• Title/Summary/Keyword: curing compound

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A Study on the Resin Finishing of Silk Fabric -Silicone Resin Finishing- (견직물의 수지가공에 관한 연구)

  • 남중희;탁태문
    • Journal of Sericultural and Entomological Science
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    • v.27 no.2
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    • pp.28-39
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    • 1985
  • The structural and useful characteristics of silk habutae treated with silicone resin by emulsion finishing method were studied. The results were obtained through crease recovery test, water repellency test, scanning micrograph observation, amino acid analysis, X-Ray diffraction analysis, and Fourier Transform Infrared Spectroscopy. The results are summarized as follows; 1) The improvement in crease recovery of silk habutae finished with silicone resin, was observed b soaping treatment and curing conditions. 2) The higher water repellency and stiffness in silk fabrics finished with silicone resin was found by the fabric inspection and the scanning electron microscopic observation. It is suggested that silicone resin impregnated into the void of silk fibroin. 3) The polar side chains of amino acid composition were decreased, when the silicone resin was treated on silk fibroin. 4) Through Amino acid analysis of silicone resin finished fibroin, the different amounts of amino acid composition was indicated due to silk fibroin silicone polymer reaction and the structural difference of its fibroin were also proved by X-ray diffractograms. 5) The functionality of the siloxane compound may be deduced from the silicone finished silk habutae by Fourier Transform Spectroscopy. It was concluded from the above results that the useful characteristics of silk fabric can be improved by silicone resin finishing.

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소적보중환(消積保中丸)의 항종양효과(抗腫瘍效果)에 대한 실험적(實驗的) 연구(硏究)

  • No, Hun-Jeong;Jeon, Byeong-Hun;Mun, Gu;Mun, Seok-Jae
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.2 no.1
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    • pp.43-56
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    • 1996
  • The sprig of Sojekbojungwhan(消積保中丸) has been used for curing as a traditional medicine without any experimental evidence to support the rational basis for their clinical use. This experiment was carried out to evaluate the possible therapeutic or antitumoral effects of Sojekbojungwhan extract against cancer, and to study some mechanisms responsible for its effect. The cytotoxic and antitumor effects were evaluated on human cell lines(A549, hep3B, Caki-1, Sarcoma 180) after esposure to Sojekbojungwhan extract using in ILS, colony forming efficiency and SRB assay which were regarded as a valuable method for cytotoxic and antitumor effects of unknown compound on tumor cell lines. The results obtained in this studies were as follows. 1. As a result of exposure to Sojekbojungwhan extract, the proliferation of A549, hep3B, Caki-1, good correlations were shown from the results of SRB assay and those of clogenetic assay. 2. The oral administration of Sojekbojungwhan extact showed significant effects of increase of MST(mean survival time) and ILS(increased life span) depending on the increasing concentration. 3. Against squamous cell carcinoma induced by MCA, Sojekbojungwhan decreased not only the frequency of tumor production but also the number and weight of tumors per tumor bearing mice(TBM). Sojekbojungwhan also significantly suppressed the development of 3LL cell-implanted tumors by frequency and their size, and some developed tumors were regressed by the continuous treatment of Sojekbojungwhan extract into TBM. 4. Sojekbojungwhan extract also increased NK cell activities. According to the above results, it could be suggested that Sojekbojungwhan extract has some antitumor effects.

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Flip Chip Assembly Using Anisotropic Conductive Adhesives with Enhanced Thermal Conductivity

  • Yim, Myung-Jin;Kim, Hyoung-Joon;Paik, Kyung-Wook
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.1 s.34
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    • pp.9-16
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    • 2005
  • This paper presents the development of new anisotropic conductive adhesives with enhanced thermal conductivity for the wide use of adhesive flip chip technology with improved reliability under high current density condition. The continuing downscaling of structural profiles and increase in inter-connection density in flip chip packaging using ACAs has given rise to reliability problem under high current density. In detail, as the bump size is reduced, the current density through bump is also increased. This increased current density also causes new failure mechanism such as interface degradation due to inter-metallic compound formation and adhesive swelling due to high current stressing, especially in high current density interconnection, in which high junction temperature enhances such failure mechanism. Therefore, it is necessary for the ACA to become thermal transfer medium to improve the lifetime of ACA flip chip joint under high current stressing condition. We developed thermally conductive ACA of 0.63 W/m$\cdot$K thermal conductivity using the formulation incorporating $5 {\mu}m$ Ni and $0.2{\mu}m$ SiC-filled epoxy-bated binder system to achieve acceptable viscosity, curing property, and other thermo-mechanical properties such as low CTE and high modulus. The current carrying capability of ACA flip chip joints was improved up to 6.7 A by use of thermally conductive ACA compared to conventional ACA. Electrical reliability of thermally conductive ACA flip chip joint under current stressing condition was also improved showing stable electrical conductivity of flip chip joints. The high current carrying capability and improved electrical reliability of thermally conductive ACA flip chip joint under current stressing test is mainly due to the effective heat dissipation by thermally conductive adhesive around Au stud bumps/ACA/PCB pads structure.

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Solidification/stabilization of simulated cadmium-contaminated wastes with magnesium potassium phosphate cement

  • Su, Ying;Yang, Jianming;Liu, Debin;Zhen, Shucong;Lin, Naixi;Zhou, Yongxin
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.15-21
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    • 2016
  • Magnesium potassium phosphate cement (MKPC) is an effective agent for solidification/stabilization (S/S) technology. To further explore the mechanism of the S/S by MKPC, two kinds of Cd including $Cd(NO_3)_2$ solution (L-Cd) and municipal solid waste incineration fly ash (MSWI FA) adsorbed Cd (S-Cd), were used to compare the effects of the form of heavy metal on S/S. The results showed that all the MKPC pastes had a high unconfined compressive strength (UCS) above 11 MPa. For L-Cd pastes, Cd leaching concentration increased with the increase of Cd content, and decreased with the increase of curing time. With the percentage of MSWI FA below 20%, S-Cd pastes exhibited similar Cd leaching concentrations as those of L-Cd pastes, while when the content of MSWI FA come up to 30%, the Cd leaching concentration increased significantly. To meet the standard GB5085.3-2007, the highest addition of S-Cd was 30% MSWI FA (6% Cd contained), with the Cd leaching concentration of 0.817 mg/L. The S/S of L-Cd is mainly due to chemical fixation, and the hydration compound of Cd was $NaCdPO_4$, while the S/S of S-Cd is due to physical encapsulation, which is dependent on the pore/crack size and porosity of the MKPC pastes.

Effect of Carbon Black on Mechanical and Damping Properties of EPDM/Carbon Black System (EPDM/Carbon Black계에서 Carbon Black에 따른 기계적 성질 및 방진 특성)

  • No, Tae-Kyeong;Kang, Dong-Guk;Seo, Jae-Sik;Yang, Kyung-Mo;Seo, Kwan-Ho
    • Elastomers and Composites
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    • v.47 no.3
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    • pp.231-237
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    • 2012
  • This study measured the mechanical and damping properties of EPDM compounds including fillers. Semi-reinforcing furnace black (SRF), high abrasion furnace black (HAF) and acetylene black were used as fillers. Dicumyl peroxide (DCP) were used as curing agents. The measurements were conducted using a moving die rheometer (MDR), durometer, universal testing machine (UTM), compression set and dynamic mechanical analysis (DMA). The tensile strength and elongation at break increased with increasing SRF contents in EPDM compounds. However, they decreased with increasing the amount of acetylene black. In the inspecting temperature range, EPDM compound filled acetylene black had stable storage modulus. Furthermore, the tan ${\delta}$ of the EPDM compounds obtained was enhanced by compounding with acetylene black.

UV-Curing System for the Filament Winding of Large Diameter Pipe (대구경 파이프용 필라멘트 와인딩을 위한 UV 경화시스템)

  • Choi, Jae-Wan;Kim, Se-Il;Chung, Yong-Chan;Chun, Byaung-Chul
    • Clean Technology
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    • v.16 no.4
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    • pp.245-253
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    • 2010
  • Optimum conditions for UV-radiated photopolymerization of unsaturated polyester that could be used as protecting layer of large diameter pipe were investigated in this paper. UV photopolymerization method was selected to solve the problems, arising when thermal polymerization by organic peroxide was used, such as the instability of peroxide initiator, the evolution of volatile organic compound, and thermal deformation of product. Two of the photo-initiators (Irgacure 819 and Darocure 1173) well known for its penetrating ability deep into the polymer layer were selected, and the optimum conditions for photopolymerization (1.5 phr initiator content, 1:1.2 initiator ratio, Ga lamp for UV source) were found from the thermal and mechanical test results of the resultant UP polymers. In addition, composite materials containing UP polymer and glass fiber were tested for hardness, impact strength, and flexural strength to find that the impact strength of composite significantly improved.

Characteristics of Ammonia in Alkaline Stabilization Facility of Sludge from Sewage Treatment Plant (하수처리오니 알칼리 안정화 처리시설에서의 암모니아 발생특성)

  • Kim, Yong-Jun;Chung, David;Jeong, Mi-Jeong;Yoo, Hye-Young;Yoon, Cheol-Woo;Shin, Sun-Kyoung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.24 no.3
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    • pp.23-33
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    • 2016
  • The characteristics of ammonia generated from alkaline stabilization facilities was investigated which are for organic sewage sludge from wastewater treatment plants. The highest concentration of ammonia was found in mixing and curing process in alkaline stabilization facility and ammonia mainly showed a range of 87.78 ppm($66.62mg/m^3$) to 1,933 ppm($1,467.01mg/m^3$) by detection tube. This is presumed to occur because nitrogen oxides are converted into ammonia as the sewage sludge is mixed with lime. In some facilities, hydrogen sulfide and methyl mercaptan were detected in relatively high concentrations, but odor materials except ammonia were not detected in most of the facilities. The concentration of ammonia caused by process was generally high in the order of "mixing > curing > output > storage > drying > input." It was found that odor compounds are removed by wet absorption using sulfuric acid and sodium hypochlorite in the 5 alkaline stabilization facilities currently in operation. Each facility was designed to meet the concentration of after-treatment emission in 1 ppm($0.76mg/m^3$), 50 ppm($37.95mg/m^3$) or 100 ppm($75.89mg/m^3$), but no facility satisfied the design standard for their emssion limit. In case of ammonia, some workplaces in alkaline stabilization facilities exceeded the exposure limits established by the Ministry of Labor. It appears that proper ventilation should be provided for the safety of workers in future. No odor compound including ammonia was found by detection tubes in the border of the facilities, but trace amounts of odor compounds are expected to exist, given the current operational status of facilities.

Antibacterial Activity of Ceftizoxime Against Gram Negative Enteric Bacteria in vitro and in vivo (Ceftizoxime의 장내세균에 대한 시험관내 및 생체내 항균효과)

  • Byun, Woo-Mok;Chang, Jae-Chun;Park, Bok-Hwan;Kim, Hee-Sun;Kim, Sung-Kwang
    • Journal of Yeungnam Medical Science
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    • v.6 no.1
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    • pp.59-68
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    • 1989
  • Ceftizoxime sodium is a new synthetic ${\beta}$-lactam antibiotic combining potent antibacterial activity with high stability to a wide range of bacterial ${\beta}$-lactamase. This experiment was achieved to evaluate the antibacterial activities of ceftizoxime sodium againist Gram negative enteric bacteria isolated from in outpatient visiting Yeungnam university hospital and to study the emergence of drug induced bacterial varients which resist to ceftizoxime in vitro. The antibacterial activity of the ceftizoxime was compared with that of antibiotics and its effect on population of normal intestinal flora in mice was observed. The results are summarized as follows : 1. Highly effective antibacterial activity of ceftizoxime against Gram negative enteric bacilli was demonstrated and this antibacterial activity was superior to that of ampicillin. 2. Several test strains shows multiple antibiotic resistence. Among 15 strains of Escherichia coli, 1 strain was resistent to ampicillin, cefadroxyl, gentamicin, tetracycline, and 2 strains were resistent to ampicillin, cefadroxyl, tetracycline, five strains of Escherichia coli and Enterobacter cloacae was resistent to amplicillin, tetracycline and Shigella dysenteria was resistent to ampicillin, gentamicin, tetracycline. 3. The frequency of in vitro emergence of resistent varients among ceftizoxime sensitive bacteria in the presence of increasing concentrations of the compound was found to be low. 4. Plasmid was isolated in 6 of 9 strains (6 strains of Escherichia coli, Shigella dysenteriae, Enterobacter cloaceae and Salmonella typhi) That showed different antibiotic resistance. They were 5 strains of Escherichia coli and 1 strain of Shigella dysenteriae. However, plasmid could not be considered as a hallmark for antibiotic resistance by this. Further studies with curing experiment are to be accomplished for this purpose. 5. Changes in the bacterial count of normal intestinal flora following 25mg/kg/day administration of ceftizoxime over S consecutive days were not significant. In conclusion, ceftizoxime appeared to be a drug of choice in the treatment of Gram negative enteric bacilli infection.

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A Study on the '$\bar{A}yurveda$' (아유르베다'($\bar{A}yurveda$)에 관한 소고(小考))

  • Kim, Ki-Wook;Seo, Ji-Young;Park, Hyun-Kuk
    • The Journal of Dong Guk Oriental Medicine
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    • v.10
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    • pp.161-175
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    • 2008
  • The '$\bar{A}yurveda$', Buddhistic medicine, and the present of traditional medicine can be summed up as thus. 1. The '$\bar{A}yurveda$' is a transliteration of the Sanskrit Ayur - veda and is a compound of the words 'Ayus(life)' and 'Veda(knowledge)' and means "The study of life", which means the preservation of health and the understanding and curing of diseases. 2. The '$\bar{A}yurveda$', which originated from ancient experience, was recorded in Sanskrit, which was a theorization of knowledge, and also was written in verses to make memorizing easy, and made medicine the exclusive possession of the Brahmin. The first annotations were 1060 for the "Charaka", 1200 for the "Sushruta", 1150 for the "Ashtanga Sangraha samhita", and 1100 for the "Nidana". The use of various mineral medicines in the "Charaka" or the use of mercury as internal medicine in the "Ashtanga Sangraha samhita", and the palpation of the pulse for diagnosing in the '$\bar{A}yurveda$' and XiZhang' medicine are similar to TCM's pulse diagnostics. The coexistence with Arabian 'Unani' medicine, compromise with western medicine and the reactionism trend restored the '$\bar{A}yurveda$ today. 3. When we look at the present of the education and research of the '$\bar{A}yurveda$', after gaining independence from England, India set up a modern education system of the '$\bar{A}yurveda$' and set it on an equal position with western medicine. According to the 1976 study the '$\bar{A}yurveda$' is taught in a 5 and a half year university curriculum, and the main textbooks are the Charaka - samhita("開羅迦集" - internal medicine), Sushruta-samhita("妙聞集", surgery), Madhavanidana(diagnostics), 3 volumes of Bhavaprakasa(pharmacology internal medicine, mineral medicine}, Rajanighantu (pharmacology), $Vrks\bar{A}yurveda$(plant therapy), Mahabharata(military medicine), Arthasastra(forensic medicine, toxicology) Kamasastra(science of intercourse), etc. in 10 subjects and there are 232227 certified doctors that have graduated from the 95 colleges and passed the exams.

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Synthesis of Novel Prepolymers Containing No Bisphenol A and Preparation of Organic Matrices for Dental Applications (비스페놀 A를 함유하지 않은 치과용 신규 프리폴리머의 합성 및 유기 매트릭스의 제조)

  • Son, Jun-Sik;Lee, Ki-Baek;Park, Kwi-Deok;Kim, Jae-Jin;Ahn, Kwang-Duk;Kim, Jung-Hyun;Han, Dong-Keun
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.538-544
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    • 2006
  • Two kinds of novel bifunctional methacrylated prepolymers (170-2MA and 631-2MA) which have similar structure with 2,2-bis[4- (2'-hynroxy-3'-methacryloyloxypropoxy)phenyl] propane (Bis-GMA) was synthesized for dental applications as an alternative to Bis-GMA containing bisphenol A that is doubtful as an endocrine disrupter. The organic matrices were prepared by mixing a diluent and/or a monomer with the synthesized methacrylated prepolymers. The yield, viscosity, and chemical structures of the prepolymers and the physical and methanical properties of the organic matrices were evaluated. The yields of the prepolymers synthesized through a ring-opening reaction of epoxy compound and methacrylic acid were above 90% and the viscosities of the prepolymers were much lower than that of the Bis-GMA control. From the results of $^1H-NMR$ and FTIR analyses, the chemical structures of the prepolymers were similar to that of Bis-GMA. In addition, the curing time, poly-merization shrinkage, photoconversion, polymerization depth, and compressive strength of the organic matrices formulated with 170-2MA and 631-2MA prepolymers exhibited comparable to or better than those of the existing Bis-GMA-based one. These results suggest that the novel methacrylated prepolymers which have no endocrine disrupter can be an alternative to Bis-GMA and be applicable to dental polymer materials.