3,663 research outputs found
Multi-component catalysts with integrated MWW-type layers and mixed oxide domains for glucose-to-formic acid oxidation
No full text[EN] The development of efficient and multi-component catalysts with distinct active sites is essential to promote chemically and economically circular processes and to achieve sustainable development. In this work, various multi-component materials were synthesized combining the properties of MWW zeolitic layers and MgAl mixed oxides. Synthesis conditions were successfully developed and optimized to achieve the in situ formation of nanometric sub-domains of layered double hydroxides (LDHs) on the surfaces and within the microporous cavities and channels of MWW layers (methods I and II). Additionally, multi-component materials were prepared by mixing MWW lamellar precursors and preformed layered double hydroxides, using swelling and exfoliation techniques and combined with sonification and ball-milling techniques (method III). Calcination yielded materials effectively integrating zeolitic MWW layers with MgAl oxides, displaying distinct structural features depending on the synthesis method. The catalytic performance of these materials was evaluated in the oxidation of glucose to formic acid (FA) using H2O2 as the oxidant. Among the catalysts investigated, MWW@MgAl-in situ-40, which combined suitable textural properties and basicity, showed superior activity, achieving a 47.7% FA yield at 66.2% glucose conversion after 7.5 h at 363 K in dioxane.The authors are grateful for the financial support from the Spanish Ministry (projects PID2023-146114NB-C21 and CEX2021-001230-S, funded by MCIN/AEI/10.13039/501100011033). This study forms part of the Advanced Materials program and was supported by MCIN with funding from the European Union NextGeneration (PRTRC17.I1) and by Generalitat Valenciana (MFA/2022/003). C. E. has been partially supported by the Spanish Government through the FPI pre-doctoral scholarship number PRE2019-089547 under project SEV-2016-0683-19-3. The authors acknowledge the Microscopy Service of the Universitat Politecnica de Valencia.Esteban-Barrera, Cristina;Velty, Alexandra;Díaz, Urbano (2025). Multi-component catalysts with integrated MWW-type layers and mixed oxide domains for glucose-to-formic acid oxidation. Materials Advances. 6(19):7032-7055. https://doi.org/10.1039/d5ma00633cS7032705561
Author, Philosopher Alexandra Stoddard to Speak March 2 at Williams Library
No full textOXFORD, Miss. – Contemporary philosopher, author, interior designer and speaker Alexandra Stoddard gives an inspirational lecture and reading March 2 at the University of Mississippi
Stages for the More Sustainable Farm
No full textCurrently, agricultural farm units are faced with a double and most times contradictory challenge, in order to be successful: on the one hand the invested capital has to be profitable and the economic performance has to be maximised. On the other hand, given the socio-environmental situation, it is necessary to preserve and to protect the environment and natural resources. Given the potential conflict of the two aims, since the satisfaction of one implies the underperformance of the other (and vice versa), the question then is: which is the solution to choose? We intend, in this work, to formulate a farm plan with the purpose of reconciling the criteria of environmental sustainability with that of economic competitiveness. For this achievement we proceed to the comparative study of sustainability of different groups of farms identified in the study area (first evaluation cycle) through MESMIS (“Marco para la Evaluación de Sistemas de Manejo de Recursos Naturales Mediante Indicadores de Sustentabilidad” - Framework for Evaluation of Natural-Resource Systems Handling through Sustainability Indicators) methodology, that allowed to select the more sustainable group of farms. Based on the found potentialities and weakness on these production systems, we stepped to the planning of a production unit of bovine meat, which obeys simultaneously to economic and environmental objectives, using Multicriteria Decision. We finished the work with the sustainability evaluation between groups of farms identified previously and the planned farms (second evaluation cycle), based, again, in the MESMIS methodology, to confirm (or not) the greatest sustainability of the last ones. Analyses of the results allow us to confirm the greatest relative sustainability of the planned farm, for the diverse traced scenarios.Decision taking, planning, sustainability, Environmental Economics and Policy, Farm Management,
Strong Organic Bases as Building Blocks of Mesoporous Hybrid Catalysts for C-C Forming Bond Reactions
No full text[EN] 1,8-Bis(tetramethylguanidino)naphthalene (TMGN), a neutral organic base that combines the properties of guanidine and the properties of proton sponges, was used as a building block to produce organicinorganic silica-based mesoporous hybrids with strong basic properties. The TMGN-based mesoporous hybrids (TMGN/SiO2) were prepared by a solgel route working at a neutral pH and low temperatures, which avoided the use of SDAs. TMGN has been modified in order to have two terminal reactive silyl groups able to perform co-condensation with a conventional organosilane (TMOS) used as a silicon source. This synthesis has allowed us to directly introduce the unmodified, functionalized TMGN as part of the walls of the mesoporous silica by a one-pot synthesis. TMGN/SiO2 hybrid materials present excellent catalytic properties for CC bond forming reactions: Knoevenagel, Henry (nitroaldol), and ClaisenSchmidt condensations. The activity of the hybrid materials is higher than that of the counterpart homogeneous catalyst.The authors thank the Spanish Government by Consolider Ingenio 2010 MULTICAT (number CSD2009-00050) and MAT2011 (number 29020-C02-01) projects. E. G. is grateful for the financial support from the Marie Curie Fellowship (grant number FP7-PEO-PLE-2009-IEF).Gianotti, E.; Díaz Morales, UM.; Velty, A.; Corma Canós, A. (2012). Strong organic bases as building blocks of mesoporous hybrid catalysts for C-C forming bond reactions. European Journal of Inorganic Chemistry. 32:5175-5185. https://doi.org/10.1002/ejic.201200716S5175518532Wight, A. P., & Davis, M. E. (2002). Design and Preparation of Organic−Inorganic Hybrid Catalysts. Chemical Reviews, 102(10), 3589-3614. doi:10.1021/cr010334mBigi, F., Carloni, S., Maggi, R., Mazzacani, A., & Sartori, G. (2000). Nitroaldol condensation promoted by organic bases tethered to amorphous silica and MCM-41-type materials. 12th International Congress on Catalysis, Proceedings of the 12th ICC, 3501-3506. doi:10.1016/s0167-2991(00)80565-0Cheng, S., Wang, X., & Chen, S.-Y. (2009). Applications of Amine-functionalized Mesoporous Silica in Fine Chemical Synthesis. Topics in Catalysis, 52(6-7), 681-687. doi:10.1007/s11244-009-9216-2Rodriguez, I., Iborra, S., Corma, A., Rey, F., & Jordá, J. L. (1999). MCM-41–Quaternary organic tetraalkylammonium hydroxide composites as strong and stable Brønsted base catalysts. Chemical Communications, (7), 593-594. doi:10.1039/a900384cRodriguez, I., Iborra, S., Rey, F., & Corma, A. (2000). Heterogeneized Brönsted base catalysts for fine chemicals production: grafted quaternary organic ammonium hydroxides as catalyst for the production of chromenes and coumarins. Applied Catalysis A: General, 194-195, 241-252. doi:10.1016/s0926-860x(99)00371-3Blanc, A. C., Valle, S., Renard, G., Brunel, D., Macquarrie, D. J., & Quinn, C. R. (2000). The preparation and use of novel immobilised guanidine catalysts in base-catalysed epoxidation and condensation reactions. Green Chemistry, 2(6), 283-288. doi:10.1039/b005929nGianotti, E., Diaz, U., Coluccia, S., & Corma, A. (2011). Hybrid organic–inorganic catalytic mesoporous materials with proton sponges as building blocks. Physical Chemistry Chemical Physics, 13(24), 11702. doi:10.1039/c1cp20588aAlder, R. W. (1989). Strain effects on amine basicities. Chemical Reviews, 89(5), 1215-1223. doi:10.1021/cr00095a015Staab, H. A., Saupe, T., & Krieger, C. (2006). 4,5-Bis(dimethylamino)fluoren, ein neuer „Protonenschwamm”︁. Angewandte Chemie, 95(9), 748-749. doi:10.1002/ange.19830950924Staab, H. A., Höne, M., & Krieger, C. (1988). Synthesis, structure and basicity of 1,9-bis(dimethylamino)-dibenzothiophene and 1,9-bis(dimethylamino)-dibenzoselenophene1,2). 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Insignificance of P−H···P Hydrogen Bonding: Structural Chemistry of Neutral and Protonated 1,8-Di(phosphinyl)naphthalene. Journal of the American Chemical Society, 126(48), 15833-15843. doi:10.1021/ja045460xOzeryanskii, V. A., Pozharskii, A. F., Bieńko, A. J., Sawka-Dobrowolska, W., & Sobczyk, L. (2005). [NHN]+Hydrogen Bonding in Protonated 1,8-Bis(dimethylamino)-2,7-dimethoxynaphthalene. X-ray Diffraction, Infrared, and Theoretical ab Initio and DFT Studies. The Journal of Physical Chemistry A, 109(8), 1637-1642. doi:10.1021/jp040618lRaab, V., Kipke, J., Gschwind, R. M., & Sundermeyer, J. (2002). 1,8-Bis(tetramethylguanidino)naphthalene (TMGN): A New, Superbasic and Kinetically Active «Proton Sponge». Chemistry - A European Journal, 8(7), 1682-1693. doi:10.1002/1521-3765(20020402)8:73.0.co;2-rKovačević, B., Maksić, Z. B., Vianello, R., & Primorac, M. (2002). Computer aided design of organic superbases: the role of intramolecular hydrogen bonding. New J. 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Angewandte Chemie, 113(17), 3280-3282. doi:10.1002/1521-3757(20010903)113:173.0.co;2-rWild, U., Hübner, O., Maronna, A., Enders, M., Kaifer, E., Wadepohl, H., & Himmel, H.-J. (2008). The First Metal Complexes of the Proton Sponge 1,8-Bis(N,N,N′,N′-tetramethylguanidino)naphthalene: Syntheses and Properties. European Journal of Inorganic Chemistry, 2008(28), 4440-4447. doi:10.1002/ejic.200800677Pope, E. J. A., & Mackenzie, J. D. (1986). Sol-gel processing of silica. Journal of Non-Crystalline Solids, 87(1-2), 185-198. doi:10.1016/s0022-3093(86)80078-3Winter, R., Chan, J.-B., Frattini, R., & Jonas, J. (1988). The effect of fluoride on the sol-gel process. Journal of Non-Crystalline Solids, 105(3), 214-222. doi:10.1016/0022-3093(88)90310-9Reale, E., Leyva, A., Corma, A., Martínez, C., García, H., & Rey, F. (2005). A fluoride-catalyzed sol–gel route to catalytically active non-ordered mesoporous silica materials in the absence of surfactants. Journal of Materials Chemistry, 15(17), 1742. doi:10.1039/b415066jDíaz, U., García, T., Velty, A., & Corma, A. (2009). Hybrid organic–inorganic catalytic porous materials synthesized at neutral pH in absence of structural directing agents. Journal of Materials Chemistry, 19(33), 5970. doi:10.1039/b906821jXia, Y., Yang, Z.-Y., Xia, P., Bastow, K. F., Nakanishi, Y., & Lee, K.-H. (2000). Antitumor agents. Part 202: Novel 2′-amino chalcones: design, synthesis and biological evaluation. Bioorganic & Medicinal Chemistry Letters, 10(8), 699-701. doi:10.1016/s0960-894x(00)00072-xHSIEH, H.-K., TSAO, L.-T., WANG, J.-P., & LIN, C.-N. (2000). Synthesis and Anti-inflammatory Effect of Chalcones. Journal of Pharmacy and Pharmacology, 52(2), 163-171. doi:10.1211/0022357001773814Satyanarayana, M., Tiwari, P., Tripathi, B. K., Srivastava, A. ., & Pratap, R. (2004). Synthesis and antihyperglycemic activity of chalcone based aryloxypropanolamines. Bioorganic & Medicinal Chemistry, 12(5), 883-889. doi:10.1016/j.bmc.2003.12.026Qian, H., Liu, D., & Lv, C. (2011). Synthesis of Chalcones via Claisen-Schmidt Reaction Catalyzed by Sulfonic Acid-Functional Ionic Liquids. Industrial & Engineering Chemistry Research, 50(2), 1146-1149. doi:10.1021/ie101790kSeo, Y.-K., Park, S.-B., & Ho Park, D. (2006). Mesoporous hybrid organosilica containing urethane moieties. Journal of Solid State Chemistry, 179(4), 1285-1288. doi:10.1016/j.jssc.2006.01.021Kawahara, K., Hagiwara, Y., Shimojima, A., & Kuroda, K. (2008). Stepwise silylation of double-four-ring (D4R) silicate into a novel spherical siloxane with a defined architecture. Journal of Materials Chemistry, 18(27), 3193. doi:10.1039/b807533fCLIMENT, M. (2004). Increasing the basicity and catalytic activity of hydrotalcites by different synthesis procedures. Journal of Catalysis, 225(2), 316-326. doi:10.1016/j.jcat.2004.04.027Rodriguez, I., Sastre, G., Corma, A., & Iborra, S. (1999). Catalytic Activity of Proton Sponge: Application to Knoevenagel Condensation Reactions. Journal of Catalysis, 183(1), 14-23. doi:10.1006/jcat.1998.2380Prout, F. S., Beaucaire, V. D., Dyrkacz, G. R., Koppes, W. M., Kuznicki, R. E., Marlewski, T. A., … Puda, J. M. (1973). Konevenagel Reaction. Kinetic study of the reaction of (+)-3-methyl-cyclohexanone with malononitrile. The Journal of Organic Chemistry, 38(8), 1512-1517. doi:10.1021/jo00948a015Guyot, J., & Kergomard, A. (1983). Cinétique et mécanisme de la réaction de knoevenagel dans le benzène—1. Tetrahedron, 39(7), 1161-1166. doi:10.1016/s0040-4020(01)91879-4Luzzio, F. A. (2001). The Henry reaction: recent examples. Tetrahedron, 57(6), 915-945. doi:10.1016/s0040-4020(00)00965-0Sartori, G. (2004). Catalytic activity of aminopropyl xerogels in the selective synthesis of (E)-nitrostyrenes from nitroalkanes and aromatic aldehydes. Journal of Catalysis, 222(2), 410-418. doi:10.1016/j.jcat.2003.11.016Climent, M. J., Corma, A., & Iborra, S. (2011). Heterogeneous Catalysts for the One-Pot Synthesis of Chemicals and Fine Chemicals. Chemical Reviews, 111(2), 1072-1133. doi:10.1021/cr1002084Hara, T., Kanai, S., Mori, K., Mizugaki, T., Ebitani, K., Jitsukawa, K., & Kaneda, K. (2006). Highly Efficient C−C Bond-Forming Reactions in Aqueous Media Catalyzed by Monomeric Vanadate Species in an Apatite Framework. The Journal of Organic Chemistry, 71(19), 7455-7462. doi:10.1021/jo0614745Poe, S. L., Kobašlija, M., & McQuade, D. T. (2006). Microcapsule Enabled Multicatalyst System. Journal of the American Chemical Society, 128(49), 15586-15587. doi:10.1021/ja066476lMotokura, K., Tada, M., & Iwasawa, Y. (2008). Cooperative Catalysis of Primary and Tertiary Amines Immobilized on Oxide Surfaces for One-Pot CC Bond Forming Reactions. Angewandte Chemie, 120(48), 9370-9375. doi:10.1002/ange.200802515Sharma, K. K., & Asefa, T. (2007). Efficient Bifunctional Nanocatalysts by Simple Postgrafting of Spatially Isolated Catalytic Groups on Mesoporous Materials. Angewandte Chemie, 119(16), 2937-2940. doi:10.1002/ange.200604570Xie, Y., Sharma, K. K., Anan, A., Wang, G., Biradar, A. V., & Asefa, T. (2009). Efficient solid-base catalysts for aldol reaction by optimizing the density and type of organoamine groups on nanoporous silica. Journal of Catalysis, 265(2), 131-140. doi:10.1016/j.jcat.2009.04.018Anan, A., Sharma, K. K., & Asefa, T. (2008). Selective, efficient nanoporous catalysts for nitroaldol condensation: Co-placement of multiple site-isolated functional groups on mesoporous materials. Journal of Molecular Catalysis A: Chemical, 288(1-2), 1-13. doi:10.1016/j.molcata.2008.03.027Wang, Q., & Shantz, D. F. (2010). Nitroaldol reactions catalyzed by amine-MCM-41 hybrids. Journal of Catalysis, 271(2), 170-177. doi:10.1016/j.jcat.2010.01.010Ballesteros, J. F., Sanz, M. J., Ubeda, A., Miranda, M. A., Iborra, S., Paya, M., & Alcaraz, M. J. (1995). Synthesis and Pharmacological Evaluation of 2’-Hydroxychalcones and Flavones as Inhibitors of Inflammatory Mediators Generation. Journal of Medicinal Chemistry, 38(14), 2794-2797. doi:10.1021/jm00014a032Wattenberg, L. W., Coccia, J. B., & Galbraith, A. R. (1994). Inhibition of carcinogen-induced pulmonary and mammary carcinogenesis by chalcone administered subsequent to carcinogen exposure. Cancer Letters, 83(1-2), 165-169. doi:10.1016/0304-3835(94)90314-xDinkova-Kostova, A. T., Abeygunawardana, C., & Talalay, P. (1998). Chemoprotective Properties of Phenylpropenoids, Bis(benzylidene)cycloalkanones, and Related Michael Reaction Acceptors: Correlation of Potencies as Phase 2 Enzyme Inducers and Radical Scavengers†. Journal of Medicinal Chemistry, 41(26), 5287-5296. doi:10.1021/jm980424sNovak, M., & Loudon, G. M. (1977). The pKa of acetophenone in aqueous solution. 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Hybrid organic-inorganic nanoparticles with associated functionality for catalytic transformation of biomass substrates
No full text[EN] We present the one-pot synthesis of functionalized organosilica nanoparticles to generate multi-functional hybrid catalysts. Octadecyl, alkyl-thiol and alkyl-amino moieties were used separately and in different combinations, to generate different hybrid spherical nanoparticles with tunable acidic, basic and amphiphilic properties, covalently incorporating up to three organic functional elements onto the surface of the nanoparticles. Several parameters were optimised such as the concentration of the base employed during the hydrolysis and condensation synthesis process that showed a strong influence on the particle size. The physico-chemical properties of the hybrid materials were fully characterized by XRD, elemental and thermogravimetric analysis, electron microscopy, nitrogen adsorption isotherms and C-13 and Si-29 NMR spectroscopy. Finally, the potential uses of the prepared materials as amphiphilic catalysts, with acidic or basic properties for the conversion of biomass molecules into platform chemicals were evaluated.The authors acknowledge support from Grant PID2020-112590GB-C21 and from Severo Ochoa excellence program CEX2021-001230-S, both funded by MCIN/AEI/10.13039/501100011033. This study forms part of the Advanced Materials program and was supported by MICIN with funding from European Union NextGeneration (PRTR-C17.I1) and by Generalitat Valenciana (MFA/2022/003). A. C. acknowledge financial support from JAE-Intro 2020 - CSIC (JAEINT20_EX_0986).Coloma-Molina, A.; Velty, A.; Díaz, U. (2023). Hybrid organic-inorganic nanoparticles with associated functionality for catalytic transformation of biomass substrates. RSC Advances. 13(15):10144-10156. https://doi.org/10.1039/d3ra01486jS1014410156131
Exhibiting Fashion Symposium: Dr. Alexandra Palmer “Fashion Exhibitions: The Good, the Bad, and the Pointless”
No full textThe Museum at FIT presented Exhibiting Fashion, its twenty-first academic symposium on Friday, March 8, 2019. This symposium explored the history of fashion curating, the different ways fashion is displayed in museum settings, and how national and regional identities influence fashion exhibitions. The symposium was organized in conjunction with Exhibitionism: 50 Years of The Museum at FIT, which commemorated the rich history of the museum, the site of more than 200 exhibitions since the 1970s.Dr. Alexandra Palmer is the Nora E. Vaughan Senior Curator at the Royal Ontario Museum. She has curated numerous exhibitions including Christian Dior, and she is the author of the book Christian Dior: History and Modernity, 1947–1957
Reescrita de si pelo outro: identidade portuguesa e paródia em Deus-dará, de Alexandra Lucas Coelho / Rewriting oneself through the other: Portuguese identity and parody in Deus-dará, by Alexandra Lucas Coelho
No full textResumo: O artigo aponta o modo como o romance Deus-dará de Alexandra Lucas Coelho, escritora portuguesa contemporânea, pode ser compreendido como um exercício de renegociação da identidade portuguesa em relação a questões referentes à colonização no Brasil. Mais do que isso, problematiza-se como, por meio da estratégia da paródia no texto ficcional, a autora consegue expressar uma necessidade e possibilidade de se redefinir pelo outro em um movimento contrário ao do discurso colonial – o que também ocorre em suas entrevistas e em suas narrativas de viagens, tais como em Vai, Brasil e Cinco Voltas na Bahia e um beijo para Caetano Veloso. Palavras-chave: identidade portuguesa; paródia; pós-modernismo; escrita portuguesa contemporânea; Alexandra Lucas Coelho. Abstract: The article observes how the novel Deus-dará, by Alexandra Lucas Coelho, a Portuguese contemporary writer consists in an exercise of renegotiation for the Portuguese identity in relation to issues that refer to the colonization process in Brazil. Moreover, this text seeks to show how parody as a fictional literary strategy helps the author in expressing a necessity and a possibility of redefining oneself through the other, in a direction that goes in the opposite way of the colonial speech. This necessity and this possibility also appear in the author’s interviews and travel books, such as Vai, Brasil and Cinco Voltas na Bahia e um beijo para Caetano Veloso, which will also be mentioned in this article.Keywords: Portuguese identity; parody; post-modernism; Portuguese contemporary writing; Alexandra Lucas Coelho
Active Base Hybrid Organosilica Materials based on Pyrrolidine Builder Units for Fine Chemicals Production
No full text[EN] The catalytic activity of "pyrrolidine type" fragments included or anchored in the mesoporous silica supports or polymeric frameworks have been fully reported for enantioselective transformation. Nevertheless, low attention was focused on their catalytic abilities to perform base-catalyzed reaction. Accordingly, hybrid materials including pyrrolidine fragments in the mesoporous silica supports were prepared following different synthesis methods, such as micellar and fluoride sol-gel routes in absence of structural directing agents. Their great catalytic performance was explored for various base-catalyzed reactions to the formation of C-C bond through Knoevenagel, Claisen-Schmidt and Henry condensations under microwave irradiation. The benefits of microwave irradiation combined with suitable catalytic properties of pyrrolidine hybrid materials with strong base sites and high accessibility to active centers, allowed carrying out successfully base-catalyzed condensation reactions for the production of fine chemicals. Moreover, the hybrid catalyst exhibited high selectivity and good stability over different catalytic cycles contributing to environmental sustainability.The authors are grateful for financial support from the Spanish Government, MAT2017-82288-C2-1-P and PID2020112590GB C21/AEI/10.13039/501100011033, and MULTY2HYCAT European project (EUHorizon 2020 funded project under grant agreement no. 720783).Llopis-Perez, S.; Velty, A.; Díaz Morales, UM. (2021). Active Base Hybrid Organosilica Materials based on Pyrrolidine Builder Units for Fine Chemicals Production. ChemCatChem. 13(23):5012-5024. https://doi.org/10.1002/cctc.202101031S50125024132
Author Rights Workshop
No full textLearning material associated with Alexandra Kohn's presentation as a part of the ABC Copyright 2020 Fall Speaker Series, hosted by the University of Alberta Copyright Office
Athaliah and Alexandra: Gender and Queenship in Josephus [Author Accepted Manuscript]
No full textAthaliah and Alexandra were the only two women to rule as queens of Judah/Judaea in their own right and both women’s reigns are reported in Josephus’ writings. Despite their uniqueness, however, Athaliah and Alexandra are rarely compared in scholarship; the former is usually dismissed, and focus centred on the latter. This article contends that there are historical similarities between the two, but literary differences. Josephus could have referred to Athaliah or used elements of her portrayal in his presentation of Alexandra but does not, creating the impression that Alexandra was completely different to her predecessor. It may be instructive, therefore, to consider why Josephus literarily isolates the queens and what this means for his interpretation of Alexandra
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