• Journal of Advanced Marine Engineering and Technology
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• 제30권5호
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• pp.636-644
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• 2006

Recently, there were some successful examples that the laser welding was introduced into production line. However, the spread of laser welding is not sufficient in many industries. There are several reasons why it is difficult to penetrate the laser welding into production lines. Because it is different from reflection, absorption and permeation of laser beam according to material and surface condition. Moreover, there are significant problems in processing such as absorption and scattering of beam by the induced plasma or plume. Therefore, understanding of mechanism on formation of weld defect in laser welding of the laminated core for motor is very important. In this paper, it was analyzed in terms of materials which was source of defect in laser welding and conventional arc welding. As a results of analysis, insulation coating film of the laminated core was judged to main factor of weld defect. it could be well aware as tracing carbon volume, and it was deduced that weld defect by insulation coating film was caused by difference of mechanism between the two heat sources.

• 한국건축시공학회지
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• 제12권5호
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• pp.539-547
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• 2012

To manufacture laminated wood with improved mechanical properties by providing uniform adhesiveness, the adhesive was applied and the plate adhesive was laminated on the wood surface. Then, after laminating the wood on the top part of the adhesivebond, it was heated and dried while the adhesive was stiffened using microwaves, and the test piece was manufactured by compressing it with the press machine for thirty minutes. The temperature and the water content were examined according to the heating time of the wood heated with the microwave, and testing was conducted on the shear strength and flexural strength of the wood. In addition, the microstructure of the adhesive bond between the wood was recorded to confirm the penetrabilityinto the wood structure for the adhesive. After the test was conducted, it was found that the test piece manufactured with wood that has its water content leveled with the microwave heating showed improved shear strength and bending strength compared to the standard test piece. With regard to adhesives, liquefied polyvinyl acetate resin and plate's PVB resin were found to have superior adhesive strength. Also, after filming the cellular microstructure, it was found that when the laminated wood is heated with microwaves, the infiltration of the adhesive into the inside of the wood becomes easy, which makes it effective for improving adhesiveness.

• 한국철도학회논문집
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• 제19권1호
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• pp.1-10
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• 2016

본 논문은 고속열차 객실 내 유리창의 차음 성능을 향상시키기 위한 기반연구로, 접합유리에 사용되는 고분자 필름의 물성과 음향학적 특성을 분석하여 그 상관관계를 살펴보고자 하였다. 기존에 사용되고 있는 PVB(polyvinyl butyal) 필름 및 다른 단량체 비율을 가지는 PVB 유도체, 그리고 유리 사이 차음재로 사용가능 한 PC(polycarbonate)의 동적기계적 특성을 분석(DMA)하였다. DMA 분석을 통해 상온에 가까운 온도범위에서 유리전이온도($T_g$)를 가지며 tan ${\delta}$(loss tangent) 값이 큰 것으로 나타난 PVB-HEMU 시편의 댐핑(damping) 성능이 가장 우수할 것으로 예측하고, 이를 고속철도 차량의 접합유리창과 동일한 구조에서의 투과손실 시험과 해석을 통해 검증하고자 하였다. 접합필름의 종류에 따른 유리창 투과손실 값을 투과손실 측정(인텐시티법)과 FE 해석을 이용해 도출하고, 고분자 필름의 물성과 음향성능 간 상관관계 분석을 위한 기초자료를 구축하였다.

• 한국지역사회생활과학회지
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• 제15권2호
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• pp.179-187
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• 2004

The purpose of this study is to investigate the preservation of traditional sesame dasik when stored in different packaging material by comparing its physical and sensorial characteristics. The quality and sensory characteristics of sesame dasik that were evaluated were moisture content, water activity, number of microflora, texture profile, Hunter color different value, and sensory properties (color, chewiness, overall acceptability, etc) during the storage at 35\pm1^\circ{C}$ temperature and $73\pm{2%}$ relative humidity. And the packaging materials were paper boxes (coated 0.02mm thickness polyethylene film), plastic boxes, and oriented polypropylene laminated film. Traditional sesame dasik is made from sesame powder 100g, honey 25g, rice syrup 25g, and table salt 0.5g. During the storage period, the changes in water content and water activity of sesame dasik with different packaging material showed a slight decline. On the other hand, it increased in hardness, and "a" and "b" value of Hunter color difference during the storage. Texture profile analysis data change in hardness was the greatest after the third day in a paper box, and it was affected by the moisture content of dasik and the temperature and relative humidity of the air. Therefore plastic boxes or oriented polypropylene laminated film was found to be better suited than paper boxes for storing sesame dasik.

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.813-820
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• 2015

We have studied commercialization and process optimization of protective film on transparent conductive coated substrate, nano silver on flexible PET (poly ethylene terephthalate), by means of roll-to-roll micro-gravure coater. Nanosilver on flexible PET substrate is potential materials to replace ITO (indium tin oxide). Protective film is most important to maintain unique silver pattern on top of transparent PET. PSA pressure sensitive adhesives) was developed solely for nano silver on PET and protective film was successfully laminated. We have optimized all process conditions such as coating thickness, line speed and aging time & temperature via experimental design. Transparent conductive film and its protective film developed in this research are commercially available at this moment.

• 한국식품과학회지
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• 제28권4호
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• pp.714-719
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• 1996

현미를 투습 투기성이 없는 플라스틱 필름 적층 4겹 포장재에 넣고 저장 온도를 달리 하면서 물리화학적 변화를 관찰 하였다. 곡립의 경도는 $20^{\circ}C$ 이하에서는 거의 변화가 없었으며 $30^{\circ}C$에서는 저장기간이 길수록 증가하였다. 그러나 $40^{\circ}C$에서의 경우는 $30^{\circ}C$와는 다른 양상으로 증가하였다. 곡립의 색도는 L, a, b값 모두 $30^{\circ}C$에서는 큰 변화를 보이지 않았지만 a와 b값은 급격히 증가하였으며, L값은 오히려 저장 3개월 이후부터 급격한 감소 현상을 보였다. 발아율은 $20^{\circ}C$에서는 변화가 없었으나 $30^{\circ}C$에서는 저장 2개월 이후부터 급격히 감소하였으며 $40^{\circ}C$에서는 저장 1개월에 전혀 발아되지 않았다. 현미 가루의 DSC 특성치는 큰 변화를 보이지 않았지만 호화 온도 범위는 저장온도 $30^{\circ}C$까지는 저장 온도가 높을수록 저장 기간이 길수록 증가하는 현상을 보였다. 이러한 결과로 볼 때, 저장중 현미의 품질을 유지하기 위해서는 플라스틱필름 적층 4겹 포장재를 이용하여 $20^{\circ}C$ 이하의 온도에서 저장하는 것도 하나의 방법임을 알 수 있었다.

• Advances in nano research
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• 제5권4호
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• pp.337-357
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• 2017

Knowledge of thin films mechanical properties is strongly associated to the reliability and the performances of Nano Electro Mechanical Systems (NEMS). In the literature, there are several methods for micro materials characterization. Bulge test is an established nondestructive technique for studying the mechanical properties of thin films. This study improve the performances of NEMS by investigating the mechanical behavior of Nano rectangular thin film (NRTF) made of new material embedded in Nano Electro Mechanical Systems (NEMS) by developing the bulge test technique. The NRTF built from adhesively-bonded layers of basalt fiber reinforced polymer (BFRP) laminate composite materials in Nano size at room temperature and were used for plane-strain bulging. The NRTF is first pre-stressed to ensure that is no initial deflection before applied the loads on NRTF and then clamped between two plates. A differential pressure is applying to a deformation of the laminated composite NRTF. This makes the plane-strain bulge test idea for studying the mechanical behavior of laminated composite NRTF in both the elastic and plastic regimes. An exact solution of governing equations for symmetric cross-ply BFRP laminated composite NRTF was established with taking in-to account the effect of the residual strength from pre-stressed loading. The stress-strain relationship of the BFRP laminated composite NRTF was determined by hydraulic bulging test. The NRTF thickness gradation in different points of hemisphere formed in bulge test was analysed.

• 한국포장학회지
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• 제7권2호
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• pp.1-5
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• 2001

기능성 MA필름을 생산하여 이를 골판지 상자의 내부에 첨합시킨 FC상자의 활용가능성을 조사하고자 골판지 상자와 기능성 MA필름을 골판지 상자 내부의 1면당 5곳씩 첨합시킨 FC포장구와 LDPE 및 기능성필름으로 토마토를 포장하여 $25^{\circ}C$에 저장하여 품질변화를 조사한 결과, FC 상자와 LD와 CE 포장구는 대조구 보다는 중량감소율이 현저히 낮았으며 비타민 C의 함량도 14% 높게 유지되고 있었다. 산도는 포장구들간에는 큰 차이가 없었고 당도는 FC 포장구 보다 대조구에서 19% 더 높아 그만큼 품질 변화가 일어난 것으로 판단되었다. 외관 및 부패를 조사한 결과 대조구에 비해 개발 포장구에서 품질이 더 높게 유지되고 있어 FC 포장재를 토마토 포장용 상자로 활용 가능성이 확인되었다.

• Archives of Pharmacal Research
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• 제19권1호
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• pp.1-5
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• 1996

Laminated films composed of drug-containing reservoir layer and drug-free membrane were prepared. Zero-order drug release with lag time was achieved by laminating drug-free film onto the reservoir layer, while burst effect was observed on cast-on film. The rate controlling membrane was either attached to or cast directly into the reservoir. The release rate was independent on the reservoir composition but dependent on the composition of rate-controlling membrane. In growth inhibitory test of cephalexin from Eudragit RS film to Streptococcus Mutans, the disk even after release test for 72 hours showed more bacterial growth inhibition than that of control. Permeation of drug through rat skin was proportional to the HPC fraction in the film. We could control the release of cephalexin from the film by changing the fraction of Eudragit RS, HPC and DEP content. Consequently, Eudragit RS/HPC film was found to be very effective system for local delivery of drugs.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.44.1-44.1
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• 2007