• Title/Summary/Keyword: Silica gel 60

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Development of Adsorption Desalination System Utilizing Silica-gel (실리카겔을 이용한 흡착식 담수화 시스템 개발)

  • Hyun, Jun-Ho;Israr, Farrukh;Lee, Yoon-Joon;Chun, Won-Gee
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.364-369
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    • 2012
  • The development of solar thermal energy used adsorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar thermal energy used and adsorption desalination system was introduced. Silica gel type adsorption desalination system is considered to be a promising low-temperature heat utilization system. The design is divided into three parts. First, the evaporator for the vaporization of the tap water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basic research, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar thermal energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. Desalination is processes that permeate our daily lives, but It requires substantial energy input, powered either from electricity or from thermal input. From the environmental and sustainability perspecives, innovative thermodynamic cycles are needed to produce the above-mentioned useful effects at a lower specific energy input. This article describes the development of adsorption cycles for the production of desalting effects. We want that this adsorption system can be driven by low temperature heat sources at 60 to $80^{\circ}C$, such as renewable, solar thermal energy.

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Nanosulfated Silica as a Potential Heterogeneous Catalyst for the Synthesis of Nitrobenzene

  • Khairul Amri;Aan Sabilladin;Remi Ayu Pratika;Ari Sudarmanto;Hilda Ismail;Budhijanto;Mega Fia Lestari;Won-Chun Oh;Karna Wijaya
    • Korean Journal of Materials Research
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    • v.33 no.7
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    • pp.265-272
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    • 2023
  • In this study, the synthesis of nitrobenzene was carried out using sulfated silica catalyst. The study delved into H2SO4/SiO2 as a solid acid catalyst and the effect of its weight variation, as well as the use of a microwave batch reactor in the synthesis of nitrobenzene. SiO2 was prepared using the sol-gel method from TEOS precursor. The formed gel was then refluxed with methanol and calcined at a temperature of 600 ℃. SiO2 with a 200-mesh size was impregnated with 98 % H2SO4 by mixing for 1 h. The resulting 33 % (w/w) H2SO4/SiO2 catalyst was separated by centrifugation, dried, and calcined at 600 ℃. The catalyst was then used as a solid acid catalyst in the synthesis of nitrobenzene. The weights of catalyst used were 0.5; 1; and 1.5 grams. The synthesis of nitrobenzene was carried out with a 1:3 ratio of benzene to nitric acid in a microwave batch reactor at 60 ℃ for 5 h. The resulting nitrobenzene liquid was analyzed using GC-MS to determine the selectivity of the catalyst. Likewise, the use of a microwave batch reactor was found to be appropriate and successful for the synthesis of nitrobenzene. The thermal energy produced by the microwave batch reactor was efficient enough to be used for the nitration reaction. Reactivity and selectivity tests demonstrated that 1 g of H2SO4/SiO2 could generate an average benzene conversion of 40.33 %.

Hydrolysis of Egg Yolk Protein in a Packed Bed Reactor by Immobilized Enzyme (충진층 반응기에서 고정화 효소에 의한 난황 단백질의 가수분해)

  • Kang, Byung-Chul
    • Journal of Life Science
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    • v.20 no.11
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    • pp.1656-1661
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    • 2010
  • Alkaline protease for the hydrolysis of egg yolk protein was immobilized on five carriers - Duolite A568, Celite R640, Dowex-1, Dowex 50W and Silica gel R60. Duolite A568 showed a maximum immobilization yield of 24.7%. Optimum pH for the free and immobilized enzyme was pH 8 and 9, respectively. However, no change was observed in optimum temperature ($50^{\circ}C$). Thermal stability was observed in immobilized enzymes compared to free enzymes. The immobilized enzyme retained 86% activity after 10 cycle operations in a repeated batch process. The effect of flow rate on the stability of enzyme activity in continuous packed-bed reactor was investigated. Lowering flow rate increased the stability of the immobilized enzyme. After 96 hr of continuous operation in a packed-bed reactor, the immobilized enzyme retained 83 and 61% activity when casein and egg yolk were used as a raw materials, respectively.

Antioxidative Activity of Hot Water and Ethanol Extracts of Lespedeza cuneata Seeds (야관문(Lespedeza cuneata) 종자의 열수 및 Ethanol 추출물의 항산화 효과)

  • Kim, Seon-Jae;Kim, Du-Woon
    • Food Science and Preservation
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    • v.14 no.3
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    • pp.332-335
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    • 2007
  • Hot water and 95%(v/v) ethanol extracts were prepared from dried Lespedeza cuneata seeds and antioxidant compounds were isolated by solvent fractionation, silica gel adslorption chromatography, Sephadex LH-20 column chromatography, and preparative HPLC. Antioxidant activity was measured using DPPH radical scavenging activity. The 80%(v/v)ethanol and ethylacetate fraction of Lespedeza cuneata seed extracts had stronger antioxidant effects than did the n-hexane fraction. The active antioxidant compounds obtained from hot water and 95%(v/v) ethanol extracts may be identical, based on analysis by Sephadex LH-20 column chromatography and preparative HPLC.

Lipoxygenase Inhibitor from Defatted Nutmeg Seed

  • Kim, Hyo-Jin;Chung, Shin-Kyo;Park, Sang-Won
    • Preventive Nutrition and Food Science
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    • v.3 no.3
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    • pp.216-220
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    • 1998
  • Lipoxygenase inhibitory acitivity of the methanolic extract of 60 different kinds of plant seeds was determined by a spectrophotometric method using a soybean lipoxigenase(SLO) and linolenic acid. Among the extracts examined, the methanolic extract of nutmeg(Myristical fragrans)seed showed the most potent SLO inhibitory activity. To isolate SLO inhibitor, hence, the defatted methanol extract was further partitioned with ether, ehtylacetate , and n-butanol , stepwise. The ether souble fraction was successively chromatographed on silica gel, Sephadex LH-20 and preparative TLC. Three phenolic compounds were isolated , and one of them showing a strong SLO inhibition activity was identified as a 2,6-dihydroxy-9-(3', 4', -dihydroxyphenyl)nonylphenone (IC50a=0.39$\mu\textrm{g}$/ml) by 1H-& 13C0NMR, IR, and MS spectroscopy.

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Anti-inflammatory Activities of Cinanamomum burmanni Bl

  • Khatib, Alfi;Kim, Mi-Yeon;Chung, Shin-Kyo
    • Food Science and Biotechnology
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    • v.14 no.2
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    • pp.223-227
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    • 2005
  • Anti-inflammatory assay was conducted on 20 kinds of traditional Indonesian medicinal herbs using soybean lipoxygenase (SLO) and hyaluronidase (HAse). Cinnamomun burmanni Bl showed highest anti-inflammatory activity. Ethyl acetate fraction from methanol extract of C. burmanni Bl bark showing high SLO inhibitory activity was isolated using silica gel-60 column chromatography. Two compounds were isolated and purified through preparative HPLC. Through analyses of UV, $^1H-NMR$, $^{13}C-NMR$, EI-MS and $FAB^+-MS$, compounds 1 and 2 were identified as coumarin and 2-hydroxy cinnamaldehyde, respectively, among which 2-hydroxy cinnamaldehyde showed SLO inhibitory activity of $IC_{50}\;=\;60\;{\mu}M$. Both compounds did not exhibit HAse inhibitory activity.

Physico-chemical Characteristics of the Inhibitory Substance on the Germination of Mung Bean (녹두 발아 조해물질(阻害物質)의 이화학적(理化學的) 성질(性質))

  • Kim, Kwang-Hyeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.1
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    • pp.57-60
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    • 1985
  • The inhibitory substance on the growth of mung bean seedling was amorphous crystal that had a single spot on silica gel thin layer chromatography under ultra-violet irradiation in dark room. The Rf value was 0.85 in n-butanol-acetic acid-formic acid-water(15 : 12 : 3 : 10) system, and 0.92 in n-butanol-acetic acid-water(4 : 1 : 5) system, respectively. Biochemical reaction of the inhibitor was negative to $FeCl_3$, pyrimidine, ninhydrine, folin, fehling, Salkowski and Ehrlich reaction, but the inhibitor had a blue fluorescence from irradiation of ultra-violet rays and had maximum absorption at 252nm on UV spectrum. On IR spectrum, the Peaks of the inhibitor appeared at $3300{\sim}3500,\;2900{\sim}3000,\;1600{\sim}1700,\;and\;1400cm^{(-1)}$. The strain tested was identified to be similar Streptomyces iuteogriseus by morphorogical and physiological characteristics.

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Purification and Characterization of an Antifungal Antibiotic from Bacillus subtilis LAM 97-44 (Bacillus subtilis LAM 97-44가 생산하는 항진균성 항생물질의 정제 및 특성)

  • Lee, No-Woon;Kwon, Tae-Jong;Yi, Dong-Heui
    • Applied Biological Chemistry
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    • v.46 no.2
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    • pp.69-73
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    • 2003
  • A novel antifungal antibiotic for azole-resistant Candida albicans was purified from the culture broth of Bacillus subtilis LAM 97-44 by butanol extraction, Diaion HP-20 and Dowex-50 adsorption chromatography, silica gel flash chromatography followed by HPLC and designated LAM-44A. LAM-44A was stable for 60 min at $100^{\circ}C$, and pH range from 2 to 10. MIC values were observed at $0.5-3.5\;{\mu}g/ml$ against various Candida albicans strains. The antibiotic showed no cytotoxicity for S180, MKN-45, P388, HeLa and 373 at the concentration of 1 mg/ml. LAM-f4A was colorless powder soluble in water, methanol, ethanol, butanol and negative to ninhydrin reaction. The antibiotic had maximum absorption at 273 nm in methanol, and melting point was $202^{\circ}C$. The molecular weight and formula were determined to be 282 and $C_{14}H_{34}O_5$ by $^1H-NMR,\;^{13}C-NMR$, IR spectrum and elemental analysis.

Purification of Materials Produced by Amylocolatosis sp. and Anticancer Effect in Oral Cancer Model (Amylocolatosis sp.가 생산하는 항암물질의 정제 및 구강암 모델에 미치는 항암 효과)

  • Kim, Jung;Park, Young-Min;Lim, Do-Seon
    • Journal of dental hygiene science
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    • v.3 no.1
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    • pp.11-14
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    • 2003
  • A methylotrophic Actinomycetes strain, which produce the anti-oral cancer activity compound, was isolated from soil and estimated as Amylocolatosis sp. based on taxonomic studies. A methanol didn't have influence on the production of the anticancer compounds. These compound were isolated by ethylacetate extract, silica gel column chromatography, sephadex LH-20 column and reverse phase HPLC. The compounds were very stable under heat ($121^{\circ}C$), acid(pH 2.0) and alkali(pH 11.0) treatment. The cytotoxic effect of isolated anticancer compounds on various cancer cell lines such as A549, SNU-1, KB, L1210, and Sarcoma 180 was investigated by MTT assay method. And these produced compounds also showed the broad antimicrobial spectrum to test strains such as bacteria and yeast.

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Isolation of Lipids from the Aerial Parts of Spathiphyllum cannifolium (스파티필름(Spathiphyllum cannifolium) 지상부로부터 지질화합물의 분리)

  • Lee, Dae-Young;Park, Ji-Hae;Yoo, Jong-Su;Song, Myoung-Chong;Baek, Nam-In;Lee, Youn-Hyung
    • Applied Biological Chemistry
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    • v.51 no.1
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    • pp.60-64
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    • 2008
  • The aerial parts of Spathiphyllum cannifolium were extracted with 80% aqueous MeOH and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three compounds were isolated through the repeated silica gel, ODS, Sephadex LH-20 column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as stigmasterol (1), $(2S)1-O-linolenoyl-2-0-myristoyl-3-0-{\beta}-D-galactopyranosyl-sn-glycerol$ (2) and stigmasterol glucoside (3). They were the first to be isolated from Spathiphyllum cannifolium.