• Title/Summary/Keyword: Condition of isolation

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The Influence of Interphase Condition and Fiber Content on the Dynamic Properties of Short-fiber Reinforced Rubber (계면상 조건과 단섬유 함유량이 강화고무의 동적 특성에 미치는 영향)

  • 류상렬;이동주
    • Composites Research
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    • v.13 no.3
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    • pp.30-37
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    • 2000
  • The dynamic properties of short-fiber reinforced Chloroprene rubber have been studied as functions of interphase conditions and fiber content. The loss factor generally decreased with fiber content and showed different patterns according to interphase conditions. The better interphase condition showed the lower loss modulus, $E_2$. Also, the dynamic ratio decreased with fiber content and rapidly decreased in the case of double coatings, i.e., model C. Therefore, the short-fiber reinforced rubber could have the better isolation in frequency ratio($\sqrt{2}$ min.) compared to frequency ratio($\sqrt{2}$ max.). And we have investigate the possibility of applying short-fiber reinforced rubber to automotive engine mount.

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Isolation, Identification and Culture Condition of Microorganism Producing Glutathione (Glutathione 생산균주의 분리 동정 및 생산조건)

  • 신원철;김대선;유주현;유재홍
    • Microbiology and Biotechnology Letters
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    • v.21 no.1
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    • pp.1-5
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    • 1993
  • The strain which produced glutathione was isolated from soil samples. The isolated strain was identified as the genus Candida through its morphological. cultural and physiological characteristics. The highest production of glutathione by Candida sp. was obtained after cultivation with shaking for 36 hours in the culture medium containing fructose 1.0%, yeast extract 4.0%. NaCI 0.04%, thiamine-HCI $5{\mu}g$/ml, and L-cysteine 0.04%. The optimal pH and temperature for the glutathione production were pH 6.0 and $25^{\circ}C$, respectively. The glutathione production by Candida sp. under the optimal culture condition was $92{\mu}g/ml$.

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Culture of Rat Salivary Acinar Cells (백서 타액선 선포 세포의 배양)

  • Lee, Sung-Woo;Han, Song;Kho, Hong-Seop
    • Journal of Oral Medicine and Pain
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    • v.24 no.2
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    • pp.163-169
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    • 1999
  • We investigated the culture condition and effects of various growth factors on the culture of salivary gland acinar cells. Male, Sprague-Dawley rats (about 6 weeks old) were sacrificed and their submandibular, sublingual, and parotid glands were used as specimens. High oxygen level more than 90% and coating of Matrigel on culture dish were important factors to help increase the survival time of acinar cells, Proper concentration of enzymes such as collagenase and hyaluronidase during isolation steps was also important. Addition of various growth factors such as dexamethasone, insulin, transferrin, selenous acid, reduced glutathione, epidermal growth factor, isoproterenol, and putrescine in culture medium helped to increase lifetime of cultured salivary acinar cells.

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A Study on the Failure of Grands Ensembles of France and on the Methods of Renovation (프랑스의 대형 주거단지 '그랑 앙상블'의 실패와 그 재생수법에 관한 연구)

  • Sohn, Sei-Kwan
    • Journal of the Korean housing association
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    • v.25 no.5
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    • pp.113-124
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    • 2014
  • The grands ensembles, or large-scale high-rise housing projects, are widely regarded as notorious products of postwar French government policy in the area of housing and urban planning. There was a general consensus that the grands ensembles had been a 'failure'. They were perceived as the source of all the ills of the contemporary city, as responsible for a social breakdown stemming from lack of infrastructure, geographical isolation, and monotonous environments. French government embarked on a broad renovation effort in light of the deteriorated condition of grands ensembles in the 1980s, which has been approved as generally 'successful'. This study focusing on French cases allowed me to demonstrate that following qualifications are critically important for successful housing projects: urban contextual continuity, socially mixed community, authentic planning for achieving sense of place, relationship between collective and individual expression, et cetera.

Isolation and Characterization of a Methylotroph Producing 3-hydroxybutyrate-3-hydroxyvalerate Copolymer

  • JUNG HOE KIM;KIM, PIL;SEON WON KIM;GYUN MIN LEE;HYUN SOO LEE
    • Journal of Microbiology and Biotechnology
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    • v.5 no.3
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    • pp.167-171
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    • 1995
  • A bacterial strain C-02 using methanol as a carbon source was isolated from Gumi Industrial Estate and selected based on its rapid growth and capability of poly-$\beta$-hydroxybutyrate accumulation. Characteristics of strain C-02 showed that it belongs to the Methylococcaceae family, Type II subgroup. Strain C-02 could incorporate valerate into the PHB chain to form 3-hydroxybutyrate and 3-hydroxyvalerate (P(3HB-co-3HV)). Among various nutrient limitation tests, the nitrogen limitation test resulted in the highest content of P(3HB-co-3HV) per dry cell weight, 50$%$. Under the nitrogen limited condition, the average molecular weight of P(3HB-co-3HV) obtained was determined to be approximately $2.8\times 10^5$ daltons.

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Analysis of improved solar cell modeling (개선된 태양전지 모델링 해석)

  • Kim Sun-Ja;Jeong Byung-Hwan;Park Jong-Chan;Choe Gyu-Ha
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.113-116
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    • 2004
  • Output power of a photovoltaic system changes continuously as it strongly depends on the weather condition(isolation and temperature). Therefore, it is necessary the theoretical model realizes the electrical output characteristics of solar cell. Of several theoretical models for real solar cell, both parametric model and interpolation model are used widely. In this paper, we have propose a improved model of solar cell using its output characteristics that can be extended to calculate the rear solar cell characteristics at various temperatures and insolation. And more, the theoretical research of several models of solar cell using simulation analysis.

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Isolation and characterization of glutamate dehydrogenase defective mutant of brevibacterium flavum (Brevibacterium flavum의 glutamate dehydrogenase결핍돌연변이주의 분리 및 특성)

  • 최순영;성하진;민경희
    • Korean Journal of Microbiology
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    • v.26 no.2
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    • pp.93-100
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    • 1988
  • In order to understand the regulation of glutamate dehydrogenase(GDH) synthesis in Brevibacterium flavum, we have isolated a mutant lacking NADP-linked GDH activity by ethlmethane sulfonate treatment. The $gdh^-$ mutant was grown on the minimal plate with 1mM ammonium chloride and not that with 300mM ammonium chloride. The cell-free extracts from $gdh^-$ mutant and prototroph were also examined with glutamine synthetase(GS) and glutamate synthase (GOGAT) production by niteogen sources. The growth of $gdh^-$ mutant in presence of 20mM ammonium chloride means that GOGAT synthesis is sufficient to allow growth in this condition. GS production of $gdh^-$ mutant as well as parental strain was induced by 1mM urea and ammonium tartrate, but it was repressed by higher concentration of ammonia, and also induced by 20mM to 50mM glutamate as a substrate. It was special attention that GOGAT synthesis from $gdh^-$ strain was more repressed by higher concentration of ammonia than prototroph as described in E. coli system.

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Integration of Single-Cell RNA-Seq Datasets: A Review of Computational Methods

  • Yeonjae Ryu;Geun Hee Han;Eunsoo Jung;Daehee Hwang
    • Molecules and Cells
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    • v.46 no.2
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    • pp.106-119
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    • 2023
  • With the increased number of single-cell RNA sequencing (scRNA-seq) datasets in public repositories, integrative analysis of multiple scRNA-seq datasets has become commonplace. Batch effects among different datasets are inevitable because of differences in cell isolation and handling protocols, library preparation technology, and sequencing platforms. To remove these batch effects for effective integration of multiple scRNA-seq datasets, a number of methodologies have been developed based on diverse concepts and approaches. These methods have proven useful for examining whether cellular features, such as cell subpopulations and marker genes, identified from a certain dataset, are consistently present, or whether their condition-dependent variations, such as increases in cell subpopulations in particular disease-related conditions, are consistently observed in different datasets generated under similar or distinct conditions. In this review, we summarize the concepts and approaches of the integration methods and their pros and cons as has been reported in previous literature.

A Study on Optimal Design Factors of Frictional bearing for Isolated Bridges (교량의 마찰형 지진격리장치 최적 인자 결정에 관한 연구)

  • 고현무;박관순;김동석;송현섭
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.451-458
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    • 2002
  • To secure structures from strong earthquakes occurred recently and design economically seismic isolation design is spread rapidly. Specially, frictional isolator has superiority in application to bridge because it has many advantages. however, because isolator lies between pier and girder, responses of pier and superstructure contradict each other and we need to control the two responses to minimize the bridge's failure probability. In this study, frictional coefficient and horizontal stiffness is defined as design parameters of frictional isolator. the optimal design parameters of frictional isolator to minimize the bridge's failure probability are presented according to strength of earthquake and soil conditions. The result says that optimal friction coefficient is higher as the strength of earthquake is increased. And it is also higher as the soils are more flexible. But, optimal horizontal stiffness of rubber spring is insensitive to strength of earthquake and soil condition.

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Effects of thermal aging on mechanical properties of laminated lead and natural rubber bearing

  • Kim, Dookie;Oh, Ju;Do, Jeongyun;Park, Jinyoung
    • Earthquakes and Structures
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    • v.6 no.2
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    • pp.127-140
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    • 2014
  • Laminated rubber bearing is very popular base isolation of earthquake engineering pertaining to the passive structural vibration control technologies. Rubber used in fabricating NRB and LRB can be easily attacked by various environmental factors such as oxygen, heat, light, dynamic strain, and organic liquids. Among these factors, this study carried out thermal aging test to investigate the effect of thermal aging on the mechanical properties of laminated rubber bearings in accelerated exposure condition of $70^{\circ}C$ temperature for 168 hours. The compressive-shear test was carried out to identify the variation of compressive and shear properties of the rubber bearings before and after thermal aging. In contrast to tensile strength and elongation tests, the hardness of rubber materials showed the increasing tendency dependent on exposure temperature and period. Based on the test results, the property changes of rubber bearing mainly aged by heat are quantitatively presented.