• Journal of Korean Society of Water and Wastewater
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• v.31 no.3
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• pp.249-256
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• 2017

Recently, application areas based on M2M (Machine-to-Machine communications) and IoT (Internet of Things) technologies are expanding rapidly. Accordingly, water flow and water quality management improvements are being pursued by applying this technology to water and sewage facilities. Especially, water management will collect and store accurate data based on various ICT technologies, and then will expand its service range to remote meter-reading service using smart metering system. For this, the error in flow rate data transmitting should be minimized to obtain credibility on related additional service system such as real time water flow rate analysis and billing. In this study, we have identified the structural problems in transmitting process and protocol to minimize errors in flow rate data transmission and its handling process which is essential to water supply pipeline management. The result confirmed that data acquisition via communication system is better than via analogue current values and pulse, and for communication method case, applying the industrial standard protocol is better for minimizing errors during data acquisition versus applying user assigned method.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.6
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• pp.705-709
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• 2005

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.13-16
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• 2017

Water issue, especially water pollution, is a serious issue of 21st century. Being an significant technique for securing water resources, superconducting magnetic separation wastewater system was indispensable. A large bore conduction-cooled magnet was custom-tailored for wastewater treatment. The superconducting magnet has been designed, fabricated and tested. The superconducting magnet was composed of NbTi solenoid coils with an effective horizontal warm bore of 400 mm and a maximum central field of 2.56T. The superconducting magnet system was cooled by a two-stage 1.5W 4K GM cryocooler. The NbTi solenoid coils were wound around an aluminum former that is thermally connected to the second stage cold head of the cryocooler through a conductive copper link. The temperature distribution along the conductive link was measured during the cool-down process as well as at steady state. The magnet was cooled down to 4.8K in approximately 65 hours. The test of the magnetic field and quench analysis has been performed to verify the safe operation for the magnet system. Experimental results show that the superconducting magnet reached the designed magnetic performance.

• Food Science of Animal Resources
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• v.34 no.6
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• pp.777-783
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• 2014

This study investigated the effect of various freezing and thawing techniques on the quality of beef. Meat samples were frozen using natural convection freezing (NF), individual quick freezing (IQF), or cryogenic freezing (CF) techniques, followed by natural convection thawing (NCT) or running water thawing (RT). The meat was frozen until the core temperature reached $-12^{\circ}C$ and then stored at $-24^{\circ}C$, followed by thawing until the temperature reached $5^{\circ}C$. Quality parameters, such as the pH, water binding properties, CIE color, shear force, and microstructure of the beef were elucidated. Although the freezing and thawing combinations did not cause remarkable changes in the quality parameters, rapid freezing, in the order of CF, IQF, and NF, was found to minimize the quality deterioration. In the case of thawing methods, NCT was better than RT and the meat quality was influence on the thawing temperature rather than the thawing rate. Although the microstructure of the frozen beef exhibited an excessive loss of integrity after the freezing and thawing, it did not cause any remarkable change in the beef quality. Taken together, these results demonstrate that CF and NCT form the best combination for beef processing; however, IQF and NCT may have practical applications in the frozen food industry.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1267-1268
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• 2005

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.11 s.242
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• pp.1229-1238
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• 2005

The objective of the present study was to investigate the efficacy of physical water treatment (PWT) technologies using different catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling in a once-through flow system with mini-channel heat exchanger. Effects of flow velocity and water hardness on the effectiveness of PWT technologies were experimentally studied. The artificial water hardness varied from 5.0 to 10 mo1/m$^{3}$ as CaCO$_{3}$. For 10 mo1/m$^{3}$ solution, fouling resistance reduced by 13-40$\%$ depending on flow velocity and types of PWT devices. On the other hand, fouling resistance reduced by 21-29$\%$ depending on the PWT devices for 5 mo11m3 solutions. The PWT device using alloy of Cu and Zn as catalyst (CM2) was slightly more effective than the others. SEM photographs of scale produced from the 10 mol/m$^{3}$ solution at 1.0 m/s indicated that calcium carbonate scales without PWT devices were needle-shaped aragonite, which is sticky, dense and difficult to remove. Scales with the PWT devices showed a cluster of spherical or elliptic shape crystals. Both the heat transfer test results and SEM photographs strongly support the efficacy of PWT technologies using catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.683-687
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• 2008

When suspended solids are removed by natural sedimentation, it is necessary to use mainly huge equipments and waste great cost. This is a problem that must be solved certainly as soon as possible. In this study, suspended solids of yellow soil water were rapidly removed by controlling pH and amounts of magnetic powder, organic and inorganic flocculants. In the case of the suspended solids of 0.3% yellow soil water, the most excellent turbidity was achieved at pH between 7 and 7.5.

• Membrane and Water Treatment
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• v.6 no.2
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• pp.103-112
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• 2015

In India, recycling of treated effluent plays a major role in the industry. Particularly in copper industry, recycling techniques for treated effluents adopt conventional technologies which are not energy efficient and recovery of high quality process water, free flowing salts and sludge's is very low. This paper presents an overview of enhanced modern technology for treated effluents in copper industry making it more efficient with high recovery of high quality process water and free flowing salts. Life cycle cost (LCC) would be 15-20% lower than the conventional technologies. The conventional technology can be replaced with this proposed technique in the existing and upcoming copper industries.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.797-803
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• 2013

Recently, a number of countries are now considering the reuse of effluents from wastewater treatment for various water applications. To improve the reuse of wastewater effluent, the development of appropriate micro-pollutant removal technology is necessary. Although several researche have been studied for removing micro-pollutants in water, little study has been conducted for the removal of emerging contaminant such as antibiotic resistant genes (ARGs) by disinfection processes. Therefore, the aim of this study is to compare the capacity of disinfection technologies such as chlorination, ozone, and electron beam, for removing antibiotic resistant bacteria (ARB) and ARGs. Based on this study, better ARG removal can be achieved by ozonation and electron beam. Relatively, high CT values of chlorination or ozonation are needed to remove ARB and ARG compared to conventional pathogens.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.15-16
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• 2015

In this research, the application of repair methods of water leakage cracks using self-healing technologies for subway tunnels is presented. In order to apply crack self-healing water stop agents and quick setting agents in subway tunnels, laboratory and field tests were performed based on various previous researches. Especially, this study focused on development of crack repair materials and their new repair methods. Therefore, various repair materials were examined for new repair materials with self-healing capability applied to crack sealing method and to patching repair method.