• Title/Summary/Keyword: modifiers

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Effect of $Al_{2}O_{3}$ filler addition on sintering behavior of low-firing $BaO-B_{2}O_{3}-ZnO$ glass ceramic system

  • Kim, Young-Nam;Kim, Byung-Sook;Lee, Joon-Hyung;Kim, Jeong-Joo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.814-817
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    • 2003
  • The sintering behavior of $BaO-B_{2}O_{3}-ZnO$, which is Pb-free glass-ceramic system, was examined as functions of the composition and the amount and particle size of $Al_{2}O_{3}$ filler. Different kinds of modifiers were added and $Al_{2}O_{3}$ fillers with different particle sizes ($1.5{\mu}m$ and $4.5{\mu}m$) were added. The glass frit-filler composites were sintered in the temperature range $520{\sim}580^{\circ}C$. X-ray diffraction results revealed that some of the composites crystallized during sintering. Dielectric constant and thermal expansion coefficient the glass-ceramics were analyzed.

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Effects of Processing Modifiers on Dispersion and Rheology of Nonaqueous Mullite/Zirconia System Suspensions (뮬라이트/지르코니아계 비수성 현탁액의 분산 및 레올로지에 미치는 공정보조제의 영향)

  • Kim, Ji-Hyun;Yang, Tae-Young;Lee, Yoon-Bok;Park, Chan;Park, Hong-Chae
    • Journal of the Korean Ceramic Society
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    • v.38 no.6
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    • pp.537-544
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    • 2001
  • 뮬라이트, 지르코니아, 뮬라이트/지르코니아 비수성 현탁액의 분산 및 레올로지에 미치는 공정보조제의 영향이 침전밀도, 점도, 입자크기를 측정함으로써 검토되었다. 현탁액의 분산안정성 (높은 침전밀도와 낮은 점도로 특징 된)은 분산제+가소제+결합제를 함유하는 경우에 비하여 분산제 또는 분산제+가소제를 함유하는 경우가 우수하였다. Ball mulling 후의 입자크기분포는 공정보조제의 종류에 거의 영향을 받지 않았다. 결합제를 부가적으로 함유하는 현탁액은 상대적으로 강한 shear thinning 거동을 나타내었다.

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High Throughput Magnetic Separation for Human DNA by Aminosilanized Iron Oxide Nanoparticles (아미노실란화 철산화물 나노입자를 이용한 Human DNA의 초고속 자성분리)

  • Kang, Ki-Ho;Chang, Jeong-Ho
    • Journal of the Korean Ceramic Society
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    • v.45 no.10
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    • pp.605-609
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    • 2008
  • This work describes the preparation of functionalized magnetic nanoparticles(MNPs) and their bioapplication to human DNA separation. Silica coated MNPs were prepared by changing the volume ratio of tetraethyl orthosilicate(TEOS) for controlled coating thickness on the original nanoparticle of MNPs. The sol-gel process in silica coating on MNPs surface was adapted for relatively mild reaction condition, low-cost, and surfactant-free. And then amino functionalized magnetic nanoparticles were synthesized using amine groups as surface modifiers. The result of adsorption efficiency for human DNA with amino-functionalized silica coated MNPs was calculated as a function of the number of amine groups.

Animal Models of Arthritis: Pharmacological Intervention

  • Ryn, Joanne van
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.41-76
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    • 2001
  • Rheumatoid arthritis is an incurable chronic inflammatory and destructive arthopathy that affects 1% of the population world-wide. It has substantial personal, social and economic costs. The long-term prognosis is poor: 80 percent of affected patients will become disabled within 20 years after onset of disease. Medical costs of rheumatoid arthritis average ∼$ 6000 (US) per patient (1), Current antirheumatic drugs have limited efficacy and many side effects and more importantly they do not improve the long-term prognosis of rheumatoid arthritis (2). After a decade of few notable advances in therapy, several biological response modifiers that target pathophysiological processes in the disease have now emerged in the clinic. These new drugs are termed biological agents, and although information about their use in the clinic is still limited to short term treatment, they appear to have the ability to modify disease progress. In addition, COX-2 selective agents have now been approved that have comparable efficacy with standard NSAIDs, but fewer gastrointestinal side effects (3). Thus today many more therapeutic options are suddenly open to patients that even five years ago had little hope of relief from chronic pain and inflammation.

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Construction of Standardized Noise Annoyance Scales in Korea according to the ICBEN Method (ICBEN 방법에 의한 환경소음의 사회적반응 측정방법)

  • Kim, Kyong-Ho;Jeon, Jin-Yong;Takashi-Yano
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.358.1-358
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    • 2002
  • Recently a number of social surveys on community response to environmental noises have been conducted. Since standardized noise annoyance scales were needed to compare the results from various areas, ICBEN(International Commission on Biological of Noise) Team 6 planned a international joint study and constructed comparable standardized noise annoyance scales using the same method. In Korea the survey was conducted in four areas such as Seoul, Taejon, Honam and Yongnam. 100 subjects participated in each area approximately. (omitted)

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Metabolic Signaling to Epigenetic Alterations in Cancer

  • Kim, Jung-Ae;Yeom, Young Il
    • Biomolecules & Therapeutics
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    • v.26 no.1
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    • pp.69-80
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    • 2018
  • Cancer cells reprogram cellular metabolism to support the malignant features of tumors, such as rapid growth and proliferation. The cancer promoting effects of metabolic reprogramming are found in many aspects: generating additional energy, providing more anabolic molecules for biosynthesis, and rebalancing cellular redox states in cancer cells. Metabolic pathways are considered the pipelines to supply metabolic cofactors of epigenetic modifiers. In this regard, cancer metabolism, whereby cellular metabolite levels are greatly altered compared to normal levels, is closely associated with cancer epigenetics, which is implicated in many stages of tumorigenesis. In this review, we provide an overview of cancer metabolism and its involvement in epigenetic modifications and suggest that the metabolic adaptation leading to epigenetic changes in cancer cells is an important non-genetic factor for tumor progression, which cooperates with genetic causes. Understanding the interaction of metabolic reprogramming with epigenetics in cancers may help to develop novel or highly improved therapeutic strategies that target cancer metabolism.

PERFORMANCE NEEDS OF TOMORROW'S DRIVELINE LUBRICANTS

  • Hong, Hyun-Soo
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10a
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    • pp.21-24
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    • 2002
  • There is a trend with driveline lubricants toward improved thermal stability, vehicle component durability and fuel efficiency. These improvements can significantly reduce vehicle operating costs and improve customer satisfaction. Of these improvements, the fuel efficiency is getting a substantial attention due to recent focus on $CO_2$ emission control in Europe, Japan and $CAF{\'{E}}$ requirement in U.S.A. Lower viscosity axle oils and transmission fluids are currently being evaluated as potential solutions since these lubricants tend to reduce the churning losses and can improve the fuel efficiency. However, these lubricants should provide adequate gear and bearing protection, while increasing the overall efficiency of the driveline components. In this paper, the development of new fuel efficient axle was discussed with the focus on the effect of base oils, additives, and viscosity modifiers on the fuel efficiency of driveline components.

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The Effects of Sc on the Microstructure of Hypoeutectic Al-Si Alloys (아공정 Al-Si합금 조직에 미치는 Sc의 효과)

  • Kim, Myung-Han;Lee, Jong-Tae
    • Journal of Korea Foundry Society
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    • v.24 no.3
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    • pp.145-152
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    • 2004
  • The eutectic Si in Al-8.5wt.%Si alloy was changed from large flake to fine lemellar(or fibrous) shape when the Sc amount in the Al-Si alloy reaches 0.2wt.%. The optimum amount of Sc for the best modification effect was 0.8wt.% and slight decrease of modification effect occurred over this value. The study on the distribution of the modifiers(Sr, Na, and Sc) and the measurement of the surface tension of the Al-8.5wt.%Si alloy melt added with Sr, Na, and Sc modifier, respectively, reveals that Sc modifies the eutectic Si by the decrease of surface tension, while Sr and Na modify the eutectic Si mainly by impurity induced twinning mechanism.

Experimental Study on the Development of Fuel-Efficient Gasoline Engine Oil (가솔린 엔진오일의 개선을 통한 연비절감에 관한 연구)

  • Moon, W.S.;Lee, J.H.;Kim, S.H.;Lee, D.H.;Ryoo, S.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.3
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    • pp.46-54
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    • 1993
  • In order to develop a fuel-efficient gasoline engine oil, an experimental study was conducted using an engine dynamometer, a passenger car and the SRV machine. Oil samples with different viscosity were prepared by adding several friction modifiers to select the best one and also to investigate the effect of the viscosity grade. From the study, we have developed engine oils which result in good fuel economy. The viscosity grade of 7.5W/30 was best among the oils investigated with respect to fuel economy and a fatty amine type friction modifier had the good fuel-economy property.

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Traffic Noise Reducing Technology using RSBS(Radial type SBS) Modifiers Into Double Layer Pavement (RSBS(Radial type SBS)를 이용한 복층포장구조에 의해 도로교통소음을 저감하는 기술)

  • Kim, Byung Chae;Park, Jin Su;Hwang, Kyung Tae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.568-572
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    • 2013
  • This is traffic noise reducing technology with higher porosity and durability by using small aggregate in upper layer and big aggregate in lower layer utilizing RSBS modifier. We can reduce average 9dB(A) of traffic noise compare to normal pavement by double layer structure with higher durability using small gap over bigger gap. Also, it increases a porosity more than 22% with more durability by RSBS modifier.

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