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Analysis of Contents and Deviations of Chemical Constituents of flue-cured leaf Tobacco from 1997 to 2001 Crop Years (연산별 황색종 가공엽의 화학성분 함량 및 편차 분석)

  • 김상범;정기택;조수헌;김용규
    • Journal of the Korean Society of Tobacco Science
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    • v.25 no.1
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    • pp.20-26
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    • 2003
  • To investigate the effects of reduction of leaf processing factories on the uniformity of processed leaf quality, the contents and their C.V.(Coefficient of Variation) of chemical constituents of flue-cured leaf tobacco produced from 1997 to 2001 and processed at various factories were analysed. The average leaf chemical contents of 12 grades for 5 years ranged as follows ; nicotine 2.00∼0.85%. total sugar 10.7∼16.9%, total nitrogen 2.36∼2.78%, crude ash 14.6∼15.6% and chlorine 0.50∼0.75%. The variations of chemical contents among crop years was higher in total sugar content while lower in crude ash content. The C.V. of chemical content in same grade leaves was higher in chlorine content while lower in total nitrogen and crude ash contents, and the ratio of C.V. among processing factories/C.V. in total population was higher in total sugar content while lower in crude ash content. When the leaves were processed at one factory, the deviations of chemical contents reduced considerably. Particularly, the decreasing effect of deviation was higher in total sugar content.

Synthesis and Properties of Exfoliated Poly(methyl methacrylate-co-acrylonitrile)/Clay Nanocomposites via Emulsion Polymerization

  • Mingzhe Xu;Park, Yeong-Suk;Wang, Ki-Hyun;Kim, Jong-Hyun;Chung, In-Jae
    • Macromolecular research
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    • v.11 no.6
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    • pp.410-417
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    • 2003
  • Poly(methyl methacrylate-co-acrylonitrile) [P(MMA-co-AN)]/Na-MMT nanocomposites were synthesized through emulsion polymerization with pristine Na-MMT. The nanocomposites were exfoliated up to 20 wt% content of pristine Na-MMT relative to the amount of MMA and AN, and exhibited enhanced storage moduli, E', relative to the neat copolymer. The exfoliated morphology of the nanocomposite was confirmed by XRD and TEM. 2-Acryla-mido-2-methyl-1-propane sulfonic acid (AMPS) widened the galleries between the clay layers before polymerization and facilitated the comonomers, penetration into the clay to create the exfoliated nanocomposites. The onset of the thermal decomposition of the nanocomposites shifted to a higher temperature as the clay content increased. By calculating areas of tan$\delta$ of the nanocomposites, we observed that the nanocomposites show more solid-like behavior as the clay content increases. The dynamic storage modulus and complex viscosity increased with clay content. The complex viscosity showed shear-thinning behavior as the clay content increased. The Young's moduli of the nano-composites are higher than that of the neat copolymer and they increase steadily as the silicate content increases, as a result of the exfoliated structure at high clay content.

Prediction of Chemical and Physical Properties by Climatic Factors in Flue-cured Tobacco (기상요인에 의한 황색종 잎담배의 이화학적 특성 예측)

  • Jeong, Kee-Taeg;Cho, Soo-Heon;Bock, Jin-Young;Lee, Joung-Ryoul
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.1
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    • pp.1-7
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    • 2007
  • This study was conducted in order to predict the chemical and physical properties by climatic factors during the growing season of flue-cured tobacco as soon as possible. The data of eight chemical and five physical properties were collected from "Analysis of physical and chemical properties on farm leaf tobacco" conducted at KT&G Central Research Institute from 1987 through 2006. Data of climatic factors from April to July in 10 districts were collected from Korea Meteorological Adminstration. Except for yellowness(b), all probabilities of linear regression equations between the climatic factors(X) and the average contents of twelve grades(whole plant) for chemical and physical properties(Y) were significant($P{\leq}0.05$). The predicable probabilities within ${\pm}20%$ range of difference were 100% in ether extract content, in nicotine content, and in filling value, 90% in total nitrogen content, and 70% in total sugar content. These results suggest that the regression equations may be useful to predict the average content of twelve grades for eight chemical and four physical properties by climatic factors during the growing season of flue-cured tobacco at the beginning of August.

Comparison of sodium content of workplace and homemade meals through chemical analysis and salinity measurements

  • Shin, Eun-Kyung;Lee, Yeon-Kyung
    • Nutrition Research and Practice
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    • v.8 no.5
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    • pp.558-563
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    • 2014
  • BACKGROUND/OBJECTIVES: Most Koreans consume nearly 70-80% of the total sodium through their dishes. The use of a salinometer to measure salinity is recommended to help individuals control their sodium intake. The purpose of this study was to compare sodium content through chemical analysis and salinity measurement in foods served by industry foodservice operations and homemade meals. MATERIALS/METHODS: Workplace and homemade meals consumed by employees in 15 cafeterias located in 8 districts in Daegu were collected and the sodium content was measured through chemical analysis and salinity measurements and then compared. The foods were categorized into 9 types of menus with 103 workplace meals and 337 homemade meals. RESULTS: Workplace meals did not differ significantly in terms of sodium content per 100 g of food but had higher sodium content via chemical analysis in roasted foods per portion. Homemade meals had higher broth salt content and higher salt content by chemical analysis per 100 g of roasted foods and hard-boiled foods. One-dish workplace meals had higher salinity (P < 0.05), while homemade broths and stews had higher sodium content (P < 0.05 and P < 0.01, respectively). The sodium content per 100 g of foods was higher in one-dish workplace meals (P < 0.05) and in homemade broths and stews (P < 0.01 and P < 0.05, respectively). CONCLUSIONS: The use of a salinometer may be recommended to estimate the sodium content in foods and control one's sodium intake within the daily intake target as a way to promote cooking bland foods at home. However, estimated and actual measured values may differ.

Preparation of Nanocapsules Containing Phase Change Materials by Miniemulsion Polymerization

  • Oh, Keun Jin;Kim, Dae-Su;Lee, Jae Heung;Choi, Kil-Yeong;Lee, Changjin
    • Journal of Adhesion and Interface
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    • v.4 no.1
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    • pp.35-42
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    • 2003
  • Polystyrene nanocapsules containing octadecane as a core material were prepared by miniemulsion polymerization. The morphology and size of the nanocapsules were measured with varying the surfactant concentration, content of initiator, core/shell ratio and content of comonomer. The morphologies of the prepared nanoparticles were examined by a scanning electron microscope, a transmission electron microscope and the core material was confirmed by a differential scanning calorimeter. The particles below 70 nm in diameter were formed at a high surfactant concentration. The size of the nanoparticles was not significantly affected by the initiator content. With increasing the core/shell ratio and polar comonomer content, the particle size and its distribution were increased.

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A New Chromogenic Water Sensing System Utilizing Deprotonation and Protonation of Anion Receptor

  • Kim, Young-Hee;Han, Yeon-Kun;Kang, Jong-Min
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4244-4246
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    • 2011
  • A simple chromogenic system based on 1-fluoride was developed to determine water content in organic solvent. This system utilized deprotonation and protonation of the anion receptor 1. The water content evaluated from this system gave close value to the real water content in the range of 0 to 0.35% in acetonitrile and 0.2 to 0.5% in DMSO. Therefore, protonation and deprotonation phenomenon from the anion receptor by basic anion could be promising method for water sensing system.

Analysis of Chemical Compositions and Energy Contents of Different Parts of Yellow Poplar for Development of Bioenergy Technology

  • Myeong, Soo-Jeong;Han, Sim-Hee;Shin, Soo-Jeong
    • Journal of Korean Society of Forest Science
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    • v.99 no.5
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    • pp.706-710
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    • 2010
  • Understanding of chemical composition and energy contents in tree is important to develope strategies of renewable energy policy to cope with climate change. Residual biomass as renewable energy source was evaluated and focused on the bark-containing branches. Chemical analysis studies were conducted for different part of yellow poplar (Liriodendron tulipifera), which were partitioned to inner bark, outer bark, small branches, medium branches, big branches and trunk. The variations in hydrophobic extractives, hydrophilic extractives, lignin, carbohydrate compositions, energy contents (higher heating value) and the ash content were determined. The inner and outer bark had higher ash content, hydrophobic and hydrophilic extractives content, and higher energy content than those of tree trunk. Polysaccharides content in inner and outer bark was quite lower than those of stem or branches. Based on the energy content of residual biomass, replacement of fossil fuel and greenhouse gas emission abatement were calculated.

Development of Highly Conductive and Corrosion-Resistant Cr-Diamond-like Carbon Films

  • Ko, Minjung;Jun, Yee Sle;Lee, Na Rae;Kang, Suhee;Moon, Kyoung Il;Lee, Caroline Sunyong
    • Journal of the Korean Ceramic Society
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    • v.56 no.3
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    • pp.317-324
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    • 2019
  • Cr-diamond-like carbon (Cr-DLC) films were deposited using a hybrid method involving both physical vapor deposition and plasma-enhanced chemical vapor deposition. DLC sputtering was carried out using argon and acetylene gases. With an increase in the DC power, the Cr content increased from 14.7 to 29.7 at%. The Cr-C bond appeared when the Cr content was 17.6 at% or more. At a Cr content of 17.6 at%, the films showed an electrical conductivity of > 363 S/cm. The current density was 9.12 × 10-2 ㎂/㎠, and the corrosion potential was 0.240 V. Therefore, a Cr content of 17.6 at% was found to be optimum for the deposition of the Cr-DLC thin films. The Cr-DLC thin films developed in this study showed high conductivity and corrosion resistance, and hence, are suitable for applications in separators.

The Effect of Comonomer Type and Content on the Properties of Ziegler-Natta Bimodal High-Density Polyethylene (공단량체의 종류 및 조성이 지글러-나타 중합된 이중 분자량 분포 고밀도 폴리에틸렌의 물성에 미치는 영향)

  • Meng, Weijuan;Li, Hongbo;Li, Jianwei;Chen, Biaohua
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.673-679
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    • 2011
  • Bimodal high-density polyethylenes with different comonomer type and content were synthesized by polymerization of ethylene using Ziegler-Natta catalyst. Their structure and properties were studied using GPC, NMR, DSC and tensile test. It was found that ethylene/1-hexene copolymer exhibits higher tensile strength and elongation at break than that of ethylene/1-butylene copolymer with similar comonomer content. The molecular weight decreases as the comonomer content of the polymer increases. Short chain branching affects the crystallinity and thus the morphology and consequently the mechanical properties of the corresponding bimodal high-density polyethylenes. After SSA treated, the multiple endothermic peaks were observed. Multiple endothermic peaks are mainly attributed to the heterogeneity of ethylene sequence length and lamellar thickness. The difference of broadness index indicates that SCB distribution of polyethylene containing higher comonomer content has improved uniformity.

Effect of Locations, Production Year and Leaf Position on Physical and Chemical Characteristics of Tobacco Leaves. (지역, 년도 및 엽분에 따른 잎담배 이화학성 차이)

  • 안동명;민영근;이경구;이완남
    • Journal of the Korean Society of Tobacco Science
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    • v.13 no.1
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    • pp.74-81
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    • 1991
  • This study was conducted to find out physical and chemical characteristics of burley and flue-cured tobacco leaves followed by location, growing season and leaf position during the period 1985 to 1989. The locations of flue-cured tobacco were 7(65farms) and burley tobacco were 4(40 farms). 1. Flue-cured tobacco leaves The locations of Ch'unch'on and Suwon were higher nicotine and ether extract content, Taegu and Chinju were higher total nitrogen content but Chiniju was lower red color of cured leaves than that of other location. Nicotine content increased but total sugar content decreased during the period 1985 to 1989. Nicotine and total nitrogen content increased but crude ash decreased from lower leaf position to higher leaf position. Total sugar and ether extract content were variable followed by leaf position. 2. Burley tobacco leaves. The location of Ch'onju was higher ether extract content than that of others location, but there was no significant difference the others chemical component among location. Nicotine content and red color of cured leaves increased during the period 1985 to 1989. Nicotine, total nitrogen and ether extract content increased but decreased crude ash content and brightness of cured leaf from lower leaf position to higher leaf position.

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