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Sample records for salinity oxygen depth

  1. Dissolved oxygen, salinity, temperature, and depth data from bottle casts in the North Atlantic Ocean from 07 February 1987 to 18 February 1991 (NODC Accession 0000290)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, temperature, and depth data were collected using bottle casts in the North Atlantic Ocean from February 7, 1987 to February 18, 1991....

  2. Dissolved oxygen, salinity, temperature, and depth data from bottle casts in the North Atlantic Ocean from 05 February 1973 to 19 August 1980 (NODC Accession 0000289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dissolved oxygen, salinity, temperature, and depth data were collected using bottle casts in the North Atlantic Ocean from February 5, 1973 to August 19, 1980. These...

  3. Temperature, salinity, dissolved oxygen, phosphate, nitrite, pH, alkalinity, bottom depth, and meteorology data collected from Arctic Seas and North Western Pacific by various Soviet Union institutions from 1925-11-16 to 1989-05-18 (NODC Accession 0075099)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, dissolved oxygen, phosphate, nitrite, pH, alkalinity, bottom depth, and meteorology data collected from Arctic Seas and North Western Pacific...

  4. Salinity-dependent limitation of photosynthesis and oxygen exchange in microbial mats

    DEFF Research Database (Denmark)

    Garcia-Pichel, F.; Kühl, Michael; Nübel, U.

    1999-01-01

    was specific for each community and in accordance with optimal performance at the respective salinity of origin. This pattern was lost after long-term exposure to varying salinities when responses to salinity were found to approach a general pattern of decreasing photosynthesis and oxygen exchange capacity...... with increasing salinity. Exhaustive measurements of oxygen export in the light, oxygen consumption in the dark and gross photosynthesis indicated that a salinity-dependent limitation of all three parameters occurred. Maximal values for all three parameters decreased exponentially with increasing salinity...

  5. The effect of temperature and salinity on oxygen consumption in the ...

    African Journals Online (AJOL)

    The aquatic oxygen consumption of the estuarine brachyuran crab, Cyclograpsus punctatus, was investigated after a 24-hour acclimation period at different temperature (12.5, 20, 30°C) and salinity (9, 17.5, 35, and 44‰) combinations . Salinity had no significant effect on oxygen consumption at 12.5 and 20°C in both large ...

  6. DEPTH - OBSERVATION and Other Data (NODC Accession 9700138)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity and other data were collected in the North Sea and other locations. Data include water depths, temperatures, salinities, and oxygen...

  7. Oxygen, salinity, and other data from bottle casts in the Northwest Atlantic Ocean from 25 February 1973 to 04 May 1981 (NODC Accession 0000344)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oxygen, salinity, temperature, and depth data were collected using bottle casts in the Northwest Atlantic Ocean from February 25, 1973 to May 4, 1981. Data were...

  8. Quantifying salinity and season effects on eastern oyster clearance and oxygen consumption rates

    Science.gov (United States)

    Casas, S.M.; Lavaud, Romain; LaPeyre, Megan K.; Comeau, L. A.; Filgueira, R.; LaPeyre, Jerome F.

    2018-01-01

    There are few data on Crassostrea virginica physiological rates across the range of salinities and temperatures to which they are regularly exposed, and this limits the applicability of growth and production models using these data. The objectives of this study were to quantify, in winter (17 °C) and summer (27 °C), the clearance and oxygen consumption rates of C. virginica from Louisiana across a range of salinities typical of the region (3, 6, 9, 15 and 25). Salinity and season (temperature and reproduction) affected C. virginica physiology differently; salinity impacted clearance rates with reduced feeding rates at low salinities, while season had a strong effect on respiration rates. Highest clearance rates were found at salinities of 9–25, with reductions ranging from 50 to 80 and 90 to 95% at salinities of 6 and 3, respectively. Oxygen consumption rates in summer were four times higher than in winter. Oxygen consumption rates were within a narrow range and similar among salinities in winter, but varied greatly among individuals and salinities in summer. This likely reflected varying stages of gonad development. Valve movements measured at the five salinities indicated oysters were open 50–60% of the time in the 6–25 salinity range and ~ 30% at a salinity of 3. Reduced opening periods, concomitant with narrower valve gap amplitudes, are in accord with the limited feeding at the lowest salinity (3). These data indicate the need for increased focus on experimental determination of optimal ranges and thresholds to better quantify oyster population responses to environmental changes.

  9. Laser measure of sea salinity, temperature and turbidity in depth

    Science.gov (United States)

    Hirschberg, J. G.; Wouters, A. W.; Byrne, J. D.

    1974-01-01

    A method is described in which a pulsed laser is used to probe the sea. Backscattered light is analyzed in time, intensity and wavelength. Tyndall, Raman and Brillouin scattering are used to obtain the backscatter turbidity, sound velocity, salinity, and the temperature as a function of depth.

  10. The study of coastal groundwater depth and salinity variation using time-series analysis

    International Nuclear Information System (INIS)

    Tularam, G.A.; Keeler, H.P.

    2006-01-01

    A time-series approach is applied to study and model tidal intrusion into coastal aquifers. The authors examine the effect of tidal behaviour on groundwater level and salinity intrusion for the coastal Brisbane region using auto-correlation and spectral analyses. The results show a close relationship between tidal behaviour, groundwater depth and salinity levels for the Brisbane coast. The known effect can be quantified and incorporated into new models in order to more accurately map salinity intrusion into coastal groundwater table

  11. Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Tsao-Melcer, D. C.; Schoellhamer, D.H.; Fregien, S.; Athearn, N.D.

    2009-01-01

    Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wetlands for waterbirds is not well understood, including how different avian foraging guilds use invertebrate prey resources at different salinities and depths. The aim of this study was to investigate the dietary flexibility of waterbirds by examining the population number and diet of three feeding guilds across a salinity and depth gradient in former salt ponds of the Napa-Sonoma Marshes. Although total invertebrate biomass and species richness were greater in low than high salinity salt ponds, waterbirds fed in ponds that ranged from low (20 g l-1) to very high salinities (250 g l -1). American avocets (surface sweeper) foraged in shallow areas at pond edges and consumed a wide range of prey types (8) including seeds at low salinity, but preferred brine flies at mid salinity (40-80 g l-1). Western sandpipers (prober) focused on exposed edges and shoal habitats and consumed only a few prey types (2-4) at both low and mid salinities. Suitable depths for foraging were greatest for ruddy ducks (diving benthivore) that consumed a wide variety of invertebrate taxa (5) at low salinity, but focused on fewer prey (3) at mid salinity. We found few brine shrimp, common in higher salinity waters, in the digestive tracts of any of these species. Dietary flexibility allows different guilds to use ponds across a range of salinities, but their foraging extent is limited by available water depths. ?? 2009 USGS, US Government.

  12. Alteration in Solid State Phosphorous With Depth in Sediments Along the Salinity Transition Zone of a Major Chesapeake Bay Tributary

    Science.gov (United States)

    Hartzell, J. L.; Jordan, T. E.

    2006-05-01

    Determining the fate of particulate phosphorus in estuaries is essential for addressing the widespread problem of estuarine eutrophication, and is key to understanding P cycling and developing accurate global P budgets. Prominent reservoirs of P in surficial sediments include particulate P associated with iron or organic C. However, the importance of these reservoirs changes with the decomposition of organic matter and the reduction of iron. Also, the importance of iron bound P may decrease with increasing salinity due to the formation of iron sulfides. To investigate estuarine P burial and its relationship to salinity, we collected sediment cores of one-meter depth along the salinity gradient of the Patuxent River estuary (Maryland, USA), a major tributary of Chesapeake Bay. The sediments were analyzed using a sequential sedimentary extraction procedure that quantifies five separate reservoirs of particulate P. Total phosphorus concentrations in freshwater sediments were significantly higher than those in more saline sediments at all depths. Conversely, porewater phosphate concentrations were significantly lower in freshwater sediments than in the more saline sediments. Total P in the saline sediment cores decreased with depth, correlating to a reduction in iron-bound P. However, we did not find a concurrent increase in authigenic apatite with depth. Our findings indicate that mechanisms controlling changes in P sorption to sediments change profoundly with salinity and may contribute to increased bioavailability of phosphates with increasing salinity.

  13. Depth, salinity, and other data were collected from the R/V ALPHA HELIX in the Bering Sea as part of the Inner Shelf Transport and Recycling Project (ISHTAR) from 17 September 1986 to 25 September 1986 (NODC Accession 0000275)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Depth, fluorescence, oxygen, salinity, and water temperature data were collected from the R/V ALPHA HELIX from September 17, 1986 to September 25, 1986. Data were...

  14. The diversity and abundance of bacteria and oxygenic phototrophs in saline biological desert crusts in Xinjiang, northwest China.

    Science.gov (United States)

    Li, Ke; Liu, Ruyin; Zhang, Hongxun; Yun, Juanli

    2013-07-01

    Although microorganisms, particularly oxygenic phototrophs, are known as the major players in the biogeochemical cycles of elements in desert soil ecosystems and have received extensive attention, still little is known about the effects of salinity on the composition and abundances of microbial community in desert soils. In this study, the diversity and abundance of bacteria and oxygenic phototrophs in biological desert crusts from Xinjiang province, which were under different salinity conditions, were investigated by using clone library and quantitative PCR (qPCR). The 16S rRNA gene phylogenetic analysis showed that cyanobacteria, mainly Microcoleus vagnitus of the order Oscillatoriales, were predominant in the low saline crusts, while other phototrophs, such as diatom, were the main microorganism group responsible for the oxygenic photosynthesis in the high saline crusts. Furthermore, the higher salt content in crusts may stimulate the growth of other bacteria, including Deinococcus-Thermus, Bacteroidetes, and some subdivisions of Proteobacteria (β-, γ-, and δ-Proteobacteria). The cpcBA-IGS gene analysis revealed the existence of novel M. vagnitus strains in this area. The qPCR results showed that the abundance of oxygenic phototrophs was significantly higher under lower saline condition than that in the higher saline crusts, suggesting that the higher salinity in desert crusts could suppress the numbers of total bacteria and phototrophic bacteria but did highly improve the diversity of salt-tolerant bacteria.

  15. The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent and its impact on the near-coastal salinity, oxygen, and nutrient distributions

    Science.gov (United States)

    Thomsen, Soeren; Kanzow, Torsten; Krahmann, Gerd; Greatbatch, Richard J.; Dengler, Marcus; Lavik, Gaute

    2016-01-01

    The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent (PCUC) in January and February 2013 is investigated using a multiplatform four-dimensional observational approach. Research vessel, multiple glider, and mooring-based measurements were conducted in the Peruvian upwelling regime near 12°30'S. The data set consists of >10,000 glider profiles and repeated vessel-based hydrography and velocity transects. It allows a detailed description of the eddy formation and its impact on the near-coastal salinity, oxygen, and nutrient distributions. In early January, a strong PCUC with maximum poleward velocities of ˜0.25 m/s at 100-200 m depth was observed. Starting on 20 January, a subsurface anticyclonic eddy developed in the PCUC downstream of a topographic bend, suggesting flow separation as the eddy formation mechanism. The eddy core waters exhibited oxygen concentration of deficit of ˜17 μmol/L, and potential vorticity close to zero, which seemed to originate from the bottom boundary layer of the continental slope. The eddy-induced across-shelf velocities resulted in an elevated exchange of water masses between the upper continental slope and the open ocean. Small-scale salinity and oxygen structures were formed by along-isopycnal stirring, and indications of eddy-driven oxygen ventilation of the upper oxygen minimum zone were observed. It is concluded that mesoscale stirring of solutes and the offshore transport of eddy core properties could provide an important coastal open ocean exchange mechanism with potentially large implications for nutrient budgets and biogeochemical cycling in the oxygen minimum zone off Peru.

  16. The impact of gyre dynamics on the mid-depth salinity signature of the eastern North Atlantic

    Science.gov (United States)

    Burkholder, K. C.; Lozier, M. S.

    2009-04-01

    The Mediterranean Overflow Water (MOW) is widely recognized for its role in establishing the mid-depth salinity signature of the subtropical North Atlantic. However, recent work has revealed an intermittent impact of MOW on the salinity signature of the eastern subpolar basin. This impact results from a temporally variable penetration of the northward flowing branch of the MOW past Porcupine Bank into the eastern subpolar basin. It has been shown that the salinity signature of the eastern subpolar basin, in particular the Rockall Trough, varies with the state of the North Atlantic Oscillation (NAO): during persistent periods of strong winds (high NAO index), when the subpolar front moves eastward, waters in the subpolar gyre block the northward flowing MOW, preventing its entry into the subpolar gyre. Conversely, during persistent periods of weak winds (low NAO index), the front moves westward, allowing MOW to penetrate north of Porcupine Bank and into the subpolar gyre. Here, we investigate the manner in which the spatial and temporal variability in the northward penetration of the MOW and the position of the eastern limb of the subpolar front affect the mid-depth property fields not only in the subpolar gyre, but in the subtropical gyre as well. Using approximately 55 years of historical hydrographic data and output from the 1/12° FLAME model, we analyze the temporal variability of salinity along the eastern boundary and compare this variability to the position of the subpolar front in both the observational record and the FLAME model. We conclude that when the zonal position of the subpolar front moves relatively far offshore and the MOW is able to penetrate to the north, high salinity anomalies are observed at high latitudes and low salinity anomalies are observed at low latitudes. Conversely, when the frontal position shifts to the east, the MOW (and thus, the high salinity signature) is blocked, resulting in a drop in salinity anomalies at high latitudes

  17. Impacts of Salinity and Oxygen on Particle-Associated Microbial Communities in the Broadkill River, Lewes DE

    Directory of Open Access Journals (Sweden)

    Kristin M. Yoshimura

    2018-03-01

    Full Text Available Particulate matter in estuarine systems hosts microbial communities that can impact biogeochemical cycles. While the bacterial community composition on suspended particles has been previously investigated, especially with regards to how salinity may structure these communities, the archaeal fraction of the microbial community has not received the same attention. Here we investigate both the bacterial and archaeal community composition on two sizes of particles along a riverine discharge gradient in the Broadkill River, DE, USA, to determine whether the archaeal community is selected by similar environmental stressors as the bacteria. We measured salinity, nutrients, and diatom abundances, and use particle size as a proxy for oxygen concentrations. We show that salinity is a strong environmental factor that controls both bacterial and archaeal community composition and oxygen is an additional factor, impacting archaea more than bacteria.

  18. Plasma osmolality and oxygen consumption of perch Perca fluviatilis in response to different salinities and temperatures

    DEFF Research Database (Denmark)

    Christensen, Emil Aputsiaq Flindt; Svendsen, Morten Bo Søndergaard; Steffensen, John Fleng

    2017-01-01

    with salinity at 10 and 20° C. Maximum metabolic rate (MMR) and aerobic scope was lowest at salinity of 15 at 5° C, yet at 20° C, they were lowest at a salinity of 0. A cost of osmoregulation (SMR at a salinity of 0 and 15 compared with SMR at a salinity of 10) could only be detected at a salinity of 15 at 20...... of osmoregulation (28%) at a salinity of 15 at 20° C indicates that the cost of osmoregulation in P. fluviatilis increases with temperature under hyperosmotic conditions and a power analysis showed that the cost of osmoregulation could be lower than 12·5% under other environmental conditions. The effect of salinity......The present study determined the blood plasma osmolality and oxygen consumption of the perch Perca fluviatilis at different salinities (0, 10 and 15) and temperatures (5, 10 and 20° C). Blood plasma osmolality increased with salinity at all temperatures. Standard metabolic rate (SMR) increased...

  19. Quantitative analysis of oxygen depth distribution by means of deuteron reaction

    International Nuclear Information System (INIS)

    Dyumin, A.N.; Eremin, V.K.; Konnikov, S.G.

    1993-01-01

    Experimentally are investigated and realized possibilities for using the reaction for quantitative determination of the depth profiles of the oxygen distribution in HTSC structures in layers up to 10 4 A. It is concluded that in the near-surface layers when profiling the oxygen content is achieved the spatial resolution of 150 A

  20. Numerical Simulation of Salinity and Dissolved Oxygen at Perdido Bay and Adjacent Coastal Ocean

    Science.gov (United States)

    Environmental Fluid Dynamic Code (EFDC), a numerical estuarine and coastal ocean circulation hydrodynamic model, was used to simulate the distribution of the salinity, temperature, nutrients and dissolved oxygen (DO) in Perdido Bay and adjacent Gulf of Mexico. External forcing fa...

  1. Tuning of redox regulatory mechanisms, reactive oxygen species and redox homeostasis under salinity stress

    Directory of Open Access Journals (Sweden)

    Hossain eSazzad

    2016-05-01

    Full Text Available Soil salinity is a crucial environmental constraint which limits biomass production at many sites on a global scale. Saline growth conditions cause osmotic and ionic imbalances, oxidative stress and perturb metabolism, e.g. the photosynthetic electron flow. The plant ability to tolerate salinity is determined by multiple biochemical and physiological mechanisms protecting cell functions, in particular by regulating proper water relations and maintaining ion homeostasis. Redox homeostasis is a fundamental cell property. Its regulation includes control of reactive oxygen species (ROS generation, sensing deviation from and readjustment of the cellular redox state. All these redox related functions have been recognized as decisive factors in salinity acclimation and adaptation. This review focuses on the core response of plants to overcome the challenges of salinity stress through regulation of ROS generation and detoxification systems and to maintain redox homeostasis. Emphasis is given to the role of NADH oxidase (RBOH, alternative oxidase (AOX, the plastid terminal oxidase (PTOX and the malate valve with the malate dehydrogenase isoforms under salt stress. Overwhelming evidence assigns an essential auxiliary function of ROS and redox homeostasis to salinity acclimation of plants.

  2. The mobility of U and Th in subduction zone fluids: an indicator of oxygen fugacity and fluid salinity

    Science.gov (United States)

    Bali, Enikő; Audétat, Andreas; Keppler, Hans

    2011-04-01

    The solubility of U and Th in aqueous solutions at P-T-conditions relevant for subduction zones was studied by trapping uraninite or thorite saturated fluids as synthetic fluid inclusions in quartz and analyzing their composition by Laser Ablation-ICPMS. Uranium is virtually insoluble in aqueous fluids at Fe-FeO buffer conditions, whereas its solubility increases both with oxygen fugacity and with salinity to 960 ppm at 26.1 kbar, Re-ReO2 buffer conditions and 14.1 wt% NaCl in the fluid. At 26.1 kbar and 800°C, uranium solubility can be reproduced by the equation: log {{U}} = 2.681 + 0.1433log f{{O}}2 + 0.594{{Cl,}} where fO2 is the oxygen fugacity, and Cl is the chlorine content of the fluid in molality. In contrast, Th solubility is generally low (uranium increases strongly both with oxygen fugacity and with salinity. We show that reducing or NaCl-free fluids cannot produce primitive arc magmas with U/Th ratio higher than MORB. However, the dissolution of several wt% of oxidized, saline fluids in arc melts can produce U/Th ratios several times higher than in MORB. We suggest that observed U/Th ratios in arc magmas provide tight constraints on both the salinity and the oxidation state of subduction zone fluids.

  3. Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

    Science.gov (United States)

    Reum, Jonathan C P; Alin, Simone R; Feely, Richard A; Newton, Jan; Warner, Mark; McElhany, Paul

    2014-01-01

    Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal ecosystems.

  4. Seasonal Carbonate Chemistry Covariation with Temperature, Oxygen, and Salinity in a Fjord Estuary: Implications for the Design of Ocean Acidification Experiments

    Science.gov (United States)

    Reum, Jonathan C. P.; Alin, Simone R.; Feely, Richard A.; Newton, Jan; Warner, Mark; McElhany, Paul

    2014-01-01

    Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008–2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (aragonite were widespread (Ωar<1). We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal

  5. Sub-keV secondary ion mass spectrometry depth profiling: comparison of sample rotation and oxygen flooding

    International Nuclear Information System (INIS)

    Liu, R.; Wee, A.T.S.

    2004-01-01

    Following the increasingly stringent requirements in the characterization of sub-micron IC devices, an understanding of the various factors affecting ultra shallow depth profiling in secondary ion mass spectrometry (SIMS) has become crucial. Achieving high depth resolution (of the order of 1 nm) is critical in the semiconductor industry today, and various methods have been developed to optimize depth resolution. In this paper, we will discuss ultra shallow SIMS depth profiling using B and Ge delta-doped Si samples using low energy 0.5 keV O 2 + primary beams. The relationship between depth resolution of the delta layers and surface topography measured by atomic force microscopy (AFM) is studied. The effect of oxygen flooding and sample rotation, used to suppress surface roughening is also investigated. Oxygen flooding was found to effectively suppress roughening and gives the best depth resolution for B, but sample rotation gives the best resolution for Ge. Possible mechanisms for this are discussed

  6. Efficacy of nebulised L-adrenaline with 3% hypertonic saline versus normal saline in bronchiolitis

    Directory of Open Access Journals (Sweden)

    Shabnam Sharmin

    2016-08-01

    Full Text Available Background: Bronchiolitis is one of the most common respiratory diseases requiring hospitalization. Nebulized epineph­rine and salbutamol therapy has been used in different centres with varying results. Objective: The objective of the study was to compare the efficacy of nebulised adrenaline diluted with 3% hypertonic saline with nebulised adrenaline diluted with normal saline in bronchiolitis. Methods: Fifty three infants and young children with bronchiolitis, age ranging from 2 months to 2 years, presenting in the emergency department of Manikganj Sadar Hospital were enrolled in the study. After initial evaluation, patients were randomized to receive either nebulized adrenaline I .5 ml ( 1.5 mg diluted with 2 ml of3% hypertonic saline (group I ornebulised adrenaline 1.5 ml (1.5 mg diluted with 2 ml of normal saline (group II. Patients were evaluated again 30 minutes after nebulization. Results: Twenty eight patients in the group I (hypertonic saline and twenty five in groupII (normal saline were included in the study. After nebulization, mean respiratory rate decreased from 63.7 to 48.1 (p<.01, mean clinical severity score decreased from 8.5 to 3.5 (p<.01 and mean oxygen satw·ation increased 94.7% to 96.9% (p<.01 in group I. In group II, mean respiratory rate decreased from 62.4 to 47.4 (p<.01, mean clinical severity score decreased from 7.2 to 4.1 (p<.01 and mean oxygen saturation increased from 94. 7% to 96. 7% (p<.01. Mean respiratory rate decreased by 16 in group I versus 14.8 (p>.05 in group 11, mean clinical severity score decreased by 4.6 in group versus 3 (p<.05 in group, and mean oxygen saturation increased by 2.2% and 1.9% in group and group respectively. Difference in reduction in clinical severity score was statistically significant , though the changes in respiratory rate and oxygen saturation were not statistically significant. Conclusion: The study concluded that both nebulised adrenaline diluted with 3% hypertonic saline and

  7. Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

    Directory of Open Access Journals (Sweden)

    Jonathan C P Reum

    Full Text Available Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall. pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm at all depths and seasons sampled except for the near-surface waters (< 10 m in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (Ωar<1. We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31, was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight

  8. Spatial sensitivity and penetration depth of three cerebral oxygenation monitors

    Science.gov (United States)

    Gunadi, Sonny; Leung, Terence S.; Elwell, Clare E.; Tachtsidis, Ilias

    2014-01-01

    The spatial sensitivities of NIRO-100, ISS Oximeter and TRS-20 cerebral oxygenation monitors are mapped using the local perturbation method to inform on their penetration depths and susceptibilities to superficial contaminations. The results show that TRS-20 has the deepest mean penetration depth and is less sensitive than the other monitors to a localized absorption change in the superficial layer. However, an integration time of more than five seconds is required by the TRS-20 to achieve an acceptable level of signal-to-noise ratio, which is the poorest amongst the monitors. With the exception of NIRO-100 continuous wave method, the monitors are not significantly responsive to layer-wide absorption change that occurs in the superficial layer. PMID:25401006

  9. Regulation of reactive oxygen and nitrogen species by salicylic acid in rice plants under salinity stress conditions

    Science.gov (United States)

    Mun, Bong-Gyu; Khan, Abdul Latif; Waqas, Muhammad; Kim, Hyun-Ho; Shahzad, Raheem; Imran, Muhammad

    2018-01-01

    This study investigated the regulatory role of exogenous salicylic acid (SA) in rice and its effects on toxic reactive oxygen and nitrogen species during short-term salinity stress. SA application (0.5 and 1.0 mM) during salinity-induced stress (100 mM NaCl) resulted in significantly longer shoot length and higher chlorophyll and biomass accumulation than with salinity stress alone. NaCl-induced reactive oxygen species production led to increased levels of lipid peroxidation in rice plants, which were significantly reduced following SA application. A similar finding was observed for superoxide dismutase; however, catalase (CAT) and ascorbate peroxidase (APX) were significantly reduced in rice plants treated with SA and NaCl alone and in combination. The relative mRNA expression of OsCATA and OsAPX1 was lower in rice plants during SA stress. Regarding nitrogenous species, S-nitrosothiol (SNO) was significantly reduced initially (one day after treatment [DAT]) but then increased in plants subjected to single or combined stress conditions. Genes related to SNO biosynthesis, S-nitrosoglutathione reductase (GSNOR1), NO synthase-like activity (NOA), and nitrite reductase (NIR) were also assessed. The mRNA expression of GSNOR1 was increased relative to that of the control, whereas OsNOA was expressed at higher levels in plants treated with SA and NaCl alone relative to the control. The mRNA expression of OsNR was decreased in plants subjected to single or combination treatment, except at 2 DAT, compared to the control. In conclusion, the current findings suggest that SA can regulate the generation of NaCl-induced oxygen and nitrogen reactive species in rice plants. PMID:29558477

  10. 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.

  11. Physico-chemical conditions for plankton in Lake Timsah, a saline lake on the Suez Canal

    Science.gov (United States)

    El-Serehy, H. A. H.; Sleigh, M. A.

    1992-02-01

    Lake Timsah receives high salinity water from the Suez Canal, mainly from the south, and freshwater from a Nile canal and other sources, producing a salinity stratification with surface salinities of 20-40‰ and over 40‰ in deeper water. Water temperature at a depth of 50-70 cm fell to below 20 °C in winter and rose to above 30 °C in summer; oxygen concentration at the same depth ranged between 6-10 mg l -1 and the pH was 8·1-8·3, and at mid-day this water was supersaturated with oxygen through 6-8 months of the year. The main chemical nutrients reached their highest levels in winter (December-February) and their lowest levels in summer (May-August), silicate varying between 1-7 μ M, phosphate between 0·1 and 0·8 μ M and nitrate between 4-10 μ M; nitrite varied in a more complex manner, usually between 0·25 and 0·4 μ M. The atomic ratio of N/P was generally well above the Redfield ratio level, except for a few months in midwinter. These nutrient concentrations are high in comparison with those of unpolluted seas of the region, but are typical of the more eutrophic coastal waters in most parts of the world.

  12. Oxygen input and oxygen yield of tanks of great depth in theory and practice; Theorie und Praxis von Sauerstoffeintrag und -ertrag bei groesseren Beckentiefen

    Energy Technology Data Exchange (ETDEWEB)

    Poepel, H.J.; Wagner, M. [Technische Hochschule Darmstadt (Germany). Inst. fuer Wasserversorgung, Abwasserbeseitigung und Raumplanung; Weidmann, F.

    1999-07-01

    Activated sludge tanks are nowadays planned and built with greater depths (8.00 to 12.00 m) than hitherto (4.00 to 6.00 m); some are already in operation. For such depths there exist no confirmed dimensioning approaches. The fundamentals of oxygen transfer in deep tanks are pointed out and a model for calculating the influence of depth is set up. It is confirmed via an extensive test program with variation of water depth, the rate of density of membrane aerators, and air volume flows. It permits converting oxygen supply parameters of an aeration system established for a certain blow-in depth to a given alternative depth. For oxygen yield, too, relations are developed, which indicate gross yield for different compressor types (sliding vane rotary compressor, turbo compressor, screw-type compressor) as a function of blow-in-depth, air volume flow and rate of density with great accuracy. (orig.) [German] Belebungsbecken werden heute tiefer (8,00 bis 12,00 m) als bisher (4,00 bis 6,00 m) geplant, gebaut und bereits betrieben. Fuer diese Tiefen liegen keine gesicherten Bemesssungsansaetze vor. Die Grundlagen des Sauerstoffuebergangs in tiefen Becken werden dargelegt und ein Modell zur Berechnung des Tiefeneinflusses erstellt. Ueber ein ausfuehrliches Versuchsprogramm mit Variation der Wassertiefe, der Belegungsdichte mit Membranbelueftern und der Luftvolumenstroeme wird das Modell bestaetigt. Damit koennen Sauerstoffzufuhrparametern eines Belueftungssystems, die fuer eine bestimmte Einblastiefe bekannt sind, auf beliebige andere Tiefen umgerechnet werden. Auch fuer den Sauerstoffertrag werden Beziehungen entwickelt, die den Bruttoertrag fuer unterschiedliche Verdichterarten (Drehkolben-, Turbo- und Schraubenverdichter) in Abhaengigkeit von Einblastiefe, Luftvolumenstrom und Belegungsdichte mit grosser Genauigkeit festlegen. (orig.)

  13. Ice-Tethered Profiler observations: Vertical profiles of temperature, salinity, oxygen, and ocean velocity from an Ice-Tethered Profiler buoy system

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains repeated vertical profiles of ocean temperature and salinity versus pressure, as well as oxygen and velocity for some instruments. Data were...

  14. Photoirradiation system with depth optical dosimetry control in initial oxygen saturation measurement

    International Nuclear Information System (INIS)

    Quintanar, L.; Stolik, S.; Rosa, J. de la; Moreno, E.

    2012-01-01

    Photodynamic Therapy is a technique in which a photosensitizing substance is applied that is activated by light and it generates reactive oxygen species which cause selective cell destruction. The efficiency of the therapy is affected by the parameters dose. In this work it is shown a photo-irradiation system for superficial Photodynamic Therapy, using as a light source a light emitting diode with an automatic control of optical power based on a model of the distribution of light in depth that was tested in tissue phantoms. It also has a reflective pulse oximeter for the measurement of the initial oxygen saturation. (Author)

  15. Evidence for Upward Flow of Saline Water from Depth into the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

    Science.gov (United States)

    Larsen, D.; Paul, J.

    2017-12-01

    Groundwater salinization is occurring in the Mississippi River Valley Alluvial (MRVA) aquifer in southeastern Arkansas (SE AR). Water samples from the MRVA aquifer in Chicot and Desha counties have yielded elevated Cl-concentrations with some as high as 1,639 mg/L. Considering that the MRVA aquifer is the principle source of irrigation water for the agricultural economy of SE AR, salinization needs to be addressed to ensure the sustainability of crop, groundwater, and soil resources in the area. The origin of elevated salinity in MRVA aquifer was investigated using spatial and factor analysis of historical water quality data, and sampling and tracer analysis of groundwater from irrigation, municipal, and flowing industrial wells in SE AR. Spatial analysis of Cl- data in relation to soil type, geomorphic features and sand-blow density indicate that the Cl- anomalies are more closely related to the sand-blow density than soil data, suggesting an underlying tectonic control for the distribution of salinity. Factor analysis of historical geochemical data from the MRVA and underlying Sparta aquifer shows dilute and saline groups, with saline groups weighted positively with Cl- or Na+ and Cl-. Tracer data suggest a component of evaporatively evolved crustal water of pre-modern age has mixed with younger, fresher meteoric sources in SE AR to create the saline conditions in the MRVA aquifer. Stable hydrogen and oxygen values of waters sampled from the Tertiary Sparta and MRVA aquifers deviate from the global and local meteoric water lines along an evaporative trend (slope=4.4) and mixing line with Eocene Wilcox Group groundwaters. Ca2+ and Cl- contents vary with Br- along mixing trends between dilute MRVA water and Jurassic Smackover Formation pore fluids in southern AR. Increasing Cl- content with C-14 age in MRVA aquifer groundwater suggests that the older waters are more saline. Helium isotope ratios decrease with He gas content for more saline water, consistent with

  16. Oxygen consumption remains stable while ammonia excretion is reduced upon short time exposure to high salinity in Macrobrachium acanthurus (Caridae: Palaemonidae, a recent freshwater colonizer

    Directory of Open Access Journals (Sweden)

    Carolina A. Freire

    2017-10-01

    Full Text Available ABSTRACT Palaemonid shrimps occur in the tropical and temperate regions of South America and the Indo-Pacific, in brackish/freshwater habitats, and marine coastal areas. They form a clade that recently (i.e., ~30 mya invaded freshwater, and one included genus, Macrobrachium Bate, 1868, is especially successful in limnic habitats. Adult Macrobrachium acanthurus (Wiegmann, 1836 dwell in coastal freshwaters, have diadromous habit, and need brackish water to develop. Thus, they are widely recognized as euryhaline. Here we test how this species responds to a short-term exposure to increased salinity. We hypothesized that abrupt exposure to high salinity would result in reduced gill ventilation/perfusion and decreased oxygen consumption. Shrimps were subjected to control (0 psu and experimental salinities (10, 20, 30 psu, for four and eight hours (n = 8 in each group. The water in the experimental containers was saturated with oxygen before the beginning of the experiment; aeration was interrupted before placing the shrimp in the experimental container. Dissolved oxygen (DO, ammonia concentration, and pH were measured from the aquaria water, at the start and end of each experiment. After exposure, the shrimp’s hemolymph was sampled for lactate and osmolality assays. Muscle tissue was sampled for hydration content (Muscle Water Content, MWC. Oxygen consumption was not reduced and hemolymph lactate did not increase with increased salinity. The pH of the water decreased with time, under all conditions. Ammonia excretion decreased with increased salinity. Hemolymph osmolality and MWC remained stable at 10 and 20 psu, but osmolality increased (~50% and MWC decreased (~4% at 30 psu. The expected reduction in oxygen consumption was not observed. This shrimp is able to tolerate significant changes in water salt concentrations for a few hours by keeping its metabolism in aerobic mode, and putatively shutting down branchial salt uptake to avoid massive salt

  17. Influence of oxygen partial pressure and salinity on the community composition of ammonia-oxidizing bacteria in the Schelde estuary

    NARCIS (Netherlands)

    Bollmann, A.; Laanbroek, H.J.

    2002-01-01

    The influence of environmental factors on the community structure of ammoniaoxidizing bacteria (AOB) was investigated in the Schelde estuary. Simultaneously with the increase of oxygen and salinity, a shift of the dominant AOB was observed. Molecular analysis based on 16S rRNA genes showed that

  18. Influence of oxygen partial pressure and salinity on the community composition of ammonia-oxidizing bacteria in the Schelde estuary

    NARCIS (Netherlands)

    Bollmann, A.; Laanbroek, H.J.

    2002-01-01

    The influence of environmental factors on the community structure of ammonia-oxidizing bacteria (AOB) was investigated in the Schelde estuary. Simultaneously with the increase of oxygen and salinity, a shift of the dominant AOB was observed. Molecular analysis based on 16S rRNA genes showed that the

  19. World Ocean Atlas 2005, Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  20. Oceanographic profile temperature, salinity, oxygen measurements collected using bottle from multiple platforms in the Azov, Black Seas from 1924-1990 (NODC Accession 0002717)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen measurements collected using bottle from multiple platforms in the Azov, Black Seas from 1924-1990

  1. Coupled geochemical/hydrogeological modelling to assess the origin of salinity at the Tono area (Japan)

    International Nuclear Information System (INIS)

    Guimera, Jordi; Ruiz, Eduardo; Luna, Miguel; Arcos, David; Jordana, Salvador; Saegusa, Hiromitsu

    2005-01-01

    Numerical models are powerful tools for the characterization of groundwater flow, especially when integrating geochemical and hydrogeological data. This paper describes modeling exercises performed in the area surrounding the Mizunami Underground Research Laboratory (MIU) Construction Site in central Japan. A particular issue being investigated at the MIU Site is the presence of saline water detected at depth in certain boreholes. The main objective of this study is to develop conceptual physical models for the origin of this salinity and to test these conceptual models using numerical modeling techniques. One scenario being investigated is that the saline fluids represent residual Miocene age seawater which has been slightly altered by water-rock interactions. It is likely that during Miocene times, seawater inundated the Tono area. This hypothesis is partially supported by carbon and oxygen isotopic data of the calcite fracture filling materials. (author)

  2. Physical, chemical, and other data collected using GEOSECS oxygen probe, deep sea reversing thermometers, and bottle cast(s) from the MOANA WAVE from as a part of the International Decade of Ocean Exploration / North Pacific Experiment (IDOE/NORPAX) project from 11 February to 27 May 1975 (NODC Accession 7700524)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Depth, temperature, salinity, dissolved oxygen, chlorophyll a, phosphate, nitrate, nitrite, silicate, and pressure data were collected using GEOSECS oxygen probe,...

  3. Temperature, salinity, dissolved oxygen, nutrients, and currents data from the Chesapeake Bay region from multiple platforms, July 1949 - July 1965 (NODC Accession 7000995)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are currently only available in analog form. A digital scan of the pages containing measured values for temperature, salinity, dissolved oxygen,...

  4. Topology and immersion depth of an integral membrane protein by paramagnetic rates from dissolved oxygen.

    Science.gov (United States)

    Al-Abdul-Wahid, M Sameer; Verardi, Raffaello; Veglia, Gianluigi; Prosser, R Scott

    2011-09-01

    In studies of membrane proteins, knowledge of protein topology can provide useful insight into both structure and function. In this work, we present a solution NMR method for the measurement the tilt angle and average immersion depth of alpha helices in membrane proteins, from analysis of the paramagnetic relaxation rate enhancements arising from dissolved oxygen. No modification to the micelle or protein is necessary, and the topology of both transmembrane and amphipathic helices are readily determined. We apply this method to the measure the topology of a monomeric mutant of phospholamban (AFA-PLN), a 52-residue membrane protein containing both an amphipathic and a transmembrane alpha helix. In dodecylphosphocholine micelles, the amphipathic helix of AFA-PLN was found to have a tilt angle of 87° ± 1° and an average immersion depth of 13.2 Å. The transmembrane helix was found to have an average immersion depth of 5.4 Å, indicating residues 41 and 42 are closest to the micelle centre. The resolution of paramagnetic relaxation rate enhancements from dissolved oxygen compares favourably to those from Ni (II), a hydrophilic paramagnetic species.

  5. Topology and immersion depth of an integral membrane protein by paramagnetic rates from dissolved oxygen

    International Nuclear Information System (INIS)

    Al-Abdul-Wahid, M. Sameer; Verardi, Raffaello; Veglia, Gianluigi; Prosser, R. Scott

    2011-01-01

    In studies of membrane proteins, knowledge of protein topology can provide useful insight into both structure and function. In this work, we present a solution NMR method for the measurement the tilt angle and average immersion depth of alpha helices in membrane proteins, from analysis of the paramagnetic relaxation rate enhancements arising from dissolved oxygen. No modification to the micelle or protein is necessary, and the topology of both transmembrane and amphipathic helices are readily determined. We apply this method to the measure the topology of a monomeric mutant of phospholamban (AFA-PLN), a 52-residue membrane protein containing both an amphipathic and a transmembrane alpha helix. In dodecylphosphocholine micelles, the amphipathic helix of AFA-PLN was found to have a tilt angle of 87° ± 1° and an average immersion depth of 13.2 Å. The transmembrane helix was found to have an average immersion depth of 5.4 Å, indicating residues 41 and 42 are closest to the micelle centre. The resolution of paramagnetic relaxation rate enhancements from dissolved oxygen compares favourably to those from Ni (II), a hydrophilic paramagnetic species.

  6. Oceanographic profile temperature, salinity, oxygen, nutrients, and plankton measurements collected using bottle from the Parizeau in the North Pacific Ocean (NODC Accession 0002242)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen and other profile data received at NODC on 09/09/04 by Sydney Levitus from the Institute of Ocean Sciences (Sidney, B.C.), digitized...

  7. Faunal and oxygen isotopic evidence for surface water salinity changes during sapropel formation in the eastern Mediterranean

    International Nuclear Information System (INIS)

    Williams, D.F.; Thunell, R.C.

    1979-01-01

    The discovery of the widespread anaerobic deposits (sapropels) in late Cenozoic sediments of the eastern Mediteranean has prompted many workers to propose the periodic occurrence of extremely low surface salinites in the Mediterranean. Oxygen isotopic determinations and total faunal analyses were made at 1000-year intervals across two equivalent sapropels in two piston cores from the Levantine Basin. The sapropel layers were deposited approximately 9000 y.B.P. (Sapropel A) and 80, 000 y. B.P. (Sapropel B). Significant isotopic anomalies were recorded by the foraminiferal species within Sapropels A and B in both cores. The surface dwelling species record a larger 18 O depletion than the mesopelagic species suggesting that surface salinities were reduced by 2-3per 1000 during sapropel formation. The faunal changes associated with the sapropels also indicate that the oceanographic conditions which lead to anoxic conditions in the eastern Mediteranean involve the formation of a low salinity surface layer. The source of the low salinity water might be meltwater produced by disintegration of the Fennoscandian Ice Sheet which drained into the Black Sea, into the Aegean Sea and finally into the eastern Mediterranean. (Auth.)

  8. Abacus to determine soils salinity in presence of saline groundwater in arid zones case of the region of Ouargla

    Science.gov (United States)

    Fergougui, Myriam Marie El; Benyamina, Hind; Boutoutaou, Djamel

    2018-05-01

    In order to remedy the limit of salt intake to the soil surface, it is necessary to study the causes of the soil salinity and find the origin of these salts. The arid areas in the region of Ouargla lie on excessively mineralized groundwater whose level is near the soil surface (0 - 1.5 m). The topography and absence of a reliable drainage system led to the rise of the groundwater beside the arid climatic conditions contributed to the salinization and hydromorphy of the soils. The progress and stabilization of cultures yields in these areas can only occur if the groundwater is maintained (drained) to a depth of 1.6 m. The results of works done to the determination of soil salinity depend mainly on the groundwater's salinity, its depth and the climate.

  9. Physiological impact of salinity increase at organisms and red blood cell levels in the European flounder (Platichthys flesus

    DEFF Research Database (Denmark)

    Jensen, F.B.; Lecklin, T.; Busk, M.

    2002-01-01

    Erythrocyte, Hyperosmotic shrinkage, Oxygen affinity, Oxygenation-dependent RVI, Salinity challenge, Volume regulation......Erythrocyte, Hyperosmotic shrinkage, Oxygen affinity, Oxygenation-dependent RVI, Salinity challenge, Volume regulation...

  10. Dissolved Oxygen Availability on Traditional Pond Using Silvofishery Pattern in Mahakam Delta

    Directory of Open Access Journals (Sweden)

    Ismail Fahmy Almadi

    2013-06-01

    Full Text Available The development of aquaculture system should meet the community’s basic need economically by taking into account the carrying capacity and environmental sustainability. The development of the environmentally friendly system such as silvofishery is being promoted by government however its yield has not reached the target yet. Dissolved oxygen availability is an important indicator which determines the success of the aquaculture system. The objective of the research was to determine dissolved oxygen availability on traditional pond systems using silvofishery pattern. Time series data collection was conducted once in 14 days with 2 measuring times; in the morning (06.00 am and in the evening (06.00 pm for 112 days. The research was conducted at four different silvofishery pond patterns, Pond Pattern 1 (0% mangrove canopy covered, Pond Pattern 2 (35% mangrove canopy covered, Pond Pattern 3 (67% mangrove canopy covered, and Pond Pattern 4 (75% mangrove canopy covered. Measurement was observed openly in the pond (in situ with parameters: dissolved oxygen, temperature, Water pH, Salinity, Transparency, Wind Speed, and Depth of Water Table, while chlorofil-a was ex-situ measured. The result from each parameter was compared to optimum concentration rate for shrimp growth. From the experiment, Pond Pattern 1 showed the most satisfaction results. Its dissolved oxygen availability during the research was ≥ 4 mg/L which was 5.88 mg/L ±0.48 mg/L in the evening (06.00 pm and 4.33 mg/L ±1.24 mg/L in the morning (06.00 am. It was also supported by optimum condition of other parameters such as temperature, Water pH, Salinity, Wind Speed, and Depth of Water Table. However, it was not supported by fertility and transparency of water. Thus, the traditional pattern of conservation still needs additional technology to maintain adequate dissolved oxygen availability for optimum shrimp growth.

  11. Oxygen depth profiling using the 16O(d,α)14N nuclear reaction

    International Nuclear Information System (INIS)

    Khubeis, I.; Al-Rjob, R.

    1997-01-01

    The excitation function of the 16 O(d,α) 14 N nuclear reaction has been determined in the deuteron energy range of 0.88-2.28 MeV. Major resonances are observed at deuteron energies of 0.98, 1.31, 1.53, 1.60, 1.73 and 2.22 MeV. The present results show good agreement with those of Haase and Khubeis, however there is a shift of 60 keV in the first resonance compared with the measurements of Amsel. The use of a thin surface barrier detector (t=22 μm) and a bias voltage of +20 V coupled with a proper pile-up rejection circuit has allowed the determination of the oxygen depth profiling to a resolution of 16 nm for thick targets. This method is efficient in eliminating interferences from other nuclear reactions such as 16 O(d,p) 17 O and 12 C(d,p) 19 C, where emitted protons have severely obscured α-particles from the 16 O(d,α) 14 N reaction. A 1.08 MeV deuteron beam has been employed to increase the α-yield from the target. The target has been tilted at 70 to enhance depth resolution. This reaction is well suited for the determination of oxygen concentration in oxides of high temperature superconductors. (orig.)

  12. Temperature, salinity, oxygen and nutrients bottle and CTD data collected in the northern North Atlantic, Nordic and Arctic Seas from 1901 to 2011 (NODC Accession 0105532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen and nutrients bottle and CTD data collected in the Arctic Ocean, Barents Sea, Greenland Sea, Kara Sea, North Atlantic Ocean,...

  13. Determination of dissolved oxygen in saline waters applying mathematical methods and as a membrane electrode sensor; Determinacion de oxigeno disuelto en aguas salinas aplicando modelos matematicos y como sensor electrodo de membrana

    Energy Technology Data Exchange (ETDEWEB)

    Mayari, R.; Espinosa, M. C.; Ruiz, M. [Centro Nacional de Investigaciones Ceintificas. La Habana (Cuba); Romero, E. [Universidad de Huelva (Spain)

    2000-07-01

    This work shows as specific methodology for the determination of dissolved oxygen in saline waters that allows to consider the variations of temperature and of concentration of salts. Both factors influence the solubility of the gases in water, making possible in place measurements, in bodies of water with content of salts unto of the concentration of sea water, with greater dependability. The mathematical models obtained are shown, the errors due to equipment, as well as the results obtained when applying this methodology in saline waters with diverse levels of contamination this allows to discern when the decrease of dissolved oxygen levels is due to an increase in the salinity or to an increase in the contamination of the water body. (Author) 7 refs.

  14. Roughness development in the depth profiling with 500 eV O2+ beam with the combination of oxygen flooding and sample rotation

    International Nuclear Information System (INIS)

    Gui, D.; Xing, Z.X.; Huang, Y.H.; Mo, Z.Q.; Hua, Y.N.; Zhao, S.P.; Cha, L.Z.

    2008-01-01

    Roughness development is one of the most often addressed issues in the secondary ion mass spectrometry (SIMS) ultra-shallow depth profiling. The effect of oxygen flooding pressure on the roughness development has been investigated under the bombardment of 500 eV O 2 + beam with simultaneous sample rotation. Oxygen flooding had two competing effects on the surface roughening, i.e., enhancement of initiating roughening and suppression of roughening development, which were suggested to be described by the onset depth z on and transient width w tr of surface roughening. Both z on and w tr decreased as oxygen flooding pressure increased. As the result, surface roughening was most pronounced at the intermediate pressure from 4.4E-5 Pa to 5.8E-5 Pa. The surface roughening is negligible while without flooding or with flooding at the saturated pressure. No flooding is preferable for depth profiling ultra-shallow B implantation because of the better B profile shape and short analysis time

  15. Oceanographic profile temperature, salinity, oxygen and other measurements collected using bottle in the Barents, Kara, Laptev, White, and Norwegian Seas from 1970 through 1975 (NODC Accession 0002125)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen and other measurements collected using bottle in the Barents, Kara, Laptev, White, and Norwegian Seas from 1970...

  16. Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, and Norwegian Seas from 1976 through 1982 (NODC Accession 0002126)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic profile temperature, salinity, oxygen and other measurement collected using bottle in the Barents, Kara, Laptev, White, and Norwegian Seas from 1976...

  17. Effects of recoil-implanted oxygen on depth profiles of defects and annealing processes in P{sup +}-implanted Si studied using monoenergetic positron beams

    Energy Technology Data Exchange (ETDEWEB)

    Uedono, Akira; Moriya, Tsuyoshi; Tanigawa, Shoichiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science; Kitano, Tomohisa; Watanabe, Masahito; Kawano, Takao; Suzuki, Ryoichi; Ohdaira, Toshiyuki; Mikado, Tomohisa

    1996-04-01

    Effects of oxygen atoms recoiled from SiO{sub 2} films on depth profiles of defects and annealing processes in P{sup +}-implanted Si were studied using monoenergetic positron beams. For an epitaxial Si specimen, the depth profile of defects was found to be shifted toward the surface by recoil implantation of oxygen atoms. This was attributed to the formation of vacancy-oxygen complexes and a resultant decrease in the diffusion length of vacancy-type defects. The recoiled oxygen atoms stabilized amorphous regions introduced by P{sup +}-implantation, and the annealing of these regions was observed after rapid thermal annealing (RTA) at 700degC. For a Czochralski-grown Si specimen fabricated by through-oxide implantation, the recoiled oxygen atoms introduced interstitial-type defects upon RTA below the SiO{sub 2}/Si interface, and such defects were dissociated by annealing at 1000degC. (author)

  18. Effect of salinity changes on the bacterial diversity, photosynthesis and oxygen consumption of cyanobacterial mats from an intertidal flat of the Arabian Gulf.

    Science.gov (United States)

    Abed, Raeid M M; Kohls, Katharina; de Beer, Dirk

    2007-06-01

    The effects of salinity fluctuation on bacterial diversity, rates of gross photosynthesis (GP) and oxygen consumption in the light (OCL) and in the dark (OCD) were investigated in three submerged cyanobacterial mats from a transect on an intertidal flat. The transect ran 1 km inland from the low water mark along an increasingly extreme habitat with respect to salinity. The response of GP, OCL and OCD in each sample to various salinities (65 per thousand, 100 per thousand, 150 per thousand and 200 per thousand) were compared. The obtained sequences and the number of unique operational taxonomic units showed clear differences in the mats' bacterial composition. While cyanobacteria decreased from the lower to the upper tidal mat, other bacterial groups such as Chloroflexus and Cytophaga/Flavobacteria/Bacteriodetes showed an opposite pattern with the highest dominance in the middle and upper tidal mats respectively. Gross photosynthesis and OCL at the ambient salinities of the mats decreased from the lower to the upper tidal zone. All mats, regardless of their tidal location, exhibited a decrease in areal GP, OCL and OCD rates at salinities > 100 per thousand. The extent of inhibition of these processes at higher salinities suggests an increase in salt adaptation of the mats microorganisms with distance from the low water line. We conclude that the resilience of microbial mats towards different salinity regimes on intertidal flats is accompanied by adjustment of the diversity and function of their microbial communities.

  19. Oxygen depth profiling in Kr+-implanted polycrystalline alpha titanium by means of 16O(α,α)16O resonance scattering

    International Nuclear Information System (INIS)

    Nsengiyumva, S.; Riviere, J.P.; Raji, A.T.; Comrie, C.M.; Britton, D.T.; Haerting, M.

    2011-01-01

    The 16 O(α,α) 16 O resonance scattering was applied to study the effects of ion implantation on the oxygen distribution in the near surface region of polycrystalline titanium implanted with 180 keV krypton ions at fluences, ranging between 1 x 10 14 and 5 x 10 15 Kr + /cm 2 . Two sample sets were chosen: as-received polycrystalline titanium discs rolled and annealed in half-hard condition which had a thick oxygen layer and similar samples in which this surface layer was removed by polishing. An increase of the mean oxygen concentration observed in both unpolished and polished samples at low fluence suggests a knock-on implantation of surface oxygen atoms. At high fluence, an overall decrease in the mean oxygen concentration and mean oxygen depth suggests an out-diffusion of near-surface oxygen atoms.

  20. Structure and composition of oligohaline marsh plant communities exposed to salinity pulses

    Science.gov (United States)

    Howard, R.J.; Mendelssohn, I.A.

    2000-01-01

    The response of two oligohaline marsh macrophyte communities to pulses of increased salinity was studied over a single growing season in a greenhouse experiment. The plant communities were allowed a recovery period in freshwater following the pulse events. The experimental treatments included: (1) salinity influx rate (rate of salinity increase from 0 to 12 gl-1); (2) duration of exposure to elevated salinity; and (3) water depth. The communities both included Sagittaria lancifolia L.; the codominant species were Eleocharis palustris (L.) Roemer and J.A. Schultes in community 1 and Schoenoplectus americanus (Pers.) Volk. ex Schinz and R. Keller in community 2. Effects of the treatments on sediment chemical characteristics (salinity, pH, redox potential, and sulfide and ammonium concentrations) and plant community attributes (aboveground and belowground biomass, stem density, leaf tissue nutrients, and species richness) were examined. The treatment effects often interacted to influence sediment and plant communities characteristics following recovery in fresh water. Salinity influx rate per se, however, had little effect on the abiotic or biotic response variables; significant influx effects were found when the 0 gl-1 (zero influx) treatment was compared to the 12 gl-1 treatments, regardless of the rate salinity was raised. A salinity level of 12 gl-1 had negative effects on plant community structure and composition; these effects were usually associated with 3 months of salinity exposure. Water depth often interacted with exposure duration, but increased water depth did independently decrease the values of some community response measures. Community 1 was affected more than community 2 in the most extreme salinity treatment (3 months exposure/15-cm water depth). Although species richness in both communities was reduced, structural changes were more dramatic in community 1. Biomass and stem density were reduced in community 1 overall and in both dominant species

  1. Mid-depth respired carbon storage and oxygenation of the eastern equatorial Pacific over the last 25,000 years

    Science.gov (United States)

    Umling, Natalie E.; Thunell, Robert C.

    2018-06-01

    A growing body of evidence suggests that respired carbon was stored in mid-depth waters (∼1-3 km) during the last glacial maximum (LGM) and released to the atmosphere from upwelling regions during deglaciation. Decreased ventilation, enhanced productivity, and enhanced carbonate dissolution are among the mechanisms that have been cited as possible drivers of glacial CO2 drawdown. However, the relative importance of each of these mechanisms is poorly understood. New approaches to quantitatively constrain bottom water carbonate chemistry and oxygenation provide methods for estimating historic changes in respired carbon storage. While increased CO2 drawdown during the LGM should have resulted in decreased oxygenation and a shift in dissolved inorganic carbon (DIC) speciation towards lower carbonate ion concentrations, this is complicated by the interplay of carbonate compensation, export productivity, and circulation. To disentangle these processes, we use a multiproxy approach that includes boron to calcium (B/Ca) ratios of the benthic foraminifera Cibicidoides wuellerstorfi to reconstruct deep-water carbonate ion concentrations ([CO32-]) and the uranium to calcium (U/Ca) ratio of foraminiferal coatings in combination with benthic foraminiferal carbon isotopes to reconstruct changes in bottom water oxygen concentrations ([O2]) and organic carbon export. Our records indicate that LGM [CO32-] and [O2] was reduced at mid water depths of the eastern equatorial Pacific (EEP), consistent with increased respired carbon storage. Furthermore, our results suggest enhanced mixing of lower Circumpolar Deep Water (LCDW) to EEP mid water depths and provide evidence for the importance of circulation for oceanic-atmospheric CO2 exchange.

  2. Temperature, salinity, oxygen, silicate, phosphate, nitrite, and pH data collected in Okhotsk Sea by multiple platforms from 1985-03-20 to 1989-09-07 (NODC Accession 0075740)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, silicate, phosphate, nitrite, and pH data collected in the Okhotsk Sea by multiple Soviet Union platforms in March 1985 and...

  3. The oxygen isotope effect on the in-plane penetration depth in cuprate superconductors

    International Nuclear Information System (INIS)

    Khasanov, R; Shengelaya, A; Morenzoni, E; Conder, K; Savic, I M; Keller, H

    2004-01-01

    Muon spin rotation (μSR) studies of the oxygen isotope ( 16 O/ 18 O) effect (OIE) on the in-plane magnetic field penetration depth λ ab in cuprate high-temperature superconductors (HTS) are presented. First, the doping dependence of the OIE on the transition temperature T c in various HTS is briefly discussed. It is observed that different cuprate families show similar doping dependences of the OIE on T c . Then, bulk μSR, low-energy μSR, and magnetization studies of the total and site-selective OIE on λ ab are described in some detail. A substantial OIE on λ ab was observed in various cuprate families at all doping levels, suggesting that cuprate HTS are non-adiabatic superconductors. The experiments clearly demonstrate that the total OIE on T c and λ ab arise from the oxygen sites within the superconducting CuO 2 planes, demonstrating that the phonon modes involving the movement of planar oxygen are dominantly coupled to the supercarriers. Finally, it is shown that the OIE on T c and λ ab exhibit a relation that appears to be generic for different families of cuprate HTS. The observation of these unusual isotope effects implies that lattice effects play an essential role in cuprate HTS and have to be considered in any realistic model of high-temperature superconductivity

  4. Monitoring of soil chemical characteristics with time as affected by irrigation with saline water

    International Nuclear Information System (INIS)

    Mostafa, A. Z.; Galal, Y.G.M.; Lotfy, S.M.

    2012-01-01

    A lysimeter study was conducted to investigate the effect of irrigation with saline water on soil chemical characteristics at two depth (0-20) and (20-40 cm).Both fertilized (60, 120 KgN/ha) and unfertilized (0) soil were simulated in a total of 84 lysimeter. Data indicated that the electric conductivity (EC) values tended to increase with time intervals also EC-values as affected by soil depth after 105 days were high in 20 cm depth as compared to 40 cm depth. Chloride concentration did not reflect great variations as affected by time of nitrogen application where the values were nearly closed to each other. At the end of the experiment, much of Cl - content was occurred in the second layer of soil depth (20-40) as compared to depth of 0-20 cm. This was the case under all salinity levels. The irrigation with fresh water did not reflect any significant different in EC values between 120 KgN/ha , 60 KgN/ha or soil depth, however, it tend to increase with increasing water salinity levels. There were no much differences between the nitrogen application time (T1, T2 and T3). In contrast with Cl - , sodium was remained in the upper layer of 0-20 cm soil depth but still increase with increasing water salinity levels.

  5. Climatology and seasonality of upper ocean salinity: a three-dimensional view from argo floats

    Science.gov (United States)

    Chen, Ge; Peng, Lin; Ma, Chunyong

    2018-03-01

    Primarily due to the constraints of observation technologies (both field and satellite measurements), our understanding of ocean salinity is much less mature compared to ocean temperature. As a result, the characterizations of the two most important properties of the ocean are unfortunately out of step: the former is one generation behind the latter in terms of data availability and applicability. This situation has been substantially changed with the advent of the Argo floats which measure the two variables simultaneously on a global scale since early this century. The first decade of Argo-acquired salinity data are analyzed here in the context of climatology and seasonality, yielding the following main findings for the global upper oceans. First, the six well-defined "salty pools" observed around ±20° in each hemisphere of the Pacific, Atlantic and Indian Oceans are found to tilt westward vertically from the sea surface to about 600 m depth, forming six saline cores within the subsurface oceans. Second, while potential temperature climatology decreases monotonically to the bottom in most places of the ocean, the vertical distribution of salinity can be classified into two categories: A double-halocline type forming immediately above and below the local salinity maximum around 100-150 m depths in the tropical and subtropical oceans, and a single halocline type existing at about 100 m depth in the extratropical oceans. Third, in contrast to the midlatitude dominance for temperature, seasonal variability of salinity in the oceanic mixed layer has a clear tropical dominance. Meanwhile, it is found that a two-mode structure with annual and semiannual periodicities can effectively penetrate through the upper ocean into a depth of 2000 m. Fourth, signature of Rossby waves is identified in the annual phase map of ocean salinity within 200-600 m depths in the tropical oceans, revealing a strongly co-varying nature of ocean temperature and salinity at specific depths

  6. Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia

    Science.gov (United States)

    Mather, Caroline C.; Skrzypek, Grzegorz; Dogramaci, Shawan; Grierson, Pauline F.

    2018-04-01

    Groundwater dolocrete occurring within the Fortescue Marsh, a large inland wetland in the Pilbara region of northwest Australia, has been investigated to provide paleoenvironmental and paleohydrological records and further the understanding of low temperature dolomite formation in terrestrial settings over the Quaternary Period. Two major phases of groundwater dolocrete formation are apparent from the presence of two distinct units of dolocrete, based on differences in depth, δ18O values and mineral composition. Group 1 (G1) occurs at depth 20-65 m b.g.l. (below ground level) and contains stoichiometric dolomite with δ18O values of -4.02-0.71‰. Group 2 (G2) is shallower (0-23 m b.g.l.), occurring close to the current groundwater level, and contains Ca-rich dolomite ± secondary calcite with a comparatively lower range of δ18O values (-7.74 and -6.03‰). Modelled δ18O values of paleogroundwater from which older G1 dolomite precipitated indicated highly saline source water, which had similar stable oxygen isotope compositions to relatively old brine groundwater within the Marsh, developed under a different hydroclimatic regime. The higher δ18O values suggest highly evaporitic conditions occurred at the Marsh, which may have been a playa lake to saline mud flat environment. In contrast, G2 dolomite precipitated from comparatively fresher water, and modelled δ18O values suggested formation from mixing between inflowing fresher groundwater with saline-brine groundwater within the Marsh. The δ18O values of the calcite indicates formation from brackish to saline groundwater, which suggests this process may be associated with coeval gypsum dissolution. In contrast to the modern hydrology of the Marsh, which is surface water dependent and driven by a flood and drought regime, past conditions conducive to dolomite precipitation suggest a groundwater dependent system, where shallow groundwaters were influenced by intensive evaporation.

  7. Historical temperature, salinity, oxygen, nutrients and meteorological data collected in the Arctic Ocean and Atlantic Ocean by various countries from 20 Jul 1870 to 17 Jul 1995 (NODC Accession 0085914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, nutrients and meteorological data collected in the Arctic Ocean and Atlantic Ocean by various countries from 1870 to 1995,...

  8. Influence of the depth of sedation on regional cerebral oxygen saturation monitoring in neurosurgery of supratentorial gliomas

    Directory of Open Access Journals (Sweden)

    ZHANG Kai⁃ying

    2012-12-01

    Full Text Available Objective To investigate the influence on regional cerebral oxygen saturation (rScO2 of sedation depth during anesthesia induction and maintenance in supratentorial glioma resections. Methods Thirty patients with Ⅰ - Ⅱ supratentorial glioma (graded by American Society of Anesthesiologists underwent elective supratentorial glioma resection were included in this study. Rocuronium, sufentanil and propofol were used for anesthesia induction. After trachea cannula, total intravenous anesthesia (TIVA was maintained with plasma concentration of propofol 2.80-3.20 μg/ml and remifentanil 0.10-0.20 μg/(kg·min. Thirty groups of rScO2, bispectral index (BIS, mean arterial pressure (MAP and heart rate (HR were recorded continuously till the incision. Results During anesthesia induction, BIS decreased along with the infusion of anesthetics, and there was significant negative correlation between BIS and rScO2 (r = ⁃0.803, P = 0.001. During anesthesia maintenance, rScO2 and BIS were not significantly related (r = 0.147, P = 0.396. Conclusion The rScO2 monitoring can reflect the influence of sedation depth on cerebral oxygen delivery and consumption balance during supratentorial glioma resection under TIVA.

  9. The oxygen isotope effect on the in-plane penetration depth in cuprate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Khasanov, R [Physik-Institut der Universitaet Zuerich, CH-8057 Zurich (Switzerland); Shengelaya, A [Physik-Institut der Universitaet Zuerich, CH-8057 Zurich (Switzerland); Morenzoni, E [Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Conder, K [Laboratory for Neutron Scattering, ETH Zuerich and PSI Villigen, CH-5232 Villigen PSI (Switzerland); Savic, I M [Faculty of Physics, University of Belgrade, 11001 Belgrade (Serbia and Montenegro); Keller, H [Physik-Institut der Universitaet Zuerich, CH-8057 Zurich (Switzerland)

    2004-10-13

    Muon spin rotation ({mu}SR) studies of the oxygen isotope ({sup 16}O/{sup 18}O) effect (OIE) on the in-plane magnetic field penetration depth {lambda}{sub ab} in cuprate high-temperature superconductors (HTS) are presented. First, the doping dependence of the OIE on the transition temperature T{sub c} in various HTS is briefly discussed. It is observed that different cuprate families show similar doping dependences of the OIE on T{sub c}. Then, bulk {mu}SR, low-energy {mu}SR, and magnetization studies of the total and site-selective OIE on {lambda}{sub ab} are described in some detail. A substantial OIE on {lambda}{sub ab} was observed in various cuprate families at all doping levels, suggesting that cuprate HTS are non-adiabatic superconductors. The experiments clearly demonstrate that the total OIE on T{sub c} and {lambda}{sub ab} arise from the oxygen sites within the superconducting CuO{sub 2} planes, demonstrating that the phonon modes involving the movement of planar oxygen are dominantly coupled to the supercarriers. Finally, it is shown that the OIE on T{sub c} and {lambda}{sub ab} exhibit a relation that appears to be generic for different families of cuprate HTS. The observation of these unusual isotope effects implies that lattice effects play an essential role in cuprate HTS and have to be considered in any realistic model of high-temperature superconductivity.

  10. Saline agriculture in Mediterranean environments

    Directory of Open Access Journals (Sweden)

    Albino Maggio

    2011-03-01

    Full Text Available Salinization is increasingly affecting world's agricultural land causing serious yield loss and soil degradation. Understanding how we could improve crop productivity in salinized environments is therefore critical to meet the challenging goal of feeding 9.3 billion people by 2050. Our comprehension of fundamental physiological mechanisms in plant salt stress adaptation has greatly advanced over the last decades. However, many of these mechanisms have been linked to salt tolerance in simplified experimental systems whereas they have been rarely functionally proven in real agricultural contexts. In-depth analyses of specific crop-salinity interactions could reveal important aspects of plant salt stress adaptation as well as novel physiological/agronomic targets to improve salinity tolerance. These include the developmental role of root vs. shoot systems respect to water-ion homeostasis, morphological vs. metabolic contributions to stress adaptation, developmental processes vs. seasonal soil salinity evolution, residual effects of saline irrigation in non-irrigated crops, critical parameters of salt tolerance in soil-less systems and controlled environments, response to multiple stresses. Finally, beneficial effects of salinization on qualitative parameters such as stress-induced accumulation of high nutritional value secondary metabolites should be considered, also. In this short review we attempted to highlight the multifaceted nature of salinity in Mediterranean agricultural systems by summarizing most experimental activity carried out at the Department of Agricultural Engineering and Agronomy of University of Naples Federico II in the last few years.

  11. Seasonal variations of the upper ocean salinity stratification in the Tropics

    Science.gov (United States)

    Maes, Christophe; O'Kane, Terence J.

    2014-03-01

    In comparison to the deep ocean, the upper mixed layer is a region typically characterized by substantial vertical gradients in water properties. Within the Tropics, the rich variability in the vertical shapes and forms that these structures can assume through variation in the atmospheric forcing results in a differential effect in terms of the temperature and salinity stratification. Rather than focusing on the strong halocline above the thermocline, commonly referred to as the salinity barrier layer, the present study takes into account the respective thermal and saline dependencies in the Brunt-Väisälä frequency (N2) in order to isolate the specific role of the salinity stratification in the layers above the main pycnocline. We examine daily vertical profiles of temperature and salinity from an ocean reanalysis over the period 2001-2007. We find significant seasonal variations in the Brunt-Väisälä frequency profiles are limited to the upper 300 m depth. Based on this, we determine the ocean salinity stratification (OSS) to be defined as the stabilizing effect (positive values) due to the haline part of N2 averaged over the upper 300 m. In many regions of the tropics, the OSS contributes 40-50% to N2 as compared to the thermal stratification and, in some specific regions, exceeds it for a few months of the seasonal cycle. Away from the tropics, for example, near the centers of action of the subtropical gyres, there are regions characterized by the permanent absence of OSS. In other regions previously characterized with salinity barrier layers, the OSS obviously shares some common variations; however, we show that where temperature and salinity are mixed over the same depth, the salinity stratification can be significant. In addition, relationships between the OSS and the sea surface salinity are shown to be well defined and quasilinear in the tropics, providing some indication that in the future, analyses that consider both satellite surface salinity

  12. Shallow rainwater lenses in deltaic areas with saline seepage

    Directory of Open Access Journals (Sweden)

    P. G. B. de Louw

    2011-12-01

    Full Text Available In deltaic areas with saline seepage, freshwater availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence and size. Our findings are based on different types of field measurements and detailed numerical groundwater models applied in the south-western delta of the Netherlands. By combining the applied techniques we could extrapolate measurements at point scale (groundwater sampling, temperature and electrical soil conductivity (TEC-probe measurements, electrical cone penetration tests (ECPT to field scale (continuous vertical electrical soundings (CVES, electromagnetic survey with EM31, and even to regional scale using helicopter-borne electromagnetic measurements (HEM. The measurements show a gradual mixing zone between infiltrating fresh rainwater and upward flowing saline groundwater. The mixing zone is best characterized by the depth of the centre of the mixing zone Dmix, where the salinity is half that of seepage water, and the bottom of the mixing zone Bmix, with a salinity equal to that of the seepage water (Cl-conc. 10 to 16 g l−1. Dmix is found at very shallow depth in the confining top layer, on average at 1.7 m below ground level (b.g.l., while Bmix lies about 2.5 m b.g.l. The model results show that the constantly alternating upward and downward flow at low velocities in the confining layer is the main mechanism of mixing between rainwater and saline seepage and determines the position and extent of the mixing zone (Dmix and Bmix. Recharge, seepage flux, and drainage depth are the controlling factors.

  13. Regional acidification trends in Florida shellfish estuaries: A 20+ year look at pH, oxygen, temperature, and salinity

    Science.gov (United States)

    Robbins, Lisa L.; Lisle, John T.

    2018-01-01

    Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

  14. Regional acidification trends in Florida shellfish estuaries: A 20+ year look at pH, oxygen, temperature and salinity

    Science.gov (United States)

    Robbins, Lisa L.; Lisle, John T.

    2018-01-01

    Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

  15. Autonomous observations of in vivo fluorescence and particle backscatteringin an oceanic oxygen minimum zone.

    Science.gov (United States)

    Whitmire, A L; Letelier, R M; Villagrán, V; Ulloa, O

    2009-11-23

    The eastern South Pacific (ESP) oxygen minimum zone (OMZ) is a permanent hydrographic feature located directly off the coasts of northern Chile and Peru. The ESP OMZ reaches from coastal waters out to thousands of kilometers offshore, and can extend from the near surface to depths greater than 700 m. Oxygen minimum zones support unique microbial assemblages and play an important role in marine elemental cycles. We present results from two autonomous profiling floats that provide nine months of time-series data on temperature, salinity, dissolved oxygen, chlorophyll a, and particulate backscattering in the ESP OMZ. We observed consistently elevated backscattering signals within low-oxygen waters, which appear to be the result of enhanced microbial biomass in the OMZ intermediate waters. We also observed secondary chlorophyll a fluorescence maxima within low-oxygen waters when the upper limit of the OMZ penetrated the base of the photic zone. We suggest that autonomous profiling floats are useful tools for monitoring physical dynamics of OMZs and the microbial response to perturbations in these areas.

  16. Temperature, salinity, oxygen, phosphate, silicate, nitrite, alkalinity, and pH data collected by multiple former Soviet Union institutions from Okhotsk Sea from 1981-09-23 to 1988-06-17 (NODC Accession 0081217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, phosphate, silicate, nitrite, alkalinity, and pH data collected by multiple former Soviet Union institutions from Okhotsk...

  17. Carbon and nitrogen uptake of calcareous benthic foraminifera along a depth-related oxygen gradient in the OMZ of the Arabian Sea

    Directory of Open Access Journals (Sweden)

    Annekatrin Julie Enge

    2016-02-01

    Full Text Available Foraminifera are an important faunal element of the benthos in oxygen-depleted settings such as Oxygen Minimum Zones (OMZs where they can play a relevant role in the processing of phytodetritus. We investigated the uptake of phytodetritus (labeled with 13C and 15N by cal-careous foraminifera in the 0-1 cm sediment horizon under different oxygen concentrations within the OMZ in the eastern Arabian Sea. The in situ tracer experiments were carried out along a depth transect on the Indian margin over a period of 4 to 10 days. The uptake of phy-todetrital carbon within 4 days by all investigated species shows that phytodetritus is a rele-vant food source for foraminifera in OMZ sediments. The decrease of total carbon uptake from 540 to 1100 m suggests a higher demand for carbon by species in the low-oxygen core region of the OMZ or less food competition with macrofauna. Especially Uvigerinids showed high uptake of phytodetrital carbon at the lowest oxygenated site. Variation in the ratio of phytodetrital carbon to nitrogen between species and sites indicates that foraminiferal carbon and nitrogen use can be decoupled and different nutritional demands are found between spe-cies. Lower ratio of phytodetrital carbon and nitrogen at 540 m could hint for greater demand or storage of food-based nitrogen, ingestion or hosting of bacteria under almost anoxic condi-tions. Shifts in the foraminiferal assemblage structure (controlled by oxygen or food availabil-ity and in the presence of other benthic organisms account for observed changes in the pro-cessing of phytodetritus in the different OMZ habitats. Foraminifera dominate the short-term processing of phytodetritus in the OMZ core but are less important in the lower OMZ bounda-ry region of the Indian margin as biological interactions and species distribution of foraminif-era change with depth and oxygen levels.

  18. Groundwater salinity at Olkiluoto and its effects on a spent fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Vieno, T. [VTT Energy, Espoo (Finland)

    2000-06-01

    The Olkiluoto island rose from the Baltic Sea 2500 to 3000 years ago. The layered sequence of groundwaters can be related to climatic and shoreline changes from modern tune through former Baltic stages to the deglaciation phase about 10 000 years ago and even to preglacial times. Fresh groundwater is found to the depth of about 150 metres, brackish between 100 and 400 metres, deeper groundwaters are saline. At the depth of 500 meters, the content of Total Dissolved Solids (TDS) varies between 10 and 25 g/l. The most saline waters at depths greater than 800 metres have TDS values between 30 and 75 g/l. These deep saline waters seem to have been undisturbed during the most recent glaciation and even much longer in the past. Today fresh water infiltrating at the surface gradually displaces brackish and saline groundwater in the bedrock. Due to the still ongoing postglacial land uplift, Olkiluoto is likely to become an inland site with brackish or fresh groundwater at the depth of 500 metres within the next 10 000 years. During the construction and operation phases groundwater will be drawn into the repository from the surrounding bedrock. As a consequence, more saline groundwaters, presently laying 100 to 200 metres below the repository level, may rise to the disposal level. After the closing of the repository the salinity distribution will gradually return towards the natural state. During the glacial cycle groundwater salinity may increase, for example, during freezing of groundwater into permafrost, when dissolved solids concentrate in the remaining water phase, and in a situation where deep saline groundwaters from under the centre of the glacier are pushed to the upper parts of the bedrock at the periphery of the glacier. The most significant open issue related to saline groundwater is the performance of the tunnel backfill which in the BS-3 concept has been planned to consist of a mixture of crushed rock and 10-30% of bentonite. Saline groundwater may

  19. Oceanographic temperature, salinity, oxygen, phosphate, total phosphorus, silicate, nitrite, pH, alkalinity measurements collected using bottle on multiple platforms in the Pacific, Atlantic, Arctic, Mediterranean from 1910 to 1982 (NODC Accession 0038350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, oxygen, and other measurements found in dataset OSD taken from the AGASSIZ; A., ALBACORE and other platforms in the Coastal N...

  20. Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin from R/Vs GORIZONT and OKEANOGRAF, 1960 - 1969 (NODC Accession 0074609)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin of the Mediterranean...

  1. Salinity information in coral δ18O records

    Science.gov (United States)

    Conroy, J. L.; Thompson, D. M.; Dassié, E. P.; Stevenson, S.; Konecky, B. L.; DeLong, K. L.; Sayani, H. R.; Emile-Geay, J.; Partin, J. W.; Abram, N. J.; Martrat, B.

    2017-12-01

    Coral oxygen isotopic ratios (δ18O) are typically utilized to reconstruct sea surface temperature (SST), or SST-based El Niño-Southern Oscillation metrics (e.g., NIÑO3.4), despite the influence of both SST and the oxygen isotopic composition of seawater (δ18Osw) on coral δ18O. The ideal way to isolate past δ18Osw variations is to develop independent and univariate SST and δ18Osw responders, for instance, via paired coral δ18O and Sr/Ca analyses. Nonetheless, many coral δ18O records without paired Sr/Ca records already exist in the paleoclimatic literature, and these may be able to provide some insight into past δ18Osw and salinity changes due to the nature of the significant positive relationship between instrumental salinity and δ18Osw. Here we use coral δ18O records from the new PAGES Iso2k database to assess the regions in which coral δ18O has the greatest potential to provide salinity information based on the strength of the relationship between instrumental salinity and coral δ18O values. We find from annual pseudocoral similations that corals in the western tropical Pacific share a substantial fraction of their variance with δ18Osw rather than SST. In contrast, in the Indian Ocean and eastern tropical Pacific it is SST that predominantly explains coral δ18O variance. In agreement with this variance decomposition, we find that coral δ18O time series from the western tropical Pacific are significantly correlated with mid to late 20th century salinity. However, variations in the strength of the δ18Osw-salinity relationship across the western tropical Pacific will likely have a significant influence on coral δ18O-based salinity reconstructions. Additionally, in some cases a strong, negative correlation between SST and δ18Osw might not allow their influences to be adequately separated in coral δ18O records without the use of coupled Sr/Ca estimates of the temperature contribution. Overall, we find a range of modern salinity and SST

  2. Oxygen depth profiling in Kr{sup +}-implanted polycrystalline alpha titanium by means of {sup 16}O({alpha},{alpha}){sup 16}O resonance scattering

    Energy Technology Data Exchange (ETDEWEB)

    Nsengiyumva, S., E-mail: schadnse@hotmail.com [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa); Department of Physics and Electronics, Rhodes University, Grahamstown 6140 (South Africa); Department of Physics, Kigali Institute of Education, P.O. Box 5039 Kigali (Rwanda); Riviere, J.P. [Laboratoire de Physique des Materiaux UMR6630-CNRS, 86960 (France); Raji, A.T.; Comrie, C.M.; Britton, D.T.; Haerting, M. [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa)

    2011-07-15

    The {sup 16}O({alpha},{alpha}){sup 16}O resonance scattering was applied to study the effects of ion implantation on the oxygen distribution in the near surface region of polycrystalline titanium implanted with 180 keV krypton ions at fluences, ranging between 1 x 10{sup 14} and 5 x 10{sup 15} Kr{sup +}/cm{sup 2}. Two sample sets were chosen: as-received polycrystalline titanium discs rolled and annealed in half-hard condition which had a thick oxygen layer and similar samples in which this surface layer was removed by polishing. An increase of the mean oxygen concentration observed in both unpolished and polished samples at low fluence suggests a knock-on implantation of surface oxygen atoms. At high fluence, an overall decrease in the mean oxygen concentration and mean oxygen depth suggests an out-diffusion of near-surface oxygen atoms.

  3. Importance of ocean salinity for climate and habitability.

    Science.gov (United States)

    Cullum, Jodie; Stevens, David P; Joshi, Manoj M

    2016-04-19

    Modeling studies of terrestrial extrasolar planetary climates are now including the effects of ocean circulation due to a recognition of the importance of oceans for climate; indeed, the peak equator-pole ocean heat transport on Earth peaks at almost half that of the atmosphere. However, such studies have made the assumption that fundamental oceanic properties, such as salinity, temperature, and depth, are similar to Earth. This assumption results in Earth-like circulations: a meridional overturning with warm water moving poleward at the surface, being cooled, sinking at high latitudes, and traveling equatorward at depth. Here it is shown that an exoplanetary ocean with a different salinity can circulate in the opposite direction: an equatorward flow of polar water at the surface, sinking in the tropics, and filling the deep ocean with warm water. This alternative flow regime results in a dramatic warming in the polar regions, demonstrated here using both a conceptual model and an ocean general circulation model. These results highlight the importance of ocean salinity for exoplanetary climate and consequent habitability and the need for its consideration in future studies.

  4. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Energy Technology Data Exchange (ETDEWEB)

    Steinberger, R., E-mail: roland.steinberger@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Celedón, C.E., E-mail: carlos.celedon@usm.cl [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Departamento de Física, Universidad Técnica Federico Santa María, Valaparaíso, Casilla 110-V (Chile); Bruckner, B., E-mail: barbara.bruckner@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Roth, D., E-mail: dietmar.roth@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Duchoslav, J., E-mail: jiri.duchoslav@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Arndt, M., E-mail: martin.arndt@voestalpine.com [voestalpine Stahl GmbH, voestalpine-Straße 3, 4031 Linz (Austria); Kürnsteiner, P., E-mail: p.kuernsteiner@mpie.de [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); and others

    2017-07-31

    Highlights: • Investigation on the impact of residual gas prevailing in UHV chambers. • For some metals detrimental oxygen uptake could be observed within shortest time. • Totally different behavior was found: no changes, solely adsorption and oxidation. • The UHV residual gas may severely corrupt results obtained from depth profiling. • A well-considered data acquisition sequence is the key for reliable depth profiles. - Abstract: Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  5. Groundwater salinity in coastal aquifer of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Mashiatullah, A.; Qureshi, R.M.; Ahmad, E.; Tasneem, M.A.; Sajjad, M.I.; Khan, H.A.

    2002-01-01

    Potable groundwater salinity has become a problem of great concern in the Karachi Metropolis, which is not only the most populous and biggest industrial base but also the largest coastal dwelling of Pakistan. Stable isotope techniques [O/sup 18/ content of Oxygen in the water molecular and C/sup 13/ content of the Total Dissolved Inorganic Carbon (TDIC)] have been used, in conjunction with physiochemical tools (temperature, dissolved oxygen, pH, redox electrical conductivity, salinity), to examine the quality of potable water and the source of salinity. Surface water samples (12 No.) were collected from polluted streams, namely: Layeri River, Malir River; Hub River/Hub Lake and the Indus River. Shallow groundwater samples (7 No. ) were collected from operating dug wells. Relatively deep groundwater samples (12 No.) were collected from operating dug wells, relatively deep groundwater samples (12 No.) were collected from pumping wells/tube-wells. Physicochemical analysis of water samples was completed in the field. In the laboratory, water samples were analyzed for O/sup 18/ content of oxygen in the water molecule and C/sup 13/ content of the TDIC, using specific gas extraction systems and a modified GD-150 gas source mass spectrometer. It is concluded from this preliminary investigation that the potable aquifer system in coastal Karachi hosts a mixture of precipitation (rainwater only) from hinterlands, trapped seawater in relatively deep aquifer system, as well as intruded seawater under natural infiltration conditions and/or induced recharge conditions (in shallow aquifers). (author)

  6. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth

    Science.gov (United States)

    Brewer, Peter G.; Peltzer, Edward T.

    2017-08-01

    For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol-1, leading to a Q10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

  7. Historical temperature, salinity, oxygen, nutrients, and meteorological data collected by various Russian and former Soviet Union institutions from North Pacific Ocean and Okhotsk Sea from 1930-07-23 to 2004-04-18 (NODC Accession 0083635)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, nutrients, and meteorological data collected by various Russian and former Soviet Union institutions from North Pacific...

  8. Mid-depth temperature maximum in an estuarine lake

    Science.gov (United States)

    Stepanenko, V. M.; Repina, I. A.; Artamonov, A. Yu; Gorin, S. L.; Lykossov, V. N.; Kulyamin, D. V.

    2018-03-01

    The mid-depth temperature maximum (TeM) was measured in an estuarine Bol’shoi Vilyui Lake (Kamchatka peninsula, Russia) in summer 2015. We applied 1D k-ɛ model LAKE to the case, and found it successfully simulating the phenomenon. We argue that the main prerequisite for mid-depth TeM development is a salinity increase below the freshwater mixed layer, sharp enough in order to increase the temperature with depth not to cause convective mixing and double diffusion there. Given that this condition is satisfied, the TeM magnitude is controlled by physical factors which we identified as: radiation absorption below the mixed layer, mixed-layer temperature dynamics, vertical heat conduction and water-sediments heat exchange. In addition to these, we formulate the mechanism of temperature maximum ‘pumping’, resulting from the phase shift between diurnal cycles of mixed-layer depth and temperature maximum magnitude. Based on the LAKE model results we quantify the contribution of the above listed mechanisms and find their individual significance highly sensitive to water turbidity. Relying on physical mechanisms identified we define environmental conditions favouring the summertime TeM development in salinity-stratified lakes as: small-mixed layer depth (roughly, ~wind and cloudless weather. We exemplify the effect of mixed-layer depth on TeM by a set of selected lakes.

  9. Hydrochemical Characteristics and Formation of the Saline or Salty Springs in Eastern Sichuan Basin of China

    Science.gov (United States)

    Zhou, X.

    2017-12-01

    Saline or salty springs provide important information on the hydrogeochemical processes and hydrology within subsurface aquifers. More than 20 saline and salty springs occur in the core of anticlines in the eastern Sichuan Basin in southwestern China where the Lower and Middle Triassic carbonates outcrop. Water samples of 8 saline and salty springs (including one saline hot spring) were collected for analyses of the major and minor constituents, trace elements and stable oxygen and hydrogen isotopes. The TDS of the springs range from 4 to 83 g/L, and they are mainly of Cl-Na type. Sr, Ba and Li are the predominant trace elements. The δ2H and δ18O of the water samples indicate that they are of meteoric origin. The source of salinity of the springs originates from dissolution of minerals in the carbonates, including halite, gypsum, calcite and dolomite. The formation mechanism of the springs is that groundwater receives recharge from infiltration of precipitation, undergoes shallow or deep circulation in the core of the anticline and incongruent dissolution of the salt-bearing carbonates occurs, and emerges in the river valley in the form of springs with relatively high TDS. The 8 springs can be classified into 4 springs of shallow groundwater circulation and 4 springs of deep groundwater circulation according to the depth of groundwater circulation, 7 springs of normal temperature and 1 hot spring according to temperature. There are also 2 up-flow springs: the carbonate aquifers are overlain by relatively impervious sandstone and shale, groundwater may flows up to the ground surface through the local portion of the overlying aquiclude where fractures were relatively well developed, and emerges as an up-flow spring. Knowledge of the hydrochemical characteristics and the geneses of the saline and salty springs are of important significance for the utilization and preservation of the springs.

  10. High-Energy-Density Metal-Oxygen Batteries: Lithium-Oxygen Batteries vs Sodium-Oxygen Batteries.

    Science.gov (United States)

    Song, Kyeongse; Agyeman, Daniel Adjei; Park, Mihui; Yang, Junghoon; Kang, Yong-Mook

    2017-12-01

    The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O 2 ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O 2 battery is lower than that of the lithium-oxygen (Li-O 2 ) battery, the abundance and low cost of sodium resources offer major advantages for its practical application in the near future. However, little has so far been reported regarding the cell chemistry, to explain the rate-limiting parameters and the corresponding low round-trip efficiency and cycle degradation. Consequently, an elucidation of the reaction mechanism is needed for both lithium-oxygen and sodium-oxygen cells. An in-depth understanding of the differences and similarities between Li-O 2 and Na-O 2 battery systems, in terms of thermodynamics and a structural viewpoint, will be meaningful to promote the development of advanced metal-oxygen batteries. State-of-the-art battery design principles for high-energy-density lithium-oxygen and sodium-oxygen batteries are thus reviewed in depth here. Major drawbacks, reaction mechanisms, and recent strategies to improve performance are also summarized. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

    Science.gov (United States)

    Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

    2018-02-01

    In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

  12. About the issue of monitoring method of Ararat valley soils salinization

    Directory of Open Access Journals (Sweden)

    A.G. Yeghiazaryan

    2017-12-01

    Full Text Available The short description of the agro-ameliorative situation of the Republic of Armenia, particularly, that of Ararat valley shows that the unpredictable and unmanageable process of regime procedures at this area can cause serious consequences, pushing out the agricultural golden fund of the republic from the agricultural turnover, namely the land of Ararat valley. Numerous investigations on the soil reclaimed state in Ararat valley at the Republic of Armenia reveal that they are currently in an extremely threatening condition. The result analyses show that more than 35% of Ararat valley lands of agricultural importance are in insufficiently reclaimed state, moreover the 54% of them are weakly salinized, 11,8% are averagely and strongly salinized and 34.2% are strongly salinized. The analyses of the conducted theoretical and experimental research results show that the above mentioned negative processes are promoted by the depth of the ground water allocation, which in Ararat valley fluctuates within the depth of 1 m, 1-3 m and more than 3 m. According to the distribution area the ground waters on 6,6% land areas of Ararat valley irrigated soils are allocated at the depth of 1 m, in 27,8% land areas the ground waters are allocated at the depth of 1–3 m, and in the rest of 65,6% land area waters are allocated at the depth of more than 3 m. For the prevention of the soils salinization process at Ararat valley and for the development of measures for struggling against it, the impact of ground waters installation depth, their mineralization, calculated evapo-transpiration from the soil and plants, irrigation norm, watering regime and technique, pressure nutrition caused from underground water basin and the impact of evaporation raising from the ground water surfaces on the ground waters level change in the vegetation period is evaluated in the current work. For the evaluation of the above mentioned individual factors the integral

  13. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth.

    Science.gov (United States)

    Brewer, Peter G; Peltzer, Edward T

    2017-09-13

    For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol -1 , leading to a Q 10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

  14. Physiological performance of the soybean crosses in salinity stress

    Science.gov (United States)

    Wibowo, F.; Armaniar

    2018-02-01

    Plants grown in saline soils will experience salinity stress. Salinity stresses, one of which causes oxidative stress, that cause an imbalance in the production ROS compounds (Reactive Oxygen Species), antioxidants and chlorophyll. Where the reaction of this compound can affect plant growth and plant production. This study aims to inform performance and action gene to soybean physiological character that potential to tolerant from salinity soil that characterized by the presence of SOD and POD antioxidant compounds and chlorophyll. This research used a destructive analysis from crossbred (AxN) and (GxN). A = Anjasmoro varieties and G = Grobogan varieties as female elders and N = Grobogan varieties as male elders (N1, N2, N3, N4, N5) that have been through the stage of saline soil selection. Research result can be concluded that GxN cross is more potential for Inheritance of the offspring. This can be seen from the observed skewness of character SOD, POD compounds, Chlorophyll a and chlorophyll b.

  15. Salinization and Saline Environments

    Science.gov (United States)

    Vengosh, A.

    2003-12-01

    One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

  16. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2001 and 2002: A salinity gradient approach

    Science.gov (United States)

    Merino, J.H.; Carter, J.; Merino, S.L.

    2009-01-01

    Distribution of marine submerged aquatic vegetation (SAV; i.e., seagrass) in the northern Gulf of Mexico coast has been documented, but there are nonmarine submersed or SAV species occurring in estuarine salinities that have not been extensively reported. We sampled 276 SAV beds along the gulf coast in Florida, Alabama, Mississippi, Louisiana, and Texas in 2001 and 2002 in oligohaline to polyhaline (0 to 36 parts per thousand) waters to determine estuarine SAV species distribution and identify mesohaline SAV communities. A total of 20 SAV and algal species was identified and habitat characteristics such as salinity, water depth, pH, conductivity, turbidity, dissolved oxygen, and sediment composition were collected. Fourteen SAV species occurred two or more times in our samples. The most frequently occurring species was Ruppia maritima L. (n = 148), occurring in over half of SAV beds sampled. Eleocharis sp. (n = 47), characterized with an emergent rather than submerged growth form, was a common genus in the SAV beds sampled. A common marine species was Halodule wrightii Asch. (n = 36). Nonindigenous species Myriophyllum spicatum L. (n = 31) and Hydrilla verticillata (L. f.) Royle (n = 6) were present only in oligohaline water. Analyzing species occurrence and environmental characteristics using canonical correspondence and two-way indicator species analysis, we identify five species assemblages distinguished primarily by salinity and depth. Our survey increases awareness of nonmarine SAV as a natural resource in the gulf, and provides baseline data for future research. ?? 2009 by the Marine Environmental Sciences Consortium of Alabama.

  17. Latitudinal variations in intermediate depth ventilation and biological production over northeastern Pacific Oxygen Minimum Zones during the last 60 ka

    Science.gov (United States)

    Cartapanis, Olivier; Tachikawa, Kazuyo; Bard, Edouard

    2012-10-01

    Mechanisms affecting past variability in the Oxygen Minimum Zone (OMZ) in the Eastern Tropical North Pacific (ETNP) are poorly known. We analyzed core MD02-2524, obtained from the Nicaragua Margin in the present ETNP OMZ for major and minor elements (titanium (Ti), brome (Br), silicon (Si), potassium (K), and calcium (Ca)) using an X-ray Fluorescence (XRF) core scanner, and redox-sensitive trace elements (uranium (U), molybdenum (Mo), and nickel (Ni)) determined by ICP-MS. The U and Mo content was higher during the deglaciation than during the Holocene and the last glacial maximum, whereas enrichment was not observed for Ni, an element closely associated with organic matter. High-resolution XRF scanning indicated that the Ca-based carbonate content had millennial-scale variability inversely correlated with Br-based organic matter and Si/K-based opal content during the last glacial period. The available data suggest no clear regional trend in biological productivity during the last deglaciation, but significant local variability in the coastal eastern equatorial Pacific. The trace element enrichment and the lack of a concomitant increase in biogenic phases indicated that an enhanced ETNP OMZ, at least between 15°N and 12°N at a water depth of 500-900 m, was principally caused by a reduced oxygen supply driven by oceanic circulation to the Nicaragua Basin during the deglaciation. The observed patterns can be interpreted as the distinct changes in the oxygenation state of northern and southern water masses at intermediate depths. We also found evidence for a decoupling between local productivity and pore water oxygenation for several millennial-scale events during Marine Isotopic Stage 3, indicating that remote oxygen consumption and/or oceanic ventilation impacted OMZ intensity. Multi-millennial scale variations of the productivity at Papagayo upwelling cell displayed an opposite trend from productivity at the Costa Rica Dome, in relation with the latitudinal shift

  18. A New Method to Infer Advancement of Saline Front in Coastal Groundwater Systems by 3D: The Case of Bari (Southern Italy Fractured Aquifer

    Directory of Open Access Journals (Sweden)

    Costantino Masciopinto

    2016-02-01

    Full Text Available A new method to study 3D saline front advancement in coastal fractured aquifers has been presented. Field groundwater salinity was measured in boreholes of the Bari (Southern Italy coastal aquifer with depth below water table. Then, the Ghyben-Herzberg freshwater/saltwater (50% sharp interface and saline front position were determined by model simulations of the freshwater flow in groundwater. Afterward, the best-fit procedure between groundwater salinity measurements, at assigned water depth of 1.0 m in boreholes, and distances of each borehole from the modelled freshwater/saltwater saline front was used to convert each position (x, y in groundwater to the water salinity concentration at depth of 1.0 m. Moreover, a second best-fit procedure was applied to the salinity measurements in boreholes with depth z. These results provided a grid file (x, y, z, salinity suitable for plotting the actual Bari aquifer salinity by 3D maps. Subsequently, in order to assess effects of pumping on the saltwater-freshwater transition zone in the coastal aquifer, the Navier-Stokes (N-S equations were applied to study transient density-driven flow and salt mass transport into freshwater of a single fracture. The rate of seawater/freshwater interface advancement given by the N-S solution was used to define the progression of saline front in Bari groundwater, starting from the actual salinity 3D map. The impact of pumping of 335 L·s−1 during the transition period of 112.8 days was easily highlighted on 3D salinity maps of Bari aquifer.

  19. Effects of environmental variables on survey catch rates and distribution by size of shallow- and deep-water Cape hakes, Merluccius capensis and Merluccius paradoxus off Namibia

    DEFF Research Database (Denmark)

    Kainge, Paulus Inekela; van der Plas, A. K.; Bartholomae, C. H.

    2017-01-01

    In order to study the effects of temperature, oxygen, salinity and time of day on survey trawl catches, we modeled observed catches of juvenile, small, medium and large hakes per station as functions of zenith angle of the sun, geographical position, year, temperature, salinity, oxygen and depth....

  20. Impeller Submergence Depth for Stirred Tanks

    Directory of Open Access Journals (Sweden)

    Thiyam T. Devi

    2011-11-01

    Full Text Available Impeller submergence governs the performance of mixing tanks employed in oxygen transfer operation. Present work experimentally investigates the effect of impeller submergence depths on oxygen transfer and corresponding power consumption. It has been found that at higher range of impeller submergence, mixing tanks consume less power and gives higher values of oxygen transfer coefficient. Optimal range of submergence depth is 0.7 to 0.9 times the impeller diameter. Copyright ©2011 BCREC UNDIP. All rights reserved.(Received: 4th March 2011; Revised: 12nd July 2011; Accepted: 14th July 2011[How to Cite: T.T. Devi, A.P. Sinha, M. Thakre, and B. Kumar. (2011. Impeller Submergence Depth for Stirred Tanks. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 123-128. doi:10.9767/bcrec.6.2.826.123-128][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.826.123-128 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/826] | View in 

  1. Establishing a baseline of estuarine submerged aquatic vegetation resources across salinity zones within coastal areas of the northern Gulf of Mexico

    Science.gov (United States)

    Hillmann, Eva R.; DeMarco, Kristin; LaPeyre, Megan K.

    2016-01-01

    Coastal ecosystems are dynamic and productive areas that are vulnerable to effects of global climate change. Despite their potentially limited spatial extent, submerged aquatic vegetation (SAV) beds function in coastal ecosystems as foundation species, and perform important ecological services. However, limited understanding of the factors controlling SAV distribution and abundance across multiple salinity zones (fresh, intermediate, brackish, and saline) in the northern Gulf of Mexico restricts the ability of models to accurately predict resource availability. We sampled 384 potential coastal SAV sites across the northern Gulf of Mexico in 2013 and 2014, and examined community and species-specific SAV distribution and biomass in relation to year, salinity, turbidity, and water depth. After two years of sampling, 14 species of SAV were documented, with three species (coontail [Ceratophyllum demersum], Eurasian watermilfoil [Myriophyllum spicatum], and widgeon grass [Ruppia maritima]) accounting for 54% of above-ground biomass collected. Salinity and water depth were dominant drivers of species assemblages but had little effect on SAV biomass. Predicted changes in salinity and water depths along the northern Gulf of Mexico coast will likely alter SAV production and species assemblages, shifting to more saline and depth-tolerant assemblages, which in turn may affect habitat and food resources for associated faunal species.

  2. Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

    Directory of Open Access Journals (Sweden)

    M.A. Kameli

    2017-04-01

    Full Text Available Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. Saline-sodic and sodic soil sample was leached in soil column by diluted wastewater of amirkabir sugar manufacture in Khuzestan Province of Iran at constant water head. Sodium, electric conductivity and chemical oxygen demand of soil column leachate were measured per each pore volume. The experimental kinetics of wastewater organic compounds on two saline-sodic and sodic soil were also investigated by three pseudo second order, intra particle diffusion and elovich model. The results of current study showed that electric conductivity of saline-sodic soil was decreased to 90% during 3 initial pore volumes, from other side exchangeable sodium percent of saline-sodic and sodic soil decreased 30 and 71 percent, respectively. There were no significant different between wastewater chemical oxygen demand removal by saline-sodic and sodic soil in both batch and column studies. Wastewater chemical oxygen demand was decreased to 35% during pass through soil column. The results showed that the adsorption kinetics of wastewater organic compounds were best fitted by the pseudo-second order model with 99 percent correlation coefficient (r2=0.99%.

  3. Effect of salinity on survival, growth and biochemical parameters in juvenile Lebranch mullet Mugil liza (Perciformes: Mugilidae

    Directory of Open Access Journals (Sweden)

    Viviana Lisboa

    Full Text Available Teleost fish growth may be improved under isosmotic condition. Growth and metabolic performance of juvenile Mugil liza (isosmotic point: 12‰ were evaluated after 40 days in different salinities (0, 6, 12 and 24‰. Tests were performed in quadruplicate (30 fish/tank; 0.48 ± 0.1 g body weight; 3.27 ± 0.1 cm total length under controlled water temperature (28.2 ± 0.1ºC and oxygen content (>90% saturation. Fish were fed on artificial diet (50% crude protein four times a day until apparent satiation. Results showed that salinity influenced juvenile mullet growth. Fish reared at salinity 24‰ grew better than those maintained in freshwater (salinity 0‰. Gill Na+,K+-ATPase activity and whole body oxygen consumption showed an U-shape-type response over the range of salinities tested, with the lower values being observed at the intermediate salinities. Although no significant difference was observed in liver glycogen content at different salinities, it tended to augment with increasing salinity. These findings indicate that energy demand for osmorregulation in juvenile M. liza can be minimized under isosmotic condition. However, the amount of energy spared is not enough to improve fish growth. Results also suggest that M. liza is able to alternate between different energy-rich substrates during acclimation to environmental salinity.

  4. Dissolved oxygen (DO) is essential for respiration in aquatic fauna ...

    African Journals Online (AJOL)

    spamer

    more, thermal and salinity stratification inhibits ex- change of ... 2000) and larval densities (Harris and. Cyrus 1999) ...... dissolved oxygen and effects of short-term oxygen stress ... in the shrimp Crangon crangon exposed to hypoxia, anoxia.

  5. Cation exchange in a temporally fluctuating thin freshwater lens on top of saline groundwater

    NARCIS (Netherlands)

    Eeman, S.; Louw, de P.G.B.; Zee, van der S.E.A.T.M.

    2017-01-01

    In coastal-zone fields with a high groundwater level and sufficient rainfall, freshwater lenses are formed on top of saline or brackish groundwater. The fresh and the saline water meet at shallow depth, where a transition zone is found. This study investigates the mixing zone that is characterized

  6. Seasonal salinity, temperature and density data for the Canadian Beaufort Sea shelf, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Hopky, G E; Chiperzak, D B; Lawrence, M J

    1988-01-01

    This report contains salinity, temperature and density (CTD) data collected in the waters of the Canadian Beaufort Sea Shelf during 1987. A major objective of such data collection is to identify and characterize estuarine and marine habitats of significance to the biological communities, primarily fish, with a view to provide background data for assessing the implications of hydrocarbon development and production on those habitats. Salinity and temperature profile data were measured using a Guildline Model 8870 probe deployed from the ice surface in March and May, and from a ship during July to September. Ice thickness and secchi depth were measured during periods of ice cover and open water, respectively. Salinity values for samples collected from bottle casts were measured with an Autosal Model 8400 salinometer. Density was calculated using salinity and temperature values. During the ice cover periods of March and May, CTD profiles were measured at five and nine stations, respectively. For the open water July to September period, CTD profiles were measured at 41 stations. One additional station was sampled using bottle casts. Replicate CTD profiling was conducted at a number of stations, on a seasonal basis. The maximum depths of profiles measured from the ice surface ranged from 3.1 to 23.5 dbar. Salinity and temperature measurements ranged from 0.00 to 31.70, and -1.74 to 0.02/sup 0/C, respectively. Maximum depths of profiles measured during the open water period ranged from 2.9 to 196.4 dbar. During this same period, profile measurements of salinity and temperature ranged from 0.08 to 33.94, and -1.62 to 16.51/sup 0/C, respectively. 4 refs., 60 figs., 57 tabs.

  7. Effects of reduction in porosity and permeability with depth on storage capacity and injectivity in deep saline aquifers: A case study from the Mount Simon Sandstone aquifer

    Science.gov (United States)

    Medina, C.R.; Rupp, J.A.; Barnes, D.A.

    2011-01-01

    The Upper Cambrian Mount Simon Sandstone is recognized as a deep saline reservoir that has significant potential for geological sequestration in the Midwestern region of the United States. Porosity and permeability values collected from core analyses in rocks from this formation and its lateral equivalents in Indiana, Kentucky, Michigan, and Ohio indicate a predictable relationship with depth owing to a reduction in the pore structure due to the effects of compaction and/or cementation, primarily as quartz overgrowths. The regional trend of decreasing porosity with depth is described by the equation: ??(d)=16.36??e-0.00039*d, where ?? is the porosity and d is the depth in m. The decrease of porosity with depth generally holds true on a basinwide scale. Bearing in mind local variations in lithologic and petrophysical character within the Mount Simon Sandstone, the source data that were used to predict porosity were utilized to estimate the pore volume available within the reservoir that could potentially serve as storage space for injected CO2. The potential storage capacity estimated for the Mount Simon Sandstone in the study area, using efficiency factors of 1%, 5%, 10%, and 15%, is 23,680, 118,418, 236,832, and 355,242 million metric tons of CO2, respectively. ?? 2010 Elsevier Ltd.

  8. Ecophysiological adaptations to variable salinity environments in the crab Hemigrapsus crenulatus from the Southeastern Pacific coast: Sodium regulation, respiration and excretion.

    Science.gov (United States)

    Urzúa, Ángel; Urbina, Mauricio A

    2017-08-01

    The estuarine crab Hemigrapsus crenulatus is a key benthic species of estuarine and intertidal ecosystems of the South Pacific, habitats that experience wide fluctuations in salinity. The physiological strategies that allow this crab to thrive under variable salinities, and how they change during the benthic stages of their life cycle, were evaluated under laboratory conditions. Oxygen consumption, ammonia excretion and the regulatory capacity of Na + through the normal range of environmental salinities (i.e. 5, 10, 15, 20, 25, 30) were evaluated in three size classes, ranging from juveniles to adults. In all sizes, the oxygen consumption, ammonia excretion and regulatory capacity of Na + decreased as salinity increased, with the highest values at 5 and the lowest values at 30 salinity. Bigger crabs showed a higher capacity to regulate Na + , as well as higher respiration and excretion rates compared to smaller crabs, suggesting that they are better equipped to exploit areas of the estuary with low salinity. Regardless of its size, H. crenulatus is a strong hyper regulator in diluted media (i.e. 5-20) while a conformer at salinities higher than 20. The regulatory capacity of Na + was positively related with oxygen consumption and ammonia excretion rates. These relationships between sodium regulation, respiration and excretion are interpreted as adaptive physiological mechanisms that allow H. crenulatus to maintain the osmotic and bioenergetic balance over a wide range of environmental salinities. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Scales and sources of pH and dissolved oxygen variability in a shallow, upwelling-driven ecosystem

    Science.gov (United States)

    Tanner, C. A.; Martz, T.; Levin, L. A.

    2011-12-01

    In the coastal zone extreme variability in carbonate chemistry and oxygen is driven by fluctuations in temperature, salinity, air-sea gas exchange, mixing processes, and biology. This variability appears to be magnified in upwelling-driven ecosystems where low oxygen and low pH waters intrude into shallow depths. The oxygen and carbon chemistry signal can be further confounded by highly productive ecosystems such as kelp beds where photosynthesis and respiration consume and release significant amounts of dissolved inorganic carbon and oxygen. This variability poses a challenge for scientists assessing the impacts of climate change on nearshore ecosystems. We deployed physical & biogeochemical sensors in order to observe these processes in situ. The "SeapHOx" instruments used in this study consist of a modified Honeywell Durafet° ISFET pH sensor, an Aanderra Optode Oxygen sensor, and a SBE-37 conductivity, temperature, pressure sensor. The instruments were deployed on and around the La Jolla Kelp Forest at a variety of depths. Our goals were to (a) characterize the link between pH and oxygen and identify the magnitude of pH and oxygen variability over a range of intra-annual time scales and (b) investigate spatial patterns of pH and oxygen variability associated with depth, proximity to shore, and presence of kelp. Results thus far reveal a strong relationship between oxygen and pH. Temporal variability is greatest at the semidiurnal frequency where pH (at 7 m) can range up to 0.3 units and oxygen can change 50% over 6 h. Diurnal variability is a combination of the diurnal tidal component and diel cycles of production and respiration. Event-scale dynamics associated with upwelling can maintain pH and oxygen below 7.8 units and 200 μmol kg-1, respectively, for multiple days. Frequent current reversals drive changes in the observed oxygen and pH variability. When alongshore currents are flowing southward, driven by upwelling-favorable winds, the magnitude of

  10. Temperature, salinity, nutrients, oxygen, chlorophyll and other measurements found in dataset SISMER taken from the VAUBAN, JEAN CHARCOT (FNOY) and other platforms in the South Pacific, Coastal North Atlantic and other locations from 1983 to 2007 (NODC Accession 0046621)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, oxygen, chlorophyll and other measurements found in CTD and OSD datasets taken from the VAUBAN, JEAN CHARCOT (FNOY) and other...

  11. Saline catholytes as alternatives to phosphate buffers in microbial fuel cells

    KAUST Repository

    Ahn, Yongtae; Logan, Bruce E.

    2013-01-01

    Highly saline solutions were examined as alternatives to chemical buffers in microbial fuel cells (MFCs). The performance of two-chamber MFCs with different concentrations of saline solutions in the cathode chamber was compared to those with a buffered catholyte (50mM PBS). The use of a NaCl catholyte improved the CE to 43-60% (28% with no membrane) due to a reduction in oxygen transfer into the anolyte. The saline catholyte also reduced the membrane and solution resistance to 23Ω (41Ω without a membrane). The maximum power density of 491mW/m2 (240mM NaCl) was only 17% less than the MFC with 50mM PBS. The decrease in power output with highest salinity was due to reduced proton transfer due to the ion exchange membrane, and pH changes in the two solutions. These results show that MFC performance can be improved by using a saline catholyte without pH control. © 2013 Elsevier Ltd.

  12. Saline catholytes as alternatives to phosphate buffers in microbial fuel cells

    KAUST Repository

    Ahn, Yongtae

    2013-03-01

    Highly saline solutions were examined as alternatives to chemical buffers in microbial fuel cells (MFCs). The performance of two-chamber MFCs with different concentrations of saline solutions in the cathode chamber was compared to those with a buffered catholyte (50mM PBS). The use of a NaCl catholyte improved the CE to 43-60% (28% with no membrane) due to a reduction in oxygen transfer into the anolyte. The saline catholyte also reduced the membrane and solution resistance to 23Ω (41Ω without a membrane). The maximum power density of 491mW/m2 (240mM NaCl) was only 17% less than the MFC with 50mM PBS. The decrease in power output with highest salinity was due to reduced proton transfer due to the ion exchange membrane, and pH changes in the two solutions. These results show that MFC performance can be improved by using a saline catholyte without pH control. © 2013 Elsevier Ltd.

  13. DEPTH - OBSERVATION and Other Data from MULTIPLE SHIPS (NODC Accession 9700185)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — STD and other data were collected from the Mediterranean Sea and other locations from multiple ships. Data include profiles of temperature, salinity, and oxygen...

  14. Physiological response in the European flounder (Platichthys flesus) to variable salinity and oxygen conditions

    DEFF Research Database (Denmark)

    Lundgreen, Kim; Kiilerich, Pia; Tipsmark, Christian Kølbæk

    2008-01-01

    . Muscle water content was the same at all three salinities, indicating complete cell volume regulation. Gill Na+/K+-ATPase activity did not change with salinity, but hypoxia caused a 25 % decrease in branchial Na+/K+-ATPase activity at all three salinities. Furthermore, hypoxia induced a significant...... the erythrocytic nucleoside triphosphate content, a common mechanism for increasing blood O2 affinity. It is concluded that moderate hypoxia induced an energy saving decrease in branchial Na+/K+-ATPase activity, which did not compromise extracellular osmoregulation....

  15. RNS60, a charge-stabilized nanostructure saline alters Xenopus Laevis oocyte biophysical membrane properties by enhancing mitochondrial ATP production

    Science.gov (United States)

    Choi, Soonwook; Yu, Eunah; Kim, Duk-Soo; Sugimori, Mutsuyuki; Llinás, Rodolfo R

    2015-01-01

    We have examined the effects of RNS60, a 0.9% saline containing charge-stabilized oxygen nanobubble-based structures. RNS60 is generated by subjecting normal saline to Taylor–Couette–Poiseuille (TCP) flow under elevated oxygen pressure. This study, implemented in Xenopus laevis oocytes, addresses both the electrophysiological membrane properties and parallel biological processes in the cytoplasm. Intracellular recordings from defolliculated X. laevis oocytes were implemented in: (1) air oxygenated standard Ringer's solution, (2) RNS60-based Ringer's solution, (3) RNS10.3 (TCP-modified saline without excess oxygen)-based Ringer's, and (4) ONS60 (saline containing high pressure oxygen without TCP modification)-based Ringer's. RNS60-based Ringer's solution induced membrane hyperpolarization from the resting membrane potential. This effect was prevented by: (1) ouabain (a blocker of the sodium/potassium ATPase), (2) rotenone (a mitochondrial electron transfer chain inhibitor preventing usable ATP synthesis), and (3) oligomycin A (an inhibitor of ATP synthase) indicating that RNS60 effects intracellular ATP levels. Increased intracellular ATP levels following RNS60 treatment were directly demonstrated using luciferin/luciferase photon emission. These results indicate that RNS60 alters intrinsic the electrophysiological properties of the X. laevis oocyte membrane by increasing mitochondrial-based ATP synthesis. Ultrastructural analysis of the oocyte cytoplasm demonstrated increased mitochondrial length in the presence of RNS60-based Ringer's solution. It is concluded that the biological properties of RNS60 relate to its ability to optimize ATP synthesis. PMID:25742953

  16. Enhanced oxygen delivery induced by perfluorocarbon emulsions in capillary tube oxygenators.

    Science.gov (United States)

    Vaslef, S N; Goldstick, T K

    1994-01-01

    Previous studies showed that a new generation of perfluorocarbon (PFC) emulsions increased tissue PO2 in the cat retina to a degree that could not be explained by the small increase in arterial O2 content seen after the infusion of low doses of 1 g PFC/kg body weight. It seems that increased O2 delivery at the tissue level after PFC infusion is caused by a local effect in the microcirculation. The authors studies this effect in vitro at steady state in a closed loop circuit, consisting of one of two types of capillary tube oxygenators, deoxygenator(s), a reservoir bag filled with anticoagulated bovine blood or saline (control), and a roller pump, to see if the addition of PFC would have an effect on the PO2 difference (delta PO2) across the capillary tube membrane oxygenator at a blood flow rate of 3 l/min. Perfluorocarbon was added in three incremental doses, each giving about 0.7 vol% of PFC. The delta PO2 across the oxygenator was measured before and after each dose. The mean percent increases in delta PO2 in blood for two types of oxygenators were 19.2 +/- 8% (mean +/- SD, n = 6, P = 0.002) and 9.9 +/- 4% (n = 3, P = 0.05), respectively, whereas the mean percent change in delta PO2 in saline was -4.9 +/- 2% (n = 2, P = 0.2). Inlet PO2s to the oxygenator were only minimally increased. The authors conclude that O2 delivery was significantly enhanced after injection of PFC in blood in this capillary tube model. A near wall excess of PFC particles may account for the augmentation of O2 diffusion in this model.

  17. Numerical study of hydrodynamic and salinity transport processes in the Pink Beach wetlands of the Liao River estuary, China

    Directory of Open Access Journals (Sweden)

    H. Qiao

    2018-06-01

    Full Text Available Interaction studies of vegetation within flow environments are essential for the determination of bank protection, morphological characteristics and ecological conditions for wetlands. This paper uses the MIKE 21 hydrodynamic and salinity model to simulate the hydrodynamic characteristics and salinity transport processes in the Pink Beach wetlands of the Liao River estuary. The effect of wetland plants on tidal flow in wetland areas is represented by a varying Manning coefficient in the bottom friction term. Acquisition of the vegetation distribution is based on Landsat TM satellites by remote sensing techniques. Detailed comparisons between field observation and simulated results of water depth, salinity and tidal currents are presented in the vegetated domain of the Pink Beach wetlands. Satisfactory results were obtained from simulations of both flow characteristics and salinity concentration, with or without vegetation. A numerical experiment was conducted based on variations in vegetation density, and compared with the tidal currents in non-vegetated areas; the computed current speed decreased remarkably with an increase in vegetation density. The impact of vegetation on water depth and salinity was simulated, and the findings revealed that wetland vegetation has an insignificant effect on the water depth and salinity in this wetland domain. Several stations (from upstream to downstream in the Pink Beach wetlands were selected to estimate the longitudinal variation of salinity under different river runoff conditions; the results showed that salinity concentration decreases with an increase in river runoff. This study can consequently help increase the understanding of favourable salinity conditions for particular vegetation growth in the Pink Beach wetlands of the Liao River estuary. The results also provide crucial guidance for related interaction studies of vegetation, flow and salinity in other wetland systems.

  18. Oceanographic profile temperature, salinity, oxygen, and nutrients measurements collected using bottle from the LCM Red in the Alaskan Coastal waters, from the Gerda in the Atlantic Ocean, and from DeSteiguer in the Pacific Ocean (NODC Accession 0002231)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen and other profile data received at NODC on 06/10/04 by Olga Baranova, digitized from "William J. Teague, Zachariah R. Hallock, Jan M....

  19. Buoyancy of gas-filled bladders at great depth

    Science.gov (United States)

    Priede, Imants G.

    2018-02-01

    At high hydrostatic pressures exceeding 20 MPa or 200 bar, equivalent to depths exceeding ca.2000 m, the behaviour of gases deviates significantly from the predictions of standard equations such as Boyle's Law, the Ideal Gas Law and Van der Waals equation. The predictions of these equations are compared with experimental data for nitrogen, oxygen and air at 0 °C and 15 °C, at pressures up to 1100 bar (110 MPa) equivalent to full ocean depth of ca. 11000 m. Owing to reduced compressibility of gases at high pressures, gas-filled bladders at full ocean depth have a density of 847 kg m-3 for Oxygen, 622 kg m-3 for Nitrogen and 660 kg m-3 for air providing potentially useful buoyancy comparable with that available from man-made materials. This helps explain why some of the deepest-living fishes at ca. 7000 m depth (700 bar or 70 MPa) have gas-filled swim bladders. A table is provided of the density and buoyancy of oxygen, nitrogen and air at 0 °C and 15 °C from 100 to 1100 bar.

  20. Oxygenation measurement by multi-wavelength oxygen-dependent phosphorescence and delayed fluorescence: catchment depth and application in intact heart

    NARCIS (Netherlands)

    Balestra, Gianmarco M.; Aalders, Maurice C. G.; Specht, Patricia A. C.; Ince, Can; Mik, Egbert G.

    2015-01-01

    Oxygen delivery and metabolism represent key factors for organ function in health and disease. We describe the optical key characteristics of a technique to comprehensively measure oxygen tension (PO(2)) in myocardium, using oxygen-dependent quenching of phosphorescence and delayed fluorescence of

  1. Study on substrate metabolism process of saline waste sludge and its biological hydrogen production potential.

    Science.gov (United States)

    Zhang, Zengshuai; Guo, Liang; Li, Qianqian; Zhao, Yangguo; Gao, Mengchun; She, Zonglian

    2017-07-01

    With the increasing of high saline waste sludge production, the treatment and utilization of saline waste sludge attracted more and more attention. In this study, the biological hydrogen production from saline waste sludge after heating pretreatment was studied. The substrate metabolism process at different salinity condition was analyzed by the changes of soluble chemical oxygen demand (SCOD), carbohydrate and protein in extracellular polymeric substances (EPS), and dissolved organic matters (DOM). The excitation-emission matrix (EEM) with fluorescence regional integration (FRI) was also used to investigate the effect of salinity on EPS and DOM composition during hydrogen fermentation. The highest hydrogen yield of 23.6 mL H 2 /g VSS and hydrogen content of 77.6% were obtained at 0.0% salinity condition. The salinity could influence the hydrogen production and substrate metabolism of waste sludge.

  2. Depth distribution of carrier lifetime in 65 MeV oxygen ion irradiated silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in

    2006-03-15

    CZ-grown, n-doped crystalline Si(1 1 1) of resistivity 60 {omega} cm and 140 {omega} cm were irradiated with 65 MeV energy oxygen ions, in the fluence range of 2 x 10{sup 1}-10{sup 14} ions/cm{sup 2}. The depth and spatial profile of excess minority carrier recombination time {tau} (lifetime) was measured using photoconductive decay (PCD) method. Lifetime measurements were carried out before the stopping range of impinging ions. Results show a monotonous decrease in lifetime with fluence, which is attributed to defect creation mechanism by electronic energy loss based on the thermal spike model. Also, surface modification is expected with a small loss in crystalline quality. This surface is considered to be a multi-crystalline surface with large grain boundaries that act as trapping sites for excess holes in n-Si(1 1 1). Annealing of the irradiated samples showed a near complete recovery at 750 deg. C for a period of 1 h.

  3. Matching soil salinization and cropping systems in communally managed irrigation schemes

    Science.gov (United States)

    Malota, Mphatso; Mchenga, Joshua

    2018-03-01

    Occurrence of soil salinization in irrigation schemes can be a good indicator to introduce high salt tolerant crops in irrigation schemes. This study assessed the level of soil salinization in a communally managed 233 ha Nkhate irrigation scheme in the Lower Shire Valley region of Malawi. Soil samples were collected within the 0-0.4 m soil depth from eight randomly selected irrigation blocks. Irrigation water samples were also collected from five randomly selected locations along the Nkhate River which supplies irrigation water to the scheme. Salinity of both the soil and the irrigation water samples was determined using an electrical conductivity (EC) meter. Analysis of the results indicated that even for very low salinity tolerant crops (ECi water was suitable for irrigation purposes. However, root-zone soil salinity profiles depicted that leaching of salts was not adequate and that the leaching requirement for the scheme needs to be relooked and always be adhered to during irrigation operation. The study concluded that the crop system at the scheme needs to be adjusted to match with prevailing soil and irrigation water salinity levels.

  4. Salinization of the soil solution decreases the further accumulation of salt in the root zone of the halophyte Atriplex nummularia Lindl. growing above shallow saline groundwater.

    Science.gov (United States)

    Alharby, Hesham F; Colmer, Timothy D; Barrett-Lennard, Edward G

    2018-01-01

    Water use by plants in landscapes with shallow saline groundwater may lead to the accumulation of salt in the root zone. We examined the accumulation of Na + and Cl - around the roots of the halophyte Atriplex nummularia Lindl. and the impacts of this increasing salinity for stomatal conductance, water use and growth. Plants were grown in columns filled with a sand-clay mixture and connected at the bottom to reservoirs containing 20, 200 or 400 mM NaCl. At 21 d, Na + and Cl - concentrations in the soil solution were affected by the salinity of the groundwater, height above the water table and the root fresh mass density at various soil depths (P soil solution therefore had a feedback effect on further salinization within the root zone. © 2017 John Wiley & Sons Ltd.

  5. Towards the development of a salinity impact category for South ...

    African Journals Online (AJOL)

    DRINIE

    2003-07-03

    Jul 3, 2003 ... nature from existing categories to warrant a separate salinity impact category. A conceptual method is ... compounds to the environment from all stages of a product's life- cycle are ... Marine. - Terrestrial. • Photo-oxidant formation. • Acidification .... algae. Reduced light input. Oxygen depletion near bottom.

  6. subsurface sequence delineation and saline water mapping of lagos

    African Journals Online (AJOL)

    A subsurface sequence delineation and saline water mapping of Lagos State was carried out. Ten (10) deep boreholes with average depth of 300 m were drilled within the sedimentary basin. The boreholes were lithologically and geophysically logged. The driller's lithological logs aided by gamma and resistivity logs, ...

  7. Forward Modeling of Carbonate Proxy Data from Planktonic Foraminifera using Oxygen Isotope Tracers in a Global Ocean Model

    Science.gov (United States)

    Schmidt, Gavin A.

    1999-01-01

    The distribution and variation of oxygen isotopes in seawater are calculated using the Goddard Institute for Space Studies global ocean model. Simple ecological models are used to estimate the planktonic foraminiferal abundance as a function of depth, column temperature, season, light intensity, and density stratification. These models are combined to forward model isotopic signals recorded in calcareous ocean sediment. The sensitivity of the results to the changes in foraminiferal ecology, secondary calcification, and dissolution are also examined. Simulated present-day isotopic values for ecology relevant for multiple species compare well with core-top data. Hindcasts of sea surface temperature and salinity are made from time series of the modeled carbonate isotope values as the model climate changes. Paleoclimatic inferences from these carbonate isotope records are strongly affected by erroneous assumptions concerning the covariations of temperature, salinity, and delta (sup 18)O(sub w). Habitat-imposed biases are less important, although errors due to temperature-dependent abundances can be significant.

  8. Carbon mineralization and oxygen dynamics in sediments with deep oxygen penetration, Lake Superior

    DEFF Research Database (Denmark)

    Li, Jiying; Crowe, Sean Andrew; Miklesh, David

    2012-01-01

    To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep ...... volume-specific carbon degradation rates were 0.3–1.5 µmol cm−3 d−1; bioturbation coefficient near the sediment surface was 3–8 cm2 yr−1. These results indicate that carbon cycling in large freshwater systems conforms to many of the same trends as in marine systems.......To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep......, suggesting that temporal variability in deeply oxygenated sediments may be greater than previously acknowledged. The oxygen uptake rates (4.4–7.7 mmol m−2 d−1, average 6.1 mmol m−2 d−1) and carbon mineralization efficiency (∼ 90% of deposited carbon) were similar to those in marine hemipelagic and pelagic...

  9. Machine Learning for Mapping Groundwater Salinity with Oil Well Log Data

    Science.gov (United States)

    Chang, W. H.; Shimabukuro, D.; Gillespie, J. M.; Stephens, M.

    2016-12-01

    An oil field may have thousands of wells with detailed petrophysical logs, and far fewer direct measurements of groundwater salinity. Can the former be used to extrapolate the latter into a detailed map of groundwater salinity? California Senate Bill 4, with its requirement to identify Underground Sources of Drinking Water, makes this a question worth answering. A well-known obstacle is that the basic petrophysical equations describe ideal scenarios ("clean wet sand") and even these equations contain many parameters that may vary with location and depth. Accounting for other common scenarios such as high-conductivity shaly sands or low-permeability diatomite (both characteristic of California's Central Valley) causes parameters to proliferate to the point where the model is underdetermined by the data. When parameters outnumber data points, however, is when machine learning methods are most advantageous. We present a method for modeling a generic oil field, where groundwater salinity and lithology are depth series parameters, and the constants in petrophysical equations are scalar parameters. The data are well log measurements (resistivity, porosity, spontaneous potential, and gamma ray) and a small number of direct groundwater salinity measurements. Embedded in the model are petrophysical equations that account for shaly sand and diatomite formations. As a proof of concept, we feed in well logs and salinity measurements from the Lost Hills Oil Field in Kern County, California, and show that with proper regularization and validation the model makes reasonable predictions of groundwater salinity despite the large number of parameters. The model is implemented using Tensorflow, which is an open-source software released by Google in November, 2015 that has been rapidly and widely adopted by machine learning researchers. The code will be made available on Github, and we encourage scrutiny and modification by machine learning researchers and hydrogeologists alike.

  10. Salinity controls on Na incorporation in Red Sea planktonic foraminifera

    Science.gov (United States)

    Mezger, E. M.; de Nooijer, L. J.; Boer, W.; Brummer, G. J. A.; Reichart, G. J.

    2016-12-01

    Whereas several well-established proxies are available for reconstructing past temperatures, salinity remains challenging to assess. Reconstructions based on the combination of (in)organic temperature proxies and foraminiferal stable oxygen isotopes result in relatively large uncertainties, which may be reduced by application of a direct salinity proxy. Cultured benthic and planktonic foraminifera showed that Na incorporation in foraminiferal shell calcite provides a potential independent proxy for salinity. Here we present the first field calibration of such a potential proxy. Living planktonic foraminiferal specimens from the Red Sea surface waters were collected and analyzed for their Na/Ca content using laser ablation quadrupole inductively coupled plasma mass spectrometry. Using the Red Sea as a natural laboratory, the calibration covers a broad range of salinities over a steep gradient within the same water mass. For both Globigerinoides ruber and Globigerinoides sacculifer calcite Na/Ca increases with salinity, albeit with a relatively large intraspecimen and interspecimen variability. The field-based calibration is similar for both species from a salinity of 36.8 up to 39.6, while values for G. sacculifer deviate from this trend in the northernmost transect. It is hypothesized that the foraminifera in the northernmost part of the Red Sea are (partly) expatriated and hence should be excluded from the Na/Ca-salinity calibration. Incorporation of Na in foraminiferal calcite therefore provides a potential proxy for salinity, although species-specific calibrations are still required and more research on the effect of temperature is needed.

  11. Soil salinization processes in rice irrigation schemes in the Senegal River Delta

    International Nuclear Information System (INIS)

    Ceuppens, J.; Wopereis, M.C.S.; Miezan, K.M.

    1997-01-01

    Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy clay soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a beneficial effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth. (author)

  12. [Effect of abiotic and biotic factors on the structural and functional organization of the saline lake ecosystems in Crimea].

    Science.gov (United States)

    Balushkina, E V; Golubkov, S M; Golubkov, M S; Litvinchuk, L F; Shadrin, N V

    2009-01-01

    Decrease of both zooplankton and zoobenthos species richness and a trend toward decrease of their biomass with the salinity increase was recorded in the hypersaline lakes of Crimea. The most of structural and functional characteristics of macrobenthos is positively correlated with abiotic and biotic characteristics of those lakes. Abundance, biomass, productivity of macrobenthos and ration of non-predating macrozoobenthos decrease with salinity increase, while they increase with the depth and growth of amount of chlorophyll a and primary production. Macrozoobenthos portion in the total zooplankton and macrozoobenthos biomass decreases with both salinity and depth increase. Zooplankton community is less controlled by abiotic factors as compared to macrozoobenthos, while the former's species number significantly decrease with salinity increase. Effect of salinity on zooplankton biomass is slightly significant, unlike that of macrozoobenthos. Comparison of total amount of rations of zooplankton and macrozoobenthos with amount of primary production indicates intense trophic interactions in the lakes under study.

  13. Record of carbonate preservation and the Mid-Brunhes climatic shift from a seamount top with low sedimentation rates in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Sijinkumar, A.V.; Borole, D.V.; Gupta, S.M.; Mergulhao, L.P.; Mascarenhas-Pereira, M.B.L.; Ramaswamy, V.; Guptha, M.V.S.; Possnert, G.; Aldahan, A.; Khadge, N.H.; Sharma, R.

    of chemical properties of the water column in the CIB show three equator-ward moving water masses (de Sousa et al. 2001). The fastest moving water mass with subsurface salinity is 3 maximum in the depth range 125-200 m, characterized by high salinity (34....74-34.77 psu) and oxygen minimum associated with weak maxima in nutrients. The second water mass with deep oxygen maximum (234-245 µm) is in the depth range of 250-750 m, which is associated with minima in nutrients and relatively high pH. The third water...

  14. Transport of Astyanax altiparanae Garutti and Britski, 2000 in saline water

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Salaro

    2015-08-01

    Full Text Available Two experiments were performed. The first aimed to assess the tolerance of fingerlings Astyanax altiparanae to water salinity. Fish were exposed to salinity of 0, 3, 6, 9, 12 or 15 g NaCl L-1 for 96 hours. The fish mortality was 0%, in the levels of 0, 3 and 6 g L-1; 75% in the level of 9 g L-1and 100% at 12 and 15 g L-1 of common salt. The second experiment aimed to assess the parameters of water quality, mortality and blood glucose during transport. For this, A. altiparanae were stored in plastic bags at 22, 30 and 37 g of fish L-1 stocking densities and salinity of 0, 3, 6 and 9 g L-1, for. Fish showed similar mortality levels in the different salinities and stocking densities. The increase in fish density reduced the dissolved oxygen levels and salinity decreased the pH. The blood glucose levels were higher in those fish with 0 g L-1 salinity and higher stocking densities. The addition of salt to the water reduces the stress responses of A. altiparanae during transport.

  15. Reduced oxygen at high altitude limits maximum size.

    Science.gov (United States)

    Peck, L S; Chapelle, G

    2003-11-07

    The trend towards large size in marine animals with latitude, and the existence of giant marine species in polar regions have long been recognized, but remained enigmatic until a recent study showed it to be an effect of increased oxygen availability in sea water of a low temperature. The effect was apparent in data from 12 sites worldwide because of variations in water oxygen content controlled by differences in temperature and salinity. Another major physical factor affecting oxygen content in aquatic environments is reduced pressure at high altitude. Suitable data from high-altitude sites are very scarce. However, an exceptionally rich crustacean collection, which remains largely undescribed, was obtained by the British 1937 expedition from Lake Titicaca on the border between Peru and Bolivia in the Andes at an altitude of 3809 m. We show that in Lake Titicaca the maximum length of amphipods is 2-4 times smaller than other low-salinity sites (Caspian Sea and Lake Baikal).

  16. Geophysical, geochemical and hydrological analyses of water-resource vulnerability to salinization: case of the Uburu-Okposi salt lakes and environs, southeast Nigeria

    Science.gov (United States)

    Ukpai, S. N.; Okogbue, C. O.

    2017-11-01

    Until this study, the location and depth of the saline units in Uburu-Okposi salt lake areas and environs have been unknown. This study aimed at delineating the saline lithofacies and dispersal configurations to water bodies, using electrical geophysical methods such as constant separation traversing (CST) and vertical electrical sounding (VES). Results showed weathered zones that represent aquifers mostly at the fourth geoelectric layer: between upper layered aquitards and underlying aquitards at depths 30-140 m. Lateral distribution of resistivity variance was defined by the CST, whereas the VES tool, targeted at low-resistivity zones, detected isolated saline units with less than 10 ohm-m at depths generally >78 m. The saline lithofacies were suspected to link freshwater zones via shear zones, which steer saline water towards the salt lakes and influence the vulnerability of groundwater to salinization. The level of salinization was verified by water sampling and analysis, and results showed general alkaline water type with a mean pH of 7.66. Water pollution was indicated: mean total dissolved solids (TDS) 550 mg/l, electrical conductivity (EC) 510 μS/cm, salinity 1.1‰, Cl- 200 mg/l, N03 -35.5 mg/l, Na+ 19.6 mg/l and Ca2+ 79.3 mg/l. The salinity is controlled by NaCl salt, as deduced from correlation analysis using the software package Statistical Product for Service Solutions (SPSS). Generally, concentrations of dissolved ions in the water of the area are enhanced via mechanisms such as evaporation, dissociation of salts, precipitation run off and leaching of dissolved rock minerals.

  17. Oxygen dynamics around buried lesser sandeels Ammodytes tobianus (Linnaeus 1785): mode of ventilation and oxygen requirements

    DEFF Research Database (Denmark)

    Behrens, Jane W; Stahl, Henrik J; Steffensen, John F

    2007-01-01

    The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport...... down along the body, referred to as ;plume ventilation'. Yet, within approximately 30 min the oxic plume was replenished by oxygen-depleted water from the gills. The potential for cutaneous respiration by the buried fish was thus of no quantitative importance. Calculations derived by three independent...... methods (each with N=3) revealed that the oxygen uptake of sandeel buried for 6-7 h was 40-50% of previous estimates on resting respirometry of non-buried fish, indicating lower O(2) requirements during burial on a diurnal timescale. Buried fish exposed to decreasing oxygen tensions gradually approached...

  18. Limnology of Kharland (saline) ponds of Ratnagiri, Maharashtra in relation to prawn culture potential.

    Science.gov (United States)

    Saksena, D N; Gaidhane, D M; Singh, H

    2006-01-01

    The coastal saline soils, Kharlands, have great potential for their use in aquaculture. This study has been taken up to understand the limnology of the ponds in Kharland area for assessing their prawn culture potential. This study was carried out during September, 1999 to August, 2001. Each Kharland pond has an area of 0.045 hectare. During the study, depth of pond water was 47.7 to 120.0 cm, temperature varied from 25.7 to 34.5 degrees C; transparency from nil to 65.0 cm; specific conductivity from 1.78 to 94.5 microS.cm(-1); total dissolved solids from 0.89 to 27.55 ppt; pH 5.42 to 8.25; dissolved oxygen 1.6 to 8 mg.l(-1); free carbon dioxide 10.00 to 44.00 mg.l(-1); total alkalinity 5.00 to 142.00 mg.l(-1); salinity 0.45 to 39.55 ppt; total hardness 245.00 to 5945.00; calcium 56.05 to 1827.6; magnesium 110.74 to 4507.75 mg.l(-1); dissolved organic matter 1.45 to 9.68 mg.l(-1); ammonia 1.00-8.00 microg.l(-1); nitrite nil to 20.00 micro l(-1) and nitrate 7.5 to 17.5 microg.l(-1). These Kharland ponds are unique in physio-chemical characteristics during their seasonal cycle. From July to October, these ponds have nearly freshwater while from November to May pond water becomes saline. Thus, there is a great possibility of taking up monoculture of both the freshwater and brackish water prawns as well as polyculture of prawns and fishes in the Kharland ponds.

  19. NODC Standard Product: Experimental Compact Disk NODC-01 Pacific Ocean Temperature-Salinity Profiles (1900-1988) (NODC Accession 0086259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanographic Data Center (NODC) created a compact disk containing over 1.3 million temperature-depth and salinity-depth profiles taken in the Pacific...

  20. On the role of model depth and hydraulic properties for groundwater flow modelling during glacial climate conditions

    International Nuclear Information System (INIS)

    Vidstrand, Patrik; Rhen, Ingvar

    2011-03-01

    A common assumption in regional groundwater flow simulations of periods with glacial climate conditions is that the salinity at the bottom boundary of the model domain is stable (constant over time). This assumption is partly based on the general fact that water density increases with increasing salinity, but also supported by measurements, e.g. the mobile (fracture water) and immobile (porewater) salinity typically increase with depth, whereas the conductive fracture frequency and fracture transmissivity often decrease with depth. Plausibly, the depth to stable hydrogeological conditions varies between sites, and the question studied here is whether hydrogeological disturbances could occur at 2-4 km depth during glacial climate conditions. With regard to the results of SDM-Site and SR-Site, the hydrogeological conditions at repository depth indicate less groundwater flow during glacial climate conditions at Forsmark than at Laxemar. For this reason, this study uses the Laxemar site as a hypothetical site of potentially more permeable conditions, hence more readily affected during glacial climate conditions. A series of flow simulations conducted with DarcyTools in an approximately 5 km deep, super-regional model domain centred on the Laxemar site are reported. The studied cases (model variants) represent a variety of different property specifications along with variations in initial conditions concerning salinity. The model domain is subjected to a transient top boundary representing an advancing ice sheet margin. The behaviour of the grid cell pressure, Darcy flux and mobile salinity is monitored at four different elevations along a vertical scan line through the centre of the suggested location for a KBS-3 repository at Laxemar. The studied monitoring points are located at -0.5 km, -2.5 km, -3.0 km, and -3.5 km. These elevations are chosen with the objective to study the range of hydrogeological disturbance that could occur at 2-4 km depth. The flow model is run

  1. On the role of model depth and hydraulic properties for groundwater flow modelling during glacial climate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik (TerraSolve AB (Sweden)); Rhen, Ingvar (SWECO Environment AB (Sweden))

    2011-03-15

    A common assumption in regional groundwater flow simulations of periods with glacial climate conditions is that the salinity at the bottom boundary of the model domain is stable (constant over time). This assumption is partly based on the general fact that water density increases with increasing salinity, but also supported by measurements, e.g. the mobile (fracture water) and immobile (porewater) salinity typically increase with depth, whereas the conductive fracture frequency and fracture transmissivity often decrease with depth. Plausibly, the depth to stable hydrogeological conditions varies between sites, and the question studied here is whether hydrogeological disturbances could occur at 2-4 km depth during glacial climate conditions. With regard to the results of SDM-Site and SR-Site, the hydrogeological conditions at repository depth indicate less groundwater flow during glacial climate conditions at Forsmark than at Laxemar. For this reason, this study uses the Laxemar site as a hypothetical site of potentially more permeable conditions, hence more readily affected during glacial climate conditions. A series of flow simulations conducted with DarcyTools in an approximately 5 km deep, super-regional model domain centred on the Laxemar site are reported. The studied cases (model variants) represent a variety of different property specifications along with variations in initial conditions concerning salinity. The model domain is subjected to a transient top boundary representing an advancing ice sheet margin. The behaviour of the grid cell pressure, Darcy flux and mobile salinity is monitored at four different elevations along a vertical scan line through the centre of the suggested location for a KBS-3 repository at Laxemar. The studied monitoring points are located at -0.5 km, -2.5 km, -3.0 km, and -3.5 km. These elevations are chosen with the objective to study the range of hydrogeological disturbance that could occur at 2-4 km depth. The flow model is run

  2. Efeitos da lixiviação e salinidade da água sobre um solo salinizado cultivado com beterraba Effects of leaching and water salinity on a saline soil cultivated with sugar beet

    Directory of Open Access Journals (Sweden)

    Paulo A. Ferreira

    2006-09-01

    Full Text Available Os efeitos de cinco lâminas de lixiviação e quatro níveis de salinidade da água de irrigação sobre a salinidade de um Neossolo Flúvico e a produtividade da cultura da beterraba (Beta vulgaris L. foram estudados em lisímetros de drenagem. Os tratamentos foram dispostos em arranjo fatorial com quatro níveis de condutividade elétrica da água de irrigação (1,0, 2,0, 3,0 e 4,0 dS m-1, a 25 °C e cinco lâminas de lixiviação equivalente a 0,25, 0,50, 0,75, 1,00 e 1,25 do volume de poros do solo ou 53, 106, 159, 206 e 248 mm, respectivamente, no delineamento inteiramente casualizado, com quatro repetições. Os componentes avaliados foram a produtividade da cultura e as salinidades no solo e no lixiviado. Os resultados obtidos mostraram incrementos da salinidade no lixiviado com o decréscimo das lâminas de lixiviação. Os maiores índices de salinidade no perfil do solo, ao final do ciclo da cultura, corresponderam aos tratamentos que receberam as menores lâminas de lixiviação e condutividade elétrica da água de irrigação. A produtividade total da beterraba e a produção das raízes com diâmetros maiores que 3, 4, 5, 6 e 7 cm, não foram influenciadas pelos níveis de salinidade da água de irrigação e lâminas de lixiviação.The effects of five leaching depths and four salinity levels of the irrigation water on the salinity of a Neossol Fluvent and the productivity of sugar beet crop were studied using drainage lysimeters. A completely randomized experimental design was used with four replications, the treatments being displayed in a factorial scheme with four electrical conductivity levels of the irrigation water (1.0, 2.0, 3.0 and 4.0 dS m-1 at 25 °C and five leaching depths equivalent to 0.25, 0.50, 0.75, 1.00 and 1.25 of the soil pores volume or 53, 106, 159, 206 e 248 mm, respectively. The crop productivity and the salinity of soil and leachate were evaluated. The results showed increased salinity in the leachate

  3. Cropping Effects on Microbial Population and Nitrogenase Activity in Saline Arid Soil

    OpenAIRE

    EGAMBERDIEVA, Dilfuza; KUCHAROVA, Zulfiya

    2008-01-01

    Soil salinization is a major problem in irrigated agriculture. A field study was conducted in the Sariosiyo district in the Surkhandarya region of southeast Uzbekistan to evaluate soil nitrogenase activity and nitrogen-fixing bacteria populations in saline serozem soils under wheat, maize, and alfalfa, as well as from adjacent fallow land. Composite soil samples were randomly collected from depths of 0-10, 10-20, and 20-30 cm in autumn, winter, spring, and summer, which were then 2-mm sieved ...

  4. Variação sazonal de oxigênio dissolvido, temperatura e salinidade na costa sul brasileira (28º-35ºS; 48º-54ºW Seasonal variation of dissolved oxygen, temperature and salinity in southern Brazilian coast (28 - 35ºS; 48 - 54ºW

    Directory of Open Access Journals (Sweden)

    Argeo Magliocca

    1982-01-01

    Full Text Available The seasonal and spacial distributions of dissolved oxygen, temperature and salinity of surface and bottom waters over the continental shelf south of Torres, southern Brazil, were investigated from April 1968 to March 1969. The maxima and minima values of oxygen concentration in the upper layers were observed during the winter and summer along the coast (10-35 nm, respectively. Near the bottom this characteristics changes reflecting the northward advection of low oxygen water along the coast. For the sections along the continental shelf covering distances up to 100 nautical miles, the association of high oxygen concentration with low temperatures and low oxygen concentration with higher temperatures was also observed for distances no longer than 60 ran. Further east and below the surface layer, this tendency is modified by the advection of oceanic water from tropical and subantarctic origin. Near the coast, the oxygen maxima (5.0 ml/l is associated with salinity values ranging from 30 to 33‰ (temperature values between 12 and 15ºC, indicating that (its occurrence is probably due to the fresh water run-off from La Plata River. Some results of the changes in the nutrient concentrations during 1972 are also described.

  5. Historical temperature, salinity, oxygen, pH, and meteorological data collected from Former Soviet Union platforms Lomonosov, Murmanets, and Akademik Shokalsky in 1933 - 1962 years from Arctic Ocean, Barents Sea, Bering Sea, Chukchi Sea, East Siberian Sea, Kara Sea, and Laptev Sea (NODC Accession 0108117)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen, pH, and meteorological data collected from Former Soviet Union platforms Lomonosov,Murmanets, and Akademik Shokalsky in...

  6. Comparative performance of the mussels Perna perna and Perna viridis, cultivated at four different depths

    Directory of Open Access Journals (Sweden)

    Marielyn García

    Full Text Available Abstract This study aims to evaluate the effect of environmental variability on the growth and survival of the subtropical and tropical mussels Perna perna and Perna viridis at four different culture depths in the Gulf of Cariaco during an annual cycle. Juveniles of P. perna (39.1±1.88 mm in shell length and P. viridis (36.7±1.87 mm were sown on nylon ropes (3/4" and suspended from a raft at 1, 3, 6 and 9 m depths. Every six weeks, three replicates of each species were sampled (10 individuals per replicate at each depth. Growth parameters were determined: mass and shell length, dry mass of soft tissues as well as fouling and survival rates. Temperature, transparency, chlorophyll a, oxygen, salinity and particulate organic and inorganic matter were recorded at each culture depth for the purpose of relating growth and survival to environmental change. The results show that the growth of both species was linked to the environment, especially with regard to the influence of the food and temperature. A period of stagnant growth of P. perna was associated with the higher temperature and lower phytoplankton biomass that is characteristic of the season with prevalent water column stratification (August-November 2007. By contrast, the growth of P. viridis did not stagnate, although it was gradual and relatively lower. At the end, P. perna achieved higher growth rates than P. viridis. Possible culture strategies to improve the production of both mussel species are discussed.

  7. The very deep hole concept - Geoscientific appraisal of conditions at great depth

    International Nuclear Information System (INIS)

    Juhlin, C.; Wallroth, T.; Smellie, J.; Leijon, B.; Eliasson, T.; Ljunggren, C.; Beswick, J.

    1998-06-01

    One of the alternative systems for disposal of high-level radioactive nuclear waste being studied by SKB is the very deep hole (2000 - 4000 m) concept. As part of SKB's research programme a study has been carried out to increase the level of knowledge on the expected geological conditions in the depth interval 1000-5000 m in older crystalline rock. As a first step, existing data from relevant areas throughout the world have been compiled. The majority of the data come from deep boreholes, mines, and surface geophysical surveys. An attempt has been made to interpret these data in an integrated manner and to develop a conceptual geological model on the conditions in the Baltic Shield down to a depth of 5 km. One of the main features of the suggested model is that the upper 1 km of crust contains significantly more open fractures than the rock below. However, hydraulically conductive fractures and fracture zones may exist at great depth. In areas of low topography active groundwater circulation is primarily limited to the upper 1 km with the water below 1 km having high salinity. The high salinity reflects the near hydraulically stagnant conditions which exist relatively shallow in areas of low topography. In areas with greater topographic relief fresh water penetrates to great depth and near stagnant conditions are first encountered much deeper. The report also covers how the studied parameters which describe the geological conditions vary with depth. A number of recommendations are made on how the presented conceptual model can be tested and improved aside from obtaining data from new boreholes. These recommendations include the following geoscientific surveys and studies: Reflection and refraction seismics for mapping discrete sub-horizontal fracture zones and the upper more fractured part of the crust; Geoelectric methods for mapping the depth to saline water; Detailed hydrogeological measurements in existing deep boreholes; Isotope studies on fracture minerals

  8. The very deep hole concept - Geoscientific appraisal of conditions at great depth

    Energy Technology Data Exchange (ETDEWEB)

    Juhlin, C. [Christopher Juhlin Consulting (Sweden); Wallroth, T. [Bergab Consulting Geologists (Sweden); Smellie, J.; Leijon, B. [Conterra AB (Sweden); Eliasson, T. [Geological Survey of Sweden (Sweden); Ljunggren, C. [Vattenfall Hydropower AB (Sweden); Beswick, J. [EDECO Petroleum Services Ltd. (United Kingdom)

    1998-06-01

    One of the alternative systems for disposal of high-level radioactive nuclear waste being studied by SKB is the very deep hole (2000 - 4000 m) concept. As part of SKB`s research programme a study has been carried out to increase the level of knowledge on the expected geological conditions in the depth interval 1000-5000 m in older crystalline rock. As a first step, existing data from relevant areas throughout the world have been compiled. The majority of the data come from deep boreholes, mines, and surface geophysical surveys. An attempt has been made to interpret these data in an integrated manner and to develop a conceptual geological model on the conditions in the Baltic Shield down to a depth of 5 km. One of the main features of the suggested model is that the upper 1 km of crust contains significantly more open fractures than the rock below. However, hydraulically conductive fractures and fracture zones may exist at great depth. In areas of low topography active groundwater circulation is primarily limited to the upper 1 km with the water below 1 km having high salinity. The high salinity reflects the near hydraulically stagnant conditions which exist relatively shallow in areas of low topography. In areas with greater topographic relief fresh water penetrates to great depth and near stagnant conditions are first encountered much deeper. The report also covers how the studied parameters which describe the geological conditions vary with depth. A number of recommendations are made on how the presented conceptual model can be tested and improved aside from obtaining data from new boreholes. These recommendations include the following geoscientific surveys and studies: Reflection and refraction seismics for mapping discrete sub-horizontal fracture zones and the upper more fractured part of the crust; Geoelectric methods for mapping the depth to saline water; Detailed hydrogeological measurements in existing deep boreholes; Isotope studies on fracture minerals

  9. Submesoscale-selective compensation of fronts in a salinity-stratified ocean.

    Science.gov (United States)

    Spiro Jaeger, Gualtiero; Mahadevan, Amala

    2018-02-01

    Salinity, rather than temperature, is the leading influence on density in some regions of the world's upper oceans. In the Bay of Bengal, heavy monsoonal rains and runoff generate strong salinity gradients that define density fronts and stratification in the upper ~50 m. Ship-based observations made in winter reveal that fronts exist over a wide range of length scales, but at O(1)-km scales, horizontal salinity gradients are compensated by temperature to alleviate about half the cross-front density gradient. Using a process study ocean model, we show that scale-selective compensation occurs because of surface cooling. Submesoscale instabilities cause density fronts to slump, enhancing stratification along-front. Specifically for salinity fronts, the surface mixed layer (SML) shoals on the less saline side, correlating sea surface salinity (SSS) with SML depth at O(1)-km scales. When losing heat to the atmosphere, the shallower and less saline SML experiences a larger drop in temperature compared to the adjacent deeper SML on the salty side of the front, thus correlating sea surface temperature (SST) with SSS at the submesoscale. This compensation of submesoscale fronts can diminish their strength and thwart the forward cascade of energy to smaller scales. During winter, salinity fronts that are dynamically submesoscale experience larger temperature drops, appearing in satellite-derived SST as cold filaments. In freshwater-influenced regions, cold filaments can mark surface-trapped layers insulated from deeper nutrient-rich waters, unlike in other regions, where they indicate upwelling of nutrient-rich water and enhanced surface biological productivity.

  10. Salinity and temperature variations around Peninsula Malaysia coastal waters

    International Nuclear Information System (INIS)

    Abdul Kadir Ishak; Jeremy Andy Anak Dominic; Nazrul Hizam Yusof; Mohd Rafaei Murtadza

    2004-01-01

    Vertical profiles of salinity and temperature were measured at several offshore stations along east and west coast of Peninsula Malaysia coastal waters. The measurements which covered South China Sea and Straits of Malacca were made during sampling cruises for Marine Database Project for Peninsula Malaysia, and during an IAEA regional training course for Marine Pollution Project. The results show that the water temperature is highest at the surface and minimum at bottom, while the salinity is lowest at the surface and highest at the bottom. In Malacca Straits, the highest surface water temperature was 30.6 degree C and the lowest bottom water temperature was 20.4 degree C, recorded at a station located in Andaman Sea. The same station also recorded the highest surface and bottom salinity i.e. 31.3 ppt and 34.4 ppt, respectively. For South China Sea, the maximum surface water temperature was 30.4 degree C and the minimum bottom temperature was 25.9 degree C, while the highest surface salinity was 33.2 ppt and the highest bottom salinity was 34.1 ppt. The water in South China Sea also showed some degrees of stratifications with thermocline zones located between 10-40 m water depths. In Malacca Straits, stronger thermocline develops at higher latitude, while at lower latitude the water is more readily mixed. Beside the spatial variations, the seawater temperature and salinity around Peninsula Malaysia also subjected to temporal variation as seawater. (Author)

  11. Problems of irrigated agriculture in saline groundwater areas: farmers' perceptions

    International Nuclear Information System (INIS)

    Ahmad, S.; Yasin, M.; Ahmad, M.M.; Hussain, Z.; Khan, Z.; Akbar, G.

    2005-01-01

    A research study was conducted using participatory interactive dialogue in the brackish groundwater area of Mona SCARP-II, Bhalwal district Sargodha, Pakistan. The Participatory Rural Appraisal (PRA) was conducted in thirteen villages to identify macro- and micro-level issues related to irrigated agriculture in saline groundwater areas. SCARP tube wells have been abandoned or few have been handed over to farmers' organizations. Groundwater in the Indus basin contributes around 35% to the total water available for agriculture. Water quality of 60% area of the Indus basin is marginal to brackish. Minimum land holding of cultivated land in the elected villages varied from 0.10 to 4 ha. The maximum land holding of cultivated area in selected villages varied for 6 to 50 ha. However, the average size of farm was around 4 ha. The average salt-affected area per household was 17% of the total cultivated area. The salt-affected lands in 8 villages out of 13 were barren, where mainly rice crop is grown during kharif season. About 67% farms had access to conjunctive use of water, as water from both canal and private tube wells is available. In addition, 10% farms were having tube well water only. Therefore, 77% farms are having access to the groundwater. According to the farmers' perceptions, 100% villages have fresh groundwater to a depth of 7.5 m and 62% villages had depth ranging from 15-30 m. Furthermore, in all thirteen selected villages, groundwater quality beyond 30 m depth was brackish. Laboratory analysis confirmed the farmer's perception that groundwater quality is a function of depth. About 92% farmers groups indicated that non-availability and high price of inputs was a major problem. The second major issue was related to the shortage of canal water supplies and 77% villages are facing this problem. Moreover, 31% farmers' groups of selected villages indicated that water logging and salinity are the major concerns affecting agricultural productivity. This figure is

  12. The Diffusive Boundary-Layer of Sediments - Oxygen Microgradients Over a Microbial Mat

    DEFF Research Database (Denmark)

    JØRGENSEN, BB; MARAIS, DJD

    1990-01-01

    Oxygen microelectrodes were used to analyze the distribution of the diffusive boundary layer (DBL) at the sedimen-water interface in relation to surface topography and flow velocity. The sediment, collected from saline ponds, was covered by a microbial mat that had high oxygen consumption rate...

  13. Influence of Microsprinkler Irrigation Amount on Water, Soil, and pH Profiles in a Coastal Saline Soil

    Directory of Open Access Journals (Sweden)

    Linlin Chu

    2014-01-01

    Full Text Available Microsprinkler irrigation is a potential method to alleviate soil salinization. After conducting a homogeneous, highly saline, clayey, and coastal soil from the Bohai Gulf in northern China in a column experiment, the results show that the depth of the wetting front increased as the water amount applied increased, low-salinity and low-SAR enlarged after irrigation and water redistribution, and the soil pH increased with an increase in irrigation amount. We concluded that a water amount of 207 mm could be used to reclaim the coastal saline soil in northern China.

  14. Modelling soil salinity in Oued El Abid watershed, Morocco

    Science.gov (United States)

    Mouatassime Sabri, El; Boukdir, Ahmed; Karaoui, Ismail; Arioua, Abdelkrim; Messlouhi, Rachid; El Amrani Idrissi, Abdelkhalek

    2018-05-01

    Soil salinisation is a phenomenon considered to be a real threat to natural resources in semi-arid climates. The phenomenon is controlled by soil (texture, depth, slope etc.), anthropogenic factors (drainage system, irrigation, crops types, etc.), and climate factors. This study was conducted in the watershed of Oued El Abid in the region of Beni Mellal-Khenifra, aimed at localising saline soil using remote sensing and a regression model. The spectral indices were extracted from Landsat imagery (30 m resolution). A linear correlation of electrical conductivity, which was calculated based on soil samples (ECs), and the values extracted based on spectral bands showed a high accuracy with an R2 (Root square) of 0.80. This study proposes a new spectral salinity index using Landsat bands B1 and B4. This hydro-chemical and statistical study, based on a yearlong survey, showed a moderate amount of salinity, which threatens dam water quality. The results present an improved ability to use remote sensing and regression model integration to detect soil salinity with high accuracy and low cost, and permit intervention at an early stage of salinisation.

  15. Salinity controls on plant transpiration and soil water balance

    Science.gov (United States)

    Perri, S.; Molini, A.; Suweis, S. S.; Viola, F.; Entekhabi, D.

    2017-12-01

    Soil salinization and aridification represent a major threat for the food security and sustainable development of drylands. The two problems are deeply connected, and their interplay is expected to be further enhanced by climate change and projected population growth. Salt-affected land is currently estimated to cover around 1.1 Gha, and is particularly widespread in semi-arid to hyper-arid climates. Over 900 Mha of these saline/sodic soils are potentially available for crop or biomass production. Salt-tolerant plants have been recently proposed as valid solution to exploit or even remediate salinized soils. However the effects of salinity on evapotranspiration, soil water balance and the long-term salt mass balance in the soil, are still largely unexplored. In this contribution we analyze the feedback of evapotranspiration on soil salinization, with particular emphasis on the role of vegetation and plant salt-tolerance. The goal is to introduce a simple modeling framework able to shed some light on how (a) soil salinity controls plant transpiration, and (b) salinization itself is favored/impeded by different vegetation feedback. We introduce at this goal a spatially lumped stochastic model of soil moisture and salt mass dynamics averaged over the active soil depth, and accounting for the effect of salinity on evapotranspiration. Here, the limiting effect of salinity on ET is modeled through a simple plant response function depending on both salt concentration in the soil and plant salt-tolerance. The coupled soil moisture and salt mass balance is hence used to obtain the conditional steady-state probability density function (pdf) of soil moisture for given salt tolerance and salinization level, Our results show that salinity imposes a limit in the soil water balance and this limit depends on plant salt-tolerance mainly through the control of the leaching occurrence (tolerant plants exploit water more efficiently than the sensitive ones). We also analyzed the

  16. Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

  17. Some oceanographic observations in the polynya and along a section in the southwest Indian/ Antarctic Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    which reduces the surface salinity. A sub-surface oxygen maximum is observed in January associated with a maximum in primary production. Oxygen concentrations at all depths exhibit decreases from January to February in conjunction with increases...

  18. Oxygation enhances growth, gas exchange and salt tolerance of vegetable soybean and cotton in a saline vertisol.

    Science.gov (United States)

    Bhattarai, Surya P; Midmore, David J

    2009-07-01

    Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC(e). In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na+ and Cl- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na+ or Cl- concentration. Oxygation invariably increased, whereas salinity reduced the K+ : Na+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.

  19. The Temperature and Salinity Variabilities at Cisadane Estuary

    Directory of Open Access Journals (Sweden)

    Hadikusumah

    2008-11-01

    Full Text Available The study was conducted at Cisadane Estuary at 18 oceanographic station in Transition Monsoon Season I, East Monsoon Season, and Transition Monsoon Season II from 2003 to 2005. The area of the study was located at the longitude of 106.58° - 106.70° E and the latitude of 5.96° - 6.02°S. The measurements of temperature, salinity, tubidity and light transmision used CTD (Conductivity, Temperature and Depth Model SBE-19. The result shows that the temperature and salinity vertical profil variabilities at Cisadane Estuary underwent a change in the influence of Transition Monsoon Season I, East Monsoon Season, and Transition Monsoon Season II, for example it was obtained the leg time of the maximum salinity of Transition Monsoon Season II as the same as that of East Monsoon Season. Based on the horizontal and vertical distribution pattern analysis of the interaction between low salinity fresh water of Cisadane River and high salinity sea water of Java Sea, it was also influenced by the season variability and tide. The surface layer was much more influenced by the low salinity and the heat of sunray (seasonal variability with the weaker intensity to the lower layer. The change of the heat energy by the increase of seasonal temperature occurred in September 2003 to May 2004 ((ΔE = 600.6 ⋅ 105 Joule, July to November 2005 (ΔE = 84.9 Joule. The decrease of the heat energy occurred in June to September 2003 ((-267.6 ⋅ 105, May ke October 2004 (ΔE = 189.3 ⋅ 105 Joule and October 2004 to July 2005 (ΔE = -215.4 ⋅ 105 Joule.

  20. Salinity, temperature and density data for the Canadian Beaufort Sea shelf, March 1988

    Energy Technology Data Exchange (ETDEWEB)

    Hopky, G E; Chiperzak, D B; Lawrence, M J

    1988-01-01

    This report contains salinity, temperature and density (CTD) data collected in the waters of the Canadian Beaufort Sea Shelf during March 1988. Salinity and temperature profile data were measured using a Guildline Model 8870 probe deployed from the ice surface. Ice thickness was also measured. Density was calculated using salinity and temperature values. CTD profiles were measured at five stations. The maximum depths of profiles measured from the ice surface ranged from 31.2 to 16.8 dbar. Salinity and temperature measurements ranged from 0.35 to 34.83, and -1.87 to 1.08/sup 0/C, respectively. The data presented in this report will assist in the identification and delineation of potential habitat types, as part of the Critical Arctic Estuarine and Marine Habitat Project of the Northern Oil and Gas Program. 5 refs., 7 figs., 6 tabs.

  1. The hydrogeochemical and isotopic investigations of the two-layered Shiraz aquifer in the northwest of Maharlou saline lake, south of Iran

    Science.gov (United States)

    Tajabadi, Mehdi; Zare, Mohammad; Chitsazan, Manouchehr

    2018-03-01

    Maharlou saline lake is the outlet of Shiraz closed basin in southern Iran, surrounded by several disconnected alluvial fresh water aquifers. These aquifers in the west and northwest of the lake are recharged by karstic anticlines such as Kaftarak in the north and Barmshour in the south. Here groundwater salinity varies along the depth so that better quality water is located below brackish or saline waters. The aim of this study is to investigate the reason for the salinity anomaly and the origin of the fresher groundwater in lower depth. Hence, the change in groundwater salinity along depth has been investigated by means of a set of geoelectrical, hydrogeological, hydrogeochemical, and environmental isotopes data. The interpretation of geoelectrical profiles and hydrogeological data indicates that the aquifer in the southeast of Shiraz plain is a two-layer aquifer separated by a fine-grained (silt and clay) layer with an approximate thickness of 40 m at the depth of about 100-120 m. Hydrgeochemistry showed that the shallow aquifer is recharged by Kaftarak karstic anticline and is affected by the saline lake water. The lake water fraction varies in different parts from zero for shallow aquifer close to the karstic anticlines to ∼70 percent in the margin of the lake. The deep aquifer is protected from the intrusion of saline lake water due to the presence of the above-mentioned confining layer with lake water fraction of zero. The stable isotopes signatures also indicate that the 'fresh' groundwater belonging to the deep aquifer is not subject to severe evaporation or mixing which is typical of the karstic water of the area. It is concluded that the characteristics of the deep aquifer are similar to those of the karstic carbonate aquifer. This karstic aquifer is most probably the Barmshour carbonated anticline buried under the shallow aquifer in the southern part. It may also be the extension of the Kaftarak anticline in the northern part.

  2. Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica.

    Science.gov (United States)

    Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C; Amaral-Zettler, Linda

    2014-10-01

    We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies. © 2014 Marine Biological Laboratory.

  3. Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton net from the R/V Italica in the Ross Sea and Magellan Strait during 10th Italian Antarctic Expedition from 1994-11-13 to 1995-04-02 (NCEI Accession 0068289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton...

  4. Salinity of deep groundwater in California: Water quantity, quality, and protection

    Science.gov (United States)

    Kang, Mary; Jackson, Robert B.

    2016-01-01

    Deep groundwater aquifers are poorly characterized but could yield important sources of water in California and elsewhere. Deep aquifers have been developed for oil and gas extraction, and this activity has created both valuable data and risks to groundwater quality. Assessing groundwater quantity and quality requires baseline data and a monitoring framework for evaluating impacts. We analyze 938 chemical, geological, and depth data points from 360 oil/gas fields across eight counties in California and depth data from 34,392 oil and gas wells. By expanding previous groundwater volume estimates from depths of 305 m to 3,000 m in California’s Central Valley, an important agricultural region with growing groundwater demands, fresh [groundwater volume is almost tripled to 2,700 km3, most of it found shallower than 1,000 m. The 3,000-m depth zone also provides 3,900 km3 of fresh and saline water, not previously estimated, that can be categorized as underground sources of drinking water (USDWs; freshwater zones and USDWs, respectively, in the eight counties. Deeper activities, such as wastewater injection, may also pose a potential threat to groundwater, especially USDWs. Our findings indicate that California’s Central Valley alone has close to three times the volume of fresh groundwater and four times the volume of USDWs than previous estimates suggest. Therefore, efforts to monitor and protect deeper, saline groundwater resources are needed in California and beyond. PMID:27354527

  5. The Baltic Sea natural long-term variability of salinity

    Science.gov (United States)

    Schimanke, Semjon; Markus Meier, H. E.

    2015-04-01

    The Baltic Sea is one of the largest brackish sea areas of the world. The sensitive state of the Baltic Sea is sustained by a fresh-water surplus by river discharge and precipitation on one hand as well as inflows of highly saline and oxygen-rich water masses from the North Sea on the other. Major inflows which are crucial for the renewal of the deep water occur very intermittent with a mean frequency of approximately one per year. Stagnation periods (periods without major inflows) lead for instance to a reduction of oxygen concentration in the deep Baltic Sea spreading hypoxic conditions. Depending on the amount of salt water inflow and fresh-water supply the deep water salinity of the Baltic Sea varies between 11 to 14 PSU on the decadal scale. The goal of this study is to understand the contribution of different driving factors for the decadal to multi-decadal variability of salinity in the Baltic Sea. Continuous measurement series of salinity exist from the 1950 but are not sufficiently long for the investigation of long-term fluctuations. Therefore, a climate simulation of more than 800 years has been carried out with the Rossby Center Ocean model (RCO). RCO is a biogeochemical regional climate model which covers the entire Baltic Sea. It is driven with atmospheric data dynamical downscaled from a GCM mimicking natural climate variability. The analysis focus on the role of variations in river discharge and precipitation, changes in wind speed and direction, fluctuations in temperature and shifts in large scale pressure patterns (e.g. NAO). Hereby, the length of the simulation will allow to identify mechanisms working on decadal to multi-decadal time scales. Moreover, it will be discussed how likely long stagnation periods are under natural climate variability and if the observed exceptional long stagnation period between 1983-1993 might be related to beginning climate change.

  6. Effect of elevated pCO2 on metabolic responses of porcelain crab (Petrolisthes cinctipes) Larvae exposed to subsequent salinity stress.

    Science.gov (United States)

    Miller, Seth H; Zarate, Sonia; Smith, Edmund H; Gaylord, Brian; Hosfelt, Jessica D; Hill, Tessa M

    2014-01-01

    Future climate change is predicted to alter the physical characteristics of oceans and estuaries, including pH, temperature, oxygen, and salinity. Investigating how species react to the influence of such multiple stressors is crucial for assessing how future environmental change will alter marine ecosystems. The timing of multiple stressors can also be important, since in some cases stressors arise simultaneously, while in others they occur in rapid succession. In this study, we investigated the effects of elevated pCO2 on oxygen consumption by larvae of the intertidal porcelain crab Petrolisthes cinctipes when exposed to subsequent salinity stress. Such an exposure mimics how larvae under future acidified conditions will likely experience sudden runoff events such as those that occur seasonally along portions of the west coast of the U.S. and in other temperate systems, or how larvae encounter hypersaline waters when crossing density gradients via directed swimming. We raised larvae in the laboratory under ambient and predicted future pCO2 levels (385 and 1000 µatm) for 10 days, and then moved them to seawater at ambient pCO2 but with decreased, ambient, or elevated salinity, to monitor their respiration. While larvae raised under elevated pCO2 or exposed to stressful salinity conditions alone did not exhibit higher respiration rates than larvae held in ambient conditions, larvae exposed to elevated pCO2 followed by stressful salinity conditions consumed more oxygen. These results show that even when multiple stressors act sequentially rather than simultaneously, they can retain their capacity to detrimentally affect organisms.

  7. Desiccation-crack-induced salinization in deep clay sediment

    Directory of Open Access Journals (Sweden)

    S. Baram

    2013-04-01

    Full Text Available A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water content and on the chemical and isotopic composition of the sediment and pore water in it. The isotopic composition of water stable isotopes (δ18O and δ2H in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ~ 3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl− concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a desiccation-crack-induced salinization (DCIS conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

  8. Salp distribution and grazing in a saline intrusion off NW Spain

    Science.gov (United States)

    Huskin, Iñaki; Elices, Ma. José; Anadón, Ricardo

    2003-07-01

    Salp distribution and grazing were studied along three transects (19 stations) and a Lagrangian phase (7 stations) off Galician coast (NW Spain) in November 1999 during GIGOVI 99 cruise. A poleward saline intrusion was detected at the shelf-break, reaching salinity values above 35.90 u.p.s. at 100-m depth. The salp community was dominated by Salpa fusiformis, although Cyclosalpa bakeri, Thalia democratica and Iasis zonaria were also found in the study area. Total salp abundance ranged from 4 to 4500 ind m -2, representing biomass values between 0.2 and 2750 mg C m -2. Maximum densities were located in the frontal area separating the saline body from coastal waters. S. fusiformis pigment ingestion was estimated using the gut fluorescence method. Gut contents were linearly related to salp body size. Total pigment ingestion ranged from 0.001 to 15 mg Chl- a m -2 d -1, with maximum values at the coastal edge of the saline body. Estimated ingestion translates into an average daily grazing impact of 7% of chlorophyll standing stock, ranging from <1% to 77%.

  9. The vanadium/oxygen system in the analysis of sodium for oxygen

    International Nuclear Information System (INIS)

    Walker, J.A.J.; Price, W.B.

    1981-05-01

    An investigation of the V-O-Na system at 1023 K is described for oxygen in sodium contents of 5 to 25 ppm. Electron spectroscopy combined with depth profiling is used to determine the vanadium/oxygen ratios inwards from the surface of vanadium foil and these ratios are compared with theoretical predictions. The validity of the vanadium wire technique as an analytical method is examined and a model for the vanadium oxidation is suggested. (author)

  10. Deciphering the modern calcification depth of Globigerina bulloides in the southwestern Indian Ocean from its oxygen isotopic composition

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Khare, N.

    -fit results. Similarly, the estimated seawater salinity was calculated using the seawater delta sup(18)O calculated from G. bulloides delta sup(18)O, and measured seawater temperature taken from the Levitus database. A comparison of seawater salinity...

  11. Geoelectric imaging for saline water intrusion in Geopark zone of Ciletuh Bay, Indonesia

    Science.gov (United States)

    Ardi, N. D.; Iryanti, M.; Asmoro, C. P.; Yusuf, A.; Sundana, A. N. A.; Safura, H. Y.; Fitri, M.; Anggraeni, M.; Kurniawan, R.; Afrianti, R.; Sumarni

    2018-05-01

    Saline water intrusion in estuary is an urgent ecological encounter across the world. The Ciletuh Bay, located in the southern Sukabumi district, is an area with high cultivated potential becoming one of the most important geology tourism zones in Indonesia. However, salt water intrusion along the creek is a natural spectacle that disturbs the economic growth of the whole region. This research was intended at plotting the subsurface level of saltwater interventions into aquifers at the northern part of Ciletuh creek, Indonesia. The study implemented geoelectric imaging methods. 37 imaging datum were acquired using Wenner array configuration. The saline water were identified across the study area. The result of two dimensional cross-sectional resistivity shows that there is an indication of sea content in our measured soil, i.e. the smallest resistivity value is 0.579 Ωm found at a depth of 12.4 m to 19.8 m at a track length of 35 m to 60 m is categorized in the clayey which shows low groundwater quality. However, when compared with the results of direct observation of groundwater from the wells of residents, the water obtained is brackish water. A water chemistry test is conducted to ascertain the initial results of this method so that a potential sea intrusion potential map can be interpreted more clearly. This can consequently help as an extrapolative model to define depth to saline water at any site within the saline water zone in the study area.

  12. Biogeochemical cycling of arsenic in coastal salinized aquifers: Evidence from sulfur isotope study

    International Nuclear Information System (INIS)

    Kao, Yu-Hsuan; Wang, Sheng-Wei; Liu, Chen-Wuing; Wang, Pei-Ling; Wang, Chung-Ho; Maji, Sanjoy Kumar

    2011-01-01

    Arsenic (As) contamination of groundwater, accompanied by critical salinization, occurs in the southwestern coastal area of Taiwan. Statistical analyses and geochemical calculations indicate that a possible source of aqueous arsenic is the reductive dissolution of As-bearing iron oxyhydroxides. There are few reports of the influence of sulfate-sulfide redox cycling on arsenic mobility in brackish groundwater. We evaluated the contribution of sulfate reduction and sulfide re-oxidation on As enrichment using δ 34 S [SO 4 ] and δ 18 O [SO 4 ] sulfur isotopic analyses of groundwater. Fifty-three groundwater samples were divided into groups of high-As content and salinized (Type A), low-As and non-salinized (Type B), and high-As and non-salinized (Type C) groundwaters, based on hydro-geochemical analysis. The relatively high enrichment of 34 S [SO 4 ] and 18 O [SO 4 ] present in Type A, caused by microbial-mediated reduction of sulfate, and high 18 O enrichment factor (ε [SO 4 -H 2 O] ), suggests that sulfur disproportionation is an important process during the reductive dissolution of As-containing iron oxyhydroxides. Limited co-precipitation of ion-sulfide increased the rate of As liberation under anaerobic conditions. In contrast to this, Type B and Type C groundwater samples showed high δ 18 O [SO 4 ] and low δ 34 S [SO 4 ] values under mildly reducing conditions. Base on 18 O mass balance calculations, the oxide sources of sulfate are from infiltrated atmospheric O 2 , caused by additional recharge of dissolved oxygen and sulfide re-oxidation. The anthropogenic influence of extensive pumping also promotes atmospheric oxygen entry into aquifers, altering redox conditions, and increasing the rate of As release into groundwater. - Highlights: → Seawater intrusion and elevated As are the main issues of groundwater in Taiwan. → Sulfur and oxygen isotopes of sulfate were analyzed to evaluate the As mobility. → Reductive dissolution of Fe minerals and

  13. Salinity effects on behavioural response to hypoxia in the non-native Mayan cichlid Cichlasoma urophthalmus from Florida Everglades wetlands.

    Science.gov (United States)

    Schofield, P J; Loftus, W F; Fontaine, J A

    2009-04-01

    This study quantified the hypoxia tolerance of the Mayan cichlid Cichlasoma urophthalmus over a range of salinities. The species was very tolerant of hypoxia, using aquatic surface respiration (ASR) and buccal bubble holding when oxygen tensions dropped to <20 mmHg (c. 1.0 mg l(-1)) and 6 mmHg, respectively. Salinity had little effect on the hypoxia tolerance of C. urophthalmus, except that bubble holding was more frequent at the higher salinities tested. Levels of aggression were greatest at the highest salinity. The ASR thresholds of C. urophthalmus were similar to native centrarchid sunfishes from the Everglades, however, aggression levels for C. uropthalmus were markedly higher.

  14. Real-Time Monitoring of Singlet Oxygen and Oxygen Partial Pressure During the Deep Photodynamic Therapy In Vitro.

    Science.gov (United States)

    Li, Weitao; Huang, Dong; Zhang, Yan; Liu, Yangyang; Gu, Yueqing; Qian, Zhiyu

    2016-09-01

    Photodynamic therapy (PDT) is an effective noninvasive method for the tumor treatment. The major challenge in current PDT research is how to quantitatively evaluate therapy effects. To our best knowledge, this is the first time to combine multi-parameter detection methods in PDT. More specifically, we have developed a set of system, including the high-sensitivity measurement of singlet oxygen, oxygen partial pressure and fluorescence image. In this paper, the detection ability of the system was validated by the different concentrations of carbon quantum dots. Moreover, the correlation between singlet oxygen and oxygen partial pressure with laser irradiation was observed. Then, the system could detect the signal up to 0.5 cm tissue depth with 660 nm irradiation and 1 cm tissue depth with 980 nm irradiation by using up-conversion nanoparticles during PDT in vitro. Furthermore, we obtained the relationship among concentration of singlet oxygen, oxygen partial pressure and tumor cell viability under certain conditions. The results indicate that the multi-parameter detection system is a promising asset to evaluate the deep tumor therapy during PDT. Moreover, the system might be potentially used for the further study in biology and molecular imaging.

  15. Predictive spatial modelling for mapping soil salinity at continental scale

    Science.gov (United States)

    Bui, Elisabeth; Wilford, John; de Caritat, Patrice

    2017-04-01

    Soil salinity is a serious limitation to agriculture and one of the main causes of land degradation. Soil is considered saline if its electrical conductivity (EC) is > 4 dS/m. Maps of saline soil distribution are essential for appropriate land development. Previous attempts to map soil salinity over extensive areas have relied on satellite imagery, aerial electromagnetic (EM) and/or proximally sensed EM data; other environmental (climate, topographic, geologic or soil) datasets are generally not used. Having successfully modelled and mapped calcium carbonate distribution over the 0-80 cm depth in Australian soils using machine learning with point samples from the National Geochemical Survey of Australia (NGSA), we took a similar approach to map soil salinity at 90-m resolution over the continent. The input data were the EC1:5 measurements on the randomly sampled trees were built using the training data. The results were good with an average internal correlation (r) of 0.88 between predicted and measured logEC1:5 (training data), an average external correlation of 0.48 (test subset), and a Lin's concordance correlation coefficient (which evaluates the 1:1 fit) of 0.61. Therefore, the rules derived were mapped and the mean prediction for each 90-m pixel was used for the final logEC1:5 map. This is the most detailed picture of soil salinity over Australia since the 2001 National Land and Water Resources Audit and is generally consistent with it. Our map will be useful as a baseline salinity map circa 2008, when the NGSA samples were collected, for future State of the Environment reports.

  16. Ecology of Pleuromamma indica Wolfenden (Copepoda - Calanoida) in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswathy, M.; Iyer, H.K.

    , strong oxygen minimum above 500m depth and a wide range of salinity varying from 32 x 10-3 in Bay of Bengal to more than 37 x 10 -3 in the northern Arabian Sea were characteristics of the study area. P. indica showed a positive correlation with salinity...

  17. DEPTH - OBSERVATION and Other Data from HAI JIAN 73 and Other Platforms (NODC Accession 9400160)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The salinity, depth, conductivity and temperature data in this accession were provided by the Chinese National Oceanographic Data Center via File Transfer Protocol....

  18. Effect of Vetiver Grass on Reduction of Soil Salinity and Some Minerals

    Directory of Open Access Journals (Sweden)

    Masoud Noshadi

    2017-02-01

    Full Text Available Introduction: Soil salinity is one of the major limitations of agriculture in the warm and dry regions. Soil sodification also damages soil structure and reduce soil permeability. Therefore, control of soil salinity and sodium is very important. Vetiver grass has unique characteristics that can be useful in phytoremediation. Materials and Methods: This research was conducted to investigate the effects of irrigation with different salinities on vetiver grass and the effects of this plant on the control of soil salinity and soil reclamation.The experimental design was randomized complete block design. Irrigation water salinities were 0.68(blank, 2, 4, 6, 8 and 10 dS/m, respectively, which artificially were constructed using sodium chloride and calcium chloride. At first, vetiver was transplanted and then moved to the farm. The amount of soil moisture was measured by the neutron probe. Irrigation depth was applied to refill soil water deficit up to field capacity. To evaluate the soil salinity in above salinity treatments, soil was sampled in each plot from 0-30, 30-60 and 60-90 cm depths and for each layer, electrical conductivity of saturated extract (ECe, sodium, potassium and chloride concentrations was measured .To measure the sodium, potassium and chloride concentrations in the leaves and roots of vetiver plant, samples were dried in oven. The dried samples were powdered and passed through the sieve (No. 200 and they were reduced to ash in 250 ◦C. 5 ml HCl was added to one gram of the ash, and after passing through filter paper, the volume of sample was brought to 50 ml by boiled distilled water. After preparing plant samples, the sodium, potassium and chloride concentrations were measured by Flame Photometer. Reults and discussion: The results showed that the vetiver grass was able to decrease soil salinity at different salinity levels except highest water salinity (10 dS/m and prevented salt accumulation in the soil. However, in the

  19. Salinity variations and chemical compositions of waters in the Frio Formation, Texas Gulf Coast. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Garrett, C.M. Jr.; Posey, J.S.; Han, J.H.; Jirik, L.A.

    1981-11-01

    Waters produced from sandstone reservoirs of the deep Frio Formation exhibit spatial variations in chemical composition that roughly coincide with the major tectonic elements (Houston and Rio Grande Embayments, San Marcos Arch) and corresponding depositional systems (Houston and Norias deltas, Greta-Carancahua barrier/strandplain system) that were respectively active along the upper, lower, and middle Texas Coast during Frio deposition. Within an area, salinities are usually depth dependent, and primary trends closely correspond to pore pressure gradients and thermal gradients. Where data are available (mainly in Brazoria County) the increases in TDS and calcium with depth coincide with the zone of albitization, smectite-illite transition, and calcite decrease in shales. Waters have fairly uniform salinities when produced from the same sandstone reservoir within a fault block or adjacent fault blocks with minor displacement. In contrast, stratigraphically equivalent sandstones separated by faults with large displacement usually yield waters with substantially different salinities owing to the markedly different thermal and pressure gradients across the faults that act as barriers to fluid movement.

  20. Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh.

    Science.gov (United States)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin; Jensen, Peter Kjaer Mackie

    2015-04-01

    To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources. © 2015 John Wiley & Sons Ltd.

  1. Depth-dependent positron annihilation in different polymers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.; Zhang, P.; Cheng, G.D.; Li, D.X.; Wu, H.B.; Li, Z.X.; Cao, X.Z. [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Jia, Q.J. [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Yu, R.S. [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Wang, B.Y., E-mail: wangboy@ihep.ac.cn [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China)

    2013-09-01

    Depth-dependent positron annihilation Doppler broadening measurements were conducted for polymers with different chemical compositions. Variations of the S parameter with respect to incident positron energy were observed. For pure hydrocarbons PP, HDPE and oxygen-containing polymer PC, S parameter rises with increasing positron implantation depth. While for PI and fluoropolymers like PTFE, ETFE and PVF, S parameter decreases with higher positron energy. For chlorine-containing polymer PVDC, S parameter remains nearly constant at all incident positron energies. It is suggested that these three variation trends are resulted from a competitive effect between the depth-dependent positronium formation and the influence of highly electronegative atoms on positron annihilation characteristics.

  2. Crescimento e desenvolvimento da cultura do melão sob diferentes lâminas de irrigação e salinidade da água Growth and development of the melon crop under different irrigation depths and water salinity

    Directory of Open Access Journals (Sweden)

    Carlos H. de A. Farias

    2003-12-01

    Full Text Available Avaliar o crescimento, o desenvolvimento foliar e o acúmulo de matéria seca da cultura de melão ‘Gold mine’, submetido a diferentes lâminas de irrigação, utilizando-se água com dois níveis de salinidade, foi o objetivo deste trabalho. O experimento foi conduzido em condições de campo, na Fazenda São João, município de Mossoró, RN, cujo delineamento experimental adotado foi o de blocos casualizados, em esquema fatorial 6 x 2. Os tratamentos consistiram na introdução de seis lâminas de irrigação (0,55; 0,70; 0,85; 1,00; 1,15 e 1,30 da evapotranspiração máxima da cultura e dois níveis de salinidade da água de irrigação 0,55 e 2,65 dS m-1. A falta de água no período crítico afetou significativamente o restante do ciclo da cultura, causando decréscimo, no peso da fitomassa seca, para lâminas abaixo do tratamento da lâmina padrão (266 mm. O acúmulo de fitomassa foi afetado pela água de maior salinidade (2,65 dS m-1 ao longo de todo ciclo.The aim of this study was to evaluate the growth, vegetative development and accumulation of dry matter of the "Gold mine" melon submitted to different depths of irrigation using two levels of salinity. The experiment was conducted under field conditions at Fazenda São João, Mossoró, RN, in random blocks and 6 x 2 factorial experimental design. The treatments consisted of 6 depths of irrigation (0.55; 0.70; 0.85; 1.00; 1.15; 1.3 of the maximum crop evapotranspiration and two levels of salinity of the irrigation water (0.55 and 2.65 dS m-1. The absence of water in the critical period significantly affected the rest of the cycle, causing decrease in the dry weight in the treatment of irrigation depth considered as of the most appropriate depth (266 mm. The water of higher salinity (2.65 dS m-1 affected the accumulation of dry matter in the cycle.

  3. Temperature profile, salinity, dissolved oxygen, phosphate and other measurements collected using bottle and CTD casts from the New Horizon and NOAA Ship David Starr Jordan in the North East Pacific Ocean as part of the California Cooperative Fisheries Investigation (CALCOFI) project, from 23 March - 2004-07-28 (NODC Accession 0002180)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, dissolved oxygen, phosphate, conductivity, phytoplankton, and other data were collected using CalBOBL, manta net, pairovet, bottle, and CTD...

  4. Putting Temperature and Oxygen Thresholds of Marine Animals in Context of Environmental Change: A Regional Perspective for the Scotian Shelf and Gulf of St. Lawrence.

    Directory of Open Access Journals (Sweden)

    Catherine E Brennan

    Full Text Available We conducted a literature review of reported temperature, salinity, pH, depth and oxygen preferences and thresholds of important marine species found in the Gulf of St. Lawrence and Scotian Shelf region. We classified 54 identified fishes and macroinvertebrates as important either because they support a commercial fishery, have threatened or at risk status, or meet one of the following criteria: bycatch, baitfish, invasive, vagrant, important for ecosystem energy transfer, or predators or prey of the above species. The compiled data allow an assessment of species-level impacts including physiological stress and mortality given predictions of future ocean physical and biogeochemical conditions. If an observed, multi-decadal oxygen trend on the central Scotian Shelf continues, a number of species will lose favorable oxygen conditions, experience oxygen-stress, or disappear due to insufficient oxygen in the coming half-century. Projected regional trends and natural variability are both large, and natural variability will act to alternately amplify and dampen anthropogenic changes. When estimates of variability are included with the trend, species encounter unfavourable oxygen conditions decades sooner. Finally, temperature and oxygen thresholds of adult Atlantic wolffish (Anarhichas lupus and adult Atlantic cod (Gadus morhua are assessed in the context of a potential future scenario derived from high-resolution ocean models for the central Scotian Shelf.

  5. Oxygen flooding and sample cooling during depth profiling of HfSiON thin films

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, Shiro [Materials Analysis Center, Materials Laboratories, Sony Corporation, 4-16-1 Okata, Atsugi 243-0021 (Japan)], E-mail: Shiro.Miwa@jp.sony.com

    2008-12-15

    A combination of oxygen flooding and. Cs primary ion bombardment can suppress the enhancement of the secondary ion signal at the surface and at the interface of a thin HfSiON layer on a Si substrate. The surface concentration of both Cs and O during Cs primary ion bombardment with oxygen flooding was higher than that without oxygen flooding, as confirmed by X-ray photoelectron spectroscopy. When the sample was cooled to about -150 deg. C, the enhancement of the secondary ion signal could be suppressed at a lower oxygen pressure.

  6. Decadal trends in deep ocean salinity and regional effects on steric sea level

    Science.gov (United States)

    Purkey, S. G.; Llovel, W.

    2017-12-01

    We present deep (below 2000 m) and abyssal (below 4000 m) global ocean salinity trends from the 1990s through the 2010s and assess the role of deep salinity in local and global sea level budgets. Deep salinity trends are assessed using all deep basins with available full-depth, high-quality hydrographic section data that have been occupied two or more times since the 1980s through either the World Ocean Circulation Experiment (WOCE) Hydrographic Program or the Global Ship-Based Hydrographic Investigations Program (GO-SHIP). All salinity data is calibrated to standard seawater and any intercruise offsets applied. While the global mean deep halosteric contribution to sea level rise is close to zero (-0.017 +/- 0.023 mm/yr below 4000 m), there is a large regional variability with the southern deep basins becoming fresher and northern deep basins becoming more saline. This meridional gradient in the deep salinity trend reflects different mechanisms driving the deep salinity variability. The deep Southern Ocean is freshening owing to a recent increased flux of freshwater to the deep ocean. Outside of the Southern Ocean, the deep salinity and temperature changes are tied to isopycnal heave associated with a falling of deep isopycnals in recent decades. Therefore, regions of the ocean with a deep salinity minimum are experiencing both a halosteric contraction with a thermosteric expansion. While the thermosteric expansion is larger in most cases, in some regions the halosteric compensates for as much as 50% of the deep thermal expansion, making a significant contribution to local sea level rise budgets.

  7. Natural environmental radioactivity and estimation of radiation exposure from saline soils

    International Nuclear Information System (INIS)

    Akhtar, N.; Tufail, M.; Ashraf, M.

    2005-01-01

    The study was conducted for the investigation of amount of radioactivity in the barren and cultivated soil of Bio saline Research Station in Pakka Anna, established by Nuclear Institute for Agriculture and Biology in 1990, 34 km. away from the city of Faisalabd, in the Punjab Province of Pakistan. The studies were done on an area of about 100 hectares of two types of virgin and fertilized saline soils. The technique of gamma ray spectrometry was applied using High Purity Germanium gamma ray detector and a P C based MCA. Activity concentration levels due to 40 K, 137 Cs, 226 Ra and 232 Th were measured in 250 saline soil samples collected at a spacing of about 4 hectares at the depth level of 0-25 cm. with a step of 5 cm. depth. Activity concentration ranges of the concerned radionuclides for both of the soils were as follows: 40 K, for virgin and cultivated saline soil was 500-610.2 and Bq/kg 560.2-635.6 respectively; 137 Cs, 3.57-3.63 and 1.98-5.15 Bq/kg 238 U, 26.3-31.6 and 30.6-38.7 Bq/kg, and 232 Th, 50.6-55.3 and 50.6-64.0 Bq/kg respectively. The absorbed dose rate in air lies in the region 63-73 nGyh -1 and 68-83 nGyh -1 for virgin and fertilized soils respectively. This indicates that this region lies in the area of higher radiation background, while comparing with the worlds' average. The slightly higher value of dose in the fertilized farm may be due to the use of fertilizers for cultivation. Before the radiometric measurements, chemical analysis for concentration of Na, Ca and Mg was also carried out along with the measurement of electrical conductivity and p H of the soil samples

  8. Evaluation of water quality by chlorophyll and dissolved oxygen

    International Nuclear Information System (INIS)

    Latif, Z.; Tasneem, M.A.; Javed, T.; Butt, S.; Fazil, M.; Ali, M.; Sajjad, M.I.

    2002-01-01

    This paper focuses on the impact of Chlorophyll and dissolved Oxygen on water quality. Kalar Kahar and Rawal lakes were selected for this research. A Spectrophotometer was used for determination of Chlorophyll a, Chlorophyll b, Chlorophyll c and Pheophytin pigment. Dissolved Oxygen was measured in situ, using dissolved oxygen meter. The gamma O/sup 18/ of dissolved Oxygen, like concentration, is affected primarily by three processes: air water gas exchange, respiration and photosynthesis; gamma O/sup 18/ is analyzed on isotopic ratio mass spectrometer, after extraction of dissolved Oxygen from water samples, followed by purification and conversion into CO/sub 2/. Rawal lake receives most of the water from precipitation during monsoon period and supplemented by light rains in December and January. This water is used throughout the year for drinking purposes in Rawalpindi city. The water samples were collected from 5, 7.5, and 10 meters of depth for seasonal studies of physiochemical and isotopic parameters of water and dissolved Oxygen. Optimum experimental conditions for delta O/sup 18/ analysis of dissolved Oxygen from aqueous samples were determined. Stratification of dissolved Oxygen was observed in Rawal Lake before rainy season in summer. The water quality deteriorates with depth, because the respiration exceeds the photosynthesis and gas exchange. The concentration and delta O/sup 18/ of dissolved Oxygen show no variation with depth in 1998 winter sampling. Kalar Kahar lake gets water from springs, which are recharged by local rains on the nearby mountains. It is a big lake, with shallow and uniform depth of nearly 1.5 meters. A lot of vegetation can be seen on the periphery of the lake. Algae have grown on the floor of the lake Water samples were collected from the corner with large amount of vegetation and from the center of the lake for dissolved Oxygen and Chlorophyll measurements. Chlorophyll result shows that Kalar Kahar Lake falls in Eutrophic category

  9. Salinization of aquifers at the regional scale by marine transgression: Time scales and processes

    Science.gov (United States)

    Armandine Les Landes, A.; Davy, P.; Aquilina, L.

    2014-12-01

    Saline fluids with moderate concentrations have been sampled and reported in the Armorican basement at the regional scale (northwestern France). The horizontal and vertical distributions of high chloride concentrations (60-1400mg/L) at the regional scale support the marine origin and provide constraints on the age of these saline fluids. The current distribution of fresh and "saline" groundwater at depth is the result mostly of processes occurring at geological timescales - seawater intrusion processes followed by fresh groundwater flushing -, and only slightly of recent anthropogenic activities. In this study, we focus on seawater intrusion mechanisms in continental aquifers. We argue that one of the most efficient processes in macrotidal environments is the gravity-driven downconing instability below coastal salinized rivers. 2-D numerical experiments have been used to quantify this process according to four main parameter types: (1) the groundwater system permeability, (2) the salinity degree of the river, (3) the river width and slope, and (4) the tidal amplitude. A general expression of the salinity inflow rates have been derived, which has been used to estimate groundwater salinization rates in Brittany, given the geomorphological and environmental characteristics (drainage basin area, river widths and slopes, tidal range, aquifer permeability). We found that downconing below coastal rivers entail very high saline rates, indicating that this process play a major role in the salinization of regional aquifers. This is also likely to be an issue in the context of climate change, where sea-level rise is expected.

  10. Acclimation of juvenile Mugil liza Valenciennes, 1836 (Mugiliformes: Mugilidae to different environmental salinities

    Directory of Open Access Journals (Sweden)

    Viviana Lisboa

    Full Text Available Survival and physiological parameters associated with metabolism and osmoregulation were evaluated in juveniles of the Lebranche mullet Mugil liza acclimated to different water salinities (5, 10, 20, 30, and 40‰ for 15 days. Room temperature (25ºC and photoperiod (12L:12D were fixed. Fish were fed twice-a-day with commercial diet (28% crude protein until satiation. After acclimation, whole body oxygen consumption was measured and fish were euthanized and sampled for blood, gills, and liver. Whole body oxygen consumption and plasma osmolality did not change in the range of salinities tested. The isosmotic point was estimated as 412.7 mOsmol kg-1 (13.5‰. Gill Na+,K+-ATPase activity tended to be lower at 20 and 30‰, while liver glycogen content was significantly higher at 20‰ than at 5 and 40‰. These results indicate that juvenile M. liza is able to acclimate for a short-period of time (15 days to a wide range of salinities (5-40‰. This condition is achieved through adjustments in gill Na+,K+-ATPase activity and carbohydrate metabolism to regulate plasma osmolality and aerobic/energy metabolism. Therefore, our findings support the idea of catching juveniles M. liza in sea water and rear them in estuarine and marine waters.

  11. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Science.gov (United States)

    Steinberger, R.; Celedón, C. E.; Bruckner, B.; Roth, D.; Duchoslav, J.; Arndt, M.; Kürnsteiner, P.; Steck, T.; Faderl, J.; Riener, C. K.; Angeli, G.; Bauer, P.; Stifter, D.

    2017-07-01

    Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  12. Chemical interaction of fresh and saline waters with compacted bentonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Lehikoinen, J.; Melamed, A.; Pitkaenen, P.

    1996-01-01

    The interaction of compacted sodium bentonite with fresh and saline ground-water simulant was studied. The parameters varied in the experiments were the compositions of the solutions and oxygen and carbon dioxide content in the surroundings. The main interests of the study were the chemical changes in the experimental solution, bentonite porewater and bentonite together with the microstructural properties of bentonite. The major processes with fresh water were the diffusion of sodium, potassium, sulphate, bicarbonate and chloride from bentonite to the solution, and the diffusion of calcium and magnesium from the solution into bentonite. The major processes in the experiments with saline water were the diffusion of the sodium, magnesium, sulphate and bicarbonate from bentonite into the solution, and the diffusion of calcium from the solution into bentonite

  13. Chemical composition of selected Kansas brines as an aid to interpreting change in water chemistry with depth

    Science.gov (United States)

    Dingman, R.J.; Angino, E.E.

    1969-01-01

    Chemical analyses of approximately 1,881 samples of water from selected Kansas brines define the variations of water chemistry with depth and aquifer age. The most concentrated brines are found in the Permian rocks which occupy the intermediate section of the geologic column of this area. Salinity decreases below the Permian until the Ordovician (Arbuckle) horizon is reached and then increases until the Precambrian basement rocks are reached. Chemically, the petroleum brines studied in this small area fit the generally accepted pattern of an increase in calcium, sodium and chloride content with increasing salinity. They do not fit the often-predicted trend of increases in the calcium to chloride ratio, calcium content and salinity with depth and geologic age. The calcium to chloride ratio tends to be asymptotic to about 0.2 with increasing chloride content. Sulfate tends to decrease with increasing calcium content. Bicarbonate content is relatively constant with depth. If many of the hypotheses concerning the chemistry of petroleum brines are valid, then the brines studied are anomolous. An alternative lies in accepting the thesis that exceptions to these hypotheses are rapidly becoming the rule and that indeed we still do not have a valid and general hypothesis to explain the origin and chemistry of petroleum brines. ?? 1969.

  14. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1931 to 1955

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1931 to 1955 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  15. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1912 to 1930

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1912 to 1930 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  16. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1956 to 1980

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1956 to 1980 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  17. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1981 to 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1981 to 2005 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  18. Element depth profiles of porous silicon

    International Nuclear Information System (INIS)

    Kobzev, A.P.; Nikonov, O.A.; Kulik, M.; Zuk, J.; Krzyzanowska, H.; Ochalski, T.J.

    1997-01-01

    Element depth profiles of porous silicon were measured on the Van-de-Graaff accelerator in the energy range of 4 He + ions from 2 to 3.2 MeV. Application of complementary RBS, ERD and 16 O(α,α) 16 O nuclear reaction methods permits us to obtain: 1) the exact silicon, oxygen and hydrogen distribution in the samples, 2) the distribution of partial pore concentrations. The oxygen concentration in porous silicon reaches 30%, which allows one to assume the presence of silicon oxide in the pores and to explain the spectrum shift of luminescence into the blue area

  19. Assessing the impacts of deoxygenation on marine species using blood-oxygen binding thresholds as proxies for hypoxia tolerance in the water column

    Science.gov (United States)

    Smith-Mislan, A.; Deutsch, C.; Dunne, J. P.; Sarmiento, J. L.

    2016-02-01

    Oxygen and temperature decrease, often rapidly, from shallow to deeper depths, restricting the ability of marine species to use the vertical habitat. One physiological trait that determines the tolerance of organisms to low oxygen is the oxygen affinity of respiratory pigments, hemoglobin and hemocyanin, in the blood. Oxygen affinity is sensitive to temperature because the reversible reaction between oxygen and blood pigments absorbs or releases energy, called the heat of oxygenation. To quantify the range of oxygen affinities for marine species, we surveyed the literature for measurements of oxygen binding to blood at multiple temperatures. Oxygen affinity is mapped within the ocean environment using the depth at which oxygen pressure decreases to the point at which the blood is 50% oxygenated (P50 depth) as organisms move from the surface to depth in the ocean water column. We calculate P50 depths for hydrographic observations and model simulations and find that vertical gradients in both temperature and oxygen impact the vertical position and areal extent of P50 depths. Shifts in P50 due to temperature cause physiological types with the same P50 in the surface ocean to have different P50 depths and physiological types with different P50's in the surface ocean to have the same P50 depth. The vertical distances between P50 depths are spatially variable, which may determine the frequency of ecological interactions, such as competition and predation. P50 depths provide new insights into the historical and future impacts of changing hypoxic zones on species living in pelagic habitats.

  20. Variations of marine pore water salinity and chlorinity in Gulf of Alaska sediments (IODP Expedition 341)

    Science.gov (United States)

    März, Christian; Mix, Alan C.; McClymont, Erin; Nakamura, Atsunori; Berbel, Glaucia; Gulick, Sean; Jaeger, John; Schneider (LeVay), Leah

    2014-05-01

    Pore waters of marine sediments usually have salinities and chlorinities similar to the overlying sea water, ranging around 34-35 psu (Practical Salinity Units) and around 550 mM Cl-, respectively. This is because these parameters are conservative in the sense that they do not significantly participate in biogeochemical cycles. However, pore water studies carried out in the frame of the International Ocean Discovery Program (IODP) and its predecessors have shown that salinities and chlorinities of marine pore waters can substantially deviate from the modern bottom water composition in a number of environmental settings, and various processes have been suggested to explain these phenomena. Also during the recent IODP Expedition 341 that drilled five sites in the Gulf of Alaska (Northeast Pacific Ocean) from the deep Surveyor Fan across the continental slope to the glaciomarine shelf deposits, several occurrences of pore waters with salinities and chlorinities significantly different from respective bottom waters were encountered during shipboard analyses. At the pelagic Sites U1417 and U1418 (~4,200 and ~3,700 m water depth, respectively), salinity and chlorinity maxima occur around 20-50 m sediment depth, but values gradually decrease with increasing drilling depths (down to 30 psu in ~600 m sediment depth). While the pore water freshening at depth is most likely an effect of clay mineral dehydration due to increasing burial depth, the shallow salinity and chlorinity maxima are interpreted as relicts of more saline bottom waters that existed in the North Pacific during the Last Glacial Maximum (Adkins et al., 2002). In contrast, the glaciomarine slope and shelf deposits at Site U1419 to U1421 (~200 to 1,000 m water depth) are characterised by unexpectedly low salinitiy and chlorinity values (as low as 16 psu and 295 mM Cl-, respectively) already in very shallow sediment depths (~10 m), and their records do not show systematic trends with sediment depth. Freshening

  1. Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

    Energy Technology Data Exchange (ETDEWEB)

    Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

    2004-06-01

    The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC{sub 50} values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC{sub 50} obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC{sub 50}). This LC{sub 50} value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC{sub 50}. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC{sub 50} and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC{sub 50} of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC{sub 50} values. In contrast, LC{sub 50} determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature.

  2. Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

    International Nuclear Information System (INIS)

    Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

    2004-01-01

    The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC 50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC 50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC 50 ). This LC 50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC 50 . For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC 50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC 50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC 50 values. In contrast, LC 50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

  3. Oceanographic temperature, salinity and oxygen profiles and other measurements from CTD casts by the National Park Service (NPS) and United States Geological Survey (USGS) for the Inventory and Monitoring Program of the Southeast Alaska Network (SEAN) from multiple platforms in Glacier Bay, Alaska from 1993-07-01 to 2016-10-04 (NODC Accession 0074611)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains temperature, salinity, pressure, photosynthetically active radiation (PAR), optical backscatterance (OBS turbidity), dissolved oxygen, and...

  4. Quantification and characterization of putative diazotrophic bacteria from forage palm under saline water irrigation

    Directory of Open Access Journals (Sweden)

    Gabiane dos Reis Antunes

    2017-09-01

    Full Text Available The aim of this study was to evaluate the density and phenotypical diversity of diazotrophic endophytic bacteria from the forage palm irrigated with different saline water depths. Opuntia stricta (IPA-200016 received five depths of saline water (L1: 80%. ETo; L2: 60%.ETo; L3: 40%; ETo; L4: 20%; ETo and, L5: 0% ETo, where ETo is the reference evapotranspiration. The roots were collected in the field, disinfected, grounded and serial diluted from 10-1 to 10-4. The total concentration of diazotrophic bacteria was determined by the most probable number method (MPN and the isolated bacteria were characterized phenotipically. The concentration of bacteria found in forage palm roots ranged from 0.36 x 104 to 109.89 104 cells per gram of root, with highest occurrence on the 60 and 80% ETo. In the dendrogram of similarity it was possible to observe the formation of 24 phenotypic groups with 100% similarity. All bacteria presented similarity superior to 40%. Among these groups, 14 are rare groups, formed by only a single bacterial isolate. In the Semi-Arid conditions, the forage palm that receives the highest amount of saline water, presents a higher density of putative nitrogen-fixing endophytic bacteria with high phenotypic diversity.

  5. Effects of proline on photosynthesis, root reactive oxygen species ...

    African Journals Online (AJOL)

    Effects of 0.2 mM proline applied to saline nutrient solution on biomass, chlorophyll content, photosynthetic parameters, reactive oxygen species and antioxidant enzymes activities of two melon cultivars (cv. Yuhuang and cv. Xuemei) were examined. Results indicate that exogenous proline increased the fresh and dry ...

  6. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from CAPE HATTERAS from 1988-10-01 to 1991-09-30 (NODC Accession 9500082)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Bottle biochemistry data from 16 casts containing Depth/ Temperature/ Salinity/ Oxygen/ phosphate/ nitrate/ nitrite/ chlorophyll/ phaeophytin/ pressure/ bacteria...

  7. Response function during oxygen sputter profiling and its application to deconvolution of ultrashallow B depth profiles in Si

    International Nuclear Information System (INIS)

    Shao Lin; Liu Jiarui; Wang Chong; Ma, Ki B.; Zhang Jianming; Chen, John; Tang, Daniel; Patel, Sanjay; Chu Weikan

    2003-01-01

    The secondary ion mass spectrometry (SIMS) response function to a B 'δ surface layer' has been investigated. Using electron-gun evaporation combined with liquid nitrogen cooling of target, we are able to deposit an ultrathin B layer without detectable island formation. The B spatial distribution obtained from SIMS is exponentially decaying with a decay length approximately a linear function of the incident energy of the oxygen during the SIMS analysis. Deconvolution with the response function has been applied to reconstruct the spatial distribution of ultra-low-energy B implants. A correction to depth and yield scales due to transient sputtering near the Si surface region was also applied. Transient erosion shifts the profile shallower, but beam mixing shifts it deeper. These mutually compensating effects make the adjusted distribution almost the same as original data. The one significant difference is a buried B peak observed near the surface region

  8. Phreatophytes under stress: transpiration and stomatal conductance of saltcedar (Tamarix spp.) in a high-salinity environment

    Science.gov (United States)

    Glenn, Edward P.; Nagler, Pamela L.; Morino, Kiyomi; Hultine, Kevin

    2013-01-01

    Background and aims: We sought to understand the environmental constraints on an arid-zone riparian phreatophtye, saltcedar (Tamarix ramosissima and related species and hybrids), growing over a brackish aquifer along the Colorado River in the western U.S. Depth to groundwater, meteorological factors, salinity and soil hydraulic properties were compared at stress and non-stressed sites that differed in salinity of the aquifer, soil properties and water use characteristics, to identify the factors depressing water use at the stress site.

  9. Box Model of Freshwater, Salinity and Nutrient in the Delta Mahakam, East Kalimantan

    Directory of Open Access Journals (Sweden)

    Marojahan Simanjuntak

    2011-04-01

    Full Text Available Box Model of Freshwater, Salinity and Nutrient in the Delta Mahakam, East Kalimantan. Research has been conducted in the southern part of the Mahakam Delta, East Kalimantan. Method of measuring temperature, salinity, light transmission and turbidity by using CTD model 603 SBE and current measurement and bathymetry by using ADCP model RDI. Measurement parameters on the nutrient chemistry are based of water samples taken using Nansen bottles from two depths. The purpose of this study to determine the mechanism of freshwater, salinity and nutrient transport from the land of the Mahakam River which interact with seawater by using box models. The results illustrate that the vertical distribution of salinity in the Mahakam Delta has obtained a high stratification, where the freshwater salinity 12.30 psu at the surface of a river flowing toward the sea, and seawater of high salinity 30.07 psu flowing in the direction river under the surface that are separated by a layer of mixture. Freshwater budget of the sea (VSurf obtained for 0,0306 x 109 m3 day-1, and the sea water salinity budget is going into the bottom layer system (VDeep.SOcn-d obtained for 20,727 x 109 psu day-1. While time dilution (Syst obtained for 0.245 day-1 or 5.87 hours. Nutrient budget in the surface layer obtained by the system is autotrophic while in layers near the bottom tend to be heterotrophic

  10. Temperature-salinity structure of the AMOC in high-resolution ocean simulations and in CMIP5 models

    Science.gov (United States)

    Wang, F.; Xu, X.; Chassignet, E.

    2017-12-01

    On average, the CMIP5 models represent the AMOC structure, water properties, Heat transport and Freshwater transport reasonably well. For temperature, CMIP5 models exhibit a colder northward upper limb and a warmer southward lower limb. the temperature contrast induces weaker heat transport than observation. For salinity, CMIP5 models exhibit saltier southward lower limb, thus contributes to weaker column freshwater transport. Models have large spread, among them, AMOC strength contributes to Heat transport but not freshwater transport. AMOC structure (the overturning depth) contributes to transport-weighted temperature not transport-weighted salinity in southward lower limb. The salinity contrast in upper and lower limb contributes to freshwater transport, but temperature contrast do not contribute to heat transport.

  11. Biogeochemical cycling of arsenic in coastal salinized aquifers: Evidence from sulfur isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Yu-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Sheng-Wei [Agricultural Engineering Research Center, Chungli 320, Taiwan, ROC (China); Liu, Chen-Wuing, E-mail: lcw@gwater.agec.ntu.edu.tw [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Pei-Ling [Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Chung-Ho [Institute of Earth Sciences, Academia Sinica, Taipei 115, Taiwan, ROC (China); Maji, Sanjoy Kumar [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2011-10-15

    Arsenic (As) contamination of groundwater, accompanied by critical salinization, occurs in the southwestern coastal area of Taiwan. Statistical analyses and geochemical calculations indicate that a possible source of aqueous arsenic is the reductive dissolution of As-bearing iron oxyhydroxides. There are few reports of the influence of sulfate-sulfide redox cycling on arsenic mobility in brackish groundwater. We evaluated the contribution of sulfate reduction and sulfide re-oxidation on As enrichment using {delta}{sup 34}S{sub [SO{sub 4]}} and {delta}{sup 18}O{sub [SO{sub 4]}} sulfur isotopic analyses of groundwater. Fifty-three groundwater samples were divided into groups of high-As content and salinized (Type A), low-As and non-salinized (Type B), and high-As and non-salinized (Type C) groundwaters, based on hydro-geochemical analysis. The relatively high enrichment of {sup 34}S{sub [SO{sub 4]}} and {sup 18}O{sub [SO{sub 4]}} present in Type A, caused by microbial-mediated reduction of sulfate, and high {sup 18}O enrichment factor ({epsilon}{sub [SO{sub 4-H{sub 2O]}}}), suggests that sulfur disproportionation is an important process during the reductive dissolution of As-containing iron oxyhydroxides. Limited co-precipitation of ion-sulfide increased the rate of As liberation under anaerobic conditions. In contrast to this, Type B and Type C groundwater samples showed high {delta}{sup 18}O{sub [SO{sub 4]}} and low {delta}{sup 34}S{sub [SO{sub 4]}} values under mildly reducing conditions. Base on {sup 18}O mass balance calculations, the oxide sources of sulfate are from infiltrated atmospheric O{sub 2}, caused by additional recharge of dissolved oxygen and sulfide re-oxidation. The anthropogenic influence of extensive pumping also promotes atmospheric oxygen entry into aquifers, altering redox conditions, and increasing the rate of As release into groundwater. - Highlights: {yields} Seawater intrusion and elevated As are the main issues of groundwater in Taiwan

  12. Influence of oceanographic fronts and low oxygen on the distribution ...

    African Journals Online (AJOL)

    The horizontal and vertical distributions of eggs and larvae of sardine Sardinops sagax, anchovy Engraulis encrasicolus and horse mackerel Trachurus trachurus capensis were examined in relation to distribution patterns of temperature, salinity and dissolved oxygen. Samples were collected during February–March 2002 ...

  13. Seasonal plant water uptake patterns in the saline southeast Everglades ecotone.

    Science.gov (United States)

    Ewe, Sharon M L; Sternberg, Leonel da S L; Childers, Daniel L

    2007-07-01

    The purpose of this study was to determine the seasonal water use patterns of dominant macrophytes coexisting in the coastal Everglades ecotone. We measured the stable isotope signatures in plant xylem water of Rhizophora mangle, Cladium jamaicense, and Sesuvium portulacastrum during the dry (DS) and wet (WS) seasons in the estuarine ecotone along Taylor River in Everglades National Park, FL, USA. Shallow soilwater and deeper groundwater salinity was also measured to extrapolate the salinity encountered by plants at their rooting zone. Average soil water oxygen isotope ratios (delta(18)O) was enriched (4.8 +/- 0.2 per thousand) in the DS relative to the WS (0.0 +/- 0.1 per thousand), but groundwater delta(18)O remained constant between seasons (DS: 2.2 +/- 0.4 per thousand; WS: 2.1 +/- 0.1 per thousand). There was an inversion in interstitial salinity patterns across the soil profile between seasons. In the DS, shallow water was euhaline [i.e., 43 practical salinity units (PSU)] while groundwater was less saline (18 PSU). In the WS, however, shallow water was fresh (i.e., 0 PSU) but groundwater remained brackish (14 PSU). All plants utilized 100% (shallow) freshwater during the WS, but in the DS R. mangle switched to a soil-groundwater mix (delta 55% groundwater) while C. jamaicense and S. portulacastrum continued to use euhaline shallow water. In the DS, based on delta(18)O data, the roots of R. mangle roots were exposed to salinities of 25.4 +/- 1.4 PSU, less saline than either C. jamaicense (39.1 +/- 2.2 PSU) or S. portulacastrum (38.6 +/- 2.5 PSU). Although the salinity tolerance of C. jamaicense is not known, it is unlikely that long-term exposure to high salinity is conducive to the persistence of this freshwater marsh sedge. This study increases our ecological understanding of how water uptake patterns of individual plants can contribute to ecosystem levels changes, not only in the southeast saline Everglades, but also in estuaries in general in response to

  14. Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    Science.gov (United States)

    Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

    2011-01-01

    Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

  15. Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    Science.gov (United States)

    Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

    2010-08-01

    Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

  16. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Science.gov (United States)

    Timms, W. A.; Young, R. R.; Huth, N.

    2012-04-01

    The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (2000 mm yr-1) such as parts of Australia's Murray-Darling Basin (MDB). In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8-1.2 m depth under perennial vegetation and at 2.0-2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91-229 t ha-1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m-1 at 21 to 37 m depth (N = 5), whereas deeper groundwater was less saline (290 mS m-1) with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM) software package predicted deep drainage of 3.3-9.5 mm yr-1 (0.7-2.1% rainfall) based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total), and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditions after changes in land use and a thick clay dominated vadose zone. This is in

  17. Water and salinity stress in grapevines: early and late changes in transcript and metabolite profiles.

    Science.gov (United States)

    Cramer, Grant R; Ergül, Ali; Grimplet, Jerome; Tillett, Richard L; Tattersall, Elizabeth A R; Bohlman, Marlene C; Vincent, Delphine; Sonderegger, Justin; Evans, Jason; Osborne, Craig; Quilici, David; Schlauch, Karen A; Schooley, David A; Cushman, John C

    2007-04-01

    Grapes are grown in semiarid environments, where drought and salinity are common problems. Microarray transcript profiling, quantitative reverse transcription-PCR, and metabolite profiling were used to define genes and metabolic pathways in Vitis vinifera cv. Cabernet Sauvignon with shared and divergent responses to a gradually applied and long-term (16 days) water-deficit stress and equivalent salinity stress. In this first-of-a-kind study, distinct differences between water deficit and salinity were revealed. Water deficit caused more rapid and greater inhibition of shoot growth than did salinity at equivalent stem water potentials. One of the earliest responses to water deficit was an increase in the transcript abundance of RuBisCo activase (day 4), but this increase occurred much later in salt-stressed plants (day 12). As water deficit progressed, a greater number of affected transcripts were involved in metabolism, transport, and the biogenesis of cellular components than did salinity. Salinity affected a higher percentage of transcripts involved in transcription, protein synthesis, and protein fate than did water deficit. Metabolite profiling revealed that there were higher concentrations of glucose, malate, and proline in water-deficit-treated plants as compared to salinized plants. The metabolite differences were linked to differences in transcript abundance of many genes involved in energy metabolism and nitrogen assimilation, particularly photosynthesis, gluconeogenesis, and photorespiration. Water-deficit-treated plants appear to have a higher demand than salinized plants to adjust osmotically, detoxify free radicals (reactive oxygen species), and cope with photoinhibition.

  18. Depth distributions of light action spectra for skin chromophores

    Science.gov (United States)

    Barun, V. V.; Ivanov, A. P.

    2010-03-01

    Light action spectra over wavelengths of 300-1000 nm are calculated for components of the human cutaneous covering: melanin, basal (bloodless) tissue, and blood oxy- and deoxyhemoglobin. The transformation of the spectra with depth in biological tissue results from two factors. The first is the wavelength dependence of the absorption coefficient corresponding to a particular skin chromophore and the second is the spectral selectivity of the radiation flux in biological tissue. This factor is related to the optical properties of all chromophores. A significant change is found to take place in the spectral distribution of absorbed radiant power with increasing depth. The action spectrum of light for the molecular oxygen contained in all components of biological tissue is also studied in the 625-645 nm range. The spectra are found to change with both the volume fraction of blood vessels and the degree of oxygenation of the blood. These results are useful for analyzing processes associated with optical absorption that are possible mechanisms for the interaction of light with biological tissues: photodissociation of oxyhemoglobin and the light-oxygen effect.

  19. Fluid resuscitation does not improve renal oxygenation during hemorrhagic shock in rats

    OpenAIRE

    Legrand, Matthieu; Mik, Egbert; Balestra, Gianmarco; Lutter, Rene; Pirracchio, Romain; Payen, Didier; Ince, Can

    2010-01-01

    textabstractBackground: The resuscitation strategy for hemorrhagic shock remains controversial, with the kidney being especially prone to hypoxia. Methods: The authors used a three-phase hemorrhagic shock model to investigate the effects of fluid resuscitation on renal oxygenation. After a 1-h shock phase, rats were randomized into four groups to receive either normal saline or hypertonic saline targeting a mean arterial pressure (MAP) of either 40 or 80 mmHg. After such resuscitation, rats w...

  20. The role of floridoside in osmoadaptation of coral-associated algal endosymbionts to high-salinity conditions

    KAUST Repository

    Ochsenkuhn, Michael A.

    2017-08-17

    The endosymbiosis between Symbiodinium dinoflagellates and stony corals provides the foundation of coral reef ecosystems. The survival of these ecosystems is under threat at a global scale, and better knowledge is needed to conceive strategies for mitigating future reef loss. Environmental disturbance imposing temperature, salinity, and nutrient stress can lead to the loss of the Symbiodinium partner, causing so-called coral bleaching. Some of the most thermotolerant coral-Symbiodinium associations occur in the Persian/Arabian Gulf and the Red Sea, which also represent the most saline coral habitats. We studied whether Symbiodinium alter their metabolite content in response to high-salinity environments. We found that Symbiodinium cells exposed to high salinity produced high levels of the osmolyte 2-O-glycerol-α-d-galactopyranoside (floridoside), both in vitro and in their coral host animals, thereby increasing their capacity and, putatively, the capacity of the holobiont to cope with the effects of osmotic stress in extreme environments. Given that floridoside has been previously shown to also act as an antioxidant, this osmolyte may serve a dual function: first, to serve as a compatible organic osmolyte accumulated by Symbiodinium in response to elevated salinities and, second, to counter reactive oxygen species produced as a consequence of potential salinity and heat stress.

  1. Characteristics of time-domain optical coherence tomography profiles generated from blood-saline mixtures

    International Nuclear Information System (INIS)

    Popescu, Dan P; Sowa, Michael G

    2009-01-01

    Time-domain optical coherence tomography (OCT) employing a 1300 nm broadband source is used to study flowing blood-saline mixtures with blood concentration ranging from 20% to 100%. The study emphasizes the characteristics of the recorded OCT signal and its connection with the properties of the corresponding fluids. There are three regions with distinct properties along the compounded OCT profiles showing the signal dependence on depth. The recorded OCT signal increases for the first 80 μm into the fluid. The flow characteristics of the solution and the average spatial orientation of the blood cells can be extracted from this region of the OCT profile. In the second region, the OCT signal decreases with depth into the sample. An admixture of quasi-ballistic light detected after a single reflection and light recorded after undergoing multiple-scattering interactions with blood cells contributes to the signal recorded in this region. As a consequence, the attenuation of OCT signal with depth into the sample shows a weak dependence on the concentration of blood over this region. The third region starts at a depth of approximately 0.6 mm within all the studied blood-saline mixtures. OCT signal recorded from this region is dominated by light detected after multiple-scattering interactions with blood cells. This region of the OCT profile is characterized by a reduced rate of attenuation with depth compared to the rate recorded along the second region of the compounded profile. A geometrical method is used to estimate the contribution from multiple-scattered light to the OCT signal. The multiple-scattered component shows a parabolic dependence on blood concentration with a maximum contribution at a blood concentration of 55%.

  2. Salinity-induced stratification and the onset of hypoxia during the Holocene Thermal Maximum and the Medieval Climate Anomaly

    Science.gov (United States)

    Papadomanolaki, Nina; Dijkstra, Nikki; van Helmond, Niels; Sangiorgi, Francesca; Hagens, Mathilde; Kotthoff, Ulrich; Slomp, Caroline

    2016-04-01

    During the past ~8000 years the Baltic Sea has experienced three distinct intervals of hypoxia, of which the last one is still ongoing. These intervals are characterized by enhanced sedimentary organic matter burial and enrichment of redox-sensitive metals, such as molybdenum and iron. The first two of these intervals occurred during the Holocene Thermal Maximum (HTM) and the Medieval Climate Anomaly (MCA), two phases with high temperatures and changed precipitation patterns. Studies focussing on the Holocene sedimentary record of the Baltic Sea aim at clarifying the causes of the initiation, evolution and termination of these hypoxic intervals, as well as their consequences. This information could help to potentially aid in finding solutions for the mitigation of present-day hypoxia in the Baltic Sea. The factors contributing to hypoxia development during the HTM and MCA are still debated. Here we present data from a core retrieved during Integrated Ocean Drilling Program (IODP) Expedition 347 in the Landsort Deep basin, the deepest basin of the Baltic Sea at 463m water depth. Sediments were analysed at a high resolution using inorganic geochemical and (mainly marine) palynological proxies. Dinoflagellate cyst (dinocyst) assemblages and total elemental compositions provide clues on the role of salinity in enhancing stratification, ultimately causing hypoxia. During the onset of the HTM changes in salinity, as indicated by the palynology, closely follow changes in sedimentary organic carbon burial and trace metal concentrations. This suggests that stratification was an important cause of hypoxia during the HTM. In contrast, the palynology suggests that reduced stratification did not contribute to re-oxygenation during the termination of the HTM. We did not observe major changes in the palynology throughout the hypoxic interval of the MCA. Our results thus suggest that changes in salinity did not cause the onset and termination of hypoxia during the MCA.

  3. Dissolved oxygen, CDOM, Chl a, temperature, salinity and other variables collected from profile and continuous observations using CTD and other instruments from NOAA Ship Gordon Gunter off the U.S. East Coast during the 2015 East Coast Ocean Acidification (ECOA) Cruise from 2015-06-20 to 2015-07-23 (NCEI Accession 0157080)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains CTD profile data of dissolved oxygen, CDOM, chlorophyll a, temperature and salinity data that were collected during the East Coast...

  4. Effects of tailwater depth on spillway aeration

    African Journals Online (AJOL)

    2011-04-15

    Apr 15, 2011 ... 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 ...

  5. Use of gypsum residues as a corrective for saline-sodic soil

    Directory of Open Access Journals (Sweden)

    Paulo Medeiros dos Santos

    2014-03-01

    Full Text Available One of the hugest problems faced by the civil construction sector is the final destination of residues, especially gypsum, which presents recycling restrictions. However, these residues present a high amount of calcium in their composition, and can be alternatively used for replacing mined gypsum as a saline-sodic soil corrective. This study aimed at evaluating the efficiency of gypsum residues from the civil construction, when compared to mined gypsum, for correcting a saline-sodic soil. A randomized blocks design was used, in a factorial arrangement consisting of two kinds of corrective (gypsum residue and mined gypsum and five leaching depths (0.5, 1.0, 1.5, 2.0 and 2.5 times the soil pores volume, with three replications. Electric conductivity, soluble cations and sodium adsorption ratio were evaluated in the soil saturation extract. The use of gypsum residue proved to be effective in leaching salts and soluble sodium in saline-sodic soil, and can be recommended as a calcium source for recovering from sodicity.

  6. Monitoring bioremediation of weathered diesel NAPL using oxygen depletion profiles

    International Nuclear Information System (INIS)

    Davis, G.B.; Johnston, C.D.; Patterson, B.M.; Barber, C.; Bennett, M.

    1995-01-01

    Semicontinuous logging of oxygen concentrations at multiple depths has been used to evaluate the progress of an in situ bioremediation trial at a site contaminated by weathered diesel nonaqueous-phase liquid (NAPL). The evaluation trial consisted of periodic addition of nutrients and aeration of a 100-m 2 trial plot. During the bioremediation trial, aeration was stopped periodically, and decreases in dissolved and gaseous oxygen concentrations were monitored using data loggers attached to in situ oxygen sensors placed at multiple depths above and within a thin NAPL-contaminated zone. Oxygen usage rate coefficients were determined by fitting zero- and first-order rate equations to the oxygen depletion curves. For nutrient-amended sites within the trial plot, estimates of oxygen usage rate coefficients were significantly higher than estimates from unamended sites. These rates also converted to NPL degradation rates, comparable to those achieved in previous studies, despite the high concentrations and weathered state of the NAPL at this test site

  7. Snohomish Estuary nutrient enhanced coastal acidification pH time series and grab samples

    Data.gov (United States)

    U.S. Environmental Protection Agency — High-resolution (15-minute frequency) monitoring of pH, dissolved oxygen, salinity, temperature, depth, and chlorophyll was conducted from July 15-October 1, 2015 in...

  8. Temperature, salinity, and dissolved oxygen profile data collected via CTD casts from R/V Bell Shimada in the Pacific Ocean along the U.S. West Coast during the West Coast Ocean Acidification cruise 2012 as Part of the North American Carbon Program from September 5, 2012 to September 16, 2012 (NODC Accession 0099810)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One ASCII listing contains 1-dbar averaged CTD data. File cc112.lst contains 1-dbar averaged profiles of pressure, temperature, salinity, and oxygen data. Each...

  9. Fine-scale variability of isopycnal salinity in the California Current System

    Science.gov (United States)

    Itoh, Sachihiko; Rudnick, Daniel L.

    2017-09-01

    This paper examines the fine-scale structure and seasonal fluctuations of the isopycnal salinity of the California Current System from 2007 to 2013 using temperature and salinity profiles obtained from a series of underwater glider surveys. The seasonal mean distributions of the spectral power of the isopycnal salinity gradient averaged over submesoscale (12-30 km) and mesoscale (30-60 km) ranges along three survey lines off Monterey Bay, Point Conception, and Dana Point were obtained from 298 transects. The mesoscale and submesoscale variance increased as coastal upwelling caused the isopycnal salinity gradient to steepen. Areas of elevated variance were clearly observed around the salinity front during the summer then spread offshore through the fall and winter. The high fine-scale variances were observed typically above 25.8 kg m-3 and decreased with depth to a minimum at around 26.3 kg m-3. The mean spectral slope of the isopycnal salinity gradient with respect to wavenumber was 0.19 ± 0.27 over the horizontal scale of 12-60 km, and 31%-35% of the spectra had significantly positive slopes. In contrast, the spectral slope over 12-30 km was mostly flat, with mean values of -0.025 ± 0.32. An increase in submesoscale variability accompanying the steepening of the spectral slope was often observed in inshore areas; e.g., off Monterey Bay in winter, where a sharp front developed between the California Current and the California Under Current, and the lower layers of the Southern California Bight, where vigorous interaction between a synoptic current and bottom topography is to be expected.

  10. Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes.

    Science.gov (United States)

    Cooper, Ryan N; Wissel, Björn

    2012-11-27

    Salinity is restricting habitatability for many biota in prairie lakes due to limited physiological abilities to cope with increasing osmotic stress. Yet, it remains unclear how salinity effects vary among major taxonomic groups and what role other environmental parameters play in shaping food-web composition. To answer these questions, we sampled fish, zooplankton and littoral macroinvertebrates in 20 prairie lakes (Saskatchewan, Canada) characterized by large gradients in water chemistry and lake morphometry. We showed that salinity thresholds differed among major taxonomic groups, as most fishes were absent above salinities of 2 g L-1, while littoral macroinvertebrates were ubiquitous. Zooplankton occurred over the whole salinity range, but changed taxonomic composition as salinity increased. Subsequently, the complexity of fish community (diversity) was associated with large changes in invertebrate communities. The directional changes in invertebrate communities to smaller taxa indicated that complex fish assemblages resulted in higher predation pressure. Most likely, as the complexity of fish community decreased, controls of invertebrate assemblages shifted from predation to competition and ultimately to productivity in hypersaline lakes. Surprisingly, invertebrate predators did not thrive in the absence of fishes in these systems. Furthermore, the here identified salinity threshold for fishes was too low to be a result of osmotic stress. Hence, winterkill was likely an important factor eliminating fishes in low salinity lakes that had high productivity and shallow water depth. Ultimately, while salinity was crucial, intricate combinations of chemical and biological mechanisms also played a major role in controlling the assemblages of major taxonomic groups in prairie lakes.

  11. Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    Directory of Open Access Journals (Sweden)

    D. G. Wright

    2011-01-01

    Full Text Available Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models.

    First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies.

    Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol

  12. Environmental and zooplankton parameter changes during the drying of a saline shallow temporary lake in central Argentina

    Directory of Open Access Journals (Sweden)

    Alicia María Vignatti

    2017-09-01

    Full Text Available Central Argentina has numerous saline lakes sustained by groundwater sources and rainfall. These lakes are temporary and experience significant changes in water level and salinity, depending on wet and dry climate cycles. This study aims to investigate the scarcely known dynamics of environmental and zooplankton parameters during the drying phase of one of these lakes. Monthly samples were taken from December 2 012 to July 2 013 in the Ojo de Agua Uriburu lake, previous to its drying. At the beginning of the study, the lake’s depth was 0.7 m and its salinity was 16.65 g L−1, later, in July, its depth decreased to 0.06 m and its salinity increased to 92.9 g L−1. Zooplankton species richness was low (three crustaceans and three rotifers, with Boeckella poopoensis and Moina eugeniae dominating in the system. Maximum density and biomass were attained by the two dominant species in April (318.5 i nd L−1 and 3 029.1 µg L−1 dry weight; and 242.4 i nd L −1 and 1 530.4 µg L−1 dry weight, for B. poopoensis and M. ugeniae, respectively, and no correlation was found between these parameters and salinity. Maximum average body lengths for both species were observed in the last months of sampling (M. eugeniae: 1 020 ± 84.2 µm and B. poopoensis: 1 348.8 ± 89.0 µm. At this point of the study, neither juvenile nor larval stages were found. The increase in average body size is, arguably, the result of increased salinity in the system through a negative effect on reproduction. Because this lake reached hypersalinity, its ecological dynamics are unique among those of other temporary, saline lakes that dried in central Argentina. Similar studies on other temporary ecosystems are needed to increase the information on these little known ecological aspects.

  13. Effects of salinity and flooding on seedlings of cabbage palm (Sabal palmetto).

    Science.gov (United States)

    Perry, L; Williams, K

    1996-03-01

    Sabal palmetto (Walt.) Lodd. ex Schultes (cabbage palm) dominates the coastal limit of many forests in North Florida and Georgia, United States. Changes in saltwater flooding due to sea level rise have been credicted with pushing the coastal limit of cabbage palms inland, eliminating regeneration before causing death of mature trees. Localized freshwater discharge along the coast causes different forest stands to experience tidal flooding with waters that differ in salinity. To elucidate the effect of such variation on regeneration failure under tidal flooding, we examined relative effects of flooding and salinity on the performance of cabbage palm seedlings. We examined the relationship between seedling establishment and degree of tidal inundation in the field, compared the ability of seedlings to withstand tidal flooding at two coastal sites that differed in tidal water salinity, and investigated the physiological responses of cabbage palm seedlings to salinity and flooding in a factorial greenhouse experiment. Seedling survival was inversely correlated with depth and frequency of tidal flooding. Survival of seedlings at a coastal site flooded by waters low in salinity [c. 3 parts per thousand (ppt)] was greater than that at a site flooded by waters higher in salinity (up to 23 ppt). Greenhouse experiments revealed that leaves of seedlings in pots flushed twice daily with salt solutions of 0 ppt and 8 ppt exhibited little difference in midmorning net CO 2 assimilation rates; those flushed with solutions of 15 ppt and 22 ppt, in contrast, had such low rates that they could not be detected. Net CO 2 assimilation rates also declined with increasing salinity for seedlings in pots that were continuously inundated. Continuous root zone inundation appeared to ameliorate effects of salinity on photosynthesis, presumably due to increased salt concentrations and possibly water deficits in periodically flushed pots. Such problems associated with periodic flushing by salt

  14. Saline-water intrusion related to well construction in Lee County, Florida

    Science.gov (United States)

    Boggess, Durward Hoye; Missimer, T.M.; O'Donnell, T. H.

    1977-01-01

    Ground water is the principle source of water supply in Lee County, Florida where an estimated 30,000 wells have been drilled since 1990. These wells ranges in depth from about 10 to 1,240 feet and tap the water table aquifer or one or more of the artesian water-bearing units or zones in the Tamiami Formation, the upper part of the Hawthorn Formation, the lower part of the Hawthorn Formation and the Tampa Limestone and the Suwannee Limestone. Before 1968, nearly all wells were constructed with galvanized or black iron pipe. Many of these wells are sources of saline-water intrusion into freshwater-bearing zones. The water-bearing zones in the lower part of the Hawthorn Formation, Tampa Limestone, and Suwannee Limestone are artesian-they have higher water levels and usually contain water with a higher concentration of dissolved solids than do the aquifers occurring at shallower depths. The water from these deeper aquifers generally range in dissolved solids concentration from about 1,500 to 2,400 mg/L, and in chloride from about 500 to 1,00 mg/L. A maximum chloride concentration of 15,200 mg/L has been determined. Few of the 3,00 wells estimated to have been drilled to these zones contain sufficient casing to prevent upward flow into overlaying water-bearing zones. Because of water-level differentials, upward movement and lateral intrusion of saline water occurs principally into the upper part of the Hawthorn Formation where the chloride concentrations in water unaffected by saline-water intrusion ranges from about 80 to 150 mg/L. Where intrusion from deep artesian zones has occurred, the chloride concentration in water from the upper part of the Hawthorn Formation ranges from about 300 to more than 2,100 mg/L Surface discharges of the saline water from wells tapping the lower part of the Hawthorn Formation and the Suwannee Limestone also had affected the water-table aquifer which normally contains water with 10 to 50 mg/L of chloride. In one area, the chloride

  15. Solubility and diffusion coefficient of oxygen in silicon

    International Nuclear Information System (INIS)

    Itoh, Yoshiko; Nozaki, Tadashi

    1985-01-01

    The solubility and diffusion coefficient of oxygen in silicon between 1000 0 C and 1375 0 C were examined by charged particle activation analysis with the 16 O( 3 He,p) 18 F reaction, in which oxygen was activated with an equal probability over the depth of up to 250μm by a specially devised apparatus. Silicon wafers of known histories were heated in oxygen or argon for 12 to 473 hours, and the resultant oxygen depth profiles were determined by the activation, subsequent stepwise etching and 18 F activity measurement. The solubility thus obtained is given as 9.3 x 10 21 exp[-27.6kcal mol -1 /RT] at.cm -3 ; the diffusion coefficient has been found to be approximated as 3.2 exp[-67.1kcal mol -1 /RT] cm 2 s -1 over 1150 0 C, under which the apparent activation energy seems to decrease with decrease of temperature. (author)

  16. Effects of the amplitude and frequency of salinity fluctuations on antioxidant responses in juvenile tongue sole, Cynoglossus semilaevis

    Energy Technology Data Exchange (ETDEWEB)

    Khairnar, S.A.; Tian, X.; Dong, S.; Fang, Z.; Solanki, B.V.; Shanthanagouda, H.A.

    2016-11-01

    To understand the tolerance of tongue sole, Cynoglossus semilaevis, to varying salinities, the effects of the amplitude (2, 4, 6 and 8 g/L) and frequency (2, 4 and 8 days) of salinity fluctuations on the activities of antioxidant responses, including acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD) from antioxidant system in liver, muscle, gills and kidney were investigated in this study. The results showed that the antioxidant responses of tongue sole were highly tissue-specific during the varying salinity fluctuations. In all tissues, ACP and AKP activity was found to be highest at moderate salinity fluctuations compared to the control, low and high salinity treatments (p<0.05). SOD and CAT activities had significant effect due to salinity fluctuations in all tissues (p<0.05), except in hepatic and renal tissues. Variations in branchial SOD activity proved that salinity fluctuations had greater impact on tongue sole at moderate and high fluctuating salinities compared to the control and low fluctuating salinities, whereas the branchial CAT activities showed contrasting trend. Further, cortisol levels were significantly affected in lower and higher salinity fluctuations. However, plasma cortisol levels remained low in moderate salinity fluctuations and control (p<0.05). Taken together, the results indicated that salinity fluctuations could effectively stimulate and enhance the antioxidant enzyme activity in the liver, kidney, gills and muscle of the juvenile tongue sole, thus effectively eliminating the excessive reactive oxygen species and minimizing the body damage in tongue sole or could be for any other euryhaline teleosts. (Author)

  17. Hydrologic regulation of plant rooting depth.

    Science.gov (United States)

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

    2017-10-03

    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.

  18. 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.

  19. Soil and plant responses from land application of saline-sodic waters: Implications of management

    Energy Technology Data Exchange (ETDEWEB)

    Vance, G.F.; King, L.A.; Ganjegunte, G.K. [University of Wyoming, Laramie, WY (United States). Department for Renewable Resources

    2008-09-15

    Land application of co-produced waters from coalbed natural gas (CBNG) wells is one management option used in the Powder River Basin (PRB) of Wyoming and Montana. Unfortunately the co-produced CBNG waters may be saline and/or sodic. The objective of this study was to examine the effects of irrigation with CBNG waters on soils and plants in the PRB. Soil properties and vegetation responses resulting from 1 to 4 yr of saline sodic water (electrical conductivity (EC) 1.6-4.8 dS m{sup -1} sodium adsorption ratio (SAR), 17-57 mmol L- applications were studied during 2003 and 2004 field seasons on sites (Ustic Torriorthent Haplocambid, Haplargid and Paleargid) representing native range grasslands seeded grass hayfields and alfalfa hayfields. Parameters measured from each irrigated site were compared directly with representative non-irrigated sites. Soil chemical and physical parameters including pH, EC, SAR, exchangeable sodium percent, texture, bulk density, infiltration and Darcy flux rates, were measured at various depth intervals to 120 cm. Mulitple-year applications of saline sodic water produced consistent trends of increased soil EC AND SAR values to depths of 30 cm reduced surface infiltration rates and lowered Darcy flux rates to 120 cm. Significant differences (p {le} 0.05) were determined between irrigated and non-irrigated areas for EC, SAR infiltration rates and Darcy flux (p {le} 0.10) at most sites. Saline sodic CBNG water applications significantly increased native perennial grass biomass production and cover on irrigated as compared with non-irrigated sites; however overall species evenness decreased. Biological effects were variable and complex reflecting site-specific conditions and water and soil management strategies.

  20. Soil salinity under deficit drip irrigation of potato and millet in in an arid environment

    Directory of Open Access Journals (Sweden)

    Kamel Nagaz

    2017-06-01

    Full Text Available The influence of deficit irrigation (DI with saline water on soil salinity in a drip-irrigated potato and millet fields was investigated. We had compared proportional soil salinity developed under Full and DI under drip irrigation. For both experiments, the treatments were (1 Full, control treatment where rooting zone soil water content was increased to field capacity at each irrigation; (2 DI80; (3 DI60 and DI40; 20, 40 and 60% deficit irrigation compared to Full treatment were applied, respectively. Soil salinity was assessed using the isosalinity maps constructed with grid soil sampling of plant root zone at harvest. Results show that high spatial variability was observed in salinity along soil profiles when applying saline water with drip irrigation for potato. For the DI40 and DI60 treatments, high soil salinity was recorded in the upper soil layer close to the emitter. Increase of soil salinity within soil depths of 30 cm or below was also observed under DI60 and DI40 treatments. The lowest increase was noted under the full treatment. Surface soil salinity was somewhat higher under DI60 and DI40 compared with that of full and DI80 irrigation treatments. The distribution of salts around the dripper changes during the crop season according to applied irrigation treatments, with overall higher concentrations between the drippers and towards the margin of wetted band. Iso-salinity maps at harvest of potato showed that the surface layer of 30 cm depth had the lowest salinity which gradually increased at deeper zones irrespective of the treatment. Salt accumulation essentially occurred at wetting front between the drippers and the plant row. Although salt accumulation was relatively highest along the row under DI treatments, the area of accumulation was relatively shifted toward the center between the rows and the drip line. The results also show the importance of the potato cropping season to benefit from the leaching of soluble salts with the

  1. Mapping deep aquifer salinity trends in the southern San Joaquin Valley using borehole geophysical data constrained by chemical analyses

    Science.gov (United States)

    Gillespie, J.; Shimabukuro, D.; Stephens, M.; Chang, W. H.; Ball, L. B.; Everett, R.; Metzger, L.; Landon, M. K.

    2016-12-01

    The California State Water Resources Control Board and the California Division of Oil, Gas and Geothermal Resources are collaborating with the U.S. Geological Survey to map groundwater resources near oil fields and to assess potential interactions between oil and gas development and groundwater resources. Groundwater resources having salinity less than 10,000 mg/L total dissolved solids may be classified as Underground Sources of Drinking Water (USDW) and subject to protection under the federal Safe Drinking Water Act. In this study, we use information from oil well borehole geophysical logs, oilfield produced water and groundwater chemistry data, and three-dimensional geologic surfaces to map the spatial distribution of salinity in aquifers near oil fields. Salinity in the southern San Joaquin Valley is controlled primarily by depth and location. The base of protected waters occurs at very shallow depths, often 1,500 meters, in the eastern part of the San Joaquin Valley where higher runoff from the western slopes of the Sierra Nevada provide relatively abundant aquifer recharge. Stratigraphy acts as a secondary control on salinity within these broader areas. Formations deposited in non-marine environments are generally fresher than marine deposits. Layers isolated vertically between confining beds and cut off from recharge sources may be more saline than underlying aquifers that outcrop in upland areas on the edge of the valley with more direct connection to regional recharge areas. The role of faulting is more ambiguous. In some areas, abrupt changes in salinity may be fault controlled but, more commonly, the faults serve as traps separating oil-bearing strata that are exempt from USDW regulations, from water-bearing strata that are not exempt.

  2. Impact of water quality and irrigation management on soil salinization in the Drâa valley of Morocco.

    Science.gov (United States)

    Beff, L.; Descamps, C.; Dufey, J.; Bielders, C.

    2009-04-01

    Under the arid climatic conditions of the Drâa valley in southern Morocco, irrigation is essential for crop production. Two sources of water are available to farmers: (1) moderate salinity water from the Oued Drâa (classified as C3-S1 in the USDA irrigation water classification diagram) which is available only a few times per year following discrete releases from the Mansour Eddahbi dam, and (2) high salinity water from wells (C4-S2). Soil salinization is frequently observed, principally on plots irrigated with well water. As Oued water is available in insufficient amounts, strategies must be devised to use well and Oued water judiciously, without inducing severe salinization. The salinization risk under wheat production was evaluated using the HP1 program (Jacques and Šimůnek, 2005) for different combinations of the two main water sources, different irrigation frequencies and irrigation volumes. The soil was a sandy clay loam (topsoil) to sandy loam (40 cm depth). Soil hydrodynamic properties were derived from in situ measurements and lab measurements on undisturbed soil samples. The HP1 model was parameterized for wheat growth and 12 scenarios were run for 10 year periods using local climatic data. Water quality was measured or estimated on the basis of water samples in wells and various Oueds, and the soil chemical properties were determined. Depending on the scenario, soil salinity in the mean root zone increased from less than 1 meq/100g of soil to more than 5 meq/100g of soil over a ten year period. Salt accumulation was more pronounced at 45 cm soil depth, which is half of the maximum rooting depth, and when well water was preferentially used. Maximum crop yield (water transpired / potential water transpired) was achieved for five scenarios but this implied the use of well water to satisfy the crop water requirements. The usual Drâa Valley irrigation scenario, with five, 84 mm dam water applications per year, lead to a 25% yield loss. Adding the amount

  3. Hydrogen in oxygen-free, phosphorus-doped copper-Charging techniques, hydrogen contents and modelling of hydrogen diffusion and depth profile

    International Nuclear Information System (INIS)

    Martinsson, Aasa; Sandstroem, Rolf; Lilja, Christina

    2013-01-01

    In Sweden spent nuclear fuel is planned to be disposed of by encapsulating in cast iron inserts protected by a copper shell. The copper can be exposed to hydrogen released during corrosion processes in the inserts. If the hydrogen is taken up by the copper, it could lead to hydrogen embrittlement. Specimens from oxygen-free copper have been hydrogen charged using two different methods. The purpose was to investigate how hydrogen could be introduced into copper in a controlled way. The thermal charging method resulted in a reduction of the initial hydrogen content. After electrochemical charging of cylindrical specimens, the measured hydrogen content was 2.6 wt. ppm which should compared with 0.6 wt. ppm before charging. The retained hydrogen after two weeks was reduced by nearly 40%. Recently the paper 'Hydrogen depth profile in phosphorus-doped, oxygen-free copper after cathodic charging' (Martinsson and Sandstrom, 2012) has been published. The paper describes experimental results for bulk specimens as well as presenting a model. Almost all the hydrogen is found to be located less than 100 μm from the surface. This model is used to interpret the experimental results on foils in the present report. Since the model is fully based on fundamental equations, it can be used to analyse what happens in new situations. In this report the effect of the charging intensity, the grain size, the critical nucleus size for hydrogen bubble formation as well as the charging time are analysed

  4. Hydrogen in oxygen-free, phosphorus-doped copper - Charging techniques, hydrogen contents and modelling of hydrogen diffusion and depth profile

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Aasa [Swerea KIMAB, Kista (Sweden); Sandstroem, Rolf [Swerea KIMAB, Kista (Sweden); Div. of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm (Sweden); Lilja, Christina [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2013-01-15

    In Sweden spent nuclear fuel is planned to be disposed of by encapsulating in cast iron inserts protected by a copper shell. The copper can be exposed to hydrogen released during corrosion processes in the inserts. If the hydrogen is taken up by the copper, it could lead to hydrogen embrittlement. Specimens from oxygen-free copper have been hydrogen charged using two different methods. The purpose was to investigate how hydrogen could be introduced into copper in a controlled way. The thermal charging method resulted in a reduction of the initial hydrogen content. After electrochemical charging of cylindrical specimens, the measured hydrogen content was 2.6 wt. ppm which should compared with 0.6 wt. ppm before charging. The retained hydrogen after two weeks was reduced by nearly 40%. Recently the paper 'Hydrogen depth profile in phosphorus-doped, oxygen-free copper after cathodic charging' (Martinsson and Sandstrom, 2012) has been published. The paper describes experimental results for bulk specimens as well as presenting a model. Almost all the hydrogen is found to be located less than 100 {mu}m from the surface. This model is used to interpret the experimental results on foils in the present report. Since the model is fully based on fundamental equations, it can be used to analyse what happens in new situations. In this report the effect of the charging intensity, the grain size, the critical nucleus size for hydrogen bubble formation as well as the charging time are analysed.

  5. BAROMETRIC PRESSURE and Other Data from MOANA WAVE and Other Platforms From North Pacific Ocean from 19900103 to 19901220 (NODC Accession 9300148)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Depth, Salinity, dissolved Oxygen (CTD); and Ocean chemistry data collected in North Pacific Ocean between January 3, 1990 and December 20, 1990 during...

  6. Ultra-shallow arsenic implant depth profiling using low-energy nitrogen beams

    International Nuclear Information System (INIS)

    Fearn, Sarah; Chater, Richard; McPhail, David

    2004-01-01

    Sputtering of silicon by low-energy nitrogen primary ion beams has been studied by a number of authors to characterize the altered layer, ripple formation and the sputtered yields of secondary ions [Surf. Sci. 424 (1999) 299; Appl. Phys. A: Mater. Sci. Process 53 (1991) 179; Appl. Phys. Lett. 73 (1998) 1287]. This study examines the application of low-energy nitrogen primary ion beams for the possible depth profiling of ultra-shallow arsenic implants into silicon. The emphasis of this work is on the matrix silicon signals in the pre-equilibrium surface region that are used for dose calibration. Problems with these aspects of the concentration depth profiling can give significant inconsistencies well outside the error limits of the quoted dose for the arsenic implantation as independently verified by CV profiling. This occurs during depth profiling with either oxygen primary ion beams (with and without oxygen leaks) or cesium primary ion beams

  7. Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure.

    Science.gov (United States)

    Zhou, Bao-Chun; Liu, Li-Jun; Liu, Bing

    2016-09-01

    Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO 2 ) and oxygen partial pressure (PaO 2 ). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO 2 were measured. The controls were also examined for rSO 2 and PaO 2 , but received no treatment. rSO 2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO 2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

  8. Capability of microalgae for local saline sewage treatment towards biodiesel production

    Science.gov (United States)

    Wu, K.-C.; Yau, Y.-H.; Ho, K.-C.

    2017-08-01

    Seawater flushing was introduced in Hong Kong since 1950’s. High salinity has an inhibitory effect on nitrification and biological phosphorus uptake of microorganisms. Therefore, saline sewage has impact on traditional biological wastewater treatment. Saline conditions of domestic wastewater then pose opportunity to use algal technology in wastewater treatment. During the treatment (phycoremediation), biodiesel can be produced. This study aims to give an in-depth investigation and development on application of local microalgal strains on biodiesel production. Dunaliella tertiolecta was selected the appropriate algal species with high potential for phycoremediation then biodiesel production. D.tertiolecta was further investigated by optimizing its growth in different process condition in preliminary effluent as based medium. The optimized process condition were acclimated culture with medium initial cell number (5.0 ×105 cells mL-1), under 5% CO2 aerations in preliminary effluent adjust to 15 psu (denoting practical salinity unit). Results showed that lipid content increased from 30.2% to 42%, and biomass productivity reached 463.3 mg L-1day-1 by Fatty acid Methyl Ester (FAME) profile was found for biodiesel production in optimized stage. The treatment period of preliminary effluent was shortened from 15d in original design (unacclimated culture, low initial cell number (5.0 ×105 cells mL-1), without CO2 aeration) to 4d.

  9. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Directory of Open Access Journals (Sweden)

    W. A. Timms

    2012-04-01

    Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, potential evapotranspiration >2000 mm yr−1 such as parts of Australia's Murray-Darling Basin (MDB. In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m−1 with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low

  10. Hurricane Ingrid and Tropical Storm Hanna's effects on the salinity of the coastal aquifer, Quintana Roo, Mexico

    Science.gov (United States)

    Kovacs, Shawn E.; Reinhardt, Eduard G.; Stastna, Marek; Coutino, Aaron; Werner, Christopher; Collins, Shawn V.; Devos, Fred; Le Maillot, Christophe

    2017-08-01

    There is a lack of information on aquifer dynamics in anchialine systems, especially in the Yucatán Peninsula of Mexico. Most of our knowledge is based on ;spot; measurements of the aquifer with no long-term temporal monitoring. In this study spanning four years (2012-2016), sensors (water depth and conductivity (salinity)) were deployed and positioned (-9 and -10 m) in the meteoric Water Mass (WM) close to the transition with the marine WM (halocline) in 2 monitoring sites within the Yax Chen cave system to investigate precipitation effects on the salinity of the coastal aquifer. The results show variation in salinity (95 mm) such as Hurricane Ingrid (2013) and Tropical Storm Hanna (2014) shows meteoric water mass salinity rapidly increasing (approx. 6.39 to >8.6 ppt), but these perturbations have a shorter duration (weeks and days). Wavelet analysis of the salinity record indicates seasonal mixing effects in agreement with the wet and dry periods, but also seasonal effects of tidal mixing (meteoric and marine water masses) occurring on shorter time scales (diurnal and semi-diurnal). These results demonstrate that the salinity of the freshwater lens is influenced by precipitation and turbulent mixing with the marine WM. The salinity response is scaled with precipitation; larger more intense rainfall events (>95 mm) create a larger response in terms of the magnitude and duration of the salinity perturbation (>1 ppt). The balance of precipitation and its intensity controls the temporal and spatial patterning of meteoric WM salinity.

  11. Temperature and other data were collected using thermometer and bottle casts in the Chukchi and Bering Sea from 1947-02-11 to 1949-07-26 (NODC Accession 9700081)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, depth, oxygen, and salinity data were collected using thermometer and bottle casts from the USS CACOPAN, USS NEREUS, and HMCS CEDARWOOD in the Chukchi...

  12. The Diffusive Boundary-Layer of Sediments - Oxygen Microgradients Over a Microbial Mat

    DEFF Research Database (Denmark)

    JØRGENSEN, BB; MARAIS, DJD

    1990-01-01

    Oxygen microelectrodes were used to analyze the distribution of the diffusive boundary layer (DBL) at the sedimen-water interface in relation to surface topography and flow velocity. The sediment, collected from saline ponds, was covered by a microbial mat that had high oxygen consumption rate...... and well-defined surface structure. Diffusion through the DBL constituted an important rate limitation to the oxygen uptake of the sediment. The mean effective DBL thickness decreased from 0.59 to 0.16 mm as the flow velocity of the overlying water was increased from 0.3 to 7.7 cm s-1 (measured 1 cm above...

  13. A Method for Combined Retinal Vascular and Tissue Oxygen Tension Imaging.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Tan, Michael R; Blair, Norman P; Shahidi, Mahnaz

    2017-09-06

    The retina requires adequate oxygenation to maintain cellular metabolism and visual function. Inner retinal oxygen metabolism is directly related to retinal vascular oxygen tension (PO 2 ) and inner retinal oxygen extraction fraction (OEF), whereas outer retinal oxygen consumption (QO 2 ) relies on oxygen availability by the choroid and is contingent upon retinal tissue oxygen tension (tPO 2 ) gradients across the retinal depth. Thus far, these oxygenation and metabolic parameters have been measured independently by different techniques in separate animals, precluding a comprehensive and correlative assessment of retinal oxygenation and metabolism dynamics. The purpose of the current study is to report an innovative optical system for dual oxyphor phosphorescence lifetime imaging to near-simultaneously measure retinal vascular PO 2 and tPO 2 in rats. The use of a new oxyphor with different spectral characteristics allowed differentiation of phosphorescence signals from the retinal vasculature and tissue. Concurrent measurements of retinal arterial and venous PO 2 , tPO 2 through the retinal depth, inner retinal OEF, and outer retinal QO 2 were demonstrated, permitting a correlative assessment of retinal oxygenation and metabolism. Future application of this method can be used to investigate the relations among retinal oxygen content, extraction and metabolism under pathologic conditions and thus advance knowledge of retinal hypoxia pathophysiology.

  14. 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...

  15. Temperature, salinity, and oxygen profiles from CTD casts from the OCEANUS and other platforms from the North Atlantic Ocean as part of the International Decade of Ocean Exploration / International Ocean Studies / First Dynamic Response and Kinematics Experiment in the Drake Passage (IDOE/ISOS/FDRAKE) from 19 January 1983 to 17 May 1983 (NODC Accession 8600397)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and oxygen profiles were collected from CTD casts from the OCEANUS and other platforms in the North Atlantic Ocean from 19 January 1983 to 17...

  16. Using BOLD imaging to measure renal oxygenation dynamics in rats injected with diuretics

    International Nuclear Information System (INIS)

    Kusakabe, Yoshinori; Matsushita, Taro; Honda, Saori; Okada, Sakie; Murase, Kenya

    2010-01-01

    We used blood oxygenation level-dependent magnetic resonance imaging (BOLD MRI) to measure renal oxygenation dynamics in rats injected with diuretics and evaluated diuretic effect on renal oxygenation. We performed BOLD MRI studies in 32 rats using a 1.5-tesla MR imaging system for animal experiments. We intravenously injected rats with saline (n=7), furosemide (n=7), acetazolamide (n=6), or mannitol (n=6). For controls, 6 rats were not injected with drugs. We estimated the apparent transverse relaxation rate (R 2 *) from the apparent transverse relaxation time (T 2 *)-weighted images and measured the time course of R 2 * at 4-min intervals over approximately 30 min. Compared with preadministration values, the R 2 * value did not change significantly in either the cortex or medulla in the control and mannitol groups but decreased significantly in the saline group; the R 2 * value significantly decreased in the medulla but did not change significantly in the cortex in the furosemide group; and the R 2 * value significantly increased in the medulla and significantly decreased in the cortex in the acetazolamide group. Our study results suggest that BOLD MRI is useful for evaluating the dynamics of renal oxygenation in response to various diuretics in the renal cortex and in the medulla. (author)

  17. Metabolic Prosthesis for Oxygenation of Ischemic Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Elias [ORNL

    2009-01-01

    This communication discloses new ideas and preliminary results on the development of a "metabolic prosthesis" for local oxygenation of ischemic tissue under physiological neutral conditions. We report for the first time the selective electrolysis of physiological saline by repetitively pulsed charge-limited electrolysis for the production of oxygen and suppression of free chlorine. For example, using 800 A amplitude current pulses and <200 sec pulse durations, we demonstrated prompt oxygen production and delayed chlorine production at the surface of a shiny 0.85 mm diameter spherical platinum electrode. The data, interpreted in terms of the ionic structure of the electric double layer, suggest a strategy for in situ production of metabolic oxygen via a new class of "smart" prosthetic implants for dealing with ischemic disease such as diabetic retinopathy. We also present data indicating that drift of the local pH of the oxygenated environment can be held constant using a feedback-controlled three electrode electrolysis system that chooses anode and cathode pair based on pH data provided by local microsensors. The work is discussed in the context of diabetic retinopathy since surgical techniques for multielectrode prosthetic implants aimed at retinal degenerative diseases have been developed.

  18. Estuarine circulation reversals and related rapid changes in winter near-bottom oxygen conditions in the Gulf of Finland, Baltic Sea

    Directory of Open Access Journals (Sweden)

    T. Liblik

    2013-10-01

    Full Text Available The reversal of estuarine circulation caused by southwesterly wind forcing may lead to vanishing of stratification and subsequently to oxygenation of deep layers during the winter in the Gulf of Finland. Six conductivity, temperature, depth (CTD+oxygen transects (130 km long, 10 stations were conducted along the thalweg from the western boundary to the central gulf (21 December 2011–8 May 2012. Two bottom-mounted ADCP were installed, one near the western border and the second in the central gulf. A CTD with a dissolved oxygen sensor was deployed close to the western ADCP. Periods of typical estuarine circulation were characterized by strong stratification, high salinity, hypoxic conditions and inflow to the gulf in the near-bottom layer. Two circulation reversals were observed: one in December–January and one in February. The first reversal event was well developed; it caused the disappearance of the stratification and an increase in the oxygen concentration from hypoxic values to 270 μmol L−1 (to 6 mL L−1 throughout the water column along the thalweg and lasted approximately 1.5 months. Shifts from estuarine circulation to reversed circulation and vice versa were both associated with strong longitudinal (east–west gulf currents (up to 40 cm s−1 in the deep layer. The change from oxygenated to hypoxic conditions in the western near-entrance area of the gulf occurred very rapidly, within less than a day, due to the intrusion of the hypoxic salt wedge from the NE Baltic Proper. In the eastern part of the gulf, good oxygen conditions caused by reversals remained for a few months.

  19. Morpho-physiological response of Acacia auriculiformis as influenced by seawater induced salinity stress

    Energy Technology Data Exchange (ETDEWEB)

    Haque, A.; Rahman, M.; Nihad, S.A.I.; Howlader, R.A.; Akand, M.H.

    2016-07-01

    Aim of the study: To evaluate the morpho-physiological changes of Acacia auriculiformis in response to seawater induced salinity stress along with its tolerance limit. Area of study: Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh. Material and methods: Three saline treatments (4, 8, 12 dS m-1) were applied to six-month aged Acacia auriculiformis seedlings from January 2014 to June 2014 and the tap water was used as control treatment. To observe salinity effects, the following parameters were measured by using various established techniques: plant height and leaf number, plant biomass, shoot and root distribution as well as shoot and root density, water uptake capacity (WUC), water saturation deficit (WSD) and water retention capacity (WRC), exudation rate, and cell membrane stability. Main results: Diluted seawater caused a notable reduction in shoot and root distribution in addition to shoot and root density, though plant height, leaf number and plant biomass were found to be decreased to some extent compared to control plants. Water status of the plant also altered when plants were subjected to salinity stress. Nevertheless, membrane stability revealed good findings towards salinity tolerance. Research highlights: Considering the above facts, despite salinity exerts some negative effects on overall plant performance, interestingly the percent reduction value doesn’t exceed 50% as compared to control plants, and the plants were successful to tolerate salinity stress till the end of the experiment (150 days) through adopting some tolerance mechanisms. Abbreviations used: BSMRAU (Bangabandhu Sheikh Mujibur Rahman Agricultural University); RCBD (randomized complete block design); DATI (days after treatment imposition); RWC (relative water content); WUC (water uptake capacity); WSD (water saturation deficit); WRC (water retention capacity); FW (fresh weight); DW (dry weight); TW (turgid weight); ROS (reactive oxygen species). (Author)

  20. Rapid estimation of aquifer salinity structure from oil and gas geophysical logs

    Science.gov (United States)

    Shimabukuro, D.; Stephens, M.; Ducart, A.; Skinner, S. M.

    2016-12-01

    We describe a workflow for creating aquifer salinity maps using Archie's equation for areas that have geophysical data from oil and gas wells. We apply this method in California, where geophysical logs are available in raster format from the Division of Oil, Gas, and Geothermal Resource (DOGGR) online archive. This method should be applicable to any region where geophysical logs are readily available. Much of the work is controlled by computer code, allowing salinity estimates for new areas to be rapidly generated. For a region of interest, the DOGGR online database is scraped for wells that were logged with multi-tool suites, such as the Platform Express or Triple Combination Logging Tools. Then, well construction metadata, such as measured depth, spud date, and well orientation, is attached. The resultant local database allows a weighted criteria selection of wells that are most likely to have the shallow resistivity, deep resistivity, and density porosity measurements necessary to calculate salinity over the longest depth interval. The algorithm can be adjusted for geophysical log availability for older well fields and density of sampling. Once priority wells are identified, a student researcher team uses Neuralog software to digitize the raster geophysical logs. Total dissolved solid (TDS) concentration is then calculated in clean, wet sand intervals using the resistivity-porosity method, a modified form of Archie's equation. These sand intervals are automatically selected using a combination of spontaneous potential and the difference in shallow resistivity and deep resistivity measurements. Gamma ray logs are not used because arkosic sands common in California make it difficult to distinguish sand and shale. Computer calculation allows easy adjustment of Archie's parameters. The result is a semi-continuous TDS profile for the wells of interest. These profiles are combined and contoured using standard 3-d visualization software to yield preliminary salinity

  1. BAROMETRIC PRESSURE and Other Data from XIANG YANG HONG 09 and Other Platforms (NODC Accession 9400159)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The depth, temperature, salinity, and oxygen data in this accession were provided by the Chinese National Oceanographic Data Center during 4th meeting of US/PRC...

  2. PHYSIOLOGICAL AND BIOCHEMICAL MARKERS OF SALINITY TOLERANCE IN PLANTS

    Directory of Open Access Journals (Sweden)

    Mustafa YILDIZ

    2011-02-01

    Full Text Available Salt stress limits plant productivity in arid and semi arid regions. Salt stress causes decrease in plant growth by adversely affecting physiological processes, especially photosynthesis. Salinity tolerance is defined as the ability of plant to maintain normal rowth and development under salt conditions. Salt stress results in accumulation of low molecular weight compounds, termed compatible solutes, which do not interfere with the normal biochemical reactions. These compatible solutes such as carbohydrates, polyols, amino acids and amides, quaternary ammonium compounds, polyamines andsoluble proteins may play a crucial role in osmotic adjustment, protection of macromolecules, maintenance of cellular pH and detoxification of free radicals. On the other hand, plants subjected to environmental stresses such as salinity produce reactive oxygen species (ROS and these ROS are efficiently eliminated by antioxidant enzyme systems. In plant breeding studies, the use of some physiological and biochemical markers for improving the salt tolerance in plants is crucial. In this review, the possibility of using some physiological and biochemical markers as selection criteria for salt tolerance is discussed.

  3. Salinity and sodicity of weathered minesoils in Northwestern New Mexico and Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Musslewhite, B.D.; Vinson, J.R.; Johnston, C.R.; Brown, T.H.; Wendt, G.W.; Vance, G.F. [BHP Billiton, Farmington, NM (United States). New Mexico Coal

    2009-05-15

    Evolving relationships between electrical conductivity (EC) and sodium adsorption ratio (SAR) in reconstructed soils at surface mines have been insufficiently documented in the literature. Some minesoils (i.e., rootzone material) are classified as saline, sodic, or saline-sodic and are considered unsuitable for revegetation. Weatherable minerals such as calcite and gypsum are common in alkaline minesoils and on dissolution tend to mitigate elevated SAR levels by maintaining or increasing electrolytes in the soil and providing sources of exchangeable calcium and magnesium. Topsoils (i.e., coversoils) contribute to mitigation of sodic conditions when soluble cations are translocated from coversoils into the underlying minesoils. This study evaluated the weathering characteristics of minesoils sites from three surface coal mines in northwestern New Mexico and northeastern Arizona. Minesoils were grouped into 11 classes based on EC and SAR. After 6 to 14 yr, differences between upper and lower halves of the coversoils suggest general increases occurred with EC, SAR, chloride (Cl{sup -}), and sulfate (SO{sub 4}{sup 2-}) with depth. Within the reclaimed minesoils, there were several significant (P < 0.05 or < 0.10) relationships among EC and SAR that related to Minesoil Class. Lower SAR levels with corresponding increases in EC compared to baseline minesoils were more apparent in upper minesoil depths (0-5 and 5-15 cm). Minesoil anion concentrations suggested coversoil leachates and gypsum dissolution influenced EC and SAR chemistry. Over time, chemical changes have increased the apparent stability of the saline and sodic reclaimed minesoils studied thereby reducing risks associated with potential aggregate slaking and clay particle dispersion.

  4. NODC Standard Product: International ocean atlas Volume 12 - Climatic atlas of the North Pacific Seas 2009 (NODC Accession 0098576)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Atlas contains monthly climatic charts of temperature, salinity, and oxygen at the sea surface and at standard depth levels for the Bering Sea, Sea of Okhotsk,...

  5. The distribution and origins of extremely acidic saline groundwaters in the south of Western Australia - Groundwater and digital mapping datasets provide new insights

    Science.gov (United States)

    Lillicrap, Adam M.; Biermann, Vera; George, Richard J.; Gray, David J.; Oldham, Carolyn E.

    2018-01-01

    Some of the largest extents of naturally occurring acidic waters are found across southern Australia. The origins of these systems remain poorly understood with many hypotheses for their genesis. Australian government agency groundwater datasets and mapping data (vegetation, geology, regolith and soils) for south-western Australia, unavailable to previous researchers, were statistically analysed to better understand the origins of acidic groundwater and guide additional fieldwork to study the origins of acidic saline groundwater. The groundwater data showed a distinct bimodal distribution in pH; the 'acid' population had a median pH of 3.5 and the larger 'non-acid' population had a median pH of 6.6. Acidic groundwater became progressively more common further from the coast towards the drier internally drained regions. Acidic groundwater was mostly confined to the lower slopes and valley floors with localised controls on distribution. Paradoxically, subsoil alkalinity within the internally drained inland regions had the strongest correlation with acidic groundwater (r2 = 0.85). Vegetation was also a strong predictor of acidic groundwater. Acidic groundwater had the highest occurrence under Eucalyptus woodlands and shrublands that grew on alkaline calcareous soils. Pre-clearing soil data in areas with acidic saline groundwater showed that the upper 1 m of the unsaturated zone had a pH around 8 while the pH at depths greater than 5 m decreased to calcium is sourced from the deeper profile where the root biota exchanges calcium for hydrogen ions to maintain charge balance. Iron is mobilised from the upper soil profile and concentrates lower in the profile at depths >1.5 m. There, the iron is reduced around roots and the alkalinity generated by microbial iron reduction is removed by biogenic calcification processes. The iron moves in solution further down the profile following roots where it comes in contact with the oxygenated unsaturated zone matrix and is oxidised

  6. 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...

  7. 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...

  8. Salinity altered root distribution and increased diversity of bacterial communities in the rhizosphere soil of Jerusalem artichoke

    Science.gov (United States)

    Yang, Hui; Hu, Jinxiang; Long, Xiaohua; Liu, Zhaopu; Rengel, Zed

    2016-02-01

    The interaction between roots and bacterial communities in halophytic species is poorly understood. Here, we used Jerusalem artichoke cultivar Nanyu 1 (NY-1) to characterise root distribution patterns and determine diversity and abundance of bacteria in the rhizosphere soil under variable salinity. Root growth was not inhibited within the salinity range 1.2 to 1.9 g salt/kg, but roots were mainly confined to 0-20 cm soil layer vertically and 0-30 cm horizontally from the plant centre. Root concentrations of K+, Na+, Mg2+ and particularly Ca2+ were relatively high under salinity stress. High salinity stress decreased soil invertase and catalase activity. Using a next-generation, Illumina-based sequencing approach, we determined higher diversity of bacteria in the rhizosphere soil at high than low salinity. More than 15,500 valid reads were obtained, and Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria predominated in all samples, accounting for >80% of the reads. On a genus level, 636 genera were common to the low and high salinity treatments at 0-5 cm and 5-10 cm depth. The abundance of Steroidobacter and Sphingomonas was significantly decreased by increasing salinity. Higher Shannon and Chao 1 indices with increasing severity of salt stress indicated that high salt stress increased diversity in the bacterial communities.

  9. Short-Term Exposure of Mytilus coruscus to Decreased pH and Salinity Change Impacts Immune Parameters of Their Haemocytes.

    Science.gov (United States)

    Wu, Fangli; Xie, Zhe; Lan, Yawen; Dupont, Sam; Sun, Meng; Cui, Shuaikang; Huang, Xizhi; Huang, Wei; Liu, Liping; Hu, Menghong; Lu, Weiqun; Wang, Youji

    2018-01-01

    With the release of large amounts of CO 2 , ocean acidification is intensifying and affecting aquatic organisms. In addition, salinity also plays an important role for marine organisms and fluctuates greatly in estuarine and coastal ecosystem, where ocean acidification frequently occurs. In present study, flow cytometry was used to investigate immune parameters of haemocytes in the thick shell mussel Mytilus coruscus exposed to different salinities (15, 25, and 35‰) and two pH levels (7.3 and 8.1). A 7-day in vivo and a 5-h in vitro experiments were performed. In both experiments, low pH had significant effects on all tested immune parameters. When exposed to decreased pH, total haemocyte count (THC), phagocytosis (Pha), esterase (Est), and lysosomal content (Lyso) were significantly decreased, whereas haemocyte mortality (HM) and reactive oxygen species (ROS) were increased. High salinity had no significant effects on the immune parameters of haemocytes as compared with low salinity. However, an interaction between pH and salinity was observed in both experiments for most tested haemocyte parameters. This study showed that high salinity, low salinity and low pH have negative and interactive effects on haemocytes of mussels. As a consequence, it can be expected that the combined effect of low pH and changed salinity will have more severe effects on mussel health than predicted by single exposure.

  10. Saline groundwater in crystalline bedrock

    International Nuclear Information System (INIS)

    Lampen, P.

    1992-11-01

    The State-of-art report describes research made on deep saline groundwaters and brines found in crystalline bedrock, mainly in site studies for nuclear waste disposal. The occurrence, definitions and classifications of saline groundwaters are reviewed with a special emphasis on the different theories concerning the origins of saline groundwaters. Studies of the saline groundwaters in Finland and Sweden have been reviewed more thoroughly. Also the mixing of different bodies of groundwaters, observations of the contact of saline groundwaters and permafrost, and the geochemical modelling of saline groundwaters as well as the future trends of research have been discussed. (orig.)

  11. Spatio-temporal impacts of dairy lagoon water reuse on soil: heavy metals and salinity.

    Science.gov (United States)

    Corwin, Dennis L; Ahmad, Hamaad Raza

    2015-10-01

    Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. The spatial impact and sustainability of dairy lagoon water reuse from concentrated animal feeding operations (CAFOs) has not been evaluated at field scale. The objective of this study is to monitor the impact of dairy lagoon water blended with recycled water on a 32 ha field near San Jacinto, CA from 2007 to 2011. Spatial monitoring was based on soil samples collected at locations identified from apparent soil electrical conductivity (ECa) directed sampling. Soil samples were taken at depth increments of 0-0.15, 0.15-0.3, 0.3-0.6, 0.6-0.9, 0.9-1.2, 1.2-1.5, and 1.5-1.8 m at 28 sample sites on 7-11 May 2007 and again on 31 May - 2 June 2011 after 4 years of irrigation with the blended waters. Chemical analyses included salinity (electrical conductivity of the saturation extract, ECe), pHe (pH of the saturation extract), SAR (sodium adsorption ratio), trace elements (As, B, Mo, Se), and heavy metals (Cd, Cu, Mn, Ni, Zn). Results indicate a decrease in mean values of pHe at all depth increments; a decrease in ECe and SAR above a depth of 0.15 m, but an increase below 0.15 m; a decrease in all trace elements except B, which increased throughout the 1.8 m profile; and the accumulation of Cd, Mn, and Ni at all depth increments, while Cu was readily leached from the 1.8 m profile. Zinc showed little change. The results focused concern on the potential long-term agronomic effect of salinity, SAR, and B, and the long-term environmental threat of salinity and Cu to detrimentally impact groundwater. The accumulation of Cd, Mn, and Ni in the soil profile raised concern since it provided a potential future source of metals for leaching. The long-term sustainability of dairy lagoon water reuse hinges on regular monitoring to provide spatial feedback for site-specific management.

  12. Salinity-Induced Palmella Formation Mechanism in Halotolerant Algae Dunaliella salina Revealed by Quantitative Proteomics and Phosphoproteomics

    Directory of Open Access Journals (Sweden)

    Sijia Wei

    2017-05-01

    Full Text Available Palmella stage is critical for some unicellular algae to survive in extreme environments. The halotolerant algae Dunaliella salina is a good single-cell model for studying plant adaptation to high salinity. To investigate the molecular adaptation mechanism in salinity shock-induced palmella formation, we performed a comprehensive physiological, proteomics and phosphoproteomics study upon palmella formation of D. salina using dimethyl labeling and Ti4+-immobilized metal ion affinity chromatography (IMAC proteomic approaches. We found that 151 salinity-responsive proteins and 35 salinity-responsive phosphoproteins were involved in multiple signaling and metabolic pathways upon palmella formation. Taken together with photosynthetic parameters and enzyme activity analyses, the patterns of protein accumulation and phosphorylation level exhibited the mechanisms upon palmella formation, including dynamics of cytoskeleton and cell membrane curvature, accumulation and transport of exopolysaccharides, photosynthesis and energy supplying (i.e., photosystem II stability and activity, cyclic electron transport, and C4 pathway, nuclear/chloroplastic gene expression regulation and protein processing, reactive oxygen species homeostasis, and salt signaling transduction. The salinity-responsive protein–protein interaction (PPI networks implied that signaling and protein synthesis and fate are crucial for modulation of these processes. Importantly, the 3D structure of phosphoprotein clearly indicated that the phosphorylation sites of eight proteins were localized in the region of function domain.

  13. Evaluating management-induced soil salinization in golf courses in semi-arid landscapes

    Science.gov (United States)

    Young, J.; Udeigwe, T. K.; Weindorf, D. C.; Kandakji, T.; Gautam, P.; Mahmoud, M. A.

    2015-04-01

    Site-specific information on land management practices are often desired to make better assessments of their environmental impacts. A study was conducted in Lubbock, Texas, in the Southern High Plains of the United States, an area characterized by semi-arid climatic conditions, to (1) examine the potential management-induced alterations in soil salinity indicators in golf course facilities and (2) develop predictive relationships for a more rapid soil salinity examination within these urban landscape soils using findings from a portable X-ray fluorescence (PXRF) spectrometer. Soil samples were collected from managed (well irrigated) and non-managed (non-irrigated) areas of seven golf course facilities at 0-10, 10-20, and 20-30 cm depths and analyzed for a suite of chemical properties. Among the extractable cations, sodium (Na) was significantly (p golf facilities. Soil electrical conductivity (EC), exchangeable sodium percentage (ESP), and sodium adsorption ratio (SAR), parameters often used in characterizing soil salinity and sodicity, were for the most part significantly (p < 0.05) higher in the managed areas. Water quality reports collected over a 22-year period (1991-2013, all years not available) indicated a gradual increase in pH, EC, SAR, total alkalinity, and extractable ions, thus supporting the former findings. Findings from the PXRF suggested possible differences in chemical species and sources that contribute to salinity between the managed and non-managed zones. PXRF-quantified Cl and S, and to a lesser extent Ca, individually and collectively explained 23-85% of the variability associated with soil salinity at these facilities.

  14. Impact of hydrogeological factors on groundwater salinization due to ocean-surge inundation

    Science.gov (United States)

    Yang, Jie; Zhang, Huichen; Yu, Xuan; Graf, Thomas; Michael, Holly A.

    2018-01-01

    Ocean surges cause seawater inundation of coastal inland areas. Subsequently, seawater infiltrates into coastal aquifers and threatens the fresh groundwater resource. The severity of resulting salinization can be affected by hydrogeological factors including aquifer properties and hydrologic conditions, however, little research has been done to assess these effects. To understand the impacts of hydrogeological factors on groundwater salinization, we numerically simulated an ocean-surge inundation event on a two-dimensional conceptual coastal aquifer using a coupled surface-subsurface approach. We varied model permeability (including anisotropy), inland hydraulic gradient, and recharge rate. Three salinization-assessment indicators were developed, based on flushing time, depth of salt penetration, and a combination of the two, weighted flushing time, with which the impact of hydrogeological factors on groundwater vulnerability to salinization were quantitatively assessed. The vulnerability of coastal aquifers increases with increasing isotropic permeability. Low horizontal permeability (kx) and high vertical permeability (kz) lead to high aquifer vulnerability, and high kx and low kz lead to low aquifer vulnerability. Vulnerability decreases with increasing groundwater hydraulic gradient and increasing recharge rate. Additionally, coastal aquifers with a low recharge rate (R ≤ 300 mm yr-1) may be highly vulnerable to ocean-surge inundation. This study shows how the newly introduced indicators can be used to quantitatively assess coastal aquifer vulnerability. The results are important for global vulnerability assessment of coastal aquifers to ocean-surge inundation.

  15. Hydrologic Regulation of Plant Rooting Depth and Vice Versa

    Science.gov (United States)

    Fan, Y.; Miguez-Macho, G.

    2017-12-01

    How deep plant roots go and why may hold the answer to several questions regarding the co-evolution of terrestrial life and its environment. In this talk we explore how plant rooting depth responds to the hydrologic plumbing system in the soil/regolith/bedrocks, and vice versa. Through analyzing 2200 root observations of >1000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients, we found 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 groundwater capillary fringe. We explore the global significance of this framework using an inverse model, and the implications to the coevolution of deep roots and the CZ in the Early-Mid Devonian when plants colonized the upland environments.

  16. Hydrogeologic framework and salinity distribution of the Floridan aquifer system of Broward County, Florida

    Science.gov (United States)

    Reese, Ronald S.; Cunningham, Kevin J.

    2014-01-01

    Concerns about water-level decline and seawater intrusion in the surficial Biscayne aquifer, currently the principal source of water supply to Broward County, prompted a study to refine the hydrogeologic framework of the underlying Floridan aquifer system to evaluate its potential as an alternative source of supply. This report presents cross sections that illustrate the stratigraphy and hydrogeology in eastern Broward County; maps of the upper surfaces and thicknesses of several geologic formations or units within the Floridan aquifer system; and maps of two of the potentially productive water-bearing zones within the system, the Upper Floridan aquifer and the Avon Park permeable zone. An analysis of data on rock depositional textures, associated pore networks, and flow zones in the Floridan aquifer system shows that groundwater moves through the system in two ways. These data support a conceptual, dual-porosity model of the system wherein groundwater moves either as concentrated flow in discrete, thin bedding-plane vugs or zones of vuggy megaporosity, or as diffuse flow through rocks with primarily interparticle and moldic-particle porosity. Because considerable exchange of groundwater may occur between the zones of vuggy and matrix-dominated porosity, understanding the distribution of that porosity and flow zone types is important to evaluating the suitability of the several units within the Floridan aquifer system for managing the water through practices such as aquifer storage and recovery (ASR). The salinity of the water in the Floridan aquifer system is highest in the central part of the study area, and lower toward the north and south. Although salinity generally increases with depth, in the western part of the study area a zone of relatively high saline water is perched above water of lower salinity in the underlying Avon Park permeable zone. Overall, the areas of highest salinity in the aquifer system coincide with those with the lowest estimated

  17. Oceanographic influences on the distribution of Baltic cod, Gadus morhua , during spawning in the Bornholm Basin of the Baltic Sea

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Lehmann, K.M.; St. John, Michael

    1998-01-01

    proportion of males to females. On the basin slopes, aggregations of cod were found near the bottom. These individuals were mainly immature and maturing stages with an increasing proportion of females to males with size. Salinity and oxygen conditions were found to be the major factors influencing...... the vertical and horizontal distribution of adult cod. Abundance of immature cod was also positively related to decreasing bottom depths. The effect of temperature was minor. The observed size- and sex-dependent spawning aggregation patterns, in association with habitat volume and stock size, may influence cod......The Baltic Sea is a stratified, semi-enclosed sea typified by a low-salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing...

  18. FRESHEM - Fresh-saline groundwater distribution in Zeeland (NL) derived from airborne EM

    Science.gov (United States)

    Siemon, Bernhard; van Baaren, Esther; Dabekaussen, Willem; Delsman, Joost; Gunnik, Jan; Karaoulis, Marios; de Louw, Perry; Oude Essink, Gualbert; Pauw, Pieter; Steuer, Annika; Meyer, Uwe

    2017-04-01

    In a setting of predominantly saline surface waters, the availability of fresh water for agricultural purposes is not obvious in Zeeland, The Netherlands. Canals and ditches are mainly brackish to saline due to saline seepage, which originates from old marine deposits and salt-water transgressions during historical times. The only available fresh groundwater is present in the form of freshwater lenses floating on top of the saline groundwater. This fresh groundwater is vital for agricultural, industrial, ecological, water conservation and drinking water functions. An essential first step for managing this fresh groundwater properly is to know the present spatial fresh-brackish-saline groundwater distribution. As traditional salinity monitoring is labour-intensive, airborne electromagnetics (AEM), which is fast and can cover large areas in short time, is an efficient alternative. A consortium of BGR, Deltares and TNO started FRESHEM Zeeland (FREsh Salt groundwater distribution by Helicopter ElectroMagnetic survey in the Province of Zeeland) in October 2014. Within 3x2 weeks of the first project year, the entire area of about 2000 km2 was surveyed using BGR's helicopter-borne geophysical system totalling to about 10,000 line-km. The HEM datasets of 17 subareas were carefully processed using advanced BGR in-house software and inverted to 2.5 Million resistivity-depth models. Ground truthing demonstrated that the large-scale HEM results fit very well with small-scale ground EM data (ECPT). Based on this spatial resistivity distribution, a 3D voxel model for Chloride concentration was derived for the entire province taking into account geological model data (GeoTOP) for the lithology correction and local in-situ groundwater measurements for the translation of water conductivity to Chloride concentration. The 3D voxel model enables stakeholders to implement spatial Chloride concentration in their groundwater models.

  19. Temperature Dependence of Apparent Respiratory Quotients and Oxygen Penetration Depth in Contrasting Lake Sediments

    Science.gov (United States)

    Sobek, Sebastian; Gudasz, Cristian; Koehler, Birgit; Tranvik, Lars J.; Bastviken, David; Morales-Pineda, María.

    2017-11-01

    Lake sediments constitute an important compartment in the carbon cycle of lakes, by burying carbon over geological timescales and by production and emission of greenhouse gases. The degradation of organic carbon (OC) in lake sediments is linked to both temperature and oxygen (O2), but the interactive nature of this regulation has not been studied in lake sediments in a quantitative way. We present the first systematic investigation of the effects of temperature on the apparent respiratory quotient (RQ, i.e., the molar ratio between carbon dioxide (CO2) production and O2 consumption) in two contrasting lake sediments. Laboratory incubations of sediment cores of a humic lake and an eutrophic lake across a 1-21°C temperature gradient over 157 days revealed that both CO2 production and O2 consumption were positively, exponentially, and similarly dependent on temperature. The apparent RQ differed significantly between the lake sediments (0.63 ± 0.26 and 0.99 ± 0.28 in the humic and the eutrophic lake, respectively; mean ± SD) and was significantly and positively related to temperature. The O2 penetration depth into the sediment varied by a factor of 2 over the 1-21°C temperature range and was significantly, negatively, and similarly related to temperature in both lake sediments. Accordingly, increasing temperature may influence the overall extent of OC degradation in lake sediments by limiting O2 supply to aerobic microbial respiration to the topmost sediment layer, resulting in a concomitant shift to less effective anaerobic degradation pathways. This suggests that temperature may represent a key controlling factor of the OC burial efficiency in lake sediments.

  20. Hypertonic Saline Suppresses NADPH Oxidase-Dependent Neutrophil Extracellular Trap Formation and Promotes Apoptosis

    Directory of Open Access Journals (Sweden)

    Ajantha Nadesalingam

    2018-03-01

    Full Text Available Tonicity of saline (NaCl is important in regulating cellular functions and homeostasis. Hypertonic saline is administered to treat many inflammatory diseases, including cystic fibrosis. Excess neutrophil extracellular trap (NET formation, or NETosis, is associated with many pathological conditions including chronic inflammation. Despite the known therapeutic benefits of hypertonic saline, its underlying mechanisms are not clearly understood. Therefore, we aimed to elucidate the effects of hypertonic saline in modulating NETosis. For this purpose, we purified human neutrophils and induced NETosis using agonists such as diacylglycerol mimetic phorbol myristate acetate (PMA, Gram-negative bacterial cell wall component lipopolysaccharide (LPS, calcium ionophores (A23187 and ionomycin from Streptomyces conglobatus, and bacteria (Pseudomonas aeruginosa and Staphylococcus aureus. We then analyzed neutrophils and NETs using Sytox green assay, immunostaining of NET components and apoptosis markers, confocal microscopy, and pH sensing reagents. This study found that hypertonic NaCl suppresses nicotinamide adenine dinucleotide phosphate oxidase (NADPH2 or NOX2-dependent NETosis induced by agonists PMA, Escherichia coli LPS (0111:B4 and O128:B12, and P. aeruginosa. Hypertonic saline also suppresses LPS- and PMA- induced reactive oxygen species production. It was determined that supplementing H2O2 reverses the suppressive effect of hypertonic saline on NOX2-dependent NETosis. Many of the aforementioned suppressive effects were observed in the presence of equimolar concentrations of choline chloride and osmolytes (d-mannitol and d-sorbitol. This suggests that the mechanism by which hypertonic saline suppresses NOX2-dependent NETosis is via neutrophil dehydration. Hypertonic NaCl does not significantly alter the intracellular pH of neutrophils. We found that hypertonic NaCl induces apoptosis while suppressing NOX2-dependent NETosis. In contrast, hypertonic

  1. Decadal oxygen change in the eastern tropical North Atlantic

    Directory of Open Access Journals (Sweden)

    J. Hahn

    2017-07-01

    Full Text Available Repeat shipboard and multi-year moored observations obtained in the oxygen minimum zone (OMZ of the eastern tropical North Atlantic (ETNA were used to study the decadal change in oxygen for the period 2006–2015. Along 23° W between 6 and 14° N, oxygen decreased with a rate of −5.9 ± 3.5 µmol kg−1 decade−1 within the depth covering the deep oxycline (200–400 m, while below the OMZ core (400–1000 m oxygen increased by 4.0 ± 1.6 µmol kg−1 decade−1 on average. The inclusion of these decadal oxygen trends in the recently estimated oxygen budget for the ETNA OMZ suggests a weakened ventilation of the upper 400 m, whereas the ventilation strengthened homogeneously below 400 m. The changed ventilation resulted in a shoaling of the ETNA OMZ of −0.03 ± 0.02 kg m−3 decade−1 in density space, which was only partly compensated by a deepening of isopycnal surfaces, thus pointing to a shoaling of the OMZ in depth space as well (−22 ± 17 m decade−1. Based on the improved oxygen budget, possible causes for the changed ventilation are analyzed and discussed. Largely ruling out other ventilation processes, the zonal advective oxygen supply stands out as the most probable budget term responsible for the decadal oxygen changes.

  2. Photoacoustic Imaging in Oxygen Detection

    Directory of Open Access Journals (Sweden)

    Fei Cao

    2017-12-01

    Full Text Available Oxygen level, including blood oxygen saturation (sO2 and tissue oxygen partial pressure (pO2, are crucial physiological parameters in life science. This paper reviews the importance of these two parameters and the detection methods for them, focusing on the application of photoacoustic imaging in this scenario. sO2 is traditionally detected with optical spectra-based methods, and has recently been proven uniquely efficient by using photoacoustic methods. pO2, on the other hand, is typically detected by PET, MRI, or pure optical approaches, yet with limited spatial resolution, imaging frame rate, or penetration depth. Great potential has also been demonstrated by employing photoacoustic imaging to overcome the existing limitations of the aforementioned techniques.

  3. The effect of hyperbaric oxygen treatment on aspiration pneumonia.

    Science.gov (United States)

    Sahin, Sevtap Hekimoglu; Kanter, Mehmet; Ayvaz, Suleyman; Colak, Alkin; Aksu, Burhan; Guzel, Ahmet; Basaran, Umit Nusret; Erboga, Mustafa; Ozcan, Ali

    2011-08-01

    We have studied whether hyperbaric oxygen (HBO) prevents different pulmonary aspiration materials-induced lung injury in rats. The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250 to 300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + HBO treated, BIO + HBO treated, and HCl + HBO treated. Saline, BIO, HCl were injected into the lungs in a volume of 2 ml/kg. A total of seven HBO sessions were performed at 2,4 atm 100% oxygen for 90 min at 6-h intervals. Seven days later, rats were sacrificed, and both lungs in all groups were examined biochemically and histopathologically. Our findings show that HBO inhibits the inflammatory response reducing significantly (P fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonar aspiration significantly increased the tissue HP content, malondialdehyde (MDA) levels and decreased (P < 0.05) the antioxidant enzyme (SOD, GSH-Px) activities. HBO treatment significantly (P < 0.05) decreased the elevated tissue HP content, and MDA levels and prevented inhibition of SOD, and GSH-Px (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase, TUNEL and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with HBO therapy. It was concluded that HBO treatment might be beneficial in lung injury, therefore, shows potential for clinical use.

  4. The effects of dexamethasone on post-asphyxial cerebral oxygenation in the preterm fetal sheep

    Science.gov (United States)

    Lear, Christopher A; Koome, Miriam E; Davidson, Joanne O; Drury, Paul P; Quaedackers, Josine S; Galinsky, Robert; Gunn, Alistair J; Bennet, Laura

    2014-01-01

    Exposure to clinical doses of the glucocorticoid dexamethasone increases brain activity and causes seizures in normoxic preterm fetal sheep without causing brain injury. In contrast, the same treatment after asphyxia increased brain injury. We hypothesised that increased injury was in part mediated by a mismatch between oxygen demand and oxygen supply. In preterm fetal sheep at 0.7 gestation we measured cerebral oxygenation using near-infrared spectroscopy, electroencephalographic (EEG) activity, and carotid blood flow (CaBF) from 24 h before until 72 h after asphyxia induced by 25 min of umbilical cord occlusion. Ewes received dexamethasone intramuscularly (12 mg 3 ml–1) or saline 15 min after the end of asphyxia. Fetuses were studied for 3 days after occlusion. During the first 6 h of recovery after asphyxia, dexamethasone treatment was associated with a significantly greater fall in CaBF (P < 0.05), increased carotid vascular resistance (P < 0.001) and a greater fall in cerebral oxygenation as measured by the difference between oxygenated and deoxygenated haemoglobin (delta haemoglobin; P < 0.05). EEG activity was similarly suppressed in both groups. From 6 to 10 h onward, dexamethasone treatment was associated with a return of CaBF to saline control levels, increased EEG power (P < 0.005), greater epileptiform transient activity (P < 0.001), increased oxidised cytochrome oxidase (P < 0.05) and an attenuated increase in [delta haemoglobin] (P < 0.05). In conclusion, dexamethasone treatment after asphyxia is associated with greater hypoperfusion in the critical latent phase, leading to impaired intracerebral oxygenation that may exacerbate neural injury after asphyxia. PMID:25384775

  5. Effect of Different Alternate Irrigation Strategies using Saline and Non-Saline Water on Corn Yield, Salinity and Moisture Distribution in Soil Profile

    Directory of Open Access Journals (Sweden)

    Ali Reza Kiani

    2017-01-01

    Full Text Available Introduction: Lack of water and deterioration in the quality of soil and water resources are considered to be the prime cause of reduced crop yield in arid and semi-arid regions ‘More crop per drop’ by trickle irrigation, deficit irrigation, and uncommon water are the best strategies for mitigating water crises. Different irrigation management strategies are needed to increase production in different areas. In areas where sufficient water is available, a full irrigation strategy could be a suitable option, while in areas where water is limited, deficit irrigation would be an appropriate method, and finally in areas where water resources are saline, management strategies for achieving sustainable production as well as economic yields would be suitable. Maize is the third most important grain crop in the world following wheat and rice and it is the main source of nutrition for humans and animals. Because of the importance of maize in the world, increasing maize production under environmental stresses is a big challenge for agricultural scientists. Different methods of irrigation and the use of saline water that had satisfactory results for increasing agricultural production have been studied by several investigators . The main objective of this study was to establish an efficient use of limited water resources as well as to explore the possibility of replacing saline water with fresh water using different management techniques. Materials and Methods: A field experiment was conducted over two maize cropping seasons (2012–2013 in northern Iran (Gorgan Agricultural Research Station to compare different alternate irrigation scenarios using saline water on corn yield, salinity and soil moisture distribution in a randomized complete block design with three replications. Treatments were: T1 and T2 = 100 and 50 % of crop water requirement with non-saline water, respectively; T3 and T4 = variable and fixed full irrigation with saline and non-saline

  6. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, R.; Hauss, H.; Buchholz, F.; Melzner, F.

    2015-10-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  7. Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile

    Science.gov (United States)

    Parris, Darren J.; Ganesh, Sangita; Edgcomb, Virginia P.; DeLong, Edward F.; Stewart, Frank J.

    2014-01-01

    Molecular surveys are revealing diverse eukaryotic assemblages in oxygen-limited ocean waters. These communities may play pivotal ecological roles through autotrophy, feeding, and a wide range of symbiotic associations with prokaryotes. We used 18S rRNA gene sequencing to provide the first snapshot of pelagic microeukaryotic community structure in two cellular size fractions (0.2–1.6 μm, >1.6 μm) from seven depths through the anoxic oxygen minimum zone (OMZ) off northern Chile. Sequencing of >154,000 amplicons revealed contrasting patterns of phylogenetic diversity across size fractions and depths. Protist and total eukaryote diversity in the >1.6 μm fraction peaked at the chlorophyll maximum in the upper photic zone before declining by ~50% in the OMZ. In contrast, diversity in the 0.2–1.6 μm fraction, though also elevated in the upper photic zone, increased four-fold from the lower oxycline to a maximum at the anoxic OMZ core. Dinoflagellates of the Dinophyceae and endosymbiotic Syndiniales clades dominated the protist assemblage at all depths (~40–70% of sequences). Other protist groups varied with depth, with the anoxic zone community of the larger size fraction enriched in euglenozoan flagellates and acantharean radiolarians (up to 18 and 40% of all sequences, respectively). The OMZ 0.2–1.6 μm fraction was dominated (11–99%) by Syndiniales, which exhibited depth-specific variation in composition and total richness despite uniform oxygen conditions. Metazoan sequences, though confined primarily to the 1.6 μm fraction above the OMZ, were also detected within the anoxic zone where groups such as copepods increased in abundance relative to the oxycline and upper OMZ. These data, compared to those from other low-oxygen sites, reveal variation in OMZ microeukaryote composition, helping to identify clades with potential adaptations to oxygen-depletion. PMID:25389417

  8. Low oxygen levels slow embryonic development of Limulus polyphemus

    DEFF Research Database (Denmark)

    Funch, Peter; Wang, Tobias; Pertoldi, Cino

    2016-01-01

    The American horseshoe crab Limulus polyphemus typically spawns in the upper intertidal zone, where the developing embryos are exposed to large variations in abiotic factors such as temperature, humidity, salinity, and oxygen, which affect the rate of development. It has been shown that embryonic...... pronounced hypoxia in later embryonic developmental stages, but also in earlier, previously unexplored, developmental stages....... development is slowed at both high and low salinities and temperatures, and that late embryos close to hatching tolerate periodic hypoxia. In this study we investigated the influence of hypoxia on both early and late embryonic development in L. polyphemus under controlled laboratory conditions. Embryos were...

  9. Physical features of nearshore waters off Karwar

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinathan, C.K.; Joseph, P.S.

    Very little change in the hydrographic properties with depth during October 1975 to October 1976 was observed except during August-October, when waters of low temperature ( 24 degrees C), high salinity ( 35.5 ppt) and low dissolved oxygen ( 3 ml...

  10. Measurement of salinity of fluids in earth formations by comparison of inelastic and capture gamma ray spectra

    International Nuclear Information System (INIS)

    1979-01-01

    A method of borehole logging by detecting and counting gamma rays from inelastic scattering of fast neutrons by carbon, oxygen, silicon and calcium, gamma rays from capture of thermal neutrons by calcium, chlorine and silicon and comparing the former with the latter thereby deriving an estimate of the salinity of the fluids in the borehole, is given (UK)

  11. 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...

  12. A method for volumetric retinal tissue oxygen tension imaging.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Teng, Pang-Yu; Blair, Norman P; Shahidi, Mahnaz

    2018-01-01

    Inadequate retinal oxygenation occurs in many vision-threatening retinal diseases, including diabetic retinopathy, retinal vascular occlusions, and age-related macular degeneration. Therefore, techniques that assess retinal oxygenation are necessary to understand retinal physiology in health and disease. The purpose of the current study is to report a method for the three-dimensional (3D) imaging of retinal tissue oxygen tension (tPO 2 ) in rats. Imaging was performed in Long Evans pigmented rats under systemic normoxia (N = 6) or hypoxia (N = 3). A vertical laser line was horizontally scanned on the retina and a series of optical section phase-delayed phosphorescence images were acquired. From these images, phosphorescence volumes at each phase delay were constructed and a 3D retinal tPO 2 volume was generated. Retinal tPO 2 volumes were quantitatively analyzed by generating retinal depth profiles of mean tPO 2 (M tPO2 ) and the spatial variation of tPO 2 (SV tPO2 ). The effects of systemic condition (normoxia/hypoxia) and retinal depth on M tPO2 and SV tPO2 were determined by mixed linear model. Each 3D retinal tPO 2 volume was approximately 500 × 750 × 200 μm (horizontal × vertical × depth) and consisted of 45 en face tPO 2 images through the retinal depth. M tPO2 at the chorioretinal interface was significantly correlated with systemic arterial oxygen tension (P = 0.007; N = 9). There were significant effects of both systemic condition and retinal depth on M tPO2 and SV tPO2 , such that both were lower under hypoxia than normoxia and higher in the outer retina than inner retina (P < 0.001). For the first time, 3D imaging of retinal tPO 2 was demonstrated, with potential future application for assessment of physiological alterations in animal models of retinal diseases.

  13. Balancing tissue perfusion demands: cardiovascular dynamics of Cancer magister during exposure to low salinity and hypoxia.

    Science.gov (United States)

    McGaw, Iain J; McMahon, Brian R

    2003-01-01

    Decapod crustaceans inhabit aquatic environments that are frequently subjected to changes in salinity and oxygen content. The physiological responses of decapod crustaceans to either salinity or hypoxia are well documented; however, there are many fewer reports on the physiological responses during exposure to these parameters in combination. We investigated the effects of simultaneous and sequential combinations of low salinity and hypoxia on the cardiovascular physiology of the Dungeness crab, Cancer magister. Heart rate, as well as haemolymph flow rates through the anterolateral, hepatic, sternal and posterior arteries were measured using a pulsed-Doppler flowmeter. Summation of flows allowed calculation of cardiac output and division of this by heart rate yielded stroke volume. When hypoxia and low salinity were encountered simultaneously, the observed changes in cardiac properties tended to be a mix of both factors. Hypoxia caused a bradycardia, whereas exposure to low salinity was associated with a tachycardia. However, the hypoxic conditions had the dominant effect on heart rate. Although hypoxia caused an increase in stroke volume of the heart, the low salinity had a more pronounced effect, causing an overall decrease in stroke volume. The patterns of haemolymph flow through the arterial system also varied when hypoxia and low salinity were offered together. The resulting responses were a mix of those resulting from exposure to either parameter alone. When low salinity and hypoxia were offered sequentially, the parameter experienced first tended to have the dominant effect on cardiac function and haemolymph flows. Low salinity exposure was associated with an increase in heart rate, a decrease in stroke volume and cardiac output, and a concomitant decrease in haemolymph flow rates. Subsequent exposure to hypoxic conditions caused a slight decrease in rate, but other cardiovascular variables were largely unaffected. In contrast, when low salinity followed

  14. Effects of irrigation regime and salinity on soil characteristics and yield of tomato

    Directory of Open Access Journals (Sweden)

    Rita Leogrande

    2012-03-01

    Full Text Available A field experiment was conducted in Mediterranean conditions to evaluate the effects of different irrigation volumes and water quality on yield performance of tomato crop. The tomato crop was irrigated re-establishing 50 (I1, 75 (I2 and 100% (I3 of the crop evapotranspiration (ETc with two water quality: fresh water with EC 0.9 dS m-1 (FW and saline water with EC 6 dSm-1 (SW. At harvest, total and marketable yield, weight, number, , total soluble solids (TSS and dry matter of fruit were calculated, The results showed no statistical differences among the three different irrigation volumes on tomato yield and quality. The salinity treatment did not affect yield, probably because the soil salinity in the root zone on average remained below the threshold of tomato salt tolerance. Instead, salinity improved fruit quality parameters as dry matter and TSS by 13 and 8 %, respectively. After the first field application of saline water, soil saturated extract cations (SSEC, electrical conductivity of soil paste extract (ECe, sodium absorption ratio (SAR and exchangeable sodium percentage (ESP cations increased; the largest increase of cations, in particular of Na, occurred in the top layer. At the end of the experiment, the absolute value of SSEC, ECe and SAR, for all the effects studied, were lower than those recorded in 2007. This behavior was suitable to the reduced volumes of treatments administered in 2009 in respect to the 2007. Furthermore, the higher total rainfall recorded in 2009 increased the leaching and downward movement of salts out of the sampling depth.

  15. Light-enhanced oxygen respiration in benthic phototrophic communities

    DEFF Research Database (Denmark)

    Epping, EHG; Jørgensen, BB

    1996-01-01

    Two microelectrode studies demonstrate the effect of Light intensity and photosynthesis on areal oxygen respiration in a hypersaline mat at Guerrero Negro, Mexico, and in an intertidal sediment at Texel, The Netherlands. The hypersaline mat was studied in the laboratory at light intensities of 0...... the day at prevailing light intensities. A 1-dimensional diffusion-reaction model was used to estimate gross photosynthesis and oxygen respiration per volume of sediment, as well as the euphotic depth and the sediment-water interface concentration of oxygen. Areal gross photosynthesis ranged from 9...

  16. Influence of the impurities on the depth of penetration with carbon steel weldings

    Directory of Open Access Journals (Sweden)

    O. Savytsky

    2014-04-01

    Full Text Available In this paper the results of the research about the influence of the impurities on the depth of penetration with carbon steels weldings of different chemical composition are presented. These data suggest that presence of those impurities, such as sulphure and oxygen, in the steel, increases the depth of penetration to 1,3 - 1,5 times compared to welding refined steels. Applying activating fluxes for welding high tensile steels, provides an increase in the depth of penetration of 2 - 3 times.

  17. Finding a solution: Heparinised saline versus normal saline in the maintenance of invasive arterial lines in intensive care.

    Science.gov (United States)

    Everson, Matthew; Webber, Lucy; Penfold, Chris; Shah, Sanjoy; Freshwater-Turner, Dan

    2016-11-01

    We assessed the impact of heparinised saline versus 0.9% normal saline on arterial line patency. Maintaining the patency of arterial lines is essential for obtaining accurate physiological measurements, enabling blood sampling and minimising line replacement. Use of heparinised saline is associated with risks such as thrombocytopenia, haemorrhage and mis-selection. Historical studies draw variable conclusions but suggest that normal saline is at least as effective at maintaining line patency, although recent evidence has questioned this. We conducted a prospective analysis of the use of heparinised saline versus normal saline on unselected patients in the intensive care of our hospital. Data concerning duration of 471 lines insertion and reason for removal was collected. We found a higher risk of blockage for lines flushed with normal saline compared with heparinised saline (RR = 2.15, 95% CI 1.392-3.32, p  ≤ 0.001). Of the 56 lines which blocked initially (19 heparinised saline and 37 normal saline lines), 16 were replaced with new lines; 5 heparinised saline lines and 11 normal saline lines were reinserted; 5 of these lines subsequently blocked again, 3 of which were flushed with normal saline. Our study demonstrates a clinically important reduction in arterial line longevity due to blockages when flushed with normal saline compared to heparinised saline. We have determined that these excess blockages have a significant clinical impact with further lines being inserted after blockage, resulting in increased risks to patients, wasted time and cost of resources. Our findings suggest that the current UK guidance favouring normal saline flushes should be reviewed.

  18. Evaluation of the Thickness and Oxygen Transmission Rate before and after Thermoforming Mono- and Multi-layer Sheets into Trays with Variable Depth

    Directory of Open Access Journals (Sweden)

    Mieke Buntinx

    2014-12-01

    Full Text Available During thermoforming, plastic sheets are heated and subsequently deformed through the application of mechanical stretching and/or pressure. This process directly impacts sheet properties such as material thickness in walls, corners, and bottom, crystallinity in the constituent layers, and particularly the oxygen gas permeability. The aim of this study was to quantify the impact of thermoforming on thickness and oxygen transmission rate (OTR of selected packaging materials (polypropylene (PP; PP/ethylene-vinyl alcohol co-polymer/PP (PP/EVOH/PP; polystyrene/EVOH/polyethylene (PS/EVOH/PE; amorphous polyethylene terephtalate/PE (APET/PE; APET/PE/EVOH/PE; polyamide/PE (PA/PE; and (PE/PA/EVOH/PA/PE. These materials were extruded in two different thicknesses and thermoformed into trays with the same top dimensions and variable depths of 25, 50, and/or 75 mm and a 50 mm tray with a variable radius of the corners. The distribution of the material thickness in the trays was visualized, showing the locations that were most affected by the deep drawn process. The OTR results indicate that the calculated OTR, based on a homogeneous material distribution, can be used as a rough approximation of the measured OTR. However, detailed analysis of crystallization and unequal thinning, which is also related to the tray design, remains necessary to explain the deviation of the measured OTR as compared to the predicted one.

  19. Reconstruct the past thermocline circulation in the Atlantic: calcification depths and Mg/Ca-temperature calibrations for 6 deep-dwelling planktonic foraminifera

    Science.gov (United States)

    Cleroux, C.; deMenocal, P.; Arbuszewski, J.; Linsley, B.

    2012-04-01

    The subtropical cells are shallow meridional overturning circulations driven by the atmospheric circulation and the deep thermohaline circulation. They connect the mid-latitude and the tropic, release latten heat to the atmosphere and impact climate on decadal to longer time scale. The upper water column temperature and salinity structures of the ocean reflect this circulation. We present proxies to study these past structures. We performed stable oxygen isotope (δ18O) and trace element ratio measurements on one surface-dwelling (G. ruber)1 and six deep-dwelling planktonic foraminifera species (N. dutertrei, G. inflata, G. tumida, G. truncatulinoides, G. hirsuta and G. crassaformis) on 66 coretops spanning from 35°N to 20°S along the Mid-Atlantic ridge. Comparison between measured δ18O and predicted δ18O (using water column temperature and seawater δ18O), shows that N. dutertrei, G. tumida, G. hirsuta and G. crassaformis keep the same apparent calcification depth along the transect (respectively: 125m, 150m, 700m and 800m). Calcification at two depth levels was also tested. For the six deep-dwelling species, we establish Mg/Ca-temperature calibrations with both atlas temperature at the calcification depth and isotopic temperature. We present Mg/Ca-temperature equations for species previously very poorly calibrated. The δ18O and temperature (Mg/Ca derived) on the six planktonic foraminifera species faithfully reproduce the modern water column structure of the upper 800 m depth, establishing promising proxies for past subsurface reconstruction. 1 Arbuszewski, J. J., P. B. deMenocal, A. Kaplan, and C. E. Farmer (2010), On the fidelity of shell-derived δ18Oseawater estimates, Earth and Planetary Science Letters, 300(3-4), 185-196.

  20. Enhanced deep ocean ventilation and oxygenation with global warming

    Science.gov (United States)

    Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

    2014-12-01

    Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

  1. Porewater salinity and the development of swelling pressure in bentonite-based buffer and backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A. [Atomic Energy of Canada Limited (Canada)

    2000-06-01

    At the depths proposed for a nuclear fuel waste repository, it is likely that saline groundwater conditions will be encountered in the granitic rocks of Finland and Canada. The potential for saline groundwater to influence of the ability of bentonite-based buffer and backfilling materials to swell and thereby generate swelling pressure has been reviewed. Based on the data collected from existing literature, it would appear that porewater salinities as high as 100 g/l will not compromise the ability of confined, bentonite-based materials to develop a swelling pressure of at least 100 kPa on its confinement, provided the effective clay dry density (ECDD), exceeds approximately 0.9 Mg/m{sup 3}. At densities less than approximately 0.9 Mg/m{sup 3} the swelling pressure of bentonite-based materials may be reduced and become sensitive to salt concentration. The influence of porewater salinity on swelling pressure can be compared on the basis of the ECDD required to develop 100 kPa of swelling pressure. In order to generate 100 kPa of swelling pressure an ECDD of approximately 0.7 Mg/m{sup 3} is required to be present under fresh water or brackish porewater conditions. This density would need to be increased to approximately 0.9 Mg/m{sup 3} where the groundwater conditions were saline. The impact that groundwater salinity will have on density specifications for buffer and backfilling materials are discussed with reference to the nuclear fuel waste disposal concepts of Finland and Canada. (orig.)

  2. The Influence of Physical Forcing on Bottom-water Dissolved Oxygen within the Caloosahatchee River Estuary, FL

    Science.gov (United States)

    Environmental Fluid Dynamic Code (EFDC), a numerical estuarine and coastal ocean circulation hydrodynamic model, was used to simulate the distribution of dissolved oxygen (DO), salinity, temperature, nutrients (nitrogen and phosphorus), and chlorophyll a in the Caloosahatchee Riv...

  3. Impact of salinity on cathode catalyst performance in microbial fuel cells (MFCs)

    KAUST Repository

    Wang, Xi

    2011-10-01

    Several alternative cathode catalysts have been proposed for microbial fuel cells (MFCs), but effects of salinity (sodium chloride) on catalyst performance, separate from those of conductivity on internal resistance, have not been previously examined. Three different types of cathode materials were tested here with increasingly saline solutions using single-chamber, air-cathode MFCs. The best MFC performance was obtained using a Co catalyst (cobalt tetramethoxyphenyl porphyrin; CoTMPP), with power increasing by 24 ± 1% to 1062 ± 9 mW/m2 (normalized to the projected cathode surface area) when 250 mM NaCl (final conductivity of 31.3 mS/cm) was added (initial conductivity of 7.5 mS/cm). This power density was 25 ± 1% higher than that achieved with Pt on carbon cloth, and 27 ± 1% more than that produced using an activated carbon/nickel mesh (AC) cathode in the highest salinity solution. Linear sweep voltammetry (LSV) was used to separate changes in performance due to solution conductivity from those produced by reductions in ohmic resistance with the higher conductivity solutions. The potential of the cathode with CoTMPP increased by 17-20 mV in LSVs when the NaCl addition was increased from 0 to 250 mM independent of solution conductivity changes. Increases in current were observed with salinity increases in LSVs for AC, but not for Pt cathodes. Cathodes with CoTMPP had increased catalytic activity at higher salt concentrations in cyclic voltammograms compared to Pt and AC. These results suggest that special consideration should be given to the type of catalyst used with more saline wastewaters. While Pt oxygen reduction activity is reduced, CoTMPP cathode performance will be improved at higher salt concentrations expected for wastewaters containing seawater. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  4. Saline agriculture: A technology for economic utilization and improvement of saline environments (abstract)

    International Nuclear Information System (INIS)

    Aslam, Z.; Malik, K.A.; Khurshid, S.J.; Awan, A.R.; Akram, M.; Hashmi, Z.; Ali, Y.; Gulnaz, A.; Hussain, M.; Hussain, F.

    2005-01-01

    The salinity problem is one of the severe constraints for agriculture in Pakistan. In a socio-economic and salinity and drainage survey over an area of about 25000 acres of salt-affected land recently, crop production is found to be very low. Livestock is underfed and malnourished. Pakistan has spent and allocated over one billion US dollars on Salinity Control and Reclamation Projects (SCARP), of course, with dubious results. Over the years, a Saline Agriculture Technology has been developed as a cheap alternative at NIAB for comfortably living with salinity and to profitably utilize saline land rather than its reclamation. The soil improvement is a fringe benefit in this approach. The Saline Agriculture Technology has been tested at laboratory level, at field stations and at farms of some progressive farmers. Now we are sharing this technology with farming communities through a 'Saline Agriculture Farmer Participatory Development Project in Pakistan', with assistance from the National Rural Support Programme. The new project has been launched simultaneously in all four provinces of Pakistan on 25000 acres of salt-affected land. Under this project seeds of salt tolerant crop varieties wheat, cotton, rice, castor, brassica and barley and saplings of trees/shrubs, e.g. Acacia ampliceps, A. nilotica, Casuarina glauca, ber, jaman, etc selected for development work in various institutions of Pakistan are being provided to farmers. Know-how on new irrigation techniques like bed-and-corrugation and bed-and-furrow, agronomic practices like laser land leveling, planting on beds and in auger holes and soil/water amendment practices (use of gypsum and mineral acids) are being shared with farmers. These interventions are quite efficient, save water up to 40% and enable farmers to utilize bad quality water. In general, farmers are being familiarized with prevalent animal diseases, nutritional problems and prophylactic techniques. They are being helped in developing Saline

  5. Simultaneous removal of organic matter and salt ions from saline wastewater in bioelectrochemical systems

    KAUST Repository

    Kim, Younggy

    2013-01-01

    A new bioelectrochemical system is proposed for simultaneous removal of salinity and organic matter. In this process, exoelectrogenic microorganisms oxidize organic matter and transfer electrons to the anode, hydrogen is evolved at the cathode by supplying additional voltage, and salt is removed from the wastewater due to the electric potential generated and the use of two ion-exchange membranes. Salinity removal (initial conductivity ~40mS/cm) increased from 21 to 84% by increasing the substrate (sodium acetate) from 2 to 8g/L. A total of 72-94% of the chemical oxygen demand was degraded in the anode and cathode chambers, with 1-4% left in the anode chamber and the balance lost through the anion-exchange membrane into the concentrate waste chamber. The maximum hydrogen production rate was 3.6m3-H2/m3-electrolyte per day at an applied potential of 1.2V. The Coulombic efficiency was ~100%, while the cathode recovery varied from 57 to 100%, depending on the extent of methanogenesis. Exoelectrogenic microbes generated high current densities (7.8mA/cm2) at ≤36g/L of total dissolved solids, but >41g/L eliminated current. These results provide a new method for achieving simultaneous removal of salinity and organic matter from a saline wastewater with H2 production. © 2012 Elsevier B.V.

  6. Evidence for the existence of Persian Gulf Water and Red Sea Water in the Bay of Bengal

    Science.gov (United States)

    Jain, Vineet; Shankar, D.; Vinayachandran, P. N.; Kankonkar, A.; Chatterjee, Abhisek; Amol, P.; Almeida, A. M.; Michael, G. S.; Mukherjee, A.; Chatterjee, Meenakshi; Fernandes, R.; Luis, R.; Kamble, Amol; Hegde, A. K.; Chatterjee, Siddhartha; Das, Umasankar; Neema, C. P.

    2017-05-01

    The high-salinity water masses that originate in the North Indian Ocean are Arabian Sea High-Salinity Water (ASHSW), Persian Gulf Water (PGW), and Red Sea Water (RSW). Among them, only ASHSW has been shown to exist in the Bay of Bengal. We use CTD data from recent cruises to show that PGW and RSW also exist in the bay. The presence of RSW is marked by a deviation of the salinity vertical profile from a fitted curve at depths ranging from 500 to 1000 m; this deviation, though small (of the order of 0.005 psu and therefore comparable to the CTD accuracy of 0.003 psu), is an order of magnitude larger than the 0.0003 psu fluctuations associated with the background turbulence or instrument noise in this depth regime, allowing us to infer the existence of RSW throughout the bay. PGW is marked by the presence of a salinity maximum at 200-450 m; in the southwestern bay, PGW can be distinguished from the salinity maximum due to ASHSW because of the intervening Arabian Sea Salinity Minimum. This salinity minimum and the maximum associated with ASHSW disappear east and north of the south-central bay (85°E, 8°N) owing to mixing between the fresher surface waters that are native to the bay (Bay of Bengal Water or BBW) with the high-salinity ASHSW. Hence, ASHSW is not seen as a distinct water mass in the northern and eastern bay and the maximum salinity over most of the bay is associated with PGW. The surface water over most of the bay is therefore a mixture of ASHSW and the low-salinity BBW. As a corollary, we can also infer that the weak oxygen peak seen within the oxygen-minimum zone in the bay at a depth of 250-400 m is associated with PGW. The hydrographic data also show that these three high-salinity water masses are advected into the bay by the Summer Monsoon Current, which is seen to be a deep current extending to 1000 m. These deep currents extend into the northern bay as well, providing a mechanism for spreading ASHSW, PGW, and RSW throughout the bay.

  7. Respiratory ATP cost and benefit of arbuscular mycorrhizal symbiosis with Nicotiana tabacum at different growth stages and under salinity.

    Science.gov (United States)

    Del-Saz, Néstor Fernández; Romero-Munar, Antonia; Alonso, David; Aroca, Ricardo; Baraza, Elena; Flexas, Jaume; Ribas-Carbo, Miquel

    2017-11-01

    Growth and maintenance partly depend on both respiration and ATP production during oxidative phosphorylation in leaves. Under stress, ATP is needed to maintain the accumulated biomass. ATP production mostly proceeds from the cytochrome oxidase pathway (COP), while respiration via the alternative oxidase pathway (AOP) may decrease the production of ATP per oxygen consumed, especially under phosphorus (P) limitation and salinity conditions. Symbiosis with arbuscular mycorrhizal (AM) fungi is reputed by their positive effect on plant growth under stress at mature stages of colonization; however, fungal colonization may decrease plant growth at early stages. Thus, the present research is based on the hypothesis that AM fungus colonization will increase both foliar respiration and ATP production at mature stages of plant growth while decreasing them both at early stages. We used the oxygen-isotope-fractionation technique to study the in vivo respiratory activities and ATP production of the COP and AOP in AM and non-AM (NM) tobacco plants grown under P-limiting and saline conditions in sand at different growth stages (14, 28 and 49days). Our results suggest that AM symbiosis represents an ATP cost detrimental for shoot growth at early stages, whilst it represents a benefit on ATP allowing for faster rates of growth at mature stages, even under salinity conditions. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. 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...

  9. Strategies for safe exploitation of fresh water through multi-strainer skimming wells in saline groundwater areas

    International Nuclear Information System (INIS)

    Alam, M.M.; Jaffery, H.M.; Hanif, M.

    2005-01-01

    Indus Basin of Pakistan to develop strategies for the safe exploitation of fresh upper groundwater layer through multi-strainer skimming wells in the areas having deeper saline groundwater. Results of detailed investigations are given in this paper. A methodology was designed for investigations and to study the movement of saline-fresh water interface. For this purpose deep observation wells were installed and water samples from various depths over a period of wells operational hours have been collected. Water quality of these samples was tested to evaluate the movement of saline-fresh water interface. Results indicated that there exists a relatively fresh water aquifer above the depth of 20m. Relatively impervious layer and clay lenses of variable thickness exists at various locations in the area. There is relatively less contribution from the lower aquifer as compared to the lateral movement of water to the well above the impervious layers. The skimming wells were operated for a different number of hours and water quality evaluated. The results show that the quality and quantity of the pumped groundwater can be improved with intermittent pumping for 4-6 hours per day under drought conditions and recovery of the water-table is quick. Moreover, the intermittent pumping maintained a minimum suction lift that helped get a relatively good discharge. Continuous long term pumping proved to be dangerous which can cause saline water intrusion. It is recommended to avoid long term pumping of skimming wells. Intermittent short hours operation can be helpful for safe exploitation of fresh water and make skimming well operation more cost effective. It is further added that 4-6 strainers make these skimming wells cost effective as compared to having a large number of strainers in a skimming well. (author)

  10. Investigation of oxygen distribution in HTSC-insulator in film structures on light ion beam

    International Nuclear Information System (INIS)

    Verbitskaya, E.M.; Grekhov, I.V.; Eremin, V.K.; Konnikov, S.G.; Linijchuk, I.A.; Razumov, S.V.; Semchinova, O.K.; Strokan, N.B.; Dyumin, A.N.; Lebedev, V.M.

    1992-01-01

    Use of nuclear reaction method on accelerated ions for profiling of oxygen concentration in thin-film HTSC structures is considered. Reaction on 16 O(d, α) 14 N deuterons, in course of which ∼ 2.6 MeV α-particles are generated, is used. Detected in experiment 2.0-2.6 MeV α-particle spectrum permits to recognstruct oxygen concentration profile in sample depth. Results obtained on YBa 2 Cu 3 O 7-δ and Y 2 BaCuO 5 film om MgO sunstrates, relating to the case of both uniform and nonuniform oxygen distribution, are presented. Resolution in the depth ∼ 200 A and accuracy of concentration measurement (relatively MgO substrate) of several percents are attained during oxygen profiling

  11. Dextrose saline compared with normal saline rehydration of hyperemesis gravidarum: a randomized controlled trial.

    Science.gov (United States)

    Tan, Peng Chiong; Norazilah, Mat Jin; Omar, Siti Zawiah

    2013-02-01

    To compare 5% dextrose-0.9% saline against 0.9% saline solution in the intravenous rehydration of hyperemesis gravidarum. Women at their first hospitalization for hyperemesis gravidarum were enrolled on admission to the ward and randomly assigned to receive either 5% dextrose-0.9% saline or 0.9% saline by intravenous infusion at a rate 125 mL/h over 24 hours in a double-blind trial. All participants also received thiamine and an antiemetic intravenously. Oral intake was allowed as tolerated. Primary outcomes were resolution of ketonuria and well-being (by 10-point visual numerical rating scale) at 24 hours. Nausea visual numerical rating scale scores were obtained every 8 hours for 24 hours. Persistent ketonuria rates after the 24-hour study period were 10 of 101 (9.9%) compared with 11 of 101 (10.9%) (P>.99; relative risk 0.9, 95% confidence interval 0.4-2.2) and median (interquartile range) well-being scores at 24 hours were 9 (8-10) compared with 9 (8-9.5) (P=.73) in the 5% dextrose-0.9% saline and 0.9% saline arms, respectively. Repeated measures analysis of variance of the nausea visual numerical rating scale score as assessed every 8 hours during the 24-hour study period showed a significant difference in favor of the 5% dextrose-0.9% saline arm (P=.046) with the superiority apparent at 8 and 16 hours, but the advantage had dissipated by 24 hours. Secondary outcomes of vomiting, resolution of hyponatremia, hypochloremia and hypokalemia, length of hospitalization, duration of intravenous antiemetic, and rehydration were not different. Intravenous rehydration with 5% dextrose-0.9% saline or 0.9% saline solution in women hospitalized for hyperemesis gravidarum produced similar outcomes. ISRCTN Register, www.controlled-trials.com/isrctn, ISRCTN65014409. I.

  12. CTD data from the N. E. Atlantic 31N to 46N, July 1982 Discovery cruise 130

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, P M

    1983-01-01

    Lists and graphs of CTD data obtained aboard RRS Discovery during July 1982 are presented. A series of 14 stations were occupied between approximate 31 deg N 24 deg W and 46 deg N 14 deg W in support of sound ranging trials. A further 20 stations were occupied in the vicinity of Discovery Gap, a channel for deep flow between the Madeira and Iberian basins near 37 deg 30 N 15 deg 30 W. All CTD data were reconciled with reversing thermometer measurements, and salinity and oxygen samples. Root mean square differences for pressure, temperature, salinity and oxygen were 7 dB, .012 deg C, .007 PSU and 0.3 ml/l in the depth interval 0 to 2,000 dB and 6 dB, .005 deg C, .003 PSU and .16 ml/l for depths 2,000 to 5,600 dB.

  13. Determinants of oxygen and carbon dioxide transfer during extracorporeal membrane oxygenation in an experimental model of multiple organ dysfunction syndrome.

    Science.gov (United States)

    Park, Marcelo; Costa, Eduardo Leite Vieira; Maciel, Alexandre Toledo; Silva, Débora Prudêncio E; Friedrich, Natalia; Barbosa, Edzangela Vasconcelos Santos; Hirota, Adriana Sayuri; Schettino, Guilherme; Azevedo, Luciano Cesar Pontes

    2013-01-01

    Extracorporeal membrane oxygenation (ECMO) has gained renewed interest in the treatment of respiratory failure since the advent of the modern polymethylpentene membranes. Limited information exists, however, on the performance of these membranes in terms of gas transfers during multiple organ failure (MOF). We investigated determinants of oxygen and carbon dioxide transfer as well as biochemical alterations after the circulation of blood through the circuit in a pig model under ECMO support before and after induction of MOF. A predefined sequence of blood and sweep flows was tested before and after the induction of MOF with fecal peritonitis and saline lavage lung injury. In the multivariate analysis, oxygen transfer had a positive association with blood flow (slope = 66, Pmembrane PaCO(2) (slope = -0.96, P = 0.001) and SatO(2) (slope = -1.7, Ptransfer had a positive association with blood flow (slope = 17, Pmembrane PaCO(2) (slope = 1.2, Ptransfers were significantly determined by blood flow. Oxygen transfer was modulated by the pre-membrane SatO(2) and CO(2), while carbon dioxide transfer was affected by the gas flow, pre-membrane CO(2) and hemoglobin.

  14. Investigation of Lake Water Salinity by Using Four-Band Salinity Algorithm on WorldView-2 Satellite Image for a Saline Industrial Lake

    Science.gov (United States)

    Budakoǧlu, Murat; Karaman, Muhittin; Damla Uça Avcı, Z.; Kumral, Mustafa; Geredeli (Yılmaz), Serpil

    2014-05-01

    Salinity of a lake is an important characteristic since, these are potentially industrial lakes and the degree of salinity can significantly be used for determination of mineral resources and for the production management. In the literature, there are many studies of using satellite data for salinity related lake studies such as determination of salinity distribution and detection of potential freshwater sources in less salt concentrated regions. As the study area Lake Acigol, located in Denizli (Turkey) was selected. With it's saline environment, it's the major sodium sulphate production resource of Turkey. In this study, remote sensing data and data from a field study was used and correlated. Remote sensing is an efficient tool to monitor and analyze lake properties by using it complementary to field data. Worldview-2 satellite data was used in this study which consists of 8 bands. At the same time with the satellite data acquisition, a field study was conducted to collect the salinity values in 17 points of the laker with using YSI 556 Multiparametre for measurements. The values were measured as salinity amount in grams per kilogram solution and obtained as ppt unit. It was observed that the values vary from 34 ppt - 40.1 ppt and the average is 38.056 ppt. In Thalassic serie, the lake was in mixoeuhaline state in the time of issue. As a first step, ATCOR correction was performed on satellite image for atmospheric correction. There were some clouds on the lake field, hence it was decided to continue the study by using the 12 sampling points which were clear on the image. Then, for each sampling point, a spectral value was obtained by calculating the average at a 11*11 neighborhood. The relation between the spectral reflectance values and the salinity was investigated. The 4-band algorithm, which was used for determination of chlorophyll-a distribution in highly turbid coastal environment by Wei (2012) was applied. Salinity α (Λi-1 / Λj-1) * (Λk-1 / Λm-1) (i

  15. 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, supply 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.

  16. Salinity Trends in the Upper Colorado River Basin Upstream From the Grand Valley Salinity Control Unit, Colorado, 1986-2003

    Science.gov (United States)

    Leib, Kenneth J.; Bauch, Nancy J.

    2008-01-01

    In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or 'units' of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in western Colorado. The U. S. Geological Survey has done extensive studies and research in the Grand Valley Salinity Control Unit that provide information to aid the U.S. Bureau of Reclamation and the Natural Resources Conservation Service in determining where salinity-control work may provide the best results, and to what extent salinity-control work was effective in reducing salinity concentrations and loads in the Colorado River. Previous studies have indicated that salinity concentrations and loads have been decreasing downstream from the Grand Valley Salinity Control Unit, and that the decreases are likely the result of salinity control work in these areas. Several of these reports; however, also document decreasing salinity loads upstream from the Grand Valley Salinity Control Unit. This finding was important because only a small amount of salinity-control work was being done in areas upstream from the Grand Valley Salinity Control Unit at the time the findings were reported (late 1990?s). As a result of those previous findings, the U.S. Bureau of Reclamation entered into a cooperative agreement with the U.S. Geological Survey to investigate salinity trends in selected areas bracketing the Grand Valley Salinity Control Unit and regions upstream from the Grand Valley Salinity Control Unit. The results of the study indicate that salinity loads were decreasing upstream from the Grand Valley Salinity Control Unit from 1986 through 2003, but the rates of decrease have slowed during the last 10 years. The average rate of decrease in salinity load upstream from the Grand Valley

  17. Sea surface freshening inferred from SMOS and ARGO salinity: impact of rain

    Directory of Open Access Journals (Sweden)

    J. Boutin

    2013-02-01

    Full Text Available The sea surface salinity (SSS measured from space by the Soil Moisture and Ocean Salinity (SMOS mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 × 100 km2 in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography SSS is on the order of 0.3–0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (−0.1 observed in the tropical Pacific Ocean between 5° N and 15° N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as detected from SSM/Is (Special Sensor Microwave Imager rain rates, are removed from the SMOS–ARGO comparisons. The SMOS freshening is linearly correlated to SSM/Is rain rate with a slope estimated to −0.14 mm−1 h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with ARGO measurements concomitant with rain events collocated with SMOS measurements under no rain, the mean −0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.

  18. Constraining the origin of the Messinian gypsum deposits using coupled measurement of δ^{18}O$/δD in gypsum hydration water and salinity of fluid inclusions

    Science.gov (United States)

    Evans, Nicholas P.; Gázquez, Fernando; McKenzie, Judith A.; Chapman, Hazel J.; Hodell, David A.

    2016-04-01

    We used oxygen and hydrogen isotopes of gypsum hydration water (GHW) coupled with salinity deduced from ice melting temperatures of primary fluid inclusions in the same samples (in tandem with 87Sr/86Sr, δ34S and other isotopic measurements) to determine the composition of the mother fluids that formed the gypsum deposits of the Messinian Salinity Crisis from shallow and intermediate-depth basins. Using this method, we constrain the origin of the Messinian Primary Lower Gypsum (PLG) of the Sorbas basin (Betic foreland) and both the Upper Gypsum (UG) and the Lower Gypsum of the Sicilian basin. We then compare these results to measurements made on UG recovered from the deep Ionian and Balearic basins drilled during DSDP Leg 42A. The evolution of GHW δ18O/δD vs. salinity is controlled by mixing processes between fresh and seawater, coupled with the degree of evaporation. Evaporation and subsequent precipitation of gypsum from fluids dominated by freshwater will result in a depressed 87Sr/86Sr values and different trajectory in δ18O/δD vs. salinity space compared to fluids dominated by seawater. The slopes of these regression equations help to define the end-members from which the fluid originated. For example, salinity estimates from PLG cycle 6 in the Sorbas basin range from 18 to 51ppt, and after correction for fractionation factors, estimated δ18O and δD values of the mother water are low (-2.6 meteoric water during gypsum deposition, while 87Sr/86Sr (0.708942 fall below those expected from the evaporation of seawater alone, the slope of the regression equation is similar to that of seawater evaporation. This implies that there is a change up-section from a dominantly marine environment in cycle 2 to a greater influence of meteoric water in cycle 6. The UG from the Sicilian basin display greater δ18O/δD values (2.9 meteoric water that subsequently underwent intense evaporation. This observation concurs with the low values of 87Sr/86Sr from the same UG

  19. Measurement of flowing water salinity within or behind wellbore casing

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1981-01-01

    Water flowing within or behind a wellbore casing is irradiated with 14 MeV neutrons from a source in a downhole sonde. Gamma radiation from the isotope nitrogen-16 induced from the O 16 (n,p)N 16 reaction and the products of either the Na 23 (n,α)F 20 or the Cl 37 (n,α)P 34 reactions is measured in intensity and energy with detectors in the sonde. From the gamma radiation measurements, the relative presence of oxygen to at least one of sodium or chlorine in the water is measured, and from the measurement the salinity of the water is to be determined. (author)

  20. Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

    NARCIS (Netherlands)

    van Aken, H.M.; de Jong, M.F.; Yashayaev, I.

    2011-01-01

    Time series of profiles of potential temperature, salinity, dissolved oxygen, and planetary potential vorticity at intermediate depths in the Labrador Sea, the Irminger Sea, and the Iceland Basin have been constructed by combining the hydrographic sections crossing the sub-arctic gyre of the North

  1. N2-fixation in fababean (vicia faba l.) grown in saline and non saline conditions using 15N tracer technique

    International Nuclear Information System (INIS)

    Khalifa, Kh.; Kurdali, F.

    2002-09-01

    A pot experiment was conducted to study the performance of growing fababean and barley under saline conditions, in terms of, dry matter yield, total nitrogen and, percentages and amount of N derived from soil, fertilizer and atmosphere using 15 N isotope dilution method. Three saline treatments were performed: First, plants were grown in saline soil and irrigated with saline water (Ws Ss), Second, Plants were grown in saline soil and irrigated with saline water (Ws Ss); and Third, Plants grown in non saline soil and irrigated with saline water (Ws Sn). Furthermore, a control treatment was performed by using non-saline soil and non-saline water (Wn Sn). The different salinity treatments reduced plant growth and the reduction was more pronounced in fababean than in barley. However, under conditions of either saline soil-soft irrigation water or non saline soil-salty irrigation water, the relative growth reduction did not exceed 50% of the control; whereas, a significant negative effect was obtained when plants were grown under completely saline conditions of both soil and irrigation water. Percentage of N 2 -fixed (% Ndfa) was not negatively affected by saline conditions. However, our results clearly demonstrated that the effect of salinity in fababean was more evident on plant growth than on N 2 -fixing activity. Further studies are needed to obtain more salt tolerant faba bean genotypes in terms of growth and yield. This could be simultaneously improve yield and N 2 -fixation under sever saline conditions. (author)

  2. Evaluating the effect of salinity on a simulated American crocodile (Crocodylus acutus) population with applications to conservation and Everglades restoration

    NARCIS (Netherlands)

    Richards, P.M.; Mooij, W.M.; DeAngelis, D.L.

    2004-01-01

    Everglades restoration will alter the hydrology of South Florida, affecting both water depth and salinity levels in the southern fringes of the Everglades, the habitat of the endangered American crocodile (Crocodylus acutus). A key question is what the effects of these hydrologic changes will be on

  3. Oxygen incorporation into GST phase-change memory matrix

    Energy Technology Data Exchange (ETDEWEB)

    Golovchak, R., E-mail: holovchakr@apsu.edu [Department of Physics and Astronomy, Austin Peay State University, Clarksville, TN 37044 (United States); Choi, Y.G. [Department of Materials Science and Engineering, Korea Aerospace University, Gyeonggi 412-791 (Korea, Republic of); Kozyukhin, S. [Kurnakov Institute of General and Inorganic Chemistry of RAS, 31 Leninsky Pr., Moscow 119991 (Russian Federation); National Research Tomsk State University, 36 Lenin Pr., Tomsk 634050 (Russian Federation); Chigirinsky, Yu. [Scientific-Research Physicotechnical Institute at the Nizhnii Novgorod State University, Nizhnii Novgorod 603600 (Russian Federation); Kovalskiy, A.; Xiong-Skiba, P.; Trimble, J. [Department of Physics and Astronomy, Austin Peay State University, Clarksville, TN 37044 (United States); Pafchek, R.; Jain, H. [Department of Materials Science and Engineering, Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States)

    2015-03-30

    Graphical abstract: - Highlights: • Surfaces of GST-225 films are depleted in Te as a result of the reaction with oxygen. • Top layers of oxidized GST-225 are formed by Sb and Ge oxide complexes. • Depth profiles of Sb and Ge oxide complexes are found to be different. • Crystallization at 300 °C in O{sub 2} atmosphere leads to Ge redistribution. - Abstract: Structural changes in amorphous and crystallized GST-225 films induced by the reaction with oxygen are studied at different depth scales. The mechanism of interaction of the very top surface layers with oxygen is studied with low-energy ion scattering (LEIS) technique, while the modifications of chemistry in the underlying surface layers are investigated with high-resolution X-ray photoelectron spectroscopy (XPS). The changes averaged through the overall film thickness are characterized by micro-Raman spectroscopy. The oxygen exposure leads to a depletion of GST-225 film surfaces in Te and formation of the antimony and germanium oxides. The antimony oxide complexes are found throughout the whole thickness of the films after their prolonged storage in air, whereas no evidence for formation of pure GeO{sub 2} phase is found in the volume of the films through Raman spectroscopy. A tendency to form Ge-rich phase within the ∼10 nm surface layer is additionally observed by LEIS profiling during crystallization of GST-225 film at 300 °C in oxygen atmosphere.

  4. Hydrogen-rich saline may be an effective and specific novel treatment for osteoradionecrosis of the jaw

    Directory of Open Access Journals (Sweden)

    Chen Y

    2015-10-01

    Full Text Available Yuanli Chen, Chunlin Zong, Yuxuan Guo, Lei Tian Department of Cranio-facial Trauma and Orthognathic Surgery Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Shaanxi Key Laboratory of Stomatology, Xi’an, People’s Republic of China Abstract: Hydrogen, a therapeutic medical gas, can exert antioxidant activity via selectively reducing cytotoxic reactive oxygen species such as hydroxyl radicals. Hydrogen-rich saline is an alternative form of molecular hydrogen that has been widely used in many studies, including metabolic syndrome, cerebral, hepatic, myocardial ischemia/reperfusion, and liver injuries with obstructive jaundice, with beneficial results. Osteoradionecrosis of the jaw is a serious complication following radiotherapy for head and neck cancers. It has long been known that most radiation-induced symptoms are caused by free radicals generated by radiolysis of H2O, and the hydroxyl radical is the most reactive of these. Reducing the hydroxyl radical can distinctly improve the protection of cells from radiation damage. We hypothesized that hydrogen-rich saline might be an effective and specific method of managing and preventing osteoradionecrosis of the jaw. Keywords: osteoradionecrosis, hydrogen, reactive oxygen species

  5. Sulfate reduction controlled by organic matter availability in deep sediment cores from the saline, alkaline Lake Van (Eastern Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Clemens eGlombitza

    2013-07-01

    Full Text Available As part of the International Continental Drilling Program (ICDP deep lake drilling project PaleoVan, we investigated sulfate reduction (SR in deep sediment cores of the saline, alkaline (salinity 21.4 ‰, alkalinity 155 m mEq-1, pH 9.81 Lake Van, Turkey. The cores were retrieved in the Northern Basin (NB and at Ahlat Ridge (AR and reached a maximum depth of 220 m. Additionally, 65-75 cm long gravity cores were taken at both sites. Sulfate reduction rates (SRR were low (≤ 22 nmol cm-3 d-1 compared to lakes with higher salinity and alkalinity, indicating that salinity and alkalinity are not limiting SR in Lake Van. Both sites differ significantly in rates and depth distribution of SR. In NB, SRR are up to 10 times higher than at AR. Sulfate reduction (SR could be detected down to 19 meters below lake floor (mblf at NB and down to 13 mblf at AR. Although SRR were lower at AR than at NB, organic matter (OM concentrations were higher. In contrast, dissolved OM in the pore water at AR contained more macromolecular OM and less low molecular weight OM. We thus suggest, that OM content alone cannot be used to infer microbial activity at Lake Van but that quality of OM has an important impact as well. These differences suggest that biogeochemical processes in lacustrine sediments are reacting very sensitively to small variations in geological, physical or chemical parameters over relatively short distances. 

  6. Shave-off depth profiling: Depth profiling with an absolute depth scale

    International Nuclear Information System (INIS)

    Nojima, M.; Maekawa, A.; Yamamoto, T.; Tomiyasu, B.; Sakamoto, T.; Owari, M.; Nihei, Y.

    2006-01-01

    Shave-off depth profiling provides profiling with an absolute depth scale. This method uses a focused ion beam (FIB) micro-machining process to provide the depth profile. We show that the shave-off depth profile of a particle reflected the spherical shape of the sample and signal intensities had no relationship to the depth. Through the introduction of FIB micro-sampling, the shave-off depth profiling of a dynamic random access memory (DRAM) tip was carried out. The shave-off profile agreed with a blue print from the manufacturing process. Finally, shave-off depth profiling is discussed with respect to resolutions and future directions

  7. Differential Gene Expression in Liver, Gill, and Olfactory Rosettes of Coho Salmon (Oncorhynchus kisutch) After Acclimation to Salinity.

    Science.gov (United States)

    Maryoung, Lindley A; Lavado, Ramon; Bammler, Theo K; Gallagher, Evan P; Stapleton, Patricia L; Beyer, Richard P; Farin, Federico M; Hardiman, Gary; Schlenk, Daniel

    2015-12-01

    Most Pacific salmonids undergo smoltification and transition from freshwater to saltwater, making various adjustments in metabolism, catabolism, osmotic, and ion regulation. The molecular mechanisms underlying this transition are largely unknown. In the present study, we acclimated coho salmon (Oncorhynchus kisutch) to four different salinities and assessed gene expression through microarray analysis of gills, liver, and olfactory rosettes. Gills are involved in osmotic regulation, liver plays a role in energetics, and olfactory rosettes are involved in behavior. Between all salinity treatments, liver had the highest number of differentially expressed genes at 1616, gills had 1074, and olfactory rosettes had 924, using a 1.5-fold cutoff and a false discovery rate of 0.5. Higher responsiveness of liver to metabolic changes after salinity acclimation to provide energy for other osmoregulatory tissues such as the gills may explain the differences in number of differentially expressed genes. Differentially expressed genes were tissue- and salinity-dependent. There were no known genes differentially expressed that were common to all salinity treatments and all tissues. Gene ontology term analysis revealed biological processes, molecular functions, and cellular components that were significantly affected by salinity, a majority of which were tissue-dependent. For liver, oxygen binding and transport terms were highlighted. For gills, muscle, and cytoskeleton-related terms predominated and for olfactory rosettes, immune response-related genes were accentuated. Interaction networks were examined in combination with GO terms and determined similarities between tissues for potential osmosensors, signal transduction cascades, and transcription factors.

  8. Oceanographic profile plankton, Temperature Salinity and other measurements collected using bottle from various platforms in the South Pacific Ocean from 1997 to 1998 (NODC Accession 0014651)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, oxygen, nutrients, and other measurements found in the bottle dataset taken from the SNP-1, HUAMANGA (fishing boat) and other platforms in the...

  9. Hydrogen sulfide: a new endogenous player in an old mechanism of plant tolerance to high salinity

    Directory of Open Access Journals (Sweden)

    Cristiane J. da-Silva

    2017-10-01

    Full Text Available ABSTRACT High salinity affects plants due to stimulation of osmotic stress. Cell signaling triggered by nitric oxide (NO and hydrogen sulfide (H2S activates a cascade of biochemical events that culminate in plant tolerance to abiotic and biotic stresses. For instance, the NO/H2S-stimulated biochemical events that occur in plants during response to high salinity include the control of reactive oxygen species, activation of antioxidant system, accumulation of osmoprotectants in cytosol, induction of K+ uptake and Na+ cell extrusion or its vacuolar compartmentation among others. This review is a compilation of what we have learned in the last 10 years about NO participation during cell signaling in response to high salinity as well as the role of H2S, a new player in the mechanism of plant tolerance to salt stress. The main sources of NO and H2S in plant cells is also discussed together with the evidence of interplay between both signaling molecules during response to stress.

  10. Mechanisms of Contrast-Induced Nephropathy Reduction for Saline (NaCl and Sodium Bicarbonate (NaHCO3

    Directory of Open Access Journals (Sweden)

    W. Patrick Burgess

    2014-01-01

    Full Text Available Nephropathy following contrast media (CM exposure is reduced by administration before, during, and after the contrast procedure of either isotonic sodium chloride solution (Saline or isotonic sodium bicarbonate solution (IsoBicarb. The reasons for this reduction are not well established for either sodium salt; probable mechanisms are discussed in this paper. For Saline, the mechanism for the decrease in CIN is likely related primarily to the increased tubular flow rates produced by volume expansion and therefore a decreased concentration of the filtered CM during transit through the kidney tubules. Furthermore, increased tubular flow rates produce a slight increase in tubular pH resulting from a fixed acid excretion in an increased tubular volume. The mechanism for the decreased CIN associated with sodium bicarbonate includes the same mechanisms listed for Saline in addition to a renal pH effect. Increased filtered bicarbonate anion raises both tubular pH and tubular bicarbonate anion levels toward blood physiologic levels, thus providing increased buffer for reactive oxygen species (ROS formed in the tubules as a result of exposure to CM in renal tubular fluid.

  11. Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

    Directory of Open Access Journals (Sweden)

    A. I. Lenkin

    2012-01-01

    Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

  12. RNA-seq for gene identification and transcript profiling in relation to root growth of bermudagrass (Cynodon dactylon) under salinity stress.

    Science.gov (United States)

    Hu, Longxing; Li, Huiying; Chen, Liang; Lou, Yanhong; Amombo, Erick; Fu, Jinmin

    2015-08-04

    Soil salinity is one of the most significant abiotic stresses affecting plant shoots and roots growth. The adjustment of root architecture to spatio-temporal heterogeneity in salinity is particularly critical for plant growth and survival. Bermudagrass (Cynodon dactylon) is a widely used turf and forage perennial grass with a high degree of salinity tolerance. Salinity appears to stimulate the growth of roots and decrease their mortality in tolerant bermudagrass. To estimate a broad spectrum of genes related to root elongation affected by salt stress and the molecular mechanisms that control the positive response of root architecture to salinity, we analyzed the transcriptome of bermudagrass root tips in response to salinity. RNA-sequencing was performed in root tips of two bermudagrass genotypes contrasting in salt tolerance. A total of 237,850,130 high quality clean reads were generated and 250,359 transcripts were assembled with an average length of 1115 bp. Totally, 103,324 unigenes obtained with 53,765 unigenes (52 %) successfully annotated in databases. Bioinformatics analysis indicated that major transcription factor (TF) families linked to stress responses and growth regulation (MYB, bHLH, WRKY) were differentially expressed in root tips of bermudagrass under salinity. In addition, genes related to cell wall loosening and stiffening (xyloglucan endotransglucosylase/hydrolases, peroxidases) were identified. RNA-seq analysis identified candidate genes encoding TFs involved in the regulation of lignin synthesis, reactive oxygen species (ROS) homeostasis controlled by peroxidases, and the regulation of phytohormone signaling that promote cell wall loosening and therefore root growth under salinity.

  13. Microbial Gene Abundance and Expression Patterns across a River to Ocean Salinity Gradient.

    Directory of Open Access Journals (Sweden)

    Caroline S Fortunato

    Full Text Available Microbial communities mediate the biogeochemical cycles that drive ecosystems, and it is important to understand how these communities are affected by changing environmental conditions, especially in complex coastal zones. As fresh and marine waters mix in estuaries and river plumes, the salinity, temperature, and nutrient gradients that are generated strongly influence bacterioplankton community structure, yet, a parallel change in functional diversity has not been described. Metagenomic and metatranscriptomic analyses were conducted on five water samples spanning the salinity gradient of the Columbia River coastal margin, including river, estuary, plume, and ocean, in August 2010. Samples were pre-filtered through 3 μm filters and collected on 0.2 μm filters, thus results were focused on changes among free-living microbial communities. Results from metagenomic 16S rRNA sequences showed taxonomically distinct bacterial communities in river, estuary, and coastal ocean. Despite the strong salinity gradient observed over sampling locations (0 to 33, the functional gene profiles in the metagenomes were very similar from river to ocean with an average similarity of 82%. The metatranscriptomes, however, had an average similarity of 31%. Although differences were few among the metagenomes, we observed a change from river to ocean in the abundance of genes encoding for catabolic pathways, osmoregulators, and metal transporters. Additionally, genes specifying both bacterial oxygenic and anoxygenic photosynthesis were abundant and expressed in the estuary and plume. Denitrification genes were found throughout the Columbia River coastal margin, and most highly expressed in the estuary. Across a river to ocean gradient, the free-living microbial community followed three different patterns of diversity: 1 the taxonomy of the community changed strongly with salinity, 2 metabolic potential was highly similar across samples, with few differences in

  14. Microbial Gene Abundance and Expression Patterns across a River to Ocean Salinity Gradient.

    Science.gov (United States)

    Fortunato, Caroline S; Crump, Byron C

    2015-01-01

    Microbial communities mediate the biogeochemical cycles that drive ecosystems, and it is important to understand how these communities are affected by changing environmental conditions, especially in complex coastal zones. As fresh and marine waters mix in estuaries and river plumes, the salinity, temperature, and nutrient gradients that are generated strongly influence bacterioplankton community structure, yet, a parallel change in functional diversity has not been described. Metagenomic and metatranscriptomic analyses were conducted on five water samples spanning the salinity gradient of the Columbia River coastal margin, including river, estuary, plume, and ocean, in August 2010. Samples were pre-filtered through 3 μm filters and collected on 0.2 μm filters, thus results were focused on changes among free-living microbial communities. Results from metagenomic 16S rRNA sequences showed taxonomically distinct bacterial communities in river, estuary, and coastal ocean. Despite the strong salinity gradient observed over sampling locations (0 to 33), the functional gene profiles in the metagenomes were very similar from river to ocean with an average similarity of 82%. The metatranscriptomes, however, had an average similarity of 31%. Although differences were few among the metagenomes, we observed a change from river to ocean in the abundance of genes encoding for catabolic pathways, osmoregulators, and metal transporters. Additionally, genes specifying both bacterial oxygenic and anoxygenic photosynthesis were abundant and expressed in the estuary and plume. Denitrification genes were found throughout the Columbia River coastal margin, and most highly expressed in the estuary. Across a river to ocean gradient, the free-living microbial community followed three different patterns of diversity: 1) the taxonomy of the community changed strongly with salinity, 2) metabolic potential was highly similar across samples, with few differences in functional gene abundance

  15. Up-and-down shift in residence depth of slickheads (Alepocephalidae) revealed by otolith stable oxygen isotopic composition.

    Science.gov (United States)

    Shiao, J C; Liu, E Y; Sui, T D

    2016-03-01

    Otolith δ(18)O profiles for four slickhead species (Alepocephalidae) suggested that Alepocephalus umbriceps, Talismania okinawensis and Rouleina watasei migrated hundreds of metres to shallower depths during the juvenile to young stages before returning to their original depth or even deeper waters. Xenodermichthys nodulosus gradually shifted residence depth from shallow to deeper water during their life. These migratory patterns indicated that the slickheads examined had allopatric residence depths at different life stages, which might enhance the pelagic survival and growth rates of the juvenile and young fishes. © 2016 The Fisheries Society of the British Isles.

  16. Abundance and Diversity of Denitrifying and Anammox Bacteria in Seasonally Hypoxic and Sulfidic Sediments of the Saline Lake Grevelingen

    Science.gov (United States)

    Lipsewers, Yvonne A.; Hopmans, Ellen C.; Meysman, Filip J. R.; Sinninghe Damsté, Jaap S.; Villanueva, Laura

    2016-01-01

    Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity, and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways. Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria, aprA gene of sulfur-oxidizing and sulfate-reducing bacteria, and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters. Samples were collected down to 5 cm depth (1 cm resolution) at three different locations before (March) and during summer hypoxia (August). The abundance of denitrifying bacteria did not vary despite of differences in oxygen and sulfide availability in the sediments, whereas anammox bacteria were more abundant in the summer hypoxia but in those sediments with lower sulfide concentrations. The potential activity of denitrifying and anammox bacteria as well as of sulfur-oxidizing, including sulfide-dependent denitrifiers and sulfate-reducing bacteria, was potentially inhibited by the competition for nitrate and nitrite with cable and/or Beggiatoa-like bacteria in March and by the accumulation of sulfide in the summer hypoxia. The simultaneous presence and activity of organoheterotrophic denitrifying bacteria, sulfide-dependent denitrifiers, and anammox bacteria suggests a tight network of bacteria coupling carbon-, nitrogen-, and sulfur cycling in Lake Grevelingen sediments. PMID:27812355

  17. Abundance and diversity of denitrifying and anammox bacteria in seasonally hypoxic and sulfidic sediments of the saline Lake Grevelingen

    Directory of Open Access Journals (Sweden)

    Yvonne A. Lipsewers

    2016-10-01

    Full Text Available Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways. Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria, aprA gene of sulfur-oxidizing and sulfate-reducing bacteria, and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters. Samples were collected down to 5 cm depth (1 cm resolution at three different locations before (March and during summer hypoxia (August. The abundance of denitrifying bacteria did not vary despite of differences in oxygen and sulfide availability in the sediments, whereas anammox bacteria were more abundant in the summer hypoxia but in those sediments with lower sulfide concentrations. The potential activity of denitrifying and anammox bacteria as well as of sulfur-oxidizing, including sulfide-dependent denitrifiers and sulfate-reducing bacteria, was potentially inhibited by the competition for nitrate and nitrite with cable and/or Beggiatoa-like bacteria in March and by the accumulation of sulfide in the summer hypoxia. The simultaneous presence and activity of organoheterotrophic denitrifying bacteria, sulfide-dependent denitrifiers and anammox bacteria suggests a tight network of bacteria coupling carbon-, nitrogen- and sulfur cycling in Lake Grevelingen sediments.

  18. Modulation of estrogenic exposure effects via alterations in salinity and dissolved oxygen in male fathead minnows, Pimephales promelas

    Science.gov (United States)

    Laboratory exposure data indicate that estrogens and estrogen mimics can cause endocrine disruption in male fathead minnows (Pimephales promelas). In the wild, conditions are not static as is often the case in the laboratory. Changes in water quality parameters, such as salinity influx due to road s...

  19. Characterization of saline groundwater across the coastal aquifer of Israel as resource for desalination

    Science.gov (United States)

    Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yospeh; Oren, Yoram; Kasher, Roni

    2015-04-01

    In arid countries with access to marine water seawater desalination is becoming an important water source in order to deal with the water scarcity and population growth. Seawater reverse osmosis (RO) facilities use open seawater intake, which requires pretreatment processes to remove particles in order to avoid fouling of the RO membrane. In small and medium size desalination facilities, an alternative water source can be saline groundwater in coastal aquifers. Using saline groundwater from boreholes near the shore as feed water may have the advantage of natural filtration and low organic content. It will also reduce operation costs of pretreatment. Another advantage of using groundwater is its availability in highly populated areas, where planning of large RO desalination plants is difficult and expensive due to real-estate prices. Pumping saline groundwater underneath the freshwater-seawater interface (FSI) might shift the interface towards the sea, thus rehabilitating the fresh water reservoirs in the aquifer. In this research, we tested the potential use of saline groundwater in the coastal aquifer of Israel as feed water for desalination using field work and desalination experiments. Specifically, we sampled the groundwater from a pumping well 100 m from the shore of Tel-Aviv and sea water from the desalination plant in Ashqelon, Israel. We used an RO cross flow system in a pilot plant in order to compare between the two water types in terms of permeate flux, permeate flux decline, salt rejection of the membrane and the fouling on the membrane. The feed, brine and fresh desalinated water from the outlet of the desalination system were chemically analyzed and compared. Field measurements of dissolved oxygen, temperature, pH and salinity were also conducted in situ. Additionally, SDI (silt density index), which is an important index for desalination, and total organic carbon that has a key role in organic fouling and development of biofouling, were measured and

  20. A global algorithm for estimating Absolute Salinity

    Science.gov (United States)

    McDougall, T. J.; Jackett, D. R.; Millero, F. J.; Pawlowicz, R.; Barker, P. M.

    2012-12-01

    The International Thermodynamic Equation of Seawater - 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density) than does Practical Salinity. When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg-1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p) in the world ocean. To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally).

  1. Study of damaged depth profiles of ion-irradiated PEEK

    Czech Academy of Sciences Publication Activity Database

    Vacík, Jiří; Hnatowicz, Vladimír; Červená, Jarmila; Apel, P. Yu.; Posta, S.; Kobayashi, Y.

    2007-01-01

    Roč. 201, 19-20 (2007), s. 8370-8372 ISSN 0257-8972 R&D Projects: GA MPO(CZ) 1H-PK2/05; GA MŠk 1P04LA213 Institutional research plan: CEZ:AV0Z10480505 Keywords : Oxygen irradiation * Poly-aryl-ether-ether ketone * Thermal neutron depth profiling (TNDP) Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.678, year: 2007

  2. Using Argo-O2 data to examine the impact of deep-water formation events on oxygen uptake in the Labrador Sea

    Science.gov (United States)

    Wolf, M. K.; Hamme, R. C.; Gilbert, D.; Yashayaev, I.

    2016-02-01

    Deep-water formation allows the deep ocean to communicate with the atmosphere, facilitating exchanges of heat as well as important gases such as CO2 and oxygen. The Labrador Sea is the most studied location of deep convection in the North Atlantic Ocean and a strong contributor to the global thermohaline circulation. Since there are no internal sources of oxygen below the euphotic zone, deep-water formation is vital for oxygen transport to the deep ocean. Recent studies document large interannual variability in the strength and depth of convection in the Labrador Sea, from mixed layers of 100m to greater than 1000m. A weakening of this deep convection starves the deep ocean of oxygen, disrupting crucial deep sea biological processes, as well as reducing oceanic CO2 uptake and ocean circulation. We used data from the extensive Argo float network to examine these deep-water formation events in the Labrador Sea. The oxygen optodes onboard many Argo floats suffer from biases whose amplitude must be determined; therefore we investigated and applied various optode calibration methods. Using calibrated vertical profiles of oxygen, temperature, and salinity, we observed the timing, magnitude, and location of deep convection, restratification, and spring phytoplankton blooms. In addition, we used surface oxygen values along with NCEP wind speeds to calculate the air-sea oxygen flux using a range of air-sea gas exchange parameterizations. We then compared this oxygen flux to the rate of change of the measured oxygen inventory. Where the inventory and flux did not agree, we identified other oceanic processes such as biological activity or lateral advection of water masses occurring, or advection of the float itself into a new area. The large role that horizontal advection of water or the float has on oxygen uptake and cycling leads us to conclude that this data cannot be easily interpreted as a 1-D system. Oxygen exchanges with the atmosphere at a faster rate than CO2, is

  3. Desenvolvimento vegetativo do pepino enxertado irrigado com água salina Vegetative development on grafted cucumber plants irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Marcos Vinícius Folegatti

    2000-09-01

    Full Text Available A salinização dos solos em ambiente protegido devido ao excesso de fertilizantes e falta de lixiviação tem resultado na redução da produtividade das culturas. Este trabalho teve o objetivo de avaliar os efeitos da irrigação com água salina no desenvolvimento vegetativo do pepino enxertado cultivado em ambiente protegido. Foram utilizadas águas de diferentes salinidades (S1=1,58; S2=3,08 e S3=5,13 dS m-1, lâminas de água de irrigação (L0=1,00 x ETc e L1=1,25 x ETc e freqüências de aplicação da lâmina L1 (F1=em todas as irrigações e F2=quando a lâmina de água de irrigação acumulada em L0 atingia 100 mm. Os resultados demonstraram que a altura das plantas, área foliar unitária e índice de área foliar foram afetados linearmente pela salinidade da água, não apresentando diferença para as diferentes lâminas e frequências de aplicação de L1.Greenhouse soil salinization by excessive fertilization and lack of leaching has been a common cause of cucumber yield reduction in Brazil. The aim of this work was to evaluate the effects of irrigation with saline water on the vegetative development of grafted cucumber plants in a greenhouse. Three water salinities (S1=1.58; S2=3.08 e S3=5.13 dS m-1, two irrigation water depths (L0=1.00 x ETc e L1=1.25 x ETc and two application frequencies of L1 (F1=in all irrigations and F2=when the irrigation water depth of L0 reached 100 mm were used. Irrigation water depths and frequencies of L1 were grouped and, therefore, the experimental design was in a factorial scheme 3x3, with randomized blocks. Results showed that plant height, unit leaf area and leaf area index were linearly affected by water salinity. No differences were observed for the various irrigation water depths and frequencies of L1 application.

  4. A Pacific hydrographic section at 88°W: Water-property distribution

    Science.gov (United States)

    Tsuchiya, Mizuki; Talley, Lynne D.

    1998-06-01

    Full-depth conductivity-temperature-depth (CTD)/hydrographic measurements with high horizontal and vertical resolution were made in February-April 1993 along a line lying at a nominal longitude of 88°W and extending from southern Chile (54°S) to Guatemala (14°N). It crossed five major deep basins (Southeast Pacific, Chile, Peru, Panama, and Guatemala basins) east of the East Pacific Rise. Vertical sections of potential temperature, salinity, potential density, oxygen, silica, phosphate, nitrate, and nitrite are presented to illustrate the structure of the entire water column. Some features of interest found in the sections are described, and an attempt is made to interpret them in terms of the isopycnal property distributions associated with the large-scale ocean circulation. These features include: various near-surface waters observed in the tropical and subtropical regions and the fronts that mark the boundaries of these waters; the possible importance of salt fingering to the downward salt transfer from the high-salinity subtropical water; a shallow thermostad (pycnostad) developed at 16°-18.5°C in the subtropical water; low-salinity surface water in the subantarctic zone west of southern Chile; large domains of extremely low oxygen in the subpycnocline layer on both sides of the equator and a secondary nitrite maximum associated with a nitrate minimum in these low-oxygen domains; high-salinity, low-oxygen, high-nutrient subpycnocline water that is carried poleward along the eastern boundary by the Peru-Chile Undercurrent; the Subantarctic Mode and Antarctic Intermediate waters; middepth isopycnal property extrema observed at the crest of the Sala y Gomez Ridge; influences of the North Pacific and the North Atlantic upon deep waters along the section; and the characteristics and sources of the bottom waters in the five deep basins along the section.

  5. Ketogenic diet for high partial pressure oxygen diving.

    Science.gov (United States)

    Valadao, Jason M; Vigilante, John A; DiGeorge, Nicholas W; O'Connor, Sunila E; Bear, Alexandria; Kenyon, Jeffrey; Annis, Heather; Dituri, Joseph; Dituri, Amy E; Whelan, Harry T

    2014-01-01

    A ketogenic diet (KD) may decrease central nervous system oxygen toxicity symptoms in divers, and in view of this implication a feasibility/ toxicity pilot study was performed to demonstrate tolerance of KD while performing normal diving profiles. The exact mechanism of neuroprotection from the KD remains unknown; however, evidence to support the efficacy of the KD in reducing seizures is present in epilepsy and oxygen toxicity studies, and may provide valuable insight in diving activities. Three divers (two males and one female ages 32-45 with a history of deep diving and high pO2 exposure) on the KD made dives to varying depths in Hawaii using fully closed-circuit MK-15 and Inspiration rebreathers. These rebreathers have an electronically controlled set point, allowing the divers to monitor and control the oxygen level in the breathing loop, which can be varied manually by the divers. Oxygen level was varied during descent, bottom depth and ascent (decompression). Divers fasted for 12-18 hours before diet initiation. The ketosis level was verified by urinating on a Ketostix (reagent strips for urinalysis). Ketosis was achieved and was easily monitored with Ketostix in the simulated operational environment. The KD did not interfere with the diving mission; no seizure activity or signs or symptoms of CNS toxicity were observed, and there were no adverse effects noted by the divers while on the KD.

  6. Effects of the Oxygen-Carrying Solution OxyVita C on the Cerebral Microcirculation and Systemic Blood Pressures in Healthy Rats

    Directory of Open Access Journals (Sweden)

    Rania Abutarboush

    2014-11-01

    Full Text Available The use of hemoglobin-based oxygen carriers (HBOC as oxygen delivering therapies during hypoxic states has been hindered by vasoconstrictive side effects caused by depletion of nitric oxide (NO. OxyVita C is a promising oxygen-carrying solution that consists of a zero-linked hemoglobin polymer with a high molecular weight (~17 MDa. The large molecular weight is believed to prevent extravasation and limit NO scavenging and vasoconstriction. The aim of this study was to assess vasoactive effects of OxyVita C on systemic blood pressures and cerebral pial arteriole diameters. Anesthetized healthy rats received four intravenous (IV infusions of an increasing dose of OxyVita C (2, 25, 50, 100 mg/kg and hemodynamic parameters and pial arteriolar diameters were measured pre- and post-infusion. Normal saline was used as a volume-matched control. Systemic blood pressures increased (P ≤ 0.05 with increasing doses of OxyVita C, but not with saline. There was no vasoconstriction in small (<50 µm and medium-sized (50–100 µm pial arterioles in the OxyVita C group. In contrast, small and medium-sized pial arterioles vasoconstricted in the control group. Compared to saline, OxyVita C showed no cerebral vasoconstriction after any of the four doses evaluated in this rat model despite increases in blood pressure.

  7. Salinity does not alter the effectiveness of menthol as an anesthetic and sedative during the handling and transport of juvenile fat snook (Centropomus parallelus

    Directory of Open Access Journals (Sweden)

    L. C. O.’R. Sepulchro

    Full Text Available Abstract The effectiveness of menthol as anesthetic and sedative for fat snook (Centropomus parallelus was tested at different salinities. In the first experiment, the fish were exposed to different concentrations of menthol (25, 37 and 50 mg L–1 in water at different salinities (0, 17 and 36 ppt. In the second experiment, the fish were transported for 10 hours in water with menthol at concentrations of 0, 3.7 and 7.4 mg L–1 under different salinities. Na+ and K+ ions from fish body and water were analyzed after transport. The optimal concentrations of menthol for a short handling period and surgical induction was 37 and 50 mg L–1, respectively, and these values were independent of salinity. After transport, neither mortality nor significant changes in ammonia or dissolved oxygen were observed between treatments at the different salinities. The nitrite levels were lower in freshwater than in brackish and saltwater, but did not change with mentol. The total body levels of Na+ increased with the salinity increase. Menthol is an effective anesthetic for handling of juvenile fat snook at different salinities. Menthol did not influence the measured water parameters and body ions, and it is not necessary for the transport of fat snook.

  8. Salinity does not alter the effectiveness of menthol as an anesthetic and sedative during the handling and transport of juvenile fat snook (Centropomus parallelus).

    Science.gov (United States)

    Sepulchro, L C O 'r; Carvalho, M A G; Gomes, L C

    2016-04-19

    The effectiveness of menthol as anesthetic and sedative for fat snook (Centropomus parallelus) was tested at different salinities. In the first experiment, the fish were exposed to different concentrations of menthol (25, 37 and 50 mg L-1) in water at different salinities (0, 17 and 36 ppt). In the second experiment, the fish were transported for 10 hours in water with menthol at concentrations of 0, 3.7 and 7.4 mg L-1 under different salinities. Na+ and K+ ions from fish body and water were analyzed after transport. The optimal concentrations of menthol for a short handling period and surgical induction was 37 and 50 mg L-1, respectively, and these values were independent of salinity. After transport, neither mortality nor significant changes in ammonia or dissolved oxygen were observed between treatments at the different salinities. The nitrite levels were lower in freshwater than in brackish and saltwater, but did not change with mentol. The total body levels of Na+ increased with the salinity increase. Menthol is an effective anesthetic for handling of juvenile fat snook at different salinities. Menthol did not influence the measured water parameters and body ions, and it is not necessary for the transport of fat snook.

  9. Effect of Salinity on Germination and Its Relationship with Vegetative growth in Bromus danthoniae Genotypes from Saline and Non-Saline Areas of Iran

    Directory of Open Access Journals (Sweden)

    M. Rezaei

    2018-02-01

    Full Text Available Bromus danthoniae Trin. is an annual grass species that is well adapted to harsh climates and could be considered as an important genetic resources for tolerance to environmental stresses such as salinity. In this study, 24 genotypes collected from Ilam, Kurdistan, Kermanshah (non-saline areas and West Azerbaijan (saline area: shores of Uremia Salt Lake provinces of Iran were investigated at the germination stage under salt treatments with concentrations of 0, 60, 120, 180, 240 and 300 mM sodium chloride. Germination percentage, germination rate index, seed vigor, root length, shoot length and seedling fresh and dry weights were measured. In addition, the relationship between the percentage of germination in 300 mM sodium chloride and the survival rate (% after four weeks in 350 mM sodium chloride at the vegetative stage was evaluated. The results of analysis of variance showed that salinity treatments caused significant reductions in all the studied traits. Genotypic variation and the interaction of genotype × salt treatments were also significant. Genotypes USLN3 and KER4 were found to be the most tolerant and sensitive genotypes to salinity stress, with 13% and 98% reduction in germination percentage at 300 mM NaCl, respectively. Cluster analysis divided the genotypes into three groups, with one group containing only tolerant genotypes from Uremia Salt Lake, another one comprising only sensitive genotypes from non-saline regions, and the third one containing genotypes from both regions. The correlation between the germination percentage and the survival rate at the vegetative stage was not significant, indicating that different mechanisms are, perhaps, responsible for salinity tolerance at the germination and vegetative stages in B. danthoniae.

  10. CO{sub 2} storage in saline aquifers; Stockage du CO{sub 2} dans les aquiferes salins

    Energy Technology Data Exchange (ETDEWEB)

    Bentham, M.; Kirby, G. [British Geological Survey (BGS), Kingsley Dunham Centre, Keyworth, Nottingham (United Kingdom)

    2005-06-01

    Saline aquifers represent a promising way for CO{sub 2} sequestration. Storage capacities of saline aquifers are very important around the world. The Sleipner site in the North Sea is currently the single case world-wide of CO{sub 2} storage in a saline aquifer. A general review is given on the specific risks for CO{sub 2} storage in saline aquifer. The regional distribution of CO{sub 2} storage potential is presented. Finally, the knowledge gaps and the future research in this field are defined. (authors)

  11. A global algorithm for estimating Absolute Salinity

    Directory of Open Access Journals (Sweden)

    T. J. McDougall

    2012-12-01

    Full Text Available The International Thermodynamic Equation of Seawater – 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density than does Practical Salinity.

    When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic, Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg−1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p in the world ocean.

    To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811. In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally.

  12. Administration of Oxygen Ultra-Fine Bubbles Improves Nerve Dysfunction in a Rat Sciatic Nerve Crush Injury Model

    Directory of Open Access Journals (Sweden)

    Hozo Matsuoka

    2018-05-01

    Full Text Available Ultra-fine bubbles (<200 nm in diameter have several unique properties and have been tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUBs on a sciatic nerve crush injury (SNC model rats. Rats were intraperitoneally injected with 1.5 mL saline, OUBs diluted in saline, or nitrogen ultra-fine bubbles (NUBs diluted in saline three times per week for 4 weeks in four groups: (1 control, (sham operation + saline; (2 SNC, (crush + saline; (3 SNC+OUB, (crush + OUB-saline; (4 SNC+NUB, (crush + NUB-saline. The effects of the OUBs on dorsal root ganglion (DRG neurons and Schwann cells (SCs were examined by serial dilution of OUB medium in vitro. Sciatic functional index, paw withdrawal thresholds, nerve conduction velocity, and myelinated axons were significantly decreased in the SNC group compared to the control group; these parameters were significantly improved in the SNC+OUB group, although NUB treatment did not affect these parameters. In vitro, OUBs significantly promoted neurite outgrowth in DRG neurons by activating AKT signaling and SC proliferation by activating ERK1/2 and JNK/c-JUN signaling. OUBs may improve nerve dysfunction in SNC rats by promoting neurite outgrowth in DRG neurons and SC proliferation.

  13. Salinity, sound velocity, and other data from CTD, XBT, XSV, AXBT, and XCTD casts from 20 May 1978 to 01 September 2000 (NODC Accession 0000383)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity, sound velocity, depth, and temperature data were collected using CTD, XBT, XSV, AXBT, and XCTD casts from May 20, 1978 to September 1, 2000. Data were...

  14. Isolation of a halophilic bacterium, Bacillus sp. strain NY-6 for organic contaminants removal in saline wastewater on ship

    Science.gov (United States)

    Gao, Jie; Yu, Zhenjiang; Zhang, Xiaohui; Zhao, Dan; Zhao, Fangbo

    2013-06-01

    The objective of this research was to examine if certain strains of Bacillus bacteria, could survive in dry powder products and if so, could the bacteria degrade organic contaminants in saline wastewater on a ship. As part of the study, we isolated 7 domesticated strains named NY1, NY2,..., and NY7, the strain NY6 showed to have the best performance for organic matter degradation and could survive in dry powder more than 3 months. NY6 was identified as Bacillus aerius, based on the morphological and physic-chemical properties. Its optimal growth conditions were as follows: salinity was 2%; temperature was 37°C; pH was in 6.5-7.0; best ratio of C: N: P was 100:5:1. The capability of its dry powder for Chemical Oxygen Demand (COD) removal was 800mg COD/g in synthesized marine wastewater with 2% salinity. The spores in the dry powder were 1.972×108 g -1.

  15. Effects of salinity and pH on the activity and oxygen consumption of Brachionus plicatilis (rotatoria)

    Energy Technology Data Exchange (ETDEWEB)

    Epp, R.W.; Winston, P.W.

    1978-01-01

    Activity and respiratory rates of the rotifer, Brachionus plicatilis, were determined following exposure to pH values of 6.5, 7.5 and 8.5 and to concentrations of 10, 50 and 100 mosm. Changes in the hydrogen-ion concentration had no detectable effect on either activity or metabolism. Acute reduction in osmolarity of the medium resulted in a reduction in oxygen consumption and activity. Both activity and oxygen consumption increased upon acclimatization to osmolarities of 50 and 100 mosm.

  16. Impacts of sea-surface salinity in an eddy-resolving semi-global OGCM

    Science.gov (United States)

    Furue, Ryo; Takatama, Kohei; Sasaki, Hideharu; Schneider, Niklas; Nonaka, Masami; Taguchi, Bunmei

    2018-02-01

    To explore the impacts of sea-surface salinity (SSS) on the interannual variability of upper-ocean state, we compare two 10-year runs of an eddy-resolving ocean general circulation model (OGCM): in one, SSS is strongly restored toward a monthly climatology (World Ocean Atlas '98) and in the other, toward the SSS of a monthly gridded Argo product. The inclusion of the Argo SSS generally improves the interannual variability of the mixed layer depth; particularly so in the western tropical Pacific, where so-called "barrier layers" are reproduced when the Argo SSS is included. The upper-ocean subsurface salinity variability is also improved in the tropics and subtropics even below the mixed layer. To understand the reason for the latter improvement, we separate the salinity difference between the two runs into its "dynamical" and "spiciness" components. The dynamical component is dominated by small-scale noise due to the chaotic nature of mesoscale eddies. The spiciness difference indicates that as expected from the upper-ocean general circulation, SSS variability in the mixed layer is subducted into the thermocline in subtropics; this signal is generally advected downward, equatorward, and westward in the equator-side of the subtropical gyre. The SSS signal subducted in the subtropical North Pacific appears to enter the Indian Ocean through the Indonesian Throughflow, although this signal is weak and probably insignificant in our model.

  17. Accumulation of Fe oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent Fe oxidation

    Science.gov (United States)

    Heller, Maija I.; Lam, Phoebe J.; Moffett, James W.; Till, Claire P.; Lee, Jong-Mi; Toner, Brandy M.; Marcus, Matthew A.

    2017-08-01

    Oxygen minimum zones (OMZs) have been proposed to be an important source of dissolved iron (Fe) into the interior ocean. However, previous studies in OMZs have shown a sharp decrease in total dissolved Fe (dFe) and/or dissolved Fe(II) (dFe(II)) concentrations at the shelf-break, despite constant temperature, salinity and continued lack of oxygen across the shelf-break. The loss of both total dFe and dFe(II) suggests a conversion of the dFe to particulate form, but studies that have coupled the reduction-oxidation (redox) speciation of both dissolved and particulate phases have not previously been done. Here we have measured the redox speciation and concentrations of both dissolved and particulate forms of Fe in samples collected during the U.S. GEOTRACES Eastern tropical Pacific Zonal Transect (EPZT) cruise in 2013 (GP16). This complete data set allows us to assess possible mechanisms for loss of dFe. We observed an offshore loss of dFe(II) within the oxygen deficient zone (ODZ), where dissolved oxygen is undetectable, accompanied by an increase in total particulate Fe (pFe). Total pFe concentrations were highest in the upper ODZ. X-ray absorption spectroscopy revealed that the pFe maximum was primarily in the Fe(III) form as Fe(III) oxyhydroxides. The remarkable similarity in the distributions of total particulate iron and nitrite suggests a role for nitrite in the oxidation of dFe(II) to pFe(III). We present a conceptual model for the rapid redox cycling of Fe that occurs in ODZs, despite the absence of oxygen.

  18. Alleviation of adverse impact of salinity on faba bean (vicia faba l.) by arbuscular mycorrhizal fungialleviation of adverse impact of salinity on faba bean (vicia faba l.) by arbuscular mycorrhizal fungi

    International Nuclear Information System (INIS)

    Abeer, H.; Didamony, E.L.

    2014-01-01

    The present study was conducted to assess the effect of different concentrations of sodium chloride (NaCl) in presence and absence of AMF on growth, physio-biochemical and enzymatic activity in faba bean (Vicia faba). Different concentrations of NaCl showed reduction in growth and yield parameters, which indicates the deleterious effects of salinity on the plant. The total spore count and colonization by arbuscular mycorrhizal fungi (AMF) is also decreasing at higher concentrations of NaCl. Application of AMF mitigates the effect of NaCl stress and improved the growth and yield in the present study. NaCl also decreased the nodulation as well as nodule activity and pigments content, however the supplementation of by AMF to plants treated with sodium chloride showed enhancement in nodule activity and pigment content. Polyamines (Putresciene, Spermidine, Spermine), acid and alkaline phosphates increased with increasing concentration of sodium chloride and application of by AMF showed further increase in the above phytoconstituents, proving the protective role of these phytoconstituents against salt stress. Salinity stress is responsible for the generation of reactive oxygen species, which lead to the membrane damage through lipid peroxidation in the present study. Maximum lipid peroxidation was observed at higher concentration of sodium chloride and AMF treatment minimized the effect of salinity on lipid peroxidation. To combat with the reactive oxygen species, plants upregulate the enzymatic antioxidants like superoxide dismutase, catalase, peroxidase and ascorbate peroxidase. As the concentration of sodium chloride increases the enzyme activity also increases and further increase was observed with supplementation of AMF to salt treated plants. Arbuscular mycorrhizal fungi also restores the potassium and calcium contents and maintain their ratio that was hampered with increasing concentration of sodium chloride in the present study. In conclusion, application of AMF

  19. Identification of the mechanisms and origin of salinization of groundwaters in coastal aquifers by means of isotopic techniques

    International Nuclear Information System (INIS)

    Araguas, L. J.; Quejido, A. J.

    2007-01-01

    To study the origin of salinity and the mechanisms operating in coastal aquifers, a set of tools is available to determine the essential aspects of the hydrogeological behaviour of the system. these tools are based on the integrated use of hydrochemical parameters (major constituents and trace elements) and isotopic parameters (oxygen, hydrogen, sulfur, carbon, strontium and boron). In addition to the active intrusion of seawater, salinization in coastal areas may be influenced by various human activities that accelerate the degradation of water quality, such as concentrated pumping, intensive farming techniques with return of irrigation water, or reuse of urban and industrial waste water. Characterization of the dominant processes and mechanisms is required for suitable management of the resource and implementation of corrective measures. (Author)

  20. Ecosystem variability along the estuarine salinity gradient: Examples from long-term study of San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.; Schraga, Tara; Kress, Erica S.; Martin, Charles A.

    2017-01-01

    The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

  1. Millennial changes of the Baltic Sea salinity. Studies of the sensitivity of the salinity to climate change

    International Nuclear Information System (INIS)

    Gustafsson, Bo G.

    2004-05-01

    An important question for safety assessments of nuclear waste repositories is the salinity of the Baltic Sea under different conditions. The salinity affects the potential recipient ecosystems, the water turnover along the coast and the hydrology as well as the groundwater chemistry. In this report a model that enables computation of the Baltic Sea salinity for different sea level positions and freshwater supplies is presented. The model is used to compute the salinities in Baltic proper, Bothnian Sea and Bothnian Bay for all combinations of global sea level changes from -10 m to 10 m and freshwater supplies from 0 to 60,000 m 3 /s. The results are presented in a series of graphs that enables the reader to make an assessment of the impact of a given climatic change. The model is also used to compute the decrease of the salinity in Bothnian Sea and Bothnian Bay during the next few millennia due to the postglacial uplift. The results show that modest changes in global sea level, say ±1 m, give a salinity change of the order of 1 psu in southern Baltic proper. Changing the freshwater supply with about 2,000 m 3 /s (approximately 10%) gives a similar salinity change. Further, a sea level drop of about 5 m or an increase of the freshwater supply by a factor of 3 is needed to reduce the salinity in southern Baltic proper below 1 psu. In this limit large parts of the Baltic would be limnic. A 50% decrease of the freshwater supply increase the salinity in the southern Baltic proper by a factor of 2 to some 15 psu, but the effect is even more drastic in Bothnian Sea and Bothnian Bay where the salinity increase to 13 and 10 psu, respectively. A less windy climate might have a significant effect in lowering the Baltic salinity due to a combined effect of lowered mixing in Kattegat and lowered exchange between Kattegat and the Baltic. A windier climate will not have such strong effect since increased mixing does not affect the Baltic as much. Most probably the shoreline

  2. Millennial changes of the Baltic Sea salinity. Studies of the sensitivity of the salinity to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Bo G. [Oceanus Havsundersoekningar, Goeteborg (Sweden)

    2004-05-01

    An important question for safety assessments of nuclear waste repositories is the salinity of the Baltic Sea under different conditions. The salinity affects the potential recipient ecosystems, the water turnover along the coast and the hydrology as well as the groundwater chemistry. In this report a model that enables computation of the Baltic Sea salinity for different sea level positions and freshwater supplies is presented. The model is used to compute the salinities in Baltic proper, Bothnian Sea and Bothnian Bay for all combinations of global sea level changes from -10 m to 10 m and freshwater supplies from 0 to 60,000 m{sup 3}/s. The results are presented in a series of graphs that enables the reader to make an assessment of the impact of a given climatic change. The model is also used to compute the decrease of the salinity in Bothnian Sea and Bothnian Bay during the next few millennia due to the postglacial uplift. The results show that modest changes in global sea level, say {+-}1 m, give a salinity change of the order of 1 psu in southern Baltic proper. Changing the freshwater supply with about 2,000 m{sup 3}/s (approximately 10%) gives a similar salinity change. Further, a sea level drop of about 5 m or an increase of the freshwater supply by a factor of 3 is needed to reduce the salinity in southern Baltic proper below 1 psu. In this limit large parts of the Baltic would be limnic. A 50% decrease of the freshwater supply increase the salinity in the southern Baltic proper by a factor of 2 to some 15 psu, but the effect is even more drastic in Bothnian Sea and Bothnian Bay where the salinity increase to 13 and 10 psu, respectively. A less windy climate might have a significant effect in lowering the Baltic salinity due to a combined effect of lowered mixing in Kattegat and lowered exchange between Kattegat and the Baltic. A windier climate will not have such strong effect since increased mixing does not affect the Baltic as much. Most probably the

  3. Past 20,000-year history of Himalayan aridity: Evidence from oxygen isotope records in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.

    Late Quaternary climate history of the Himalayas is inferred from sea surface salinity (SSS) changes determined from the oxygen isotope in planktonic foraminifers, in a turbidity-free, 14C-dated core from the Bay of Bengal. The heaviest d18O...

  4. Seasonal variation of hydrographic and nutrient fields during the US JGOFS Arabian Sea Process Study

    Science.gov (United States)

    Morrison, J. M.; Codispoti, L. A.; Gaurin, S.; Jones, B.; Manghnani, V.; Zheng, Z.

    Between September 1994 and December 1995, the US JGOFS Arabian Sea Process Experiment collected extensive, high quality hydrographic data (temperature, salinity, dissolved oxygen and nutrients) during all seasons in the northern Arabian Sea. An analysis of this unique data suite suggests the presence of many features that are described in the canonical literature, but these new data provided the following insights. Although the seasonal evolution of mixed-layer depths was in general agreement with previous descriptions, the deepest mixed-layer depths in our data occurred during the late NE Monsoon instead of the SW Monsoon. The region exhibits considerable mesoscale variability resulting in extremely variable temperature-salinity (TS) distributions in the upper 1000 db. This mesoscale variability is readily observed in satellite imaging, in the high resolution data taken by a companion ONR funded project, and in underway ADCP data. The densest water reaching the sea surface during coastal upwelling appeared to have maximum offshore depths of ˜150 m and σθ's close to the core value (˜25) for the saline Arabian Sea Water (ASW), but salinities in these upwelling waters were relatively low. The densest water found at the sea surface during late NE Monsoon conditions has σθ's>24.8 and relatively high salinities, suggesting that they are a source for the ASW salinity maximum. Persian Gulf Water (PGW) with a core σθ of 26.6 forms a widespread salinity maximum. Despite the considerable extent of this feature, Persian Gulf outflow water, with a salinity (4) of ˜39 at its source, can only be a minor contributor. Within the standard US JGOFS sampling grid, maximum salinities on this surface are ˜36.8 at stations near the Gulf, falling to values as low as ˜35.3 at the stations farthest removed from its influence. Even at our standard stations closest to the Gulf (N-1 and N-2), the high-salinity, low-nutrient Persian Gulf water has only a modest direct effect on

  5. Saline water irrigation for crop production

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Singh, S S; Singh, S R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India)

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation.

  6. Saline water irrigation for crop production

    International Nuclear Information System (INIS)

    Khan, A.R.; Singh, S.S.; Singh, S.R.

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation

  7. 40 CFR 230.25 - Salinity gradients.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Salinity gradients. 230.25 Section 230.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b... Physical and Chemical Characteristics of the Aquatic Ecosystem § 230.25 Salinity gradients. (a) Salinity...

  8. Turbidity and salinity affect feeding performance and physiological stress in the endangered delta smelt.

    Science.gov (United States)

    Hasenbein, Matthias; Komoroske, Lisa M; Connon, Richard E; Geist, Juergen; Fangue, Nann A

    2013-10-01

    Coastal estuaries are among the most heavily impacted ecosystems worldwide with many keystone fauna critically endangered. The delta smelt (Hypomesus transpacificus) is an endangered pelagic fish species endemic to the Sacramento-San Joaquin Estuary in northern California, and is considered as an indicator species for ecosystem health. This ecosystem is characterized by tidal and seasonal gradients in water parameters (e.g., salinity, temperature, and turbidity), but is also subject to altered water-flow regimes due to water extraction. In this study, we evaluated the effects of turbidity and salinity on feeding performance and the stress response of delta smelt because both of these parameters are influenced by water flows through the San Francisco Bay Delta (SFBD) and are known to be of critical importance to the completion of the delta smelt's life cycle. Juvenile delta smelt were exposed to a matrix of turbidities and salinities ranging from 5 to 250 nephelometric turbidity units (NTUs) and 0.2 to 15 parts per thousand (ppt), respectively, for 2 h. Best statistical models using Akaike's Information Criterion supported that increasing turbidities resulted in reduced feeding rates, especially at 250 NTU. In contrast, best explanatory models for gene transcription of sodium-potassium-ATPase (Na/K-ATPase)-an indicator of osmoregulatory stress, hypothalamic pro-opiomelanocortin-a precursor protein to adrenocorticotropic hormone (expressed in response to biological stress), and whole-body cortisol were affected by salinity alone. Only transcription of glutathione-S-transferase, a phase II detoxification enzyme that protects cells against reactive oxygen species, was affected by both salinity and turbidity. Taken together, these data suggest that turbidity is an important determinant of feeding, whereas salinity is an important abiotic factor influencing the cellular stress response in delta smelt. Our data support habitat association studies that have shown greater

  9. Salinity induced oxidative stress enhanced biofuel production potential of microalgae Scenedesmus sp. CCNM 1077.

    Science.gov (United States)

    Pancha, Imran; Chokshi, Kaumeel; Maurya, Rahulkumar; Trivedi, Khanjan; Patidar, Shailesh Kumar; Ghosh, Arup; Mishra, Sandhya

    2015-01-01

    Microalgal biomass is considered as potential feedstock for biofuel production. Enhancement of biomass, lipid and carbohydrate contents in microalgae is important for the commercialization of microalgal biofuels. In the present study, salinity stress induced physiological and biochemical changes in microalgae Scenedesmus sp. CCNM 1077 were studied. During single stage cultivation, 33.13% lipid and 35.91% carbohydrate content was found in 400 mM NaCl grown culture. During two stage cultivation, salinity stress of 400 mM for 3 days resulted in 24.77% lipid (containing 74.87% neutral lipid) along with higher biomass compared to single stage, making it an efficient strategy to enhance biofuel production potential of Scenedesmus sp. CCNM 1077. Apart from biochemical content, stress biomarkers like hydrogen peroxide, lipid peroxidation, ascorbate peroxidase, proline and mineral contents were also studied to understand the role of reactive oxygen species (ROS) mediated lipid accumulation in microalgae Scenedesmus sp. CCNM 1077. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Growth of anodic oxide films on oxygen-containing niobium

    Energy Technology Data Exchange (ETDEWEB)

    Habazaki, H. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)]. E-mail: habazaki@eng.hokudai.ac.jp; Ogasawara, T. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Konno, H. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Shimizu, K. [University Chemical Laboratory, Keio University, Yokohama 223-8522 (Japan); Asami, K. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Saito, K. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Nagata, S. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Skeldon, P. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom); Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)

    2005-09-20

    The present study is directed at understanding of the influence of oxygen in the metal on anodic film growth on niobium, using sputter-deposited niobium containing from about 0-52 at.% oxygen, with anodizing carried out at high efficiency in phosphoric acid electrolyte. The findings reveal amorphous anodic niobia films, with no significant effect of oxygen on the field strength, transport numbers, mobility of impurity species and capacitance. However, since niobium is partially oxidized due to presence of oxygen in the substrate, less charge is required to form the films, hence reducing the time to reach a particular film thickness and anodizing voltage. Further, the relative thickness of film material formed at the metal/film interface is increased by the incorporation of oxygen species into the films from the substrate, with an associated altered depth of incorporation of phosphorus species into the films.

  11. Increase of urban lake salinity by road deicing salt

    International Nuclear Information System (INIS)

    Novotny, Eric V.; Murphy, Dan; Stefan, Heinz G.

    2008-01-01

    Over 317,000 tonnes of road salt (NaCl) are applied annually for road deicing in the Twin Cities Metropolitan Area (TCMA) of Minnesota. Although road salt is applied to increase driving safety, this practice influences environmental water quality. Thirteen lakes in the TCMA were studied over 46 months to determine if and how they respond to the seasonal applications of road salt. Sodium and chloride concentrations in these lakes were 10 and 25 times higher, respectively, than in other non-urban lakes in the region. Seasonal salinity/chloride cycles in the lakes were correlated with road salt applications: High concentrations in the winter and spring, especially near the bottom of the lakes, were followed by lower concentrations in the summer and fall due to flushing of the lakes by rainfall runoff. The seasonal salt storage/flushing rates for individual lakes were derived from volume-weighted average chloride concentration time series. The rate ranged from 9 to 55% of a lake's minimum salt content. In some of the lakes studied salt concentrations were high enough to stop spring turnover preventing oxygen from reaching the benthic sediments. Concentrations above the sediments were also high enough to induce convective mixing of the saline water into the sediment pore water. A regional analysis of historical water quality records of 38 lakes in the TCMA showed increases in lake salinity from 1984 to 2005 that were highly correlated with the amount of rock salt purchased by the State of Minnesota. Chloride concentrations in individual lakes were positively correlated with the percent of impervious surfaces in the watershed and inversely with lake volume. Taken together, the results show a continuing degradation of the water quality of urban lakes due to application of NaCl in their watersheds

  12. Circulation, eddies, oxygen, and nutrient changes in the eastern tropical South Pacific Ocean

    Science.gov (United States)

    Czeschel, R.; Stramma, L.; Weller, R. A.; Fischer, T.

    2015-06-01

    A large subsurface oxygen deficiency zone is located in the eastern tropical South Pacific Ocean (ETSP). The large-scale circulation in the eastern equatorial Pacific and off the coast of Peru in November/December 2012 shows the influence of the equatorial current system, the eastern boundary currents, and the northern reaches of the subtropical gyre. In November 2012 the equatorial undercurrent (EUC) is centered at 250 m depth, deeper than in earlier observations. In December 2012, the equatorial water is transported southeastward near the shelf in the Peru-Chile undercurrent (PCUC) with a mean transport of 1.4 Sv. In the oxygen minimum zone (OMZ), the flow is overlaid with strong eddy activity on the poleward side of the OMZ. Floats with parking depth at 400 m show fast westward flow in the mid-depth equatorial channel and sluggish flow in the OMZ. Floats with oxygen sensors clearly show the passage of eddies with oxygen anomalies. The long-term float observations in the upper ocean lead to a net community production estimate at about 18° S of up to 16.7 mmol C m-3 yr-1 extrapolated to an annual rate and 7.7 mmol C m-3 yr-1 for the time period below the mixed layer. Oxygen differences between repeated ship sections are influenced by the Interdecadal Pacific Oscillation (IPO), by the phase of El Niño, by seasonal changes, and by eddies, and hence have to be interpreted with care. At and south of the Equator the decrease in oxygen in the upper ocean since 1976 is related to an increase in nitrate, phosphate, and in part silicate.

  13. OPTIMUM, CRITICAL AND THRESHOLD VALUES FOR WATER OXYGENATION FOR MULLETS (MUGILIDAE AND FLATFISHES (PLEURONECTIDAE IN ONTOGENESIS

    Directory of Open Access Journals (Sweden)

    P. Shekk

    2014-12-01

    Full Text Available Purpose. To determine the optimum, critical, and threshold values of water oxygenation for embryos, larvae and fingerlings of mullets and flatfishes under different temperature conditions. Methodology. Oxygen consumption was studied in chronic experiments with «interrupted flow» method with automatic fixation of dissolved oxygen in water with the aid of an oxygen sensor and automatic, continuous recording of the obtained results. «Critical» (Pcrit., and the «threshold» (Pthr. oxygen tension in the water have been determined. Findings. Under optimum conditions, the normal embryogenesis of mullets and flatfish to the gastrulation stage, provided 90–130% oxygen saturation. The critical content was 80–85%, the threshold – 65–70% of the saturation. At the stage of «movable embryo» depending on water temperature and fish species, the optimum range of water oxygenation was within 70‒127.1%. The most tolerant to oxygen deficiency was flounder Platichthys luscus (Pcrit – 25.4–27,5; Pthr. – 20.5–22.5%, the least resistant to hypoxia was striped mullet Mugil серhalus (Pcrit. – 50–60; Pthr. – 35–40%. The limits of the critical and threshold concentration of dissolved oxygen directly depended on the temperature and salinity, at which embryogenesis occurred. An increase in water temperature and salinity resulted in an increase in critical and threshold values for oxygen tension embryos. Mullet and flatfish fingerlings in all stages of development had a high tolerance to hypoxia, which increased as they grew. They were resistant to the oversaturation of water with oxygen. The most demanding for the oxygen regime are larvae and fingerlings of striped mullet and Liza aurata. Hypoxia tolerance of Psetta maeoticus (Psetta maeoticus and flounder at all stages of development is very high. The fingerlings of these species can endure reduction of the dissolved oxygen in water to 2.10 and 1.65 mgO2/dm3 respectively for a long time

  14. Electrocapillary Phenomena at Edible Oil/Saline Interfaces.

    Science.gov (United States)

    Nishimura, Satoshi; Ohzono, Takuya; Shoji, Kohei; Yagihara, Shin; Hayashi, Masafumi; Tanaka, Hisao

    2017-03-01

    Interfacial tension between edible oil and saline was measured under applied electric fields to understand the electrocapillary phenomena at the edible oil/saline interfaces. The electric responses of saline droplets in edible oil were also observed microscopically to examine the relationship between the electrocapillary phenomena and interfacial polarization. When sodium oleate (SO) was added to edible oil (SO-oil), the interfacial tension between SO-oil and saline decreased. However, no decrease was observed for additive-free oil or oleic acid (OA)-added oil (OA-oil). Microscopic observations suggested that the magnitude of interfacial polarization increased in the order of additive-free oil oil oil. The difference in electrocapillary phenomena between OA- and SO-oils was closely related to the polarization magnitude. In the case of SO-oil, the decrease in interfacial tension was remarkably larger for saline (pH 5.4~5.6) than that for phosphate-buffered saline (PBS, pH 7.2~7.4). However, no difference was observed between the electric responses of PBS and saline droplets in SO-oil. The difference in electrocapillary phenomena for PBS and saline could not be simply explained in terms of polarization magnitude. The ratio of ionized and non-ionized OA at the interfaces changed with the saline pH, possibly leading to the above difference.

  15. Effects of acute changes in salinity and temperature on routine metabolism and nitrogen excretion in gambusia (Gambusia affinis) and zebrafish (Danio rerio).

    Science.gov (United States)

    Uliano, E; Cataldi, M; Carella, F; Migliaccio, O; Iaccarino, D; Agnisola, C

    2010-11-01

    Acute stress may affect metabolism and nitrogen excretion as part of the adaptive response that allows animals to face adverse environmental changes. In the present paper the acute effects of different salinities and temperatures on routine metabolism, spontaneous activity and excretion of ammonia and urea were studied in two freshwater fish: gambusia, Gambusia affinis and zebrafish, Danio rerio, acclimated to 27 degrees C. The effects on gill morphology were also evaluated. Five salinities (0 per thousand, 10 per thousand, 20 per thousand, 30 per thousand and 35 per thousand) were tested in gambusia, while four salinities were used in zebrafish (0 per thousand, 10 per thousand, 20 per thousand and 25 per thousand). Each salinity acute stress was tested alone or in combination with an acute temperature reduction to 20 degrees C. In gambusia, both salinity and temperature acute stress strongly stimulated urea excretion. Routine oxygen consumption was barely affected by acute salinity or temperature stress, and was reduced by the combined effects of temperature and high salinity. Gills maintained their structural integrity in all stressing conditions; hyperplasia and hypertrophy of mitochondria-rich cells were observed. In zebrafish, temperature and salinity acute changes, both alone and in combination, scarcely affected any parameter tested. The major effect observed was a reduction of nitrogen excretion at 20 degrees C-25 per thousand; under these extreme conditions a significant structural disruption of gills was observed. These results confirm the high tolerance to acute salinity and temperature stress in gambusia, and demonstrate the involvement of urea excretion modulation in the stress response in this species. Copyright 2010 Elsevier Inc. All rights reserved.

  16. PHOTOGENERATION OF SINGLET OXYGEN AND FREE RADICALS IN DISSOLVED ORGANIC MATTER ISOLATED FROM THE MISSISSIPPI AND ATCHAFALAYA RIVER PLUMES

    Science.gov (United States)

    The photoreactivity to UV light of ultrafiltered dissolved organic matter (DOM) collected during cruises along salinity transects in the Mississippi and Atchafalaya River plumes was examined by measuring photogenerated free radicals and singlet molecular oxygen (1O2) photosensiti...

  17. Manipulating the antioxidant capacity of halophytes to increase their cultural and economic value through saline cultivation.

    Science.gov (United States)

    Boestfleisch, Christian; Wagenseil, Niko B; Buhmann, Anne K; Seal, Charlotte E; Wade, Ellie Merrett; Muscolo, Adele; Papenbrock, Jutta

    2014-08-13

    Halophytes, salt-tolerant plants, are a source of valuable secondary metabolites with potential economic value. The steady-state pools of many stress-related metabolites are already enhanced in halophytes when compared with glycophytes, but growth under conditions away from the optimum can induce stress and consequently result in changes to secondary metabolites such as antioxidants. However, direct evidence for increasing the concentration of valuable secondary metabolites as a consequence of altering the salinity of the growing environment still remains equivocal. To address this, we analysed a range of metabolites with antioxidant capacity (including total phenols, flavonoids, ascorbate, reduced/oxidized glutathione and reactive oxygen species scavenging enzymes) in seedlings and plants from different families (Amaranthaceae, Brassicaceae, Plantaginaceae and Rhizophoraceae) and habitats grown under different salt concentrations. We show that it is possible to manipulate the antioxidant capacity of plants and seedlings by altering the saline growing environment, the length of time under saline cultivation and the developmental stage. Among the species studied, the halophytes Tripolium pannonicum, Plantago coronopus, Lepidium latifolium and Salicornia europaea demonstrated the most potential as functional foods or nutraceuticals. Published by Oxford University Press on behalf of the Annals of Botany Company.

  18. A Sensitive Technique Using Atomic Force Microscopy to Measure the Low Earth Orbit Atomic Oxygen Erosion of Polymers

    Science.gov (United States)

    deGroh, Kim K.; Banks, Bruce A.; Clark, Gregory W.; Hammerstrom, Anne M.; Youngstrom, Erica E.; Kaminski, Carolyn; Fine, Elizabeth S.; Marx, Laura M.

    2001-01-01

    Polymers such as polyimide Kapton and Teflon FEP (fluorinated ethylene propylene) are commonly used spacecraft materials due to their desirable properties such as flexibility, low density, and in the case of FEP low solar absorptance and high thermal emittance. Polymers on the exterior of spacecraft in the low Earth orbit (LEO) environment are exposed to energetic atomic oxygen. Atomic oxygen erosion of polymers occurs in LEO and is a threat to spacecraft durability. It is therefore important to understand the atomic oxygen erosion yield (E, the volume loss per incident oxygen atom) of polymers being considered in spacecraft design. Because long-term space exposure data is rare and very costly, short-term exposures such as on the shuttle are often relied upon for atomic oxygen erosion determination. The most common technique for determining E is through mass loss measurements. For limited duration exposure experiments, such as shuttle experiments, the atomic oxygen fluence is often so small that mass loss measurements can not produce acceptable uncertainties. Therefore, a recession measurement technique has been developed using selective protection of polymer samples, combined with postflight atomic force microscopy (AFM) analysis, to obtain accurate erosion yields of polymers exposed to low atomic oxygen fluences. This paper discusses the procedures used for this recession depth technique along with relevant characterization issues. In particular, a polymer is salt-sprayed prior to flight, then the salt is washed off postflight and AFM is used to determine the erosion depth from the protected plateau. A small sample was salt-sprayed for AFM erosion depth analysis and flown as part of the Limited Duration Candidate Exposure (LDCE-4,-5) shuttle flight experiment on STS-51. This sample was used to study issues such as use of contact versus non-contact mode imaging for determining recession depth measurements. Error analyses were conducted and the percent probable

  19. Depth profiles of H and O in thin films of a-Si:H

    International Nuclear Information System (INIS)

    Sie, S.H.; Ryan, C.J.

    1985-01-01

    Detailed depth profiles of hydrogen and oxygen were measured, in thin film samples of a-Si:H produced under varying conditions, using the reaction 1 H( 19 F,α γ) 16 O in the vicinity of the resonance at E( 19 F) = 6.417 MeV to profile hydrogen, and resonant elastic α scattering near the resonance at Eα = 3.0359 MeV to profile oxygen. Contrasting results reflecting the different fabrication conditions were obtained and these were correlated with the measured electrical properties

  20. Humidification of Blow-By Oxygen During Recovery of Postoperative Pediatric Patients: One Unit's Journey.

    Science.gov (United States)

    Donahue, Suzanne; DiBlasi, Robert M; Thomas, Karen

    2018-02-02

    To examine the practice of nebulizer cool mist blow-by oxygen administered to spontaneously breathing postanesthesia care unit (PACU) pediatric patients during Phase one recovery. Existing evidence was evaluated. Informal benchmarking documented practices in peer organizations. An in vitro study was then conducted to simulate clinical practice and determine depth and amount of airway humidity delivery with blow-by oxygen. Informal benchmarking information was obtained by telephone interview. Using a three-dimensional printed simulation model of the head connected to a breathing lung simulator, depth and amount of moisture delivery in the respiratory tree were measured. Evidence specific to PACU administration of cool mist blow-by oxygen was limited. Informal benchmarking revealed that routine cool mist oxygenated blow-by administration was not widely practiced. The laboratory experiment revealed minimal moisture reaching the mid-tracheal area of the simulated airway model. Routine use of oxygenated cool mist in spontaneously breathing pediatric PACU patients is not supported. Copyright © 2017 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  1. COMPARATIVE EFFICACY OF HYPERTONIC SALINE AND NORMAL SALINE SOLUTIONS IN EXPERIMENTALLY INDUCED ENDOTOXIC SHOCK IN DOGS

    Directory of Open Access Journals (Sweden)

    M. A. ZAFAR, G. MUHAMMAD, M. H. HUSSAIN, T. AHMAD, A. YOUSAF AND I. SARFARAZ

    2009-07-01

    Full Text Available This study was contemplated to determine the comparative beneficial effects of hypertonic saline solution and sterile saline solution in induced endotoxic shock in dogs. For this purpose, 12 healthy Mongrel dogs were randomly divided into two equal groups (A and B. All the animals were induced endotoxaemia by slow intravenous administration of Escherichia coli endotoxins 0111:B4. Group A was treated with normal saline solution @ 90 ml/kg BW, while group B was given hypertonic saline solution @ 4 ml/kg BW, followed by normal saline solution @ 10 ml/kg BW. Different parameters were observed for evaluation of these fluids including clinical and haematological parameters, serum electrolytes, mean arterial pressure, and blood gases at different time intervals up to 24 hours post treatments. After infusion of respective fluids, all parameters returned to baseline values in both the groups but group B showed better results than group A except bicarbonates, which better recovered in group A. Thus, it was concluded that a small-volume of hypertonic saline solution could be effectively used in reversing the endotoxaemia. Moreover, it provides a rapid and inexpensive resuscitation from endotoxic shock.

  2. Oceanographic data collected from the Sir John Franklin in the Beaufort Sea, September 1989

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, R W; Carmack, E C; O' Brien, M C; McLaughlin, F A; Minkley, B G; Berger-North, K

    1989-09-01

    The data reported here were collected from the Canadian Coast Guard ship Sir John Franklin during a cruise to the Canadian Beaufort Sea from August 21 to Sept 5, 1989. The cruise had two broad objectives: to collect chemical and conductivity temperature depth (CTD) data at a deep station in the Canadian Basin, and to survey intensively the shelf break with the Mackenzie Canyon as a focus. Conductivity temperature depth was measured using a CTD guideline system. Water samples consisting of hydrocast for 6 shelf edge stations at 200 m depth and one deep station at 3200 m depth were tested for salinity, temperature, dissolved oxygen, nutrients, and chlorophyll a. In addition, samples were collected for analysis of tritium, C-14, and oxygen isotope composition and acoustic profiles were run. Isotope composition and acoustic profile data are not included in this report.

  3. Microbial diversity from chlorophyll maximum, oxygen minimum and bottom zones in the southwestern Atlantic Ocean

    Science.gov (United States)

    Medina-Silva, Renata; de Oliveira, Rafael R.; Pivel, Maria A. G.; Borges, Luiz G. A.; Simão, Taiz L. L.; Pereira, Leandro M.; Trindade, Fernanda J.; Augustin, Adolpho H.; Valdez, Fernanda P.; Eizirik, Eduardo; Utz, Laura R. P.; Groposo, Claudia; Miller, Dennis J.; Viana, Adriano R.; Ketzer, João M. M.; Giongo, Adriana

    2018-02-01

    Conspicuous physicochemical vertical stratification in the deep sea is one of the main forces driving microbial diversity in the oceans. Oxygen and sunlight availability are key factors promoting microbial diversity throughout the water column. Ocean currents also play a major role in the physicochemical stratification, carrying oxygen down to deeper zones as well as moving deeper water masses up towards shallower depths. Water samples within a 50-km radius in a pockmark location of the southwestern Atlantic Ocean were collected and the prokaryotic communities from different water depths - chlorophyll maximum, oxygen minimum and deep-sea bottom (down to 1355 m) - were described. At phylum level, Proteobacteria were the most frequent in all water depths, Cyanobacteria were statistically more frequent in chlorophyll maximum zone, while Thaumarchaeota were significantly more abundant in both oxygen minimum and bottom waters. The most frequent microorganism in the chlorophyll maximum and oxygen minimum zones was a Pelagibacteraceae operational taxonomic unit (OTU). At the bottom, the most abundant genus was the archaeon Nitrosopumilus. Beta diversity analysis of the 16S rRNA gene sequencing data uncovered in this study shows high spatial heterogeneity among water zones communities. Our data brings important contribution for the characterisation of oceanic microbial diversity, as it consists of the first description of prokaryotic communities occurring in different oceanic water zones in the southwestern Atlantic Ocean.

  4. Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

    Science.gov (United States)

    Lotter, Oliver; Held, Manuel; Schiefer, Jennifer; Werner, Ole; Medved, Fabian; Schaller, Hans-Eberhard; Rahmanian-Schwarz, Afshin; Jaminet, Patrick; Rothenberger, Jens

    2015-01-01

    Currently, the diagnosis of burn depth is primarily based on a visual assessment and can be dependent on the surgeons' experience. The goal of this study was to determine the ability of laser Doppler flowmeter combined with a tissue spectrophotometer to discriminate burn depth in a miniature swine burn model. Burn injuries of varying depth, including superficial-partial, deep-partial, and full thickness, were created in seven Göttingen minipigs using an aluminium bar (100 °C), which was applied to the abdominal skin for periods of 1, 3, 6, 12, 30, and 60 seconds with gravity alone. The depth of injury was evaluated histologically using hematoxylin and eosin staining. All burns were assessed 3 hours after injury using a device that combines a laser light and a white light to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. The blood flow (41 vs. 124 arbitrary units [AU]) and relative amount of hemoglobin (32 vs. 52 AU) were significantly lower in full thickness compared with superficial-partial thickness burns. However, no significant differences in hemoglobin oxygenation were observed between these depths of burns (61 vs. 60%). These results show the ability of laser Doppler flowmeter and tissue spectrophotometer in combination to discriminate between various depths of injury in the minipig model, suggesting that this device may offer a valuable tool for burn depth assessment influencing burn management. © 2014 by the Wound Healing Society.

  5. SIMS study of oxygen diffusion in monoclinic HfO2

    Science.gov (United States)

    Mueller, Michael P.; De Souza, Roger A.

    2018-01-01

    The diffusion of oxygen in dense ceramics of monoclinic HfO2 was studied by means of (18O/16O) isotope exchange annealing and subsequent determination of isotope depth profiles by Secondary Ion Mass Spectrometry. Anneals were performed in the temperature range of 573 ≤T /K ≤ 973 at an oxygen partial pressure of p O2=200 mbar . All measured isotope profiles exhibited two features: the first feature, closer to the surface, was attributed mainly to slow oxygen diffusion in an impurity silicate phase; the second feature, deeper in the sample, was attributed to oxygen diffusion in bulk monoclinic HfO2 . The activation enthalpy of oxygen tracer diffusion in bulk HfO2 was found to be ΔHD∗≈0.5 eV .

  6. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across Wake Island from 2014-03-16 to 2014-03-19 (NCEI Accession 0162248)

    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...

  7. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across Jarvis Island from 2016-05-19 to 2016-05-23 (NCEI Accession 0162245)

    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...

  8. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across American Samoa from 2015-02-15 to 2015-03-28 (NCEI Accession 0161169)

    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. In situ bioremediation under high saline conditions

    International Nuclear Information System (INIS)

    Bosshard, B.; Raumin, J.; Saurohan, B.

    1995-01-01

    An in situ bioremediation treatability study is in progress at the Salton Sea Test Base (SSTB) under the NAVY CLEAN 2 contract. The site is located in the vicinity of the Salon Sea with expected groundwater saline levels of up to 50,000 ppm. The site is contaminated with diesel, gasoline and fuel oils. The treatability study is assessing the use of indigenous heterotrophic bacteria to remediate petroleum hydrocarbons. Low levels of significant macro nutrients indicate that nutrient addition of metabolic nitrogen and Orthophosphate are necessary to promote the process, requiring unique nutrient addition schemes. Groundwater major ion chemistry indicates that precipitation of calcium phosphorus compounds may be stimulated by air-sparging operations and nutrient addition, which has mandated the remedial system to include pneumatic fracturing as an option. This presentation is tailored at an introductory level to in situ bioremediation technologies, with some emphasize on innovations in sparge air delivery, dissolved oxygen uptake rates, nutrient delivery, and pneumatic fracturing that should keep the expert's interest

  10. Airborne EM, Lithology and in-situ Data Used for Quantizing Groundwater Salinity in Zeeland (NL)

    Science.gov (United States)

    Meyer, U.; Siemon, B.; van Baaren, E.; Dabekaussen, W.; Delsman, J. R.; Karaoulis, M.; Gunnink, J.; Pauw, P.; Vermaas, T.

    2017-12-01

    In a setting of predominantly saline surface waters in Zeeland, the Netherlands, the only available shallow fresh groundwater is present in the form of freshwater lenses floating on top of the saline groundwater. This fresh water is vital for agricultural, industrial, ecological, water conservation and drinking water functions. An essential first step for managing the usable water properly is to know the present spatial fresh-brackish-saline groundwater distribution. As traditional salinity monitoring is labor-intensive, airborne electromagnetics, which is fast and can cover large areas in short time, is an efficient alternative. A consortium of BGR, Deltares and TNO conducted FRESHEM Zeeland (FREsh Salt groundwater distribution by Helicopter ElectroMagnetic survey in the Province of Zeeland) in 2014-17. An area of more than 2000 square km was surveyed using BGR's helicopter-borne geophysical system totaling to about 9,600 line-km. The HEM data, after inversion to 2.5 Million resistivity-depth models for each of the three 1D inversion procedures applied (Marquardt single site, smooth and sharp laterally constrained inversion), served as base-line information for further interpretation. A probabilistic Monte Carlo approach combines HEM resistivities, 3D lithology model data (GeoTOP), laboratory results (formation factor and surface conductivity) and local in-situ groundwater measurements for the translation of resistivity to Chloride concentration. The resulting 3D voxel model enables stakeholders to implement spatial Chloride concentration in their groundwater models.

  11. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  12. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  13. The Effects of In-Hospital Intravenous Cold Saline in Postcardiac Arrest Patients Treated with Targeted Temperature Management.

    Science.gov (United States)

    Suppogu, Nissi; Panza, Gregory A; Kilic, Sena; Gowdar, Shreyas; Kallur, Kamala R; Jayaraman, Ramya; Lundbye, Justin; Fernandez, Antonio B

    2018-03-01

    Recent data suggest that rapid infusion of intravenous (IV) cold saline for Targeted Temperature Management (TTM) after cardiac arrest is associated with higher rates of rearrest, pulmonary edema, and hypoxia, with no difference in neurologic outcomes or survival when administered by Emergency Medical Services. We sought to determine the effects of IV cold saline administration in the hospital setting in postcardiac arrest patients to achieve TTM and its effect on clinical parameters and neurologic outcomes. A cohort of 132 patients who completed TTM after cardiac arrest in a single institution was retrospectively studied. Patients who did not receive cold saline were matched by age, gender, Glasgow coma scale, downtime, and presenting rhythm to patients who received cold saline. Demographics, cardiac rearrest, diuretic use, time to target temperature, and Cerebral Performance Category (CPC) scores were recorded among other variables. Patients who received cold saline achieved target temperature sooner (280 vs. 345 minutes, p = 0.05), had lower lactate levels on day 1 (4.2 ± 3.5 mM vs. 6.0 ± 4.9 mM, p = 0.019) and day 2 (1.3 ± 2.2 mM vs. 2.2 ± 3.2 mM, p = 0.046), increased incidence of pulmonary edema (51.5% vs. 31.8%, p = 0.006), and increased diuretic utilization (63.6% vs. 42.4%, p = 0.014). There was no significant difference in cardiac rearrest, arterial oxygenation, and CPC scores (ps > 0.05). Infusion of IV cold saline is associated with shorter time to target temperature, increased incidence of pulmonary edema, and diuretic use, with no difference in cardiac rearrest, survival, and neurologic outcomes.

  14. Method for measurement of flowing water salinity within or behind wellbore casing

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1986-01-01

    Water flowing within or behind a wellbore casing is irradiated with 14 MeV neutrons from a source in a downhole sonde. Gamma radiation from the isotope nitrogen-16 induced from the O 16 (n,p)N 16 reaction and the products of either the Na 23 (n,α)F 20 or the Cl 37 (n,α)p 34 reactions is measured in intensity and energy with detectors in the sonde. From the gamma radiation measurements, the relative presence of oxygen to at least one of sodium or chlorine in the water is measured, and from the measurement the salinity of the water is determined

  15. Detecting the Spatio-temporal Distribution of Soil Salinity and Its Relationship to Crop Growth in a Large-scale Arid Irrigation District Based on Sampling Experiment and Remote Sensing

    Science.gov (United States)

    Ren, D.; Huang, G., Sr.; Xu, X.; Huang, Q., Sr.; Xiong, Y.

    2016-12-01

    Soil salinity analysis on a regional scale is of great significance for protecting agriculture production and maintaining eco-environmental health in arid and semi-arid irrigated areas. In this study, the Hetao Irrigation District (Hetao) in Inner Mongolia Autonomous Region, with suffering long-term soil salinization problems, was selected as the case study area. Field sampling experiments and investigations related to soil salt contents, crop growth and yields were carried out across the whole area, during April to August in 2015. Soil salinity characteristics in space and time were systematically analyzed for Hetao as well as the corresponding impacts on crops. Remotely sensed map of soil salinity distribution for surface soil was also derived based on the Landsat OLI data with a 30 m resolution. The results elaborated the temporal and spatial dynamics of soil salinity and the relationships with irrigation, groundwater depth and crop water consumption in Hetao. In addition, the strong spatial variability of salinization was clearly presented by the remotely sensed map of soil salinity. Further, the relationship between soil salinity and crop growth was analyzed, and then the impact degrees of soil salinization on cropping pattern, leaf area index, plant height and crop yield were preliminarily revealed. Overall, this study can provide very useful information for salinization control and guide the future agricultural production and soil-water management for the arid irrigation districts analogous to Hetao.

  16. Depth profiling using C60+ SIMS-Deposition and topography development during bombardment of silicon

    International Nuclear Information System (INIS)

    Gillen, Greg; Batteas, James; Michaels, Chris A.; Chi, Peter; Small, John; Windsor, Eric; Fahey, Albert; Verkouteren, Jennifer; Kim, K.J.

    2006-01-01

    A C 60 + primary ion source has been coupled to an ion microscope secondary ion mass spectrometry (SIMS) instrument to examine sputtering of silicon with an emphasis on possible application of C 60 + depth profiling for high depth resolution SIMS analysis of silicon semiconductor materials. Unexpectedly, C 60 + SIMS depth profiling of silicon was found to be complicated by the deposition of an amorphous carbon layer which buries the silicon substrate. Sputtering of the silicon was observed only at the highest accessible beam energies (14.5 keV impact) or by using oxygen backfilling. C 60 + SIMS depth profiling of As delta-doped test samples at 14.5 keV demonstrated a substantial (factor of 5) degradation in depth resolution compared to Cs + SIMS depth profiling. This degradation is thought to result from the formation of an unusual platelet-like grain structure on the SIMS crater bottoms. Other unusual topographical features were also observed on silicon substrates after high primary ion dose C 60 + bombardment

  17. Microbial communities associated with the anthropogenic, highly alkaline environment of a saline soda lime, Poland

    OpenAIRE

    Kalwasi?ska, Agnieszka; Felf?ldi, Tam?s; Szab?, Attila; Deja-Sikora, Edyta; Kosobucki, Przemys?aw; Walczak, Maciej

    2017-01-01

    Soda lime is a by-product of the Solvay soda process for the production of sodium carbonate from limestone and sodium chloride. Due to a high salt concentration and alkaline pH, the lime is considered as a potential habitat of haloalkaliphilic and haloalkalitolerant microbial communities. This artificial and unique environment is nutrient-poor and devoid of vegetation, due in part to semi-arid, saline and alkaline conditions. Samples taken from the surface layer of the lime and from the depth...

  18. Evaluating physiological responses of plants to salinity stress

    KAUST Repository

    Negrão, Sónia

    2016-10-06

    Background Because soil salinity is a major abiotic constraint affecting crop yield, much research has been conducted to develop plants with improved salinity tolerance. Salinity stress impacts many aspects of a plant’s physiology, making it difficult to study in toto. Instead, it is more tractable to dissect the plant’s response into traits that are hypothesized to be involved in the overall tolerance of the plant to salinity. Scope and conclusions We discuss how to quantify the impact of salinity on different traits, such as relative growth rate, water relations, transpiration, transpiration use efficiency, ionic relations, photosynthesis, senescence, yield and yield components. We also suggest some guidelines to assist with the selection of appropriate experimental systems, imposition of salinity stress, and obtaining and analysing relevant physiological data using appropriate indices. We illustrate how these indices can be used to identify relationships amongst the proposed traits to identify which traits are the most important contributors to salinity tolerance. Salinity tolerance is complex and involves many genes, but progress has been made in studying the mechanisms underlying a plant’s response to salinity. Nevertheless, several previous studies on salinity tolerance could have benefited from improved experimental design. We hope that this paper will provide pertinent information to researchers on performing proficient assays and interpreting results from salinity tolerance experiments.

  19. Numerical simulation of permafrost depth during a future glaciation, Campine area, Northern Belgium

    International Nuclear Information System (INIS)

    Govaerts, Joan; Weetjens, Eef; Beerten, Koen

    2012-01-01

    (= location where the temperature reaches 0 C and the soil is 50 % frozen) is shown in function of time. The 50 % frozen iso-line (or the 0 C isotherm, the light blue line) is used as a conservative estimate for permafrost depth, which is independent of the liquid-to-solid temperature interval. The curves for the two calculation cases show the same trend, with a maximum thickness during the period of maximum cold around 19 ka BP and 60 ka BP. In the first calculation case (without vegetation and snow), the permafrost thickness ranges between 150 m and 210 m around 60 ka, and between 160 m and 215 m around 19 ka (light blue line). During the coldest stages of the last glacial, the calculation results show that the first few meters of the Boom Clay were completely frozen (dark blue line) without considering snow or vegetation. In the second calculation case (with vegetation and snow), the permafrost depth is at least 60 m less, which is in agreement with minimum permafrost depths of between 12 m and 20 m during the Weichselian in the Netherlands, based on observations of melted ice bodies from pingo's, and maximum permafrost depths of between 100 m and 150 m based on numerical simulations of other authors. The calculated maximum depths of the permafrost front can be seen as conservative over-estimations as no unsaturated zone, which acts like an insulating layer, was taken into account. Also the freezing of groundwater during permafrost development may lead to the production of residual saline pore waters at the pro-gradation front, which have a lower freezing point because of the salinity. Since no effect of salinity increase is taken into account, permafrost development may be inhibited more than would be expected from these simplified calculations. (authors)

  20. Microstrip Patch Sensor for Salinity Determination.

    Science.gov (United States)

    Lee, Kibae; Hassan, Arshad; Lee, Chong Hyun; Bae, Jinho

    2017-12-18

    In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under -20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of -35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.

  1. Hurricane-induced failure of low salinity wetlands

    Science.gov (United States)

    Howes, Nick C.; FitzGerald, Duncan M.; Hughes, Zoe J.; Georgiou, Ioannis Y.; Kulp, Mark A.; Miner, Michael D.; Smith, Jane M.; Barras, John A.

    2010-01-01

    During the 2005 hurricane season, the storm surge and wave field associated with Hurricanes Katrina and Rita eroded 527 km2 of wetlands within the Louisiana coastal plain. Low salinity wetlands were preferentially eroded, while higher salinity wetlands remained robust and largely unchanged. Here we highlight geotechnical differences between the soil profiles of high and low salinity regimes, which are controlled by vegetation and result in differential erosion. In low salinity wetlands, a weak zone (shear strength 500–1450 Pa) was observed ∼30 cm below the marsh surface, coinciding with the base of rooting. High salinity wetlands had no such zone (shear strengths > 4500 Pa) and contained deeper rooting. Storm waves during Hurricane Katrina produced shear stresses between 425–3600 Pa, sufficient to cause widespread erosion of the low salinity wetlands. Vegetation in low salinity marshes is subject to shallower rooting and is susceptible to erosion during large magnitude storms; these conditions may be exacerbated by low inorganic sediment content and high nutrient inputs. The dramatic difference in resiliency of fresh versus more saline marshes suggests that the introduction of freshwater to marshes as part of restoration efforts may therefore weaken existing wetlands rendering them vulnerable to hurricanes. PMID:20660777

  2. Integrated approach for demarcating subsurface pollution and saline water intrusion zones in SIPCOT area: a case study from Cuddalore in Southern India.

    Science.gov (United States)

    Sankaran, S; Sonkamble, S; Krishnakumar, K; Mondal, N C

    2012-08-01

    This paper deals with a systematic hydrogeological, geophysical, and hydrochemical investigations carried out in SIPCOT area in Southern India to demarcate groundwater pollution and saline intrusion through Uppanar River, which flows parallel to sea coast with high salinity (average TDS 28, 870 mg/l) due to back waters as well as discharge of industrial and domestic effluents. Hydrogeological and geophysical investigations comprising topographic survey, self-potential, multi-electrode resistivity imaging, and water quality monitoring were found the extent of saline water intrusion in the south and pockets of subsurface pollution in the north of the study area. Since the area is beset with highly permeable unconfined quaternary alluvium forming potential aquifer at shallow depth, long-term excessive pumping and influence of the River have led to lowering of the water table and degradation of water quality through increased salinity there by generating reversal of hydraulic gradient in the south. The improper management of industrial wastes and left over chemicals by closed industries has led surface and subsurface pollution in the north of the study area.

  3. Use of LANDSAT 8 images for depth and water quality assessment of El Guájaro reservoir, Colombia

    Science.gov (United States)

    González-Márquez, Luis Carlos; Torres-Bejarano, Franklin M.; Torregroza-Espinosa, Ana Carolina; Hansen-Rodríguez, Ivette Renée; Rodríguez-Gallegos, Hugo B.

    2018-03-01

    The aim of this study was to evaluate the viability of using Landsat 8 spectral images to estimate water quality parameters and depth in El Guájaro Reservoir. On February and March 2015, two samplings were carried out in the reservoir, coinciding with the Landsat 8 images. Turbidity, dissolved oxygen, electrical conductivity, pH and depth were evaluated. Through multiple regression analysis between measured water quality parameters and the reflectance of the pixels corresponding to the sampling stations, statistical models with determination coefficients between 0.6249 and 0.9300 were generated. Results indicate that from a small number of measured parameters we can generate reliable models to estimate the spatial variation of turbidity, dissolved oxygen, pH and depth, as well the temporal variation of electrical conductivity, so models generated from Landsat 8 can be used as a tool to facilitate the environmental, economic and social management of the reservoir.

  4. 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...

  5. 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...

  6. Depth-dependent flow and pressure characteristics in cortical microvascular networks.

    Directory of Open Access Journals (Sweden)

    Franca Schmid

    2017-02-01

    Full Text Available A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations with discrete tracking of red blood cells (RBCs are performed in three realistic microvascular networks from the mouse cerebral cortex. Our analysis is based on trajectories of individual RBCs and focuses on layer-specific flow phenomena until a cortical depth of 1 mm. The individual RBC trajectories reveal that in the capillary bed RBCs preferentially move in plane. Hence, the capillary flow field shows laminar patterns and a layer-specific analysis is valid. We demonstrate that for RBCs entering the capillary bed close to the cortical surface (< 400 μm the largest pressure drop takes place in the capillaries (37%, while for deeper regions arterioles are responsible for 61% of the total pressure drop. Further flow characteristics, such as capillary transit time or RBC velocity, also vary significantly over cortical depth. Comparison of purely topological characteristics with flow-based ones shows that a combined interpretation of topology and flow is indispensable. Our results provide evidence that it is crucial to consider layer-specific differences for all investigations related to the flow and pressure distribution in the cortical vasculature. These findings support the hypothesis that for an efficient oxygen up-regulation at least two regulation mechanisms must be playing hand in hand, namely cerebral blood flow increase and microvascular flow homogenization. However, the contribution of both regulation mechanisms to oxygen up-regulation likely varies over depth.

  7. Earth Observation and Geospatial techniques for Soil Salinity and Land Capability Assessment over Sundarban Bay of Bengal Coast, India

    Directory of Open Access Journals (Sweden)

    Das Sumanta

    2016-12-01

    Full Text Available To guarantee food security and job creation of small scale farmers to commercial farmers, unproductive farms in the South 24 PGS, West Bengal need land reform program to be restructured and evaluated for agricultural productivity. This study established a potential role of remote sensing and GIS for identification and mapping of salinity zone and spatial planning of agricultural land over the Basanti and Gosaba Islands(808.314sq. km of South 24 PGS. District of West Bengal. The primary data i.e. soil pH, Electrical Conductivity (EC and Sodium Absorption ratio (SAR were obtained from soil samples of various GCP (Ground Control Points locations collected at 50 mts. intervals by handheld GPS from 0–100 cm depths. The secondary information is acquired from the remotely sensed satellite data (LANDSAT ETM+ in different time scale and digital elevation model. The collected field samples were tested in the laboratory and were validated with Remote Sensing based digital indices analysisover the temporal satellite data to assess the potential changes due to over salinization. Soil physical properties such as texture, structure, depth and drainage condition is stored as attributes in a geographical soil database and linked with the soil map units. The thematic maps are integrated with climatic and terrain conditions of the area to produce land capability maps for paddy. Finally, The weighted overlay analysis was performed to assign theweights according to the importance of parameters taken into account for salineareaidentification and mapping to segregate higher, moderate, lower salinity zonesover the study area.

  8. Benthic dinitrogen fixation traversing the oxygen minimum zone off Mauritania (NW Africa)

    DEFF Research Database (Denmark)

    Gier, Jessica; Löscher, Carolin R.; Dale, Andrew W.

    2017-01-01

    metabolisms, such as sulfate reduction. In the present study, benthic N2 fixation together with sulfate reduction and other heterotrophic metabolisms were investigated at six station between 47 and 1,108 m water depth along the 18°N transect traversing the highly productive upwelling region known...... as Mauritanian oxygen minimum zone (OMZ). Bottom water oxygen concentrations ranged between 30 and 138 μM. Benthic N2 fixation determined by the acetylene reduction assay was detected at all stations with highest rates (0.15 mmol m-2 d-1) on the shelf (47 and 90 m water depth) and lowest rates (0.08 mmol m-2 d-1......) below 412 m water depth. The biogeochemical data suggest that part of the N2 fixation could be linked to sulfate- and iron-reducing bacteria. Molecular analysis of the key functional marker gene for N2 fixation, nifH, confirmed the presence of sulfate- and iron-reducing diazotrophs. High N2 fixation...

  9. Estuarine turbidity, flushing, salinity, and circulation

    Science.gov (United States)

    Pritchard, D. W.

    1972-01-01

    The effects of estuarine turbidity, flushing, salinity, and circulation on the ecology of the Chesapeake Bay are discussed. The sources of fresh water, the variations in salinity, and the circulation patterns created by temperature and salinity changes are analyzed. The application of remote sensors for long term observation of water temperatures is described. The sources of sediment and the biological effects resulting from increased sediments and siltation are identified.

  10. Microstrip Patch Sensor for Salinity Determination

    Directory of Open Access Journals (Sweden)

    Kibae Lee

    2017-12-01

    Full Text Available In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS, and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under −20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of −35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF tunable sensors for salinity determination.

  11. Diffusion and Monod kinetics model to determine in vivo human corneal oxygen-consumption rate during soft contact lens wear

    Directory of Open Access Journals (Sweden)

    Luis F. Del Castillo

    2015-01-01

    Conclusion: Present results are relevant for the calculation on the partial pressure of oxygen, available at different depths into the corneal tissue behind contact lenses of different oxygen transmissibility.

  12. Development of an oxygen saturation measuring system by using near-infrared spectroscopy

    Science.gov (United States)

    Kono, K.; Nakamachi, E.; Morita, Y.

    2017-08-01

    Recently, the hypoxia imaging has been recognized as the advanced technique to detect cancers because of a strong relationship with the biological characterization of cancer. In previous studies, hypoxia imaging systems for endoscopic diagnosis have been developed. However, these imaging technologies using the visible light can observe only blood vessels in gastric mucous membrane. Therefore, they could not detect scirrhous gastric cancer which accounts for 10% of all gastric cancers and spreads rapidly into submucous membrane. To overcome this problem, we developed a measuring system of blood oxygen saturation in submucous membrane by using near-infrared (NIR) spectroscopy. NIR, which has high permeability for bio-tissues and high absorbency for hemoglobin, can image and observe blood vessels in submucous membrane. NIR system with LED lights and a CCD camera module was developed to image blood vessels. We measured blood oxygen saturation using the optical density ratio (ODR) of two wavelengths, based on Lambert-Beer law. To image blood vessel clearly and measure blood oxygen saturation accurately, we searched two optimum wavelengths by using a multilayer human gastric-like phantom which has same optical properties as human gastric one. By using Monte Carlo simulation of light propagation, we derived the relationship between the ODR and blood oxygen saturation and elucidated the influence of blood vessel depth on measuring blood oxygen saturation. The oxygen saturation measuring methodology was validated with experiments using our NIR system. Finally, it was confirmed that our system can detect oxygen saturation in various depth blood vessels accurately.

  13. Salinity tolerance of the South African endemic amphipod ...

    African Journals Online (AJOL)

    Salinities were prepared using natural seawater and synthetic sea salt. Grandidierella lignorum tolerated all salinities, but showed highest survival at salinities of 7–42. Salinity tolerance was modified by temperature, with highest survival occurring between 10 and 25 °C. These represent the range of conditions at which ...

  14. Triple oxygen isotope systematics of structurally bonded water in gypsum

    Science.gov (United States)

    Herwartz, Daniel; Surma, Jakub; Voigt, Claudia; Assonov, Sergey; Staubwasser, Michael

    2017-07-01

    The triple oxygen isotopic composition of gypsum mother water (gmw) is recorded in structurally bonded water in gypsum (gsbw). Respective fractionation factors have been determined experimentally for 18O/16O and 17O/16O. By taking previous experiments into account we suggest using 18αgsbw-gmw = 1.0037; 17αgsbw-gmw = 1.00195 and θgsbw-gmw = 0.5285 as fractionation factors in triple oxygen isotope space. Recent gypsum was sampled from a series of 10 ponds located in the Salar de Llamara in the Atacama Desert, Chile. Total dissolved solids (TDS) in these ponds show a gradual increase from 23 g/l to 182 g/l that is accompanied by an increase in pond water 18O/16O. Gsbw falls on a parallel curve to the ambient water from the saline ponds. The offset is mainly due to the equilibrium fractionation between gsbw and gmw. However, gsbw represents a time integrated signal biased towards times of strong evaporation, hence the estimated gmw comprises elevated 18O/16O compositions when compared to pond water samples taken on site. Gypsum precipitation is associated with algae mats in the ponds with lower salinity. No evidence for respective vital effects on the triple oxygen isotopic composition of gypsum hydration water is observed, nor are such effects expected. In principle, the array of δ18Ogsbw vs. 17Oexcess can be used to: (1) provide information on the degree of evaporation during gypsum formation; (2) estimate pristine meteoric water compositions; and (3) estimate local relative humidity which is the controlling parameter of the slope of the array for simple hydrological situations. In our case study, local mining activities may have decreased deep groundwater recharge, causing a recent change of the local hydrology.

  15. High-spatial-resolution mapping of the oxygen concentration in cortical tissue (Conference Presentation)

    Science.gov (United States)

    Jaswal, Rajeshwer S.; Yaseen, Mohammad A.; Fu, Buyin; Boas, David A.; Sakadžic, Sava

    2016-03-01

    Due to a lack of imaging tools for high-resolution imaging of cortical tissue oxygenation, the detailed maps of the oxygen partial pressure (PO2) around arterioles, venules, and capillaries remain largely unknown. Therefore, we have limited knowledge about the mechanisms that secure sufficient oxygen delivery in microvascular domains during brain activation, and provide some metabolic reserve capacity in diseases that affect either microvascular networks or the regulation of cerebral blood flow (CBF). To address this challenge, we applied a Two-Photon PO2 Microscopy to map PO2 at different depths in mice cortices. Measurements were performed through the cranial window in the anesthetized healthy mice as well as in the mouse models of microvascular dysfunctions. In addition, microvascular morphology was recorded by the two-photon microscopy at the end of each experiment and subsequently segmented. Co-registration of the PO2 measurements and exact microvascular morphology enabled quantification of the tissue PO2 dependence on distance from the arterioles, capillaries, and venules at various depths. Our measurements reveal significant spatial heterogeneity of the cortical tissue PO2 distribution that is dominated by the high oxygenation in periarteriolar spaces. In cases of impaired oxygen delivery due to microvascular dysfunction, significant reduction in tissue oxygenation away from the arterioles was observed. These tissue domains may be the initial sites of cortical injury that can further exacerbate the progression of the disease.

  16. Zonally asymmetric response of the Southern Ocean mixed-layer depth to the Southern Annular Mode

    Science.gov (United States)

    Sallée, J. B.; Speer, K. G.; Rintoul, S. R.

    2010-04-01

    Interactions between the atmosphere and ocean are mediated by the mixed layer at the ocean surface. The depth of this layer is determined by wind forcing and heating from the atmosphere. Variations in mixed-layer depth affect the rate of exchange between the atmosphere and deeper ocean, the capacity of the ocean to store heat and carbon and the availability of light and nutrients to support the growth of phytoplankton. However, the response of the Southern Ocean mixed layer to changes in the atmosphere is not well known. Here we analyse temperature and salinity data from Argo profiling floats to show that the Southern Annular Mode (SAM), the dominant mode of atmospheric variability in the Southern Hemisphere, leads to large-scale anomalies in mixed-layer depth that are zonally asymmetric. From a simple heat budget of the mixed layer we conclude that meridional winds associated with departures of the SAM from zonal symmetry cause anomalies in heat flux that can, in turn, explain the observed changes of mixed-layer depth and sea surface temperature. Our results suggest that changes in the SAM, including recent and projected trends attributed to human activity, drive variations in Southern Ocean mixed-layer depth, with consequences for air-sea exchange, ocean sequestration of heat and carbon, and biological productivity.

  17. NOAA Average Annual Salinity (3-Zone)

    Data.gov (United States)

    California Natural Resource Agency — The 3-Zone Average Annual Salinity Digital Geography is a digital spatial framework developed using geographic information system (GIS) technology. These salinity...

  18. NW Pacific mid-depth ventilation changes during the Holocene

    Science.gov (United States)

    Rella, S.; Uchida, M.

    2010-12-01

    During the last 50 years the oxygen content of North Pacific Intermediate Water primarily originating in the Okhotsk Sea has declined suggesting decreased mid-depth water circulation, likely leading to changes in biological productivity in the NW Pacific realm and a decrease in CO2 drawdown. It is therefore of high interest to elucidate the climate-oceanic interconnections of the present interglacial period (Holocene) in the NW Pacific, in order to predict possible future climate and surface productivity changes associated with a decrease in mid-depth ventilation in this ecologically sensitive region. However, such efforts have been hampered so far by the lack of appropriate sediment cores with fast sedimentation rates during the Holocene. Core CK05-04 that was recovered in 2005 from off Shimokita peninsula, Japan, at ~1000 m depth shows sedimentation rates of ~80 cm/kyr during the Holocene and therefore presents an ideal opportunity to reconstruct for the first time the Holocene ventilation history of the NW Pacific Ocean. We employ Accelerator Mass Spectroscopy (NIES-TERRA, Tsukuba) radiocarbon analysis of co-existing benthic and planktonic foraminifera to conclude on the ventilation age of the mid-depth water using benthic-planktonic radiocarbon age differences. At the conference we would like to present the results.

  19. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Northwestern Hawaiian Islands from 2015-07-31 to 2015-08-19 (NCEI Accession 0161170)

    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...

  20. Saline water in southeastern New Mexico

    Science.gov (United States)

    Hiss, W.L.; Peterson, J.B.; Ramsey, T.R.

    1969-01-01

    Saline waters from formations of several geologic ages are being studied in a seven-county area in southeastern New Mexico and western Texas, where more than 30,000 oil and gas tests have been drilled in the past 40 years. This area of 7,500 sq. miles, which is stratigraphically complex, includes the northern and eastern margins of the Delaware Basin between the Guadalupe and Glass Mountains. Chloride-ion concentrations in water produced from rocks of various ages and depths have been mapped in Lea County, New Mexico, using machine map-plotting techniques and trend analyses. Anomalously low chloride concentrations (1,000-3,000 mg/l) were found along the western margin of the Central Basin platform in the San Andres and Capitan Limestone Formations of Permian age. These low chloride-ion concentrations may be due to preferential circulation of ground water through the more porous and permeable rocks. Data being used in the study were obtained principally from oil companies and from related service companies. The P.B.W.D.S. (Permian Basin Well Data System) scout-record magnetic-tape file was used as a framework in all computer operations. Shallow or non-oil-field water analyses acquired from state, municipal, or federal agencies were added to these data utilizing P.B.W.D.S.-compatible reference numbers and decimal latitude-longitude coordinates. Approximately 20,000 water analyses collected from over 65 sources were coded, recorded on punch cards and stored on magnetic tape for computer operations. Extensive manual and computer error checks for duplication and accuracy were made to eliminate data errors resulting from poorly located or identified samples; non-representative or contaminated samples; mistakes in coding, reproducing or key-punching; laboratory errors; and inconsistent reporting. The original 20,000 analyses considered were reduced to 6,000 representative analyses which are being used in the saline water studies. ?? 1969.

  1. Role of oxygen concentration distribution and microstructure in luminescent properties of laser-irradiated silicon

    International Nuclear Information System (INIS)

    Zhu, Min; Li, Xiaohong; Li, Guoqiang; Xie, Changxin; Qiu, Rong; Li, Jiawen; Huang, Wenhao

    2015-01-01

    Graphical abstract: Photoluminescence (PL) of monocrystalline silicon irradiated by femtosecond laser pulses was studied. The visible blue luminescence is observed both from the deionized water and air. The position and shape of emission luminescence peaks in the visible range are same at 330 nm. The PL is confirmed to be not merely induced by the oxygen defects or quantum confinement effects, but is commonly decided by the concentration distribution of SiO x and the depth of the surface microstructure. The PL gets strongest only when depth of the surface microstructure is not deeper and the distribution of the shallow SiO x is more intensive. - Highlights: • Different morphologies and compositions of the surface microstructures are formed. • The SiO x concentration and surface microstructure depth commonly decide the PL. • The PL intensity can be controlled by changing the experimental conditions. - Abstract: We study the photoluminescence (PL) of monocrystalline silicon irradiated by femtosecond laser pulses in different environments (deionized water and air) and energy intensities. The fluorescence spectroscopy measurement results indicate that the visible blue luminescence is observed both from the silicon surfaces ablated in the deionized water and air. The more interesting phenomenon is that the position and shape of the emission luminescence peaks in the visible range are substantially the same at the same excitation wavelength 330 nm. Compared with the granular-like microstructure generated on the silicon surface in air, the smaller and stripe-like microstructure is formed in the deionized water as the field emission scanning electron microscope (FESEM) measures. The results of the energy dispersive spectroscopy (EDS) show that silicon and oxygen is the main elemental composition on laser-induced silicon surfaces, and the oxygen content on the sample surfaces formed in air is nearly four times more than that in the deionized water. The studies confirm

  2. Salinity: Electrical conductivity and total dissolved solids

    Science.gov (United States)

    The measurement of soil salinity is a quantification of the total salts present in the liquid portion of the soil. Soil salinity is important in agriculture because salinity reduces crop yields by reducing the osmotic potential making it more difficult for the plant to extract water, by causing spe...

  3. SALINE WATER RESOURCES IN CLUJ-NAPOCA SURROUNDINGS

    Directory of Open Access Journals (Sweden)

    B. CZELLECZ

    2016-03-01

    Full Text Available Saline waters are usually researched in those places where it is used for balneotherapy or other industrial purposes. The aim of this study is to describe the saline water sources from less known areas, as they are an important natural mineral water resource. Twenty nine water samples were analyzed from Cojocna-Pata-Sopor region, thirteen of them can be considered saline waters. The visited locations are 21, 15 and 3 km far from Cluj-Napoca. Highly concentrated springs are to be found in the old mine area from Pata village and in the slough from Cojocna. Beside the well known saline lakes from Cojocna, five other saline lakes were identified; most of them are having artificial origin.

  4. Capacitive mixing power production from salinity gradient energy enhanced through exoelectrogen-generated ionic currents

    KAUST Repository

    Hatzell, Marta C.; Cusick, Roland D.; Logan, Bruce E.

    2014-01-01

    Several approaches to generate electrical power directly from salinity gradient energy using capacitive electrodes have recently been developed, but power densities have remained low. By immersing the capacitive electrodes in ionic fields generated by exoelectrogenic microorganisms in bioelectrochemical reactors, we found that energy capture using synthetic river and seawater could be increased ∼65 times, and power generation ∼46 times. Favorable electrochemical reactions due to microbial oxidation of organic matter, coupled to oxygen reduction at the cathode, created an ionic flow field that enabled more effective passive charging of the capacitive electrodes and higher energy capture. This ionic-based approach is not limited to the use of river water-seawater solutions. It can also be applied in industrial settings, as demonstrated using thermolytic solutions that can be used to capture waste heat energy as salinity gradient energy. Forced charging of the capacitive electrodes, using energy generated by the bioelectrochemical system and a thermolytic solution, further increased the maximum power density to 7 W m -2 (capacitive electrode). © 2014 The Royal Society of Chemistry.

  5. Soil salinity decreases global soil organic carbon stocks.

    Science.gov (United States)

    Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

    2013-11-01

    Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Numerical assessment of the origin of deep salinity in a low permeability fractured medium

    International Nuclear Information System (INIS)

    Guimera, Jordi; Ruiz, Eduardo; Luna, Miguel; Arcos, David; Domenech, Cristina; Jordana, Salvador; Saegusa, Hiromitsu; Iwatsuki, Teruki

    2007-01-01

    Many possible origins have been proposed for the saline groundwater observed in many deep geological environments. In particular, samples obtained from deep boreholes located in granite at the Mizunami Underground Research Laboratory in Central Japan show total dissolved solids increasing to 50 mmol/L at depths below 800 m. Different hypothesis have been formulated to explain the observed fluid composition, among them, long-term water-rock interaction, mixing with residual fluids of magmatic origin and relict seawater dating from Miocene times. A review of the hydrochemical and isotopic data suggests that the three above hypotheses may be valid, at least to different degrees, or that processes acting over more recent geological times may be involved. The origin of the salinity was assessed by simulating land emersion by means of changing the upper recharge boundary. In this manner the Miocene seawater was modeled as being continually mixed with fresh water until the present time. The effects of different retardation processes were considered by varying factors such as matrix diffusion and fracture conductivity. Finally, geochemical reactions reproduced trends in major ions and master variables. This study shows that the salinity observed in the boreholes can be explained qualitatively as residual Miocene age seawater subjected to alteration due to long-term contact with the host material and continuous mixing with meteoric groundwater. (authors)

  7. Coherent mesoscale eddies in the North Atlantic subtropical gyre: 3-D structure and transport with application to the salinity maximum

    Science.gov (United States)

    Amores, Angel; Melnichenko, Oleg; Maximenko, Nikolai

    2017-01-01

    The mean vertical structure and transport properties of mesoscale eddies are investigated in the North Atlantic subtropical gyre by combining historical records of Argo temperature/salinity profiles and satellite sea level anomaly data in the framework of the eddy tracking technique. The study area is characterized by a low eddy kinetic energy and sea surface salinity maximum. Although eddies have a relatively weak signal at surface (amplitudes around 3-7 cm), the eddy composites reveal a clear deep signal that penetrates down to at least 1200 m depth. The analysis also reveals that the vertical structure of the eddy composites is strongly affected by the background stratification. The horizontal patterns of temperature/salinity anomalies can be reconstructed by a linear combination of a monopole, related to the elevation/depression of the isopycnals in the eddy core, and a dipole, associated with the horizontal advection of the background gradient by the eddy rotation. A common feature of all the eddy composites reconstructed is the phase coherence between the eddy temperature/salinity and velocity anomalies in the upper ˜300 m layer, resulting in the transient eddy transports of heat and salt. As an application, a box model of the near-surface layer is used to estimate the role of mesoscale eddies in maintaining a quasi-steady state distribution of salinity in the North Atlantic subtropical salinity maximum. The results show that mesoscale eddies are able to provide between 4 and 21% of the salt flux out of the area required to compensate for the local excess of evaporation over precipitation.

  8. Are Low Salinity Waters the Remedy to Noctiluca scintillans Blooms in the Arabian Sea?

    Science.gov (United States)

    Gibson, J.

    2017-12-01

    Noctiluca scintillans (Noctiluca) is a mixotrophic, green dinoflagellate that for the past two decades has been producing problematic algal blooms in the Arabian Sea (AS). As a mixotroph, Noctiluca obtains energy from both consumption of phytoplankton as well as its intracellular photosynthesizing endosymbionts named, Pedinomonas noctilucae. It is this autotrophic and heterotrophic dual capability that has largely enabled Noctiluca to be a highly dominant species at the planktonic trophic layer in the AS. Exacerbated by non-point source/point-source pollution in the AS, ocean acidification, and intensified monsoons, Noctiluca currently algal blooms can be as big as three times the size of Texas. By depleting the AS of oxygen, clogging the gills of fish, and altering the AS food web, these algal blooms result in mass fish die offs. In turn this propagates financial and food insecurity issues in countless coastal communities. However, through satellite imaging over the years, it has been observed that the proliferation of Noctiluca is precluded or encounters a "wall" about mid-way along the west coast of India. It is theorized that this "wall" is due to a significant change in salinity. Snow from atop the Himalayan Mountains melts and adds fresh water to the Bay of Bengal (BB), and in winter the East Indian Coastal Current (EICC) carries this fresher water around the southern tip of India and towards the AS. It is believed that this dilution effect impedes the growth of Noctiluca further south. Ultimately, in this study the salinity gradient from the Bay of Bengal (BB) around the horn of India into the AS was replicated in six pairs of culture bottles. Noctiluca was grown in six different salinities including 26, 28, 30, 32, 34, and 38 psu. Algae grown in the 34 and 38 psu bottles, were healthier and 38 psu treated Noctiluca provided optimal conditions for its photosynthesizing endosymbionts. Noctiluca does not grow well at lower salinities, thus applications of low

  9. Depth as an organizer of fish assemblages in floodplain lakes

    Science.gov (United States)

    Miranda, L.E.

    2011-01-01

    Depth reduction is a natural process in floodplain lakes, but in many basins has been accelerated by anthropogenic disturbances. A diverse set of 42 floodplain lakes in the Yazoo River Basin (Mississippi, USA) was examined to test the hypothesis of whether depth reduction was a key determinant of water quality and fish assemblage structure. Single and multiple variable analyses were applied to 10 commonly monitored water variables and 54 fish species. Results showed strong associations between depth and water characteristics, and between depth and fish assemblages. Deep lakes provided less variable environments, clearer water, and a wider range of microhabitats than shallow lakes. The greater environmental stability was reflected by the dominant species in the assemblages, which included a broader representation of large-body species, species less tolerant of extreme water quality, and more predators. Stability in deep lakes was further reflected by reduced among-lake variability in taxa representation. Fish assemblages in shallow lakes were more variable than deep lakes, and commonly dominated by opportunistic species that have early maturity, extended breeding seasons, small adult size, and short lifespan. Depth is a causal factor that drives many physical and chemical variables that contribute to organizing fish assemblages in floodplain lakes. Thus, correlations between fish and water transparency, temperature, oxygen, trophic state, habitat structure, and other environmental descriptors may ultimately be totally or partly regulated by depth. In basins undergoing rapid anthropogenic modifications, local changes forced by depth reductions may be expected to eliminate species available from the regional pool and could have considerable ecological implications. ?? 2010 Springer Basel AG (outside the USA).

  10. Engineering zonal cartilaginous tissue by modulating oxygen levels and mechanical cues through the depth of infrapatellar fat pad stem cell laden hydrogels.

    Science.gov (United States)

    Luo, Lu; O'Reilly, Adam R; Thorpe, Stephen D; Buckley, Conor T; Kelly, Daniel J

    2017-09-01

    Engineering tissues with a structure and spatial composition mimicking those of native articular cartilage (AC) remains a challenge. This study examined if infrapatellar fat pad-derived stem cells (FPSCs) can be used to engineer cartilage grafts with a bulk composition and a spatial distribution of matrix similar to the native tissue. In an attempt to mimic the oxygen gradients and mechanical environment within AC, FPSC-laden hydrogels (either 2 mm or 4 mm in height) were confined to half of their thickness and/or subjected to dynamic compression (DC). Confining FPSC-laden hydrogels was predicted to accentuate the gradient in oxygen tension through the depth of the constructs (higher in the top and lower in the bottom), leading to enhanced glycosaminoglycan (GAG) and collagen synthesis in 2 mm high tissues. When subjected to DC alone, both GAG and collagen accumulation increased within 2 mm high unconfined constructs. Furthermore, the dynamic modulus of constructs increased from 0.96 MPa to 1.45 MPa following the application of DC. There was no synergistic benefit of coupling confinement and DC on overall levels of matrix accumulation; however in all constructs, irrespective of their height, the combination of these boundary conditions led to the development of engineered tissues that spatially best resembled native AC. The superficial region of these constructs mimicked that of native tissue, staining weakly for GAG, strongly for type II collagen, and in 4 mm high tissues more intensely for proteoglycan 4 (lubricin). This study demonstrated that FPSCs respond to joint-like environmental conditions by producing cartilage tissues mimicking native AC. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Changes in hydrology and salinity accompanying a century of agricultural conversion in Argentina.

    Science.gov (United States)

    Jayawickreme, Dushmantha H; Santoni, Celina S; Kim, John H; Jobbágy, Esteban G; Jackson, Robert B

    2011-10-01

    Conversions of natural woodlands to agriculture can alter the hydrologic balance, aquifer recharge, and salinity of soils and groundwater in ways that influence productivity and sustainable land use. Using a land-use change chronosequence in semiarid woodlands of Argentina's Espinal province, we examined the distribution of moisture and solutes and estimated recharge rates on adjacent plots of native woodlands and rain-fed agriculture converted 6-90 years previously. Soil coring and geoelectrical profiling confirmed the presence of spatially extensive salt accumulations in dry woodlands and pervasive salt losses in areas converted to agriculture. A 1.1-km-long electrical resistivity transect traversing woodland, 70-year-old agriculture, and woodland, for instance, revealed a low-resistivity (high-salinity) horizon between approximately 3 m and 13 m depth in the woodlands that was virtually absent in the agricultural site because of leaching. Nine-meter-deep soil profiles indicated a 53% increase in soil water storage after 30 or more years of cultivation. Conservative groundwater-recharge estimates based on chloride tracer methods in agricultural plots ranged from approximately 12 to 45 mm/yr, a substantial increase from the led to >95% loss of sulfate and chloride ions from the shallow vadose zone in most agriculture plots. These losses correspond to over 100 Mg of sulfate and chloride salts potentially released to the region's groundwater aquifers through time with each hectare of deforestation, including a capacity to increase groundwater salinity to >4000 mg/L from these ions alone. Similarities between our findings and those of the dryland salinity problems of deforested woodlands in Australia suggest an important warning about the potential ecohydrological risks brought by the current wave of deforestation in the Espinal and other regions of South America and the world.

  12. THE CONDITION INDEX OF MUSSELS (Mytilus galloprovincialis IN BUDAVA AND RAŠA BAY

    Directory of Open Access Journals (Sweden)

    Nives Marušić

    2009-07-01

    Full Text Available Condition index is a factor that can show of some area for shellfish cultivation. Analysis of the condition index from various sites may show importance of these sites for cultivation and shellfish during the year. By monitoring the condition index it is possible to determine dynamic of meat amount change in time. Condition index depends on mussel spawning period, presence of food and changes of environmental factors (temperature, salinity, concentration of dissolved oxygen. The research of condition index was monitored in Budava and Ra{a Bay at depth of 0.5 and 2.5 m. In summer months (July and August when the sea water temperature and salinity were in optimum, the mussel condition index had maximum value. Value of the condition index is proportional with sea temperature and salinity. The condition index of mussels significantly changed over the year period, at different sites (Budava and Raška Bay and at different depth (0.5 and 2.5 m.

  13. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Pacific Remote Island Areas from 2015-01-26 to 2015-04-28 (NCEI Accession 0162247)

    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...

  14. Oxygen isotope studies of the Salton Sea geothermal field

    International Nuclear Information System (INIS)

    Olson, E.R.

    1978-01-01

    Interbedded shales and sandstones were drilled to a depth of 1588 metres in Sinclair Number Four Well, Salton Sea Geothermal Field. Bottom hole temperatures are approximately 290 0 C. The oxygen dels of hydrothermal and detrital calcite have a systematic relationship at any depth in the geothermal reservoir. Typical values are: vein calcite, +6 0 / 00 ; calcite in white sandstone, +10 0 / 00 ; calcite in dark gray shale, +11 0 / 00 ; calcite in light gray shale, +17 0 / 00 ; calcite in red-brown shale, +20 0 / 00 . This succession represents decreasing water-rock interaction that is also indicated by the clay mineralogy of the shales. Permeability has a marked effect on the equilibration of water and rocks at any given temperature. Original differences in permeability have resulted in partial preservation of original detrital sedimentary compositions. The fluids in the Salton Sea Geothermal Field are probabaly partially evaporated Colorado River water, and their oxygen del values vary as much as 4 0 / 00 throughout the field. Truesdell's (1974) data suggest that dissolved salts may make the water oxygen activity del as much as 6 0 / 00 greater than the concentration del in the geothermal reservoir. Such an uncertainty is a serious impediment to precise isotope geothermometry in this system.(auth.)

  15. The influence of propofol on P-selectin expression and nitric oxide production in re-oxygenated human umbilical vein endothelial cells.

    LENUS (Irish Health Repository)

    Corcoran, T B

    2012-02-03

    BACKGROUND: Reperfusion injury is characterized by free radical production and endothelial inflammation. Neutrophils mediate much of the end-organ injury that occurs, requiring P-selectin-mediated neutrophil-endothelial adhesion, and this is associated with decreased endothelial nitric oxide production. Propofol has antioxidant properties in vitro which might abrogate this inflammation. METHODS: Cultured human umbilical vein endothelial cells were exposed to 20 h of hypoxia and then returned to normoxic conditions. Cells were treated with saline, Diprivan 5 microg\\/l or propofol 5 microg\\/l for 4 h after re-oxygenation and were then examined for P-selectin expression and supernatant nitric oxide concentrations for 24 h. P-selectin was determined by flow cytometry, and culture supernatant nitric oxide was measured as nitrite. RESULTS: In saline-treated cells, a biphasic increase in P-selectin expression was demonstrated at 30 min (P = 0.01) and 4 h (P = 0.023) after re-oxygenation. Propofol and Diprivan prevented these increases in P-selectin expression (P < 0.05). Four hours after re-oxygenation, propofol decreased endothelial nitric oxide production (P = 0.035). CONCLUSION: This is the first study to demonstrate an effect of propofol upon endothelial P-selectin expression. Such an effect may be important in situations of reperfusion injury such as cardiac transplantation and coronary artery bypass surgery. We conclude that propofol attenuates re-oxygenation-induced endothelial inflammation in vitro.

  16. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Science.gov (United States)

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  17. Depth Profiling Analysis of Aluminum Oxidation During Film Deposition in a Conventional High Vacuum System

    Science.gov (United States)

    Kim, Jongmin; Weimer, Jeffrey J.; Zukic, Muamer; Torr, Douglas G.

    1994-01-01

    The oxidation of aluminum thin films deposited in a conventional high vacuum chamber has been investigated using x-ray photoelectron spectroscopy (XPS) and depth profiling. The state of the Al layer was preserved by coating it with a protective MgF2 layer in the deposition chamber. Oxygen concentrations in the film layers were determined as a function of sputter time (depth into the film). The results show that an oxidized layer is formed at the start of Al deposition and that a less extensively oxidized Al layer is deposited if the deposition rate is fast. The top surface of the Al layer oxidizes very quickly. This top oxidized layer may be thicker than has been previously reported by optical methods. Maximum oxygen concentrations measured by XPS at each Al interface are related to pressure to rate ratios determined during the Al layer deposition.

  18. Oxygen isotope ratios of the Icelandic crust

    International Nuclear Information System (INIS)

    Hattori, K.; Muehlenbachs, K.

    1982-01-01

    Oxygen isotope ratios of hydrothermally altered basalts from depth of up to approx.3 km are reported from three localities in Iceland: International Research Drilling Project (IRDP) core at Reydarfjordur, eastern Iceland (Tertiary age); drill cuttings from Reykjavik (Plio-Pleistocene age); and Halocene drill cuttings from the active Krafla central volcano. Whole rock samples from these three localities have delta 18 O values averaging +3.9 +- 1.3, +2.4 +- 1.1, and -7.7 +- 2.4%, respectively. The observed values in the deeper samples from Krafla are as low as the values for any rocks previously reported. There seems to be a slight negative gradient in delta 18 O with depth at the former two localities and a more pronounced one at Krafla. Oxygen isotope fractionations between epidote and quartz and those between calcite and fluid suggests that the basalts were altered at temperatures of 300 0 --400 0 C. Low deltaD and delta 18 O of epidote and low delta 34 S of anhydrite indicate that the altering fluids in all three areas originated as meteoric waters and have undergone varied 'oxygen shifts'. Differences in the 18 O shift of the fluids are attributed to differences in hydrothermal systems; low water/rock ratios ( 5) at Krafla. The convective hydrothermal activity, which is probably driven by silicic magma beneath the central volcanoes, has caused strong subsolidus depletion of 18 O in the rocks. The primary-magnetic delta 18 O value of the rocks in the Tertiary IRDP core was about +3.9%, which is lower than that obtained for fresh basalt from other places. Such exceptionally low delta 18 O magmas are common in Iceland and may occur as the result of oxygen isotope exchange with or assimilation of altered rocks that form a thick sequence beneath the island due to isostatic subsidence

  19. Biochar mitigates salinity stress in potato

    DEFF Research Database (Denmark)

    Saleem Akhtar, Saqib; Andersen, M.N.; Liu, Fulai

    2015-01-01

    capability of biochar. Results indicated that biochar was capable to ameliorate salinity stress by adsorbing Na+. Increasing salinity level resulted in significant reductions of shoot biomass, root length and volume, tuber yield, photosynthetic rate (An), stomatal conductance (gs), midday leaf water......A pot experiment was conducted in a climate-controlled greenhouse to investigate the growth, physiology and yield of potato in response to salinity stress under biochar amendment. It was hypothesized that addition of biochar may improve plant growth and yield by mitigating the negative effect...... potential, but increased abscisic acid (ABA) concentration in both leaf and xylem sap. At each salinity level, incorporation of biochar increased shoot biomass, root length and volume, tuber yield, An, gs, midday leaf water potential, and decreased ABA concentration in the leaf and xylem sap as compared...

  20. Investigation of Soil Salinity to Distinguish Boundary Line between ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Investigation of Soil Salinity to Distinguish Boundary Line between Saline and ... Setting 4 dSm-1 as the limit between saline and non-saline soils in kriging algorithms resulted in a .... number of sample points within the search window,.

  1. The Depths of the Ocean and the Question of Radioactive Waste Disposal in Them

    Energy Technology Data Exchange (ETDEWEB)

    Bogorov, V. G.; Tareev, B. A.; Fedorov, K. N. [Oceanographical Institute of the Academy of Sciences of the USSR, Moscow, USSR (Russian Federation)

    1960-07-01

    There are 23 deep water troughs with depths of more than 6,000 m in the oceans of the world. None of the troughs has any morphological features which might prevent the free circulation of deep water in them. An increase in water temperature at the bottom of the troughs, beginning at a depth of 3-5 km, results in the vertical convective mixing of deep water. It has been proved theoretically that in spite of the stabilizing effect of the earth's rotation, steady cellular convection will take place in the deep layers even when there are very small superadiabatic temperature gradients. The vertical distribution of oxygen, showing a characteristic increase in percentage saturation and absolute concentration with depth from a minimum level of 1,000 m to the bottom, may be taken as evidence of the existence of both vertical and horizontal movements or horizontal mixing throughout the deep water mass. Otherwise the biochemical consumption of oxygen (not less than 0.1 ml/1 per year) would lead to complete exhaustion of oxygen resources in deep water after a very short time (40-60 years). Horizontal currents with comparatively high velocities (5-17 cm/sec) have been detected at depths of 1,000-3,000 m by direct measurements in the Atlantic and the Pacific Oceans. The physical circulation of water is not the only means by which dissolved and suspended materials are dispersed in the ocean. The continuous migration of living organisms adds to the risk that radioactive materials, which have accumulated in living tissue, will be dispersed and transmitted through the food chain over large distances at great speeds, which was the case after experimental atomic explosions in the Pacific. It must therefore be recognized that radioactive waste disposal in the deep water troughs cannot be permitted without endangering the health of the whole of mankind through radioactive contamination. (author)

  2. Salinity and Temperature Constraints on Microbial Methanogenesis in the Lei-Gong-Huo Mud Volcano of Eastern Taiwan

    Science.gov (United States)

    Sun, W.; Lin, L.; Wang, P.

    2012-12-01

    Terrestrial mud volcano is thought to be one of the most important natural sources of methane emission. Previous studies have shown that methane cycling in terrestrial mud volcanoes involves a complex reaction network driven by the interactions between subsurface and surface abiotic and microbial processes. In situ methanogenesis appears to produce methane at quantities exceeding those of deeply-sourced thermogenic methane and the capacities of anaerobic methanotrophy at shallow depth levels, thereby contributing significantly to the methane emission. Various degrees of evaporation at surface also lead to the enhancement of chloride concentrations in pore water, favoring the proliferation of halo-tolerant and/or halophilic methanogens. The goal of this study is to investigate the extent of methanogenesis in terrestrial mud volcanoes by incubating mud slurries with various precursors (H2/CO2, acetate, methanol, and methylamine) at different salinities (up to 2000 mM) and temperatures (up to 50 oC). Methane concentrations were monitored through time and molecular analyses were applied to investigate the changes of methanogenic communities. Methanogenesis was stimulated by any investigated precursor at room temperature. However, the methanogenic response to salinity varied. Of the investigated precursors, H2/CO2 and methyl-compounds (methanol and methylamine) stimulated methanogenesis at all investigated salinities. The rates and yields of hydrogen- and methyl-utilizing methanogenesis declined significantly at salinities greater than 1500 mM. Acetate-utilizing methanogenesis proceeded at salinities less than 700 mM. At 40 oC, methanogenesis was stimulated by all investigated precursors at the in situ salinity (~400 mM). At 50 oC, only H2-utilizing methanogenesis was stimulated. Analyses of terminal restriction fragment length polymorphism (TRFLP) for 16S rRNA genes revealed various patterns upon different precursors and salinities. The TRFLP results combined with

  3. Oxidative defense metabolites induced by salinity stress in roots of Salicornia herbacea.

    Science.gov (United States)

    Lee, Seung Jae; Jeong, Eun-Mi; Ki, Ah Young; Oh, Kyung-Seo; Kwon, Joseph; Jeong, Jae-Hyuk; Chung, Nam-Jin

    2016-11-01

    High salinity is a major abiotic stress that affects the growth and development of plants. This type of stress can influence flowering, the production of crops, defense mechanisms and other physiological processes. Previous studies have attempted to elucidate salt-tolerance mechanisms to improve plant growth and productivity in the presence of sodium chloride. One such plant that has been studied in detail is Salicornia, a well-known halophyte, which has adapted to grow in the presence of high salt. To further the understanding of how Salicornia grows and develops under high saline conditions, Salicornia herbacea (S. herbacea) was grown under varying saline concentrations (0, 50, 100, 200, 300, and 400mM), and the resulting phenotype, ion levels, and metabolites were investigated. The optimal condition for the growth of S. herbacea was determined to be 100mM NaCl, and increased salt concentrations directly decreased the internal concentrations of other inorganic ions including Ca 2+ , K + , and Mg 2+ . Metabolomics were performed on the roots of the plant as a systematic metabolomics study has not yet been reported for Salicornia roots. Using ethylacetate and methanol extraction followed by high resolution ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), 1793 metabolites were identified at different NaCl levels. Structural and functional analyses demonstrated that the concentration of 53 metabolites increased as the concentration of NaCl increased. These metabolites have been linked to stress responses, primarily oxidative stress responses, which increase under saline stress. Most metabolites can be classified as polyols, alkaloids, and steroids. Functional studies of these metabolites show that shikimic acid, vitamin K1, and indole-3-carboxylic acid are generated as a result of defense mechanisms, including the shikimate pathway, to protect against reactive oxygen species (ROS) generated by salt stress. This metabolite profiling

  4. Evaluating physiological responses of plants to salinity stress

    KAUST Repository

    Negrã o, Só nia; Schmö ckel, S. M.; Tester, Mark A.

    2016-01-01

    Background Because soil salinity is a major abiotic constraint affecting crop yield, much research has been conducted to develop plants with improved salinity tolerance. Salinity stress impacts many aspects of a plant’s physiology, making

  5. Progress with the reclamation of saline soils in Peru

    International Nuclear Information System (INIS)

    Estrada, J.A.

    1983-01-01

    The present report is the result of five years' experimental work at the Costa Regional Development Institute (IRD-Costa), based in Canete, Lima, Peru, on the reclamation of land affected by salts and hence of seriously limited agricultural value (production lower than 50%). A reclamation method combining surface and at depth washing with artificial drainage of excess water has been tried out and a method of nutrition has been developed which is based on tonification of the seeds before sowing. The results obtained are rather encouraging, so the method looks very promising, especially as it also makes for considerable savings in fertilizers (some 20% less) and for better yields per unit area. Once the ionic behaviour of this method has been studied by means of radioisotopes a large contribution will have been made towards alleviating the problem of saline soils. (author)

  6. Characterizing contaminant concentrations with depth by using the USGS well profiler in Oklahoma, 2003-9

    Science.gov (United States)

    Smith, S. Jerrod; Becker, Carol J.

    2011-01-01

    Since 2003, the U.S. Geological Survey (USGS) Oklahoma Water Science Center has been using the USGS well profiler to characterize changes in water contribution and contaminant concentrations with depth in pumping public-supply wells in selected aquifers. The tools and methods associated with the well profiler, which were first developed by the USGS California Water Science Center, have been used to investigate common problems such as saline water intrusion in high-yield irrigation wells and metals contamination in high-yield public-supply wells.

  7. 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.

  8. Salinity-induced mixed and barrier layers in the southwestern tropical Atlantic Ocean off the northeast of Brazil

    Directory of Open Access Journals (Sweden)

    M. Araujo

    2011-01-01

    Full Text Available High-resolution hydrographic observations of temperature and salinity are used to analyze the formation and distribution of isothermal depth (ZT, mixed depth (ZM and barrier layer thickness (BLT in a section of the southwestern Atlantic (0°30´ N–14°00´ S; 31°24´–41°48´ W, adjacent to the northeastern Brazilian coast. Analyzed data consists of 279 CTD casts acquired during two cruises under the Brazilian REVIZEE Program. One occurred in late austral winter (August–October 1995 and another in austral summer (January–April 1997. Oceanic observations are compared to numerical modeling results obtained from the French Mercator-Coriolis Program. Results indicate that the intrusion of subtropical Salinity Maximum Waters (SMW is the major process contributing to the seasonal barrier layer formation. These waters are brought by the South Equatorial Current (SEC, from the subtropical region, into the western tropical Atlantic boundary. During late austral winter southeastern trade winds are more intense and ITCZ precipitations induce lower surface salinity values near the equator. During this period a 5–90 m thick BLT (median = 15 m is observed and BLT > 30 m is restricted to latitudes higher than 8° S, where the intrusion of salty waters between 8°–12.3° S creates shallow mixed layers over deep (ZT ≥ 90 m isothermal layers. During austral summer, shallow isothermal and mixed layers prevail, when northeasterly winds are predominant and evaporation overcomes precipitation, causing saltier waters at the surface/subsurface layers. During that period observed BLT varies from 5 to 70 m and presents thicker median value of 35 m, when comparing to the winter. Furthermore, BLT ≥ 30 m is observed not only in the southernmost part of the study area, as verified during late winter, but in the latitude range 2°–14° S, where near-surface salty waters are transported westward by the

  9. ( Phaseolus vulgaris L. ) seedlings to salinity stress

    African Journals Online (AJOL)

    The effect of salinity stress on five cultivars of common bean: Bassbeer, Beladi, Giza 3, HRS 516 and RO21 were evaluated on a sand/peat medium with different salinity levels (0, 50 and 100 mM NaCl) applied 3 weeks after germination for duration of 10 days. Salinity had adverse effects not only on the biomass yield and ...

  10. Oxygen isotope geochemistry of Laurentide ice-sheet meltwater across Termination I

    Science.gov (United States)

    Vetter, Lael; Spero, Howard J.; Eggins, Stephen M.; Williams, Carlie; Flower, Benjamin P.

    2017-12-01

    We present a new method that quantifies the oxygen isotope geochemistry of Laurentide ice-sheet (LIS) meltwater across the last deglaciation, and reconstruct decadal-scale variations in the δ18O of LIS meltwater entering the Gulf of Mexico between ∼18 and 11 ka. We employ a technique that combines laser ablation ICP-MS (LA-ICP-MS) and oxygen isotope analyses on individual shells of the planktic foraminifer Orbulina universa to quantify the instantaneous δ18Owater value of Mississippi River outflow, which was dominated by meltwater from the LIS. For each individual O. universa shell, we measure Mg/Ca (a proxy for temperature) and Ba/Ca (a proxy for salinity) with LA-ICP-MS, and then analyze the same O. universa for δ18O using the remaining material from the shell. From these proxies, we obtain δ18Owater and salinity estimates for each individual foraminifer. Regressions through data obtained from discrete core intervals yield δ18Ow vs. salinity relationships with a y-intercept that corresponds to the δ18Owater composition of the freshwater end-member. Our data suggest that from 15.5 through 14.6 ka, estimated δ18Ow values of Mississippi River discharge from discrete core intervals range from -11‰ to -21‰ VSMOW, which is consistent with δ18O values from both regional precipitation and the low-elevation, southern margin of the LIS. During the Bølling and Allerød (14.0 through 13.3 ka), estimated δ18Ow values of Mississippi River discharge from discrete core intervals range from -22‰ to -38‰ VSMOW. These values suggest a dynamic melting history of different parts of the LIS, with potential contributions to Mississippi River outflow from both the low-elevation, southern margin of the LIS and high-elevation, high-latitude domes in the LIS interior that were transported to the ablation zone. Prior to ∼15.5 ka, the δ18Owater value of the Mississippi River was similar to that of regional precipitation or low-latitude LIS meltwater, but the Ba

  11. The Interplay Between Saline Fluid Flow and Dynamic Permeability in Magmatic-Hydrothermal Systems

    Science.gov (United States)

    Weis, P.

    2014-12-01

    Magmatic-hydrothermal ore deposits document the interplay between saline fluid flow and rock permeability. Numerical simulations of multi-phase flow of variably miscible, compressible H20-NaCl fluids in concert with a dynamic permeability model can reproduce characteristics of porphyry copper and epithermal gold systems. This dynamic permeability model incorporates depth-dependent permeability profiles characteristic for tectonically active crust as well as pressure- and temperature-dependent relationships describing hydraulic fracturing and the transition from brittle to ductile rock behavior. In response to focused expulsion of magmatic fluids from a crystallizing upper crustal magma chamber, the hydrothermal system self-organizes into a hydrological divide, separating an inner part dominated by ascending magmatic fluids under near-lithostatic pressures from a surrounding outer part dominated by convection of colder meteoric fluids under near-hydrostatic pressures. This hydrological divide also provides a mechanism to transport magmatic salt through the crust, and prevents the hydrothermal system to become "clogged" by precipitation of solid halite due to depressurization of saline, high-temperature magmatic fluids. The same physical processes at similar permeability ranges, crustal depths and flow rates are relevant for a number of active systems, including geothermal resources and excess degassing at volcanos. The simulations further suggest that the described mechanism can separate the base of free convection in high-enthalpy geothermal systems from the magma chamber as a driving heat source by several kilometers in the vertical direction in tectonic settings with hydrous magmatism. This hydrology would be in contrast to settings with anhydrous magmatism, where the base of the geothermal systems may be closer to the magma chamber.

  12. Identification of the microbes mediating Fe reduction in a deep saline aquifer and their influence during managed aquifer recharge.

    Science.gov (United States)

    Ko, Myoung-Soo; Cho, Kyungjin; Jeong, Dawoon; Lee, Seunghak

    2016-03-01

    In this study, indigenous microbes enabling Fe reduction under saline groundwater conditions were identified, and their potential contribution to Fe release from aquifer sediments during managed aquifer recharge (MAR) was evaluated. Sediment and groundwater samples were collected from a MAR feasibility test site in Korea, where adjacent river water will be injected into the confined aquifer. The residual groundwater had a high salinity over 26.0 psu, as well as strong reducing conditions (dissolved oxygen, DOaquifer were found to be Citrobacter sp. However, column experiments to simulate field operation scenarios indicated that additional Fe release would be limited during MAR, as the dominant microbial community in the sediment would shift from Citrobacter sp. to Pseudomonas sp. and Limnohabitans sp. as river water injection alters the pore water chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Larval tolerance to salinity in three species of Australian anuran: an indication of saline specialisation in Litoria aurea.

    Directory of Open Access Journals (Sweden)

    Brian D Kearney

    Full Text Available Recent anthropogenic influences on freshwater habitats are forcing anuran populations to rapidly adapt to high magnitude changes in environmental conditions or face local extinction. We examined the effects of ecologically relevant elevated salinity levels on larval growth, metamorphosis and survival of three species of Australian anuran; the spotted marsh frog (Limnodynastes tasmaniensis, the painted burrowing frog (Neobatrachus sudelli and the green and golden bell frog (Litoria aurea, in order to better understand the responses of these animals to environmental change. Elevated salinity (16% seawater negatively impacted on the survival of L. tasmaniensis (35% survival and N sudelli (0% survival, while reduced salinity had a negative impact on L. aurea. (16% seawater: 85% survival; 0.4% seawater: 35% survival. L. aurea tadpoles survived in salinities much higher than previously reported for this species, indicating the potential for inter-populations differences in salinity tolerance. In L. tasmaniensis and L. aurea, development to metamorphosis was fastest in low and high salinity treatments suggesting it is advantageous for tadpoles to invest energy in development in both highly favourable and developmentally challenging environments. We propose that this response might either maximise potential lifetime fecundity when tadpoles experience favourable environments, or, facilitate a more rapid escape from pond environments where there is a reduced probability of survival.

  14. Dissolved oxygen stratification and response to thermal structure and long-term climate change in a large and deep subtropical reservoir (Lake Qiandaohu, China).

    Science.gov (United States)

    Zhang, Yunlin; Wu, Zhixu; Liu, Mingliang; He, Jianbo; Shi, Kun; Zhou, Yongqiang; Wang, Mingzhu; Liu, Xiaohan

    2015-05-15

    From January 2010 to March 2014, detailed depth profiles of water temperature, dissolved oxygen (DO), and chromophoric dissolved organic matter (CDOM) were collected at three sites in Lake Qiandaohu, a large, deep subtropical reservoir in China. Additionally, we assessed the changes in DO stratification over the past 61 years (1953-2013) based on our empirical models and long-term air temperature and transparency data. The DO concentration never fell below 2 mg/L, the critical value for anoxia, and the DO depth profiles were closely linked to the water temperature depth profiles. In the stable stratification period in summer and autumn, the significant increase in CDOM in the metalimnion explained the decrease in DO due to the oxygen consumed by CDOM. Well-developed oxygen stratification was detected at the three sites in spring, summer and autumn and was associated with thermal stratification. Oxycline depth was significantly negatively correlated with daily air temperature and thermocline thickness but significantly positively correlated with thermocline depth during the stratification weakness period (July-February). However, there were no significant correlations among these parameters during the stratification formation period (March-June). The increase of 1.67 °C in yearly average daily air temperature between 1980 and 2013 and the decrease of 0.78 m in Secchi disk depth caused a decrease of 1.65 m and 2.78 m in oxycline depth, respectively, facilitating oxygen stratification and decreasing water quality. Therefore, climate warming has had a substantial effect on water quality through changing the DO regime in Lake Qiandaohu. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Pea p68, a DEAD-box helicase, provides salinity stress tolerance in transgenic tobacco by reducing oxidative stress and improving photosynthesis machinery.

    Science.gov (United States)

    Tuteja, Narendra; Banu, Mst Sufara Akhter; Huda, Kazi Md Kamrul; Gill, Sarvajeet Singh; Jain, Parul; Pham, Xuan Hoi; Tuteja, Renu

    2014-01-01

    The DEAD-box helicases are required mostly in all aspects of RNA and DNA metabolism and they play a significant role in various abiotic stresses, including salinity. The p68 is an important member of the DEAD-box proteins family and, in animal system, it is involved in RNA metabolism including pre-RNA processing and splicing. In plant system, it has not been well characterized. Here we report the cloning and characterization of p68 from pea (Pisum sativum) and its novel function in salinity stress tolerance in plant. The pea p68 protein self-interacts and is localized in the cytosol as well as the surrounding of cell nucleus. The transcript of pea p68 is upregulated in response to high salinity stress in pea. Overexpression of p68 driven by constitutive cauliflower mosaic virus-35S promoter in tobacco transgenic plants confers enhanced tolerances to salinity stress by improving the growth, photosynthesis and antioxidant machinery. Under stress treatment, pea p68 overexpressing tobacco accumulated higher K+ and lower Na+ level than the wild-type plants. Reactive oxygen species (ROS) accumulation was remarkably regulated by the overexpression of pea p68 under salinity stress conditions, as shown from TBARS content, electrolyte leakage, hydrogen peroxide accumulation and 8-OHdG content and antioxidant enzyme activities. To the best of our knowledge this is the first direct report, which provides the novel function of pea p68 helicase in salinity stress tolerance. The results suggest that p68 can also be exploited for engineering abiotic stress tolerance in crop plants of economic importance.

  16. Salinity management in southern Italy irrigation areas

    Directory of Open Access Journals (Sweden)

    Massimo Monteleone

    Full Text Available After a synthetic review of the most worrisome pressures applied over soils and waters, general criterions and normative principles that have to lead the technical intervention on soil and water protection are accounted, both with respect to farm activity and land planning. The salinity problem is faced, then, through the analysis of the nature and origin of saline soil and of the complex quantitative relationships able to interpret the accumulation and leaching of soil salts. Having specified the theoretical bases of salinity, the related technical features are then considered in order to define a proper management of soil and waters. Particular relevance is assigned to the irrigation and leaching techniques as well as, more briefly, to other agronomic interventions in order to guarantee the most effective salinity control. Another relevant technical facet of salinity control, although quite often neglected or retained of secondary importance in comparison to irrigation, is the drainage and disposal of leached water. The increased sensibility on the environmental impacts that the disposal of these waters can produce has raised today the level of attention on these procedures that are disciplined by norms of law and, therefore, require appropriate techniques of intervention. Finally, after the different scale orders involved in the management of salinity are defined (from the field and farm level up to the land and basin, the fundamental elements in order to work out a risk analysis and an action program are illustrated; some indications about the most up to date salinity monitoring and mapping methods are also provided, considering their great importance to continuously check the possible broadening of salinization and to carefully maintain its control.

  17. Structural characterisation of oxygen diffusion hardened alpha-tantalum PVD-coatings on titanium.

    Science.gov (United States)

    Hertl, C; Koll, L; Schmitz, T; Werner, E; Gbureck, U

    2014-08-01

    Titanium substrates were coated with tantalum layers of 5 μm thickness using physical vapour deposition (PVD). The tantalum layers showed a (110)-preferred orientation. The coated samples were hardened by oxygen diffusion. Using X-ray diffraction the crystallographic structure of the tantalum coatings was characterised, comparing untreated and diffusion hardened specimen conditions. Oxygen depth profiles were determined by glow discharge spectrometry. The hardening effect of the heat treatment was examined by Vickers microhardness testing. The increase of surface hardness caused by oxygen diffusion was at least 50%. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Modeling carbon dioxide sequestration in saline aquifers: Significance of elevated pressures and salinities

    International Nuclear Information System (INIS)

    Allen, D.E.; Strazisar, B.R.; Soong, Y.; Hedges, S.W.

    2005-01-01

    The ultimate capacity of saline formations to sequester carbon dioxide by solubility and mineral trapping must be determined by simulating sequestration with geochemical models. These models, however, are only as reliable as the data and reaction scheme on which they are based. Several models have been used to make estimates of carbon dioxide solubility and mineral formation as a function of pressure and fluid composition. Intercomparison of modeling results indicates that failure to adjust all equilibrium constants to account for elevated carbon dioxide pressures results in significant errors in both solubility and mineral formation estimates. Absence of experimental data at high carbon dioxide pressures and high salinities make verification of model results difficult. Results indicate standalone solubility models that do not take mineral reactions into account will underestimate the total capacity of aquifers to sequester carbon dioxide in the long term through enhanced solubility and mineral trapping mechanisms. Overall, it is difficult to confidently predict the ultimate sequestration capacity of deep saline aquifers using geochemical models. (author)

  19. Evaluation of salinity stress on morphophysiological traits of four salin tolarant wheat cultivars

    Directory of Open Access Journals (Sweden)

    leila yadelerloo

    2009-06-01

    Full Text Available For assessment the effects of salinity on morphophysiological traits of wheat an experiment with four caltivars (Karchia, Sorkh tokhm, Sholeh and Roshan and one line (1-66-22 in four salt concentrations(0, 60, 120, and 180 mM NaCl, were conducted by factorial analysis in a completely randomized design with three replications. The rate of leaf area were measured in four stages. In booting stage, relative chlorophyll content (SPAD meter, and in pollination phase the rate of Na+ and K+ iones in four leaves(up to down were assessed and finally stem length and total dry matter were measured. Results showed that salinity reduced leaf area, total dry matter stem length of plants and relative chlorophyll content. With increasing of salinity the rate of Na+ were increased but the rate of K+ iones were decreased. Also the salt exclusion was observed at nodes of stem that of 1-66-22 was spot form.

  20. SMAP Salinity Artifacts Associated With Presence of Rain

    Science.gov (United States)

    Jacob, M. M.; Santos-Garcia, A.; Jones, L.

    2016-02-01

    The Soil Moisture Active Passive (SMAP) satellite carries an L-band radiometer, which measures sea surface salinity (SSS) over a swath of 1000 km @ 40 km resolution. SMAP can extend the Aquarius (AQ) salinity data record with improved temporal/spatial sampling. Previous studies [see references] have demonstrated significant differences between satellite and in-situ salinity measurements during rain. In the presence of precipitation, salinity stratification exists near the sea surface, which nullifies the presumption of a well-mixed salinity. In general, these salinity gradients last only a few hours and the upper layer becomes slightly fresher in salinity. This paper describes the Rain Impact Model (RIM) that simulates the effects of rain accumulation on the SSS [Santos-Garcia et al., 2014] applied to SMAP. This model incorporates rainfall information for the previous 24 hours to the measurement sample (in this case SMAP) and uses as initialization the Hybrid Coordinate Ocean Model (HYCOM) data. Given the better resolution of SMAP, the goal of this paper is to continue the analysis previously done with AQ to better understand the effects of the instantaneous and accumulated rain on the salinity measurements. Boutin, J., N. Martin, G. Reverdin, X. Yin, and F. Gaillard (2013), Sea surface freshening inferred from SMOS and ARGO salinity: Impact of rain, Ocean Sci., 9(1), 183-192, doi:10.5194/os-9-183-2013. Santos-Garcia, A., M. Jacob, L. Jones, W. Asher, Y. Hejazin, H. Ebrahimi, and M. Rabolli (2014), Investigation of rain effects on Aquarius Sea Surface Salinity measurements, J. Geophys. Res. Oceans, 119, 7605-7624, doi:10.1002/2014JC010137. Tang, W., S.H Yueh, A. Hayashi, A.G. Fore, W.L. Jones, A. Santos-Garcia, and M.M. Jacob, (2015), Rain-Induced Near Surface Salinity Stratification and Rain Roughness Correction for Aquarius SSS Retrieval, in Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of, 8(99), 1-11, doi: 10.1109/JSTARS.2015.2463768.

  1. Oxygen supply in aquatic ectotherms: partial pressure and solubility together explain biodiversity and size patterns.

    Science.gov (United States)

    Verberk, Wilco C E P; Bilton, David T; Calosi, Piero; Spicer, John I

    2011-08-01

    Aquatic ectotherms face the continuous challenge of capturing sufficient oxygen from their environment as the diffusion rate of oxygen in water is 3 x 10(5) times lower than in air. Despite the recognized importance of oxygen in shaping aquatic communities, consensus on what drives environmental oxygen availability is lacking. Physiologists emphasize oxygen partial pressure, while ecologists emphasize oxygen solubility, traditionally expressing oxygen in terms of concentrations. To resolve the question of whether partial pressure or solubility limits oxygen supply in nature, we return to first principles and derive an index of oxygen supply from Fick's classic first law of diffusion. This oxygen supply index (OSI) incorporates both partial pressure and solubility. Our OSI successfully explains published patterns in body size and species across environmental clines linked to differences in oxygen partial pressure (altitude, organic pollution) or oxygen solubility (temperature and salinity). Moreover, the OSI was more accurately and consistently related to these ecological patterns than other measures of oxygen (oxygen saturation, dissolved oxygen concentration, biochemical oxygen demand concentrations) and similarly outperformed temperature and altitude, which covaried with these environmental clines. Intriguingly, by incorporating gas diffusion rates, it becomes clear that actually more oxygen is available to an organism in warmer habitats where lower oxygen concentrations would suggest the reverse. Under our model, the observed reductions in aerobic performance in warmer habitats do not arise from lower oxygen concentrations, but instead through organismal oxygen demand exceeding supply. This reappraisal of how organismal thermal physiology and oxygen demands together shape aerobic performance in aquatic ectotherms and the new insight of how these components change with temperature have broad implications for predicting the responses of aquatic communities to

  2. Salinity tolerance of Picochlorum atomus and the use of salinity for contamination control by the freshwater cyanobacterium Pseudanabaena limnetica.

    Directory of Open Access Journals (Sweden)

    Nicolas von Alvensleben

    Full Text Available Microalgae are ideal candidates for waste-gas and -water remediation. However, salinity often varies between different sites. A cosmopolitan microalga with large salinity tolerance and consistent biochemical profiles would be ideal for standardised cultivation across various remediation sites. The aims of this study were to determine the effects of salinity on Picochlorum atomus growth, biomass productivity, nutrient uptake and biochemical profiles. To determine if target end-products could be manipulated, the effects of 4-day nutrient limitation were also determined. Culture salinity had no effect on growth, biomass productivity, phosphate, nitrate and total nitrogen uptake at 2, 8, 18, 28 and 36 ppt. 11 ppt, however, initiated a significantly higher total nitrogen uptake. While salinity had only minor effects on biochemical composition, nutrient depletion was a major driver for changes in biomass quality, leading to significant increases in total lipid, fatty acid and carbohydrate quantities. Fatty acid composition was also significantly affected by nutrient depletion, with an increased proportion of saturated and mono-unsaturated fatty acids. Having established that P. atomus is a euryhaline microalga, the effects of culture salinity on the development of the freshwater cyanobacterial contaminant Pseudanabaena limnetica were determined. Salinity at 28 and 36 ppt significantly inhibited establishment of P. limnetica in P. atomus cultures. In conclusion, P. atomus can be deployed for bioremediation at sites with highly variable salinities without effects on end-product potential. Nutrient status critically affected biochemical profiles--an important consideration for end-product development by microalgal industries. 28 and 36 ppt slow the establishment of the freshwater cyanobacterium P. limnetica, allowing for harvest of low contaminant containing biomass.

  3. Genome interrogation for novel salinity tolerant Arabidopsis mutants.

    Science.gov (United States)

    van Tol, Niels; Pinas, Johan; Schat, Henk; Hooykaas, Paul J J; van der Zaal, Bert J

    2016-12-01

    Soil salinity is becoming an increasingly large problem in agriculture. In this study, we have investigated whether a capacity to withstand salinity can be induced in the salinity sensitive plant species Arabidopsis thaliana, and whether it can be maintained in subsequent generations. To this end, we have used zinc finger artificial transcription factor (ZF-ATFs) mediated genome interrogation. Already within a relatively small collection Arabidopsis lines expressing ZF-ATFs, we found 41 lines that were tolerant to 100 mM NaCl. Furthermore, ZF-ATF encoding gene constructs rescued from the most strongly salinity tolerant lines were indeed found to act as dominant and heritable agents for salinity tolerance. Altogether, our data provide evidence that a silent capacity to withstand normally lethal levels of salinity exists in Arabidopsis and can be evoked relatively easily by in trans acting transcription factors like ZF-ATFs. © 2016 John Wiley & Sons Ltd.

  4. Depth of origin of ocean-circulation-induced magnetic signals

    Science.gov (United States)

    Irrgang, Christopher; Saynisch-Wagner, Jan; Thomas, Maik

    2018-01-01

    As the world ocean moves through the ambient geomagnetic core field, electric currents are generated in the entire ocean basin. These oceanic electric currents induce weak magnetic signals that are principally observable outside of the ocean and allow inferences about large-scale oceanic transports of water, heat, and salinity. The ocean-induced magnetic field is an integral quantity and, to first order, it is proportional to depth-integrated and conductivity-weighted ocean currents. However, the specific contribution of oceanic transports at different depths to the motional induction process remains unclear and is examined in this study. We show that large-scale motional induction due to the general ocean circulation is dominantly generated by ocean currents in the upper 2000 m of the ocean basin. In particular, our findings allow relating regional patterns of the oceanic magnetic field to corresponding oceanic transports at different depths. Ocean currents below 3000 m, in contrast, only contribute a small fraction to the ocean-induced magnetic signal strength with values up to 0.2 nT at sea surface and less than 0.1 nT at the Swarm satellite altitude. Thereby, potential satellite observations of ocean-circulation-induced magnetic signals are found to be likely insensitive to deep ocean currents. Furthermore, it is shown that annual temporal variations of the ocean-induced magnetic field in the region of the Antarctic Circumpolar Current contain information about sub-surface ocean currents below 1000 m with intra-annual periods. Specifically, ocean currents with sub-monthly periods dominate the annual temporal variability of the ocean-induced magnetic field.

  5. The density-salinity relation of standard seawater

    Science.gov (United States)

    Schmidt, Hannes; Seitz, Steffen; Hassel, Egon; Wolf, Henning

    2018-01-01

    The determination of salinity by means of electrical conductivity relies on stable salt proportions in the North Atlantic Ocean, because standard seawater, which is required for salinometer calibration, is produced from water of the North Atlantic. To verify the long-term stability of the standard seawater composition, it was proposed to perform measurements of the standard seawater density. Since the density is sensitive to all salt components, a density measurement can detect any change in the composition. A conversion of the density values to salinity can be performed by means of a density-salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement with an uncertainty of 2 g m-3 is mandatory. We present a new density-salinity relation based on such accurate density measurements. The substitution measurement method used is described and density corrections for uniform isotopic and chemical compositions are reported. The comparison of densities calculated using the new relation with those calculated using the present reference equations of state TEOS-10 suggests that the density accuracy of TEOS-10 (as well as that of EOS-80) has been overestimated, as the accuracy of some of its underlying density measurements had been overestimated. The new density-salinity relation may be used to verify the stable composition of standard seawater by means of routine density measurements.

  6. Use of microwave remote sensing in salinity estimation

    International Nuclear Information System (INIS)

    Singh, R.P.; Kumar, V.; Srivastav, S.K.

    1990-01-01

    Soil-moisture interaction and the consequent liberation of ions causes the salinity of waters. The salinity of river, lake, ocean and ground water changes due to seepage and surface runoff. We have studied the feasibility of using microwave remote sensing for the estimation of salinity by carrying out numerical calculations to study the microwave remote sensing responses of various models representative of river, lake and ocean water. The results show the dependence of microwave remote sensing responses on the salinity and surface temperature of water. The results presented in this paper will be useful in the selection of microwave sensor parameters and in the accurate estimation of salinity from microwave remote sensing data

  7. A site scale analysis of groundwater flow and salinity distribution in the Aespoe area

    International Nuclear Information System (INIS)

    Svensson, Urban

    1997-10-01

    The objective of the study is to develop, calibrate and apply a numerical simulation model of the Aespoe area. An area of 1.8 x 1.8 km 2 , centred around the Aespoe Hard Rock Laboratory (HRL), gives the horizontal extent of the model. In the vertical direction the model follows the topography at the upper boundary and has a lower boundary at 1000 metres below sea level. The model is based on a mathematical model that includes equations for the Darcy velocities, mass conservation and salinity distribution. Gravitational effects are thus fully accounted for. A regional groundwater model was used to generate boundary conditions for vertical and bottom boundaries. Transmissivities of fracture zones and conductivities for the rock in between, as used in the model, are based on field data. An extensive calibration of the model is carried out, using data for natural conditions (i.e. prior to the construction of the Aespoe HRL), drawdowns from a pump test and data collected during the excavation of the tunnel. A satisfactory agreement with field data is obtained by the calibration. Main results from the model include vertical and horizontal sections of flow, salinity and hydraulic head distributions for natural conditions and for completed tunnel. A sensitivity study, where boundary conditions and material properties are modified, is also carried out. The model is also used to describe some characteristic features of the site like infiltration rates, flux statistics at a depth of 450 metres, salinity of inflows to the tunnel and flow and salinity distributions in fracture zones. The general conclusion of the study is that the model developed can simulate the conditions at Aespoe, both natural and with Aespoe HRL present, in a realistic manner

  8. A MODEL OF OXYGEN CONDITIONS IN A SCHOOL OF FISH BASED ON EXPERIMENTAL RESPIROMETRY

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2010-01-01

    with a logging YSI CTD from a fixed position on the net cage at a depth of one meter. The data did not show lower oxygen levels in the vicinity oflhe fish compared to a position on the edge of the pen. In the near future we hope to be able to verify the model by measuring oxygen levels in large schools...... of Atlantic herring with a ROV instrumented with cameras and a logging YSJ CTD as well as an acoustic Oxyguard oxygen transmitter....

  9. Understanding of CO{sub 2} interaction with thermally grown SiO{sub 2} on Si using IBA depth profiling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deokar, Geetanjali; D’Angelo, Marie; Briand, Emrick [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Deville Cavellin, Catherine, E-mail: deville@univ-paris12.fr [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Faculté des Sciences et Technologie UPEC, 61 Av., De Gaulle, Créteil F-94010 (France)

    2013-06-01

    Interactions between CO{sub 2} and SiO{sub 2} films thermally grown on Si have been studied using {sup 18}O and {sup 13}C as isotopic tracers associated with ion beam analysis (IBA) depth profiling techniques. From secondary ion mass spectrometry (SIMS) measurements no carbon from CO{sub 2} is detected in the silica while it is found in Si. These results suggest that CO{sub 2} diffuses through the silica. Exchanges of oxygen between CO{sub 2} and silica can be observed from {sup 18}O to {sup 16}O SIMS signals variation. The oxygen concentration depth profiles were determined quantitatively using the narrow resonance near 151 keV in the {sup 18}O(p,α){sup 15}N nuclear reaction (Narrow Resonance Profiling, NRP). We demonstrate that two distinct oxygen exchanges processes co-exist and we determine the diffusion coefficient of the CO{sub 2} molecule in the silica at 1100 °C.

  10. Tissue oxygenation and haemodynamics measurement with spatially resolved NIRS

    Science.gov (United States)

    Zhang, Y.; Scopesi, F.; Serra, G.; Sun, J. W.; Rolfe, P.

    2010-08-01

    We describe the use of Near Infrared Spectroscopy (NIRS) for the non-invasive investigation of changes in haemodynamics and oxygenation of human peripheral tissues. The goal was to measure spatial variations of tissue NIRS oxygenation variables, namely deoxy-haemoglobin (HHb), oxy-haemoglobin (HbO2), total haemoglobin (HbT), and thereby to evaluate the responses of the peripheral circulation to imposed physiological challenges. We present a skinfat- muscle heterogeneous tissue model with varying fat thickness up to 15mm and a Monte Carlo simulation of photon transport within this model. The mean partial path length and the mean photon visit depth in the muscle layer were derived for different source-detector spacing. We constructed NIRS instrumentation comprising of light-emitting diodes (LED) as light sources at four wavelengths, 735nm, 760nm, 810nm and 850nm and sensitive photodiodes (PD) as the detectors. Source-detector spacing was varied to perform measurements at different depths within forearm tissue. Changes in chromophore concentration in response to venous and arterial occlusion were calculated using the modified Lambert-Beer Law. Studies in fat and thin volunteers indicated greater sensitivity in the thinner subjects for the tissue oxygenation measurement in the muscle layer. These results were consistent with those found using Monte Carlo simulation. Overall, the results of this investigation demonstrate the usefulness of the NIRS instrument for deriving spatial information from biological tissues.

  11. PRODUCTION OF TOMATO SEEDLINGS UNDER SALINE IRRIGATION

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Brasiliano Campos

    2007-01-01

    Full Text Available Processing tomato is the most important vegetable crop of the Brazilian agribusiness and few researches have been conducted to evaluate the tolerance of this crop to saline stress. In this study, the effects of five levels of salinity of the irrigation water (1, 2, 3, 4 and 5 dS m-1 and three equivalent proportions of Na:Ca:Mg (1:1:0.5, 4:1:0.5 and 7:1:0.5 were tested on the emergence and vigor of processing tomato, cultivar IPA 6. Seeds were sowed in expanded polystyrene tray (128 cells and each tray received 1 L of water after sowing. The trays were piled and, four days after sowing, they were placed on suspended supports in a greenhouse. Irrigation was accomplished daily from the fifth day after sowing. Only dry weight of shoot and root was affected by sodium proportions, while linear reductions of the speed of emergence, stem length and the dry weight of shoot and root were observed with increasing salinity. Root was more affected than shoot by salinity and relative growth ratioincreased with salinity levels on the 14-21 days after sowing period, indicating that the crop showed a certain increase of salinity tolerance with the time of exposure to salts.

  12. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  13. Bonding of xenon to oxygen in magmas at depth

    Science.gov (United States)

    Leroy, Clémence; Sanloup, Chrystèle; Bureau, Hélène; Schmidt, Burkhard C.; Konôpková, Zuzana; Raepsaet, Caroline

    2018-02-01

    The field of noble gases chemistry has witnessed amazing advances in the last decade with over 100 compounds reported including Xe oxides and Xe-Fe alloys stable at the pressure-temperature conditions of planetary interiors. The chemistry of Xe with planetary materials is nonetheless still mostly ignored, while Xe isotopes are used to trace a variety of key planetary processes from atmosphere formation to underground nuclear tests. It is indeed difficult to incorporate the possibility of Xe reactivity at depth in isotopic geochemical models without a precise knowledge of its chemical environment. The structure of Xe doped hydrous silica-rich melts is investigated by in situ high energy synchrotron X-ray diffraction using resistive heating diamond anvil cells. Obtained pair distribution functions reveal the oxidation of Xe between 0.2 GPa and 4 GPa at high T up to 1000 K. In addition to the usual interatomic distances, a contribution at 2.05 ± 0.05 Å is observed. This contribution is not observed in the undoped melt, and is interpreted as the Xe-O bond, with a coordination number of about 12 consistent with Xe insertion in rings of the melt structure. Xe solubility measurements by electron microprobe and particle induced X-rays emission analysis confirm that Xe and Ar have similar solubility values in wt% in silicate melts. These values are nonetheless an order of magnitude higher than those theoretically calculated for Xe. The formation of Xe-O bonds explains the enhanced solubility of Xe in deep continental crust magmas, revealing a mechanism that could store Xe and fractionate its isotopes. Xenon is indeed atypical among noble gases, the atmosphere being notably depleted in elemental Xe, and very strongly depleted in Xe light isotopes. These observations are known as the 'missing' Xe paradox, and could be solved by the present findings.

  14. Feasibility of saline infusion on the liver surface during radiofrequency ablation of subcapsuIar hepatic tumor: an experimentaI study

    International Nuclear Information System (INIS)

    Lee, Young Rang; Kim, Young Sun; Rhim, Hyun Chul; Seo, Heung Suk; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Kim, Sung Kyu; Paik, Seung Sam

    2004-01-01

    The purpose of the study was to evaluate the feasibility of infusion of normal saline onto the surface of the liver capsule for minimizing thermal injury of the adjacent organs during radiofrequency ablation of subcapsular hepatic tumor in an ex-vivo porcine model. We used porcine small bowel with it's serosal surface spread onto the porcine liver as an experiment model. The puncturing electrode was inserted into a 6 Fr introducer sheath, and the introducer sheath was connected to the infusion pump for creating a saline flow over the liver surface. A total of 15 ablations were divided into the control group (n=5), intermittent saline infusion group (n=5) and continuous saline infusion (n=5) group. The ablations were done during 3 minutes, and the infusion was set at 2 ml/min and stopped every 30 seconds in the intermittent saline infusion group. After the ablation, we measured the size of the ablated lesion on the surface of bowel and liver, and we also measured the depth of hepatic lesion. Ablated areas of bowel and liver surface in the control group, intermittent saline infusion group and continuous infusion group were 210.7±89.1 mm 2 , 74.6±27.2 mm 2 and 35.8±43.4 mm 2 , respectively, and 312.6±73.6 mm 2 , 228.4±110.5 mm 2 , and 80.9±55.1 mm 2 , respectively. In contrast to the broad base of the ablated area on the surface of the liver in the control group, the shapes of the lesions became narrower approaching to the liver surface in all cases of the continuous saline infusion group, and the shapes of the lesions were broad based in 3 cases and narrow based in 2 cases of the intermittent saline infusion group. Continuous infusion of normaI saline onto the surface of the liver during radiofrequency ablation of subcapsular hepatic tumor is a feasible method for minimizing thermal injury of the adjacent organs. Further exploration of the optimal parameters or techniques to maximize the hepatic ablation and simultaneously to minimize the thermal injury of

  15. Dwarfism of blue mussels in the low saline Baltic Sea — growth to the lower salinity limit

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel; Turja, Raisa

    2014-01-01

    Mussels within the Baltic Mytilus edulis × M. trossulus hybrid zone have adapted to the low salinities in the Baltic Sea which, however, results in slow-growing dwarfed mussels. To get a better understanding of the nature of dwarfism, we studied the ability of M. trossulus to feed and grow at low...... to become negative below 4.5 psu. We suggest that reduced ability to produce shell material at extremely low salinity may explain dwarfism of mussels in the Baltic Sea. Reduced bio-calcification at low salinity, however, may impede shell growth, but not somatic growth, and this may at first result...

  16. Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels.

    Science.gov (United States)

    Hariadi, Yuda; Marandon, Karl; Tian, Yu; Jacobsen, Sven-Erik; Shabala, Sergey

    2011-01-01

    Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) were studied by exposing plants to six salinity levels (0-500 mM NaCl range) for 70 d. Salt stress was administered either by pre-mixing of the calculated amount of NaCl with the potting mix before seeds were planted or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment in old leaves and between 80% and 85% of osmotic adjustment in young leaves was achieved by means of accumulation of inorganic ions (Na(+), K(+), and Cl(-)) at these NaCl levels, whilst the contribution of organic osmolytes was very limited. Consistently higher K(+) and lower Na(+) levels were found in young, as compared with old leaves, for all salinity treatments. The shoot sap K(+) progressively increased with increased salinity in old leaves; this is interpreted as evidence for the important role of free K(+) in leaf osmotic adjustment under saline conditions. A 5-fold increase in salinity level (from 100 mM to 500 mM) resulted in only a 50% increase in the sap Na(+) content, suggesting either a very strict control of xylem Na(+) loading or an efficient Na(+) removal from leaves. A very strong correlation between NaCl-induced K(+) and H(+) fluxes was observed in quinoa root, suggesting that a rapid NaCl-induced activation of H(+)-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K(+) leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na(+) sequestration, control of Na(+) and K(+) xylem loading, and their transport to the shoot.

  17. Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile

    OpenAIRE

    Parris, Darren J.; Ganesh, Sangita; Edgcomb, Virginia P.; Stewart, Frank J.; DeLong, Edward

    2014-01-01

    Molecular surveys are revealing diverse eukaryotic assemblages in oxygen-limited ocean waters. These communities may play pivotal ecological roles through autotrophy, feeding, and a wide range of symbiotic associations with prokaryotes. We used 18S rRNA gene sequencing to provide the first snapshot of pelagic microeukaryotic community structure in two cellular size fractions (0.2-1.6 µm, >1.6 µm) from seven depths through the anoxic oxygen minimum zone (OMZ) off northern Chile. Sequencing ...

  18. Dissolved oxygen content as an index of water quality in San Vicente Bay, Chile (36 degrees 45'S).

    Science.gov (United States)

    Rudolph, Anny; Ahumada, Ramón; Pérez, Claudio

    2002-08-01

    The present report describes some effects of industrial and municipal effluents on the waters of San Vicente Bay. Analyses of the main substances contained in the fishing industry effluent suggest rating criteria based on the oxygen saturation of the water as an assessment of organic pollution. Six cruises were carried out throughout the Bay, from June to December 1996. Water samples were analyzed for dissolved oxygen, oil and grease content, and sediment samples for organic matter content. Water parameters (salinity, temperature) were used to characterize the Bay's hydrography, and to calculate values for oxygen saturation. The measurements demonstrated a local broad range of oxygen deficit, with a maximum of 45% in the winter to 95% in the spring. In November more than 65% of the Bay's area showed oxygen deficits greater than 40%. Organic matter was unusually high in sediments along the northern sector of the Bay. The results suggest that the oxygen depletion was a representative parameter for establishing a relative scale of water quality in this Bay.

  19. A universal carbonate ion effect on stable oxygen isotope ratios in unicellular planktonic calcifying organisms

    OpenAIRE

    Ziveri, P.; Thoms, S.; Probert, I.; Geisen, M.; Langer, H.

    2012-01-01

    The oxygen isotopic composition (δ18O) of calcium carbonate of planktonic calcifying organisms is a key tool for reconstructing both past seawater temperature and salinity. The calibration of paloeceanographic proxies relies in general on empirical relationships derived from field experiments on extant species. Laboratory experiments have more often than not revealed that variables other than the target parameter influence the proxy signal, which makes proxy c...

  20. Influence of water depth on energy expenditure during aquatic walking in people post stroke.

    Science.gov (United States)

    Lim, Hyosok; Azurdia, Daniel; Jeng, Brenda; Jung, Taeyou

    2018-05-11

    This study aimed to investigate the metabolic cost during aquatic walking at various depths in people post stroke. The secondary purpose was to examine the differences in metabolic cost between aquatic walking and land walking among individuals post stroke. A cross-sectional research design is used. Twelve participants post stroke (aged 55.5 ± 13.3 years) completed 6 min of walking in 4 different conditions: chest-depth, waist-depth, and thigh-depth water, and land. Data were collected on 4 separate visits with at least 48 hr in between. On the first visit, all participants were asked to walk in chest-depth water at their fastest speed. The walking speed was used as a reference speed, which was applied to the remaining 3 walking conditions. The order of remaining walking conditions was randomized. Energy expenditure (EE), oxygen consumption (VO 2 ), and minute ventilation (V E ) were measured with a telemetric metabolic system. Our findings showed statistically significant differences in EE, VO 2 , and V E among the 4 different walking conditions: chest-depth, waist-depth, and thigh-depth water, and land (all p stroke consume less energy in chest-depth water, which may allow them to perform prolonged duration of training. Thigh-depth water demonstrated greater EE compared with other water depths; thus, it can be recommended for time-efficient cardiovascular exercise. Waist-depth water showed similar EE to land walking, which may have been contributed by the countervailing effects of buoyancy and water resistance. Copyright © 2018 John Wiley & Sons, Ltd.

  1. Upwelling and isolation in oxygen-depleted anticyclonic modewater eddies and implications for nitrate cycling

    DEFF Research Database (Denmark)

    Karstensen, Johannes; Schütte, Florian; Pietri, Alice

    2017-01-01

    is identified with a horizontal extent of about 70km and bounded by maxima in N2. The upper N2 maximum (3-5 × 10-4s-2) coincides with the mixed layer base and the lower N2 maximum (0.4 × 10-4s-2) is found at about 200m depth in the eddy centre. The eddy core shows a constant slope in temperature/salinity (T...

  2. Salinity anomaly as a trigger for ENSO events.

    Science.gov (United States)

    Zhu, Jieshun; Huang, Bohua; Zhang, Rong-Hua; Hu, Zeng-Zhen; Kumar, Arun; Balmaseda, Magdalena A; Marx, Lawrence; Kinter, James L

    2014-10-29

    According to the classical theories of ENSO, subsurface anomalies in ocean thermal structure are precursors for ENSO events and their initial specification is essential for skillful ENSO forecast. Although ocean salinity in the tropical Pacific (particularly in the western Pacific warm pool) can vary in response to El Niño events, its effect on ENSO evolution and forecasts of ENSO has been less explored. Here we present evidence that, in addition to the passive response, salinity variability may also play an active role in ENSO evolution, and thus important in forecasting El Niño events. By comparing two forecast experiments in which the interannually variability of salinity in the ocean initial states is either included or excluded, the salinity variability is shown to be essential to correctly forecast the 2007/08 La Niña starting from April 2007. With realistic salinity initial states, the tendency to decay of the subsurface cold condition during the spring and early summer 2007 was interrupted by positive salinity anomalies in the upper central Pacific, which working together with the Bjerknes positive feedback, contributed to the development of the La Niña event. Our study suggests that ENSO forecasts will benefit from more accurate salinity observations with large-scale spatial coverage.

  3. Identification of differentially expressed genes in flax (Linum usitatissimum L.) under saline-alkaline stress by digital gene expression.

    Science.gov (United States)

    Yu, Ying; Huang, Wengong; Chen, Hongyu; Wu, Guangwen; Yuan, Hongmei; Song, Xixia; Kang, Qinghua; Zhao, Dongsheng; Jiang, Weidong; Liu, Yan; Wu, Jianzhong; Cheng, Lili; Yao, Yubo; Guan, Fengzhi

    2014-10-01

    The salinization and alkalization of soil are widespread environmental problems, and alkaline salt stress is more destructive than neutral salt stress. Therefore, understanding the mechanism of plant tolerance to saline-alkaline stress has become a major challenge. However, little attention has been paid to the mechanism of plant alkaline salt tolerance. In this study, gene expression profiling of flax was analyzed under alkaline-salt stress (AS2), neutral salt stress (NSS) and alkaline stress (AS) by digital gene expression. Three-week-old flax seedlings were placed in 25 mM Na2CO3 (pH11.6) (AS2), 50mM NaCl (NSS) and NaOH (pH11.6) (AS) for 18 h. There were 7736, 1566 and 454 differentially expressed genes in AS2, NSS and AS compared to CK, respectively. The GO category gene enrichment analysis revealed that photosynthesis was particularly affected in AS2, carbohydrate metabolism was particularly affected in NSS, and the response to biotic stimulus was particularly affected in AS. We also analyzed the expression pattern of five categories of genes including transcription factors, signaling transduction proteins, phytohormones, reactive oxygen species proteins and transporters under these three stresses. Some key regulatory gene families involved in abiotic stress, such as WRKY, MAPKKK, ABA, PrxR and ion channels, were differentially expressed. Compared with NSS and AS, AS2 triggered more differentially expressed genes and special pathways, indicating that the mechanism of AS2 was more complex than NSS and AS. To the best of our knowledge, this was the first transcriptome analysis of flax in response to saline-alkaline stress. These data indicate that common and diverse features of saline-alkaline stress provide novel insights into the molecular mechanisms of plant saline-alkaline tolerance and offer a number of candidate genes as potential markers of tolerance to saline-alkaline stress. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

    Science.gov (United States)

    Chen, R; Hahn, C E W; Farmery, A D

    2012-08-15

    The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure P CO2 and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ≈ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Oxygen vacancies in oxides studied by annihilation of mono-energetic positrons

    Energy Technology Data Exchange (ETDEWEB)

    Hugenschmidt, Christoph; Pikart, Philip [ZWE FRM II, Technische Universitaet Muenchen, Lichtenbergstrasse 1, 85747 Garching (Germany); Physik-Department E21, Technische Universitaet Muenchen, James-Franck-Strasse, 85748 Garching (Germany); Schreckenbach, Klaus [Physik-Department E21, Technische Universitaet Muenchen, James-Franck-Strasse, 85748 Garching (Germany)

    2009-07-01

    Oxygen vacancies play a fundamental role for the material properties of various oxides, e.g. charge carrier density in high-Tc superconductors, magnetic properties of diluted magnetic semiconductors or paramagnetic properties of SiO{sub 2}. In this study, open volume defects in (metal) oxides are investigated by Doppler-broadening spectroscopy (DBS) of the positron annihilation. More detailed information about the chemical surrounding at the positron annihilation site is gained by additional coincident DBS experiments, where a signature of positrons annihilating with electrons from oxygen is observed. The mono-energetic positron beam at NEPOMUC was used which allows depth dependent measurements, and hence the investigation of thin oxide layers. Recent results for metallic oxides such as ZnO are presented and compared with various non-metallic oxides such as amorphous and crystalline SiO{sub 2}, oxygen terminated Si-surface, and ice. The role of neutral and charged oxygen vacancies and the application of the positron annihilation technique to study oxygen vacancies will be discussed.

  6. Pea p68, a DEAD-box helicase, provides salinity stress tolerance in transgenic tobacco by reducing oxidative stress and improving photosynthesis machinery.

    Directory of Open Access Journals (Sweden)

    Narendra Tuteja

    Full Text Available The DEAD-box helicases are required mostly in all aspects of RNA and DNA metabolism and they play a significant role in various abiotic stresses, including salinity. The p68 is an important member of the DEAD-box proteins family and, in animal system, it is involved in RNA metabolism including pre-RNA processing and splicing. In plant system, it has not been well characterized. Here we report the cloning and characterization of p68 from pea (Pisum sativum and its novel function in salinity stress tolerance in plant.The pea p68 protein self-interacts and is localized in the cytosol as well as the surrounding of cell nucleus. The transcript of pea p68 is upregulated in response to high salinity stress in pea. Overexpression of p68 driven by constitutive cauliflower mosaic virus-35S promoter in tobacco transgenic plants confers enhanced tolerances to salinity stress by improving the growth, photosynthesis and antioxidant machinery. Under stress treatment, pea p68 overexpressing tobacco accumulated higher K+ and lower Na+ level than the wild-type plants. Reactive oxygen species (ROS accumulation was remarkably regulated by the overexpression of pea p68 under salinity stress conditions, as shown from TBARS content, electrolyte leakage, hydrogen peroxide accumulation and 8-OHdG content and antioxidant enzyme activities.To the best of our knowledge this is the first direct report, which provides the novel function of pea p68 helicase in salinity stress tolerance. The results suggest that p68 can also be exploited for engineering abiotic stress tolerance in crop plants of economic importance.

  7. [Effects of gap junction blocking on the oxygen partial pressure in acupoints of the bladder meridian].

    Science.gov (United States)

    Wang, Qi; Yu, Wei-Chang; Jiang, Hong-Zhi; Chen, Sheng-Li; Zhang, Ming-Min; Kong, E-Sheng; Huang, Guang-Ying

    2010-12-01

    To explore the relation between gap junction and meridian phenomenon. The oxygen partial pressure in acupoints [see text for formula] and in their corresponding non-acupoints of the Bladder Meridian was observed with the needle-type tissue oxygen tension sensor in the gap junction blocking goats by 1-Heptanol injection and the Connexin 43 (Cx43) gene knockout mice. (1) The oxygen partial pressure in acupoints of Bladder Meridian on goats was higher than that in non-acupoints after 1-Heptanol injection with significant differences between them (both P oxygen partial pressure in acupoints of Bladder Meridian on goats increased significantly after injecting 1-Heptanol as compare with that either injecting normal saline or injecting nothing with significant differences between them (all P oxygen partial pressure in acupoints of the Bladder Meridian was significantly higher than that in the non-acupoint controls in Cx43 wild type (WT) mice (all P oxygen partial pressure between acupoints and non-acupoint controls showed no significant differences (all P > 0.05). (4) In acupoints, the oxygen partial pressure in Cx43 WT mice was significantly higher than that in Cx43 HT mice (all P 0.05). Gap junction maybe the essential factor in signal transduction of acupuncture.

  8. Saline sewage treatment and source separation of urine for more sustainable urban water management.

    Science.gov (United States)

    Ekama, G A; Wilsenach, J A; Chen, G H

    2011-01-01

    While energy consumption and its associated carbon emission should be minimized in wastewater treatment, it has a much lower priority than human and environmental health, which are both closely related to efficient water quality management. So conservation of surface water quality and quantity are more important for sustainable development than green house gas (GHG) emissions per se. In this paper, two urban water management strategies to conserve fresh water quality and quantity are considered: (1) source separation of urine for improved water quality and (2) saline (e.g. sea) water toilet flushing for reduced fresh water consumption in coastal and mining cities. The former holds promise for simpler and shorter sludge age activated sludge wastewater treatment plants (no nitrification and denitrification), nutrient (Mg, K, P) recovery and improved effluent quality (reduced endocrine disruptor and environmental oestrogen concentrations) and the latter for significantly reduced fresh water consumption, sludge production and oxygen demand (through using anaerobic bioprocesses) and hence energy consumption. Combining source separation of urine and saline water toilet flushing can reduce sewer crown corrosion and reduce effluent P concentrations. To realize the advantages of these two approaches will require significant urban water management changes in that both need dual (fresh and saline) water distribution and (yellow and grey/brown) wastewater collection systems. While considerable work is still required to evaluate these new approaches and quantify their advantages and disadvantages, it would appear that the investment for dual water distribution and wastewater collection systems may be worth making to unlock their benefits for more sustainable urban development.

  9. Investigations in Marine Chemistry: Salinity II.

    Science.gov (United States)

    Schlenker, Richard M.

    Presented is a science activity in which the student investigates methods of calibration of a simple conductivity meter via a hands-on inquiry technique. Conductivity is mathematically compared to salinity using a point slope formula and graphical techniques. Sample solutions of unknown salinity are provided so that the students can sharpen their…

  10. Apparatus for simultaneously measuring electrical conductivity and oxygen fugacity

    Energy Technology Data Exchange (ETDEWEB)

    Netherton, R.; Duba, A.

    1978-01-31

    Electrical conductivity studies of silicates are useful in determining temperature vs depth in the earth. Realistic laboratory measurements of conduction mechanisms require that exact determinations of oxygen fugacity (fo{sub 2}) be made in the experimental environment. An apparatus is described that monitors system fo{sub 2} with a calcia-doped zirconia-oxygen cell while measuring electrical conductivity of iron-bearing silicates at high temperature (greater than 1000 K). The fo{sub 2} calculated thermodynamically from CO/CO{sub 2} mixing ratios agreed well with measurements made with the zirconia cell at 1473 K, except for fo{sub 2} greater than 10{sup -4} Pa, where, on a log{sub 10} scale, mixing-ratio errors were as large as +- 0.2. These errors are attributed to oxygen contamination in the CO{sub 2} and to mobile carbon deposits that formed in the apparatus.

  11. Oxygen isotope fractionation and algal symbiosis in benthic foraminifera from the Gulf of Elat, Israel

    International Nuclear Information System (INIS)

    Buchardt, B.; Hansen, H.J.

    1977-01-01

    In order to investigate possible isotopic fractionations due to algal symbiosis the oxygen and carbon isotope compositions of shell carbonate from symbiont-free and symbiont-bearing benthic foraminifera have been compared to that of molluscs living at the same locality. The material was collected over a depth profile in the Gulf of Elat (Aqaba), Israel, covering the interval from 4 to 125 metres. After corrections variations for temperature with depth, characteristic 18 O-depletions were observed in the foraminiferal shell carbonate when compared to the molluscs. These depletions are interpreted as 1) a constant vital effect seen in all the foraminifera studied and 2) an additional, light-dependent vital effect observed in the symbiont-bearing forms only, caused by incorporation of photosynthetic oxygen formed by the symbiotic algae. This additional vital effect emphasizes the difficulties in applying foraminifera to oxygen isotope palaeotemperature analyses. No well-defined differences in carbon isotope compositions are observed between symbiont-bearing and symbiont-free foraminifera. (author)

  12. Oxygen isotope fractionation and algal symbiosis in benthic foraminifera from the Gulf of Elat, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Buchardt, B; Hansen, H J [Copenhagen Univ. (Denmark)

    1977-01-01

    In order to investigate possible isotopic fractionations due to algal symbiosis the oxygen and carbon isotope compositions of shell carbonate from symbiont-free and symbiont-bearing benthic foraminifera have been compared to that of molluscs living at the same locality. The material was collected over a depth profile in the Gulf of Elat (Aqaba), Israel, covering the interval from 4 to 125 metres. After correcting for variations of temperature with depth, characteristic /sup 18/O-depletions were observed in the foraminiferal shell carbonate when compared to the molluscs. These depletions are interpreted as 1) a constant vital effect seen in all the foraminifera studied and 2) an additional, light-dependent vital effect observed in the symbiont-bearing forms only, caused by incorporation of photosynthetic oxygen formed by the symbiotic algae. This additional vital effect emphasizes the difficulties in applying foraminifera to oxygen isotope palaeotemperature analyses. No well-defined differences in carbon isotope compositions are observed between symbiont-bearing and symbiont-free foraminifera.

  13. Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium

    Science.gov (United States)

    Bern, Carleton R.; Engle, Mark A.; Boehlke, Adam R.; Zupancic, John W.; Brown, Adrian; Figueroa, Linda; Wolkersdorfer, Christian

    2013-01-01

    A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached from soil by application of the CBM water and traces native salt mobilization to groundwater. Resulting selenium concentrations in groundwater at this alluvial site were generally low (0.5–23 μg/L) compared to Wyoming’s agricultural use suitability standard (20 μg/L).

  14. The influence of different salinity conditions on egg buoyancy and development and yolk sac larval survival and morphometric traits of Baltic Sea sprat (Sprattus sprattus balticus Schneider

    Directory of Open Access Journals (Sweden)

    Christoph Petereit

    2009-10-01

    Full Text Available The small pelagic sprat (Sprattus sprattus is a key ecologic player in the Baltic Sea. However, there is long-term variability in recruitment which is thought to be influenced by fluctuations in abiotic and biotic conditions experienced during the early life stages. This study concentrates on the influence of different ambient salinities on sprat egg development, egg buoyancy and survival as well as early yolk sac larval morphometric traits. Egg buoyancy significantly decreased with increasing salinity experienced during fertilization and/or incubation experiments. Field egg buoyancy measurements in 2007 and 2008 exhibited annual and seasonal differences in specific gravity, potentially associated with changes in adult sprat vertical distribution. Neither egg development time nor the duration of the yolk sac phase differed among salinity treatments. At eye pigmentation, larval standard length exhibited high variance among individuals but did not differ among treatments. The largest ecological impact of salinity experienced during spawning was the modification the buoyancy of eggs and yolk sac larvae, which determines their vertical habitat in the Baltic Sea. There are strong thermo- and oxyclines in the Baltic Sea, and thus salinity can indirectly impact the survival of these early life stages by modifying the ambient temperatures and oxygen conditions experienced.

  15. Influence of salinity and cadmium on the survival and ...

    African Journals Online (AJOL)

    osmoregulated at salinities between 5 and 25 and osmoconformed at salinities greater than 25. Chiromantes eulimene followed a hyper-hypo-osmoregulatory strategy; it hyper-regulated in salinities from 0 up to isosmotic conditions at about 28 (c.

  16. Population specific salinity tolerance in eelgrass (Zostera marina)

    DEFF Research Database (Denmark)

    Salo, Tiina Elina; Pedersen, Morten Foldager; Boström, Christoffer

    2014-01-01

    and that the lowsaline population is better adapted to hyposaline conditions. Despite the long-term adaptation of the low saline population to stable, low salinity, these plants were still able to function normally in high salinities, indicating remarkable plasticity. The results further suggest that altered salinity...

  17. The effect of salinity on resting metabolism in Eurasian perch (Perca fluviathlis L.)

    DEFF Research Database (Denmark)

    Ern, R.; Cong, N.; Houng, D.

    2008-01-01

    to properly maintain ion balance even with minor increases in the environmental salinity. The elevated resting VO2 in 10 ppt is equivalent to an increased energy consumption of 975 extra calories per day, and since food intake was unaffected, it is reasonable to assume that the reduced growth seen...... in a freshwater population of P. fluviatilis. Food intake was unaffected and we, therefore, measured resting oxygen uptake (VO2) in fish maintained for 21 days in either fresh or brackish (10 ppt) water using intermittent closed respirometry. VO2 of all fish reached stable levels within 5 h of entering...

  18. The effectiveness of dispersants under various temperature and salinity regimes

    International Nuclear Information System (INIS)

    Fingas, M.; Fieldhouse, B.; Wang, Z.; Environment Canada, Ottawa, ON

    2005-01-01

    A series of tests were conducted to determine the effectiveness of dispersants in Arctic waters where salinity and temperature interactions play a critical role. In particular, Corexit 9500 was tested on Alaska North Slope oil at different temperatures and salinity using the ASTM standard test and variations of this test. Results were compared to the only historically reported test in which both temperature and salinity were changed over a range of values. This series of tests demonstrated that there is an interaction between salinity, temperature and dispersant effectiveness. It was shown that conventional and currently available dispersants are nearly ineffective at 0 salinity. Dispersant effectiveness peaks at 20 to 40 units of salinity, depending on the type of dispersant. Corexit is less sensitive to salinity, while Corexit 9527 is more sensitive to salinity. There is a smooth gradient of effectiveness with salinity both as the salinity rises to a peak point of effectiveness and as it exceeds this value. Results from the 2 field trials in fresh water suggest that laboratory tests correctly conclude that the effectiveness of dispersants is very low in freshwater. The study also examined several analytical factors such as the total petroleum hydrocarbon (TPH) versus relative petroleum hydrocarbon (RPH) methods, specific versus general calibration curves, and automatic versus manual baseline placement. The analytical variations of effectiveness by RPH or TPH methods do not affect the fundamental relationship between salinity and temperature. 6 refs., 6 tabs., 8 figs

  19. Spectroscopic study of the microbial community in chemocline zones of relic meromictic lakes separating from the White Sea

    Science.gov (United States)

    Kharcheva, Anastasia V.; Krasnova, Elena D.; Voronov, Dmitry A.; Patsaeva, Svetlana V.

    2015-03-01

    As a result of a recent years study on the Karelia shore of the White Sea more than ten relict lakes in different stages of separation from the sea have been discovered. Five of them are located close to the Nikolai Pertsov White Sea Biological Station of Moscow State University. Such separated lakes are interesting to explore for their firm vertical stratification. Water layers differ not only by temperature, salinity and other physic and chemical characteristics and optical properties, but also by ibhabiting microorganisms and by the quality of dissolved organic matter. To study phototropic organisms in water sampled from different depths we used spectroscopic techniques. Identification of the main bands in the absorption and fluorescence spectra showed that there are two main groups of photosynthetic organisms in the redox zone (chemocline): unicellular algae containing chlorophyll a and green sulfur bacteria with bacteriochlorophylls c, d, e. Spectral data were compared with physical and chemical characteristics of the water layer (temperature, salinity, pH, dissolved oxygen and sunlight illumination at certain depth). It gave an opportunity to compare vertical profiles of oxygen and hydrogen sulphide concentration with the number and distribution of oxygenic and anoxygenic phototrophic microorganisms. Maximum abundance of both algae and green sulfur bacteria were achieved within the redox zone. Typical thickness of the layer with the highest concentration of microorganisms did not exceed 10-20 cm.

  20. Linking The Atlantic Gyres: Warm, Saline Intrusions From Subtropical Atlantic to the Nordic Seas

    Science.gov (United States)

    Hakkinen, Sirpa M.; Rhines, P. B.

    2010-01-01

    Ocean state estimates from SODA assimilation are analyzed to understand how major shifts in the North Atlantic Current path relate to AMOC, and how these shifts are related to large scale ocean circulation and surface forcing. These complement surface-drifter and altimetry data showing the same events. SODA data indicate that the warm water limb of AMOC, reaching to at least 600m depth, expanded in density/salinity space greatly after 1995, and that Similar events occurred in the late 1960s and around 1980. While there were large changes in the upper limb, there was no immediate response in the dense return flow, at least not in SODA, however one would expect a delayed response of increasing AMOC due to the positive feedback from increased salt transport. These upper limb changes are winddriven, involving changes in the eastern subpolar gyre, visible in the subduction of low potential vorticity waters. The subtropical gyre has been weak during the times of the northward intrusions of the highly saline subtropical waters, while the NAO index has been neutral or in a negative phase. The image of subtropical/subpolar gyre exchange through teleconnections within the AMOC overturning cell will be described.