• Title/Summary/Keyword: peeling methods

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A Study on the Characteristics of Low Temperature sintering Ceramic Siding Using Natural Minerals (천연광물을 활용한 저온소결 세라믹 사이딩의 특성에 관한 연구)

  • Kim, Soon-ho;Choi, Jeong-min
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.12
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    • pp.149-156
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    • 2019
  • Recently, skyscraper building and apartment fires, which were rapidly spread out from a low floor to a rooftop, have become a frequent occurrence in mass media. This fire problems have a fatal disadvantage that the exterior wall finish of the building emits toxic gas in case of fire by using dry bit method or organic insulating material. Therefore, in order to remedy these problems, many exterior wall finishing construction methods have been proposed, but the current trend is to use existing construction methods due to problems such as economy, weight, and durability. On the other hand, in countries such as Germany and Japan, ceramic sidings are used as exterior finishing material for buildings, which is environmentally friendly, excellent natural beauty, long life, easy maintenance and high-quality exterior materials. However, those ceramic sidings have still the problems such as manufacturing cost and weight problem because of boosting the sintering temperature up to 1,350℃ or more. Also, conventional CRC, MgO, FRP sidings which are composed of pulp, glass fiber and organic materials, have been reports of deformation due to ultraviolet rays, discoloration, corrosion and scattering, surface rupture, lifting and peeling. Therefore, in this study as an alternative to solve this problem, halosite nano kaolin produced in Sancheong in Korea and frit flux were used to satisfy the required properties as ceramic siding using low temperature sintering (below 1,000℃) and lightweight materials such as pearlite. This study aims to design the optimal formulation and process of materials and to study the characteristics of nano-coated ceramic siding material development and to present relevant basic data. The findings show that ceramic siding for nanocoated building materials is excellent as a natural ceramic siding building material. The fire resistance of natural minerals and nano particle refining technology satisfy the bending strength of 80kgf / cm2, the volume ratio of 2.0 and the absorption rate of less than 10.0%.

A Investigation on the Soil-Peel Methods in Conservation Method of Historical Site (유구 보존방법론 중 토층전사에 관한 고찰)

  • Wi, Koang-Chul;Seo, Jeong-Ho
    • Journal of Conservation Science
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    • v.26 no.3
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    • pp.341-348
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    • 2010
  • After excavation work of relics, historical site which has historically meaningful, are preserved using the various methods. There are three method in the relocation methods that are original relocation method, the remaining structure-peel method, and soil peel method. The original relocation method is restored after relocating in historical site such as residential site, iron foundry site, kiln site, old mound. The remaining structure-peel method are restored only the feature of exposed remaining structure using polymeric resin, when it is difficult to relocate the entire remaining structure. And soil-peel method is exhibited after peeling in case when soil layers such as grave of old mound, foundation of building site, sedimentary deposit layer, shell heap, and etc. Soil-peel method becomes important historical data of changes according to environment at that time, that is, flooding by storm, traces of fire and living features of that time such as heaps of shells discarded after eating shellfish and living wastes. In particular, in case of soil layer for preparing foundation sites of building by compacting in turn soils with different components such as clay soil, rough sand soil and etc, it becomes important data which can judge foundation technology of that time. It can be said to be an important data preservation method for utilizing these historical data as historical data as well as for the purpose of education, exhibitions and public relations which can be shared not only by experts but also by general public. In this paper, we present the reliable definition of soil-peel method in various preservation methods and explain the using polymer in this method. So, we will come up with the accurate index about this method that is used the eminent analysis method for soil layer.

A study on the color controlled of painter's work (페인트 도장공사의 색관리에 관한 연구)

  • Shim, Myung-Sup;Lee, Hyun-Jeong
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.1
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    • pp.107-114
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    • 2003
  • This study aims to find methods that prevents aging of buildings paint coating and that limits defects in construction. Defects in painting can occur in four stages: pure paint, during painting, after the paint coating has dried, and after some period of time has passed after coating. Paint may become bad due to precipitation of pigments, formation of membranes, and seeding during manufacturing. Therefore, it is important that the paint is well mixed and kept airtight at a cool, dark place. Indents, paint brush strokes, orange peel, separation of colors, and paint running and spreading during the paint work process can be prevented by using high quality materials and applying a high-level of construction method. After the paint coating has dried, boiling, yellowing, poor drying, poor bonding, and/or glen deficiency may occur. These are influenced by the levels of cleanness of the dried product, drying temperature and hydration. Then, when the coating has been left dried for some period of time, cracking, peeling, scaling, swelling, discoloring, and/or rusting may develop due to the ultraviolet and contaminants in the air. Since these defects occur due to inappropriate construction schedule and/or hot and humid condition, one must use weatherproof materials. Furthermore, poor paint color may be caused by contamination in the sample plate, discoloration, and/or discrepancies in colors which are due to material differences, level of glossiness, degree of dispersion, dual color property of metallic colors, precipitation of pigments, etc. One should achieve reduction in construction cost and effectiveness in paint work by limiting contaminations in the construction site and strictly observing to construction regulations.

Interfacial mechanical behaviors of RC beams strengthened with FRP

  • Deng, Jiangdong;Liu, Airong;Huang, Peiyan;Zheng, Xiaohong
    • Structural Engineering and Mechanics
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    • v.58 no.3
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    • pp.577-596
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    • 2016
  • FRP-concrete interfacial mechanical properties determine the strengthening effect of RC beams strengthened with FRP. In this paper, the model experiments were carried out with eight specimens to study the failure modes and the strengthening effect of RC beams strengthened with FRP. Then a theoretical model based on interfacial performances was proposed and interfacial mechanical behaviors were studied. Finite element analysis confirmed the theoretical results. The results showed that RC beams strengthened with FRP had three loading stages and that the FRP strengthening effects were mainly exerted in the Stage III after the yielding of steel bars, including the improvement of the bearing capacity, the decreased ultimate deformation due to the sudden failure of FRP and the improvement of stiffness in this stage. The mechanical formulae of the interfacial shear stress and FRP stress were established and the key influence factors included FRP length, interfacial bond-slip parameter, FRP thickness, etc. According to the theoretical analysis and experimental data, the calculation methods of interfacial shear stress at FRP end and FRP strain at midspan were proposed. When FRP bonding length was shorter, interfacial shear stress at FRP end was larger that led to concrete cover peeling failure. When FRP was longer, FRP reached the ultimate strain and the fracture failure of FRP occurred. The theoretical results were well consistent with the experimental data.

The Region Analysis of Document Images Based on One Dimensional Median Filter (1차원 메디안 필터 기반 문서영상 영역해석)

  • 박승호;장대근;황찬식
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.3
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    • pp.194-202
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    • 2003
  • To convert printed images into electronic ones automatically, it requires region analysis of document images and character recognition. In these, regional analysis segments document image into detailed regions and classifies thee regions into the types of text, picture, table and so on. But it is difficult to classify the text and the picture exactly, because the size, density and complexity of pixel distribution of some of these are similar. Thu, misclassification in region analysis is the main reason that makes automatic conversion difficult. In this paper, we propose region analysis method that segments document image into text and picture regions. The proposed method solves the referred problems using one dimensional median filter based method in text and picture classification. And the misclassification problems of boldface texts and picture regions like graphs or tables, caused by using median filtering, are solved by using of skin peeling filter and maximal text length. The performance, therefore, is better than previous methods containing commercial softwares.

Comparison between Colour Intensity of Tongue Body and That of Tongue Coat under the Ultraviolet Light in RGB system of Peeling Tongue Coat Image (RGB 컬러모델에서 자외선 조명하 박락태(剝落苔)의 설태와 설질 사이의 색 강도 차이에 관한 연구)

  • Nam, Dong-Hyun;Kim, Ji-Hye;Lee, Woo-Beom;Lee, Sang-Suk;Hong, You-Sik
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.15 no.2
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    • pp.149-158
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    • 2011
  • Objectives: The objective of this study is to compare the colour intensity of tongue body and that of tongue coat under the visible light and the ultraviolet light. Methods: We selected 7 subjects with completely or partially peeled tongue coat among the recruited 94 adults for the experiment. We took each tongue picture under the visible light and the ultraviolet light (315-400 nm) and then extracted sample images from the tongue body and tongue coat regions. Mean, median and mode of colour intensity from the sample images were calculated in 256 RGB system. Results: The green and the blue colour intensities of the tongue coats were significantly higher than those of the tongue bodies under the visible light. In all channels, the red, green and blue, the colour intensities of the tongue coats were significantly higher than those of the tongue bodies under the ultraviolet light. The colour differences between tongue coats and tongue bodies under the ultraviolet light were significantly higher than the colour differences under the visible light. Especially the colour difference under the ultraviolet light was highest in the green channel. Conclusions: We suggested that green colour image of the RGB system taken under the ultraviolet light could be used for more easy separating tongue coat region from tongue body.

The effect of Er:YAG laser irradiation on the surface microstructure and roughness of hydroxyapatite-coated implant

  • Kim, Seong-Won;Kwon, Young-Hyuk;Chung, Jong-Hyuk;Shin, Seung-Il;Herr, Yeek
    • Journal of Periodontal and Implant Science
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    • v.40 no.6
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    • pp.276-282
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    • 2010
  • Purpose: The present study was performed to evaluate the effect of erbium:yttrium-aluminium-garnet (Er:YAG) laser irradiation on the change of hydroxyapatite (HA)-coated implant surface microstructure according to the laser energy and the application time. Methods: The implant surface was irradiated by Er:YAG laser under combination condition using the laser energy of 100 mJ/pulse, 140 mJ/pulse and 180 mJ/pulse and application time of 1 minute, 1.5 minutes and 2 minutes. The specimens were examined by surface roughness evaluation and scanning electron microscopic observation. Results: In scanning electron microscope, HA-coated implant surface was not altered by Er:YAG laser irradiation under experimental condition on 100 mJ/pulse, 1 minute. Local areas with surface melting and cracks were founded on 100 mJ/pulse, 1.5 minutes and 2 minutes. One hundred forty mJ/pulse and 180 mJ/pulse group had surface melting and peeling area of HA particles, which condition was more severe depending on the increase of application time. Under all experimental condition, the difference of surface roughness value on implant surface was not statistically significant. Conclusions: Er:YAG laser on HA-coated implant surface is recommended to be irradiated below 100 mJ/pulse, 1 minute for detoxification of implant surface without surface alteration.

An Architectural Feature Study on the Restoration of Tongbanga-House at Samcheok (삼척 대이리 통방앗간 복원에 관한 건축적 특성 연구)

  • Choi, Jang-Soon;Kim, Jin-Won
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.1
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    • pp.101-109
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    • 2008
  • It is very hard to find out Tongbanga-millhouse installed nearby a streamlet to use water with Tongbanga(a kind of water-mill) to polish cereals by pounding like a visage of its old days. It plays an important part in folkloric, architectural and educational aspects. The purpose of this study is to analyse the architectural features of Tongbanga and millhouse itself so that to find the way how to build and fabricate the materials and frame members. Therefore this study has been focused on the composition principle and fabrication method of Tongbanga-millhouse on the side of architecture. The fabrication methods of its house in accordance with regular sequences are as follows. ${\cdot}$ Firstly the decision of location of Tongbanga-millhouse and Hwak(a big mortar made of stone). ${\cdot}$ Slantly three rafter installation at an angle of $50^{\circ}$ to err on the safe side and then slantly fifteen rafter installation making a circular cone shape. ${\cdot}$ Installation of twigs to be circles from bottom to top. ${\cdot}$ Manifoldly covering of trunks peeling the barks from flax plants. ${\cdot}$ Threefoldly thatching with upside barks of oak trees. ${\cdot}$ Placing woods alike rafter on the bark thatches as a weight not to fly away by wind. ${\cdot}$ Binding woods alike rafter with vines of arrowroots to maintain the proper place. The decayed Tongbanga-millhouse by means of upper ways was restored out of all recognition.

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Chemical composition of cassava-based feed ingredients from South-East Asia

  • Natalia S. Fanelli;Leidy J. Torres-Mendoza;Jerubella J. Abelilla;Hans H. Stein
    • Animal Bioscience
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    • v.36 no.6
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    • pp.908-919
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    • 2023
  • Objective: Information about the chemical composition of cassava-based feed ingredients is needed to accurately formulate animal diets. A study was conducted to determine the chemical composition of cassava-based feed ingredients and to test the hypothesis that there is variation in chemical composition among cassava products originating from different South-East Asian countries. Methods: Sources of dried peeled and unpeeled cassava roots, cassava chips, cassava meal, high-ash cassava meal, and cassava residue were used. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid-hydrolyzed ether extract (AEE), ash, minerals, total starch, insoluble dietary fiber, and soluble dietary fiber. Samples of peeled and unpeeled cassava roots, cassava chips, and cassava meal were also analyzed for sugars. Results: High-ash cassava meal had greater (p<0.05) dry matter and ash, but lower (p<0.05) total starch and gross energy than all other cassava products. Peeled cassava roots, unpeeled cassava roots, and cassava chips had greater (p<0.05) total starch than the other cassava-based ingredients. Cassava residue had greater (p<0.05) concentrations of lysine, insoluble dietary fiber, and soluble dietary fiber compared with the other cassava products, but tryptophan and glutamic acid were greater (p<0.05) in peeled cassava roots, cassava chips, and cassava meal samples compared with the other ingredients. Concentration of most minerals was greater (p<0.05) in high-ash cassava meal than in the other cassava products. Conclusion: Cassava-based ingredients sold as peeled roots, unpeeled roots, chips, or meal have chemical compositions that are not different from each other, and peeling has little impact on chemical composition. High-ash cassava meal has lower nutritional quality compared with other cassava products due to low starch and gross energy. The high fiber content in cassava residue makes this ingredient more suitable for ruminants and sows than for younger pigs or poultry.

Identification of Causes and Prevention Measures for Health Disorders Such as Erythema of Restaurant Workers in Manufacturing Company (제조사업장 식당 종사자의 홍반 등 건강장해 원인 규명 및 예방 방안)

  • Jee Yeon Jeong;Gwangyong Yi;Seung-Hyeon Park
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.34 no.3
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    • pp.238-246
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    • 2024
  • Objectives: A collective of workers in the company's cafeteria encountered symptoms such as stinging and watering in and around the eyes, a sensation of sand in the eyes, erythema, swelling, and peeling of the skin on the face and neck. The objective of this study is to pinpoint the causes of these symptoms and propose preventive measures. Methods: Following preliminary on-site investigations, worker interviews, and literature research, it was determined that the most probable cause of the symptoms was ultraviolet rays emitted from a UV sterilizer. Consequently, the study measured and assessed the effective amount of ultraviolet radiation emitted by the sterilizer. Results: When operating with the curtain-type door of the ultraviolet sterilizer open, it was observed to surpass the 0.1 μW/cm2 8-hour work exposure standard recommended by ACGIH TLV in most kitchen workspaces. The evaluation of the maximum allowable exposure time based on the distance from the ultraviolet sterilizer indicated only 4.2 seconds at a distance of 0.2 m with the curtain door open, and merely 1.7 minutes at a distance of 1 m. Conclusions: This study confirmed that the symptoms among restaurant workers emerged immediately after the installation of the ultraviolet sterilizer, and these symptoms were consistent with those associated with exposure to ultraviolet rays. Furthermore, the assessment revealed that the exposure level to ultraviolet rays could be exceeded established exposure standards. It was recommended that the existing ultraviolet sterilizer be replaced with one featuring a glass door, and facility improvements should be made, such as implementing an automatic mechanism to turn off the ultraviolet lamp when the door is opened.