• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.587-591
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• 2014

Experiments for a control method that enhances the yield to produce high quality red ginsengs have been performed. In the first steaming process of a series of processes to produce red ginsengs from raw ginsengs, there occur several undesirable defects on ginsengs such as cracks of ginseng body, inside cavity and inside white. These defects lead to deterioration in product qualities. Therefore an improved control method that minimizes these undesirable defects is needed in order to increase the yield of high quality red ginsengs. Until these days, the steaming process control methods such as controlling the steaming temperature and/or pressure have been studied. However, such control methods are not adequate enough to minimize the undesirable defects in steamed ginsengs. On the other hand, in this experiment, we suggest a control method that minimizes the undesirable defects through a weight control of steamed ginsengs, keeping the steaming temperature at $96{\sim}99^{\circ}C$ as usual. Experiments with the weight control show that amount of cracks on the steamed ginseng body can be reduced.

• Journal of Environmental Science International
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• v.4 no.3
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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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.530-535
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• 1999

In recently, annealing process of cold rolled sheet tend to change to continuous annealing process for improving quality, saving yield. In the meantime as demand for various kind and small lot of products has been increasing, batch annealing has been appreciated for its small restriction for the operation. So, we tested on the effect for the proper heating temperatures, heating time of cycle, cooling time and total cycle time in this annealing process of hi tensile strength steel for automobile. As a result of several investigation. we confirmed for the following characteristics; In this process, we knew that 68$0^{\circ}C$ is suitable for this heating temp. cycle heating time of 38 Hr, cooling time of 31 Hr and total cycle time of 70 Hr. Still more, we could know that it is proper for cold rolling before annealing to be managed by 7 pass because of the act on high pressure.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.204-210
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• 2001

Paclitaxel can be produced in high yield and with a high degree of purify from plant cell cultures of Taxus chinensis. The complete purification method was systematically established and described. This method was an efficient procedure for the purification of paclitaxel from crude paclitaxel, consisting or reverse-phase chromatography, followed by a normal-phase chromatography. The two-stage HPLC purification scheme serves as an effective and economical approach for resolving paclitaxel from complex mixtures of taxoids, with high purify (>99%) and low impurities (<0.1%). The process is readily scalable to a pilot plant and eventually to a production environment where multikilogram quantities of material are expected to be produced. The process has been optimized to minimize solvent usage, complexity, and operating costs.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.02a
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• pp.389-394
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• 2000

• Clean Technology
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• v.30 no.3
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• pp.195-202
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• 2024

Plant polyphenols have attracted attention recently because of their abundance in the human diet, high antioxidant effects, and ability to prevent various diseases associated with oxidative stress, such as cancer and cardiovascular and neurodegenerative diseases. Therefore, this study demonstrated the extraction of bioactive phenolic compounds from Allium hoorkei root (AHR) using subcritical water extraction (scWE) under various temperatures (120 ~ 160 ℃) and times (30 ~ 180 min) at a fixed pressure (10 MPa) and AHR to water ratio (1:20, w/w). Furthermore, this study used severity factors, the combined effect of the temperature and time, in order to optimize the conditions for achieving a high yield and efficient recovery of target bioactive phenolic compounds while minimizing the degradation of the extracted products and maintaining a high selectivity. Subcritical water extraction at 160 ℃ for 30 min (severity of 3.24) produced a relatively high yield (88%) and high number of bioactive compounds including total phenolic contents (31.3 mg GAE/g dry AHR) and rare sugars (D-picose, D-talose, and D-tagatose) compared to Soxhlet extracts obtained from extraction for 8 h with water and 75% ethanol. As a result, the extracts obtained from the green scWE process may have high potential applications in medicines and functional foods because of their high bioactivity and safety.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.365-373
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• 2005

There is increasing need for high-strength steel especially for the high-rise steel building structure. High- strength steels, however, may have mechanical properties that are significantly different from those of the conventional steels.The application of high-strength steels to building structures should be reviewed as to whether inelastic behavior equivalent to that of conventional steels can be attained or not. In this study, SM570TMC steel, which was developed recently in Korea, was tested to evaluate mechanical properties and welding characteristics for use as a structural steel. Yield phenomenon of SM570TMC steel, which is continuous yielding, is quite different from that of conventional steel. The distributions of yield strength of SM570TMC steel were uniform regardless of thickness, while the minimum yield strength was 440MPa. Also, the flat distributions of hardness in z-direction were found to comprise one of the important properties. Results of the charpy impact tests at -5oC revealed toughness values of SM570TMC steel, which were higher than those of equivalent as rolled steel. Carbon equivalent(Ceq) values of SM570TMC steel, which were related to welding performance, were lower than those of equivalent as rolled steel.

• Food Engineering Progress
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• v.15 no.3
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• pp.203-208
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• 2011

Effects of particle size and high pressure processing on the extraction rate of oil compounds from soybean powder were evaluated by Soxhlet method using hexane and supercritical fluid extraction (SFE) using $CO_{2}$. SFE was carried out at 4,000 psi and $50^{\circ}C$ for 4 hr. The mean particle sizes were varied from 26.7 to 862.0 ${\mu}m$ by controlling milling time. Saturation solubility increased as the particle size decreased. At large particle size, high pressure processing (HPP) showed higher extraction yield in both hexane extraction and SFE, but, as the particle size decreased, the HPP was irrelevant to the extraction yield in SFE. The higher extraction rate obtained from the smaller particle size. The scanning electronic microscopy of soybean powder treated by HPP showed pores on the surface of the particle. The higher extraction rate and yield from HPP treatment might be due to the less internal resistance of transferring the solvent and miscellar in the solid matrix by collapsing of tissues.

• Journal of the Korean Society of Combustion
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• v.10 no.4
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• pp.24-32
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• 2005

Various types of plasma source applied in $CH_4$ decomposition process are compared. DBD by pulse and AC power, spark by pulse and AC power, rotating arc and hollow cathode plasma are chosen to be compared. The results show that $CH_4$ conversion per given unit power is relatively high in hollow cathode plasma and rotating arc that induces rather high temperature condition and that is why both thermal dehydration and plasma induced decomposition contribute for the overall process. In case of DBD wherein high temperature electron and low temperature gas molecule coexist, the process shows low conversion rate, for in rather low temperature condition the contribution of thermal dehydration is lowered. Selectivity of $C_2H_6$ and $C_2H_2$ is shown to be a good parameter of the relative contribution of plasma chemistry in the overall process. From the results we concluded that required condition of plasma source for a cost effective and high yield $CH_4$ decomposition is to have characteristics of both thermal plasma and non thermal plasma in which temperature is high above a certain threshold state for thermal dehydration and electron induced collision is maximized in the same breath.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.236-241
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• 2005

A decolorization process using ion exchange chromatography was developed to refine rhEGF as a cosmetic ingredient. A macroreticular resin (D314) was selected, with respect to its high decolorization rate and recovery yield of rhEGF, and the operational conditions of the decolorization process optimized. The optimum conditions were as follows: the rhEGF effluent was ion exchanged at a flow rate of 60.0mL/h, with an effluent pH 5.0, using a chromatographic column (i.d. 16mm) packed with D314, with a 7.5cm in bed height. The decolorization process was carried out under the optimum conditions, and halted when the effluent volume reached 350mL, giving a decolorization rate and recovery yield of rhEGF higher than 67 and $80\%$, respectively. When the decolorization rate exceeded $67\%$, the final product turned out to be white or light yellowish, which was to the satisfaction of the cosmetic standard.