• Analytical Science and Technology
• /
• v.30 no.4
• /
• pp.205-212
• /
• 2017

Rice endosperm, the portion that remains after milling, is the part of the rice seed that is primarily consumed as a source of nutrients. There have been many studies on polysaccharides, such as hemicellulose, cellulose, and pectins, derived from the cell walls of various plant groups. It has been reported that the acidic polysaccharide fractions, which contain water-soluble pectins that have been shown to have pharmacological effects in vivo and in vitro, have common chemical structures that include galacturonic acid polymers, rhamnose, arabinose, and galactose. However, few studies have been conducted on the acidic polysaccharides contained in the endosperm of rice. In this study, we quantitatively compared the differences in the acidic polysaccharide contents from samples from two of the main varieties of rice consumed as staple foods, japonica and indica, using a colorimetric method. Rice samples were collected from 39 different regions in Korea, China, Thailand and Vietnam. Acidic polysaccharide fractions were obtained by precipitation of the alcohol-insoluble residue (AIR) and enzyme treatment of each sample. The total amount of carbohydrates and uronic acid in each acidic polysaccharide fraction were measured using the phenol-sulfuric acid method and the carbazole-sulfuric acid method, respectively. The differences in the total polysaccharide contents in the acidic polysaccharide fractions were not statistically significant (p = 0.07), but the uronic acid contents were significantly different between the two groups (p = 0.04).

• Korean Journal of Pharmacognosy
• /
• v.50 no.4
• /
• pp.305-311
• /
• 2019

The purpose of this study was to examine the changes in seasonal bioactive components of 4 and 6 years old fresh ginseng (Panax ginseng) and to provide basic information on the development of functional food using fresh ginseng. Seasonal changes were investigated by ginseng saponin analysis using HPLC method and acidic polysaccharides by carbazole sulfuric acid method. Total saponins showed the highest content of fresh ginseng collected in May, followed by March, July, and September. Fresh ginseng collected in May showed 2.5 times (4 years old) - 3.0 times (6 years old) higher than fresh ginseng collected in September. Acidic polysaccharides showed high content of fresh ginseng collected in March and September, and low content of fresh ginseng collected in May and July. From these results, the fresh ginseng collected in May can develop high concentrations of saponin. On the other hand, fresh ginseng collected in March and September is thought to be able to develop high concentration products of acidic polysaccharides.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.453-457
• /
• 1997

Sugars in Korean and Japanese pumpkin were studied. The sugars in pumpkin were crushed and extracted by boiling for 30 min. Korean pumpkin was found to contain 0.41% of sucrose, 0.54% of fructose, 0.61% of glucose and 0.68% of starch. Japanese pumpkin was found to contain 2.60% of sucrose, 2.76% of fructose, 1.91% of glucose and 1.22% of starch. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. Starch in Japanese pumpkin showed only signal of $\alpha$-1,4-glucosidic linkage by proton NMR analysis, and showed 86% of absorbance by iodine reaction compared with amylose(DP 117). These results indicated that starch in Japanese pumpkin is composed by only amylose. Pectin contents of Korean and Japanese pumpkin sowed 6.29% and 2.67%, respectively, as galacturonic acid by carbazole analysis.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.480-484
• /
• 1997

Sugars in Korean ginseng(Panax ginseng C. A. Meyer) were studied by HPLC, TLC and NMR. The sugars in Korean ginseng were crushed and extracted by boiling for 30min. Korean ginseng was found to contain 3.77% of sucrose, 3.50% of maltose, 0.09% of fructose and 0.04% of glucose and 3.90% of starch. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. Starch in ginseng showed only signal of $\alpha$-1, 4-glucosidic linkage by proton NMR analysis, and showed 92% of absorbance by iodine reaction compared with amylose(DP 117). These results indicated that starch in Korean ginseng is composed by only amylose. Pectin content in ginseng showed 0.22% as galcturonic acid by carbazole analysis.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2006.10a
• /
• pp.154-157
• /
• 2006

ITO(indium tin oxide)/glass 기판 위에 PEDOT:PSS[poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)]와 PVK[poly(N-vinyl carbazole)] 고분자 물질을 정공 주입 및 수송층으로, 발광층으로 PFO-poss[Poly(9,9-dioctylfluorenyl-2,7-diyl) end capped with POSS]를 사용하여 스핀코팅법과 열 증착법으로 ITO/PEDOT:PSS/PVK/PFO-poss/LiF/Al 구조의 고분자 발광 다이오드를 제작하였다. PFO-poss 유기발광 층의 열처리 조건 (온도, 시간)이 PLED 소자의 전기적, 광학적 특성에 미치는 영향을 조사하였다. 1 wt%의 농도를 갖는 PFO-poss 유기물 발광 층을 200C 온도로 3시간 열처리 할 경우 11 V 인가전압에서 $1497\;cd/m^2$의 최대 휘도를 나타내었다. 동일온도에서 열처리 시간을 1시간에서 3시간으로 증가시킬 경우 휘도의 증가와 함께 발광 개시온도가 감소하는 경향을 보여주었다. 또한 열처리 온도와 시간을 증가시킬 경우 제2발광피크인 excimer 피크가 크게 나타났으며 청색에서 황색 발광 쪽으로 천이되는 경향을 나타내었다.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.8 no.1
• /
• pp.46-50
• /
• 2008

The effect of physicochemical properties of solvents on the microstructure of polyvinyl carbazole (PVK) film for non-volatile polymer memory was investigated. For the solubilization of PVK molecules and the preparation of PVK films, four solvents with different physicochemical properties of the Hildebrand solubility parameter and vapor pressure were considered: chloroform, tetrahydrofuran (THF), 1,1,2,2-tetrachloroethane (TCE), and N,N-dimehtylformamide (DMF). The solubility of PVK molecules in the solvents was observed by ultravioletvisible spectroscopy. PVK molecules were observed to be more soluble in chloroform, with a low Hildebrand solubility parameter, than solvents with higher values. The aggregated size and micro-/nano-topographical properties of PVK films were characterized using optical and atomic force microscopes. The PVK film cast from chloroform exhibited enhanced surface roughness compared to that from TCE and DMF. It was also confirmed that the microstructure of PVK film has an effect on the performance of non-volatile polymer memory.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.471-471
• /
• 2012

유기발광소자는 낮은 동작전압, 낮은 전력소비와 높은 색 순도의 장점을 가지고 있어 차세대 디스플레이로 관심을 받고 있다. 시장을 주도하고 있다. 최근 스마트폰의 사용증가에 따른 저전력과 색 표현력에 대한 연구가 필요하며, 발광 효율과 색 순도를 증가하기 위하여 형광 또는 인광 발광 호스트 물질을 사용한 유기발광소자에 대한 연구가 진행되고 있다. 하지만 적색 및 녹색 유기발광소자보다 청색 유기발광소자는 상대적으로 발광 효율과 색순도가 낮기 때문에 청색 유기발광소자를 사용하여 전색 디스플레이를 구현하는데 문제점이 있다. 본 연구에서는 청색 유기발광소자의 색순도와 발광효율을 향상시키기 위하여 형광호스트물질과 인광호스트물질을 혼합하여 구성된 발광층을 가진 청색 유기발광소자에 대한 연구를 하였다. 1,3-bis(carbazole-9-yl)benzene (mCP)에 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN)을 다양한 혼합비율로 구성한 발광층을 가진 청색 유기발광소자를 제작하여 광학적 성질과 전기적 성질을 관찰하였다. 형광호스트물질과 인광호스트물질의 혼합된 발광층을 적용한 청색 유기발광소자에서 엑시톤의 에너지이동이 원활해지고, 안정된 전자와 정공의 균형으로 인해 동작전압이 감소하고 발광 효율이 증가한다. 위 연구 결과는 낮은 동작전압과 높은 발광효율 갖는 형광물질과 인광물질의 혼합된 발광층 구조를 사용한 청색 유기발광소자를 전색디스플레이에 응용할 경우에 저전압 고효율 전색 발광소자의 제작에 관한 연구에 기여한다.

• Transactions on Electrical and Electronic Materials
• /
• v.6 no.3
• /
• pp.101-105
• /
• 2005

Electroluminescence(EL) and current-voltage(I-V) characteristics of hybrid EL devices containing Pr and Mn co-doped ZnS nanoparticles were investigated in this study. For the insertion of a hole transport layer of poly (N-vinyl carbazole)(PVK), the current level became lower due to the accumulation of electrons at the interface between PVK and nanoparticles. When both PVK and buffer layer $BaF_2$ were simultaneously introduced, the enhanced EL efficiency and improved I-V characteristics were obtained. This results from the additional increase of hole injection owing to the internal field induced by the significant accumulation of electrons at the interface. The presence of buffer layer $BaF_2$ together with PVK makes it possible the charge accumulation enough to induce the sufficient internal field for further hole injection.

• Macromolecular Research
• /
• v.11 no.4
• /
• pp.250-255
• /
• 2003

We prepared the photorefractive sol-gel glass based on organic-inorganic hybrid materials containing a charge transporting molecule, second-order nonlinear optical (NLO) chromophore, photosensitizer, and plasticizer. Carbazole and 2-{ 4-[(2-hydroxy-ethyl)-methyl-amino]-benzylidene}-malononitrile were reacted with isocyanato-triethoxy silane and the functionalized silanes were employed to fabricate the efficient photorefractive media induding 2,4,7-trinitrot1uorenone (TNF) to form a charge transfer complex. The prepared sol-gel glass samples showed a large net gain coefficient and high diffraction efficiency at a certain composition. As the concentration of photosensitizer increased, the photorefractive properties were enhanced due to an increment of charge carrier density. Dynamic behavior of the diffraction efficiency was also investigated with the concentration of the photosensitizer.

• Korean Journal of Food Science and Technology
• /
• v.28 no.2
• /
• pp.389-392
• /
• 1996

Crude polysaccharide fractions were isolated from white ginseng and red ginseng (Panax ginseng). The amount of crude polysaccharide fraction in red ginseng was higher than that of white ginseng. The glucose contents of crude polysaccharide fraction isolated from white ginseng and red ginseng were determined as 95.1% and 89.9% by HPLC, respectively. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharide in white ginseng and red ginseng. The amount of acidic polysaccharide in red ginseng was higher than that of white ginseng. Whereas, contents of minerals (Cu, Zn, Fe, Mg) in crude polysaccharide fraction from white ginseng were higher than those of crude Polysaccharide fraction from red ginseng.