• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.440-446
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• 2017

This study was aimed at evaluating the effects of carbohydrate, protein and lipid content of substrate on hydrogen yields and microbial communities. The hydrogen yields were linearly correlated to carbohydrate content of substrates while others (content of proteins and lipids) did not make a significant contribution. The chemical composition of substrates produced effects on the final products of anaerobic hydrogen fermentation. Acetate and butyrate were the main fermentation products, with their concentration proving to correlate with carbohydrate and protein content of substrates. The result of microbial community analysis revealed that the relative abundances of Clostridium butyricum increased and Clostridium perfringens decreased as the carbohydrate content increased.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.278-282
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• 1988

Rice straw was used in the acetone-butanol fermentation by semultaneous saccharification and fermentation (SSF) using Clostridium acetobutylicum and cellulolytic enzyme. Over 230 mM of solvent was produced from alkali treated rice straw of from ball-milled microcrystalline cellulose whilst only acidic fermentation products were formed from ball-milled rice straw. From the results it is concluded that rice straw used in the study contained an inhibitor for the solventogenesis by the organism which is insoluble in water and some organic solvent and destroyed by alkaline treatment.

• Sleep Medicine and Psychophysiology
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• v.17 no.2
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• pp.63-68
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• 2010

Narcolepsy is a central neurologic system disease. It begins early in life with disabling symptoms including excessive daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucination and nocturnal sleep fragmentation. Patient with typical symptoms of narcolepsy is diagnosed by objective data from nocturnal polysomnography and multiple sleep latency tests. Narcolepsy is controlled with various medications. Nowadays, modafinil with favorable side effects profiles compared with traditional stimulant is mainly used. Gamma hydroxyl butyrate is effective in cataplexy. Cataplexy is also controlled with antidepressant such as Venlafaxine, SSRI, and TCA. As the knowledge of pathophysiology of narcolepsy expands, new treatment including immunological method, application of hypocretin and histamine systems have been tried.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.5
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• pp.427-433
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• 2018

This study was performed to evaluate initial pH and substrate concentration on hydrogen fermentation of protein. The optimum initial pH and substrate concentration of hydrogen fermentation using protein was 8.0 and 1.0 g peptone/L, respectively. The maximum hydrogen yield at initial pH 8.0 and 1.0 g peptone/L was $19.2{\pm}0.8mL\;H_2/g$ peptone. As results of VFAs analysis, percentages of valerate was similar to hydrogen yield. Also, C. stickalandii, which was hydrogen and valerate producing bacteria, was dominated.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.461-467
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• 1998

In spite of significant nonlinearities even in the simplest model, some types of steady-state and dynamic behavior common for nonlinear systems have never been associated with distillation columns. In recent years, multiplicity of steady states has been a subject of much research and is now widely accepted. Subsequently, stability of steady states has been explored. Another phenomenon that. although widely observed in chemical reactors, has not been associated with models of distillation columns is the existence of periodic oscillations. In this article we study the steady-state and dynamic behavior of the azeotropic distillation of the ternary homogeneous system methanol-methyl butyrate-toluene. Our simulations reveal nonlinear behavior not reported in earlier studies. Under certain conditions, the open-loop distillation system shows a sustained oscillation associated with branching to periodic solutions. The limit cycles are accompanied by traveling waves inside the column. Significant underdamped oscillations are also observed over a wide range of product rates.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.62-66
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• 2007

Four different biopolyester films, two aliphatic polyesters including polylactides (PLA) and poly(3-hydroxy-butyrate-co-3-hydroxyvalerate (PHBV), and two aliphatic-aromatic copolyesters including Ecoplex and Biomax, were prepared using by thermo-compression, and their tensile and water barrier properties were determined. Among the films tested, PLA film was the most transparent (T: 95.8%), strongest, and stiffest (TS, 40.98 MPa; E, 1916 MPa), however it was rather brittle. In contrast, Ecoplex film was translucent while being the most flexible and resilient (EB, 766.8%). Biomax film was semitransparent and was the most brittle film tested (EB, 0.03%). All biopolyester films were water resistant exhibiting very low water solubility (WS) values ranging from 0.0.3 to 0.36%. PHBV film showed the lowest water vapor permeability (WVP) value ($1.26{\times}10^{-11}\;g{\cdot}m/m^2{\cdot}sec{\cdot}Pa$) followed by Biomax, PLA, and Ecoflex films, respectively. The water vapor barrier properties of each film were approximately 100 times higher than those of carbohydrate or protein-based films, but about 100 times lower than those of commodity polyolefin films such as low-density polyethylene (LDPE) or polypropylene (PP).

• KSBB Journal
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• v.15 no.5
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• pp.529-536
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• 2000

Results from experiments and mathematical modeling were compared for pervaporative butanol fermentation. The developed model includes expressions to predict characteristics of butanol fermentation, such as, microbial growth, solvent (butanol, acetone, and ethanol) formation and organic acid (acetate and butyrate) production. Butanol diffusivity was 1.15${\times}$10(sup)-7 ㎡/hr at 1.5 L/min-tubing of air flow rate using a pervaporative module. The model correlated well with experimental results (cell growth, glucose consumption and concentrations of solvents and organic acids) for batch fermentation with and without pervaporation. Larger surface area and thinner module tubing resulted in an increased glucose consumption and a decreased residual butanol concentration. Optimum membrane area and thickness were 0.34 ㎡ and 120 $\mu\textrm{m}$, respectively.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.322-326
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• 2005

연속반응조에서의 수소생산에 대한 수리학적체류시간(희석율, D)의 영향을 $1\%$ sucrose를 함유한 $37{\pm}1^{\circ}C$ 조건에서 조사하였다. 실험결과 수리학적체류시간(희석율)의 각각의 조건에 따라 생성된 가스중 수소성분은 $50~71\%$의 범위로 발생되었다. $H_2/CO_2$ 비율은 희석율이 증가할 때 $H_2/CO_2$ 비율도 증가하였다. 최대수소생성 수율은 희석율 0.14 l/h까지는 증가하다가 이후에는 감소하였고, 수소생성 수율은 0.81 l/g sucrose이었다. Acetate 생성 수율은 butyrate생성 수율 보다 희석율 조건변화에 민감하게 변화하였다. propionate 및 solvents는 희석율 변화에 영향을 받지 않았다 biomass 수율은 희석율이 0.2 l/h 까지는 증가하였으나, 그 이상의 조건에서는 감소하였다.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.1-5
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• 2000

연속형 혐기성처리 반응조에서 배양된 수소발생 슬러지를 이용하여 증온 조건에서 회분식 혐기성 처리방법으로 유기성 폐수로부터 전환되는 수소가스 및 대사산물들에 대한 연구를 수행하였다. 수소발생에 대한 기질로는 sucrose를 이용하였다. 처리과정에서 발생된 누적수소가스, 휘발성지방산(VFAs) 및 solvents는 Gompertz equation을 이용한 비선형회귀분석을 통하여 계산하였다. 처리과정 중 수소가스는 반응초기에 발생하였고, 발생된 가스내 수소가스가 차지하는 비율은 약 20%이었다. 반응 전과정에서 메탄가스는 발생하지 않았다. 비수소가스발생율은 sucrose 농도가 40 g/l일 때 0.956 ml/g VSs/h이었으며, sucrose 농도가 300g/l의 경우는 0.011 ml/g VSS/h이었다. 수소가 발생하는 기간 동안 VFAs의 생성은 acetate, butyrate의 순으로 높게 생성되었으나, propionate로의 전환은 발견되지 않았다. solvents의 경우 butanol이 가장 높게 발생하였다.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.322-327
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• 1997

Photosynthetic bacterium strain N-1 was isolated from the eutrophic wet soil and identified as Rhodospirillum rubrum. The optimum conditions for the cultivation of R. rubrum N-1 were estimated as 0.2% (w/v) of sodium acetate, 0.2% (w/v) of sodium propionate, 0.2% (w/v) of sodium butyrate in the Lasscelles basal medium at 30$circ$C, pH 7.0 under 4000 lux of the illumination. The removal efficiencies of total organic acid and chemical oxygen demand (COD$_{Cr}$) in swine wastewater were 80% and 87%, respectively, when 10% (v/v) of R. rubrum N-1 was inoculated.