• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.54-59
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• 2021

The pretreatment of cellulosic biomass is essentially needed because it has more lignin compared with a starch biomass. Ethanol as an organosolv for pretreatment can easily separate some components which can inhibit enzymatic hydrolysis and be re-usuable by distillation. The flow-through process have some strength, separating components continuously, development for scale up. In this research, two-kinds (wheat straw, miscanthus) of biomass was pretreated for development of enzymatic hydrolysis by adoption of pretreatment process of corn stover.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.92-96
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• 2001

Soil physical-chemical properties and phosphorous adsorption characteristics were investigated to obtain the informations of the appropriate fertilization and soil management in Baicheng region, China, where agricultural circumstances at present forces to consider the use of land for crop production. Soils were collected from one uncultivated and three cultivated lands on August 1993. Soil $_PH$ was very higher in uncultivated land than in cultivated land, their values were 10.2 and 7.4, respectively. Regardless of cultivation, soil organic matter contents were below 2%, and concentrations of available soil phosphorus expressed as Bray 1 P and Olson P were less than 10 mg P $kg^{-1}$, however, cation exchange capacity was higher than 20 cmol(+) $kg^{-1}$. For uncultivated soil, the values of exchangeable sodium percent and calcium saturation percent were higher than 100%. The major cation of soil saturation paste extracts was Na regardless of land use type. Based on electrical conductivity and sodium adsorption ratio of saturation paste extracts, uncultivated soil was classified as saline-sodic soil and cultivated soil was classified as sodic or normal soil. The maximum adsorption capacity of phosphorus calculated by Langmuir isotherm ranged from 406 to 521 mg P ,$kg^{-1}$. The constraints of soils in Baicheng regions for agricultural cops werw high salt concentration, unfavorable soil chemical composition such as low concentration of available phosphorous, and poor drainage due to soil dispersion by high Na concentration. Therefore, the soil in Baicheng region, need the application of phosphorus fertilizer to increase the soil fertility and the proper soil management to improve the soil physical property especially permeability and soil structure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.647-652
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• 2008

Quality characteristics of Chrysanthemum indicum L. flower tea were investigated with the number of pan-firing. Total nitrogen, tannin and caffeine contents of tea were increased as the number of pan-firing increased, whereas chlorophyll and total amino acid (AA) contents were decreased. TAA content was in the range of $5,226{\sim}6,561mg%$ with the number of pan-firing. The content of caffeine and chlorophyll was not changed with the number of pan-firing. As the number of pan-firing increased, total polyphenol, flavonoid content, and antioxidant activity was also increased. The highest total polyphenol and flavonoid content was 17.44 and 11.09 mg/g at 7 times pan-firing, respectively. Total antioxidant activity was the highest value of 16.45 mg AA eq/g at 7 times of pan-firing. Based on the sensory evaluation, the best overall quality of the tea was obtained with 5 times of pan-firing.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.297-302
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• 2008

In this study, Chrysanthemum indicum L. flower tea was prepared according to different pan-firing times (5, 7.5, 10, 12.5, and 15 min) and its quality characteristics were investigated. Total nitrogen and tannin contents increased with increasing pan-firing time, whereas chlorophyll and total amino acid (AA) contents decreased. The total AA contents of the samples ranged from 6,399 to 7,068 mg%, and the highest content (7,068 mg%) was found with the 10 min panfiring treatment. The AAs occurring in the C. indicum L. flower tea included glutamic acid and aspartic acid, which are desirable flavor components. As the pan-firing time increased, antioxidant activity as well as total polyphenol and flavonoid contents increased. The highest total polyphenol and flavonoid contents were found in the 15 min treatment at levels of 13.85 mg tannic acid equiv./g and 9.77 mg catechin equiv./g, respectively. The 15 min pan-firing treatment also had the highest total antioxidant activity at 19.33 mg ascorbic acid equiv. eg/100 g. Finally, based on sensory evaluations, the 10 min pan-fired C. indicum L. flower tea had the best overall quality.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.16-23
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• 1986

Physico-chemical and sensory characteristics of 28 black tea samples prepared by oaring the mixing ratio of 1 kind of Korean and 9 kinds of foreign black tea were determined, and their relationship was statistically analysed. Korean black tea was found to be lower in bulk density, caffeine, theobromine, crude protein, theaflavin, thearubigin and soluble solids, and higher in Hunter L- and b- value, neutral detergent fiber, calcium and ratio of oxidized matter as compared with foreign black tea. The palatability for 8 kinds of foreign black tea was generally increased by mixing with Korean black tea. The number of black tea whose palatability were higher than that of Korean black tea was 12, which was mostly mixed black tea. Theaflavin. Hunter a-value, soluble solids of the tea infusion, and potassium of the manufactured tea were the major guiding characteristics as a result of stepwise multiple regression analysis, and about 67% of the total variations in the palatability of black tea could be explained by the regression equation formulated by the preceding 4 characteristics.

• Resources Recycling
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• v.26 no.1
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• pp.51-58
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• 2017

The present study to develop a process for extracting nitric acid and gold from aqua regia leach solution using TBP(tributyl phosphate) was conducted. The pure aqua regia was used to investigate the extractive behavior of nitric acid depending on the concentration of extractant, concentration ratio of nitric and hydrochloric acid. The extraction rate of nitric acid and gold from the gold bearing aqua regia was also examined. The theoretical extraction number was verified by counter current using the number of operations and the phase ratio obtained from McCabe-Thiele diagram. Stripping experiments were carried out for continuous recovery of nitric acid and gold in loaded organic. Considering the effect of extraction acid and gold, the simulation showed that greater than 99.9% extraction of $103.0mg{\cdot}L^{-1}$ gold and 98.0% of $151.2g{\cdot}L^{-1}$ nitric acid could be attained in a two and three-stage counter-current extraction at an O/A phase ratio of 1:0.85. Distilled water and sodium thiosulfate were used as the nitric acid and gold stripping solution. The stripping rates were 99.5% and 92.0%, respectively. The study revealed that the recovery of nitric acid and gold from gold bearing aqua regia was a plausible approach through simultaneous extraction and continuous stripping of nitric acid and gold.

• Resources Recycling
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• v.27 no.4
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• pp.16-22
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• 2018

Inconel713C which of a commercial Ni super alloy have the compositions of 70 wt.% Ni, 12 wt.% Cr, 6 wt.% Al and 4 wt.% Mo. In this study, solvent extraction has been performed to separate Mo from the synthetic leaching solution, formation of Inconel713C alloy similarly and is found the optimum conditions of recovery of Mo from the leaching solution. The effects of some variables, such as the nature and concentration of the extractants, $H_2SO_4$ concentrations, and the presence of impurities were investigated. The extraction percentage of Mo by Cyanex272 is 96% in the condition of pH 1 and 4% of concentration of Cyanex272 but Alamine336 is 99% in the condition of the range of pH 1 to 4 and 1 wt.% of concentration of Alamine336. In the case of Alamine336, the extraction percentage of Mo is increased by increasing of the concentration of Alamine336. The optimum condition of this experiment is pH 1 in aqueous phase, 1% concentration of Alamine336 and activation ratio of $H_2SO_4$ 1:0.5.

• Resources Recycling
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• v.30 no.6
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• pp.61-67
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• 2021

This work investigated the cementation of iridium from iridium-containing hydrochloric acid leachate. Zinc powder was used as the reducing agent, and the effects of the stoichiometric ratio of Zn/Ir, initial Ir concentration, initial pH, reaction time, and ultrasound irradiation on iridium recovery were investigated. When only the stirrer was used for cementation, the iridium recovery increased with the addition amount of zinc, and the recovery of about 70% at 40 times the stoichiometric ratio of Zn/Ir. In contrast, when employing ultrasonic irradiation with stirring, the recovery of iridium decreased at 20 times or less the stoichiometric amount of zinc. The recovery of iridium increased at 40 times the stoichiometric ratio of Zn/Ir. This result may be due to the ionization of zinc and re-dissolution of iridium during the ultrasound irradiation treatment. When a combination of ultrasonic irradiation and stirring was used for cementation, the iridium recovery increased by more than 27% compared to that when using only the stirrer. It was possible to recover 99% of iridium under the following conditions: reaction time, 60 min; initial pH, 0.01; volume of leachate, 100 mL; 1770 ppm Ir, 40 times the stoichiometric ratio of Zn/Ir.

• KSBB Journal
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• v.20 no.4
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• pp.317-322
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• 2005

Various recovery methods were investigated to maximize hemicellulose recovery from lignocellulosic material hydrolyzed by pure water. The pretreatment conditions of water hydrolysis were $170\~180^{\circ}C$ and 1 hour of reaction time. The percentage of hemicellulose solubilized increased as the temperature increased from 170 to $180^{\circ}C$. However, significant decomposition of sugar was observed at temperature of $180^{\circ}C$. From the results of water hydrolysis, the total amount of glucan in solid residue and liquid hydrolyzate was close to the total glucan in the original biomass. For hemicellulose, however, there was a significant difference between both contents. To prove this difference, various recovery methods were proposed. From the total sugar accountability (sugar in liquid + sugar in solid), it was confirmed that hemicellulose recovery in the hydrolyzate was increased if the product including both hydrolyzate and solid residue was physically stimulated by such as heating and ultrasound irradiation. This indicated that, in commercial scale processes that much bigger substrate sizes are used and a sufficient amount of leaching solvent can not be used after pretreatment, a significant amount of oligomers could be trapped in the solid matrix.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.64-68
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• 2000

The immunopotentiating effects of the polysaccharides, both intracellular and extracellular, was examined by an animal feeding test. The results are summarized as follows. The oral administration of intracellular and extracellular polysaccharides of Agrocybe cylindracea for 10 days resulted in the enhanced phagocytic activity of peritoneal exudate cells(PEC), spleen cells(SC), and monolymphocytes(ML). In the experiment of PFC(plaque forming cell) and RFC(rosette forming cell), the results showed that all the polysaccharide fractions enhanced the immune related cells. The EAC II group(the extracellular polysaccharide of Agrocybe cylindracea 10 mg/0.2 ml distilled water/day/ mouse) increased the PFC and RFC by 46~50% and 43%, respectively, compared to the control group. On the other hand, the IAC I group(the intracellular polysaccharide of Agrocybe cylindracea 1 mg/0.2 ml distilled water/day/mouse) increased the PFC and RFC by 49~70% and 91%, respectively. In terms of the mitogenic activity, the extracellular polysaccharides of A. cylindracea showed a higher activity than the intracellular polysaccharides.