• Progress in Superconductivity and Cryogenics
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• v.11 no.4
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• pp.8-11
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• 2009

This study introduced wastewater treatment method by High Gradient Magnetic Separation (HGMS). HGMS treatment was high efficient method for various industrial wastewaters. The system is currently research state, but we have surveyed commercialize the technology for industry. In rolling plate process, coolant wastewater was recycled by sedimentation and sand filter system. It needs several large reservoirs and long time to remove suspended solid (SS) like metal fines and iron oxide in hot rolling plate making process. If removing rate of suspended solid in rolling coolant wastewater is improved by using HGMS system, the productivity of working process can be increased and the area of reservoir can be reduced. We manufactured high temperature superconducting HGMS system that had a purpose to treatment of coolant wastewater in rolling plate process. We fabricated the prototypes of magnetic matrix filter consisting of stainless steel 430 mesh, which is a core component in the magnetic separation system, In our basic preliminary experiment using HGMS system, it has been clear that the fine paramagnetic particles in the coolant wastewater obtained from rolling plate process of POSCO can be separated with high efficiency.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.745-750
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• 2000

Steel plate bonding technique is most widely used in strengthening of existing concrete structures, but it has inherently a problem of the premature failure such as interface separation and rip off. So far, many studies have been arid out in the manner of laboratory tests for the reinforced concrete beams to find out he mechanism of the premature failure. However, in order to verify the characteristics of the premature failure, more reasonable local investigations are needed rather than such relatively global experimental works. In this study, therefore, the double lap test which simulate the pure shear loadings and the half beam tests which consider combined flexure-shear force have been done. There are, however, difficulties in getting the normal stress caused to premature failure, so that finite element analysis was performed, too. In numerical study, material nonlinearity was considered, and the interface element was applied to model the interface between steel plate and adhesive. From the results of experimental and numerical studies, a realistic failure criterion on the separation of steel plates has been derived.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.4
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• pp.359-369
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• 2006

This study aims deriving analysis the flow characteristic of kitchen hood system with using 3-D numerical analysis method and improving the system to expel pollutes more efficiently. This system is applied with $k-{\varepsilon}$ turbulent model and using incompressibility viscosity flow range and boundary condition which are related to Bossinesq approximation following density variation in control volume. To understand the flow characteristics of four models, this study only focuses on velocity field, temperature field, and concentration field varying with followings whether separation plate is set or not and the shapes of separation plates. The quantity of air, speed of exhaust fan and temperature and concentration of heating source are concerned as constant values.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.374-379
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• 1994

This paper deals with the problem of plate separation and anchorage at the ends of steel plates strengthened by EBSP. Test results show that the reinforced concrete beams strengthened by EBSP occurs the premature failure without the beams achieving their full flexural strength at the end of plates. The premature failure is the cause of stress concentrations in the adhesive layer of plate, reinforced concrete incase of lack of plate length. Then a simple, approximate procedure for predicting the shear and normal stress concentrations is investigated by Robert's the ory based on partial interaction theory. The theoretical results are compared, and show close agreement with test results. A method is derived for determining the plate length that prevents the premature anchorage zone failure

• Journal of the Optical Society of Korea
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• v.13 no.4
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• pp.423-427
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• 2009

The results of the experimental and theoretical studies conducted on terahertz filtering using two parallel-plate waveguides (PPWGs) are presented herein. The first PPWG with 355 ${\mu}m$ plate separation generates 4 THz bandwidth TM modes ($TM_0,\;TM_2,\;and\;TM_4$), whereas the second PPWG with 100 ${\mu}m$ plate separation operated the THz filter for the generated TM modes with 1.5 THz cutoff frequency. The outgoing THz wave of the two PPWGs was truncated until 1.5 THz, and the system was operated using a high-pass THz filter. The absorption and dispersion of the combined TM and TE modes for the filtering system were calculated. The theoretical calculation and measurement results for the cutoff and oscillation frequency in the spectrum domain agreed well.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.99-103
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• 2019

Recently, as the high-precision machinery industry has developed rapidly, peripheral equipment has been developed to improve machining efficiency. Peripheral equipment for machining includes cooling units, housings, oil separators, and much more. Oil, such as cleaning and cutting fluids, is used for machining. When waste oil is reused, the contamination of the workpieces and reduction in machining accuracy are generated by the waste oil, including sludge. Therefore, the development of an oil separator is necessary for efficiently separating oil, water, and sludge. The purpose of this study is to analyze the oil separation efficiency and flow characteristics of a high-speed centrifugal separator according to the rotation velocity and diffusion plate. The oil separation efficiency and flow characteristics were analyzed using hydrodynamic theory and computational fluid dynamics (CFD). The results of this study will be used as basic data for the development of a high-speed centrifugal separator.

• KCI Concrete Journal
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• v.14 no.1
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• pp.51-60
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• 2002

Strengthening of existing concrete structures is a major concern in recent years as the number of degraded structures increases. The purpose of this paper is to investigate the static and fatigue behavior of reinforced concrete (RC) beams strengthened with steel plates. To this end, a comprehensive test program has been set up and many series of strengthened beams have been tested. The major test variables include the plate thickness, adhesive thickness, and the shear-span to depth ratio. The test results indicate that the separation of plates is the dominant failure mechanism even for the full-span-length strengthened beams with steel plate. The theoretical ultimate load capacities for strengthened beams based on the full composite action of concrete beam and steel plate are found to be larger than the actual measured load capacities. The strengthened beams exhibit more dominant shear cracking as the shear-span to depth ratio decreases. The ultimate capacity of strengthened beams increases slightly with the increase of adhesive thickness, which may be caused by the late initiation of plate separation in the beams with thicker adhesive. A realistic concept of ductility for plate-strengthened beams is proposed in this study. It is seen that the strengthened beams show relatively low ductility compared with unstrengthened beams. The present study indicates that the strengthened beams exhibit much higher fatigue resistance than the unstrengthened beams. The increase of deflections of strengthened beams according to the number of load cycles is much smaller than that of unstrengthened beams. The present study provides very useful results for the realistic application of plate-strengthening method in reinforced concrete structures.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.5-13
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• 2017

Polypropylene is the main existing material in the domestic market being used for the filter plate because of its moldability, low cost, and commercial availability. Polypropylene filter plate once distorted due to the high-pressure during operation may cause the problem in the continuous operation of the solid-liquid separation module. Thermoplastic Poly Urethane (TPU) can be a high-performance alternative material for the filter plate in the solid-liquid separation module of the dehydration process. Hence, to predict and evaluate the TPU for structural stability in the filter plate through analytical techniques designed and experimental verification is essential. As a result, TPU filter plate had maximum strain of 27.85 MPa at 20 bar pressure condition. This result is less than TPU stress-strain limit, which ensures the structural stability of the TPU material.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.31-37
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• 2015

Recently, mobile phones have become necessary tools for everyday life. In this study, a device that can serve as a separation between a touch panel and an LCD module in a mobile phone was devised for mass repair processes at a smaill business. We used a wire cutting method to separate the bonding plate area between the modules. The device is composed of DC motors and stepping motors that can deliver a precise cutting motion. The motor control system is connected by individual control modules to a CAN network. The developed device showed excellent performance at high temperature conditions.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.5-9
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• 1975

For analysis of Xanthene dyes according to the developing solvent and adsorbent was applied to Thin-layer chromatography with silicagel and cellulose plate. Silicagel chromato-plate used were prepared under different condition of activation. Using eight developing solvent, the influence of the condition for activation upon the separation of Xanthene dyes was investigated. The results are shown in Table 3. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) mixture and n-butanol+Ammonia water (4:1) mixture gave clear separation for Xanthene dyes, including Fluorescein, Erythrosine Rhodamin B, Eosine, Rose bengale, phloxine and Acid red those Rf values decrease in the described ordor. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) was applied to two adsorbents which were purchased from different manufactures. The results of Chromatograms are obtained Figure 6.