• 한국광물학회지
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• 제23권2호
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• pp.171-183
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• 2010

• 한국건설순환자원학회지
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• 제15권4호
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• pp.31-34
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• 2020

• 대한기계학회논문집A
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• 제21권1호
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• pp.83-92
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• 1997

In a study on the development of Cu-based sintered friction materials, the specimens pressed with various compacting pressures $(3-6 ton/cm^2/)$ have been evaluated to find the optimum condition of compacting pressure. As compacting pressure increased up to $(5 ton/cm^2/)$, mechanical properties such as density, hardness, bending strength, wear and coefficient of friction, etc. improved remarkably, but up to 6 ton/cm$^{2}$, decreased slightly because of traps of gases and water vapors in specimen. Disk assembly composed of 12 pieces of Cu-based friction materials has been compared with one of asbestos-and nonasbestos-based friction materials. In dynamic and driving tests to find burst spin strength, corrosion area rate and friction properties, etc., Cu-based sintered friction materials showed better properties than the others, especially in severe conditions because oxides such as $Cu_2O; and; SnO_2$ in the friction surface of friction materials were formed.

• 한국세라믹학회지
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• 제41권9호
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• pp.690-695
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• 2004

본 연구에서는 무기(강, 아스베스트와 카본) 및 유기(폴리아크릴과 폴리아마이드) 섬유가 포트랜드 시멘트의 물성 보강에 미치는 영향을 조사하였다. 각 시편의 하중-변형 관계도로부터 굽힘강도, 탄성계수, 파괴에너지 및 파괴인성 값을 구하여 서로 비교하였다. 그리고 따로 충격에너지 실험도 수행하였으며 파괴에너지와 비교하였다. 휨강도 개선에는 무기(아스베스트) 섬유보강이 가장 효과적이었으며, 충격에너지의 보강섬유로는 유기(폴리아크릴) 섬유가 가장 좋았다. 한편 강 섬유는 휨 강도와 충격에너지 양자를 동시에 보강하는 데에 가장 적합했다. 또한 강 섬유는 모든 섬유 중에서 가장 높은 파괴에너지와 파괴인성 값을 나타내었다.

• 한국환경보건학회지
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• 제37권1호
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• pp.57-63
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• 2011

Crocidolite quality control (QC) sampling created by the wet generation method has been validated by validation tests such as the accuracy, precision, and storage tests. For this study we designed and developed a manufacturing apparatus and standard operating procedure for making these QC samples. The most important step in the procedure of making QC samples was the stage eliminating static electricity in asbestos fibers. This static electricity hampers the fibers clog functioning. In accuracy and precision tests by phase contrast microscopy analysis, the difference between the reference values and the studied values was at maximum 17.8%. This satisfies the AIHA proficiency analytical test criteria for asbestos. We could confirm the nearly even distribution of crocidolite fibers on the membrane filter. Also, there was no loss of fibers in the storage test after the one month.

• 실내환경 및 냄새 학회지
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• 제17권4호
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• pp.322-329
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• 2018

The objective of this study is to identify the research trend in the field of indoor environment in Korea. We collected 419 papers published in the Journal of the Korean Society for indoor environment between 2004 and 2018, and attempted to produce datasets using a topic modeling technique, Latent Dirichlet Allocation(LDA). The result of topic modeling showed that 8 topics ("VOCs investigation", "Subway environment", "Building thermal environment", "School health", "Building particulate matter", "Asbestos risk", "Radon risk", "Air cleaner and treatment") could be extracted using Gibbs sampling method. In terms of topic trends, investigation of volatile organic compounds, subway environment, school health, and building particulate matter showed a decreasing tendency, while the building thermal environment, asbestos risk, radon risk, air cleaners, and air treatment showed an increasing tendency. The results of this topic modeling could help us to understand current trends related indoor environment, and provide valuable information in developing future research and policy frameworks.

• 한국환경보건학회지
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• 제48권1호
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• pp.19-27
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• 2022

The industrial development and socioeconomic structures of a society are inextricably linked to occupational accidents and diseases. Since the 1970s, a series of major occupational diseases have occurred in South Korea, such as mercury poisoning in Munsong-myeon, carbon disulfide poisoning at Wonjin Rayon, and leukemia at Samsung Electronics. These incidents have caused us to take a critical look at the level of worker safety and health management within companies and the government. These serve as symbolic and representational events. Doctors, lawyers, and labor activists concerned about employee safety and lives came together for years to struggle with the government and industry in order to determine what caused the diseases and to obtain compensation for victims. They finally achieved recognition for occupational diseases and recompense for losses. It is difficult to find similar cases to the baby powder asbestos talc cases and the radon bed case internationally, or there is no case where such a large number of consumers have been potentially harmed. It is also difficult to prove that the damage took place due to the victims' diverse geographic locations and ages, as well as the disease's long incubation period. Based on this premise, businesses and the government have been apathetic in acknowledging these diseases and compensating for damages, with few practical outcomes. Furthermore, unlike the large-scale occupational disease cases, only a few people including expert groups were organized and actively participated in the settlement of these issues, so it remains unfinished business for our society to address.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.5029-5037
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• 2015

본 연구의 목적인 우리나라 일부 학교의 석면함유 건축자재을 조사하고 EPA AHERA rule과 ASTM rule을 적용하여 위해성평가를 실시하였다. 총 100개 학교를 2010년 1월부터 12월까지 조사하였다. 건축년도에 따른 ACM 검출율은 1980년대 이전 건축물은 100%, 1990년대 이전은 94.1%, 2000년대 이전은 100%, 2000대 이후는 62.5%로 나타났다. 학교별 ACM 검출율은 유치원과 고등학교는 100%, 초등학교는 97.1%, 중학교는 92.9%, 특수학교는 80%로 나타났다. 천장 텍스는 2~8 %의 백석면과 갈석면, 밤라이트 보드는 6~11 %의 백석면이 검출되었다. 또한 개스킷과 슬레이트 지붕은 각각 16~17 %, 10~13 %의 백석면이 검출되었다. EPA AHERA rule을 이용하여 ACM의 위해성 평가를 실시한 결과, 모든 건축자재는 "Pool" 등급이 나왔으며, ASTM rule 평가에서는 모든 ACM이 "Q&M program"이 필요한 것으로 나타났다.

• 대한치과기공학회지
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• 제9권1호
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• pp.79-88
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• 1987

According as the density of prosthetic by casting among the prosthetic restorations is increasing now, the definition and the bounds as to the casting, the method of making the right casting and the establishment of concepts about a minute report and so on, the establishment of the basic principles like those are unavoidable, and then the casting shrinkage must be compensated by setting expansion thermal expansion. Hygroscopic expansion in making the good casting types as we demonstrated that already asbestos lining. We confirmed the fact that the considerable concern about the surface tension and the gas inspiration? Is necessary in making better the casting.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 춘계학술대회 논문집
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• pp.167-169
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• 2008