• Journal of Korean Society of Water and Wastewater
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• v.13 no.3
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• pp.36-41
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• 1999

High quality drinking water can be produced by membrane separation process. A major problem in the current system is a membrane fouling control. In order to investigate membrane fouling due to E.coll removal, lab scale experiment using MF and UF and semi pilot plant experiment using UV radiation or not was performed. AS a result, the possibility of membrane fouling control by repressing of micro-organism on the membrane surface was clearly verified. But it was not clearly verified in this experiment the combined effect with other factors such as Turbidity, organic and inorganic matters.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.53.4-53
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• 2001

This paper described about the system which can be inspect work roll surface for deciding a milling schedule and roll changing at hot strip mill in POSCO. Developed system consists of CCD camera, Xenon lamp with fiber bundle and mechanical control part. The water probe build up water pole between head of probe and roll surface to acquisite a good image from a work roll surface under the bad environment with steam, cooling water and high temperature. This system is possible to monitor a work roll surface of about 12${\times}$9mm. We have shown the validation of the developed system which can monitor the evolution of degradation on work roll surface.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.125-130
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• 1999

Corrosion of steam generator tubes is the major issue affecting selection of secondary water chemistry parameters. The objective of secondary side water chemistry control is to minimize corrosion damage and to thereby maximize the reliability and economic performance of the secondary system. To achieve this objective, the water chemistry has to be compatible with all parts of the system including steam generators.(Omitted)

• The Plant Pathology Journal
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• v.16 no.4
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• pp.206-210
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• 2000

The effect of the electrolyzed oxidizing water on Sphaerotheca fuliginea was investigated with germination and sporulation of the fungal conidia. The sporulation was inhibited by the electrolyzed oxidizing water of pH 2.5, 3.5, and 4.5, but was not inhibited by the distilled water adjusted pH with 1N-HCL solution. However, the electrolyzed oxidizing water did not affect conidial germination. The oxidation-reduction potential at pH 2.5 and pH 3.5 of electrolyzed oxidizing water were 1130 mV and 1060 mV, respectively, but those of distilled water adjusted with HCL solution were 550 mV and 490 mV, respectively. When the electrolyzed oxidizing water of ORP over 1100 mV was sprayed on cucumplanting, the disease severities of powdery mildew were about 8.5% and 19.2%, respectively. Disease severity of a standard control (triflumizole 30% WP, $500\textrm{mg}\textrm{/L}$) was about 3.0%, while that of plants without electrolyzed oxidizing water was to 45.8%.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.441-444
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• 2006

A lot of water is using in the paper mill for dilution, washing, sealing, and other process operation. As the regulation of water environment has been more tightened than ever before, water management in the paper mill becomes the most important task. Topics on reducing fresh water and increasing recycling water have been studied. Further, an interest in zero-effluent system has been increased. The pH of waste water in paper mill is usually weak acidic or neutral. The waste water in the paper mill includes water insoluble organic materials that are not easy to be dissolved in the water, inorganic materials that never react with water and chemical additives that are used to recycled fiber. This study investigated on the effect of various materials used in paper mill on COD. This data could be used to control the environmental load in paper mill. COD caused by raw materials and NBDCOD (Non Bio Degradable COD) after the activated sludge process are investigated in this study. Results obtained in this study can be used in a simulation program designed to control environmental load in the paper mill.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.197-205
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• 2024

This paper presents a fully automated stand-alone irrigation system with GSM (Global System for Mobile Communication) module. Solar energy is utilized to power the system and it is aimed to conserve water by reducing water losses. The system is based on a DC water pump that draws energy from solar panels along with automated water flow control using a moisture sensor. It is also fitted with alert and protection system that consists of an ultrasonic sensor and GSM messages sender that transmits signals showing the levels of the water in the reservoir and the battery charge. The control system is designed to stop the water pump from pumping water either when the battery level drops to equal or less than 10% of its full charge, or when the water level becomes less than 10 cm high in the reservoir. The experimental results revealed that the system is appropriate to use in remote areas with water scarcity and away from the national grid.

• Journal of Aquaculture
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• v.15 no.1
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.1
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• pp.56-63
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• 2003

The dough fermentation and the quality of bread prepared with different kinds of water such as distilled water, tap water and diluted hot spring water(SW) from Gyungsan Sipan hot spring were investigated. Content of total soluble solid in the hot spring water was 8,765 ppm and contents of Na, Ca, Mg and K as major elements was 2,296, 287, 65 and 8 ppm, respectively. Content of Fe, Cu, Co, F, Zn, Al, S, Mo, Se and Si as minor elements was in the range of 0.002~5.2 ppm. The pH(6.95~7.68) of the dough prepared with diluted hot spring water(I, 55 times; II, 4 times; III, 2 times) was higher than that of distilled water. The dough volume after the 1st fermentation was expecially lower in the III, but the volume of the dough prepared with III adjusted pH to 5.5 was higher than that of the control. The hardness and the strength were higher than those of the control, but the scores were love. than those of the control in case of pH adjustment(pH 5.5). The cohesiveness was also lower than that of the control in the bread with diluted hot spring water. Softness and stickiness of the bread(III) were hisher than those of the control. But overall acceptability was the highest in the II.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.17-22
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• 2013

In this study, a pH control method by carbon dioxide ($CO_2$) was applied to coagulation process in water treatment plant (WTP) to investigate the coagulation efficiency and residual dissolved aluminum when high pH raw water is flowing into the plant during algal blooming. Existing coagulant dose (1 mg/L in raw water) resulted in the pH reduction of 0.0384 by LAS, 0.0254 by PAC, 0.0201 by A-PAC, and 0.0135 by PACS2, respectively. And then the concentration of dissolved aluminum was 0.02 mg/L at pH 7.44, 0.07 mg/L at pH 7.96, 0.12 mg/L at pH 8.16, 0.39 mg/L at pH 8.38 showing the concentration increase with pH in the coagulation process. It was noteworthy that rapid increase was observed at pH above 8.0 next the rapid mixing. Therefore it is necessarily required to control pH below 7.8 in the coagulation process in order to meet drinking water quality standard of aluminum for high pH raw water into WTP, $CO_2$ injection could control pH successfully at about 7.3 even for the raw water of high pH above 8.0. In addition it was found that the pH control by $CO_2$ injection was significantly effective for coagulation in terms of turbidity removal, coagulant dosage, and residual dissolved aluminum concentration.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.