• Title/Summary/Keyword: material area

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Review on Functionalization of Laser-Induced Graphene

  • Jin Woo An;Hee Jae Kim;Seoung-Ki Lee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.3
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    • pp.203-213
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    • 2023
  • Owing to carbon materials' diverse functionalization and versatility, the design and synthesis of carbon-based three-dimensional porous structures have become important foundational research topics across various fields. Among the various methods for producing porous carbon structures, laser-induced graphene (LIG) has garnered attention because of its large surface area, controllable structure, excellent electrical conductivity, scalability, and eco-friendly synthesis process. In addition, recent research results have reported more novel functionalities by advancing further from the unique characteristics of LIG through functionalization or compounding of LIG, making it an attractive material for various applications in electronic devices, sensing, catalysis, and energy storage. This review aims to update the research trends in LIG and its functionalization, providing insights to inspire more interesting studies on functional LIG to expand its potential applications ultimately. Starting with the synthesis method and material characteristics of LIG, we introduce the functionalization of LIG, which is classified into surface modification, heteroatom doping, and hybridization based on the interaction mechanism. Finally, we summarize and discuss the prospects of LIG and its functionalization.

A Study on the Generation of the Production Material Information of a Building Block and the Simulation of the Block Erection (선체 블록의 물량 정보 생성 및 블록 탑재 시뮬레이션에 관한 연구)

  • Lee K.Y.;Roh M.I.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.2
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    • pp.115-127
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    • 2006
  • At the initial design stage, the generation process of the production material information of a building block and the simulation process of the block erection, which are required to perform the production planning and scheduling, have been manually performed by using 2D drawings, data of parent ships, and design experiences. To make these processes automatic, the accurate generation method of the production material information and the convenient simulation method of the block erection using the 3D CAD model, which was generated from the initial hull structural design system early developed by us, were proposed in this study. For this, a 3D CAD model for a whole hull structure was generated first, and the block division method for dividing the 3D CAD model into several building blocks was proposed. The generation method of the production material information for calculating the weight, center of gravity, painting area, joint length, etc. of a building block was proposed as well. Moreover, the simulation method of the block erection was proposed. Finally, to evaluate the efficiency of the proposed methods for the generation of the production material information and the simulation of the block erection, these methods were applied to corresponding processes of a deadweight 300,000 ton VLCC (Very Large Crude oil Carrier). As a result, it was shown that the production material information of a building block can be accurately generated and the block erection can be conveniently simulated in the initial design stage.

Effect of the Elasticity Modulus of the Jig Material on the Blade Edge Shape in the Grinding Process of Sapphire Medical Knife - Part 2 Verification of the Chipping Phenomenon and Elastic Modulus of the Jig Material (사파이어 의료용 나이프의 연삭가공에서 지그의 탄성계수가 날 부 형상에 미치는 영향 : 제2보 탄성계수와 치핑 현상의 검증)

  • Shin, Gun-Hwi;Kang, Byung-Ook;Kwak, Tae-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.63-68
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    • 2017
  • This study determines the selection of an appropriate jig material for the blade edge of the medical sapphire knife. The physical properties of the jig material affects the edge shape and chipping phenomenon in machining of the medical sapphire knife. If a grinding wheel is used, brittle workpieces such as sapphire are easily damaged by the propagation of cracks because the grinding force significantly increases. It is important to constantly maintain the grinding force in the grinding process of the brittle materials. The grinding force can be kept constantly by inducing the elastic deformation of the Jig material because the elastic deformation of brittle work-piece is negligibly low. The chipping phenomenon may be reduced by selecting the proper Jig material. Aluminum, copper, stainless steels and carbon steel were used as Jig materials. The experiment was conducted using a cast iron grinding wheel, which was installed on a conventional grinding machine with the ELID grinding system. The thickness and width of the chipping area were measured using an optical microscope and FE-SEM to analyze the shape of the blade edge. According to the experiment result, the chipping phenomenon decreased, and the sharp edge was formed when the jig materials with low elastic modulus were used.

Dynamic Properties of Tiny Piezoelectric linear Motor by Applied Voltage (인가 전압에 따른 초소형 압전 리니어 모터의 동특성)

  • Yoo, Kyoung-Ho;Ko, Hyun-Phill;Kang, Chong-Yun;Kim, Hyun-Jai;Ko, Tae-Kuk;Yoon, Seok-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.62-63
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    • 2005
  • Recently, a tiny piezoelectric linear motor using a vibration made of the transducer has been invented. The motor consists of a shaft, mobile element, and piezoelectric transducer using a piezoelectric radial mode bimorph disk. The fringe of the bimorph disk is fixed firmly which means this area has no degree of freedom. Therefore, the radial mode of the tranducer transfers to the flexurd mode. The mobile elements move along the shaft by the impact force generated by the flexurd mode of the piezoelectric transducer. The piezoelectric ceramic disks have thickness of 0.1 mm and diameter of 3.5 mm. The elastic disk is introduced between two disks of the ceramic, which has thickness of 0.1 mm and diameter of 3.8 mm. The fringe of the elastic disk is fixed by a brass cylinder which height is 1.2 mm. The Pyrex shaft is used which has diameter of 1 mm and height of 10 mm. The motors are operated at their resonant frequencies. The dynamic properties of the motor have been intensively measured and analyzed according to the applied voltage wave forms at the resonant frequencies. As the sawtooth and rectangular voltage waves are applied, the velocity, the thrust force, and the velocity dependence of the mobile position are measured. The dynamic characteristics are also analyzed within a period of each wave using laser vibrometer. The velocity of the mobile is moderately constant along the shaft. The better dynamic characteristics are obtained in the case of applying the rectangular wave.

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Material·Part·Equipment Industry Chungcheong Region Competitiveness Analysis Using Shift-Share Analysis (변이할당분석을 이용한 소재·부품·장비 산업 충청지역 경쟁력 분석)

  • Nayoung Lee;Seong Wook Chae
    • Journal of Intelligence and Information Systems
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    • v.29 no.4
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    • pp.415-430
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    • 2023
  • The Material·Part·Equipment industry is mostly an industry centered on small and medium-sized enterprises (SMEs) and is an important industry for revitalizing the local economy, which is the source of manufacturing competitiveness. In this study, we tried to derive the implications necessary for the development of the Material·Part·Equipment industries by analyzing the competitiveness of the Material·Part·Equipment industries in the Chungcheong region. To this end, we analyzed the industrial development stage and competitiveness of each region (Daejeon, Sejong, Chungnam, and Chungbuk) based on business scale factor, industrial growth rate, industrial specialization, and regional competitiveness for the Material·Part·Equipment industries in the Chungcheong region. Using data such as the number of employees, the number of businesses, and the amount of production in 2014 and 2019, significant industrial groups by region were identified considering the level of industrial specialization and regional competitiveness. In addition, by identifying the positions of these significant industrial groups in the stage of industrial development, suggestions for the development of the Material·Part·Equipment industries in the Chungcheong region were presented.

A Study on the Spatial Composition and Area Planning of the Intensive Care Units in the Public District Hospitals (지역거점공공의료원 중환자부 공간구성 및 면적계획에 관한 연구)

  • Yun, Woo Yong;Chai, Choul Gyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.2
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    • pp.47-61
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    • 2017
  • Purpose: This study aims to suggest the spatial composition and area of the intensive care units through analysis of current situation for the standards establishment of the intensive care units in public district hospitals in the future. Methods: Three Methods have been used in this paper. 1) Literature reviews about composition, location, foreign standards on intensive care units. 2) Comparative analysis on the architectural drawing for the space program and the area. 3) Field survey in order to confirm differences between architectural drawing and current situation. Results: 1) The intensive care units is required to be linked by the operating department, the emergency department and the sterile supply department upon considerations of accessibility of emergency patients and the infection control. 2) The intensive care unit consists of five areas such as the patient area, the medical staff area, the material and equipment area, the patient family area, and the public area. 3) The location of spaces in the intensive care unit is classified by three methods such as connection by view, circulation and connection to corridor. The [table 20] summarizes the type of space and the average size of the space in intensive care unit. Implications: This study is a basic research for guideline of intensive care units, and need to be followed by further study using various perspectives and methods in the future.

Identifying business ethics components according to business area for small and medium-sized fashion companies (중소 패션기업의 업무영역별 비즈니스 윤리 요소 도출)

  • Kim, Soo-Kyung;Yoh, Eunah
    • The Research Journal of the Costume Culture
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    • v.27 no.5
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    • pp.415-432
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    • 2019
  • The purpose of the present study was to generate a list of business ethics components according to business area for small and medium-sized fashion companies. Based on the literature review, 21 components of business ethics components were identified within five business areas. Ten CEOs(Chief Executive Officers) each participated in an in-depth interview, sharing ethical and unethical cases from their own businesses. Constant comparative analysis was used to generate important business ethics components from those cases. In results, important business ethics components for each business area are: 1) using human-friendly materials, strengthening sustainable technologies, using vegan materials, concerning safe process, and reducing waste in the material production and sourcing area, 2) enhancing an efficiency in design, developing recycle/reuse designs, avoiding to copy designs, and using messages for public interest in the product design area, 3) concerning fair-trade, reducing harmful substance, saving energy, and using ethical supply channels in the distribution and logistics area, 4) acquiring certifications, promoting consumer protection, avoiding exaggerative/false advertisements, and promoting social contributions in the management and marketing area, and 5) promoting workers' rights, complying with the law, and investing on employee educations in the labor management area. All of the ethical and unethical cases of the ten companies have involved aspects of the 21 components, thereby enhancing understandings on how each issue is being seriously considered and/or handled in the small and medium-sized fashion companies. Study findings may provide a basis for development of a research model for quantitative studies and/or educational programs related to business ethics in the fashion industry.

Life Evaluation of Nano-Composites According to the Addition of MgO (산화마그네슘 첨가에 따른 나노컴퍼지트의 수명평가)

  • Shin, Jong-Yeol;Jeong, In-Bum;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.6
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    • pp.390-395
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    • 2015
  • Molded insulation materials are widely used from large electric power transformer apparatus to small electrical machinery and apparatus. In this study, by adding MgO with the average particle of several tens nm and the excellent thermal conductivity into molding material, we improved the problem of insulation breakdown strength decrease according to rising temperature in overload or in bad environmental condition. We confirmed the life evaluation by using the insulation breakdown and inverse involution to investigate the electrical characteristics of nano-composites materials. By using a scanning electron microscope, it is confirmed that MgO power with the average particle size of several tens nm is distributed and the filler particles is uniformly distributed in the cross section of specimens. And it is confirmed that the insulation breakdown strength of Virgin specimens is rapidly decreased at the high temperature area. But it is confirmed that the insulation breakdown strength of specimens added MgO slow decreased by thermal properties in the high temperature area improved by the contribution of the heat radiation of MgO and the suppression of tree. The results of life prediction using inverse involution, it is confirmed that the life of nano-composites is improved by contribution of MgO according to the predicted insulation breakdown strength after 10 years of specimens added 5.0 wt% of MgO is increased about 2.9 times at RT, and 4.9 times at $100^{\circ}C$ than Virgin specimen, respectively.

물질사용자의 관계구조에 관한 목회상담 연구 - 교도소 마약 재소자를 대상으로 -

  • Jang, Chang-Min
    • 한국사회복지학회:학술대회논문집
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    • 2004.04a
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    • pp.705-731
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    • 2004
  • This study is to be used for research material for pastoral counseling, by analyzing grounded-theoretically how substance abusers' awareness of self and experience of relations affects problems in abusing drugs. The subject of this study was chosen as 9 prisoners who were able to participate in group counseling, among those who were in prison for substance abuse and had more than 6 months of penal servitude left. In addition, in order to indicate counseling research methods through this study, 12 group counselings were carried out during October 24th. 2002 and February 14th. 2003 and verbatim were written out to be used as original material. After the research material was analyzed, they could be categorized into 60 concepts on the whole from 'conflict' and 'constraining thinking' to 'rationalization' and 'avoidance'. When these concepts were organized into groups of similarity, there were all together 20 categories. From this study, it can be found that substance abusers had "problems about self" and "problems about relations". The factor which affected their use of drugs was the area of relations, where as henceforth their use of drugs, the situation in which they could not escape from the use of substances was affected by problems within the area of self. When facing such problems as substance abuse, the pastoral counselor must create a holding environment through counseling, and perform good enough mothering by being insightful and providing active support on the problem. They must also help one's growth into "an empathizing self", "an accepting self", "a trusting self", "a hopeful self", who can empathize, accept, trust and hope, through experience in separation from the problem, conversion, meta-communication, self-rumination, relations and inspiration of hope. Likewise, the church must be able to act as a "place of growth and skill" which aids in the forming of relations and helps to be aware of self through experience in, and understanding of, relations.

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Effect of Mulching Materials on Growth and Agronomic Characteristics of Angelica gigas in Southern Area (남부지방에서 피복재료가 참당귀(Angelica gigas Nakai)의 생육과 주요 형질에 미치는 영향)

  • 윤혜경;최성규;이종일;윤경원;서영남;천상욱
    • Korean Journal of Plant Resources
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    • v.13 no.1
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    • pp.11-17
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    • 2000
  • In an effort to produce high quality Angelica gigas in the southern area of Korea, a variety of mulching materials were used to prevent withering during the summer. The experimental results are summarized as follows. Soil water content and temperature under various mulching materials were higher than those without mulching, in all the cases studied. Among various mulching materials P. E.(polyethylene) mulching material showed the highest effect. The appearance of weeds was the lowest when using the black P. E. mulching, while growth of weeds was the greatest when using transparent mulching. Growth and development of the plant were better with P. E. mulching than straw mulching or no mulching, allowed for more and bigger leaves. The bolting rate was about 2∼5%, with a slightly larger value under P. E. mulching. Under P. E. mulching, probably due to good physical properties of the soil the number of roots was large, and the length and diameter were good. Active growth of roots under P. E. mulching resulted in a yield increase of the plant. The black P. E. mulching material showed a prominent effect on suppression of weed growth, and the black P. E. material was considered to be the most recommendable among various P. E. mulching materials when there is a lack of labor.

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