• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.4
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• pp.463-472
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• 1996

Experiments were carried out to study the operation characteristics of a regenerator with a thermo-syphon pump and a surface-flame burner for a lithium bromide (LiBr)-water absorption heat pump. A cylindrical-shape metal-fiber burner and commercial grade propane were used. The emission of carbon monoxide and nitric oxide was measured by a combustion gas analyzer. Ther regeneration rate of water vapor as a refrigerant was measured. It could be as a reference value showing the performance of the regenerator. The circulation rate of the LiBr-water solution was also measured from both the tanks for the weak-and the strong-solution. Using a refractometer, the LiBr concetration in the solution was calculated from the measured refractory index of the solution. Temperature of the solution and the condensed water was recorded at several points in the experimental apparatus with thermocouples, using a personal computer. This data collecting system for measuring temperature was calibrated with a set of standard thermometers. The generating rate of water vapor as refrigerant increased linearly with heat supplied. It was about 4.0g/s with the heat supplied at a rate of 16,500kcal/h. The circulation rate of LiBr solution also increases with the heat supplied. The difference in LiBr concentrations between the weak and the strong solution was in the range of 1 to 5% when the concentration of the strong solution was about 60%. It was dependent upon both the heat supplied and the circulation rate of the solution. The initial concentration and the level of the LiBr solution in the regenerator were measured and recorded before experiments. The effect of them on the generating rate of water vapor and the circulation rate of the solution was also studied. The generating rate of water vapor was not strongly dependent upon both the level of the LiBr solution and the initial LiBr concentration. However, the concentration difference of the solution increases with the initial level of the LiBr solution.

• Microbiology and Biotechnology Letters
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• v.28 no.2
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• pp.105-110
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• 2000

Various environmental factors such as pH, temperature and initial glucose concentration were investigated for enhancing cell growth in fermentations of Phellinus linteus WI-OOl, a producer of polysaccarides with potent anticancer activities. Optimal pH and temperature were around 5.5 and $28^{\circ}C$, respectively. Relatively little variation of pH was observed ranging between 5.5 and 6.5 during the whole fermentation period. Maximum cell concentration and specific growth rate were investigated in the media containing initial glucose concentrations of 0.5%, 1 %, 2%, 3% and 4%. High initial glucose concentration enhanced biomass production but showed negative effect on specific growth rate. In bioreactor experiments with various feeding strategies, increases of 28% and 42% in final cell concentration were obtaind as compared to conventional batch process, by adopting pulse and continuous supplement of 2% glucose solution, respectively.

• KSBB Journal
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• v.14 no.6
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• pp.665-671
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• 1999

In this study, enhanced production of 10-deacetylbaccatin III(10-DAB), a precursor of taxol in semisynthesis, was investigated in Taxus cuspidata cell suspension cultures. The effects of initial inoculum size and sugar concentration were examined to prove the relationship between the production of 10-DAB and cell growth. The cell growth was found to be stimulated in Schenk and Hildebrandt(SH) medium. The lower the inoculum size as well as initial sugar concentration, the faster the cell growth rate. When the initial sugar concentration was dept low, the production of 10-DAB into medium was increased. By using perfusion culture, continuous cell growth was possible until the end of culture and more than 34.67 g/L of cell concentration could by obtained. This is about 2.5 times higher level than that of control batch culture.

• KSBB Journal
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• v.21 no.2
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• pp.123-128
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• 2006

A transgenic hairy root clone AG-04 of Astragalus membranaceus was obtained following co-cultivation of leaf explants with Agrobacterium rhizogenes ATCC15834. This clone was examined for its growth and production of cyclolanostane-type saponins, astragalosides I, II, and III, under various culture conditions. Among the five basal media tested, Shenk and Hildebrandt(SH)(18) medium was best for roots growth and astragalosides production. The maximum root biomass was obtained at inoculum size of 500 mg FRW per flask, initial sucrose concentration of 3%, and shaking speeds of 90 rpm. The astagalosides production was promoted when the hairy root clone AG-04 was cultured at shaking speeds of 120 rpm and light irradiation of 18 h. Astragaloside contents was also stimulated with high initial sucrose concentration, and the maximum astargalosides contents of 6.21 %/g DRW was obtained at initial sucrose concentration of 6%. The addition of chitosan(100 mg/L) to the culture medium was significantly increased astragalosides production. This was 2.1 times higher than that obtained in a control culture without chitosan.

• Food Engineering Progress
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• v.14 no.3
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• pp.217-221
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• 2010

Various conditions of acetic acid fermentation by Acetobacter aceti B20 strain were investigated and evaluated to optimize the fermentative production of acetic acid. The effects of the initial ethanol concentration on growth and acid productivity in a flask and fermentor were also studied. The growth of A. aceti B20 strain was inhibited as the concentration of ethanol increased. However, the highest total acidity and fermentation yield were 5.34% and 56.1%, respectively when the initial concentration of ethanol was 7% in the batch fermentation. Although the concentration of initial glucose influenced the growth rate of B20 strain, it did not influence the total acidity in the flask culture. When the agitation speed increased, the growth, total acidity and fermentation yield were all improved. In fed-batch fermentation, total acidities and fermentation yields were 7.14-8.76% and 39.1-53.0%, respectively, and their values mostly depended on the feeding methods.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.395-408
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• 2023

This study presents a novel method for addressing the issue of high-concentration contaminants (ammonium, phosphate, antibiotics) in leachate arising from decomposing livestock carcasses. Antibiotics, developed to eliminate microorganisms, often have low biodegradability and can persist in the ecosystem. This research proposes design elements to prevent contamination spread from carcass burial sites. The adsorbents used were low-grade charcoal (an industrial by-product), Alum-based Adsorbent (ABA), and Zeolite, a natural substance. These effectively removed the main leachate contaminants: low-grade charcoal for antibiotics (initial concentration 1.05 mg/L, removal rate 73.4%), ABA for phosphate (initial concentration 2.53 mg/L, removal rate 99.9%), and zeolite for ammonium (initial concentration 38.92 mg/L, removal rate 100.0%). The optimal mix ratio for purifying leachate is 1:1:10 of low-grade charcoal, ABA, and zeolite. The average adsorbent usage per burial site was 1,800 kg, costing KRW 2,000,000 per ton. The cost for the minimum leachate volume (about 12.4 m³) per site is KRW 2,880,000, and for the maximum volume (about 19.7 m³) is KRW 4,620,000. These findings contribute to resolving issues related to livestock carcass burial sites and suggest post-management strategies by advocating for the effective use of adsorbents in leachate purification.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.45-53
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• 2003

Based on the 4-compartmental pharmacokinetic model developed in PART1, target-controlled infusion(TCI) pump system was designed and evaluated. The TCI system consists of digital board including microcontroller and digital signal process(DSP), analog board, motor-driven actuator, user friendly interface, power management and controller. It provides two modes according to the drugs: plasma target concentration and effect target concentration. Anaesthetist controls the depth of anaesthesia for patients by adjusting the required concentration to maintain both plasma and effect site in drug concentration. The data estimated in DSP include infusion rate, initial load dose, and rotation number of motor encoder. During TCI operation, plasma concentration. effect site concentration, awaken concentration, context-sensitive decrement time and system error information are displayed in real time. Li-ion battery guarantees above 2 hours without power line failure. For high reliability of the system, two microprocessors were used to perform independent functions for both pharmacokinetic algorithm and motor control strategy.

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.106-108
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• 1997

Blue green algaes (NIES 19, 39, 46) have been cultivated to product sigle cell protein. After 7 days of cultivation under 5000 (W/M$^{2}$) of ligth intensity, final cell concentration was 2.8 (g/L) and chlorophyll a was 4.9 (mg/L). When initial concentration of NaHCOC was 1.7% and NaNO$_{3}$ was0.25%, maximum cell concentration was obtained. Spirulina platensis NIES 39 showed faster growth rate than NIES 46. While most 39 sedimented, most 46 floated.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.798-802
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• 1996

The photochemical decomposition of aqueous ammonia in the absence (saturated with argon) and the presence of O2 (saturated with air or oxygen) has been investigated using 184.9 nm UV light. The decomposition of ammonia depended on the concentration of oxygen in the solution. With increasing the concentration of oxygen, the decomposition of ammonia diminishes. Hydrazine is found the major product from the irradiation. In the presence of oxygen, hydrogenperoxide was also produced. The product yields depended also on the concentration of oxygen in the solution. The initial quantum yield of the products and of the ammonia decomposed were determined. Probable reaction mechanisms for the reaction were presented from the products analysis.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.360-367
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• 2005

We have performed to analyze the trophic state resulting of Lake Yongdam as a result of water quality and nutrient concentration. Lake Yongdam is artifitial multi-purpose Dam resulting from the floods of 2001. The water quality of Lake Yongdam may affect the status of the Geum river basin including the Daecheong reservoir. It is necessary to understand the trophic state to assess water quality until stability after flooding. Water quality was surveyed using depth and hydraulic condition analysis. Further density flow was estimated for stratification and trophic state of Lake Yongdam by chlorophyll ${\alpha}$ concentration (2001~2004). And Environmental factors on chlorophyll ${\alpha}$ concentration were analyzed statistically. Trophic state was evaluated as the oligotrophic state at the main stream of the reservoir and eutrophic state at the upper stream in 2001, but evaluated as eutrophic state in 2002 and 2003 by TSI of Aizaki. From the results of multiple regression analysis using stepwise method, chlorophyll ${\alpha}$ concentration was shown to be very significant when nutrient concentration is high upon initial filling of the Dam. Chlorophyll ${\alpha}$ concentration varied according to sample site, season and year. Concentration were high in the upper stream of Lake Yongdam 4, algae bloom in these watershed were affected by location and high nutrient levels in the summer season which have in turn increased phytoplankton bloom into the reservoir.