• Journal of the Korean Society of Tobacco Science
• /
• v.29 no.1
• /
• pp.14-22
• /
• 2007

This study was conducted to investigate the effect of the total sugar contents on chemical, smoke and sensory properties and to estimate the desirable chemical composition contents from sensory properties in flue-cured leaf tobacco. The leaves used in the study were in 2005 and in $1997{\sim}2006$ crop year. Nicotine and total nitrogen contents, filling value, impact, irritation and bitterness were reduced with increasing the total sugar contents of B2O(leaf) and C2L(cutters), whereas tar and CO contents and puff number were increased. The desirable sugar contents estimated from the best overall tobacco taste of smoke were 25.9% in B2O and 26.9% in C2L. All of regression equations among total sugar/nicotine ratio, total sugar, nicotine and total nitrogen contents were significant($p{\leqq}0.05$). There were no significant difference between the 4 grade(A2O, B2O, C2L, D2L) average and the whole plant(12 grade) average contents in total sugar, nicotine and total nitrogen contents. All of regression equations between the ratio of each grade content to the average content of twelve grades and stalk position[number ; from bottom(1) to top(12)] in total sugar, nicotine and total nitrogen contents were significant($p{\leqq}0.05$). The estimated desirable chemical properties which based on the best overall tobacco taste were 23.2% of total sugar, 2.39% of nicotine, 9.7 of total sugar/nicotine ratio, 2.57% of total nitrogen, 1.08 of total nitrogen/nicotine ratio in average of four grades. With decrease the total sugar content from 32.0% to 24.0%, filling value was enhanced by 14.1% in average of B2O and C2L, also tar and CO contents of smoke were decreased by 13.2% and 10.5%, respectively. These results suggest that the estimated desirable chemical composition contents may be useful to produce good leaf tobacco, and to enhance filling value and to reduce tar and CO contents of smoke in flue-cured leaf tobacco.

• Journal of the Korean Society of Tobacco Science
• /
• v.18 no.1
• /
• pp.49-53
• /
• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.14 no.4
• /
• pp.295-306
• /
• 1994

The object of this experiment was to suggest the suitable cutting frequency and cutting height for orchardgrass (0G)-red clover(RC) mixtures under the intensive system of short-term pasture utilization. The fields trials were conducted over 3-year period(1991-1993) to evaluate dry matter yield, botanical composition, chemical composition and CP, DDM yield on the cutting frequency (30, 40 and 50 days) and cutting height(5, 7 and 9cm) With decreasing the cutting frequency, the DM yield of OG in the OG-RC mixtures was significantly increased(P

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.3
• /
• pp.368-373
• /
• 2003

This experiment was conducted to examine the effects on the composition and rumen degradation in sacco of rice straw treated with animal urine (1 l of 2.9 g N/kg DM straw) and urea plus calcium hydroxide (2% urea plus 0.5% $Ca(OH)_2$/kg DM straw) as a cheap and relatively safe alternative for ammonia (3% ammonia solution/kg DM straw). Mold occurred in urine treated straw, but other treatments were apparently mold-free. All treatments significantly (p<0.05) increased CP content in the straw compared with untreated one. Ammonia-treated straw contained CP at about twice that in urine or urea-calcium hydroxide treated straw. NDF and hemicellulose contents decreased significantly (p<0.05) in all treatments, while ADF and cellulose showed no differences compared with untreated straw. The degradable fraction of DM, CP, NDF, hemicellulose and cellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments than for urine treated or untreated straw except for CP of urine treated straw. Chemical treatment of rice straw increased the readily degradable fraction of CP, while it decreased the slowly degradable fraction for urine or urea-calcium hydroxide treated rice straw. The degradation rate of hemicellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments compared to urine treated or untreated straw. However, no effect on cellulose degradation rate was found by any of the treatments. There was no improvement in the degradation kinetics caused by the urine treatment despite the improvement of the chemical composition. Although the improvement in rumen degradability was less in the urea-calcium hydroxide treatment than in the ammonia treatment, its use may be more desirable because it is less expensive to obtain, less hazardous nature, and readily available. For further improvement it is necessary to investigate the supplementation of slowly degradable nitrogen to ureacalcium hydroxide treated rice straw diet.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.61 no.4
• /
• pp.225-227
• /
• 2012

This paper presents a chemical etching system for groove manufacturing for the fluid and aero dynamic bearings. To manufacture the grooves to thrust and journal surface of the fluid and aero dynamic bearing, it is very important for grooves' depth to be smaller tolerance. It is very difficult for the internal surface of journal bearing to make the grooves precise. If the precision of the groove is not exact, we can not get the desirable performance for the target of the dynamic bearing. To make the groove of bearing precise, we propose the method of chemical etching system. It has known that the method of chemical etching can not make the groove on the internal surface of journal bearing excepts for on the surface of thrust bearing. However, this paper has shown the solution to make the grooves on it. We obtain the condition and the parameters of the system such as time, chemical material composition and so on. In this paper, we get the experimental results to verify the precise groove manufacturing for the fluid and aero dynamic bearing.

• Journal of the Korean Society of Tobacco Science
• /
• v.8 no.1
• /
• pp.41-48
• /
• 1986

This experiment was carries out to study on the effect of temperature raising rate to chemical composition of tobacco leaves during the midrib drying stage of flue-curing. The results were as follows : In the case of the temperature raising rate became more rapidly during midrib drying stage. It had a tendency to increase in oxailic acid, succinlc acid, ammonia, polyphenol; there was a large loss of total sugar, reducing sugar, malic acid, palmitic acid and linolenic acid; leaf color became more reddish; the leaf quality index value decreased, thereby the quality of external appearance deteriorated. It is desirable that the temperature raising rate had to be more slowly.

• KSBB Journal
• /
• v.19 no.6 s.89
• /
• pp.421-426
• /
• 2004

The extraction and separation of isoflavones from Korean soybean were peformed by various mechanical and chemical extraction methods. They included solvent extraction, stirring, supersonification and sub/supercritical water extraction. From the experimental results of the variation of solvent extraction by change in composition, the increase in extraction of a specific compound by stirring or supersonic energy, and the application of supercritical fluid with superior solvating power over solvents, the sonification was the most desirable extraction method in extracting aglycone isoflavones, daidzein and genistein from Korean soybean.

• Applied Biological Chemistry
• /
• v.31 no.4
• /
• pp.387-393
• /
• 1988

Changes in chemical composition, viscosity and color during fermentation of improved Kochoojang from four starch sources (wheat, barley, rice and glutinous rice) were examined. Analyses included measurements of moisture, reducing sugars, amino nitrogen, pH, total acidity, viscosity, color and sensory panel scores for viscosity, color, odor and taste. Changes in chemical composition were similar for all Kochoojang products. Decrease in viscosity was greatest during the first 10 days of fermentation. Hunter tristimulus values decreased gradually during fermentation, and total color difference after 60 days was greatest for rice flour Kochoojang. Sensory evaluation showed that the viscosity of rice flour Kochoojang was less desirable than that of the others. However, no significant differences were found in color, odor and taste of all Kochoojang products. A high negative correlation was observed between Hunter a value and visual preference.

• Textile Coloration and Finishing
• /
• v.6 no.4
• /
• pp.1-8
• /
• 1994

To improve the antimicrobial activity and crease resistance of Korean traditional Hansan ramie fabrics, partially saponified polyethylene(PPS) was used as a softening water repellent agent and 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride(QAC) as a antimicrobial agent. The antimicrobial activity was effective by treatments of PPS, QAC and PPS/QAC for shake flask test. For the halo test, PPS/QAC showed good antimicrobial activity. It was found that the desirable composition of H$_{2}$O/PPS/QAC is 98/1/1 for improving the antimicrobial activity and crease resistance of the fabrics.

• Journal of the Korean Applied Science and Technology
• /
• v.6 no.1
• /
• pp.9-14
• /
• 1989

Effectiveness of some natural antioxidants were investigated by measuring the physico-chemical charcteristics and fatty acid composition during thermal oxidation in palm oil. Tocopherol showed most enhanced thermal oxidation stabilities compared to the other natural antioxidants. AR spice was no good AOM stability and changes of acid value but the other parameters were obtained desirable results. The changes of linoleic aicd content was slightly decreased during thermal oxidation. Addition of rosemary and glycyrriza extract increased the stabilities of oil less than tocopherol and AR spice. Order of antioxdative effects was tocopherol, AR spice and others. There was no significiant difference in stability of rosemary and glycyrriza extract.