• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.702-706
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• 2009

The urethane based on prototype mold is very useful for making prototype. Especially, the method of stereolithography mold was turned out to be rapid and accurate 3-dimensional modeling data. Urethane resin (TSR-755) has heat resistant and is good for make hundreds of prototypes. In this study, we compared with various designed cooling channel and analyzed of cooling effect and deformation using commercial code Simpoe-Mold for injection mold. As a result, efficiently arranged cooling channel could make 19% of shrinkage to reduce and 46% cooling time to reduce.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.331-335
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• 1997

'인체공학적 학생용 책상과 의자 개발(김정용, 1996)'에 관한 연구에서 제작된 1차 시제품을 면밀히 재평가한 결과, 책상 상판의 상하 탄력으로 인한 안전성, 파이프 처리 기술과 높이 조절의 용이성, 한 호수의 의자로 초등 학생부터 고등 학생까지 만족시키지 못하는 신체 적합도 등의 보완점이 제기되었 다. 이를 해결하기 위해 1차 시제품에서 추구하고자 했던 인체공학적 설계 요소를 유지하면서 재료역 학적인 요소와 파이프 가공 기술 등을 고려하여 개선안을 제시하였다. 책상의 무게중심이 중앙에 위치 하도록 다리를 안쪽으로 이동시켜 상판의 흔들림을 방지하였고, 파이프 사이에 삽입된 PVC와 열쇠 모 양의 조립 구멍, 특수 설계된 나사로 조절이 용이하고 고정성과 안전성이 향상되었으며, 파이프 용접 방식으로 넓은 범위의 신체 특성을 포함할 수 있게 되었다. 의자는 초등 학생용과 중.고등 학생용으로 나누어 2호로 설계하였고, 좌판의 곡면을 보다 완만하게 디자인하여 Lumbar와 오금 부위의 압박을 최 소화하였다. 이 외에도 좌판 밑부분에 보조 서랍을 두어 수납 공간의 부족 문제를 해결하였으며, 등받 이에 손잡이용 구멍을 뚫어 이동 시 편의를 제공하였다. 다양하고 세심한 평가 결과를 바탕으로 세부 설계를 완성하였고, 개선된 2차 시제품은 신체 적합도가 더욱 향상되고, 기능성과 편이도가 증대되어 초.중.고등 학생용 교구로서 학생들의 건강한 신체 발달과 학습 의욕 증가 및 중소기업의 이윤 향상 이 기대된다.

• Journal of the Speleological Society of Korea
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• no.79
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• pp.65-72
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• 2007

인공토굴(人工土窟) 숙성식품의 장기가공보관 수단의 원조로 자리 잡아, 광천옹암리 토굴이 전통식품 산업의 지혜와 관광산업의 역동으로 변신하고, 인공 굴은 폐광토굴에서 농산물저장을 위한 인공제작 굴의 활용기술로 이어져 산업화사회에 기여하고 있다. 대표적인 인공토굴중의 하나는 광천토굴이며, 마을뒤편 야산에 활석암으로 된 암반을 굴착한 토굴이다. 폭과 높이가 각각 2m 정도, 200여 m의 토굴 속에 수많은 젓갈을 담은 드럼통을 저장하여 숙성, 발효시킨다. 젓갈은 우리나라의 대표적인 수산발효식품이며, 어패류 등에 비교적 다량의 식염을 가해 자가소화효소 및 미생물분해 작용으로 알맞게 숙성되는 원리를 이용한다. 젓갈은 일종의 균 식품으로 식품을 발효시킴으로써 독특한 맛과 향 영양을 갖게 되며, 빵, 요구르트, 장류(간장 된장 등), 김치, 막걸리, 동동주, 식혜뿐 아니라 심지어는 버섯조차도 균 식품에 해당한다. 특히 어패류를 염장 발효시켜서 독특한 감칠맛이 나도록 한 우리나라 특유의 저장식품으로 예로부터 기호식품, 조미료 및 김치의 재료로서 널리 식용되어 왔던 양질의 단백질인 동시에 칼슘과 지방질 공급원이기도 하다. 최근에는 상품화된 자연친화적 농산물저장 굴로 사용되는 인공토굴도 등장하였다. 그것은 타공판과 흙을 이용한 생태환경지중건축물(生態環境地中建築物)로서 우리조상들이 오래전부터 지열을 이용하여 주거와 농산물을 저장하였던 재래식 토굴을 현대화시킨 구조물의 지중저장토굴 공간이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.1
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• pp.42-46
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• 2003

Liquid PVC, which is used widely as fiber coating, has brilliant non-luster effect, but it decreases flexibility of coated fiber surface. We used liquid silicone rubber in elastomer series as a coating material to alleviate this problem. We have conducted the former liquid PVC processing and used pressure of roller and preliminary hardening of processing. In this experiment, We measured 70 degree of hardness, 10.3 MPa of tensile strength and 200fs of tensile elongation of Liquid PVC-coated plastic fiber. We measured 40 degree of hardness, 5.1 MPa of tensile strength and 460% of tensile elongation of Liquid silicone PVC-coated plastic fiber. Therefore, Without the second process, Liquid silicone rubber coating increased non-luster effect and flexibility of plastic fiber surface more than Liquid PVC coating.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1215-1219
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• 2007

In this paper, we present a study on the polypropylene/thermotropic liquid crystalline polymer blends. In previous researches, the blends are fabricated at very high temperatures, at least 300oC, since the TLCPs investigated in most studies have melting temperatures higher than 270oC. As a consequence, the thermal degradation of PP can not be avoidable. In order to obtain high physical properties, the excess amount of TLCP must be added. In this study, a new type of TLCP was used in the PP/TLCP blends. Since the new TLCP has a melting point of 220oC, the blending can be performed at much lower temperature than the previous studios. The new PP/TLCP shows similar or somewhat higher physical properties than those of the previous studies. It is proved that the new TLCP can be used as a reinforcement material in PP based blends.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.235-235
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• 2010

장비와 cutting기술의 발전으로, 높은 효율성을 지닌 어려운 작업 재료들의 고속 건조 가공기술은 생산성, 가격 인하 그리고 환경적인 관점에서 중요성이 증가하게 되었다. AlTiN에서 Si의 첨가는 40GPa이상의 고경도와 1000도 이상의 산화온도를 지닌 나노혼합물 코팅을 형성시키는 것으로 알려졌다. 또한 Si가 아닌 다른 soft 물질을 첨가하고 3성분 이상의 다성분계 박막을 형성하는 실험을 하여, 물성이 어떻게 달라지는지 확인하였다. 특히, 나노 코팅층 형성이 매우 어려운 Al-Ti-N 합금계에서 Si, Cu 첨가의 영향 및 이러한 코팅층 형성을 단일합금을 이용하여 행하였을 때, 장점을 확인하였다. 이러한 연구를 위하여 Ti-Al의 합금 조성을 경도가 가장 우수한 것으로 알려진 50 : 50으로 하여 타겟을 만들고 증착시켜 기초실험을 진행하여 물성조건을 확인하고 이에 근거하여 실험을 진행하였다. 또한 3 원계 합금으로서 Cu, Si를 첨가한 연구를 수행하였다. 또한, 최적 조성의 합금 조성을 확인한 후, 단일 합금 타겟을 제조하였으며 이를 이용하여 형성된 코팅층과 다성분계 타겟을 이용한 박막의 물성을 비교하였다. 증착된 박막의 분석장비로는 SEM, EDS, XRD 와 AFM등을 이용하였으며, 막의 조직과 증착 두께, 조도 그리고 경도를 확인하고 막의 물성 특성이 향상됨을 입증하였다.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.73-84
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• 2018

Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

• Journal of the Korean Institute of Gas
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• v.2 no.1
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• pp.99-106
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• 1998

In order to investigate the impact properties of structural materials for LNG tank, instrumented Charpy impact tests were carried out at cryogenic temperatures. $9\%$ Ni steel showed a superior fracture resistance because of less degradation in toughness until 77 K. From the load-deflection curve obtained by an instrumented methods it was found that with the decrease of temperature from 173 K to 77 K, the peak load in the curve increased, but the total absorbed energy decreased. In addition, the energy absorbed during the crack growth was larger than one absorbed in the process of crack initiation. In SUS304L material, the energy absorbed in the process of the crack initiation was relatively large, but the energy absorbed in the process of crack growth was small, the behavior of absorbed energy was well agreed with the observations of the fracture surface which showed a relatively smooth fracture surface. The absorbed Charpy impact energy in the case of A5083 alloy was lower as compared with other steels, and some cracks were observed along the crack propagation direction at the fracture surface of 77 K.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4388-4397
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• 2015

The purpose of this study was to research the property change of acrylic resins depending on the induced-beam change and research the improved physical property of dry-heat and microwave-cured dental place acrylic resin in order to develop the acrylic resins with the optimum characteristic. As a result of observing flexural rigidity, hardness and color difference, the dry-heat-cured specimens of Vertex RS and Paladent 20 showed ideal property at 5, 15, and 25 kGy irradiation. The microwave-cured specimens of Vertex RS and Paladent 20 showed ideal property at 5 kGy irradiation. The correlation analysis showed a positive correlation among ARD, flexural rigidity (0 418), E coefficient (0.675) and Barcol hardness (0 588). The radiation cure technology is helpful for relieving the contamination caused by the manufacture of polymer composite. It can significantly contribute to the fusion of ultra violet cure technology and nano technology and the improvement of mechanical property without giving effect to the workability of polymer.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.685-693
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• 2015

In this study, we found that it is necessary to use the relatively new resource from seaweed extracts to extract and process pulp and create a local brand that can contribute to the local fishermen, development of new bio material, establishment of natural infrastructure, and acquisition of foreign investment. This study's seaweed pulp separation process is very overwhelming as seaweed is a compound of glycoside and polysaccharide. Nevertheless, we intend to develop a purification process and introduce applied technology to explore a new applied technology of pulp process. Once this technology is fully developed and mass produced, it would contribute to greater exports and increasing income level for the local fishermen. The ultimate goal of this study is to gather technical data from the first and second years of application, apply seaweed pulp to increase bio effect, and develop new functional bio-plastic packaging material, raw material, and samples with special characteristics of high molecules.