• Title/Summary/Keyword: Recyclable

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Magnetically separable Au-TiO2/nanocube ZnFe2O4 composite for chlortetracycline removal in wastewater under visible light

  • Jia, Yuefa;Liu, Jia;Cha, Sangwon;Choi, Soobin;Park, Yun Chang;Liu, Chunli
    • Journal of Industrial and Engineering Chemistry
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    • v.47
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    • pp.303-314
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    • 2017
  • Magnetically recyclable $Au-TiO_2/nanocube$ $ZnFe_2O_4$ ($Au-TiO_2/NC\;ZFO$) composite photocatalysts have been successfully prepared by a hydrothermal method. It was revealed that Au-$TiO_2/NC\;ZFO$ composite with 25% mass percentage of $Au-TiO_2$ exhibited a significantly enhanced photocatalytic efficiency toward chlortetracycline (CTC) degradation as compared to the binary $TiO_2/NC\;ZFO$ composite. The enhanced performance can be attributed to the addition of Au nanoparticles, which act as electron traps aiding the electron-hole separation and increasing the light absorption through the surface plasmon resonance effect. The synthesized catalyst showed good stability after three cycles and could be easily separated by a magnet and reused.

Recyclable single-stranded DNA template for synthesis of siRNAs

  • Ali, Mussa M.;Obregon, Demian;Agrawal, Krishna C.;Mansour, Mahmoud;Abdel-Mageed, Asim B.
    • BMB Reports
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    • v.43 no.11
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    • pp.732-737
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    • 2010
  • RNA interference is a post-transcriptional silencing mechanism triggered by the bioavailability and/or exogenous introduction of double-stranded RNA (dsRNA) into cells. Here we describe a novel method for the synthesis of siRNA in a single vessel. The method employs in vitro transcription and a single-stranded DNA (ssDNA) template and design, which incorporates upon self-annealing, two promoters, two templates, and three loop regions. Using this method of synthesis we generated efficacious siRNAs designed to silence both exogenous and endogenous genes in mammalian cells. Due to its unique design the single-stranded template is easily amenable to adaptation for attachment to surface platforms for synthesis of siRNAs. A siRNA synthesis platform was generated using a 3' end-biotinylated ssDNA template tethered to a streptavidin coated surface that generates stable siRNAs under multiple cycles of production. Together these data demonstrate a unique and robust method for scalable siRNA synthesis with potential application in RNAi-based array systems.

Practical Process Development of AMCA from Recyclable Source MFB (재사용이 가능한 MFB로부터 AMCA의 합성 공정 개발)

  • Kim, Jong Cheon;Ryu, Young;Kim, Seok Chan
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.508-511
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    • 2016
  • A facile synthesis of 4-(aminomethyl)cyclohexanecarboxylic acid (AMCA) from recyclable methyl 4-formylbenzoate (MFB) was described. In particular, we investigated the best process variables such as catalyst, hydrogen pressure, reaction temperature, and reaction time for AMCA conversion from AMBA through hydrogenation reaction. The best conditions were found to be as follows: the catalyst as [5% Pd/C, 5% Pt/C, 5% Rh/C (1 : 1 : 1)] which is a composite catalyst, the pressure as 30 bar, the reaction time as 8 hours and the reaction temperature at $130^{\circ}C$. Under the condition, a 90% yield (purity 99.9%) for the mass production of AMCA was achieved.

Mean-Variance Analysis for Optimal Operation and Supply Chain Coordination in a Green Supply Chain

  • Yamaguchi, Shin;Goto, Hirofumi;Kusukawa, Etsuko
    • Industrial Engineering and Management Systems
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    • v.16 no.1
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    • pp.22-43
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    • 2017
  • It is urgently-needed to construct a green supply chain (GSC) from collection of used products through recycling of them to sales of products using the recycled parts. Besides, it is necessary to consider the uncertainty in product demand as a risk in a GSC. This study proposes the optimal operations for a GSC with a retailer and a manufacturer. A retailer pays an incentive for collection of used products from customers and sells a single type of products in a market. A manufacturer produces the products ordered by the retailer, using recyclable parts with acceptable quality and compensates the collection cost of used products as to the recycled parts. This paper discusses the following risk attitudes: risk-neutral attitude, risk-averse attitude, and risk-prone attitude. Using mean-variance analysis, the optimal decisions for product order quantity, collection incentive, and lower limit of quality level, in the decentralized GSC (DGSC) and the integrated GSC (IGSC) are made. DGSC optimizes the utility function of each member. IGSC does that of the whole system. The analysis numerically investigates how (i) risk attitude and (ii) quality of recyclable parts affect the optimal operations. Supply chain coordination between GSC members to shift IGSC from DGSC is discussed.

One Pot Four-Component Synthesis of Novel Substituted 2-Phenyl-4(3H) Quinazolinones Using Recyclable Nanocrystalline CuMnO3 Catalyst

  • Borhade, A.V.;Tope, D.R.;Gare, G D.;Dabhade, G.B.
    • Journal of the Korean Chemical Society
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    • v.61 no.4
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    • pp.157-162
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    • 2017
  • In the present study, nanocrystalline mixed metal oxide, $CuMnO_3$ catalyst have been synthesized by mechanochemical method with green chemistry approach. The synthesized catalyst was characterized by analytical techniques including FTIR, XRD, SEM, TEM and BET surface area. The synthesized catalyst shows high surface area is $121.06m^2/g$ with particle size 18 nm. The one pot four component synthesis of substituted 2-phenyl-4(3H) quinazolinone from the reaction of anthranilic acid, benzoyl chloride, hydrazine hydrate and substituted benzaldehyde in presence of $CuMnO_3$ nanocatalyst has been carried out. It affords the corresponding products with high yield (76-95%) in very short reaction time. All the obtained products were characterized with $^1HNMR$, $^{13}CNMR$, FTIR and EIMS.

Peroxopolyoxotungsten-based Ionic Hybrid as a Highly Efficient Recyclable Catalyst for Epoxidation of Vegetable oil with H2O2

  • Wu, Jianghao;Jiang, Pingping;Qin, Xiaojie;Ye, Yuanyuan;Leng, Yan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1675-1680
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    • 2014
  • A peroxopolyoxotungsten-based ionic hybrid was synthesized by anion-change of peroxopolyoxometalate (POM) $PW_4O{_{24}}^{3-}$ with dicationic long-chain alkyl imidazolium ionic liquids. The characterization was conducted by FT-IR, TGA, $^1H$-NMR and CHN Elemental analyses. Its catalytic performance was evaluated by the epoxidation of soybean oil with $H_2O_2$ under solvent-free condition, including testing of organic cations influence, catalytic reusability and reaction conditions. The catalyst was proved to be a highly efficient recyclable catalyst for epoxidation of various vegetable oils with $H_2O_2$, showing high $H_2O_2$ utilization efficiency, high catalytic activity, convenient recovery and good reuse ability.