS changed the least (13-17 g mm kPa-1 m-2 day), while that of the LD changed the most (13-35 g mm kPa-1 m-2 day-1 ). There were no differences (P > 0.05) in the TS between the HS and LS. LD had the greatest decrease of TS and the lowest TS among the groups. The earlier the yuba films were collected, the greater the elongation of the films was: 129% (HS), 113% (LS), and 155% (LD). The initial concentration and the depth of soymilk changed the chemical composition and structure of the yuba films. The LS yuba produced more uniform edible films with good mechanical properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Malheur NWR: Initial Survey Instructions for Water Table Depth Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Water table wells assist in filling a critical information gap related to fluctuating water table depth and its influence on habitat expression within wet meadow...

  5. Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

    Science.gov (United States)

    Guerreiro, Catarina V.; Baumann, Karl-Heinz; Brummer, Geert-Jan A.; Fischer, Gerhard; Korte, Laura F.; Merkel, Ute; Sá, Carolina; de Stigter, Henko; Stuut, Jan-Berend W.

    2017-10-01

    Coccolithophores are calcifying phytoplankton and major contributors to both the organic and inorganic oceanic carbon pumps. Their export fluxes, species composition, and seasonal patterns were determined in two sediment trap moorings (M4 at 12° N, 49° W and M2 at 14° N, 37° W) collecting settling particles synchronously from October 2012 to November 2013 at 1200 m of water depth in the open equatorial North Atlantic. The two trap locations showed a similar seasonal pattern in total coccolith export fluxes and a predominantly tropical coccolithophore settling assemblage. Species fluxes were dominated throughout the year by lower photic zone (LPZ) taxa (Florisphaera profunda, Gladiolithus flabellatus) but also included upper photic zone (UPZ) taxa (Umbellosphaera spp., Rhabdosphaera spp., Umbilicosphaera spp., Helicosphaera spp.). The LPZ flora was most abundant during fall 2012, whereas the UPZ flora was more important during summer. In spite of these similarities, the western part of the study area produced persistently higher fluxes, averaging 241×107 ± 76×107 coccoliths m-2 d-1 at station M4 compared to only 66×107 ± 31×107 coccoliths m-2 d-1 at station M2. Higher fluxes at M4 were mainly produced by the LPZ species, favoured by the westward deepening of the thermocline and nutricline. Still, most UPZ species also contributed to higher fluxes, reflecting enhanced productivity in the western equatorial North Atlantic. Such was the case of two marked flux peaks of the more opportunistic species Gephyrocapsa muellerae and Emiliania huxleyi in January and April 2013 at M4, indicating a fast response to the nutrient enrichment of the UPZ, probably by wind-forced mixing. Later, increased fluxes of G. oceanica and E. huxleyi in October-November 2013 coincided with the occurrence of Amazon-River-affected surface waters. Since the spring and fall events of 2013 were also accompanied by two dust flux peaks, we propose a scenario in which atmospheric dust also

  6. Water depth penetration film test

    Science.gov (United States)

    Lockwood, H. E.; Perry, L.; Sauer, G. E.; Lamar, N. T.

    1974-01-01

    As part of the National Aeronautics and Space Administration Earth Resources Program, a comparative and controlled evaluation of nine film-filter combinations was completed to establish the relative effectiveness in recording water subsurface detail if exposed from an aerial platform over a typical water body. The films tested, with one exception, were those which prior was suggested had potential. These included an experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and a black-and-white infrared film. Selective filtration was used with all films.

  7. Wave Loads on Ships Sailing in Restricted Water Depth

    DEFF Research Database (Denmark)

    Vidic-Perunovic, Jelena; Jensen, Jørgen Juncher

    2003-01-01

    moment a ship may be subjected to during its operational lifetime. Whereas the influence of forward speed and ship heading with respect to the waves usually is accounted for, the effect of water depth is seldom considered, except in non-linear time domain formulations where a confined water domain must...... be specified anyhow. Usually, two-dimensional strip theories, either linear or non-linear, are applied for actual design cases and these theories are normally based on incident deep-water waves and furthermore apply added mass and damping calculations based on infinite water depth. Only a few papers have...... in the past addressed the influence of water depth on the ship response. In an early work Kim (1968) presented results for the variation of the added mass and hydrodynamic damping and for the heave and pitch motion for a Series 60 model using a relative motion strip theory formulation. A significant reduction...

  8. Depth to ground water of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a raster-based, depth to ground-water data set for the State of Nevada. The source of this data set is a statewide water-table contour data set constructed...

  9. The interplay between rainfall infiltration depth, rooting depth and water table depth in regulating Amazon evapotranspiration (ET)

    Science.gov (United States)

    Miguez-Macho, Gonzalo; Fan, Ying; Dominguez, Francina

    2017-04-01

    Plants link the subsurface to the atmosphere via water and carbon fluxes and are therefore a key player in climate. The Amazon, one of Earth's largest ecosystems, is an important climate regulator. As a large source of evapotranspiration, it has significant influence on regional and remote precipitation dynamics. For its equatorial position, it impacts significantly the global climate engine. The Amazon receives abundant annual rainfall but parts of it experience a multi-month dry season. Here we elucidate the interplay among three hydrological depths: precipitation infiltration depth, root water uptake-depth, and the water table depth in regulating dry-season ET, using inverse modeling based on observed productivity, ERA Interim reanalysis atmosphere, and a novel integrated soil-surface-groundwater model with dynamic root uptake to meet the transpiration demand. We perform high-resolution ( 1km) multi-year simulations over the region, with shallow soil, deep soil, with and without groundwater, with and without dynamic rooting depth; attempting to tease out these components. The results demonstrate the strong interactions among the three depths and what each factor does in regulating dry season ET, shedding light on how future global change may preferentially impact Amazon ecosystem functioning.

  10. WAVECALC: an Excel-VBA spreadsheet to model the characteristics of fully developed waves and their influence on bottom sediments in different water depths

    Science.gov (United States)

    Le Roux, Jacobus P.; Demirbilek, Zeki; Brodalka, Marysia; Flemming, Burghard W.

    2010-10-01

    The generation and growth of waves in deep water is controlled by winds blowing over the sea surface. In fully developed sea states, where winds and waves are in equilibrium, wave parameters may be calculated directly from the wind velocity. We provide an Excel spreadsheet to compute the wave period, length, height and celerity, as well as horizontal and vertical particle velocities for any water depth, bottom slope, and distance below the reference water level. The wave profile and propagation can also be visualized for any water depth, modeling the sea surface change from sinusoidal to trochoidal and finally cnoidal profiles into shallow water. Bedload entrainment is estimated under both the wave crest and the trough, using the horizontal water particle velocity at the top of the boundary layer. The calculations are programmed in an Excel file called WAVECALC, which is available online to authorized users. Although many of the recently published formulas are based on theoretical arguments, the values agree well with several existing theories and limited field and laboratory observations. WAVECALC is a user-friendly program intended for sedimentologists, coastal engineers and oceanographers, as well as marine ecologists and biologists. It provides a rapid means to calculate many wave characteristics required in coastal and shallow marine studies, and can also serve as an educational tool.

  11. Anchoring International sets new water depth record

    Energy Technology Data Exchange (ETDEWEB)

    Noble, H.J.

    1983-07-01

    Santa Barbara Channel has a history steeped in firsts in techniques for the production of offshore oil. Landscaped drilling and production islands, production piers, and directional drilling from land rigs to production under the channel, to name a few. The latest such project was handled by Anchoring International, Inc., a pipe line anchoring company headquartered in Houston, Texas. Contracted by Healy Tibbets Construction Company, prime contractor, Anchoring was commissioned to handle a new deep water record breaking anchoring job. The job was to anchor J-tube extensions in 820 feet of water--the deepest pipe line anchoring job ever undertaken. In most shallow water pipe line anchoring jobs, anchors and anchor installation unit placement over the pipe line is handled from a crane topside with visual assist from divers. However, due to the extreme depth of this project, the installation unit with anchors had to be modified for submersible operator-assisted placement capability. Anchoring International handled the anchor design and installation equipment, and submersible operator assistance was furnished by Oceaneering, International. WASP and JIM atmospheric diving systems were used. All ocean bottom activities were monitored topside with the JERED video-equipped remote controlled vehicle. Since the weight of the anchor sets and power installation unit are minimum, the entire operation was conducted from a small boat sufficient to carry dive equipment and the anchor installation unit power supply. A small pedestal crane was used to lower and retrieve the anchor installation unit.

  12. Electroacoustic Process Study of Plasma Sparker Under Different Water Depth

    KAUST Repository

    Huang, Yifan

    2015-01-05

    The plasma sparker has been applied in oceanic high-resolution seismic exploration for decades. Normally it is towed on the water surface. This is suitable for shallow water, but if the water depth is great, the resolution will decrease dramatically, especially in the horizontal direction. This paper proposes the concept of a deep-towed plasma sparker and presents an experimental study of plasma sparker performance in terms of electric parameters, bubble behavior, and acoustic characteristics. The results show that hydrostatic pressure at a source depth ranging from 1 to 2000 m has a negligible influence on the electric parameters but a strong influence on bubble behavior, wherein both the maximum bubble radius and oscillation period are decreased. The collapse pulse vanishes when the source depth reaches 1000 m or deeper, and no bubble oscillation can be distinguished. The source level (evaluated by the expansion pulse) is also decreased as the source depth increases; moreover, the greater the discharge energy, the smaller the source level loss. The discharge energy per electrode should be greater than 20 J for the deep-towed plasma sparker, which can make the source level loss induced by hydrostatic pressure smaller than the transmission loss. The fast Fourier transform (FFT) results show that the dominant energy is around 20 kHz, which is mainly induced by the expansion pulse and its oscillation. According to the simulation results, the fundamental frequency of the acoustic waveform increases with source depth in accord with a log linear trend, and also reaches tens of kilohertz in deep water. So, before the development of deep-towed plasma sparker, a new technical solution will need to be developed to solve this problem. © 1976-2012 IEEE.

  13. Annual Thaw Depths and Water Depths in Tanana Flats, Alaska, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Thaw depths and water depths were monitored at 1 m to 2 m intervals along a 255-m transect across an area of discontinuous and degrading permafrost on the Tanana...

  14. A boundary element model for diffraction of water waves on varying water depth

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Sanne

    1997-12-31

    In this thesis a boundary element model for calculating diffraction of water waves on varying water depth is presented. The varying water depth is approximated with a perturbed constant depth in the mild-slope wave equation. By doing this, the domain integral which is a result of the varying depth is no longer a function of the unknown wave potential but only a function of position and the constant depth wave potential. The number of unknowns is the resulting system of equations is thus reduced significantly. The integration procedures in the model are tested very thoroughly and it is found that a combination of analytical integration in the singular region and standard numerical integration outside works very well. The gradient of the wave potential is evaluated successfully using a hypersingular integral equation. Deviations from the analytical solution are only found on the boundary or very close to, but these deviations have no significant influence on the accuracy of the solution. The domain integral is evaluated using the dual reciprocity method. The results are compared with a direct integration of the integral, and the accuracy is quite satisfactory. The problem with irregular frequencies is taken care of by the CBIEM (or CHIEF-method) together with a singular value decomposition technique. This method is simple to implement and works very well. The model is verified using Homma`s island as a test case. The test cases are limited to shallow water since the analytical solution is only valid in this region. Several depth ratios are examined, and it is found that the accuracy of the model increases with increasing wave period and decreasing depth ratio. Short waves, e.g. wind generated waves, can allow depth variations up to approximately 2 before the error exceeds 10%, while long waves can allow larger depth ratios. It is concluded that the perturbation idea is highly usable. A study of (partially) absorbing boundary conditions is also conducted. (EG)

  15. Modelling mid-span water table depth and drainage discharge ...

    African Journals Online (AJOL)

    2015-04-03

    Apr 3, 2015 ... groundwater table depth at varied drain depth and spacing combinations (ASAE Standards, 1999). ... Where ∆Va is the change in water pore space (cm) at any time increment ∆t (h); F is the amount of water ...... and nitrogen losses in a cold climate using DRAINMOD 5.1. Trans. ASAE 53 (2) 385−395.

  16. Photonic crystal fiber coil sensor for water-depth sensing

    Science.gov (United States)

    Fan, Chen-Feng; Yu, Chin-Ping

    2013-05-01

    We fabricate a PCF coil sensor for water-depth sensing by winding a PCF on a plastic straw. Due to the bending-induced birefringence along the PCF, we can observe clear interference pattern in the output spectrum by placing the PCF coil into a Sagnac fiber loop. As we horizontally immerse the fabricated PCF coil into water, a nonlinear relationship between the water depth and the wavelength shift can be obtained. We have also measured the interference spectrum by vertically immersing the PCF coil into water. We can observe a linear relationship between the water depth and the wavelength shift, and the measured water-depth sensitivity for vertical immersion is -1.17 nm/mm.

  17. WATER DEPTH and Other Data (NCEI Accession 9400181)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NIRO-MET data set containing water depth and other data in this accession was sent by Borris Trotsenko from Southern Scientific Research Institute of Marine...

  18. An opaque surface influences the depth from the Pulfrich phenomenon.

    Science.gov (United States)

    Kham, Keetaek

    2004-01-01

    When a pendulum, swinging in a frontoparallel plane, is viewed with a neutral density filter before one eye, the pendulum bob appears to rotate in an elliptical path. This illusion, known as the Pulfrich phenomenon, was used to examine depth cue interaction in a natural environment. An opaque surface was placed behind the pendulum. This intervention put the 'Pulfrich depth' of the pendulum in conflict with the information provided by other depth cues, such as interposition, and observers reported that the 'far' part of the pendulum's Pulfrich trajectory appeared to be flat. This was not the case when the surface was transparent. If the opaque surface was placed farther behind the pendulum's physical path, the far trajectory became increasingly elliptical. These results suggest that the opaque surface influences the pendulum's depth qualitatively and quantitatively. That is, the depth order between the surface and the pendulum is determined by interposition, but the absolute depth of the pendulum's Pulfrich trajectory is constrained by the surface's depth.

  19. Differences in water depth determine leaf-litter decomposition in streams: implications on impact assessment reliability

    Directory of Open Access Journals (Sweden)

    Martínez A.

    2016-01-01

    Full Text Available Leaf-litter decomposition is a widespread functional indicator to assess the stream ecosystem status. However, the spatial location of leaf-bags could distort the impact assessment since intrinsic features of a given site have an important role in the spatial distribution of macroinvertebrates, which could affect decomposition rate. A source of variability that can be easily controlled is the water depth at which bags are incubated in stream bed. Therefore, we tested if water depth within a same mesohabitat (riffles can determine decomposition rates. Due to the seasonal variability of macroinvertebrate assemblages in temperate regions, the study was performed in autumn-winter and spring to test the consistency of the findings. In three streams from North of Spain 15 mesh bags with alder leaves were placed in riffles covering a gradient of depths. Depth had a positive effect on decomposition rates and biomass of associated total invertebrates and shredders in autumn-winter, fauna variables helping to explain the differences in rates. In spring, depth affected negatively rates, the observed variability being weakly explained by invertebrates, which did not show differences along depth. Despite the opposite trend between seasons, water depth influences the decomposition rates, which may reduce or increase differences among systems if the water depth distribution is greatly biased. Our study highlights the importance of covering a similar range of water depths in the different systems being compared.

  20. Depth

    Science.gov (United States)

    Koenderink, Jan J; van Doorn, Andrea J; Wagemans, Johan

    2011-01-01

    Depth is the feeling of remoteness, or separateness, that accompanies awareness in human modalities like vision and audition. In specific cases depths can be graded on an ordinal scale, or even measured quantitatively on an interval scale. In the case of pictorial vision this is complicated by the fact that human observers often appear to apply mental transformations that involve depths in distinct visual directions. This implies that a comparison of empirically determined depths between observers involves pictorial space as an integral entity, whereas comparing pictorial depths as such is meaningless. We describe the formal structure of pictorial space purely in the phenomenological domain, without taking recourse to the theories of optics which properly apply to physical space—a distinct ontological domain. We introduce a number of general ways to design and implement methods of geodesy in pictorial space, and discuss some basic problems associated with such measurements. We deal mainly with conceptual issues. PMID:23145244

  1. The Antiproton Depth-Dose Curve in Water

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael; Jäkel, Oliver

    2008-01-01

    We have measured the depth-dose curve of 126 MeV antiprotons in a water phantom using ionization chambers. Since the antiproton beam provided by CERN has a pulsed structure and possibly carries a high-LET component from the antiproton annihilation, it is necessary to correct the acquired charge...

  2. Effects of tailwater depth on spillway aeration | Aras | Water SA

    African Journals Online (AJOL)

    Hydraulic structures such as spillways or weirs with their water-air controlling mechanisms are not only important for their structural properties but also for their effects on downstream ecology. Tailwater depth is an important factor affecting dissolved oxygen transfer and aeration rates of spillways. In this study, effects of ...

  3. Modelling mid-span water table depth and drainage discharge ...

    African Journals Online (AJOL)

    Water table depths were monitored in 1.7 m deep piezometers installed mid-way between two drains by using an electronic dip meter with a beeper, while DDs were measured at drain lateral outlet points, using a bucket and a stop watch. Both WTDs and DDs were monitored from September 2011 to February 2012. Results ...

  4. The influence of age and depth of dentin on bonding.

    Science.gov (United States)

    Burrow, M F; Takakura, H; Nakajima, M; Inai, N; Tagami, J; Takatsu, T

    1994-07-01

    The purpose of this study was to investigate what influence the two variables of dentin depth and age may have on the tensile bond strengths of three bonding systems. Dentin discs prepared from human molars were divided into young and old, superficial and deep surfaces. Three bonding systems, Scotchbond Multi-purpose (3M Dental Products), Superbond D-liner (Sun Medical Co.), and Liner Bond II (Kuraray Co.) were the materials tested for tensile bond strength. In addition, the structural variation of the resin-impregnated, or hybrid, layer was compared among the two variables and three bonding systems. Tensile bond strengths exceeding 10 MPa were obtained for all materials. After ANOVA, an effect on tensile bond strength could be attributed to dentin age or depth for only Superbond D-liner used on deep-young dentin as compared with old-superficial dentin. All other group comparisons failed to show any variation between dentin depth or age. However, specimens bonded to deeper dentin showed slightly lower strengths. SEM observations showed thicker resin-impregnated layers for Scotchbond MP and Superbond D-liner compared with Liner Bond II. Liner Bond II exhibited a thinner and more diffuse resin-impregnated layer, believed to be due to the different dentin conditioning method. Dentin age or depth may not show as great an influence on bond strengths with the newer type of bonding systems. The resin-impregnated layer quality, rather than thickness, is believed to be the most important factor for obtaining high tensile bond strengths.

  5. An analysis of depth dose characteristics of photon in water.

    Science.gov (United States)

    Buzdar, Saeed Ahmad; Rao, Muhammad Afzal; Nazir, Aalia

    2009-01-01

    Photon beam is most widely being used for radiation therapy. Biological effect of radiation is concerned with the evaluation of energy absorbed in the tissues. It was aimed to analyse the depth dose characteristics of x-ray beams of diverse energies to enhance the quality of radiotherapy treatment planning. Depth dose characteristics of different energy photon beams in water have been analysed. Photon beam is attenuated by the medium and the transmitted beam with less intensity causes lesser absorbed dose as depth increases. Relative attenuation on certain points on the beam axis and certain percentage of doses on different depths for available energies has been investigated. Photon beam depth dose characteristics do not show identical attributes as interaction of x-ray with matter is mainly governed by beam quality. Attenuation and penetration parameters of photon show variation with dosimetric parameters like field size due to scattering and Source to Surface Distance due to inverse square law, but the major parameter in photon interactions is its energy. Detailed analysis of photon Depth Dose characteristics helps to select appropriate beam for radiotherapy treatment when variety of beam energies available. Evaluation of this type of characteristics will help to establish theoretical relationships between dosimetric parameters to confirm measured values of dosimetric quantities, and hence to increase accuracy in radiotherapy treatment.

  6. Simulation of emergence of winter wheat in response to soil temperature, water potential and planting depth

    Science.gov (United States)

    Seedling emergence is a critical stage in the establishment of dryland wheat. Soil temperature, soil water potential and planting depth are important factors influencing emergence. These factors have considerable spatio-temporal variation making it difficult to predict the timing and percentage of w...

  7. How do jet time, pressure and bone volume fraction influence the drilling depth when waterjet drilling in porcine bone?

    NARCIS (Netherlands)

    den Dunnen, Steven; Dankelman, Jenny; Kerkhoffs, Gino M. M. J.; Tuijthof, Gabrielle J. M.

    2016-01-01

    Using water jets for orthopedic procedures that require bone drilling can be beneficial due to the absence of thermal damage and the always sharp cut. Previously, the influence of the water jet diameter and bone architectural properties on the drilling depth have been determined. To develop water

  8. Nest Survival of American Coots Relative to Grazing, Burning, and Water Depths

    Directory of Open Access Journals (Sweden)

    Jane E. Austin

    2011-12-01

    Full Text Available Water and emergent vegetation are key features influencing nest site selection and success for many marsh-nesting waterbirds. Wetland management practices such as grazing, burning, and water-level manipulations directly affect these features and can influence nest survival. We used model selection and before-after-control-impact approaches to evaluate the effects of water depth and four common land-management practices or treatments, i.e., summer grazing, fall grazing, fall burning, and idle (no active treatment on nest survival of American coots (Fulica americana nesting at Grays Lake, a large montane wetland in southeast Idaho. The best model included the variables year × treatment, and quadratic functions of date, water depth, and nest age; height of vegetation at the nest did not improve the best model. However, results from the before-after-control-impact analysis indicate that management practices affected nest success via vegetation and involved interactions of hydrology, residual vegetation, and habitat composition. Nest success in idled fields changed little between pre- and post-treatment periods, whereas nest success declined in fields that were grazed or burned, with the most dramatic declines the year following treatments. The importance of water depth may be amplified in this wetland system because of rapid water-level withdrawal during the nesting season. Water and land-use values for area ranchers, management for nesting waterbirds, and long-term wetland function are important considerations in management of water levels and vegetation.

  9. MODIS Retrieval of Aerosol Optical Depth over Turbid Coastal Water

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2017-06-01

    Full Text Available We present a new approach to retrieve Aerosol Optical Depth (AOD using the Moderate Resolution Imaging Spectroradiometer (MODIS over the turbid coastal water. This approach supplements the operational Dark Target (DT aerosol retrieval algorithm that currently does not conduct AOD retrieval in shallow waters that have visible sediments or sea-floor (i.e., Class 2 waters. Over the global coastal water regions in cloud-free conditions, coastal screening leads to ~20% unavailability of AOD retrievals. Here, we refine the MODIS DT algorithm by considering that water-leaving radiance at 2.1 μm to be negligible regardless of water turbidity, and therefore the 2.1 μm reflectance at the top of the atmosphere is sensitive to both change of fine-mode and coarse-mode AODs. By assuming that the aerosol single scattering properties over coastal turbid water are similar to those over the adjacent open-ocean pixels, the new algorithm can derive AOD over these shallow waters. The test algorithm yields ~18% more MODIS-AERONET collocated pairs for six AERONET stations in the coastal water regions. Furthermore, comparison of the new retrieval with these AERONET observations show that the new AOD retrievals have equivalent or better accuracy than those retrieved by the MODIS operational algorithm’s over coastal land and non-turbid coastal water product. Combining the new retrievals with the existing MODIS operational retrievals yields an overall improvement of AOD over those coastal water regions. Most importantly, this refinement extends the spatial and temporal coverage of MODIS AOD retrievals over the coastal regions where 60% of human population resides. This expanded coverage is crucial for better understanding of impact of anthropogenic aerosol particles on coastal air quality and climate.

  10. Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

    Science.gov (United States)

    Manning, Andrew H.; Verplanck, Philip L.; Caine, Jonathan S.; Todd, Andrew S.

    2013-01-01

    Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite

  11. Compact water depth sensor with LPFG using the photoelastic effect and heat-shrinkable tube

    Science.gov (United States)

    Takama, Shinya; Kudomi, Takamasa; Ohashi, Masaharu; Miyoshi, Yuji

    2011-12-01

    We propose a compact water depth sensor with a long period fiber grating (LPFG) using a heat-shrinkable tube. The pressure property of the LPFG is investigated experimentally to confirm the feasibility of the water depth sensor. Moreover, the water depth in the 2m long water-filled pipe is successfully estimated by the proposed water sensors.

  12. Optimizing water depth for wetland-dependent wildlife could increase wetland restoration success, water efficiency, and water security

    Science.gov (United States)

    Nadeau, Christopher P.; Conway, Courtney J.

    2015-01-01

    Securing water for wetland restoration efforts will be increasingly difficult as human populations demand more water and climate change alters the hydrologic cycle. Minimizing water use at a restoration site could help justify water use to competing users, thereby increasing future water security. Moreover, optimizing water depth for focal species will increase habitat quality and the probability that the restoration is successful. We developed and validated spatial habitat models to optimize water depth within wetland restoration projects along the lower Colorado River intended to benefit California black rails (Laterallus jamaicensis coturniculus). We observed a 358% increase in the number of black rails detected in the year after manipulating water depth to maximize the amount of predicted black rail habitat in two wetlands. The number of black rail detections in our restoration sites was similar to those at our reference site. Implementing the optimal water depth in each wetland decreased water use while simultaneously increasing habitat suitability for the focal species. Our results also provide experimental confirmation of past descriptive accounts of black rail habitat preferences and provide explicit water depth recommendations for future wetland restoration efforts for this species of conservation concern; maintain surface water depths between saturated soil and 100 mm. Efforts to optimize water depth in restored wetlands around the world would likely increase the success of wetland restorations for the focal species while simultaneously minimizing and justifying water use.

  13. Water uptake depth analyses using stable water isotopes in rice-based cropping systems in Southeastern Asia

    Science.gov (United States)

    Mahindawansha, Amani; Kraft, Philipp; Orlowski, Natalie; Racela, Healthcliff S. U.; Breuer, Lutz

    2017-04-01

    Rice is one of the most water-consuming crop in the world. Understanding water source utilization of rice-based cropping systems will help to improve water use efficiency (WUE) in paddy management. The objectives of our study were to (1) determine the contributions of various water sources to plant growth in diversified rice-based production systems (wet rice, aerobic rice) (2) investigate water uptake depths at different maturity periods during wet and dry conditions, and (3) calculate WUE of the cropping systems. Our field experiment is based on changes of stable water isotope concentrations in the soil-plant-atmosphere continuum due to transpiration and evaporation. Soil samples were collected together with root sampling from nine different depths under vegetative, reproductive, and matured periods of plant growth together with stem samples. Soil and plant samples were extracted by cryogenic vacuum extraction. Groundwater, surface water, rain, and irrigation water were sampled weekly. All water samples were analyzed for hydrogen and oxygen isotope ratios (δ2H and δ18O) via a laser spectroscope (Los Gatos DLT100). The direct inference approach, which is based on comparing isotopic compositions between plant stem water and soil water, were used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These estimations were used to determine the proportion of water from upper soil horizons and deep horizons for rice in different maturity periods during wet and dry seasons. Shallow soil water has the higher evaporation than from deeper soil water where the highest evaporation effect is at 5 cm depth (drying front). Water uptake is mostly taking place from surface water in the vegetative and between 5-10 cm in the reproductive period, since roots have grown widely and deeper in the reproductive stage. This will be

  14. Estimating plant water uptake source depths with optimized stable water isotope labeling

    Science.gov (United States)

    Seeger, Stefan; Weiler, Markus

    2016-04-01

    Depth profiles of pore water stable isotopes in soils in conjunction with measurements of stable water isotopes (SWI) in plant transpiration allow the estimation of the contributions of different soil depths to plant water uptake (PWU).
 However, SWI depth profiles that result from the variations of SWI in natural precipitation may lead to highly ambiguous results, i.e. the same SWI signature in transpiration could result from different PWU patterns or SWI depth profiles. The aim of this study was to find an optimal stable water isotope depth profile to estimate plant water uptake patterns and to compare different PWU source depth estimation methods. We used a new soil water transport model including fractionation effects of SWI and exchange between the vapor and liquid phase to simulate different irrigation scenarios. Different amounts of water with differing SWI signatures (glacier melt water, summer precipitation water, deuterated water) were applied in order to obtain a wide variety of SWI depth profiles. Based on these simulated SWI depth profiles and a set of hypothetical PWU patterns, the theoretical SWI signatures of the respective plant transpiration were computed. In the next step, two methods - Bayesian isotope mixing models (BIMs) and optimization of a parametric distribution function (beta function) - were used to estimate the PWU patterns from the different SWI depth profiles and their respective SWI signatures in the resulting transpiration. Eventually, the estimated and computed profiles were compared to find the best SWI depth profile and the best method. The results showed, that compared to naturally occurring SWI depth profiles, the application of multiple, in terms of SWI, distinct labeling pulses greatly improves the possible spatial resolution and at the same time reduces the uncertainty of PWU estimates.
 For the PWU patterns which were assumed for this study, PWU pattern estimates based on an optimized parametric distribution function

  15. Peroperative depth of anaesthesia may influence postoperative opioid requirements

    DEFF Research Database (Denmark)

    Henneberg, S W; Rosenborg, D; Weber Jensen, E

    2005-01-01

    Studies on monitoring the depth of anaesthesia have shown that with the use of these monitors the peroperative consumption of anaesthetics can be reduced. Studies have also indicated that the peroperative depth of anaesthesia may affect the postoperative course. The purpose of this study was to e...

  16. A preliminary evaluation of lake morphometric traits influence on the maximum growing depth of macrophytes

    Directory of Open Access Journals (Sweden)

    Mattia M. Azzella

    2014-03-01

    Full Text Available Underwater light regime is widely considered the principal determinant of aquatic plant depth distribution. The majority of previous studies dealing with macrophytes in lakes have singled out Secchi disk transparency (SD values as the key empirical proxy to explain the maximum depth of macrophyte colonization (Zc. Few studies have investigated the role played by lake morphometry in structuring macrophyte beds. Using a balanced dataset including 20 Italian lakes (10 shallow and 10 deep lakes, we analysed transparency and lake morphometric traits to investigate their possible effects on Zc. Our results demonstrate that lake area plays a significant role, and confirm a direct influence of SD values on Zc. Considering lakes with an equal degree of transparency, smaller lakes may yield a lower Zc than larger ones. Morphology has a great influence on lake ecological characteristics especially on water thermal conditions and mixing depth. Based on our data, we argue that the thermal stratification plays a non negligible role in explaining macrophytes zonation, due to its influence on macrophytes life cycles and phytoplankton vertical distribution. Therefore, the present data suggest the need to enhance and refine our knowledge about the relationship between aquatic plants distribution and lake thermal conditions to better model the response of macrophytes to climate change and eutrophication.

  17. Executive Functions of Divers Are Selectively Impaired at 20-Meter Water Depth

    Directory of Open Access Journals (Sweden)

    Fabian Steinberg

    2017-06-01

    Full Text Available Moving and acting underwater within recreational or occupational activities require intact executive functions, since they subserve higher cognitive functions such as successful self-regulation, coping with novel situations, and decision making; all of which could be influenced by nitrogen narcosis due to elevated partial pressure under water. However, specific executive functions that could provide a differentiated view on humans’ cognitive performance ability have not yet been systematically analyzed in full-water immersion, which is a research gap addressed within this approach to contribute to a better understanding of nitrogen narcosis. In this study, 20 young, healthy, and certified recreational divers participated and performed three different executive-function tests: the Stroop test (Inhibition, the Number/Letter test (Task switching, the 2-back test (Updating/Working memory, and a simple reaction time test (Psychomotor performance. These tests were performed once on land, at 5-meter (m water depth, and at 20-meter (m water depth of an indoor diving facility in standardized test conditions (26°C in all water depths. A water-proofed and fully operational tablet computer was used to present visual stimuli and to register reaction times. Performance of the simple reaction time test was not different between underwater and land testing, suggesting that reaction times were not biased by the utilization of the tablet in water immersion. Executive functions were not affected by the shallow water immersion of 5-m water depth. However, performance scores in 20-m water depth revealed a decreased performance in the incongruent test condition (i.e., an index of inhibitory control ability of the Stroop test, while all other tests were unaffected. Even though only one out of the three tested cognitive domains was affected, the impairment of inhibitory control ability even in relatively shallow water of 20-m is a critical component that should be

  18. Using a Cell Phone to Investigate the Skin Depth Effect in Salt Water

    Science.gov (United States)

    Rayner, John

    2017-01-01

    This paper describes an experimental investigation of the skin depth effect for electromagnetic waves in salt water using a cell phone that is immersed to a critical depth where it no longer responds when called. We show that this critical depth is directly proportional to the theoretical skin depth for a range of salt concentrations.

  19. Simulating streamflow and water table depth with a coupled hydrological model

    Directory of Open Access Journals (Sweden)

    Alphonce Chenjerayi Guzha

    2010-09-01

    Full Text Available A coupled model integrating MODFLOW and TOPNET with the models interacting through the exchange of recharge and baseflow and river-aquifer interactions was developed and applied to the Big Darby Watershed in Ohio, USA. Calibration and validation results show that there is generally good agreement between measured streamflow and simulated results from the coupled model. At two gauging stations, average goodness of fit (R2, percent bias (PB, and Nash Sutcliffe efficiency (ENS values of 0.83, 11.15%, and 0.83, respectively, were obtained for simulation of streamflow during calibration, and values of 0.84, 8.75%, and 0.85, respectively, were obtained for validation. The simulated water table depths yielded average R2 values of 0.77 and 0.76 for calibration and validation, respectively. The good match between measured and simulated streamflows and water table depths demonstrates that the model is capable of adequately simulating streamflows and water table depths in the watershed and also capturing the influence of spatial and temporal variation in recharge.

  20. Variation in winter snowpack depth and duration influences summer soil respiration in a subalpine meadow

    Science.gov (United States)

    Arnold, C. L.; Ghezzehei, T. A.; Berhe, A. A.

    2012-12-01

    Subalpine meadows in the Sierra Nevada rely on the depth and duration of the winter snowpack to supply ample water to restore the water table in the meadow during the spring snowmelt. This study examines the role that interannual variability in the winter snowpack plays in the overall rate of summer soil respiration along a hydrologic gradient in a subalpine meadow. Carbon dioxide efflux from the meadow was measured from June through September in 2011 and 2012 using soil collars and a LICOR 8100A infrared gas analyzer. Preliminary results show that soil respiration rates are influenced by the hydrologic gradient across the meadow, with drier regions peaking earlier in the summer as compared to wetter regions. We also show that high snowpack years can suppress soil respiration in the meadow until late in the summer season as compared to low snowpack years, where soil respiration peaks early in the summer.

  1. Estimated Depth to Ground Water and Configuration of the Water Table in the Portland, Oregon Area

    Science.gov (United States)

    Snyder, Daniel T.

    2008-01-01

    Reliable information on the configuration of the water table in the Portland metropolitan area is needed to address concerns about various water-resource issues, especially with regard to potential effects from stormwater injection systems such as UIC (underground injection control) systems that are either existing or planned. To help address these concerns, this report presents the estimated depth-to-water and water-table elevation maps for the Portland area, along with estimates of the relative uncertainty of the maps and seasonal water-table fluctuations. The method of analysis used to determine the water-table configuration in the Portland area relied on water-level data from shallow wells and surface-water features that are representative of the water table. However, the largest source of available well data is water-level measurements in reports filed by well constructors at the time of new well installation, but these data frequently were not representative of static water-level conditions. Depth-to-water measurements reported in well-construction records generally were shallower than measurements by the U.S. Geological Survey (USGS) in the same or nearby wells, although many depth-to-water measurements were substantially deeper than USGS measurements. Magnitudes of differences in depth-to-water measurements reported in well records and those measured by the USGS in the same or nearby wells ranged from -119 to 156 feet with a mean of the absolute value of the differences of 36 feet. One possible cause for the differences is that water levels in many wells reported in well records were not at equilibrium at the time of measurement. As a result, the analysis of the water-table configuration relied on water levels measured during the current study or used in previous USGS investigations in the Portland area. Because of the scarcity of well data in some areas, the locations of select surface-water features including major rivers, streams, lakes, wetlands, and

  2. Depth of soil water uptake by tropical rainforest trees during dry periods: does tree dimension matter?

    Science.gov (United States)

    Stahl, Clément; Hérault, Bruno; Rossi, Vivien; Burban, Benoit; Bréchet, Claude; Bonal, Damien

    2013-12-01

    Though the root biomass of tropical rainforest trees is concentrated in the upper soil layers, soil water uptake by deep roots has been shown to contribute to tree transpiration. A precise evaluation of the relationship between tree dimensions and depth of water uptake would be useful in tree-based modelling approaches designed to anticipate the response of tropical rainforest ecosystems to future changes in environmental conditions. We used an innovative dual-isotope labelling approach (deuterium in surface soil and oxygen at 120-cm depth) coupled with a modelling approach to investigate the role of tree dimensions in soil water uptake in a tropical rainforest exposed to seasonal drought. We studied 65 trees of varying diameter and height and with a wide range of predawn leaf water potential (Ψpd) values. We confirmed that about half of the studied trees relied on soil water below 100-cm depth during dry periods. Ψpd was negatively correlated with depth of water extraction and can be taken as a rough proxy of this depth. Some trees showed considerable plasticity in their depth of water uptake, exhibiting an efficient adaptive strategy for water and nutrient resource acquisition. We did not find a strong relationship between tree dimensions and depth of water uptake. While tall trees preferentially extract water from layers below 100-cm depth, shorter trees show broad variations in mean depth of water uptake. This precludes the use of tree dimensions to parameterize functional models.

  3. Wave spectral response to sudden changes in wind direction in finite depth waters

    Science.gov (United States)

    2015-11-14

    Virtual Special Issue Ocean Surface Waves Wave spectral response to sudden changes in wind direction in finite -depth waters Saima Aijaz a , ∗, W...exact solutions of the nonlinear term n two-dimensional models, in particular for finite -depth waters. In ddition to the complexities of shallow water...vary in time. This study seeks to investigate the wave response in finite -depth aters due to sudden changes in wind by conducting numerical imulations

  4. Assessment of water depth change patterns in 120° sharp bend using numerical model

    Directory of Open Access Journals (Sweden)

    Azadeh Gholami

    2016-10-01

    Full Text Available In this study, FLUENT software was employed to simulate the flow pattern and water depth changes in a 120° sharp bend at four discharge rates. To verify the numerical model, a 90° sharp bend was first modeled with a three-dimensional numerical model, and the results were compared with available experimental results. Based on the numerical model validation, a 120° bend was simulated. The results show that the rate of increase of the water depth at the cross-section located 40 cm before the bend, compared with the cross-sections located 40 cm and 80 cm after the bend, decreases with the increase of the normal water depth in the 120° curved channel. Moreover, with increasing normal water depth, the dimensionless water depth change decreases at all cross-sections. At the interior cross-sections of the bend, the transverse water depth slope of the inner half-width is always greater than that of the outer half-width of the channel. Hence, the water depth slope is nonlinear at each cross-section in sharp bends. Two equations reflecting the relationships between the maximum and minimum dimensionless water depths and the normal water depth throughout the channel were obtained.

  5. The influence of tray type and other variables on the palatal depth of casts made from irreversible hydrocolloid impressions.

    Science.gov (United States)

    Frank, Richard P; Thielke, Stephen M; Johnson, Glen H

    2002-01-01

    There are conflicting data regarding the effect of various factors on the palatal depth of casts made from irreversible hydrocolloid impressions. This study examined the influence of tray type, water temperature, pouring technique, and stone expansion on the palatal depth of casts. Irreversible hydrocolloid impressions were made of a model under simulated oral conditions. Palatal depth was measured relative to a reference plane with a microscope. The reference planes were standardized by subjecting the data to three 2-dimensional mathematic rotations. A 2-factor analysis of variance (alpha=.05) was used to determine whether differences existed among tray types and among palatal locations. The palatal depth of the casts increased approximately 0.06 mm compared with the master model with all but 2 variables. Statistical testing revealed that increased depth was not attributable to water temperature (52 degrees F or 72 degrees F) or tray type (custom resin, perforated metal, metal rimlock, or rimlock with built-up palate). Custom resin tray impressions poured with a lower expansion stone and perforated tray impressions inverted onto a base made from the same mix of stone resulted in casts with palatal depths most similar to that of the master model (Ppalatal contours of comparable accuracy were obtained with the use of a stock metal or customized tray and the use of differing water temperatures to mix the impression material.

  6. Rooting depth: a key trait connecting water and carbon metabolism of trees

    Science.gov (United States)

    Savi, Tadeja; Dal Borgo, Anna; Casolo, Valentino; Bressan, Alice; Stenni, Barbara; Zini, Luca; Bertoncin, Paolo; Nardini, Andrea

    2015-04-01

    Drought episodes accompanied by heat waves are thought to be the main cause of increasing rates of tree decline and mortality in several biomes with consequent ecological/economical consequences. Three possible and not mutually exclusive mechanisms have been proposed to be the drivers of this phenomenon: hydraulic failure caused by massive xylem cavitation and leading to strong reduction of root-to-leaf water transport, carbon starvation caused by prolonged stomatal closure and leading to impairment of primary and secondary metabolism, and finally attacks of biotic agents. The different mechanisms have been reported to have different relevance in the different species. We analyzed the seasonal changes of water relations, xylem sap isotopic composition, and concentration of non-structural carbohydrates in four different woody species co-occurring in the same habitat during a summer drought. Analysis of rain and deep soil water isotopic composition were also performed. Different species showed differential access to deep water sources which influences the gas exchanges and the concentration of non structural carbohydrates (NSC) during the dry season. Species with access to deeper water maintained higher NSC content and were also able to better preserve the integrity of the water transport pathway. On the basis of our results, we propose that rooting depth is a key trait connecting water and carbon plant metabolism, thus mediating the likelihood of hydraulic failure vs carbon starvation in trees subjected to global warming.

  7. Influence of sampling depth and post-sampling analysis time on the ...

    African Journals Online (AJOL)

    Bacteriological analysis was carried out for samples taken at water depth and at 1, 6, 12 and 24 hours post-sampling. It was observed that the total and faecal coliform bacteria were significantly higher in the 3 m water depth samples than in the surface water samples (ANOVA, F = 59.41, 26.751, 9.82 (T.C); 46.41, 26.81, ...

  8. Numerical comparison between deep water and intermediate water depth expressions applied to a wave energy converter

    Directory of Open Access Journals (Sweden)

    Pedro Beirão

    2015-09-01

    Full Text Available The energy that can be captured from the sea waves and converted into electricity should be seen as a contribution to decrease the excessive dependency and growing demand of fossil fuels. Devices suitable to harness this kind of renewable energy source and convert it into electricity—wave energy converters (WECs—are not yet commercially competitive. There are several types of WECs, with different designs and working principles. One possible classification is their distance to the shoreline and thus their depth. Near-shore devices are one of them since they are typically deployed at intermediate water depth (IWD. The selection of the WEC deployment site should be a balance between several parameters; water depth is one of them. Another way of classifying WECs is grouping them by their geometry, size and orientation. Considering a near-shore WEC belonging to the floating point category, this paper is focused on the numerical study about the differences arising in the power captured from the sea waves when the typical deep water (DW assumption is compared with the more realistic IWD consideration. Actually, the production of electricity will depend, among other issues, on the depth of the deployment site. The development of a dynamic model including specific equations for the usual DW assumption as well as for IWD is also described. Derived equations were used to build a time domain simulator (TDS. Numerical results were obtained by means of simulations performed using the TDS. The objective is to simulate the dynamic behavior of the WEC due to the action of sea waves and to characterize the wave power variations according with the depth of the deployment site.

  9. Monitoring waterbird abundance in wetlands: The importance of controlling results for variation in water depth

    Science.gov (United States)

    Bolduc, F.; Afton, A.D.

    2008-01-01

    Wetland use by waterbirds is highly dependent on water depth, and depth requirements generally vary among species. Furthermore, water depth within wetlands often varies greatly over time due to unpredictable hydrological events, making comparisons of waterbird abundance among wetlands difficult as effects of habitat variables and water depth are confounded. Species-specific relationships between bird abundance and water depth necessarily are non-linear; thus, we developed a methodology to correct waterbird abundance for variation in water depth, based on the non-parametric regression of these two variables. Accordingly, we used the difference between observed and predicted abundances from non-parametric regression (analogous to parametric residuals) as an estimate of bird abundance at equivalent water depths. We scaled this difference to levels of observed and predicted abundances using the formula: ((observed - predicted abundance)/(observed + predicted abundance)) ?? 100. This estimate also corresponds to the observed:predicted abundance ratio, which allows easy interpretation of results. We illustrated this methodology using two hypothetical species that differed in water depth and wetland preferences. Comparisons of wetlands, using both observed and relative corrected abundances, indicated that relative corrected abundance adequately separates the effect of water depth from the effect of wetlands. ?? 2008 Elsevier B.V.

  10. Wind Speed Influences on Marine Aerosol Optical Depth

    Directory of Open Access Journals (Sweden)

    Colin O'Dowd

    2010-01-01

    Full Text Available The Mulcahy (Mulcahy et al., 2008 power-law parameterization, derived at the coastal Atlantic station Mace Head, between clean marine aerosol optical depth (AOD and wind speed is compared to open ocean MODIS-derived AOD versus wind speed. The reported AOD versus wind speed (U was a function of ∼U2. The open ocean MODIS-derived AOD at 550 nm and 860 nm wavelengths, while in good agreement with the general magnitude of the Mulcahy parameterization, follows a power-law with the exponent ranging from 0.72 to 2.47 for a wind speed range of 2–18 m s−1. For the four cases examined, some MODIS cases underestimated AOD while other cases overestimated AOD relative to the Mulcahy scheme. Overall, the results from MODIS support the general power-law relationship of Mulcahy, although some linear cases were also encountered in the MODIS dataset. Deviations also arise between MODIS and Mulcahy at higher wind speeds (>15 m s−1, where MODIS-derived AOD returns lower values as compared to Mulcahy. The results also support the suggestion than wind generated sea spray, under moderately high winds, can rival anthropogenic pollution plumes advecting out into marine environments with wind driven AOD contributing to AOD values approaching 0.3.

  11. Influence of flowing water

    Science.gov (United States)

    Wirtz, S.; Zell, A.; Wagner, C.; Seeger, M.; Ries, J. B.

    2009-04-01

    In literature authors often state that turbulence is an important or even "the critical" factor for soil erosion. But in erosion modelling the influence of turbulence is largely disregarded until now. The Reynolds number is often used as value of turbulence for a flowing liquid. In technical physics for example it is used to test the viscoelastic behavior of diluted polymer solutions and their elastic instabilities, in hydraulic engineering to characterise flow processes. Single factors that are included into the calculation of the Reynolds number (flow length, flow velocity and liqiud density) are used in many models but not the viscosity. In a study of rill erosion dynamics in Andalusia the Reynolds number is calculated for the collected samples. The scientific question reads as follow: Is there a correlation between turbulence (Reynolds number) and soil erosion (sediment concentration)? And what kind of influence has the turbulence to soil erosion? The factors for calculation of the Reynolds number are the liquid's density, a characteristic flow velocity, a characteristic flow length and the (dynamic) viscosity. The density of the sample is calculated using sediment concentration and the grain density, the flow velocity has been measured in the field experiments and the viscosity is measured by a cone-plate rheometer. For the flow length, a value of 1 meter is used following the assumption that the processes leading to the measured sediment concentrations mainly take place in the last meter before the sampling point. In the study it was ascertained that 1) high flow velocities cause high sediment concentrations and 2) viscosity increase with increasing sediment concentration. So there should be an influence on Reynolds number. Due to the fact that flow velocity is in the numerator and viscosity in the denominator of the Reynolds equation it could be expected that there are two different sections: In one section the Reynolds number increases with increasing

  12. Depth to ground water contours of hydrographic area 153, Diamond Valley, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of depth to ground water contours for hydrographic-area (HA) 153, Diamond Valley, Nevada. These data represent static ground-water levels...

  13. Ascii grids of predicted pH in depth zones used by domestic and public drinking water supply depths, Central Valley, California

    Science.gov (United States)

    Zamora, Celia; Nolan, Bernard T.; Gronberg, JoAnn M.

    2017-01-01

    0.70 and the RMSE in standard pH units was were 0.26. The holdout r-squared was 0.43 and RMSE in standard pH units was 0.37. Predictor variables consisting of more than 60 variables from 7 sources (see metadata) were assembled to develop a model that incorporates regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrology. Previously developed Central Valley model outputs of textures (Central Valley Textural Model, CVTM; Faunt et al. 2010) and MODFLOW-simulated vertical water fluxes and predicted depth to water table (Central Valley Hydrologic Model, CVHM; Faunt, 2009) were used to represent aquifer textures and groundwater hydraulics, respectively. In this work, wells were attributed to predictor variable values in ArcGIS using a 500-m buffer. Results of the predictor variable influence as defined by Friedman (2001) for variables used in the final BRT model used for mapping can be downloaded from this landing page (see file named PredictorVariableInfluence_CentralValley_pH_BRT.csv).

  14. Depth-dependent influence of different land-use systems on bacterial biogeography.

    Science.gov (United States)

    Seuradge, Brent J; Oelbermann, Maren; Neufeld, Josh D

    2017-02-01

    Despite progress in understanding microbial biogeography of surface soils, few studies have investigated depth-dependent distributions of terrestrial microorganisms in subsoils. We leveraged high-throughput sequencing of 16S rRNA genes obtained from soils collected from the RARE: Charitable Research Reserve (Cambridge, ON, Canada) to assess the influence of depth on bacterial communities across various land-use types. Although bacterial communities were strongly influenced by depth across all sites, the magnitude of this influence was variable and demonstrated that land-use attributes also played a significant role in shaping soil bacterial communities. Soil pH exhibited a large gradient across samples and strongly influenced shifts in bacterial communities with depth and across different land-use systems, especially considering that physicochemical conditions showed generally consistent trends with depth. We observed significant (p ≤ 0.001) and strongly correlated taxa with depth and pH, with a strong predominance of positively depth-correlated OTUs without cultured representatives. These findings highlight the importance of depth in soil biogeographical surveys and that subsurface soils harbour understudied bacterial members with potentially unique and important functions in deeper soil horizons that remain to be characterized. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Underwater Depth and Temperature Sensing Based on Fiber Optic Technology for Marine and Fresh Water Applications.

    Science.gov (United States)

    Duraibabu, Dinesh Babu; Leen, Gabriel; Toal, Daniel; Newe, Thomas; Lewis, Elfed; Dooly, Gerard

    2017-05-27

    Oceanic conditions play an important role in determining the effects of climate change and these effects can be monitored through the changes in the physical properties of sea water. In fact, Oceanographers use various probes for measuring the properties within the water column. CTDs (Conductivity, Temperature and Depth) provide profiles of physical and chemical parameters of the water column. A CTD device consists of Conductivity (C), Temperature (T) and Depth (D) probes to monitor the water column changes with respect to relative depth. An optical fibre-based point sensor used as a combined pressure (depth) and temperature sensor and the sensor system are described. Measurements accruing from underwater trials of a miniature sensor for pressure (depth) and temperature in the ocean and in fresh water are reported. The sensor exhibits excellent stability and its performance is shown to be comparable with the Sea-Bird Scientific commercial sensor: SBE9Plus.

  16. Underwater Depth and Temperature Sensing Based on Fiber Optic Technology for Marine and Fresh Water Applications

    Directory of Open Access Journals (Sweden)

    Dinesh Babu Duraibabu

    2017-05-01

    Full Text Available Oceanic conditions play an important role in determining the effects of climate change and these effects can be monitored through the changes in the physical properties of sea water. In fact, Oceanographers use various probes for measuring the properties within the water column. CTDs (Conductivity, Temperature and Depth provide profiles of physical and chemical parameters of the water column. A CTD device consists of Conductivity (C, Temperature (T and Depth (D probes to monitor the water column changes with respect to relative depth. An optical fibre-based point sensor used as a combined pressure (depth and temperature sensor and the sensor system are described. Measurements accruing from underwater trials of a miniature sensor for pressure (depth and temperature in the ocean and in fresh water are reported. The sensor exhibits excellent stability and its performance is shown to be comparable with the Sea-Bird Scientific commercial sensor: SBE9Plus.

  17. Nitrogen Uptake in Soils under Different Water Table Depths ...

    African Journals Online (AJOL)

    A mathematical model was used to examine the interactions of NH4 + transport to rice roots, as well as to calculate root length densities required to relate N uptake to concentrations of NH4 + in solution around the rooting medium for three water treatments: water table 30 cm below the surface, 15 cm below the surface and ...

  18. Decreased summer water table depth affects peatland vegetation

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Robroek, B.J.M.; Limpens, J.; Heijmans, M.M.P.D.; Schouten, M.G.C.; Berendse, F.

    2009-01-01

    Climate change can be expected to increase the frequency of summer droughts and associated low water tables in ombrotrophic peatlands. We studied the effects of periodic water table drawdown in a mesocosm experiment. Mesocosms were collected in Southern Sweden, and subsequently brought to an

  19. Constraining water uptake depths in semiarid environments using water stable isotopes

    Science.gov (United States)

    Beyer, Matthias; Königer, Paul; Himmelsbach, Thomas

    2017-04-01

    The biophysical process of transpiration recently received increased attention by ecohydrologists as it has been proven the largest flux of the global water balance. However, fundamental aspects related to the questions how and from which sources plants receive their water are not fully understood. Especially the process of plant water uptake from deeper soil and its impact on the water balance requires increased scientific effort. In this study we combined tracer experiments with the analysis of natural isotopic compositions in order to: i) derive a suitable site-specific root water uptake distribution for hydrological modeling; ii) find indicators for groundwater use by specific plants; and iii) evaluate the importance of deep unsaturated zone water uptake using HYDRUS 1D. The bayesian mixing model MixSIAR was applied at a semiarid site with a deep unsaturated zone in northern Namibia in order to identify source water contributions of the most abundant species (A.erioloba, B.plurijuga, C.collinum, S.luebertii and T.sericea). In addition, a previously developed method for the investigation of root water uptake depths based on deuterium labeling (2H2O) at specific depths (0.5 to 4 m) and monitoring of tracer uptake by plants was carried out with a focus on the deeper unsaturated zone. With the experimental results a root water uptake distribution for the lateral root zone was derived which allows to constrain the source water contributions estimated with MixSIAR. Finally, a HYDRUS 1D model was established and unsaturated zone water transport was evaluated. The analysis of the natural isotopic compositions reveals a significant contribution of groundwater (median: 48%) to the isotopic composition of A.erioloba at the end of the dry season indicating the presence of deep tap roots for a number of individuals. All other investigated species obtain their water from the shallow (median: 22%) or deeper (median: 62%) unsaturated zone at this time of the year. The water

  20. Sea Water Characterization at Ujung Kulon Coastal Depth as Raw Water Source for Desalination and Potential Energy

    Directory of Open Access Journals (Sweden)

    Mugisidi Dan

    2018-01-01

    Full Text Available Fresh water is basic need for life while the source is limited. Therefore, sea water is used as fresh water through desalination process. Sea water has different physical and chemical properties ranging from the surface to the seabed. The energy potential that can be obtained from the hydrostatic pressure also changes according to the depth. As part of the research of the utilization of sea water into fresh water, the aim of this study is to know the characteristics of sea water in the depth that can be utilized as source of fresh water. The sea water samples were taken at 11km from Ujung Kulon beach with depth of 0m, 20m, 40m, 60m, 80m, and 100m under the surface. The results showed that the physical properties at every depth were below the maximum allowable drinking water except for the amount of dissolved solids. Chemical characteristics at any depth above allowable level were fluoride, hardness (CaCo3, chloride, sodium, sulphate, and (KMnO4. In addition to the properties, pressure is one of the considerations in this study to determine the depth of sea water as sources for desalination. Pressure increased by 36.11% as the depth of the sea increased.

  1. Standing Water Depth on Larsen B Ice Shelf, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set addresses why surface melt water lakes on ice shelves and ice sheets are notably influential in triggering ice-shelf break-up and modulating seasonal...

  2. The Everglades Depth Estimation Network (EDEN) surface-water model, version 2

    Science.gov (United States)

    Telis, Pamela A.; Xie, Zhixiao; Liu, Zhongwei; Li, Yingru; Conrads, Paul

    2015-01-01

    The Everglades Depth Estimation Network (EDEN) is an integrated network of water-level gages, interpolation models that generate daily water-level and water-depth data, and applications that compute derived hydrologic data across the freshwater part of the greater Everglades landscape. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for EDEN in order for EDEN to provide quality-assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan.

  3. Modelling mid-span water table depth and drainage discharge ...

    African Journals Online (AJOL)

    2015-04-03

    Apr 3, 2015 ... during calibration period, showed that there was a very strong agreement between simulated and observed WTDs with a goodness-of-fit (R2) of 0.826 ..... DRAINMOD model calibration, evaluation and statistical analysis ..... EL-SADEK A (2007) Up-scaling field scale hydrology and water quality modeling to ...

  4. Infrared spectra of penetration depth of into water and of water refraction-index

    Science.gov (United States)

    Ichikawa, Mahito

    1990-01-01

    Infrared radiation heating is becoming widely applied to drying processes of wet industrial materials and to heating processes for food-stuff containing water etc. Thus a growing importance is attributed to clarify the exactpenetration depth of IR radiation into water from heating engineering view point. Many IR transmittance data on water film have been published by various authors. All of them as far as the author knows, however, failed to indicate the detailed optical data of the two window plates used to fix water film thickness. Accordingly the exact penetration depth (or inverse of Lambert absorption coefficient) into water cannot be known, since multi-reflection takes place within bounded water and window plates too, thus affecting the transmittance value to be measured. Moreover in the measurement of very thin water film, there takes place often an interference between forward going electro-magnetic wave and successively reflected backward one. This too affects the measurement particularly in IR region of higher transmittance. Messrs. Robertson & Williams tackled with the captioned theme in the early years, and indicated, in their report" difficulty to remove the unfavorable effects introduced by window plates in view of finding Lambert coeff. of water. The difficulty had been experienced those days by many authors. Robertson & Williams elaborated a special precise absorption cell with window plates of either CaF2 or KRS-5, and succeeded in giving fairly good Lambert coeff.~ for 2.33 - 33.3 micro-meter wavelength region. They seemed to have paid enough experimental consideration and made some corrections on the inevitable interference effect, but not enough on the multi-reflection effect. Accordingly their derived formula for giving~ was not fully theoretically correct, since taking ratio of the two transmittance values with different water thickness did not cancel out all of the window plate effect. The author has carefully taken into consideration the

  5. Predicted pH at the domestic and public supply drinking water depths, Central Valley, California

    Science.gov (United States)

    Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, Jo Ann M.

    2017-03-08

    This scientific investigations map is a product of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project modeling and mapping team. The prediction grids depicted in this map are of continuous pH and are intended to provide an understanding of groundwater-quality conditions at the domestic and public supply drinking water zones in the groundwater of the Central Valley of California. The chemical quality of groundwater and the fate of many contaminants is often influenced by pH in all aquifers. These grids are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to pH. In this work, the median well depth categorized as domestic supply was 30 meters below land surface, and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically boosted regression trees (BRT) with a Gaussian error distribution within a statistical learning framework within the computing framework of R (http://www.r-project.org/). The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1,337 wells and was compiled from two sources: USGS National Water Information System (NWIS) database (all data are publicly available from the USGS: http://waterdata.usgs.gov/ca/nwis/nwis) and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: http://www.waterboards.ca.gov/gama/geotracker_gama.shtml). Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993–2014 was used. A total of 1,003 wells (training dataset) were used to train the BRT

  6. Impact of interspecific interactions on the soil water uptake depth in a young temperate mixed species plantation

    Science.gov (United States)

    Grossiord, Charlotte; Gessler, Arthur; Granier, André; Berger, Sigrid; Bréchet, Claude; Hentschel, Rainer; Hommel, Robert; Scherer-Lorenzen, Michael; Bonal, Damien

    2014-11-01

    Interactions between tree species in forests can be beneficial to ecosystem functions and services related to the carbon and water cycles by improving for example transpiration and productivity. However, little is known on below- and above-ground processes leading to these positive effects. We tested whether stratification in soil water uptake depth occurred between four tree species in a 10-year-old temperate mixed species plantation during a dry summer. We selected dominant and co-dominant trees of European beech, Sessile oak, Douglas fir and Norway spruce in areas with varying species diversity, competition intensity, and where different plant functional types (broadleaf vs. conifer) were present. We applied a deuterium labelling approach that consisted of spraying labelled water to the soil surface to create a strong vertical gradient of the deuterium isotope composition in the soil water. The deuterium isotope composition of both the xylem sap and the soil water was measured before labelling, and then again three days after labelling, to estimate the soil water uptake depth using a simple modelling approach. We also sampled leaves and needles from selected trees to measure their carbon isotope composition (a proxy for water use efficiency) and total nitrogen content. At the end of the summer, we found differences in the soil water uptake depth between plant functional types but not within types: on average, coniferous species extracted water from deeper layers than did broadleaved species. Neither species diversity nor competition intensity had a detectable influence on soil water uptake depth, foliar water use efficiency or foliar nitrogen concentration in the species studied. However, when coexisting with an increasing proportion of conifers, beech extracted water from progressively deeper soil layers. We conclude that complementarity for water uptake could occur in this 10-year-old plantation because of inherent differences among functional groups (conifers

  7. Tracking water pathways in steep hillslopes by δ18O depth profiles of soil water

    Science.gov (United States)

    Mueller, Matthias H.; Alaoui, Abdallah; Kuells, Christoph; Leistert, Hannes; Meusburger, Katrin; Stumpp, Christine; Weiler, Markus; Alewell, Christine

    2014-11-01

    Assessing temporal variations in soil water flow is important, especially at the hillslope scale, to identify mechanisms of runoff and flood generation and pathways for nutrients and pollutants in soils. While surface processes are well considered and parameterized, the assessment of subsurface processes at the hillslope scale is still challenging since measurement of hydrological pathways is connected to high efforts in time, money and personnel work. The latter might not even be possible in alpine environments with harsh winter processes. Soil water stable isotope profiles may offer a time-integrating fingerprint of subsurface water pathways. In this study, we investigated the suitability of soil water stable isotope (δ18O) depth profiles to identify water flow paths along two transects of steep subalpine hillslopes in the Swiss Alps. We applied a one-dimensional advection-dispersion model using δ18O values of precipitation (ranging from -24.7 to -2.9‰) as input data to simulate the δ18O profiles of soil water. The variability of δ18O values with depth within each soil profile and a comparison of the simulated and measured δ18O profiles were used to infer information about subsurface hydrological pathways. The temporal pattern of δ18O in precipitation was found in several profiles, ranging from -14.5 to -4.0‰. This suggests that vertical percolation plays an important role even at slope angles of up to 46°. Lateral subsurface flow and/or mixing of soil water at lower slope angles might occur in deeper soil layers and at sites near a small stream. The difference between several observed and simulated δ18O profiles revealed spatially highly variable infiltration patterns during the snowmelt periods: The δ18O value of snow (-17.7 ± 1.9‰) was absent in several measured δ18O profiles but present in the respective simulated δ18O profiles. This indicated overland flow and/or preferential flow through the soil profile during the melt period. The applied

  8. Neon-20 depth-dose relations in water

    Science.gov (United States)

    Wilson, J. W.; Townsend, L. W.; Bidasaria, H. B.; Schimmerling, W.; Wong, M.; Howard, J.

    1984-01-01

    The dose from heavy ion beams has been calculated using a one-dimensional transport theory and evaluated for 670 MeV/amu 20 Ne beams in water. The result is presented so as to be applicable to arbitrary ions for which the necessary interaction data are known. The present evaluation is based on thar Silberg-Tsao fragmentation parameters augmented with light fragment production from intranuclear cascades, recently calculated nuclear absorption cross sections, and evaluated stopping power data. Comparison with recent experimental data obtained at the Lawrence Berkeley Laboratory reveals the need for more accurate fragmentation data.

  9. Modelling of influence of spherical aberration coefficients on depth of focus of optical systems

    Science.gov (United States)

    Pokorný, Petr; Šmejkal, Filip; Kulmon, Pavel; Mikš, Antonín.; Novák, Jiří; Novák, Pavel

    2017-06-01

    This contribution describes how to model the influence of spherical aberration coefficients on the depth of focus of optical systems. Analytical formulas for the calculation of beam's caustics are presented. The conditions for aberration coefficients are derived for two cases when we require that either the Strehl definition or the gyration radius should be the identical in two symmetrically placed planes with respect to the paraxial image plane. One can calculate the maximum depth of focus and the minimum diameter of the circle of confusion of the optical system corresponding to chosen conditions. This contribution helps to understand how spherical aberration may affect the depth of focus and how to design such an optical system with the required depth of focus. One can perform computer modelling and design of the optical system and its spherical aberration in order to achieve the required depth of focus.

  10. A Method for Energy and Resource Assessment of Waves in Finite Water Depths

    Directory of Open Access Journals (Sweden)

    Wanan Sheng

    2017-04-01

    Full Text Available This paper presents a new method for improving the assessment of energy and resources of waves in the cases of finite water depths in which the historical and some ongoing sea wave measurements are simply given in forms of scatter diagrams or the forms of (significant wave heights and the relevant statistical wave periods, whilst the detailed spectrum information has been discarded, thus no longer available for the purpose of analysis. As a result of such simplified wave data, the assessment for embracing the effects of water depths on wave energy and resources becomes either difficult or inaccurate. In many practical cases, the effects of water depths are simply ignored because the formulas for deep-water waves are frequently employed. This simplification may cause large energy under-estimations for the sea waves in finite water depths. To improve the wave energy assessment for such much-simplified wave data, an approximate method is proposed for approximating the effect of water depth in this research, for which the wave energy period or the calculated peak period can be taken as the reference period for implementing the approximation. The examples for both theoretical and measured spectra show that the proposed method can significantly reduce the errors on wave energy assessment due to the approximations and inclusions of the effects of finite water depths.

  11. Interrelationships of petiolar air canal architecture, water depth, and convective air flow in Nymphaea odorata (Nymphaeaceae).

    Science.gov (United States)

    Richards, Jennifer H; Kuhn, David N; Bishop, Kristin

    2012-12-01

    Nymphaea odorata grows in water up to 2 m deep, producing fewer larger leaves in deeper water. This species has a convective flow system that moves gases from younger leaves through submerged parts to older leaves, aerating submerged parts. Petiolar air canals are the convective flow pathways. This study describes the structure of these canals, how this structure varies with water depth, and models how convective flow varies with depth. • Nymphaea odorata plants were grown at water depths from 30 to 90 cm. Lamina area, petiolar cross-sectional area, and number and area of air canals were measured. Field-collected leaves and leaves from juvenile plants were analyzed similarly. Using these data and data from the literature, we modeled how convective flow changes with water depth. • Petioles of N. odorata produce two central pairs of air canals; additional pairs are added peripherally, and succeeding pairs are smaller. The first three pairs account for 96% of air canal area. Air canals form 24% of petiolar cross-sectional area. Petiolar and air canal cross-sectional areas increase with water depth. Petiolar area scales with lamina area, but the slope of this relationship is lower in 90 cm water than at shallower depths. In our model, the rate of convective flow varied with depth and with the balance of influx to efflux leaves. • Air canals in N. odorata petioles increase in size and number in deeper water but at a decreasing amount in relation to lamina area. Convective flow also depends on the number of influx to efflux laminae.

  12. Heterophylly in the yellow waterlily, Nuphar variegata (Nymphaeaceae): effects of [CO2], natural sediment type, and water depth.

    Science.gov (United States)

    Titus, J E; Gary Sullivan, P

    2001-08-01

    We transplanted Nuphar variegata with submersed leaves only into natural lake sediments in pH-, [CO(2)]-, depth-, and temperature-controlled greenhouse tanks to test the hypotheses that more fertile sediment, lower free [CO(2)], and shallower depth would all stimulate the development of floating leaves. Sediment higher in porewater [NH(4)(+)] favored floating leaf development. Low CO(2)-grown plants initiated floating leaf development significantly earlier than high CO(2)-grown plants, which produced significantly more submersed leaves and fewer floating leaves. Mean floating leaf biomass was significantly greater than mean submersed leaf biomass but was not influenced by CO(2) enrichment, whereas mean submersed leaf biomass increased 88% at high [CO(2)]. At the shallower depth (35 cm), floating leaves required 50% less biomass investment per leaf than at 70 cm, and a significantly greater proportion of plants had floating leaves (70 vs. 23-43% at 35 vs. 70 cm, respectively) for the last three of the eight leaf censuses. Sediment type, water depth, and especially free [CO(2)] all can influence leaf morphogenesis in Nuphar variegata, and the development of more and larger submersed leaves with CO(2) enrichment favors the exploitation of high [CO(2)] when it is present in the water column.

  13. Influence of Bit Depth on Subjective Video Quality Assessment for High Resolutions

    Directory of Open Access Journals (Sweden)

    Juraj Bienik

    2017-01-01

    Full Text Available This paper deals with the influence of bit depth on the subjective video quality assessment. To achieve this goal, eight video sequences, each representing a different content prototype, were analysed. Subjective evaluation was performed using the ACR method. The analysed video sequences were encoded to 8 and 10-bit bit depth. Two most used compression standards H.264 and H.265 were evaluated with 1, 3, 5, 10 and 15 Mbps bitrate in Full HD and UHD resolution. Finally, the perceived quality of both compression standards using the subjective tests with emphasis on bit-depth was compared. From the results we can state, that the practical application of 10-bit bit depth is not appropriate for Full HD resolution in the range of bitrate from 1 to 15 Mbps, for Ultra HD resolution, it is appropriate only for videos encoded by H.265/HEVC compression standard.

  14. Mediterranean water structure in the central Atlantic: Results of remote acoustic and conductivity-temperature-depth measurements

    Science.gov (United States)

    Berezutskii, V.; Maximov, S. E.; Rodionov, V. B.; Sklyarov, V. E.

    1994-10-01

    In March 1990, combined acoustic and conductivity-temperature-depth measurements were carried out in the central Atlantic (29°-35°N, 20°-26°W) to study volume sound backscattering (VSB) at depths of Mediterranean Intermediate Water (MIW). Spatial variability of VSB in the presence of MIW was found. The influence of the intermittent character of the MIW structure on VSB at depths of 700-1900 m was revealed and examined. The possibility of acoustic detection and monitoring of both meddies and thermohaline fine structure features directly from the sea surface was discovered. This paper presents the first acoustic imaging of the MIW structure and dynamics in the central Atlantic.

  15. The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth.

    Directory of Open Access Journals (Sweden)

    Stephen M Techtmann

    Full Text Available The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly

  16. The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth.

    Science.gov (United States)

    Techtmann, Stephen M; Fortney, Julian L; Ayers, Kati A; Joyner, Dominique C; Linley, Thomas D; Pfiffner, Susan M; Hazen, Terry C

    2015-01-01

    The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA) analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly affect microbial

  17. Water depth selection, daily feeding routines and diets of waterbirds in coastal lagoons in Ghana

    NARCIS (Netherlands)

    Ntiamoa-Baidu, Y; Piersma, T; Wiersma, P; Poot, M; Battley, P; Gordon, C

    Water depth requirements, diet, feeding styles and diurnal activity patterns are described for waterbirds using two brackish water lagoon systems in coastal Ghana, the Songor and Keta Lagoons, We project the habitat and activity data on a guild structure defined on the basis of individual feeding

  18. Regression analysis of growth responses to water depth in three wetland plant species

    DEFF Research Database (Denmark)

    Sorrell, Brian K; Tanner, Chris C; Brix, Hans

    2012-01-01

    ) differing in depth preferences in wetlands, using non-linear and quantile regression analyses to establish how flooding tolerance can explain field zonation. Methodology Plants were established for 8 months in outdoor cultures in waterlogged soil without standing water, and then randomly allocated to water...

  19. Effect of growing media, sowing depth, and hot water treatment on ...

    African Journals Online (AJOL)

    To optimize seedling production for reforestation of degraded dryland with A. senegal seeds, a study was conducted on the effect of boiled water treatment, growing media, sowing depth on seed germination and seedling growth of A. senegal. Three different growing media (farm soil, forest soil and sand soil), boiled water ...

  20. Stability of eelgrass (Zostera marina L.) depth limits: influence of habitat type

    DEFF Research Database (Denmark)

    Greve, T. M.; Krause-Jensen, D.

    2005-01-01

    extending from inner bays over outer bays to open coastal waters. We defined stability in terms of the ‘stability properties' of ‘constancy', ‘resilience', and/or ‘persistence'. Our data allowed us to investigate the stability property constancy expressed as temporal variability in eelgrass depth limits...

  1. Estimation of missing water-level data for the Everglades Depth Estimation Network (EDEN), 2013 update

    Science.gov (United States)

    Petkewich, Matthew D.; Conrads, Paul

    2013-01-01

    The Everglades Depth Estimation Network is an integrated network of real-time water-level gaging stations, a ground-elevation model, and a water-surface elevation model designed to provide scientists, engineers, and water-resource managers with water-level and water-depth information (1991-2013) for the entire freshwater portion of the Greater Everglades. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for the Everglades Depth Estimation Network in order for the Network to provide quality-assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. In a previous study, water-level estimation equations were developed to fill in missing data to increase the accuracy of the daily water-surface elevation model. During this study, those equations were updated because of the addition and removal of water-level gaging stations, the consistent use of water-level data relative to the North American Vertical Datum of 1988, and availability of recent data (March 1, 2006, to September 30, 2011). Up to three linear regression equations were developed for each station by using three different input stations to minimize the occurrences of missing data for an input station. Of the 667 water-level estimation equations developed to fill missing data at 223 stations, more than 72 percent of the equations have coefficients of determination greater than 0.90, and 97 percent have coefficients of determination greater than 0.70.

  2. Water Reverberation Travel Time Analysis Acquired Using Multi-Depth Streamers

    OpenAIRE

    Po-Yen Tseng; Young-Fo Chang; Chih-Hsiung Chang; Ruey-Chyuan Shih

    2016-01-01

    Ghost reflections and water reverberations are major and inevitable seismic noises in marine seismic exploration. More recently, new receiver deployment techniques at different sea depths for signal-to-noise ratio (SNR) enhancement are developing. The reverberation characteristics must be known before applying the reverberation attenuation methods. This paper studies the characteristics of reverberations acquired using multi-depth streamers by analyzing the seismic ray path geometry and the s...

  3. Optimizing the Use of Secchi Depth as a Proxy for Euphotic Depth in Coastal Waters: An Empirical Study from the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Hanna Luhtala

    2013-12-01

    Full Text Available Potential zone for photosynthesis in natural waters is restricted to a relatively thin illuminated surface water layer. The thickness of this layer is often indirectly estimated by measuring the depth in which 1% of the photosynthetically active radiation entering the water remains. This depth is referred to as the euphotic depth. A coarser way to evaluate the underwater light penetration is to measure the Secchi depth, which is a visual measure of water transparency. The numerical relationship between these two optical parameters, i.e., conversion coefficient m, varies according to the changes in the optical properties of water, especially in transitional coastal waters. The aim of our study is to assess which is the most suitable criterion to base these coefficients on. We tested nine methods, seven of which were locally calibrated with our own in situ data from the optically heterogeneous Baltic Sea archipelago coast of SW Finland. We managed to significantly improve the accuracy of modeling euphotic depths from Secchi depths by using scalable and locally calibrated methods instead of a single fixed coefficient. The best results were achieved by using methods, either continuous functions or series of constants, which are based on water transparency values.

  4. INFLUENCE OF DIFFERENT SOIL TILLAGE VARIANTS ON QUALITY OF SEED DISTRIBUTION QUALITY PER SURFACE AND DEPTH

    Directory of Open Access Journals (Sweden)

    Luka Šumanovac

    2000-12-01

    Full Text Available The paper aims to present influence of different soil tillage variants on quality of seed distribution per surface and depth. A sowing experiment was set up in three soil tillage variants: a repeated disking, b conventional tillage, c ploughing + harrowing. Soil levelling, effects of longitudinal and transverzal distribution as well as seed distribution per depth were analyzed by the investigation. The research results indicate the fact that no soil tillage variant is characterized by achieving satisfactory sowing quality . It means that reduced soil tillage application is justifiable in terms of energetic aspect, work productivity increase, sowing performance in optimal agricultural terms etc., compared to conventional soil tillage.

  5. The influence of depth on mercury levels in pelagic fishes and their prey.

    Science.gov (United States)

    Choy, C Anela; Popp, Brian N; Kaneko, J John; Drazen, Jeffrey C

    2009-08-18

    Mercury distribution in the oceans is controlled by complex biogeochemical cycles, resulting in retention of trace amounts of this metal in plants and animals. Inter- and intra-specific variations in mercury levels of predatory pelagic fish have been previously linked to size, age, trophic position, physical and chemical environmental parameters, and location of capture; however, considerable variation remains unexplained. In this paper, we focus on differences in ecology, depth of occurrence, and total mercury levels in 9 species of commercially important pelagic fish (Thunnus obesus, T. albacares, Katsuwonus pelamis, Xiphias gladius, Lampris guttatus, Coryphaena hippurus, Taractichthys steindachneri, Tetrapturus audax, and Lepidocybium flavobrunneum) and in numerous representatives (fishes, squids, and crustaceans) of their lower trophic level prey sampled from the central North Pacific Ocean. Results indicate that total mercury levels of predatory pelagic fishes and their prey increase with median depth of occurrence in the water column and mimic concentrations of dissolved organic mercury in seawater. Stomach content analysis results from this study and others indicate a greater occurrence of higher-mercury containing deeper-water prey organisms in the diets of the deeper-ranging predators, X. gladius, T. obesus, and L. guttatus. While present in trace amounts, dissolved organic mercury increases with depth in the water column suggesting that the mesopelagic habitat is a major entry point for mercury into marine food webs. These data suggest that a major determinant of mercury levels in oceanic predators is their depth of forage.

  6. Fluctuating water depths affect American alligator (Alligator mississippiensis) body condition in the Everglades, Florida, USA

    Science.gov (United States)

    Brandt, Laura A.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Cherkiss, Michael S.; Mazzotti, Frank J.

    2016-01-01

    Successful restoration of wetland ecosystems requires knowledge of wetland hydrologic patterns and an understanding of how those patterns affect wetland plant and animal populations.Within the Everglades, Florida, USA restoration, an applied science strategy including conceptual ecological models linking drivers to indicators is being used to organize current scientific understanding to support restoration efforts. A key driver of the ecosystem affecting the distribution and abundance of organisms is the timing, distribution, and volume of water flows that result in water depth patterns across the landscape. American alligators (Alligator mississippiensis) are one of the ecological indicators being used to assess Everglades restoration because they are a keystone species and integrate biological impacts of hydrological operations through all life stages. Alligator body condition (the relative fatness of an animal) is one of the metrics being used and targets have been set to allow us to track progress. We examined trends in alligator body condition using Fulton’s K over a 15 year period (2000–2014) at seven different wetland areas within the Everglades ecosystem, assessed patterns and trends relative to restoration targets, and related those trends to hydrologic variables. We developed a series of 17 a priori hypotheses that we tested with an information theoretic approach to identify which hydrologic factors affect alligator body condition. Alligator body condition was highest throughout the Everglades during the early 2000s and is approximately 5–10% lower now (2014). Values have varied by year, area, and hydrology. Body condition was positively correlated with range in water depth and fall water depth. Our top model was the “Current” model and included variables that describe current year hydrology (spring depth, fall depth, hydroperiod, range, interaction of range and fall depth, interaction of range and hydroperiod). Across all models, interaction

  7. Assessing the Effect of Different Water Table Depths on Water Use, Yield and Water Productivity of the Okra Crop

    Directory of Open Access Journals (Sweden)

    Nazir Gul

    2018-01-01

    Full Text Available An experimental study was carried out on a Lysimeter with the aim of partially meeting WRs (Water Requirements of the Okra crop through SWT (Shallow Water Table while maintaining the SWT at various levels below the ground surface. Under the study, CWR (Crop Water Requirement, yield, water productivity, salt accrual and contribution of SWTs towards meeting the CWR are assessed. The study was designed in accordance with the principles of CRD (Complete Randomized Design with three treatments and four replications. The treatments; viz. T1, T2, and T3 consisted of maintaining the WTDs (Water Table Depths at 45, 60 and 75 cm, respectively, below the ground surface. The crop was irrigated with a good quality water having ECw = 0.50 dS m-1 and pH = 7.3. The results of the study showed that the crop consumed the maximum amount of water under T1 treatment, followed by T2 and then by T3 treatment. Accordingly, the contribution of SWTs towards the CWR is 94.8, 93.2 and 42.9% of the total CWR under the T1, T2, and T3 treatments, respectively. Maximum yield is attained under T3 treatment, followed by T2 treatment and then by T1 treatment. Likewise, maximum water productivity is achieved under T3 treatment, followed by T2 treatment and then by T1 treatment. The dry bulk density (ρd of the soil, under T1 and T2 treatments, increased slightly; however, it remained unchanged under the T3 treatment. The ECse (Electrical Conductivity of the soil increased, whereas, the pH value of the soil decreased under all the treatments. Statistically, significant difference (p 0.05 under the three treatments. Accordingly, to make profitable use of SWTs, improve WUE and productivity, and maintain soil fertility, the depth of SWT be controlled at 75 cm for growing of the Okra crop. Adapting to this guideline will help in availing the maximum contribution of SWTs towards meeting the CWR and achieve the larger aim of water conservation.

  8. Influence of computation algorithm on the accuracy of rut depth measurement

    Directory of Open Access Journals (Sweden)

    Di Wang

    2017-04-01

    Full Text Available Rutting is one of the dominant pavement distresses, hence, the accuracy of rut depth measurements can have a substantial impact on the maintenance and rehabilitation (M & R strategies and funding allocation. Different computation algorithms such as straight-edge method and wire line method, which are based on the same raw data, may lead to rut depth estimation which are not always consistent. Therefore, there is an urgent need to assess the impact of algorithm types on the accuracy of rut depth computation. In this paper, a 13-point-based laser sensor detection technology, commonly accepted in China for rut depth measurements, was used to obtain a database of 85,000 field transverse profiles having three representative rutting shapes with small, medium and high severity rut levels. Based on the reconstruction of real transverse profiles, the consequences from two different algorithms were compared. Results showed that there is a combined effect of rut depth and profile shape on the rut depth computation accuracy. As expected, the difference between the results obtained with the two computation methods increases with deeper rutting sections: when the distress is above 15 mm (severe level, the average difference between the two computation methods is above 1.5 mm, normally, the wire line method provides larger results. The computation suggests that the rutting shapes have a minimal influence on the results. An in-depth analysis showed that the upheaval outside of the wheel path is a dominant shape factor which results in higher computation differences.

  9. Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

    Directory of Open Access Journals (Sweden)

    Scarla Weeks

    2012-11-01

    Full Text Available Detecting changes to the transparency of the water column is critical for understanding the responses of marine organisms, such as corals, to light availability. Long-term patterns in water transparency determine geographical and depth distributions, while acute reductions cause short-term stress, potentially mortality and may increase the organisms’ vulnerability to other environmental stressors. Here, we investigated the optimal, operational algorithm for light attenuation through the water column across the scale of the Great Barrier Reef (GBR, Australia. We implemented and tested a quasi-analytical algorithm to determine the photic depth in GBR waters and matched regional Secchi depth (ZSD data to MODIS-Aqua (2002–2010 and SeaWiFS (1997–2010 satellite data. The results of the in situ ZSD/satellite data matchup showed a simple bias offset between the in situ and satellite retrievals. Using a Type II linear regression of log-transformed satellite and in situ data, we estimated ZSD and implemented the validated ZSD algorithm to generate a decadal satellite time series (2002–2012 for the GBR. Water clarity varied significantly in space and time. Seasonal effects were distinct, with lower values during the austral summer, most likely due to river runoff and increased vertical mixing, and a decline in water clarity between 2008–2012, reflecting a prevailing La Niña weather pattern. The decline in water clarity was most pronounced in the inshore area, where a significant decrease in mean inner shelf ZSD of 2.1 m (from 8.3 m to 6.2 m occurred over the decade. Empirical Orthogonal Function Analysis determined the dominance of Mode 1 (51.3%, with the greatest variation in water clarity along the mid-shelf, reflecting the strong influence of oceanic intrusions on the spatio-temporal patterns of water clarity. The newly developed photic depth product has many potential applications for the GBR from water quality monitoring to analyses of

  10. Water depth affects reproductive allocation and reproductive allometry in the submerged macrophyte Vallisneria natans.

    Science.gov (United States)

    Li, Lei; Bonser, Stephen P; Lan, Zhichun; Xu, Ligang; Chen, Jiakuan; Song, Zhiping

    2017-12-04

    In freshwater ecosystems, shifts in hydrological regimes have profound effects on reproductive output (R), along with vegetative biomass (V) and survival of plants. Because reproductive allocation (RA) is allometric, it remains unclear whether the observed variation of RA in response to water level variability is due to fixed patterns of development or plasticity in the developmental trajectories. Here, we investigated shifts in RA of a submerged macrophyte Vallisneria natans in response to water depth to test the hypothesis that allometric trajectories of RA are highly plastic. Plants were grown at three water depths (50, 100 and 150 cm) and measured after 26 weeks of growth. The relationships between R and V among treatments were compared. Deep water affected both biomass and number of fruits produced per plant, leading to less sexual reproduction. Plants in deep water started flowering at a smaller size and despite their small mature size, had a relatively high RA. Furthermore, these plants had a much lower log R-log V relationship than shallow- or intermediate-water plants. In conclusion, reproduction of V. natans is highly variable across water depth treatments, and variations in reproductive allometry represent different strategies under an important stress gradient for these freshwater angiosperms.

  11. Bottom depth and type for shallow waters: Hyperspectral observations from a blimp

    Energy Technology Data Exchange (ETDEWEB)

    Lee, ZhongPing; Carder, K.; Steward, R. [Univ. of South Florida, St. Petersburg, FL (United States)] [and others

    1997-08-01

    In a study of a blimp transect over Tampa Bay (Florida), hyperspectral upwelling radiance over the sand and seagrass bottoms was measured. These measurements were converted to hyperspectral remote-sensing reflectances. Using a shallow-water remote-sensing-reflectance model, in-water optical properties, bottom depths and bottom albedos were derived analytically and simultaneously by an optimization procedure. In the process, curvatures of sand and seagrass albedos were used. Also used was a model of absorption spectrum of phytoplankton pigments. The derived bottom depths were compared with bathymetry charts and found to agree well. This study suggests that a low-flying blimp is a useful platform for the study and mapping of coastal water environments. The optical model as well as the data-reduction procedure used are practical for the retrieval of shallow water optical properties.

  12. Creating a water depth map from Earth Observation-derived flood extent and topography data

    Science.gov (United States)

    Matgen, Patrick; Giustarini, Laura; Chini, Marco; Hostache, Renaud; Pelich, Ramona; Schlaffer, Stefan

    2017-04-01

    Enhanced methods for monitoring temporal and spatial variations of water depth in rivers and floodplains are very important in operational water management. Currently, variations of water elevation can be estimated indirectly at the land-water interface using sequences of satellite EO imagery in combination with topographic data. In recent years high-resolution digital elevation models (DEM) and satellite EO data have become more readily available at global scale. This study introduces an approach for efficiently converting remote sensing-derived flood extent maps into water depth maps using a floodplain's topography information. For this we make the assumption of uniform flow, that is the depth of flow with respect to the drainage network is considered to be the same at every section of the floodplain. In other words, the depth of water above the nearest drainage is expected to be constant for a given river reach. To determine this value we first need the Height Above Nearest Drainage (HAND) raster obtained by using the area of interest's DEM as source topography and a shapefile of the river network. The HAND model normalizes the topography with respect to the drainage network. Next, the HAND raster is thresholded in order to generate a binary mask that optimally fits, over the entire region of study, the flood extent map obtained from SAR or any other remote sensing product, including aerial photographs. The optimal threshold value corresponds to the height of the water line above the nearest drainage, termed HANDWATER, and is considered constant for a given subreach. Once the HANDWATER has been optimized, a water depth map can be generated by subtracting the value of the HAND raster at the each location from this parameter value. These developments enable large scale and near real-time applications and only require readily available EO data, a DEM and the river network as input data. The approach is based on a hierarchical split-based approach that subdivides a

  13. Planting depth effects and water potential effects on oak seedling emergence and acorn germination

    Science.gov (United States)

    Wayne A. Smiles; Jeffrey O. Dawson

    1995-01-01

    The effects of four planting depths (0, 3, 7, 11 cm) and acorn size on the percentage seedling emergence of red, pin, and black oak were determined. In a complimentary study, the effects of five water potential treatments (0, -.2, -.4, -.6, -1.0 MPa) on the percentage germination of red, pin, and black oak acorns were measured.

  14. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh.

    Directory of Open Access Journals (Sweden)

    Hong Yan

    Full Text Available A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China. Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged and three submerged conditions (5 cm, 15 cm and 25 cm water level. Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH activity decreased but malondialdehyde (MDA content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation.

  15. Tree specific traits vs. stand level characteristics - assessing the source depths of plant water uptake in a mixed forest stand

    Science.gov (United States)

    Seeger, Stefan; Brinkmann, Nadine; Kahmen, Ansgar; Weiler, Markus

    2017-04-01

    Due to differences in fine root distributions, physiological root characteristics and plant plasticity, the spatial and temporal characteristics of plant water uptake are expected to vary between different tree species. This has implications on the overall water budget of a forest stand as well as on the drought sensitivity of particular trees. A four-year time series of climate data, soil moisture, and stable water isotopes in soil and tree xylem was used to investigate plant water uptake dynamics of four tree species (beech - Fagus sylvatica, spruce - Picea abies, ash - Fraxinus excelsior and maple - Acer pseudoplatanus) in a mixed forest stand. Modeling with a modified version of the soil hydrological model Hydrus-1D allowed us to simulate continuous time series of stable water isotopes in plant water uptake, which were compared to the measured values in tree xylem water and soil water. We found that different estimated species specific fine root distributions and root water uptake parameters lead to very similar simulated water balances and soil water isotope depth profiles for all four species. According to our simulations, differences in evaporative demand (i.e. LAI) had the biggest influence on water uptake and soil water distributions. Comparing the isotopic signatures of simulated root water uptake and measured xylem water, the simulations for beech were most suited to predict the observed signatures of all four species. This indicates that isolated, tree specific parametrized 1-D simulations are not suited to predict actual water uptake of different trees in a mixed stand. Due to overlapping root spaces dominant trees (in our case beeches with an LAI of around 5.5) may influence the soil water storage below accompanying trees (spruces, ashes and maples with LAIs between 1.8 and 3.1) in a degree that their actual water uptake cannot be predicted with 1-D simulations based on their smaller LAI values. Consequently, for a mixed forest stand the interplay of

  16. Predicting Nutrient Effects on Secchi Depth using the Tampa Bay Water Clarity Model (TBWCM)

    Science.gov (United States)

    Rogers, J. E.; Russell, M.

    2016-02-01

    The Tampa Bay Water Clarity Model was developed to predict the impact of changing nutrient loads on water clarity as measured by secchi depth. The model combines a physical mixing model with an irradiance model and nutrient cycling model. A 10 segment bifurcated box model based on salt and water balance, which assumed complete mixing of each segment at each time step, was used to physically mix the Bay. The irradiance model predicted light levels just below the Bay surface from atmospheric conditions appropriate for Tampa Bay. The nutrient cycling model was primarily based on the growth of phytoplankton, their death and the recycling of inorganic nutrients as described in WASP. Secchi depths were calculated from Kd values based on light absorption by water, total chlorophyll (a, b and c), colored disolved organic matter, and the effects of turbidity. The model was calibrated against monthly salinity, total chlorophyll, ammonia, total kjeldahl nitrogen, and dissolved oxygen data collected during 1985 through 1991. The model was calibrated in two stages: (1) by first calibrating the exchange coefficients using the box model and (2) by calibrating selected nutrient cycling parameters using the complete water clarity model. Validation of the model was conducted with a similar data set collected during 1992 through 1994. We assessed the sensitivity of the model to changes in nutrient load by running the model in predictive mode. Scenarios were run with nutrient inputs from gauged rivers and unguaged drainage basins scaled by factors of 50% to 500%. A linear relationship was found between nutrient inputs and average secchi depth, ammonia, and total chlorophyll for the seven year (1985-1991) model runs. A 5-fold increase in gauged river nitrogen input resulted in a 10 percent decrease in secchi depth which resulted in a 30 percent decrease in the maximum depth for seagrass growth in the middle portion of Old Tampa Bay.

  17. The Depths of Hydraulic Fracturing and Accompanying Water Use Across the United States.

    Science.gov (United States)

    Jackson, Robert B; Lowry, Ella R; Pickle, Amy; Kang, Mary; DiGiulio, Dominic; Zhao, Kaiguang

    2015-08-04

    Reports highlight the safety of hydraulic fracturing for drinking water if it occurs "many hundreds of meters to kilometers underground". To our knowledge, however, no comprehensive analysis of hydraulic fracturing depths exists. Based on fracturing depths and water use for ∼44,000 wells reported between 2010 and 2013, the average fracturing depth across the United States was 8300 ft (∼2500 m). Many wells (6900; 16%) were fractured less than a mile from the surface, and 2600 wells (6%) were fractured above 3000 ft (900 m), particularly in Texas (850 wells), California (720), Arkansas (310), and Wyoming (300). Average water use per well nationally was 2,400,000 gallons (9,200,000 L), led by Arkansas (5,200,000 gallons), Louisiana (5,100,000 gallons), West Virginia (5,000,000 gallons), and Pennsylvania (4,500,000 gallons). Two thousand wells (∼5%) shallower than one mile and 350 wells (∼1%) shallower than 3000 ft were hydraulically fractured with >1 million gallons of water, particularly in Arkansas, New Mexico, Texas, Pennsylvania, and California. Because hydraulic fractures can propagate 2000 ft upward, shallow wells may warrant special safeguards, including a mandatory registry of locations, full chemical disclosure, and, where horizontal drilling is used, predrilling water testing to a radius 1000 ft beyond the greatest lateral extent.

  18. Greenhouse irrigation water depths in relation to rose stem and bud qualities

    Directory of Open Access Journals (Sweden)

    Folegatti Marcos Vinícius

    2001-01-01

    Full Text Available The cultivation of roses occupies a special place in the flower production of Brazil, the concern with the quality of the buds being intimately related with the appropriate supply of water and nutrients to the plant. With the objective of evaluating stem and bud quality the rose variety 'Osiana' was cultivated in a greenhouse using different irrigation water depths based on fractions of pan evaporation (0.25, 0.50, 0.75, 1.00 and 1.25. The experimental design consisted of total randomized blocks with five replications and five treatments. There is a linear tendency of increasing the length and diameter of the stems and the length and diameter of the buds with increasing irrigation water depths.

  19. Abundance of macrozoobenthos in relation to bottom soil textural types and water depth In aquaculture ponds

    Directory of Open Access Journals (Sweden)

    N. Nupur

    2013-12-01

    Full Text Available The present experiment was conducted to evaluate the effects of bottom soil textural classes and different water depths on abundance of macrozoobenthos in aquaculture ponds. Three treatments, i.e., ponds bottom with sandy loam (T1, with loam (TS2 and with clay loam (T3 were considered in this experiment. Samples were collected from three different depths (60.96 cm, 106.68 cm and 152.40 cm with three replications. The ranges of water quality parameters were suitable for the growth of macrozoobenthos during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed comparatively higher ranges in T2. Eight genera were recorded belonging to major groups of Chironomidae, Oligochaeta, Mollusca and Ceratoponogonidae. The highest population densities of Oligochaeta (1200±4.25 per m2, Chironomidae (1422±4.88 per m2, Ceratopogonidae (399±1.56 per m2 and Mollusca (977±2.24 per m2 were found in T2. The population densities of macrozoobenthos showed fortnightly variations in all the treatments. Among the three depths, significantly highest densities of macrozoobenthos were recorded in 106.68 cm in every treatment. The mean abundance of macrozoobenthos was significantly highest in T2. The present study indicates that loamy soil pond bottom along with water depth 106.68 cm is suitable for the growth and production of macrozoobenthos in aquaculture ponds.

  20. Corrosion in sea water at different depths. Korrosion i havsvatten paa olika djup

    Energy Technology Data Exchange (ETDEWEB)

    Sund, G.

    1990-05-17

    The sea and the sea bottom contain great resources which only during the last decades have begun to be used to any great extent. In this connection, stationary constructions for oil and gas extraction attract great interest, but floating factories, plants for water usage and desalting plants can also be mentioned. The ultimate goal of the project was to provide a comprehensive picture of how the corrosion rate varies at different depths in sea water by: - determining the risk for local corrosion of stainless steels. - determining the corrosion rate during the general corrosion of carbon steel and low alloy steels and the risk of hydrogen embrittlement of welded high-tensile steels. - studying galvanic effects when stainless steels/titanium are joined to carbon steel, Ni-resist and copper alloys. The investigation was carried out in the Koster fiord at a depth of ca 10 m and at a depth level corresponding to 130 m and at the Norske Veritas test station outside Bergen at depths of 10 m and 110 m. A lot of information concerning sea water parameters and growth was obtained and compiled for the different test sites. A large amount of data are presented in the report. (16 figs., 21 tabs., 12 refs.).

  1. Estimating the Depth and Shape of Lake Vostok's Water Cavity from Aerogravity Data

    Science.gov (United States)

    Studinger, M.; Bell, R. E.; Tikku, A. A.

    2003-12-01

    The water circulation within Lake Vostok provides a viable mechanism for transporting mass and energy through the lake, enhancing the potential for the support of biota. The circulation pattern depends primarily on the geometry of the lake bathymetry. Water in shallow regions will warm more from the geothermal heat flux than in deeper parts, resulting in subtle lateral changes of water density. This temperature-induced change in water density is the primary driving force for the horizontal circulation within the lake. To date, only a few seismic soundings have provided estimates of the water depth of Lake Vostok. To determine the depth and shape of the water cavity over the entire lake we use gravity data acquired along a grid of flight lines traversing the region. The free-air gravity anomaly field reflects density variations related to both major geological and topographic structures and changes in the water depth of the lake. The gravity contribution from the deeper geological structures can be removed from the free-air anomaly by low-pass filtering of the data. The subglacial topography outside the lake and the geometry of the overlying ice sheet are well constrained from ice-penetrating radar measurements. The unknown parameter that dominates the filtered gravity anomaly is the relief of the bedrock-water interface. Assuming a constant density contrast across this boundary, the gravity data can be inverted for the bathymetry of the lake. The results show that Lake Vostok consists of two sub-basins, a northern and southern. The southern sub-basin is much deeper and approximately double the spatial area of the smaller northern sub-basin. The two sub-basins are separated by a saddle with very shallow water depths. The separation of Lake Vostok in two distinct sub-basins has important ramifications for the water circulation within the lake. The lake volume estimated from the inversion of gravity data is 5200 cubic km, three times bigger than previously thought

  2. Forcing of a bottom-mounted circular cylinder by steep regular water waves at finite depth

    DEFF Research Database (Denmark)

    Paulsen, Bo Terp; Bredmose, Henrik; Bingham, Harry B.

    2014-01-01

    with the experimental data was found. Time-domain computations of the normalized inline force history on the cylinder were analysed as a function of dimensionless wave height, water depth and wavelength. Here the dependence on depth was weak, while an increase in wavelength or wave height both lead to the formation......-harmonic force, a good agreement with the perturbation theories of Faltinsen, Newman & Vinje (J. Fluid Mech., vol. 289, 1995, pp. 179–198) and Malenica & Molin (J. Fluid Mech., vol. 302, 1995, pp. 203–229) was found. It was shown that the third-harmonic forces were estimated well by a Morison force formulation...

  3. Topsoil depth substantially influences the responses to drought of the foliar metabolomes of Mediterranean forests

    Energy Technology Data Exchange (ETDEWEB)

    Rivas-Ubach, Albert; Barbeta, Adrià; Sardans, Jordi; Guenther, Alex; Ogaya, Romà; Oravec, Michal; Urban, Otmar; Peñuelas, Josep

    2016-08-01

    Soils provide physical support, water, and nutrients to terrestrial plants. Upper soil layers are crucial for forest dynamics, especially under drought conditions, because many biological processes occur there and provide support, water and nutrients to terrestrial plants. We postulated that tree size and overall plant function manifested in the metabolome composition, the total set of metabolites, were dependent on the depth of upper soil layers and on water availability. We sampled leaves for stoichiometric and metabolomic analyses once per season from differently sized Quercus ilex trees under natural and experimental drought conditions as projected for the coming decades. Different sized trees had different metabolomes and plots with shallower soils had smaller trees. Soil moisture of the upper soil did not explain the tree size and smaller trees did not show higher concentrations of biomarker metabolites related to drought stress. However, the impact of drought treatment on metabolomes was higher in smaller trees in shallower soils. Our results suggested that tree size was more dependent on the depth of the upper soil layers, which indirectly affect the metabolomes of the trees, than on the moisture content of the upper soil layers. Metabolomic profiling of Q. ilex supported the premise that water availability in the upper soil layers was not necessarily correlated with tree size. The higher impact of drought on trees growing in shallower soils nevertheless indicates a higher vulnerability of small trees to the future increase in frequency, intensity, and duration of drought projected for the Mediterranean Basin and other areas. Metabolomics has proven to be an excellent tool detecting significant metabolic changes among differently sized individuals of the same species and it improves our understanding of the connection between plant metabolomes and environmental variables such as soil depth and moisture content.

  4. Variables Influencing the Depth of Conscious Sedation in Plastic Surgery: A Prospective Study

    Directory of Open Access Journals (Sweden)

    Hyeonjung Yeo

    2017-01-01

    Full Text Available BackgroundConscious sedation has been widely utilized in plastic surgery. However, inadequate research has been published evaluating adequate drug dosage and depth of sedation. In clinical practice, sedation is often inadequate or accompanied by complications when sedatives are administered according to body weight alone. The purpose of this study was to identify variables influencing the depth of sedation during conscious sedation for plastic surgery.MethodsThis prospective study evaluated 97 patients who underwent plastic surgical procedures under conscious sedation. Serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, creatinine, and glucose levels were measured. Midazolam and ketamine were administered intravenously according to a preset protocol. Bispectral index (BIS recordings were obtained to evaluate the depth of sedation 4, 10, 15, and 20 minutes after midazolam administration. Associations between variables and the BIS were assessed using multiple regression analysis.ResultsAlcohol intake and female sex were positively associated with the mean BIS (P<0.01. Age was negatively associated with the mean BIS (P<0.01. Body mass index (P=0.263, creatinine clearance (P=0.832, smoking history (P=0.398, glucose (P=0.718, AST (P=0.729, and ALT (P=0.423 were not associated with the BIS.ConclusionsOlder patients tended to have a greater depth of sedation, whereas females and patients with greater alcohol intake had a shallower depth of sedation. Thus, precise dose adjustments of sedatives, accounting for not only weight but also age, sex, and alcohol consumption, are required to achieve safe, effective, and predictable conscious sedation.

  5. Water Constituents and Water Depth Retrieval from Sentinel-2A—A First Evaluation in an Oligotrophic Lake

    Directory of Open Access Journals (Sweden)

    Katja Dörnhöfer

    2016-11-01

    Full Text Available Satellite remote sensing may assist in meeting the needs of lake monitoring. In this study, we aim to evaluate the potential of Sentinel-2 to assess and monitor water constituents and bottom characteristics of lakes at spatio-temporal synoptic scales. In a field campaign at Lake Starnberg, Germany, we collected validation data concurrently to a Sentinel-2A (S2-A overpass. We compared the results of three different atmospheric corrections, i.e., Sen2Cor, ACOLITE and MIP, with in situ reflectance measurements, whereof MIP performed best (r = 0.987, RMSE = 0.002 sr−1. Using the bio-optical modelling tool WASI-2D, we retrieved absorption by coloured dissolved organic matter (aCDOM(440, backscattering and concentration of suspended particulate matter (SPM in optically deep water; water depths, bottom substrates and aCDOM(440 were modelled in optically shallow water. In deep water, SPM and aCDOM(440 showed reasonable spatial patterns. Comparisons with in situ data (mean: 0.43 m−1 showed an underestimation of S2-A derived aCDOM(440 (mean: 0.14 m−1; S2-A backscattering of SPM was slightly higher than backscattering from in situ data (mean: 0.027 m−1 vs. 0.019 m−1. Chlorophyll-a concentrations (~1 mg·m−3 of the lake were too low for a retrieval. In shallow water, retrieved water depths exhibited a high correlation with echo sounding data (r = 0.95, residual standard deviation = 0.12 m up to 2.5 m (Secchi disk depth: 4.2 m, though water depths were slightly underestimated (RMSE = 0.56 m. In deeper water, Sentinel-2A bands were incapable of allowing a WASI-2D based separation of macrophytes and sediment which led to erroneous water depths. Overall, the results encourage further research on lakes with varying optical properties and trophic states with Sentinel-2A.

  6. A correlation for predicting the abrasive water jet cutting depth for natural stones

    Directory of Open Access Journals (Sweden)

    Irfan C. Engin

    2012-09-01

    Full Text Available The abrasive water jet (AWJ cutting method has been used widely for the cutting and processing of materials because of its cool, damage-free, and precise cutting technique. Nowadays, the use of AWJ cutting in the natural stone industry is increasing. However, the effectiveness of AWJ cutting of natural stones is dependent on the rock properties and machine operating parameters. In this study, injection-type AWJ cutting was applied to 42 different types of natural stones to investigate the effects of rock properties and operating parameters on the cutting depth. Shore hardness, Bohme surface abrasion resistance and the density of the rocks were the most significant rock properties affecting the cutting depth. The working pump pressure and traverse velocity were the most significant operating parameters affecting cutting, as has been shown previously. The relationships between the rock properties or operating parameters and the cutting depth were evaluated using multiple linear and nonlinear regression analyses, and estimation models were developed. Some of the models included only rock properties under fixed operating conditions, and others included both rock properties and operating parameters to predict cutting depth. The models allow for the preselection of particular operating parameters for the cutting of specific rocks types. The prediction of cutting depth is a valuable tool for the controlled surface machining of rock materials.

  7. Water Reverberation Travel Time Analysis Acquired Using Multi-Depth Streamers

    Directory of Open Access Journals (Sweden)

    Po-Yen Tseng

    2016-01-01

    Full Text Available Ghost reflections and water reverberations are major and inevitable seismic noises in marine seismic exploration. More recently, new receiver deployment techniques at different sea depths for signal-to-noise ratio (SNR enhancement are developing. The reverberation characteristics must be known before applying the reverberation attenuation methods. This paper studies the characteristics of reverberations acquired using multi-depth streamers by analyzing the seismic ray path geometry and the scaled physical model data. The study results show that the primary reflection waveforms and reverberations are broadened with an increase in offset. The reverberation waveforms are quite different from those of primary reflections due to the wide-angle reflection. Under shallow water and small spread approximation, new arrival time equations for the primary reflections and reverberations are derived and fit the scaled physical model data very well. The depth-arrival time relationships of the primary reflections and reverberations in the common-source vertical-array gather are linear but their depth-arrival time relationship slopes are different. The primary reflection slopes are the same for different common-source vertical-array offsets but the reverberation slopes increase with offsets.

  8. Vegetation type and layer depth influence nitrite-dependent methane-oxidizing bacteria in constructed wetland.

    Science.gov (United States)

    Yang, Mengxi; Guo, Qingwei; Tong, Tianli; Li, Ningning; Xie, Shuguang; Long, Yan

    2017-04-01

    Nitrite-dependent anaerobic methane oxidation (n-damo) process might be an important methane sink in wetland system. However, information on n-damo microorganisms in constructed wetland (CW) system for water treatment is still lacking. The present study investigated the n-damo communities in five full-scale vertical-flow CW systems with different plants. N-damo bacterial abundance did not show a considerable shift in CW planted with Cyperus papyrus, but varied greatly in other CW systems. However, the evident vertical change of n-damo community diversity occurred in each CW system. These CW systems displayed the different vertical change trends for either n-damo community abundance or diversity. In addition, CW n-damo community structure could change with wetland layer depth. At a given wetland layer depth, the evident difference of n-damo community abundance, diversity and structure could be observed in the five different CW systems. Both wetland layer depth and vegetation type could contribute to the shift of n-damo bacterial abundance and community structure in CWs.

  9. Elemental Water Impact Test: Phase 3 Plunge Depth of a 36-Inch Aluminum Tank Head

    Science.gov (United States)

    Vassilakos, Gregory J.

    2014-01-01

    Spacecraft are being designed based on LS-DYNA water landing simulations. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. Phase 3 featured a composite tank head that was tested at a range of heights to verify the ability to predict structural failure of composites. To support planning for Phase 3, a test series was conducted with an aluminum tank head dropped from heights of 2, 6, 10, and 12 feet to verify that the test article would not impact the bottom of the test pool. This report focuses on the comparisons of the measured plunge depths to LS-DYNA predictions. The results for the tank head model demonstrated the following. 1. LS-DYNA provides accurate predictions for peak accelerations. 2. LS-DYNA consistently under-predicts plunge depth. An allowance of at least 20% should be added to the LS-DYNA predictions. 3. The LS-DYNA predictions for plunge depth are relatively insensitive to the fluid-structure coupling stiffness.

  10. Spatio-temporal representativeness of euphotic depth in situ sampling in transitional coastal waters

    Science.gov (United States)

    Luhtala, Hanna; Tolvanen, Harri

    2016-06-01

    In dynamic coastal waters, the representativeness of spot sampling is limited to the measurement time and place due to local heterogeneity and irregular water property fluctuations. We assessed the representativeness of in situ sampling by analysing spot-sampled depth profiles of photosynthetically active radiation (PAR) in dynamic coastal archipelago waters in the south-western Finnish coast of the Baltic Sea. First, we assessed the role of spatio-temporality within the underwater light dynamics. As a part of this approach, an anomaly detection procedure was tested on a dataset including a large archipelago area and extensive temporal coverage throughout the ice-free season. The results suggest that euphotic depth variability should be treated as a spatio-temporal process rather than considering spatial and temporal dimensions separately. Second, we assessed the representativeness of spot sampling through statistical analysis of comparative data from spatially denser sampling on three test sites on two optically different occasions. The datasets revealed variability in different dimensions and scales. The suitability of a dataset to reveal wanted phenomena can usually be improved by careful planning and by clearly defining the data sampling objectives beforehand. Nonetheless, conducting a sufficient in situ sampling in dynamic coastal area is still challenging: detecting the general patterns at all the relevant dimensions is complicated by the randomness effect, which reduces the reliability of spot samples on a more detailed scale. Our results indicate that good representativeness of a euphotic depth sampling location is not a stable feature in a highly dynamic environment.

  11. Effects of surrounding land use and water depth on seagrass dynamics relative to a catastrophic algal bloom.

    Science.gov (United States)

    Breininger, David R; Breininger, Robert D; Hall, Carlton R

    2017-02-01

    Seagrasses are the foundation of many coastal ecosystems and are in global decline because of anthropogenic impacts. For the Indian River Lagoon (Florida, U.S.A.), we developed competing multistate statistical models to quantify how environmental factors (surrounding land use, water depth, and time [year]) influenced the variability of seagrass state dynamics from 2003 to 2014 while accounting for time-specific detection probabilities that quantified our ability to determine seagrass state at particular locations and times. We classified seagrass states (presence or absence) at 764 points with geographic information system maps for years when seagrass maps were available and with aerial photographs when seagrass maps were not available. We used 4 categories (all conservation, mostly conservation, mostly urban, urban) to describe surrounding land use within sections of lagoonal waters, usually demarcated by land features that constricted these waters. The best models predicted that surrounding land use, depth, and year would affect transition and detection probabilities. Sections of the lagoon bordered by urban areas had the least stable seagrass beds and lowest detection probabilities, especially after a catastrophic seagrass die-off linked to an algal bloom. Sections of the lagoon bordered by conservation lands had the most stable seagrass beds, which supports watershed conservation efforts. Our results show that a multistate approach can empirically estimate state-transition probabilities as functions of environmental factors while accounting for state-dependent differences in seagrass detection probabilities as part of the overall statistical inference procedure. © 2016 Society for Conservation Biology.

  12. Determinants of the spatial covariation of primary productivity and water table depth

    Science.gov (United States)

    Koirala, S.; Jung, M.; de Graaf, I. E. M.; Reichstein, M.; Carvalhais, N.

    2015-12-01

    This study explores when, where and how the spatial variations of gross primary productivity (GPP) and water table depth (WTD) are linked at the global scale. Latest observation-based global datasets, at a relatively high resolution of ~10 km (5 arc-minutes), are used to analyse spatial partial correlations between GPP and WTD. Results indicate that strength, direction, and spatial distribution of the partial correlation change with climate, vegetation cover, and seasonal availability of precipitation and radiation. Shallower water table depth is associated with larger GPP (negative correlation) in 14.3-23.9% of the global land area in different seasons. Such negative correlations between GPP and WTD seem to prevail in arid to temperate climatic regions with crop, shrub, or Savanna vegetation covers. These regions often have WTD shallower than 15-20 m. Positive correlations, on the other hand, mostly occur in relatively humid forested regions, suggesting that large water uptake by tree roots decreases groundwater recharge and thus draws the water table down. Gradients of primarily positive to primarily negative correlations are arranged along decreasing tree cover, and increasing coverage of plants with C4-photosynthesis. This possibly indicates that the water use efficiency of ecosystems may also play a critical role in determining productivity-groundwater relationships.

  13. Modeling of the influence of transparency of the derivatives market on financial depth

    Directory of Open Access Journals (Sweden)

    Irina Burdenko

    2016-07-01

    Full Text Available The market of derivative tools becomes an integral part of the financial market, the functions which are carrying out in it peculiar only to it: hedging, distribution of risks, ensuring liquidity of basic assets, information support of future movement of the prices, decrease in asymmetry of information in the financial markets. However, the insufficiency or lack of transparent information can lead to emergence of the crisis phenomena, shocks in the financial market and growth of system risk. Emergence of need for strengthening of information function of the market of derivatives changes of requirements to transparency of information had been caused by financial crisis of 2008-2009. In this article the attempt of an assessment of influence was made by means of autoregressive models the change of requirements to standard transparency, such as qualitative characteristic of the derivatives market, on quantitative indices of the financial market, in particular financial depth. The results of research demonstrate that reforming of the legislation concerning strengthening of transparency in the derivatives market positively influences the growth of financial depth. The research of this question will promote the best understanding of importance of reforming of regulation of the derivatives market, in particular strengthening of requirements to transparency. Recommendations of the further researches concern the needs of input of reforms of financial regulation in the derivatives market in Ukraine, and, thus, to provide the corresponding conditions for his development

  14. Area, depth and elevation of cryoconite holes in the Arctic do not influence Tardigrada densities

    Directory of Open Access Journals (Sweden)

    Zawierucha Krzysztof

    2016-06-01

    Full Text Available Water bears (Tardigrada are known as one of the most extremophile animals in the world. They inhabit environments from the deepest parts of the oceans up to the highest mountains. One of the most extreme and still poorly studied habitats which tardigrades inhabit are cryoconite holes. We analysed the relation between area, depth, elevation and tardigrades densities in cryoconite holes on four glaciers on Spitsbergen. The mean (±SD of cryoconite area was 1287.21±2400.8 cm2, while the depth was on average 10.8±11.2 cm, the elevation 172.6±109.66 m a.s.l., and tardigrade density 24.9±33.0 individuals per gram of wet material (n = 38. The densities of tardigrades on Hans Glacier reached values of up to 168 ind. cm3, 104 ind. g−1 wet weight, and 275 ind. g−1 dry weight. The densities of tardigrades of the three glaciers in Billefjorden were up to 82 ind. cm2, 326 ind. g−1 wet weight and 624 ind. g−1 dry weight. Surprisingly, although the model included area, depth and elevation as independent variables, it cannot explain Tardigrada density in cryoconite holes. We propose that due to the rapid melting of the glacier surface in the Arctic, the constant flushing of cryoconite sediments, and inter-hole water-sediment mixing, the functioning of these ecosystems is disrupted. We conclude that cryoconite holes are dynamic ecosystems for microinvertebrates in the Arctic.

  15. Testing peatland water-table depth transfer functions using high-resolution hydrological monitoring data

    Science.gov (United States)

    Swindles, Graeme T.; Holden, Joseph; Raby, Cassandra L.; Turner, T. Edward; Blundell, Antony; Charman, Dan J.; Menberu, Meseret Walle; Kløve, Bjørn

    2015-07-01

    Transfer functions are now commonly used to reconstruct past environmental variability from palaeoecological data. However, such approaches need to be critically appraised. Testate amoeba-based transfer functions are an established method for the quantitative reconstruction of past water-table variations in peatlands, and have been applied to research questions in palaeoclimatology, peatland ecohydrology and archaeology. We analysed automatically-logged peatland water-table data from dipwells located in England, Wales and Finland and a suite of three year, one year and summer water-table statistics were calculated from each location. Surface moss samples were extracted from beside each dipwell and the testate amoebae community composition was determined. Two published transfer functions were applied to the testate-amoeba data for prediction of water-table depth (England and Europe). Our results show that estimated water-table depths based on the testate amoeba community reflect directional changes, but that they are poor representations of the real mean or median water-table magnitudes for the study sites. We suggest that although testate amoeba-based reconstructions can be used to identify past shifts in peat hydrology, they cannot currently be used to establish precise hydrological baselines such as those needed to inform management and restoration of peatlands. One approach to avoid confusion with contemporary water-table determinations is to use residuals or standardised values for peatland water-table reconstructions. We contend that our test of transfer functions against independent instrumental data sets may be more powerful than relying on statistical testing alone.

  16. Water masses transform at mid-depths over the Antarctic Continental Slope

    Science.gov (United States)

    Mead Silvester, Jess; Lenn, Yueng-Djern; Polton, Jeffrey; Phillips, Helen E.; Morales Maqueda, Miguel

    2017-04-01

    The Meridional Overturning Circulation (MOC) controls the oceans' latitudinal heat distribution, helping to regulate the Earth's climate. The Southern Ocean is the primary place where cool, deep waters return to the surface to complete this global circulation. While water mass transformations intrinsic to this process predominantly take place at the surface following upwelling, recent studies implicate vertical mixing in allowing transformation at mid-depths over the Antarctic continental slope. We deployed an EM-Apex float near Elephant Island, north of the Antarctic Peninsula's tip, to profile along the slope and use potential vorticity to diagnose observed instabilities. The float captures direct heat exchange between a lens of Upper Circumpolar Deep Water (UCDW) and surrounding Lower Circumpolar Deep Waters (LCDW) at mid-depths and over the course of several days. Heat fluxes peak across the top and bottom boundaries of the UCDW lens and peak diffusivities across the bottom boundary are associated with shear instability. Estimates of diffusivity from shear-strain finestructure parameterisation and heat fluxes are found to be in reasonable agreement. The two-dimensional Ertel potential vorticity is elevated both inside the UCDW lens and along its bottom boundary, with a strong contribution from the shear term in these regions and instabilities are associated with gravitational and symmetric forcing. Thus, shear instabilities are driving turbulent mixing across the lower boundary between these two water masses, leading to the observed heat exchange and transformation at mid-depths over the Antarctic continental slope. This has implications for our understanding of the rates of upwelling and ocean-atmosphere exchanges of heat and carbon at this critical location.

  17. Hydrologic record extension of water-level data in the Everglades Depth Estimation Network (EDEN), 1991-99

    Science.gov (United States)

    Conrads, Paul; Petkewich, Matthew D.; O'Reilly, Andrew M.; Telis, Pamela A.

    2015-01-01

    The real-time Everglades Depth Estimation Network (EDEN) has been established to support a variety of scientific and water management purposes. The expansiveness of the Everglades, limited number of gaging stations, and extreme sensitivity of the ecosystem to small changes in water depth have created a need for accurate water-level and water-depth maps. The EDEN water-surface elevation model uses data from approximately 240 gages in the Everglades to create daily continuous interpolations of the water-surface elevation and water depth for the freshwater portion of the Everglades from 2000 to the present (2014). These maps provide hydrologic data previously unavailable for assessing biological and ecological studies.

  18. Influence of notch depth on tearing morphology and tearing energy in carbon-black-loaded SBR (styrene butadiene rubber)

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A.; LeMay, J.D.; Sanchez, R.J.; Stone, J.C.; Patt, J.

    1987-01-30

    Tearing energies (T) have been evaluated for carbon-black-reinforced SBR tested in uniaxial tension. The influence of notch depth on T and fracture morphology have also been determined. The influence of notch depth on the stress-strain behavior and on the failure stress and failure strain is also illustrated. The ratio of recovered-to-input energy as a function of both stress and strain was determined for notched and notch-free samples.

  19. Historical Tracking of Nitrate in Contrasting Vineyard Using Water Isotopes and Nitrate Depth Profiles

    Science.gov (United States)

    Sprenger, M.; Erhardt, M.; Riedel, M.; Weiler, M.

    2015-12-01

    The European Water Framework Directive (EWFD) aims to achieve a good chemical status for the groundwater bodies in Europe by the year 2015. Despite the effort to reduce the nitrate pollution from agriculture within the last two decades, there are still many groundwater aquifers that exceed nitrate concentrations above the EWFD threshold of 50 mg/l. Viticulture is seen as a major contributor of nitrate leaching and sowing of a green cover was shown to have a positive effect on lowering the nitrate loads in the upper 90 cm of the soil. However, the consequences for nitrate leaching into the subsoil were not yet tested. We analyzed the nitrate concentrations and pore water stable isotope composition to a depth of 380 cm in soil profiles under an old vineyard and a young vineyard with either soil tillage or permanent green cover in between the grapevines. The pore water stable isotopes were used to calibrate a soil physical model, which was then used to infer the age of the soil water at different depths. This way, we could relate elevated nitrate concentrations below an old vineyard to tillage processes that took place during the winter two years before the sampling. We further showed that the elevated nitrate concentration in the subsoil of a young vineyard can be related to the soil tillage prior to the planting of the new vineyard. If the soil is kept bare due to tillage, a nitrate concentration of 200 kg NO3--N/ha is found in 290 to 380 cm depth 2.5 years after the installation of the vineyard. The amount of nitrate leaching is considerably reduced due to a seeded green cover between the grapevines that takes up a high share of the mobilized nitrate reducing a potential contamination of the groundwater.

  20. Using inferential sensors for quality control of Everglades Depth Estimation Network water-level data

    Science.gov (United States)

    Petkewich, Matthew D.; Daamen, Ruby C.; Roehl, Edwin A.; Conrads, Paul

    2016-09-29

    The Everglades Depth Estimation Network (EDEN), with over 240 real-time gaging stations, provides hydrologic data for freshwater and tidal areas of the Everglades. These data are used to generate daily water-level and water-depth maps of the Everglades that are used to assess biotic responses to hydrologic change resulting from the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. The generation of EDEN daily water-level and water-depth maps is dependent on high quality real-time data from water-level stations. Real-time data are automatically checked for outliers by assigning minimum and maximum thresholds for each station. Small errors in the real-time data, such as gradual drift of malfunctioning pressure transducers, are more difficult to immediately identify with visual inspection of time-series plots and may only be identified during on-site inspections of the stations. Correcting these small errors in the data often is time consuming and water-level data may not be finalized for several months. To provide daily water-level and water-depth maps on a near real-time basis, EDEN needed an automated process to identify errors in water-level data and to provide estimates for missing or erroneous water-level data.The Automated Data Assurance and Management (ADAM) software uses inferential sensor technology often used in industrial applications. Rather than installing a redundant sensor to measure a process, such as an additional water-level station, inferential sensors, or virtual sensors, were developed for each station that make accurate estimates of the process measured by the hard sensor (water-level gaging station). The inferential sensors in the ADAM software are empirical models that use inputs from one or more proximal stations. The advantage of ADAM is that it provides a redundant signal to the sensor in the field without the environmental threats associated with field conditions at stations (flood or hurricane, for example). In the

  1. Depth-variable settlement patterns and predation influence on newly settled reef fishes (Haemulon spp., Haemulidae.

    Directory of Open Access Journals (Sweden)

    Lance K B Jordan

    Full Text Available During early demersal ontogeny, many marine fishes display complex habitat-use patterns. Grunts of the speciose genus Haemulon are among the most abundant fishes on western North Atlantic coral reefs, with most species settling to shallow habitats (≤12 m. To gain understanding into cross-shelf distributional patterns exhibited by newly settled stages of grunts (<2 cm total length, we examined: 1 depth-specific distributions of congeners at settlement among sites at 8 m, 12 m, and 21 m, and 2 depth-variable predation pressure on newly settled individuals (species pooled. Of the six species identified from collections of newly settled specimens (n = 2125, Haemulon aurolineatum (tomtate, H. flavolineatum (French grunt, and H. striatum (striped grunt comprised 98% of the total abundance; with the first two species present at all sites. Prevalence of H. aurolineatum and H. flavolineatum decreased substantially from the 8-m site to the two deeper sites. In contrast, H. striatum was absent from the 8-m site and exhibited its highest frequency at the 21-m site. Comparison of newly settled grunt delta density for all species on caged (predator exclusion and control artificial reefs at the shallowest site (8-m revealed no difference, while the 12-m and 21-m sites exhibited significantly greater delta densities on the caged treatment. This result, along with significantly higher abundances of co-occurring piscivorous fishes at the deeper sites, indicated lower predation pressure at the 8-m site. This study suggests habitat-use patterns of newly settled stages of some coral reef fishes that undergo ontogenetic shifts are a function of depth-variable predation pressure while, for at least one deeper-water species, proximity to adult habitat appears to be an important factor affecting settlement distribution.

  2. Influence of Corrugation Depth on Lateral Stability of Cold-Formed Steel Beams of Corrugated Webs

    Directory of Open Access Journals (Sweden)

    Ungureanu Viorel

    2016-06-01

    Full Text Available The beams of thin corrugated web afford a significant weight reduction compared with hot-rolled or welded ones. In the initial solutions, the flanges are made of flat plates, welded to the sinusoidal web sheet, requiring a specific welding technology. A new solution is proposed by the authors, in which the beam is composed by a web of trapezoidal cold-formed steel sheet and flanges of back-to-back lipped channel sections. For connecting flanges to the web self-drilling screws are used. The paper summarizes the experimental and numerical investigations carried out at the CEMSIG Research Centre (www.ct.upt.ro/centre/cemsig/ of the Politehnica University of Timisoara and, at the end, presents the influence of corrugation depth of web on the lateral stability of the beams.

  3. Isotope and fatty acid trends along continental shelf depth gradients: Inshore versus offshore hydrological influences on benthic trophic functioning

    Science.gov (United States)

    Chouvelon, T.; Schaal, G.; Grall, J.; Pernet, F.; Perdriau, M.; A-Pernet, E. J.; Le Bris, H.

    2015-11-01

    Anthropogenic activities and land-based inputs into the sea may influence the trophic structure and functioning of coastal and continental shelf ecosystems, despite the numerous opportunities and services the latter offer to humans and wildlife. In addition, hydrological structures and physical dynamics potentially influence the sources of organic matter (e.g., terrestrial versus marine, or fresh material versus detrital material) entering marine food webs. Understanding the significance of the processes that influence marine food webs and ecosystems (e.g., terrestrial inputs, physical dynamics) is crucially important because trophic dynamics are a vital part of ecosystem integrity. This can be achieved by identifying organic matter sources that enter food webs along inshore-offshore transects. We hypothesised that regional hydrological structures over wide continental shelves directly control the benthic trophic functioning across the shelf. We investigated this issue along two transects in the northern ecosystem of the Bay of Biscay (north-eastern Atlantic). Carbon and nitrogen stable isotope analysis (SIA) and fatty acid analysis (FAA) were conducted on different complementary ecosystem compartments that include suspended particulate organic matter (POM), sedimentary organic matter (SOM), and benthic consumers such as bivalves, large crustaceans and demersal fish. Samples were collected from inshore shallow waters (at ∼1 m in depth) to more than 200 m in depth on the offshore shelf break. Results indicated strong discrepancies in stable isotope (SI) and fatty acid (FA) compositions in the sampled compartments between inshore and offshore areas, although nitrogen SI (δ15N) and FA trends were similar along both transects. Offshore the influence of a permanently stratified area (described previously as a ;cold pool;) was evident in both transects. The influence of this hydrological structure on benthic trophic functioning (i.e., on the food sources available for

  4. Monitoring plant water status and rooting depth for precision irrigation in the vineyards of Classic Karst

    Science.gov (United States)

    Savi, Tadeja; Moretti, Elisa; Dal Borgo, Anna; Petruzzellis, Francesco; Stenni, Barbara; Bertoncin, Paolo; Dreossi, Giuliano; Zini, Luca; Martellos, Stefano; Nardini, Andrea

    2017-04-01

    The extreme summer drought and heat waves that occurred in South-Europe in 2003 and 2012 have led to the loss of more than 50% of winery production in the Classic Karst (NE Italy). The irrigation of vineyards in this area is not appropriately developed and, when used, it does not consider the actual water status and needs of plants, posing risks of inappropriate or useless usage of large water volumes. The predicted future increase in frequency and severity of extreme climate events poses at serious risk the local agriculture based on wine business. We monitored seasonal trends of pre-dawn (Ψpd) and minimum (Ψmin) leaf water potential, and stomatal conductance (gL) of 'Malvasia' grapevine in one mature (MV, both in 2015 and 2016) and one young vineyard (YV, in 2016). Moreover, we extracted xylem sap form plant stems and soil water from samples collected in nearby caves, by cryo-vacuum distillation. We also collected precipitation and irrigation water in different months. Oxygen isotope composition (δ18O) of atmospheric, plant, soil and irrigation water was analyzed to get information about rooting depth. In 2015, at the peak of summer aridity, two irrigation treatments were applied according to traditional management practices. The treatments were performed in a sub-area of the MV, followed by physiological analysis and yield measurements at grape harvest. In 2016, the soil water potential (Ψsoil) at 50 cm depth was also monitored throughout the season. Under harsh environmental conditions the apparently deep root system ensured relatively favorable plant water status in both MV and YV and during both growing seasons. The Ψsoil at 50 cm depth gradually decreased as drought progressed, reaching a minimum value of about -1.7 MPa, far more negative than Ψpd recorded in plants (about -0.5 MPa). In July, significant stomatal closure was observed, but Ψmin never surpassed the critical threshold of -1.3 MPa, indicating that irrigation was not needed. The xylem sap

  5. Technology Concept of TLP Platform Towing and Installation in Waters with Depth of 60 m

    Directory of Open Access Journals (Sweden)

    Dymarski Czesław

    2017-04-01

    Full Text Available The article is part of the design and research work conducted at the Gdansk University of Technology, Faculty of Ocean Engineering and Ship Technology, in cooperation with a number of other research centres, which concerns offshore wind farms planned to be built in the Polish zone of the Baltic sea in the next years. One of most difficult tasks in this project is building suitable foundations for each power unit consisting of a tower and a wind turbine mounted on its top. Since the water regions selected for building those wind farms have different depths, there was need to study different possible technical variants of this task, with the reference to both the foundation structures themselves, and the technology of their transport and setting, or anchoring. The article presents the technology of towing, from the shipyard to the setting place, and installation of the foundation having the form of a floating platform of TLP (Tension Leg Platform type, anchored by tight chains to suction piles in the waters with depth of 60 m.

  6. The Spatial and Temporal Variability of Water Content in an Organic Soil in Dartmoor National Park, UK and its Relation to Microtopography and Organic Soil Horizon Depth.

    Science.gov (United States)

    Rogers, J.; Miles, H.; Berg, A.

    2009-05-01

    The water content of organic and mineral soils is an important parameter which links energy and mass balances at the earth's surface and as such is essential to understanding the spatial and temporal organization of many biological, biogeochemical, and hydrological processes. The characterization of surface water content in space and time is also important for the continued development of regional-scale and global circulation climate models and has large implications for agriculture and land-use planning. A field study was performed in Dartmoor National Park, Devon, UK in August 2008 for the purpose of exploring the predictive power of terrain indices on wetness patterns in an organic soil. Point samples were taken over the course of three days on two hill slopes of varying aspect in order to assess the influence of incident solar radiation on water storage. Additionally, the depth of the organic layer was estimated for each sample location and topographic information collected for the creation of a digital elevation model. A weak correlation between peat water content and organic soil layer depth was demonstrated and found to be strongest in shallow soils. Microtopography was found to influence the variability of soil moisture over the sampled area with surface roughness (measured by using residual elevation from the mean transect slope). Based on repeated observations over the sampling grids temporal persistence of water content patterns is evident and can be linked to terrain indices and depth of the organic layer.

  7. Space-time modeling of water table depth using a regionalized time series model and the Kalman filter

    NARCIS (Netherlands)

    Bierkens, M.F.P.; Knotters, M.; Hoogland, T.

    2001-01-01

    Water authorities in the Netherlands are not only responsible for managing surface water, but also for managing the groundwater reserves. Particularly the water table depth is an important variable, determining agricultural production and the potential for nature development. Knowledge of the

  8. The importance of atmospheric correction for airborne hyperspectral remote sensing of shallow waters: application to depth estimation

    Science.gov (United States)

    Castillo-López, Elena; Dominguez, Jose Antonio; Pereda, Raúl; de Luis, Julio Manuel; Pérez, Ruben; Piña, Felipe

    2017-10-01

    Accurate determination of water depth is indispensable in multiple aspects of civil engineering (dock construction, dikes, submarines outfalls, trench control, etc.). To determine the type of atmospheric correction most appropriate for the depth estimation, different accuracies are required. Accuracy in bathymetric information is highly dependent on the atmospheric correction made to the imagery. The reduction of effects such as glint and cross-track illumination in homogeneous shallow-water areas improves the results of the depth estimations. The aim of this work is to assess the best atmospheric correction method for the estimation of depth in shallow waters, considering that reflectance values cannot be greater than 1.5 % because otherwise the background would not be seen. This paper addresses the use of hyperspectral imagery to quantitative bathymetric mapping and explores one of the most common problems when attempting to extract depth information in conditions of variable water types and bottom reflectances. The current work assesses the accuracy of some classical bathymetric algorithms (Polcyn-Lyzenga, Philpot, Benny-Dawson, Hamilton, principal component analysis) when four different atmospheric correction methods are applied and water depth is derived. No atmospheric correction is valid for all type of coastal waters, but in heterogeneous shallow water the model of atmospheric correction 6S offers good results.

  9. Depth and Areal Distribution of Cs-137 in the Soil of a Small Water Catchment in the Sopron Mountains

    National Research Council Canada - National Science Library

    Ervin Kiss; Péter Volford

    2013-01-01

    The study presents the depth and areal distribution of Cs-137 activity concentration in the forest soils of Farkas Trench, a small water catchment in the Sopron Mountains, in 2001 and 2010, moreover...

  10. Calculation of intercepted runoff depth based on stormwater quality and environmental capacity of receiving waters for initial stormwater pollution management.

    Science.gov (United States)

    Peng, Hai-Qin; Liu, Yan; Gao, Xue-Long; Wang, Hong-Wu; Chen, Yi; Cai, Hui-Yi

    2017-11-01

    While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1 mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4 mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

  11. Temperate carbonate cycling and water mass properties from intertidal to bathyal depths (Azores

    Directory of Open Access Journals (Sweden)

    M. Wisshak

    2010-08-01

    Full Text Available The rugged submarine topography of the Azores supports a diverse heterozoan association resulting in intense biotically-controlled carbonate-production and accumulation. In order to characterise this cold-water (C factory a 2-year experiment was carried out in the southern Faial Channel to study the biodiversity of hardground communities and for budgeting carbonate production and degradation along a bathymetrical transect from the intertidal to bathyal 500 m depth.

    Seasonal temperatures peak in September (above a thermocline and bottom in March (stratification diminishes with a decrease in amplitude and absolute values with depth, and tidal-driven short-term fluctuations. Measured seawater stable isotope ratios and levels of dissolved nutrients decrease with depth, as do the calcium carbonate saturation states. The photosynthetic active radiation shows a base of the euphotic zone in ~70 m and a dysphotic limit in ~150 m depth.

    Bioerosion, being primarily a function of light availability for phototrophic endoliths and grazers feeding upon them, is ~10 times stronger on the illuminated upside versus the shaded underside of substrates in the photic zone, with maximum rates in the intertidal (−631 g/m2/yr. Rates rapidly decline towards deeper waters where bioerosion and carbonate accretion are slow and epibenthic/endolithic communities take years to mature. Accretion rates are highest in the lower euphotic zone (955 g/m2/yr, where the substrate is less prone to hydrodynamic force. Highest rates are found – inversely to bioerosion – on down-facing substrates, suggesting that bioerosion may be a key factor governing the preferential settlement and growth of calcareous epilithobionts on down-facing substrates.

    In context of a latitudinal gradient, the Azores carbonate cycling rates plot between known values from the cold-temperate Swedish Kosterfjord and the tropical Bahamas, with a total range of

  12. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  13. Lipid composition and molecular interactions change with depth in the avian stratum corneum to regulate cutaneous water loss.

    Science.gov (United States)

    Champagne, Alex M; Allen, Heather C; Williams, Joseph B

    2015-10-01

    The outermost 10-20 µm of the epidermis, the stratum corneum (SC), consists of flat, dead cells embedded in a matrix of intercellular lipids. These lipids regulate cutaneous water loss (CWL), which accounts for over half of total water loss in birds. However, the mechanisms by which lipids are able to regulate CWL and how these mechanisms change with depth in the SC are poorly understood. We used attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to measure lipid-lipid and lipid-water interactions as a function of depth in the SC of house sparrows (Passer domesticus Linnaeus) in the winter and summer. We then compared these molecular interactions at each depth with lipid composition at the same depth. We found that in both groups, water content increased with depth in the SC, and likely contributed to greater numbers of gauche defects in lipids in deeper levels of the SC. In winter-caught birds, which had lower rates of CWL than summer-caught birds, water exhibited stronger hydrogen bonding in deeper layers of the SC, and these strong hydrogen bonds were associated with greater amounts of polar lipids such as ceramides and cerebrosides. Based on these data, we propose a model by which polar lipids in deep levels of the SC form strong hydrogen bonds with water molecules to increase the viscosity of water and slow the permeation of water through the SC. © 2015. Published by The Company of Biologists Ltd.

  14. Changing Energy Inputs at Earth's Surface Translates to Differences in Water Availability, Weathering Rates, and Biotic Activity at Depth

    Science.gov (United States)

    McIntosh, J. C.; Zapata-Rios, X.; Rasmussen, C.; Brooks, P. D.; Gallery, R. E.; Pelletier, J. D.; Chorover, J.

    2016-12-01

    The Critical Zone (CZ), the thin skin of the Earth, from the top of canopies down to saturated bedrock, provides vital environmental and human services, including water storage, elemental cycling and climate regulation. CZ structure develops over both long (geologic) timescales in response to variations in water, energy and carbon availability, or short (episodic) timescales due to disturbance, such as fire and land use change. This structural heterogeneity in turn mediates dissipative products of CZ development altering water and solute fluxes, transit times and flowpaths. Understanding how these coupled process control CZ evolution across timescales is one of the grand challenges for CZ science. Here, we investigate how microclimate and hydrologic fluxes related to aspect and landscape position influence CZ structure and function across time scales in seasonally water-limited montane catchments. We show how CZ topographic structure interacts with climate change and associated disturbance to control inputs of water, energy and carbon into the CZ, which translates to differences in water availability, weathering rates, and biotic activity at depth. Beyond temporal and elevational trends in climatic forcing, we observe strong impacts of aspect variation on biological productivity in water-limited systems, largely because of the aspect induced diurnal covariation of solar radiation with temperature, that increases potential ET on S- or W-facing slopes relative to N- or E-facing slopes. This directly impacts the amount of water, carbon and energy available for subsurface weathering, leading to deeper regolith on N- and E-facing slopes. Consequently, we see longer water transit times and greater weathering fluxes in N-facing slopes. Higher weathering fluxes and microbial activity are also seen in convergent areas characterized by higher values of topographic wetness index, due to greater lateral fluxes of water and DOC. In so far as CZ evolution depends on meteorologic

  15. Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

    Science.gov (United States)

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

    2015-12-01

    Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

  16. The influence of sedimentation particles’ distribution in depth on the working length of gravity clarifier basins

    Directory of Open Access Journals (Sweden)

    Mikhaylov Ivan Evgrafovich

    2016-11-01

    Full Text Available The authors calculated the settlement probability of suspended particles inflowing to the clarifier. The limit distributions of dangerous sedimentation particles are considered: in a parabola and uniform for all the groups of particles, as well as distribution in trapezia having upper and lower bases with gradual increase of the length of the upper base from zero to the length of the lower base. It was stated that the sedimentation pattern of the particles in depth of the flow at the inlet of the settling basin greatly influences the required length of the basins. It was established that at the 80 % probability of dangerous particles’ sedimentation and at the flow velocity of 0.5 m/s the fluctuations range of the relative basin length S/H is 5 ea, for 94 % probability - 8.5 ea, and the fluctuations range is increasing with the increase of the probability. It is recommended to organize the experimental study of the distribution of suspended particles’ concentration at the inlet of operating clarifier basins and to take a uniform or close to the uniform distribution before obtaining this experimental data.

  17. Condition and biochemical profile of blue mussels (Mytilus edulis L.) cultured at different depths in a cold water coastal environment

    Science.gov (United States)

    Gallardi, Daria; Mills, Terry; Donnet, Sebastien; Parrish, Christopher C.; Murray, Harry M.

    2017-08-01

    The growth and health of cultured blue mussels (Mytilus edulis) are affected by environmental conditions. Typically, culture sites are situated in sheltered areas near shore (i.e., conflicts and environmental impact in coastal areas are concerns and interest in developing deep water (> 20 m depth) mussel culture has been growing. This study evaluated the effect of culture depth on blue mussels in a cold water coastal environment (Newfoundland, Canada). Culture depth was examined over two years from September 2012 to September 2014; mussels from three shallow water (5 m) and three deep water (15 m) sites were compared for growth and biochemical composition; culture depths were compared for temperature and chlorophyll a. Differences between the two years examined were noted, possibly due to harsh winter conditions in the second year of the experiment. In both years shallow and deep water mussels presented similar condition; in year 2 deep water mussels had a significantly better biochemical profile. Lipid and glycogen analyses showed seasonal variations, but no significant differences between shallow and deep water were noted. Fatty acid profiles showed a significantly higher content of omega-3 s (20:5ω3; EPA) and lower content of bacterial fatty acids in deep water sites in year 2. Everything considered, deep water appeared to provide a more favorable environment for mussel growth than shallow water under harsher weather conditions.

  18. Wind wave analysis in depth limited water using OCEANLYZ, A MATLAB toolbox

    Science.gov (United States)

    Karimpour, Arash; Chen, Qin

    2017-09-01

    There are a number of well established methods in the literature describing how to assess and analyze measured wind wave data. However, obtaining reliable results from these methods requires adequate knowledge on their behavior, strengths and weaknesses. A proper implementation of these methods requires a series of procedures including a pretreatment of the raw measurements, and adjustment and refinement of the processed data to provide quality assurance of the outcomes, otherwise it can lead to untrustworthy results. This paper discusses potential issues in these procedures, explains what parameters are influential for the outcomes and suggests practical solutions to avoid and minimize the errors in the wave results. The procedure of converting the water pressure data into the water surface elevation data, treating the high frequency data with a low signal-to-noise ratio, partitioning swell energy from wind sea, and estimating the peak wave frequency from the weighted integral of the wave power spectrum are described. Conversion and recovery of the data acquired by a pressure transducer, particularly in depth-limited water like estuaries and lakes, are explained in detail. To provide researchers with tools for a reliable estimation of wind wave parameters, the Ocean Wave Analyzing toolbox, OCEANLYZ, is introduced. The toolbox contains a number of MATLAB functions for estimation of the wave properties in time and frequency domains. The toolbox has been developed and examined during a number of the field study projects in Louisiana's estuaries.

  19. Incidence of marine debris in seabirds feeding at different water depths.

    Science.gov (United States)

    Tavares, D C; de Moura, J F; Merico, A; Siciliano, S

    2017-06-30

    Marine debris such as plastic fragments and fishing gears are accumulating in the ocean at alarming rates. This study assesses the incidence of debris in the gastrointestinal tracts of seabirds feeding at different depths and found stranded along the Brazilian coast in the period 2010-2013. More than half (55%) of the species analysed, corresponding to 16% of the total number of individuals, presented plastic particles in their gastrointestinal tracts. The incidence of debris was higher in birds feeding predominantly at intermediate (3-6m) and deep (20-100m) waters than those feeding at surface (debris in organisms mainly feeding at the ocean surface provides a limited view about the risks that this form of pollution has on marine life and highlight the ubiquitous and three-dimensional distribution of plastic in the oceans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. In-air fluence profiles and water depth dose for uncollimated electron beams

    Science.gov (United States)

    Toutaoui, Abedelkadar; Aichouche, Amar Nassim; Adjidir, Kenza Adjidir; Chami, Ahmed Chafik

    2008-01-01

    Advanced electron beam dose calculation models for radiation treatment planning systems require the input of a phase space beam model to configure a clinical electron beam in a computer. This beam model is a distribution in position, energy, and direction of electrons and photons in a plane in front of the patient. The phase space beam model can be determined by Monte Carlo simulation of the treatment head or from a limited set of measurements. In the latter case, parameters of the electron phase space beam model are obtained by fitting measured to calculated dosimetric data. In the present work, data for air fluence profiles and water depth doses have been presented for electron beams without an applicator for a medical linear accelerator. These data are used to parameterize the electron phase space beam model to a Monte Carlo dose calculation module available in the first commercial (MDS Nordion, now Nucletron) Monte Carlo treatment planning for electron beams. PMID:19893707

  1. Sensitivity of stream flow and water table depth to potential climatic variability in a coastal forested watershed

    Science.gov (United States)

    Zhaohua Dai; Carl Trettin; Changsheng Li; Devendra M. Amatya; Ge Sun; Harbin Li

    2010-01-01

    A physically based distributed hydrological model, MIKE SHE, was used to evaluate the effects of altered temperature and precipitation regimes on the streamflow and water table in a forested watershed on the southeastern Atlantic coastal plain. The model calibration and validation against both streamflow and water table depth showed that the MIKE SHE was applicable for...

  2. Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect

    Directory of Open Access Journals (Sweden)

    A. Arola

    2013-08-01

    Full Text Available The diurnal variability of aerosol optical depth (AOD can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF or aerosol direct radiative effect (ADRE. The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on

  3. Modelling contrasting responses of wetland productivity to changes in water table depth

    Directory of Open Access Journals (Sweden)

    R. F. Grant

    2012-11-01

    Full Text Available Responses of wetland productivity to changes in water table depth (WTD are controlled by complex interactions among several soil and plant processes, and hence are site-specific rather than general in nature. Hydrological controls on wetland productivity were studied by representing these interactions in connected hummock and hollow sites in the ecosystem model ecosys, and by testing CO2 and energy fluxes from the model with those measured by eddy covariance (EC during years with contrasting WTD in a shrub fen at Lost Creek, WI. Modelled interactions among coupled processes for O2 transfer, O2 uptake, C oxidation, N mineralization, N uptake and C fixation by diverse microbial, root and mycorrhizal populations enabled the model to simulate complex responses of CO2 exchange to changes in WTD that depended on the WTD at which change was occurring. At the site scale, greater WTD caused the model to simulate greater CO2 influxes and effluxes over hummocks vs. hollows, as has been found at field sites. At the landscape scale, greater WTD caused the model to simulate greater diurnal CO2 influxes and effluxes under cooler weather when water tables were shallow, but also smaller diurnal CO2 influxes and effluxes under warmer weather when water tables were deeper, as was also apparent in the EC flux measurements. At an annual time scale, these diurnal responses to WTD in the model caused lower net primary productivity (NPP and heterotrophic respiration (Rh, but higher net ecosystem productivity (NEP = NPP − Rh, to be simulated in a cooler year with a shallower water table than in a warmer year with a deeper one. This difference in NEP was consistent with those estimated from gap-filled EC fluxes in years with different water tables at Lost Creek and at similar boreal fens elsewhere. In sensitivity tests of the model, annual NEP

  4. Semi-empirical lake level (SELL) model for mapping lake water depths from partially clouded satellite data

    Science.gov (United States)

    Velpuri, N.; Senay, G. B.

    2011-12-01

    Information on the variability in surface water is critical to understand the impact of climate change and global water cycle. Surface water features such as lakes, or reservoirs can affect local weather and regional climate. Hence, there is a widespread demand for accurate and quantitative global observations of surface water variability. Satellite imagery provides a direct way to monitor variations in surface water. However, estimating accurate surface area from satellite imagery can be a problem due to clouds. Hence, the use of optical imagery for operational implementation has been a challenge for monitoring variations in surface water. In this research, a semi-empirical lake level (SELL) model is developed to derive lake/reservoir water levels from partially covered satellite imagery. SRTM elevation combined with bathymetry was used to derive the relationships between lake depth vs. surface area and shore line (L). Using these relationships, lake level/depth (D) was estimated from the surface area (A) and/or shore line (L) delineated from Landsat and MODIS data. The SELL model was applied on Lake Turkana, one of the rift valley lakes in East Africa. First, Lake Turkana water levels were delineated using cloud-free or partially clouded Landsat and MODIS imagery over 1993-2009 and 2002-2009 time periods respectively. Historic lake depths were derived using 1972-1992 Landsat imagery. Lake depths delineated using this approach were validated using TOPEX/Poseidon/Jason satellite altimetry data. It was found that lake depths derived using SELL model matched reasonably well with the satellite altimetry data. The approach presented in this research can be used to (a) simulate lake water level variations in data scarce regions (b) increase the frequency of observation in regions where cloud cover is a problem (c) operationally monitor lake water levels in ungauged basins (d) derive historic lake level information using satellite data.

  5. Effective cloud optical depth and enhancement effects for broken liquid water clouds in Valencia (Spain)

    Science.gov (United States)

    Marín, M. J.; Serrano, D.; Utrillas, M. P.; Núñez, M.; Martínez-Lozano, J. A.

    2017-10-01

    Partly cloudy skies with liquid water clouds have been analysed, founding that it is essential to distinguish data if the Sun is obstructed or not by clouds. Both cases can be separated considering simultaneously the Cloud Modification Factor (CMF) and the clearness index (kt). For partly cloudy skies and the Sun obstructed the effective cloud optical depth (τ) has been obtained by the minimization method for overcast skies. This method was previously developed by the authors but, in this case, taking into account partial cloud cover. This study has been conducted for the years 2011-2015 with the multiple scattering model SBDART and irradiance measurements for the UV Erythemal Radiation (UVER) and the broadband ranges. Afterwards a statistical analysis of τ has shown that the maximum value is much lower than for overcast skies and there is more discrepancy between the two spectral ranges regarding the results for overcast skies. In order to validate these results the effective cloud optical depth has been correlated with several transmission factors, giving similar fit parameters to those obtained for overcast skies except for the clearness index in the UVER range. As our method is not applicable for partly cloudy skies with the visible Sun, the enhancement of radiation caused by clouds when the Sun is visible has been studied. Results show that the average enhancement CMF values are the same for both ranges although enhancement is more frequent for low cloud cover in the UVER and medium-high cloud cover in the broadband range and it does not depend on the solar zenith angle.

  6. Performance of the drag type of Horizontal Axis Water Turbine (HAWT) as effect of depth to width ratio of blade

    Science.gov (United States)

    Hadi, Syamsul; Apdila, Rio Jevri; Purwono, Arif Hidayat; Budiana, Eko Prasetya; Tjahjana, Dominicus Danardono Dwi Prija

    2017-01-01

    Application of wind turbine to the water turbine is an interesting topic because of different energy momentum. A Horizontal Axis Water Turbine (HWAT) was proposed to produce energy in building the pipeline. A preliminary study using simulation and experimentally study of depth to width ratio of the blade was examined in order to determine optimum performance of the turbine using several variations of depth to width ratio of the blade with a constant head of 2 m and angle of the blocking system of 30°. Effect of the existing of different depth to width ratio of the blade for debit was reported. The optimal performance of the turbine was obtained at depth to width ratio of 0.29 that shown by highest obtained voltage of 8.62 Volt, the power output of 3.447 Watt and coefficient power of 2.73×10-2.

  7. The effects of water depth and light on oviposition and egg cannibalism in the bluefin killifish Lucania goodei.

    Science.gov (United States)

    Sandkam, B A; Fuller, R C

    2011-03-01

    This study showed that sex and depth had strong effects on egg cannibalism, whereas water clarity (clear v. tea-stained) had no effect on cannibalism or oviposition in the bluefin killifish Lucania goodei. These results are consistent with the extreme levels of iteroparity in L. goodei where females appear to spread their eggs across multiple locations and depths presumably to avoid egg predation. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  8. Climate change influence on drinking water quality

    Science.gov (United States)

    Kovacs, Melinda Haydee; Ristoiu, Dumitru; Voica, Cezara; Moldovan, Zaharie

    2013-11-01

    Although it are quite well known the possible effects of climate changes on surface waters availability and their hydrological risks, their consequences on drinking water quality is not well defined yet. Disinfection agents (as Cl2, O3, etc.) or multiple combinations of them for water treatment and disinfection purposes are applied by water treatment plants at worldwide level. Unfortunately, besides the benefits of these processes were also highlighted some undesirable effects such as formation of several disinfection by-products (DBPs) after reaction of disinfection agent with natural organic matter (NOM) from water body. DBPs formation in drinking water, suspected to posses adverse health effects to humans are strongly regulated in our days. Thus, throughout this study kinetics experiments both the main physicochemical factors that influencing the quality of drinking waters were evaluated as well how they act through possible warming or the consequences of extreme events. Increasing water temperatures with 1 - 5 °C above its normal value has showed that NOMs are presented in higher amount which led to the need for greater amount of disinfectant agent (5 - 15 %). Increasing the amount of disinfecting agent resulted in the formation of DBPs in significantly higher concentrations (between 5 - 30 %).

  9. Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

    Science.gov (United States)

    Miller, L. A.; Papakyriakou, T. N.

    2015-12-01

    In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.

  10. Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

    Directory of Open Access Journals (Sweden)

    Izaias M Fernandes

    Full Text Available The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance and qualitative data (presence-absence. Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm, while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm. However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered.

  11. A semi-analytical model for calculating the penetration depth of a high energy electron beam in a water phantom with a magnetic field.

    Science.gov (United States)

    You, Shihu; Gou, Chengjun; Wu, Zhangwen; Hou, Qing

    2015-07-01

    As an electron beam is incident on a uniform water phantom in the presence of a lateral magnetic field, the depth-dose distribution of the electron beam changes significantly and forms the well-known 'Bragg peak', with a depth-dose distribution similar to that of heavy ions. This phenomenon has pioneered a new field in the clinical application of electron beams. For such clinical applications, evaluating the penetration depth of electron beams quickly and accurately is the critical problem. This paper describes a model for calculating the penetration depth of an electron beam rapidly and correctly in a water phantom under the influence of a magnetic field. The model was used to calculate the penetration depths under different conditions: the energies of electron beams of 6, 8, 12 and 15 MeV and the magnetic induction intensities of 0.75, 1.0, 1.5, 2.0 and 3.0 T. In addition, the calculation results were compared with the results of a Monte Carlo simulation. The comparison results indicate that the difference between the two calculation methods was less than 0.5 cm. Moreover, the computing time of the calculation model was less than a second. The semi-analytical model proposed in the present study enables the penetration depth of the electron beam in the presence of a magnetic field to be obtained with a computational efficiency higher than that of the Monte Carlo approach; thus, the proposed model has high potential for application. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  12. [Effects of water depth on the growth of Vallisneria natans and photosynthetic system II photochemical characteristics of the leaves].

    Science.gov (United States)

    Yang, Xin; Zhang, Qi-Chao; Sun, Shu-Yun; Chen, Kai-Ning

    2014-06-01

    The effects of water depth on the growth of Vallisneria natans and photosynthetic system II photochemical characteristics of the leaves were investigated at three depths of 0.6, 1.3 and 2.0 m. The rapid fluorescence induction kinetics curves (OJIP) of the leaves were measured with Plant Efficiency Analyzer and analyzed with JIP-test. The results indicated that the light intensities at water depths of 0.6, 1.3 and 2.0 m were obviously different and the growth of V. natans was restricted under water depth of 2.0 m. Biomass, number of ramets, number of leaves, total root length, root surface area and other morphological indices decreased significantly with the increasing water depth, and the maximum leaf length, average leaf length, maximum leaf width changed insignificantly with the water depth. With the increasing water depth, absorption flux per reaction center (ABS/RC), trapped energy flux per RC (TR0/RC), electron transport flux per RC (ET0/RC), reduction of end acceptors at photosynthetic system I (PS I ) electron acceptor side per RC (RE0/ RC) decreased significantly. The dissipated energy flux per RC (DI0/RC) also decreased significantly, which led to no obvious difference in quantum yield for the reduction of end acceptors of PS I per photon absorbed (phiR0) and the efficiency for the trapped exciton to move an electron into the electron transport chain from QA- to the PS I end electron acceptors (deltaR0). Because the amount of active PS II RCs per CS increased significantly, photosynthesis per area of V. natans grown at 2.0 m was significantly greater than that of V. natans grown at 0.6 m. The performance index PIs, Ples, Plabs,.otal photochemistry efficiency of leaves of V. natans grown at 2.0 m was significantly in- creased, suggesting that light stress may promote a more efficient conversion of light energy to active chemical energy. V. natans leaves accommodate the low light intensity environment through activating inactive reaction centers but not

  13. Analyzing Conductivity Profiles in Stream Waters Influenced by Mine Water Discharges

    Science.gov (United States)

    Räsänen, Teemu; Hämäläinen, Emmy; Hämäläinen, Matias; Turunen, Kaisa; Pajula, Pasi; Backnäs, Soile

    2015-04-01

    Conductivity is useful as a general measure of stream water quality. Each stream inclines to have a quite constant range of conductivity that can be used as a baseline for comparing and detecting influence of contaminant sources. Conductivity in natural streams and rivers is affected primarily by the geology of the watershed. Thus discharges from ditches and streams affect not only the flow rate in the river but also the water quality and conductivity. In natural stream waters, the depth and the shape of the river channel change constantly, which changes also the water flow. Thus, an accurate measuring of conductivity or other water quality indicators is difficult. Reliable measurements are needed in order to have holistic view about amount of contaminants, sources of discharges and seasonal variation in mixing and dilution processes controlling the conductivity changes in river system. We tested the utility of CastAway-CTD measuring device (SonTek Inc) to indicate the influence of mine waters as well as mixing and dilution occurring in the recipient river affected by treated dewatering and process effluent water discharges from a Finnish gold mine. The CastAway-CTD measuring device is a small, rugged and designed for profiling of depths of up to 100m. Device measures temperature, salinity, conductivity and sound of speed using 5 Hz response time. It has also built-in GPS which produces location information. CTD casts are normally used to produce vertical conductivity profile for rather deep waters like seas or lakes. We did seasonal multiple Castaway-CTD measurements during 2013 and 2014 and produced scaled vertical and horizontal profiles of conductivity and water temperature at the river. CastAway-CTD measurement pinpoints how possible contaminants behave and locate in stream waters. The conductivity profiles measured by CastAway-CTD device show the variation in maximum conductivity values vertically in measuring locations and horizontally in measured cross

  14. Influence of sowing depth on the germination of Karoo shrubs and ...

    African Journals Online (AJOL)

    Knowledge of the germination behaviour of desirable plants to be sown in the veld for veld improvement is still inadequate. To gain this knowledge, seed of different species of Karoo bushes and grasses were planted on two soil types at different planting depths.Germination percentage of all species tested were significantly ...

  15. Hydrogeochemical contrast between brown and grey sand aquifers in shallow depth of Bengal Basin: consequences for sustainable drinking water supply.

    Science.gov (United States)

    Biswas, Ashis; Nath, Bibhash; Bhattacharya, Prosun; Halder, Dipti; Kundu, Amit K; Mandal, Ujjal; Mukherjee, Abhijit; Chatterjee, Debashis; Mörth, Carl-Magnus; Jacks, Gunnar

    2012-08-01

    Delineation of safe aquifer(s) that can be targeted by cheap drilling technology for tubewell (TW) installation becomes highly imperative to ensure access to safe and sustainable drinking water sources for the arsenic (As) affected population in Bengal Basin. This study investigates the potentiality of brown sand aquifers (BSA) as a safe drinking water source by characterizing its hydrogeochemical contrast to grey sand aquifers (GSA) within shallow depth (water guidelines, which warrants rigorous assessment of attendant health risk for Mn prior to considering mass scale exploitation of the BSA for possible sustainable drinking water supply. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Water relations and foliar isotopic composition of Prosopis tamarugo Phil. an endemic tree of the Atacama Desert growing under three levels of water table depth.

    Directory of Open Access Journals (Sweden)

    Marco eGarrido

    2016-03-01

    Full Text Available Prosopis tamarugo Phil. is a strict phreatophyte tree species endemic to the Pampa del Tamarugal, Atacama Desert. The extraction of water for various uses has increased the depth of the water table in the Pampa aquifers threatening its conservation. This study aimed to determine the effect of the groundwater table depth on the water relations of P. tamarugo and to present thresholds of groundwater depth (GWD that can be used in the groundwater management of the P. tamarugo ecosystem. Three levels of GWD, 11.2 ± 0.3 m, 10.3 ± 0.3 m and 7.1 ± 0.1 m, (the last GWD being our reference were selected and groups of 4 individuals per GWD were studied in the months of January and July of the years 2011 through 2014. When the water table depth exceeded 10 m, P. tamarugo had lower pre-dawn and midday water potential but no differences were observed in minimum leaf stomatal resistance when compared to the condition of 7.1 m GWD; the leaf tissue increased its δ13C and δ18O composition. Furthermore, a smaller green canopy fraction of the trees and increased foliage loss in winter with increasing water table depth was observed. The differences observed in the physiological behavior of P. tamarugo trees, attributable to the ground water depth; show that increasing the depth of the water table from 7 to 11 m significantly affects the water status of P. tamarugo. The results indicate that P. tamarugo has an anisohydric stomatal behaviour and that given a reduction in water supply it regulates the water demand via foliage loss. The growth and leaf physiological activities are highly sensitive to GWD. The foliage loss appears to prevent the trees from reaching water potentials leading to complete loss of hydraulic functionality by cavitation. The balance achieved between water supply and demand was reflected in the low variation of the water potential and of the variables related to gas exchange over time for a given GWD. This acclimation capacity of P

  17. Ecosystem respiration in a heterogeneous temperate peatland and its sensitivity to peat temperature and water table depth

    Czech Academy of Sciences Publication Activity Database

    Juszczak, R.; Humphreys, E.; Acosta, Manuel; Michalak-Galczewska, M.; Kayzer, D.; Olejnik, Janusz

    2013-01-01

    Roč. 366, 1-2 (2013), s. 505-520 ISSN 0032-079X Institutional support: RVO:67179843 Keywords : Ecosystem respiration * Geogenous peatland * Chamber measurements * CO2 fluxes * Water table depth Subject RIV: EH - Ecology, Behaviour Impact factor: 3.235, year: 2013

  18. Diurnal variations in depth profiles of UV-induced DNA damage and inhibition of bacterioplankton production in tropical coastal waters

    NARCIS (Netherlands)

    Visser, PM; Poos, JJ; Scheper, BB; Boelen, P; van Duyl, FC

    2002-01-01

    In this study, diurnal changes in bacterial production and DNA damage in bacterio-plankton (measured as cyclobutane pyrimidine dimers, CPDs) incubated in bags at different depths in tropical coastal waters were investigated. The DNA damage and inhibition of the bacterial production was highest at

  19. Effect of water depth and temperature on germination characteristics of rice and barnyard grass in the laboratory conditions

    Directory of Open Access Journals (Sweden)

    M. HaghighiKhah

    2016-05-01

    Full Text Available Response of seed germination of a crop to different environmental conditions is one of the most important determination factors to indicate its ability in competition with weeds. In order to evaluate the effects of water depth and temperature on the germination of different varieties of rice and barnyard grass, an experiment was conducted in the Seed Laboratory, Faculty of Agriculture, Ferdowsi University of Mashhad, as a factorial design based on a Complete Randomized Blocks in four replications of 25 seeds. First factor was water depth in six levels (0, 2, 4, 6, 8, and 10 cm, second factor was temperature in seven levels (10, 15, 20, 25, 30, 35 and 40 oC, and third one was different cultivars (Khazar, Hashemi and Domsiah and barnyard grass. According to the results the best germination characteristics of all rice varieties and barnyard grass obtained at 30 oC. With increasing temperature up to 30oC germination increased. However, temperatures above 30oC reduced the germination. Increasing water depth lead to reduce the speed and percentage of germination in all varieties, But the effect of water depth on the germination of rice varieties was lower than the barnyard grass.

  20. Transverse structure of tidal flow, residual flow and sediment concentration in estuaries: sensitivity to tidal forcing and water depth

    NARCIS (Netherlands)

    Huijts, K.M.H.|info:eu-repo/dai/nl/304831867; de Swart, H.E.|info:eu-repo/dai/nl/073449725; Schramkowski, G.P.; Schuttelaars, H.M.

    2011-01-01

    An analytical and a numerical model are used to understand the response of velocity and sediment distributions over Gaussian-shaped estuarine cross-sections to changes in tidal forcing and water depth. The estuaries considered here are characterized by strong mixing and a relatively weak

  1. Topsoil depth substantially influences the responses to drought of the foliar metabolomes of Mediterranean forests

    Czech Academy of Sciences Publication Activity Database

    Rivas-Ubach, A.; Barbeta, A.; Sardans, J.; Guenther, A.; Ogaya, R.; Oravec, Michal; Urban, Otmar; Peňuelas, J.

    2016-01-01

    Roč. 21, aug (2016), s. 41-54 ISSN 1433-8319 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061; GA MŠk EE2.3.20.0246 Institutional support: RVO:67179843 Keywords : vegetation structure * soil depth * soil moisture * metabolomics * Quercus ilex Subject RIV: ED - Physiology Impact factor: 3.123, year: 2016

  2. Effects of water depth, seasonal exposure, and substrate orientation on microbial bioerosion in the Ionian Sea (Eastern Mediterranean.

    Directory of Open Access Journals (Sweden)

    Claudia Färber

    Full Text Available The effects of water depth, seasonal exposure, and substrate orientation on microbioerosion were studied by means of a settlement experiment deployed in 15, 50, 100, and 250 m water depth south-west of the Peloponnese Peninsula (Greece. At each depth, an experimental platform was exposed for a summer period, a winter period, and about an entire year. On the up- and down-facing side of each platform, substrates were fixed to document the succession of bioerosion traces, and to measure variations in bioerosion and accretion rates. In total, 29 different bioerosion traces were recorded revealing a dominance of microborings produced by phototrophic and organotrophic microendoliths, complemented by few macroborings, attachment scars, and grazing traces. The highest bioerosion activity was recorded in 15 m up-facing substrates in the shallow euphotic zone, largely driven by phototrophic cyanobacteria. Towards the chlorophyte-dominated deep euphotic to dysphotic zones and the organotroph-dominated aphotic zone the intensity of bioerosion and the diversity of bioerosion traces strongly decreased. During summer the activity of phototrophs was higher than during winter, which was likely stimulated by enhanced light availability due to more hours of daylight and increased irradiance angles. Stable water column stratification and a resulting nutrient depletion in shallow water led to lower turbidity levels and caused a shift in the photic zonation that was reflected by more phototrophs being active at greater depth. With respect to the subordinate bioerosion activity of organotrophs, fluctuations in temperature and the trophic regime were assumed to be the main seasonal controls. The observed patterns in overall bioeroder distribution and abundance were mirrored by the calculated carbonate budget with bioerosion rates exceeding carbonate accretion rates in shallow water and distinctly higher bioerosion rates at all depths during summer. These findings

  3. Depth-to-water area polygons, isopleths showing mean annual runoff, 1912-1963, and water-level altitude contours for the Humboldt River Basin, Nevada

    Science.gov (United States)

    Welborn, Toby L.; Medina, Rose L.

    2017-01-01

    This USGS data release represents the 1:500,000-scale geospatial data for the following publication:Eakin, T.E., and Lamke, R.D., 1966, Hydrologic reconnaissance of the Humboldt River basin, Nevada: Nevada Department of Conservation and Natural Resources, Water Resources Bulletin 32, 107 p.The data set consists of 3 separate items:1. Depth-to-water area polygons2. Isopleths showing mean annual runoff, 1912-19633. Water-level altitude contours

  4. Factors influencing antibiotic prescribing in long-term care facilities: a qualitative in-depth study

    NARCIS (Netherlands)

    van Buul, L.W.; van der Steen, J.T.; Doncker, S.M.; Achterberg, W.P.; Schellevis, F.G.; Veenhuizen, R.B.; Hertogh, C.M.P.M.

    2014-01-01

    Background: Insight into factors that influence antibiotic prescribing is crucial when developing interventions aimed at a more rational use of antibiotics. We examined factors that influence antibiotic prescribing in long-term care facilities, and present a conceptual model that integrates these

  5. Depth to water in the High Plains Aquifer in Colorado, 2000.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data are in support of report DS 456 (Arnold and others, 2009). This grid represents the depth to groundwater in the High Plains Aquifer in Colorado in 2000....

  6. Airborne detection of oceanic turbidity cell structure using depth-resolved laser-induced water Raman backscatter

    Science.gov (United States)

    Hoge, F. E.; Swift, R. N.

    1983-01-01

    Airborne laser-induced, depth-resolved water Raman backscatter is useful in the detection and mapping of water optical transmission variations. This test, together with other field experiments, has identified the need for additional field experiments to resolve the degree of the contribution to the depth-resolved, Raman-backscattered signal waveform that is due to (1) sea surface height or elevation probability density; (2) off-nadir laser beam angle relative to the mean sea surface; and (3) the Gelbstoff fluorescence background, and the analytical techniques required to remove it. When converted to along-track profiles, the waveforms obtained reveal cells of a decreased Raman backscatter superimposed on an overall trend of monotonically decreasing water column optical transmission.

  7. The influence of mixing water and abrasives on the quality of machined surface

    Directory of Open Access Journals (Sweden)

    A. Stoić

    2014-04-01

    Full Text Available This paper shows the impact of mixing water and abrasives in water jet cutting process on the quality of the machined surface. The tests were done with polymer material SIPAS, where the influence of cutting parameters was researched (cutting pressure, cutting feed and abrasive mass flow. The surface roughness was measured on several zones, regarding the depth of materials, because the roughness is increased with the material thickness.

  8. Benthic Habitat Mapping by Combining Lyzenga’s Optical Model and Relative Water Depth Model in Lintea Island, Southeast Sulawesi

    Science.gov (United States)

    Hafizt, M.; Manessa, M. D. M.; Adi, N. S.; Prayudha, B.

    2017-12-01

    Benthic habitat mapping using satellite data is one challenging task for practitioners and academician as benthic objects are covered by light-attenuating water column obscuring object discrimination. One common method to reduce this water-column effect is by using depth-invariant index (DII) image. However, the application of the correction in shallow coastal areas is challenging as a dark object such as seagrass could have a very low pixel value, preventing its reliable identification and classification. This limitation can be solved by specifically applying a classification process to areas with different water depth levels. The water depth level can be extracted from satellite imagery using Relative Water Depth Index (RWDI). This study proposed a new approach to improve the mapping accuracy, particularly for benthic dark objects by combining the DII of Lyzenga’s water column correction method and the RWDI of Stumpt’s method. This research was conducted in Lintea Island which has a high variation of benthic cover using Sentinel-2A imagery. To assess the effectiveness of the proposed new approach for benthic habitat mapping two different classification procedures are implemented. The first procedure is the commonly applied method in benthic habitat mapping where DII image is used as input data to all coastal area for image classification process regardless of depth variation. The second procedure is the proposed new approach where its initial step begins with the separation of the study area into shallow and deep waters using the RWDI image. Shallow area was then classified using the sunglint-corrected image as input data and the deep area was classified using DII image as input data. The final classification maps of those two areas were merged as a single benthic habitat map. A confusion matrix was then applied to evaluate the mapping accuracy of the final map. The result shows that the new proposed mapping approach can be used to map all benthic objects in

  9. The Ecological Response of Carex lasiocarpa Community in the Riparian Wetlands to the Environmental Gradient of Water Depth in Sanjiang Plain, Northeast China

    Directory of Open Access Journals (Sweden)

    Zhaoqing Luan

    2013-01-01

    Full Text Available The response of Carex lasiocarpa in riparian wetlands in Sanjiang Plain to the environmental gradient of water depth was analyzed by using the Gaussian Model based on the biomass and average height data, and the ecological water-depth amplitude of Carex lasiocarpa was derived. The results indicated that the optimum ecological water-depth amplitude of Carex lasiocarpa based on biomass was [13.45 cm, 29.78 cm], while the optimum ecological water-depth amplitude of Carex lasiocarpa based on average height was [2.31 cm, 40.11 cm]. The intersection of the ecological water-depth amplitudes based on biomass and height confirmed that the optimum ecological water-depth amplitude of Carex lasiocarpa was [13.45 cm, 29.78 cm] and the optimist growing water-depth of Carex lasiocarpa was 21.4 cm. The TWINSPAN, a polythetic and divisive classification tool, was used to classify the wetland ecological series into 6 associations. Result of TWINSPAN matrix classification reflected an obvious environmental gradient in these associations: water-depth gradient. The relation of biodiversity of Carex lasiocarpa community and water depth was determined by calculating the diversity index of each association.

  10. Radiocarbon Distribution of Atlantic Water Masses Over the Last 30 kyr - Results From a South Atlantic Sediment Depth Transect

    Science.gov (United States)

    Charles, C. D.; Kashgarian, M.; Slowey, N. C.

    2006-12-01

    Here we present the results of a field experiment to document the changes in mid-depth water masses in the mid-depth ocean. Our sediment cores are from the southeastern Atlantic, offshore Angola and Namibia, and range in water depth from 500 to 3200 meters, with a vertical spacing of approximately 200 meters. This is a region where, within a limited area, the seafloor intersects all the principal watermasses involved in the thermohaline circulation of the Atlantic — including those of northern and southern hemisphere origin, allowing the possibility for a detailed history of the intermediate water masses (Antarctic Intermediate Water and Labrador Sea Water) throughout the last deglaciation. These cores are all characterized by sediment rates in excess of 5 cm/kyr and can be correlated stratigraphically with each other to within a few cms on the basis of physical properties and isotopic profiles. We present a detailed calibration of the planktonic/benthic radiocarbon age difference from thirty sediment core tops that are younger than 3 ka (radiocarbon years). These analyses involve a mixed benthic foraminiferal radiocarbon determination, as well as planktonic foraminiferal dates from either or both Orbulina universa or Globigerina bulloides. These data allow an evaluation of the radiocarbon information in different planktonic foraminifera species: for example, there is a significant offset between O. universa and G. bulloides radiocarbon content that undoubtedly reflects habitat differences. The core top calibration also allows determination of the extent to which benthic and planktonic age pairs represent water column radiocarbon distribution. Using stringent selection criteria guided by the core top results, we analyze the radiocarbon distribution in ice age and deglacial water masses, deduced from over 100 planktonic-benthic foraminiferal age pairs. The reconstructed water column profiles can then be cross-checked with other tracers such as oxygen isotopes

  11. Influence of Exclusive Binocular Rivalry on Perceived Depth in the `Sieve Effect'

    Science.gov (United States)

    Matsumiya, Kazumichi

    An impression of a surface seen through holes is created when one fuses dichoptic pairs of discs with one member of each pair black and the other white. This is referred to as the ‘sieve effect’. This stimulus contains no positional disparities. The impression of depth in the sieve effect is most evident when the size, contrast, and rim thickness of rivalrous patterns are such as to produce exclusive rivalry. I investigated how long it took for the sieve effect to recover from exclusive rivalry suppression. The magnitude of perceived depth in the effect was measured after exclusive rivalry suppression of one half-image of the sieve-effect stimulus. The results showed that the sieve effect takes approximately 630 ms to recover from exclusive rivalry suppression, compared with 200 ms for disparity-based stereopsis. Considered together with the previous report [Matsumiya and Howard: Invest. Ophthalmol. Visual Sci. 42 (2001) S403] that the sieve effect is positively correlated with the rate of exclusive rivalry, these findings suggest that the effect and exclusive rivalry are processed in the identical channel.

  12. Estimation of Concrete Carbonation Depth Considering Multiple Influencing Factors on the Deterioration of Durability for Reinforced Concrete Structures

    Directory of Open Access Journals (Sweden)

    Hae-Chang Cho

    2016-01-01

    Full Text Available While the durability of concrete structures is greatly influenced by many factors, previous studies typically considered only a single durability deterioration factor. In addition, these studies mostly conducted their experiments inside the laboratory, and it is extremely hard to find any case in which data were obtained from field inspection. Accordingly, this study proposed an Adaptive Neurofuzzy Inference System (ANFIS algorithm that can estimate the carbonation depth of a reinforced concrete member, in which combined deterioration has been reflected based on the data obtained from field inspections of 9 buildings. The proposed ANFIS algorithm closely estimated the carbonation depths, and it is considered that, with further inspection data, a higher accuracy would be achieved. Thus, it is expected to be used very effectively for durability estimation of a building of which the inspection is performed periodically.

  13. Investigation of Arctic and Antarctic spatial and depth patterns of sea water in CTD profiles using chemometric data analysis

    DEFF Research Database (Denmark)

    Kotwa, Ewelina Katarzyna; Lacorte, Silvia; Duarte, Carlos

    2014-01-01

    In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 1......-chemical properties of the water samples; and 4) we confirm the ability to predict fluorescence values from physical measurements when the 3-way data structure is used in N-way PLS regression.......In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 174...... locations. The output from these devices can be arranged in a 3-way data structure (according to sea water depth, measured variables, and geographical location). We used and compared 2- and 3-way statistical tools including PCA, PARAFAC, PLS, and N-PLS for exploratory analysis, spatial patterns discovery...

  14. Influence of snow depth and surface flooding on light transmission through Antarctic pack ice

    Science.gov (United States)

    Arndt, Stefanie; Meiners, Klaus M.; Ricker, Robert; Krumpen, Thomas; Katlein, Christian; Nicolaus, Marcel

    2017-03-01

    Snow on sea ice alters the properties of the underlying ice cover as well as associated physical and biological processes at the interfaces between atmosphere, sea ice, and ocean. The Antarctic snow cover persists during most of the year and contributes significantly to the sea-ice mass due to the widespread surface flooding and related snow-ice formation. Snow also enhances the sea-ice surface reflectivity of incoming shortwave radiation and determines therefore the amount of light being reflected, absorbed, and transmitted to the upper ocean. Here, we present results of a case study of spectral solar radiation measurements under Antarctic pack ice with an instrumented Remotely Operated Vehicle in the Weddell Sea in 2013. In order to identify the key variables controlling the spatial distribution of the under-ice light regime, we exploit under-ice optical measurements in combination with simultaneous characterization of surface properties, such as sea-ice thickness and snow depth. Our results reveal that the distribution of flooded and nonflooded sea-ice areas dominates the spatial scales of under-ice light variability for areas smaller than 100 m-by-100 m. However, the heterogeneous and highly metamorphous snow on Antarctic pack ice obscures a direct correlation between the under-ice light field and snow depth. Compared to the Arctic, light levels under Antarctic pack ice are extremely low during spring (sea ice and snow properties with seasonal snow cover (including strong surface melt and summer melt ponds) in the Arctic and a year-round snow cover and widespread surface flooding in the Southern Ocean.

  15. Noncontact methods for measuring water-surface elevations and velocities in rivers: Implications for depth and discharge extraction

    Science.gov (United States)

    Nelson, Jonathan M.; Kinzel, Paul J.; McDonald, Richard R.; Schmeeckle, Mark

    2016-01-01

    Recently developed optical and videographic methods for measuring water-surface properties in a noninvasive manner hold great promise for extracting river hydraulic and bathymetric information. This paper describes such a technique, concentrating on the method of infrared videog- raphy for measuring surface velocities and both acoustic (laboratory-based) and laser-scanning (field-based) techniques for measuring water-surface elevations. In ideal laboratory situations with simple flows, appropriate spatial and temporal averaging results in accurate water-surface elevations and water-surface velocities. In test cases, this accuracy is sufficient to allow direct inversion of the governing equations of motion to produce estimates of depth and discharge. Unlike other optical techniques for determining local depth that rely on transmissivity of the water column (bathymetric lidar, multi/hyperspectral correlation), this method uses only water-surface information, so even deep and/or turbid flows can be investigated. However, significant errors arise in areas of nonhydrostatic spatial accelerations, such as those associated with flow over bedforms or other relatively steep obstacles. Using laboratory measurements for test cases, the cause of these errors is examined and both a simple semi-empirical method and computational results are presented that can potentially reduce bathymetric inversion errors.

  16. Cost of oviposition site selection in a water strider Aquarius paludum insularis: egg mortality increases with oviposition depth.

    Science.gov (United States)

    Hirayama, Hiroyuki; Kasuya, Eiiti

    2010-06-01

    Females generally avoid selecting sites for oviposition which have a high predation risk to increase offspring survival. Previous studies have focused on costs to ovipositing females. However, although offspring may also incur costs by being oviposited at low predation risk sites, no studies have focused on costs to offspring. Such costs to offspring were examined by using Aquarius paludum insularis, females of which avoid eggs parasitism by ovipositing at deep sites. Deep sites are safe from egg parasitism but may be unsuitable for hatching due to environmental factors. We examined the costs to offspring at deep sites by comparing the hatching rate, the duration to hatching and the proportion of drowned larvae between eggs that were set at three levels of water depth (0 cm, 25 cm and 50 cm depth). While the hatching rate at 50 cm was lower than that at 0 cm, the rate at 25 cm did not differ from that at 0 cm. Duration to hatching and the proportion of drowned larvae did not differ between the three depths. It is suggested that the declining survival rate of A. paludum eggs was due to increased water pressure at greater depth. Such a cost may exist in other species and such an observation may aid in understanding oviposition site selection. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. Characterizing the Breadth and Depth of Volunteer Water Monitoring Programs in the United States

    Science.gov (United States)

    Stepenuck, Kristine F.; Genskow, Kenneth D.

    2018-01-01

    A survey of 345 volunteer water monitoring programs in the United States was conducted to document their characteristics, and perceived level of support for data to inform natural resource management or policy decisions. The response rate of 86% provided information from 46 states. Programs represented a range of ages, budgets, objectives, scopes, and level of quality assurance, which influenced data uses and perceived support by sponsoring agency administrators and external decision makers. Most programs focused on rivers, streams, and lakes. Programs had not made substantial progress to develop EPA or state-approved quality assurance plans since 1998, with only 48% reporting such plans. Program coordinators reported feeling slightly more support for data to be used for management as compared to policy decisions. Programs with smaller budgets may be at particular risk of being perceived to lack credibility due to failure to develop quality assurance plans. Over half of programs identified as collaborative, in that volunteers assisted scientists in program design, data analysis and/or dissemination of results. Just under a third were contributory, in which volunteers primarily collected data in a scientist-defined program. Recommendations to improve perceived data credibility, and to augment limited budgets include developing quality assurance plans and gaining agency approval, and developing partnerships with other organizations conducting monitoring in the area to share resources and knowledge. Funding agencies should support development of quality assurance plans to help ensure data credibility. Service providers can aid in plan development by providing training to program staff over time to address high staff turnover rates.

  18. Water-Depth-Based Prediction Formula for the Blasting Vibration Velocity of Lighthouse Caused by Underwater Drilling Blasting

    Directory of Open Access Journals (Sweden)

    Wenbin Gu

    2017-01-01

    Full Text Available Lighthouses are the most important hydraulic structures that should be protected during underwater drilling blasting. Thus, the effect of blasting vibration on lighthouse should be studied. On the basis of the dimensional analysis, we deduced a revised formula for water depth based on Sodev’s empirical formula and established the linear fitting model. During the underwater reef project in the main channel of Shipu Harbor in the Ningbo–Zhoushan Port, the blasting vibration data of the lighthouse near the underwater blasting area were monitored. The undetermined coefficient, resolvable coefficient, and F value of the two formulas were then obtained. The comparison of the data obtained from the two formulas showed that they can effectively predict the blasting vibration on the lighthouse. The correction formula that considers water depth can obviously reduce prediction errors and accurately predict blasting vibration.

  19. Ecological Gradients Influencing Waterbird Communities in Black Water Lakes in the Anavilhanas Archipelago, Central Amazonia

    Directory of Open Access Journals (Sweden)

    Renato Cintra

    2012-01-01

    Full Text Available For the first time, and in a large spatial scale, the influence of ecological properties on the aquatic bird community of black water lakes in Brazilian Amazonia is evaluated. Bird surveys were conducted in 45 lakes. A total of 3626 individuals in 48 bird species were recorded; of these, 31 are aquatic, and 18 of these are primarily piscivorous. Bird richness and abundance were not significantly related to lake shape and productivity but were influenced by hydrological period (low versus high, water depth, transparency, lake isolation, and habitat richness. Matrices of bird species by lake were subjected to multivariate analyses (NMDS to evaluate how these parameters influence bird community. The variation in bird species composition was positively correlated to lake depth and isolation and negatively correlated to water transparency and habitat richness. The results indicate that period, lake physical characteristics (depth, water transparency, isolation, and habitat richness are determinants of aquatic bird community composition in the black water lake systems of Amazonia.

  20. Depth Estimation of Submerged Aquatic Vegetation in Clear Water Streams Using Low-Altitude Optical Remote Sensing

    Science.gov (United States)

    Visser, Fleur; Buis, Kerst; Verschoren, Veerle; Meire, Patrick

    2015-01-01

    UAVs and other low-altitude remote sensing platforms are proving very useful tools for remote sensing of river systems. Currently consumer grade cameras are still the most commonly used sensors for this purpose. In particular, progress is being made to obtain river bathymetry from the optical image data collected with such cameras, using the strong attenuation of light in water. No studies have yet applied this method to map submergence depth of aquatic vegetation, which has rather different reflectance characteristics from river bed substrate. This study therefore looked at the possibilities to use the optical image data to map submerged aquatic vegetation (SAV) depth in shallow clear water streams. We first applied the Optimal Band Ratio Analysis method (OBRA) of Legleiter et al. (2009) to a dataset of spectral signatures from three macrophyte species in a clear water stream. The results showed that for each species the ratio of certain wavelengths were strongly associated with depth. A combined assessment of all species resulted in equally strong associations, indicating that the effect of spectral variation in vegetation is subsidiary to spectral variation due to depth changes. Strongest associations (R2-values ranging from 0.67 to 0.90 for different species) were found for combinations including one band in the near infrared (NIR) region between 825 and 925 nm and one band in the visible light region. Currently data of both high spatial and spectral resolution is not commonly available to apply the OBRA results directly to image data for SAV depth mapping. Instead a novel, low-cost data acquisition method was used to obtain six-band high spatial resolution image composites using a NIR sensitive DSLR camera. A field dataset of SAV submergence depths was used to develop regression models for the mapping of submergence depth from image pixel values. Band (combinations) providing the best performing models (R2-values up to 0.77) corresponded with the OBRA findings

  1. Depth Estimation of Submerged Aquatic Vegetation in Clear Water Streams Using Low-Altitude Optical Remote Sensing.

    Science.gov (United States)

    Visser, Fleur; Buis, Kerst; Verschoren, Veerle; Meire, Patrick

    2015-09-30

    UAVs and other low-altitude remote sensing platforms are proving very useful tools for remote sensing of river systems. Currently consumer grade cameras are still the most commonly used sensors for this purpose. In particular, progress is being made to obtain river bathymetry from the optical image data collected with such cameras, using the strong attenuation of light in water. No studies have yet applied this method to map submergence depth of aquatic vegetation, which has rather different reflectance characteristics from river bed substrate. This study therefore looked at the possibilities to use the optical image data to map submerged aquatic vegetation (SAV) depth in shallow clear water streams. We first applied the Optimal Band Ratio Analysis method (OBRA) of Legleiter et al. (2009) to a dataset of spectral signatures from three macrophyte species in a clear water stream. The results showed that for each species the ratio of certain wavelengths were strongly associated with depth. A combined assessment of all species resulted in equally strong associations, indicating that the effect of spectral variation in vegetation is subsidiary to spectral variation due to depth changes. Strongest associations (R²-values ranging from 0.67 to 0.90 for different species) were found for combinations including one band in the near infrared (NIR) region between 825 and 925 nm and one band in the visible light region. Currently data of both high spatial and spectral resolution is not commonly available to apply the OBRA results directly to image data for SAV depth mapping. Instead a novel, low-cost data acquisition method was used to obtain six-band high spatial resolution image composites using a NIR sensitive DSLR camera. A field dataset of SAV submergence depths was used to develop regression models for the mapping of submergence depth from image pixel values. Band (combinations) providing the best performing models (R²-values up to 0.77) corresponded with the OBRA

  2. Growth and production of tomato fertilized with ash and castor cake and under varying water depths, cultivated in organic potponics

    Directory of Open Access Journals (Sweden)

    Daniela Pinto Gomes

    2017-04-01

    Full Text Available Two experiments were performed to evaluate the effect of ash (40, 80, and 120 g per plant, castor cake (140 and 280 g per plant and water depth (135, 165, 191, and 213 mm on the growth and production of organic tomato cultivated in pots in a greenhouse. The experimental design was randomized blocks, and the irrigation was managed using an automatic irrigation device. The following variables were evaluated: plant heights, numbers of leaves, bunches, flowers and fruits, total mass of fruits, mass of marketable fruits, mass of fruits with blossom-end rot, total diameter of fruits, and diameter of marketable fruits. Most of the growth variables showed gains with the application of 140 g of ash and 280 g of cake. The dose of 280 g of castor cake was responsible for the greatest mass of marketable fruits (1.78 kg per plant, regardless of the ash dose. The water deficit reduced values of most of the variables of growth and production. The irrigation depth of 213 mm was responsible for the greatest mass of marketable fruits (4.04 kg per plant. The highest water use efficiencies, 37.00 and 37.93 kg m-3, were observed at irrigation depths of 191 and 213 mm, respectively.

  3. Predicting shape and stability of air-water interface on superhydrophobic surfaces comprised of pores with arbitrary shapes and depths

    Science.gov (United States)

    Emami, B.; Tafreshi, H. Vahedi; Gad-el-Hak, M.; Tepper, G. C.

    2012-01-01

    An integro-differential equation for the three dimensional shape of air-water interface on superhydrophobic surfaces comprised of pores with arbitrary shapes and depths is developed and used to predict the static critical pressure under which such surfaces depart from the non-wetting state. Our equation balances the capillary forces with the pressure of the air entrapped in the pores and that of the water over the interface. Stability of shallow and deep circular, elliptical, and polygonal pores is compared with one another and a general conclusion is drawn for designing pore shapes for superhydrophobic surfaces with maximum stability.

  4. Penetration depth measurement of a 6 MeV electron beam in water by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    B. E. Hammer

    2011-11-01

    Full Text Available We demonstrate magnetic resonance imaging (MRI visualization of a 6 MeV electron beam in ferrous-doped water; a 25 mm penetration depth was measured. Time domain nuclear magnetic resonance was used to investigate the effect of generated free radicals on the free induction decay (FID in nondoped water; no apparent effects to the FID were observed. We show that MRI visualization of charged particle beams used in medical applications will require exogenous agents to provide contrast enhancement.

  5. Investigating the relationship between Aerosol Optical Depth and Precipitation over Southeast Asia with Relative Humidity as an influencing factor.

    Science.gov (United States)

    Ng, Daniel Hui Loong; Li, Ruimin; Raghavan, Srivatsan V; Liong, Shie-Yui

    2017-10-17

    Atmospheric aerosols influence precipitation by changing the earth's energy budget and cloud properties. A number of studies have reported correlations between aerosol properties and precipitation data. Despite previous research, it is still hard to quantify the overall effects that aerosols have on precipitation as multiple influencing factors such as relative humidity (RH) can distort the observed relationship between aerosols and precipitation. Thus, in this study, both satellite-retrieved and reanalysis data were used to investigate the relationship between aerosols and precipitation in the Southeast Asia region from 2001 to 2015, with RH considered as a possible influencing factor. Different analyses in the study indicate that a positive correlation was present between Aerosol Optical Depth (AOD) and precipitation over northern Southeast Asia region during the autumn and the winter seasons, while a negative correlation was identified over the Maritime Continent during the autumn season. Subsequently, a partial correlation analysis revealed that while RH influences the long-term negative correlations between AOD and precipitation, it did not significantly affect the positive correlations seen in the winter season. The result of this study provides additional evidence with respect to the critical role of RH as an influencing factor in AOD-precipitation relationship over Southeast Asia.

  6. Depth to water in the eastern Snake River Plain and surrounding tributary valleys, southwestern Idaho and eastern Oregon, calculated using water levels from 1980 to 1988

    Science.gov (United States)

    Maupin, Molly A.

    1992-01-01

    The vulnerability of ground water to contamination in Idaho is being assessed by the IDHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Orotection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability or ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantha,, Idaho Department of Health and Welfare, written commun., 1989). A digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a sols data set developed by the SCS (Soil Conservation Service) and IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (Idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) developed digital depth-to-water values for eleven 1:100,000-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

  7. Depth to water in the western Snake River Plain and surrounding tributary valleys, southwestern Idaho and eastern Oregon, calculated using water levels from 1980 to 1988

    Science.gov (United States)

    Maupin, Molly A.

    1991-01-01

    The vulnerability of ground water to contamination in Idaho is being assessed by the ISHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Protection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability of ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantham, Idaho Department of Health and Welfare, written commun., 1989). Digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a soils data set developed by the SCS (Soul Conservation Service) and the IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) has developed digital depth-to-water values for eleven 1:100,00-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

  8. Occurrence and risk assessment of antibiotics in surface water and groundwater from different depths of aquifers: A case study at Jianghan Plain, central China.

    Science.gov (United States)

    Yao, Linlin; Wang, Yanxin; Tong, Lei; Deng, Yamin; Li, Yonggang; Gan, Yiqun; Guo, Wei; Dong, Chuangju; Duan, Yanhua; Zhao, Ke

    2017-01-01

    The occurrence of 14 antibiotics (fluoroquinolones, tetracyclines, macrolides and sulfonamides) in groundwater and surface water at Jianghan Plain was investigated during three seasons. The total concentrations of target compounds in the water samples were higher in spring than those in summer and winter. Erythromycin was the predominant antibiotic in surface water samples with an average value of 1.60μg/L, 0.772μg/L and 0.546μg/L respectively in spring, summer and winter. In groundwater samples, fluoroquinolones and tetracyclines accounted for the dominant proportion of total antibiotic residues. The vertical distributions of total antibiotics in groundwater samples from three different depths boreholes (10m, 25m, and 50m) exhibited irregular fluctuations. Consistently decreasing of antibiotic residues with increasing of depth was observed in four (G01, G02, G03 and G05) groundwater sampling sites over three seasons. However, at the sampling sites G07 and G08, the pronounced high concentrations of total antibiotic residues were detected in water samples from 50m deep boreholes instead of those at upper aquifer in winter sampling campaign, with the total concentrations of 0.201μg/L and 0.100μg/L respectively. The environmental risks posed by the 14 antibiotics were assessed by using the methods of risk quotient and mixture risk quotient for algae, daphnids and fish in surface water and groundwater. The results suggested that algae might be the aquatic organism most sensitive to the antibiotics, with the highest risk levels posed by erythromycin in surface water and by ciprofloxacin in groundwater among the 14 antibiotics. In addition, the comparison between detected antibiotics in groundwater samples and the reported effective concentrations of antibiotics on denitrification by denitrifying bacteria, indicating this biogeochemical process driven by microorganisms won't be inhibitory influenced by the antibiotic residues in groundwater. Copyright © 2016

  9. Urban water consumption and its influencing factors in China

    NARCIS (Netherlands)

    Fan, Liangxin; Gai, Lingtong; Tong, Yan; Li, Ruihua

    2017-01-01

    Factors that affect water consumption should be identified to develop effective public policies. However, factors influencing domestic water consumption in cities in China, particularly on a national scale, are unclear. In this study, urban water consumption and its influencing factors in 286

  10. Estimating space-time mean concentrations of nutrients in surface waters of variable depth

    NARCIS (Netherlands)

    Knotters, M.; Brus, D.J.

    2010-01-01

    A monitoring scheme has been designed to test whether the space-time mean concentration total Nitrogen (N-total) in the surface water in the Northern Frisian Woodlands (NFW, The Netherlands) complies with standards of the European Water Framework directive. Since in statistical testing for

  11. Interrelationships of petiole air canal architecture, water depth and convective air flow in Nymphaea odorata (Nymphaeaceae)

    Science.gov (United States)

    Premise of the study--Nymphaea odorata grows in water up to 2 m deep, producing fewer, larger leaves in deeper water. This species has a convective flow system that moves gases from younger leaves through submerged parts to older leaves, aerating submerged parts. Petiole air canals are in the conv...

  12. TOWARDS THE INFLUENCE OF A CAR WINDSHIELD ON DEPTH CALCULATION WITH A STEREO CAMERA SYSTEM

    Directory of Open Access Journals (Sweden)

    A. Hanel

    2016-06-01

    Full Text Available Stereo camera systems in cars are often used to estimate the distance of other road users from the car. This information is important to improve road safety. Such camera systems are typically mounted behind the windshield of the car. In this contribution, the influence of the windshield on the estimated distance values is analyzed. An offline stereo camera calibration is performed with a moving planar calibration target. In a standard procedure bundle adjustment, the relative orientation of the cameras is estimated. The calibration is performed for the identical stereo camera system with and without a windshield in between. The base lengths are derived from the relative orientation in both cases and are compared. Distance values are calculated and analyzed. It can be shown, that the difference of the base length values in the two cases is highly significant. Resulting effects on the distance calculation up to a half meter occur.

  13. Towards the Influence of a CAR Windshield on Depth Calculation with a Stereo Camera System

    Science.gov (United States)

    Hanel, A.; Hoegner, L.; Stilla, U.

    2016-06-01

    Stereo camera systems in cars are often used to estimate the distance of other road users from the car. This information is important to improve road safety. Such camera systems are typically mounted behind the windshield of the car. In this contribution, the influence of the windshield on the estimated distance values is analyzed. An offline stereo camera calibration is performed with a moving planar calibration target. In a standard procedure bundle adjustment, the relative orientation of the cameras is estimated. The calibration is performed for the identical stereo camera system with and without a windshield in between. The base lengths are derived from the relative orientation in both cases and are compared. Distance values are calculated and analyzed. It can be shown, that the difference of the base length values in the two cases is highly significant. Resulting effects on the distance calculation up to a half meter occur.

  14. Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

    Science.gov (United States)

    Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.

    2009-01-01

    Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.

  15. A Semianalytical Ocean Color Inversion Algorithm with Explicit Water Column Depth and Substrate Reflectance Parameterization

    Science.gov (United States)

    Mckinna, Lachlan I. W.; Werdell, P. Jeremy; Fearns, Peter R. C.; Weeks, Scarla J.; Reichstetter, Martina; Franz, Bryan A.; Shea, Donald M.; Feldman, Gene C.

    2015-01-01

    A semianalytical ocean color inversion algorithm was developed for improving retrievals of inherent optical properties (IOPs) in optically shallow waters. In clear, geometrically shallow waters, light reflected off the seafloor can contribute to the water-leaving radiance signal. This can have a confounding effect on ocean color algorithms developed for optically deep waters, leading to an overestimation of IOPs. The algorithm described here, the Shallow Water Inversion Model (SWIM), uses pre-existing knowledge of bathymetry and benthic substrate brightness to account for optically shallow effects. SWIM was incorporated into the NASA Ocean Biology Processing Group's L2GEN code and tested in waters of the Great Barrier Reef, Australia, using the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua time series (2002-2013). SWIM-derived values of the total non-water absorption coefficient at 443 nm, at(443), the particulate backscattering coefficient at 443 nm, bbp(443), and the diffuse attenuation coefficient at 488 nm, Kd(488), were compared with values derived using the Generalized Inherent Optical Properties algorithm (GIOP) and the Quasi-Analytical Algorithm (QAA). The results indicated that in clear, optically shallow waters SWIM-derived values of at(443), bbp(443), and Kd(443) were realistically lower than values derived using GIOP and QAA, in agreement with radiative transfer modeling. This signified that the benthic reflectance correction was performing as expected. However, in more optically complex waters, SWIM had difficulty converging to a solution, a likely consequence of internal IOP parameterizations. Whilst a comprehensive study of the SWIM algorithm's behavior was conducted, further work is needed to validate the algorithm using in situ data.

  16. CO2 snow depth and subsurface water-ice abundance in the northern hemisphere of Mars.

    Science.gov (United States)

    Mitrofanov, I G; Zuber, M T; Litvak, M L; Boynton, W V; Smith, D E; Drake, D; Hamara, D; Kozyrev, A S; Sanin, A B; Shinohara, C; Saunders, R S; Tretyakov, V

    2003-06-27

    Observations of seasonal variations of neutron flux from the high-energy neutron detector (HEND) on Mars Odyssey combined with direct measurements of the thickness of condensed carbon dioxide by the Mars Orbiter Laser Altimeter (MOLA) on Mars Global Surveyor show a latitudinal dependence of northern winter deposition of carbon dioxide. The observations are also consistent with a shallow substrate consisting of a layer with water ice overlain by a layer of drier soil. The lower ice-rich layer contains between 50 and 75 weight % water, indicating that the shallow subsurface at northern polar latitudes on Mars is even more water rich than that in the south.

  17. Prestimulus default mode activity influences depth of processing and recognition in an emotional memory task.

    Science.gov (United States)

    Soravia, Leila M; Witmer, Joëlle S; Schwab, Simon; Nakataki, Masahito; Dierks, Thomas; Wiest, Roland; Henke, Katharina; Federspiel, Andrea; Jann, Kay

    2016-03-01

    Low self-referential thoughts are associated with better concentration, which leads to deeper encoding and increases learning and subsequent retrieval. There is evidence that being engaged in externally rather than internally focused tasks is related to low neural activity in the default mode network (DMN) promoting open mind and the deep elaboration of new information. Thus, reduced DMN activity should lead to enhanced concentration, comprehensive stimulus evaluation including emotional categorization, deeper stimulus processing, and better long-term retention over one whole week. In this fMRI study, we investigated brain activation preceding and during incidental encoding of emotional pictures and on subsequent recognition performance. During fMRI, 24 subjects were exposed to 80 pictures of different emotional valence and subsequently asked to complete an online recognition task one week later. Results indicate that neural activity within the medial temporal lobes during encoding predicts subsequent memory performance. Moreover, a low activity of the default mode network preceding incidental encoding leads to slightly better recognition performance independent of the emotional perception of a picture. The findings indicate that the suppression of internally-oriented thoughts leads to a more comprehensive and thorough evaluation of a stimulus and its emotional valence. Reduced activation of the DMN prior to stimulus onset is associated with deeper encoding and enhanced consolidation and retrieval performance even one week later. Even small prestimulus lapses of attention influence consolidation and subsequent recognition performance. © 2015 Wiley Periodicals, Inc.

  18. Characterization of spatial heterogeneity of groundwater-stream water interactions using multiple depth streambed temperature measurements at the reach scale

    Directory of Open Access Journals (Sweden)

    C. Schmidt

    2006-01-01

    Full Text Available Streambed temperatures can be easily, accurately and inexpensively measured at many locations. To characterize patterns of groundwater-stream water interaction with a high spatial resolution, we measured 140 vertical streambed temperature profiles along a 220 m section of a small man-made stream. Groundwater temperature at a sufficient depth remains nearly constant while stream water temperatures vary seasonally and diurnally. In summer, streambed temperatures of groundwater discharge zones are relatively colder than downwelling zones of stream water. Assuming vertical flow in the streambed, the observed temperatures are correlated to the magnitude of water fluxes. The water fluxes are then estimated by applying a simple analytical solution of the heat conduction-advection equation to the observed vertical temperature profiles. The calculated water fluxes through the streambed ranged between 455 Lm−2 d−1 of groundwater discharging to the stream and approximately 10 Lm−2 d−1 of stream water entering the streambed. The investigated reach was dominated by groundwater discharge with two distinct high discharge locations accounting for 50% of the total flux on 20% of the reach length.

  19. Remote sensing of euphotic depth in shallow tropical inland waters of Lake Naivasha using MERIS data

    CSIR Research Space (South Africa)

    Majozi, NP

    2014-05-01

    Full Text Available Freshwater resources are deteriorating rapidly due to human activities and climate change. Remote sensing techniques have shown potential for monitoring water quality in shallow inland lakes, especially in data-scarce areas. The purpose...

  20. INFLUENCE OF TECHNOLOGICAL PARAMETERS ON AGROTEXTILES WATER ABSORBENCY USING ANOVA MODEL

    Directory of Open Access Journals (Sweden)

    LUPU Iuliana G.

    2016-05-01

    Full Text Available Agrotextiles are now days extensively being used in horticulture, farming and other agricultural activities. Agriculture and textiles are the largest industries in the world providing basic needs such as food and clothing. Agrotextiles plays a significant role to help control environment for crop protection, eliminate variations in climate, weather change and generate optimum condition for plant growth. Water absorptive capacity is a very important property of needle-punched nonwovens used as irrigation substrate in horticulture. Nonwovens used as watering substrate distribute water uniformly and act as slight water buffer owing to the absorbent capacity. The paper analyzes the influence of needling process parameters on water absorptive capacity of needle-punched nonwovens by using ANOVA model. The model allows the identification of optimal action parameters in a shorter time and with less material expenses than by experimental research. The frequency of needle board and needle depth penetration has been used as independent variables while the water absorptive capacity as dependent variable for ANOVA regression model. Based on employed ANOVA model we have established that there is a significant influence of needling parameters on water absorbent capacity. The higher of depth needle penetration and needle board frequency, the higher is the compactness of fabric. A less porous structure has a lower water absorptive capacity.

  1. Barotropic wind-driven circulation patterns in a closed rectangular basin of variable depth influenced by a peninsula or an island

    Directory of Open Access Journals (Sweden)

    B. V. Chubarenko

    Full Text Available We study how a coastal obstruction (peninsula or coastal island affects the three-dimensional barotropic currents in an oblong rectangular basin with variable bathymetry across the basin width. The transverse depth profile is asymmetric and the peninsula or island lies in the middle of the long side of the rectangle. A semi-spectral model for the Boussinesq-approximated shallow water equations, developed in Haidvogel et al. and altered for semi-implicit numerical integration in time in Wang and Hutter, is used to find the steady barotropic state circulation pattern to external winds. The structural (qualitative rearrangements and quanti2tative features of the current pattern are studied under four principal wind directions and different lengths of the peninsula and its inclination relative to the shore. The essentially non-linear relationships of the water flux between the two sub-basins (formed by the obstructing peninsula and the corresponding cross-sectional area left open are found and analysed. It is further analysed whether the depth-integrated model, usually adopted by others, is meaningful when applied to the water exchange problems. The flow through the channel narrowing is quantitatively estimated and compared with the three-dimensional results. The dynamics of the vortex structure and the identification of the up-welling/down-welling zones around the obstruction are discussed in detail. The influence of the transformation of the peninsula into a coastal island on the global basin circulation is considered as are the currents in the channel. The geometric and physical reasons for the anisotropy of the current structure which prevail through all obtained solutions are also discussed.

    Key words: Oceanography: general (limnology; numerical modeling - Oceanography: physical (currents

  2. Barotropic wind-driven circulation patterns in a closed rectangular basin of variable depth influenced by a peninsula or an island

    Directory of Open Access Journals (Sweden)

    B. V. Chubarenko

    2000-06-01

    Full Text Available We study how a coastal obstruction (peninsula or coastal island affects the three-dimensional barotropic currents in an oblong rectangular basin with variable bathymetry across the basin width. The transverse depth profile is asymmetric and the peninsula or island lies in the middle of the long side of the rectangle. A semi-spectral model for the Boussinesq-approximated shallow water equations, developed in Haidvogel et al. and altered for semi-implicit numerical integration in time in Wang and Hutter, is used to find the steady barotropic state circulation pattern to external winds. The structural (qualitative rearrangements and quanti2tative features of the current pattern are studied under four principal wind directions and different lengths of the peninsula and its inclination relative to the shore. The essentially non-linear relationships of the water flux between the two sub-basins (formed by the obstructing peninsula and the corresponding cross-sectional area left open are found and analysed. It is further analysed whether the depth-integrated model, usually adopted by others, is meaningful when applied to the water exchange problems. The flow through the channel narrowing is quantitatively estimated and compared with the three-dimensional results. The dynamics of the vortex structure and the identification of the up-welling/down-welling zones around the obstruction are discussed in detail. The influence of the transformation of the peninsula into a coastal island on the global basin circulation is considered as are the currents in the channel. The geometric and physical reasons for the anisotropy of the current structure which prevail through all obtained solutions are also discussed.Key words: Oceanography: general (limnology; numerical modeling - Oceanography: physical (currents

  3. Evaluating the influence of ventilation and ventilation-compression synchronization on chest compression force and depth during simulated neonatal resuscitation.

    Science.gov (United States)

    Dellimore, K H; Scheffer, C; Smith, J; Van Den Heever, D J; Lloyd, D L

    2017-06-01

    To investigate the influence of ventilation and ventilation-compression synchronization on compression force and sternal displacement during simulated neonatal cardiopulmonary resuscitation (NCPR) on an infant manikin. Five Neonatal Resuscitation Program trained clinicians were recruited to perform simulated NCPR on an infant manikin using two-finger (TF) and two-thumb (TT) compression, with synchronous and asynchronous ventilation, as well as without ventilation. The sternal displacement and force were recorded and analyzed. Synchronous ventilation and compression yielded sternal displacements and forces in the range of 22.8-32.4 mm and 15.0-29.8 N, respectively, while asynchronous ventilation and compression produced depths and forces in the range of 21.2-32.4 mm and 14.0-28.8 N, respectively. Ventilation exerts a significant influence on sternal displacement and force during simulated NCPR, regardless of the compression method used. Ventilation-compression synchronization, however, is only significant during TF compression with lower compression forces measured during synchronous ventilation than in asynchronous ventilation. This occurs for two reasons: (i) the strong influence of ventilation forces on the lower magnitude compression forces produced during TF compression relative to TT compression and (ii) in asynchronous ventilation, compression and ventilation may occur simultaneously, with inflation and deflation providing an opposing force to the applied compression force.

  4. Ancestry and BMI Influences on Facial Soft Tissue Depths for A Cohort of Chinese and Caucasoid Women in Dunedin, New Zealand.

    Science.gov (United States)

    Baillie, Louisa J; Mirijali, Seyed Ali; Niven, Brian E; Blyth, Phil; Dias, George J

    2015-09-01

    This study measured and assessed facial soft tissue depths (FSTDs) in adult female Chinese and New Zealand (NZ) Europeans (Caucasoids). Ultrasound was used to obtain depths at nine landmarks on 108 healthy subjects (51 Chinese, 57 NZ European), erect positioned, of same age group (18-29 years). Height and weight were also recorded. Statistical analysis focused on comparison of tissue depth between the two ancestry groups and the influence of Body Mass Index (BMI) (kg/m2). Results showed mean depth differences at Supra M2 and Infra M2 landmarks significantly greater for Chinese than Caucasoid women for all three BMI Classes (BMIancestry and BMI influence on FSTDs to be observed and compared for two distinct groups. Results add to knowledge about facial tissue depth variation. © 2015 American Academy of Forensic Sciences.

  5. Coherent flow structures in a depth-limited flow over a gravel surface: The influence of surface roughness

    Science.gov (United States)

    Hardy, Richard J.; Best, James L.; Lane, Stuart N.; Carbonneau, Patrice E.

    2010-09-01

    Turbulent flows moving over a gravel bed develop large-scale, macroturbulent flow structures that are initiated at anchor clasts in the bed and grow and dissipate as they move upward through the flow depth. This paper extends previous research in which we investigated the influence of the Reynolds number on coherent flow structures generated over a gravel bed by assessing the importance of effective bed roughness. Here, we report on flume experiments in which flows over beds of decreasing surface roughness have been quantified through the application of digital particle imaging velocimetry, which allows study of the downstream and vertical components of velocity over the entire flow field. These results indicate that as the effective roughness increases (1) the visual distinctiveness of the coherent flow structures becomes more defined throughout the flow depth, (2) the upstream angle of slope of the coherent flow structure increases, and (3) the reduction in streamwise flow velocity and turbulence intensity toward the upstream side of the structure becomes greater. Applying standard scaling laws, these structures appear shear-generated and form through a combination of both wake flapping and the reattachment of localized shear layers associated with flow separation around individual topographic protrusions. As the effective protrusion decreases, the scale of these coherent flow structures also decreases.

  6. Discoloration of polyvinyl chloride (PVC) tape as a proxy for water-table depth in peatlands: validation and assessment of seasonal variability

    Science.gov (United States)

    Booth, Robert K.; Hotchkiss, Sara C.; Wilcox, Douglas A.

    2005-01-01

    Summary: 1. Discoloration of polyvinyl chloride (PVC) tape has been used in peatland ecological and hydrological studies as an inexpensive way to monitor changes in water-table depth and reducing conditions. 2. We investigated the relationship between depth of PVC tape discoloration and measured water-table depth at monthly time steps during the growing season within nine kettle peatlands of northern Wisconsin. Our specific objectives were to: (1) determine if PVC discoloration is an accurate method of inferring water-table depth in Sphagnum-dominated kettle peatlands of the region; (2) assess seasonal variability in the accuracy of the method; and (3) determine if systematic differences in accuracy occurred among microhabitats, PVC tape colour and peatlands. 3. Our results indicated that PVC tape discoloration can be used to describe gradients of water-table depth in kettle peatlands. However, accuracy differed among the peatlands studied, and was systematically biased in early spring and late summer/autumn. Regardless of the month when the tape was installed, the highest elevations of PVC tape discoloration showed the strongest correlation with midsummer (around July) water-table depth and average water-table depth during the growing season. 4. The PVC tape discoloration method should be used cautiously when precise estimates are needed of seasonal changes in the water-table.

  7. The influence of larval migration and dispersal depth on potential larval trajectories of a deep-sea bivalve

    Science.gov (United States)

    McVeigh, Doreen M.; Eggleston, David B.; Todd, Austin C.; Young, Craig M.; He, Ruoying

    2017-09-01

    Many fundamental questions in marine ecology require an understanding of larval dispersal and connectivity, yet direct observations of larval trajectories are difficult or impossible to obtain. Although biophysical models provide an alternative approach, in the deep sea, essential biological parameters for these models have seldom been measured empirically. In this study, we used a biophysical model to explore the role of behaviorally mediated migration from two methane seep sites in the Gulf of Mexico on potential larval dispersal patterns and population connectivity of the deep-sea mussel ;Bathymodiolus; childressi, a species for which some biological information is available. Three possible larval dispersal strategies were evaluated for larvae with a Planktonic Larval Duration (PLD) of 395 days: (1) demersal drift, (2) dispersal near the surface early in larval life followed by an extended demersal period before settlement, and (3) dispersal near the surface until just before settlement. Upward swimming speeds varied in the model based on the best data available. Average dispersal distances for simulated larvae varied between 16 km and 1488 km. Dispersal in the upper water column resulted in the greatest dispersal distance (1173 km ± 2.00), followed by mixed dispersal depth (921 km ± 2.00). Larvae originating in the Gulf of Mexico can potentially seed most known seep metapopulations on the Atlantic continental margin, whereas larvae drifting demersally cannot (237 km ± 1.43). Depth of dispersal is therefore shown to be a critical parameter for models of deep-sea connectivity.

  8. Solving the linear inviscid shallow water equations in one dimension, with variable depth, using a recursion formula

    Science.gov (United States)

    Hernandez-Walls, R.; Martín-Atienza, B.; Salinas-Matus, M.; Castillo, J.

    2017-11-01

    When solving the linear inviscid shallow water equations with variable depth in one dimension using finite differences, a tridiagonal system of equations must be solved. Here we present an approach, which is more efficient than the commonly used numerical method, to solve this tridiagonal system of equations using a recursion formula. We illustrate this approach with an example in which we solve for a rectangular channel to find the resonance modes. Our numerical solution agrees very well with the analytical solution. This new method is easy to use and understand by undergraduate students, so it can be implemented in undergraduate courses such as Numerical Methods, Lineal Algebra or Differential Equations.

  9. TOPMODEL simulations of streamflow and depth to water table in Fishing Brook Watershed, New York, 2007-09

    Science.gov (United States)

    Nystrom, Elizabeth A.; Burns, Douglas A.

    2011-01-01

    TOPMODEL, a physically based, variable-source area rainfall-runoff model, was used to simulate streamflow and depth to water table for the period January 2007-September 2009 in the 65.6 square kilometers of Fishing Brook Watershed in northern New York. The Fishing Brook Watershed is located in the headwaters of the Hudson River and is predominantly forested with a humid, cool continental climate. The motivation for applying this model at Fishing Brook was to provide a simulation that would be effective later at this site in modeling the interaction of hydrologic processes with mercury dynamics.

  10. Development and design of a semi-floater substructure for multi-megawatt wind turbines at 50+ m water depths

    DEFF Research Database (Denmark)

    NJOMO WANDJI, Wilfried; Natarajan, Anand; Dimitrov, Nikolay Krasimirov

    2016-01-01

    A semi-floater concept as a substructure for multi-megawatt wind turbines is developed herein for installation at 50þ m water depths. The semi-floater concept is a hybrid between a fixed monopile type support structure and a floating spar buoy. The configuration of the substructure is composed...... turbine components, and to exhibit low platform displacement at the mean sea level. Finally, the overall performance of the structure related to energy production is similar to that of a reference wind turbine situated on land....

  11. Seed Burial Depth and Soil Water Content Affect Seedling Emergence and Growth of Ulmus pumila var. sabulosa in the Horqin Sandy Land

    Directory of Open Access Journals (Sweden)

    Jiao Tang

    2016-01-01

    Full Text Available We investigated the effects of seed burial depth and soil water content on seedling emergence and growth of Ulmus pumila var. sabulosa (sandy elm, an important native tree species distributed over the European-Asian steppe. Experimental sand burial depths in the soil were 0.5, 1.0, 1.5, 2.0 and 2.5 cm, and soil water contents were 4%, 8%, 12% and 16% of field capacity. All two-way ANOVA (five sand burial depths and four soil water contents results showed that seed burial depths, soil water content and their interactions significantly affected all the studied plant variables. Most of the times, seedling emergence conditions were greater at the lower sand burial depths (less than 1.0 cm than at the higher (more than 1.0 cm seed burial depths, and at the lower water content (less than 12% than at the higher soil water content. However, high seed burial depths (more than 1.5 cm or low soil water content (less than 12% reduced seedling growth or change in the root/shoot biomass ratios. In conclusion, the most suitable range of sand burial was from 0.5 to 1.0 cm soil depth and soil water content was about 12%, respectively, for the processes of seedling emergence and growth. These findings indicate that seeds of the sandy elm should be kept at rather shallow soil depths, and water should be added up to 12% of soil capacity when conducting elm planting and management. Our findings could help to create a more appropriate sandy elm cultivation and understand sparse elm woodland recruitment failures in arid and semi-arid regions.

  12. Remote sensing of euphotic depth in shallow tropical inland waters of Lake Naivasha using MERIS data

    NARCIS (Netherlands)

    Majozi, N.P.; Salama, M.S.; Bernard, S.; Harper, D.M.; Habte, M.G.

    2014-01-01

    Freshwater resources are deteriorating rapidly due to human activities and climate change. Remote sensing techniques have shown potential for monitoring water quality in shallow inland lakes, especially in data-scarce areas. The purpose of this study was to determine the spectral diffuse attenuation

  13. Colliding jets provide depth control for water jetting in bone tissue

    NARCIS (Netherlands)

    den Dunnen, S.; Dankelman, J.; Kerkhoffs, G. M.; Tuijthof, G.

    2017-01-01

    In orthopaedic surgery, water jet drilling provides several advantages over classic drilling with rigid drilling bits, such as the always sharp cut, absence of thermal damage and increased manoeuvrability. Previous research showed that the heterogeneity of bone tissue can cause variation in drilling

  14. Assessment of satellite derived diffuse attenuation coefficients and euphotic depths in south Florida coastal waters

    Science.gov (United States)

    Optical data collected in coastal waters off South Florida and in the Caribbean Sea between January 2009 and December 2010 were used to evaluate products derived with three bio-optical inversion algorithms applied to MOIDS/Aqua, MODIS/Terra, and SeaWiFS satellite observations. Th...

  15. Influence of Root Diameter and Soil Depth on the Xylem Anatomy of Fine- to Medium-Sized Roots of Mature Beech Trees in the Top- and Subsoil.

    Science.gov (United States)

    Kirfel, Kristina; Leuschner, Christoph; Hertel, Dietrich; Schuldt, Bernhard

    2017-01-01

    Despite their importance for water uptake and transport, the xylem anatomical and hydraulic properties of tree roots have only rarely been studied in the field. We measured mean vessel diameter (D), vessel density (VD), relative vessel lumen area (lumen area per xylem area) and derived potential hydraulic conductivity (Kp) in the xylem of 197 fine- to medium-diameter roots (1-10 mm) in the topsoil and subsoil (0-200 cm) of a mature European beech forest on sandy soil for examining the influence of root diameter and soil depth on xylem anatomical and derived hydraulic traits. All anatomical and functional traits showed strong dependence on root diameter and thus root age but no significant relation to soil depth. Averaged over topsoil and deep soil and variable flow path lengths in the roots, D increased linearly with root diameter from ∼50 μm in the smallest diameter class (1-2 mm) to ∼70 μm in 6-7 mm roots (corresponding to a mean root age of ∼12 years), but remained invariant in roots >7 mm. D never exceeded ∼82 μm in the 1-10 mm roots, probably in order to control the risk of frost- or drought-induced cavitation. This pattern was overlain by a high variability in xylem anatomy among similar-sized roots with Kp showing a higher variance component within than between root diameter classes. With 8% of the roots exceeding average Kp in their diameter class by 50-700%, we obtained evidence of the existence of 'high-conductivity roots' indicating functional differentiation among similar-sized roots. We conclude that the hydraulic properties of small to medium diameter roots of beech are mainly determined by root age, rendering root diameter a suitable predictor of hydraulic functioning, while soil depth - without referring to path length - had a negligible effect.

  16. Influence of Root Diameter and Soil Depth on the Xylem Anatomy of Fine- to Medium-Sized Roots of Mature Beech Trees in the Top- and Subsoil

    Directory of Open Access Journals (Sweden)

    Kristina Kirfel

    2017-07-01

    Full Text Available Despite their importance for water uptake and transport, the xylem anatomical and hydraulic properties of tree roots have only rarely been studied in the field. We measured mean vessel diameter (D, vessel density (VD, relative vessel lumen area (lumen area per xylem area and derived potential hydraulic conductivity (Kp in the xylem of 197 fine- to medium-diameter roots (1–10 mm in the topsoil and subsoil (0–200 cm of a mature European beech forest on sandy soil for examining the influence of root diameter and soil depth on xylem anatomical and derived hydraulic traits. All anatomical and functional traits showed strong dependence on root diameter and thus root age but no significant relation to soil depth. Averaged over topsoil and deep soil and variable flow path lengths in the roots, D increased linearly with root diameter from ∼50 μm in the smallest diameter class (1–2 mm to ∼70 μm in 6–7 mm roots (corresponding to a mean root age of ∼12 years, but remained invariant in roots >7 mm. D never exceeded ∼82 μm in the 1–10 mm roots, probably in order to control the risk of frost- or drought-induced cavitation. This pattern was overlain by a high variability in xylem anatomy among similar-sized roots with Kp showing a higher variance component within than between root diameter classes. With 8% of the roots exceeding average Kp in their diameter class by 50–700%, we obtained evidence of the existence of ‘high-conductivity roots’ indicating functional differentiation among similar-sized roots. We conclude that the hydraulic properties of small to medium diameter roots of beech are mainly determined by root age, rendering root diameter a suitable predictor of hydraulic functioning, while soil depth – without referring to path length – had a negligible effect.

  17. Biofouling reduction for improvement of depth water filtration. Filter production and testing

    Directory of Open Access Journals (Sweden)

    Sztuk - Sikorska Ewa

    2016-09-01

    Full Text Available Water is a strategic material. Recycling is an important component of balancing its use. Deep-bed filtration is an inexpensive purification method and seems to be very effective in spreading water recovery. Good filter designs, such as the fibrous filter, have high separation efficiency, low resistance for the up-flowing fluid and high retention capacity. However, one of the substantial problems of this process is the biofouling of the filter. Biofouling causes clogging and greatly reduces the life of the filter. Therefore, the melt-blown technique was used for the formation of novel antibacterial fibrous filters. Such filters are made of polypropylene composites with zinc oxide and silver nanoparticles on the fiber surface. These components act as inhibitors of bacterial growth in the filter and were tested in laboratory and full scale experiments. Antibacterial/bacteriostatic tests were performed on Petri dishes with E. coli and B. subtilis. Full scale experiments were performed on natural river water, which contained abiotic particles and mutualistic bacteria. The filter performance at industrial scale conditions was measured using a particle counter, a flow cytometer and a confocal microscope. The results of the experiments indicate a significant improvement of the composite filter performance compared to the regular fibrous filter. The differences were mostly due to a reduction in the biofouling effect.

  18. Variability in estuarine water temperature gradients and influence on ...

    African Journals Online (AJOL)

    Variability in estuarine water temperature gradients and influence on the distribution of zooplankton: a biogeographical perspective. TH Wooldridge, SHP Deyzel. Abstract. Structure and variability of water temperature gradients and potential influence on distribution of two tropical zooplankters (the mysid Mesopodopsis ...

  19. Comparison of stratum corneum thickness between two proposed methods of calculation using Raman spectroscopic depth profiling of skin water content.

    Science.gov (United States)

    Lee, M; Won, K; Kim, E J; Hwang, J S; Lee, H K

    2018-02-20

    The stratum corneum (SC) is the most important layer for the barrier function of skin, so investigation of the SC is very important in cosmetic and medical research. Here, we calculated the SC thickness using the depth profile of the skin's water concentration based on previously described methods, and then compared the results. Seven Korean women in their 30s participated in this study. Raman spectroscopy was used to measure the in vivo depth profile of skin water concentration. A total of 21 areas were measured at forearm. Microsoft Excel 2007 was used to calculate SC thickness based on the slope and intersection methods. The slope method and the intersection method gave a forearm SC thickness calculated at 21.3 ± 2.6 μm and 17.6 ± 2.8 μm, respectively. There was a significant difference between the two calculation methods but the two methods showed strong correlation of SC thickness results (r = .899). Although there was a difference in calculated SC thickness of about 20% between the two methods, these results reveal that the two SC thickness calculation methods using Raman spectroscopy were suitable for measuring SC thickness, a finding consistent with other published results. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Effect of water depth on amount of flexion and extension of joints of the distal aspects of the limbs in healthy horses walking on an underwater treadmill.

    Science.gov (United States)

    Mendez-Angulo, Jose L; Firshman, Anna M; Groschen, Donna M; Kieffer, Philip J; Trumble, Troy N

    2013-04-01

    To determine the maximum amount of flexion and extension of the carpal, tarsal, metacarpophalangeal, and metatarsophalangeal joints and the percentage duration of the stance and swing phases of the stride for horses walking on an underwater treadmill in various water depths. 9 healthy adult horses. Zinc oxide markers were placed on the forelimbs and hind limbs of the horses. Video was recorded of horses walking (0.9 m/s) on an underwater treadmill during baseline conditions (joints). Maximum amount of joint flexion and extension, range of motion (ROM), and the percentage durations of the stance and swing phases of the stride were determined with 2-D motion analysis software. The ROM was greater for all evaluated joints in any amount of water versus ROM for joints in baseline conditions (primarily because of increases in amount of joint flexion). The greatest ROM for carpal joints was detected in a tarsal joint water depth, for tarsal joints in a stifle joint water depth, and for metacarpophalangeal and metatarsophalangeal joints in metatarsophalangeal and tarsal joint water depths. As water depth increased, the percentage durations of the stance and swing phases of the stride significantly decreased and increased, respectively. Results of this study suggested that exercise on an underwater treadmill is useful for increasing the ROM of various joints of horses during rehabilitation and that the depth of water affects the amount of flexion and extension of joints.

  1. Linking Plant Water-Use Efficiency and Depth of Water Uptake to Field­-Level Productivity Under Surplus and Deficit Irrigation in Almond Orchards

    Science.gov (United States)

    Seely, T.; Shackel, K.; Silva, L. C. R.

    2016-12-01

    The impact of water stress on depth of water uptake, as well as water­-use efficiency (WUE) at the tree-level and field-level was examined in almond orchards under varying degrees of deficit and surplus irrigation treatments. Three different orchards, spanning a latitudinal gradient (35° to 39° N) were sampled during two growing seasons in the central valley of CA. The orchards encompass a range of climatic and edaphic conditions, providing an opportunity for comparisons of WUE and orchard yield under contrasting environmental conditions. In each orchard, the control treatment received 100% replacement of water lost to evapotranspiration (ET), while the surplus treatment received 110% and the deficit treatment received 70% replenishment of ET, the latter simulating conditions of water stress. Preliminary results based on the analysis of carbon isotope ratios (δ13C) in leaves throughout the 2015 and 2016 growing seasons, reveal a significant change in WUE in all three orchard sites, increasing up to 20% on average in the deficit irrigation treatment relative to controls. In contrast, trees growing under surplus irrigation had the lowest WUE across all orchard sites. The difference in WUE between surplus irrigated trees and control irrigated trees within each orchard was not always statistically significant. These physiological responses to levels of water availability were not reflected in field-level orchard productivity, which was highly variable across orchard sites and treatments. Additionally, analysis of oxygen (δ18O) and hydrogen (δ2H) isotope ratios of stem, leaf, and soil water has been undertaken to determine the effect of water stress on the depth of root water uptake. The hypothesis that almond trees can effectively acclimate to water stress through higher WUE and deeper root water uptake compared to well-watered trees will be tested. This multi-scale, ecohydrological study will elucidate the impacts of drought on almond orchards, one of the most

  2. Does Depth Matter Examining Factors that Could Influence the Acoustic Identification of Odontocete Species on Bottom Moored Recorders

    Science.gov (United States)

    2015-09-30

    researchers to make species identifications occur independently of recording depth and are therefore truly invariant and distinctive features...in-depth analysis to characterize signal differences among recorders. These analyses will be presented at the upcoming Society for Marine Mammalogy

  3. Temperature profile and water depth data collected from HARKNESS in the Indian Ocean from 15 December 1986 to 14 January 1987 (NODC Accession 8700087)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the HARKNESS in the Indian Ocean and TOGA Area - India Ocean. Data were collected...

  4. Temperature profile and water depth data collected from R/V ENDEAVOR using CTD casts from 14 September 1981 to 01 October 1981 (NODC Accession 8600220)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using CTD casts from the R/V ENDEAVOR. Data were collected from 14 September 1981 to 01 October 1981 by Woods...

  5. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago in 2013 (NCEI Accession 0161327)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  6. Temperature profile and water depth data collected from USS MOBILE BAY in the NW Atlantic Ocean from 05 March 1987 to 31 March 1987 (NODC Accession 8700170)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean and Caribbean Sea. Data were...

  7. Temperature profile and water depth data collected from DOWNES in the NW Pacific (limit-180W) from 09 September 1986 to 29 September 1986 (NODC Accession 8700044)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the DOWNES in the Northeast Pacific Ocean. Data were collected from 09 September 1986...

  8. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Pacific Remote Island Areas since 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  9. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across American Samoa in 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  10. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Mariana Archipelago in 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  11. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago since 2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  12. Measurement of LET (linear energy transfer) spectra using CR-39 at different depths of water irradiated by 171 MeV protons: A comparison with Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, G.S. [Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tripathy, S.P., E-mail: sam.tripathy@gmail.com [Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Molokanov, A.G.; Aleynikov, V.E. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Sharma, S.D. [Homi Bhabha National Institute, Mumbai 400094 (India); Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bandyopadhyay, T. [Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Homi Bhabha National Institute, Mumbai 400094 (India)

    2016-05-11

    In this work, we have used CR-39 detectors to estimate the LET (linear energy transfer) spectrum of secondary particles due to 171 MeV proton beam at different depths of water including the Bragg peak region. The measured LET spectra were compared with those obtained from FLUKA Monte Carlo simulation. The absorbed dose (D{sub LET}), dose equivalent (H{sub LET}) were estimated using the LET spectra. The values of D{sub LET} and H{sub LET} per incident proton fluence were found to increase with the increase in depth of water and were maximum at Bragg peak. - Highlights: • Measurement of LET spectrometry using CR-39 detectors at different depths of water. • Comparison of measured spectra with FLUKA Monte carlo simulation. • Absorbed dose and dose equivalent was found to increase with depth of water.

  13. Temperature profile and water depth data collected from HARKNESS in the Indian Ocean from 01 March 1987 to 10 March 1987 (NODC Accession 8700159)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the HARKNESS in the Indian Ocean and TOGA Area - Indian Ocean. Data were collected from...

  14. Temperature profile and water depth data collected from COCHRANE in the South China Sea and other seas from 09 January 1987 to 22 February 1987 (NODC Accession 8700095)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the COCHRANE in the South China and other seas. Data were collected from 09 January...

  15. 1000 meters water depth rigid TLP riser; Riser rigido de plataforma de pernas atirantadas para lamina d'agua de 1000 metros

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Mauro Jacinto Pastor

    1990-07-01

    A procedure to estimate the fatigue life of a TLP riser in 1000 meters water depth based on a hydro-elastic analysis of an integrated riser-TLP model in the time domain is presented . The computational architecture is shown that makes it feasible to process and store the great amount of data involved. The procedure is applied to a 1000 meters water depth TLP with a set of 40 risers 8 inches in diameter equipped with a floatation layer. (author)

  16. The influence of passenger car front shape on pedestrian injury risk observed from German in-depth accident data.

    Science.gov (United States)

    Li, Guibing; Lyons, Mathew; Wang, Bingyu; Yang, Jikuang; Otte, Dietmar; Simms, Ciaran

    2017-04-01

    Quantified relationships between passenger car front shape and pedestrian injury risk derived from accident data are sparse, especially considering the significant recent changes in car front design. The purpose of this paper is therefore to investigate the detailed effects of passenger car front shape on injury risk to a pedestrian's head, thorax, pelvis and leg in the event of a vehicle pedestrian impact. Firstly, an accident sample of 594 pedestrian cases captured during 2000-2015 from the German In-Depth Accident Study (GIDAS) database was employed. Multicollinearity diagnostic statistics were then used to detect multicollinearity between the predictors. Following this, logistic regression was applied to quantify the effects of passenger car front shape on injury risks while controlling for impact speed and pedestrian age. Results indicate that the bumper lower depth (BLD), bumper lower height (BLH), bumper upper height (BUH) and normalised bumper lower/upper height (NBLH/NBUH) are statistically significant for AIS2+ leg injury risk. The normalised bonnet leading edge height (NBLEH) has a statistically significant influence on AIS2+ femur/pelvis injury occurrence. The passenger car front shape did not show statistical significance for AIS3+ thorax and head injuries. The impact speed and pedestrian age are generally significant factors influencing AIS2+ leg and pelvis injuries, and AIS3+ thorax and head injuries. However, when head impacts are fixed on the central windscreen region both pedestrian age and impact speed are not statistically significant for AIS3+ head injury. For quantified effects, when controlling for speed, age and BUH, an average 7% and 6% increase in AIS2+ leg injury odds was observed for every 1cm increase in BLD and BLH respectively; 1cm increase in BUH results in a 7% decrease in AIS2+ leg injury odds when the BLD or BLH are fixed respectively (again controlling for impact speed and pedestrian age); the average AIS2+ femur/pelvis injury

  17. Pacific and Atlantic water influence on the Beaufort Sea slope tracked by epifaunal invertebrate biogeography

    Science.gov (United States)

    Bluhm, B.

    2016-02-01

    As an interior Arctic sea with a narrow shelf and a steep slope, the US Beaufort Sea is influenced by complex vertical and horizontal domains of water masses and current regimes. The benthic invertebrates inhabiting that area form communities that reflect the long-term (year to decadal) environmental conditions and waters mass source. During six expeditions over five years, we deployed plumb-staff beam trawls to collect epifauna invertebrates at >150 locations spanning the shelf and slope to 1000 m and across the primary water masses of the region (as defined by T/S). The >250 species sampled in this effort are dominated in species richness by crustaceans and gastropods, and in abundance and biomass by echinoderms and crustaceans, with proportional variations across water depths. We find strong turnover in species and/or community composition with water depth, and moderate shifts along the west-east axis. Depth-related species/community shifts are gradual, but most pronounced around the 20 m isobaths, at the shelf break (between 100 and 200 m) and between 350 and 500 m. Inshore of 20 m, the dynamic environment (ice gouging, variable salinity) results in a species-poor community. At locations deeper than 350 m, communities increasingly include species common in the Atlantic-influenced Arctic and Atlantic-boreal regions, roughly matching the transition from Pacific-origin to Atlantic-origin waters. We conclude that benthic community distribution can delineate boundaries in hydrographic conditions that are characteristic of different water mass types that reside on the shelf and slope of the Beaufort Sea.

  18. Evaluation of compost influence on soil water retention

    OpenAIRE

    Pavel Zemánek

    2011-01-01

    The experiment was focused on evaluation of influence of compost application on soil water retention. Soil retention is a major soil water property that governs soil functioning as a ecosystem. Soil moisture forms a major buffer against flooding, and water capacity in subsoil is a major factor for plant growth. The effects of changes in soil water retention depend on the proportions of the textural components and the amount of organic carbon present in the soil. During seasons of 2009 and 201...

  19. Effects of different depth of grain colour on antioxidant capacity during water imbibition in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Shin, Oon Ha; Kim, Dae Yeon; Seo, Yong Weon

    2017-07-01

    The importance of the effect of phytochemical accumulation in wheat grain on grain physiology has been recognised. In this study, we tracked phytochemical concentration in the seed coat of purple wheat during the water-imbibition phase and also hypothesised that the speed of germination was only relevant to its initial phytochemical concentration. The results indicate that the speed of germination was significantly reduced in the darker grain groups within the purple wheat. Total phenol content was slightly increased in all groups compared to their initial state, but the levels of other phytochemicals varied among groups. It is revealed that anthocyanin was significantly degraded during the water imbibition stage. Also, the activities of peroxidase, ascorbate peroxidase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase in each grain colour group did not correlated with germination speed. Overall antioxidant activity was reduced as imbibition progressed in each group. Generally, darker grain groups showed higher total antioxidant activities than did lighter grain groups. These findings suggested that the reduced activity of reactive oxygen species, as controlled by internal antioxidant enzymes and phytochemicals, related with germination speed during the water imbibition stage in grains with greater depth of purple colouring. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior.

    Science.gov (United States)

    Tatari, K; Smets, B F; Albrechtsen, H-J

    2016-09-15

    The biokinetic behavior of NH4(+) removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4(+) loadings in a continuous-flow lab-scale assay. NH4(+) removal capacity, estimated from short term loading up-shifts, was at least 10 times higher in the top than in the middle and bottom filter layers, consistent with the stratification of Ammonium Oxidizing Bacteria (AOB). AOB density increased consistently with the NH4(+) removal rate, indicating their primarily role in nitrification under the imposed experimental conditions. The maximum AOB cell specific NH4(+) removal rate observed at the bottom was at least 3 times lower compared to the top and middle layers. Additionally, a significant up-shift capacity (4.6 and 3.5 times) was displayed from the top and middle layers, but not from the bottom layer at increased loading conditions. Hence, AOB with different physiological responses were active at the different depths. The biokinetic analysis predicted that despite the low NH4(+) removal capacity at the bottom layer, the entire filter is able to cope with a 4-fold instantaneous loading increase without compromising the effluent NH4(+). Ultimately, this filter up-shift capacity was limited by the density of AOB and their biokinetic behavior, both of which were strongly stratified. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. ABCC5, a gene that influences the anterior chamber depth, is associated with primary angle closure glaucoma.

    Directory of Open Access Journals (Sweden)

    Monisha E Nongpiur

    2014-03-01

    Full Text Available Anterior chamber depth (ACD is a key anatomical risk factor for primary angle closure glaucoma (PACG. We conducted a genome-wide association study (GWAS on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size =  -0.045 mm, P = 8.17 × 10(-9. This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046. The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9; 3,458 cases vs. 3,831 controls. Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.

  2. Rainfall simulation experiments: Influence of water temperature, water quality and plot design on soil erosion and runoff

    Science.gov (United States)

    Iserloh, Thomas; Pegoraro, Dominique; Schlösser, Angelika; Thesing, Hannah; Seeger, Manuel; Ries, Johannes B.

    2015-04-01

    Field rainfall simulators are designed to study soil erosion processes and provide urgently needed data for various geomorphological, hydrological and pedological issues. Due to the different conditions and technologies applied, there are several methodological aspects under review of the scientific community, particularly concerning design, procedures and conditions of measurement for infiltration, runoff and soil erosion. This study aims at contributing fundamental data for understanding rainfall simulations in depth by studying the effect of the following parameters on the measurement results: 1. Plot design - round or rectangular plot: Can we identify differences in amount of runoff and erosion? 2. Water quality: What is the influence of the water's salt load on interrill erosion and infiltration as measured by rainfall experiments? 3. Water temperature: How much are the results conditioned by the temperature of water, which is subject to changes due to environmental conditions during the experiments? Preliminary results show a moderate increase of soil erosion with the water's salt load while runoff stays almost on the same level. With increasing water temperature, runoff increases continuously. At very high temperatures, soil erosion is clearly increased. A first comparison between round and rectangular plot indicates the rectangular plot to be the most suitable plot shape, but ambiguous results make further research necessary. The analysis of these three factors concerning their influence on runoff and erosion shows that clear methodological standards are necessary in order to make rainfall simulation experiments comparable.

  3. A measurement of the muon-induced neutron yield in lead at a depth of 2850 m water equivalent

    Energy Technology Data Exchange (ETDEWEB)

    Reichhart, L.; Ghag, C. [School of Physics and Astronomy, SUPA University of Edinburgh, UK and High Energy Physics Group, Department of Physics and Astronomy, University College London (United Kingdom); Lindote, A.; Chepel, V.; DeViveiros, L.; Lopes, M. I.; Neves, F.; Pinto da Cunha, J.; Silva, C.; Solovov, V. N. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Akimov, D. Yu.; Belov, V. A.; Burenkov, A. A.; Kobyakin, A. S.; Kovalenko, A. G.; Stekhanov, V. N. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Araújo, H. M.; Bewick, A.; Currie, A.; Horn, M. [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); and others

    2013-08-08

    We present results from the measurement of the neutron production rate in lead by high energy cosmic-ray muons at a depth of 2850 m water equivalent (mean muon energy of 260 GeV). A tonne-scale highly segmented plastic scintillator detector was utilised to detect both the energy depositions from the traversing muons as well as the delayed radiative capture signals of the induced neutrons. Complementary Monte Carlo simulations reproduce well the distributions of muons and detected muon-induced neutrons. Absolute agreement between simulation and data is of the order of 25%. By comparing the measured and simulated neutron capture rates a neutron yield in pure lead of (5.78{sub −0.28}{sup +0.21})×10{sup −3} neutrons/muon/(g/cm{sup 2}) has been obtained.

  4. Response of N₂O emissions to elevated water depth regulation: comparison of rhizosphere versus non-rhizosphere of Phragmites australis in a field-scale study.

    Science.gov (United States)

    Gu, Xiao-Zhi; Chen, Kai-Ning; Wang, Zhao-de

    2016-03-01

    Emissions of nitrous oxide (N2O) from wetland ecosystems are globally significant and have recently received increased attention. However, relatively few direct studies of these emissions in response to water depth-related changes in sediment ecosystems have been conducted, despite the likely role they play as hotspots of N2O production. We investigated depth-related differential responses of the dissolved inorganic nitrogen distribution in Phragmites australis (Cav.) Trin. ex Steud. rhizosphere versus non-rhizosphere sediments to determine if they accelerated N2O emissions and the release of inorganic nitrogen. Changes in static water depth and P. australis growth both had the potential to disrupt the distribution of porewater dissolved NH4 (+), NO3 (-), and NO2 (-) in profiles, and NO3 (-) had strong surface aggregation tendency and decreased significantly with depth. Conversely, the highest NO2 (-) contents were observed in deep water and the lowest in shallow water in the P. australis rhizosphere. When compared with NO3 (-), NH4 (+), and NO2 (-), fluxes from the rhizosphere were more sensitive to the effects of water depth, and both fluxes increased significantly at a depth of more than 1 m. Similarly, N2O emissions were obviously accelerated with increasing depth, although those from the rhizosphere were more readily controlled by P. australis. Pearson's correlation analysis showed that water depth was significantly related to N2O emission and NO2 (-) fluxes, and N2O emissions were also strongly dependent on NO2 (-) fluxes (r = 0.491, p < 0.05). The results presented herein provide new insights into inorganic nitrogen biogeochemical cycles in freshwater sediment ecosystems.

  5. Water-level fluctuations influence sediment porewater ...

    Science.gov (United States)

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management a

  6. Influence of depth of neuromuscular blockade on surgical conditions during low-pressure pneumoperitoneum laparoscopic cholecystectomy: A randomized blinded study.

    Science.gov (United States)

    Barrio, Javier; Errando, Carlos L; García-Ramón, Jaime; Sellés, Rafael; San Miguel, Guillermo; Gallego, Juan

    2017-11-01

    To evaluate the influence of neuromuscular blockade (NMB) on surgical conditions during low-pressure pneumoperitoneum (8mmHg) laparoscopic cholecystectomy (LC), while comparing moderate and deep NMB. Secondary objective was to evaluate if surgical conditions during low-pressure pneumoperitoneum LC performed with deep NMB could be comparable to those provided during standard-pressure pneumoperitoneum (12mmHg) LC. Prospective, randomized, blinded clinical trial. Operating room. Ninety ASA 1-2 patients scheduled for elective LC. Patients were allocated into 3 groups: Group 1: low-pressure pneumoperitoneum with moderate-NMB (1-3 TOF), Group 2: low-pressure pneumoperitoneum with deep-NMB (1-5 PTC) and Group 3: standard pneumoperitoneum (12mmHg). Rocuronium was used to induce NMB and acceleromiography was used for NMB monitoring (TOF-Watch-SX). Three experienced surgeons evaluated surgical conditions using a four-step scale at three time-points: surgical field exposure, dissection of the gallbladder and extraction/closure. Low-pressure pneumoperitoneum (Group 1 vs. 2): good conditions: 96.7 vs. 96.7%, 90 vs. 80% and 89.6 vs. 92.3%, respectively for the time-points, p>0.05. No differences in optimal surgical conditions were observed between the groups. Surgery completion at 8mmHg pneumoperitoneum: 96.7 vs. 86.7%, p=0.353. Standard-pressure pneumoperitoneum vs. low-pressure pneumoperitoneum with deep NMB (Group 3 vs. 2): good conditions: 100% in Group 3 for the three time-points (p=0.024 vs. Group 2 at dissection of the gallbladder). Significantly greater percentage of optimal conditions during standard-pressure pneumoperitoneum LC at the three time points of evaluation. The depth of NMB was found not to be decisive neither in the improvement of surgical conditions nor in the completion of low-pressure pneumoperitoneum LC performed by experienced surgeons. Surgical conditions were considered better with a standard-pressure pneumoperitoneum, regardless of the depth of NMB

  7. A depth-averaged 2-D shallow water model for breaking and non-breaking long waves affected by rigid vegetation

    Science.gov (United States)

    This paper presents a depth-averaged two-dimensional shallow water model for simulating long waves in vegetated water bodies under breaking and non-breaking conditions. The effects of rigid vegetation are modelled in the form of drag and inertia forces as sink terms in the momentum equations. The dr...

  8. Aurelia labiata (Scyphozoa) jellyfish in Roscoe Bay: Their spatial distribution varies with population size and their behaviour changes with water depth

    Science.gov (United States)

    Albert, David J.

    2009-02-01

    During 2003 and 2004, there were large numbers of Aurelia labiata medusae in Roscoe Bay and they distributed themselves across the entire bay. A smaller population present during 2006 and 2007 typically formed an aggregation in the west half of the bay. Since currents would have been the same during these two time periods, the behaviour of medusae must have influenced their distribution. The way medusae spaced themselves in aggregations appeared to interact with tidal currents to produce the difference in medusae distribution during the two time periods. In a second series of observations, I found that medusae were not stranded on a Roscoe Bay beach by ebb tides. When the depth of the water column declined to about 1 m or less, medusae in an intertidal zone dove down and bumped into the bottom or swam into rocks or oysters. Their response to these collisions was to swim to the surface or within a few centimetres of the surface. Since the ebb stream was at the surface, being at the surface increased the probability that medusae drifted out of the intertidal zone. The influence of medusae behaviour on their distribution and on their avoidance of stranding is a further indication of the importance of adaptive behaviour in the ecology of Aurelia labiata medusae.

  9. The influence of water table depth and the free atmospheric state on convective rainfall predisposition

    Science.gov (United States)

    Sara Bonetti; Gabriele Manoli; Jean-Christopher Domec; Mario Putti; Marco Marani; Gabriel G. Katul

    2015-01-01

    A mechanistic model for the soil-plant system is coupled to a conventional slab representation of the atmospheric boundary layer (ABL) to explore the role of groundwater table (WT) variations and free atmospheric (FA) states on convective rainfall predisposition (CRP) at a Loblolly pine plantation site situated in the lower coastal plain of North Carolina....

  10. A feasibility study to estimate minimum surface-casing depths of oil and gas wells to prevent ground-water contamination in four areas of western Pennsylvania

    Science.gov (United States)

    Buckwalter, T.F.; Squillace, P.J.

    1995-01-01

    Hydrologic data were evaluated from four areas of western Pennsylvania to estimate the minimum depth of well surface casing needed to prevent contamination of most of the fresh ground-water resources by oil and gas wells. The areas are representative of the different types of oil and gas activities and of the ground-water hydrology of most sections of the Appalachian Plateaus Physiographic Province in western Pennsylvania. Approximate delineation of the base of the fresh ground-water system was attempted by interpreting the following hydrologic data: (1) reports of freshwater and saltwater in oil and gas well-completion reports, (2) water well-completion reports, (3) geophysical logs, and (4) chemical analyses of well water. Because of the poor quality and scarcity of ground-water data, the altitude of the base of the fresh ground-water system in the four study areas cannot be accurately delineated. Consequently, minimum surface-casing depths for oil and gas wells cannot be estimated with confidence. Conscientious and reliable reporting of freshwater and saltwater during drilling of oil and gas wells would expand the existing data base. Reporting of field specific conductance of ground water would greatly enhance the value of the reports of ground water in oil and gas well-completion records. Water-bearing zones in bedrock are controlled mostly by the presence of secondary openings. The vertical and horizontal discontinuity of secondary openings may be responsible, in part, for large differences in altitudes of freshwater zones noted on completion records of adjacent oil and gas wells. In upland and hilltop topographies, maximum depths of fresh ground water are reported from several hundred feet below land surface to slightly more than 1,000 feet, but the few deep reports are not substantiated by results of laboratory analyses of dissolved-solids concentrations. Past and present drillers for shallow oil and gas wells commonly install surface casing to below the

  11. Efficient Wetland Surface Water Detection and Monitoring via Landsat: Comparison with in situ Data from the Everglades Depth Estimation Network

    Directory of Open Access Journals (Sweden)

    John W. Jones

    2015-09-01

    Full Text Available The U.S. Geological Survey is developing new Landsat science products. One, named Dynamic Surface Water Extent (DSWE, is focused on the representation of ground surface inundation as detected in cloud-/shadow-/snow-free pixels for scenes collected over the U.S. and its territories. Characterization of DSWE uncertainty to facilitate its appropriate use in science and resource management is a primary objective. A unique evaluation dataset developed from data made publicly available through the Everglades Depth Estimation Network (EDEN was used to evaluate one candidate DSWE algorithm that is relatively simple, requires no scene-based calibration data, and is intended to detect inundation in the presence of marshland vegetation. A conceptual model of expected algorithm performance in vegetated wetland environments was postulated, tested and revised. Agreement scores were calculated at the level of scenes and vegetation communities, vegetation index classes, water depths, and individual EDEN gage sites for a variety of temporal aggregations. Landsat Archive cloud cover attribution errors were documented. Cloud cover had some effect on model performance. Error rates increased with vegetation cover. Relatively low error rates for locations of little/no vegetation were unexpectedly dominated by omission errors due to variable substrates and mixed pixel effects. Examined discrepancies between satellite and in situ modeled inundation demonstrated the utility of such comparisons for EDEN database improvement. Importantly, there seems no trend or bias in candidate algorithm performance as a function of time or general hydrologic conditions, an important finding for long-term monitoring. The developed database and knowledge gained from this analysis will be used for improved evaluation of candidate DSWE algorithms as well as other measurements made on Everglades surface inundation, surface water heights and vegetation using radar, lidar and hyperspectral

  12. Drought tolerance is associated with rooting depth and stomatal control of water use in clones of Coffea canephora.

    Science.gov (United States)

    Pinheiro, Hugo A; Damatta, Fábio M; Chaves, Agnaldo R M; Loureiro, Marcelo E; Ducatti, Carlos

    2005-07-01

    Drought is a major environmental constraint affecting growth and production of Coffea canephora. Selection of C. canephora clones has been largely empirical as little is known about how clones respond physiologically to drought. Using clones previously shown to differ in drought tolerance, this study aimed to identify the extent of variation of water use and the mechanisms responsible, particularly those associated morphological traits. * Clones (14 and 120, drought-tolerant; 46 and 109A, drought-sensitive, based on their abilities to yield under drought) were grown in 120-L pots until they were 12-months old, when an irrigation and a drought treatment were applied; plants were droughted until the pressure potential (psi(x)) before dawn (pre-dawn) reached -3.0 MPa. Throughout the drought period, psi(x) and stomatal conductance (g(s)) were measured. At the end of the experiment, carbon isotope ratio and parameters from pressure-volume curves were estimated. Morphological traits were also assessed. * With irrigation, plant hydraulic conductance (K(L)), midday psi(x) and total biomass were all greater in clones 109A and 120 than in the other clones. Root mass to leaf area ratio was larger in clone 109A than in the others, whereas rooting depth was greater in drought-tolerant than in drought-sensitive clones. Predawn psi(x) of -3.0 MPa was reached fastest by 109A, followed progressively by clones 46, 120 and 14. Decreases in g(s) with declining psi(x), or increasing evaporative demand, were similar for clones 14, 46, and 120, but lower in 109A. Carbon isotope ratio increased under drought; however, it was lower in 109A than in other clones. For all clones, psi(x), g(s) and K(L) recovered rapidly following re-watering. Differences in root depth, K(L) and stomatal control of water use, but not osmotic or elastic adjustments, largely explained the differences in relative tolerance to drought stress of clones 14 and 120 compared with clones 46 and 109A.

  13. Efficient wetland surface water detection and monitoring via Landsat: Comparison with in situ data from the Everglades Depth Estimation Network

    Science.gov (United States)

    Jones, John W.

    2015-01-01

    The U.S. Geological Survey is developing new Landsat science products. One, named Dynamic Surface Water Extent (DSWE), is focused on the representation of ground surface inundation as detected in cloud-/shadow-/snow-free pixels for scenes collected over the U.S. and its territories. Characterization of DSWE uncertainty to facilitate its appropriate use in science and resource management is a primary objective. A unique evaluation dataset developed from data made publicly available through the Everglades Depth Estimation Network (EDEN) was used to evaluate one candidate DSWE algorithm that is relatively simple, requires no scene-based calibration data, and is intended to detect inundation in the presence of marshland vegetation. A conceptual model of expected algorithm performance in vegetated wetland environments was postulated, tested and revised. Agreement scores were calculated at the level of scenes and vegetation communities, vegetation index classes, water depths, and individual EDEN gage sites for a variety of temporal aggregations. Landsat Archive cloud cover attribution errors were documented. Cloud cover had some effect on model performance. Error rates increased with vegetation cover. Relatively low error rates for locations of little/no vegetation were unexpectedly dominated by omission errors due to variable substrates and mixed pixel effects. Examined discrepancies between satellite and in situ modeled inundation demonstrated the utility of such comparisons for EDEN database improvement. Importantly, there seems no trend or bias in candidate algorithm performance as a function of time or general hydrologic conditions, an important finding for long-term monitoring. The developed database and knowledge gained from this analysis will be used for improved evaluation of candidate DSWE algorithms as well as other measurements made on Everglades surface inundation, surface water heights and vegetation using radar, lidar and hyperspectral instruments

  14. Lithological and hydrological influences on ground-water composition in a heterogeneous carbonate-clay aquifer system

    Science.gov (United States)

    Kauffman, S.J.; Herman, J.S.; Jones, B.F.

    1998-01-01

    The influence of clay units on ground-water composition was investigated in a heterogeneous carbonate aquifer system of Miocene age in southwest Florida, known as the Intermediate aquifer system. Regionally, the ground water is recharged inland, flows laterally and to greater depths in the aquifer systems, and is discharged vertically upward at the saltwater interface along the coast. A depth profile of water composition was obtained by sampling ground water from discrete intervals within the permeable carbonate units during coring and by squeezing pore water from a core of the less-permeable clay layers. A normative salt analysis of solute compositions in the water indicated a marine origin for both types of water and an evolutionary pathway for the clay water that involves clay diagenesis. The chemical composition of the ground water in the carbonate bedrock is significantly different from that of the pore water in the clay layers. Dissolution of clays and opaline silica results in high silica concentrations relative to water in other parts of the Intermediate aquifer system. Water enriched in chloride relative to the overlying and underlying ground water recharges the aquifer inland where the confining clay layer is absent, and it dissolves carbonate and silicate minerals and reacts with clays along its flow path, eventually reaching this coastal site and resulting in the high chloride and silica concentrations observed in the middle part of the Intermediate aquifer system. Reaction-path modeling suggests that the recharging surficial water mixes with sulfate-rich water upwelling from the Upper Floridan aquifer, and carbonate mineral dissolution and precipitation, weathering and exchange reactions, clay mineral diagenesis, clay and silica dissolution, organic carbon oxidation, and iron and sulfate reduction result in the observed water compositions.A study was conducted to clarify the influence of clay units on ground-water composition in a heterogeneous

  15. Influence of Water quality on the biodiversity of phytoplankton in ...

    African Journals Online (AJOL)

    Michael Horsfall

    Influence of Water quality on the biodiversity of phytoplankton in Dhamra River. Estuary of Odisha Coast, Bay of Bengal. PALLEYI, S ... ecosystem and play a major role in the global cycling of carbon, nitrogen, phosphorus and other ... Water samples for the measurement of salinity, turbidity and nutrient parameters were ...

  16. Seasonal influence on microbial quality of water sources in some ...

    African Journals Online (AJOL)

    This work examined fifteen (15) different water sources in some rural communities of Zaria, Nigeria for microbial index of water quality in relation to seasonal influence from June, 2005 to May, 2006. The microbiological quality indices indicated widespread fecal contamination with the on-set of rainy season Escherichia coli ...

  17. Influence of the selected structural parameter on a depth of intergranular corrosion of Al-Si7-Mg0,3 aluminum alloy

    Directory of Open Access Journals (Sweden)

    L. Bernat

    2015-10-01

    Full Text Available The paper presents an influence of the Dendrite Arm Spacing (DAS microstructure parameter on the intergranular corrosion of AlSi7Mg aluminum alloy. The samples were subjected to the corrosion process for: 2,5; 12; 24; 48 and 96 hours in NaCl + HCl + H2O solution. It was noted that the DAS parameter significantly influenced on a distribution and depth of the intergranular corrosion of the hypoeutectic Al - Si - Mg silumin.

  18. Distribution and biogeographic trends of decapod assemblages from Galicia Bank (NE Atlantic) at depths between 700 and 1800 m, with connexions to regional water masses

    Science.gov (United States)

    Cartes, J. E.; Papiol, V.; Frutos, I.; Macpherson, E.; González-Pola, C.; Punzón, A.; Valeiras, X.; Serrano, A.

    2014-08-01

    The Galicia Bank (NE Atlantic, 42°67‧N-11°74‧W) is an isolated seamount, near NW Spain, a complex geomorphological and sedimentary structure that receives influences from contrasting water masses of both northern and southern origins. Within the project INDEMARES, three cruises were performed on the bank in 2009 (Ecomarg0709), 2010 (BanGal0810) and 2011 (BanGal0811) all in July-August. Decapods and other macrobenthic crustaceans (eucarids and peracarids) were collected with different sampling systems, mainly beam trawls (BT, 10 mm of mesh size at codend) and a GOC73 otter trawl (20 mm mesh size). Sixty-seven species of decapod crustaceans, 6 euphausiids, 19 peracarids and 1 ostracod were collected at depths between 744 and 1808 m. We found two new species, one a member of the Chirostylidae, Uroptychus cartesi Baba & Macpherson, 2012, the other of the Petalophthalmidae (Mysida) Petalophthalmus sp. A, in addition to a number of new biogeographic species records for European or Iberian waters. An analysis of assemblages showed a generalized species renewal with depth, with different assemblages between 744 and ca. 1400 m (the seamount top assemblage, STA) and between ca. 1500 and 1800 m (the deep-slope assemblage over seamount flanks, DSA). These were respectively associated with Mediterranean outflow waters (MOW) and with Labrador Sea Water (LSW). Another significant factor separating different assemblages over the Galician Bank was the co-occurrence of corals (both colonies of hard corals such as Lophelia pertusa and Madrepora oculata and/or gorgonians) in hauls. Munidopsids (Munidopsis spp.), chirostylids (Uroptychus spp.), and the homolodromiid Dicranodromia mahieuxii formed a part of this coral-associated assemblage. Dominant species at the STA were the pandalid Plesionika martia (a shrimp of subtropical-southern distribution) and the crabs Bathynectes maravigna and Polybius henslowii, whereas dominant species in the DSA were of northern origin, the

  19. 33 CFR 2.34 - Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water.

    Science.gov (United States)

    2010-07-01

    ...; waters subject to the ebb and flow of the tide; mean high water. 2.34 Section 2.34 Navigation and....34 Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water. (a) Waters subject to tidal influence and waters subject to the ebb and flow of the tide are waters...

  20. Assessment of depth and turbidity with airborne Lidar bathymetry and multiband satellite imagery in shallow water bodies of the Alaskan North Slope

    Science.gov (United States)

    Saylam, Kutalmis; Brown, Rebecca A.; Hupp, John R.

    2017-06-01

    Airborne Lidar bathymetry (ALB) is an effective and a rapidly advancing technology for mapping and characterizing shallow coastal water zones as well as inland fresh-water basins such as rivers and lakes. The ability of light beams to detect and traverse shallow water columns has provided valuable information about unmapped and often poorly understood coastal and inland water bodies of the world. Estimating ALB survey results at varying water clarity and depth conditions is essential for realizing project expectations and preparing budgets accordingly. In remote locations of the world where in situ water clarity measurements are not feasible or possible, using multiband satellite imagery can be an effective tool for estimating and addressing such considerations. For this purpose, we studied and classified reflected electromagnetic energy from selected water bodies acquired by RapidEye sensor and then correlated findings with ALB survey results. This study was focused not on accurately measuring depth from optical bathymetry but rather on using multiband satellite imagery to quickly predict ALB survey results and identify potentially turbid water bodies with limited depth penetration. For this study, we constructed an in-house algorithm to confirm ALB survey findings using bathymetric waveform information. The study findings are expected to contribute to the ongoing understanding of forecasting ALB survey expectations in unknown and varying water conditions, especially in remote and inaccessible parts of the world.

  1. Modelling effects of seasonal variation in water table depth on net ecosystem CO2 exchange of a tropical peatland

    Science.gov (United States)

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

    2014-02-01

    Seasonal variation in water table depth (WTD) determines the balance between aggradation and degradation of tropical peatlands. Longer dry seasons together with human interventions (e.g. drainage) can cause WTD drawdowns making tropical peatland C storage highly vulnerable. Better predictive capacity for effects of WTD on net CO2 exchange is thus essential to guide conservation of tropical peat deposits. Mathematical modelling of basic eco-hydrological processes under site-specific conditions can provide such predictive capacity. We hereby deploy a process-based mathematical model ecosys to study effects of seasonal variation in WTD on net ecosystem productivity (NEP) of a drainage affected tropical peat swamp forest at Palangkaraya, Indonesia. Simulated NEP suggested that the peatland was a C source (NEP ~ -2 g C m-2 d-1, where a negative sign represents a C source and a positive sign a C sink) during rainy seasons with shallow WTD, C neutral or a small sink (NEP ~ +1 g C m-2 d-1) during early dry seasons with intermediate WTD and a substantial C source (NEP ~ -4 g C m-2 d-1) during late dry seasons with deep WTD from 2002 to 2005. These values were corroborated by regressions (P 0.8, intercepts approaching 0 and slopes approaching 1. We also simulated a gradual increase in annual NEP from 2002 (-609 g C m-2) to 2005 (-373 g C m-2) with decreasing WTD which was attributed to declines in duration and intensity of dry seasons following the El Niño event of 2002. This increase in modelled NEP was corroborated by EC-gap filled annual NEP estimates. Our modelling hypotheses suggested that (1) poor aeration in wet soils during shallow WTD caused slow nutrient (predominantly phosphorus) mineralization and consequent slow plant nutrient uptake that suppressed gross primary productivity (GPP) and hence NEP (2) better soil aeration during intermediate WTD enhanced nutrient mineralization and hence plant nutrient uptake, GPP and NEP and (3) deep WTD suppressed NEP through a

  2. Validity of Core Temperature Measurements at 3 Rectal Depths During Rest, Exercise, Cold-Water Immersion, and Recovery.

    Science.gov (United States)

    Miller, Kevin C; Hughes, Lexie E; Long, Blaine C; Adams, William M; Casa, Douglas J

    2017-04-01

      No evidence-based recommendation exists regarding how far clinicians should insert a rectal thermistor to obtain the most valid estimate of core temperature. Knowing the validity of temperatures at different rectal depths has implications for exertional heat-stroke (EHS) management.   To determine whether rectal temperature (Trec) taken at 4 cm, 10 cm, or 15 cm from the anal sphincter provides the most valid estimate of core temperature (as determined by esophageal temperature [Teso]) during similar stressors an athlete with EHS may experience.   Cross-sectional study.   Laboratory.   Seventeen individuals (14 men, 3 women: age = 23 ± 2 years, mass = 79.7 ± 12.4 kg, height = 177.8 ± 9.8 cm, body fat = 9.4% ± 4.1%, body surface area = 1.97 ± 0.19 m2).   Rectal temperatures taken at 4 cm, 10 cm, and 15 cm from the anal sphincter were compared with Teso during a 10-minute rest period; exercise until the participant's Teso reached 39.5°C; cold-water immersion (∼10°C) until all temperatures were ≤38°C; and a 30-minute postimmersion recovery period. The Teso and Trec were compared every minute during rest and recovery. Because exercise and cooling times varied, we compared temperatures at 10% intervals of total exercise and cooling durations for these periods.   The Teso and Trec were used to calculate bias (ie, the difference in temperatures between sites).   Rectal depth affected bias (F2,24 = 6.8, P = .008). Bias at 4 cm (0.85°C ± 0.78°C) was higher than at 15 cm (0.65°C ± 0.68°C, P .05). Bias varied over time (F2,34 = 79.5, P < .001). Bias during rest (0.42°C ± 0.27°C), exercise (0.23°C ± 0.53°C), and recovery (0.65°C ± 0.35°C) was less than during cooling (1.72°C ± 0.65°C, P < .05). Bias during exercise was less than during postimmersion recovery (0.65°C ± 0.35°C, P < .05).   When EHS is suspected, clinicians should insert the flexible rectal thermistor to 15 cm (6 in) because it is the most valid depth. The low

  3. Temperature influence on water transport in hardened cement pastes

    Energy Technology Data Exchange (ETDEWEB)

    Drouet, Emeline [CEA, DEN, DPC, SECR, Laboratoire d' Etude du Comportement des Bétons et des Argiles, F-91191 Gif sur Yvette Cedex (France); Poyet, Stéphane, E-mail: stephane.poyet@cea.fr [CEA, DEN, DPC, SECR, Laboratoire d' Etude du Comportement des Bétons et des Argiles, F-91191 Gif sur Yvette Cedex (France); Torrenti, Jean-Michel [Université Paris-Est, IFSTTAR, Département Matériaux & Structures, 14-52 boulevard Newton, F-77447 Marne la Vallée cedex 2 (France)

    2015-10-15

    Describing water transport in concrete is an important issue for the durability assessment of radioactive waste management reinforced concrete structures. Due to the waste thermal output such structures would be submitted to moderate temperatures (up to 80 °C). We have then studied the influence of temperature on water transport within hardened cement pastes of four different formulations. Using a simplified approach (describing only the permeation of liquid water) we characterized the properties needed to describe water transport (up to 80 °C) using dedicated experiments. For each hardened cement paste the results are presented and discussed.

  4. Spatio-temporal distribution of Diaphanosoma brachyurum (Cladocera: Sididae in freshwater reservoir ecosystems: importance of maximum water depth and macrophyte beds for avoidance of fish predation

    Directory of Open Access Journals (Sweden)

    Jong-Yun Choi

    2014-10-01

    Full Text Available In empirical studies, Cladocera is commonly utilized as a primary food source for predators such as fish, thus, predator avoidance are important strategies to sustain their population in freshwater ecosystems. In this study, we tested the hypothesis that water depth is an important factor in determining the spatial distribution of Diaphanosoma brachyurum Liévin, 1848 in response to fish predation. Quarterly monitoring was implemented at three water layers (i.e., water surface and middle and bottom layers in 21 reservoirs located in the southeastern part of South Korea. D. brachyurum individuals were frequently observed at the study sites and exhibited different spatial patterns of distribution in accordance with the maximum depth of the reservoirs. In the reservoirs with a maximum depth of more than 6 m, high densities of D. brachyurum were observed in the bottom layers; however, in the shallower reservoirs (maximum depth <6 m, D. brachyurum were concentrated in the surface layer. Moreover, during additional surveys, we observed a trend in which D. brachyurum densities increased as the maximum depth or macrophyte biomass increased. Gut contents analysis revealed that predatory fishes in each reservoir frequently consumed D. brachyurum; however, the consumption rate abruptly decreased in reservoirs where the maximum depth was more than 11 m or in the shallow reservoirs supporting a macrophyte bed. Interestingly, the reservoirs more than 11-m depth supported high densities of D. brachyurum in the bottom layer and in the surface macrophyte bed. Based on these results, reservoirs with a maximum depth of more than 11 m or those with a macrophyte bed may provide a refuge for D. brachyurum to avoid fish predation. Compared with other cladoceran species, D. brachyurum readily exploits various types of refugia (in this study, the deep layer or surface macrophyte bed, which may help explain why this species is abundant in various types of reservoirs.

  5. Depth intensity relations of muons in the standard rock, the K. G. F. rock and the sea water, and their related problems including prompt muon production

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Nobusuke; Kujirai, Hideyuki; Adachi, Atsuko; Ogita, Naofumi; Misaki, Akeo.

    1984-07-01

    In order to analyze world wide data of muon fluxes in the standard rock, the K.G.F. flux and expected data in the sea water which will be obtained from future Dumand project, depth intensity relations of muons are calculated in the Monte Carlo method in which rigorous techniques are utilized as much as possible. Calculational results obtained here are as follows: Depth intensity relations of muon in the standard rock, the K.G.F. rock and the sea water are obtained, in which the powers of differential energy spectra at sea level are changed from 3.6 to 3.9 in unit of 0.05. (author).

  6. Influences of water molecules on the electronic properties of atomically thin molybdenum disulfide

    Science.gov (United States)

    Zhang, Kang; Wang, Xingli; Sun, Leimeng; Zou, Jianping; Wang, Jingyuan; Liu, Zheng; Chen, Tupei; Tay, Beng Kang; Zhang, Qing

    2017-07-01

    Although it is well known that the performances of two-dimensional transition metal dichalcogenide (2D-TMD) based devices are strongly affected by humidity, the roles of water molecules in the electronic properties of 2D-TMDs are still unclear. In this work, the influence of water molecules on the electrical properties of monolayer molybdenum disulfide (MoS2) is studied systemically using the dielectric force microscopy (DFM) technique. Taking the advantage of the DFM technique and other nondestructive characterization techniques, the electronic properties (surface potential, dielectrics, and carrier mobility) of atomically thin MoS2 exposed to different levels of humidity are investigated. Furthermore, Raman spectroscopy manifested the correlation between the optical phonon and the mobility drop of MoS2 flakes when subjected to humidity variations. Our results provide an in-depth understanding of the mechanism of water molecules interacting with MoS2.

  7. Frameworks for Assessing Human Influence on Water Availability

    Science.gov (United States)

    AghaKouchak, A.; Mehran, A.; Mazdiyasni, O.; Ashraf, B.

    2016-12-01

    The water cycle is tightly coupled with water management and human water use behavior. Human activities and water use behavior can intensify the effects of a meteorological drought (a notion referred to as Anthropogenic Drought). In this presentation, we provide a general definition of anthropogenic drought. We then briefly review two different methods for assessing human influence on water availability: (1) a data-driven multivariate approach that links the information on inflow and surface reservoir storage to water demand; (2) A model-based framework that brings a top-down and bottom-up approach to provide localized water assessment based on local available infrastructure and projected water demands. Finally, we will show how the proposed methods can be used for water management scenario analysis (e.g., local water availability based on different human water demands scenarios). This presentation is primarily based on Mehran et al (Mehran A., Mazdiyasni O., AghaKouchak A., 2015, A Hybrid Framework for Assessing Socioeconomic Drought: Linking Climate Variability, Local Resilience, and Demand, Journal of Geophysical Research, 120 (15), 7520-7533, doi: 10.1002/2015JD023147.) and AghaKouchak et al (AghaKouchak A., Feldman D., Hoerling M., Huxman T., Lund J., 2015, Recognize Anthropogenic Drought, Nature, 524 (7566), 409-4011, doi:10.1038/524409a).

  8. Optimizing subsurface dripline installation depth with Hydrus 2D/3D to improve irrigation water use efficiency in the central Tunisia

    Directory of Open Access Journals (Sweden)

    Ghazouani Hiba

    2015-01-01

    Full Text Available The main objective of the work is to optimize drip installation depth for Eggplant crop irrigated with surface or subsurface drip irrigation systems to improve irrigation Water Use Effeciency (WUE, by means of field measurements and simulations carried out with Hydrus-2D model. Initially, a comparison between simulated Soil Water Contents (SWC and the corresponding measured in two plots, in which laterals with coextruded emitters are laid on the soil surface (T0 and at 20 cm depth (T20, respectively. In order to choose the best position of the lateral, the results of different simulation run, carried out by choosing a deeper installation (T45 depth. Simulated SWC’s resulted fairly close to the corresponding measured at different distances from the emitter and therefore the model was able to predict SWC’s in the root zone with values of the Root Mean Square Error generally lower than 4%. This result is consequent to the appropriate schematization of the root distribution, as well as of the root water uptake. The values of WUE associated to the different examined installation depths tend to a very slight increase when the position of the lateral is situated on 20 cm and start to decrease for the higher depths.

  9. Estimating Snow Depth and Snow Water Equivalence Using Repeat-Pass Interferometric SAR in the Northern Piedmont Region of the Tianshan Mountains

    Directory of Open Access Journals (Sweden)

    Hui Li

    2017-01-01

    Full Text Available Snow depth and Snow Water Equivalence (SWE are important parameters for hydrological applications. In this application, a theoretical method of snow depth estimation with repeat-pass InSAR measurements was proposed, and a preliminary sensitivity analysis of snow phase changes versus the incident angle and snow density was developed. Moreover, the snow density and incident angle parameters were analyzed and calibrated, and the local incident angle was used as a substitute for the satellite incident angle to improve the snow depth estimation. From the results, the coherence images showed that a high degree of coherence can be found for dry snow, and, apart from the effect of snow, land use/cover change due to a long temporal baseline and geometric distortion due to the rugged terrain were the main constraints for InSAR technique to measure snow depth and SWE in this area. The result of snow depth estimation between July 2008 and February 2009 demonstrated that the average snow depth was about 20 cm, which was consistent with the field survey results. The areal coverage of snow distribution estimated from the snow depth and SWE results was consistent with snow cover obtained from HJ-1A CCD optical data at the same time.

  10. Using "residual depths" to monitor pool depths independently of discharge

    Science.gov (United States)

    Thomas E. Lisle

    1987-01-01

    As vital components of habitat for stream fishes, pools are often monitored to follow the effects of enhancement projects and natural stream processes. Variations of water depth with discharge, however, can complicate monitoring changes in the depth and volume of pools. To subtract the effect of discharge on depth in pools, residual depths can be measured. Residual...

  11. User’s manual for the Automated Data Assurance and Management application developed for quality control of Everglades Depth Estimation Network water-level data

    Science.gov (United States)

    Petkewich, Matthew D.; Daamen, Ruby C.; Roehl, Edwin A.; Conrads, Paul

    2016-09-29

    The generation of Everglades Depth Estimation Network (EDEN) daily water-level and water-depth maps is dependent on high quality real-time data from over 240 water-level stations. To increase the accuracy of the daily water-surface maps, the Automated Data Assurance and Management (ADAM) tool was created by the U.S. Geological Survey as part of Greater Everglades Priority Ecosystems Science. The ADAM tool is used to provide accurate quality-assurance review of the real-time data from the EDEN network and allows estimation or replacement of missing or erroneous data. This user’s manual describes how to install and operate the ADAM software. File structure and operation of the ADAM software is explained using examples.

  12. Plasticity in the Huber value contributes to homeostasis in leaf water relations of a mallee Eucalypt with variation to groundwater depth.

    Science.gov (United States)

    Carter, Jennifer L; White, Donald A

    2009-11-01

    Information on how vegetation adapts to differences in water supply is critical for predicting vegetation survival, growth and water use, which, in turn, has important impacts on site hydrology. Many field studies assess adaptation to water stress by comparing between disparate sites, which makes it difficult to distinguish between physiological or morphological changes and long-term genetic adaptation. When planting trees into new environments, the phenotypic adaptations of a species to water stress will be of primary interest. This study examined the response to water availability of Eucalyptus kochii ssp. borealis (C. Gardner) D. Nicolle, commonly integrated with agriculture in south-western Australia for environmental and economic benefits. By choosing a site where the groundwater depth varied but where climate and soil type were the same, we were able to isolate tree response to water supply. Tree growth, leaf area and stand water use were much larger for trees over shallow groundwater than for trees over a deep water table below a silcrete hardpan. However, water use on a leaf area basis was similar in trees over deep and shallow groundwater, as were the minimum leaf water potential observed over different seasons and the turgor loss point. We conclude that homeostasis in leaf water use and water relations was maintained through a combination of stomatal control and adjustment of sapwood-to-leaf area ratios (Huber value). Differences in the Huber value with groundwater depth were associated with different sapwood-specific conductivity and water use on a sapwood area basis. Knowledge of the coordination between water supply, leaf area, sapwood area and leaf transpiration rate for different species will be important when predicting stand water use.

  13. The Influence of Prosodic Stress Patterns and Semantic Depth on Novel Word Learning in Typically Developing Children

    Science.gov (United States)

    Gladfelter, Allison; Goffman, Lisa

    2013-01-01

    The goal of this study was to investigate the effects of prosodic stress patterns and semantic depth on word learning. Twelve preschool-aged children with typically developing speech and language skills participated in a word learning task. Novel words with either a trochaic or iambic prosodic pattern were embedded in one of two learning…

  14. Discovering Optimum Method to Extract Depth Information for Nearshore Coastal Waters from SENTINEL-2A - Case Study: Nayband Bay, Iran

    Science.gov (United States)

    Kabiri, K.

    2017-09-01

    The capabilities of Sentinel-2A imagery to determine bathymetric information in shallow coastal waters were examined. In this regard, two Sentinel-2A images (acquired on February and March 2016 in calm weather and relatively low turbidity) were selected from Nayband Bay, located in the northern Persian Gulf. In addition, a precise and accurate bathymetric map for the study area were obtained and used for both calibrating the models and validating the results. Traditional linear and ratio transform techniques, as well as a novel integrated method, were employed to determine depth values. All possible combinations of the three bands (Band 2: blue (458-523 nm), Band 3: green (543-578 nm), and Band 4: red (650-680 nm), spatial resolution: 10 m) have been considered (11 options) using the traditional linear and ratio transform techniques, together with 10 model options for the integrated method. The accuracy of each model was assessed by comparing the determined bathymetric information with field measured values. The correlation coefficients (R2), and root mean square errors (RMSE) for validation points were calculated for all models and for two satellite images. When compared with the linear transform method, the method employing ratio transformation with a combination of all three bands yielded more accurate results (R2Mac = 0.795, R2Feb = 0.777, RMSEMac = 1.889 m, and RMSEFeb =2.039 m). Although most of the integrated transform methods (specifically the method including all bands and band ratios) have yielded the highest accuracy, these increments were not significant, hence the ratio transformation has selected as optimum method.

  15. INFLUENCE OF CLIMATE CHANGES ON WATER RESOURCES IN MOLDOVA

    Directory of Open Access Journals (Sweden)

    Violeta Ivanov

    2012-06-01

    Full Text Available The paper aims to analyze the current state of affairs with water resources in Moldova, the challenges it faces for its national human and economic development, having in mind that the water resources are quite limited in Moldova, which encounters pollution, degradation influenced by climate change and unwise human activity to their biodiversity and ecosystems, availability and accessibility. It also attempts to highlight the relationship between climate change and water resources in Moldova, which has adverse effects on both environment and people’s health, and raise significant hurdles to the international, regional and sectoral development.

  16. Estimation of the depth to the fresh-water/salt-water interface from vertical head gradients in wells in coastal and island aquifers

    Science.gov (United States)

    Izuka, Scot K.; Gingerich, Stephen B.

    An accurate estimate of the depth to the theoretical interface between fresh, water and salt water is critical to estimates of well yields in coastal and island aquifers. The Ghyben-Herzberg relation, which is commonly used to estimate interface depth, can greatly underestimate or overestimate the fresh-water thickness, because it assumes no vertical head gradients and no vertical flow. Estimation of the interface depth needs to consider the vertical head gradients and aquifer anisotropy that may be present. This paper presents a method to calculate vertical head gradients using water-level measurements made during drilling of a partially penetrating well; the gradient is then used to estimate interface depth. Application of the method to a numerically simulated fresh-water/salt-water system shows that the method is most accurate when the gradient is measured in a deeply penetrating well. Even using a shallow well, the method more accurately estimates the interface position than does the Ghyben-Herzberg relation where substantial vertical head gradients exist. Application of the method to field data shows that drilling, collection methods of water-level data, and aquifer inhomogeneities can cause difficulties, but the effects of these difficulties can be minimized. Résumé Une estimation précise de la profondeur de l'interface théorique entre l'eau douce et l'eau salée est un élément critique dans les estimations de rendement des puits dans les aquifères insulaires et littoraux. La relation de Ghyben-Herzberg, qui est habituellement utilisée pour estimer la profondeur de cette interface, peut fortement sous-estimer ou surestimer l'épaisseur de l'eau douce, parce qu'elle suppose l'absence de gradient vertical de charge et d'écoulement vertical. L'estimation de la profondeur de l'interface requiert de prendre en considération les gradients verticaux de charge et l'éventuelle anisotropie de l'aquifère. Cet article propose une méthode de calcul des

  17. Influence of the kind of peat and the depth of sampling on the biochemical properties of Tagan peatland

    Science.gov (United States)

    Wojciech Szajdak, Lech; Inisheva, Lydia I.

    2010-05-01

    The upper layer of a peat bog in which organic matter decomposes aerobically much more rapidly than in the underlying, anaerobic catotelm. As litter accumulates at the surface the size of the catotelm increases, because the thickness of the acrotelm is limited to depth at which aerobic respiration can occur. Although the rate of decomposition per unit volume of material is much greater in the acrotelm than in the catotelm, a point is reached at which the difference in volume between the two layers is such that the total rate of decomposition in the catotelm is equal to that in the acrotelm. This limits the thickness to which the bog can grow. Should there be a climate change (e.g. an increase in precipitation) growth can resume. Bogs therefore preserve a record of climatic conditions. Soils samples were taken from four places marked as No 1, 2, 3 and 4 each from two depth 0-25 and 50-75 cm of the peatland Tagan. Peatlands Tagan is located near Tomsk, West Siberia, Russia. Place No 1 in both layers represents grasses peat with the degree of the decomposition ranged from 25 to 35% (pH 6.31-7.95). Point 2 is characterized by wooden and wooden grasses peat with 35% degree of the decomposition (pH 5.16-9.31. There is buckbean peat in the points 3 and 4 (pH 6.4-6.49). However, 1.5 m depth of sapropel is located in point 4. The activity of the following enzymes: xanthine oxidase, phenolic oxidase, peroxidase, urease, nitrate reductase were measured and two forms of organic carbon (total organic carbon and dissolved organic carbon) and two form of iron Fe(II) and Fe(III) were determined in these samples. These enzymes participate in several biochemical pathways in soil connected with redox potential. The concentrations of indole-3-acetic acid, very famous fitohormone were also measured. It was observed in all places of sampling significant increase of the total organic carbon with an increase of the depth. However, the quantity of dissolved organic carbon closely decreased

  18. Influence of Water Content on Pullout Behaviour of Geogrid

    Science.gov (United States)

    Chen, Rong; Song, Yang-yang; Hao, Dong-xue; Gao, Yu-cong

    2017-06-01

    The interaction between geogrid and soil is fundamental and crucial factor on safety and stability of geogrid-reinforced earth structure. Therefore, the interface index between geogrid and soil is of vital importance in the design of reinforced earth structures. The pullout behaviour of geogrid in soil is studied, an experimental investigation is conducted using geogrid in four groups of soil with 20%, 24%, 28%, 32% water contents, which correspond to normal stresses of 50, 100, 200 and 300 kPa respectively. The results indicate that the geogrid embedded in soil mainly represents pullout failure, and the ultimate pullout force is sensitive to water content. It decreases with the increase of the water content firstly. Besides, the water content influences the process of the pullout behaviour. The increase of water content leads to the ultimate pullout force soon.

  19. In vivo confocal Raman microscopic determination of depth profiles of the stratum corneum lipid organization influenced by application of various oils.

    Science.gov (United States)

    Choe, ChunSik; Schleusener, Johannes; Lademann, Jürgen; Darvin, Maxim E

    2017-08-01

    The intercellular lipids (ICL) of stratum corneum (SC) play an important role in maintaining the skin barrier function. The lateral and lamellar packing order of ICL in SC is not homogenous, but rather depth-dependent. This study aimed to analyze the influence of the topically applied mineral-derived (paraffin and petrolatum) and plant-derived (almond oil and jojoba oil) oils on the depth-dependent ICL profile ordering of the SC in vivo. Confocal Raman microscopy (CRM), a unique tool to analyze the depth profile of the ICL structure non-invasively, is employed to investigate the interaction between oils and human SC in vivo. The results show that the response of SC to oils' permeation varies in the depths. All oils remain in the upper layers of the SC (0-20% of SC thickness) and show predominated differences of ICL ordering from intact skin. In these depths, skin treated with plant-derived oils shows more disordered lateral and lamellar packing order of ICL than intact skin (poils do not influence the lateral packing order of SC ICL (p>0.1), except plant-derived oils at the depth 30% of SC thickness. In the deeper layers of the SC (60-100% of SC thickness), no difference between ICL lateral packing order of the oil-treated and intact skin can be observed, except that at the depths of 70-90% of the SC thickness, where slight changes with more disorder states are measured for plant-derived oil treated skin (poil types remain in the superficial layers of the SC (0-20% of the SC thickness). Skin treated with mineral- and plant-derived oils shows significantly higher disordered lateral and lamellar packing order of ICL in these layers of the SC compared to intact skin. Plant-derived oils significantly changed the ICL ordering in the depths of 30% and 70-90% of the SC thickness, which is likely due to the penetration of free fatty acids in the deeper layers of the SC. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights

  20. Influence of water waves on hyperspectral remote sensing of subsurface water features

    Science.gov (United States)

    Bostater, Charles R., Jr.; Bassetti, Luce

    2004-11-01

    Modeled hyperspectral reflectance signatures with water wave influences are simulated using an analytical-based, iterative radiative transport model applicable to shallow or deep waters. Light transport within the water body is simulated using a fast, accurate radiative transfer model that calculates the light distribution in any layered media and incorporates realistic water surfaces which are synthesized using empirically-based spectral models of the water surface to generate water surface wave facets. The model simulated synthetic images are displayed as 24 bit RGB images of the water surface using selected channels from the simulated synthetic hyperspectral image cube. We show selected channels centered at 490, 530 and 676 nm. We also demonstrate the use of the model to show the capability of the sensor and image modeling approach to detect or "recover" known features or targets submerged within or on the shallow water bottom in a tidal inlet area in Indian River Lagoon, Florida. Line targets are simulated in shallow water and indicate the influence of water waves in different water quality conditions. The technique demonstrates a methodology to help to develop remote sensing protocols for shallow water remote sensing as well as to develop information useful for future hyperspectral sensor system developments.

  1. The influence of nitrogen and defoliation on production and water ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the influence of different nitrogen fertiliser application levels in combination with different defoliation intervals on the dry matter (DM) production and water-use efficiency of ryegrass (Lolium multiflorum) cv. Midmar. In a field trial, four nitrogen levels (0, 150, 300 and 450kg N ha-1) ...

  2. Ecotoxicology of waters under the influence of a petrochemical complex

    Energy Technology Data Exchange (ETDEWEB)

    Noll, R.; Zandonai, V.; Ries, M.A. [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petrquimico do Sul

    1993-12-31

    This work summarizes the regular monitoring and studies conducted by SITEL - The Integrated Wastewater Treatment System of South Petrochemical Complex (South Brazil) - in order to evaluate the full environmental impact on waters in the area of influence of the effluents of the above mentioned Complex. 8 refs., 1 fig., 5 tabs.

  3. Surface water assessment on the influence of space distribution on ...

    African Journals Online (AJOL)

    In this work, the influence of space distribution on physico-chemical parameters of refinery effluent discharge has been studied, using treated effluent water discharged from the Port Harcourt Refinery Company (PHRC) into the Ekerekana Creek in Okrika as reference. Samples were collected at surface level from the ...

  4. Soil water and mineral nitrogen content as influenced by crop ...

    African Journals Online (AJOL)

    ) and wheat–medic rotation (McWMcW) and tillage, conventional-till (CT), minimum-till (MT), no-till (NT) and zero-till (ZT) were studied. Crop rotation did not influence soil moisture content. Soil water content in CT tended to be lower compared ...

  5. Environment influence on water characteristics of soils in two semi ...

    African Journals Online (AJOL)

    Environment influence on water characteristics of soils in two semi-arid catchments in Laikipia, Kenya. G Kironchi, SM Kinyali, JP Mbuvi. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Article Metrics. Metrics Loading ... Metrics ...

  6. Decentralised water systems: emotional influences on resource decision making.

    Science.gov (United States)

    Mankad, Aditi

    2012-09-01

    The study of emotion has gathered momentum in the field of environmental science, specifically in the context of community resource decision-making. Of particular interest in this review is the potential influence of emotion, risk and threat perception on individuals' decisions to acceptance and adopt decentralised water systems, such as rainwater tanks and greywater systems. The role of message framing is also considered in detail, as well as the influences that different types of framing can have on decision making. These factors are considered as possible predictors for analysing community acceptance of decentralised water in urban environments. Concepts believed to be influenced by emotion, such as trust and framing, are also discussed as potentially meaningful contributors to an overall model of community acceptance of decentralised water. Recommendations are made for how emotion-based concepts, such as risk and threat, can be targeted to facilitate widespread adoption of decentralised systems and how researchers can explore different types of emotions that influence decision making in distinct ways. This review is an important theoretical step in advancing the psycho-social understanding of acceptance and adoption of on-site water sources. Avenues for future research are recommended, including the need for greater theoretical development to encourage future social science research on decentralised systems. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  7. Influence of discharged effluent on the quality of surface water ...

    African Journals Online (AJOL)

    This article reports on the level of toxic trace metals (Cd, Pb, Mn, Zn, Cu and Ni) in surface water and sediment along the Blaauwbankspruit in the West Rand District of South Africa. This spruit serves as receiving channel of wastewaters from sewage treatment plant and a gold mine. Some physical and chemical influences ...

  8. Influence of water air content on cavitation erosion in distilled water

    CSIR Research Space (South Africa)

    Auret, JG

    1993-12-01

    Full Text Available The influence of increased air content of the cavitating liquid (distilled water) was studied in a rotating disk test rig. A rise in the total air content including dissolved and entrained air of the water in the under saturated range resulted...

  9. Calibrating water depths of Ordovician communities: lithological and ecological controls on depositional gradients in Upper Ordovician strata of southern Ohio and north-central Kentucky, USA

    Directory of Open Access Journals (Sweden)

    Carlton E. Brett

    2015-02-01

    Full Text Available Limestone and shale facies of the Upper Ordovician Grant Lake Formation (Katian: Cincinnatian, Maysvillian are well exposed in the Cincinnati Arch region of southern Ohio and north-central Kentucky, USA. These rocks record a gradual change in lithofacies and biofacies along a gently northward-sloping ramp. This gradient spans very shallow, olive-gray, platy, laminated dolostones with sparse ostracodes in the south to offshore, nodular, phosphatic, brachiopod-rich limestones and marls in the north. This study uses facies analysis in outcrop to determine paleoenvironmental parameters, particularly those related to water depth (e.g., position of the photic zone and shoreline, relative degree of environmental energy. Within a tightly correlated stratigraphic interval (the Mount Auburn and Straight Creek members of the Grant Lake Formation and the Terrill Member of the Ashlock Formation, we document the occurrence of paleoenvironmental indicators, including desiccation cracks and light-depth indicators, such as red and green algal fossils and oncolites. This permitted recognition of a ramp with an average gradient of 10–20 cm water depth per horizontal kilometer. Thus, shallow subtidal (“lagoonal” deposits in the upramp portion fall within the 1.5–6 m depth range, cross-bedded grainstones representing shoal-type environments fall within the 6–18 m depth range and subtidal, shell-rich deposits in the downramp portion fall within the 20–30 m depth range. These estimates match interpretations of depth independently derived from faunal and sedimentologic evidence that previously suggested a gentle ramp gradient and contribute to ongoing and future high-resolution paleontologic and stratigraphic studies of the Cincinnati Arch region.

  10. Quantifying the influence of environmental and water conservation attitudes on household end use water consumption.

    Science.gov (United States)

    Willis, Rachelle M; Stewart, Rodney A; Panuwatwanich, Kriengsak; Williams, Philip R; Hollingsworth, Anna L

    2011-08-01

    Within the research field of urban water demand management, understanding the link between environmental and water conservation attitudes and observed end use water consumption has been limited. Through a mixed method research design incorporating field-based smart metering technology and questionnaire surveys, this paper reveals the relationship between environmental and water conservation attitudes and a domestic water end use break down for 132 detached households located in Gold Coast city, Australia. Using confirmatory factor analysis, attitudinal factors were developed and refined; households were then categorised based on these factors through cluster analysis technique. Results indicated that residents with very positive environmental and water conservation attitudes consumed significantly less water in total and across the behaviourally influenced end uses of shower, clothes washer, irrigation and tap, than those with moderately positive attitudinal concern. The paper concluded with implications for urban water demand management planning, policy and practice. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  11. Effect of the spatial distribution of physical aquifer properties on modelled water table depth and stream discharge in a headwater catchment

    Directory of Open Access Journals (Sweden)

    C. Gascuel-Odoux

    2010-07-01

    Full Text Available Water table depth and its dynamics on hillslopes are often poorly predicted despite they control both water transit time within the catchment and solute fluxes at the catchment outlet. This paper analyses how relaxing the assumption of lateral homogeneity of physical properties can improve simulations of water table depth and dynamics. Four different spatial models relating hydraulic conductivity to topography have been tested: a simple linear relationship, a linear relationship with two different topographic indexes, two Ks domains with a transitional area. The Hill-Vi model has been modified to test these hypotheses. The studied catchment (Kervidy-Naizin, Western France is underlain by schist crystalline bedrock. A shallow and perennial groundwater highly reactive to rainfall events mainly develops in the weathered saprolite layer. The results indicate that (1 discharge and the water table in the riparian zone are similarly predicted by the four models, (2 distinguishing two Ks domains constitutes the best model and slightly improves prediction of the water table upslope, and (3 including spatial variations in the other parameters such as porosity or rate of hydraulic conductivity decrease with depth does not improve the results. These results underline the necessity of better investigations of upslope areas in hillslope hydrology.

  12. Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

    Science.gov (United States)

    Agudelo-Vera, Claudia M.; Blokker, Mirjam; de Kater, Henk; Lafort, Rob

    2017-09-01

    The water temperature in the drinking water distribution system and at customers' taps approaches the surrounding soil temperature at a depth of 1 m. Water temperature is an important determinant of water quality. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at customers' taps is not allowed to exceed 25 °C. In recent decades, the urban (sub)surface has been getting more occupied by various types of infrastructures, and some of these can be heat sources. Only recently have the anthropogenic sources and their influence on the underground been studied on coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Routine water quality samples at the tap in urban areas have shown up locations - so-called hotspots - in the city, with relatively high soil temperatures - up to 7 °C warmer - compared to the soil temperatures in the surrounding rural areas. Yet the sources and the locations of these hotspots have not been identified. It is expected that with climate change during a warm summer the soil temperature in the hotspots can be above 25 °C. The objective of this paper is to find a method to identify heat sources and urban characteristics that locally influence the soil temperature. The proposed method combines mapping of urban anthropogenic heat sources, retrospective modelling of the soil temperature, analysis of water temperature measurements at the tap, and extensive soil temperature measurements. This approach provided insight into the typical range of the variation of the urban soil temperature, and it is a first step to identifying areas with potential underground heat stress towards thermal underground management in cities.

  13. Influence of water quality on the embodied energy of drinking water treatment.

    Science.gov (United States)

    Santana, Mark V E; Zhang, Qiong; Mihelcic, James R

    2014-01-01

    Urban water treatment plants rely on energy intensive processes to provide safe, reliable water to users. Changes in influent water quality may alter the operation of a water treatment plant and its associated energy use or embodied energy. Therefore the objective of this study is to estimate the effect of influent water quality on the operational embodied energy of drinking water, using the city of Tampa, Florida as a case study. Water quality and water treatment data were obtained from the David L Tippin Water Treatment Facility (Tippin WTF). Life cycle energy analysis (LCEA) was conducted to calculate treatment chemical embodied energy values. Statistical methods including Pearson's correlation, linear regression, and relative importance were used to determine the influence of water quality on treatment plant operation and subsequently, embodied energy. Results showed that influent water quality was responsible for about 14.5% of the total operational embodied energy, mainly due to changes in treatment chemical dosages. The method used in this study can be applied to other urban drinking water contexts to determine if drinking water source quality control or modification of treatment processes will significantly minimize drinking water treatment embodied energy.

  14. Hydrologic regulation of plant rooting depth

    Science.gov (United States)

    Fan, Ying; Miguez-Macho, Gonzalo; Jobbágy, Esteban G.; Jackson, Robert B.; Otero-Casal, Carlos

    2017-10-01

    Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observations of >1,000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients. Results reveal strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). In well-drained uplands, rooting depth follows infiltration depth; in waterlogged lowlands, roots stay shallow, avoiding oxygen stress below the water table; in between, high productivity and drought can send roots many meters down to the groundwater capillary fringe. This framework explains the contrasting rooting depths observed under the same climate for the same species but at distinct topographic positions. We assess the global significance of these hydrologic mechanisms by estimating root water-uptake depths using an inverse model, based on observed productivity and atmosphere, at 30″ (˜1-km) global grids to capture the topography critical to soil hydrology. The resulting patterns of plant rooting depth bear a strong topographic and hydrologic signature at landscape to global scales. They underscore a fundamental plant-water feedback pathway that may be critical to understanding plant-mediated global change.

  15. Influence of the unfrozen magnetized water on juices

    Directory of Open Access Journals (Sweden)

    K. Mikhaylova

    2017-12-01

    Full Text Available Influence of magnetic field on water has been described in the paper. The patented device constructed on the basis of a stator of three-phase asynchronous motor has been used for processing of water in the experiments.It has been found that the water, processed in the electromagnetic field contains less mineral salts, has bigger cell permeability, and is characterized by falling of reduction-oxidation potential, and also by decreasing of electromotive force of the system. Electro physical indices may be used for rapid estimation of sanitary effect of water which is processed in the rotating magnetic field, and it is used for dilution of fresh-squeezed juices. Such juices have more positive action on a human body in comparison with non-diluted ones.The electromotive force of the system, which correlated with the value of reduction-oxidation potential of the system, has been measured. The decreasing of electromotive force confirms the sanitary effect of pure magnetized water, as well as the mix of fresh-squeezed juices with magnetized water. One of the main disadvantages, which interferes with wide introduction of magnetized water into the institutions, which are not equipped with special equipment, is the gradual loss of the obtained by the water properties with time. The results of the investigation show that the water threatened by electro magnetic field after freezing, low-temperature storage, and defrosting, preserves the obtained properties for a long time. It has been shown in the paper, that application of defrosted magnetic water for germination of seeds accelerates the processes of growth. Diluting of juices, such as apple, carrot, beat, and ash berry ones, by magnetized water, reduce of electro physical indices.

  16. Effects of soil temperature and depth to ground water on first-year growth of a dryland riparian phreatophyte, Glycyrrhiza lepidota (American licorice)

    Science.gov (United States)

    Andersen, Douglas C.; Nelson, S. Mark

    2014-01-01

    We investigated the effects of soil temperature and depth to ground water on first-year growth of a facultative floodplain phreatophyte, Glycyrrhiza lepidota, in a 2-×-2 factorial greenhouse experiment. We grew plants in mesocosms subirrigated with water low in dissolved oxygen, mimicking natural systems, and set depth of ground water at 63 or 100 cm and soil temperature at cold (ambient) or warm (≤2.7°C above ambient). We hypothesized the moister (63 cm) and warmer soil would be most favorable and predicted faster growth of shoots and roots and greater nitrogen-fixation (thus, less uptake of mineral nitrogen) under those conditions. Growth in height was significantly faster in the moister treatment but was not affected by soil temperature. Final biomass of shoots and of roots, total biomass of plants, and root:shoot ratio indicated a significant effect only from depth of ground water. Final levels of soil mineral-nitrogen were as predicted, with level of nitrate in the moister treatment more than twice that in the drier treatment. No effect from soil temperature on level of soil-mineral nitrogen was detected. Our results suggest that establishment of G. lepidotarequires strict conditions of soil moisture, which may explain the patchy distribution of the species along southwestern dryland rivers.

  17. Maps showing predicted probabilities for selected dissolved oxygen and dissolved manganese threshold events in depth zones used by the domestic and public drinking water supply wells, Central Valley, California

    Science.gov (United States)

    Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, JoAnn M.

    2018-01-31

    The purpose of the prediction grids for selected redox constituents—dissolved oxygen and dissolved manganese—are intended to provide an understanding of groundwater-quality conditions at the domestic and public-supply drinking water depths. The chemical quality of groundwater and the fate of many contaminants is influenced by redox processes in all aquifers, and understanding the redox conditions horizontally and vertically is critical in evaluating groundwater quality. The redox condition of groundwater—whether oxic (oxygen present) or anoxic (oxygen absent)—strongly influences the oxidation state of a chemical in groundwater. The anoxic dissolved oxygen thresholds of water, making drinking water undesirable with respect to taste, staining, or scaling. Three dissolved manganese thresholds, water wells. The 50 µg/L event threshold represents the secondary maximum contaminant level (SMCL) benchmark for manganese (U.S. Environmental Protection Agency, 2017; California Division of Drinking Water, 2014), whereas the 300 µg/L event threshold represents the U.S. Geological Survey (USGS) health-based screening level (HBSL) benchmark, used to put measured concentrations of drinking-water contaminants into a human-health context (Toccalino and others, 2014). The 150 µg/L event threshold represents one-half the USGS HBSL. The resultant dissolved oxygen and dissolved manganese prediction grids may be of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions. Prediction grids for selected redox constituents and thresholds were created by the USGS National Water-Quality Assessment (NAWQA) modeling and mapping team.

  18. Influence of a water regulation event on the age of Yellow River water in the Bohai

    Science.gov (United States)

    Li, Zhen; Wang, Haiyan; Guo, Xinyu; Liu, Zhe; Gao, Huiwang; Zhang, Guiling

    2017-10-01

    Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled using constituent-oriented age and residence time theory to better understand the change in the environmental function of the hydrodynamic field owing to human activities. The water ages in Laizhou Bay, the central basin, and the Bohai strait are sensitive to water regulation. The surface ages in those areas can decrease by about 300 days, particularly in July, and the age stratification is also strengthened. A water regulation event can result in declines in the water age in early July ahead of declines in the water age under climatological conditions (without the regulation event) by about 1 and 5 months in the central basin and Laizhou Bay, respectively. The change in the coastal circulation due to the water regulation event is the primary reason for the change in the Yellow River water age. The high Yellow River flow rate can enhance the density flow and, therefore, reduce the age of the Yellow River water. The subsequent impact of a single water regulation event can last about 1.0 to 4.0 years in different subregions.

  19. Assimilation of snow cover and snow depth into a snow model to estimate snow water equivalent and snowmelt runoff in a Himalayan catchment

    Directory of Open Access Journals (Sweden)

    E. E. Stigter

    2017-07-01

    Full Text Available Snow is an important component of water storage in the Himalayas. Previous snowmelt studies in the Himalayas have predominantly relied on remotely sensed snow cover. However, snow cover data provide no direct information on the actual amount of water stored in a snowpack, i.e., the snow water equivalent (SWE. Therefore, in this study remotely sensed snow cover was combined with in situ observations and a modified version of the seNorge snow model to estimate (climate sensitivity of SWE and snowmelt runoff in the Langtang catchment in Nepal. Snow cover data from Landsat 8 and the MOD10A2 snow cover product were validated with in situ snow cover observations provided by surface temperature and snow depth measurements resulting in classification accuracies of 85.7 and 83.1 % respectively. Optimal model parameter values were obtained through data assimilation of MOD10A2 snow maps and snow depth measurements using an ensemble Kalman filter (EnKF. Independent validations of simulated snow depth and snow cover with observations show improvement after data assimilation compared to simulations without data assimilation. The approach of modeling snow depth in a Kalman filter framework allows for data-constrained estimation of snow depth rather than snow cover alone, and this has great potential for future studies in complex terrain, especially in the Himalayas. Climate sensitivity tests with the optimized snow model revealed that snowmelt runoff increases in winter and the early melt season (December to May and decreases during the late melt season (June to September as a result of the earlier onset of snowmelt due to increasing temperature. At high elevation a decrease in SWE due to higher air temperature is (partly compensated by an increase in precipitation, which emphasizes the need for accurate predictions on the changes in the spatial distribution of precipitation along with changes in temperature.

  20. Development of inferential sensors for real-time quality control of water-level data for the Everglades Depth Estimation Network

    Science.gov (United States)

    Daamen, Ruby C.; Edwin A. Roehl, Jr.; Conrads, Paul

    2010-01-01

    The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level gaging stations, ground-elevation models, and watersurface models designed to provide scientists, engineers, and water-resource managers with current (2000-present) water-depth information for the entire freshwater portion of the greater Everglades. The generation of EDEN waterlevel surfaces is derived from real-time data. Real-time data are automatically checked for outliers using minimum, maximum, and rate-of-change thresholds for each station. Smaller errors in the real-time data, such as gradual drift of malfunctioning pressure transducers, are more difficult to immediately identify with visual inspection of time-series plots and may only be identified during on-site inspections of the gages. Correcting smaller errors in the data often is time consuming and water-level data may not be finalized for several months. To provide water-level surfaces on a daily basis, EDEN needed an automated process to identify errors in water-level data and to provide estimates for missing or erroneous waterlevel data.

  1. Using ground penetrating radar to investigate the water table depth in weathered granites : Sardon case study, Spain

    NARCIS (Netherlands)

    Mahmoudzadeh, M.R.; Frances, A.P.; Lubczynski, M.; Lambot, S.

    2012-01-01

    Precise and non-invasive measurement of groundwater depth is essential to support management of groundwater resources. In that respect, GPR is a promising tool for high resolution, large scale characterization and monitoring of hydrological systems. We applied GPR in a semi-arid catchment (Sardon,

  2. Influence of teleconnection on water quality in agricultural river catchments

    Science.gov (United States)

    Mellander, Per-Erik; Jordan, Phil; Shore, Mairead; McDonald, Noeleen; Shortle, Ger

    2015-04-01

    Influences such as weather, flow controls and lag time play an important role in the processes influencing the water quality of agricultural catchments. In particular weather signals need to be clearly considered when interpreting the effectiveness of current measures for reducing nitrogen (N) and phosphorus (P) losses from agricultural sources to water bodies. In north-western Europe weather patterns and trends are influenced by large-scale systems such as the North Atlantic Oscillation (NAO) and the position of the Gulf Stream, the latter expressed as the Gulf Stream North Wall index (GSNW index). Here we present five years of monthly data of nitrate-N concentration in stream water and groundwater (aggregated from sub-hourly monitoring in the stream outlet and monthly sampling in multilevel monitoring wells) from four agricultural catchments (ca. 10 km2) together with monitored weather parameters, long-term weather data and the GSNW index. The catchments are situated in Ireland on the Atlantic seaboard and are susceptible to sudden and seasonal shifts in oceanic climate patterns. Rain anomalies and soil moisture deficit dynamics were similar to the dynamics of the GSNW index. There were monitored changes in nitrate-N concentration in both groundwater and surface water with no apparent connection to agricultural management; instead such changes also appeared to follow the GSNW index. For example, in catchments with poorly drained soils and a 'flashy hydrology' there were seasonal dynamics in nitrate-N concentration that correlated with the seasonal dynamics of the GSNW index. In a groundwater driven catchment there was a consistent increase in nitrate-N concentration over the monitored period which may be the result of increasingly more recharge in summer and autumn (as indicated by more flux in the GSNW index). The results highlight that the position of the Gulf Stream may influence the nitrate-N concentration in groundwater and stream water and there is a risk

  3. Effect of Water Depth on the Underwater Wet Welding of Ferritic Steels Using Austenitic Ni-Based Alloy Electrodes

    National Research Council Canada - National Science Library

    Sheakley, Brian

    2000-01-01

    ...), slag inclusions, oxide inclusions, and porosity. To avoid underbead cracking three weld samples were made using an austenitic nickel weld metal with an Oxylance coating at 10 feet of salt water, 25 feet of salt water, and 33 feet of salt water...

  4. Ground-Penetrating-Radar Profiles of Interior Alaska Highways: Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost

    Science.gov (United States)

    2016-08-01

    Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost Co ld R eg io ns R es ea rc h an d En...within the discontinuous permafrost zone ............................................................. 7 4 (A) 1958 surficial geology map (Péwé...looking north and reveals that the valley walls are not steep. Figure 4. (A) 1958 surficial geology map (Péwé 1958) showing that the Elliott

  5. Mathematical simulation of water biological macrosystems dynamics accounting antropogenical influence

    Energy Technology Data Exchange (ETDEWEB)

    Janchauskas, R. (Institute of Mathematics and Informatics, Akademijos 4, Vilnius, Lithuania (SU)); Shvitra, D. (Centre of Ecosystem Analysis, Klaipeda, Lithuania (SU))

    1991-01-01

    Kursiu bay is subject to more powerful antropogenical influence in present time. There are many dangerous to biota toxicants, which may cause changes of the chemical structure of the water such as pH, gas regime and so on. We used the model experiments to evaluate the level of the danger of such toxicants and to define the limits of antropogenical influence. It is extremly important to define objective laws of the parameters dynamic to save one. The toxicants of organical nature are utilised not long after, so heavy metals remain harmful to a great extent longer. Our purpose is to define maximum relatively safe concentrations of some toxicants. We shall consider the most common toxicants - heavy metals Cd, Cr, Cu, Zn and chlorine as the main factors influencing Kursiu bay ecosystem. The biological macrosystem we investigated, consists of the populations, essential for the ecosystem of the bay. The main attention we shall devote to simulation of ichthyocenosis. (author).

  6. Importance of depth and intensity of convection on the isotopic composition of water vapor as seen from IASI and TES δD observations

    Science.gov (United States)

    Lacour, Jean-Lionel; Risi, Camille; Worden, John; Clerbaux, Cathy; Coheur, Pierre-François

    2018-01-01

    We use tropical observations of the water vapor isotopic composition, derived from IASI and TES spaceborne measurements, to show that the isotopic composition of water vapor in the free troposphere is sensitive to both the depth and the intensity of convection. We find that for any given precipitation intensity, vapor associated with deep convection is isotopically depleted relative to vapor associated with shallow convection. The intensity of precipitation also plays a role as for any given depth of convection, the relative enrichment of water vapor decreases as the intensity of precipitation increases. Shallow convection, via the uplifting of enriched boundary layer air into the free troposphere and the convective detrainment, enriches the free troposphere. In contrast, deep convection is associated with processes that deplete the water vapor in the free troposphere, such as rain re-evaporation. The results of this study allow for a better identification of the parameters controlling the isotopic composition of the free troposphere and indicate that the isotopic composition of water vapor can be used to evaluate the relative contributions of shallow and deep convection in global models.

  7. The influence of depth of focus on visibility of monocular head-mounted display symbology in simulation and training applications

    Science.gov (United States)

    Winterbottom, Marc D.; Patterson, Robert; Pierce, Byron J.; Covas, Christine; Winner, Jennifer

    2005-05-01

    The Joint Helmet Mounted Cueing System (JHMCS),is being considered for integration into the F-15, F-16, and F-18 aircraft. If this integration occurs, similar monocular head-mounted displays (HMDs) will need to be integrated with existing out-the-window simulator systems for training purposes. One such system is the Mobile Modular Display for Advanced Research and Training (M2DART), which is constructed with flat-panel rear-projection screens around a nominal eye-point. Because the panels are flat, the distance from the eye point to the display screen varies depending upon the location on the screen to which the observer is directing fixation. Variation in focal distance may create visibility problems for either the HMD symbology or the out-the-window imagery presented on the simulator rear-projection display screen because observers may not be able to focus both sets of images simultaneously. The extent to which blurring occurs will depend upon the difference between the focal planes of the simulator display and HMD as well as the depth of focus of the observer. In our psychophysical study, we investigated whether significant blurring occurs as a result of such differences in focal distances and established an optimal focal distance for an HMD which would minimize blurring for a range of focal distances representative of the M2DART. Our data suggest that blurring of symbology due to differing focal planes is not a significant issue within the range of distances tested and that the optimal focal distance for an HMD is the optical midpoint between the near and far rear-projection screen distances.

  8. Influence of Depth of Hypnosis on Pupillary Reactivity to a Standardized Tetanic Stimulus in Patients Under Propofol-Remifentanil Target-Controlled Infusion: A Crossover Randomized Pilot Study.

    Science.gov (United States)

    Sabourdin, Nada; Peretout, Jean-Baptiste; Khalil, Eliane; Guye, Marie-Laurence; Louvet, Nicolas; Constant, Isabelle

    2018-01-01

    Pupillometry allows the measurement of pupillary diameter variations in response to nociceptive stimuli. This technique has been used to monitor the balance between analgesia and nociception. Under general anesthesia, the amplitude of pupillary dilation is related to the amount of administered opioids. The objective of this study was to determine whether at a constant infusion rate of opioids, the pupillary response was influenced by depth of hypnosis assessed by the bispectral index (BIS). Twelve patients (14-20 years) anesthetized for orthopedic surgery were included. Under propofol-remifentanil target-controlled infusion, remifentanil effect site target concentration was fixed at 1 ng/mL. Two measures of pupillary reflex dilation were performed on each patient in a randomized order: one at BIS 55 and one at BIS 25. These levels of BIS were obtained by adjusting propofol target concentration and maintained for 10 minutes before each measure. For each measure, we applied a standardized tetanic stimulation on the patient's forearm (60 mA, 100 Hz, 5 seconds). All measures were performed before the beginning of surgery. Pupillary dilation was significantly greater at BIS 55 than at BIS 25: 32.1% ± 5.3% vs 10.4% ± 2.5% (mean difference estimate [95% confidence interval]: 21.8% [12.9-30.6], P constant infusion of remifentanil at a target concentration of 1 ng/mL, pupillary dilation after a standardized tetanic stimulation was influenced by depth of hypnosis assessed by the BIS.

  9. Influence of organobentonite structure on toluene adsorption from water solution

    Directory of Open Access Journals (Sweden)

    Nuria Vidal

    2012-12-01

    Full Text Available Due to increase water pollution by organic compound derived from hydrocarbons such as toluene, several alternative technologies for remediation of polluted water have been originated. In this work natural bentonites were modified with cetyltrimethylammonium (CTMA+ for obtaining organophilic bentonites. The obtained CTMA-bentonites would be suitable for use as adsorbents of toluene present in water. The influence of structural characteristics of CTMA-bentonites on their adsorption capacity was studied. It was shown that adsorption of toluene depended on homogeneous interlayer space associated with arrangements of CTMA+ paraffin-monolayer and bilayer models, accompanied by a high degree ordering of the carbon chain of organic cation in both arrangements. However, packing density would not have an evident influence on the retention capacity of these materials. The solids obtained were characterized by chemical analysis, X-ray diffractions and infrared spectroscopy. Toluene adsorption was measured by UV-visible spectrophotometer. Adsorption capacity was studied by determining adsorption isotherms and adsorption coefficient calculation. The adsorption isotherms were straight-line indicating a partition phenomenon of toluene between the aqueous and organic phase present in organophilic bentonites.

  10. Expansive Soil Crack Depth under Cumulative Damage

    Directory of Open Access Journals (Sweden)

    Bei-xiao Shi

    2014-01-01

    Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.

  11. Geographic setting influences Great Lakes beach microbiological water quality

    Science.gov (United States)

    Haack, Sheridan K.; Fogarty, Lisa R.; Stelzer, Erin A.; Fuller, Lori M.; Brennan, Angela K.; Isaacs, Natasha M.; Johnson, Heather E.

    2013-01-01

    Understanding of factors that influence Escherichia coli (EC) and enterococci (ENT) concentrations, pathogen occurrence, and microbial sources at Great Lakes beaches comes largely from individual beach studies. Using 12 representative beaches, we tested enrichment cultures from 273 beach water and 22 tributary samples for EC, ENT, and genes indicating the bacterial pathogens Shiga-toxin producing E. coli (STEC), Shigella spp., Salmonella spp, Campylobacter jejuni/coli, and methicillin-resistant Staphylococcus aureus, and 108–145 samples for Bacteroides human, ruminant, and gull source-marker genes. EC/ENT temporal patterns, general Bacteroides concentration, and pathogen types and occurrence were regionally consistent (up to 40 km), but beach catchment variables (drains/creeks, impervious surface, urban land cover) influenced exceedances of EC/ENT standards and detections of Salmonella and STEC. Pathogen detections were more numerous when the EC/ENT Beach Action Value (but not when the Geometric Mean and Statistical Threshold Value) was exceeded. EC, ENT, and pathogens were not necessarily influenced by the same variables. Multiple Bacteroides sources, varying by date, occurred at every beach. Study of multiple beaches in different geographic settings provided new insights on the contrasting influences of regional and local variables, and a broader-scale perspective, on significance of EC/ENT exceedances, bacterial sources, and pathogen occurrence.

  12. Influence of mine hydrogeology on mine water discharge chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Rees, S.B.; Bowell, R.J.; Wiseman, I. [SRK Consulting, Cardiff (United Kingdom)

    2002-10-01

    Using data for 18 coal mine discharges in the UK, the influence of discharge hydrogeology on discharge chemistry is assessed and typical chemical parameters derived for five discharge types. A combination of modified and new classification schemes is used to differentiate between the various discharge sources. Drainage from spoil tips generally has a pH below 5 and net-alkalinity values as low as -2500 mgl{sup -1} CaCO{sub 3}. Drainage from flooded workings and pumped discharges are net-alkaline, while drainage from flooded and free draining workings are either moderately net-alkaline or net-acidic. Iron is the major contaminant of concern, although many mine waters contain less than 30 mgl{sup -1} and Fe/SO{sub 4} ratios are less than unity. The classification schemes developed can be used to assess mine water treatment requirements and processes operating in passive treatment systems. 11 refs., 7 figs., 2 tabs.

  13. Watering regime influences Cd concentrations in cultivated spinach.

    Science.gov (United States)

    Tack, Filip M G

    2017-01-15

    In washed spinach, a maximum Cd concentration of 0.20 mg/kg fresh weight (FW) is allowed according to European regulations. Producers experience that this concentration can sometimes be exceeded even on soils with baseline Cd concentrations. There is a growing need to quantify the factors determining Cd uptake in the crop in order to anticipate the risk of exceedance when selecting a field for cultivation. Interseasonal variation in precipitation may be one of the factors influencing Cd uptake by crops. A pot experiment was set up where spinach plants were subject to different watering regimes. Treatment with more limited water supply during periods of high demand resulted in significantly higher accumulated Cd concentrations (0.25-0.31 versus 0.17-0.23 mg/kg FW). Concentrations at or above the maximum allowed limit were of concern, considering that the soil used in the experiment originated from a typical field in an agricultural region without any specific contamination. Probabilities to exceed maximum concentrations in the different watering regimes were estimated using Monte Carlo simulation. Results suggested that the watering regimes significantly determine the effective risk of exceeding the maximum concentrations. Their effects may be of high practical importance in the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Changes in the Functional Potential of Diverse and Active Bacterial Communities in Arctic Deep-Sea Sediments along a Water Depth Gradient

    Science.gov (United States)

    Rapp, J. Z.; Bienhold, C.; Offre, P.; Boetius, A.

    2016-02-01

    The deep sea covers approximately 70% of the Earth's surface and the majority of its seafloor is composed of fine-grained sediments. Bacteria are the dominant organisms in these sediments, accounting for up to 90% of total benthic biomass. Although benthic bacterial communities are assumed to play a central role in biogeochemical cycling at the seafloor, we still have very limited knowledge of their diversity, activity and ecological functions. We sampled Arctic deep-sea surface sediments from seven stations along a gradient from 1000 m to 5500 m water depth at the long-term ecological research station HAUSGARTEN in Fram Strait. Bacterial cell numbers decreased with depth from 3.8*108 to 1.3*108 cells per ml sediment. Illumina 16S rRNA gene surveys based on DNA and cDNA revealed substantial shifts in the structure of the total and active bacterial community along this gradient, which could be linked to environmental parameters, especially organic matter availability. The functional potential and actual activity of microbial communities was investigated using meta-genomic and -transcriptomic sequencing of four representative samples. Reconstruction of 16S rRNA genes from metagenomic data indicated a stronger contribution of certain groups at 1200-2500 m depth (e.g. OM190, Planctomycetacia, Betaproteobacteria) as compared to 3500-5500 m depth (e.g. SAR202 clade, Subgroup 22, Cytophagia). Analysis of orthologous gene clusters and protein families suggested that the genetic potential of microbial communities at the deepest station varied from that of communities at shallower depth, with higher representation of genes involved in the TCA cycle and in the biosynthesis of fatty acids, amino acids and vitamin biosynthesis at the deepest station. The observed variations may result from the accumulation of organic matter at the deepest station caused by the funnel-like topography at this site. The research contributes to European Research Council Advanced Investigator grant

  15. Mineralogical influences on porosity-depth trends of shelf deposits (Miocene-Pleistocene) along the northwest shelf of Australia (IODP Expedition 356)

    Science.gov (United States)

    Knierzinger, Wolfgang; Lee, Eun Young; Wagreich, Michael

    2017-04-01

    Porosity in sediments is influenced by various factors such as mineralogical composition, burial depth, connate fluids, and stratigraphic layering. This work focuses on processes underlying porosity anomalies in carbonate shelf deposits along the northwest shelf of Australia by using different techniques (polarization microscopy, electron microscopy, XRD, XRF). IODP expedition 356 recovered cored seven sites (U1458-U1464), covering a latitudinal range of 29°S-18°S on the northwest shelf. Strong negative deviations from general porosity-depth trends for these carbonate rich sediments are clear for samples with higher contents of dolomite, calcium sulfates, and non-skeletal calcite. No significant influence of aragonite on porosity values has yet been detected. However, it is likely that the occurrence of high amounts of aragonite is a crucial element with regard to porosity values in these carbonate rich deposits, since elongated aragonite needles commonly enhance interparticle porosity. Further insight might be gained through the application of electron microscopy. In general, sediments in the northern part of the study area (Sites U1462, U1463, U1464) tend to show slightly higher porosity values compared to sediments form the south (Sites U1459, U1460). This may reflect the influence of calcium sulfate, because mineralogical analyses show, calcium sulfate is relatively rare at the southern sites, whereas higher amounts of calcium sulfates occur in the north. The lack of detrital particles in calcium sulfate components indicates an evaporitic origin. Deposits at Site U 1461 differ from other analyzed sediments insofar as higher amounts of feldspars and micas are apparent. *This research is conducted within the frame of the 'International Ocean Discovery Program', funded by the Ministry of Oceans and Fisheries, Korea.

  16. Carbonate-derived CO 2 purging magma at depth: Influence on the eruptive activity of Somma-Vesuvius, Italy

    Science.gov (United States)

    Dallai, Luigi; Cioni, Raffaello; Boschi, Chiara; D'Oriano, Claudia

    2011-10-01

    Mafic phenocrysts from selected products of the last 4 ka volcanic activity at Mt. Vesuvius were investigated for their chemical and O-isotope composition, as a proxy for primary magmas feeding the system. 18O/ 16O ratios of studied Mg-rich olivines suggest that near-primary shoshonitic to tephritic melts experienced a flux of sedimentary carbonate-derived CO 2, representing the early process of magma contamination in the roots of the volcanic structure. Bulk carbonate assimilation (physical digestion) mainly occurred in the shallow crust, strongly influencing magma chamber evolution. On a petrological and geochemical basis the effects of bulk sedimentary carbonate digestion on the chemical composition of the near-primary melts are resolved from those of carbonate-released CO 2 fluxed into magma. An important outcome of this process lies in the effect of external CO 2 in changing the overall volatile solubility of the magma, enhancing the ability of Vesuvius mafic magmas to rapidly rise and explosively erupt at the surface.

  17. The Influence Of Ground Water Dynamics In A Periodically Flooded Ecosystem The Great Dismal Swamp

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Frequency, duration, depth, and timing of flooding are major influences on the structure and functional dynamics of wetland ecosystems. In the present study,...

  18. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2016-01-01

    -flow lab-scale assay. NH4 + removal capacity, estimated from short term loading up-shifts, was at least 10 times higher in the top than in the middle and bottom filter layers, consistent with the stratification of Ammonium Oxidizing Bacteria (AOB). AOB density increased consistently with the NH4 + removal...... rate, indicating their primarily role in nitrification under the imposed experimental conditions. The maximum AOB cell specific NH4 + removal rate observed at the bottom was at least 3 times lower compared to the top and middle layers. Additionally, a significant up-shift capacity (4.6 and 3.5 times......) was displayed from the top and middle layers, but not from the bottom layer at increased loading conditions. Hence, AOB with different physiological responses were active at the different depths. The biokinetic analysis predicted that despite the low NH4 + removal capacity at the bottom layer, the entire filter...

  19. Factors influencing biological treatment of MTBE contaminated ground water

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William T.; Hines Jr., Robert D.; Cockrum, Dirk K.; Kilkenny, Scott T.

    2001-09-14

    Methyl tert-butyl ether (MTBE) contamination has complicated the remediation of gasoline contaminated sites. Many sites are using biological processes for ground water treatment and would like to apply the same technology to MTBE. However, the efficiency and reliability of MTBE biological treatment is not well documented. The objective of this study was to examine the operational and environmental variables influencing MTBE biotreatment. A fluidized bed reactor was installed at a fuel transfer station and used to treat ground water contaminated with MTBE and gasoline hydrocarbons. A complete set of chemical and operational data was collected during this study and a statistical approach was used to determine what variables were influencing MTBE treatment efficiency. It was found that MTBE treatment was more sensitive to up-set than gasoline hydrocarbon treatment. Events, such as excess iron accumulation, inhibited MTBE treatment, but not hydrocarbon treatment. Multiple regression analysis identified biomass accumulation and temperature as the most important variables controlling the efficiency of MTBE treatment. The influent concentration and loading of hydrocarbons, but not MTBE, also impacted MTBE treatment efficiency. The results of this study suggest guidelines for improving MTBE treatment. Long cell retention times in the reactor are necessary for maintaining MTBE treatment. The onset of nitrification only occurs when long cell retention times have been reached and can be used as an indicator in fixed film reactors that conditions favorable to MTBE treatment exist. Conversely, if the reactor can not nitrify, it is unlikely to have stable MTBE treatment.

  20. WATER PURIFICATION BY COAGULATION UNDER THE INFLUENCE OF ULTRASONIC FIELD

    Directory of Open Access Journals (Sweden)

    Vikulina Vera Borisovna

    2016-03-01

    Full Text Available The authors carried out experiments on the in-fluence of ultrasound on the subsidence of suspended materials. The efficiency of coagulation process in wa-ter purification in ultrasound field is estimated. The influence of ultrasound on the water with suspended materials before introducing coagulant was a condition of the experiment. The magnetostriction method for obtaining ultrasound oscillations with the help of ultra-sound generator of batch production was applied. The samples were chosen and the coagulation process was controlled using standard procedures. The experimental data was obtained which estimate the efficiency in-crease in the subsidence of suspended materials de-pending on the duration of ultrasound processing. Dur-ing one minute of ultrasound processing the following results were obtained: the subsidence efficiency in-creased by 25.83 % in case of coagulant share Al2O3 2.5 mg/l; the subsidence efficiency increased by 23.70 % in case of coagulant share Al2O3 5.0 mg/l.

  1. Use of Contour Maps of Water Depths to Predict Flora and Fauna Abundance in Moist Soil Management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of this project was to develop a technique to quantitatively predict the area of moist soil that would be exposed as a result of a water drawdown of any...

  2. How cold-water coral mounds modify their physical environment and therefore influence reef development

    Science.gov (United States)

    Mienis, F.; Duineveld, G.; Lavaleye, M.; van Haren, H.; Mohn, C.; Cyr, F.

    2015-12-01

    Cold-water coral framework acts as a sediment trap and as a result kilometres long and up to 360m high mound structures have formed on the SE Rockall Bank. Earlier observations showed that most of the mounds have their summits around 550 m water depth and summits have been reported as being covered with living coral. Pelagia cruises in 2012 and 2013 revealed completely new insights in mound development. Video transects across mounds with different morphology showed that summits of the highest and largest mounds are presently not covered by living coral as opposed to smaller and lower mounds which are covered with a thriving living coral framework. Measurements in the water column with CTD and near-bottom with benthic landers and thermistor string showed that turbulence is likely the most important factor influencing nutrient and food supply and thus coral growth. It seems that the large mounds have outgrown themselves and that their relatively large size and flat summits are limiting turbulence, thereby limiting oxygen, nutrient and food replenishment. Redistribution of nutrients, oxygen and food is vital for ecosystem functioning and reef development. The presence of a healthy coral cover on the summits of the small mounds was also shown by the vertical mound growth rate measured in sediment cores. These showed fourfold higher sedimentation rates during the Holocene on small mounds compared to highest mounds.

  3. Influence of surface structure and chemistry on water droplet splashing.

    Science.gov (United States)

    Koch, Kerstin; Grichnik, Roland

    2016-08-06

    Water droplet splashing and aerosolization play a role in human hygiene and health systems as well as in crop culturing. Prevention or reduction of splashing can prevent transmission of diseases between animals and plants and keep technical systems such as pipe or bottling systems free of contamination. This study demonstrates to what extent the surface chemistry and structures influence the water droplet splashing behaviour. Smooth surfaces and structured replicas of Calathea zebrina (Sims) Lindl. leaves were produced. Modification of their wettability was done by coating with hydrophobizing and hydrophilizing agents. Their wetting was characterized by contact angle measurement and splashing behaviour was observed with a high-speed video camera. Hydrophobic and superhydrophilic surfaces generally showed fewer tendencies to splash than hydrophobic ones. Structuring amplified the underlying behaviour of the surface chemistries, increasing hydrophobic surfaces' tendency to splash and decreasing splash on hydrophilic surfaces by quickly transporting water off the impact point by capillary forces. The non-porous surface structures found in C. zebrina could easily be applied to technical products such as plastic foils or mats and coated with hydrophilizing agents to suppress splash in areas of increased hygiene requirements or wherever pooling of liquids is not desirable.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  4. Measurement of the Muon Atmospheric Production Depth with the Water Cherenkov Detectors of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Molina Bueno, Laura [Univ. of Granada (Spain)

    2015-09-01

    Ultra-high-energy cosmic rays (UHECR) are particles of uncertain origin and composition, with energies above 1 EeV (1018 eV or 0.16 J). The measured flux of UHECR is a steeply decreasing function of energy. The largest and most sensitive apparatus built to date to record and study cosmic ray Extensive Air Showers (EAS) is the Pierre Auger Observatory. The Pierre Auger Observatory has produced the largest and finest amount of data ever collected for UHECR. A broad physics program is being carried out covering all relevant topics of the field. Among them, one of the most interesting is the problem related to the estimation of the mass composition of cosmic rays in this energy range. Currently the best measurements of mass are those obtained by studying the longitudinal development of the electromagnetic part of the EAS with the Fluorescence Detector. However, the collected statistics is small, specially at energies above several tens of EeV. Although less precise, the volume of data gathered with the Surface Detector is nearly a factor ten larger than the fluorescence data. So new ways to study composition with data collected at the ground are under investigation. The subject of this thesis follows one of those new lines of research. Using preferentially the time information associated with the muons that reach the ground, we try to build observables related to the composition of the primaries that initiated the EAS. A simple phenomenological model relates the arrival times with the depths in the atmosphere where muons are produced. The experimental confirmation that the distributions of muon production depths (MPD) correlate with the mass of the primary particle has opened the way to a variety of studies, of which this thesis is a continuation, with the aim of enlarging and improving its range of applicability. We revisit the phenomenological model which is at the root of the analysis and discuss a new way to improve some aspects of the model. We carry

  5. Quantification of groundwater-stream water interactions based on temperature depth profiles under strong upwelling conditions in a sand-bed stream

    Science.gov (United States)

    Gaona, Jaime; Lewandowski, Jörg

    2017-04-01

    The quantification of groundwater-surface water interactions is not only required for budgets but also for an understanding of the complex relations between hyporheic exchange flows (HEF) and the associated chemical and biological processes that take place in hyporheic zones (HZ). Thus, there is a strong need to improve methods for flux estimation.The present study aims to quantify the vertical fluxes across the riverbed from data of temperature depth profiles recorded at the River Schlaube in East Brandenburg, Germany. In order to test the capabilities and limitations of existing methods, fluxes were calculated with an analytical (VFLUX, based on the amplitude attenuation and phase shift analysis) and a numerical (1DTempPro, parametrization based on observed values) approach for heat conduction. We conclude that the strong limitations of the flux estimates are caused by thermal and hydraulic heterogeneities of the sediment properties. Consequently, upscaling of fluxes must include other thermal techniques able to portray the spatial variability of thermal patterns, along with further developments of methods to link thermal depth profiles, thermal patterns of the surface of the streambed and all the other factors involved. Considering time and costs of temperature depth profiles of riverbeds, and the need for multiple devices to cover larger areas, it is additionally tested whether vertical fluxes can be infered from the uppermost temperature sensors of a data set. That would ease hyporheic investigations at larger scales.

  6. Rock-Eval analysis of French forest soils: the influence of depth, soil and vegetation types on SOC thermal stability and bulk chemistry

    Science.gov (United States)

    Soucemarianadin, Laure; Cécillon, Lauric; Baudin, François; Cecchini, Sébastien; Chenu, Claire; Mériguet, Jacques; Nicolas, Manuel; Savignac, Florence; Barré, Pierre

    2017-04-01

    Soil organic matter (SOM) is the largest terrestrial carbon pool and SOM degradation has multiple consequences on key ecosystem properties like nutrients cycling, soil emissions of greenhouse gases or carbon sequestration potential. With the strong feedbacks between SOM and climate change, it becomes particularly urgent to develop reliable routine methodologies capable of indicating the turnover time of soil organic carbon (SOC) stocks. Thermal analyses have been used to characterize SOM and among them, Rock-Eval 6 (RE6) analysis of soil has shown promising results in the determination of in-situ SOC biogeochemical stability. This technique combines a phase of pyrolysis followed by a phase of oxidation to provide information on both the SOC bulk chemistry and thermal stability. We analyzed with RE6 a set of 495 soils samples from 102 permanent forest sites of the French national network for the long-term monitoring of forest ecosystems (''RENECOFOR'' network). Along with covering pedoclimatic variability at a national level, these samples include a range of 5 depths up to 1 meter (0-10 cm, 10-20 cm, 20-40 cm, 40-80 cm and 80-100 cm). Using RE6 parameters that were previously shown to be correlated to short-term (hydrogen index, HI; T50 CH pyrolysis) or long-term (T50 CO2 oxidation and HI) SOC persistence, and that characterize SOM bulk chemical composition (oxygen index, OI and HI), we tested the influence of depth (n = 5), soil class (n = 6) and vegetation type (n = 3; deciduous, coniferous-fir, coniferous-pine) on SOM thermal stability and bulk chemistry. Results showed that depth was the dominant discriminating factor, affecting significantly all RE6 parameters. With depth, we observed a decrease of the thermally labile SOC pool and an increase of the thermally stable SOC pool, along with an oxidation and a depletion of hydrogen-rich moieties of the SOC. Soil class and vegetation type had contrasted effects on the RE6 parameters but both affected significantly T

  7. Comparison of PALSAR-2 Interferometric Estimates of Snow Water Equivalent, Airborne Snow Observatory Snow Depths, and Results from a Distributed Energy Balance Snow Model (iSnobal)

    Science.gov (United States)

    Deeb, E. J.; Marshall, H. P.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.; Havens, S.; Forster, R. R.; Siqueira, P.

    2016-12-01

    The interferometric approach to estimating snow water equivalent (SWE) leverages the fact that at relatively low frequencies ( 1 GHz, L-Band), differences in snow microstructure and layering do not significantly affect the radar backscatter of dry snow. At these frequencies, the main contribution of the radar backscatter is the snow/ground interface, and the difference in the timing of the radar propagation through the snowpack is controlled by snow depth, density and liquid water content. While engineering limitations prevent direct measurement of absolute radar travel-time, interferometric phase shift between acquisitions can be used to monitor changes in radar travel-time, caused by changes in snow properties. PALSAR-2 is a L-Band synthetic aperture radar (SAR) aboard the Japan Aerospace Exploration Agency's (JAXA) ALOS-2 satellite. Launched in 2014, PALSAR-2 interferometric pairs geographically and temporally overlap data collected by the NASA/JPL Airborne Snow Observatory (ASO) which provides spatial distribution of snow depths across basins (e.g. Tuolumne, CA and Grand Mesa, CO) identified as contributing significantly to NASA's multi-year airborne SnowEx campaign. As part of ASO's operational requirements, a spatially distributed energy balance snow model (iSnobal) is run over these domains estimating density (and other snow properties) and providing SWE products for water resource managers as well as other cryospheric science applications. This effort identifies PALSAR-2 satellite pairs closely coincident with ASO collections, processes interferometric products of coherence and phase change, and compares these results with the spatially distributed snow depths from ASO and modeled snow densities from iSnobal. Moreover, for satellite acquisitions not temporally matching the ASO collections, the modeled snow properties (depths and densities) from iSnobal are used for comparison with interferometric estimates of SWE. The integration of ground measurements

  8. An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system

    OpenAIRE

    Zlatanović, L.; van der Hoek, J.P.; Vreeburg, J.H.G.

    2017-01-01

    The drinking water quality changes during the transport through distribution systems. Domestic drinking water systems (DDWSs), which include the plumbing between the water meter and consumer's taps, are the most critical points in which water quality may be affected. In distribution networks, the drinking water temperature and water residence time are regarded as indicators of the drinking water quality. This paper describes an experimental research on the influence of stagnation time and tem...

  9. Life Cycle Water Consumption and Water Resource Assessment for Utility-Scale Geothermal Systems: An In-Depth Analysis of Historical and Forthcoming EGS Projects

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Corrie E. [Argonne National Lab. (ANL), Argonne, IL (United States); Harto, Christopher B. [Argonne National Lab. (ANL), Argonne, IL (United States); Schroeder, Jenna N. [Argonne National Lab. (ANL), Argonne, IL (United States); Martino, Louis E. [Argonne National Lab. (ANL), Argonne, IL (United States); Horner, Robert M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-08-01

    This report is the third in a series of reports sponsored by the U.S. Department of Energy Geothermal Technologies Program in which a range of water-related issues surrounding geothermal power production are evaluated. The first report made an initial attempt at quantifying the life cycle fresh water requirements of geothermal power-generating systems and explored operational and environmental concerns related to the geochemical composition of geothermal fluids. The initial analysis of life cycle fresh water consumption of geothermal power-generating systems identified that operational water requirements consumed the vast majority of water across the life cycle. However, it relied upon limited operational water consumption data and did not account for belowground operational losses for enhanced geothermal systems (EGSs). A second report presented an initial assessment of fresh water demand for future growth in utility-scale geothermal power generation. The current analysis builds upon this work to improve life cycle fresh water consumption estimates and incorporates regional water availability into the resource assessment to improve the identification of areas where future growth in geothermal electricity generation may encounter water challenges. This report is divided into nine chapters. Chapter 1 gives the background of the project and its purpose, which is to assess the water consumption of geothermal technologies and identify areas where water availability may present a challenge to utility-scale geothermal development. Water consumption refers to the water that is withdrawn from a resource such as a river, lake, or nongeothermal aquifer that is not returned to that resource. The geothermal electricity generation technologies evaluated in this study include conventional hydrothermal flash and binary systems, as well as EGSs that rely on engineering a productive reservoir where heat exists, but where water availability or permeability may be limited. Chapter 2

  10. Mudpuppy (Necturus maculosus maculosus ) spatial distribution, breeding water depth, and use of artificial spawning habitat in the Detroit River

    Science.gov (United States)

    Craig, Jaquelyn M.; Mifsud, David A.; Briggs, Andrew S.; Boase, James C.; Kennedy, Gregory W.

    2015-01-01

    Mudpuppy (Necturus maculosus maculosus) populations have been declining in the Great Lakes region of North America. However, during fisheries assessments in the Detroit River, we documented Mudpuppy reproduction when we collected all life stages from egg through adult as by-catch in fisheries assessments. Ten years of fisheries sampling resulted in two occurrences of Mudpuppy egg collection and 411 Mudpuppies ranging in size from 37–392 mm Total Length, collected from water 3.5–15.1 m deep. Different types of fisheries gear collected specific life stages; spawning females used cement structures for egg deposition, larval Mudpuppies found refuge in eggmats, and we caught adults with baited setlines and minnow traps. Based on logistic regression models for setlines and minnow traps, there was a higher probability of catching adult Mudpuppies at lower temperatures and in shallower water with reduced clarity. In addition to documenting the presence of all life stages of this sensitive species in a deep and fast-flowing connecting channel, we were also able to show that standard fisheries research equipment can be used for Mudpuppy research in areas not typically sampled in herpetological studies. Our observations show that typical fisheries assessments and gear can play an important role in data collection for Mudpuppy population and spawning assessments.

  11. Compensation method for the influence of angle of view on animal temperature measurement using thermal imaging camera combined with depth image.

    Science.gov (United States)

    Jiao, Leizi; Dong, Daming; Zhao, Xiande; Han, Pengcheng

    2016-12-01

    In the study, we proposed an animal surface temperature measurement method based on Kinect sensor and infrared thermal imager to facilitate the screening of animals with febrile diseases. Due to random motion and small surface temperature variation of animals, the influence of the angle of view on temperature measurement is significant. The method proposed in the present study could compensate the temperature measurement error caused by the angle of view. Firstly, we analyzed the relationship between measured temperature and angle of view and established the mathematical model for compensating the influence of the angle of view with the correlation coefficient above 0.99. Secondly, the fusion method of depth and infrared thermal images was established for synchronous image capture with Kinect sensor and infrared thermal imager and the angle of view of each pixel was calculated. According to experimental results, without compensation treatment, the temperature image measured in the angle of view of 74° to 76° showed the difference of more than 2°C compared with that measured in the angle of view of 0°. However, after compensation treatment, the temperature difference range was only 0.03-1.2°C. This method is applicable for real-time compensation of errors caused by the angle of view during the temperature measurement process with the infrared thermal imager. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system

    Science.gov (United States)

    Nguyen, Hoang Minh; Rountrey, Adam N.; Meeuwig, Jessica J.; Coulson, Peter G.; Feng, Ming; Newman, Stephen J.; Waite, Anya M.; Wakefield, Corey B.; Meekan, Mark G.

    2015-01-01

    The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats. PMID:25761975

  13. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Japan Sea from 11 January 1989 to 17 January 1989 (NODC Accession 8900027)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Japan Sea. Data were collected from 11 January 1989 to 17...

  14. Temperature profile and water depth data collected from KIDD using BT and XBT casts in the North/South Pacific Ocean from 06 August 1977 to 30 April 1990 (NODC Accession 9000141)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected from thirty three different ships used for 44 cruises. The data was collected between August 6, 1987 to April 30,...

  15. Temperature profile and water depth data collected from IOWA using BT and XBT casts in the North Pacific Ocean from 31 May 1985 to 23 March 1990 (NODC Accession 9000092)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected using two dozen different ships through a grant to Dr. Douglas C. Biggs MMS # 14-35-0001-30501. The data was...

  16. Temperature profile and water depth data collected from USCGC GLACIER using BT and XBT casts in the NW / SW Pacific Ocean from 25 October 1986 to 31 January 1987 (NODC Accession 8700140)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts in the NW / SW Pacific Ocean from USCGC GLACIER. Data were collected from 25 October...

  17. Temperature profile and water depth data collected from USCGC GLACIER in the NW/SE Pacific Ocean and other seas from 31 January 1987 to 08 April 1987 (NODC Accession 8700183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC GLACIER in the Northwest/Southeast Pacific Ocean and other seas. Data...

  18. Temperature profile and water depth data from BT and XBT casts in the Atlantic Ocean from USCGC POLAR SEA from 14 December 1983 to 06 May 1984 (NODC Accession 8600108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC POLAR SEA in the Atlantic Ocean. Data were collected from 14 December...

  19. Temperature profile and water depth data collected from BT and XBT casts in the Northwest Atlantic Ocean from OCEANUS from 17 January 1981 to 05 May 1981 (NODC Accession 8600391)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth were collected using BT and XBT casts from the OCEANUS in the Northwest Atlantic Ocean. Data were collected from 17 January 1981...

  20. Temperature profile and water depth data collected from BAINBRIDGE using BT and XBT casts in the North Pacific Ocean from 03 July 1975 to 31 October 1977 (NODC Accession 8900230)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the BAINBRIDGE in the North Pacific Ocean and TOGA Area - Pacific Ocean. Data...

  1. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago from 2016-09-01 to 2016-09-27 (NCEI Accession 0161171)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  2. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Mariana Archipelago from 2014-03-24 to 2014-05-05 (NCEI Accession 0161168)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  3. Temperature profile and water depth data collected from USS ROBERT G. BRADLEY using BT and XBT casts in the NE/NW Atlantic Ocean and other seas from 03 May 1988 to 31 May 1988 (NODC Accession 8800213)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS ROBERT G. BRADLEY in the Northwest / Northeast Atlantic Ocean, Arabian...

  4. Temperature profile and water depth data collected from AUSTRALIA STAR and other platforms using XBT casts in the TOGA Area - Atlantic and Pacific Ocean from 05 October 1989 to 21 December 1992 (NODC Accession 9400035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using XBT casts from the AUSTRALIA STAR and other platforms in the TOGA Area - Atlantic and Pacific Ocean,...

  5. Temperature profile and water depth collected from W.V. PRATT using BT and XBT casts in the NW Atlantic Ocean from 09 January 1987 to 30 January 1987 (NODC Accession 8700076)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the W.V. PRATT in the Northwest Atlantic Ocean and TOGA in the Atlantic Ocean. Data...

  6. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Indian Ocean and other seas from 05 April 1988 to 11 April 1988 (NODC Accession 8800140)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Indian Ocean, Arabian Sea, and Gulf of Oman. Data were...

  7. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the TOGA Area - Pacific Ocean and other areas from 03 November 1988 to 01 December 1988 (NODC Accession 8800327)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the TOGA Area - Pacific Ocean, Bay of Bengal, Indian Ocean,...

  8. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the Indian Ocean and other seas from 02 December 1988 to 28 December 1988 (NODC Accession 8900015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the Indian Ocean, Arabian Sea, Gulf of Oman, Gulf of Iran, and...

  9. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Indian Ocean and other seas from 17 May 1988 to 01 June 1988 (NODC Accession 8800181)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in Arabian Sea, Indian Ocean, Gulf of Oman, Laccadive Sea, and...

  10. Temperature profile and water depth data collected from USS Merrill using BT and XBT casts in the Indian Ocean and other seas from 1988-03-01 to 1988-03-29 (NODC Accession 8800110)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Arabian Sea, Gulf of Oman, and Indian Ocean. Data were...

  11. Temperature profile and water depth data collected from USS HENRY B. WILSON using BT and XBT casts in the Indian Ocean and other seas from 22 October 1986 to 26 November 1986 (NODC Accession 8800183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HENRY B. WILSON in the Indian Ocean, Gulf of Oman, Gulf of Iran, and...

  12. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Northeast Pacific Ocean and other sea from 09 November 1988 to 20 November 1988 (NODC Accession 8800331)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northeast Pacific Ocean and Inland Sea. Data were collected...

  13. Temperature profile and water depth data collected from HMAS DARWIN and other platforms using BT and XBT casts in the North / South Pacific Ocean and Indian Ocean from 29 April 1985 to 12 April 1988 (NODC Accession 8800166)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the HMAS DARWIN and other platforms in the North / South Pacific Ocean and Indian...

  14. Temperature profile and water depth data collected from USS MOBILE BAY using BT and XBT casts in the NW Atlantic Ocean from 01 April 1987 to 07 April 1987 (NODC Accession 8700192)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean and TOGA Area - Atlantic...

  15. Temperature profile and water depth collected from XIANG YANG HONG 05 in the South China Sea using BT and XBT casts from 16 November 1986 to 03 December 1986 (NODC Accession 8700009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth were collected using BT and XBT casts from the XIANG YANG HONG 05 in the South China Sea. Data were collected from 16 November...

  16. Temperature profile and water depth data collected from BT and XBT casts in the Indian Ocean from ANRO AUSTRALIA and other platforms from 31 May 1983 to 02 November 1986 (NODC Accession 8700034)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the ANRO AUSTRALIA, FLINDERS, and other platforms in Indian Ocean. Data were...

  17. Temperature profile and water depth data collected from AMERICAN RESERVIST using BT and XBT casts in the North Pacific Ocean from 20 January 1974 to 29 September 1977 (NODC Accession 8900287)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the AMERICAN RESERVIST in the North Pacific Ocean and TOGA Area - Pacific Ocean....

  18. Temperature profile and water depth data collected from USCGC BOUTWELL using BT and XBT casts in the NW Pacific Ocean from 03 February 1987 to 17 February 1987 (NODC Accession 8700161)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the USCGC BOUTWELL in the Northwest Pacific Ocean. Data were collected from 03 February...

  19. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Northwest Pacific Ocean from 11 August 1992 to 27 August 1992 (NODC Accession 9200253)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Northwest Pacific Ocean. Data were collected from 11...

  20. Temperature profile and water depth data collected from USS COCHRANE using BT and XBT casts in the East China sea and other seas from 07 March 1987 to 19 March 1987 (NODC Accession 8700263)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS COCHRANE in the South China sea, East China Sea, and Philippine Sea. Data...

  1. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the NE/NW Pacific Ocean from 02 June 1988 to 19 June 1988 (NODC Accession 8800215)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northeast / Northwest Pacific Ocean and TOGA Area - Pacific...

  2. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Northwest Pacific Ocean from 21 March 1988 to 22 March 1988 (NODC Accession 8800144)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northwest Pacific Ocean. Data were collected from 21 March...

  3. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Indian Ocean and other seas from 01 December 1987 to 21 December 1987 (NODC Accession 8800028)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Indian Ocean and other seas. Data were collected from 01...

  4. Temperature profile and water depth data collected from USS COCHRANE using BT and XBT casts in the Indian Ocean and other seas from 01 August 1987 to 27 September 1987 (NODC Accession 8700394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS COCHRANE in the Indian Ocean, Arabian Sea, Laccadive Sea, and Philippine...

  5. Temperature profile and water depth data collected from USS JOUETT using BT and XBT casts in the Northwest Pacific Ocean from 14 July 1987 to 16 July 1987 (NODC Accession 8700264)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS JOUETT in the Northwest Pacific Ocean. Data were collected from 14 July...

  6. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the NE/NW Pacific Ocean and other seas from 17 June 1988 to 27 June 1988 (NODC Accession 8800217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Northeast / Northwest Pacific Ocean, Japan Sea and Inland...

  7. Temperature profile and water depth data collected from USS ROBERT G. BRADLEY using BT and XBT casts in the Northwest Atlantic Ocean from 15 December 1988 to 28 February 1989 (NODC Accession 8900110)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS ROBERT G. BRADLEY in the Northwest Atlantic Ocean and TOGA Area -...

  8. Temperature profile and water depth data collected from USCGC HAMILTON using BT and XBT casts in the Northwest Pacific Ocean and Bering Sea from 23 October 1991 to 09 May 1992 (NODC Accession 9200241)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC HAMILTON in the Northeast / Northwest Pacific Ocean and Bering Sea....

  9. Temperature profile and water depth data collected from USS HARRY E. YARNELL using BT and XBT casts in the Bay of Biscay and other seas from 30 June 1992 to 17 September 1992 (NODC Accession 9200283)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HARRY E. YARNELL in the Bay of Biscay, English Channel, Northeast...

  10. Temperature profile and water depth data collected from SAXON STAR and other platforms in a World wide distribution from 09 March 1983 to 12 November 1986 (NODC Accession 8700035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the SAXON STAR and other platforms in a World wide distribution. Data were collected...

  11. Temperature profile and water depth data collected from USS MOBILE BAY using BT and XBT casts in the NW Atlantic Ocean from 15 May 1987 to 27 May 19876 (NODC Accession 8700223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean. Data were collected from 15...

  12. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the Indian ocean and other seas from 07 January 1989 to 31 January 1989 (NODC Accession 8900034)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the Indian Ocean, South China Sea, Burma Sea, and Malacca of...

  13. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the TOA Area - Pacific Ocean and other seas from 02 October 1988 to 30 October 1988 (NODC Accession 8800335)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the TOGA Area - Pacific Ocean, Inland Sea, South China Sea,...

  14. Temperature profile and water depth data collected from USS HAYLER using BT and XBT casts in the Arabian Sea and other seas from 31 October 1984 to 22 October 1985 (NODC Accession 9200289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HAYLER in the Arabian Sea and other seas. Data were collected from 31...

  15. Temperature profile and water depth data collected from SAMUEL B. ROBERTS in the NW Atlantic (limit-40 W) from 22 September 1986 to 07 October 1986 (NODC Accession 8600353)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the USS SAMUEL B. ROBERTS in the Northwest Atlantic Ocean. Data were collected from 22...

  16. Temperature profile and water depth collected from EDGAR M. QUEENY from BT and XBT casts in the Gulf of Mexico from 13 December 1985 to 22 December 1985 (NODC Accession 8600318)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the EDGAR M. QUEENY in the Gulf of Mexico. Data were collected from 13 December...

  17. Influence of Bulk PDMS Network Properties on Water Wettability

    Science.gov (United States)

    Melillo, Matthew; Walker, Edwin; Klein, Zoe; Efimenko, Kirill; Genzer, Jan

    Poly(dimethylsiloxane) (PDMS) is one of the most common elastomers, with applications ranging from sealants and marine antifouling coatings to absorbents for water treatment. Fundamental understanding of how liquids spread on the surface of and absorb into PDMS networks is of critical importance for the design and use of another application - medical devices. We have systematically studied the effects of polymer molecular weight, loading of tetra-functional crosslinker, and end-group chemical functionality on the mechanical and surface properties of end-linked PDMS networks. Wettability was investigated through the sessile drop technique, wherein a DI water droplet was placed on the bulk network surface and droplet volume, shape, surface area, and contact angle were monitored as a function of time. Various silicone substrates ranging from incredibly soft and flexible materials (E' 50 kPa) to highly rigid networks (E' 5 MPa) were tested. The dynamic behavior of the droplet on the surfaces demonstrated equilibration times between the droplet and surface on the order of 5 minutes. Similar trends were observed for the commercial PDMS material, Sylgard-184. Our results have provided new evidence for the strong influence that substrate modulus and molecular network structure have on the wettability of PDMS elastomers. These findings will aid in the design and implementation of efficient, accurate, and safe PDMS-based medical devices and microfluidic materials that involve aqueous media.

  18. Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

    Science.gov (United States)

    Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

    2015-12-01

    Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

  19. Depth profiles of 230Th excess, transition metals and mineralogy of ferromanganese crusts of the Central Indian Ocean basin and implications for palaeoceanographic influence on crust genesis

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Borole, D.V.

    6 M HCl leachates of the depth samples using a Perkin Elmer@ 5000 atomic absorption spec- trometer (AAS). (Standard error lo; preci- sion within ? 6% ) . Mineralogical studies were carried out on depth samples using a Philips@ X...

  20. Water and salt budget in the Azikode estuary during postmonsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Revichandran, C.; Shyam, K.R.; Varma, P.U.; Pylee, A.

    Computed values of flux showed that seaward Eulerian residual flow of water was the major factor influencing the salt and water budget in the Azikode Estuary. Depth integrated residual flow was seaward at all depths. Upstream transport of salt...

  1. The Northern Gulf of Mexico During OAE2 and the Relationship Between Water Depth and Black Shale Development

    Science.gov (United States)

    Lowery, Christopher M.; Cunningham, Robert; Barrie, Craig D.; Bralower, Timothy; Snedden, John W.

    2017-12-01

    Despite their name, Oceanic Anoxic Events (OAEs) are not periods of uniform anoxia and black shale deposition in ancient oceans. Shelf environments account for the majority of productivity and organic carbon burial in the modern ocean, and this was likely true in the Cretaceous as well. However, it is unlikely that the mechanisms for such an increase were uniform across all shelf environments. Some, like the northwest margin of Africa, were characterized by strong upwelling, but what might drive enhanced productivity on shelves not geographically suited for upwelling? To address this, we use micropaleontology, carbon isotopes, and sedimentology to present the first record of Oceanic Anoxic Event 2 (OAE2) from the northern Gulf of Mexico shelf. Here OAE2 occurred during the deposition of the well-oxygenated, inner neritic/lower estuarine Lower Tuscaloosa Sandstone. The overlying organic-rich oxygen-poor Marine Tuscaloosa Shale is entirely Turonian in age. We trace organic matter enrichment from the Spinks Core into the deepwater Gulf of Mexico, where wireline log calculations and public geochemical data indicate organic enrichment and anoxia throughout the Cenomanian-Turonian boundary interval. Redox change and organic matter preservation across the Gulf of Mexico shelf were driven by sea level rise prior to the early Turonian highstand, which caused the advection of nutrient-rich, oxygen-poor waters onto the shelf. This results in organic matter mass accumulation rates 1-2 orders of magnitude lower than upwelling sites like the NW African margin, but it likely occurred over a much larger geographic area, suggesting that sea level rise was an important component of the overall increase in carbon burial during OAE2.

  2. Rooting depth, water relations and non-structural carbohydrate dynamics in three woody angiosperms differentially affected by an extreme summer drought.

    Science.gov (United States)

    Nardini, Andrea; Casolo, Valentino; Dal Borgo, Anna; Savi, Tadeja; Stenni, Barbara; Bertoncin, Paolo; Zini, Luca; McDowell, Nathan G

    2016-03-01

    In 2012, an extreme summer drought induced species-specific die-back in woody species in Northeastern Italy. Quercus pubescens and Ostrya carpinifolia were heavily impacted, while Prunus mahaleb was largely unaffected. By comparing seasonal changes in isotopic composition of xylem sap, rainfall and deep soil samples, we show that P. mahaleb has a deeper root system than the other two species. This morphological trait allowed P  mahaleb to maintain higher water potential (Ψ), gas exchange rates and non-structural carbohydrates content (NSC) throughout the summer, when compared with the other species. More favourable water and carbon states allowed relatively stable maintenance of stem hydraulic conductivity (k) throughout the growing season. In contrast, in Quercus pubescens and Ostrya carpinifolia, decreasing Ψ and NSC were associated with significant hydraulic failure, with spring-to-summer k loss averaging 60%. Our data support the hypothesis that drought-induced tree decline is a complex phenomenon that cannot be modelled on the basis of single predictors of tree status like hydraulic efficiency, vulnerability and carbohydrate content. Our data highlight the role of rooting depth in seasonal progression of water status, gas exchange and NSC, with possible consequences for energy-demanding mechanisms involved in the maintenance of vascular integrity. © 2015 John Wiley & Sons Ltd.

  3. How Does Leaf Anatomy Influence Water Transport outside the Xylem?

    Science.gov (United States)

    Buckley, Thomas N; John, Grace P; Scoffoni, Christine; Sack, Lawren

    2015-08-01

    Leaves are arguably the most complex and important physicobiological systems in the ecosphere. Yet, water transport outside the leaf xylem remains poorly understood, despite its impacts on stomatal function and photosynthesis. We applied anatomical measurements from 14 diverse species to a novel model of water flow in an areole (the smallest region bounded by minor veins) to predict the impact of anatomical variation across species on outside-xylem hydraulic conductance (Kox). Several predictions verified previous correlational studies: (1) vein length per unit area is the strongest anatomical determinant of Kox, due to effects on hydraulic pathlength and bundle sheath (BS) surface area; (2) palisade mesophyll remains well hydrated in hypostomatous species, which may benefit photosynthesis, (3) BS extensions enhance Kox; and (4) the upper and lower epidermis are hydraulically sequestered from one another despite their proximity. Our findings also provided novel insights: (5) the BS contributes a minority of outside-xylem resistance; (6) vapor transport contributes up to two-thirds of Kox; (7) Kox is strongly enhanced by the proximity of veins to lower epidermis; and (8) Kox is strongly influenced by spongy mesophyll anatomy, decreasing with protoplast size and increasing with airspace fraction and cell wall thickness. Correlations between anatomy and Kox across species sometimes diverged from predicted causal effects, demonstrating the need for integrative models to resolve causation. For example, (9) Kox was enhanced far more in heterobaric species than predicted by their having BS extensions. Our approach provides detailed insights into the role of anatomical variation in leaf function. © 2015 American Society of Plant Biologists. All Rights Reserved.

  4. A 3D, map based approach to reconstruct and calibrate palaeo-bathymetries - Testing the Cretaceous water depth of the Hammerfest Basin, southwestern Barents Sea

    Science.gov (United States)

    Emmel, B.; de Jager, G.; Zieba, K.; Kurtev, K.; Grøver, A.; Lothe, A.; Lippard, S. J.; Roli, O. A.

    2015-04-01

    A new 3D approach to quantify and calibrate palaeo-water depth (PWD) has been applied to evaluate the Aptian to Maastrichtian/Danian (Cretaceous) bathymetric development in a sub-basin scale within the Hammerfest Basin, southwestern Barents Sea. The results indicate PWD's varying between ca. 200 m and 95 m, recording a local sea-level decrease of ca. 105 m. A calibration against shale volume based on gamma-ray logs from four exploration wells indicates a model sensitivity of ca. +50 m and -150 m. These results are in agreement with empirical PWD estimates obtained from sedimentological and micropalaeontological observations. A comparison with the global eustatic sea level curve indicates that the PWD decrease in the Hammerfest Basin contradicts the general, global trend indicating a primary control by local tectonics such as differential subsidence and uplift along the evolving continental margin offshore north-west Norway.

  5. Reduction of fatigue loads on jacket substructure through blade design optimization for multi-megawatt wind turbines at 50 m water depths

    Science.gov (United States)

    Njomo Wandji, W.; Pavese, C.; Natarajan, A.; Zahle, F.

    2016-09-01

    This paper addresses the reduction of the fore-aft damage equivalent moment at the tower base for multi-megawatt offshore wind turbines mounted on jacket type substructures at 50 m water depths. The study investigates blade design optimization of a reference 10 MW wind turbine under standard wind conditions of onshore sites. The blade geometry and structure is optimized to yield a design that minimizes tower base fatigue loads without significant loss of power production compared to that of the reference setup. The resulting blade design is then mounted on a turbine supported by a jacket and placed under specific offshore site conditions. The new design achieves alleviate fatigue damage equivalent loads also in the jacket members, showing the possibility to prolong its design lifetime or to save material in comparison to the reference jacket. Finally, the results suggest additional benefit on the efficient design of other components such as the constituents of the nacelle.

  6. [Influence of the placing depth of implants with platform switching on the marginal bone level in the posterior mandible: a clinical study].

    Science.gov (United States)

    Luo, Jia; Hu, Xiu-lian; Lin, Ye; Qiu, Li-xin; Di, Ping; Li, Jian-hui

    2012-02-18

    The purpose of this study was to evaluate the influence of the placing depth of the implants with platform switching (Ankylos) on the marginal bone remodeling, by means of radiological observation. 111 Ankylos implants in the posterior mandible from 46 patients (20 male and 27 female) were enrolled in this study. Followed up by 58.1 months on average (from 36 to 85), 222 mesial and distal sites of these implants were evaluated by means of measuring the level of the marginal bone (LMB) on the panoramic radiograph. Among these 111 successfully functional loaded implants, there were no significant differences with the marginal bone absorption values, no matter the implants were placed below, at, or above the bone level (P>0.05). Concerning the stabilization of the marginal bone, when placed below the bone level, 67.7% of the implant sites had their LMBs stabilized at or above the implant platform, and 23.3% absorbed vertically, respectively 19.7% and 80.3% when placed at the bone level, with significant difference (P<0.001). Based on a long-term (over 3 years) observation, the implants placed below, as compared to at or above, the alveolar crest level, might have more chance to keep the marginal bone stabilized at or above the implant platform.

  7. The Influence of Perceived Gender Roles on the Use of Water Services in Chiapas, Mexico

    OpenAIRE

    Sainburg, Estrella

    2016-01-01

    Two intersecting concerns in development studies include gender inequality and inaccessibility to safe and affordable drinking water. In five rural communities of Mexico where non-governmental initiated and community managed water systems seek to address these concerns, this original ethnographic research asked how the gender composition of the management of a water service influences people’s perception of the given water service. This question was influenced by the need for research on perc...

  8. Quantitative evaluation of sputtering induced surface roughness and its influence on AES depth profiles of polycrystalline Ni/Cu multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yan, X.L.; Coetsee, E. [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa); Wang, J.Y., E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063, Guangdong (China); Swart, H.C., E-mail: swartHC@ufs.ac.za [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa); Terblans, J.J., E-mail: terblansjj@ufs.ac.za [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa)

    2017-07-31

    Highlights: • Linear Least Square (LLS) method used to separate Ni and Cu Auger spectra. • The depth-dependent ion sputtering induced roughness was quantitatively evaluated. • The depth resolution better when profiling with dual-ion beam vs. a single-ion beam. • AES depth profiling with a lower ion energy results in a better depth resolution. - Abstract: The polycrystalline Ni/Cu multilayer thin films consisting of 8 alternating layers of Ni and Cu were deposited on a SiO{sub 2} substrate by means of electron beam evaporation in a high vacuum. Concentration-depth profiles of the as-deposited multilayered Ni/Cu thin films were determined with Auger electron spectroscopy (AES) in combination with Ar{sup +} ion sputtering, under various bombardment conditions with the samples been stationary as well as rotating in some cases. The Mixing-Roughness-Information depth (MRI) model used for the fittings of the concentration-depth profiles accounts for the interface broadening of the experimental depth profiling. The interface broadening incorporates the effects of atomic mixing, surface roughness and information depth of the Auger electrons. The roughness values extracted from the MRI model fitting of the depth profiling data agrees well with those measured by atomic force microscopy (AFM). The ion sputtering induced surface roughness during the depth profiling was accordingly quantitatively evaluated from the fitted MRI parameters with sample rotation and stationary conditions. The depth resolutions of the AES depth profiles were derived directly from the values determined by the fitting parameters in the MRI model.

  9. Perception of drinking water safety and factors influencing acceptance and sustainability of a water quality intervention in rural southern India.

    Science.gov (United States)

    Francis, Mark Rohit; Nagarajan, Guru; Sarkar, Rajiv; Mohan, Venkata Raghava; Kang, Gagandeep; Balraj, Vinohar

    2015-07-30

    Acceptance and long-term sustainability of water quality interventions are pivotal to realizing continued health benefits. However, there is limited research attempting to understand the factors that influence compliance to or adoption of such interventions. Eight focus group discussions with parents of young children--including compliant and not compliant households participating in an intervention study, and three key-informant interviews with village headmen were conducted between April and May 2014 to understand perceptions on the effects of unsafe water on health, household drinking water treatment practices, and the factors influencing acceptance and sustainability of an ongoing water quality intervention in a rural population of southern India. The ability to recognize health benefits from the intervention, ease of access to water distribution centers and the willingness to pay for intervention maintenance were factors facilitating acceptance and sustainability of the water quality intervention. On the other hand, faulty perceptions on water treatment, lack of knowledge about health hazards associated with drinking unsafe water, false sense of protection from locally available water, resistance to change in taste or odor of water and a lack of support from male members of the household were important factors impeding acceptance and long term use of the intervention. This study highlights the need to effectively involve communities at important stages of implementation for long term success of water quality interventions. Timely research on the factors influencing uptake of water quality interventions prior to implementation will ensure greater acceptance and sustainability of such interventions in low income settings.

  10. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    Science.gov (United States)

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.

  11. Quantitative evaluation of sputtering induced surface roughness and its influence on AES depth profiles of polycrystalline Ni/Cu multilayer thin films

    Science.gov (United States)

    Yan, X. L.; Coetsee, E.; Wang, J. Y.; Swart, H. C.; Terblans, J. J.

    2017-07-01

    The polycrystalline Ni/Cu multilayer thin films consisting of 8 alternating layers of Ni and Cu were deposited on a SiO2 substrate by means of electron beam evaporation in a high vacuum. Concentration-depth profiles of the as-deposited multilayered Ni/Cu thin films were determined with Auger electron spectroscopy (AES) in combination with Ar+ ion sputtering, under various bombardment conditions with the samples been stationary as well as rotating in some cases. The Mixing-Roughness-Information depth (MRI) model used for the fittings of the concentration-depth profiles accounts for the interface broadening of the experimental depth profiling. The interface broadening incorporates the effects of atomic mixing, surface roughness and information depth of the Auger electrons. The roughness values extracted from the MRI model fitting of the depth profiling data agrees well with those measured by atomic force microscopy (AFM). The ion sputtering induced surface roughness during the depth profiling was accordingly quantitatively evaluated from the fitted MRI parameters with sample rotation and stationary conditions. The depth resolutions of the AES depth profiles were derived directly from the values determined by the fitting parameters in the MRI model.

  12. Parameters influencing deposit estimation when using water sensitive papers

    Directory of Open Access Journals (Sweden)

    Emanuele Cerruto

    2013-10-01

    Full Text Available The aim of the study was to assess the possibility of using water sensitive papers (WSP to estimate the amount of deposit on the target when varying the spray characteristics. To identify the main quantities influencing the deposit, some simplifying hypotheses were applied to simulate WSP behaviour: log-normal distribution of the diameters of the drops and circular stains randomly placed on the images. A very large number (4704 of images of WSPs were produced by means of simulation. The images were obtained by simulating drops of different arithmetic mean diameter (40-300 μm, different coefficient of variation (0.1-1.5, and different percentage of covered surface (2-100%, not considering overlaps. These images were considered to be effective WSP images and then analysed using image processing software in order to measure the percentage of covered surface, the number of particles, and the area of each particle; the deposit was then calculated. These data were correlated with those used to produce the images, varying the spray characteristics. As far as the drop populations are concerned, a classification based on the volume median diameter only should be avoided, especially in case of high variability. This, in fact, results in classifying sprays with very low arithmetic mean diameter as extremely or ultra coarse. The WSP image analysis shows that the relation between simulated and computed percentage of covered surface is independent of the type of spray, whereas impact density and unitary deposit can be estimated from the computed percentage of covered surface only if the spray characteristics (arithmetic mean and coefficient of variation of the drop diameters are known. These data can be estimated by analysing the particles on the WSP images. The results of a validation test show good agreement between simulated and computed deposits, testified by a high (0.93 coefficient of determination.

  13. Water hardness influences Flavobacterium columnare pathogenesis in channel catfish

    Science.gov (United States)

    Studies were conducted to determine aspects of water chemistry responsible for large differences in pathogenesis and mortality rates in challenges of channel catfish Ictalurus punctatus with Flavobacterium columnare; challenges were conducted in water supplying the Stuttgart National Aquaculture Res...

  14. Influence of water availability on the enzymatic hydrolysis of proteins

    NARCIS (Netherlands)

    Butré, C.I.; Wierenga, P.A.; Gruppen, H.

    2014-01-01

    The overall rate of enzymatic protein hydrolysis decreases with increasing protein concentration (0.1–30% (w/v)) at constant enzyme/substrate ratio. To understand the role of water, the amount of available water was expressed as the ratio between free and bound water and experimentally determined

  15. Spatial Autocorrelation, Source Water and the Distribution of Total and Viable Microbial Abundances within a Crystalline Formation to a Depth of 800 m.

    Science.gov (United States)

    Beaton, E D; Stuart, Marilyne; Stroes-Gascoyne, Sim; King-Sharp, Karen J; Gurban, Ioana; Festarini, Amy; Chen, Hui Q

    2017-01-01

    Proposed radioactive waste repositories require long residence times within deep geological settings for which we have little knowledge of local or regional subsurface dynamics that could affect the transport of hazardous species over the period of radioactive decay. Given the role of microbial processes on element speciation and transport, knowledge and understanding of local microbial ecology within geological formations being considered as host formations can aid predictions for long term safety. In this relatively unexplored environment, sampling opportunities are few and opportunistic. We combined the data collected for geochemistry and microbial abundances from multiple sampling opportunities from within a proposed host formation and performed multivariate mixing and mass balance (M3) modeling, spatial analysis and generalized linear modeling to address whether recharge can explain how subsurface communities assemble within fracture water obtained from multiple saturated fractures accessed by boreholes drilled into the crystalline formation underlying the Chalk River Laboratories site (Deep River, ON, Canada). We found that three possible source waters, each of meteoric origin, explained 97% of the samples, these are: modern recharge, recharge from the period of the Laurentide ice sheet retreat (ca. ∼12000 years before present) and a putative saline source assigned as Champlain Sea (also ca. 12000 years before present). The distributed microbial abundances and geochemistry provide a conceptual model of two distinct regions within the subsurface associated with bicarbonate - used as a proxy for modern recharge - and manganese; these regions occur at depths relevant to a proposed repository within the formation. At the scale of sampling, the associated spatial autocorrelation means that abundances linked with geochemistry were not unambiguously discerned, although fine scale Moran's eigenvector map (MEM) coefficients were correlated with the abundance data

  16. Patterns and drivers of fungal community depth stratification in Sphagnum peat.

    Science.gov (United States)

    Lamit, Louis J; Romanowicz, Karl J; Potvin, Lynette R; Rivers, Adam R; Singh, Kanwar; Lennon, Jay T; Tringe, Susannah G; Kane, Evan S; Lilleskov, Erik A

    2017-07-01

    Peatlands store an immense pool of soil carbon vulnerable to microbial oxidation due to drought and intentional draining. We used amplicon sequencing and quantitative PCR to (i) examine how fungi are influenced by depth in the peat profile, water table and plant functional group at the onset of a multiyear mesocosm experiment, and (ii) test if fungi are correlated with abiotic variables of peat and pore water. We hypothesized that each factor influenced fungi, but that depth would have the strongest effect early in the experiment. We found that (i) communities were strongly depth stratified; fungi were four times more abundant in the upper (10-20 cm) than the lower (30-40 cm) depth, and dominance shifted from ericoid mycorrhizal fungi to saprotrophs and endophytes with increasing depth; (ii) the influence of plant functional group was depth dependent, with Ericaceae structuring the community in the upper peat only; (iii) water table had minor influences; and (iv) communities strongly covaried with abiotic variables, including indices of peat and pore water carbon quality. Our results highlight the importance of vertical stratification to peatland fungi, and the depth dependency of plant functional group effects, which must be considered when elucidating the role of fungi in peatland carbon dynamics. Published by Oxford University Press on behalf of FEMS 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  17. Persuasion factors influencing the decision to use sustainable household water treatment.

    Science.gov (United States)

    Kraemer, Silvie M; Mosler, Hans-Joachim

    2010-02-01

    Solar water disinfection (SODIS) is a sustainable water treatment method. With the help of the sun and plastic bottles, water is treated and illnesses prevented. This paper aims to identify the factors influencing SODIS uptake, that is, why someone may become a SODIS user. This uptake decision can be influenced by persuasion. From behaviour theory, variables are recognised which have been proven to influence intention and behaviour and simultaneously can be influenced by persuasion. A total of (n = 878) structured interviews were conducted in a field study in Zimbabwe. Linear and binary logistic regressions showed that several of the initially proposed persuasion variables have significant influence. Persuasion factors have a stronger influence on the uptake of SODIS use and on intention to use SODIS in the future than on the amount of SODIS water consumed. Ideas are presented for using the effective variables in future SODIS campaigns and campaigns in other fields.

  18. Influence of water concentrations on the phase transformation of a model surfactant/co-surfactant/water system

    Science.gov (United States)

    Lunkad, Raju; Srivastava, Arpita; Debnath, Ananya

    2017-02-01

    The influence of water concentrations on phase transformations of a surfactant/co-surfactant/water system is investigated by using all atom molecular dynamics simulations. At higher water concentrations, where surfactant (behenyl trimethyl ammonium chloride, BTMAC) to co-surfactant (stearyl alcohol, SA) ratio is fixed, BTMAC and SA self-assemble into spherical micelles, which transform into strongly interdigitated one dimensional rippled lamellar phases upon decreasing water concentrations. Fragmentation or fusions of spherical micelles of different sizes are evident from the radial distribution functions at different temperatures. However, at lower water concentrations rippled lamellar phase transforms into an LβI phase upon heating. Our simulations reveal that the concentrations of water can influence available space around the head groups which couple with critical thickness to accommodate the packing fraction required for respective phases. This directs towards obtaining a controlling factor to design desired phases important for industrial and medical applications in the future.

  19. Monte Carlo model of the penetration depth for polarization gating spectroscopy: influence of illumination-collection geometry and sample optical properties

    Science.gov (United States)

    Gomes, Andrew J.; Turzhitsky, Vladimir; Ruderman, Sarah; Backman, Vadim

    2013-01-01

    Polarization-gating has been widely used to probe superficial tissue structures, but the penetration depth properties of this method have not been completely elucidated. This study employs a polarization-sensitive Monte Carlo method to characterize the penetration depth statistics of polarization-gating. The analysis demonstrates that the penetration depth depends on both the illumination-collection geometry [illumination-collection area (R) and collection angle (θc)] and on the optical properties of the sample, which include the scattering coefficient (μs), absorption coefficient (μa), anisotropy factor (g), and the type of the phase function. We develop a mathematical expression relating the average penetration depth to the illumination-collection beam properties and optical properties of the medium. Finally, we quantify the sensitivity of the average penetration depth to changes in optical properties for different geometries of illumination and collection. The penetration depth model derived in this study can be applied to optimizing application-specific fiber-optic probes to target a sampling depth of interest with minimal sensitivity to the optical properties of the sample. PMID:22781238

  20. Influence of depth on the verification of fluence for diode array; Influencia de la profundidad en la verficacion de fluencias para una matriz de diodos

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Pastor, R.; Gonzalez Polez, A.; Tobarra Gonzalez, B.

    2011-07-01

    The dosimetric verification of treatment intensity modulated radiotherapy (IMRT) is used, among other devices, arrays of detectors. Comparisons can be performed in relative or absolute mode, being necessary in the first case a specific calibration of the detector. In the checks with such detectors the depth at which the comparison is carried out usually small (1-2 cm) and very different from the representative depth treatment. For this reason in this work is to study the results of verification both relative and absolute, for JMRT dynamic fields depending on the depth at which they are made.

  1. Influence of feed ingredients on water quality parameters in RAS

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg; Pedersen, Lars-Flemming; Suhr, Karin Isabel

    2011-01-01

    Although feed by far is providing the major input to RAS, relatively little is published about the correlation between feed composition and the resulting water quality in such systems. In a set-up with 6 identical RAS, each consisting of a fish tank (0.5 m3), a swirl separator, a submerged...... had impact on water quality in the systems as well as on matter removed by the swirl separators. In the RAS water, phosphorous (Ptot and Pdiss) concentrations were reduced by guar gum. Organic matter content (CODdiss) in the water was also reduced. Corresponding to this, more dry matter, more COD...... to the systems for 49 consecutive days. Each week, 24h-water samples (1 sample/hour) were collected from each system. The sludge collected in the swirl separator that day was also collected. Water and sludge were subsequently analysed for nitrogen, phosphorous and organic matter content. Inclusion of guar gum...

  2. Factors Influencing Water Consumption in Multifamily Housing in Tempe Arizona

    Science.gov (United States)

    Wentz, E. A.

    2012-12-01

    Central to the "Smart Growth" movement is that compact development reduces vehicle miles traveled, carbon emissions, and water use. Empirical efforts to evaluate compact development have examined residential densities, but have not distinguished decreasing lot sizes from multifamily apartments as mechanisms for compact development. Efforts to link design features to water use have emphasized single-family at the expense of multifamily housing. This study isolates the determinants of water use in large (>50) unit apartment complexes in the city of Tempe, Arizona. In July 2007, per-bedroom water use increased with pool area, dishwashers, in-unit laundry facilities, and irrigated landscaping. We explain nearly 50% of the variation in water use with these variables. These results inform public policy for reducing water use in multifamily housing structures, suggesting strategies to construct and market "green" apartment units.

  3. Influences of management of Southern forests on water quantity and quality

    Science.gov (United States)

    Ge Sun; Mark Riedel; Rhett Jackson; Randy Kolka; Devendra Amatya; Jim Shepard

    2004-01-01

    Water is a key output of southern forests and is critical to other processes, functions, and values of forest ecosystems. This chapter synthesizes published literature about the effects of forest management practices on water quantity and water quality across the Southern United States region. We evaluate the influences of forest management at different temporal and...

  4. Predicting the impact of riverbed excavation on the buried depth of groundwater table and capillary water zone in the river banks-taking Xinfeng hydropower station as an example

    Science.gov (United States)

    Shi, Jie; Lan, Jun-Kang

    2017-06-01

    In order to obtain a larger water level drop for power generation, Xinfeng hydropower station proposed to dig 0∼3m depth under the riverbed of downstream. This will affect the burial depth of the groundwater level and capillary water zone on both sides of the river and the nearby resident life and agriculture production. In this study, a three-dimensional groundwater numerical model was set using GMS software to predict the flow field changes after the downstream of riverbed was deepen in Xinfeng hydropower station. Simulation results showed that groundwater level near the bank will greatly decline, affecting water consumption of local residents. Because of the local developed canal system and abundant irrigation water amount, riverbed excavation barely affects agriculture production when increasing the irrigation water volume and frequency.

  5. Influence of Hudiara Drain Water Irrigation on Trace Elements Load ...

    African Journals Online (AJOL)

    MICHAEL

    Demand (COD) and Biological Oxygen Demand (BOD) requirements of Drain water were also found higher than the. National Environmental Quality Standards (NEQS) established under the Pakistan Environmental Protection Act, 1997. It was concluded that continuous use of untreated drain's water is not suitable for ...

  6. How improved water management is influencing economic and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-02-12

    Feb 12, 2015 ... Climate change will affect water availability in Chile, Colombia, and Bolivia, in the three basins this project is studying. Increased demand for water—including urban, agricultural, and industrial use—combined with a projected decrease in water supply, calls for adaptation measures. However, each basin is ...

  7. Influence of salt concentration and topographical position on water ...

    African Journals Online (AJOL)

    2005-04-02

    Apr 2, 2005 ... tribute to classifying the different basins according to their potential power. Exploitation of this innate water power has been realised through temporal regulation of water flow by placing hydroelectric power plants in dams located in the most favourable areas. In Spain, operational hydroelectric power plants.

  8. The influence of the community of water macrophytes on regulation ...

    African Journals Online (AJOL)

    plzfg

    Numerous investigations have shown that natural biohydrocommunities may be of great help in preventing the introduction of pollutants into waters (Banuelos et al. 1997; Amaya-Chávez et al. 2006). Macrophytes, the prime components of broad shallow waters, may play a key role in the processes (Singhal & Mahto 2004; ...

  9. Genetic and environmental influences on water loss in ostrich eggs

    African Journals Online (AJOL)

    zanellb

    Results from studies by Deeming (1995), Ar (1996) and Blood et al. (1998) showed that the optimal water loss for artificially incubated ostrich eggs amounts to approximately 15% but, like other birds, ostriches show some latitude in the amount of water loss at which eggs will still hatch successfully. Eggs which lost less than ...

  10. Influence of salt concentration and topographical position on water ...

    African Journals Online (AJOL)

    Water resource quality (WRQ) is affected by salt concentration and topographical position. Indeed, an increase in salt concentration, which decreases water availability for animal and plant nutrition, and lower altitude, which diminishes the potential for production of hydropower, negatively affects WRQ. Therefore, it is useful ...

  11. Influence of salt concentration and topographical position on water ...

    African Journals Online (AJOL)

    2005-04-02

    Apr 2, 2005 ... 2 Departamento de Silvopascicultura, ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain. Abstract. Water resource quality (WRQ) is affected by salt concentration and topographical position. Indeed, an increase in salt concen- tration, which decreases water ...

  12. Heavy metal contents in the sediments of astatic ponds: Influence of geomorphology, hydroperiod, water chemistry and vegetation.

    Science.gov (United States)

    Gołdyn, Bartłomiej; Chudzińska, Maria; Barałkiewicz, Danuta; Celewicz-Gołdyn, Sofia

    2015-08-01

    The contents of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were analysed in the bottom sediments of 30 small, astatic ponds located in the agricultural landscape of Western Poland. The samples were collected from 118 stations located in patches of four vegetation types. Relationships between the contents of particular elements and four groups of factors (geomorphology, hydroperiod, water quality and vegetation) were tested using Redundancy Analysis (RDA). The most important factors influencing the heavy metal contents were the maximum depth and area of the pond, its hydroperiod, water pH and conductivity values. In general, low quantities of heavy metals were recorded in the sediments of kettle-like ponds (small but located in deep depressions) and high in water bodies of the shore-bursting type (large but shallow). Moreover, quantities of particular elements were influenced by the structure of the vegetation covering the pond. Based on the results, we show which types of astatic ponds are most exposed to contamination and suggest some conservation practices that may reduce the influx of heavy metals. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Tidal Current Power Resources and Influence of Sea-Level Rise in the Coastal Waters of Kinmen Island, Taiwan

    Directory of Open Access Journals (Sweden)

    Wei-Bo Chen

    2017-05-01

    Full Text Available The tidal current power (TCP resource, the impact of TCP extraction on hydrodynamics and the influence of sea-level rise (SLR on TCP output in the coastal waters of Kinmen Island (Taiwan are investigated using a state-of-the-art unstructured-grid depth-integrated numerical model. The model was driven by eight tidal constituents extracted from a global tidal prediction model and verified with time series of measured data for tide level and depth-averaged current. The simulations showed reasonable agreement with the observations; the skill index was in the excellent (0.71–0.93 range with regard to simulating tide level and currents. Model predictions indicated that the channel between Kinmen and Lieyu serves as an appropriate site for deploying the tidal turbines because of its higher tidal current and deeper water depth. The bottom friction approach was utilized to compute the average TCP over a spring-neap cycle (i.e., 15 days. Mean TCP reached its maximum to 45.51 kW for a coverage area of 0.036 km2 when an additional turbine friction coefficient (Ct increased to 0.08, and a cut-in speed of 0.5 m/s was used. The annual TCP output was estimated to be 1.08 MW. The impact of TCP extraction on the change in current is significant, with a maximum reduction rate of instant current exceeding 60%, and the extent of influence for the average current is 1.26 km in length and 0.30 km in width for the −0.05 m/s contour line. However, the impact of TCP extraction on the change in tide level is insignificant; the maximum change in amplitude is only 0.73 cm for the K2 tide. The influence of SLR on the TCP output in Kinmen waters was also estimated. Modeling assessments showed that due to SLR produces faster tidal current, the annual TCP output increased to 1.52 MW, 2.01 MW, 2.48 MW and 2.97 MW under the same cut-in speed and coverage area conditions when SLR 0.25 m, SLR 0.5 m, SLR 0.75 m and SLR 1.0 m were imposed on the model.

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

    Science.gov (United States)

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

  15. Persistent Urban Influence on Surface Water Quality via Impacted Groundwater.

    Science.gov (United States)

    Gabor, Rachel S; Hall, Steven J; Eiriksson, David P; Jameel, Yusuf; Millington, Mallory; Stout, Trinity; Barnes, Michelle L; Gelderloos, Andrew; Tennant, Hyrum; Bowen, Gabriel J; Neilson, Bethany T; Brooks, Paul D

    2017-09-05

    Growing urban environments stress hydrologic systems and impact downstream water quality. We examined a third-order catchment that transitions from an undisturbed mountain environment into urban Salt Lake City, Utah. We performed synoptic surveys during a range of seasonal baseflow conditions and utilized multiple lines of evidence to identify mechanisms by which urbanization impacts water quality. Surface water chemistry did not change appreciably until several kilometers into the urban environment, where concentrations of solutes such as chloride and nitrate increase quickly in a gaining reach. Groundwater springs discharging in this gaining system demonstrate the role of contaminated baseflow from an aquifer in driving stream chemistry. Hydrometric and hydrochemical observations were used to estimate that the aquifer contains approximately 18% water sourced from the urban area. The carbon and nitrogen dynamics indicated the urban aquifer also serves as a biogeochemical reactor. The evidence of surface water-groundwater exchange on a spatial scale of kilometers and time scale of months to years suggests a need to evolve the hydrologic model of anthropogenic impacts to urban water quality to include exchange with the subsurface. This has implications on the space and time scales of water quality mitigation efforts.

  16. Influence of Reservoir Water Level Fluctuations on Sediment ...

    Science.gov (United States)

    Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have elevated methylmercury (MeHg) concentrations compared to natural lakes and rivers. This impact is most pronounced in newly created reservoirs where methylation is fueled by the decomposition of flooded organic material, which can release Hg and enhance microbial activity. Much less is known about the longer-term water-level management impacts on Hg cycling in older reservoirs. The objective of our study was to understand the role of on-going water-level fluctuations on sediment MeHg concentrations and sulfur speciation within a reservoir 75 years after initial impoundment. The study was performed at the Cottage Grove Reservoir located 15 km downstream of the historical Black Butte Hg mine. For 8 months each year, the water level is lowered resulting in roughly half of the reservoir’s sediment being exposed to the atmosphere. Water samples from the inflow, water-column, outflow, and sediment were collected seasonally over a year for total-Hg, MeHg, and several ancillary parameters. The results showed that conditions in the reservoir were favorable to methylation with a much higher %MeHg observed in the outflowing water (34%) compared to the inflow (7%) during the late-summer. An

  17. Influence of Surface and Bulk Water Ice on the Reactivity of a Water-forming Reaction

    Science.gov (United States)

    Lamberts, Thanja; Kästner, Johannes

    2017-09-01

    On the surface of icy dust grains in the dense regions of the interstellar medium, a rich chemistry can take place. Due to the low temperature, reactions that proceed via a barrier can only take place through tunneling. The reaction {{H}}+{{{H}}}2{{{O}}}2\\longrightarrow {{{H}}}2{{O}}+{OH} is such a case with a gas-phase barrier of ˜26.5 kJ mol-1. Still, the reaction is known to be involved in water formation on interstellar grains. Here, we investigate the influence of a water ice surface and of bulk ice on the reaction rate constant. Rate constants are calculated using instanton theory down to 74 K. The ice is taken into account via multiscale modeling, describing the reactants and the direct surrounding at the quantum mechanical level with density functional theory (DFT), while the rest of the ice is modeled on the molecular mechanical level with a force field. We find that H2O2 binding energies cannot be captured by a single value, but rather they depend on the number of hydrogen bonds with surface molecules. In highly amorphous surroundings, the binding site can block the routes of attack and impede the reaction. Furthermore, the activation energies do not correlate with the binding energies of the same sites. The unimolecular rate constants related to the Langmuir-Hinshelwood mechanism increase as the activation energy decreases. Thus, we provide a lower limit for the rate constant and argue that rate constants can have values up to two order of magnitude larger than this limit.

  18. The influence of downstream changes in water quality on ...

    African Journals Online (AJOL)

    Links between spatial differences in phytoplankton composition and changes in environmental variables in the Vaal River, South Africa, were investigated. Multivariate analysis showed that the most important environmental variables influencing algal abundance were turbidity, conductivity, nutrient concentrations and ...

  19. Influence of trophic variables on the depth-range distributions and zonation rates of deep-sea megafauna: the case of the Western Mediterranean assemblages

    Science.gov (United States)

    Cartes, Joan E.; Carrassón, Maite

    2004-02-01

    We studied in a deep-sea megafaunal community the relationship of different trophic variables to the depth ranges inhabited by and depth zonation of species, after the ordination of fish and decapod crustaceans in feeding guilds. The variables studied included trophic level of species, food sources exploited, mean weight of predators and prey, feeding intensity and dietary diversity of species. We compiled data on the diets of 18 species of fish and 14 species of decapod crustaceans distributed between 862 and 2261 m in the Catalano-Balearic Basin (Western Mediterranean). Feeding guilds were identified for fish and decapods separately and at two depth strata (862-1400 and 1400-2261 m). The zonation rates (degree of depth overlap) between species within each trophic guild differed by guild and taxon (fish and decapods). The three guilds (G1, G2 and G3) of decapod crustaceans showed quite significantly distinct overlap. G1 (plankton feeders) showed the widest overlap (1326-1381 m) and G3 (benthos feeders) the narrowest (330-476 m). Among the four guilds established for fish, G1, comprising larger predators such as sharks, showed the lowest overlap (between 194 and 382 m). Macrourids overlap ranged between 122 and 553 m, the rest of benthopelagic feeders ranged between 423 and 970 m, and G3 (benthos feeders) gave overlaps between 867 and 1067 m. Significant differences were detected between the depth overlap of most feeding guilds excluding the paired comparisons between G1/macrourids, and G2/G3. Among decapods higher zonation rates (=lower depth overlap) were identified in those guilds occupying higher trophic levels (TL), with a similar, though not as general, trend among fish. In the ordination of species in feeding guilds, TL as indicated by δ15N measurements, was significantly correlated with Dimension 1 (D1) of ordination—MDS-analysis, both in fish and decapods at 862-1400 m. However, deeper (at 1400-2261 m), D1 was not significantly correlated with TL but

  20. Efeito da profundidade de soldagem no hidrogênio difusível de soldas molhadas Effect of water depth on diffusible hydrogen on wet welds

    Directory of Open Access Journals (Sweden)

    Weslley Carlos Dias da Silva

    2012-12-01

    Full Text Available Em soldagem subaquática molhada, a ocorrência de poros e trincas a frio pode ter um efeito bastante prejudicial nas propriedades mecânicas da junta soldada. O hidrogênio contribui diretamente para o aparecimento destas duas descontinuidades. A quantidade de hidrogênio difusível (Hdif no metal de solda pode ser influenciada por diversos fatores. Todavia, pouco se sabe sobre a influência da profundidade de soldagem (pressão sobre a quantidade de Hdif no metal de solda. Neste trabalho, diversas medições de hidrogênio difusível foram feitas nas profundidades de 0,30 m, 10 m e 20 m e 30 m em soldagem molhada. O consumível utilizado foi o eletrodo comercial E6013 envernizado. As medições de hidrogênio difusível foram feitas através do método da cromatografia. Para medição de porosidade foi utilizado o método macrográfico e um programa analisador de imagem. O hidrogênio residual também foi medido. Os resultados mostraram que o hidrogênio difusível reduziu significativamente com o aumento da pressão hidrostática ao contrário da porosidade, que aumentou com o aumento da pressão hidrostática. Não se observou alterações apreciáveis no hidrogênio residual do metal de solda. Desta forma, é possível concluir que a profundidade de soldagem afeta diversos aspectos da soldagem subaquática molhada, em especial, o hidrogênio difusível e porosidade, conforme foi observado neste trabalho.In underwater wet welding, cold cracking and pores might have a deleterious effect in the mechanical properties of welded joint. The hydrogen might act in the occurrence of theses discontinuities. The amount of diffusible hydrogen in the weld metal can be influenced by several factors. However, not yet known whether the depth of welding (pressure affects the amount of diffusible hydrogen in weld metal. In this work, several measurements of diffusible hydrogen were made at following depth: 0.30 m, 10 m, 20 m and 30 m atwet welding. The

  1. Influence of salinity and water regime on tomato for processing

    Directory of Open Access Journals (Sweden)

    Vito Cantore

    2012-03-01

    Full Text Available The effects of salinity and watering regime on tomato crop are reported. The trials have been carried out over two years in Southern Italy on a deep loam soil. Three saline levels of irrigation water (with electrical conductivity of 0.5, 5 and 10 dS m-1, three watering regimes (at 20, 40 and 60% of available water depletion, and two cultivars (HLY19 and Perfectpeel were compared. The overall results related to the salinity tolerance are in agreement with those from the literature indicating that water salinity reduced marketable yield by 55% in respect to the control treatments. The irrigation regimes that provided higher total and marketable yield were at 40 and 60% of available water depletion (on average, 90.5 and 58.1 Mg ha-1 against 85.3 and 55.5 Mg ha-1 of the 20% available water depletion. Saline and irrigation treatments did not affect sunburned fruits, while affected incidence of fruits with blossom-end rot. The former disease appeared more dramatically in saline treatments (+28% in respect to the control, and occurred mainly in HLY19. The disease incidence was by 52% lower in W2 respect to the W1 and W3. Fruit firmness was higher in S0, whereas it was not affected by irrigation regimes. Total soluble solids and dry matter content of tomato fruits were increased by salinity, whereas it was not affected by irrigation regimes and cultivars. The pH and the titratable acidity remained unchanged between the years, the cultivar and the saline and irrigation treatments. Similarly to the last parameters, the fruit ascorbic acid content remained unchanged in relation to the treatments, but it was higher in HLY19. The recommended thresholds of easily available water to preserve total and marketable yield were at 40 and 60%, respectively. Watering more frequently, instead, on the soil type of the trial, probably caused water-logging and root hypoxia affecting negatively yield.

  2. Water-to-air transfer of branched and linear PFOA: Influence of pH, concentration and water type

    Directory of Open Access Journals (Sweden)

    Jana H. Johansson

    2017-03-01

    Full Text Available The volatilisation of perfluorooctanoic acid (PFOA was measured experimentally at a range of pH values using a previously published laboratory method. Water-to-air transfer was studied for five structural isomers, namely: the linear isomer (n-PFOA and the four most commonly occurring branched isomers (3-, 4-, 5- and 6-PFOA. The influence of water concentration and water type on the pH-dependent water-to-air transfer was also investigated for n-PFOA. The water-to-air transfer was studied over the course of 48 h at pH values ranging from 0.2 to 5.5. Under all experimental conditions tested, the volatilisation of PFOA was negligible at pH > 2.5. In experiments performed with MilliQ water, volatilisation increased with decreasing water pH. In experiments performed with tap water and lake water, maximum volatilisation was observed at pH 1. The concentration of PFOA in water had no influence on the pH value at which water-to-air transfer was observed (i.e. at pH < 2.5 for the concentration range tested (0.1–50 μg/L PFOA in deionised water. Although the percentage of PFOA volatilised was significantly different for the four branched isomers at low pH, volatilisation was not observed above pH 2.5 for any branched isomer suggesting that all PFOA isomers have a low pKa. Overall, these laboratory results demonstrate that volatilisation of any structural isomer of PFOA from water is negligible at environmentally-relevant conditions. It is unlikely that PFOA isomers will be fractionated in the environment as a result of volatilisation because it is a process of negligible environmental relevance.

  3. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Science.gov (United States)

    Mezbahuddin, Mohammad; Grant, Robert F.; Flanagan, Lawrence B.

    2017-12-01

    Water table depth (WTD) effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1) oxygen transport, which controls energy yields from microbial and root oxidation-reduction reactions, and (2) vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May-October WTD drawdown of ˜ 0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re) by 0.26 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen) status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP) and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss) GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. Similar increases in GPP and Re caused no significant WTD effects on modeled

  4. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Directory of Open Access Journals (Sweden)

    M. Mezbahuddin

    2017-12-01

    Full Text Available Water table depth (WTD effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1 oxygen transport, which controls energy yields from microbial and root oxidation–reduction reactions, and (2 vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May–October WTD drawdown of  ∼  0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re by 0.26 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. Similar increases in

  5. Factors influencing the persistence of fecal Bacteroides in stream water.

    Science.gov (United States)

    Bell, Alyssa; Layton, Alice C; McKay, Larry; Williams, Dan; Gentry, Randy; Sayler, Gary S

    2009-01-01

    Laboratory microcosm experiments were used to assess the effects of environmental parameters on the persistence of the Bacteroides 16S rRNA genes derived from equine fecal samples in stream water to investigate the utility of Bacteroides spp. as fecal indicator organisms. Quantitative real-time polymerase chain reaction (qPCR) was used to measure gene concentrations over time with treatments designed to compare filtered vs. unfiltered stream water, fecal aggregate size, initial fecal concentrations, and water temperatures. Comparison of Bacteroides16S rRNA genes/mL in microcosms constructed with unfiltered stream water and filtered stream water indicated that stream water filtration to remove indigenous microorganisms followed by temperature had the largest effects on gene persistence. First-order exponential decay functions were fitted to the data from each microcosm constructed using unfiltered stream water, and the decay constants (k) ranged from 0.0071 h(-1) in the microcosms incubated at 5 degrees C to 0.0336 h(-1) in a set of microcosms incubated at 25 degrees C. Analysis of k calculated from the 10 experimental treatments indicated that k is more highly correlated to temperature than initial Bacteroides 16S rRNA gene starting concentrations. The equation resulting from graphing k (as the dependent variable) vs. temperature (as the independent variable) best fit a peak, Gaussian, 3 parameter function with a maximum decay at 30 degrees C, a r(2) of 0.83 and all parameters were significant (P < 0.0015). Thus this data suggest that factors that reduce biological activity, such as physical removal of stream microorganisms by filtration and low temperature, result in slower Bacteroides 16S rRNA gene decay.

  6. Influence of light-exposure methods and depths of cavity on the microhardness of dual-cured core build-up resin composites

    Science.gov (United States)

    YOSHIDA, Keiichi; MENG, Xiangfeng

    2014-01-01

    Objective The purpose of this study was to evaluate the Knoop hardness number (KHN) of dual-cured core build-up resin composites (DCBRCs) at 6 depths of cavity after 3 post-irradiation times by 4 light-exposure methods. Material and Methods Five specimens each of DCBRCs (Clearfil DC Core Plus [DCP] and Unifil Core EM [UCE]) were filled in acrylic resin blocks with a semi-cylindrical cavity and light-cured using an LED light unit (power density: 1,000 mW/cm2)at the top surface by irradiation for 20 seconds (20 s), 40 seconds (40 s), bonding agent plus 20 seconds (B+20 s), or 40 seconds plus light irradiation of both sides of each acrylic resin block for 40 seconds each (120 s). KHN was measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours, 24 hours, and 7 days post-irradiation. Statistical analysis was performed using repeated measures ANOVA and Tukey's compromise post-hoc test with a significance level of p0.05). In DCP, and not UCE, at 24 hours and 7 days post-irradiation, the B+20 s method showed significantly higher KHN at all depths of cavity, except the depth of 0.5 mm (p<0.05). Conclusion KHN depends on the light-exposure method, use of bonding agent, depth of cavity, post-irradiation time, and material brand. Based on the microhardness behavior, DCBRCs are preferably prepared by the effective exposure method, when used for a greater depth of cavity. PMID:24626248

  7. Influence factors analysis of water environmental quality of main rivers in Tianjin

    Science.gov (United States)

    Li, Ran; Bao, Jingling; Zou, Di; Shi, Fang

    2018-01-01

    According to the evaluation results of the water environment quality of main rivers in Tianjin in 1986-2015, this paper analyzed the current situation of water environmental quality of main rivers in Tianjin retrospectively, established the index system and multiple factors analysis through selecting factors influencing the water environmental quality of main rivers from the economy, industry and nature aspects with the combination method of principal component analysis and linear regression. The results showed that water consumption, sewage discharge and water resources were the main factors influencing the pollution of main rivers. Therefore, optimizing the utilization of water resources, improving utilization efficiency and reducing effluent discharge are important measures to reduce the pollution of surface water environment.

  8. Influence of salinity and water content on soil microorganisms

    Directory of Open Access Journals (Sweden)

    Nan Yan

    2015-12-01

    Full Text Available Salinization is one of the most serious land degradation problems facing world. Salinity results in poor plant growth and low soil microbial activity due to osmotic stress and toxic ions. Soil microorganisms play a pivotal role in soils through mineralization of organic matter into plant available nutrients. Therefore it is important to maintain high microbial activity in soils. Salinity tolerant soil microbes counteract osmotic stress by synthesizing osmolytes which allows them to maintain their cell turgor and metabolism. Osmotic potential is a function of the salt concentration in the soil solution and therefore affected by both salinity (measured as electrical conductivity at a certain water content and soil water content. Soil salinity and water content vary in time and space. Understanding the effect of changes in salinity and water content on soil microorganisms is important for crop production, sustainable land use and rehabilitation of saline soils. In this review, the effects of soil salinity and water content on microbes are discussed to guide future research into management of saline soils.

  9. Influence of Heavy Metal Stress On Water Regime of A Model Forest Ecosystem

    Science.gov (United States)

    Menon, M.; Abbaspour, K. C.; Schulin, R.

    Among various toxic substances that contaminate the soil, the effects of heavy metals are particularly severe on all aspects of soil-plant system. The Swiss Federal Institute for Forest Snow and Land Research (WSL) is addressing comprehensively the issue of heavy metal toxicity in a forest ecosystem in a project titled Sfrom cell to treeT. As & cedil; part of the above project an investigation is being carried out to evaluate the impact of heavy metal stress on water regime of a young forest ecosystem grown in sixteen open top lysimeters. The factorial treatments of the lysimeters include variations of rainwa- ter acidity (acidic, neutral), subsoil type (acidic, calcareous), and heavy metal con- centration (with and without heavy metals in the top 20 cm). Filling of lysimeters was completed in November 1999. Each model ecosystem was planted in spring 2000 with the same collection of trees and herbaceous plants. Each lysimeters is equipped with tensiometers for monitoring of pressure head, time domain reflectometry for moni- toring of water content, and sprinkler devices for application of controlled irrigation. Drainage water data are measured regularly from the canisters installed at the bot- tom of lysimeters and evapotranspiration is calculated through water balancing. Our preliminary analyses of the data shoed the following results. Weekly data collected from May to October 2001 indicated higher amount of percolating water in acidic soil compared to the neutral soil due to textural difference. At 12 cm depth in both soils, control and acidic rain showed lower water potential than heavy metal and combina- tion of acidic rain with heavy metal treatments. In lower depths, water potential did not show much difference between treatments. Water contents showed differences be- tween treatments in the upper part of the profile where the soil is contaminated with heavy metals. Higher water content was observed in heavy metal treatment at 0-25 cm depth than 25-50 cm

  10. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests.

    Science.gov (United States)

    Barbeta, Adrià; Peñuelas, Josep

    2017-12-01

    Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ13 C and δ18 O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO2 . Tree-ring δ18 O for both species were mostly correlated with δ18 O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ18 O but had a positive effect on Q. ilex tree-ring δ18 O. Furthermore, tree-ring δ18 O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions. © 2017 John Wiley & Sons Ltd.

  11. Fluctuations in Anoxia and the Depth of the Eastern Equatorial Pacific Thermocline Inferred from a 2000 Year Sediment Record of Water-Column Denitrification Off Baja California.

    Science.gov (United States)

    van Geen, A.; Mey, J. L., IV; Thunell, R.; Berelson, W.; Deutsch, C. A.

    2014-12-01

    High-resolution records of sediment 15N at three sites along the western margin of North America were recently shown to indicate a gradual weakening of water-column denitrification and therefore anoxia from 1860 to 1990 followed by two decades of intensifying denitrification and anoxia (Deutsch et al., Science August 8, 2014). An ocean general circulation model driven by wind and buoyancy fluxes reproduces these variations for the last 50 years and mechanistically links them to changes in the depth of the thermocline in the eastern Pacific. The data-model comparison shows that strong denitrification and anoxia are associated with a shallow thermocline in the eastern equatorial Pacific and vice-versa. We present here a longer record of sediment 15N from one of the previously studied sites, Soledad basin, indicating that the period of particularly weak denitrification and anoxia in the eastern Pacific reached in the early 1990s was unprecedented for the past 2000 years. This supports the notion that a concomitant deepening of the thermocline during the 20th century simulated by Intergovernmental Panel on Climate Change models may have been driven by the anthropogenic buildup of greenhouse gases. At the other end of the spectrum, the extended sediment 15N record indicates a period of particularly strong denitrification and anoxia extending from about 800 to 1200 AD. This coincides with the Medieval Warm Period of prolonged droughts indicated by tree-ring studies in the American West as well as reduced runoff recorded off coastal Peru. The particularly shallow thermocline inferred from the Soledad basin 15N record for this interval is consistent with the prolonged La Nina-like conditions in the equatorial Pacific that have been proposed to explain the Medieval droughts.

  12. Influence of Water Salinity on Air Purification from Hydrogen Sulfide

    Directory of Open Access Journals (Sweden)

    Leybovych L.I.

    2015-12-01

    Full Text Available Mathematical modeling of «sliding» water drop motion in the air flow was performed in software package FlowVision. The result of mathematical modeling of water motion in a droplet with diameter 100 microns at the «sliding» velocity of 15 m/s is shown. It is established that hydrogen sulfide oxidation occurs at the surface of phases contact. The schematic diagram of the experimental setup for studying air purification from hydrogen sulfide is shown. The results of the experimental research of hydrogen sulfide oxidation by tap and distilled water are presented. The dependence determining the share of hydrogen sulfide oxidized at the surface of phases contact from the dimensionless initial concentration of hydrogen sulfide in the air has been obtained.

  13. Temperature profile and water depth data collected from USS McInerney from expendable bathythermographs (XBT) in the Red Sea from 07 December 1992 to 28 December 1992 (NODC Accession 9300017)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS McInerney in the Red Sea. Data were collected from 07 December 1992 to 28...

  14. Restoration of New Chicago Marsh : Hydrologic and water-quality influences and proposed operations plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a report on directions which the Peninsula Open Space Trust (POST) might pursue in managing the hydrology and water quality influences affecting restoration...

  15. Unravelling the Influence of Cognitive Style on Chinese Students' Classroom Behaviours: The Mediating Effects of the Structure-Oriented/Depth-Oriented Learning Approach

    Science.gov (United States)

    Cheng, Hong-Yu; Guan, Shu-Yi

    2015-01-01

    This study was designed to investigate how cognitive style affects Chinese students' learning behaviours in the classroom. A concept labelled as the structure-oriented vs. depth-oriented learning approach was constructed, and its mediating effects in the link between cognitive style and learning behaviour were proposed and examined in this study.…

  16. Influence of water extract of Mexican sunflower (Tithonia diversifolia ...

    African Journals Online (AJOL)

    Laboratory analysis of the water extract of Tithonia diversifolia shoot and root on infra-red spectrometer to determine the phytotoxic potential and greenhouse experiments to evaluate its phytotoxic effect and growth promoting attribute on cowpea (Vigna unguiculata L.) were carried out. T. diversifolia contained some ...

  17. Influence of Molding Water Content on Shear Strength Characteristic ...

    African Journals Online (AJOL)

    A laboratory investigation was carried out to determine the shear strength characteristics of compacted cement kiln dust treated lateritic soils for use in liners and covers with up to 12.5% cement kiln dust by dry weight of soil. Specimens were prepared at molding water contents of -2, 0, +2 and +4% of the optimum moisture ...

  18. influence of tanks liner material on water quality and growth

    African Journals Online (AJOL)

    DR A O AKINWOLE

    PVC lined tanks had better growth performance when compared to other tanks liner materials. It would be beneficial with respect to fish growth and culture water quality, to use polyvinylchloride materials in lining fish culture ponds and rearing tanks. Keywords : Aquaculture, Liners, Fish Farming, Tank, Clarias gariepinus.

  19. Influence of discharged effluent on the quality of surface water ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... This article reports on the level of toxic trace metals (Cd, Pb, Mn, Zn, Cu and Ni) in surface water and sediment along the Blaauwbankspruit in the West Rand District of South Africa. This spruit serves as receiving channel of wastewaters from sewage treatment plant and a gold mine. Some physical and.

  20. Climate influences on upper Limpopo River flow | Jury | Water SA

    African Journals Online (AJOL)

    This study demonstrates how the regional climate affects river flow in the upper Limpopo Valley of southern Africa (21–24.5S, 26–30E). The catchment basin receives inflow from the Crocodile, Marico, Mahalapse and Lotsane Rivers, and lies on the eastern fringe of the Kalahari plateau, known for water-deficit conditions.

  1. Genetic and environmental influences on water loss in ostrich eggs

    African Journals Online (AJOL)

    zanellb

    Abstract. Data obtained from a pair-mated ostrich flock located at Oudtshoorn, South Africa, were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21. (WL21) and 35 (WL35) days of incubation, and pipping time (PT) for between 13 806 and 19 913 artificially incubated ...

  2. Influence of water on the anodic oxidation mechanism of ...

    African Journals Online (AJOL)

    The following successive scans showed a high decrease of the current intensity and that is due to the formation of an insulating coating layer on the electrode surface. When water is added to the non-aqueous electrolyte, a DETA oxidation wave appears on the voltammograms. That oxidation wave is observed on the ...

  3. Influence of Hudiara Drain Water Irrigation on Trace Elements Load ...

    African Journals Online (AJOL)

    cultivated area along the Drain by lifting the drain's water through electric pumps, peter engines and tractor driven devices. The density of tubewells is 7 pumps per kilometres for irrigating the farmer's fields and it is increasing day by day. Three points were selected for sampling the vegetables along the 54.6 km stretch of ...

  4. Influence of Clarias gariepinus (Teugels) cage cultures on water ...

    African Journals Online (AJOL)

    Water quality, periphyton and phytoplankton growing as a function Clarias gariepinus (Burchell, 1822) cage cultures have rarely been investigated. Physical and chemical factors associated with cage culture of Clarias gariepinus in relation to phytoplankton and periphyton were examined fortnightly from May to June 2009 ...

  5. influence of molding water content on shear strength characteristic

    African Journals Online (AJOL)

    eobe

    well as water content, clays compacted dry of optimum are initially stronger than when compacted wet of optimum. Compacted soil strength can be evaluated in terms of confined compression strength,. [1] selected minimum unconfined compressive strength of 200kN/m2. (200kPa) to represent adequate shear strength for ...

  6. Iodine-129 concentrations in marginal seas of the North Pacific and Pacific-influenced waters of the Arctic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Lee W.; Grebmeier, Jacqueline M. [Tennessee Univ., Dept. of Ecology and Evolutionary Biology, Knoxville, TN (United States); Hong, Gi H. [Korea Ocean Research and Development Inst., Seoul (Korea); Beasley, Tom M. [US Dept. of Energy, New York, NY (United States)

    2001-07-01

    Water sampling during the 1993 IV Russian-US Joint Expedition to the Bering and Chukchi Seas (BERPAC) indicates that Pacific Ocean burdens of the long-lived radionuclide {sup 129}I are relatively low in the Pacific-influenced Arctic, particularly compared to high latitude water influenced by the North Atlantic. These low concentrations occur despite the presence of potential submerged anthropogenic sources in the East Sea (Sea of Japan), and in the northwest Pacific Ocean, east of the Kamchatka Peninsula. The concentration of {sup 129}I entering the Arctic Ocean through Bering Strait, {approx}0.7x10{sup 8} atoms kg {sup -1}, is only slightly higher than observed in deep Pacific water. Similar concentrations (0.44-0.76x10{sup 8}atoms kg{sup -1}) measured in Long Strait indicate no significant transfer of {sup 129}I eastward into the Chukchi Sea in the Siberian Coastal Current from the Siberian marginal seas to the west, However, the concentrations reported here are more than an order to magnitude higher than the Bering Strait input concentration estimated (1.0x10{sup 6}atoms kg{sup -1}) from bomb fallout mass balances, which supports other existing evidence for a significant atmospheric deposition term for this radionuclide in surface ocean waters. Near-bottom water samples collected in productive waters of the Bering and Chukchi Seas also suggest that sediment regeneration may locally elevate {sup 129}I concentrations, and impact its utility as a water mass tracer. As part of this study, two deep {sup 129}I profiles were also measured in the East Sea in 1993-1994. The near-surface concentration of {sup 129}I ranged from 0.12 to 0.31x10{sup 8}atoms kg{sup -1}. The {sup 129}I concentration showed a steady decrease with depth, although because of active deep water ventilation, the entire 3000 m water column exceeded natural concentrations of the radionuclide. Atom ratios of {sup 129}I/{sup 137}Cs in the East Sea also suggest an excess of {sup 129}I above bomb fallout

  7. Influence of water stress on Botryosphaeriaceae disease expression in grapevines

    Directory of Open Access Journals (Sweden)

    Jan VAN NIEKERK

    2011-12-01

    Full Text Available Several species in Botryosphaeriaceae have been associated with grapevine trunk diseases. To evaluate the effect of water stress on infection of grapevines by Botryosphaeriaceae spp., 1-year-old Shiraz/101-14 Mgt nursery grapevine plants were planted in plastic potting bags and placed outdoors under shade netting. Five weeks after planting, vines were pruned and the pruning wounds inoculated with spore suspensions of Neofusicoccum australe, Neofusicoccum parvum, Lasiodiplodia theobromae or Diplodia seriata. Control treatments consisted of applications of sterile water or a Trichoderma harzianum spore suspension. Stem inoculations were done by inserting a colonised or uncolonised agar plug into a wound made in each stem. Four different irrigation regimes were introduced 12 weeks after planting to simulate varying degrees of water stress. Measurements of stomatal conductance, photosynthetic rate and leaf spectrometry were made to monitor physiological stress. Eight months after inoculation, vines were uprooted and the root, shoot and plant mass of each vine determined. Lesions observed in the inoculated pruning wounds and stems were also measured. Vines subjected to the lowest irrigation regime were significantly smaller than optimally irrigated vines. Water stressed vines also had significantly lower photosynthetic rates and levels of stomatal conductance compared with vines receiving optimal irrigation, indicating that these plants experienced significantly higher levels of physiological stress. The mean lesion length was significantly longer in the pruning wounds and stems of plants subjected to the lowest irrigation regime, with lesion length declining linearly with increasing irrigation volume. These results clearly indicate that when a grapevine is exposed to water stress, colonisation and disease expression by Botryosphaeriaceae spp. are much more severe.

  8. Modeling the influence of temperature, water activity and water mobility on the persistence of Salmonella in low-moisture foods.

    Science.gov (United States)

    Farakos, S M Santillana; Frank, J F; Schaffner, D W

    2013-09-02

    Salmonella can survive in low-moisture foods for long periods of time. Reduced microbial inactivation during heating is believed to be due to the interaction of cells and water, and is thought to be related to water activity (a(w)). Little is known about the role of water mobility in influencing the survival of Salmonella in low-moisture foods. The aim of this study was to determine how the physical state of water in low-moisture foods influences the survival of Salmonella and to use this information to develop mathematical models that predict the behavior of Salmonella in these foods. Whey protein powder of differing water mobilities was produced by pH adjustment and heat denaturation, and then equilibrated to aw levels between 0.19±0.03 and 0.54±0.02. Water mobility was determined by wide-line proton-NMR. Powders were inoculated with a four-strain cocktail of Salmonella, vacuum-sealed and stored at 21, 36, 50, 60, 70 and 80°C. Survival data was fitted to the log-linear, the Geeraerd-tail, the Weibull, the biphasic-linear and the Baranyi models. The model with the best ability to describe the data over all temperatures, water activities and water mobilities (f(test)survival kinetics for Salmonella. The influence of temperature, aw and water mobility on the survival of Salmonella was evaluated using multiple linear regression. Secondary models were developed and then validated in dry non-fat dairy and grain, and low-fat peanut and cocoa products within the range of the modeled data. Water activity significantly influenced the survival of Salmonella at all temperatures, survival increasing with decreasing a(w). Water mobility did not significantly influence survival independent of a(w). Secondary models were useful in predicting the survival of Salmonella in various low-moisture foods providing a correlation of R=0.94 and an acceptable prediction performance of 81%. The % bias and % discrepancy results showed that the models were more accurate in predicting

  9. The influence of soil type, soil water and share sharpness of a mouldboard plough on energy consumption, rate of work and tillage quality

    Energy Technology Data Exchange (ETDEWEB)

    Natsis, A. [Station of Agricultural Power and Machinery of Sarante, Finiq (Albania); Agricultural University of Athens (Greece); Papadakis, G.; Pitsilis, J. [Agricultural University of Athens (Greece)

    1999-07-01

    The results of field tests to investigate the influence of soil type and soil water on the wear of soil tillage tools are presented. The soil water had a positive effect for loam and clay soils because the wear decreased as the water content increased. For sandy soils however, wear increased with soil water. As the thickness of the cutting edge of the plough increased, draught force and fuel consumption increased considerably, while rate of work and tillage depth increased. The quality of the tillage was seriously reduced, that is, the size of the soil clods increased as the thickness of the cutting edge of the plough increased. Also, the percentage of surface residues was greater as the thickness of the cutting edge of the plough increased. The best overall performance of the plough was obtained from the sharpest share cutting edge with a thickness of 1 mm. (author)

  10. Storms do not alter long-term watershed development influences on coastal water quality.

    Science.gov (United States)

    Chen, Yushun; Cebrian, Just; Lehrter, John; Christiaen, Bart; Stutes, Jason; Goff, Josh

    2017-09-15

    A twelve year (2000-2011) study of three coastal lagoons in the Gulf of Mexico was conducted to assess the impacts of local watershed development and tropical storms on water quality. The lagoons have similar physical and hydrological characteristics, but differ substantially in the degree of watershed urban development and nutrient loading rates. In total the lagoons experienced 22 storm events during the period studied. Specifically, we examine (1) whether there are influences on water quality in the lagoons from watershed development, (2) whether there are influences on water quality in the lagoons from storm activity, and (3) whether water quality is affected to a greater degree by watershed development versus storm activity. The two urbanized lagoons typically showed higher water-column nitrate, dissolved organic nitrogen, and phosphate compared with the non-urbanized lagoon. One of the urbanized lagoons had higher water-column chlorophyll a concentrations than the other two lagoons on most sampling dates, and higher light extinction coefficients on some sampling dates. The non-urbanized lagoon had higher water-column dissolved oxygen concentrations than other lagoons on many sampling dates. Our results suggest long-term influences of watershed development on coastal water quality. We also found some evidence of significant storm effects on water quality, such as increased nitrate, phosphate, and dissolved oxygen, and decreased salinity and water temperature. However, the influences of watershed development on water quality were greater. These results suggest that changes in water quality induced by human watershed development pervade despite the storm effects. These findings may be useful for environmental management since they suggest that storms do not profoundly alter long-term changes in water quality that resulted from human development of watersheds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Factors influencing farmers’ willingness to participate in water allocation trading. A case study in southern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Giannoccaro, G.; Castillo, M.; Berbel, J.

    2016-11-01

    This study aims to uncover the factors that influence farmers’ attitudes towards water allocation trading. In the study, we simulate two water availability scenarios, an average year and a drought year, in a contingent valuation experiment with 241 farmers. A survey was held in the spring of 2012 in the Guadalquivir and Almanzora River Basins. First, we estimated a multinomial logit model to determine the factors that influence farmers to decide to participate in our hypothetical market. We then analysed the structural and socio-economic factors determining the monetary value of traded water using Heckman’s two-step model. Our results indicate that those farmers who are more innovative and have had agricultural training show a higher willingness to participate in water trading. Additionally, low water-supply guarantee and appropriate information about seasonal water availability increase the probability of participation. Higher willingness to pay (WTP) for water is found in horticulture and among farmers who grow citrus and other permanent crops; lower water selling value (WTA) is found in farms with extensive annual crops and traditional olive groves. However, monetary values (WTP/WTA) are strongly dependent on the current cost of irrigation water services. While findings of this research seem to support the idea of diffusion innovation theory, the existence of ethical concerns that might influence farmers’ acceptance of irrigation water markets needs further analysis. (Author)

  12. Factors influencing farmers’ willingness to participate in water allocation trading. A case study in southern Spain

    Directory of Open Access Journals (Sweden)

    Giacomo Giannoccaro

    2016-03-01

    Full Text Available This study aims to uncover the factors that influence farmers’ attitudes towards water allocation trading. In the study, we simulate two water availability scenarios, an average year and a drought year, in a contingent valuation experiment with 241 farmers. A survey was held in the spring of 2012 in the Guadalquivir and Almanzora River Basins. First, we estimated a multinomial logit model to determine the factors that influence farmers to decide to participate in our hypothetical market. We then analysed the structural and socio-economic factors determining the monetary value of traded water using Heckman’s two-step model. Our results indicate that those farmers who are more innovative and have had agricultural training show a higher willingness to participate in water trading. Additionally, low water-supply guarantee and appropriate information about seasonal water availability increase the probability of participation. Higher willingness to pay (WTP for water is found in horticulture and among farmers who grow citrus and other permanent crops; lower water selling value (WTA is found in farms with extensive annual crops and traditional olive groves. However, monetary values (WTP/WTA are strongly dependent on the current cost of irrigation water services. While findings of this research seem to support the idea of diffusion innovation theory, the existence of ethical concerns that might influence farmers’ acceptance of irrigation water markets needs further analysis.

  13. Decisive key-factors influencing farm households' soil and water conservation investments

    NARCIS (Netherlands)

    Kessler, A.

    2006-01-01

    In the inter-Andean valleys of Bolivia decisive key-factors influencing farm households' soil and water conservation investments were determined. The household's progressiveness most influences the decision how much to invest; dynamic and responsible families are among the first. Economic stratum is

  14. The influence of natural mineral water on aquaporin water permeability and human natural killer cell activity.

    Science.gov (United States)

    Kitagawa, Yoshichika; Liu, Chengwei; Ding, Xiaodong

    2011-05-27

    Aquaporins are the intrinsic membrane proteins functioning as water channel to transport water and/or mineral nutrients across the biological membrane systems. In this research, we aimed to clarify if the selected mineral water can affect aquaporin functions in vitro and the assumption of the mineral water can modify aquaporin expression and activate natural killer cell activity in human body. First, we expressed six human and eight plant aquaporin genes in oocytes and compared the effect of different kinds of natural mineral water on aquaporin activity. The oocyte assay data show that Hita tenryosui water could promote water permeability of almost all human and plant aquaporins in varying degrees, and freeze-dry and organic solvent extraction could reduce AQP2 activity but pH change and boiling could not. Second, each volunteer in two groups (10 in one group) received an oral Hita tenryosui or tap water load of 1000 ml/day for total four weeks. We found that these two kinds of water did not directly affect the relative expression levels of AQP1 and AQP9 in the blood cells, but intriguingly, the natural killer cell activities of the volunteers drinking Hita tenryosui water were significantly improved, suggesting that Hita tenryosui water has obvious health function, which opens a new and interesting field of investigation related to the link between mineral water consumption and human health and the therapies for some chronic diseases. Published by Elsevier Inc.

  15. THE INFLUENCE OF SELECTED ORGANIC MICROPOLLUTANTS ON WATER ECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Edyta Anna Kudlek

    2017-06-01

    Full Text Available The paper presents a literature review in terms of the impact of selected micropollutants from the group of pharmaceutical compounds, food preservatives, pesticides and organic UV filters on various plants and animals species, which inhabit the water ecosystems. During own studies the impact of concentrations of micropollutants in the water environment on selected indicator organisms was evaluated. The study was conducted using saltwater Aliivibrio fischer bacteria, freshwater Daphnia magna and saltwater Artemia fanciscana crustaceans, as well as vascular plants Lemna minor. It was shown that the test organisms are characterized by a different sensitivity for the presence of micropollutants. For all applied tests an increase in the response of indicator organisms with the increasing compound concentration was observed. It demonstrates the growing toxic impact of micropollutants. The solution of benzophenone-3 at a concentration of 5 mg/dm3 was characterized by the highest toxic effects against both bacteria, crustaceans and vascular plants.

  16. Biosorption Of Heavy Metals From Mining Influenced Water Onto Chitin Products

    Science.gov (United States)

    Mining influenced water (MIW) emanating from mine sites poses a major environmental concern due to its impact on water contamination caused by low pH and the presence of high concentrations of toxic metals. Chitorem SC-20® (raw crushed crab shells containing 40% w/w C...

  17. Conductivity, temperature, depth, water quality and pigment data from R/V Bellows cruise BE-1311, 2012-12-12 to 2012-12-14 (NCEI Accession 0159411)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains conductivity, temperature, and depth data collected during R/V Bellows cruise BE-1311 of the offshore shelf of the Florida Panhandle Bight at...

  18. Influence of solar water disinfection on immunity against cholera: a review

    CSIR Research Space (South Africa)

    Ssemakalu, CC

    2014-09-01

    Full Text Available on the spread of waterborne diseases 115 The consumption of SODIS water in sub-Saharan African and various East Asian countries 116 has reduced the percentage of individuals acquiring water borne diseases such as dysentery 117 typhoid and cholera (Conroy, et... review, the possible influence that solar water disinfection may have on the immunity 35 against cholera is discussed. 36 Keywords: Cholera, SODIS, Solar Ultraviolet Radiation, Vaccine, V. cholerae, Waterborne 37 disease 38 39 40 3...

  19. Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product.

    Science.gov (United States)

    Crum, Alia J; Phillips, Damon J; Goyer, J Parker; Akinola, Modupe; Higgins, E Tory

    2016-01-01

    This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, "AquaCharge Energy Water," falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water.

  20. Ground water chlorinated ethenes in tree trunks: case studies, influence of recharge, and potential degradation mechanism

    Science.gov (United States)

    Don A. Vroblesky; Barton D. Clinton; James M. Vose; Clifton C. Casey; Gregory J. Harvey; Paul M. Bradley

    2004-01-01

    Trichloroethene (TCE) was detected in cores of trees growing above TCE-contaminated ground at three sites: the Carswell Golf Course in Texas, Air Force Plant PJKS in Colorado, and Naval Weapons Station Charleston in South Carolina. This was true even when the depth to water was 7.9 m or when the contaminated aquifer was confined beneath ~3 m of clay. Additional ground...

  1. VERIFIKASI PERCENTAGE DEPTH DOSE (PDD) DAN PROFILE DOSE PESAWAT LINEAR ACCELERATOR (LINAC) BERKAS ELEKTRON 6 MeV, 9 MeV, 12 MeV DAN 15 MeV MENGGUNAKAN WATER PHANTOM

    OpenAIRE

    Marten Padang, Jumedi

    2015-01-01

    Abstrak Telah dilakukan penelitian tentang Verifikasi Percentage Depth Dose (PDD) dan Profile Dose Pesawat Linear Accelerator (LINAC) Berkas Elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV Menggunakan Water Phantom. Penelitian ini bertujuan untuk menganalisis Percentage Depth Dose (PDD) dan Profile Dose pesawat linac jenis HCX 5640 berkas elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV untuk luas lapangan 10 x 10 cm2. Penelitian ini membandingkan data acuan yang telah ada sebelumnya dan data yang dipero...

  2. A Water Availability Intervention in New York City Public Schools: Influence on Youths’ Water and Milk Behaviors

    Science.gov (United States)

    Mijanovich, Tod; Abrams, Courtney; Cantor, Jonathan; Dunn, Lillian; Nonas, Cathy; Cappola, Kristin; Onufrak, Stephen; Park, Sohyun

    2015-01-01

    Objectives. We determined the influence of “water jets” on observed water and milk taking and self-reported fluid consumption in New York City public schools. Methods. From 2010 to 2011, before and 3 months after water jet installation in 9 schools, we observed water and milk taking in cafeterias (mean 1000 students per school) and surveyed students in grades 5, 8, and 11 (n = 2899) in the 9 schools that received water jets and 10 schools that did not. We performed an observation 1 year after implementation (2011–2012) with a subset of schools. We also interviewed cafeteria workers regarding the intervention. Results. Three months after implementation we observed a 3-fold increase in water taking (increase of 21.63 events per 100 students; P schools. At 1 year, relative to baseline, there was a similar increase in water taking and no decrease in milk taking. Cafeteria workers reported that the water jets were simple to clean and operate. Conclusions. An environmental intervention in New York City public schools increased water taking and was simple to implement. PMID:25521867

  3. A water availability intervention in New York City public schools: influence on youths' water and milk behaviors.

    Science.gov (United States)

    Elbel, Brian; Mijanovich, Tod; Abrams, Courtney; Cantor, Jonathan; Dunn, Lillian; Nonas, Cathy; Cappola, Kristin; Onufrak, Stephen; Park, Sohyun

    2015-02-01

    We determined the influence of "water jets" on observed water and milk taking and self-reported fluid consumption in New York City public schools. From 2010 to 2011, before and 3 months after water jet installation in 9 schools, we observed water and milk taking in cafeterias (mean 1000 students per school) and surveyed students in grades 5, 8, and 11 (n=2899) in the 9 schools that received water jets and 10 schools that did not. We performed an observation 1 year after implementation (2011-2012) with a subset of schools. We also interviewed cafeteria workers regarding the intervention. Three months after implementation we observed a 3-fold increase in water taking (increase of 21.63 events per 100 students; Pschools. At 1 year, relative to baseline, there was a similar increase in water taking and no decrease in milk taking. Cafeteria workers reported that the water jets were simple to clean and operate. An environmental intervention in New York City public schools increased water taking and was simple to implement.

  4. Influence of geology on arsenic concentrations in ground and surface water in central Lesvos, Greece.

    Science.gov (United States)

    Aloupi, Maria; Angelidis, Michael O; Gavriil, Apostolos M; Koulousaris, Michael; Varnavas, Soterios P

    2009-04-01

    The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos-Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos-Lisvori does not affect the presence of As in groundwater and streams.

  5. Spatiotemporal Variability of Snow Depth across Eurasian Continent from 1966 to 2008

    Science.gov (United States)

    Zhong, X.; Zhang, T.; Wang, K.

    2013-12-01

    Snow depth is one of the important parameters of snow cover, and it affects the surface energy balance, assessment of snow water equivalent, ecosystem, soil temperatures, and water cycle as a whole. In this study, the long-term observed snow depth from 1972 meteorological stations and snow course sites were used to investigate snow depth climatology and its spatiotemporal variations over Eurasian Continent from 1966 to 2008. Preliminary results showed that snow depth was affected by latitude, which in general snow depth increased with the increasing latitude. The higher values of snow depth were found in the northeastern European Russia, the east of western Siberia, the west of central Siberia, Kamchatka Peninsula, and some areas of Sakhalin. While the lower snow accumulation occurred in most areas of China except for the north of Xinjiang Autonomous Region of China, Northeast China, and some regions of the southwestern Tibet. Both of the trends in inter-annual variability of annual mean snow depth and annual maximum snow depth were not significant. However, the long-term monthly mean snow depth had obvious increasing trends from February to May. There were similar spatial distributions of linear trend coefficients of annual mean snow depth and annual maximum snow depth across the former Soviet Union (USSR). The most significant trends of changes in annual mean snow depth and annual maximum snow depth were found between 40° to 70°N. The obvious trends of variability in monthly mean snow depth appeared in the areas between 50° to 60°N. The significant decreasing trends in monthly mean snow depth were observed in most areas of China from February to March. This may be largely influenced by climate change, which leads to an advancing of the end date of snow cover.

  6. The Influence of topography on formation characteristics of hygroscopic and condensate water in Shapotou

    Science.gov (United States)

    Pan, Yanxia; Li, Xinrong; Hui, Rong; Zhao, Yang

    2016-04-01

    The formation characteristics of hygroscopic and condensate water for different topographic positions were observed using the PVC pipes manual weighing and CPM method in the typical mobile dunes fixed by straw checkerboard barriers in Shapotou. The results indicated that the formation amounts and duration of hygroscopic and condensate water show moderate spatial heterogeneity at the influence of topography. The formation amounts of hygroscopic and condensate water at different aspects conform to the classical convection model, in which the hygroscopic and condensate water amounts are highest at hollow, and windward aspect gets more water than leeward aspect, the hygroscopic and condensate water amounts at different aspects are expressed as: hollow>Western-faced aspect>Northern-faced aspect>hilltop>Southern-faced aspect>Eastern-faced aspect. The hygroscopic and condensate water amounts at different slope positions for every aspect are as follows: the foot of slope>middle slope>hilltop. A negatively linear correlation is got between slope angles and hygroscopic and condensate water amounts, hygroscopic and condensate water amounts decrease gradually along with the increase of slope angles, the amounts of hygroscopic and condensate water at the vertical aspect are only half of horizontal aspect, which indicated topography were important influence factors for the formation of the hygroscopic and condensate water in arid area.

  7. Influence of Palm Sugar Water in the Native Chicken Performance

    OpenAIRE

    Aryanti, Fera; Aji, Muhammad Bayu; Budiono, Nugroho

    2013-01-01

    Palm sugar containing 66,18% sukrose is an additional source of energi quickly available to the chicken. A study to examine the effect of palm sugar in the native chicken performance was held in animal health training center, Cinagara-Bogor lasted from August until November 2012. This present experiment using 1274 native chicken that were kept starting DOC. Palm sugar concentrations given in the drinking water as much as one percent started to be given to the chcken when they were still DOC. ...

  8. Influence of Palm Sugar Water in the Native Chicken Performance

    OpenAIRE

    Aryanti, Fera; Aji, Muhammad Bayu; Budiono, Nugroho

    2014-01-01

    Abstract Palm sugar containing 66,18% sukrose is an additional source of energi quickly available to the chicken. A study to examine the effect of palm sugar in the native chicken performance was held in animal health training center, Cinagara-Bogor lasted from August until November 2012. This present experiment using 1274 native chicken that were kept starting DOC. Palm sugar concentrations given in the drinking water as much as one percent started to be given to the chcken when they were st...

  9. Influence of urban surface properties and rainfall characteristics on surface water flood outputs - insights from a physical modelling environment

    Science.gov (United States)

    Green, Daniel; Pattison, Ian; Yu, Dapeng

    2017-04-01

    Surface water (pluvial) flooding occurs when excess rainfall from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flood events pose a major hazard to urban regions across the world, with nearly two thirds of flood damages in the UK being caused by surface water flood events. The perceived risk of surface water flooding appears to have increased in recent years due to several factors, including (i) precipitation increases associated with climatic change and variability; (ii) population growth meaning more people are occupying flood risk areas, and; (iii) land-use changes. Because urban areas are often associated with a high proportion of impermeable land-uses (e.g. tarmacked or paved surfaces and buildings) and a reduced coverage of vegetated, permeable surfaces, urban surface water flood risk during high intensity precipitation events is often exacerbated. To investigate the influence of urbanisation and terrestrial factors on surface water flood outputs, rainfall intensity, catchment slope, permeability, building density/layout scenarios were designed within a novel, 9m2 physical modelling environment. The two-tiered physical model used consists of (i) a low-cost, nozzle-type rainfall simulator component which is able to simulate consistent, uniformly distributed rainfall events of varying duration and intensity, and; (ii) a reconfigurable, modular plot surface. All experiments within the physical modelling environment were subjected to a spatiotemporally uniform 45-minute simulated rainfall event, while terrestrial factors on the physical model plot surface were altered systematically to investigate their hydrological response on modelled outflow and depth profiles. Results from the closed, controlled physical modelling experiments suggest that meteorological factors, such as the duration and intensity of simulated rainfall, and terrestrial factors, such as model slope

  10. Influence of radiolysis products of water in cytotoxicity assay

    Energy Technology Data Exchange (ETDEWEB)

    Camillo, Maria A.P.; Luly, Juliana H.; Silva, Jose A. Alves da; Magalhaes, Vanessa D.; Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia]. E-mail: mcamillo@ipen.br

    2007-07-01

    The ionizing radiation has shown to be an useful tool in the improvement of immunogens such as toxins; venoms; protozoa among others. A recent study has demonstrated that hydroxyl radical is the main radiolysis product of water involved in the protein irradiation. It promotes important structural modifications in the toxins meanwhile the immunogenic properties are preserved. Tests of biological activity are essential to determine the detoxification of the samples and the safety of the inoculum. The in vitro cytotoxicity assay, determining the cellular viability, was chosen for this analysis. This test has good reproducibility; it can be carried out with little amount of sample and has been useful for biological evaluation of biomaterials. Herein are presented the results gotten with gyroxin (a serine protease, glycoprotein with 26 kDa) isolated from the rattlesnake Crotalus durissus terrificus venom. The toxin was irradiated with 2 kGy of gamma ray of cobalt-60 in saline solution. The evaluation of the biological activity was carried out with different cell lines, using MTS dye or {sup 3}H-thymidine incorporation as indicators of cells viability. The best correlation between the cellular viability assay and lethality assay in vivo was obtained with endothelial cells (HUVECs) and {sup 3}H-thymidine incorporation. The MTS evaluation presented a false-positive result of cytotoxicity, probably due to the reaction with free radicals formed by radiolysis of water during the irradiation process. (author)

  11. A study of water pressure influence on failure of large diameter water pipelines

    OpenAIRE

    Rathnayaka, Suranji Uditha Priyankara

    2017-01-01

    This research is part of a large research project investigating how, when, and where critical pipes (diameter≥300mm) fail in water supply networks. The failure of large- diameter pipe is critical, as it may have devastating consequences for both the public and the water utility. Factors contributing to pipe failure, such as internal pressure, external load, and corrosion, are examined in this research. The objective of the study is to understand the contribution of internal water pressur...

  12. An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system.

    Science.gov (United States)

    Zlatanović, Lj; van der Hoek, J P; Vreeburg, J H G

    2017-10-15

    The drinking water quality changes during the transport through distribution systems. Domestic drinking water systems (DDWSs), which include the plumbing between the water meter and consumer's taps, are the most critical points in which water quality may be affected. In distribution networks, the drinking water temperature and water residence time are regarded as indicators of the drinking water quality. This paper describes an experimental research on the influence of stagnation time and temperature change on drinking water quality in a full-scale DDWS. Two sets of stagnation experiments, during winter and summer months, with various stagnation intervals (up to 168 h of stagnation) were carried out. Water and biofilms were sampled at two different taps, a kitchen and a shower tap. Results from this study indicate that temperature and water stagnation affect both chemical and microbial quality in DDWSs, whereas microbial parameters in stagnant water appear to be driven by the temperature of fresh water. Biofilm formed in the shower pipe contained more total and intact cells than the kitchen pipe biofilm. Alphaproteobacteria were found to dominate in the shower biofilm (78% of all Proteobacteria), while in the kitchen tap biofilm Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were evenly distributed. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Water heater temperature set point and water use patterns influence Legionella pneumophila and associated microorganisms at the tap.

    Science.gov (United States)

    Rhoads, William J; Ji, Pan; Pruden, Amy; Edwards, Marc A

    2015-12-01

    Lowering water heater temperature set points and using less drinking water are common approaches to conserving water and energy; yet, there are discrepancies in past literature regarding the effects of water heater temperature and water use patterns on the occurrence of opportunistic pathogens, in particular Legionella pneumophila. Our objective was to conduct a controlled, replicated pilot-scale investigation to address this knowledge gap using continuously recirculating water heaters to examine five water heater set points (39-58 °C) under three water use conditions. We hypothesized that L. pneumophila levels at the tap depend on the collective influence of water heater temperature, flow frequency, and the resident plumbing ecology. We confirmed temperature setting to be a critical factor in suppressing L. pneumophila growth both in continuously recirculating hot water lines and at distal taps. For example, at 51 °C, planktonic L. pneumophila in recirculating lines was reduced by a factor of 28.7 compared to 39 °C and was prevented from re-colonizing biofilm. However, L. pneumophila still persisted up to 58 °C, with evidence that it was growing under the conditions of this study. Further, exposure to 51 °C water in a low-use tap appeared to optimally select for L. pneumophila (e.g., 125 times greater numbers than in high-use taps). We subsequently explored relationships among L. pneumophila and other ecologically relevant microbes, noting that elevated temperature did not have a general disinfecting effect in terms of total bacterial numbers. We documented the relationship between L. pneumophila and Legionella spp., and noted several instances of correlations with Vermamoeba vermiformis, and generally found that there is a dynamic relationship with this amoeba host over the range of temperatures and water use frequencies examined. Our study provides a new window of understanding into the microbial ecology of potable hot water systems and helps to resolve

  14. Influence of collisional rate coefficients on water vapour excitation

    Science.gov (United States)

    Daniel, F.; Goicoechea, J. R.; Cernicharo, J.; Dubernet, M.-L.; Faure, A.

    2012-11-01

    Context. Water is a key molecule in many astrophysical studies that deal with star or planet forming regions, evolved stars, and galaxies. Its high dipole moment makes this molecule subthermally populated under the typical conditions of most astrophysical objects. This motivated calculation of various sets of collisional rate coefficients (CRC) for H2O (with He or H2), which are needed to model its rotational excitation and line emission. Aims: The most accurate set of CRC are the quantum rates that involve H2. However, they have been published only recently, and less accurate CRC (quantum with He or quantum classical trajectory (QCT) with H2) were used in many studies before that. This work aims to underline the impact that the new available set of CRC have on interpretations of water vapour observations. Methods: We performed accurate non-local, non-LTE radiative transfer calculations using different sets of CRC to predict the line intensities from transitions that involve the lowest energy levels of H2O (E find that the intensities based on the quantum and QCT CRC are in good agreement. However, at relatively low H2 volume density (n(H2) find differences in the predicted line intensities of up to a factor of ~3 for the bulk of the lines. Most of the recent studies interpreting early Herschel Space Observatory spectra have used the QCT CRC. Our results show that, although the global conclusions from those studies will not be drastically changed, each case has to be considered individually, since depending on the physical conditions, the use of the QCT CRC may lead to a mis-estimate of the water vapour abundance of up to a factor of ~3. Additionally, the comparison of the quantum state-to-state and thermalised CRC, including the description of the population of the H2 rotational levels, show that above TK ~ 100 K, large differences are expected from those two sets for the p-H2 symmetry. Finally, we find that at low temperature (i.e. TK < 100 K) modelled line

  15. The influence of temperature on corn seed water uptake

    Directory of Open Access Journals (Sweden)

    Lekić Slavoljub S.

    2000-01-01

    Full Text Available Temperature is a very important factor which effects seed water uptake. In this paper we investigated the effect of high temperature and high humidity on seed rate imbibition for five corn hybrids. Seeds were placed at the temperature of 41°C and 95-100% relative humidity (treatment . These seeds were compared with control. Seeds were hydrated at 12°C and 20°C for 6, 12, 24, 48 h. The highest imbibition rate was shown by ZP SC 599 hydride seed. The lowest imbibition rate was shown by ZP SC 599 hybrid seed. The seed treated at 12°C had the lowest imbibition rate. At 20°C differences in imbibition rate were lower than at 12°C. .

  16. Arbuscular mycorrhizal fungi influence growth, osmotic adjustment and photosynthesis of citrus under well-watered and water stress conditions.

    Science.gov (United States)

    Wu, Qiang-Sheng; Xia, Ren-Xue

    2006-03-01

    The influence of arbuscular mycorrhizal (AM) fungus Glomus versiforme on plant growth, osmotic adjustment and photosynthesis of tangerine (Citrus tangerine) were studied in potted culture under well-watered and water stress conditions. Seven-day-old seedlings of tangerine were transferred to pots containing Glomus versiforme or non-AMF. After 97 days, half of the seedlings were subject to water stress and the rest were well-watered for 80 days. AM colonization significantly stimulated plant growth and biomass regardless of water status. The soluble sugar of leaves and roots, the soluble starch of leaves, the total non-structural carbohydrates (NSC) of leaves and roots, and the Mg(2+) of leaves were higher in AM seedlings than those in corresponding non-AM seedlings. The levels of K(+) and Ca(2+) in leaves and roots were higher in AM seedlings than those in non-AM seedlings, but differences were only significant under water stress conditions. Moreover, AM colonization increased the distributed proportions of soluble sugar and NSC to roots. However, the proline was lower in AM seedlings compared with that in non-AM seedlings. AM seedlings had higher leaf water potential (Psi), transpiration rates (E), photosynthetic rates (Pn), stomatal conductance (g(s)), relative water content (RWC), and lower leaf temperature (Lt) than corresponding non-AM seedlings. This research also suggested that AM colonization improved the osmotic adjustment originating not from proline but from NSC, K(+), Ca(2+) and Mg(2+), resulting in the enhancement of drought tolerance.

  17. Influence of electrical conductivity on water uptake and vase life of cut gladiolus stems

    Directory of Open Access Journals (Sweden)

    Lucas Cavalcante da Costa

    2015-08-01

    Full Text Available Several experiments reveal that distilled water varies among different laboratories and also does not have a standard composition. Water electrical conductivity (EC of vase solution is one of the parameters that influence the water uptake by cut flowers. Therefore, the objective of this work was to evaluate the influence of electrical conductivity on water uptake and vase life in cut stems of gladiolus. The stems harvested and kept in distilled water (pH 6.6, EC <0.01dS m-1 and tap water (pH 7.0, EC 0.75 dS m-1 at room temperature. Flowers kept in tap water showed lower fresh weight loss after the second day and higher water uptake during vase life. In a second set of experiments, we verified the limit EC saturation supported by the flower. For this, flowers were placed in individual test tubes containing four different solutions with varying ion concentrations. Solution 2 (EC 0.60 dS m-1 promoted increased vase life and allowed maximum water uptake by the flowers. The results show that the electrical conductivity of vase solution is a major parameter in experiments with vase life of cut gladiolus. The presence of ions in the vase solution increases the overall vase life and improves water uptake of flowers with favorable optimal EC between 0.60 to 0.87 dS m-1.

  18. Silicate fertilizer and irrigation depth in corn production

    Directory of Open Access Journals (Sweden)

    Edvaldo Eloy Dantas Júnior

    2013-08-01

    Full Text Available Calcium-magnesium silicates improve the soil physicochemical properties and provide benefits to plant nutrition, since they are sources of silica, calcium and magnesium. The objective of this study was to evaluate the grain yield of irrigated corn fertilized with calcium-magnesium silicate. The experiment was carried out in a greenhouse in Campina Grande - PB, Brazil, using plastic pots containing 80 kg of soil. The treatments consisted of the combination of four irrigation depths, related to water replacement of 50, 75, 100 and 125% of the crop evapotranspiration, with fertilizer levels of 0, 82, 164 and 246 g of calcium-magnesium silicate, with three replications. The experimental design was in randomized blocks, with the irrigation depths distributed in bands while the silicon levels constituted the subplots. Corn yield was influenced by calcium-magnesium silicate and by irrigation depth, obtaining the greatest grain yield with the dose of 164 g pot-1 irrigated at the highest water level. The water-use efficiency of in corn production tended to decrease when the irrigation depth was increased. The best water-use efficiency was observed when the irrigation level was between 87 and 174 mm, and the dose of silicate was 164 g pot-1.

  19. Modelling the influence of plants on the spatial heterogeneity of soil water

    Science.gov (United States)

    Malchow, Melanie; van Schaik, Loes; Tietjen, Britta

    2015-04-01

    Plants are sessile organisms and as such depend on sufficient local water supply. At the same time, plants themselves directly influence the spatial water distribution in the soil. Thus, plants partly regulate their own water supply. Current ecohydrological models apply simplified approaches to assess infiltration and the spatial distribution of water. They often neglect the influence of the vegetation the spatial heterogeneity in soil water. For example, the shape of the leafage and the rooting system strongly impact the amount of water that reaches the soil and how it is spatially distributed. If rainfall hits the leafage only a fraction of the water falls trough directly. The remaining fraction is intercepted and firstly accumulates on the leaves. This water either runs down the stem (stem flow) or evaporates directly. As a result, more water is received in the local environment of the stem than under the remaining canopy. The rooting system additionally influences the amount of infiltrated water and its distribution in the soil: Roots lead to preferential flow paths and form small caverns that increase the water storage capacity. In our work we developed a simulation model (using Netlogo) to track the path of rainfall from its first contact with the leafage to its storage in the soil. Our model structure supports simulations for different morphological plant types that allow us to evaluate the effect of branch structure, leaf density and the rooting system on water fluxes and thus local availability. The parameterization of morphological traits is based on 2-D profiles derived by simple image processing of pictures. This provides a highly flexible framework to evaluate different scenarios, which we aim to couple with a dynamic vegetation model in the future.

  20. Physical fitness influences water turnover and body water changes during trekking.

    Science.gov (United States)

    Fusch, C; Gfrörer, W; Dickhuth, H H; Moeller, H

    1998-05-01

    This study was performed to assess water turnover and changes of body water during a trekking tour at moderate altitude. Fifteen healthy normally trained adults participated in a 7-d backpack trek tour in the Swiss Alps (total walking distance: 120.5 km; cumulated altitude difference: 6990 m (uphill) and 7550 m downhill; lowest point: 1285 m; highest point: 3317 m). Total body water and water turnover were measured using deuterium dilution and elimination (oral load of 0.33 g 99.8% D2O per kg body weight, overnight equilibration period, pre- and postdose saliva samples immediately before and after sleep, analysis of D2O concentrations in saliva using Fourier-transform infrared spectroscopy, CV cycle ergometer. Body water decreased from the evening of day 0 to the evening of day 4 (from 45.3 +/- 7.3 L to 43.4 +/- 7.6 L, P < 0.05), and did not significantly decrease (43.5 +/- 7.9 L) until the evening of day 5 (maximum of trekking exercise intensity). Mean daily water turnover was 5.7 +/- 1.8 L x d(-1) corresponding to 78.7 +/- 17.5 mL x kg(-1) x d(-1). Body water changes and water turnover were significantly related to the exercise intensity obtained at the lactate threshold as well as at the level of 4 mM lactate. This correlation may be in part explained by differing glycogen content of muscle tissue.

  1. Soil spatial variability and the estimation of the irrigation water depth Variabilidade espacial do solo e a estimativa da lâmina de irrigação

    Directory of Open Access Journals (Sweden)

    Klaus Reichardt

    2001-09-01

    Full Text Available The effects of soil water spatial variability previous to irrigation and of the field capacity on the estimation of irrigation water depth are evaluated. The experiment consisted of a common bean (Phaseolus vulgaris L. crop established on a Kandiudalfic Eutrudox of Piracicaba, SP, Brazil, irrigated by central pivot, in which soil water contents were evaluated with a depth neutron gauge, in a grid of 20x4 points with lag of 0.5 m. In a given situation, the 80 calculated irrigation water depths presented a coefficient of variation of 29.3%, with an average water value of 18 mm, maximum of 41mm and minimum of 9 mm. It is concluded that the only practical way of irrigation is the use of an average water depth, due to the inherent variability of the soil, and that the search for better field capacity values does not imply in better water depth estimates.A influência da variabilidade espacial da umidade do solo em uma situação pré-irrigação e da capacidade de campo é avaliada no cálculo da lâmina de irrigação. O experimento constou de cultura de feijão (Phaseolus vulgaris L. estabelecida em um ARGISSOLO da região de Piracicaba, SP, irrigada por pivô central, tendo as medidas de umidade sido feitas com sonda de nêutrons, em uma malha de 20x4 pontos, espaçados de 0.5 m. Em determinada situação, os 80 valores de lâmina de irrigação calculados apresentaram um coeficiente de variação de 29.3%, para uma média de 18 mm, com valor mínimo de 9 mm e máximo de 41mm. É concluído que a única forma prática de irrigação é o uso de uma lâmina média devido à variabilidade inerente ao solo, e que a procura de melhores valores para a capacidade de campo não implica em melhores estimativas da lâmina de irrigação.

  2. Crystalline Coating and Its Influence on the Water Transport in Concrete

    Directory of Open Access Journals (Sweden)

    Pavel Reiterman

    2016-01-01

    Full Text Available The presented paper deals with an experimental study of the efficiency of surface coating treatment based on secondary crystallization as an additional protection of the subsurface concrete structure loaded by moisture or ground water pressure. The aim of the experimental program was the evaluation of the depth impact of the crystalline coating and the assessment of the reliability of construction joints performed on models simulating real conditions of the concrete structure. The evolution of the secondary crystallizing process was monitored using the water absorption test carried out at different depths of the samples. The coefficient of adsorption decreased to 60% of the reference mixture for a surface layer of up to 40 mm at 28 days and to 50% at 180 days after the coating’s application. Furthermore, the electrical resistivity method was applied with respect to the nature of measurement and the low accessibility of real subsurface concrete structures. The results of moisture measurement at a depth of 180–190 mm from the surface treated with a crystalline coating showed an essential decrease in moisture content percentage in comparison with untreated specimens (measured 125 days after the coating’s application.

  3. The Shoreline Management Tool, an ArcMap Tool for Analyzing Water Depth, Inundated Area, Volume, and Selected Habitats, with an Example for the Lower Wood River Valley, Oregon

    Science.gov (United States)

    Snyder, D. T.; Haluska, T. L.; Respini-Irwin, D.

    2012-12-01

    The Shoreline Management Tool is a GIS-based program developed to assist water- and land-resource managers in assessing the benefits and impacts of changes in surface-water stage on water depth, inundated area, and water volume. In addition, the tool can be used to identify aquatic or terrestrial habitat areas where conditions may be suitable for specific plants or animals as defined by user-specified criteria, including water depth, land-surface slope, and land-surface aspect or to delineate areas for use in determining a variety of hydrologic budget components such as surface-water storage, precipitation, runoff, or evapotranspiration. The Shoreline Management Tool consists of two parts, a graphical user interface for use with ArcMap GIS software to interact with the user to define scenarios and map results, and a spreadsheet in Microsoft Excel® developed to display tables and graphs of the results. The graphical user interface allows the user to define a scenario consisting of an inundation level (stage), land areas (parcels), and habitats (areas meeting user-specified conditions) based on water depth, slope, and aspect criteria. The tool uses data consisting of land-surface elevation, tables of stage/volume and stage/area, and delineated parcel boundaries to produce maps (data layers) of inundated areas and areas that meet the habitat criteria. The tool can be run in a Single-Time Scenario mode or in a Time-Series Scenario mode which uses an input file of dates and associated stages. The spreadsheet portion of the tool uses a macro to process the results from the graphical user interface to create tables and graphs of inundated water volume, inundated area, dry area, and mean water depth for each land parcel based on the user-specified stage. The macro also creates tables and graphs of the area, perimeter, and number of polygons comprising the user-specified habitat areas within each parcel. The Shoreline Management Tool is designed to be highly transferable

  4. The Shoreline Management Tool - an ArcMap tool for analyzing water depth, inundated area, volume, and selected habitats, with an example for the lower Wood River Valley, Oregon

    Science.gov (United States)

    Snyder, Daniel T.; Haluska, Tana L.; Respini-Irwin, Darius

    2013-01-01

    The Shoreline Management Tool is a geographic information system (GIS) based program developed to assist water- and land-resource managers in assessing the benefits and effects of changes in surface-water stage on water depth, inundated area, and water volume. Additionally, the Shoreline Management Tool can be used to identify aquatic or terrestrial habitat areas where conditions may be suitable for specific plants or animals as defined by user-specified criteria including water depth, land-surface slope, and land-surface aspect. The tool can also be used to delineate areas for use in determining a variety of hydrologic budget components such as surface-water storage, precipitation, runoff, or evapotranspiration. The Shoreline Management Tool consists of two parts, a graphical user interface for use with Esri™ ArcMap™ GIS software to interact with the user to define scenarios and map results, and a spreadsheet in Microsoft® Excel® developed to display tables and graphs of the results. The graphical user interface allows the user to define a scenario consisting of an inundation level (stage), land areas (parcels), and habitats (areas meeting user-specified conditions) based on water depth, slope, and aspect criteria. The tool uses data consisting of land-surface elevation, tables of stage/volume and stage/area, and delineated parcel boundaries to produce maps (data layers) of inundated areas and areas that meet the habitat criteria. The tool can be run in a Single-Time Scenario mode or in a Time-Series Scenario mode, which uses an input file of dates and associated stages. The spreadsheet part of the tool uses a macro to process the results from the graphical user interface to create tables and graphs of inundated water volume, inundated area, dry area, and mean water depth for each land parcel based on the user-specified stage. The macro also creates tables and graphs of the area, perimeter, and number of polygons comprising the user-specified habitat areas

  5. Lung management during cardiopulmonary bypass: influence on extravascular lung water.

    Science.gov (United States)

    Boldt, J; King, D; Scheld, H H; Hempelmann, G

    1990-02-01

    Progressive respiratory insufficiency secondary to cardiopulmonary bypass (CPB) is still a hazard after cardiac surgery. Pathophysiologically, impaired capillary endothelial integrity seems to be the fundamental lesion, followed by increased interstitial fluid accumulation. The reasons for this pulmonary damage are controversial; however, management of the nonperfused lungs during CPB has been widely neglected and may be partly responsible. In this study, 90 patients undergoing coronary artery bypass grafting were randomly divided into six groups (15 patients each) with different management of the lungs during CPB: group 1, lungs collapsed (0/0); group 2, static inflation with +5 cm H2O and F1O2 1.0 (+5/1.0); group 3, static inflation with +5 cm H2O and F1O2 0.21 (+5/0.21); group 4, static inflation with +15 cm H2O and F1O2 1.0 (+15/1.0); group 5, static inflation with +15 cm H2O and F1O2 0.21 (+15/0.21); and group 6, controlled mechanical ventilation as before start of CPB (positive end-expiratory pressure [PEEP] +5 cm H2O; F1O2 1.0) (ventilation). In addition to hemodynamic monitoring, extravascular lung water (EVLW) was measured by means of a double-indicator dilution technique with heat and indocyanine green. Measurements were performed after induction of anesthesia, before onset of CPB, and immediately after weaning from bypass, as well as 60 minutes and 5 hours after termination of CPB. Pulmonary gas exchange (PaO2) and intrapulmonary shunting (Qs/Qt) were also measured. Starting from comparable, normal baseline values, EVLW was increased in all groups after weaning from CPB, with the most pronounced increase in group 4 (maximum, +35%) and group 5 (+40%).(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Influence of Space-Time Heterogeneity of Water Consumption Conditions on the Parameters of a Water Supply System

    Science.gov (United States)

    Ogiołda, Ewa; Nowogoński, Ireneusz; Babiuch, Maciej

    2017-03-01

    The work presents the results of the analysis of an existing water supply system. It contains a description of the analysed area in which the analysed system was located, as well as its parameters regarding water intakes and transport of water with pumps, the length and diameter of pipes, and a complication of the materials used to construct the network. Water demand accounting for the nature of the consumers using the water supply network was subject to analysis. The influence of changes in the distribution of water within a day for the basic categories of recipients was accounted for. The EPANET 2.0 program for the simulating water supply network operation, made available by the U.S. Environmental Protection Agency through a public-domain licence, was used to construct the model of the system. The obtained results of the simulation allowed for indicating the main problems with the use of the analysed system. Subject to analysis was the pressure pattern in characteristic nodes of the network from which mining companies, industrial plants and residential households were supplied. Usefulness of the developed simulation model in preparing the assessment of future modernization works was confirmed, allowing for the effects of their implementation to be assessed.

  7. [Study on pipe material's influence on chlorine dioxide drinking water disinfection].

    Science.gov (United States)

    He, Tao; Yue, Yinling; Ling, Bo; Zhang, Lan

    2010-09-01

    To study the pipe material's influence on chlorine dioxide drinking water disinfection. 0.8 mg/L chlorine dioxide solution was injected into 5 kinds of pipes respectively, PPR, PVC-U, Steel with Zinc coating, copper and PE pipes. Dipped free from light for 48 hours and the concentrations of chlorine dioxide, chlorite and chlorate were tested from samples taken from each kind of pipe at 1, 2, 3, 4, 5, 6, 12, 24 and 48 hours respectively. Chlorine dioxides decay rates in the water dipping the pipes increase as the dipping time increases and the decay of chlorine dioxide mainly occurs within 6 hours after the dipping. But for different pipe, the influence of decay differs. The consumption of chlorine dioxide of the metal pipes is more than that of the plastic pipes. And with 2 hours after the dipping experiment begins, the concentrations of the chlorite of the copper pipe and of the steel with zinc coating pipe increase quickly and reach the maximum concentration. But then the chlorite concentration decreases greatly. After dipped 24 hours, the chlorite in the water in the pipe can not be detected. For other plastic piples, all the chlorite concentrations in the dipping water increase as the dipping time increase. Compared with the start of the dipping experiment, the chlorate concentration in the dipping water of each pipe has no obvious change. The material of the water transportation pipe does have influence on chlorine dioxide drinking water disinfection.

  8. The Influence of Religiously and Scientifically Framed Messages on Agreement with Water Use Restrictions

    Directory of Open Access Journals (Sweden)

    John M. Clements

    2016-11-01

    Full Text Available Recent droughts in 2012 and 2013 have increased attention to water use issues in the United States. Cities, government agencies, and environmental nonprofit organizations use scientifically-framed messages to advocate for water conservation. In addition, some religious organizations use messages based on religious teachings to promote water conservation. Because approximately 70% of the U.S. public reports some religious affiliation, it is important to investigate the influence of religious and scientific messages for promoting water conservation. I report the results of an experiment that examines how scientifically- and religiously-framed messages influence attitudes about water use restrictions. I found that Christians were no more or less likely to agree with a policy calling for water use restrictions than non-Christians and non-religious people. However, a Christian religious message negatively influenced agreement with water use restrictions in the entire sample—and in a Christian subsample. Results suggest that religiously framed messages may not increase environmental concern.

  9. Capillary depth measurement for process control

    Science.gov (United States)

    Dorsch, F.; Dubitzky, W.; Effing, L.; Haug, P.; Hermani, J.-P.; Plasswich, S.

    2017-02-01

    In laser welding applications optical coherence tomography (OCT) is used to measure the capillary depth for process monitoring and process control. A controlled constant weld depth is expected to run applications closer to their process limits and reduce the number of destructive sample inspections. An essential premise is a reliable weld depth measurement independent from influencing factors. This work analyzes the influence of laser power, beam diameter, feed rate, and work piece material on the weld depth measured using the OCT technology. The results obtained by using fixed laser optics are compared to the corresponding results from scanner optics.

  10. ACCURACY ANALYSIS OF KINECT DEPTH DATA

    Directory of Open Access Journals (Sweden)

    K. Khoshelham

    2012-09-01

    Full Text Available This paper presents an investigation of the geometric quality of depth data obtained by the Kinect sensor. Based on the mathematical model of depth measurement by the sensor a theoretical error analysis is presented, which provides an insight into the factors influencing the accuracy of the data. Experimental results show that the random error of depth measurement increases with increasing distance to the sensor, and ranges from a few millimetres up to about 4 cm at the maximum range of the sensor. The accuracy of the data is also found to be influenced by the low resolution of the depth measurements.

  11. Consequences of the mismatch between the depth at which planktonic foraminifera live and the calibration depth of SST transfer functions

    Science.gov (United States)

    Telford, R. J.; Kucera, M.

    2012-04-01

    Although many palaeoceanographic proxies are described as sea-surface temperature (SST) proxies, there is a growing realisation that the seasonal and depth sensitivity of proxies may differ substantially. Exploiting information on the seasonal and depth sensitivity of proxies can give new insights into palaeoceanographic processes, and deliver more precise reconstructions. Transfer functions for quantitatively reconstructing past sea surface temperatures from planktonic foraminifera assemblages are typically calibrated against temperatures at 10m water depth. However, planktonic foraminifera are not usually most abundant at 10m depth, but have a geographically variable peak in abundance often near or even below the thermocline. This discrepancy between the depth at which foraminifera live, and the depth against they are calibrated may bias SST reconstructions. With a collation of 18 North Atlantic foraminifera records that cover the time since the Last Glacial Maximum, we make reconstructions of summer and winter temperatures for each standard depth in the World Ocean Atlas down to 500m using the modern analogue technique. We test how much of the variance in the fossil data is explained by each reconstruction, and whether each reconstruction explains more than expected under the null hypothesis that temperature did not influence assemblage composition. We find that changes in North Atlantic foraminifera assemblages since the Last Glacial Maximum are, for most records, better explained by variability near the thermocline than at the surface, and that reconstructions of summer temperatures within the seasonal thermocline are often poor. If the thermal structure of the water column has changed over time, such that the relationship between 10m temperature and the temperature at the depth which most affects foraminifera assemblages is not constant, then reconstructions of SST calibrated to 10m temperature may be biased. This bias will propagate into, for example

  12. Assimilation of snow cover and snow depth into a snow model to estimate snow water equivalent and snowmelt runoff in a Himalayan catchment

    NARCIS (Netherlands)

    Stigter, Emmy E.; Wanders, Niko; Saloranta, Tuomo M.; Shea, Joseph M.; Bierkens, M.F.P.; Immerzeel, W.W.

    2017-01-01

    Snow is an important component of water storage in the Himalayas. Previous snowmelt studies in the Himalayas have predominantly relied on remotely sensed snow cover. However, snow cover data provide no direct information on the actual amount of water stored in a snowpack, i.e., the snow water

  13. Influence from sea water constituents on the efficiency of water electrolysis by PEM-cells

    DEFF Research Database (Denmark)

    Agersted, Karsten; Bentzen, Janet Jonna; Yde-Andersen, S.

    Among the sea-water specific impurities tested, magnesium has the most profound effect on PEM-cell degradation. Significant amounts of the cation was retrieved in the NAFION®-membrane structure after testing. Degradation was seen from a magnesium concentration as low as 3 10-7 mol/l, and increasing...... to purify the feed water to ~1 μS/cm or even further while particularly focusing on the concentrations of polyvalent cations. e.g. magnesium....

  14. Influência de distintas lâminas de irrigação no desenvolvimento e na qualidade visual da grama-batatais = Influence of irrigation depths the desevelopment and visual quality of the grass (Paspalum notatum

    Directory of Open Access Journals (Sweden)

    Denise de Freitas Silva

    2010-01-01

    Full Text Available Atualmente, expandem-se as áreas verdes nas cidades com a proliferação dos gramados em diversas áreas (condomínios residenciais, campos de futebol, campos de golfe etc.. Os recursos hídricos são limitados e nem sempre suficientes para atender a todos os usuários simultaneamente. Portanto, torna-se necessária a utilização racional da água para irrigação. Neste trabalho, objetivou-se avaliar o efeito da aplicação das lâminas de águacorrespondentes a 40, 60, 80 e 100% da ETo sobre a produção de matéria seca (MS da grama-batatais, visando obter a lâmina mínima de água que preserve a qualidade visual, com economia de água e energia. A aparência do gramado foi avaliada por meio da aplicação deum questionário a 16 avaliadores. Após cada corte, avaliou-se a produção de MS, determinando a eficiência do uso da água (EUA. Os modelos foram escolhidos utilizandose o teste t, com nível de até 15% de probabilidade no coeficiente de determinação (R2. Concluiu-se que a produção de MS e a qualidade visual da grama-batatais não foramafetadas pelas diferentes lâminas de água aplicadas nos meses mais frios. Para a gramabatatais, recomenda-se a lâmina de 40% da ETo no mês de julho; nos outros meses, recomenda-se a lâmina de 80% da ETo.Green areas have been expanding in cities with the proliferation of green areas at many sites (residential condominium gardens, soccer fields, golf courses etc.. Unfortunately, the water resources are limited and are not enough to attend all users simultaneously. Therefore, the rational use of water becomes necessary, mainly for irrigation purposes. This work had the main objective of evaluating the effect of water depths application, according to different reposition of the grass (Paspalum notatum reference evapotranspiration (ETo (40, 60, 80 and 100%, on grass dry matter production, aiming to obtain the minimum water depth necessary to maintain the visual quality of grass with water and

  15. Compact Raman Lidar Measurement of Liquid and Vapor Phase Water Under the Influence of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Shiina Tatsuo

    2016-01-01

    Full Text Available A compact Raman lidar has been developed for studying phase changes of water in the atmosphere under the influence of ionization radiation. The Raman lidar is operated at the wavelength of 349 nm and backscattered Raman signals of liquid and vapor phase water are detected at 396 and 400 nm, respectively. Alpha particles emitted from 241Am of 9 MBq ionize air molecules in a scattering chamber, and the resulting ions lead to the formation of liquid water droplets. From the analysis of Raman signal intensities, it has been found that the increase in the liquid water Raman channel is approximately 3 times as much as the decrease in the vapor phase water Raman channel, which is consistent with the theoretical prediction based on the Raman cross-sections. In addition, the radius of the water droplet is estimated to be 0.2 μm.

  16. Assessment of river water quality under urban influence: a case study.

    Science.gov (United States)

    Ram, Shobharam; Joshi, Himanshu

    2012-01-01

    In this study, the water quality status of river Solani in India was assessed under the influence of urbanization. Physico-chemical and biological analysis of water reflected maximum adverse impact during summer low flow season. Variation in river flows during monsoon, post monsoon and low flow seasons was found to substantially affect the river water quality regime. Whereas the monsoon season displayed addition of suspended impurities and provided dilution in the dissolved components, the summer low flow season revealed an anaerobic condition in the river as the entire river flow comprised of only drain effluents. All the drains were observed to carry contaminated water with impurities from various point and non-point sources emanating from diverse human activities. The present study indicated that the drain waste water deserves a prior treatment in order to protect the Solani river water from pollution.

  17. [Water intake and its influencing factors of children and adolescents in Shanghai].

    Science.gov (United States)

    Wang, Zhengyuan; Shi, Aizhen; Chen, Yiqiong; Cheng, Wei; Song, Jun; Zhu, Zhenni; Zou, Shurong; Ma, Guansheng

    2014-01-01

    To describe the total drinking water intake and its influencing factors among children and adolescents in Shanghai, and to accumulate basis for developing adequate water intakes for children and adolescents in China. A total of 1454 children and adolescents aged 8-17 years from two districts of Shanghai was selected by using stratified random sampling method. The information on amounts and types of daily drinking water was recorded by subjects for seven consecutive days using a quantitative measurement. Total drinking water was the sum of plain water and beverages. The median of total drinking water of subjects was 1014 ml/d, and the median of plain water and beverages was 580 and 339 ml/d, respectively. The consumption of total drinking water, plain water, and beverages in boys was significantly higher than that in girls, was increasing with aging and in urban was significantly higher than that in suburbs (P beverages (P < 0.05). The total drinking water of children and adolescents in Shanghai was less. To establish adequate intake of water, the comprehensive effect of gender, age, BMI and region when should be considered.

  18. INFLUENCE OF THE COMPOSITION OF MILK POWDER ON WATER ACTIVITY APPLYING THE GAB MODEL

    Directory of Open Access Journals (Sweden)

    Julio Gil

    2016-03-01

    Full Text Available The use of sorption isotherms at 25°C, for analyze the influence of water activity (aw of the different compositions of whole milk, skim and low in lactose powder, was study. Precisely the latter incorporating previous work can extend the differential behavior of the various components. The work can establish the relationship between the moisture content of the milk powders studied, with its water activity (aw. The experimental results are evaluated with reference model GAB, noting that the layout of the isotherms and the model parameters were successfully adjusted to the values obtained. The clear influence of the presence of monosaccharides (glucose and galactose in the reduced-lactose milk, which reduce the water activity aw from greater value of 0.4 due to the higher solubility of these, is observed. The fat content in whole milk, not being adsorbent is manifested in higher values for water activity.

  19. Socioeconomics Influences on the Water Competencies of Young Adult Polish Males

    Directory of Open Access Journals (Sweden)

    Moran Kevin

    2017-06-01

    Full Text Available Despite the popularity of aquatic recreation and its well-promoted prophylactic and therapeutic values, not a lot is known about how socio-cultural background influences the acquisition of water competency. The aim of this study was to assess the influence of socio-economic and environmental factors on the swimming and rescue skills of male university students (n = 521 aged 19-20 years residing in the Region of Warmia and Mazury, Poland.

  20. [Influence factors of deposition induced by melt water erosion in Naqu region, China].

    Science.gov (United States)

    Feng, Jun-yuan; Cai, Qiang-guo; Li, Zhao-xia; Sun, Li-ying

    2015-02-01

    Melt water erosion is one of the important soil erosion forms caused by the melt water from glacier and snow in high altitude cold areas of China. This paper investigated the influencing factors of deposition caused by melt water erosion in Naqu region. Alluvial fan ratio was presented as an index to characterize the degree of the deposition induced by melt water erosion. Minimum polygon was determined based on spatial overlay technology of Geographic Information System (GIS). The regression equation between the deposition index and the influencing factors was established through the stepwise regression analysis based on minimum polygon. Key influencing factors were identified according to the stepwise regression equation. The results showed that large amounts of alluvial fan were observed in Naqu region; extensive alluvial fans were centered at gentle slope areas in the central part of Naqu region with great spatial differences; alluvial fans were mainly distributed at valley exits, most of which were at large scale with vast differences in area and thickness. Wind speed, normalized difference vegetation index (NDVI), K value of soil erodibility, annual temperature range and the steep slope area ratio were identified as the key influencing factors on the deposition induced by melt water erosion in the studied area. Index of deposition was positively correlated with the wind speed and NDVI, and showed negative relationships with the K value of soil erodibility, the annual temperature range and steep slope area ratio.