• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.51-56
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• 2015

A 8-week trial was conducted to evaluate the effects of photoperiod manipulation on the growth performance and hematological parameters of juvenile Caspian roach, Rutilus rutilus caspicus (average weight $1.46{\pm}0.12g$ mean${\pm}$SD) reared under five photoperiods (24 h Light, 24L; 18 h Light & 6 h Dark, 18L:6D; 12 h Light & 12 h Dark, 12L:12D; 6 h Light & 18 h Dark, 6L:18D; 24 h Dark, 24D) with constant light intensity 1,500 lx on the water surface. Triplicate of 20 fish were allocated into each of 15 fiberglass tanks of 50 L capacity and they were fed three times per day with the commercial feed (SFK, Co., Sari - Iran) contains 50.0% protein and 10.5% lipid. At the end of experimental period, final body weight, weight gain and specific growth rates of fish exposed to 24L were significantly higher than those of fish exposed to 12L:12D, 6L:18D and 24D (P < 0.05). Red blood cell and hemoglobin of fish exposed to 24L were significantly higher than those of fish exposed to 24D. No significant difference observed in hematocrit, white blood cell and plasma glucose among the different treatments groups. Therefore, these results demonstrated that the growth performance of juvenile Caspian roach can be significantly stimulated by using 24L and 18L:6D photoperiods without any measurable significant stress response such as plasma glucose concentration.

• Advances in Energy Research
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• 제2권1호
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• pp.1-9
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• 2014

The green microalgae Chlamydomonas reinhardtti is well-known specie in the terms of $H_2$ production by photo fermentation and has been studying for a long time. Although the $H_2$ production yield is promising; there are some bottlenecks to enhance the yield and efficiency to focus on a well-designed, sustainable production and also scaling up for further studies. D1 protein of photosystem II (PSII) plays an important role in photosystem damage repair and related to $H_2$ production. Because Chlamydomonas is the model algae and the genetic basis is well-studied; metabolic engineering tools are intended to use for enhanced production. Mutations are focused on D1 protein which aims long-lasting hydrogen production by blocking the PSII repair system thus $O_2$ sensitive hydrogenases catalysis hydrogen production for a longer period of time under anaerobic and sulfur deprived conditions. Chlamydomonas CC124 as control strain and D1 mutant strains(D240, D239-40 and D240-41)are cultured photomixotrophically at $80{\mu}mol\;photons\;m^{-2}s^{-1}$, by two sides. Cells are grown in TAP medium as aerobic stage for culture growth; in logarithmic phase cells are transferred from aerobic to an anaerobic and sulfur deprived TAP- S medium and 12 mg/L initial chlorophyll content for $H_2$ production which is monitored by the water columns and later detected by Gas Chromatography. Total produced hydrogen was $82{\pm}10$, $180{\pm}20$, $196{\pm}20$, $290{\pm}30mL$ for CC124, D240, D239-40, D240-41, respectively. $H_2$ production rates for mutant strains was $1.3{\pm}0.5mL/L.h$ meanwhile CC124 showed 2-3 fold lower rate as $0.57{\pm}0.2mL/L.h$. Hydrogen production period was $5{\pm}2days$ for CC124 and mutants showed a longer production time for $9{\pm}2days$. It is seen from the results that $H_2$ productions for mutant strains have a significant effect in terms of productivity, yield and production time.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.327-330
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• 2003

본 연구에서는 수질정화능력이 뛰어난 것으로 알려진 D회사의 광합성세균 및 그 겔제품의 탈질특성을 알아 보았고, 실제적용을 위한 해수농도 (3.5% NaCl)에서의 이용 가능성 여부도 알아보았다. 각 염농도별(0, 1, 2, 3.5%) 평균 최대 비증식속도는 각각 0.22, 0.22, 0.20, $0.11\;h^{-1}$ 로 계산되었다. 또한, 낮은 pH에서 배양할 경우 성장에 상당한 영향을 받음을 알 수 있었다. 고정화 비-드의 경우, 최대 $N_2$생성율$(dN_2/dt)$는 각각 0.09-0.10 (직경 0.7cm), 0.09-0.11(직경 1.0cm) ml/h로 계산되었고, 비-드 당 평균 $N_2$생성율$(dN_2/dt)$은 각각 5, $5.5\;{\mu}l$/h/bead이었다. D 광합성세균과 탈질미생물간의 두 균 사이에는 어떠한 길항작용도 없었다.

• 한국산림과학회지
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• 제3권1호
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• pp.10-14
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• 1963

광야소재(光陽所在) 천연성(天然性) 소나무에 대(對)하여 조사(調査)한 결과(結果)는 다음과 같다. 1. 수고성장(樹高成長) $H=4.76+0.125D+0.0026D^2$ 2. 소나무의 입목재적식(立木材積式)은 $V=0.0000839D^{2.3}H^{0.2}$ 3. 이용재적(利用材積)과 재장간(材長間)에는 Vu=0.1708-0.0230L 4. 이용율(利用率)은 재장(材長)을 2m로 했을 때 $P=27.37D^{0.3648}$ 5. 조재가능(造材可能)한 2m 재장(材長)의 수(數)는 $N=0.0863D^{1.16}$ 6. 이용재적식(利用材積式)은 재장(材長)을 2m로 했을 경우 $Vu=0.0000159D^2H^{1.3}$ 위의 결과(結果)는 종합적(綜合的)으로 재장(材長)을 2m 후 조재(造材)할 때 이용재적(利用材積)이 가장 많다는 것을 명백(明白)히 하였다.

• 대한화학회지
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• 제45권5호
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• pp.401-412
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• 2001

$H_{2n+1}^+$ (n=1~6) cluster들에 대하여 높은 수준의 순 이론적(ab initio) 양자역학적 방법을 사용하여 분자 구조, 진동 주파수(vibrational frequency), 그리고 해리 에너지 등을 계산하였다. 분자구조는 $H^+_g$까지는 TZ2P+ d CCSD(T) 수준에서 그리고 $H_{11}^+$과 $H_{13}^+$에 대해서는 TZ2P CCSD(T) 수준까지 최적화하였다. 진동 주파수는 여러 basis set에서 SCF 방법으로 계산하였으며, 본 연구에서 최적화된 모든 분자구조들이 local minimum 구조임을 확인하였다. $H_{2n+1}^+$로부터 $H_2$ 의 해리 에너지($D_e$)는 각각의 최적화된 분자구조에서의 에너지 차로부터 계산하였으며, 영점 진동에너지(ZPVE)를 고려하여, 지금까지의 이론 및 실험결과($D_0$)와 비교하였다.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.101-110
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• 2005

An experimental study of heat transfer of submerged water jet impinging normally on a flat plate is presented. Heat transfer measurements obtained with Reverse cone type nozzle(Rcone) were compared to those obtained with Cone type nozzle(Cone) and Square edged type nozzle(Vert) of the same diameter(D=8mm) for different jet velocities in the range of $3{\sim}7m/s(Re_D=30000{\sim}70000)$ and various nozzle-to target spacings($H/D=2{\sim}10$). The local Nusselt number profiles exhibited a sharp drop for $r/D{\leq}0.5$ and 2nd, 3rd peaks revealed at r/D=2, 3 respectively, followed by a slower decrease there after. The peaks were weakened with increasing the nozzle-to target spacing and decreasing the jet velocity. The stagnation Nusselt number of the Reverse cone type nozzle was larger than those of the other two nozzles for H/D=2. 10, but Cone type nozzle had the highest value for $H/D=4{\sim}8$. Also average Nusselt number of the Reverse cone type nozzle was higher than those of the other two nozzles at $H/D=2{\sim}10$, except for $V_o=7ms$ of H/D=6.

• 대한화장품학회지
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• 제29권1호
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• pp.185-193
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• 2003

• 상하수도학회지
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• 제29권3호
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• pp.407-414
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• 2015

The effect of activated carbon particle diameter (i.e. US sieve No. $8{\times}10$ ($d_p{\approx}2.19mm$), $18{\times}20$ ($d_p{\approx}0.92mm$), $50{\times}60$ ($d_p{\approx}0.27mm$) and $170{\times}200$ ($d_p{\approx}0.081mm$) on caffeine adsorption is investigated. BET surface area was increased with decreasing particle diameter ($d_p$), and caffeine adsorption rates increased with decreasing $d_p$. Moreover, pseudo-second order model is predicted the experimental data more accurately than pseudo-first order model, and the fastest rate constant ($k_2$) was $1.7g\;mg^{-1}min^{-1}$ when $d_p$ was 0.081 mm. Surface diffusion coefficient (Ds) was decreased with decreasing $d_p$ based on the minimum sum of square error (SSE). Practically, certain ranges of Ds are acceptable with high reliability ($R^2$) and it is determined that the effect of $d_p$ on Ds is unclear. The effect of pH on caffeine adsorption indicated the dependency of m/L ratio (mass liquid ratio) and $pH_{pzc}$. The $pH_{pzc}$ (i.e. $7.9{\pm}0.2$) was not affected by $d_p$. The higher caffeine adsorption at pH 4 and pH 7 than at pH 10 is due to $pH_{pzc}$, not $pk_a$ of caffeine.

• 한국해양공학회지
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• 제25권3호
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• pp.47-52
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• 2011

3D geometric modeling has a lot of advantages in the field of design and manufacturing. Many manufacturing processes and production lines are using 3D geometric modeling technique. These help reduce the cost and time for manufacturing. The purpose of this study is the realization of a 3D cutting shape for an H-Beam used in ships and ocean plants. The complex 3D cutting shapes could be represented by using the boolean operation of basic figures. Graphic functions with parameters were used to simply define the basic figures. The developed system can show the complex cutting shape of an H-beam simply and quickly. This system can be utilized for the automatic cutting system for an H-beam.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.329-332
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• 2001

It has been known that, in enzymatic synthesis of cephalexin, the conversion yield was reduced by high loading of ampicillin acylase. In order to elucidate this phenomena, pH-controlled synthesis of cephalexin was examined using a purified Acetobacter turbidans acylase. When the pH of the reaction mixture was maintained at $6.20{\pm}0.04$, the reduction of the maximal conversion rate was not observed even with high enzyme loading. The kinetic parameters also suggest that pH drop during the enzymatic synthesis of cephalexin was mainly attributed to the rapid hydrolysis of D-${\alpha}$-phenylglycine methyl ester to D-${\alpha}$-phenylglycine, rather than the disappearance of 7-amino-3-deacetoxycephalosporanic acid for cephalexin synthesis. At higher molar ratio of two substrates, [D-${\alpha}$-phenylglycine methyl ester]/[7-amino-3-deacetoxycephalosporanic acid], the conversion rate was also elevated under pH-controlled enzymatic synthesis, which implies that the main reason for the pH drop is due to the production of D-${\alpha}$-phenylglycine methyl easter, the effect of a water-methanol cosolvent system on the ester, the effect of a water-methanol cosolvent system on the conversion profile was also examined. Even the though the conversion rate was increased in 10% methanol solution, a higher than 16% methanol in the reaction mixture caused an inactivation of enzyme.