• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.615-623
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• 2015

The previous strut-and-tie models (STMs) to evaluate the shear strength of squat shear walls with aspect ratio less than 2.0 do not consider the axial load transfer of concrete strut and individual shear transfer contribution of horizontal and vertical shear reinforcing bars in the web. To overcome the limitation of the existing models, a simple STM was established based on the crack band theory of concrete fracture mechanics. The equivalent effective width of concrete strut having a stress relief strip was determined from the neutral axis depth and effective factor of concrete strength. The shear transfer mechanism of shear reinforcement at the extended crack band zone was calculated from an internally statically indeterminate truss system. The shear transfer capacity of concrete strut and shear reinforcement was then driven using the energy equilibrium in the stress relief strip and crack band zone. The shear strength predictions of squat shear walls evaluated from the current models are in better agreement with 150 test results than those determined from STMs proposed by Siao and Hwang et al. Furthermore, the proposed STM gives consistent agreement with the observed trend of the shear strength of shear walls against different parameters.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.488-492
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• 2003

Yeast cell wall mutant, Saccharomyces cerevisiae IS2 was screened by the NTG treatment of Saccharomyces cerevisiae KCTC 7911. The mutant was highly resistant to zymolase, which specifically degrades ${\beta}$-1,3-D-glucose chain of ${\beta}$-glucan and mechanical disruption by glass beads. These phenomena demonstrate that the yeast mutant has cell wall structure different from the wild-type. The ${\beta}$-glucan of yeast mutant and wild-type strains was recovered by sequential extraction with NaOH. The injection of ${\beta}$-glucan into the abdominal cavity of mouse resulted in an increase in the number of peritoneal immune cells, NO (nitric oxide) production, and phagocytic activity of macrophage. The number of immune cells was found to be $3.90{\times}10^6\;cells/10\;mL$ and $5.48{\times}10^6\;cells/10\;mL$ with the wild-type and mutant ${\beta}$-glucan, respectively. The effect on the NO production and phagocytic activity of mutant ${\beta}$-glucan were 1.69 and 1.43-fold higher than those of wild-type. These results indicate that the immuno-stimulating activity of alternated ${\beta}$-glucan from mutant yeast is higher than that of wild-type.

• Clean Technology
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• v.17 no.3
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• pp.273-279
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• 2011

The physicochemical properties of manufactured nanomaterials can vary depending upon the methods of manufacture, although the utilized raw materials are same. Hence, the toxicity can also vary based on the methods of nanomaterials manufacture. In this study, we compared the toxicity effect of two types of CNTs (MWCNT, multi-walled carbon nanotube; SWCNT, single-walled carbon nanotube) that differ in length and wall number. In case of MWCNTs, inflammatory responses were more strongly induced in longer groups, whereas body weights more clearly decreased in shorter groups. SWCNT significantly decreased the relative weights of brain and kidney, and the inflow of immune cells and the hematological changes were observed significantly on day 1 and day 7 after exposure, respectively. Our results showed that the length and wall number of CNTs can serve as critical factors in the exhibited inflammation and toxicity.

• Journal of Mushroom
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• v.2 no.3
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• pp.127-139
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• 2004

Laccases are multicopper-containing enzymes which catalyze the oxidation of phenolic and nonphenolic compounds with the concomitant reduction of molecular oxygen. They often occur as isoenzymes, either constitutive or inducible, that oligomerize to multilateral complexes, what allow for penetration to the woody cell wall structure. White rot basidiomycete fungi may produce a number of laccase isoenzymes, some constitutively and others after induction. Fungal laccase is commonly induced by many ions, such as $Cu^{2+}$, $Cd^{2+}$ $Ca^{2+}$, $Li^+$, $Mn^{2+}$, $Ag^+$, $Hg^{2+}$, Mn and $Fe^{3+}$, phenolic compounds, some organic compounds, such as ethanol, isopropanol, cAMP, caffeine, p-anisidine, viscosinamide and paraquat, and nitrogens and even heat shock. A combination of Cu and pHB (p-hydroxybenzoic acid) made it possible to extend the inducible laccase activities over 30-fold. But the most effective inducer of laccase in the basidiomycete and other higher fungi is 2,5-xylidine, over 160-fold stimulation of laccase activity. The laccases are frequently encoded by gene families, as e.g. in Pycnoporus cinnabarinus, from which the lcc3-1 or the allelic form lac1 and lac3-2 have been cloned and sequenced. In the case of inducible forms the post-inductional laccase formation depends upon the synthesis of mRNA and the induction is due to the synthesis of a new protein.

• Journal of fish pathology
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• v.8 no.2
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• pp.119-134
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• 1995

To induce an overpopulated melanomacrophage centers(MMCs) within spleen and kidney in tilapias, two methods were applied through the intraperitoneal inoculation of V. anguillarum FKC with a repeated dose of saline(the 1st induction group), and of colloidal carbon (the 2nd induction group). In the 1st group, both number and size of MMCs were slightly increased in spleen and head kidney. However in the 2nd group the two hemopoietic tissues were nearly occupied with quite a large number of MMCs. Regardless of induction groups, many of MMCs were confined within the walls of blood vessels in the spleen. Especially in the 2nd group, the MMCs without fibrous capsules often had concentrically or eccentrically located, thin-walled lumens of vessels, which strongly suggests to be ellipsoids. In head kidney, nearly all MMCs were located within or just around the lymphocytic areas but the precise relationship to blood vessel wall was not obvious. Despite of such overpopulated MMCs, no histopathological degenerative findings in hemopoetic parenchymas of both organs were recognized. To evaluate the effect on defensive function, tilapias of the 2nd group were challenged with E. tarda. Susceptabilities to E. tarda were never increased but rather significantly decreased compared to control. Weekly antibody titres in sera were determined for all induction groups, in which the titres in the 1st and 2nd groups were 4 or 8 times higher than in the control, and then remained high until the 4th week. Also with the hemopoietic function, cellular compositions of peripheral blood were analyzed at weekly intervals but no significant changes resulted. From those results, it is suggested that overcrowding of MMCs would not lead to any morphological as well as functional deteriorations of spleen and head kidney but have an intimate association with enhancement of protective immune system in tilapias.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.107-112
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• 2019

Most of the sign systems involved in evacuation are not useful in seismic situations where people have to evacuate with their heads bowed, given that they are at the top of the wall. Based on the analysis and understanding of seismic evacuation situations, this study proposes a sign system as a measure for rapid seismic evacuation. First, understand the seismic situation based on the video analysis of the earthquake evacuation situation. Second, the need for a sign system to help secure evacuation in earthquake situations was derived. Third, the on-site survey examined the suitability of the Sine system installed in Korea as an escape facility for the earthquake evacuation situation. Based on the video analysis and on-site survey, it was concluded that the installation of escape guidance lamps alone could not induce rapid evacuation in the earthquake situation. In this study, a sign system is proposed to help the use of doors by installing a sign system near an emergency exit light.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.38-46
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• 2008

Many researchers have reported that many biopolymers making up cell walls of the microorganisms display an ion-exchange property and play a major role in the sorption of the metal ions. Such polymers derived from microbial biomass are potentially useful as biosorbent materials for recovery various metal ions in industrial applications. although synthetic polymers such as ion-exchange resins and chelating resins have been widely used as commercial sorbents. In this study, valuable and commercial biopolymers for metal removal will be introduced.

• 월간 기계설비
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• s.277
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• pp.40-43
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• 2013

건축물 가스배관이 외벽이 아닌 벽체에 매립됨으로써 건축물 외관의 새 지평을 열게 됐다. 산업통상자원부는 도시가스 사용에 따른 국민생활과 기업 활동에 불편을 주는 애로점을 해소하기 위해 건축물 도시가스배관 매립 등의 내용을 포함한 도시가스사업법 시행규칙을 지난 7월 25일 개정 공포하고 시행에 들어갔다. 이로써 7월 25일 이후 공사 입찰 공고분부터 가스배관의 벽체 매립이 적용된다. 그동안 도시가스배관은 외부에 노출되는 것이 원칙이었으나 이번 도시가스사업법 시행규칙 개정으로 벽에 매립 설치됨으로써 도시가스배관을 이용한 범죄예방효과에 크게 기여할 뿐만 아니라 건축물 미관도 개선될 것으로 보인다. 한편 가스계량기의 설치는 계량검침 및 유지보수가 용이하도록 외부 설치가 유도됨에 따라 사생활 침해와 검침원 사칭 피해를 사전에 예방할 수 있도록 하였고, 가스콘센트를 설치토록 하여 주민불편과 비용부담이 해소될 수 있도록 하였다. 이번 도시가스사업법 시행규칙 개정은 그동안 대한설비건설협회 가스설비공사협의회(위원장 조종택)가 지속적으로 건의하여 받아들여진 것으로, 가스설비공사협의회는 건축물 내 가스배관 설치기준 연구의 정책 기술 자문위원으로 적극 참여한 바 있다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.199-202
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• 2007

본 논문에서는 탄소나노튜브 기반 비휘발성 메모리 소자를 설계하고 분자동력학 방법을 이용하여 이중벽 탄소나노튜브 구성된 소자에 대하여 동작 특성을 분석하였다. 탄소나노튜브는 탄소-탄소 반데르발스 힘과 탄소나노튜브-금속 결합력 간의 균형점에서 국부적으로 안정화 되도록 하는 방법으로, 탄소나노튜브와 양쪽에서 간격을 두고 마주대하는 소스 및 드레인 전위를 조절함으로써 탄소나노튜브에 유도된 정전기인력으로 내부 탄소나노튜브의 움직임을 제어한다. 본 나노메모리 소자는 테라급 재기록 비휘발성 나노메모리(Rewritable Non-Volatile Nano-Memory)로 활용될 수 있으며, 2bit 뿐만 아니라 3bit 정보저장 소자로 활용될 수 있다. 분자동력학 결과는 정보저장 동안에 발생되는 탄소나노튜브와 금속전극 사이의 충돌은 메모리 소자의 동작 속도 및 비휘발성 특성에 매우 중대한 영향을 미치게 될 것을 알 수 있었다.

• Magazine of the Korea Concrete Institute
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• v.9 no.4
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• pp.145-153
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• 1997

전단벽제 양단의 보강기둥은 비선형 휨거동에 주요 영향을 미치는 구조 요소이다. 본 연구에서는 전단 벽체에 일반적으로 사용되는 모델인 TVLEM에서, 수직 스프링 요소로 표현되는 보강기둥의 반복이력 모델을 제안하고 기존의 모델과 비교 검토하였다. 제안된 단순모델은 Vulcano의 모델 중 철근의 거동을 이중직선으로 가정하여 유도되었으며, 제안된 모델을 검증하기 위하여 Vulcano와 Kabeyasawa의 모델 사용시의 수치해석 값과 비교하였다. 비선형 해석은 자체 개발된 프로그램을 사용하였으며, Vallenas와 Bertero가 실험(1979)한 SP6의 모델에 대하여 수치해석을 수행하여 반복이력특성과 변위이력 및 발산에너지량을 비교하였다.