Journal articles: 'Seawater density'

1

Pawlowicz, R., D. G. Wright, and F. J. Millero. "The effects of biogeochemical processes on oceanic conductivity/salinity/density relationships and the characterization of real seawater." Ocean Science 7, no. 3 (June 1, 2011): 363–87. http://dx.doi.org/10.5194/os-7-363-2011.

Full text

Abstract:

Abstract. As seawater circulates through the global ocean, its relative composition undergoes small variations. This results in changes to the conductivity/salinity/density relationship, which is currently well-defined only for Standard Seawater obtained from a particular area in the North Atlantic. These changes are investigated here by analysis of laboratory experiments in which salts are added to seawater, by analysis of oceanic observations of density and composition anomalies, and by mathematical investigation using a model relating composition, conductivity, and density of arbitrary seawaters. Mathematical analysis shows that understanding and describing the effect of changes in relative composition on operational estimates of salinity using the Practical Salinity Scale 1978 and on density using an equation of state for Standard Seawater require the use of a number of different salinity variables and a family of haline contraction coefficients. These salinity variables include an absolute Salinity SAsoln, a density salinity SAdens, the reference salinity SR, and an added-mass salinity SAadd. In addition, a new salinity variable S∗ is defined, which represents the preformed salinity of a Standard Seawater component of real seawater to which biogeochemical processes add material. In spite of this complexity, observed correlations between different ocean biogeochemical processes allow the creation of simple formulas that can be used to convert between the different salinity and density measures, allowing for the operational reduction of routine oceanographic observations.

APA, Harvard, Vancouver, ISO, and other styles

2

Pawlowicz, R., D. G. Wright, and F. J. Millero. "The effects of biogeochemical processes on oceanic conductivity/salinity/density relationships and the characterization of real seawater." Ocean Science Discussions 7, no. 2 (April 7, 2010): 773–836. http://dx.doi.org/10.5194/osd-7-773-2010.

Full text

Abstract:

Abstract. As seawater circulates through the global ocean, its relative composition undergoes small variations. This results in changes to the conductivity/salinity/density relationship, which is currently well-defined only for Standard Seawater obtained from a particular area in the North Atlantic. These changes are investigated here by analysis of laboratory experiments in which salts are added to seawater, by analysis of oceanic observations of density and composition anomalies, and by mathematical investigation using a model relating composition, conductivity, and density of arbitrary seawaters. Mathematical analysis shows that understanding and describing the effect of changes in relative composition on operational estimates of salinity using the Practical Salinity Scale 1978 and on density using an equation of state for Standard Seawater require the use of a number of different salinity variables and a family of haline contraction coefficients. These salinity variables include an absolute salinity SAsoln, a density salinity SAdens, the reference salinity SR, and an added-mass salinity SAadd. In addition, a new salinity variable S∗ is defined, which represents the preformed salinity of a Standard Seawater component to which biogeochemical processes add material. In spite of this complexity, observed correlations between different ocean biogeochemical processes allow the creation of simple formulas that can be used to convert between the different salinity and density measures, allowing for the operational reduction of routine oceanographic observations.

APA, Harvard, Vancouver, ISO, and other styles

3

Hernández-Ayón, J. M. "pH-density relationships in seawater." Ciencias Marinas 29, no. 4 (August 1, 2003): 497–508. http://dx.doi.org/10.7773/cm.v29i4.166.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Dai, Hao, and Xining Zhang. "Uncertainties in Climatological Seawater Density Calculations." Journal of Geophysical Research: Oceans 123, no. 3 (March 2018): 2192–212. http://dx.doi.org/10.1002/2017jc013427.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Zeynolabedin, Amin, Reza Ghiassi, and Moharam Dolatshahi Pirooz. "Investigating island groundwater salinity, using vulnerability index and numerical methods." Water Supply 20, no. 7 (August 10, 2020): 2804–14. http://dx.doi.org/10.2166/ws.2020.180.

Full text

Abstract:

Abstract Seawater intrusion is one of the major issues in Qeshm Island, which is the biggest island of the Persian Gulf. To investigate seawater intrusion in this island, a modified GALDIT index is used to map the vulnerability of the whole region. Considering the vulnerability map, two critical sections which have the highest vulnerability, one in the northeast and the other in the west side of the island, are chosen for detailed investigation. To achieve this goal, two numerical models, MODFLOW and SEAWAT are applied to simulate the groundwater flow and solute transport. The results show that the aquifer is in a dangerous level of threat of vulnerability and 15 km2 of the aquifer is in danger of being salinized. A comparison is made between MT3DMS and SEAWAT results, indicating that SEAWAT simulates seawater intrusion with more accuracy. It seems because of considering salt density in SEAWAT flow equations. The numerical simulation shows that the seawater is intruding on the island at a rapid rate.

APA, Harvard, Vancouver, ISO, and other styles

6

Schmidt, Hannes, Steffen Seitz, Egon Hassel, and Henning Wolf. "The density–salinity relation of standard seawater." Ocean Science 14, no. 1 (January 4, 2018): 15–40. http://dx.doi.org/10.5194/os-14-15-2018.

Full text

Abstract:

Abstract. 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.

APA, Harvard, Vancouver, ISO, and other styles

7

García-Abdeslem, Juan. "On the seawater density in gravity calculations." Journal of Applied Geophysics 183 (December 2020): 104200. http://dx.doi.org/10.1016/j.jappgeo.2020.104200.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Mehdiyev, K. K., and Kh M. Ibrahimov. "Development of lightweight cement slurries for stabilizing producing formation in absorbing wells." Azerbaijan Oil Industry, no. 5 (May 15, 2021): 29–33. http://dx.doi.org/10.37474/0365-8554/2021-5-29-33.

Full text

Abstract:

The paper presents the results of laboratory investigations on the development of lightweighted cement compositions for improvement of stabilizing of producing formation, as well as the hermetization of the areas with low frac gradients. To obtain lightweighted cement, few optimum compositions have been specified through experiments adding the agents in various thickness and concentrations into the mixture. The distribution of optimum compositions, the beginning and end of the hermetization, the solidness and density have been defined. The density of cement slurry developed on cement+seawater is 1900 kg/m3, the density of that on the cement+seawater+chamotte+bark+polymer+CaCl2 is 1610 kg/m3, the density of one developed on the cement+seawater+bark+CaCl2+carbonate+Al powder is 1700 kg/m3 and the density of cement slurry on cement+seawater+bark+CaCl2+keramzit comprised 1590 kg/m3.

APA, Harvard, Vancouver, ISO, and other styles

9

Baronti, Federico, Gabriele Fantechi, Roberto Roncella, and Roberto Saletti. "Wireless Sensor Node for Surface Seawater Density Measurements." Sensors 12, no. 3 (March 2, 2012): 2954–68. http://dx.doi.org/10.3390/s120302954.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Krasnodubets, L. A., and M. N. Penkov. "Computer simulation of a hydrostatic seawater density meter." Monitoring systems of environment, no. 1 (March 25, 2020): 71–76. http://dx.doi.org/10.33075/2220-5861-2020-1-71-76.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Rodriguez, Carmen, and Frank J. Millero. "Modeling the Density and Isentropic Compressibility of Seawater." Journal of Solution Chemistry 42, no. 2 (February 2013): 303–16. http://dx.doi.org/10.1007/s10953-013-9961-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Purnaditya, Ngakan Putu, Herr Soeryantono, and Dwinanti Rika Marthanty. "Proposing mathematical model for seawater intrusion phenomena in the coastal aquifer." MATEC Web of Conferences 197 (2018): 10003. http://dx.doi.org/10.1051/matecconf/201819710003.

Full text

Abstract:

Seawater intrusion is one of groundwater quality problem which in this problem, the mixing between freshwater and saltwater in the coastal aquifer occurs. Mathematical modelling can be formulated to describe the mechanism of this phenomena. The main objective of this research is to develop the mathematical model of groundwater flow and solute transport that applicable to seawater intrusion mechanism. This mechanism is arranged as a differential equation and distinguished into 3 equations. The first equation is groundwater flow equation in dependent-density. It means that the density of groundwater (ρ) changes in spatial and temporal domain due freshwater and seawater are mixed in the coastal aquifer. The second equation is solute transport. Like as groundwater flow equation, in solute transport equation there is a change of solute concentration (С) in the spatial and temporal domain. The last equation is the relationship between groundwater density (ρ) and solute concentration (С). Special case for the third equation, in which this equation is adopted from USGS Seawat model. The first equation and second equation are governed by Eulerian mass conservation law. The main theoretical consideration of governing groundwater flow equation is such as fluid and porous matrix compressibility theory, Darcy's law for groundwater in motion theory and some properties of soil. In other hands, solute transport is involving advection transport and hydrodynamic dispersion transport. Hydrodynamic dispersion is arranged by diffusion Fick's law and dispersion in porous media theory and it depends on transversal and longitudinal dispersivity. Using Jacob Bear's theory which states that fluid density as temperature, concentration and pressure function, authors obtain three primary variables in this model. Those variables follow fluid density (ρ), total head (h) and concentration (С). In this model, isotropic and isobar condition is considered, hence fluid density (ρ) is a function of concentration (С) only. Finally, from this research, authors wish this mathematical model is applicable to modelling, describing and predicting seawater intrusion phenomena theoretically.

APA, Harvard, Vancouver, ISO, and other styles

13

Feistel, R., G. M. Marion, R. Pawlowicz, and D. G. Wright. "Thermophysical property anomalies of Baltic seawater." Ocean Science 6, no. 4 (November 18, 2010): 949–81. http://dx.doi.org/10.5194/os-6-949-2010.

Full text

Abstract:

Abstract. While the thermodynamic properties of Standard Seawater are very well known, the quantitative effect of sea salt composition anomalies on various properties is difficult to estimate since comprehensive lab experiments with the various natural waters are scarce. Coastal and estuarine waters exhibit significant anomalies which also influence to an unknown amount the routine salinity calculation from conductivity measurements. Recent numerical models of multi-component aqueous electrolytes permit the simulation of physical chemical properties of seawater with variable solute composition. In this paper, the FREZCHEM model is used to derive a Gibbs function for Baltic seawater, and the LSEA_DELS model to provide estimates for the conductivity anomaly relative to Standard Seawater. From additional information such as direct density measurements or empirical salinity anomaly parameterisation, the quantitative deviations of properties between Baltic and Standard Seawater are calculated as functions of salinity and temperature. While several quantities show anomalies that are comparable with their measurement uncertainties and do not demand special improvement, others exhibit more significant deviations from Standard Seawater properties. In particular density and sound speed turn out to be significantly sensitive to the presence of anomalous solute. Suitable general correction methods are suggested to be applied to Baltic Sea samples with known Practical Salinity and, optionally, directly determined density.

APA, Harvard, Vancouver, ISO, and other styles

14

Feistel, R., G. M. Marion, R. Pawlowicz, and D. G. Wright. "Thermophysical property anomalies of Baltic seawater." Ocean Science Discussions 7, no. 3 (June 30, 2010): 1103–208. http://dx.doi.org/10.5194/osd-7-1103-2010.

Full text

Abstract:

Abstract. While the thermodynamic properties of Standard Seawater are very well known, the quantitative effect of sea salt composition anomalies on various properties is difficult to estimate since comprehensive lab experiments with the various natural waters are scarce. Coastal and estuarine waters exhibit significant anomalies which also influence to an unknown amount the routine salinity calculation from conductivity measurements. Recent numerical models of multi-component aqueous electrolytes permit the simulation of physical chemical properties of seawater with variable solute composition. In this paper, the FREZCHEM model is used to derive a Gibbs function for Baltic seawater, and the LSEA_DELS model to provide estimates for the conductivity anomaly relative to Standard Seawater. From additional information such as direct density measurements or empirical salinity anomaly parameterisation, the quantitative deviations of properties between Baltic and Standard Seawater are calculated as functions of salinity and temperature. While several quantities show anomalies that are comparable with their measurement uncertainties and do not demand special improvement, others exhibit more significant deviations from Standard Seawater properties. In particular density and sound speed turn out to be significantly sensitive to the presence of anomalous solute. Suitable general correction methods are suggested to be applied to Baltic Sea samples with known Practical Salinity and, optionally, directly determined density.

APA, Harvard, Vancouver, ISO, and other styles

15

Abd-Elhamid, Hany, Akbar Javadi, Ismail Abdelaty, and Mohsen Sherif. "Simulation of seawater intrusion in the Nile Delta aquifer under the conditions of climate change." Hydrology Research 47, no. 6 (January 4, 2016): 1198–210. http://dx.doi.org/10.2166/nh.2016.157.

Full text

Abstract:

The problem of seawater intrusion is encountered in almost all coastal aquifers. Because of its higher density, the seawater migrates inland into freshwater aquifers even without any pumping activities. Excessive pumping of groundwater would accelerate seawater intrusion. Climate change and sea level rise represent critical parameters affecting the rate and degree of seawater intrusion. In this paper, a coupled transient finite element model for simulation of fluid flow and solute transport in saturated and unsaturated soils (2D-FEST) is employed to study the seawater intrusion in the Nile Delta aquifer. The results of the current model are compared to results of SEAWAT for model verification. The (2D-FEST) model is used to investigate seawater intrusion considering the impacts of climate change. Three scenarios are studied: (a) rise in sea level, (b) decline of the piezometric head at the land side due to excessive pumping, and (c) combination of sea level rise and decline of the piezometric head. The results show that the rise in the sea level has a significant effect on the position of the transition zone. The third scenario represents the worst case under which the groundwater quality would deteriorate in large areas of the Nile Delta aquifer.

APA, Harvard, Vancouver, ISO, and other styles

16

Zhang, Yu-qing, Yue-zhong Li, Bing Wang, Zhi-hong Wu, Cui-ying Zhang, Xun Gong, Zhi-jun Qiu, and Yong Zhang. "Characteristics and Living Patterns of Marine Myxobacterial Isolates." Applied and Environmental Microbiology 71, no. 6 (June 2005): 3331–36. http://dx.doi.org/10.1128/aem.71.6.3331-3336.2005.

Full text

Abstract:

ABSTRACT The growth, morphology, and life cycle of two marine myxobacterial isolates, halotolerant Myxococcus fulvus strain HW-1 and halophilic Haliangium ochraceum strain SMP-2, were studied as models to determine the living patterns of myxobacteria in the ocean. The growth, morphology, and development of halotolerant strain HW-1 shifted in response to salinity. The optimal seawater concentration for growth of HW-1 was 0 to 80% (salinity, 0.1 to 2.9%), and the strain grew poorly in media with a salinity of more than 4%. The cells became shorter as the seawater concentration increased. The fruiting body structure was complete only on agar prepared with low concentrations of seawater or salts (less than 60% seawater; salinity, 2.1%), and rudimentary structures or even simple cell mounds appeared as the seawater concentration increased. In contrast, the halophilic strain SMP-2 was unable to grow without NaCl. The cell length and the morphology of the fruiting body-like structure did not change in response to salts. In seawater liquid medium, the cells of both strains were confirmed to be able to form myxospores directly from vegetative cells, but they could not do so in medium containing a low seawater concentration (10% or less). HW-1 cells from medium containing a high concentration of seawater grew independent of cell density, while cells from medium containing a low concentration of seawater (10% or less) showed density-dependent growth. SMP-2 cells showed density-dependent growth under all salinity conditions. The results suggest that the halotolerant myxobacteria are the result of degenerative adaptation of soil myxobacteria to the marine environment, while the halophilic myxobacteria form a different evolutionary group that is indigenous to the ocean.

APA, Harvard, Vancouver, ISO, and other styles

17

Safarov, J., F. Millero, R. Feistel, A. Heintz, and E. Hassel. "Thermodynamic properties of standard seawater." Ocean Science Discussions 6, no. 1 (April 17, 2009): 689–722. http://dx.doi.org/10.5194/osd-6-689-2009.

Full text

Abstract:

Abstract. (p, ρ, T) data of standard seawater with practical salinity S≈35 (corresponding to an absolute salinity SA≈35.16504 g/kg) measured at T=(273.14 to 468.06) K and pressures up to p=140 MPa are reported with an estimated experimental relative combined standard uncertainty of 0.006% in density. The measurements were made with a newly constructed vibration-tube densimeter. The system was calibrated using double-distilled water, methanol and aqueous NaCl solutions. An empirical correlation for the density of standard seawater has been developed as a function of pressure and temperature. This equation of state was used to calculate other volumetric properties such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient, internal pressure and secant bulk modulus. The results can be used to extend the present equation of state of seawater to higher temperature as a function of pressure.

APA, Harvard, Vancouver, ISO, and other styles

18

McDougall, T. J., D. R. Jackett, F. J. Millero, R. Pawlowicz, and P. M. Barker. "A global algorithm for estimating Absolute Salinity." Ocean Science 8, no. 6 (December 21, 2012): 1123–34. http://dx.doi.org/10.5194/os-8-1123-2012.

Full text

Abstract:

Abstract. 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).

APA, Harvard, Vancouver, ISO, and other styles

19

Yang, Shaobo, Luyan Li, Xingfei Li, Fang Liang, Xia Zhang, and Wei Sun. "Dynamics Model of Buoy Unpowered Heave Considering Seawater Density." Journal of Coastal Research 99, sp1 (May 14, 2020): 439. http://dx.doi.org/10.2112/si99-060.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Алексанин, А. И., В. Ким, and И. О. Ярощук. "Seawater density estimation on surface footprints of internal waves." Podvodnye issledovaniia i robototehnika, no. 4(34) (January 24, 2020): 38–44. http://dx.doi.org/10.37102/24094609.2020.34.4.005.

Full text

Abstract:

Рассматривается проблема восстановления плотностной структуры моря на шельфе по проявлениям внутренних гравитационных волн на изображениях поверхности в поляризованном свете. По изображениям рассчитываются скорости распространения волн и их длины. Анализируется 17 случаев регистрации волн, проходивших через станции с вертикально расположенными датчиками температуры. Используется две модели вертикальной изменчивости плотности: однослойная с постоянной частотой плавучести и двухслойная с постоянной плотностью в слое. Анализируются точности решения прямых задач на основе сопоставления скоростей распространения волн, рассчитанных по профилям плотности и полученных по изображениям. Рассматриваются два варианта решения прямых задач: на основе решения задачи Штурма–Лиувилля и на основе уравнения Кортевега де Вриза. Демонстрируется возможность выбора модели среды по изменчивости скорости распространения волн на шельфе с меняющейся глубиной дна. Показывается, что при двухслойной модели среды с нижним слоем со значительно меньшей толщиной, чем у верхнего, оба подхода к решению прямых задач дают существенное занижение наблюдаемых скоростей распространения внутренних гравитационных волн. The problem of shallow water density estimation based on the surface images of internal gravity waves is considered. The images are used for calculation of internal gravity waves speed and wavelength. The seventeen cases of in-situ wave registration by vertical allocation temperature sensors are analyzed. The standard two-layer model and constant Väisälä-Brunt frequency model are explored. The wave speed is calculated by direct task solution using in situ data and image data separately, and the results are compared. Two kinds of direct task solutions are considered: as a solution of Sturm–Liouville problem and as a solution of Korteweg-de Vries equation. The relation between internal wave speed and the depth can help us to choose the density model. It is shown, that for the two-layer model with upper layer depth much higher than the bottom one both approaches to the solution of the direct task give significantly lower speed than the speed calculated from the image sequences.

APA, Harvard, Vancouver, ISO, and other styles

21

Fan, Na, Liqiang Chai, Peng Wang, and Jun Liang. "The effect of ceramic friction pairs on the tribocorrosion behavior of AISI 304 stainless steel in seawater." Industrial Lubrication and Tribology 71, no. 6 (August 12, 2019): 779–86. http://dx.doi.org/10.1108/ilt-10-2018-0377.

Full text

Abstract:

Purpose This paper aims to study the tribocorrosion behavior of 304 stainless steel (SS) sliding against SiC and Si3N4 counterparts in artificial seawater. Design/methodology/approach The tribocorrosion behavior of 304SS sliding against SiC and Si3N4 balls in artificial seawater has been investigated. The tests were conducted using a ball-on-disk rig equipped with an electrochemical workstation. The friction coefficient, surface morphology, wear volume and current density were determined. Findings When 304SS sliding against SiC ball, a smooth surface with a silica layer was formed on the top, which led to the low friction coefficient, current density and small wear volume. For 304SS-Si3N4 tribo-pair, a lot of metal debris was scattered on contact surfaces leading to high friction coefficient, current density and big wear volume. Research limitations/implications This research suggests that the lubrication effect of silicon-based ceramics is related to counterpart specimen in artificial seawater. Practical implications The results may help us to choose the appropriate ceramic ball under seawater environment. Originality/value The main originality of the work is to reveal the tribocorrosion behavior of 304SS sliding against SiC and Si3N4 balls, which help us to realize that the Si3N4 ball as water-lubricated ceramics could not exhibit lubrication effect when coupled with 304SS in artificial seawater.

APA, Harvard, Vancouver, ISO, and other styles

22

Yang, Shaolong, Zhuo Wang, Zhitao Han, and Xinxiang Pan. "Performance modelling of seawater electrolysis in an undivided cell: Effects of current density and seawater salinity." Chemical Engineering Research and Design 143 (March 2019): 79–89. http://dx.doi.org/10.1016/j.cherd.2019.01.009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Xu, Zexuan, Bill X. Hu, and Ming Ye. "Numerical modeling and sensitivity analysis of seawater intrusion in a dual-permeability coastal karst aquifer with conduit networks." Hydrology and Earth System Sciences 22, no. 1 (January 12, 2018): 221–39. http://dx.doi.org/10.5194/hess-22-221-2018.

Full text

Abstract:

Abstract. Long-distance seawater intrusion has been widely observed through the subsurface conduit system in coastal karst aquifers as a source of groundwater contaminant. In this study, seawater intrusion in a dual-permeability karst aquifer with conduit networks is studied by the two-dimensional density-dependent flow and transport SEAWAT model. Local and global sensitivity analyses are used to evaluate the impacts of boundary conditions and hydrological characteristics on modeling seawater intrusion in a karst aquifer, including hydraulic conductivity, effective porosity, specific storage, and dispersivity of the conduit network and of the porous medium. The local sensitivity analysis evaluates the parameters' sensitivities for modeling seawater intrusion, specifically in the Woodville Karst Plain (WKP). A more comprehensive interpretation of parameter sensitivities, including the nonlinear relationship between simulations and parameters, and/or parameter interactions, is addressed in the global sensitivity analysis. The conduit parameters and boundary conditions are important to the simulations in the porous medium because of the dynamical exchanges between the two systems. The sensitivity study indicates that salinity and head simulations in the karst features, such as the conduit system and submarine springs, are critical for understanding seawater intrusion in a coastal karst aquifer. The evaluation of hydraulic conductivity sensitivity in the continuum SEAWAT model may be biased since the conduit flow velocity is not accurately calculated by Darcy's equation as a function of head difference and hydraulic conductivity. In addition, dispersivity is no longer an important parameter in an advection-dominated karst aquifer with a conduit system, compared to the sensitivity results in a porous medium aquifer. In the end, the extents of seawater intrusion are quantitatively evaluated and measured under different scenarios with the variabilities of important parameters identified from sensitivity results, including salinity at the submarine spring with rainfall recharge, sea level rise, and a longer simulation time under an extended low rainfall period.

APA, Harvard, Vancouver, ISO, and other styles

24

Le, Zhikai, Wenwu Li, Qi Dang, Chengbin Jing, Wei Zhang, Junhao Chu, Liang Tang, and Ming Hu. "A high-power seawater battery working in a wide temperature range enabled by an ultra-stable Prussian blue analogue cathode." Journal of Materials Chemistry A 9, no. 13 (2021): 8685–91. http://dx.doi.org/10.1039/d0ta12052a.

Full text

Abstract:

A seawater battery assembled with a metal anode and nickel hexacyanoferrate cathode presents a high power density of over 160 mW cm⁻² and works stably in seawater in a wide temperature range (0–40 °C).

APA, Harvard, Vancouver, ISO, and other styles

25

TEY, YAO HSIEN, KOA-JEN JONG, SHIN-YUAN FEN, and HIN-CHUNG WONG. "Occurrence of Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus in the Aquacultural Environments of Taiwan." Journal of Food Protection 78, no. 5 (May 1, 2015): 969–76. http://dx.doi.org/10.4315/0362-028x.jfp-14-405.

Full text

Abstract:

The occurrence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern Taiwan was examined by the membrane filtration and colony hybridization method. The halophilic V. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log CFU/g. V. cholerae was found in both the seawater and freshwater ponds but preferentially in freshwater ponds, with a frequency of 72.2% and a mean density of 1.65 log CFU/g. V. vulnificus was identified mainly in seawater ponds, with an isolation frequency of 27.8%. The density of V. parahaemolyticus in seawater ponds was positively related to water temperature (Pearson correlation coefficient, r = 0.555) and negatively related to salinity (r = −0.333). The density of V. cholerae in all six ponds was positively related to water temperature (r = 0.342) and negatively related to salinity (r = −0.432). Two putatively pathogenic tdh+ V. parahaemolyticus isolates (1.4% of the samples) and no ctx+ V. cholerae isolates were identified. The experimental results may facilitate assessments of the risk posed by these pathogenic Vibrio species in Taiwan, where aquaculture provides a large part of the seafood supply.

APA, Harvard, Vancouver, ISO, and other styles

26

Pawlowicz, R. "A model for predicting changes in the electrical conductivity, practical salinity, and absolute salinity of seawater due to variations in relative chemical composition." Ocean Science Discussions 6, no. 3 (November 27, 2009): 2861–909. http://dx.doi.org/10.5194/osd-6-2861-2009.

Full text

Abstract:

Abstract. Salinity determination in seawater has been carried out for almost 30 years using the 1978 Practical Salinity Standard. However, the numerical value of so-called practical salinity, computed from electrical conductivity, differs slightly from the true or absolute salinity, defined as the mass of dissolved solids per unit mass of seawater. The difference arises because more recent knowledge about the composition of seawater is not reflected in the definition of practical salinity, which was chosen to maintain historical continuity with previous measures, and because of spatial and temporal variations in the relative composition of seawater. Accounting for these variations in density calculations requires the calculation of a correction factor δSA, which is known to range from 0 to 0.03 g kg−1 in the world oceans. Here a mathematical model relating compositional perturbations to δSA is developed, by combining a chemical model for the composition of seawater with a mathematical model for predicting the conductivity of multi-component aqueous solutions. Model calculations generally agree with estimates of δSA based on fits to direct density measurements, and show that biogeochemical perturbations affect conductivity only weakly. However, small systematic differences between model and density-based estimates remain. These may arise for several reasons, including uncertainty about the biogeochemical processes involved in the increase in Total Alkalinity in the North Pacific, uncertainty in the carbon content of IAPSO standard seawater, and uncertainty about the haline contraction coefficient for the constituents involved in biogeochemical processes. This model may then be important in constraining these processes, as well as in future efforts to improve parameterizations for δSA.

APA, Harvard, Vancouver, ISO, and other styles

27

Jackett, David R., Trevor J. McDougall, Rainer Feistel, Daniel G. Wright, and Stephen M. Griffies. "Algorithms for Density, Potential Temperature, Conservative Temperature, and the Freezing Temperature of Seawater." Journal of Atmospheric and Oceanic Technology 23, no. 12 (December 1, 2006): 1709–28. http://dx.doi.org/10.1175/jtech1946.1.

Full text

Abstract:

Abstract Algorithms are presented for density, potential temperature, conservative temperature, and the freezing temperature of seawater. The algorithms for potential temperature and density (in terms of potential temperature) are updates to routines recently published by McDougall et al., while the algorithms involving conservative temperature and the freezing temperatures of seawater are new. The McDougall et al. algorithms were based on the thermodynamic potential of Feistel and Hagen; the algorithms in this study are all based on the “new extended Gibbs thermodynamic potential of seawater” of Feistel. The algorithm for the computation of density in terms of salinity, pressure, and conservative temperature produces errors in density and in the corresponding thermal expansion coefficient of the same order as errors for the density equation using potential temperature, both being twice as accurate as the International Equation of State when compared with Feistel’s new equation of state. An inverse function relating potential temperature to conservative temperature is also provided. The difference between practical salinity and absolute salinity is discussed, and it is shown that the present practice of essentially ignoring the difference between these two different salinities is unlikely to cause significant errors in ocean models.

APA, Harvard, Vancouver, ISO, and other styles

28

Sun, Li Juan, Hu Yuan Sun, Kun Cao, and Rui Hua Yan. "The Electrochemical Analysis of Trace Titanium Addition to the High Pure Zinc Electrode in Seawater." Advanced Materials Research 662 (February 2013): 379–82. http://dx.doi.org/10.4028/www.scientific.net/amr.662.379.

Full text

Abstract:

High pure zinc with trace titanium of various contents was prepared by the method of master alloy preparation, and electrochemical characteristic difference in seawater was discussed. The result reveals that there is a minimum of self corrosion current density at 0.04% titanium content in high pure zinc in seawater of Qingdao seashore, and trace addition of titanium may increases the potential stability but not change the corrosion behavior of high pure zinc in seawater.

APA, Harvard, Vancouver, ISO, and other styles

29

Lewis, Lloyd F., Joseph Van Ryzin, and Luis Vega. "STEEP SLOPE SEAWATER SUPPLY PIPELINE." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 196. http://dx.doi.org/10.9753/icce.v21.196.

Full text

Abstract:

The State of Hawaii's Ocean Science and Technology (HOST) Park, the U.S. Department of Energy (DOE), and the Pacific International Center for High Technology Research (PICHTR) sponsored the construction and installation of an expanded seawater supply system at the Natural Energy Laboratory of Hawaii (NELH). This effort included the installation of a 1.0m diameter high density polyethylene pipe capable of delivering 840 1/s of cold seawater, representing the longest (2,060m) large diameter pipe traversing the steepest slope ever spanned. Acceptance testing of the system was completed in June 1988 and the design service life is 10 years.

APA, Harvard, Vancouver, ISO, and other styles

30

Qi, Xiao Ni. "Performance Analysis of Seawater Cooling Tower." Applied Mechanics and Materials 182-183 (June 2012): 598–601. http://dx.doi.org/10.4028/www.scientific.net/amm.182-183.598.

Full text

Abstract:

Due to salt deposition on the packing and subsequent airflow block, thermal performance of the tower declines after a period of time. Eliminating the fill makes the tower fully empty which is of far-reaching significance in circulating seawater with high temperature, high turbidity. Application of PCTs to industry is not practical due to salt deposition on the packing and subsequent blockage. Analysis of seawater characteristics main includes temperature, salinity, density, specific heat and other properties, which is of great significance in the seawater cooling performance. The results provide necessary theoretical bases for the extensive application of seawater cycling and cooling technology, and at the same time lay foundation for the design of seawater cooling tower.

APA, Harvard, Vancouver, ISO, and other styles

31

Komari, K. "DESIGN OF MICRO-CAPSUL GELATIN-ACACIA COACERVATION DISPERSED IN SEAWATER." KnE Life Sciences 2, no. 1 (February 1, 2015): 26. http://dx.doi.org/10.18502/kls.v1i0.80.

Full text

Abstract:

One of the prawn rearing method had been using artificial feed of gelatin-acacia microcapsule. Characteristics of this microcapsule is very small and its size can be predicted and its density is as same as sea water.This study aimed to measure size distribution of fish oil droplet and the gelatin-acacia membrane was calculated in order to get the same density of sea water. Results of this study showed that design of microcapsules were effected by density of fish oil, membrane (coacervation of gelatin – acacia), droplet size, and density of sea water. The size distribution of fish oil droplet was presented and their variation of expected size and its actual size of microcapsule can be predicted for efficiency of the encapsulation process. Keywords: design of microencapsulation, density, droplet size

APA, Harvard, Vancouver, ISO, and other styles

32

Tada, Kuninao, Toshimasa Asahi, Saho Kitatsuji, Mika Nomura, Hitomi Yamaguchi, and Kazuhiko Ichimi. "Low-active high-density Noctiluca scintillans cells in surface seawater." Oceanologia 62, no. 3 (July 2020): 402–7. http://dx.doi.org/10.1016/j.oceano.2020.02.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Allgeyer, Sébastien, and Phil Cummins. "Numerical tsunami simulation including elastic loading and seawater density stratification." Geophysical Research Letters 41, no. 7 (April 11, 2014): 2368–75. http://dx.doi.org/10.1002/2014gl059348.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Hibino, Tadashi, Masayuki Ikeda, and Katsuaki Komai. "Seawater exchange due to density intrusion under different stratification conditions." PROCEEDINGS OF HYDRAULIC ENGINEERING 46 (2002): 1055–60. http://dx.doi.org/10.2208/prohe.46.1055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Molloy, P. J., and M. J. Cowling. "Volume and density changes in polymer gels in seawater environments." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 214, no. 4 (October 2000): 223–28. http://dx.doi.org/10.1177/146442070021400404.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Pawlowicz, R. "A model for predicting changes in the electrical conductivity, practical salinity, and absolute salinity of seawater due to variations in relative chemical composition." Ocean Science 6, no. 1 (March 18, 2010): 361–78. http://dx.doi.org/10.5194/os-6-361-2010.

Full text

Abstract:

Abstract. Salinity determination in seawater has been carried out for almost 30 years using the Practical Salinity Scale 1978. However, the numerical value of so-called practical salinity, computed from electrical conductivity, differs slightly from the true or absolute salinity, defined as the mass of dissolved solids per unit mass of seawater. The difference arises because more recent knowledge about the composition of seawater is not reflected in the definition of practical salinity, which was chosen to maintain historical continuity with previous measures, and because of spatial and temporal variations in the relative composition of seawater. Accounting for these spatial variations in density calculations requires the calculation of a correction factor δSA, which is known to range from 0 to 0.03 g kg−1 in the world oceans. Here a mathematical model relating compositional perturbations to δSA is developed, by combining a chemical model for the composition of seawater with a mathematical model for predicting the conductivity of multi-component aqueous solutions. Model calculations for this estimate of δSA, denoted δSRsoln, generally agree with estimates of δSA based on fits to direct density measurements, denoted δSRdens, and show that biogeochemical perturbations affect conductivity only weakly. However, small systematic differences between model and density-based estimates remain. These may arise for several reasons, including uncertainty about the biogeochemical processes involved in the increase in Total Alkalinity in the North Pacific, uncertainty in the carbon content of IAPSO standard seawater, and uncertainty about the haline contraction coefficient for the constituents involved in biogeochemical processes. This model may then be important in constraining these processes, as well as in future efforts to improve parameterizations for δSA.

APA, Harvard, Vancouver, ISO, and other styles

37

Feistel, R., S. Weinreben, H. Wolf, S. Seitz, P. Spitzer, B. Adel, G. Nausch, B. Schneider, and D. G. Wright. "Density and Absolute Salinity of the Baltic Sea 2006–2009." Ocean Science 6, no. 1 (January 18, 2010): 3–24. http://dx.doi.org/10.5194/os-6-3-2010.

Full text

Abstract:

Abstract. The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006–2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

APA, Harvard, Vancouver, ISO, and other styles

38

Feistel, R., S. Weinreben, H. Wolf, S. Seitz, P. Spitzer, B. Adel, G. Nausch, B. Schneider, and D. G. Wright. "Density and Absolute Salinity of the Baltic Sea 2006–2009." Ocean Science Discussions 6, no. 2 (August 19, 2009): 1757–817. http://dx.doi.org/10.5194/osd-6-1757-2009.

Full text

Abstract:

Abstract. The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006–2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

APA, Harvard, Vancouver, ISO, and other styles

39

Miftahul Walid, Hozairi, and Madukil Makruf. "Analysis and Development of Seawater Density Measurement Algorithms Using Arduino Uno and YL-69 Sensor." Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) 4, no. 5 (October 30, 2020): 951–56. http://dx.doi.org/10.29207/resti.v4i5.2430.

Full text

Abstract:

In this research, an analysis was carried out to develop a measuring instrument for seawater density in salt production using a microcontroller (Arduino Uno) and YL-69 sensor, this sensor was commonly used to measure soil moisture. The experimental method was used in this research to produce initial data in the form of resistance and seawater density values, then calculations are carried out using statistical methods to find equations and produce a constant variable that connects the resistance and seawater density values. The equation was used to compile the algorithm into Arduino Uno. As for the results of this research, From six experiments conducted, two experiments produced the same sea water density value between the actual and the predicted, namely the 2nd and 5th experiments, while for other experiments there was a difference between the actual and predicted values, however, it was not too significant, the difference occurs between the value range 0 ~ 1, to determine the level of error, use the Mean Square Error (MSE) with an error level of = 0.5 and Mean Absolute Error (MAE) with an error level of = 0.6. The contribution of this research is an algorithm that can predict the density value (baume) based on the resistance value obtained from the YL 69 sensor.

APA, Harvard, Vancouver, ISO, and other styles

40

Davis, Russ E., and Jeffrey T. Sherman. "Evaluating a Lithium-Seawater Battery on Gliders." Journal of Atmospheric and Oceanic Technology 34, no. 5 (May 2017): 1175–82. http://dx.doi.org/10.1175/jtech-d-16-0151.1.

Full text

Abstract:

AbstractNeutral-buoyancy vehicles demand high-density energy sources and lithium is light with high oxidation energy. PolyPlus Battery Company has developed a prototype lithium-seawater battery that is attractive for powering long-duration autonomous oceanographic vehicles (floats and underwater gliders). These batteries were tested in the laboratory and at sea.PolyPlus batteries use “Protected Lithium Electrodes” with proprietary “windows” protecting the volatile lithium anode from water while passing lithium ions. The cathode reduces oxygen dissolved in seawater, or hydrolyzes seawater to produce hydrogen. Not requiring additional electrolyte, fuel, or pressure cases, these cells have impressive weight advantages. Good electrode–seawater mass transfer is required but can increase drag and be impeded by biofouling.Tests assessing robustness of the PolyPlus batteries in oceanographic use, evaluating mass transfer issues, and observing biofouling impacts are reported. In sea trials, two cells were tested for 69 days mounted on a Spray glider. Findings are as follows: 1) the cells were robust over 900 dives, most to 400 m; 2) without antifouling measures, the cells became substantially biofouled, but their performance was undiminished; and 3) performance was complex, depending on current density, oxygen concentration, and flow conditions. For dissolved oxygen concentration above 1 mL L−1, the cells delivered 9 W m−2 of electrode surface at 3 V. For low oxygen, the cell shifted to hydrolysis near 2.3 V, but mass transfer was less critical so current density could be increased and observed power reached 5 W m−2. This could be increased using a lower resistance load.

APA, Harvard, Vancouver, ISO, and other styles

41

Lin, Hong, Xin Min Wang, Chuan Lin Zhou, and Wei Zhong Li. "Study of Oceanic Suspended Particles Density Detecting Technology Based on Mie Scattering Theory." Applied Mechanics and Materials 192 (July 2012): 425–29. http://dx.doi.org/10.4028/www.scientific.net/amm.192.425.

Full text

Abstract:

A new technology about ocean suspended particles density detecting by Mie scattering theory is proposed. This technology is based on analyzing and studying the transmission characteristics of the laser in the seawater. Based on Mie scattering theory, the optical scattering characteristics of oceanic suspended particles is researched, and a new method of calculating the scattering coefficient and backward scattering ratio is putted forward. By detecting the laser scattering signal under the seawater, the density information of ocean suspended particles can be gain and detect. A ocean suspended particles density detecting model based on airborne lidar system is firstly established through analyzing the absorbing and scattering characteristics of the suspended particles. By simulating and calculating, it is proved that the technology can detect and monitor the density of ocean suspended particles effectively, and therefore it can predict the density change of ocean suspended particles also.

APA, Harvard, Vancouver, ISO, and other styles

42

Sánchez Pérez, Andrea Paola, and Wilson Antonio Cañas-Marín. "Prediction of live formation water densities from petroleum reservoirs with pressure-dependent seawater density correlations." DYNA 87, no. 213 (April 1, 2020): 165–72. http://dx.doi.org/10.15446/dyna.v87n213.80967.

Full text

Abstract:

We studied two density correlations developed for seawater at high pressures as potential models to predict formation water densities from petroleum reservoirs as a function of salinity, pressure, gas content, and temperature. The correlations were tested against experimental densities measured at high pressures for live formation waters sampled under bottomhole conditions from five petroleum reservoirs. As a result, one of these seawater correlations was found to be particularly promising to predict formation water densities for these samples, even out of the pressure range originally reported for such a model.

APA, Harvard, Vancouver, ISO, and other styles

43

Wright, D. G., R. Pawlowicz, T. J. McDougall, R. Feistel, and G. M. Marion. "Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10." Ocean Science 7, no. 1 (January 6, 2011): 1–26. http://dx.doi.org/10.5194/os-7-1-2011.

Full text

Abstract:

Abstract. 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 oceanography. The other two salinity variables provide alternative measures of the mass fraction of dissolved material in seawater. "Solution Salinity", denoted SAsoln, is the most obvious extension of Reference Salinity to allow for composition anomalies; it provides a direct estimate of the mass fraction of dissolved material in solution. "Added-Mass Salinity", denoted SAadd, is motivated by a method used to report laboratory experiments; it represents the component of dissolved material added to Standard Seawater in terms of the mass of material before it enters solution. We also discuss a constructed conservative variable referred to as "Preformed Salinity", denoted S∗, which will be useful in process-oriented numerical modelling studies. Finally, a conceptual framework for the incorporation of composition anomalies in numerical models is presented that builds from studies in which composition anomalies are simply ignored up to studies in which the influences of composition anomalies are accounted for using the results of biogeochemical models. 1TEOS-10: international Thermodynamic Equation of Seawater 2010, http://www.teos-10.org/.

APA, Harvard, Vancouver, ISO, and other styles

44

Yan, Y. G., W. S. Wang, W. Li, K. P. Loh, and J. Zhang. "A graphene-like membrane with an ultrahigh water flux for desalination." Nanoscale 9, no. 47 (2017): 18951–58. http://dx.doi.org/10.1039/c7nr07193k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Zhang, Shunfu, Changjun Liu, Chuanke Li, Sili Long, Jian Zhou, and Qiyi Zhang. "Analysis of Water Cycle in Weizhou Island of Beihai City, Guangxi Province, Part II: Study On Groundwater Exploitation Plan." MATEC Web of Conferences 246 (2018): 02047. http://dx.doi.org/10.1051/matecconf/201824602047.

Full text

Abstract:

To relieve the drop of groundwater and seawater intrusion in Weizhou Island caused by overexploitation, the analysis model of precipitation-runoff and variable-density groundwater flow in Weizhou Island was established and the model’s parameter identification results were used to investigate groundwater level and seawater/freshwater interface changes under different groundwater exploitation plans. Thereafter, a rational groundwater exploitation plan could be made to prevent the lowering of groundwater levels caused by ground water overexploitation and ecological deterioration caused by seawater intrusion. This could help accelerating the recovery of ground water and maintaining ecological system.

APA, Harvard, Vancouver, ISO, and other styles

46

Shacklock, Peter F., and James S. Craigie. "Winter Survival and Growth of Chondrus crispus in Onshore Culture Tanks." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 2 (February 1, 1986): 263–68. http://dx.doi.org/10.1139/f86-033.

Full text

Abstract:

Commercial aquaculture of Chondrus crispus in eastern Canada required the development of reliable methods for ensuring the winter survival of a healthy, vegetative inoculum. Two procedures were investigated. Agitated cultures of C. crispus (stocking density <6 kg∙m−2) in running seawater grew at average rates of 0.21–0.34 kg∙m−2∙wk−1 during two winters under natural irradiance. Cultures maintained in undisturbed, outdoor tanks of seawater over three winters showed little or no net production; however, survival was excellent provided that the stocking density remained below approximately 10 kg∙m−2. The plants were capable of resuming growth when environmental conditions improved. We found no difference in the responses of the several haploid and diploid isolates examined. Large vegetative inocula required for commercial aquaculture can be maintained simply and reliably in tanks of clean seawater if they are undisturbed and an ice cover is allowed to form.

APA, Harvard, Vancouver, ISO, and other styles

47

Millero, F. J., and F. Huang. "The density of seawater as a function of salinity (5 to 70 g kg." Ocean Science Discussions 6, no. 1 (January 23, 2009): 153–69. http://dx.doi.org/10.5194/osd-6-153-2009.

Full text

Abstract:

Abstract. New seawater density measurements were made as a function of temperature (0 to 90°C) and salinity (5 to 70). The measurements (N=230) from 0 to 40°C and Practical Salinity from 0 to 40 were found to be in good agreement (σ=0.0036) with the equation of state of seawater (Millero and Poisson, 1981) made on samples with a known chlorinity (Cl). These results indicate that the Practical Salinities (S) are in agreement to within ±0.003 with the values calculated from the Chlorinity, SCl=1.80655 Cl. The measurements from 25 to 90°C were used to extend the equation of state to high temperatures and salinities. All the relative densities (ρ−ρ0, where ρ0 is the density for pure water) were fitted to equations of the form (ρ−ρ0)/kg m−3 = ASA + BSA0.5 + CSA2 where A, B, and C are functions of temperature and SA (g kg−1) is the absolute salinity, SA=(35.16504/35)S. The fitted results from SA=0 to 50 and 0 to 40°C (N=247) gave standard errors of 0.0037 kg m−3. The fitted results from 25 to 90°C (N=271) gave standard errors of 0.0063 kg m−3 and all the results (N=501) from 0 to 90°C gave standard errors of 0.0062 kg m−3. The earlier density measurements used to determine the equation of state of seawater were combined to derive equations that are valid from 0 to 40°C and 0 to 90°C. The standard errors of these fits are, respectively, 0.0038 kg m−3 (N=713) and 0.0063 kg m−3 (N=962). These new measurements expand the equation of state of seawater to a wider range of temperature (0 to 90°C) and absolute salinity (0 to 70).

APA, Harvard, Vancouver, ISO, and other styles

48

Das, Amlan, and Bithin Datta. "Optimization Based Solution of Density Dependent Seawater Intrusion in Coastal Aquifers." Journal of Hydrologic Engineering 5, no. 1 (January 2000): 82–89. http://dx.doi.org/10.1061/(asce)1084-0699(2000)5:1(82).

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Ayoub, G. M., M. El‐Fadel, A. Acra, and R. Abdallah. "Critical density index for the solar production of bittern from seawater." International Journal of Environmental Studies 58, no. 1 (December 2000): 85–97. http://dx.doi.org/10.1080/00207230008711318.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Weinreben, Stefan, and Rainer Feistel. "Anomalous salinity-density relations of seawater in the eastern central Atlantic." Deep Sea Research Part I: Oceanographic Research Papers 154 (December 2019): 103160. http://dx.doi.org/10.1016/j.dsr.2019.103160.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Seawater density'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles