• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.636-642
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• 2011

The effect of different rates of ethanol additive on fermentation quality of napiergrass (Pennisetum purpureum) and residual water soluble carbohydrate were studied in the experiment. The addition rate of ethanol was 0%, 1.5%, 2.5%, 3.5%, 4.5% on fresh weight of napiergrass. The laboratory silos were kept in the room, then were opened on 1, 3, 5, 7, 14, 30 days after ensiling and the changes of silage quality were analyzed, respectively. There was a fast and large reduction in pH from the 5th day of ensiling to below 4.2 except for the 4.5% treatment. After five days the pH of silage decreased slowly and the pH of the ethanol additions was lower than the control. Lactic acid content of ethanol treatments increased significantly (p<0.05) from the 5th day of ensiling, reaching the highest value on either the 7th day or 14th day. The ethanol additive inhibited the break down of silage protein and the ammonia nitrogen content of ethanol addition silage was significantly (p<0.05) lower than the control after 30 days of ensiling. Within the initial first day of ensiling the water soluble carbohydrate content declined quickly. The efficiency of water soluble carbohydrate usage was higher in silage with ethanol than in the control. The acetic acid of ethanol treatment was significantly (p<0.05) lower than control on first and 14th day, but there was no significant (p>0.05) difference among the ethanol addition silages. The volatile fatty acids content of silage increased gradually from the first day of ensiling and reached the peak on 14th day or 30th day and the content of ethanol addition treatment was significantly (p<0.05) lower than the control. The experimental results indicated that adding ethanol inhibited the use of protein and water soluble carbohydrate of aerobic bacteria and reduced the silage losses during the early stage of ensiling and thus supplied more fermentation substrate for lactic acid bacteria and improved the fermentation quality of napiergrass.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.287-294
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• 2007

Effect of combined use of anti-microbial materials, such as ethanol, mustard and chitosan, on the quality of low salted kochujang was investigated during fermentation at $20^{\circ}C$ for 12 weeks. Viable cells of yeast increased remarkably during fermentation, but increasing ratio was significantly low in ethanol-mustard added kochujang. Activity of ${\beta}-amylase$ was high in anti-microbial material added kochujang, whereas ${\alpha}-amylase$ and protease activities were low in those groups. Water activity decreased during fermentation with being low in the control kochujang prepared with normal-salt without anti-microbial materials. Hunter L-, a- and b-values of kochujang increased during fermentation, and the degree of increase in total color difference $({\Delta}E)$ was low in ethanol added kochujang. Titratable acidity of kochujang was decreased in anti-microbial materials added group at late aging period, and oxidation-reduction potential was low in the control kochujang. Total sugar and reducing sugar contents of kochujang were high in ethanol-mustard added kochujang. Ethanol contents of kochujang increased at late aging period, with high values in ethanol-chitosan added kochujang. Amino nitrogen content increased during middle of fermentation, and ammonia nitrogen content of kochujang decreased in ethanol-mustard-chitosan added group during fermentation. After 12 weeks fermentation, sensory results showed that ethanol or ethanol-mustard added kochujang were the highest in color and flavor with the highest overall acceptability.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.449-455
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• 2005

To reduce saft content of kochujang, various combinations of sub-materials such as ethanol mustard and chitosan were added to kochujang, and their effects on microbial characteristics, enzyme activities, and physicochemical characteristics of kochujang were investigated after 12 weeks of fermentation. Activities of ${\beta}$-amylase and pretense were low in ethanol-mustard-chitosan-added kochujang, whereas no significant difference was observed in ${\alpha$-amylase activity among all groups. Number of viable yeast cells decreased remarkably in mustard-added kochujang during late aging period, and anaerobic bacterial counts decreased in sub-material-added groups. Consistency of kochujang increased by addition of sub-materials, and oxidation-reduction potential was low in chitosan-added group. Mustard-chitosan-added kochujang showed lowest increase in total color difference(${\Dalta}E$) and decrease in water activity. PH of kochujang wns highest in mustard-chitosan-added kochujang, resulting in significantly increased titratable acidity. Addition of sub-material increased reducing sugar contents of kochujang, whereas ethanol production was significantly repressed in mustard-chitosan-added kochujang. Amino nitrogen content was Highest in mustard-chitosan-added kochujang during late aging period, whereas ammonia nitrogen content was lower in ethanol-mustard-added kochujang. Results of sensory evaluation indicated ethanol-mustard-added kochujang was more acceptable than other groups in taste and overall acceptability.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.172-172
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• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.7-7
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• 2001

The increasing interest in light weight materials coupled to the need for cost -effective processing have combined to create a significant opportunity for aluminum P/M. particularly in the automotive industry in order to reduce fuel emissions and improve fuel economy at affordable prices. Additional potential markets for Al PIM parts include hand tools. Where moving parts against gravity represents a challenge; and office machinery, where reciprocating forces are important. Aluminum PIM adds light weight, high compressibility. low sintering temperatures. easy machinability and good corrosion resistance to all advantages of conventional iron bm;ed P/rv1. Current commercial alloys are pre-mixed of either the AI-Si-Mg or AL-Cu-Mg-Si type and contain 1.5% ethylene bis-stearamide as an internal lubricant. The powder is compacted in closed dies at pressure of 200-500Mpa and sintered in nitrogen at temperatures between $580~630^{\circ}C$ in continuous muffle furnace. For some applications no further processing is required. although most applications require one or more secondary operations such as sizing and finishing. These sccondary operations improve the dimension. properties or appearance of the finished part. Aluminum is often considered difficult to sinter because of the presence of a stable surface oxide film. Removal of the oxide in iron and copper based is usually achieved through the use of reducing atmospheres. such as hydrogen or dissociated ammonia. In aluminum. this occurs in the solid st,lte through the partial reduction of the aluminum by magncsium to form spinel. This exposcs the underlying metal and facilitates sintering. It has recently been shown that < 0.2% Mg is all that is required. It is noteworthy that most aluminum pre-mixes contain at least 0.5% Mg. The sintering of aluminum alloys can be further enhanced by selective microalloying. Just 100ppm pf tin chnnges the liquid phase sintering kinetics of the 2xxx alloys to produce a tensile strength of 375Mpa. an increilse of nearly 20% over the unmodified alloy. The ductility is unnffected. A similar but different effect occurs by the addition of 100 ppm of Pb to 7xxx alloys. The lend changes the wetting characteristics of the sintering liquid which serves to increase the tensile strength to 440 Mpa. a 40% increase over unmodified aIloys. Current research is predominantly aimed at the development of metal matrix composites. which have a high specific modulus. good wear resistance and a tailorable coefficient of thermal expnnsion. By controlling particle clustering and by engineering the ceramic/matrix interface in order to enhance sintering. very attractive properties can be achicved in the ns-sintered state. I\t an ils-sintered density ilpproaching 99%. these new experimental alloys hnve a modulus of 130 Gpa and an ultimate tensile strength of 212 Mpa in the T4 temper. In contest. unreinforcecl aluminum has a modulus of just 70 Gpa.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.189-200
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• 2005

Biological nitrogen fixation is an important process for academic and industrial aspects. This review will briefly compare industrial and biological nitrogen fixation and cover the characteristics of biological nitrogen fixation studied in Azotobacter vinelandii. Various organisms can carry out biological nitrogen fixation and recently the researches on the reaction mechanism were concentrated on the free-living microorganism, A. vinelandii. Nitrogen fixation, which transforms atmospheric $N_2$ into ammonia, is chemically a reduction reaction requiring electron donation. Nitrogenase, the biological nitrgen fixer, accepts electrons from biological electron donors, and transfers them to the active site, FeMo-cofactor, through $Fe_4S_4$ cluster in Fe protein and P-cluster in MoFe protein. The electron transport and the proton transport are very important processes in the nitrogenase catalysis to understand its reaction mechanism, and the interactions between FeMo-cofactor and nitrogen molecule are at the center of biological nitrogen fixation mechanism. Spectroscopic studies including protein X-ray crystallography, EPR and $M{\ddot{o}}ssbauer$, biochemical approaches including substrate and inhibitor interactions as well as site-directed mutation study, and chemical approach to synthesize the FeMo-cofactor model compounds were used for biological nitrogen fixation study. Recent research results from these area were presented, and finally, a new nitrogenase reaction mechanism will be proposed based on the various research results.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.97-104
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• 2004

Effects of sub-materials such as, ethanol, mustard, and chitosan, on enzymatic, microbial and physicochemical characteristics of kochujang were investigated during fermentation. Activity of ${\alpha}$-amylase was low in chitosan-added kochujang, whereas those of ${\beta}$-amylase and pretense did not show any remarkable difference. Viable cells of yeast and bacteria decreased in sub-material-added kochujang during fermentation, with yeast counts decreasing more rapidly in ethanol- and mustard-added kochujang than that with chitosan. Consistency of kochujang decreased during fermentation, with the highest consistency observed in ethanol-added kochujang. Oxidation-reduction potential was low in chitosan-added kochujang. Water activity of all kochujang groups decreased during fermentation with the lowest in ethanol-added kochujang. Hunter L-, a-, and b-values of chitosan-added kochujang were higher than other groups, whereas increase in total color difference of low-salt without sub-material group was lowest pH of kochujang was the highest in ethanol-added kochujang, whereas titratable acidity increased remarkably in chitosan-added group. Total sugar and reducing sugar contents of kochujang were high in ethanol-and mustard-added groups, whereas ethanol production decreased remarkably in mustard-added kochujang. Amino nitrogen content was highest in low-salt without sub-material kochujang during late aging period. Ammonia nitrogen content was lower in mustard-added kochujang. After 12 weeks of fermentation, ethanol-added kochujang was more acceptable than mustard-and chitosan-added groups in taste, color, and overall acceptabilities.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.281-287
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• 2008

Effect of combined use of anti-microbial materials, such as alcohol, mustard and chitosan, or pasteurization on the quality of low salted kochujang was investigated during storage at $30^{\circ}C$ for 12 weeks. Activity of amylase decreased during storage, with lower activity in pasteurized kochujang than the other groups. Acidic protease activity increased during storage, but neutral protease activity decreased after 4 weeks. Viable cells of yeast increased during storage, but bacterial counts decreased gradually and did not show any remarkable difference among the test groups. Hunter a-values decreased as storage time increased, whereas L- and b-values decreased after 4 weeks and the degree of increase in total color difference (${\Delta}E$) was low in the supplementary ingredients added kochujang. The moisture contents and water activities decreased during storage with being lower in supplementary ingredients added groups. Titratable acidity of kochujang was decreased after 4 weeks of storage with the highest in combination of the supplementary ingredients added group. Oxidation-reduction potential was low in the supplementary ingredients added kochujang. Total sugar and reducing sugar contents of kochujang decreased during storage, with the highest contents in the supplementary ingredients added group. Ethanol content of kochujang increased during storage, whereas ethanol production was reduced in ethanol added one. Amino-nitrogen and ammonia-nitrogen contents decreased during storage with being lower in kochujang prepared with supplementary ingredients. Therefore, supplementary ingredients added kochujang would be effective for extending shelf-life of kochujang.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.577-586
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• 2017

The aim of this study was to investigate the effects of fermented earthworm cast feed prepared with three complexed probiotics containing Bacillus subtilis separated from the earthworm casts, on egg production, egg quality and odor removal from poultry house. A total of 240 laying hens were divided into 4 treatments and completely randomized. Experimental groups were divided into control, 0.3 to 0.5% (fermented earthworm cast feed FECF3, FECF5) and 0.2% commercial probiotics (CP). The egg production rate was significantly higher in the FECF groups compared to the control group fed the normal feed, but there was no difference in the CP group. Haugh units, egg shell thickness, breaking strength, egg yolk index and albumen height were increased in FECF groups compared to control but not in CP group. The n-3 content of eggs was higher in the FECF groups than in the control group, while the n-6/n-3 ratio was lower and there was no difference from the CP group. Ammonia production was lower in the CP and FECF groups compared to the control group after 5 days storage at room temperature to poultry feces.