• 한국미생물·생명공학회지
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• 제20권5호
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• pp.607-613
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• 1992

침강조의 중앙에 깔대기 모양의 판을 설치하고 방해판 아래 다시 공기 방울과 CO2 가스의 별도 배출구를 설치하여 상부로의 난류를 방지하므로 침강 효율이 그게 향상되도록 settler를 고안하였다. 이 settler를 설치한 탑형 발효조에서 응집성효모 S.uvarum의 에탄올 생산성을 검토한 결과 방해판을 설치하지 않은 단순한 원통형 settler에 비하여 1.5배 증대되었다. 또한 탑형 발효조에서 살펴본 균체 순환율이 에탄올 생산성에 미치는 영향을 살펴본 결과 균체 순환울 1-5 사이에서는 에탄올 생산성의 변화가 거의 없었으나 6 이상에서는 균체가 유출되므로 에탄올 생산성이 감소하였다.

• ALGAE
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• 제24권3호
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• pp.139-147
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• 2009

Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

• Computers and Concrete
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• 제30권2호
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• pp.127-141
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• 2022

In this paper, a numerical procedure is proposed for achieving the minimum cost design of reinforced concrete polygonal column cross-sections under compression and biaxial bending. A methodology is developed to integrate the metaheuristic algorithm Quantum Particle Swarm Optimization (QPSO) with an algorithm for the evaluation of the strength of reinforced concrete cross-sections under combined axial load and biaxial bending, according to the design criteria of Brazilian Standard ABNT NBR 6118:2014. The objective function formulation takes into account the costs of concrete, reinforcement, and formwork. The cross-section dimensions, the number and diameter of rebar and the concrete strength are taken as discrete design variables. This methodology is applied to polygonal cross-sections, such as rectangular sections, rectangular hollow sections, and L-shaped cross-sections. To evaluate the efficiency of the methodology, the optimal solutions obtained were compared to results reported by other authors using conventional methods or alternative optimization techniques. An additional study investigates the effect on final costs for an alternative parametrization of rebar positioning on the cross-section. The proposed optimization method proved to be efficient in the search for optimal solutions, presenting consistent results that confirm the importance of using optimization techniques in the design of reinforced concrete structures.

• 한국강구조학회 논문집
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• 제25권4호
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• pp.347-357
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• 2013

최근, 콘크리트 충전강관 기둥(CFT)은 우수한 구조성능을 인정받아 현장적용이 활발하게 이뤄지고 있다. 한편 강재개발과 가격 상승으로 인해 단면을 효율적으로 사용하고자 하는 연구가 지속적으로 진행되고 있다. 본 연구실에서는 단면의 효율을 극대화 하기 위해 얇은 L형 플레이트 4개를 각형강관으로 형성한 단면을 제안한다. 이로 인해 강관 내부에 형성된 리브는 폭 중앙에 위치하고 있어 콘크리트와의 앵커역할이 가능하다. 또한 동일한 단면적을 갖는 일반 CFT기둥에 비해 우수한 좌굴내력과 변형성능이 발휘됨을 실험으로 평가되었다. 본 연구에서는 활용범위를 넓히고자 얇은 강판으로 조립된 신형상 기둥을 제안하며 구조적 성능을 재평가 하고자 한다. 실험 주요변수 폭두께비(b/t: 78,96,107) 이다. 실험결과 규준에서 제시하고 있는 폭두께비를 초과했음에도 내부에 설치된 리브의 앵커역할로 인해 충분한 내력을 발휘하며, 변형성능 향상에 유리한 것으로 분석되었다.

• 한국식품조리과학회지
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• 제28권6호
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• pp.805-811
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• 2012

This study was carried out in order to optimize the manufacturing condition of fried garlic flakes as well as to investigate the physicochemical properties of the flakes. Fried garlic flake samples were prepared as follows: garlic was sliced by a thickness of 1.5 mm, 2.0 mm, 2.5 mm, which were measured by a thickness gage. The samples were fried in vegetable oil under different temperatures of $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$. The compression strength depending on the height (h) was measured in order to find the thickness effect by the rheometer (force control: 50 N, h: 3.25 mm). Moreover, the sample with 1.5 mm thickness showed crisp phenomena of the split compared with the crush shape of the 2.0 mm and 2.5 mm thick samples. The result of strength for time dependence showed a sample with a thickness of 1.5 mm, which was measured 5~9 times more than the 2.0 mm and 2.5 mm thick samples. We thought the reason that the 1.5 mm sample had less response power equivalent to compression force than the other samples. Alliin has been found to affect the immune responses in the blood, it is a derivative of the amino acid cysteine and is also quite heat stable. The LC system with a UV detection at 210 nm consists of a separation on a Zorbax TMS column and isocratic elution with water and ACN as a mobile phase. The alliin contents of raw and fried garlic flake under $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$ were 18.10 mg/mL, 14.0 mg/mL, 11.6 mg/mL and 11.1 mg/mL, respectively. The decrement of alliin content under different temperature was a small quantity hence, we confirmed that the increasing manufacturing temperature was not affected by the alliin content. Examining for the particle structure of fried garlic flakes by a polarization microscope, the color of the sample treated at $160{\sim}170^{\circ}C$ was pure yellow. Furder, the fiber shaped particle, which has an effect on the tough texture, almost did not appear compared to the different temperature conditions. Finally, the sensory test for the preference of fried garlic flake under different conditions was carried out and the scores for various sensory characteristics were surveyed. According to the physicochemical measurements and sensory evaluation, we confirmed that the optimum manufacturing condition of fried garlic flake was 1.5 mm thick at a temperature of $160{\sim}170^{\circ}C$.

• 대한토목학회논문집
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• 제3권2호
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• pp.87-95
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• 1983

본(本) 연구(硏究)에서는 정수처리과정(淨水處理過程)에서 생성(生成)되는 trihalomethane을 제거(除去)하는 방법(方法)으로 활성탄(活性炭)으로 충전(充塡)된 고정층(固定層)에 의한 흡착(吸着)에 관하여 이론적(理論的)인 간단한 모형(模型)을 제시하고 모형(模型)의 simulation을 통하여 얻은 결과(結果)와 고정층(固定層) 흡착실험(吸着實驗)을 통해서 얻은 결과(結果)를 비교(比較), 분석(分析)하였다. 고정층흡착모형(固定層吸着模型)의 simulation 결과(結果)로 흡착효과(吸着効果)에 큰 영향을 미치는 인자(因子)인 물질전달계수(物質傳達係數) K와 Freundlich의 흡착계수(吸着係數)인 $K_F$와 n의 변화(變化)에 따른 전체적인 효율변화(効率變化)를 산정(算定)하였다. 처리효율(處理効率)은 K와 $K_F$가 증가할수록 그리고 n이 감소할수록 유리(有利)한 것으로 나타났다. 실험결과(實驗結果)로부터 얻은 breakthrough curve는 전형적(典型的)인 S자형(字形)으로 나타났으며 break point를 $100{\mu}g/l$로 정할 경우 활성탄(活性炭) 단위무게당(當) 흡착량(吸着量)은 6.3mg/g으로 등온흡착실험(等溫吸着實驗)에서 얻은 결과(結果)보다 훨씬 높았다. 또한 $5^{\circ}C$정도(程度)의 수온차이(水溫差異)는 처리효율(處理効率)에 뚜렷한 영향을 끼치지 못했다. 고정층운전결과(固定層運轉結果)와 잘 부합되는 simulation으로부터 얻은 $K_F$와 n은 등온흡착실험(等溫吸着實驗)에서 얻은 값과 약간의 차이를 나타냈다.