• 한국환경과학회지
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• 제4권3호
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• pp.259-267
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• 1995

This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated slut비e and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floe. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floe. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0mg/$\ell$ to 258 mg/$\ell$. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about loom in this study.

• KSBB Journal
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• 제13권1호
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• pp.20-25
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• 1998

Optimum conditions of the cellulose-hydrolysis reaction with mixed enzymes(cellulase extracted from Penicellium funiculosum mixed with $\beta$-glucosidase extracted from Almod) were investigated to increase the production of glucose from cellulose. Experimental result showed that optimum conditions fro pH, activity ratio of $\beta$-glucosidase to cellulase, concentration of mixed enzymes, concentration of cellulose as a substrate, and temperature range were 4.2, 0.4, 0.8, U/mL, 40 g/L, and 37$\pm$3$^\circ C$, respectively. In these conditions, quantities of glucose productions by using mixed enzymes were larger than those by using cellulase at optimum conditions.

• Membrane and Water Treatment
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• 제9권5호
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• pp.309-315
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• 2018

The applicability of the ultrafiltration process for color removal from dye-containing water has been examined in this study. The optimization of major process variables, such as dye concentration, chitosan concentration and transmembrane pressure on permeate flux and color removal efficiency was investigated. To find the most appropriate results for the experiment, the Box-Wilson experimental design method was employed. The results were correlated by a response function and the coefficients were determined by regression analysis. Permeate flux variation and color removal efficiency determined from the response functions were in good agreement with the experimental results. The optimum conditions of chitosan concentration, dye concentration and pressure were 50 mg/l, 50 mg/l and 3 bars, respectively for the highest permeate flux. On the other hand, optimum conditions for color removal efficiency were determined as 50 mg/l of dye concentration, 50 mg/l of chitosan concentration and 1 bar of pressure.

• 한국환경보건학회지
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• 제35권4호
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• pp.295-303
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• 2009

A simulated wastewater containing the dye Rhodamine B (RhB) was electrolytically treated using a three-dimensional electrode reactor equipped with granular activated carbon (GAC) as particle electrode. The effect of type of packing material (GAC, ACF, Nonwoven fabric fiber coated with activated carbon), amounts of GAC packing (25-100 g), current (0.5-3 A) and electrolyte concentration (0.5-3 g/l) was evaluated. Experimental results showed that performance for RhB decolorization of the 3 three-dimensional electrodes lie in: GAC > Nonwoven fabric fiber > ACF. When considered RhB decolorization, oxidants concentration and electric power, optimum GAC dosage was 50 g. Generated concentration of 3 oxidants ($ClO_2$, free Cl, $H_2O_2$) was increased with increase of applied current, however optimum current for RhB degradation was 2.5 A. The oxidants concentration was increased with increase of NaCl concentration and optimum NaCl dosage for RhB degradation was 1.5 g/l.

• 한국식생활문화학회지
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• 제29권5호
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• pp.415-420
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• 2014

This study was conducted to establish optimum conditions for coagulation of konjac jelly as well as antimicrobial activity by concentration of $Ca(OH)_2$. Hardness, gumminess, and chewiness of konjac jelly increased according to concentration of konjac powder, the key material of konjac jelly. The highest sensory evaluation score was acquired with konjac jelly made with 3% konjac powder. A $Ca(OH)_2$ concentration of 0.4-0.6% as a coagulation agent was optimum for coagulation of konjac jelly. Further, sensory score was highest at a $Ca(OH)_2$ concentration of 0.6%. All populations of bacteria, yeast, and mold in konjac jelly were restrained by $Ca(OH)_2$ in a concentration- dependent manner. Furthermore, all tested microorganisms were strictly restrained at $1.0{\times}10^{-2}$ N of $Ca(OH)_2$.

• 현장농수산연구지
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• 제14권1호
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• pp.47-59
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• 2012

사과 '후지'에서 유기 칼슘화합물(ACa)을 수관살포 농도별 및 생육후반기 횟수별 처리한 후 과실의 칼슘농도, 동녹 발생 및 과실품질에 미치는 영향을 조사한 결과는 다음과 같다. 생육기간중 ACa 수관살포의 적정농도는 엽에는 125배에서 1,000배, 과실에서는 125배 이었다. 생육기간중 ACa 500배 수관살포 적정횟수는 엽에는 1회 (9월 25일) ~ 3회 (9월 25일, 10월 5일, 15일), 과피에는 1회 (9월 25일), 과육에서는 2회 (9월 25일, 10월 5일) ~ 3회(9월 25일, 10월 5일, 15일)이었다. ACa 생육후반기 농도 및 살포 횟수 수관살포에 의한 약해발생은 육안으로 발견하지 못하였다.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권5호
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• pp.201-206
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• 2004

In order to investigate the optimum conditions for the effective ozone formation in a dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions differed exceedingly in the types of operating gases and dielectric materials. In dry air, dielectric material with low dielectric constant and thermal conductivity, which might contribute to the restriction of the gas temperature rise in the discharge region, proved effective in obtaining both high ozone yield and concentration. The optimum gap length was considered to be in the range of 600-800 mm. In oxygen, using a quartz glass disk as a dielectric material, the required condition to obtain the high ozone yield and concentration was expanded.

• Applied Biological Chemistry
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• 제34권3호
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• pp.273-278
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• 1991

Methanol 자화성 세균 Pseudomonas sp. ILS-003 균주를 이용하여 methanol로부터 PHB생산의 최적조건을 검토하였다. PHB 생산에 있어서 초기 pH 6.4, 온도 $30^{\circ}C$ 및 methanol 농도가 1.0(v/v)일 때 최적이었으며, 질소원으로는 $(NH_4)_2SO_4$가 최적이었으며 농도는 0.8g/l로서 C/N비가 17.4이었다. 또한 2가 금속이온의 결핍은 PHB축적효과를 나타내었다. Fed-batch culture에서 methanol 첨가의 효과는 0.25%(v/v)씩 첨가했을 때 가장 좋았다. 상기의 최적조건하에서 96시간 배양시 균체량은 2.78g/l였고 PHB의 양은 1.94g/l로서 건조균체량의 69.8%이었다.

• 한국균학회지
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• 제31권2호
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• pp.77-83
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• 2003

천연자원인 cellulose를 이용하기 위하여 섬유소분해효소의 생산성이 강한 Roseofomes subflexibilis의 배양학적 특성을 조사한 결과는 다음과 같다. 1.섬유소분해효소의 생산 및 균사체 생장에 적합한 탄소원은 glucose인 것으로 나타났으며, 균사체배양의 탄소원은 saccharose로 최적농도는 1.2%였다. 2. 균사체배양의 유기질소원은 yeast extract이었으며. 최적농도는 1.5%이었다. 또한 무기질소원은 $NH_{4}H_{2}PO_{4}$를 잘 이용하는 것으로 나타났고, 최적농도는 1.1% 첨가시 균사체의 생장이 좋았다. 3. 균사체배양의 아미노산의 영향을 조사한 결과 aspartic acid가 가장 좋았으며, 최적농도는 0.1%이었다. cysteine 첨가시 효소생산과 균사체의 생장 모두에서 효과적이었다. 4.무기염류의 영향은 $Al_{2}(SO_{4})_{3}$ 첨가시 효과적이었으며 최적농도는 0.1 M이었다. 5.배양온도는 $30{\circ}C$였으며, 최적 pH는 4.0인 것으로 나타났다.

• 설비공학논문집
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• 제9권2호
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• pp.163-170
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• 1997

Solubility on $(LiBr+CaCl_2)$ in water has been measured systematically and compared with those of pure LiBr. It has been observed that there exists optimum value of $CaCl_2(LiBr+CaCl_2)$ in solubility when total$(LiBr+CaCl_2)$ concentration is higher than 57wt%. As total concentration increases up to 65wt%, it is found that the optimum value also increases monotonically. From the experimental results, a master plot has been constructed, with which optimum ratio of LiBr to $CaCl_2$ can be found in terms of total concentration. Vapor pressure of $H_2O/(LiBr+CaCl_2)$ solution with optimum contents of $CaCl_2$ has been observed to be changed negligibly at relatiely low temperature. However, as temperature increases, it is found that increasement in vapor pressure is significant.