• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.297-302
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• 1999

Simultaneous saccharification and fermentation (SSF) experiments were carried out with a lignocellulosic biomass. The effects of temperature on enzymatic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 g/g, which was increased by 67％ or higher over the saccharification at 42℃. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate, and separation coefficient, related to the SSF combined with membrane system (semi-batch system). When the fermentation was operated in a semi-batch mode, the efficiency of the enzymes and yeast lasted three times longer than in a batch mode.

• Korean Chemical Engineering Research
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• 제50권5호
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• pp.759-765
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• 2012

바이오 디젤 생산량 증가에 따라 공정 중에 부산물로 발생하는 글리세린의 과잉공급 및 가격 하락이 이루어지고 있다. 이에 따라 글리세린에 기반한 다양한 화학제품생산과 관련된 연구가 활발히 진행되고 있으며 글리세린을 탄소원으로 한 1,3-프로판디올의 생물학적 생산은 그 중 하나이다. 1,3-프로판디올은 지금까지 화학적인 방법을 통해 생산되어 왔으나 생물학적인 방법을 통해 생산될 경우 공정의 친환경성 및 경제성 확보와 더불어 1,3-프로판디올을 중합원료로 하는 PTT (Poly(trimethylene terephthalate))의 바이오폴리머로서의 활용을 가능하게 한다. 그럼에도 글리세린 유래 1,3-프로판디올의 생물학적 생산의 경제성에 있어 핵심은 경제적인 분리공정의 수립에 있다. 본 총설에서는 1,3-프로판디올을 분리하기 위한 공정들에 대한 연구 동향을 소개하고 최근 에너지 절감과 더불어 1,3-프로판디올 분리와 부산물 제거를 동시에 달성할 있는 공정으로 주목받고 있는 수상이성분계 추출에 대한 연구개발 동향 및 전망을 제시하고자 한다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.1-8
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• 1996

Fermentation processes for the production of butanol had an economic importance in the first part of this century. Today butanol is commercially produced from the Oxo reaction of propylene because relatively low priced propylene during the cracking of petroleum. Efforts have been made during the past decade or two to improve the productivity of butanol fermentation processes. It includes strain improvements, continuous fermentation processes, cell immobilization and simultaneous product separation. This review introduces a new butanol fermentation process using pervaporative product separation and a new bacterial strain producing less amount of organic acids. This review also compares the new process with chemical processes. This kind of new fermentation process may be able to compete with the chemical synthesis of butanol and revitalize the butanol fermentation process.

• 한국작물학회지
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• 제50권2호
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• pp.73-78
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• 2005

Demand for the domestic hairy vetch seed production will be increased with the increasing interest of environment-friendly agriculture in Korea. This study was conducted during from 2000 fall to 2003 spring at upland field of National Institute of Crop Science in Suwon, Korea to compare wheat and triticale (TC) as stake crop of hairy vetch (HV), and to know proper seeding rates and ratios between TC and HV for the maximum HV seed production. As supporting crop of HV, TC was superior to wheat at the points of higher HV seed yield, stronger TC stalk for supporting, consistence of ripening stage of two seeds. In seeding method, row seeding was superior to broadcast seeding at the points of less lodging and higher HV seed yield. HV seed yield decreased with the increase of TC seeding rate in mixture cropping (row seeding), particularly at TC seeding rates over 5kg/10a. HV seed yield increased with the increase of HV seeding rate at the condition of TC seeding rates under 5kg/10a in spite of higher lodging of mixed crops at higher HV seeding rate due to higher HV aboveground dry matter. Maximum HV seed yield was obtained at TC seeding rate of $1\~1.5kg/10a$ as indicating HV seed yield 176kg/l0a (CV. Madison) at seeding rate of TC 1kg/10a + HV 2 kg/10a in 2001, and HV seed yield 96kg/10a (CV. Common) at seeding rate of TC 1.5kg/10a + HV 4.5kg/10a in 2003. Use of all-purpose combine harvester for harvesting and appliance for separation of mixed seeds using centrifugal force, which are prerequisite for HV seed production, was excellent in the simultaneous seeds production system of HV and TC.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.97-100
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• 1997

Cyclodxtrin homologues(CDs), produced by cyclodextrin glycosyltransferase(CGTase), were simultaneously partitioned in aqueous two-phase system(ATPS). Partition coefficients of CDs were measured in PEG/dextran systems. Phosphate, citrate, sulfate were tested as salt. ATPS of PEG/salt and PEG/dextran had the partition coefficients of the CDs, larger than unity. However, PEG/dextran system was observed better than PEG/salt as CGTase activity decreased sharply with salt concentration. Enzymatic rection occurred mainly in PEG-rich bottom phase because of the low partition coefficient of CGTase. The resulting CDs transferred to the PEG-rich top phase, obeying the diffusional partition. In the ATPS of 7% PEG(M.W.40, 000), 7mg/ml of CDs were obtained in top phase at 4.5 hours.

• 사상체질의학회지
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• 제25권1호
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• pp.51-61
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• 2013

Objectives We performed the simultaneous analysis for three compounds in Cheongsimyeonja-tang (CSYJT) and evaluated its anti-obesity effect. Methods The column for separation of three compounds was used Gemini $C_{18}$ column and maintained at $40^{\circ}C$. The mobile phase for gradient elution consisted of two solvent systems. The analysis was carried out at a flow rate of 1.0 mL/min with PDA detection at 275 nm. The injection volume was $10{\mu}L$. 3T3-L1 preadipocytes were differentiated into adipocytes by adding insulin, dexamethasone and 3-isobutyl-1-methylxanthine (IBMX) for 8 days in the absence or presence of CSYJT. Anti-obesity effects of CSYJT were evaluated by Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity, triglyceride contents, and leptin production. Results Calibration curves were acquired with $r^2$ >0.9999. The contents of baicalin, wogonoside and baicalein in CSYJT were 14.54-14.65 mg/g, 5.24-5.27 mg/g and 0.01-0.02 mg/g, respectively. CSYJT showed inhibitory effect on lipid accumulation and GPDH activity in the differentiated 3T3-L1 cells. Furthermore, CSYJT significantly decreased contents of triglyceride and leptin production in 3T3-L1 adipocytes. Conclusions These results will be helpful to improve quality control and anti-obesity effect of Taeeumin CSYJT.

• Wind and Structures
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• 제32권3호
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• pp.205-217
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• 2021

Cold regions with high air density and wind speed attract wind energy producers across the globe exhibiting its potential for wind exploitation. However, exposure of wind turbine blades to such cold conditions bring about devastating impacts like aerodynamic degradation, production loss and blade failures etc. A series of wind tunnel tests were performed to investigate the effect of icing on the aerodynamic properties of wind turbine blades. A baseline clean wing configuration along with four different ice accretion geometries were considered in this study. Aerodynamic force coefficients were obtained from the surface pressure measurements made over the test model using MPS4264 Simultaneous pressure scanner. 3D printed Ice templates featuring different ice geometries based on Icing Research Tunnel data is utilized. Aerodynamic characteristics of both the clean wing configuration and Ice accreted geometries were analysed over a wide range of angles of attack (α) ranging from 0° to 24° with an increment of 3° for three different Reynolds number in the order of 105. Results show a decrease in aerodynamic characteristics of the iced aerofoil when compared against the baseline clean wing configuration. The key flow field features such as point of separation, reattachment and formation of Laminar Separation Bubble (LSB) for different icing geometries and its influence on the aerodynamic characteristics are addressed. Additionally, attempts were made to understand the influence of Reynolds number on the iced-aerofoil aerodynamics.

• Membrane and Water Treatment
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• 제7권2호
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• pp.143-154
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• 2016

Acetic acid can be removed from wastewater by esterification in a membrane reactor. Pervaporation membrane reactor (PVMR) is an alternative process to conventional separation processes. It is an environmentally friendly process. The main advantages of the PVMR are simultaneous water removal and production of an ester economically. In this study, the synthetic wastewater has been used. Esterification reaction of acetic acid with isopropanol has been studied in the presence of tungstosilicic acid hydrate as a catalyst in a batch reactor and in a PVMR. The effects of important operating parameters such as reaction temperature, initial molar ratio of isopropanol to acetic acid and catalyst concentration has been examined. Removal of acetic acid (conversion of acetic acid) was obtained as 85% using a PVMR by removal of water from the reaction mixture.

• KSBB Journal
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• 제30권3호
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• pp.103-108
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• 2015

Production of foreign proteins by transgenic plant cell cultures has several advantages such as post-translational modification, low risk of product contamination and low-cost production and purification. However, target proteins are degraded by extracellular proteases existing in the media. A solution to this problem is the use of perfusion culture and ion exchange chromatography for the application of integrated bioprocess using in situ recovery. With this method, production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was investigated in this study. First, optimization of cell concentration during the induction phase for the production of hGM-CSF was examined. As cell concentration increased, the level of hGM-CSF was decreased due to the presence of extracellular proteases. Induction using sugarfree media produced 33% more hGM-CSF. The effects of pH on the binding of hGM-CSF to cationic and anionic exchange resins were also investigated. In terms of stability, optimal pH was found to be 5~7. In the case of using buffer exchange when CM-Sepharose was used as a cationic exchange resin, optimal pH for binding was 4.8 and adsorption yield was 77%. When DEAE-Sepharose was used as an anionic exchange resin, it was 5.5 (74%). Without buffer exchange, optimal pH was 4.6 (84%). From these results, an integrated bioprocess using in situ recovery with simultaneous production and separation of foreign protein in transgenic plant cell suspension cultures was found to be feasible.

• 공업화학
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• 제25권5호
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• pp.503-509
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• 2014

탄소와 다공성 실리카로 구성된 복합막을 용이한 방법으로 제작하고 이들 막을 활용하여, 키랄 에폭사이드와 키랄디올 화합물의 친수성/소수성 특성차이를 기초로 한 동시 합성 및 분리과정에 응용하였다. 막반응기에 도입한 키랄 Co(III)-$BF_3$형 살렌촉매는 ECH, 1,2-EB와 SO 등의 에폭사이드 가수분해반응에 대하여 높은 활성을 나타내었고 여러 차례의 재사용이 가능하였다. 광학순도가 높은 키랄 에폭사이드 생성물은 가수분해반응이 진행된 후에 촉매와 함께 유기용액상에서 취득되었다. 물에 용해되는 친수성의 1,2-디올은 키랄 살렌의 촉매작용에 의하여 가수분해됨으로써 생성되는데, 이들은 반응이 진행되는 동안 SBA-16 또는 NaY/SBA-16 실리카층을 통해 물층으로 확산되었다. 물은 막반응계에서 반응물이면서 동시에 용매로서 거동하였다. 연속흐름형의 막반응기를 적용함으로써, 고순도, 고수율의 광학이성체를 생성물로서 얻을 수 있었으며, 촉매는 큰 활성저하를 나타내지 않아 여러 차례 재사용이 가능하였다.