• Title, Summary, Keyword: chemical composition

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Study on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

  • Qian, Yi-Hua;Huang, Yi-Bin;Fu, Qiang;Zhong, Zhen-Sheng
    • Journal of Electrical Engineering and Technology
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    • v.8 no.3
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    • pp.588-594
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    • 2013
  • Under the condition of Baader aging, the chemical composition variation and the influence of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as interfacial tension were studied in the aging precess. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were also investigated. The results show that these parameters of physic-chemical and electrical properties of hydrogenated transformer oil relate to each other and have closed correlation with chemical composition.

Relationship between Classification of Sa-Sang Constitutional Medicine and Chemical Composition of Samgye-Tang Ingredients and Other Food (삼계탕 재료 및 각종 식품의 사상의학적 분류와 화학조성과의 상관관계)

  • 유익종;전기홍;박우문;조혜연;최성유
    • Food Science of Animal Resources
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    • v.21 no.2
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    • pp.97-102
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    • 2001
  • The characteristic fitness of food to each Sa-sang constitution and the relationship between Han-Yeoul characteristics and chemical composition after classifying Samgye-tang ingredients and other food into Ohn-Yeoul-Ryang-Han characteristic were assessed. When the suitable constitution to the each characteristic was investigated after classifying Samgye-tang ingredients and other food into Han, Ryang, Pyound, Ohn and Yeoul of which fitness case for Soeumin was 44∼63% but fitness case for Soyangin and Taeyangin was only 0∼18%. When the relationship between Samgye-tang ingredients and other food classified into Ohn-Yeoul-Ryang-Han and chemical composition of fatty acid, amino acid, vitamin and mineral was investigated, the value of correlation coefficient was extremely low. There was not the relationship between chemical composition and Han-Yeoul classification. Therefore it should be further investigated the relationship between characteristic and chemical composition by additional analysis index.

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The Chemical COmposition Analysis by AES and XPS of PbTiO$_3$ Thin Films Fabricated by CVD (화학증착법에 의해 제조된 PbTiO$_3$ 박막의 AES와 XPS에 의한 조성분석)

  • Soon Gil Yoon;Ho Gi Kim
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.83-86
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    • 1989
  • Lead titanate thin films with a perovskite structure were successfully structure were successfully fabricated on titanium substrate by Chemical Vapour Deposition(CVD). Analyses of Auger Electron Spectroscopy(AES) and X-ray Photoelectron Spectroscopy (XPS) have been performed in order to find a chemical composition of lead titanate films. The analysis of chemical composition by AES and XPS was investigated for variations of deposition temperature and Ti(C$_2$H$_{5}$O)$_4$ fractions. The chemical composition of PbTiO$_3$by XPS analysis was almost constant regardless of deposition parameters and the comparison of chemical composition by AES and XPS was performed.d.

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Essential Oil of Marrubium vulgare: Chemical Composition and Biological Activities. A Review

  • Yabrir, Benalia
    • Natural Product Sciences
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    • v.25 no.2
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    • pp.81-91
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    • 2019
  • Marrubium vulgare, plant species belonging to Marrubium genus, is widespread in the Mediterranean areas, introduced elsewhere and also cultivated in many countries. Its oil is recognized to possess a considerable biological activities with varied chemical composition. This paper aims to overview the chemical composition and biological activities of M. vulgare essential oil's considered as a medicinal plant, widely used in folk medicine overall the world. In essential oils of M. vulgare, germacrene D, ${\beta}$-caryophyllene, ${\beta}$-bisabolene, bicyclogermacrene and carvacrol are generally considered as either mains or minor constituents and each species presents its own composition. Sesquiterpenoids were the dominant fraction while monoterpenoids were present in appreciable or in trace amount. Oxygenated fractions dominated in monoterpenes however, hydrocarbon fraction overpowered in sesquiterpenes. These oils are biologically active, they exhibit an antioxidant and antimicrobial activities and other activities. Due to the variability of composition of essential oil, further studies are necessary, particularly regarding their chemical's which may cause an important change in the biological activities of oils and probably defined different chemotype.

Influence of Drought Stress on Chemical Composition of Sesame Seed

  • Kim, Kwan-Su;Ryu, Su-Noh;Chung, Hae-Gon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.1
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    • pp.73-80
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    • 2006
  • Sesame (Sesamum indicum L.) seeds contain abundant oil and antioxidative lignans related to the seed quality. To evaluate the potential effects of drought stress on the chemical composition of sesame seeds, eighteen cultivars were imposed water-deficit condition by withholding irrigation during 15 days at podding and maturing stage, compared with well-watered plants as control in seed yield and chemical composition. Drought treatments showed great decrease of seed yield with not affecting seed weight. The contents of sesamin and sesamolin decreased while lignan glycosides inversely increased in response to drought stress. Oil content was not significantly changed by drought treatment in spite of its slight decrease. In case of fatty acid composition, there were significant differences in increase of oleic acid while inverse decrease of linoleic acid under drought stress condition. These results demonstrate that the chemical composition of sesame seed may be modified with drought stress. In particular, the increase of sesaminol glucosides with strong antioxidative activity was observed.

Influence of Electrolyte Composition on Electrochemical Performance of Li-S Cells

  • Kim, Tae Jeong;Jeong, Bo Ock;Koh, Jeong Yoon;Kim, Seok;Jung, Yongju
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1299-1304
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    • 2014
  • The electrochemical performance of Li-S cells was investigated in various ternary electrolyte solutions composed of 1,2-dimethoxyethane (DME), tetra(ethylene glycol) dimethyl ether (TGM), and 1,3-dioxolane (DOX). The discharge capacity values and cycle data obtained at each composition were statistically treated with the Minitab program to obtain mixture contour plots, from which the optimal composition of the ternary solvent systems was predicted. The discharge capacities and capacity retention were quite dependent on the electrolyte composition. It was estimated from the contour plots of the capacity at 1.0 C that the discharge capacity sharply increased with a decrease in the TGM content. High capacities greater than 900 mAh/g at 1.0 C were expected for the electrolyte composition with a volume ratio of DME/TGM/DOX = 1/0/1. In contrast, it was predicted from the mixture contour plot of the capacity retention that the cycle performance would significantly increase with an increase in the DME content.

Skin permeability of compounds loaded within dissolving microneedles dependent on composition of sodium hyaluronate and carboxymethyl cellulose

  • Park, Youbin;Kim, Bumsang
    • The Korean Journal of Chemical Engineering
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    • v.34 no.1
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    • pp.133-138
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    • 2017
  • Dissolving microneedles are transdermal delivery systems designed to mechanically penetrate the skin and fully dissolve in the skin in a minimally invasive manner. In this study, the skin permeability of compounds encapsulated in microneedles was controlled by changing the composition of microneedle materials. Sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) were chosen as structural materials and amylopectin was used to increase the mechanical strength of microneedles. To determine the effect of microneedle composition on skin permeability, microneedle properties such as mechanical strength and solubility were investigated according to various compositions of SH and CMC. When the CMC fraction in the needle increased, the mechanical strength of the microneedle increased, leading to high skin permeability of rhodamine B, a model compound. Using microneedles, significantly higher skin permeability of niacinamide was also obtained. These results indicate that the microneedles developed in this study improved the skin permeability of compounds loaded in the needle, and the skin permeability could be tuned by changing the composition of microneedle materials.

Chemical Characterization of Industrial Hemp (Cannabis sativa) Biomass as Biorefinery Feedstock

  • Shin, Soo-Jeong;Han, Gyu-Seong;Choi, In-Gyu;Han, Sim-Hee
    • Korean Journal of Plant Resources
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    • v.21 no.3
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    • pp.222-225
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    • 2008
  • Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.

Chemical Composition of Archaeological Woods Submerged in the Seawater (수침고목재(水浸古木材)의 화학조성(化學組成))

  • Kim, Yoon-Soo;Bang, Joo-Wan;Kim, Ik-Joo;Choi, Kwang-Nam
    • Journal of the Korean Wood Science and Technology
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    • v.18 no.2
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    • pp.3-7
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    • 1990
  • The chemical Composition of Chinese red pine (Pinus massoniana) submerged in the Yellow Sea for more than 700 years has been examined. When compared to the recent wood, the marked chemical changes in the waterlogged wood is the higher amount of lignin with lesser amount of holocellulose and abnormally high ash content. In the heavily degraded samples, the degradation of cellulose is more severe than that of hemicellulose. However, hemicellulose is much more attacked than the cellulose at the initial stage of deterioration in the sea water. Chemical analysis suggests that the cellulolytic marine microorganisms, whether they are fungi or bacteria. can be regarded as the primary agents for the destruction of the archaeological woods submerged in the sea water.

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Effect of Chemical Composition on the Latent Hydraulic Activity of Blast Furnace Slag (고로슬래그의 잠재수경성에 미치는 화학조성의 영향)

  • 장복기;임용무
    • Journal of the Korean Ceramic Society
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    • v.37 no.5
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    • pp.453-458
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    • 2000
  • Glasses showing the composition of blast furnace slag were made in the laboratory, and the effect of the chemical composition on the latent hydraulic activity of the slags was examined. The latent hydraulicity was greatly influenced by the composition change, the optimal characteristic of the hydraulicity was achieved at the slag composition of 47CaO:20Al2O3:33SiO2. The content of CaO and Al2O3 were not equivalent to the hydraulic activity of the slags as the b-formula (KS L 5210) indicates. Good latent hydraulicity was shown when Al2O3 was richly contained at the high (CaO+Al2O3):SiO ratio, while the more the MgO content was, the more negative the result turned out.

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