• Journal of the Korean Wood Science and Technology
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• 제30권2호
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• pp.172-179
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• 2002

본 연구에서는 MDF와 잣나무 판재에 대한 난연처리 및 난연도장 처리 시험편에 대한 난연 효과에 대해 고찰하였다. 무처리 MDF와 잣나무판재에 대한 td𝜃은 각각 279.5, 182.5로 나타났으나 난연침지 처리된 무늬단판을 오버레이한 MDF를 난연도장 처리 한 경우 높은 난연성능을 나타냈다. 난연처리한 잣나무판재에 난연도장 처리를 할 경우 th𝜃가 90으로 나타났고, 난연침지 처리 된 무늬단판이 오버레이 된 MDF에 난연도장처리한 경우에는 th𝜃가 0으로 나타난 가장 뛰어난 난연성능을 나타냈다. 전체적으로 난연처리 및 난연도장처리를 한 경우 th𝜃가 감소하는 것으로 나타나 난연성능이 개선되는 것으로 나타났다. 또한 연소도 시험결과 시험편의 중량감소율은 난연처리와 난연도장처리에 의해 감소함으로써 난연성능이 개선되는 것으로 나타났다. 또한 착화시간과 잔염시간의 측정결과도 유사하게 나타났으며 난연침지 처리 된 무늬단판이 오버레이 된 MDF 및 난연처리된 잣나무판재에 난연도장 처리한 경우 무처리된 경우에 비해 착화시간은 증가되고, 잔염시간은 감소하는 것으로 나타났다.

• 한국정보전자통신기술학회논문지
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• 제16권5호
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• pp.217-222
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• 2023

본 논문은 제조공정이 단순하고, 공정시간도 매우 짧아 제조원가를 절감할 수 있는 고분자 유기하드마스크를 합성하는데 목적을 두었다. 승화 정제 장치를 통한 잔류금속을 측정한 결과, 9-Naphthalen-1-ylcarbazole(9-NC)은 4th zone에서 101.75ppb, 2-Naphthol(2-NA)은 5th zone에서 306.98ppb, 9-Fluorenone(9-F)는 4th zone에서 5th zone 사이에서 129.05ppb로 측정되었다. 그리고 합성된 유기하드마스크를 필터 시스템을 거친 후 잔류금속을 측정한 결과 9 ~ 7ppb 측정되었다. 또 열분석 변화를 측정한 결과, 2.78%로 감소하였고 분자량은 942로 측정되었고 탄소 함량은 89.74%이고 수율은 72.4%로 나타났다. 에칭 속도는 평균 18.22Å/s로 측정되었고 코팅 두께 편차는 평균 1.19로 측정되었다. 유기하드마스크의 입자크기가 0.2㎛ 이하에서는 입자가 존재하지 않았다. 코팅 속도를 1,000, 1,500, 1,800rpm으로 변화를 주어 코팅 두께를 측정한 결과, 수축률은 17.9에서 20.8%까지 측정되었고 코팅 결과 SiON과 접착력이 우수하고 유기하드마스크가 균일하게 도포되었음을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1376-1380
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• 2005

In recent automotive industry, vehicle weight can be reduced by one-step forming of tailored blanks welded with two or more sheets of metal blanks. Tailored blank(TB) welding is a production method for blanks involving welding together materials of different quality, thickness, and coating, and has proved popular in fabrication automotive parts. This paper deals with the forming characteristics of mash seam welded tailored blanks. Using these forming characteristics, the bumper beam was developed using the mash seam welded tailored blank with the different thickness. We performed the forming simulation with respect to strain distribution on blank during the stamping of the bumper rail part. Based on these results, we made some stamping tryouts with selected types of blank designs to investigate the formability of tailored blank with different thickness. During the tryouts, we knew that it was important the BHF(Blank Holding Force). We obtained to reducing 10.5% weight and cost with adapting the bumper beam of automotive component using the tailored blank of mash seam welding.

• 폴리머
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• 제36권3호
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• pp.351-356
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• 2012

디스플레이 전자 장치의 제작에 사용되는 대표적인 유기물첨가제는 아크릴 바인더이다. 이 아크릴 바인더는 라디칼 중합으로 제조되는데 본 연구에서는 glycidyl methacrylate(GMA), methyl methacrylate(MMA), methacrylic acid(MAA)를 이용하여 공중합을 시도하였다. 그리고 이 공중합체의 접착력 향상을 위해서 실란계 mercaptane 화합물을 사슬 이동제(CTA)로 사용하였다. 본 연구에서 사용된 CTA는 (3-mercaptopropyl) trimethoxysilane(MPTMS)이며, 제조된 공중합체들의 분자량, 코팅의 두께, 투과도, 접착력 등의 물성 등을 살펴보았다. 사용된 MPTMS 함량에 따라 분자량이 조절되었고, MPTMS의 함량이 증가할수록 접착력이 향상되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1337-1339
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• 2001

We have investigated the relation between the molecular weight distribution (MWD) of diffusible species and the recovery rate of hydrophobicity of room-temperature vulcanizing (RTV) silicone rubber (SIR) using solvent extraction at various temperatures. It was observed that the extract had a MWD ranging from a few hundreds g/mol to hundreds of thousands g/mol. By measuring the migration of siloxane to the extracted SIR surface through a thin carbon coating, the aspect of migration of diffusible species was observed as a real time plot, and the time constant of the migration was also calculated. According to the time dependence of IR-absorbance, the time constant was increased with the increase of MW of the extracts.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1224-1229
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• 2003

The combined effects of washing, sanitization and coating of eggshell on the physical and microbiological quality during storage were evaluated at $4^{\circ}$ and $30^{\circ}C$. The interior qualities of the eggs were assessed by weight changes, yolk index, albumen index, Haugh unit value, and microbial contamination of egg shell and egg white during 30 days of storage in untreated, washed, or sanitized and mineral oil-coated eggs. The results suggest that these changes were faster in higher temperature ($30^{\circ}C$) than lower temperature ($4^{\circ}C$) storage, and washed eggs deteriorated faster than untreated eggs. The sanitized and coated eggs maintained the best quality during storage in all parameters measured. The shelf-life of washed, sanitized and coated eggs could be extended 4-5 fold compared to that of washed or untreated eggs.

• 한국염색가공학회지
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• 제11권4호
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• pp.1-7
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• 1999

Urethane-acrylate propelymers for secondary coating of optical fiber and high - performance material were prepared from the 4,4'-diphenylmethane diisocyanate(MDI), poly(tetramethylene oxide)glycol(PTMG, Mw 650 or 1000), 1,6-hexanediol(HD), 2-hydroxyethyl acrylate(HEA), and dibutyltin dilaurate as a catalyst. UV-Curable polyurethane acrylates were formulated from the urethane-acrylate prepolymers, three types of reactive diluents(DTs) having mono-, di-, and trifunctional-phenoxyethyl acrylate(PEA), hexanediol diacrylate(HDDA), and trimethylolpropane triacrylate(TMPTA), and 1-hydtoxycyclohexyl phenyl ketone(Irgacure 184) as a photoinitiator. The UV-cured films of polyurethane acrylates were obtained by curing using a medium-pressure mercury lamp(U W/cm, $\lambda_{max}=365\;nm)$. In this work, the effects of molecular weights of polyol and diol with low molecular weight into polymer chain on mechanical and dynamic mechanical properties of UV-cured polyurethane acrylates were studied. The structure and properties of the films obtained from the UV photopolymerization of urethane-acrylate prepolymer were investigated by FT-IR spectroscopy, dynamic mechanical measurement, tensile testing, and X-ray diffractometry.

• Journal of the Korean Wood Science and Technology
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• 제20권2호
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• pp.31-42
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• 1992

In this study, the relative effectiveness of antimony trioxide-containing coat on fire retardancy of plywood, particleboard and medium density fiberboard was investigated and compared through ISO ignition test and inclined panel test with non-coated ones. The results obtained were summarized as fallows: Any treated materials was not ignited in inclined panel test with 5 minutes, but only particleboard among treated ones burned in ISO ignition test with fairly delayed time. The weight loss rate of plywood decreased with the increased addition level of fire-retardant and the least values were obtained in particleboard and MDF at addition level of 7% and 5% respectively. Carbonized area of wood based materials decreased with the increased addition level of fire retardant. The temperatures of back in plywood, particleboard treated with fire-retard ant coat containing 7% $Sb_2O_3$ showed the lowest but MDF did not show any effectiveness with the increased addition level. The first flash time of plywood treated with fire retardant coat containing 9% $Sb_2O_3$, MDF and particleboard treated with fire retardant coat containing 7% $Sb_2O_3$ were 257sec., 286.4sec., 165.4sec. respectively.

• 조명전기설비학회논문지
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• 제22권10호
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• pp.141-149
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• 2008

최근 에너지 절감과 환경개선 문제가 대두되면서 아크용접에서도 깨끗하고 불량률이 낮은 아크용접기기의 개발을 본격적으로 추진하고 있다. 본 연구에서는 알루미늄 등과 같은 비철금속에 주로 적용되는 MIG 아크용접에서의 용접성능을 개선하고자 한다. 기존의 직류펄스 MIG 아크용접은 박판 금속에 용접을 하는 경우 아크전압이 낮아 단락이 빈번하게 발생하고 용접 불량을 일으킨다. 이를 개선하기 위하여 중첩교류 펄스를 적용한 MIG 아크용접방법을 제안하고 중첩교류펄스의 설계와 실험을 통하여 그 타당성을 검증하였다.

• Computers and Concrete
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• 제34권2호
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• pp.195-212
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• 2024

The use of basalt fibers in various types of fiber-reinforced mortars has been increasing. One of the factors that expands the use of basalt fibers is that it is a natural fiber and therefore the production costs are lower than fibers such as PVA fiber. Basalt fibers have some drawbacks such as reducing the workability of mortars in which basalt fibers are added due to their structure, and negatively affecting the mechanical properties when used above a certain proportional amount depending on the type of mixture. For this purpose, in this study, as a different application, the surface of basalt fibers with different lengths (6 and 12 mm) was treated with Triton X-100 surfactant, and these disadvantages were tried to be reduced. In the study, a two-step method was followed. In the first one, the effectiveness of adding untreated and treated basalt fiber at 1, 1.25, 1.5, 1.75 and 2% by weight to the mortar mixtures was determined by conducting flow spread and flow rate as fresh mortar characteristics. In the second one, microstructural characterization and mechanical tests were performed as hardened mortar properties. The results showed that the flow characteristics of basalt fiber reinforced mortars treated with surfactant improved compared to untreated basalt fiber reinforced mortars. In terms of mechanical properties, the addition of 2% treated basalt fiber by weight to the mixtures allowed to obtain %18, %12, and%48 higher values of compressive, flexural, and tensile strength values, respectively, compared to the same amount of untreated basalt fiber mixtures.