• KSBB Journal
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• 제14권5호
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• pp.550-560
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• 1999

There have been many research efforts on biofilter modeling including Ottengraf et al. who derived a model equation for the concentration profile of pollutants(e.g., VOCs) in the biolayer and solved their outlet concentration of the waste gas stream through biofilter. However, for most of research works done so far, the effects to explain the effect of adsorption of organic particles to medium(i.e., adsorbent) have been ignored. In this work biofilter modeling accompanying process lumping has been proposed and the theoretical effect of adsorption property of the medium, on the biofilter performance of eliminating organic components in waste gas stream, is intensively discussed.

• Journal of Plant Biotechnology
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• 제46권2호
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• pp.114-118
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• 2019

Efficient protocol for plant shoot regeneration of Brassica juncea L. CZERN was established by using organic media components and growth stimulating factors of the vermicompost and coelomic fluids. Formulated organic plant tissue culture media (Vermicompost (30%) extracts supplemented with 20 mL/L coelomic fluid) have shown maximum shoot regeneration when compared with the Murashige and Skoog (MS) medium, which were supplemented with 1 mg/L 6-benzyladenine (BA) and 0.1 mg/L of Naphthaleneacetic acid (NAA). Cotyledon explants produced the highest shoot regeneration frequency from fourday-old germinated seedlings in comparison with non-germinated seedlings. The vermicompost extracts have proved to be the best organic plant growth media to induce shoots from cotyledons compared to the MS media. Statistically significant difference (P = 0.008) for the root length, shoot length (P=0.000350) and the leaves (P=0.375) of the mustard plantlets were analyzed successfully. The survival rate was 98% in the mustard cotyledons on the Vermicompost extract media and 63% on MS media respectively. The coelomic fluid also is much suitable to induce shoots from cotyledons at lower concentrations. It was also shown that the vermicompost extract, which comprised of humic acids along with coelomic fluid, affected shoot regeneration from the cotyledons. An efficient and organic shoot regeneration study was standardized and it can be applicable in the improvement of the economically important crops.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권5호
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.150-155
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• 2001

It has been observed that water, which is absolutely essential for enzyme activity, can induce the agglomeration of enzyme particles in organic media. Although enzyme agglomeration is significant in that it usually reduces enzyme activity and stability, little attention has been paid to the quantitative analysis of enzyme agglomeration behavior in nonaqueous biocatalytic systems. In this study, the effect of water and silica gel on enzyme agglomeration were investigated using Candida rugosa lipase and cyclohexane as a model enzyme and an organic medium. The extent of enzyme agglomeration was quantified by sieve analysis of freeze-dried agglomerates. Increasing the water content of the medium increased the size of the enzyme agglomerates, and it was found that water produced during the esterification reaction could also promote the agglomeration of enzyme particles suspended in organic media. On the other hand, the size of the enzyme agglomerates was remarkably reduced in the presence of silica gel at the same water content. We also show that this increase in the size of enzyme agglomerates results in lower reaction rates in organic solvents.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.443-444
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• 2007

• Applied Biological Chemistry
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• 제41권6호
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• pp.457-464
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• 1998

유기질 비료(돈분, 계분)의 시비량을 달리하여 토양에 첨가한 후 3년간 토양미생물상의 변화에 대하여 조사하였다. 통상농도의 NB(nutrient broth) 평판배지와 m배지를 $10^{-2}$배 희석한 DNB(Diluted Nutrient Broth) 평판배지를 사용하여 세균수를 측정하였다. 유기질 비료를 첨가하지 않은 대조구 및 30 Mg/ha 처리구의 경우 DNB 평판배지에서의 세균 계수치는 NB 평판배지보다 $5{\sim}10$배 이상 높은 값을 나타내었으나, 60 Mg/ha 처리구와 120 Mg/ha 처리구의 경우 3년이 지난 후에도 NB 평판배지에서의 계수치가 DNB 평판배지에서보다 $10{\sim}100$배 이상 지속적으로 높은 값을 나타내었다. 이들 토양으로부터 분리한 세균은 통상농도의 NB배지에서 증식 가능한 세균(NB세균)과 NB배지에서는 증식하지 않고 희석한 DNB배지에서만 증식하는 세균(DNB세균)으로 분류하여, 이들 세균의 분포율을 조사하였다. 대조구 토양의 경우 DNB세균은 60% 이상 높은 점유율을 나타낸 반면, 유기질 비료의 첨가량이 증가함에 따라 DNB세균의 분포율이 크게 감소하는 현상을 나타내었다. DNB세균은 유기질 비료를 과다하게 시용한 토양(60 Mg, 120 Mg/ha 처리구) 중에서 현저히 낮은 분포율(30% 이하)을 나타내었으며, 연속적으로 과다하게 시용할 경우 NB세균과 DNB세균의 동적 평형관계가 깨질 것으로 판단되었다. 한편 토양내 사상균의 경우 유기질 비료 시용량에 관계없이 $10^4{\sim}10^5\;cfu/g$로 비교적 일정한 분포율을 나타내었지만, 방선균 수는 유기질 비료를 시용함으로써 대조구 토양에 비해 $10{\sim}100$배 이상의 높은 증가율을 나타냈다.

• 에너지공학
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• 제10권4호
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• pp.318-326
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• 2001

중저온 배열회수를 통해 열설비의 열효율을 향상시키기 위하여 1 MW급 유기랭킨사이클시스템을 설계, 개발하였다. 포항제철소에 있는 두 대의 100 MW급 기력발전소에서 발생하는 175$^{\circ}C$의 배가스를 산업체에서 발생하는 대표적인 중저온배열원으로 선정하고, 환경오염을 최소화할 수 있는 신냉매인 HCFC-123을 시스템의 작동유체로 선정하였다. 유기냉킨사이클시스템의 시험운전을 통하여 유기랭킨사이클시스템이 산업체의 중저온배열을 회수하는데 유용함을 확인하였다. 열수의 가열, 터빈기동 및 전기투입방법 등의 운전방법을 최적화하였다. 그러나 HCFC-123 공급펌프의 능력부족으로 작동유체의 공급이 부족하여 정격출력보다 낮은 670kW의 전력을 생산할 수 있었다. HCFC-123의 공급유량을 증가시키기 위하여 파이프의 압력손실저하 및 펌프의 성능 향상을 위한 펌프교체 등이 고려되어야 함을 알 수 있었다.

• 한국토양비료학회지
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• 제45권6호
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• pp.998-1003
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• 2012

Pantoea agglomerans DSM3493 was isolated from green house soils collected from Chungchugnam-do province, Gongju-Gun area in South Korea and phosphate solubilization and organic acid production of the strain were assessed using three types of insoluble phosphate sources (Ca phosphate, Fe phosphate and Al phosphate) under three different pH conditions (7, 8 and 9). The highest Ca phosphate solubilization ($651{\mu}g\;mL^{-1}$) was recorded at pH 7 followed by pH 8 and 9 (428 and $424{\mu}g\;mL^{-1}$ respectively). The solubilization rate was found to be 80.4, 98.1 and $88.7{\mu}g\;mL^{-1}$ (for Fe phosphate containing medium) and 9.3, 12.1 and $29.8{\mu}g\;mL^{-1}$ (for the Al phosphate containing medium) respectively at pH 7, 8 and 9. Though increasing pH of the medium caused reduction in the rate of solubilization of Ca phosphate, solubilization of Fe and Al phosphates enhanced with increasing pH. By contrast, the highest amount of organic acid was produced with Ca phosphate while the lowest was recorded with the presence of Al phosphate. Among the organic acids, gluconic acid production was found to be the highest, followed by oxalic acid and citric acid regardless the source of phosphate. Results can thus be concluded that the production of organic acids appears to play a significant role in the inorganic phosphate solubilization.

• 한국안전학회지
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• 제34권4호
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• pp.49-58
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• 2019

There was a difference in recognition of chemical substances according to cognitive level of GHS, knowledge level of organic solvents and each department of workers. they were showed higher recognition of chemical substances by research group, partially group and good group. To identify the relationship between types of job classification(group of department, group of GHS cognitive level and group of organic solvents knowledge level) and the levels of recognition of chemical substances, a total of 153 workers in a small and medium business workplace. Descriptive statistics(SAS ver 9.2)was performed. the results of recognition of chemical substances were analyzed the mean and standard deviation by t-test, and anova, (P=0.05). These results In general, small- and medium-sized workplaces have low levels of GHS awareness and organic solvents knowledge. The perception of chemical substances according to the departments. In general, the demand for chemical substances education was highly suggested regardless of the job type. There was a significant difference in the perception of health, safety and practice according to the level of GHS cognitive, and a high perception in the incomplete group. There was not much difference in average awareness of health, safety and practice according to organic solvents knowledge level, but there was a high perception in good group. It is very important to regularly check the worker's perception of the workplace and identify problems with the work environment and improve the work environment. In addition, each department presents appropriate safety and health education such as chemical process safety, toxicity of chemical substances and human exposure. We also propose a chemical substances assessment and management plan that integrates safety and health.

• 미생물과산업
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• 제20권3호
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• pp.70-73
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• 1994

Effects of 13 organic compounds including glucose, fructose, xylose, glutamate, succinate, malate, glycine, lactate, acetate, pyruvate, citrate, formate and cis-aconitate on the oxidation of thiosulfate and the availability of these compounds as the substrate for the respiration by Thiobacillus ocncretivorus, which is known to be an obligated autotroph, were studied. Malate nad glycine at 0.5 per cent concentration nearly doubled the thiosulfate oxidation compared to the control. No other organic substances enhanced the thiosulfate oxidation compared to the control. No other organic substances enhanced the thiosulfate oxidation. Moreover, some 30 to 40 per cent decrease was recorded by fructose, sulfate-salts medium, some 30 to 40 per cent decrease was recorded by fructose, citrate, xylose, malate, flucose, glutamate and succinate. No respiration could occur when formate and pyruvate were supplied as the substrate for respiration. But it was obvious that flucose, fructose, xylose, glutamate, malate, citrate and succinate could be used as the substrate for respiration to some extent, regarding the fact that some increase in respiration rates could be recorded compared to the result from the salts medium, where neither thiosulfate nor orgnic compounds were added. Thus, it was postulated that this organism could possibly be converted into mixotroph or hetrotroph if appropriate conditions could be prepared.