• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.390-397
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• 1991

Ethanol production by calcium alginate-immobilized baker's yeast (Saccharor/tyces cereviszae) was studied in the batch fermentation using glucose medium as a feed. Immobilied cells were stable between $30^{\circ}C$ and $40^{\circ}C$ whereas free cells were stable between $30^{\circ}C$ and $37^{\circ}C$ The beads were showed constant ethanol productivity during 720 hours (30 days) over. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration of broth in fermentation. Initial glucose concentrations employed were 50, 100, 150 and 200 g/l, respectively. In 15% gucose medium, maximum specific growth rate, maximum ethanol yield and ethanol concentration were observed as 0.092 $h^{-1}$, 0.45, 67.5 g/l, respectively.

• KSBB Journal
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• v.28 no.5
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• pp.315-318
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• 2013

Ethanol fermentations were performed using separate hydrolysis and fermentation (SHF) processes with monosaccharides from pretreated seaweed, Eucheuma spinosum as the biomass. The pretreatment was carried out with 11% (w/v) seaweed slurry and 150 mM $H_2SO_4$ at $121^{\circ}C$ for 40 min. Enzyme hydrolysis after $H_2SO_4$ pretreatment was performed with Celluclast 1.5 L at $45^{\circ}C$ for 24 h. Five % active charcoal were added to hydrolysate to removed 5-hydroxy methylfurfural. Ethanol fermentation with 11% (w/v) seaweed hydrolysate was performed for 72~96 h using Kluyvermyces marxianus, Pichia stipits, Saccharomyces cervisiae and Candida tropicalis. Ethanol concentration was reached to 18 g/L by K. marxianus, 16 g/L by P. stipitis, 15 g/L by S. cerevisiae and 10 g/L by C. tropicalis, respectively. The ethanol yield from total monosugar was obtained 0.50 and ethanol productivity was obtained 0.38 g/L/h by K. marxianus.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1054-1063
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• 2022

Trehalose is a non-conventional sugar with potent applications in the food, healthcare and biopharma industries. In this study, trehalose was synthesized from maltose using whole-cell Pseudomonas monteilii TBRC 1196 producing trehalose synthase (TreS) as the biocatalyst. The reaction condition was optimized using 1% Triton X-100 permeabilized cells. According to our central composite design (CCD) experiment, the optimal process was achieved at 35℃ and pH 8.0 for 24 h, resulting in the maximum trehalose yield of 51.60 g/g after 12 h using an initial cell loading of 94 g/l. Scale-up production in a lab-scale bioreactor led to the final trehalose concentration of 51.91 g/l with a yield of 51.60 g/g and productivity of 4.37 g/l/h together with 8.24 g/l glucose as a byproduct. A one-pot process integrating trehalose production and byproduct bioremoval showed 53.35% trehalose yield from 107.4 g/l after 15 h by permeabilized P. moteilii cells. The residual maltose and glucose were subsequently removed by Saccharomyces cerevisiae TBRC 12153, resulting in trehalose recovery of 99.23% with 24.85 g/l ethanol obtained as a co-product. The present work provides an integrated alternative process for trehalose production from maltose syrup in bio-industry.

• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.5-14
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• 2016

The main objective of this study was to evaluate the removal properties of Cu from existing exfoliated vermiculite (EV) coated with a mixed solution of sulfuric acid and glycerol on the $580^{\circ}C$ in heating, which uses coated with glycerol of copper ions can be removed more effectively. Serial batch kinetic tests and batch sorption tests were conducted to determine the removal characteristics for Cu in aqueous solution. The result of batch kinetic test shows that removal rate, $K_{obs}$ (1/hr), of Cu are 0.579, 0.878, 3.459, and 6.578 for MEV weight 1 g (25 g/L), 2 g (50 g/L), 3 g (75 g/L), 4 g (100 g/L), respectively. In this case the initial pH of the solution was 3.26. The removal experiment according to the concentration, $K_{obs}$ (1/hr), of Cu are 1.96, 0.878, 1.25, and 1.04 for the initial concentration of 3 mg/L, 5 mg/L, 8 mg/L, 10 mg/L, and the initial pH of the solution are 3.46, 3.26, 3.10, 2.96, respectively. Influence of initial pHs on Cu removal were tested under 1g of MEV with 5 mg/L of Cu solution. $K_{obs}$ (1/hr) were increased from 0.263 (pH 3) to 0.525 (pH 5). It leads to the conclusion that the removal rates are inversely proportional to the initial Cu concentration and are increased proportional to the initial pHs. Sorption capacity of MEV was determined by batch sorption tests. The maximum sorption capacity ($Q_{max}$) obtained from Langmuir was 0.761 mg/g, Linear and Freundlich partition coefficients were 0.494 L/g and 0.729 L/g (1/n = 0.476). These results show that the MEV could be used as an excellent adsorbent for copper contained in various types of aqueous solutions.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1253-1255
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• 1999

This paper presents database design and construction for VSECOMs (Voltage Security On-line Monitoring System). The database design has steps of requirements collection and analysis, conceptual design, logical design, and physical design. For interconnection between New EMS and VSECOMs to get the needed data, Snapshots in ORACLE are proposed. It proved the proposal to be compatible through the case study.

• Journal of Sensor Science and Technology
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• v.6 no.2
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• pp.131-136
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• 1997

The ISFET(ion sensitive field effect transistor), a semiconductor ion sensor, has many advantages over conventional ion sensors. Various single-sensor type ISFET pH-meters have been developed. However, they could not be applied in fields because their performances are directly affected by the sensor condition. With only one sensor, the system could be easily damaged from environmental factors, and reliability of it is decreased. Therefore, a 4-channel PH-meter system is proposed to improve the reliability of ISFET pH-meter. It has 4 ISFETS as ion sensor, and a software which contains a new calibration and measurement algorithm appropriate to the system. The reliability of the system was proved by measuring hydrogen ion concentration in the pH standard solutions and buffer solutions.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.163-165
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• 2002

High-speed permanent magnet machines are currently being developed for a number of applocations including gas-turbine generator sets and machine tools. Due to the high peripheral speed of the rotor and the relatively high conductively of the magnets used, rotor eddy current loss can be substantial. On the basis of analytical and finite element method, this paper deals with an analytical method for calculating eddy current losses in the rotor with permanent magnet and retaining ring.

• KSBB Journal
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• v.17 no.4
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• pp.365-369
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• 2002

An iron-storage protein, ferritin is a spherical shell consisting of 24 H-and L-chain subunits. Soluble form of fused($F_{H}+F_{L}$ chain) ferritin was separated from disrupted recombinant E. coii cells, followed by silica powder adsorption. Ferritin was recovered from silica-poweder by distilled water, which was applied to gel filtration chromatography(GFC). Collected ferritin fractions from the GFC were assayed via iron-uptake and its molecular weight determined using GF-HPLC. Fused ferritin showed a higher activity than the M- or L- chain ferritin by two times.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.154-159
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• 1997

The crystal structure properties of TiN thin films deposited on SKD61 steel and Si(100) substrates by Ion Beam Assisted Deposition have been studied to clarify the thin film growth mechanism by using XRD, RBS, SEM, and AFM. The preferred orientation of TiN thin films changes from (111) to (100) as increasing the assisted energy. This tendency is independent of the substrate structure. The TiN thin film grow with (100) direction having surface free energy minimum as the assisted energy increases.

• Wind and Structures
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• v.12 no.4
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• pp.383-400
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• 2009

Low rise building roofs can be subjected to large fluctuating pressures during a tropical cyclone resulting in fatigue failure of cladding. Following the damage to housing in Tropical Cyclone Tracy in Darwin, Australia, the Darwin Area Building Manual (DABM) cyclic loading test criteria, that loaded the cladding for 10000 cycles oscillating from zero to a permissible stress design pressure, and the Experimental Building Station TR440 test of 10200 load cycles which increased in steps to the permissible stress design pressure, were developed for assessing building elements susceptible to low cycle fatigue failure. Recently the 'Low-High-Low' (L-H-L) cyclic test for metal roofing was introduced into the Building Code of Australia (2007). Following advances in wind tunnel data acquisition and full-scale wind loading simulators, this paper presents a comparison of wind-induced cladding damage, from a "design" cyclone proposed by Jancauskas, et al. (1994), with current test criteria developed by Mahendran (1995). Wind tunnel data were used to generate the external and net pressure time histories on the roof of a low-rise building during the passage of the "design" cyclone. The peak pressures generated at the windward roof corner for a tributary area representative of a cladding fastener are underestimated by the Australian/New Zealand Wind Actions Standard. The "design" cyclone, with increasing and decreasing wind speeds combined with changes in wind direction, generated increasing then decreasing pressures in a manner similar to that specified in the L-H-L test. However, the L-H-L test underestimated the magnitude and number of large load cycles, but overestimated the number of cycles in the mid ranges. Cladding elements subjected to the L-H-L test showed greater fatigue damage than when experiencing a five hour "design" cyclone containing higher peak pressures. It is evident that the increased fatigue damage was due to the L-H-L test having a large number of load cycles cycling from zero load (R=0) in contrast to that produced during the cyclone.