• Title/Summary/Keyword: PAI

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Electrical and thermal properties of polyamideimide-colloid silica nanohybrid for magnetic enameled wire

  • Han, S.W.;Kang, D.P.
    • Journal of Ceramic Processing Research
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    • v.13 no.spc2
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    • pp.428-432
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    • 2012
  • Polyamidimide (PAI)-colloidal silica (CS) nanohybrid films were synthesized by an advanced sol-gel process. The synthesized PAI-CS hybrid films have a uniform and stable chemical bonding and there is no interfacial defects observed by TEM. The thermal degradation ratio of PAI-CS (10 wt%) hybrid films is delayed by 100 ℃ compared with pure PAI sample determined by on set temperature range in TGA. The dielectric constant of PAI-CS (10 wt%) hybrid films decreases with increasing CS content up to about 5 wt% but increases at higher CS content, which is not explained simply by effective medium therories (EMT). The duration time of PAI-CS (10 wt%) hybrid coil is 38 sec, which is very longer than that of pure PAI coil sample. The PAI-CS (10 wt%) hybrid film has a higher breakdown voltage resistance than the pure PAI film at surge environment and exhibits superior heat resistance. The PAI-CS (10 wt%) sample shows the advanced and stable thermal emission properties in transformer module compared with the pure PAI sample. This result illustrates that the advanced thermal conductivity and expansion properties of PAI-CS sample in the case of appropriate sol-gel processes brings the stable thermal emission in transformer system. Therefore, new PAI-CS hybrid samples with such stable thermal emission properties are expected to be used as a high functional coating application in ET, IT and electric power products.

The Research Regarding Cheong-Sam Pattern of Fabric Design in the Period of the Republic of China(1912-1949) - Comparison Between Jing Pai and Hai Pai - (중국 민국시대(1912년-1949년)에 나타난 치파오 문양에 관한 연구 - 경파이 치파오와 해파이 치파오의 문양 비교를 중심으로 -)

  • Seo, A-Jeong;Oh, Hee-Kyoung;Kim, Sook-Jin
    • Journal of the Korea Fashion and Costume Design Association
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    • v.15 no.3
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    • pp.69-83
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    • 2013
  • Clothes show not just the different social status of people, but the ideology and value of former society through pattern, colour, materials, shapes, etc. The purpose of this article is to fill the academic blank of this part by researching the pattern of fabric design in Jing Pai(Beiing style) and Hai Pai(Shanghai style) cheong-sam during the period of the Republic of China. The contrastive analysis of regional pattern between Jing Pai and Hai Pai cheong-sam expect to provide the theoretical basis for the former fashion designers and scholars. There are three approaches in the article: Data collection method, comparison method and Combining theory with practice method as film. Regarding components of pattern, both Jing Pai and Hai Pai cheong-sam have mostly single or composite pattern like plants. Further the most of Jing Pai cheong-sam pattern is traditional flower pattern. But Haipai cheong-sam patterns have some western flower pattern. Beside that, it have some geometry pattern. Regarding arrangement of the pattern, both cheong-sams have scattered dot style, the border style, and pictures style. But continuous type of Jing Pai cheong-sam is less while Hai Pai cheong-sam is the most. Comparing Jing Pai cheong-sam color of patterns in "Moment in Peking" is unadorned and types are simple as chinese traditional clothes; However, "In the Mood for Love" introduces us various material colors, new types of patterns and extraneous characteristic geometry patterns of Hai Pai cheong-sam. Generally speaking, the main characteristic of Jing Pai cheong-sam is traditional and conservatism. It keeps Chinese traditional pattern and culture to the most extent. However, Hai Pai cheong-sam are confluent and open with absorbed external culture and techniques which are endowed new artistic color.

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Morphology and Tensile Properties of Polyimide/Polyamideimide Composites from Different Polyimide Precursors (Polyimide 전구체에 따른 Polyimide/Ppolyamideimide 복합체의 형태학 및 인장 특성)

  • 김진봉;최윤희;임병탁;박준상
    • Polymer(Korea)
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    • v.25 no.2
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    • pp.160-167
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    • 2001
  • The various compositions of polyimide (PI)/polyamideimide (PAI) composites were prepared by heat treatment of the solvent cast PI precursors/PAI blends. The optical micrographs showed that a good compatibility was observed between poly(amic acid) (PAA) and PAI, but in the case of PAME/PAI mixtures, a phase separation apparently occurred due to the absence of ionic and/or H-bonding forces. Regardless of PI precursors, the similar tensile properties were observed. The tensile modulus of the composites were higher than that of the neat polyimide. The X-ray diffraction patterns of the composites showed that the chain rearrangement of PI was increased due to the plasticizing effect of PAI, which has lower glass transition temperature than that of PI, during thermal imidization process.

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Polymorphism in the promoter region of the plasminogen activator inhibitor-1 (PAI-1) gene in Kawasaki disease (가와사키병 환아에서 plasminogen activator inhibitor-1 유전자 다형성에 관한 연구)

  • Han, Mi Young
    • Clinical and Experimental Pediatrics
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    • v.50 no.6
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    • pp.570-575
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    • 2007
  • Purpose : To demonstrate genetic background of pathogenesis of Kawasaki disease (KD), I examined the genetic polymorphism of plasminogen activator inhibitor-1 (PAI-1) in KD patients. Methods : PCR-RFLP of PAI- 1 promotor gene was analyzed in 56 KD patients admitted to Kyunghee University Hospital, Gachon Medical School Gil Hospital, and Eulji Hospital from March to August 2000 and 206 normal control populations. Results : There were no differences in the genotype and allelic frequency of the PAI-1-675 (4G/5G) and PAI-1-844 (G/A) polymorphic site (which are located in the promoter region) between KD and control subjects. Also I could not detect any significant differences in specific genotypes between patients with the coronary artery lesion (CAL) and patients without CAL. Conclusion : No association was observed in -844 G/A and -675 4G/5G of PAI-1 gene polymorphism with KD.

Improvement of Toughness of Tetrafunctional Epoxy (TGDDM) Resin Using Polyamideimide (PAI) Resin (폴리아미드이미드 수지를 이용한 4관능성 에폭시 수지의 강인화 향상)

  • 박수진;허건영;이재락;홍영택;최길영
    • Polymer(Korea)
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    • v.26 no.5
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    • pp.599-606
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    • 2002
  • In this study, 4,4'-tetraglycidyl diaminodiphenyl methane (TGDDM)/polyamideimide (PAI) blends were cured using diaminodiphenyl sulfone (DDS). And the effect of addition of different PAI contents to neat TGDDM was investigated in the thermal, mechanical, and morphological properties of the blends. The cure behavior and thermal stability of the cured specimens were monitored by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Also, the critical stress intensity factor (K$\_$IC/) was measured in UTM, and the phase separation behavior and final morphology of TGDDM/PAI blends were examined in scanning electron microscopy(SEM). As a result, the cure temperature and cure activation energy (E$\_$a/) were decreased with increasing the PAI content. The decreasing of cure temperature and cure activation energy were probably due to the presence of secondary amine group of PAI backbone used as co-initiator. But, the decomposition activation energy (E$\_$t/) and K$\_$IC/ value were increased up to 5. 10 phr of PAI content, respectively and they were decreased above the PAI contents. These results were explained on the basis of chain scission reaction by etherification. And morphology of blends observed from SEM was confirmed in co-continuous structures.

Inhibitory Effect of LPS-Induced Plasminogen Activator Inhibitor-1 by Ascofuranone in Rat Kidney Fibroblast Cells (Ascofuranone에 의한 plasminogen activator inhibitor-1 발현저해 효과)

  • Chang, Young-Chae
    • Journal of Life Science
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    • v.19 no.10
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    • pp.1438-1443
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    • 2009
  • Renal fibrosis is a final common manifestation of every type of chronic kidney disease. Plasminogen activator inhibitor (PAI)-1 is induced by lipopolysaccharide (LPS) and is known to play an essential role in the progress of renal fibrosis. In this paper, we found that an isoprenoid antibiotic, ascofuranone (AF), suppresses expression of profibrotic factors, PAI-1 and promoter activity of PAI-1 induced by LPS in rat kidney fibroblast cells. We therefore investigated signaling pathway mediated inhibitory effects of LPS-induced PAI-1 by AF in rNRK-49F cells. PAI-1 expression is suppressed by treatment with kinase inhibitors for MEK-1/2, as it isin inhibition of PAI-1 expression by AF, and AF inhibits phosphorylation of ERK-1/2. This study suggest that AF suppresses expression of PAI-1 through the inhibition of an ERK-1/2-dependent signal transduction pathway. The data indicates the possibility that AF can be used to prevent the development and progression of renal fibrosis.

Inhibition of Plasminogen Activator Inhibitor-1 Expression in Smoke-Exposed Alveolar Type II Epithelial Cells Attenuates Epithelial-Mesenchymal Transition

  • Song, Jeong-Sup;Kang, Chun-Mi
    • Tuberculosis and Respiratory Diseases
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    • v.70 no.6
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    • pp.462-473
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    • 2011
  • Background: Smoking is a risk factor for idiopathic pulmonary fibrosis (IPF), but the mechanism of the association remains obscure. There is evidence demonstrating that plasminogen activator inhibitor-1 (PAI-1) is involved in the progression of pulmonary fibrosis. This study was to determine whether the administration of small interfering RNA (siRNA) targeting PAI-1 or PAI-1 inhibitor to the cigarette smoking extract (CSE)-exposed rat alveolar type II epithelial cells (ATII cells) limits the epithelial-mesenchymal transition (EMT). Methods: ATII cells were isolated from lung of SD-rat using percoll gradient method and cultured with 5% CSE. The EMT was determined from the ATII cells by measuring the real-time RT PCR and western blotting after the PAI-1 siRNA transfection to the cells and after administration of tiplaxtinin, an inhibitor of PAI-1. The effect of PAI-1 inhibitor was also evaluated in the bleomycin-induced rats. Results: PAI-1 was overexpressed in the smoking exposed ATII cells and was directly associated with EMT. The EMT from the ATII cells was suppressed by PAI-1 siRNA transfection or administration of tiplaxtinin. Signaling pathways for EMT by smoking extract were through the phosphorylation of SMAD2 and ERK1/2, and finally Snail expression. Tiplaxtinin also suppressed the pulmonary fibrosis and PAI-1 expression in the bleomycin-induced rats. Conclusion: Our data shows that CSE induces rat ATII cells to undergo EMT by PAI-1 via SMAD2-ERK1/2-Snail activation. This suppression of EMT by PAI-1 siRNA transfection or PAI-1 inhibitor in primary type II alveolar epithelial cells might be involved in the attenuation of bleomycin-induced pulmonary fibrosis in rats.

Insulation Breakdown Properties of AC and DC according to Curvature Variation of PAI Organic/Inorganic Hybrid Coils (PAI 유/무기 하이브리드코일의 곡률변화에 따른 AC 및 DC 절연파괴 특성)

  • Park, Jae-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1721-1726
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    • 2016
  • 4-types of coils were prepared by coating with polyamideimide (PAI) organic/inorganic hybrid. One type was made with original PAI vanish and the other 3-types were made of double layers, that was to say, high flexural PAI layer and high anti-corona PAI/nanosilica (15 wt%) layer. Drying temperature (T/D) were $220^{\circ}C$, $240^{\circ}C$, and $260^{\circ}C$, respectively and rectangular type coil for high-voltage rotating machine was used. DC and AC electrical breakdown tests were carried out in order to study the insulation properties according to T/D temperature and coil curvature (5, 15, and $25mm{\Phi}$). As the curvature increased, electrical breakdown voltage decreased and as T/D temperature decreased, electrical breakdown voltage increased.

Thermal Stability Improvement of Nickel-Silicide using PAI in the N-type Substrate (N-type 기판에서 PAI에 의한 Nickel-Silicide의 열안정성 개선)

  • 윤장근;지희환;오순영;배미숙;황빈봉;박영호;왕진석;이희덕
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.675-678
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    • 2003
  • 본 논문에서는 N-type 기판에서 Nickel-Silicide를 적용하였을 경우에 나타나는 문제점과 PAI (Pre-amorphization Implant)의 효과에 대하여 알아보았다. N-type 기판에 RTP (Rapid Thermal Process)를 통하여 Nickel-Silicide 를 형성하게 되는데, 여기까지는 안정한 Nickel mono-Silicide (NiSi)가 형성됨을 확인하였다. 하지만 후속 열처리 공정 후 심한 응집 현상 (Agglomeration)과 이상 산화 현상 (Abnormal Oxidation Phenomenon), Silicide Island 등 열안정성 (Thermal Stability) 측면에서 여러 가지 많은 문제점들이 나타났다. 이 후속 열처리의 열안정성 취약점들을 극복하는 방안으로 Ge 및 N₂ PAI를 적용하였다. PAI를 적용하였을 경우에는 그렇지 않은 경우에 비하여 고온 열처리 후에도 면저항이 비교적 잘 유지되었으며, 두께가 얇고 안정한 Nickel-Silicide 특성을 확보할 수 있었다. 특히 Ge PAI 에 비하여 N₂ PAI 의 경우가 보다 특성 개선 효과가 크게 나타났다.

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