• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.9
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.69-75
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• 2008

This study evaluated the physicochemical and sensory characteristics of vanilla ice cream treated with gamma irradiation. The general composition of the vanilla ice cream used for the study was 45.4-53.3% moisture, 5.5-5.9% fat and 3.9-4.1% protein, and these values did not change following gamma irradiation. The Hunter L, a and b values were slightly decreased following gamma irradiation. The fatty acid composition of the ice cream included caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid and stearic acid, and there was no detectable change following irradiation. There was no significant difference in TBARS (2-thiobarbituric acid reactive substances) values between non-irradiated and irradiated samples at a dose of 3 kGy or less (p<0.05). Sensory evaluation indicated that gamma-irradiated vanilla ice cream did not show any difference in color relative to non-irradiated ice cream. However, gamma irradiation did affect the flavor, taste and overall acceptability of ice cream at doses above 3 kGy. These results indicate that gamma irradiation at 3 kGy is an effective treatment for sustaining the physicochemical characteristics of vanilla ice cream with minimal changes in sensory characteristics, though further studies should be carried out to reduce the deterioration of sensory qualities induced by gamma irradiation.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.1-27
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• 1970

The process of the forced aging of flue-cured tobacco leaves were studied extensively from various scientific points of view. The Flue-cured tobacco leaves were inoculated and fermented with nicotine resistant Hansenula yeast, or the leaves were subjected under simple forced aging. The above two processes of forced aging were studied from the summarized points of microbiology, physics, chemistry, and biochemistry, and the resulted products ware compared in their physical, chemical and biochemical quality determining factors with that of raw material tobacco leaves (dried-tobacco leaves) and 2 years aged high quality tobacco leaves. The summary results were as follows. 1) The Korean flue-cured tobacco leaves, were forcedly aged under the basic optimum aging condition, temperature $40^{\circ}C$, moisture contents 18%, relative humidity 74%. It was found that this aging condition was the best in bringing the quality of forcedly aged tobacco leaves to the utmost state. 2) Under this optimum temperature and moisture condition of forced aging in about 20 days the forcedly aged tobacco leaves both with yeast inoculation and without yeast inoculation showed the equivalent tobacco qualities comparable with that of more than 2 years aged tobacco leaves. 3) The forcedly aged tobacco leaves both with and without yeast inoculation under $40^{\circ}C$ temperature and $74^{\circ}C$ relative humidity achieved the necessary quality determining physical and chemical changes in about 20 days. 4) The microbial changes during the forced aging were as follows. The population of yeasts and bacteria increased until to 15 days of aging, then decreased thereafter. Whereas the molds grew continously until the end of fermentation. 5) The tobacco quality determing physico-chemico-properties of yeast inoculated aged and simple forcedly aged tobacco leaves, progressed as the follows in time. As the forced aging progresses, swelling and combustibility properties were improved. The pH, total reducing materials, total sugars, alkaloids contents decreased. The contents of organic and ether extractable materials increased. The total nitrogen, protein, crude fiber, ash contents showed no changes. The color properties, excitation purity, luminance, main wave length, showed equivalent changes comparable with that of 2 years aged tobacco leaves. 6) The changes in chemical components in yeast treated and simple forcedly aged tobacco leaves during $15{\sim}20{\;}days$ of forced aging were as follows. The following chemical components decreased as the aging. Sugars-sucrose. rhamnose, glucose. Pigments-chlorophyll, carotenes, xanthophyll and violax anthine. Polyphenols-rutin, chlorogenic and, coffeic acid. Organic acids-iso-butylic, crotonic, caprylic, galacturonic, tartaric, succinic, citric acid. Alkaloids-nicotine, nornicotine. The following components increased as the forced aging progressed. Sugars-frutose, maltose, raffinose. Amino acids-proline, cystine. Organic acids-formic, acetic, propionic, n-butyric, iso-valeric, n-valeric, malic, oxalic, malonic, ${\alpha}-ketoglutaric$, fumaric, glutaric acid. 7) During the forced aging of tobacco Leaves the oxygen-uptake decreased gradually. The enzyme activities of polyphenol oxidase, ${\beta}-amylase$ ${\alpha}-amylase$ decreased gradually. The activities of the enzymes, catalase, and invertase increased once then decreased at the later stage.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.376-385
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• 2008

Twenty lactating crossbred cows yielding 10 to 15 litres of milk daily during mid lactation were selected and divided into four groups of five animals to assess the effect of feeding calcium soaps of palm oil fatty acids (bypass fat) on milk yield, milk composition and nutrient utilization in lactating crossbred cows. The animals in groups 1 (control), 2, 3 and 4 were fed concentrate mixture containing 0 (no bypass fat), 2, 4 and 6% bypass fat, respectively. The average daily dry matter consumption in the various groups ranged from 13.1 to 13.6 kg and showed no significant difference among treatment groups. There was no significant difference among different groups in digestibility of DM, OM, CP and CF, however, ether extract digestibility in cows of groups 2 and 4 was significantly (p<0.05) higher than the control group. The average milk yields of the cows in group 3 (4% bypass fat) showed a significantly (p<0.05) higher value than cows of groups 1 and 2. Similarly, a significant (p<0.05) increase in fat yield, 4% FCM yield and SNF yield was observed for the cows in group 3 (4% bypass fat). The milk composition in terms of total solids, fat, lactose, protein, solids-not-fat and ash percentage showed a varying response and bypass fat feeding did not have any effect on milk composition of cows in different groups. The gross and net energetic efficiency of milk production ranged from 23.6 to 27.5% and 37.1 to 44.4%, respectively, and showed no significant difference among different treatment groups. The gross and net efficiency of nitrogen utilization for milk production ranged from 24.0 to 28.7% and 37.2 to 43.5%, respectively, and no significant difference was noted among different treatment groups. The supplementation with calcium salts of palm oil fatty acid reduced the proportion of caproic, caprylic and capric acids and significantly (p<0.01) increased the concentration of palmitic, oleic, stearic, linoleic and linolenic acids in milk fat with increase in level of bypass fat supplementation. It was concluded that incorporation of calcium salts of palm oil fatty acids at a 4% level in the concentrate mixture of lactating crossbred cows improved the milk production and milk quality in terms of polyunsaturated fatty acids without affecting the digestibility of nutrients.