• 제목/요약/키워드: Natural material

검색결과 3,462건 처리시간 0.031초

감온 Microcapsule염료를 이용한 Laminated Split Leather Film 공정 연구 (A Study of laminated split leather Process using Thermally Sensitive Color-change(Microcapsule))

  • 이상헌;이상철;신은철;김원주
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2012년도 제46차 학술발표회
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    • pp.100-100
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    • 2012
  • 상품성이 떨어지는 B, C급의 Split leather에 감온 기능성 Film을 부착하고, Film 부착 공정에서 유성 접착제의 사용을 배제한 친환경적인 고급 Laminated split leather를 제조 하였다. 온도에 따라 색이 변하는 감온 Microcapsule 염료를 이용한 Film의 색도, Touch감과 신장 등의 최적조건을 찾는 실험으로서 수성 PU 접착제, Wetting&levelling agent, 증점제, 감온 microcapsule 염료를 상온에서 혼합하여 Film을 제조한 다음 수성 PU 접착제와 Urethane용 경화제를 혼합한 접착제를 이용하여 가죽에 부착시켰다. 감온 microcapsule자체의 색도가 떨어지므로 두 번 코팅하는 방법으로 이 문제점을 보완 하였으며, 감온 microcapsule 염료의 함량에 따른 물성 평가를 하였고, 감온 microcapsule 염료를 이용한 Film 공정을 확립 하였다.

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균질화기법에 기초한 유도전동기 권선 다발의 등가물성 유도 (Derivation of Equivalent Material Properties of Induction Motor Windings Based on Homogenization Method)

  • 배징도;고우식;조진래
    • 대한기계학회논문집A
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    • 제29권4호
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    • pp.518-525
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    • 2005
  • The electromagnetic noise generates when natural frequencies of a stator core with wingdings and frame coincide with or approach natural frequencies of the magnetic motive force. In order to suppress such noise, the estimation of natural frequencies of the motor is important at the design stage. However, the natural frequency analysis is not so easy because motor stator is in the laminated plate structure and windings are composed of wires, insulation sheets and vanishs. Thus the accurate prediction of the equivalent material properties of windings becomes an essential task. In this paper, we derive the equivalent material properties using homogenization methods.

마이크로캡슐에 의한 폴리에스테르 직물의 천연염색에 관한 연구(II) - 황금을 중심으로 - (Natural Dyeing of Polyester Fabric with Microcapsules(II) - Scutellaria baicalensis -)

  • 민경혜
    • 한국의류산업학회지
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    • 제10권6호
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    • pp.1045-1050
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    • 2008
  • Developing of high technology, productivity of the fiber product has being rapidly increased and also various kinds of advanced treatment process lead consumer's needs to more high functional, clean and healthy goods. Moreover, increasing in the concern of eco-friendly material and processing, it has been getting popular that the dyeing method like as using natural dyes is more eco-friendly and natural-friendly treatment process. The method, used in this study, adhesion by binding with micro-capsulized natural material to fabric has low change in quality by external influence and high ability in spray effect by broken capsule which comes to pressure and friction when it dressed. Also it has wide application from natural fiber to synthetic fiber. The purpose of this study is development of multi-functional synthetic material with micro-capsulized Scutellaria baicalensis on PET. Moreover, it was driven by comparison of colormetric properties and fastness between regular dip-dyeing method and binding with micro-capsulized material method. Dye ability was arranged mostly low exhaustion but the PET treated by micro-capsule was more or less better than the dip-dyeing PET. Through the SEM(Scanning Electron Microscope) of PET treated by micro-capsule, it has good residence of capsules even after 5 or 10 times washing. Wash and light fastness was arranged some different grade by each condition but mostly high achievement and the micro-capsulized PET was more improved than regular dip-dyed PET.

Risk of Material Misstatement in the Stage of Audit Planning: Empirical Evidence from Vietnamese Listed Enterprises

  • NGUYEN, Hoan;NGO, Thi Kieu Trang;LE, Thi Tam
    • The Journal of Asian Finance, Economics and Business
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    • 제7권3호
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    • pp.137-148
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    • 2020
  • The purpose of this study is to investigate factors influencing risk assessment of material misstatement in Vietnamese enterprises listed on stock market. Expert interview method was conducted to discover the scales for three variables including information system, trademark, and risk assessment of material misstatement. Survey method was used to examine the impacts of eight factors on risk assessment of material misstatement. Data is collected from 317 auditors who have excellent experience in auditing financial statements of companies listed on stock market. Then, data is processed by descriptive statistics, reliability analysis, factor extracted analysis, correlative regression analysis, and analysis variance of residual change. The research findings showed that business characteristic, stakeholder pressure, and economic environment have positive relationships with risk assessment of material misstatement. Three variables including operation control and monitor, control environment, and information system negatively affect to risk assessment. Specially, business characteristic and information system, which are elements in internal control, have strongest impact on risk assessment. One the other hand, assessment of internal control plays an important role not only in the audit plan stage but also throughout the stages of the audit implementation and ending. Therefore, appropriate solutions are proposed to carry out all audit stages.

식물성 절연유의 열 열화에 따른 전기적 특성 연구 (Analysis on the Electric Characteristics of Natural Ester after Accelerated Thermal Aging)

  • 심명섭;안정식;최순호;정중일;김남렬;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.81-81
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    • 2010
  • This paper presents results of experimental investigations on natural ester regarding the breakdown strength. Aging of insulating material in a pole transformer has been studied by performing accelerated thermal aging test. Sealed aging test vessels containing copper, laminated core, Krapt paper and insulating oil(Natural oil and Mineral oil) were aged at $140^{\circ}C$ for 30days. Compared to the conventional transformer oil, electric property of the natural ester fluid is excellent.

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복합재료판 구조물의 고유진동수 위상최적화에 관한 연구 (Study on Topology Optimization for Eigenfrequency of Plates with Composite Materials)

  • 김화일;윤혁기;한경민
    • 한국소음진동공학회논문집
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    • 제19권12호
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    • pp.1356-1363
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    • 2009
  • The aim of this research is to construct eigenfrequency optimization codes for plates with Arbitrary Rank Microstructures. From among noise factors, resonance sound is main reason for floor's solid noise. But, Resonance-elusion design codes are not fixed so far. Besides, The prediction of composite material's capability and an resonance elusion by controlling natural frequency of plate depend on designer's experiences. In this paper, First, using computer program with arbitrary rank microstructure, variation on composite material properties is studied, and then natural frequency control is performed by plate topology optimization method. The results of this study are as followed. 1) Programs that calculate material properties along it's microstructure composition and control natural frequency on composite material plate are coded by Homogenization and Topology Optimization method. and it is examined by example problem. 2) Equivalent material properties, calculated by program, are examined for natural frequency. In this paper, Suggested programs are coded using $Matlab^{TM}$, Feapmax and Feap Library with Homogenization and Topology Optimization method. and Adequacy of them is reviewed by performing the maximization or minimization of natural frequency for plates with isotropic or anisotropic materials. Since the programs has been designed for widely use. If the mechanism between composite material and other structural member is identified, extension application may be possible in field of structure maintenance, reinforcement etc. through application of composite material.

시멘트 원료로 국내산 석탄재의 이용 가능성 (The Utilization of Domestic Fly Ash as a Cement Raw Material)

  • 이윤철;이세용;민경소;이창현;박태균;유동우
    • 한국재료학회지
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    • 제32권1호
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    • pp.23-29
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    • 2022
  • Fly ash is a by-product of coal fired electrical power plants and used as a material for cement and concrete; particularly, imported fly ash is mainly applied for cement production. Main objectives of this article are to replace domestic fly ash with an imported source. To verify the possibility of domestic fly ash as a material for cement from the aspect of chemical composition and physical properties, we manufactured various kinds of cement, such as using only natural raw material, shale, and partial replacement with domestic and imported fly ash. When we used the domestic and imported fly ash, there were no specific problems in terms of clinker synthesis or cement manufacturing in relation to the natural material, shale. In conclusion, domestic fly ash has been confirmed as an alternative raw material for cement because 7 days and 28 days compressive strength values were better than those of reference cement using natural raw material, on top of the process issue.

Synthesis and Characterization of New Anthracene-Based Blue Host Material

  • So, Ki-Ho;Park, Hyun-Tae;Shin, Sung-Chul;Lee, Sang-Gyeong;Lee, Dong-Hui;Lee, Kyeong-Hoon;Oh, Hyeong-Yun;Kwon, Soon-Ki;Kim, Yun-Hi
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1611-1615
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    • 2009
  • We designed new anthracene-based host material to increase color purity as well as device efficiency. The new blue host, 9,10-bis(2,4-dimethylphenyl)anthracene (BDA), has highly twisted structure and wide band gap due to ortho interaction between anthracene and introduced 2,4-dimethylphenyl substituents. BDA exhibited deep blue fluorescence in solution (${\lambda}_{max}$ = 410 nm) and in solid state (${\lambda}_{max}$ = 429 nm), respectively, with the wide optical band gap (E = 3.12 eV). Blue-light-emitting OLEDs using obtained host and 2% Flu-DPAN as emitter showed 8 cd/A of high efficiency as well as high color purity [CIE coordinates = (0.15, 015)].

Free vibration analysis of thick CGFR annular sector plates resting on elastic foundations

  • Tahouneh, Vahid
    • Structural Engineering and Mechanics
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    • 제50권6호
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    • pp.773-796
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    • 2014
  • This paper deals with free vibration analysis of continuous grading fiber reinforced (CGFR) and bi-directional FG annular sector plates on two-parameter elastic foundations under various boundary conditions, based on the three-dimensional theory of elasticity. The plates with simply supported radial edges and arbitrary boundary conditions on their circular edges are considered. A semi-analytical approach composed of differential quadrature method (DQM) and series solution is adopted to solve the equations of motion. Some new results for the natural frequencies of the plate are prepared, which include the effects of elastic coefficients of foundation, boundary conditions, material and geometrical parameters. Results indicate that the non-dimensional natural frequency parameter of a functionally graded fiber volume fraction is larger than that of a discrete laminated and close to that of a 2-layer. It results that the CGFR plate attains natural frequency higher than those of traditional discretely laminated composite ones and this can be a benefit when higher stiffness of the plate is the goal and that is due to the reduction in spatial mismatch of material properties. Moreover, it is shown that a graded ceramic volume fraction in two directions has a higher capability to reduce the natural frequency than conventional one-dimensional functionally graded material. The multidirectional graded material can likely be designed according to the actual requirement and it is a potential alternative to the unidirectional functionally graded material. The new results can be used as benchmark solutions for future researches.