• Title/Summary/Keyword: Cross linking

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Preliminary Development of A Social Work Skills Inventory (사회복지실천기술 척도의 예비적 개발)

  • Kim, Yong Seok
    • Korean Journal of Social Welfare
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    • v.64 no.4
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    • pp.57-87
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    • 2012
  • The purpose of this study was to develop the first social work skills inventory in Korea. Based upon the literature review of social work skills, the examination of an existing scale, and the comments from professionals in this field, 57 preliminary items were developed. Preliminary items were evaluated with a total of 370 social workers who were working in various fields of social work in Seoul and surrounding areas. A series of exploratory factor analyses were conducted to find out the optimal structure of the scale. After deleting 30 items with low factor loadings or being cross-loaded, the scale is composed of five factors. Confirmatory factor analysis confirmed the factor structure of the scale obtained by exploratory factor analysis. The first factor was named preparatory and assessing skills to be mostly used in the beginning phase of th social work process, the second factor was named change facilitating skills to be used to strengthen motivation to change, third factor was named ending and evaluating skills to be used to terminate the professional relationship and evaluate the outcome of the relationship, the fourth factor was named resource linking and utilizing skills to be used to utilize resources in order to solve clients' problems and the fifth factor was named ethical practice skills. Each component of the social work skills inventory is found to be reliable and valid. In sum, the social work skills inventory is an instrument encompassing basic skills necessary for social work process, skills for ethical social work practice, and skills necessary for utilizing environmental resources.

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Study on Mixing Condition of the Rubber Composite Containing Functionalized S-SBR, Silica and Silane : I. Effect of Mixing Temperature (변성 S-SBR Silica-Silane 고무복합체의 배합조건에 대한 연구 : I. 배합온도의 영향)

  • Jang, Suk-Hee;Kim, Wook-Soo;Kang, Yong-Gu;Han, Min-Hyun;Chang, Sang-Mok
    • Elastomers and Composites
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    • v.48 no.2
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    • pp.94-102
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    • 2013
  • Characteristics of rubber mixture were evaluated in order to find the optimum mixing conditions of compounds containing silica and silane at various temperatures. With different mixing temperatures of 105, 120, 130, 140 and $160^{\circ}C$, the viscosity of the compound mixed at $105^{\circ}C$ showed a very high viscosity value. Compounds mixed the temperature range from at $120^{\circ}C$ to $140^{\circ}C$ showed lower viscosity than the compound mixed at $105^{\circ}C$. However, the difference was found to be small in those temperature ranges. On the contrary, at the mixing temperature of $160^{\circ}C$, the viscosity of compound increased again. Through the physical and dynamic observations, it was verified that at the mixing temperature below $120^{\circ}C$ only insufficient silica-silane reaction has been obtained. In addition, with the elevated mixing temperature of $160^{\circ}C$, Cross-linking occurred during mixing by the sulfur contained in coupling agent. In the temperature ranges from $120^{\circ}C$ to $140^{\circ}C$, because of the fast coupling reaction at higher temperature, it was thought to be more advantageous during reaction even though the trend of viscosity and dynamic mechanical property was not clear.

Clinical Use of Thromboelastography as Monitor of Coagulopathy at the Pre and Post-Cardiopulmonary Bypass (개심술 환자의 체외순환 전후 혈전 탄성 묘사도의 임상적 이용)

  • 강경훈;김경훈
    • Journal of Chest Surgery
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    • v.30 no.11
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    • pp.1092-1096
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    • 1997
  • Thromboelastography(TEG) enables a global assessment of hemostatic function to be made from a single blood sample, documenting the interaction of platelets with protein coagulation cascade from the time of the initial platelet-fibrin interaction, through platelet aggregation, clot strengthening and fibrin cross linking to eventual clot Iysis. Thirty-five patients(mean age 34$\pm$ 12) undergoing open heart surgery from April 1st, 1996 to August 31th, 1996 were investigated at preoperatively and immediate, one hour, and 24 hours after cessation of cardiopulmonary bypass using TEG. Comparisons were made between classic hematological indices and TEG data. There were statistically significant correlation between maximal amplitude(MA) and platelet count before CPB, activating clotting time(ACT) and TEG date(R time, K time and a angle) at 24-hour after CPB. The data on the predictive accuracy for postoperative bleeding at 24-hour after CPB, the TEG was significantly better than ACT(57%) or the coagulation profiles(43%) as a predictor of postoperative bleeding, with an accuracy rate of 100% (P=0.0043). In conclusion, TEG seems to be easy to use, clinically accurate, cost effective and provides data which can effectively manage a patient's hemostasis.

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Physicochemical and Rheological Evaluation of Rice-Whole Soybean Curds Prepared by Microbial Transglutaminase (미생물 Transglutaminase를 이용하여 제조된 쌀 혼합 전두부의 이화학적 및 물성 평가)

  • Jin, Ik-Hun;Lee, Sam-Pin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.738-746
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    • 2011
  • We manufactured rice-whole soybean curd by a microbial transglutaminase (MTGase) with a mixture of hydrolyzed rice and micronized whole soybean powder (MWSP) and analyzed its rheological properties, including texture, viscoelasticity, protein cross-linking, and surface structure. A 40% rice suspension digested with a Termamyl enzyme at $85^{\circ}C$ for 20 min showed a 9.0% reducing sugar and a consistency of $1.27\;Pa{\cdot}s^n$, resulting in a great reduction in consistency. A MWSP suspension with 22% solid content was transformed into a typical tofu texture. MWSP curd fortified with 7.5% rice showed enhanced texture properties, with a hardness of 639.6 dyne/$cm^2$, and a springiness of 0.96. In a MWSP suspension (18~22% w/v) treated with 5% MTGase, viscoelasticity increased dependently with MWSP concentration, and a 22% MWSP indicated a G' value of 5.1 Pa and a G'' value of 9.0 Pa. Furthermore, soybean proteins present in the 22% MWSP curd largely disappeared or formed polymers with a high molecular weight by MTGase reaction within 30 min. MWSP (22%) fortified with 7.5% rice showed similar polymerization patterns on SDS-PAGE. The surface structure of the rice-MWSP curds was more dense and homogeneous network due to the addition of hydrolyzed rice. However, the surface structure of all rice-MWSP curds became rough and showed a non-homogeneous network after cold storage.

A Study on the Application Plan of Basic Original Technology in Science & Research Parks : Focus on Science Parks in Korea (과학연구단지의 기초원천 기술 활용방안에 관한 연구 : 지방과학연구단지를 중심으로)

  • Lee, Won Cheul;Choi, Jong-In
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.3
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    • pp.63-74
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    • 2014
  • From the 1950s, the science parks were begun the composition as a way for innovation and commercialization in the world around developed countries. Since the 1980s, Korea also starting with quantitative investment in R & D for technology innovation, so far has been a continuous effort. Korea's patent creation level according to these R & D investment is already within the world's top 10, but the fact that the domestic technology trade balance appearing current competitive level compared to the developed technology is very insufficient. This means that the creation of economic value is low as compared with financial commitment. Therefore the plans to ensure the economic value through technology are required. As one of plans to do this for local economy activation through technical advances, constructing regional innovation systems and making science parks have been made. These science parks are required to develop the basic original technology in order to secure new growth engines, but the science parks in Korea are facing difficulties of performing research and development for regional industry advancement and local economy activation. Accordingly, this study attempts to organize the concept of 'science park' is similar but there is difference, and to compare institutions with similar functions based on regional innovation systems theory. In addition, the study is to obtain the application plans of basic original technology in science & research Parks through the model for overcoming weaknesses of Korea's innovation system and enabling organic cross-linking between institutions.

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Skin Hydration Effect of Brasenia schreberi Mucilage Polysaccharide Extract (순채 점액질 다당체 추출물의 피부 보습 효과 연구)

  • Ahn, Seyeon;Gil, Soyeon;Kwon, Ohsun;Chang, Yunhee;Jin, Mu Hyun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.3
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    • pp.223-230
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    • 2017
  • In this study, we evaluated the skin moisturizing effect of Brasenia schreberi (B. schreberi) mucilage polysaccharide on human skin and in vitro and the potent cosmetic ingredient for skin. To protect skin from various environmental stresses and aging, we should increase moisture content of skin and prevent water loss. We have found that polysaccharides extracted from mucilage of B. schreberi improved the roughness of skin with its lubricating behavior. In vitro, the expression of transglutaminase 1 (TGM1) gene, which plays a role in cross-linking the skin barrier, was increased when the keratinocytes were treated with B. schreberi polysaccharides. In addition, the expression of hyaluronan synthase 3 (HAS3) gene, an enzyme that synthesizes water-binding matrix hyaluronic acid, aquaporin 3 (AQP3), which regulates the movement of water and glycerol were also increased. In addition, an experiment to evaluate its potential as a cosmetic ingredient has shown anti-inflammatory and collagen synthesis-promoting effects. As a result, the mucilaginous polysaccharide from natural products which has not existed before, showed moisturizing effect, anti-inflammation and collagen synthesis-promoting effects for skin protection and hydration.

The Antifibrotic Effects of D-penicillamine in Liver Fibrosis Animal (간섬유화 동물에서 D-페니실라민의 항섬유화 효과 검색)

  • Kim, Gi-Yeong;Yun, Gi-Jung;Mun, Hyeong-Bae
    • YAKHAK HOEJI
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    • v.40 no.5
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    • pp.550-557
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    • 1996
  • One of therapeutics in liver disease (morbus wilson) is D-penicillamin (D-pen: D-3-mercapto-valin). Especially the cross-linking of collagen molecules could be inhibited by D-pe n in extracellular space. In this study we investigated the antifibrotic effects of D-pen in rats that were induced the liver fibrosis by bile duct ligation and scission (BDL/S). Rats were treated for 4 weeks with D-pen after BDL/S operation or sham operation. The balance between fibrogenesis-marker (PNIIIP) and the fibrolysis-maker (PNIVP) were observed in sera by RIA (radioimmunoassay), and the parameter of collagen deposition in liver tissue (hydroxyproline: HYP) was measured by colorimetry. The weight of liver in BDL/S operated group was increased significantly in compared with sham operation group (15.2g${\pm}$1.1, vs 11.9g${\pm}$3.9: p<0.005, p<0.05). The rats group treated by D-pen showed the lower level of PNIIIP (6.7ng/ml${\pm}$1.5, vs 9.5ng/ml${\pm}$2.8) and the higher value of PIVCP (14.0ng/ml${\pm}$1.9, vs 7.9ng/ml${\pm}$1.5) in sera that compared to untreated rats. The content of HYP was decreased by 141% in BDL/S with D-pen treated group than that of it in BDL/S group. No correlation was revealed between collagen parameters in sera and HYP in liver tissue of BDL/S operated and D-pen treated rats. The group treated with D-pen showed the lower value of clinical biochemistry parameters (GOT: glutamate oxalacetate transaminase, Total-Bilirubin) in compared with only BDL/S operated rats, but the value of GPT (glutamate pyruvate transaminase) and Alkaline phosphatase in two BDL/S groups was nearly same. In the histological finding, we observed mild bile duct proliferation, weak inflammation and fibrosis in BDL/S with D-pen treated group, but BDL/S operated group showed the formation of septum (island of hepatocytes), massive bile duct proliferation. This result represents that the BDL/S operation induces liver fibrosis (cirrhosis) in 4 weeks, and D-pen inhibits the synthesis of collagen weakly and stimulates the degradation of collagen in the extracellular space. We conclude that the monitoring of PNIIIP, PIVCP in sera is useful parameter for screening of antifibrotic effect, and D-pen delay the liver fibrosis.

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AN EXPERIMENTAL STUDY OF THE BOND STRENGTH OF DENTURE TEETH BONDED TO DENTURE BASE MATERIALS (의치용 인공치아와 의치상용 레진간의 결합강도에 관한 실험적 연구)

  • Lee, Joo-Hee;Kim, Chang-Whe;Kim, Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.3
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    • pp.464-474
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    • 1996
  • A principal advantage of a plastic tooth over a porcelain tooth should be its ability to bond to the denture base material. But plastic teeth could craze and wear easily, so more abrasion resistant plastic denture teeth have been developed. To resist abrasion, the degree of cross-linking was increased, but bonding to denture base meterial became more difficult. The purpose of this study was to evaluate the bond strength of plastic teeth and abrasion resistant teeth bonded to heat-curing, self-curing and light-curing denture base material. Denture tooth molds were chosen that had a>8mm diameter. The denture teeth was bonded to three denture base materials and then machined to the same dimensions. Three denture base materials were used as control groups. Prior to tensile testing, the specimens were thermocycled between $5^{\circ}C\;and\;55^{\circ}C$ for 1000cycles. Tensile testing was performed on an Instron Universal testing mechine. Experimental group ; plastic teeth(Justi Imperial)+heat-curing resin(Lucitone 199) plastic teeth(Justi Imperial)+light-curing resin(Triad) plastic teeth(Justi Imperial)+self-curing resin(Vertex SC) abrasion resistant teeth(IPN)+heat-curing resin(Lucitone 199) abrasion resistant teeth(IPN)+light-curing resin(Triad) abrasion resistant teeth(IPN)+self-curing resin(Vertex SC) Control group ; heat-curing resin(Lucitone 199) light-curing resin (Triad) self-curing resin(Vertex SC). The results were as follows : 1. The denture teeth bonded to heat-curing resin showed the cohesive failure and those bonded to the other resins showed adhesive failure. 2. Tensile bond strength of the plastic teeth bonded to self-curing resin was not significantly greater than bonded to light-curing resin(p>0.05). 3. Tensile bond strength of the abrasion resistant teeth bonded to self-curing resin was not significantly greater than bonded to light-curing resin(p>0.05). 4. Tensile bond strength of the plastic teeth to self-curing resin was not significantly different from that of the abrasion-resistant teeth(p>0.05). 5. Tensile bond strength of the plastic teeth to light-curing resin was significantly greater than that of the abrasion resistant teeth(p<0.01).

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The Effects of Coupling Agent and Crosslinking Agent in the Synthesis of Acrylic Pressure Sensitive Adhesive for Polarizer Film (편광필름용 아크릴 점착제의 합성에서 커플링제와 가교제의 효과)

  • Lim, Chang-Hyuk;Ryu, Hoon;Cho, Ur-Ryong
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.319-325
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    • 2009
  • The solution polymerization was conducted to synthesize pressure sensitive adhesive for polarizer film using acrylic monomers. 2-Ethylhexylacrylate, butylacrylate, acrylic acid were used as acrylic monomers. The ratio was 2-ethylliexylacrylate:butylacrylate:acrylic acid=25:50:3.6 by reflecting $-40^{\circ}C$ of glass transition temperature in the pressure sensitive adhesive. When 1 wt% of coupling agent was added to the polymerized pressure sensitive adhesive, the light transmissivity was significantly increased. This result is due to the enhancement of adhesive power against liquid crystal cell by Si-O bond of coupling agents. Cross-linking agent was added by 0.5, 1.0, and 1.5 wt% with respect to the synthesized polymer. Initial tackiness decreased, while cohesion increased with increasing crosslinking agent. In the analysis of contact angle, the increase of crosslinking agents yielded the enhancement of surface energy, resulting in the decrease of contact angle. From the measurement of heat resistance, the acrylic pressure sensitive adhesive showed excellent heat resistance regardless of change in temperature and contents in crosslinking agent. In the observation of a cutting plane, the increased crosslinking agent represented a smoother and cleaner section. Comprehensively, the optimum additive amount of crosslinking agent was determined to be 1.0 wt% to monomer.

Design and Properties of Laminating Waterborne PSA for Eco-friendly Flexible Food Packaging (식품연포장용 라미네이트 수성 감압점착제의 친환경적 적용에 대한 연구)

  • Lee, Jin-Kyoung;Shim, Myoung-Sik;Chin, In-Joo
    • Journal of Adhesion and Interface
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    • v.17 no.2
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    • pp.49-55
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    • 2016
  • In this study, we designed an environment friendly, water-based adhesive using the acrylic emulsion method as a replacement for solvent-based adhesives, which are most commonly used in layered laminates for flexible food packaging. We designed adhesives with different combinations of anionic, non-ionic, and phosphoric ester surfactants, and with different concentrations of chain transfer agent (CTA). We also examined the effect of the degree of cross-linking by synthesizing and comparing 8 test group adhesives with different types of functional monomers. Additionally, we synthesized 2 other test group pressure-sensitive adhesives (PSA) using styrene/alpha-methyl styrene/acrylic acid (SAA) semipolymer dispersing agents (with molecular weights of 13,000 g/mol and 8,600 g/mol, respectively) to replace the conventional surfactants. We evaluated whether the 10 test group pressure-sensitive adhesives met the basic physical property criteria required for flexible food packaging by carrying out a physical analysis of their glass transition temperature (Tg), particle size, adhesion, and molecular weight. In our test, 2 test group adhesives manufactured with the combination of anionic and non-ionic surfactants, CTA concentration of 0.2%, and functional monomers of hydroxyethyl acrylate (HEA) and glycidyl methacrylate (GMA) demonstrated molecular weight and flexibility suitable for flexible packaging, with low adhesiveness and small particle size.