scholarly journals DETERMINATION OF THE INTERFACIAL EDDY DIFFUSION COEFFICIENT OF A HIGHLY STRATIFIED ESTUARY

1976 ◽  
Vol 1 (15) ◽  
pp. 180
Author(s):  
Yu-Hwa Wang
Keyword(s):  
Sea Water ◽  
Salt Water ◽  
Water Layer ◽  
Eddy Diffusion ◽  
Shear Stresses ◽  
Eddy Diffusion Coefficient ◽  
Layer Flow ◽  
Stratified Estuary ◽  
Number Of Publications ◽  
Stratified Estuaries

Estuaries may be sequentially classified into highly stratified, moderately mixed and vertically homogeneous. An important difference between moderately stratified or vertically homogeneous estuaries, and highly stratified estuaries (salt wedges) is that, in the former, tidal currents are sufficient to cause turbulent mixing of fresh water and sea water over the full depth of the estuary. In the latter, a distinct interface or interfacial layer exists which separates the two nearly homogeneous layers. The vertical advectlon of salt in this two-layer flow is the dominant process in maintaining the salt balance. This paper presents an analytical model describing this process. Experiments have been conducted in the laboratory to compare with the developed theory. A large number of publications concerning estuarine dynamics are available for moderately mixed and vertically homogeneous estuaries. Relatively little information, however, is available for highly stratified estuaries. In an earlier work Keulegan (1949) defined the critical velocity of the upper layer at which the entrainment of the salt water layer starts. A summary of Keulegan's work may be found in Chappter 11 of the book, "Estuary and Coastline Hydrodynamics" edited by Ippen (1966). Recently Partheniades et. al. (1975) reviewed Schijf-Schonfeld's analytical work and Keulegan's experimental data with regard to the length, shape and shear stresses of a saline wedge. Wang (1975) compared his laboratory measurements of interfacial stresses with Lock's Theory.

The evolution of under-ice melt ponds, or double diffusion at the freezing point

1974 ◽  
Vol 64 (3) ◽  
pp. 507-528 ◽  
Author(s):  
Seelye Martin ◽  
Peter Kauffman
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Salt Water ◽  
Ice Sheet ◽  
Water Layer ◽  
Double Diffusion ◽  
Theoretical Models ◽  
Interfacial Region ◽  
Ice Melt

In an experimental and theoretical study, we model a phenomenon observed in the summer Arctic, where a fresh-water layer at a temperature of 0°C floats both over a sea-water layer at its freezing point and under an ice layer. Our results show that the ice growth in this system takes place in three phases. First, because the fresh-water density decreases upon supercooling, the rapid diffusion of heat relative to salt from the fresh to the salt water causes a density inversion and thereby generates a high Rayleigh number convection in the fresh water. In this convection, supercooled water rises to the ice layer, where it nucleates into thin vertical interlocking ice crystals. When these sheets grow down to the interface, supercooling ceases. Second, the presence of the vertical ice sheets both constrains the temperatureTand salinitysto lie on the freezing curve and allows them to diffuse in the vertical. In the interfacial region, the combination of these processes generates a lateral crystal growth, which continues until a horizontal ice sheet forms. Third, because of theTandsgradients in the sea water below this ice sheet, the horizontal sheet both migrates upwards and increases in thickness. From one-dimensional theoretical models of the first two phases, we find that the heat-transfer rates are 5–10 times those calculated for classic thermal diffusion.

Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

2018 ◽  
Vol 6 (6) ◽  
pp. 46
Author(s):  
Raveesha P ◽  
K. E. Prakash ◽  
B. T. Suresh Babu
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Salt Water ◽  
Construction Material ◽  
Salt Content ◽  
River Estuary ◽  
Sand Sample ◽  
River Sand ◽  
Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods.  It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

Evaluation of Heavy Metal Contents in Mudflat Solar Salt, Salt Water, and Sea Water in the Nationwide Salt Pan

2012 ◽  
Vol 41 (7) ◽  
pp. 1014-1019 ◽  
Author(s):  
Hag-Lyeol Kim ◽  
Young-Joo Yoo ◽  
In-Sun Lee ◽  
Gang-Hee Ko ◽  
In-Cheol Kim
Keyword(s):  
Heavy Metal ◽  
Sea Water ◽  
Salt Water ◽  
Solar Salt ◽  
Metal Contents ◽  
Salt Pan

Studies on Salt and Water Balance in Caddis Larvae (Trichoptera)

1961 ◽  
Vol 38 (3) ◽  
pp. 521-530 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Sea Water ◽  
Salt Water ◽  
Chloride Concentration ◽  
Malpighian Tubule ◽  
Sodium Concentration ◽  
Fluid Composition ◽  
Chloride Level ◽  
Highly Sensitive ◽  
Water Media ◽  
Salt And Water Balance

1. Survival and regulation in sea-water media was studied in the freshwater caddises Limnephilus stigma and Anabolia nervosa. 2. The majority of larvae did not survive for more than a few days at external salt concentrations greater than about 6o mM./l. NaCl. 3. In sea-water media the haemolymph osmotic pressure increased to remain slightly hyper-osmotic to the medium. The haemolymph sodium level also increased to remain slightly hypertonic to the medium, but the chloride level was maintained hypotonic until just prior to death of the larvae. 4. When the haemolymph chloride concentration was raised above the normal level, the Malpighian tubule-rectal system elaborated fluid in which the chloride concentration was hypertonic to the haemolymph. The system is highly sensitive to changes in the haemolymph chloride level. 5. The regulation of body-fluid composition in the freshwater caddises is compared with that found previously in the euryhaline larvae of Limnephilus affinis. It is suggested that the maintenance of a low haemolymph sodium concentration in L. affinis larvae is an important part of the adaptation for survival in salt water.

Sea Water Intrusion Monitoring on the Sendangbiru of the Southern Malang Coastal Area based on Geoelectrical Resistivity Data

2021 ◽  
Vol 14 (9) ◽  
pp. 43-48
Author(s):  
Sunaryo .
Keyword(s):  
Data Acquisition ◽  
Cross Section ◽  
Seawater Intrusion ◽  
Cross Sections ◽  
Sea Water ◽  
Salt Water ◽  
Sea Water Intrusion ◽  
Electrical Sounding ◽  
Geoelectrical Resistivity ◽  
Intrusion Layer

The study was conducted with the objective to distinguish the presence of seawater intrusion layer or salt-water aquifer distribution along the data acquisition line at the locations. Data acquisition was conducted by using the Wenner-Schumberger configuration of geoelectrical resistivity. From this research, 4 lines and 4 points of vertical electrical sounding (VES) data for every line were obtained with the distance between electrode a as 10m. Based on the data processing, obtained depth up to 120m with the smallest resistivity value is 0.02Ωm and the largest is 6764.52Ωm. To make the distribution of resistivity values along the path line of the study, cross sections were made until a depth of 120m. Based on the cross-section, the low resistivity value (less than 1.5 Ωm) that interpreted as a seawater intrusion layer or salt water aquifer distribution is located at varying depths. There are intrusions for the SB1 cross section, there is an intrusion at a depth of 6m-7m as far as 10m, at a depth of 6m-8m as far as 10m for the SB2 cross section and at a depth of 22m - 26m as far as 25m for the SB3 cross section.

scholarly journals Reclaiming land flooded with salt water.

1953 ◽  
Vol 1 (4) ◽  
pp. 225-244
Author(s):  
C.W.C. Beekom
Keyword(s):  
Salt Concentration ◽  
Sea Water ◽  
Salt Water ◽  
Soil Layer ◽  
Weather Conditions ◽  
Phleum Pratense ◽  
Active Growth ◽  
Warm Weather ◽  
Different Types ◽  
Spring Sowing

The effect of sea floods on grassland is described and recommendations are made for the restoration of inundated grassland. Turf may be heavily damaged after +or- 4 weeks inundation with water containing more than 20 g. NaCl per 1. At lower salt concentrations Poa sp. and Trifolium repens are still badly damaged but other species, notably Lolium perenne, Agrostis stolonifera and Alopecurus sp., are capable of immediate regrowth after drainage. If grassland remains submerged during spring, rising temperatures promote active growth of the grasses followed by rapid decay caused by lack of oxygen. L. perenne is especially sensitive to submergence in warm weather. The dominant weed communities which appear on land on which the turf has been destroyed by sea-water are described. Reseeding is recommended as the quickest method of restoring badly damaged turf. The flooded land should first be thoroughly drained and then repeatedly harrowed to produce a shallow seed-bed on which herbage mixtures can be sown without the application of gypsum. Given average weather conditions, normal permanent grassland mixtures can be sown at salt concentrations, measured in spring, of up to 8-10 g. NaCl per 1. of moisture in the 5-20 cm. soil layer. At a salt concentration of about 10 g. per 1. measured in spring, L. perenne tends to dominate over other species while Poa sp. and T. repens suffer during the summer. At a salt concentration of 10-15 g. per 1. in spring, Poa sp. and T. repens should be omitted from seed mixtures, instead mixtures consisting of different types of L. perenne, Festuca pratensis and Phleum pratense should be sown. When the salt concentration of the soil moisture is higher that 15 g. per 1. in spring, sowing should be delayed and the weeds checked by mowing or grazing. Temporary rises of the salt concentration in dry symmers to 25 g. per 1. are tolerated by L. perenne, F. pratensis and Ph. pratense; similar rises up to 15-18 g. per 1. are tolerated by Poa sp. and T. repens.-W.J.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Observations of O2(¹Δg) in the atmosphere and allowable values of the eddy diffusion coefficient

1970 ◽  
Vol 75 (31) ◽  
pp. 6398-6401 ◽  
Author(s):  
L. R. Megill ◽  
J. C. Haslett ◽  
H. I. Schiff ◽  
G. W. Adams
Keyword(s):  
Diffusion Coefficient ◽  
Eddy Diffusion ◽  
Eddy Diffusion Coefficient

scholarly journals KEMISKINAN DI WILAYAH PEDESAAN NTB : STUDI KASUS WANITA PEMBUAT GARAM DI DUSUN MEDANG

Agro Ekonomi ◽  
2016 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
Maryadi Maryadi
Keyword(s):  
Sea Water ◽  
Salt Water ◽  
Poverty Line ◽  
Small Scale ◽  
Salty Water ◽  
Processing Material ◽  
Home Industries ◽  
Rural Industries ◽  
Small Scale Industries

Role of women in development has been well-known. Women roles in rural area can be identified from their involvement in rural industries either agricultural home industries or other small-scale industries processing material taken from natural resources. One of such natural resource materials is sea water to be further processed as salts. Most of women in Medang Hamlet, Village of Sekotong Barat, Nusa Tenggara Barat Province work as salt makers. Instead of drying salty water by using sunshine, the salt farmers in Medang Hamlet use wood in heating the salt water. The study finds that the income earned from this activity is considerably low. Since there is no other source of income alternative for the women in this hamlet, making salt becomes the only job that can be done. The consequence is that the villagers in this area are still live under poverty line.

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