• Title/Summary/Keyword: Physicochemical characterization

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Silk Fibroin Microsphere and Its Characterization

  • Yeo Ju-Hong;Lee Gwang-Gil;Lee Yong-U;Gwon Hae-Yong;U Sun-Ok
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 2003.04a
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    • pp.56-56
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    • 2003
  • Using gel filtration chromatography (GFC), pure separation of high molecular silk fibroin was obtained and silk fibroin microsphere particles (SFMP) could be simply made by spray dryer method. Also, some of its physicochemical properties and morphology were investigated. The average molecular weight (Mw) of pure silk fibroin protein dissolved in calcium chloride is about 61, 500 g/mol as measured by gel permeation chromatography(GPC). (omitted)

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Preparation and Characterization of Poly(vinyl alcohol)/ Sodium Alginate Blend (Poly(vinyl alcohol)/ Sodium Alginate 블렌드의 제조 및 특성)

  • Koo, Won-Mi;Jung, Du-Kam;Lee, Young-Hee;Kim, Han-Do
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.25-28
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    • 2001
  • Polymer blending constitutes a most useful method for the improvement or modification of the physicochemical properties of polymeric materials. Some of the polymer blends exhibit unusual properties, unexpected from homopolymers. An important property of a polymer blend is the miscibility of its component, because it affects the mechanical properties, the morphology, its permeability and degradation [1, 2]. (omitted)

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Phenolic Compounds from the Leaves of Rubus coreanum (복분자 딸기 잎의 페놀성 물질)

  • 이민원
    • YAKHAK HOEJI
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    • v.39 no.2
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    • pp.200-204
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    • 1995
  • Chemical examination of the leaves of Rubus coreanum has led to the isolation and characterization of six phenolic compounds. The structures of these compounds were elucidated as kaempferol(l), quercetin(2), sodium salt of quercetin 3-O-$\beta$-D-glucuronide(3), sodium carboxylate of quercetin 3-O-$\beta$-D-glucuronide(4), ellagic acid(5) and sanguiin H-5(6) on the basis of physicochemical and spectroscopic evidences.

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NMR Studies on Transient Protein Complexes: Perspectives

  • Suh, Jeong-Yong;Yu, Tae-Kyung;Yun, Young-Joo;Lee, Ko On
    • Journal of the Korean Magnetic Resonance Society
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    • v.18 no.1
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    • pp.1-4
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    • 2014
  • It is generally understood that protein-protein interactions proceed via transient encounter complexes that rapidly evolve into the functional stereospecific complex. Direct detection and characterization of the encounter complexes, however, been difficult due to their low population and short lifetimes. Recent application of NMR paramagnetic relaxation enhancement first visualized the structures of the encounter complex ensemble, and allowed the characterization of their physicochemical properties. Further, rational protein mutations that perturbed the encounter complex formation provided a clue to the target search pathway during protein-protein association. Understanding the structure and dynamics of encounter complexes will provide useful information on the mechanism of protein association.

A preparation plan proposal of nuclear power plant decommissioning radioactive waste characterization report (원자력발전소 해체 방사성폐기물 특성보고서 작성 방안 제안)

  • Kim, Chang Lak;Lee, Sun Kee;Kim, Heon;Park, Hae Soo;Sung, Suk Hyun;Kong, Chang Sig
    • Journal of the Korean Society of Systems Engineering
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    • v.17 no.1
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    • pp.76-84
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    • 2021
  • Radioactive waste generated from nuclear power plant decommissioning shall be strictly managed so that radioactive materials above the allowable limit are not leaked into the environment. Radioactive wastes shall be classified and treated for management based on characteristics such as the type of waste, physicochemical properties, nuclide concentration and radioactivity. Waste characterization report shall be prepared and submitted to the disposal facility operator to ensure that the treated waste is suitable for disposal. The disposal facility operator shall review the waste Characterization report and visit the nuclear power plant decommissioning site to ensure that the wastes are processed step by step according to the plan. The waste Characterization report may be used as input data to evaluate disposal facility safety. Domestic and foreign data are collected and reviewed to confirm the entire processes from waste generation to delivery. This paper proposes the method to prepare the waste Characterization report which contains data and information on waste characteristics, treatment facilities & method and packaging method & container.

Characterization of Individual Atmospheric Aerosols Using Quantitative Energy Dispersive-Electron Probe X-ray Microanalysis: A Review

  • Kim, Hye-Kyeong;Ro, Chul-Un
    • Asian Journal of Atmospheric Environment
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    • v.4 no.3
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    • pp.115-140
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    • 2010
  • Great concerns about atmospheric aerosols are attributed to their multiple roles to atmospheric processes. For example, atmospheric aerosols influence global climate, directly by scattering or absorbing solar radiations and indirectly by serving as cloud condensation nuclei. They also have a significant impact on human health and visibility. Many of these effects depend on the size and composition of atmospheric aerosols, and thus detailed information on the physicochemical properties and the distribution of airborne particles is critical to accurately predict their impact on the Earth's climate as well as human health. A single particle analysis technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA) that can determine the concentration of low-Z elements such as carbon, nitrogen and oxygen in a microscopic volume has been developed. The capability of quantitative analysis of low-Z elements in individual particle allows the characterization of especially important atmospheric particles such as sulfates, nitrates, ammonium, and carbonaceous particles. Furthermore, the diversity and the complicated heterogeneity of atmospheric particles in chemical compositions can be investigated in detail. In this review, the development and methodology of low-Z particle EPMA for the analysis of atmospheric aerosols are introduced. Also, its typical applications for the characterization of various atmospheric particles, i.e., on the chemical compositions, morphologies, the size segregated distributions, and the origins of Asian dust, urban aerosols, indoor aerosols in underground subway station, and Arctic aerosols, are illustrated.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

  • Wang, Xiaoxiao;Guo, Shaoqing;Zhao, Liangfu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3829-3834
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    • 2013
  • $H{\beta}$ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of $H{\beta}$ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of $H{\beta}$ and SAPO-11. The physicochemical properties of $H{\beta}$, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that $H{\beta}$/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the $H{\beta}$ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of $H{\beta}$ and SAPO-11. The composite had fewer acid sites than $H{\beta}$ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Physicochemical and Sensory Characterization of Korean Blood Sausage with Added Rice Bran Fiber

  • Choi, Yun-Sang;Choi, Ji-Hun;Han, Doo-Jeong;Kim, Hack-Youn;Lee, Mi-Ai;Kim, Hyun-Wook;Lee, Chi-Ho;Paik, Hyun-Dong;Kim, Cheon-Jei
    • Food Science of Animal Resources
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    • v.29 no.2
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    • pp.260-268
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    • 2009
  • This study was conducted to determine the effects of added rice bran fiber on the physicochemical and sensory characterization of blood sausage. Blood sausages were supplemented with rice bran fiber at levels of 0% (control), 1%, 2%, and 3%. The moisture, hardness, gumminess, and chewiness of treatments with added rice bran fiber were higher than those of controls (p<0.05). The pH, lightness, redness, and yellowness of uncooked as well as cooked blood sausages increased with increasing addition levels of rice bran fiber levels, but energy values were lower in blood sausage treatments with containing rice bran fiber than that of controls (p<0.05). As the increase levels of rice bran fiber in blood sausage the energy levels were decreased (p<0.05). All sensory scores of treatments containing rice bran fiber were higher than controls, and the highest overall acceptability was attained when 2% rice bran fiber was added to blood sausage. The blood sausage with 2% rice bran fiber can be manufactured with high quality characteristics.

Characterization of Itraconazole Semisolid Dosage Forms Prepared by Hot Melt Technique

  • Shim, Sang-Young;Ji, Chang-Won;Sah, Hong-Kee;Park, Eun-Seok;Lee, Beom-Jin
    • Archives of Pharmacal Research
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    • v.29 no.11
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    • pp.1055-1060
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    • 2006
  • The objective of this study was to formulate itraconazole semisolid dosage forms and characterize their physicochemical properties. Itraconazole and excipients such as polysorbate 80, fatty acids, fatty alcohols, oils and organic acids were melted at $160^{\circ}C$. The fused solution was then cooled immediately at $-10^{\circ}C$ to make wax-like semisolid preparations. Their physicochemical attributes were first characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometry. The solubility of itraconazole in semisolid preparations and their dispersability in the simulated gastric fluid were also determined. Our semisolid preparations did not show any distinct endothermic peak of a crystalline form of itraconazole around $160-163^{\circ}C$. This suggested that it was changed into amorphous one, when it was formulated into semisolid preparations. In addition, the distinctive functional peaks and chemical shifts of itraconazole were well retained after processing into semisolid preparations. It could be inferred from the data that itraconazole was stable during incorporation into semisolid preparations by the hot melt technique. In particular, itraconazole semisolid preparations composed of polysorbate 80, fatty acids and organic acids showed good solubility and dissolution when dispersed in an aqueous medium. It was anticipated that the semisolid dosage forms would be industrially applicable to improving the bioavailability of poorly water-soluble drugs.