scholarly journals The Possibility of Water Surface Greening by the Floating Plant Box System at the Sea Mingled with Fresh Water Region where Salt Concentration is High

2006 ◽  
Vol 69 (5) ◽  
pp. 461-464
Author(s):  
Hiroyuki YAMADA ◽  
Akie NONAKA ◽  
Atsushi NAKASHIMA ◽  
Shirou NAKAO ◽  
Shinobu YABU
Keyword(s):  
Fresh Water ◽  
Salt Concentration ◽  
Water Surface ◽  
Water Region ◽  
Floating Plant

scholarly journals Eco Friendly Dye Extraction From Cyanophyta for Textiles

2021 ◽  
Vol 10 (4) ◽  
pp. 72-74
Author(s):  
E. Ramkumar ◽  
V.S. Bala Murali ◽  
T. Guna ◽  
S.M. Dharshan ◽  
S. Ajay Vishnu
Keyword(s):  
Fresh Water ◽  
Water Body ◽  
Water Surface ◽  
Water Bodies ◽  
Raw Material ◽  
The Sun ◽  
Major Threat ◽  
Dye Extraction ◽  
Dry Out ◽  
Sun Light

In countries like India there is always a scarcity for fresh water along with it polluting the available fresh water sources is a major threat. The major fresh water bodies are affected by eutrophication. It is the phenomenon in which algae forms a layer above the water surface and does not allow the sun light to enter into the water body. Due to this reason organisms which is present in the water body gets affected and the ecosystem gets damaged. The algae which are taken from the water bodies is dropped as waste in garbage or let to dry out on roads. “One man’s waste is other man’s treasure” so instead of wasting the collected algae, the algae can be used to prepare a dye which can be used to dye clothes for different uses. The collected algae are used as a raw material in an algal dying machine where the processes carried out are cleaning, drying the algae, grind it, boil them with water and other essentials, filter the residue and finally filtrate will be used to print on cloth.

New upgrades of Open-Loop Tracking Command (OLTC) tables of nadir altimeters in 2020 and benefits for inland waters users

2021 ◽  
Author(s):  
Simon Boitard ◽  
Sophie Le Gac ◽  
Denis Blumstein ◽  
Eric Munesa ◽  
François Boy ◽  
...  
Keyword(s):  
Fresh Water ◽  
Water Surface ◽  
Open Loop ◽  
Inland Waters ◽  
Signal Acquisition ◽  
Great Effort ◽  
Close Monitoring ◽  
Alos Palsar ◽  
Major Step ◽  
Tracking Mode

<p>Fresh water is an essential resource that requires a close monitoring and a constant preservation effort. The evolution of hydrological bodies water level constitutes a key indicator on the available quantity of fresh water in a given region. The limited extent of the in situ networks currently deployed has generated a growing interest in using space borne altimetry as a complementary data source to increase the coverage of emerged fresh water stocks and ensure a more global and continuous monitoring of their water surface height.</p><p>A great effort has been carried out over the past decade to improve altimeters’ capability to acquire quality measurements over inland waters. In particular, the Open-Loop Tracking Command (OLTC), which consists in calibrating the altimeter signal acquisition window with a prior information on the overflown hydrological surface height, represents a major evolution of the tracking function. This tracking mode’s efficiency is such that it is now stated as operational mode for current Sentinel-3 and Jason-3 missions as well as the recently launched Sentinel-6A mission. The improvements brought to onboard tables contents in 2017 (Jason-3), 2018 (Sentinel-3B) and 2019 (Sentinel-3A) enhanced and confirmed the OLTC performances.</p><p>In 2020, the onboard OLTC tables of the Jason-3, Sentinel-3A and Sentinel-3B missions have benefitted from further new major upgrades. The first version of the Sentinel-6A onboard OLTC tables holds the same content as Jason-3. The tracking command defined over Jason-3 and Sentinel-6A repeat cycle now accounts for more than 30,000 hydrological targets which represents five times more targets than in the previous version. For each Sentinel-3, the number of water body surface heights coded into the OLTC has been increased by a factor of 3 to 70,000. This further major step is made possible by the analysis and merging of the most recent digital elevation models (SRTM, MERIT and ALOS/PalSAR) and water bodies databases (HydroLakes, GRaND v1.3, SWBD, GSW). This methodology ensures coherency and consistent standards between all nadir altimetry missions and types of hydrological targets.</p><p>A detailed description of the 2020 upgrades will be given as well as measurements validation results obtained since their upload. An overview of the global validation of Sentinel-6A measurements over hydrological targets will also be presented.</p><p>These 2020 OLTC upgrades constitute a great asset for building a valuable and continuous record of the water surface height of worldwide lakes, rivers, reservoirs and wetlands. In addition, for a continuous improvement of the OLTC tracking mode, the users can check the content of the onboard OLTC tables over hydrological targets for both Sentinel-3 missions on the https://www.altimetry-hydro.eu/ web portal. When relevant, they can correct existing water surface heights or submit new targets.</p>

The Adaptation of Gunda Ulvae to Salinity

1931 ◽  
Vol 8 (1) ◽  
pp. 82-94
Author(s):  
C. F. A. PANTIN
Keyword(s):  
Osmotic Pressure ◽  
Electric Conductivity ◽  
Fresh Water ◽  
Salt Concentration ◽  
Sea Water ◽  
Distilled Water ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
The Moment ◽  
Limiting Value

1. The rate of loss of salts by the estuarine worm, Gunda ulvae, on transference from sea water to various dilute solutions has been studied by measurement of the electric conductivity of the solutions. 2. Salts are lost by the worms from the moment of immersion in dilute solutions. Conditions affecting the rate of loss of salts are discussed. 3. The relation between the amount of salts lost and the total electrolyte content of the worm was determined. It is shown that the worms only lose 25 per cent. of their salts during the time that they imbibe a volume of water from the dilute solution equal to their initial volume. 4. The limiting internal salt concentration of worms surviving in waters containing calcium is about 6-10 per cent. of the normal concentration in sea water. No such limiting value can be found for distilled water, since salts are lost continuously till cytolysis occurs. The significance of the limiting concentration is discussed. 5. The effect of osmotic pressure, pH, dilute solutions of NaCl, NaHCO3, glycerol, CaCl2 and CaCO3 are studied. The presence of calcium reduces the rate of loss of salts. Other factors do not seem to influence this rate. 6. The relation of calcium to the maintenance of normal permeability to water and salts in the worm, and the significance of this to the problem of migration into fresh water are discussed.

scholarly journals Scattered Light in a Flood-plain Lake of Central Amazônia()

1972 ◽  
Vol 2 (2) ◽  
pp. 87-90
Author(s):  
W. L. B. Brinkmann
Keyword(s):  
Surface Layer ◽  
Light Intensity ◽  
Plant Communities ◽  
Water Surface ◽  
Scattered Light ◽  
Flood Plain ◽  
Near Surface ◽  
Central Amazonia ◽  
Total Light ◽  
Floating Plant

Abstract The light intensity below the surface of Lago Castanho was recorded at 10 minute intervals and compared to the total light intensity above the water surface. Scattered light of the lake water was rather constant and it was found to be sufficiently high to support the growth of photoautotrophic organisms in the near-surface layer. Below the floating plant communities scattered light was extremely low in intensity.

scholarly journals Temperature Gradient Daily Dynamics Area and Time Zoning for Local Analysis of Air-Water Interaction

2021 ◽  
Author(s):  
Christophil S. Medellu ◽  
Alfrits Komansilan
Keyword(s):  
Temperature Gradient ◽  
Fresh Water ◽  
Coastal Waters ◽  
Water Surface ◽  
Repeated Measurements ◽  
Local Analysis ◽  
Thermal Interaction ◽  
Water Interaction ◽  
Water Measurement

Abstract This article describes the results of the application of time zoning for air-water thermal interaction, and the temperature gradient daily dynamics area (TGDDA) parameters at six locations with different ecological conditions. The research locations consisted of two locations in lakes, two locations in coastal waters which were affected by fresh water and two locations in coastal waters which were not affected by fresh water. Measurement of air and water temperature was carried out in situ at several vertical positions with logarithmic distances to the water surface. The results of the analysis show that the analysis and modeling of the TGDDA parameters produce the time zoning of thermal interaction and TGDDA that vary between research locations. Repeated measurements on two consecutive days at the same location, resulted in almost the same TGDDA and time zoning duration of air-water thermal interaction. These results suggest that these parameters can be used to characterize air-water interactions. The results of this study serve as references to the chemical analysis of water and biota which is interactive or influenced by the dynamics of air-water thermal interactions.

scholarly journals Bionomics data for Anopheles (Anopheles) forattinii Wilkerson & Sallum, 1999

2001 ◽  
Vol 31 (4) ◽  
pp. 699-699 ◽  
Author(s):  
Rosa Sá Gomes HUTCHINGS ◽  
Maria Anice Mureb SALLUM
Keyword(s):  
Fresh Water ◽  
Distribution Range ◽  
Passive Dispersal ◽  
Plant Debris ◽  
Igapó Forest ◽  
Floating Plant

Immature and adult stages of Anopheles (Anopheles) forattinii were collected in the Parque Nacional do Jaú, Novo Airão, Amazonas, Brazil. Larvae and pupae were taken from fresh water among floating plant debris inside flooded "igapó" forest. This species may make use of plant debris for passive dispersal throughout its distribution range.

Water Sensitivity of Sandstones

1983 ◽  
Vol 23 (01) ◽  
pp. 55-64 ◽  
Author(s):  
Kartic C. Khilar ◽  
H. Scott Fogler
Keyword(s):  
Mathematical Model ◽  
Fresh Water ◽  
Flow Rate ◽  
Salt Concentration ◽  
Particle Migration ◽  
Clay Particle ◽  
Permeability Reduction ◽  
Clay Particles ◽  
Water Sensitivity ◽  
Shock Experiment

Abstract Experimental and theoretical studies have been carried out to elucidate the mechanism of water sensitivity of Berea sandstone and to quantify a number of important parameters. Based on the results of a number of novel experiments, a physical model has been developed. In this model, clay particles are released only when the salt concentration falls below a critical salt concentration. These colloidal clay particles remain dispersed in fresh water and are carried with the flowing fluid until they are captured at a local pore constriction, thereby decreasing the permeability. A mathematical model based on this mechanism has been developed. This model contains two parameters stemming from the rate equations of the release and capture of clay particles. Correlations of these parameters with flow rate and temperature are presented. Introduction The water sensitivity of sandstone is a colloidal phenomenon whereby the permeability of the sandstone is decreased rapidly and significantly after the sandstone is contacted with fresh water. This phenomenon is demonstrated by a standard water shock experiment in which the flow through a sandstone core is changed abruptly from salt water to fresh water. The results of a standard water shock experiment are shown in Fig. 1. The normalized permeability (k/kl) drops from 1.0 to about 0.01 after only 2 or 3 PV of fresh water have been forced through the core. Permeability reduction resulting from water sensitivity is of serious concern to the oil- and gas-producing industries. Water sensitivity, first recognized during waterflooding of petroleum reservoirs, is now a concern in many other field operations that require aqueous solutions, such as drilling, solution mining, and stimulation. Even though water sensitivity in sandstone has been recognized for 35 years, the literature on this subject is limited. The works of Gray,1 Mungan,2,3 Jones,4 and Hewitt5 are among the most widely cited. These papers document the phenomenon and concur that the water sensitivity results from clay swelling, clay particle migration, or a combination of these effects, depending on the composition of the sandstone. Clay particle migration is the most important mechanism of permeability reduction since sandstones containing very little or no swelling clays and a considerable amount of migratory or dispersible clays such as kaolinite and illite are water-sensitive. Gray,1 Mungan,2,3 and Jones4 have reported results relating permeability reduction to clay particle migration. Previous studies investigated the effects of salt solutions, pH, and rate of decrease in salinity on the water sensitivity of sandstone. However, an in-depth analysis of the processes of dispersion and plugging of clay particles and how these processes are affected by flow rate, temperature, and salt concentration has not been reported in the literature. Some effects have been explained inadequately or incorrectly. These are discussed in detail elsewhere.6 In addition, a mathematical model describing quantitatively the permeability reduction with time and other parameters has not been developed. Such a model would aid in understanding the dynamics of this phenomenon as well as in designing preventive measures. The study of water sensitivity is also of general scientific interest since the phenomenon involves a number of colloidal and interfacial phenomena, such as flocculation, peptization, filtration, and adsorption. Practical considerations and scientific interests warrant a comprehensive study of this phenomenon. In this paper, a mathematical model is developed, and comparisons with experimental observations are made. These observations include permeability restoration with saltwater reversal, sequential permeability reduction, effect of flow rate, and core length.

Solar Flash Desalination Under Hydrostatically Sustained Vacuum

2008 ◽  
Author(s):  
Mohammad Abutayeh ◽  
Yogi Goswami
Keyword(s):  
Hydrostatic Pressure ◽  
Fresh Water ◽  
Atmospheric Pressure ◽  
Water Surface ◽  
Saline Water ◽  
Ground Level ◽  
Vacuum Pump ◽  
Low Grade ◽  
Water Tank ◽  
Produce Water

Creating vacuum conditions above liquids increases their evaporation rates. This phenomenon can be integrated into a practical continuous desalination process by repeatedly flashing seawater in vacuumed chambers to produce water vapor that condenses afterwards producing fresh water. Gravity can be used to balance the hydrostatic pressure inside the flash chambers with the outdoor atmospheric pressure to maintain that vacuum, while low grade solar radiation can be used to add heat to seawater before flashing. The proposed desalination system consists of a saline water tank, a concentrated brine tank, and a fresh water tank placed on ground level plus an evaporator and a condenser located several meters above ground. The evaporator-condenser assembly, or flash chamber, is initially filled with saline water that later drops by gravity creating a vacuum above the water surface in the unit without a vacuum pump. The vacuum is maintained by the internal hydrostatic pressure balanced by the atmospheric pressure. The ground tanks are open to the atmosphere, while the flash chamber is insulated and sealed to retain both heat and vacuum.

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