• 제목/요약/키워드: organic medium

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Biosynthesis of Organic Germanium Using Cordyceps militaris (동충하초를 이용한 유기게르마늄의 생산)

  • Kim, Seung;Kim, Jae-Sung;Sapkota, Kumar;Choi, Bong-Suk;Park, Se-Eun;Park, Yeal;Chun, Hong-Sung;Yoo, Jin-Cheol;Choi, Han-Seok;Kim, Myung-Kon;Kim, Sung-Jun
    • The Korean Journal of Mycology
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    • v.34 no.2
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    • pp.84-87
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    • 2006
  • In the present study, an attempt has been made to produce a high quality medicinal mushroom Cordycops militaris supplemented with organic Ge. Cordycops militaris was cultivated in SDAY liquid medium containing yeast extract 10 g, peptone 10 g, glucose 40 g per liter and chrysalis media supplemented with inorganic Ge at 100, 500, 1000, and 5000 ppm concentrations. The greatest organic Ge production of 442.4 ppm/g and 284 ppm/g were observed in SDAY liquid and Chrysalis media cultures supplemented with 100 ppm inorganic Ge respectively. Similarly, 4,509.7 ppm/g and 1,058 ppm/g of organic Ge were obtained from liquid and chrysalis media cultures supplemented with 5,000 ppm and 1,000 ppm inorganic Ge, respectively. In addition, higher concentration of organic Ge was obtained in mycelia than fruiting bodies. These results indicate that the concentration of organic Ge increase with decreasing inorganic Ge concentration in the medium. This is the first report on production of high valuable Cordyceps militaris contained with organic Ge.

Dispersion of Silicon Nitride Particles and Sintering Additives of AlN and Nd$_2$O$_3$ in Nonaqueous Suspending Media (비수계분산매체에서 질화규소와 소결첨가제 AlN 및 Nd$_2$O$_3$의 분산)

  • 김재원;백운규;윤경진
    • Journal of the Korean Ceramic Society
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    • v.36 no.2
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    • pp.210-219
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    • 1999
  • The fundamental dispersion property of Si2N4 and a combination of AlN and Nd2O3 as sintering additives in a variety of organic solvents such as alcohols, hydrocarbons, ketones, and ethers was investigated. The stabilization mechanism and interaction between organic functional groups of the various organic additives were studied to clarify the dispersibility of the ceramic particles in the nonaqueous suspending medium. characterization of the suspensions was based mainly on electrokinetic sonic amplitude(ESA) measurements and the flow curves obtained from the rheological studies as well as estimated Hamaker constants. It was found that the contribution of electrostatic repulsive forces to the Si3N4, AlN and Nd2O3 stabilization in organic media is appreciably greater than anticipated and is dependent on the physicochemical properties of organic solvents.

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Selection of Working fluid for the Organic Rankine Cycle to Utilize Low-Temperature Waste Heat (저온 폐열을 이용하기 위한 유기랭킨 사이클의 작동유체 선정에 관한 연구)

  • Cho, Soo-Yong;Cho, Chong-Hyun
    • New & Renewable Energy
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    • v.10 no.4
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    • pp.36-46
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    • 2014
  • Low-grade heats are wasted even though an amount of their energy is huge. In the small and medium industrial complex sites, large amount of low-grade thermal energy generated during the manufacturing process is wasted if it is not used directly for building heating or air-conditioning. In order to utilize this waste thermal energy more efficiently, organic Rankine cycle (ORC) was adopted. The range of operating temperature of ORC was set to $60^{\circ}C$ from $30^{\circ}C$ applicable low-temperature waste heat. A study was conducted to select an appropriate organic working fluid based on these operating conditions. More than 60 working fluids were screened. Eleven working fluids were selected based on the requirements as working fluid for ORC such as environmentally friendly, safety, and good operation on the expander. Finally, six working fluids were selected by considering the operating temperature ranges. Then, a cycle analysis was conducted with these six working fluids. As a results, R-245fa and R-134a appeared as appropriate working fluids for ORC operating at low-temperature condition based on the system efficiency and the turbine output power.

Organic Geometry in Isabel Toledo's Collections (이사벨 톨리도 컬렉션에 나타난 유기적 기하학)

  • Yim, Eun-Hyuk
    • Journal of the Korea Fashion and Costume Design Association
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    • v.18 no.4
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    • pp.63-75
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    • 2016
  • This study examines the organic geometry in Isabel Toledo's collections in terms of the practicality of American sportswear tradition. This study conducts literary survey combined with case analysis of Toledo's works from her debut collection in 1985 to the recent ones. The organic geometry in Toledo's designs refers to the conversion of two-dimensional garment patterns into three-dimensional garment forms with the body as a medium, which is classified into the following categories in this study. First, 'fluidity' describes Toledo's highly fluid jersey dresses which maintain consistent structures by patchwork draping and suspension technique. Second, 'reductionist structure' illustrates that simple geometric shapes such as circles and squares disappear as soon as worn on the body. Third, 'origami construction' explains folding two-dimensional fabrics into three-dimensional forms, which causes the outlines of the body to appear abstract. Toledo's designs deliver the tradition of American sportswear through the organic geometry of garment construction. Toledo's works are authentic American in the aspects that they are functional and modern; they satisfy the practical needs, prioritize the movements of wearers, pursue multi-functions, and their ornamental elements are accompanied by the construction of garments. Isabel Toledo presents designs drawing on her unwavering aesthetics while continuously developing and experimenting creative ways of garment construction.

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Screening, Characterization, and Cloning of a Solvent-Tolerant Protease from Serratia marcescens MH6

  • Wan, Mao-Hua;Wu, Bin;Ren, Wei;He, Bing-Fang
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.881-888
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    • 2010
  • solvent-tolerant bacterium strain, MH6, was isolated by hydrophilic organic solvent DMSO enrichment in the medium and identified as Serratia marcescens. The extracellular protease with novel organic-solvent-stable properties from strain MH6 was purified and characterized. The molecular mass of the purified protease was estimated to be 52 kDa on SDS-PAGE. The open reading frame (ORF) of the MH6 protease encoded 504 amino acids with 471 amino acid residues in the mature protease. Based on the inhibitory effects of EDTA and 1,10-phenathroline, the MH6 protease was characterized as a metalloproteinase. The enzyme activity was increased in the presence of $Ni^{2+}$, $Mg^{2+}$, and $Ca^{2+}$. The protease could also be activated by the nonionic surfactants Tween 80 (1.0%) and Triton X-100 (1.0%). The protease showed remarkable solvent stability in the presence of 50% (v/v) solutions of long-chain alkanes and long-chain alcohols. It was also fairly stable in the presence of 25% solutions of hydrophilic organic solvents. Owing to its high stability in solvents and surfactants, the MH6 protease is an ideal candidate for applications in organic catalysis and other related fields.

Removal of Natural Organic Matter by Mixing Coagulants in Coagulation Process (응집공정에서 혼합응집제 주입에 의한 자연유기물질의 제거)

  • 명복태;우달식;최종현;이윤진;남상호
    • Journal of Environmental Health Sciences
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    • v.27 no.2
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    • pp.60-66
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    • 2001
  • Natural organic matters(NOMs) are found everywhere such as soil, surface and ground waters and consist of both humic and nonhumic components, and their heterogeneith makes each source unique. This study was carried to evaluate the removal characteristics of NOMs by mixing coagulants and the variation of apparent molecular weight distribution(AMWD) in coagulation process. Ratio of optimum coagulants dosage for removal of DOC and turbidity by mixing coagulants was 1.83 mM F $e^{3+}$/mM $Al^{3+}$. DOC removal increased at lower pH. The pH6 control focused on the removal of organic matters could reduce the amount of coagulant consumption by 2 to 3 times based on the pH8.5 of natural water. The dissolved organic matters in the natural water from the mid-stream of Han River were composed of the low molecular weight(LMW,<1 K) of 59.7%, and the medium and high molecular weight(M.HMW, 1~30 K) of 40.3%, respectively. At pH6, the DOC removal efficiencies of LMW(<1 K) and M.HMW(1~30 K) in coagulation process were 27~35%, 62~72%, respectively. The fraction smaller than 1 K was not eliminated to a noticeable degree, while the fraction of 1~30 K was relatively well removed. In conclustion, mixing coagulants were fairly effective in the removal of natural organic matter.r.

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Advances in microalgal biomass/bioenergy production with agricultural by-products: Analysis with various growth rate models

  • Choi, Hee-Jeong;Lee, Seo-Yun
    • Environmental Engineering Research
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    • v.24 no.2
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    • pp.271-278
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    • 2019
  • Mass cultivation of microalgae is necessary to achieve economically feasible production of microalgal biodiesel. However, the high cost of nutrients is a major limitation. In this study, corncob extract (CCE) was used as an inorganic and organic nutrient source for the mass cultivation of Chlorella vulgaris (C. vulgaris). Chemical composition analysis of CCE revealed that it contained sufficient nutrients for mixotrophic cultivation of C. vulgaris. The highest specific grow rate of C. vulgaris was obtained at pH of 7-8, temperature of $25-30^{\circ}C$, and CCE amount of 5 g/L. In the analysis using various growth models, Luong model was found to be the most suitable empirical formula for mass cultivation of C. vulgaris using CCE. Analysis of biomass and production of triacyglycerol showed that microalgae grown in CCE medium produced more than 17.23% and 3% more unsaturated fatty acids than cells cultured in Jaworski's Medium. These results suggest that growing microalgae in CCE-supplemented medium can increase lipid production. Therefore, CCE, agricultural byproduct, has potential use for mass cultivation of microalgae.

Preparation of Silver Nanocolloids Using Silver Alkylcarbamate Complex in Organic Medium with PVP Stabilizer

  • Park, Hyung-Seok;Park, Heon-Su;Gong, Myoung-Seon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2575-2580
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    • 2010
  • We present a method for chemically reducing silver alkylcarbamate complex with hydrazine to synthesize silver nanocolloids in an organic solvent using polyvinylpyrrolidone (PVP) as the stabilizer. To determine the optimal conditions for preparing stable silver colloids of controlled size and shape, the silver 2-ethylhexylcarbamate (Ag-EHCB) complex, PVP, hydrazine, and 2-propanol solvent concentrations in the reaction mixture were varied. The initial colloid has a mean particle diameter of 5-80 nm, and it exhibits an absorption band with various shapes in the UV region with a maximum near 420 nm. UV-vis spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the formation and growth process of the metallic silver nanocolloids.