• Title/Summary/Keyword: 분열점

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Mossbauer study of $CoCr_xFe_{2-x}O_4$ (Mossbauer 분광법에 의한 $CoCr_xFe_{2-x}O_4$의 연구)

  • 채광표;이혁진;이재광;이성호;이영배
    • Journal of the Korean Magnetics Society
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    • v.10 no.2
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    • pp.74-80
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    • 2000
  • CoCr$_{x}$ Fe$_{2-x}$O$_4$(0.0$\leq$x$\leq$1.0) ferrites have been fabricated by sol-gel method. The crystallographic and magnetic properties of the samples were investigated by means of x-ray diffraction, scanning electron microscophy, Mossbauer spectroscopy and vibrating sample magnetometry. The structure of all the samples is cubic spinel type and the lattice constant decrease with increasing Cr content. The substituted Cr ions were located only in the B-site. The particle size also decreases with increasing Cr content. The Mossbauer spectra consist of two sextets due to Fe$^{3+}$ions at A- and B sites for 0.0$\leq$x$\leq$0.6, while, a paramagnetic doublet appears for 0.8$\leq$x$\leq$1.0. The magnetic hyperfine field decreases with increasing Cr content. The relaxation spectra was shown at 0.8$\leq$x$\leq$1.0 in CoCr$_{x}$ Fe$_{2-x}$O$_4$. The coercivity decreases drastically, while, the saturation magnetization decreases linearly with increasing x.ing x.

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Expression of Recombinant Human Epidermal Growth Factor as a Active Form through Codon Optimization with E. coli and Co-expression of Chaperone (코돈 최적화 및 샤페론 공발현을 통한 활성 형태의 재조합 인간 상피세포성장인자의 발현)

  • Jang, Eun-Bin;Kim, Jun Su;Lee, Woo-Yiel
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.559-568
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    • 2020
  • Epidermal growth factor (EGF) is a hormone protein that affects cell growth and proliferation, and has various medical applications. In the present study, the gene of human EGF was codon-optimized with E. coli and the expression vector was constructed by cloning into pRSET. In order to obtain the recombinant human EGF in an active form rather than an inclusion body, chaperone co-expression was attempted along with codon optimization, for the first time. The expressed human EGF was isolated in the pure form by performing Ion Exchange Chromatography in two consecutive runs. ELISA analysis showed that the activity of purified EGF was greater than 99%, which is similar to commercially available EGF. Cell proliferation test confirmed that the recombinant human EGF has the ability to promote cell proliferation of human skin fibroblasts. The human EGF expression system of this study gives a significant amount of protein, and does not require the renaturation step and the additional chromatographic system to remove a fusion contaminant, thereby providing a very useful alternative to conventional expression systems for the preparation of recombinant human EGF.

The Sublime in Tarsem's Films : Focused on (타셈 싱의 영화에 나타난 숭고 연구 : <더 폴>을 중심으로)

  • Lee, Youn H.
    • Cartoon and Animation Studies
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    • s.32
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    • pp.245-261
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    • 2013
  • This paper analyzes films by director Tarsem Singh in relation to the theory of the sublime. The medium of film works in dimensions of both spectacle and narrative. Tarsem's strength mainly comes from spectacle. The visual style of Tarsem is unique and undeniably beautiful, but in a strange and magnificent way, rather than sweet and pleasant. If you accept the premises of Kant and Lyotard that the beautiful is a positive pleasure and the sublime is a negative pain, Tarsem's spectacle is certainly closer to the sublime than the beautiful. The Fall proves the director's ability in both spectacle and narrative. The spectacle of this film is so overwhelmingly huge, and vivid, it easily surpasses spectators' maximum capacity of imagination, which leaves the spectators in awe. Spectacle tends to hinder thinking thus obstruct the flow of narrative, but at the same time it blocks rational suspicion about the narrative. The spectacle of the Fall works as the power to immerse the spectators into the internal logic of the film. Since the spectators are deeply moved by the spectacle, they willingly follow the narrative of the film, the tragic adventure of the heroes which again gives the audience deep catharsis.

Isolation of Wild Yeasts Obtained from Waters and Soils of Riversides in Sangjubo of Nakdong River and Daechung Dam of Geumgang Midstream, Korea and Characterization of Unrecorded Wild Yeasts (낙동강 상주보와 금강중류 대청댐 주변으로부터 야생효모의 분리 및 국내 미기록 효모들의 균학적 특성)

  • Han, Sang-Min;Park, Dong-Jae;Kim, Ji-Yoon;Lim, Hyo Jin;Lee, Hyang Burm;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.48 no.3
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    • pp.237-249
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    • 2020
  • The goal of this study was to isolate wild yeasts from waters and soils in Sangjubo of Nakdong river and Daechung dam in Daejeon city, Korea and investigate characteristics of previously unrecorded novel wild yeasts. In total, 94 strains from 39 different species of wild yeasts were isolated from 47 soils and waters samples obtained from Sangjubo in Nakdong river. Among these, 3 strains, including Rhodosporidium azoricum JSL-GRU-009, represented novel yeast strains which were previous recorded. Two hundred nine strains from 105 different species of wild yeasts were isolated from 130 soils and water samples obtained from Daechungdaegyo and Daechung dam of Shintanjin in Daejeon city, Korea. Ten strains including Bullera pseudoalba JSL-GRU-005 also represented newly recorded strains in Korea. All the 13 previously unrecorded yeasts were oval or global in shape, and nine strains, including R. azoricum JSL-GRU-009, formed ascospores. Ten strains grew well in vitamin-free medium. R. azoricum JSL-GRU-009 grew well in 20% glucose-containing yeast extract-peptone-dextrose (YPD) medium and 3 strains, including Rhodotorula oryzicola JSL-GRU-003, grew well in 5% NaCl-containing YPD medium.

Possible Methods of Identifying Underground Cavities Using Seismic Waves (지진파를 이용한 지하 공동의 탐지 방법)

  • 김소구;마상윤;김지수
    • The Journal of Engineering Geology
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    • v.6 no.3
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    • pp.137-153
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    • 1996
  • The purpose of this study is to investigate the possibilities of identifying and detecting underground cavities using seismic waves recorded by the fixed and mobile stations. During 18 months of field work we recorded chemical explosions near the Bongdarn station. Seismic Stations were installed on the free surface and underground inside the Samba mine. The seismograms at the fixed(lorg-term) seismic station show abrupt change of polarization characteristics which can he associated with the appearance of P-to-S converted phase(PS) at 150 ~ 200 msec after the first P arrival. This result indicates that converted phases are generated very near to the Bongdarn station at a depth of 190m. Shear-wave splitting phenomena have also been observeci The time delay between fast shear(fS) and slow shear(sS) waves ranges between 30 and 60 msec(average is 42 msec). However, exact time delay between the fast and the slow shear waves can not be accurately measured because of the very short time delay and limitation of sampling rate. Chemical explosion experiments were recorded at stations along various paths to contrast the seismic response of areas with and without cavities. The seismograms recorded at the stations installed at cavity areas show an abrupt change of polarization characteristics but not on the other stations. Seismic waves propagating through the cavity are characterized by the attenuation of high frequency waves and predominantly low frequency seismic waves after the S wave arrivals.

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Effect of Developmental Stage of Pollen Grain and Temperature Pretreatment on Anther Culturein Lilium Asiatic Hybrid 'Dreamland' (Lilium Asiatic hybrid 'Dreamland'의 약배양에 미치는 화분 발육단계와 온도 전처리의 영향)

  • Park, Young Ae;Hwang, Yoon Jung;Park, In Sook;Suh, Dong Hee;Jeon, Su Min;Yeo, Kum-Bok;Lee, Ga Young;Chung, Jae-Dong;Lim, Ki Byung
    • FLOWER RESEARCH JOURNAL
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    • v.16 no.1
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    • pp.12-16
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    • 2008
  • This study was carried out to produce haploid plants to verify a systematic breeding program and genetic analysis. Effect of developmental stage of pollen grains and pre-treatment temperature on production of haploid plants was investigated. Microscopic investigation of the explants (Lilium Asiatic hybrid 'reamland' revealed that the length of flower bud at 23.0-24.9, 25.0-26.9, and 27.0-28.9 mm long coincided with tetrad, uninucleate, and binucleate, respectively. When the efficiency of the anther culture from microgametogenetic stages was tested, late uninucleate to early binucleate stage, having the length of 23.0 to 28.0 mm long flower bud, was the best. The frequencies of the callus induction and plant regeneration from the stage mentioned above were 17.8 and 6.7%, respectively. When calli were cultured on the MS medium containing picloram and zeatin at $25^{\circ}C$, shoots were obtained. Roots of regenerated plantlets were confirmed as haploid through an microscopic observation.

A study on the value of Korean during the Joseon Dynasty (조선시대(朝鮮時代)의 한국적 가치 연구)

  • Han, Sung Gu
    • The Journal of Korean Philosophical History
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    • no.39
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    • pp.85-114
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    • 2013
  • Traditional values refer to one's attitudes or perspectives developed by negotiating with oneself, others, society, world, nature and universe, which include thoughts on what is right, desirable, and what is dos and don'ts. The purpose of this study was to investigate values which Korean people traditionally emphasized, and their changes by epochal situation focused on the Choson Era. Also, this study intended to assist in finding values and meaning which should be passed down and manifested in contemporary society based on the study results. In this context, I select some positive values in the background of the Joseon dynasty. As traditional values or ethics in Korea destroyed and distorted going through the period of Japanese colonialism, all the existing social culture and traditional culture were denied, which resulted in vanishing common value which led community for several hundred years. The loss of common value caused community destruction and collapse, and made Korean people seek to survival, success and advancement in life as suffering from severe conflict of values. Experience of hollow state of mind caused by historical and cultural severance left distorted and degenerated values to Korea people, which made them pursue false values without realizing true meaning of traditional values. The true meaning of traditional values should be universal no matter how society changes, and could be milestone to contemporary people wandering aimlessly. Realizing and reconsidering the meaning of traditional values to found comtemporary values of Korean people by reflecting on history can produce significant results beyond age-old debate about East or West, and tradition or modernity.

What Is Cultured Meat? (배양육이란 무엇인가?)

  • Huh, Man Kyu
    • Journal of Life Science
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    • v.31 no.6
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    • pp.587-594
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    • 2021
  • By 2050, 70% more food will be needed to fulfill the demands of a growing population. Among the solutions, cultured meat or clean meat is presented as a sustainable alternative for consumers. Scientists have begun to leverage knowledge and tools accumulated in the fields of stem cell and tissue engineering in efforts aimed at the development of cell-based meat. Cultured meat has to recreate the complex structure of livestock muscles with a few cells. Cells start to divide after they are cultured in a culture medium, which provides nutrients, hormones, and growth factors. An initial problem with this type of culture is the serum used, as in vitro meat aims to be slaughter free. Thus, it is contradictory to use a medium made from the blood of dead calves. The serum is expensive and affects to a large extent the production cost of the meat. A positive aspect related to the safety of cultured meat is that it is not produced from animals raised in confined spaces and slaughtered in inhumane conditions. Thus, the risk of an outbreak is eliminated, and there is no need for vaccinations and animal welfare issues. The production of cultured meat is presented as environmentally friendly, as it is supposed to produce less greenhouse gas, consume less water, and use less land in comparison to conventional meat production.

Reflection on the Social Dimension of Spiritual Direction (영적 지도의 사회적 차원에 대한 고찰)

  • Jingu Kwon
    • Journal of Christian Education in Korea
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    • v.74
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    • pp.189-208
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    • 2023
  • Spiritual direction is not a product created and developed by an individual, but a historical product that includes the church, believers, society, and the contexts of the times. Among the social changes related to spiritual direction, this study pays attention to monasticism and the Reformation. Focusing on these two social changes, this study analyzes the social dimension of spiritual direction indicated by the occurrence and change of spiritual direction and discusses its meaning. Around the time Christianity was officially recognized by the Roman Empire, monasticism began its long history, and Athanasius spread his ideal of monastic life and at the same time pursued the unity of the church and the monastic movement. Through this process, spiritual disciplines and educational models interacted and changed. During the Reformation period, Protestantism began to form new spiritual education and training. The Catholic Church pursued renewal through new concepts and practices of spiritual direction. Spiritual direction is being formed and recognized as a means of helping the spiritual life of individual Christians. The origin and change of spiritual direction mean that spiritual direction can be understood and applied differently reflecting the contexts and situations due to social interaction. Also, it should not be overlooked that spiritual direction can act as a cause of integration or division of the Korean Protestant churches.

The success and failure of non-regular workers' struggles and their effects on organizational strength (비정규직 노동자 투쟁의 승패와 조직력 변화)

  • Ch, Donmoon
    • Korean Journal of Labor Studies
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    • v.17 no.1
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    • pp.139-176
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    • 2011
  • Non-regular workers came to the fore while working class formation was in retreat along with the democratic labor movement of regular workers. The formation of principal agents, however, is yet to occur. Then, why non-regular workers' struggles could not yield a consequence in that regard? What kind of factors are to determine the outcome of the struggles and how do they do it? It is the aim of this study to answer those questions. In contrast with regular workers' struggles, non-regular workers' struggles tend to break out in response to capitalist offensives, rely on atypical and, often, extreme measures of struggle rather than strike in the form of work stoppage, drag out for too long, and appeal for social solidarity outside when the solidarity of regular workers is not available. Non-regular workers' struggles tend to end up with failure rather than success, and with weakening rather than strengthening of their organizational strength. So as to overcome the tendency to fail, non-regular workers' struggles need regular workers' solidarity in addition to their own strong mobilization power, while social solidarity or positional power could substitute for regular workers' solidarity in some cases. So as to build up their organizational strength, non-regular workers' struggles should win victories in the struggles, while a victory could turn into a trap in the case of conversion. Both regular workers' solidarity and the internal integration of the struggles are two foremost important factors in achieving the victory of struggles and the building-up of organizational strength. Those who have got involved in struggles are from the best organized sector among all the non-regular workers. As they have gone through weakening of organizational strength, it becomes more difficult for non-regular workers to form principal agents. Without non-regular workers' struggles, however, the capitalist offensives must have carried the day. In that sense, non-regular workers' struggles did a role in at least detaining capitalist offensives, if not stopping them. The practical implication of non-regular workers' struggles is that, if non-regular workers redefine the ultimate goal of their struggles as the formation of their principal agents for working class formation, it would be a strategically rational choice to identify the strategic objective of struggles with the maintaining and strengthening of their organizational strength rather than the achievement of their immediate demands.