• Title/Summary/Keyword: ROMP

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The Effect of Processing Parameters to Manufacture Self-healing Microcapsules for Composite Materials (복합재료의 자가 치료용 캡슐 제작시 공정 변수들의 영향)

  • Yoon, YoungKi;Yoon, HiSeak
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.4
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    • pp.135-141
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    • 2001
  • An experimental study to find the effect of processing parameters for self-healing microcapules is performed. These microcapsules can be applied to accomplish the healing of delamination damage in woven E-glass/epoxy composites. This paper introduces the self-healing concept and presents a method for solving the microcapsule size and shape. Additionally, processing parameters are varied during the formation of microcapsules and these capsules are observed through optical microscope. To obtain thermogravimetric(TG) curve for the manufactured microcapsules, TGA tests are executed. From these results, the best processing conditions for the formation of capsules are found as follows: (1) temperature of solution $ 50^{\circ}C$, (2) potential of hytdrogen(pH) 3.5ppm, and (3) agitation 500~600rpm.

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Effect of Gamisamul-tang on hyperlipidemia in Ovariectomized Rats (난소절제 흰쥐의 고지혈증에 미치는 가미사물탕의 영향)

  • Jeong Young Sub;Kang Kyung Hwa;Kim Kyung Chul;Lee Yang Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.1
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    • pp.89-94
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    • 2002
  • Effect of Gamisamul-tang(GS) on body weight, uterine weight, splenial weight, serum and estrogen receptor-α (ER-α) in kidney were investigated in ovariectomized(OVX) rats. Female Sprague -Dawley rats with a body weight of 220 g were undergone ovariectomy or sham operation. The ovariectomy caused significant decrease in serum levels of HDL-cholesterol and in uterine weight compared to those of sham-operated animals. while caused significant increase in serum levels of total cholesterol, LDL-cholesterol, triglyceride, body weight and in splenial weight. In contrast, administration of OVX rats with the GS significantly elevated serum levels of HDL-cholesterol and uterine weight, but significantly depressed serum levels of total cholesterol, LDL-cholesterol, triglyceride, body weight and in splenial weight. ER-α localized in the kidney vessel endothelial cells and its expression was increased by ovariectomy and decreased by administration of OVX rats with the GS. Our results suggest that a possible protective effect of as against hyperlipidemia in postmenopausal cardiovascular disease and as increase the estrogen-estrogen receptor romp/ex in the kidney vessel endothelial cells.

Manufacturing and Numerical Analysis of Glass Fiber Chopped Strand Mat Reinforced p-DCPD Composites Processed by S-RIM (S-RIM을 이용한 Glass Fiber Chopped Strand Mat 강화 p-DCPD 복합재료 제작 및 수치해석을 통한 공정 시간 예측)

  • YOO, HYEONGMIN;UM, MOONKWANG;CHOI, SUNGWOONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.6
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    • pp.629-634
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    • 2019
  • Dicyclopentadiene is a low viscosity resin which forms a poly-dicyclopentadiene rapidly through ring opening metathesis polymerization (ROMP). This poly-dicyclopentadiene has outstanding properties of low-temperature, water and impact resistances. Due to these advantages, military and offshore structures try to apply the DCPD composites by using liquid composite molding process. In this study, 14%, 38% volume fraction fiber glass strand mat reinforced p-DCPD composites processed by structural reaction injection molding (S-RIM) which has resin-catalsyt mixing head and glass fiber preform in the mold. Additionally, S-RIM numerical analysis was conducted to predict the process time depending on fiber volume fraction and mold temperature. The process time is shorter when it has the lower fiber volume fraction or the higher mold temperature. At higher mold temperature, it is necessary to set the maximum mold temperature considering the resin curing time.

Amphiphilic Norbornene-Based Diblock Copolymers Containing Polyhedral Oligomeric Silsesquioxane Prepared by Living Ring Opening Metathesis Polymerization

  • Park, Su-Dong;Xu, Wentao;Chung, Chan-Hong;Kwon, Young-Hwan
    • Macromolecular Research
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    • v.16 no.2
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    • pp.155-162
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    • 2008
  • We report the successful synthesis of poly(NBECOOH-b-NBEPOSS) copolymers, taking advantage of the sequential, living ring opening metathesis polymerization of NBETMS and NBEPOSS using the $RuCl_2(=CHPh)(PCY_3)_2$/$CH_2Cl_2$/$20^{\circ}C$ system, followed by the hydrolysis of trimethylsilyl groups in poly(NBETMS-b-NBEPOSS) copolymers. The living behavior of ROMP of NBETMS was first investigated using two diagnostic plots, a first order kinetic plot and a $\bar{M}_n$ vs. conversion plot. The plots confirmed that no termination and chain transfer reaction had occurred during polymerization. Poly(NBECOOH-b-NBEPOSS) copolymers were prepared using the sequential monomer addition of NBEPOSS to living poly(NBETMS) chain ends, followed by the hydrolysis of trimethylsilyl groups in the poly(NBETMS-b-NBEPOSS) copolymers. The high structural integrity of poly(NBE-COOH-b-NBEPOSS) copolymers was confirmed by $^1H$-NMR, $^{13}C$-NMR spcctroscopy and GPC.

A comparative study on the performance of the parameter-based 3D human model generation techniques from a single image including multiple people (다중 인물 포함 단일 영상으로부터의 파라미터 기반 3차원 휴먼 모델 생성 기법 성능 비교 연구)

  • Gi-Mun Um;Jeong Hwan Kim;Wonjun Kim;Hee Kyung Lee;Seung-Jun Yang;Jeongil Seo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2022.11a
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    • pp.157-160
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    • 2022
  • 본 논문에서는 다중 인물 포함 단일 영상으로부터 파라미터 기반 3차원 휴먼 모델 생성 기법 중 최근 발표된 SOTA 기법 4가지에 대해 대표적인 데이터 셋들에 대해 사전 학습 모델을 사용한 복원 성능 비교 실험을 수행하였다. 실험결과, CLIFF 기법과 PyMAF-x 기법이 PARE 기법이나 ROMP 기법에 비해 우수한 결과를 보였다.

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