• 한국화재소방학회논문지
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• 제15권2호
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• pp.53-58
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• 2001

본 연구에서는 조선 및 화학공장 등 산업현장에서 용접·용단작업 공정에서 비산 되는 불티에 의한 화재 예방을 위하여 불티 차단막에 관한 방염 및 난연 성능 평가를 실시하였다. 방염성능 실험결과 기존제품의 용접불티 차단막 6종 모두 충분한 방염성능을 갖고 있었다. 그러나, 용접·용단 불꽃에 의한 난연성 실험 결과 섬유유리에 수지코팅한 제품 2종은 용접·용단 불티에 대한 화재예방성능이 부족한 것으로 나타났다. 용접 불티 차단막의 최소산소지수의 국내기준은 30이상으로 고려하는 것이 좋을 것으로 사료된다. 용접 불티 차단막의 성능향상을 위한 제속적인 연구가 필요하며, 방염 및 난연성능 기술지침 개발의 기초자료로서 활용될 수 있을 것으로 사료된다.

• 비파괴검사학회지
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• 제36권2호
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• pp.130-137
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• 2016

Non-destructive testing methods for composite materials (e.g., carbon fiber-reinforced and glass fiber-reinforced plastic) have been widely used to detect damage in the overall industry. This study detects defects using optical infrared thermography. The transient heat transport in a solid body is characterized by two dynamic quantities, namely, thermal diffusivity and thermal effusivity. The first quantity describes the speed with thermal energy diffuses through a material, whereas the second one represents a type of thermal inertia. The defect detection rate is increased by utilizing a lock-in method and performing a comparison of the defect detection rates. The comparison is conducted by dividing the irradiation method into reflection and transmission methods and the irradiation time into 50 mHz and 100 mHz. The experimental results show that detecting defects at 50 mHz is easy using the transmission method. This result implies that low-frequency thermal waves penetrate a material deeper than the high-frequency waves.

• Design & Manufacturing
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• 제10권1호
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• pp.46-50
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• 2016

Beverage industry is the largest in the domestic packaging market. Usually, beverage is packed in palstic, glass, can and paper bags. However, the cost of these packaging methods are very high and the recycling are not easy to handle. Pouch packaging method is one of the packaging method to solve the drawbacks of former beverage containers. The pouch packaging methods are difficult to control, it requires a number of processes. A vertical form-fill-seal machine which is self-developed is the capable of processing in a single apparatus. In this paper, in order to develop a pouch equipment, the structure analysis was carried out for the main unit. The stress and deformation of feed unit which removes the air inside the pouch while feeding down has been analyzed. It receives the greatest impact from the rolling part. And also, the sealing unit has been analyzed. The analysis result shows that the stress and the deformation was slight to be applicable to the actual system.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.53-59
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• 2011

Recently there have been considerable attentions on nanoimprint lithography (NIL) by the display device and semiconductor industry due to its potential abilities that enable cost-effective and high-throughput nanofabrication. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper we focused on the deformation of the $2^{nd}$ generation TFT-LCD sized ($370{\times}470mm^2$) large-area soft mold in the UV imprinting process. A mold was fabricated with PDMS(Poly-dimethyl Siloxane) layered glass back plate(t0.5). Besides, the mold includes large surrounding wall type protrusions of 1.9 mm width and the via-hole(7 ${\mu}m$ diameter) patterend area. The large surrounding wall type protrusions cause the proximity effect which severely degrades the uniformity of residual layer in the via-hole patterend area. Therefore the deformation of the mold was calculated by finite element analysis to assess the effect of large surrounding wall type protrusions and the flexiblity of the mold. The deformation of soft mold was verified by the measurements qualitatively.

• 한국재료학회지
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• 제19권8호
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• pp.407-411
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• 2009

Reflection properties, such as specular reflection and diffuse reflection, are very important optical properties for the reflector, which has high reflectance in the display and architecture industry. Calcite is lowcost, nontoxic, and stable over a wide temperature range. Therefore, it is one of the most widely using fillers in many industries and has some advantages over titania as a filler to improve reflectance. However, optical properties, especially those of ceramic-filled composites, have not been analyzed. We studied the reflectance of calcite composites with their surface roughness. The reflectance of the composites was determined using a UV-visible spectrometer. The surface morphology and the micro-structure of the composites were investigated by atomic force microscope. The reflectance of the composites was improved by increasing the content of calcite in the calcite-frit composite. The reflectance is related with the surface roughness in the composites. However, the reflectance depends on the calcite contents in materials with similar surface roughness.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.45-50
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• 2011

The efficiency of solar cell was about 4[%] in initial stage of photovoltaic industry, but it has quite a lot of efficiency through technology advances. Today, the efficiency of c-Si solar cells is about 17 to 19[%] and the efficiency of PV modules is about 14 to 15 [%]. We called that electrical losses occurred in the Conversion of solar cells to PV modules are CTM loss(Cell To Module loss), the CTM loss typically has a value of about3~5[%]. The more efficiency of solar cell increase, differences are larger because the efficiency decrease owing to physical or technical problems occurred in the Conversion of solar cells to PV modules. In this study, the power loss factors occurred in the Conversion of solar cells to PV modules are analyzed and it is proposed that how to reduce losses of the PV module. The types of power loss factor are (1)losses of front glass and encapsulant(generally EVA sheet), (2)losses by sorting miss, (3)losses by interconnection, (4)losses by the field aging of PV modules. In further study, experimental and evaluation will be conducted to make demonstrate for proposed solutions.

• 건축역사연구
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• 제13권4호
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• pp.75-88
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• 2004

The German Werkbund, which was founded in 1907, played an important role in the history of modern architecture. Its exhibition 1914 in Cologne is estimated as a meaningful event in the development of modern architecture. Especially two examples, among which were built at that time, are worthy of notice. The one is the 'Modelfactory' by Walter Gropius and the other 'Glashaus' by Bruno Taut. Generally in the Textbook on the history of modern architecture, the Taut's Glashaus is rarely mentioned or described as a early example of some expressionistic architecture, while the Modelfactory by Gropius is regarded as an essential workpiece in the early stage of modern movement. the time of searching alternative not only from rationalistic modernism but also postmodernism and today in the time of plurality, Taut's Glashaus could bring us more interesting and meaningful aspects in architectural design. Through investigating the background in the planning stage and analysing the composition of space, construction, circulation etc. it is to try to understand the building as really as what it was. Furthermore, historical meanings of the building in the modern architecture is reinterpreted in the following aspects; what should be reflected in architecture and how could 'Zeitgeist' be architecturally adopted?

• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.6-12
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• 2013

Aerosol deposition(AD) coating that enable fabricate films at low temperature have begun to be widely researched for the integration of ceramics as well to realize high-speed deposition rates. For application of ceramic thick film by AD to display and electronic ceramic industry, fabrication of dense structure with a no cracking is required. In this study, to fabricate dense ceramic thick film, the effect of crystal phase of starting powder was investigated. For this study, amorphous and crystalline $SiO_2$ powders were used as starting powders. Two types of $SiO_2$ powders were deposited on glass substrate by AD. In the case of amorphous $SiO_2$ powder, the deposited films had extremely incompact and opaque layer, irrespective of particle size. In contrast to amorphous powder, in the case of crystalline powder, porous structure layer and dense microstructure with no cracking layer were fabricated depending on the particle size. The optimized starting powder size for dense coating layer was $1{\sim}2{\mu}m$. The transmittance of film reached a maximum of 76% at 800 nm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.545-545
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• 2007

Recently, innovative process has been investigated in order to replace the conventional high-cost micro patterning processes on the electronic products. To produce desirable profit margins from this low cost products, printed circuit board(PCB), will require dramatic changes in the current manufacturing philosophies and processes. Innovative process using metal nano particles replaces the current industry standard of subtractive etched of copper as a highly efficient way to produce robust circuitry on low cost substrates. An advantage of using metal nano particles process in patterned conductive line manufacturing is that the process is additive. Material is only deposited in desired locations, thereby reducing the amount of chemical and material waste. Simply, it just draws on the substrate as glass epoxy or polyimide with metal nano particles. Particles, when their size becomes nano-meter scale, show some specific characteristics such as enhanced reactivity of surface atoms, decrease in melting point, high electric conductivity compared with the bulk. Melting temperature of metal gets low, the metal nano particles could be formated onto polymer substrates and sintered under $300^{\circ}C$, which would be applied in PCB. It can be getting the metal line of excellent electric conductivity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.77-77
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• 2007

The development of next generation displays such as flexible display is a major challenge. Most materials and processes in current flat panel display industry cannot be transferred to flexible substrates. Typically, indium tin oxide (ITO) thin films are brittle and need to be deposited at high temperature to achieve an optimal opto-electrical property, therefore ITO films cannot be used as a flexible electrode. Up to date, many alternative materials to ITO have been proposed such as conductive polymers, nanometals, solution deposited transparent conductive oxide(TCO) and carbon nanotubes(CNTs). CNT based transparent conductive films are fabricated on glass and polymer substrates. CNT thin films exhibit a sheet resistance ($R_s$) of nearby $10^3\;{\Omega}/sq$ with a transmittance of around 80% on the visible light range, which is attributed by excellent dispersion and interaction among CNTs, solvents and polymeric binders. This talk will present the current studies, opto-electrical properties, design criteria and its applications for CNT-based transparent conductive films.