• Journal of Environmental Science International
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• v.13 no.3
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• pp.319-325
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• 2004

An experimental study on the preparation of monolithic porous polymers by environmentally friend process in supercritical carbon dioxide has been carried out. Polymerization mixture composed of a cross-linking monomer, initiator and functional co-polymer was charged in the reactor with sapphire window. After the system was purged with a flow of $CO_2$ for 15 min, the reactor was pressurized with liquid $CO_2$ up to 100 bars. The reactor was isolated from and placed back to the system via quick connector for shaking until the mixture had become fully homogeneous. The reactor was then heated and pressurized to the required reaction conditions and left overnight. After cooling and $CO_2$ evacuation, the polymer was removed from the reactor as dry, white, continuous monoliths. The effect of experimental conditions on the physical properties of porous polymer was systematically examined, and it was found that monomer content had a major effect on the physical properties of the polymers.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.57-64
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• 1996

The main objectives of this research program were to study the ozonation characteristics of phenol wastewater in the continuous packed colamn reactor(PCR) and the bubble column reactor (BCR) using ozone and to provide the fundamentals of ozonizing the phenol wastewater. Among various influencing factors that affect on phenol decomposition through the oxidation by ozone, contacting method, and ozone flow rate were chosen as reaction parameters. The results were obtained from two different types of contacting methods where the countercurrent flow was more efficient than the cocurrent flow in both the phenol removal efficiency and the ozone utilization efficiency. Furthermore, PCR showed the phenol removal efficiency 1.6 to 3% higher than that of BCR in both contacting methods, as well as the ozone utilization efficiency, suggesting that the countercurrent flow is more efficient than the cocurrent flow. The phenol removal efficiency and the ozone utilization efficiency were reduced in both reactors as the influent ozone flow rate increased. Upon varing flow rate from 0.5l/min to 2.0 l/min by 0.5 l/min, the phenol removal efficiency was reduced approximately from 8.5% to 10.5% and the ozone utilization efficiency was reduced approximately from 6% to 8% in both reactors. The performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.147-156
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• 1998

A synthesis process for PZT powder using $NH_{3}$ gas as a precipitator in a bubble column reactor was experimentally successful in develope a production process of piezoelectric ceramic PZT powder. Also as a reaction by coprecipitation, the crystalized PZT ceramic powder at the condition of over pH 9 could be attained. The time needed for reaction on the condition of $NH_{3}$ gas flow rate = 0.5 1/min, Ar gas flow rate = 2.0 1/min. Feed flow rate = 2.33 ml/sec was less than five minutes, so it could synthesize PZT powder for such a few moments. And the synthesized PZT powder was $0.17{\mu}m$ in diameter on an average.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.110-117
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• 1998

A packed-bed reactor with immobilized transglucosidase (TG) was operated to test the possibility of continuous production of isomaltooligosaccharides (IMO) and the effect of concentration and feed rate of substrate solution on the production pattern as well as operational stability The pattern of formation of IMO was the same to the one of soluble TG. The concentrations of glucose and isomaltose produced by the packed-bed reactor were gradually decreased as the flow rates were increased regardless of the concentrations and kinds of maltose solution as substrate. Isomaltotriose showed the same tendency except 10% maltose solution. But the concentration of panose was increased and then decreased as the flow rates were increased. The maximum yield of IMO was 52.1% when 10% (w/v) solution was fed to the reactor at 2 mL./min feed rate. When each 20% and 30% (w/v) solution was respectively used at $0.5{\sim}1.0\;mL/min$, the maximum yield were $39.0{\sim}38.0%\;and\;12.1{\sim}14.2%$. The maximum yield was 36.3% at $0.5{\sim}1.0\;mL/min$ when a commercial maltose product containing 20% maltose was used. The reactor was stably operated at $55^{\circ}C$. 85% and 65% of initial activity was maintained for 144 hours and 288 hours of operation, respectively. A reactor analysis strongly an immobilized TG system could apply to continuous production of IMO.

• KSBB Journal
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• v.16 no.4
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• pp.398-402
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• 2001

Enzymatic hydrolysis of agar was carried out continuously to produce agarooligosaccharides by immobilized agarase in Packed-Bed Reactor. The reactor was constructed using a acryl tube with an internal diameter of 10 mm and a useful height of 140 mm. The Packed-Bed Reactor was 11 mL reactor volume as its length : diameter ratio was 14 : 1. The operation condition of reaction was performed with an 1 g/L agar concentration at 40$^{\circ}C$, 10 mM MOPS buffer(pH 7.0) and with the flow rate 3 mL∼48 mL/h at a dilution rate of 1.09∼5.45 h$\^$-1/. The hydrolysis products was identified DP6, DP4 and DP2 by HPLC. The conversion rate of agar was about 80% and amount of total agarooligosaccharide was 0.88 mg/mL at Packed-Bed Reactor.

• Environmental Engineering Research
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• v.9 no.1
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• pp.13-22
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• 2004

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.647-651
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• 1987

Yeast biomass in a biological continuous stirred tank reactor was controlled with an APPLE II microcomputer using adaptive control theory of bilinear systems. The controller used is as simple as a PID controller, but required less information. Cell concentration was well controlled by adjusting the inlet flow rate following the algorithm.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.163-170
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• 2002

This report describes the use of a transtubular bioreactor to study the relative effects of diffusion versus perfusion of medium on antibody production by a hybridoma cell line. The study was performed with a high-density cell culture maintained in a serum-free, low-protein medium for 77 days. It was determined that the reactor possessed a macro-mixing pattern residence time distribution similar to a continuous stirred tank reactor (CSTR), However, due to the arrangement of the medium lines in the reactor, the flow patterns for nutrient distribution consist of largely independent medium path lengths ranging from short to long. When operated with cyclic, reversing, transtubular medium flow, some regions of the reactor (with short residence times) are more accessible to medium than others (with long residence times). From this standpoint, the reactor can be divided into three regions: a captive volume, which consists of medium primarily delivered via diffusion; a lapped volume, which provides nutrients through unilateral convection; and a swept volume, which operates through bilateral convection. The relative sizes of these three volumes were modified experimentally by changing the period over which the direction of medium flow was reversed from 15 min (larger captive volume) to 9 h (larger swept volume). The results suggest that antibody concentration increases as the size of the diffusion-limited (captive) volume is increased to a maximum at around 30 min with a sharp decrease thereafter. As reflected by changes in measured consumption of glucose and production of lactate, no significant difference in cellular metabolism occurred as the reactor was moved between these different states. These results indicate that the mode of operation of the transtubular bioreactor may influence antibody productivity under serum-free, low-protein conditions with minimal effects on cellular metabolism.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.3
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• pp.223-230
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• 2002

Titania photocatalytic oxidation reactors were studied to investigate degradation efficiencies of hydrocarbons. In general, it is well known phenomena that thin layered titania oxidizes most of hydrocarbons to carbon dioxide and water under UV light. In this study, degradation efficiencies were measured due to changes in reactor structures, UV sources, the number of titania coatings, and various hydrocarbon chemicals. It was proven that gas degradation efficiencies are related to such factors as UV transmittance of coating substance, collision area of surface, and gas flow rate. For packing type annular reactor, about 98% degradation efficiency was achieved for achieved for propylene of 500 ppm level at a flow rate of 100 ml/min. Several gases were also tested for double-coated titania thin film under the condition of continuous flow of 100 ml/min and 365 nm UV source. It was shown that degradation efficiencies were decreasing in the order: $C_3$ $H_{6}$, n-C$_4$ $H_{10}$, $C_2$ $H_4$, $C_2$ $H_2$, $C_{6}$ $H_{6}$ and $C_2$ $H_{6}$./. 6/./.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.501-506
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• 1998

A mathematical model is developed to describe the relationship between the manipulated variables (e.g. jacket inlet temperature and feed flow rate) and the important qualities (e.g conversion and weight average molecular weight (Mw)) in a continuous polymerization reactor. The subspace-based identification method for Wiener model is used to retrieve from the discrete sample data the accurate information about both the structure and initial parameter estimates for iterative parameter optimization methods. The comparison of the output of the identified Wiener model with the outputs of a non-linear plant model shows a fairly satisfactory degree of accordance.