• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.53-60
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• 2011

As Construction & Demolition(C&D) debris increase every year, a system has enforced for recycled aggregate made out of C&D debris, then recycled aggregate usage increased in construction field. But as environmental problem by alkalinity of recycled aggregate occurred, the study for lowering alkalinity of recycled aggregate is needed. In this study we made alkalinity reducing facility and installed in the C&D debris midterm-treat field. Then we certified effect of lowering alkalinity and quality of recycled aggregates before and after carbonation. As a result, the most effective carbonation condition is 30seconds in carbonation time, -50~100 kPa of reaction pressure with change of 3cycles. This condition made pH 9.33~9.8 of recycled aggregate possible. The quality of recycled aggregate after carbonation was better than before carbonation in terms of plasticity index, modified CBR, abrasion loss, sand equivalent, liquid limit, size distribution, density and water absorption.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.8-15
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• 2018

Waste concrete accounts for the largest portion of construction waste, and the supply of natural aggregate is unstable. Therefore, importance of using recycled aggregate is emphasized. The purpose of this study is to investigate the mechanical properties of high strength concrete according to the replacement rate of recycled coarse aggregate. For this purpose, the target design compressive strength was set to 40MPa, and the substitution rates of the recycled coarse aggregate were set to 0%, 30%, 60%, and 100%, respectively. Through experiments on the unreinforced concrete and hardened concrete, The validity of the use was confirmed. In addition, LCA method was used to evaluate the environmental impact of recycled aggregates and to compare and analyze the environmental impacts of the aggregates.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.1-12
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• 2005

The primary responsibility of a perfusionist is to operate the heart-lung bypass machine during open heart surgery, which is vital for the successful operative outcome. However, despite the perfusionist's crucial role on the cardiac surgical team, no relevant studies have not yet been conducted in our country. In this regard, this study was performed about the current status of perfusionists in Korea with comparative analysis on the certification and education system of perfusionists in foreign countries. Material and Method: We analyzed the demographic data on the Korean perfusionists conducted in 1994 and 2003, with comparison of recent data on the perfusionists of the nineteen foreign countries. Result and Conclusion: Although all agree that professionalism and responsibility of the perfusionist are essential in conducting a cardiac procedure and bringing about successful outcome, the formally approved training and certification system for perfusionists have not yet been established in Korea. Adequate measures should be done as soon as possible in order to try to obtain the adequate recognition of the profession.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.953-960
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• 2012

An AMTEC (alkali metal thermal electric converter) is a device that is used for the direct conversion of heat to electricity. Sodium is used as the working fluid, and its circulation is driven by a capillary wick. The wicks used for circulation include an evaporator wick, artery wick, and condenser wick, and each wick has a pressure drop because of the circulation of liquid and vapor. For the circulation of sodium, the capillary pressure of the evaporator wick must be greater than the total pressure drop in the wicks. In this study, the pressure drop in the evaporator wick, artery wick, and condenser wick and the heat loss from the evaporator to the condenser through the artery wick were analyzed for the design of a 100 W AMTEC prototype. It was found that a particle diameter of 10 ${\mu}m$ is suitable for the evaporator wick to maintain a capillary pressure greater than total pressure drop in the circulation loop.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.1-7
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• 2013

This study was on leaching test(KSLT, TCLP) of the aggregate for the products(RA-1) and for the site(RA-2) to evaluate the characteristics of contaminants and the possibility of contamination arising from the aggregate. On the basis pH, conductivity and heavy metal contents in the aggregate, RA-1 indicated higher than RA-2. As a result of the leaching test, the pollutants were eluted from the aggregate increased as the particle size of the aggregate was smaller. The pH in the aggregate had a strong alkali by a pH value of 9.0~12.3, the conductivity was higher in less than 10mm RA-1 due to the leaching of dissolved inorganic ions. The heavy metals satisfied the leaching standards of KSLT and less 10% was eluted from the aggregate. As a result of evaluating water pollution possibility of the aggregate, the pH displayed in items with a very high possibility of contamination, conductivity and turbidity did in item with a low possibility of contamination and on the other hand the heavy metals did in item with a very low possibility of contamination.

• Land and Housing Review
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• v.13 no.4
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• pp.125-134
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• 2022

Reclaimed aggregates through waste asphalt are produced and utilized for waste resource utilization. This study conducts quality tests and performance evaluations for mixtures with Rejuvenator applied to reclaimed asphalt concrete. Through quality testing and performance evaluation, the study investigates whether there is any problem in using reclaimed asphalt concrete by replacing general hox mix asphalt. As a result, the values of ordinary hot mix asphalt are similar to those of reclaimed asphalt, suggesting that the substitution does not create critical engineering issues. Using reclaimed asphalt concrete has the advantages of increasing economic efficiency and utilizing waste resources.

• The Journal of the Society of Stroke on Korean Medicine
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• v.21 no.1
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• pp.33-38
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• 2020

■ Objectives This case report is reported to show the effect of Ukgansan and Hwangnyeonhaedok-tang on a patient who complaining myoclonic seizure due to psychogenic non epileptic seizure, occurred after traumatic stress event. ■ Methods A female patients with myolconic seizure was treated with Ukgansan and Hwangnyeonhaedok-tang during 5 days. Then we assessed dyskinesia severity by AIMS(Abnormal Involuntary Movement Scale) every two days til discharge. ■ Results Seizure decreased two days after hospitalization, then disappeared third day. There was no recurrence till discharge. When she revisited outpatients clinic, there was no symptom. ■ Conclusion This case showed the effect of Ukgansan and Hwangnyeonhaedok-tang on psychogenic epileptic seizure.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.367-375
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• 2022

In this study, the characteristics of recycled aggregate concrete according to the mixing ratio of recycled fine aggregate were analyzed by design strength to explore its use in the production of ready-mixed concrete. The results show that, depending on the ratio of recycled aggregate, the compressive strength is similar to that of normal concrete and does not deteriorate. Therefore, it is possible to achieve a strength similar to the target design strength. Furthermore, if the ratio of recycled fine aggregate for concrete is up to 25 % of the total aggregate amount (50 % of the to-tal fine aggregate), slump does not cause problems. Our findings show that the higher the de-sign standard strength, the greater the amount of powder, and management of slump reduction, unit quantity, and performance system is necessary. The obtained results show that recycled ag-gregate can be used for the production of ready-mixed concrete after adjusting its mixing ratio and concrete mix proportions.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.253-253
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• 2023

유역의 수량, 수질, 수생태, 지하수, 하천환경, 기후변화, 오염원, 하천 친수공간, 농업경작지 등 수자원 관점의 물순환의 범위를 넘어서 환경, 기후변화 적응, 경제성, 사회문화 등 다양한 분야를 포함한 통합적인 유역의 물관리 이슈와 문제점을 해결할 필요가 있다. 물순환 관리의 개념은 국토개발과 도시화에 따라 파생된 물순환 왜곡 및 그에 따른 제반 물문제(홍수량 증가에 따른 침수피해, 직접 유출량 증가에 따른 가용 수자원의 감소 등)의 해결을 위한 물관리 행위 전체로 볼 수 있다. 물순환 관리의 범위는 홍수량 감소를 위한 홍수관리, 가용 수자원의 증대를 위한 물 확보 등 물관리 전반을 포함해야 한다. 기존의 물순환 사업은 비점오염 관리에 중점을 두고 LID를 활용한 빗물 침투율 증대와 빗물 재이용 등의 관련 정책을 추진하였으나 이는 물순환 체계 전반을 다루고 있지 못하고 수질 개선에그 효과가 집중되었다. 따라서, 수량·수질·수생태·재이용 등을 종합적으로 고려한 물순환 관리에 대한 연구가 필요하며, 이를 통하여 개별적이고 시설물 중심인 기존 대책의 한계를 극복하고 통합물관리 관점의 물순환 건전성을 기반으로 유역의 안심공간 조성방안을 수립할 필요가 있다. 본 연구에서는 물순환 전반을 연계한 통합적인 물관리를 통하여 물 안심공간을 조성하기 위한 토대를 제시하는 것을 목표로 하며, 통합물관리 관점의 물순환 관련 데이터 수집, 유역별 물순환 수준의 진단 및 평가를 통하여 시범사업 모델을 마련하고, 사업에 따른 효과분석을 기반으로 중장기 추진계획 수립을 통한 실행력을 확보하는 것을 목적으로 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.195-195
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• 2021

최근 기후변화, 과도한 지하수 이용 등으로 유역 환경이 변화하고 있으며, 이에 따른 부작용으로 하천의 건천화, 지표유출량 증가, 증발산량 감소 등 물순환 구조가 왜곡되고 있다. 물순환 과정은 지역적 조건에 따라 다르게 나타나며, 모의 요소와 해석 기법도 다르다. 따라서 지속가능하고 건전화된 물순환을 위해 해당 유역의 물순환계를 정확히 파악하고 고려하여 객관적으로 정량화할 수 있어야 한다. 현재 우리나라 농업유역은 논, 용·배수로, 농업용 저수지가 존재하며, 종합적인 농촌용수 물순환 해석을 위해 농촌용수 요소별 해석 기술 및 모듈 개발, 모델링 기법 등을 이용하여 농촌수자원의 체계적·과학적 해석 및 관리 시스템 개발이 이루어져야 한다. 본 연구에서는 강원도 원주시에 위치한 흥업저수지를 대상으로 농촌용수의 물순환 과정을 정립하였으며, 저수지 시점부·말단부, 농업용 저수지, 저수지 유역으로 구분하여 물순환 분석을 수행하였다. 물순환 모의 요소로 저수지 수위, 유역 유출량, 수로부 공급량 및 배수량, 회귀수량 등으로 선정하였으며, 수로 네트워크 기반의 SWMM (Storm Water Management Model) 모형을 이용하여 종합적인 농촌용수 물순환 해석을 수행하였다. 또한, 물순환 해석 기법의 적용성 검증을 위해 모의 요소별 모니터링을 수행하였으며, SWMM 모형과 모니터링을 비교하여 적용성을 평가하였다. 본 연구 결과를 통해 농촌지역 특성 및 기후변화를 고려한 농촌수자원의 안정적인 공급과 국가 청정 수자원 확보를 위한 통합 물관리 정책을 실현하는데 기초 자료로써 활용 가능할 것이라 사료된다.