• Title/Summary/Keyword: high Tg

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Thermal and Mechanical Properties of Elastic Epoxies (탄성형 에폭시의 열적특성과 기계적 특성)

  • Lee, K.W.;Choi, Y.H.;Shin, E.M.;Sohn, H.S.;Park, D.H.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1436-1438
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    • 2003
  • In this paper thermal and mechanical properties of elastic epoxy for applying high voltage products were investigated. Glass transition temperature(Tg) of elastic epoxies can't find form room temperature to $200^{\circ}$ by DSC. It occurred weight reduce on $285^{\circ}$ and $451^{\circ}$ by thermo-gravimeter. The first temperature was effected on addictives and the other was epoxy's character. Max, tensile strain showed $28.3kgf/cm^2$ at 20% of mechanical stress in addictives 35phr. SEM micrograph of the fracture surface observed in void and tearing of elastic epoxy at addictives 35phr. The other side, SEM micrograph of rigid epoxy showed the trace which broke.

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A Study on the Space Charge Polarity Measurement Teasurement Technology of Cross-Linked Polyethylene for Power Cable (전력케이블용 가교폴리에틸렌의 공간전하 극성측정기술에 관한 연구)

  • 국상훈;서장수;김병인;박중순
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.6 no.6
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    • pp.23-31
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    • 1992
  • Charged particle in the polymers is supposed to affect the electrical conduction and to lead them th dielectrical breakdown finally. So we measured the space charge distribution made by application of high electric field and evaluated the polarity of the charged particle affected on electrical conduction and space charge formed in the insulating materials by using temperature gradient thermally stimulated current measurement method(TG-TSC measurement). As a result, in the cross-linked polyethylene, A-peak was caused from dipole polarization, C-peak was caused from ionic space charge polarization and D-peak was injected trap hole. Also we found it crossible the evaluated the polarity of injected trap carrier and electron(or hole) of carrier trap in the cross-lined polyethylene. We found that ${\gamma}$-ray irradiated low density polyethylene had a relation to the electronic trap and we also could get the value of electric field distribution in the samples of which evaluation was available.

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Synthesis of Superconductor $YBa_{2}Cu_{4}O_{8}$ by Pyrolysis of EDTA Complex

  • Jeong Cheol-Mo;Mun Seung-Ho;Kang Cheol-Hwa;Lee Cheol-Eui;Yom Sang-Seop;Kim Keon
    • Bulletin of the Korean Chemical Society
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    • v.13 no.6
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    • pp.663-665
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    • 1992
  • The superconducting $YBa_2Cu_4O_8$ was synthesized in oxygen condition at 1 atm. The starting material with 1 : 2 : 4 composition was obtained by pyrolysis of EDTA complex, which was converted to 1-2-3 phase during densification, followed by the 1-2-4 phase recovery at $810^{\circ}C$ . The phase presents were identified by XRD, TG, DTA and AC magnetic susceptibility. Our data indicated that considerable amounts of 1-2-4 phase formed but with the 1 : 2 : 3 phase or possibly 2-4-7 as visible. As the P($O_2$) increased with temperature, impurity peak, CuO ($2{\Theta}$ = 38.8), gradually decrease, and we conclude that the 1-2-4 phase is predominant bulk superconductor under the high oxygen pressure.

Biodistribition of [$^{125}I$]-labeled biotinylated dendrimer derivatives for antibody pretargeting

  • Kim, Hyung-Sik;Han, Eui-Sik;Wong, Karen J.;Paik, Chang H.
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.99.3-100
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    • 2003
  • It is desirable to improve the tumor targeting and blood clearance pharmacokinetics of radiolabeled monoclonal antibodies. To achieve this goal, several avidin-biotin (Bt) binding systems have been developed to decouple large molecular weight antibodies from small radiolabels, thereby achieving high tumor-to-background radioactivity ratios. We inserted a readily catabolizable linker, triglycine (TG), between 3-[/sup125/I]iodobenzoate and dendrimer (G3). We also neutralized the positive charges of G3 by acylation with tetrafluorophenyl glycolate, thereby blocking proximal tubular reabsorption of G3 mediated by charge attraction. (omitted)

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Effects of Sungkangwon on the Fatty Liver Induced by Alcohol Diet in Rats

  • Jeong, Kwon-Hyun;Kim, Yun-Young;Young, Choung-Se
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.108.1-108.1
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    • 2003
  • The purpose of this study is to investigate the effect of Sungkangwon (Astragalus membranaceus Bunge + Pueraria lobata Ohwi + Salvia miltiorrhiza Bunge) on fatty liver induced by alcohol diet. Rats were either fed control diet or alcohol diet. On 6 weeks, alcohol group were randomly assigned to groups as follows; supplemented without SKW and with SKW (.033g/kg, 1g/kg, and 3g/kg). all of five groups were fed the chow diet for 4 weeks. After 6 weeks. the blood and liver concentration of TG and total-C is comparably high in alcohol group. (omitted)

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Synthesis and characterization of polyimides for FPC applications

  • Yeon, J.H.;Bae, Y.U.;Yoon, T.H.
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.227-227
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    • 2006
  • It was attempted to synthesize polyimides from PPMDA and 3FPPMDA with mDAPPO/pPDA in order to afford CTE of 17ppm and adhesion property of 80g/mm, besides high Tg (>$300^{\circ}C$), good thermal stability (>$500^{\circ}C$), low water absorption and good solubility. The polyimides were prepared via a conventional two-step process; preparation of poly(amic-acid), followed by solution imidization by refluxing in NMP with o-DCB and the molar ratio of mDAPPO/pPDA was varied. The polyimides were characterized by FT-IR, NMR, DSC and TGA. In addition, intrinsic viscosity, solubility and coefficient of thermal expansion (CTE) were also measured.

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Self-Perception of Health and Body Image, Blood Lipid Profiles and Nutrient Intake of Adolescents in Incheon Area

  • Cheong, Sun-Hee;Chang, Kyung-Ja
    • Journal of Community Nutrition
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    • v.5 no.1
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    • pp.3-12
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    • 2003
  • The purpose of this study was to investigate self-perception of health and body image, blood lipid profiles and nutrient intake of adolescents. The subjects were 686 adolescent boys (379 middle school students, 307 high school students) and 613 adolescent girls (272 middle school students, 341 high school students) in Incheon. This cross-sectional survey was conducted by a self-administered questionnaire. Fasting blood samples were obtained and analyzed for triglyceride, total cholesterol and LDL- and HDL-cholesterol. Nutrient intakes collected from 3 day-recalls were analyzed by the Computer Aided Nutritional Analysis Program. Statistical analysis was conducted using SPSS 10.0 program. Average age, height and weight of male middle school students were 13.8 years, 163.5cm, 56.0kg and those of male high school students were 16.5 years, 171.7cm, 64.3kg. In female, average age, height and weight of middle school students were 13.7 years, 157.1cm, 51.5kg and those of high school students were 16.6 years, 159.7cm, 56.8kg. Female middle school students perceived their health status significantly better compared to female high school students (p < 0.001). Female high school students perceived themselves significantly fatter compared to female middle school students (p < 0.05). Average TG level of female middle school students was significantly higher compared to female high school students (p < 0.01). Nutrient intakes of the male and female students except phosphorus were lower than the Korean RDA. Especially, calcium and iron intakes of male and female students were under the 65% of the Korean RDA. Therefore, proper nutrition education is required for Korean adolescents to encourage desirable food habits and maintain nutritional lipids status. (J Community Nutrition 5(1) : 3∼12, 2003)

Effects of Soyoligosaccharide on Lipid Metabolism in Rats Fed the High Fat or Low Fat Diet (저지방 또는 고지방 섭취 시 대두올리고당의 섭취가 흰쥐의 지방대사에 미치는 영향)

  • 방명희;김우경;김주현;이정숙;이다희;김숙희
    • Journal of Nutrition and Health
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    • v.37 no.4
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    • pp.266-272
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    • 2004
  • This study investigated the effects of soyoligosaccharide consumption on lipid profile of plasma, liver and feces and immune responses in Sprague-Dawley male rats. Sixty male Sprague-Dawley rats 4-wk-old were provided the soyo-ligosaccharide containing diets for 4 weeks (0, 100 g/kg diet); each of these diets was supplemented with either 70 or 200 g fat/kg diet, giving a total of 4 experimental groups. The effect of weight reduction was most significantly observed in the group fed low fat and soyoligosacchairde diet. The plasma total lipid and cholesterol contents were not changed by either fat proportion or soyoligosaccharide supplementation in the diets. Also the plasma triglyceride lowering effect by soyoligosaccharide was not observed in rats fed either low fat or high fat diet. However, the significant decrease in TG contents was found with rats fed high fat diets compared to the control/no soyoligosaccharide diet. Elevation of plasma LDL-cholesterol and reduction of HDL-cholesterol by feeding high fat diet was not altered by supplementing soyoligosaccharide. This was also applied to the liver lipid profiles. The significant increases in liver total lipid, trigly-cerides and cholesterol by high fat diet was not abolished by feeding soyoligosaccharide. However, the desirable effects of feeding soyoligosaccharide were found with total lipid and cholesterol excretion through feces in rats fed high fat diets. Immune organ weights and spleen cell proliferations did not affected by experimental diets. These results de-monstrated that soyoligosaccharide intakes increased the lipid output via feces, especially in rats fed the high fat diet, but more researches are needed on immune responses.

Effect of Auricular Acupuncture and Aerobics Exercise in High Fat Diet-induced Obesity Rats (고지방식이로 유도된 비만 렛트에서 외이침 자극과 유산소 운동의 효과)

  • Lee, Dae-Sik;Kim, Sa-Youl;Jang, Mi-Kyung;Shin, Min-Chul;Kim, Eun-Jung;Sim, Ki-Cheol;Nam, Gi-Won;Oh, Myung-Hwa;Jeong, Hyun-Woo;Kim, Gye-Yeop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.5
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    • pp.1174-1179
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    • 2006
  • In order to study auricular acupuncture and treadmill exercise involved in high fat diet-induced obesity rats. Thirty Sprague-Dawley rats which were divided into five group. Group I : Normal diet-induced group, Group II : high fat diet-induced group, Group III: high fat diet-induced group and auricular acupuncture, Group IV : high fat diet-induced group and treadmill exercise, Group V : high fat diet-induced group and auricular acupuncture and treadmill exercise. In each group, body weight, serum lipid, histologic obserations, and fat tissue were observed and analyzed. The following results were obtained. Body weights were significantly increase in group II than group I. The level of total cholesterol, LDL-C and TG were significantly lower in experimental groups than group I. Only auricular acupuncture was tended to body weight change but not significantly different between experimental group. The above result suggest that auricular acupuncture and treadmill exercise effectively repressed in obesity. It would be considered that auricular acupuncture and treadmill exercise have an effects on relieving obesity.

Color Pure and Stable Blue Light Emitting Material Containing Anthracene and Fluorene for OLED

  • Park, Hyun-Tae;Oh, Dae-Hwan;Park, Jong-Won;Kim, Jin-Hak;Shin, Sung-Chul;Kim, Yun-Hi;Kwon, Soon-Ki
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1951-1955
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    • 2010
  • A new blue light emitting anthracene derivative, 9,10-bis-(9',9'-diethyl-7'-t-butyl-fluoren-2'-yl)anthracene (BETF), has been designed and synthesized by a palladium catalyzed Suzuki cross-coupling. A theoretical calculation of the three-dimensional structure of BETF supports that it has a non coplanar structure and inhibited intermolecular interactions resulting in high luminescent efficiency and high color purity. BETF has good thermal stability with glass-transition temperature (Tg) of $131^{\circ}C$. The PL maximum of BETF in solution and film were 438 nm and 440 nm, respectively, showing pure blue emission. A multilayer device using BETF as emitting material exhibits maximum luminescence efficiency of 2.2 cd/A and a pure blue emission (Commission Internationale de L'Eclairage (CIE) coordinates of x = 0.15, y = 0.10).