• Explosives and Blasting
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• v.23 no.1
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• pp.9-17
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• 2005

This study is to clarify the comparative relationship and mechanical anisotropy of granite distributed in the Nam-weon on the subject of weathered rock mass sea water surroundings. Artificial weathering test is defined as a test, which controls the weathering rate and agents by controlling the weathering rate and agents by artificial environmental of salt water. Increased weathering degree is large indicated by weathering salt water, such as apparent specific gravity, absorption, porosity, uniaxial compression strength, P-wave velocity, slake durability, shore hardness, indirect tensile strength(brazilian test) and cohesion were measured. As the Weathering salt water proceeds, cracks develope increasingly. A number the cracks affect the rock deformation. Therefore, stress-strain curve of weathered salt water rock in one confined state are quite differ from weathered fresh water rock those. A reason of their deformation type is the formation of micro-cracks and potential porosity caused by artificial weathering test.

• Journal of the Korean Chemical Society
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• v.46 no.1
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• pp.7-13
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• 2002

Although it has been known that the magnetized water shows different physicochemical properties, the exact nature of the magnetized water is not clearly elucidated yet. We have explored the effect of magnetized water in the precipitation of salts, i.e., $BaSO_4,\;BaCO_3,\;CaCO_3$, and in the hydration hardening of gypsum plaster. The amount of salt precipitation was measured by salt filter assay in water bath, $25^{\circ}C$ and also the hydration hardening speed of gypsum plaster was measured by the Gillmore needle method at room temperature. When the salt ions were interacted with each other in 0.1 M concentration, the precipitation reactions of $BaSO_4,\;BaCO_3$, and $CaCO_3$ increased more in the magnetized water, about 3.6%, 3.8%, and 4.4%, respectively, than in the control water. And the hydration hardening speed of gypsum plaster increased more in the magnetized water than in the control water. These data suggest that the magnetized water, which is supposed to be organized by forming numerous nano/micro clusters, induces the increase of salt precipitation and also accelerates the hydration hardening speed of gypsum plaster.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.1-6
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• 2020

To make an automated system for a salt field, it is necessary to measure the salinity and water level of the evaporation site. In this paper, a method to simultaneously measure the salinity and water level by measuring the buoyancy forces of two fixed buoyancy bodies is proposed. The proposed measurement method measures the buoyancy of the main part and reference part when the measuring device is immersed in the salty water, and simultaneously measures the salinity and water level through the sum and difference of the two buoyancy forces. Since there is no mechanical movement in the measurement of buoyancy, measurement errors and maintenance needs can be reduced in the mudy environment of salt field. By applying the proposed method, we developed a system that can simultaneously measure salinity and water level remotely at the evaporation site of a salt field. Through a measurement experiment using a reference salty water having various levels of salinity, the results of a salinity error of 0% and a water level error of 2mm were obtained, and the effectiveness of the proposed salinity and water level measuring device was verified. When an automated system is constructed using the developed salinity and water level measuring device, labor reduction, work environment improvement, and productivity improvement are expected.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.208-212
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• 1975

The study was conducted to determine the optimum conditions for keeping quality of shucked sea mussel, Mytilus edulis, during marketing under commercial handling. As quality factors, water holding capacity, pH, VBN and TMA content were measured. Water holding capacity was obviously affected by salt content of the sea mussel meat. Water was released at the salinity above $2.8\%$ and absorbed below the value. In case of distilled water added instead salt solution, $23.3\%$ weight was gained. Absorbing or releasing water of sea mussel meat was also influenced by temperature showing either water gain or loss was greater at, $3^{\circ}C\;than\;25^{\circ}C$. Osmotic quilibrium by salt between meat and liquor was held within 4 hours. The pH value of fresh sea mussle marked 6.0 which is somewhat lower when compared with that of other shellfishes, and it gradually decreased to 5.0 during storage. VBN contents of fresh muscle and shell liquor were $2.1mg\%$ and $1mg\%$ respectively. The sour odour began to be detectable with $5.0mg\%$ of VBN content. TMA in the sea mussel was not detected.

• Journal of Plant Biology
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• v.34 no.3
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• pp.185-190
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• 1991

Hypocotyl-derived callus cultures of Brassica pekinensis cv. Chungseng were grown on Murashige-Skoog medium containing NaCl, Na2SO4 and mannitol to clarify the effect of salts on callus growth, proline accumulation and water relations. Na2SO4 was more inhibitory than NaCl when survival rate, growth and fresh:dry weight ratios of established callus were measured. Fresh weight in 0.25% NaCl treatment was more than twice as increasable in comparison to the same concentration of Na2SO4 or control. Proline concentration was increased on either salt, attained at highest levels at the 5th subculture, and fluctuated as affected by both salts or mannitol. Concentrations of redeucing sugars were sharply increased after 2 or 3 times of subculture and decreased by increasing subculture. The water and osmotic potential in callus reached a maximum negative value after two weeks in culture, regardless of salt type and mannitol and tugor remained relatively constant on both salt and mannitol treatments.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1334-1338
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• 2005

A limit switch box is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or a throttle in the valve actuator. In a ship, equipments require safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box has been used in an indoor environment generally. This study developed a new limit switch box which can be used at an outdoor environment. This study designed the new limit switch box. The housing of the limit switch box was made by an aluminum die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• Magazine of the Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.16-24
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• 2015

Desalination technology is a process to remove salt from water. There are three classified In accordance with the concentration of salt The concentration of sea water 15,000~50,000mg/l, brackish water 1,500~15,000mg/l, desalination less than 500mg/l.. In general, salt to remove for using a pre-treatment UF filter, but this study is new pre-treatment technology RO Membrane process technology Suspended particulate matter is said most were treated at the pre-treatment equipment, wheat affluent particulate material was removed from the MF filter. Influent SS 16.2mg /l The treatment was effective in treatment 0.05mg /l of 99% is removed. COD is reduced to 60% in the pre-treatment device, after treatment was reduced to 30% RO membrane. Influent COD 10.2mg/l treatment was removed 1.9mg/l. The removal rate is 81.9%. Desalination removes the ionic substances in the RO Membrane. Influent EC $978.8{\mu}s/cm$ and treatment showed a result of $18.7{\mu}s/cm$.

• Membrane and Water Treatment
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• v.10 no.5
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• pp.381-385
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• 2019

Surface modification is very efficient and scalable approach to achieve improved membrane performance. We treated Reverse Osmosis Thin Film Composite (TFC RO) membrane with various concentrations of Polyethylene Glycol (PEG), a hydrophilic polymer after activation with sodium hypochlorite. This treatment resulted in an increment of the water flux by 43% and the salt rejection by 2.36% for the 3000 mg/l PEG-treated membrane. Further, these PEG-treated membranes were exposed to a mixture of 3000 mg/l PEG and 1000 mg/l sodium hypochlorite for 1 hour. Further modification of this membrane by PEG and sodium hypochlorite mixture increased the water permeance up to 133% when compared with the virgin TFC RO membrane. We characterized the treated membranes to understand the changes in wettability by contact angle analysis, changes in surface morphology and roughness by scanning electron microscope (SEM) and atomic force microscope (AFM) analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.842-845
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• 2004

When the concrete structures are in contact with seawater, concentration of chloride for estimating chloride diffusion coefficient can be defined as the chloride concentration of sea water. However, in case the concrete structures, constructed in the seashore, aren't directly in contact with seawater, it is difficult to establish the interface concentration of chloride. In addition, marine concrete structures are greatly affected by salt attack such as rebar corrosion, among the cause of salt attack, airborne sea salt is primary factor. Therefore, in this study, salt attack environment by airborne sea salt was investigated in terms of the distance from seashore at 33 spots, 6 areas in East, West, South coast for 1 year. Results indicated that airborne sea salt is decreased by $y=a{\cdot}x^{-b}$ equation to the distance from seashore.

• Membrane and Water Treatment
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• v.6 no.2
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• pp.113-126
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• 2015

Salinity gradient power (SGP) systems have strong potential to generate sustainable clean electricity for 24 hours. Here, we introduce a solid-salt pressure-retarded osmosis (PRO) system using crystal salt powders rather than seawater. Solid salts have advantages such as a small storage volume, controllable solubility, high Gibbs dissolution energy, and a single type of water intake, low pretreatment costs. The power densities with 3 M draw solutions were $11W/m^2$ with exothermic energy and $8.9W/m^2$ without at 35 bar using a HTI FO membrane (water permeability $A=0.375L\;m^{-2}h^{-1}bar^{-1}$). These empirical power densities are ~13% of the theoretical value.