• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.329-331
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• 2000

A marine bacterium, Pseudomonas aeruginosa BYK-2 KCTC 18012P was immobilized in modified polyvinyl alcohol for the continuous production of rhamnolipids. The stability of rhamnolipids production, the mechanical strength of beads and the scanning electron microscope of immobilized cell were determined in a repeated batch culture. The rhamnolipids production was maintained $80{\sim}90%$ stability of initial production, and the mechanical strength also was stable during the repeated batch culture more than 14 cycles. In the case of SEM studies, the internal distribution pattern of the cell entrapped in modified PVA beads was observed. On the basis of optimal conditions, the continuous culture was investigated in 1.8L air lift bioreactor. The result suggested 0.1g/h rhamnolipids was obtained from 1%(v/v) fish oil continuously in conditions of 1.2L working volume, 0.5vvm and 20ml/h flow rate.

• 한국세라믹학회지
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• 제47권1호
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• pp.1-7
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• 2010

Solid oxide fuel cells (SOFCs) have been under development for a variety of power generation applications. Power system sizes considered range from small watt-size units (e.g., 50-W portable devices) to very large multi-megawatt systems (e.g., 500-MW base load power plants). Because of the reversibility of its operation, the SOFC has also been developed to operate under reverse or electrolysis mode for hydrogen production from steam (In this case, the cell is referred to as solid oxide electrolysis cell or SOEC.). Potential applications for the SOEC include on-site and large-scale hydrogen production. One critical requirement for practical uses of these systems is long-term performance stability under specified operating conditions. Intrinsic material properties and operating environments can have significant effects on cell performance stability, thus performance degradation rate. This paper discusses potential applications of the SOFC/SOEC, technological status and current research and development (R&D) direction, and certain aspects of long-term performance degradation in the operation of SOFCs/SOECs for power generation/hydrogen production.

• KSBB Journal
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• 제6권1호
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• pp.9-14
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• 1991

We studied the production and excretion of alpha-interferon in recombinant Escherichia coli harboring plasmid pIF-III-B, which carries alpha-interferon gene under the control of lipoprotein and lacUV5 promoter, and lac operator. Basically, the effects of concentrations of ampicillin and an inducer, IPTG, for the expression of the cloned gene, on the productions of alpha-interferon and plasmid stability were studied. The highest production of alpha-interferon was observed at 50 mg/1 of ampicillin concentration and 0.5 mM of IPTG. The plasmid pIF-III-B was maintained very stably in medium with ampicillin but segregated rapidly in medium without ampicillin. Also, the plasmid was segregated more rapidly in medium with an inducer higher than 0.5 mM.

• Journal of Advanced Marine Engineering and Technology
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• 제37권5호
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• pp.548-556
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• 2013

생산량 증대를 위한 방법으로 다른 두 내경의 2단 튜빙을 이용한 기법이 제안되고 있다. 본 연구에서는 다양한 2단 튜빙조합을 고려하여 각 목적에 부합하는 조합들을 제시하였다. 기존연구에서 고려한 생산량뿐만 아니라 유동안정성을 확보하는 결과를 제시하였다. 유동안정성은 tubing pressure traverse, 액체부피비, 운영조건의 안정성을 통해 분석되었다. 본 연구에서 분석한 가상유전의 경우 순현재가치가 가장 큰 2단 튜빙은 하단이 4.5 in 내경에 길이가 2000 ft이며 상단은 5.5 in 내경에 길이가 8000 ft인 조합이다. 2단 튜빙간 마찰압력손실 차이는 크지 않았기 때문에 단일튜빙과 비교했을 때보다 다양한 조합이 가능하였다. 튜빙하단에선 liquid loading을 방지하기 위해 작은 액체부피비를 유지하는 것이 중요한데, 이는 2단 튜빙 하단에서 작은 내경을 사용함으로써 가능하였다. 생산운영의 분석결과로부터 다양한 튜빙 디자인이 가능함을 확인하였다.

• 펄프종이기술
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• 제43권3호
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• pp.11-20
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• 2011

The conditions to which pulp fibers are exposed during paper production, converting, storage, use, and recycling can induce various changes in fiber morphology, surface characteristics, and suitability for paper production by recycled fibers. Most of those changes can be described by hornification. Paper has highly hygroscopic properties which affect dimensional change by relative humidity variation of surrounding condition. The purpose of this study was to investigate the dimensional stability, moisture contents and dip elongation of handsheets at different relative humidity conditions of recycled kraft pulp and BCTMP. By using recycled fibers, dimensional stability was increased because hygroscopic properties of fibers decreased with repeated recycling treatment. Dip elongation of recycled pulp was higher than that of virgin pulp because of its weak fiber-to-fiber bonding. By recycling pulp, the relative bonded area was decreased because fiber could not swell more than virgin pulp. Dimensional stability largely depended on the equilibrium moisture contents of paper, the fiber-to-fiber bonding strength, and the relative bonded area.

• 품질경영학회지
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• 제50권3호
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• pp.473-490
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• 2022

Purpose: The purpose of this study is to propose a new useful suggestion to monitor the stability of process by developing a stability ratio or index related to investigating how well the process is controlled or operated to the specified target. Methods: The proposed method to monitor the stability of process is building up a new measure index which is making up for the weakness of the existing index in terms of short or long term period of production. This new index is a combined one considering both stability and capability of process to the specification limits. We suppose that both process mean and process variation(or deviation) are changing on time period. Results: The results of this study are as follows: regarding the stability of process as well as capability of process, it was shown that two indices, called SI(stability index) and PI(performance index), can be expressed in two-dimensional X-Y graph simultaneously. This graph is categorized as 4 separated partitions, which are characterized by its numerical value intervals of SI and PI which are evaluated by test statistics. Conclusion: The new revised index is more robust than the existing one in investigating the stability of process in terms of short and long period of production, even in case both process mean and variation are changing.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1036-1039
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• 2009

We have developed an automated circuit defect repair method. We focused on the resist patterns on the circuit material layer of TFT substrates before the etching process. In this paper, we report on the repair method that utilizes the syringe system and the stability of the open defect repair process.

• 한국균학회지
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• 제13권2호
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• pp.111-114
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• 1985

The production of lac case by the funguson various media was studied. The characteristics of the enzyme were also studied regarding to the optimum pH, stability, Km value, and inactivation. The maximum activity of laccase reached the 40 days of incubation and the barley straw extract appeared to be a strong inducer for laccase. The enzyme showed stability at wide range of pH with optimum pH of 6.6. Temperature stability of the enzyme was high. Laccase was not inactivated by the organic solvents used for the precipitation. The enzyme, how­ever, was completely inactivated by trichloroacetic acid and sodium azide.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.381-386
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• 2006

The advantages of precast production are fast construction, reduction of labor and insurance of good quality. In recently, the application of the precast production is increased in the earth retaining wall field. This paper presents the results of the numerical modelling that was carried out to evaluate the stability of precast and prestressed earth retaining wall under dynamic train loading. The two-dimensional explicit dynamic finite element method (ABAQUS) was used to carry out the numerical analyses. The train loading to act track is calculated by using the real measured phase angle data. Mainly, the displacement and acceleration of wall structure in time domain analyzed to evaluate the stability under the dynamic train load.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.179-187
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• 2013

Floating production storage and offloading (FPSO) facilities are used at most of the offshore oil fields worldwide. FPSO usage is expected to grow as oil fields move to deeper water, thus requiring the reliability and stability of mooring wires and risers in extreme environmental conditions. Except for the case of predictable attack angles of external loadings, FPSO facilities with turret single point mooring (SPM) systems are in general use. There are two types of turret systems: permanent systems and disconnectable turret mooring systems. Extreme environment criteria for permanent moorings are usually based on a 100-year return period event. It is common to use two or three environments including the 100-year wave with associated wind and current, and the 100-year wind with associated waves and current. When fitted with a disconnectable turret mooring system, FPSOs can be used in areas where it is desirable to remove the production unit from the field temporarily to prevent exposure to extreme events such as cyclones or large icebergs. Static and dynamic mooring analyses were performed to evaluate the stability of a spider buoy after disconnection from a turret during cyclone environmental conditions.