• Title/Summary/Keyword: 에셔

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Energy Distribution of Ion and Electron by Field Emission and Proppagation in a Diod Device) (전계에 의한 이온 및 전자의 방출과 전파에 따른 에너지 분포)

  • 조광섭;최은하;강승언
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.164-164
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    • 1998
  • 전채 방출에 의한 이온 몇 전자는 현마갱 몇 마이크로 천자소짜 ( (micro-electronic device)둥에 용용봐 어 왔다. 또한 이 온 몇 천짜의 C Cathod- Anode의 Diode구조에셔의 운동역학이 주요한 환심사이다. 현미 청과 같이 접속율 요하는 장쳐들에셔는 이들의 에녀지 분포가 접속도에 칙첩영향을 주는 Chromatic Abberation을 컬갱하게된다. 그라고 Diode 에셔의 이온 몇 천짜의 운동 또한 에너져훈포에 대한 이혜률 근거로 한 다. 본 연구에셔는 전계에 의한 이온 및 전자의 방출구조(mechanism)률 소채한다. 또한 방출극 표면에셔의 이온 몇 전짜가 갖는 에너져 환포와 양극구조에셔 뱀이 천봐하는 과청에셔의 에너져 환포의 특생용 환석한다.

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A Study on the Direction of Interior Design Application based on the M.C Escher Spatial Logic (에셔회화의 공간논리에 의한 실내디자인 적용방향에 관한 연구)

  • 문정민;김명선
    • Korean Institute of Interior Design Journal
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    • no.39
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    • pp.12-19
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    • 2003
  • M.C Escher was not a mathematician or architect, but a visual graphic woodblock artist. He expresses space in various angles such as illusion and space not represented in reality, repetition, geometric pattern and change in space vision. However, as his works represent the impossible space which is virtually not exist in reality, they were examined numerically by scientists and mathematicians rather than by designers. Because his distinctive approach to view space, his works have been highly evaluated by scholars in various fields. Based on the previous research by mathematicians and scientists, this study will examine the sp- atial logic was represented visually in the works of M.C Escher and find out the possible and adoptable alternatives for new space design and provide the design application direction in the expression of interior space.

The Development of Serum Free Medium for the Economic Production of scu-PA from HEK Cells (인간 신장세포로부터 scu-PA의 경제적 생산을 위한 무혈청 배지의 개발)

  • 김현규;김현구
    • KSBB Journal
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    • v.9 no.5
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    • pp.518-524
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    • 1994
  • Serum free medium was developed to cultivate Human Embryonic Kidney cells with Cytodex III microcarriers. The cells normally attached and spreaded on the microcarriers in serum free medium, and grew well by bead to bead processes. 85% of attachment yield was obtained on Cytodex III in this medium, compared to about 93% in 1% serum containing medium. About 90% of the attached HEK cells spreaded after 6 hours of post-attachment periods on the surface of microcarrier. Maximum cell density and scu-PA concentration in a serum free medium were $9.1{\times}10^5$ cells/ml and 1790 IU/ml, respectively, with fed-batch cultivation. Maximum cell density and scu-PA concentration in this medium with perfusion cultivation were $2.5{\times}10^6$ cells/ml and 1820 IU/ml, respectively. The conversion of single chain urokinase type plasminogen activator (scu-PA) into two chain type plasminogen activator (tc-PA) was less than 5% in a serum free medium compared to about 10% in 0.5% serum containing medium.

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Determination of Optimum Conditions for Xylose Fermentation by Pichia stipitis (Pichia stipitis에 의한 Xylose 발효의 최적조건 결정)

  • 권순효;유연우서진호
    • KSBB Journal
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    • v.8 no.5
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    • pp.452-456
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    • 1993
  • This study was carried out to optimize the fermentation conditions for direct alcohol fermentation of xylose by Pichia stipitis CBS 5776. The best cell growth and the ethanol production were obtained under 0.05 VVM aeration and 300rpm agitation at $30^{\circ}C$ using 100 g/l xylose medium of the initial pH 5.0. In the above condition, the maximum specific growth rate and maximum cell concentration were 0.14hr-1 and $1.3 \times109$ cells/ml, respectively. Pichia stipitis CBS 5776 also produced 40.2g/l ethanol utilizing about 96% of 100g/l xylose after 72hr fermentation. At this point, the overall volumetric ethanol productivity was 0.56g/1-hr and the ethanol yield was 0.42 g-ethanol/g-xylose consumed, which corresponds to 82% of the theoretical yield.

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Alteration of Recognition Sequence by Restriction Endonuclease -Effect of pH and Hydrophobicity on BamHI- (제한효소의 인식자리 변화 -BamHI 특이성에 미치는 산도와 소수성의 영향-)

  • 이강민
    • KSBB Journal
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    • v.11 no.2
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    • pp.193-200
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    • 1996
  • In molecular biology, type-II restriction endonuclease, which specifically recognize and cleave DNA at a limited number of sites, have been exploited as a means of characterizing DNA fragments, DNA mapping for genetic engineering. Type-II restriction endonucleases have been found to modulate their substrate specificity under modified conditions such as extreme pH, ionic strength, high enzyme concentration, substitution of metallic cofactors or addition of organic solvents. This study was initiated to investigate the modification of recognition specificity of BamHI according to the different pH and organic solvent under the given buffer condition. The specificity of BamHI is highly depends on the presence of hydrophobicity (LogP: partition coefficient) and pH of reaction solution. The specificity of BamHI is changed in range of LogP -1.03∼-1.35(at pH 7.5), -1.03∼-2.5 (at pH 8.0), -0.75∼-0.25(at pH 8.5), 0.32∼-2.5(at pH 8.9), respectively. Alteration of specificity appears in lower concentration of organic solvent when the reaction occurs in more alkali pH. For example, in DMSO solution, alteration of specificity appears in 20% concentration at pH 7.5 but in 4% concentration at pH 8.9.

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A Study on the Application of Spatial Configuration to Escher's Oppositive Tessellation (에셔의 대립적 테셀레이션 작품의 공간구성 적용에 관한 연구)

  • You, Jung-Hwan;Lee, Ho-Joung
    • Korean Institute of Interior Design Journal
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    • v.17 no.5
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    • pp.40-50
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    • 2008
  • This article examined the applicability of spatial configuration to Escher's works through configurative logics and rules and studied the contrasting relations among the unit elements in Escher's works and their characteristics and the creative process of the characteristics. As the results of the study on the bases to maintain and create the partial elements revealed as the characteristics, it was shown that Escher's sequential transformative works demonstrated diverse expressive characteristics as a creative process of Inter-complementary contrasting relations based on the independence of the unit elements. It was also shown that the creative process of the unit elements was actualized through the maintenance base of the fixed and absolute characteristic as the logic for the creation and the creation base of the dynamic and relative characteristic. Therefore, it was interpreted that by applying the logics for creation to Escher's unit elements through the spatial interpretation of the maintenance base and the creation base as well as by configuring the units created in such a way according to the characteristics of Escher's works, spatial possibility canbe derived out from Escher's contrasting tessellation works. The process of spatial configuration is the process to make a balance between various conditions, artists own understanding of the space and his/her intention of the space. From this viewpoint, the logics for maintenance base and for creation base seem to have the potentiality as a spatial configuration to consistently meet the given conditions as well as to derive out novelty through the transformation to maintain the fixed and absolute condition(base) and the characteristics of the independent(additional) transformation arising together with the implicit relations among the transformative units.

Antimicrobial Activity of Extracts and Coumaric Acid Isolated from Artemisia princeps var. orientalis (쑥의 추출물 및 Coumaric Acid의 항균활성)

  • 박석규;박종철
    • KSBB Journal
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    • v.9 no.5
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    • pp.506-511
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    • 1994
  • Antimicrobial activity of methanol extract and fraction from mugwort leaves(Artemisia princeps val. orientalis) was investigated for the screening of natural antiwucroblal components. By using agar diffusion method, ethyl acetate(EtOAc) layer fractionated from methanol extract of mugwort leaves showed the highest inhibitory effects against tested microorganisms. The ortho-coumaric acid(200∼600ppm) isolated from EtOAc layer showed strong antibacterial activities for Bacillus subtilis and Salmonella typhimurium. As derivatives of o-coumaric acid, antibacterial activity of para-coumaric acid was 1.2∼1.7 fold higher than that of o-coumaric acid. Three types of coumaric acids strong inhibited the growth of B. subtilis in the culture medium. Growth of S. tyhimurium, P. aeruginosa and S. aureus were effectively inhibited by o-, m- and p-coumaric acids, respectively. Minimum inhibitory dose of p-coumaric acid for B. subtilis was $\100∼200mu\textrm{g}$/paper disk.

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Kinetics of Cultivating Photosynthetic Microalga, Spirulina platensis in an Outdoor Photobioreactor (옥외 광배양조에서 광합성 미세조류인 Spirulina platensis의 대량배양에 관한 동력학적 연구)

  • 성기돈;안주희
    • KSBB Journal
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    • v.10 no.4
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    • pp.401-405
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    • 1995
  • An open pond type photobioreactor for mass cultivation of S. platensis was designed and the growth parameters from different cultivation processes were compared. 0.30(1/day) of specific growth rate and 1.69(g/$\ell$) of maximum cell density were obtained from batch cultivation. In fed-batch cultivation, specific growth rate and maximum cell density were estimated as 0.22(1/day) and 1.75(g/$\ell$), respectively. Maximum biomass productively from continuous cultivation was obtained as 0.44 (g/$\ell$/day). It proves that an outdoors-mass cultivation of S. platensis considering optimal environmental condition is economically feasible. In addition, the biomass productivity was studied in two different mixing systems such as agitation and air sparging methods. The biomass productivity by an agitation method was better than that in an air sparging method.

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