• Title/Summary/Keyword: asbestos analysis

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A Study on the Structural Safety of the Roof Improvement Project (슬레이트지붕 개량사업 구조안전성 검토)

  • Kang, Kyung-Soo
    • Journal of the Korean Institute of Rural Architecture
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    • v.20 no.1
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    • pp.19-26
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    • 2018
  • The roof improvement project is being carried out under the government's leadership for the sake of national welfare. The project is to replace the asbestos slate roof with a metallic one. In this study, the structural safety of the improved roof was examined and the project guidelines were reviewed. The causes of the roof damage were investigated and the structural analysis was performed for the roof frame subject to wind and snow loads. Metallic roof assemblies have higher strength and load resistance capability than usual slate ones, so the structural safety is governed by the frame. The stresses of the roof frame elements caused by the wind and snow loads were analyzed according to roof frame with various spacings between the rafters and the purlins. Wind load analysis was performed by 24, 28, and 38 m/sec of the basic wind speed. Snow load analysis was carried out by 0.5, 1.0 and $2.0kN/m^2$ of the ground snow load. As the analysis result, the current spacing and the size of the lumber did not satisfy the Korean building code specification. To secure the safety of the roof improvement project, the spacing of the roof frame elements and the size of the lumber should be determined based on the analysis results by structural engineers.

Selection of Priority for Revitalization by Analyzing Rural House Type (농촌주택 유형분석을 통한 재생우선순위 도출)

  • Park, Gil-Beom;Park, Jun-Mo;Kim, Ok-Kyue;Bang, Se-Ra
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.174-175
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    • 2014
  • A Rural house in Chungcheong area have been variety of matters, rapid deterioration of house and incomplete of maintenance control, that is represented lack of durability heating from lack of heat insulation property, health worsening form use of toxic substance and so on. For farmers who did not know where to repair and how to repair, they are urgently needed measures of standard and basis that is to realize a condition of rural house. Accordingly, this study drew major matters and priority for revitalization through analysis of type of rural house from research on the actual condition in order to develope of diagnostic criteria of rural house.

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Study on Effective Treatment of Waste Gases in Chung-Ju Industrial Complex with Polymeric Absorbent( I ) (고분자담지제에 의한 청주공단내 공장배기가스의 효율적 처리기술대책에 관한 연구(I) -청주공장내 공장배기가스 조사 및 분석을 중심으로-)

  • 이상혁;이영순;전종한
    • Journal of the Korean Society of Safety
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    • v.7 no.2
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    • pp.24-29
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    • 1992
  • The exhausted gases were analyzed and the countermeasures were studied to solve the environmental pollution caused by waste gases in Chung-Ju Industral Complex. The eleven working places were selected to analysis the compositions and concentrations of the exhausted gases by gas chromatograph and membrane method. The five companies which have used organic solvents were shown lower content than TLV and the environmental limits. But the concentration of lead in a electric product company was revealed higher than TLV. The waste gases of the four companies which have used asbestos were shown lower values than TLV and the environmental limit. The exhausted gases, SO$_2$and NO$_2$of two companies which have used fossile fuels were also analyzed. The NO$_2$concentration of one company which haven't disposal system was shown higher than the environmental limit.

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Analysis and Evaluation of the Brake NVH Characteristics for the Fusion-type Friction Material (퓨전형 마찰재의 브레이크 NVH 특성 해석 및 평가)

  • Kwon, Seong-Jin;Bae, Chul-Yong;Kim, Chan-Jung;Kim, Wan-Soo;Lee, Dong-Won;Lee, Bong-Hyun;Seo, Byoung-Youn;Jung, Kwang-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.606-607
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    • 2008
  • Nowadays, noise and vibration phenomena of a disc brake system have been given various names that provide some definitions of sound and vibration emitted such as grind, grunt, moan, squeak, squeal, judder and wire brush. The most common and annoying noise of a disc brake system is squeal noise. It is defined as noise whose frequency content is 1 kHz and higher with excessively high and irrigating sound pressure levels. In this paper, the noise and vibration characteristics of a disc brake system have been investigated to develop the fusion-type friction material, which overcomes the low steel and non-asbestos organic friction materials. For the purpose, both experimental evaluation and complex eigenvalue analysis have been carried out.

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A Case of Giant Cell Interstitial Pneumonia (거대세포 간절성 폐렴(Giant Cell Interstitial Pneumonia) 1예)

  • Kang, Kyeong-Woo;Park, Sang-Joon;Suh, Gee-Young;Han, Joung-Ho;Chung, Man-Pyo;Kim, Ho-Joong;Kwon, O-Jung;Rhee, Chong-H.;Choi, Jae-Wook
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.260-267
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    • 2000
  • Giant cell interstitial pneumonia. a synonym for hard metal pneumoconiosis, is a unique form of pulmonary fibrosis resulting from an exposure to hard metal dust. A case of biopsy-proved giant cell interstitial pneumonia in the absence of appropriate history of exposure to hard metal dust is reported. The patient presented with clinical features of chronic interstitial lung disease or idiopathic pulmonary fibrosis. He worked in a chemical laboratory at a fertilizer plant, where he had been exposed to various chemicals such as benzene and toluene. He denied having any other hobby in his house or job at work, which may have exposed him hard metal dust. High-resolution CT scan revealed multi-lobar distribution of ground glass opacity with peripheral and basal lung predominance. The retrieved fluid of bronchoalveolar lavage contained asbestos fiber and showed neutrotphil predominance. Surgical lung biopsy was performed for a definite diagnosis. Lung specimen showed alveolar infiltration of numerous multinucleated giant cells with mild interstitial fibrosis. Upon detailed examination of the lung tissue, one asbestos body was found. An analysis for mineral contents in lung tissue was performed. Compared with the control specimen, the amount of cobalt and several hard metal components in the lung tissue of this patient was ten times higher. We speculated that the inconsistency between occupational history and the findings of pathologic and mineralogical analyses could be explained by the difference in individual immunologic reactivity to hard metal dust despite the relatively small amount of unrecognized environmental exposure(ED: It's hard to understand what this phrase is trying to say).

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Domestic Rock Wool Toxicity Study on Respiratory System and Biopersistence Evaluation in Sprague-Dawely Rats (랫드에 주입된 국내산 암면의 호흡기 독성 및 생체내구성 평가)

  • Chung, Yong Hyun;Han, Jeong Hee;Kang, Min Gu;Lee, Sung Bae;Kim, Hyeon Yeong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.2
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    • pp.127-138
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    • 2009
  • Rock wool, a kind of asbestos substitutes, was analyzed for its physicochemical properties. After fivers of rock wool were instilled into rat lungs, These pathological changes were evaluated. In addition, the fibers in the lungs were counted and characterized after the lungs were treated for electron microscopical analysis. The lungs of rats showed pathological lesions such as granulomatous changes, but these lesions disappeared at 28 days groups after instilled rats. The rock wool fibers in the lungs decreased more 50 % after 28 days instilled into rat lungs. And rock wool showed early change in fiber compositions after 3 days compare with chrysotile showed after 7 days instilled into rat lungs. This study showed that the durability of rock wool in the lungs is more milder than chrysotile.

Types and Characteristics of Fibrous Serpentine Minerals Occurred in Serpentinite in Hongseong and Gapyeong (홍성과 가평 사문암 내에서 섬유상으로 산출되는 사문석군 광물의 종류 및 특성)

  • Jeong, Hyewon;Kang, Serku;Roh, Yul
    • Economic and Environmental Geology
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    • v.49 no.1
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    • pp.1-11
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    • 2016
  • Chrysotile is well known as a fibrous mineral in serpentinite by the previous studies in S. Korea. Previous studies in other countries showed that antigorite also occurred as asbestiform and harmful to humans. Therefore, the objective of this study was to investigate types and characteristics of fibrous serpentine minerals occurred in serpentinite in Hongseong, Chungnam and Gapyeong, Gyeonggi in S. Korea. XRD, SEM-EDS, PLM and EPMA mapping analyses were used to examine the occurrence and formation mechanism of serpentine minerals. Serpentinization partially occurred in amphibole-schist and calc-schist at two study sites, Hongseong, Chungnam and Gapyeong, Gyeonggi, respectively. Both chrysotile and antigorite occurred as a fibrous mineral at Hongseong site, but chrysotile occurred as a fibrous mineral at Gapyeong site. Based on PLM analysis with dispersion staining, the chrysotile was observed horizontally magenta and vertically blue colors. The antigorite appeared as horizontally gold to golden magenta and vertically blue magenta colors under central stop dispersion staining objective(DSO). PLM and SEM analyses showed the fibrous minerals were formed from plate form of serpentine minerals or by hydrothermal alternation of primary minerals. The EPMA mapping showed that Mg contents in chrysotile is relatively higher than that in antigorite while Si and O contents in antigorite is higher than them in chrysotile. However, more studies are necessary to know the exact variation in chemical composition of chrysotile and antigorite. These results indicate that even though asbestiform antigorite found associated with asbestos chrysotile in serpentinites, the fibrous antigorite can be distinguished from chrysotile by different dispersion staining colors.

Interpretation of the Manufacturing Characteristics and the Mineral and Chemical Composition of Neolithic Pottery Excavated from the Jungsandong Site, Yeongjong Island, South Korea (영종도 중산동 신석기시대 토기의 광물 및 화학조성과 제작특성 해석)

  • Lee, Chan Hee;Kim, Ran Hee;Shin, Sook Chung
    • Korean Journal of Heritage: History & Science
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    • v.51 no.1
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    • pp.4-31
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    • 2018
  • The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.

Analysis of charge and magnetic characteristics of brake wear particles (브레이크 마모입자의 하전 및 자성 특성 분석)

  • Chaeyeon Jo;Dongho Shin;Gunhee Lee;Sang-Hee Woo;Seokhwan Lee;Bangwoo Han;Jungho Hwang
    • Particle and aerosol research
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    • v.19 no.2
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    • pp.31-42
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    • 2023
  • The charge and magnetic characteristics of LM (Low-metallic) and NAO (Non-asbestos-organic) brake wear particles were analyzed. The ratio of charged particles from total particles is about 86% of the LM pad and about 92% of the NAO pad. Number of charge per particle from the NAO pad is also higher than that of the LM pad. The ratio of magnetic particles from total particles increases with the particle size. The ratio of magnetic particles from the LM pad is about 15% for the particles with the size of 1 ㎛, and about 74% for ones with 5 ㎛. The ratio from the NAO pad is about 5% for the particles with the size from 0.5 ㎛ to 2 ㎛, and about 80% for the particles with 5 ㎛. Through the analysis of the components of the two pads with SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), it was found that the LM pad was occupied with more iron fraction than the NAO pad and that PM2.5-10 was occupied with more iron fraction than PM2.5. The particles smaller than 10 ㎛ (i.e. PM10) from the LM pad contained about 83% of charged particles, about 43% of magnetic particles, and about 93% of charged or magnetic particles. PM10 from the NAO pad contained about 88% of charged particles, about 15% of magnetic particles, and about 89% of charged or magnetic particles.

A Study on the Measurement and Investigation of Air Quality in a University Library (대학도서관 실내 공기질 측정 및 조사 연구)

  • Lee, Jae-Won
    • Journal of Korean Library and Information Science Society
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    • v.50 no.4
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    • pp.635-658
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    • 2019
  • In this study, the harmful factors measured in S university's central library were divided into ① air harmful substance ② biological harmful factors ③ carbon monoxide, carbon dioxide, and nitrogen dioxide concentration, measured and analyzed compared to the relevant criteria. The analysis showed that the harmful substances in the air - fine dust, asbestos, volatile organic compounds and formaldehyde - were all lower than the relevant standards, and that biological harmful factors such as fungi in the air, gramophageal bacteria, and endotoxin were also found to have no particular problems. The concentration of carbon monoxide, carbon dioxide, and nitrogen dioxide in the air was also maintained without any unusual factors compared to the concentration in the ordinary atmosphere. However, the library is a multi-use facility that needs regular cleaning and ventilation to manage the environment.