• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1993년도 지하공간 건설기술에 관한 서울 심포지움 논문집
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• pp.235-247
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• 1993

The 62 m span Olympic lee Hockey cavern in Gjovik, Norway, is located in jointed gneiss of average RaD = 70% and has a rock cover of only 25 to 50m, thus posing challenging design p problems. The investigations prior to construction included two types of stress measurements, cross-hole seismic tomography, special coe logging, Q-system classification and numerical modelling with UDEC-BB. Predicted maximum deformations were 4 to 8 mm; surprisingly small due to the high horizontal stresses recorded. Extensometer (MPBX) installations from the surface prior to construction, precision surface levelling and MPBX installed from inside the cavern give a combined measure of maximum deformations in the range 7 to 8 mm with the 62 m span fully e excavated, and three adjacent caverns for the Postal Services also completed.

• KSBB Journal
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• 제27권3호
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• pp.161-166
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• 2012

The purpose of this work was to examine the antibacterial activity derived from a lactic acid bacterium isolated from korean rice wine, called makgeolli. Various physiological and biochemical properties of this strain were characterized. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was designated as Lactobacillus casei HK-9, and registered in GenBank as [JQ951606]. Growth rate, production of organic acids (e.g., lactic acid and acetic acid), and pH changes during growth were monitored. The maximum concentrations of lactic acid and acetic acid were approximately 576 mM and 199 mM, respectively, and pH was changed from 7.00 to 3.74 after 72 h of incubation. HPLC was used to confirm the production of lactic acid and acetic acid. Significant antimicrobial activity of the concentrated supernatant was demonstrated against various food-poison causing bacteria (e.g., Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, Salmonella enteritidis). Ethanol tolerance of L. casei HK-9 showed up to 12% of ethanol within the culture.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.420-423
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• 2003

[ $TiO_2$ ] thin films were fabricated by DC magnetron sputtering system at by controlling deposition times, ratios of $Ar:O_2$ partial presser ratio and substrate conditions. And the surface, cross-section morphology, microstructure, and composition ratio of the films were analyzed by FE-SEM, TEM and XPS. Besides, the optical absorption and transmittance of the $TiO_2$ films were measured by a UV-VIS-NIR Spectrophotometer, and photocatalytic properties were studied by G C Analyzer & Data Analysis system. As the result, when $TiO_2$ thin film was made at deposition time of 120[min] and $Ar:O_2$ ratio of 60:40, the best structural and optical properties among many thin films could be accepted. The best results of properties were as follows: thickness; $360{\sim}370[nm]$, grain size; 40[m], gap between two peak binding energy, $5.8{\pm}0.05[eV]$ ($2p_{3/2}$ peak and $2p_{1/2}$ peak of Ti was show at $458.3{\pm}0.05[eV]$ and $464.1{\pm}0.05[eV]$ respectively), binding energy; $530{\pm}0.05\;[eV]$, opticalenergy band gap; 3.4[eV].

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.485-487
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• 1994

A novel control scheme for a Switched Reluctance Motor(SRM) drive is described. The control scheme which is to increase torque, to decrease torque ripples and easy to commutate is suggested. The conditions for high torque drive which includes flat-topped phase current and voltage control arc analyzed and adopted in this control scheme. Flat-topped current is achived via dc-link voltage control. The suggested control system was tested to verify this suggestion.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1136-1140
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• 2008

The Rhodopseudomonas palustris KUGB306 hemA gene codes for 5-aminolevulinic acid (ALA) synthase. This enzyme catalyzes the condensation of glycine and succinyl-CoA to yield ALA in the presence of the cofactor pyridoxal 5'-phosphate. The R. palustris KUGB306 hemA gene in the pGEX-KG vector system was transformed into Escherichia coli BL21. The effects of physiological factors on the extracellular production of ALA by the recombinant E. coli were studied. Terrific Broth (TB) medium resulted in significantly higher cell growth and ALA production than did Luria-Bertani (LB) medium. ALA production was significantly enhanced by the addition of succinate together with glycine in the medium. Maximal ALA production (2.5 g/l) was observed upon the addition of D-glucose as an ALA dehydratase inhibitor in the late-log culture phase. Based on the results obtained from the shake-flask cultures, fermentation was carried out using the recombinant E. coli in TB medium, with the initial addition of 90 mM glycine and 120 mM succinate, and the addition of 45 mM D-glucose in the late-log phase. The extracellular production of ALA was also influenced by the pH of the culture broth. We maintained a pH of 6.5 in the fermenter throughout the culture process, achieving the maximal levels of extracellular ALA production (5.15 g/l, 39.3 mM).

• 한국미생물·생명공학회지
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• 제32권2호
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• pp.135-141
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• 2004

인간 과립구 성장인자(hG-CSF)는 골수에서 생산되는 단백질로 호중구의 분화 및 생성을 촉진시키는 역할을 한다. 현재 재조합 hG-CSF는 암화학요법에 의한 호중구감소증, 골수이식시 호중구 감소증, 재생불량성 빈혈에 수반되는 호중구 감소증 등으로 적응증이 확대되고 있다. 본 연구에서는 OmpA signal sequence를 삽입하여 인간 과립구 성장인자(hG-CSF)가 분비발현되도록 고안된 T7 promoter 에 의하여 발현되는 pYRCl 발현백터를 제조하였다. E. coli BL2l (pYRCl) 발현시 $37^{\circ}C$에서 배양하는 경우 많은 양의 봉입체(aggregates)를 형성한다. 이에 비하여 $10\mu$M ucose를 포함하는 변형된 MBL배지에서 10 g/$\ell$IPTG를 유도물질로 7시간동안 $25^{\circ}C$에서 배양하였을 때 전체 periplasm단백질의 15%가 soluble rhG-CSF이었다. 또한, 유가식 배양방법을 사용하여 E. coli BL2l(pYRCl)에서 soluble rhG-CSF의 생산조건을 조사하였다. 유가식 배양에서 rhG-CSF의 발현량이 비증식속도를 $0.43 h^{-1}$ 에서 0.14 $h^{-1}$ 으로, 유도 배양시간을 최적화함으로써 rhG-CSF의 발현량이 4.4mg/$\ell$에서 24mg/$\ell$ 로 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.13-14
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• 2008

This paper describes the optimal PSS parameter design for the PSS of EX2000 excitation system. The suggested tuning technique uses the model-based PSS tuning method which have three steps: generation system modeling, determination of PSS parameters, and on-site test. Using this method, the PSS parameters of EX2000 system in Dangjin T/P #4 was designed and verified by linear analysis program, PSS/E, and EMTDC/PSCAD.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.70-77
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• 2024

A low energy ion irradiation system based on the deuterium arc ion source with a high perveance of 1 µP for a single extraction aperture has been successfully developed for the investigation of ion irradiation on plasma-facing components including the first mirror of plasma optical diagnostics system. Under the optimum operating condition for mirror testing, the ion source has a beam energy of 200 eV and a current density of 3.7 mA/cm². The ion source comprises a magnetic cusp-type plasma source, an extraction system, a target system with a Faraday cup, and a power supply control system to ensure stable long time operation. Operation parameters of plasma source such as pressure, filament current, and arc power with D₂ discharge gas were optimized for beam extraction by measuring plasma parameters with a Langmuir probe. The diode electrode extraction system was designed by IGUN simulation to optimize for 1 µP perveance. It was successfully demonstrated that the ion beam current of ~4 mA can be extracted through the 10 mm aperture from the developed ion source. The target system with the Faraday cup is also developed to measure the beam current. With the assistance of the power control system, ion beams are extracted while maintaining a consistent arc power for more than 10 min of continuous operation.

• 생명과학회지
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• 제15권6호
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• pp.916-922
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• 2005

E3 ligase로 알려진 Parkin은 protein quality control에서 중요한 역할을 할 뿐만 아니라, 이런 quality control system의 이상으로 나타나는 퇴행성 뇌질환에도 밀접한 연관성이었다. 이와 같이 생체의 필수적인 업무를 담당하는 Parkin의 기능을 생화학적 측면에서 연구하기 위해서는 고 순도의 단백질을 다량 정제할 수 있는 시스템이 필요하나, 아직까지 Parkin의 발현 양상과 정제법에 관한 연구가 미흡한 상태이다. 본 연구에서는 pCEX system을 이용하여 Parkin을 대장균에서 overexpression시켜 단일 스텝으로 정제할 수 있는 방법을 정립하였다. 저온의 배양조건에서 0.01 mM의 IPTC로 발현을 유도한 결과 $90\%$ 이상의 순도를 가지는 완전한 크기의 Parkin을 정제할 수 있었다. 또한, 여러 tag을 갖는 Parkin plasmid를 제작하였을 뿐만 아니라, 이들을 HEK293 세포에 transfection하여 Parkin의 발현 양상을 비교 분석하였다. 그 결과 Parkin의 N-말단에 pretense에 민감한 절단 부위가 존재한다는 사실을 확인하였다. 본 연구에서 정립한 Parkin 정제법과 포유류 세포에서 Parkin의 발현 양상에 대한 결과는 Parkin의 기질을 탐색하고,그들이 Parkin의 효소 활성 및 기능에 미치는 영향을 조사하기 위한 다양한 연구에 활용할 수 있을 것이다.

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.101-106
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• 2005

The generation of secretory IgA antibodies (Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the heat-labile Escherichia coli enterotoxin A2B (ltxa2b) gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ltxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and westem blotting using antibodies to the maltose binding protein (MBP) or the heat labile E. coli subunit B (LTXB), plus the N-terminal amino acid sequence was analyzedd. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/LTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of LTXB. thisstudy also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA (sIgA) and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked LTXA2B acts as a useful mucosal adjuvant, and that adhesin/LTXA2A chimeric protein might be a potential antigen for oral immunization against UPEC.