• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.288-290
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• 2005

고분자전해질 연료전지는 자동차, 분산전원 및 이동전원 등에 대한 차세대 에너지원으로 채택 가능성이 높아지고 있다. 고분자전해질 연료전지 시스템의 상용화를 위한 가장 큰 걸림돌 중 한 가지로 가격문제를 들 수 있는데, 연료전지 스택이 전체 가격의 약 $50\%$를 차지하고 있다. 또한 스택을 구성하는 요소 중 분리판의 가격 비중은 약 $30\%$를 차지하고 있어, 분리판의 생산단가 저감은 연료전지의 상용화를 위해 반드시 해결해야 될 문제이다. 본 연구에서는 탄소를 재료로 하는 분리판에 대한 연구를 수행하였으며, 압축성형방식으로 제작된 다양한 복합재료 분리판 및 흑연 분리판에 대한 기계적 강도, 물리적 특성, 화학적 안정성을 조사하였으며, 가흑 운전 시 분리판내에 함유되어있는 고분자 성분의 침출에 의한 연료전지의 성능변화가 발생하는지 확인하였으며 이에 대한 단위전지의 성능평가를 수행하였다. 이러한 결과를 토대로 최적의 압축성형 복합체 분리판 제작 방향을 제시하고, 보다 신뢰성 있는 분리판 성능평가 기준을 확립하고자 하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.3
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• pp.175-182
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• 2009

The spent cationic exchange resins and anionic exchange resins were separated from mixed spent exchange resins by a fluidized bed gravimetric separator. The separated resins were identified by an elemental analysis and thermogravimetric analysis. The each test sample was prepared by diluting the slurry made by wet ball milling the cationic exchange resins and the anionic exchange resins separated as a spherical granular form for 24 hours. The resulting test samples showed a slurry form of less than $75{\mu}m$ of particle size and 25,000ppm of $COD_{cr}$. The decomposition conditions of each test samples from a thermal power plant were obtained with a lab-scale(reactor volume : 220mL) supercritical water oxidation(SCWO) facility. Then pilot plant(reactor volume : 24 L) tests were performed with the test samples from a thermal power plant and a nuclear power plant successively. Based on the optimal decomposition conditions and the operation experiences by lab-scale facility and the pilot plant, a commercial plant(capacity : 150kg/h) can be installed in a nuclear power plant was designed.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.426-431
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• 2010

68% of the manufacturing costs of solar cell wafer can be attributed to the slurry. The recycling of slurries is mandatory for reducing the costs of manufacturing wafering production, and the disposal of industrial waste, as well as for cutting down pollution levels. Slurries are currently being recycled using the centrifuge(decanter) method. However, this method is less than optimal as it does not completely remove the fine particles, leading to low quality. Also, be cause of the incomplete separation from the oil, it causes the impurities in the dried slurries. This study aims to develope a new recycling technology that overcomes the flaws of the centrifuge by utilizing chemicals. It will provide a total solution to the crucial process of recycling slurries in the making of solar cell wafer, by increasing the efficiency and renewable rate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.111-114
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• 2006

Recently, it is increased on the concern for the reuse of waste concrete because of the shortage of natural aggregate and the increase of waste concrete. And recycled coarse aggregate is used variously, but the existing wet method producted recycled fine aggregate has problem like the high price facilities, the long time progress of the work and the poor of recycled fine aggregate. The aim of this study is to investigate outline and performance evaluation of the drying specific gravity separation method to product high duality recycled fine aggregate. Finally, this study is shown investigate process flowing of drying separation type with gravity manufacture, producte system and function of detail devices. The performance of the method of drying specific gravity separation is certificated as the qualities of recycled fine aggregate satisfied the KS

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.411-419
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• 2016

This study tried to find the relationship between household income level and medical expense to household income ratio. For data analysis, it used 2010 and 2011 yearly data beta version of Korea Health Panel, co-managed by Korea Institute for Health and Social Affairs and National Health Insurance Corporation. To find out how the effect of independent variable changes in 2010 and 2011, the interaction effect between year and independent variable was examined, and separating the factors that showed interaction effect into each year, linear regression analysis was conducted using generalized estimating equations method. As a result of reviewing the factors that were related to medical expense to household income ratio among the people who used medical services, it was found that the higher the household income level, the lower the medical expense. It indicates that policy measures are needed to lessen the medical burden of low-income families.

• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.12-16
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• 1974

The amino acid pattern of embryo and endosperm of brown rice different in specific gravity was investigated using Jinheung (local leading temperate variety) and IR667-Suweon 213 (high-yielding newly bred tropical variety). 1. Embryo of IR667 (higher protein rice) showed lower protein, and lower lysine or essential amino acid per protein than that of Jinheung (lower protein rice). 2. In both embryo and endosperm nitrogen recovery as amino acids was highest in middle class of specific gravity and lowest in low class indicating that abundancy of non-protein nitrogen in low class and decomposition of amino acids by starch in high specific gravity class. 3. In both embryo and endosperm IR667 showed abundancy in order of glutamic acid, aspartic acid while Jinheung showed glutamic acid, arginine, suggesting varietal difference in nitrogen metabolism. 4. In both IR667 and Jinheung least amino acid was histidine and next leucine in embryo but histidine and next threonine in endosperm, suggesting organ difference in nitrogen metabolism.

• Resources Recycling
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• v.5 no.2
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• pp.52-56
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• 1996

Fix crushing characteristics of construction concrete wastes wcrc rnvcstigatcd in order to scparate the natural aggregatcs. A roll crushcr and a hammcr crusher wcrc used to granulate pre-crushed concrete\ulcorner below 30 rnm The crushers pruducc finer sizes far ccmcnt concrete than for asphalt concrele, and the hammer crushing resulls in separating the aggregales from thc olhers better than thc roll crushing. The narural aggregatcs of orcr 70-90% by volume were obtained from the concretes by using a riffled shaking table.

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.102-107
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• 2012

Hollow ITO powders were prepared by using polystyrene powders as a template. The specific gravity of the prepared hollow ITO powders was less than half compared with that of normal ITO spheres. As a result, the mismatch between the specific gravity of ITO and that of polymer solution was reduced. When the prepared hollow ITO powders and the polymer solutions are mixed, some portion of the hollow particles were collapsed and generated lots of small fragments. Thousands of the broken fragments from hollow ITO powders caused the increased contact area between particles and finally resulted in the higher electrical conductivity for the coating solution made of the prepared hollow ITO powders and the polymer solution.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.74-81
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• 2013

In this study, the separation efficiency of wind power selector (the direction of the air flow of the air to perform gravity separation method) of municipal solid waste which was landfilled was investigated to reduce amount of waste that is designed to increase the recycling rate of wastes for the ANSYS CFX Program's numerical methods with wind through the separator. When a suction device designed to suction 1000mL of a plastic bag, the separation efficiency was 100% and when the wind speed was 0.9 m /sec or more and when the wind speed was 1.6 m / sec or more, the efficiency of plastic bottles in a mixture of 500mL and 1500mL plastic bottle waste was 100% and the aluminum screening efficiency of 250mL aluminum can was 100 % when the wind speed was 2.3 m / sec. In the last, 5mm thick compressed aluminum can efficiency was 90 % when the wind speed was 2.4 m / sec.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.577-580
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• 2008

This paper was discussed about in-site application of heavyweight(or high density) concrete. Heavyweight concrete was placed with the method of conventional. Placement of conventionally mixed heavyweight concrete is subject to the same considerations of quality control as normal density concrete, except that it is far more susceptible to variations in quality due to improper handling. It is particularly subject to segregation during placement. Segregation of heavyweight concrete results not only in variation of strength but, far more importantly, in variation in density that are intolerable for work this type, since this adversely affects shielding properties. Heavyweight concrete materials and heavyweight concrete should be sampled and tested prior to and during construction to insure conformance with applicable standards and specifications.