• Applied Biological Chemistry
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• v.4
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• pp.17-22
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• 1963

Changes of Enzymatic activities and chemical components during Koji preparation of soy sauce with various ratio of soy bean and wheat were studied as first step for checking the current ratio of raw materials for improved soy sauce and determination of proper ratio of them in the respect to its quality and taste, and following results could be obtained. 1. The Protease in the dryed Koji were mainly conmposed of a part which active at the neutral (about pH 6.0) range, while parts which active at acid and alkaline side were inferior. The more amount of wheat increases as raw materials of Koji, the stronger Protease activities of acid and neural side were, while the weaker alkaline side were. 2. Activity of Enzymes were increased rapidly in earlier stage then gradually in later stage or Protease and ${\beta}-Amylase$ rapidly throughout except drying of ${\beta}-Amylase$ during the course of Koji preparation. The more amount of wheat as raw material increases, the stronger Protease and ${\beta}-Amylase$ activity except. ${\beta}-Amylase$ were. 3. Reducing sugar, amino nitrogen, total nitrogen were increased, while total sugar were decreased during the course of Koji preparation. 4. The more amount of wheat increases as raw materials, the more increase reducing sugar, total sugar were, while the total nitrogen were decreased, no noticeable differences were observed in the amino nitrogen among the dryed Kojies.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.266-271
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• 1994

In order to investigate the effects of the mixing ratio of rice on Doenjang, Meju Doenjang and Koji Doenjang were prepared respectively with oaring mix ratio of raw materials. The following results were obtained, after fermentation of up to 3 months. Significant differences between the kinds of Doenjang were not found in moisture and salt contents. Protein solubility $(water\;soluble\;nitrogen/total\;nitrogen{\times}100)$ was $32{\sim}50%$ and $14{\sim}24%$ in Koji Doenjang and Meju Doenjang, respectively. Protein digestibility $(formol\;nitrogen/total\;nitrogen{\times}100)$ was similar to the tendency of protein solubility. Reducing sugar content was $5{\sim}6%$ in Meju Doenjang, while $19{\sim}21%$ in Koji Doenjang. As the mixing ratio of rice increased, reducing sugar content also increased. Sensory evaluation showed that Koji Doenjang was desirable than Meju Doenjang and the mixing ratio of 20% rice was recommened for Koji Doenjang.

• YAKHAK HOEJI
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• v.53 no.5
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• pp.293-297
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• 2009

The abuse of methamphetamine (MA) is one of the most serious drug abuses in Asia. And, the prevention of precursor production for abuse drug is one of the most effective drug control system. Isotope ratio analysis at natural abundance levels have been used to establish the environmental source or the geographic origin of various biological and nonbiological materials. Ephedrine, the precursor of MA, is produced by one of three methods; extraction from Ephedra plants, full chemical synthesis or via a semi-synthetic process involving the fermentation of sugar, followed by amination. We investigated the origin of ephedrine and pseudoephedrine based on the carbon and nitrogen values for nineteen pharmaceutical powder materials (PPMs) obtained from pharmaceutical company in Korea by stable isotope ratio mass spectrometry coupled to an elemental analyser (EA-IRMS). The carbon delta values for the ephedrine and pseudoephedrine were -24.21~-22.72 (mean=-23.72) $^{\cir}/_{\circ\circ}$ and -23.79~-22.71 (mean=-23.48) $^{\cir}/_{\circ\circ}$. The nitrogen delta values were 3.51~5.55 (4.43) $^{\cir}/_{\circ\circ}$ and 2.24~8.22 (5.42) $^{\cir}/_{\circ\circ}$. These results indicate that PPMs are semi-synthetic products. Therefore the origins of ephedrine(natural, semi-synthetic or synthetic) could be discriminated by using carbon and nitrogen stable isotope ratios. we are sure tat this stable isotope ratio analysis can discriminate the origins of precursors of methamphetamine.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.218-224
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• 2021

This study was conducted to determine the mass-loss rates and the changes in carbon/nitrogen (C/N) ratio of dead woods, which were of following species: Dryobalanops aromatic, D. rappa, and Cratoxylum arborescens. These were dominant tree species in mixed Dipterocarp forests (MDF) and peat swamp forests (PSF) in Brunei Darussalam. In May, 2019, 48 dead wood samples (15 cm×4.8 cm×5 cm) were placed in MDF and PSF sites, and all the samples were collected after 16 months. The effects of species on mass loss were statistically significant (p<0.05); however, no difference was observed in the mass loss obtained from the two forest types (p>0.05). The initial density (g·cm^-3) of the dead woods D. aromatic, D. rappa, and C. arborescens, was 0.64±0.02, 0.60±0.00, and 0.44±0.01, respectively. Also the annual mass loss rate (%) was estimated to be 6.37, 8.17, and 18.53 for D. aromatic, D. rappa, and C. arborescens, respectively. The proportion of dead woods in decay class III was only 25% of C. arborescens samples, which were attacked by wood-feeding invertebrates, such as termites. The C/N ratio decreased significantly in D. aromatic and D. rappa, but the decreasing trend of C/N ratio was not statistically significant in C. arborescens. The results indicate that physical traits of dead woods, such as density, could be one of the main factors causing the decomposition of dead woods initially, as invertebrates such as termites are one of the key decomposers of dead wood in tropical rainforests. In the samples of C. arborescens, which was attacked by invertebrates, nitrogen immobilization occurred to lesser extent as compared to that observed in D. aromatic and D. rappa.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.237-248
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• 2008

Development of T. urticae was studied on the leaves of eggplant grown in hydroponics with nitrogen contents of 5 mM, 10 mM, 30 mM, and 60 mM. As the nitrogen level in hydroponics increased, it also increased in the plant whereas that of K, Ca, and Mg decreased. More nitrogen in hydroponics resulted in increased contents of water and crude protein, and decreased ash, carbohydrates, and fibers within the plant. Biomass was the heaviest as 989.5 g at 10 mM and the lightest at 60 mM. Leaf thickness and the content of chlorophyll increased as the content of nitrogen increased. Laboratory leaf disc tests obtained from plants grown at various nitrogen levels revealed that feeding and oviposition preferences of T. urticae were high at 30 mM and low at 5 mM. Ratio of damaged leaf by naturally occurring T. urticae on eggplants of 99 days post-transplant in the greenhouse was the highest as 98% at 60 mM. Degrees of damage on eggplants with and without T. urticae infestation turned up more as the differences in the levels of nitrogen in the hydroponics get bigger. No definite differences in the rate of T. urticae development was found between nitrogen treatment levels but, mortalities in immature stages dropped as the nitrogen levels went up. Adult longevity was the longest of 11.9 for female and 6.9 days for male at 60 mM. Oviposition period was also the longest as 11.7 days at 60 mM and shortened as the level of nitrogen decreased. The number of eggs oviposited was the most as 144.4 at 60 mM while it was the least as 41.0 at 5 mM. Sex ratio was 0.75 in favor of female at 10 mM. $R_o$ and T increased, no trends were detected in $r_m\;and\;{\lambda}$, while Dt decreased as the levels of nitrogen went up.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.57-63
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• 1971

1) Among five lactic acid bacteria examined, Str. thermophilus and Str. diacetilactis produced remarkably greater amount of acids in soybean milk than Str. lactis, Str. cremoris and L. bulgaricus. 2) Soybean milk and skimmed dry milk were combined in the ratio of 7 : 3 and were carried out in lactic acid fermentation for 24 hours at optimum temperature. The result indicated that the yield of precipitation and protein content of it were the most, the moisture content was the least and curd structure formed was considered too hard. 3) Based on these and other results, following procedure was used for manufacturing: soybean milk and skimmed dry milk were combined in the ratio of 7 : 3, heated at $121^{\circ}C$ for 20 min., cooled, added Str. thermophilus as lactic acid starter and incubated for 24 hours and $37{\pm}1^{\circ}C$. The curd was cooked, hooped, and pressed for 24 hours, to the surface of which, Penicillium caseicolum and sodium chloride were spread. During ripening of the curd at $15^{\circ}C$ and $85{\sim}90%$ RH for 21 days, Pen. caseicolum was highly developed after 7 days, pH was increased and proteolytie activity has reached to the peak point after 14 days. After 7 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino acids nitrogen were begun to increase. After 21 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino-N reached to 52%, 32% and 14% of total nitogen. In the soybean cheese, after 21 days of ripening, 17 or more kinds of amino acids were detected by two-dimentional paper chromatography. The product contained 63.2% of moisture, 17.5% of crude protein, 13.2% of crude fat, 2.8% of crude ash and 2.5% of sodium chloride.

• Journal of the Korean Society for Environmental Technology
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• v.19 no.6
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• pp.493-502
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• 2018

The purpose of this study was to develop EM media for water treatment and to remove nitrogen and phosphorus which cause water algae boom in water system. The ideal mixing ratio of raw material such as clay: zeolite: vermiculite: activated carbon for manufacturing the EM media was 10: 2.5: 0.1: 2, and the calcination temperature was $700^{\circ}C$. The comparison of the physical properties of manufactures using distilled water and EM activated liquid as the material mixture are as follows. Porosity and density of EM media were 39.98 % and $1.13kg/m^3$, adsorption efficiencies of nitrogen and phosphorus were 69.3 % and 38.9 %. In contrast, porosity and density of distilled water media were 37.80 % and $1.11kg/m^3$, and adsorption efficiencies of nitrogen and phosphorus were 62.5 % and 37.8 %. The adsorption rate of nitrogen and phosphorus in the EM media was higher than that of the distilled water made one by 6.8 % and 1.1 %, respectively. The adsorption characteristics of the media to nitrogen and phosphorus could be expressed by the Freudlich adsorption isotherm. The change of calcination time did not affect the adsorption efficiency of phosphorus and nitrogen when EM media was formed, but it was considered that it affects the strength of media. Nitrogen removal efficiency was the best record in 4 hours of calcination time and 3 hours of calcination time in phosphorus removal efficiency.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.33-39
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• 1986

Particulate matter was collected by Andersen Air Sampler in the Seoul area during February-October, 1985, in order to investigate size distribution of sulfate and nitrate in aerosol, and conversion of sulfur dioxide to sulfate and that of nitrogen dioxide to nitrate. The size distribution of sulfate and nitrate had fine mode. The ratio of fine sulfate to total sulfate in aerosol and that of fine nitrate to total nitrate showed between 54.6% and 86%, and 55.7% and 95%, respectively, which presumably originated from gaseous reaction of sulfur dioxide and nitrogen dioxide in the atmosphere.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.2
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• pp.79-85
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• 2004

This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. Investigated are the engine emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine can be achieved the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engines.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.59-64
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• 2003

This study was conducted to investigate anoxic-RBC-anoxic-RBC process and its application to remove biologically organics and nitrogen. BOD and total-nitrogen(T-N) removal efficiencies were decreased as volumetric loading rate increased. But, the removal efficiency changes of T-N were little, as compared to BOD. Increase of internal recycle rate had few affect of BOD and T-N removal rates. Also, influent allocation(to 2nd anoxic reactor) had few affect of BOD removal efficiency rate. However, when the influent allocation rate was 30%, T-N removal efficiency was increased to 84.1 %. BOD/N ratio applied to 2nd anoxic reactor was increased to range of 3.65-4.37 as influent allocation rate increased to range 20∼35%. But, it might also cause adverse effect such as decrease of denitrification rate in excessive influent allocation rate.