• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1224-1231
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• 2006

Sucrose esters were synthesized by transesterification of sucrose with docosahexaenoic acid ethylester mixture (DHAEE). Potassium carbonate as a base catalyst was used in the presence of dimethylsulfoxide (DMSO) for the reactions. The reactions were performed with the different reaction times and molar ratios of substrates in the presence of surfactant in vacuum. Among the reaction conditions in this study, SE#4～7 showed the relatively high conversion rate (>96%) of DHAEE, leading to the high yield of sucrose esters. In addition, the product composition was changed from sucrose mono ester to di/tri/polyesters after the prolonged reaction time while the increased molar ratio of DHAEE also resulted in the composition changes of sucrose mono ester to the sucrose di/tri/polyesters. From the reaction (SE#7), conversion ratio was 98.5% in which 87.3% mono ester and 13.7% di/tri/polyester were found, resulting in the highest content of mono ester. Therefore, the sucrose ester containing various rates of mono and di/tri/polyesters, which effects on hydrophilic lipophilic balance (HLB) values, can be manipulatively synthesized using the reaction conditions reported in this study.

• Clean Technology
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• v.29 no.2
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• pp.126-134
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• 2023

Direct catalytic decomposition is a promising method for controlling the emission of nitrous oxide (N₂O) from the semiconductor and display industries. In this study, a γ-Al₂O₃ catalyst was developed to reduce N₂O emissions by a catalytic decomposition reaction. The γ-Al₂O₃ catalyst was prepared by an extrusion method using boehmite powder, and a N₂O decomposition test was performed using a catalyst reactor that was approximately 25.4 mm (1 in) in diameter packed with approximately 5 mm of catalysts. The N₂O decomposition tests were carried out with approximately 1% N₂O at 550 to 750 ℃, an ambient pressure, and a GHSV=1800-2000 h^-1. To confirm the N₂O decomposition properties and the effect of O₂ and steam on the N₂O decomposition, nitrogen, air, and air and steam were used as atmospheric gases. The catalytic decomposition tests showed that the 1% N₂O had almost completely disappeared at 700 ℃ in an N₂ atmosphere. However, air and steam decreased the conversion rate drastically. The long term stability test carried out under an N₂ atmosphere at 700 ℃ for 350 h showed that the N₂O conversion rate remained very stable, confirming no catalytic activity changes. From the results of the N₂O decomposition tests and long-term stability test, it is expected that the prepared γ-Al₂O₃ catalyst can be used to reduce N₂O emissions from several industries including the semiconductor, display, and nitric acid manufacturing industry.

• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.294-301
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• 2012

In this study, we investigated the features of bioethanol fermentation of corncob biomass after oxalic acid pretreatment as well as enzymatic hydrolysis. The enzymatic hydrolysis was performed with Accellerase 1000 and the highest yield of monomeric sugars ($64.8g/{\ell}$) was obtained at $50^{\circ}C$ and pH 4.5 for 96 hrs hydrolysis period. For the ethanol fermentation the monomeric sugars obtained from pretreated corncob were subjected to the biological treatment using Pichia stipitis CBS 6054. It was turned out that ethanol production from oxalic acid pretreated corncob was the most feasible at 10~14% of biomass loading as well as 15 FPU enzyme amount. Under these fermentation condition, the ethanol yield was approached to 0.47 after 24 hrs fermentation period, which was corresponded to 92.2% of conversion rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.112-120
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• 2006

For the conversion of food waste into a good recycling material such as animal feed without antibiotics, thirteen lactic acid bacteria, which can be used as good probiotics for animal feed, were isolated from the intestine and feces in pigs. All isolates showed strong tolerance to high salt (4% of NaCl), acid(pH4.0), and bile juice (0.8% of oxgall). The growth rate was best at $37^{\circ}C$ in all strains. Among the isolates, Lactobacillus plantarum CJY-22, L. brevis CJY-42, L. arizonensis CJY-3, and Pediococcus sp. CJY-41 showed higher and broader spectrum of antimicrobial activities against six different pathogens such as Salmonella, typhimurium. L. plantarum CJY-22 has also grown well at $25^{\circ}C$, making this strain as an appropriate candidate for the fermentation of food waste at room temperature, thus conducting the fermentation process cost-effectively.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.661-667
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• 2013

The objective of this study was to investigate the effects of partial replacement of wheat hay with sun-dried (SOC) or acid-treated SOC (ASOC) olive cake on nutrient intake and performance of Awassi lambs. An additional objective was to study the effects of acid treatment of olive cake (OC) on its chemical composition and nutritive value. On DM basis, sun-drying of OC did not dramatically affect its chemical composition. On the other hand, treating SOC with phosphoric acid decreased (p<0.05) SOC contents of neutral detergent fiber. Twenty seven male lambs ($17.6{\pm}0.75$ kg body weight) individually housed in shaded pens were randomly assigned to one of three dietary treatments (9 lambs/treatment). Dietary treatments were formulated to be isocaloric and isonitrogenous by replacing 50% of wheat hay in the control diet (CTL) with SOC or ASOC and to meet all nutrient requirements. Dietary treatments had no effects on nutrient intake or digestibility except for ether extract. Lambs fed the SOC diet had (p = 0.05) faster growth rate, greater final body weight, and greater total body weight gain in comparison with the CTL diet, but not different from the ASOC diet. Additionally, lambs fed the SOC diet had greater (p = 0.03) hot and cold carcass weights than the ASOC diet, but not different from the CTL diet. However, feed conversion ratios and dressing percentages were similar among dietary treatments. In conclusion, replacing half of dietary wheat hay with SOC improved performance of Awassi lambs with no detrimental effects on nutrients intake or digestibility. No further improvements in the nutritive value of SOC and lambs performance were detected when SOC was treated with acid.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.168-174
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• 2023

In commercial production processes of methyl methacrylate, there is a methacryl aldehyde as an intermediate or impurities. The existence of impurities is critical factor because of significant decrease of the conversion rate and selectivity of the entire chemical reaction. This study found that an acid was the main cause of the decrease in reactivity among various impurities because an acid rapidly lowers the activity of a catalyst and promotes a side reaction, the hetero Diels-Alder reaction. Therefore, the pretreatment methods with the removal of acid were comparatively evaluated by the selective hydrogenation reaction of the carbonyl group of the reactants. Based on several experimental conditions, we believe that proposed effective pretreatment improves productivity with appropriate economical process.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.693-700
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• 1996

Background : Antituberculous therapy is set a short-term therpy used isoniazid(INH), rifampin(RFP), ethambutol(EMB), pyrazinamide(PZA) from 1970s' and treatment rate has been very improved. But drug interruption or irregular medication due to side effects and resistance of drug are serious problem to retreatment cases, specially. Ofloxasine(OFX), developed from Quinolone at 1980's is effective not only other respiratory infectious disease but also pulmonary tube rculosis. And this is useful drug instead of injection agents for retreatment patients who have side effects to other drugs, lived far distance from medical clinics. So, we will evaluate theffectiveness as four oral drugs involving OFX. Method : A retrospective study was made through the regular follow up of smear positive cases,who treated by four drug, namely, prothionamide (PTA) cycloserine(CS), OFX, paraminosalicylic acid(pAS). Results: 1) Out of 66case with positive sputum AFB smear, 42(64%)cases achieved the negative conversion. 2) Considering the negative conversion in all group, 34 case (52%) of sputum conversion occured within first 6 months, on the extent of diease was minimal, moderate, far advanced pulmonary tuberculosis, sputum AFB smear negative response to treatment was 100%, 78%, 46% respectively. 3) The roentgenological improvement occured in 38(58%), extent of diease was minimal, moderately, far advanced pulmonary tuberculosis, Roentgenological improvement to retreatment was 75%, 64%, 46%. 4) When the drnation of patients illness was less than 1 year, 1 to 3 years, 3 10 5 years and more than 5 years, sputum AFB smear negative response to retreatment was 100%, 88%, 80%, 52 %. 5) On side effects, major problems are gastrointestinal troubles, mild liver function abnormality, psychotic problemes, and skin problem(urticaria, itching sensation). Conclusion : The duration & extents of patients illness was shorter & minimal, sputum AFB smear negative response rate was better. Radiologic response is better as shorter duration and minimal extent of diease. But, as diease is longer duration & far advanced, sputum negative conversion & Roentgenological improvement is poor and limited. The adverse reaction was mainly observed gastrointestinal troubles(indigestion, abdominal pain, nausea, vomiting, diarrhea) and are well controled by symptomatic management in most patients, as regard to tolerance to the secondary drugs.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.139-143
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• 1997

This experiment was conducted to investigate the effect of dietary supplemental charcoal(CH) or charcoal extract(CE) on performance and meat quality of broiler chicks for 5 weeks. Basal diets based on corn and soybean meal contained 21% crude protein for the first 3 weeks and 19% for the rest two weeks. Two levels of dietary CH(O, 0.5%) and CE(0, 0.2%) were fed in a factorial design. There were four replicates of 10 chicks each per treatment. An increased growth rate was observed in chicks fed the basal diet supplemented with CE alone. Chicks fed the diet containing both CH and CE tended to depress the growth rate. Dietary supplemental CH and CE improved the feed conversion efficiency compared to the control group, but was not significantly different between them. The abdominal fat(%) of chicks fed CH alone or both CH and CE tended to de-crease without significant difference. The total lipid content of breast meat of chicks fed CE alone showed significant difference among treatments (P

• Analytical Science and Technology
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• v.30 no.3
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• pp.138-145
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• 2017

Microwave-assisted organic synthesis has gained a remarkable interest over the past years because of its advantages - (i) rapid energy transfer and superheating, (ii) higher yield and rapid reaction, (iii) cleaner reactions. Ionic liquids are well known for their unique properties such as negligible vapor pressure and high thermal stability. With these properties, ionic liquids have gained increasing attention as green, multi-use reaction media. Recently, ionic liquids have been applied as reaction media for biocatalysis. Lipase-catalyzed reactions in ionic liquids provide high activity and yield compared to conventional organic solvents or solvent free system. Since polar molecules are generally good absorbent to microwave radiation, ionic liquids were investigated as reaction media to improve activity and productivity. In this study, therefore, the effect of microwave irradiation in ionic liquids was investigated on lipase catalyzed reactions such as benzyl acetate synthesis and caffeic acid phenethyl ester synthesis. Comparing to conventional heating, microwave heating showed almost the same final conversion but increased initial reaction rate (3.03 mM/min) compared to 2.11 mM/min in conventional heating at $50^{\circ}C$.

• KSBB Journal
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• v.18 no.2
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• pp.127-132
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• 2003

The effect of 4 kinds of alcohols was investigated on the production of bacterial cellulose (BC) by Gluconacetobacter hansenii PJK. The addition of alcohols and acetic acid to medium caused the pellets of bacterial cellulose to aggregate into a lump, which could be easily separated from the culture medium. The growth rate of cells and the production yield of BC increased in the medium containing ethanol. Other alcohols in the medium decreased cell growth and the cellulose production rate, because of their toxic effects. The addition of ethanol depressed the conversion of a $\textrm{Cel}^{+}$ cell to a $\textrm{Cel}^{-}$ mutant in shaking culture. Cells subcultured three in a medium containing ethanol produced BC without any loss of BC production yield.