Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides

[EN] The project of this Ph.D. thesis is based on a co-supervised collaboration between Università di Bologna, ALMA MATER STUDIORUM (Italy) and Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (Spain). This Ph.D. thesis is about the synthesis, characterization and catalytic testing of complex mixed-oxide catalysts mainly related to the family of Hexagonal Tungsten Bronzes (HTBs). These materials have been little explored as catalysts, although they have a great potential as multifunctional materials. Their peculiar acid properties can be coupled to other functionalities (e.g. redox sites) by isomorphous substitution of tungsten atoms with other transition metals such as vanadium, niobium and molybdenum. In this PhD thesis, it was demonstrated how it is possible to prepare substituted-HTBs by hydrothermal synthesis; these mixed-oxide were fully characterize by a number of physicochemical techniques such as XPS, HR-TEM, XAS etc. They were also used as catalysts for the one-pot glycerol oxidehydration to acrylic acid; this reaction might represent a viable chemical route to solve the important issue related to the co-production of glycerin along the biodiesel production chain. Acrylic acid yields as high as 51% were obtained and important structure-reactivity correlations were proved to govern the catalytic performance; only fine tuning of acid and redox properties as well as the in-framework presence of vanadium are fundamental to achieve noteworthy yields into the acid monomer. The overall results reported herein might represent an important contribution for future applications of HTBs in catalysis as well as a general guideline for a multifaceted approach for their physicochemical characterization.[ES] El proyecto de esta tesis doctoral está basado en un convenio de cotutela firmado por la Università di Bologna, ALMA MATER STUDIORUM (Italia) y el Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (España). La presente tesis doctoral muestra el estudio sobre la síntesis, caracterización y ensayos catalíticos de materiales complejos a base de óxidos mixtos relacionados con la familia de los bronces de tungsteno hexagonales. Estos materiales han sido utilizados minoritariamente como catalizadores, aunque tienen un potencial importante come materiales multifuncionales. Sus peculiares propiedades acidas pueden ser acopladas con otras características (por ejemplo, sitios oxido-reductivos) a través de la substitución isomórfica de átomos de tungsteno con otros metales de transición como vanadio, niobio y molibdeno. En esta tesis doctoral se ha demostrado como sea posible preparar bronces de tungsteno hexagonales substituidos a través de síntesis hidrotermal; estos óxidos mixtos fueron caracterizados por completo empleando numerosas técnicas de caracterización quimico-fisicas como XPS, HR-TEM, XAS etc. Fueron también utilizados como catalizadores para la síntesis directa de acido acrílico de glicerol; esta es una reacción que puede representar una solución viable para el problema relacionado con la coproducción de glicerina a lo largo de la cadena productiva del biodiesel. Rendimientos en acido acrílico hasta el 51% fueron obtenidos y importantes relaciones entre las estructuras y la actividad catalítica fueron demostradas ser determinantes para el proceso catalítico; solo la afinación de las propiedades acidas y redox tanto como la presencia en-red de vanadio son esenciales para conseguir rendimientos relevantes en el monómero acido. En general, los resultados presentados en esta tesis doctoral pueden ser una contribución relevante para futuras aplicaciones de los bronces de tungsteno hexagonales en catálisis y también como una guía general para un completa caracterización quimico-fisica de estos oxidos.[CA] Esta tesi doctoral està basada en un conveni de cotutela signat per la Università di Bologna, ALMA MATER STUDIORUM (Italia) i el Institut de Tecnologia Química , Universitat Politècnica de València ITQ-UPV(Espanya). La present tesi doctoral estudia la síntesis, caracterització i assajos catalítics de òxids mixtes relacionats amb la família dels bronzes de tungstèn hexagonals. Aquestos materials presenten un gran potencial com materials multi funcionals, encara que no han sigut molt emprats com catalitzadors. Les propietats àcides particulars de aquestos materials poden ser potenciades amb altres característiques (per exemple, llocs redox) mitjançant la substitució isomòrfica d'àtoms de tungstèn amb altres metalls de transició com vanadi, niobi i molibdè. En aquesta tesi doctoral es demostra com es possible sintetitzar bronzes de tungstèn hexagonals substituïts a partir de síntesis hidrotermal. Aquestos òxids mixtes han segut caracteritzats emprant diverses tècniques de caracterització físico-químiques com XPS, HR-TEM, XAS, etc... Per altra part, s'han utilitzat com catalitzadors per a la síntesis directa de àcid acrílic a partir de glicerol, aquesta reacció pot representar una solució viable per al problema relacionat amb la coproducció de glicerina al llarg de la cadena productiva de biodiesel. S'han obtingut rendiments a àcid acrílic del 51%. A més, s'han observat importants relacions entre les estructures i la activitat catalítica, les quals han sigut determinants per al procés catalític. El ajust de les propietats àcides i redox i la presència en red de vanadi són essencials per a obtindre rendiments rellevants en el monòmer àcid. En general, el resultats presentats en aquesta tesi doctoral poden ser una contribució rellevant per a futures aplicacions del bronzes de tungstèn hexagonal en catàlisis i també com una guia general per a una completa caracterització físico-química d'aquestos òxids.Chieregato, A. (2015). Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/49558TESI

Education Professionals and the COVID-19 Pandemic : Turning Crisis into New Opportunities

The COVID-19 pandemic emergency brought human vulnerability to the proscenium revealing the uncertainty associated with existence. It appears as a symptom of a deeper crisis of modern society, whose paradigms need to be questioned. Could this be an oppor-tunity, though? The qualitative study presented here aimed to investigate the emotions experienced and the responses developed by the education professionals during the first lockdown. It explored the areas related to motivation, fears, and the ideas prompted by the change, with a focus on the conditions able to foster “creative solutions”. Teamwork and the presence of training programs appear to be crucial elements

Persistent and Transient Blank Field Sources

Blank field sources (BFS) are good candidates for hosting dim isolated neutron stars (DINS). The results of a search of BFS in the ROSAT HRI images are revised. We then focus on transient BFS, arguing that they belong to a rather large population. The perspectives of future research on DINS are then discussed.Comment: 3 pages, 0 figures. Paper presented at the Conference "Isolated Neutron Stars: from the interior to the surface", London, April 2006. Astrophysics and Space Science, in pres

Podcast e o eixo comunicação na pedagogia Freinet: um trabalho de formação docente

This work of course conclusion reports an experience of teacher training carried out in 2021 with teachers from Basic Education and Higher Education, as well as undergraduate students of the Pedagogy course at Universidade Federal de Uberlândia. Inspiration was sought in the 40s with Radio Freinet: a technique proposed by the French scholar Célestin Freinet. The objective of this research was thus established as to understand the process of overcoming Rádio Escolar to Podcast, which gained special fame in the second decade of the 21st century. The aim was to promote the Communication Axis of Freinet Pedagogy through the Podcast tool. For this, a research-intervention was established based on four workshops designed to teach how to create a Podcast program aiming at a transformative action through new technological knowledge. In addition to establishing a pedagogically planned course, this work was able to enable the publication of two Podcasts: one about Literacy with professors of the subject and another on Booktalk, with children.Pesquisa sem auxílio de agências de fomentoTrabalho de Conclusão de Curso (Graduação)Este trabalho de conclusão de curso relata uma experiência de formação docente realizada no ano de 2021 com professores da Educação Básica e Ensino Superior, bem como graduandos do curso de Pedagogia da Universidade Federal de Uberlândia. Buscou-se inspiração nos anos 40 com a Rádio Freinet: técnica proposta pelo estudioso francês Célestin Freinet. Estabeleceu-se então como objetivo desta pesquisa compreender o processo de superação da Rádio Escolar para o Podcast, que ganhou especial fama na segunda década do século XXI. O intuito foi promover o Eixo Comunicação da Pedagogia Freinet a partir da ferramenta Podcast. Para isso, estabeleceu-se uma pesquisa-intervenção a partir de quatro oficinas elaboradas para ensinar como criar um programa de Podcasts visando uma ação transformadora por meio de novos conhecimentos tecnológicos. Além de estabelecer um curso pedagogicamente planejado, este trabalho foi capaz de possibilitar a publicação de dois Podcasts: um sobre Alfabetização, com professores da temática e outro sobre Conversas Literárias, com crianças

The Ultraluminous X-ray Sources NGC 1313 X-1 and X-2

We present a detailed analysis of XMM archival data of two Ultraluminous X-ray Sources (ULXs) in the nearby spiral galaxy NGC 1313: NGC 1313 X-1 and X-2. The spectral continuum of these sources was modeled with a soft thermal component plus a power-law. If the soft component originates from an accretion disk, the inferred mass of the compact remnant is > 100 M_sun, making it an Intermediate Mass Black Hole (IMBH). A detailed analysis of the residuals of the XMM EPIC-pn spectrum shows some evidence for the presence of an Oxygen emission line in NGC 1313 X-1. The simultaneous presence of an excess in emission, although at a much reduced significance level, at different energies in the X-ray spectra of NGC 1313 X-1 and X-2 is suggestive of typical emission lines from young supernova remnants. An optical counterpart for NGC 1313 X-2 was also identified. On an ESO 3.6 m image, the Chandra error box embraces a R \~ 23 mag stellar-like object and excludes a previously proposed optical counterpart.Comment: 7 pages, 2 figures, to be published in Advances in Space Researc

Structure-reactivity correlations in Vanadium containing catalysts for the one-pot glycerol oxidehydration to acrylic acid

[EN] The design of suitable catalysts for the one-pot conversion of glycerol into acrylic acid (AA) is a complex matter, as only fine-tuning of the redox and acid properties makes it possible to obtain significant yields of AA. However, fundamental understanding behind the catalytic phenomenon is still unclear. Structure-reactivity correlations are clearly behind these results, and acid sites are involved in the dehydration of glycerol into acrolein with vanadium as the main (or only) redox element. For the first time, we propose an in-depth study to shed light on the molecular-level relations behind the overall catalytic results shown by several types of V-containing catalysts. Different multifunctional catalysts were synthesized, characterized (>X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, temperature-programmed reduction, and temperature-programmed desorption of ammonia), and tested in a flow reactor. Combining the obtained results with those acquired from an in situ FTIR spectroscopy study with acrolein (a reaction intermediate), it was possible to draw conclusions on the role played by the various physicochemical features of the different oxides in terms of the adsorption, surface reactions, and desorption of the reagents and reaction products.The Instituto de Tecnologia Quimica thanks the Spanish Government-MINECO projects (CTQ2015-68951-C3-1-R and SEV-2012-0267). CIRI Energia e Ambiente (University of Bologna) is acknowledged for a Ph.D. grant to A.C. Consorzio INSTM (Firenze) is acknowledged for a Ph.D. grant to C.B.Chieregato, A.; Bandinelli, C.; Concepción Heydorn, P.; Soriano Rodríguez, MD.; Puzzo, F.; Basile, F.; Cavani, F.... (2017). Structure-reactivity correlations in Vanadium containing catalysts for the one-pot glycerol oxidehydration to acrylic acid. ChemSusChem. 10(1):234-244. https://doi.org/10.1002/cssc.201600954S234244101T. Ohara T. Sato N. Shimizu G. Prescher H. Schwind O. Weiberg K. Marten H. Greim Ullmann's Encyclopedia of Industrial Chemistry 2011Beerthuis, R., Rothenberg, G., & Shiju, N. R. (2015). Catalytic routes towards acrylic acid, adipic acid and ε-caprolactam starting from biorenewables. Green Chemistry, 17(3), 1341-1361. doi:10.1039/c4gc02076fSattler, J. J. H. B., Ruiz-Martinez, J., Santillan-Jimenez, E., & Weckhuysen, B. M. (2014). Catalytic Dehydrogenation of Light Alkanes on Metals and Metal Oxides. Chemical Reviews, 114(20), 10613-10653. doi:10.1021/cr5002436Lanzafame, P., Centi, G., & Perathoner, S. (2014). Evolving scenarios for biorefineries and the impact on catalysis. Catalysis Today, 234, 2-12. doi:10.1016/j.cattod.2014.03.022Katryniok, B., Paul, S., & Dumeignil, F. (2013). Recent Developments in the Field of Catalytic Dehydration of Glycerol to Acrolein. ACS Catalysis, 3(8), 1819-1834. doi:10.1021/cs400354pZhang, J., Zhao, Y., Pan, M., Feng, X., Ji, W., & Au, C.-T. (2010). Efficient Acrylic Acid Production through Bio Lactic Acid Dehydration over NaY Zeolite Modified by Alkali Phosphates. ACS Catalysis, 1(1), 32-41. doi:10.1021/cs100047pChu, H. S., Ahn, J.-H., Yun, J., Choi, I. S., Nam, T.-W., & Cho, K. M. (2015). Direct fermentation route for the production of acrylic acid. Metabolic Engineering, 32, 23-29. doi:10.1016/j.ymben.2015.08.005Sheldon, R. A. (2014). Green and sustainable manufacture of chemicals from biomass: state of the art. Green Chem., 16(3), 950-963. doi:10.1039/c3gc41935eZhou, C. H., Zhao, H., Tong, D. S., Wu, L. M., & Yu, W. H. (2013). Recent Advances in Catalytic Conversion of Glycerol. Catalysis Reviews, 55(4), 369-453. doi:10.1080/01614940.2013.816610Talebian-Kiakalaieh, A., Amin, N. A. S., & Hezaveh, H. (2014). Glycerol for renewable acrolein production by catalytic dehydration. Renewable and Sustainable Energy Reviews, 40, 28-59. doi:10.1016/j.rser.2014.07.168J. L. Dubois Arkema Fr. WO 2007090991 2007J. L. Dubois Arkema Fr. WO 2008007002 2008Wang, F., Xu, J., Dubois, J.-L., & Ueda, W. (2010). Catalytic Oxidative Dehydration of Glycerol over a Catalyst with Iron Oxide Domains Embedded in an Iron Orthovanadate Phase. ChemSusChem, 3(12), 1383-1389. doi:10.1002/cssc.201000245Soriano, M. D., Concepción, P., Nieto, J. M. L., Cavani, F., Guidetti, S., & Trevisanut, C. (2011). Tungsten-Vanadium mixed oxides for the oxidehydration of glycerol into acrylic acid. Green Chemistry, 13(10), 2954. doi:10.1039/c1gc15622eDeleplanque, J., Dubois, J.-L., Devaux, J.-F., & Ueda, W. (2010). Production of acrolein and acrylic acid through dehydration and oxydehydration of glycerol with mixed oxide catalysts. Catalysis Today, 157(1-4), 351-358. doi:10.1016/j.cattod.2010.04.012Omata, K., Matsumoto, K., Murayama, T., & Ueda, W. (2016). Direct oxidative transformation of glycerol to acrylic acid over Nb-based complex metal oxide catalysts. Catalysis Today, 259, 205-212. doi:10.1016/j.cattod.2015.07.016Chieregato, A., Soriano, M. D., Basile, F., Liosi, G., Zamora, S., Concepción, P., … López Nieto, J. M. (2014). One-pot glycerol oxidehydration to acrylic acid on multifunctional catalysts: Focus on the influence of the reaction parameters in respect to the catalytic performance. Applied Catalysis B: Environmental, 150-151, 37-46. doi:10.1016/j.apcatb.2013.11.045Chieregato, A., Soriano, M. D., García-González, E., Puglia, G., Basile, F., Concepción, P., … Cavani, F. (2014). Multielement Crystalline and Pseudocrystalline Oxides as Efficient Catalysts for the Direct Transformation of Glycerol into Acrylic Acid. ChemSusChem, 8(2), 398-406. doi:10.1002/cssc.201402721Chieregato, A., Basile, F., Concepción, P., Guidetti, S., Liosi, G., Soriano, M. D., … Nieto, J. M. L. (2012). Glycerol oxidehydration into acrolein and acrylic acid over W–V–Nb–O bronzes with hexagonal structure. Catalysis Today, 197(1), 58-65. doi:10.1016/j.cattod.2012.06.024Possato, L. G., Cassinelli, W. H., Garetto, T., Pulcinelli, S. H., Santilli, C. V., & Martins, L. (2015). One-step glycerol oxidehydration to acrylic acid on multifunctional zeolite catalysts. Applied Catalysis A: General, 492, 243-251. doi:10.1016/j.apcata.2014.12.049Pestana, C. F. M., Guerra, A. C. O., Ferreira, G. B., Turci, C. C., & Mota, C. J. A. (2013). Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta. Journal of the Brazilian Chemical Society, 24(1), 100-105. doi:10.1590/s0103-50532013000100014Feng, X., Yao, Y., Su, Q., Zhao, L., Jiang, W., Ji, W., & Au, C.-T. (2015). Vanadium pyrophosphate oxides: The role of preparation chemistry in determining renewable acrolein production from glycerol dehydration. Applied Catalysis B: Environmental, 164, 31-39. doi:10.1016/j.apcatb.2014.08.049Wang, F., Dubois, J.-L., & Ueda, W. (2009). Catalytic dehydration of glycerol over vanadium phosphate oxides in the presence of molecular oxygen. Journal of Catalysis, 268(2), 260-267. doi:10.1016/j.jcat.2009.09.024Chieregato, A., López Nieto, J. M., & Cavani, F. (2015). Mixed-oxide catalysts with vanadium as the key element for gas-phase reactions. Coordination Chemistry Reviews, 301-302, 3-23. doi:10.1016/j.ccr.2014.12.003Yun, Y. S., Lee, K. R., Park, H., Kim, T. Y., Yun, D., Han, J. W., & Yi, J. (2014). Rational Design of a Bifunctional Catalyst for the Oxydehydration of Glycerol: A Combined Theoretical and Experimental Study. ACS Catalysis, 5(1), 82-94. doi:10.1021/cs501307vPastore, H. O., Coluccia, S., & Marchese, L. (2005). POROUS ALUMINOPHOSPHATES :From Molecular Sieves to Designed Acid Catalysts. Annual Review of Materials Research, 35(1), 351-395. doi:10.1146/annurev.matsci.35.103103.120732Dummer, N. F., Weng, W., Kiely, C., Carley, A. F., Bartley, J. K., Kiely, C. J., & Hutchings, G. J. (2010). Structural evolution and catalytic performance of DuPont V-P-O/SiO2 materials designed for fluidized bed applications. Applied Catalysis A: General, 376(1-2), 47-55. doi:10.1016/j.apcata.2009.10.004Soriano, M. D., Chieregato, A., Zamora, S., Basile, F., Cavani, F., & López Nieto, J. M. (2015). Promoted Hexagonal Tungsten Bronzes as Selective Catalysts in the Aerobic Transformation of Alcohols: Glycerol and Methanol. Topics in Catalysis, 59(2-4), 178-185. doi:10.1007/s11244-015-0440-7García-González, E., Soriano, M. D., Urones-Garrote, E., & López Nieto, J. M. (2014). On the origin of the spontaneous formation of nanocavities in hexagonal bronzes (W,V)O3. Dalton Trans., 43(39), 14644-14652. doi:10.1039/c4dt01465kConcepción, P., Blasco, T., López Nieto, J. M., Vidal-Moya, A., & Martı́nez-Arias, A. (2004). Preparation, characterization and reactivity of V- and/or Co-containing AlPO-18 materials (VCoAPO-18) in the oxidative dehydrogenation of ethane. Microporous and Mesoporous Materials, 67(2-3), 215-227. doi:10.1016/j.micromeso.2003.11.005Ross-Medgaarden, E. I., & Wachs, I. E. (2007). Structural Determination of Bulk and Surface Tungsten Oxides with UV−vis Diffuse Reflectance Spectroscopy and Raman Spectroscopy. The Journal of Physical Chemistry C, 111(41), 15089-15099. doi:10.1021/jp074219cWachs, I. E., Deo, G., Weckhuysen, B. M., Andreini, A., Vuurman, M. A., Boer, M. de, & Amiridis, M. D. (1996). Selective Catalytic Reduction of NO with NH3over Supported Vanadia Catalysts. Journal of Catalysis, 161(1), 211-221. doi:10.1006/jcat.1996.0179Argyle, M. D., Chen, K., Bell, A. T., & Iglesia, E. (2002). Effect of Catalyst Structure on Oxidative Dehydrogenation of Ethane and Propane on Alumina-Supported Vanadia. Journal of Catalysis, 208(1), 139-149. doi:10.1006/jcat.2002.3570Grant, J. T., Carrero, C. A., Love, A. M., Verel, R., & Hermans, I. (2015). Enhanced Two-Dimensional Dispersion of Group V Metal Oxides on Silica. ACS Catalysis, 5(10), 5787-5793. doi:10.1021/acscatal.5b01679Cavani, F., Luciani, S., Esposti, E. D., Cortelli, C., & Leanza, R. (2010). Surface Dynamics of A Vanadyl Pyrophosphate Catalyst forn-Butane Oxidation to Maleic Anhydride: An In Situ Raman and Reactivity Study of the Effect of the P/V Atomic Ratio. Chemistry - A European Journal, 16(5), 1646-1655. doi:10.1002/chem.200902017Cavani, F., De Santi, D., Luciani, S., Löfberg, A., Bordes-Richard, E., Cortelli, C., & Leanza, R. (2010). Transient reactivity of vanadyl pyrophosphate, the catalyst for n-butane oxidation to maleic anhydride, in response to in-situ treatments. Applied Catalysis A: General, 376(1-2), 66-75. doi:10.1016/j.apcata.2009.10.037Caldarelli, A., Bañares, M. A., Cortelli, C., Luciani, S., & Cavani, F. (2014). An investigation on surface reactivity of Nb-doped vanadyl pyrophosphate catalysts by reactivity experiments and in situ Raman spectroscopy. Catal. Sci. Technol., 4(2), 419-427. doi:10.1039/c3cy00705gConcepción, P., & López Nieto, J. . (2001). Novel synthesis of a vanadium–cobalt aluminophosphate molecular sieve of AEI structure (VCoAPO-18) and its catalytic behaviour for the ethane oxidation. Catalysis Communications, 2(11-12), 363-367. doi:10.1016/s1566-7367(01)00061-9Lourenço, J. P., Macedo, M. I., & Fernandes, A. (2012). Sulfonic-functionalized SBA-15 as an active catalyst for the gas-phase dehydration of Glycerol. Catalysis Communications, 19, 105-109. doi:10.1016/j.catcom.2011.12.029Massa, M., Andersson, A., Finocchio, E., & Busca, G. (2013). Gas-phase dehydration of glycerol to acrolein over Al2O3-, SiO2-, and TiO2-supported Nb- and W-oxide catalysts. Journal of Catalysis, 307, 170-184. doi:10.1016/j.jcat.2013.07.022Massa, M., Andersson, A., Finocchio, E., Busca, G., Lenrick, F., & Wallenberg, L. R. (2013). Performance of ZrO 2 -supported Nb- and W-oxide in the gas-phase dehydration of glycerol to acrolein. Journal of Catalysis, 297, 93-109. doi:10.1016/j.jcat.2012.09.021Zhang, H., Hu, Z., Huang, L., Zhang, H., Song, K., Wang, L., … Tang, Y. (2015). Dehydration of Glycerol to Acrolein over Hierarchical ZSM-5 Zeolites: Effects of Mesoporosity and Acidity. ACS Catalysis, 5(4), 2548-2558. doi:10.1021/cs5019953Foo, G. S., Wei, D., Sholl, D. S., & Sievers, C. (2014). Role of Lewis and Brønsted Acid Sites in the Dehydration of Glycerol over Niobia. ACS Catalysis, 4(9), 3180-3192. doi:10.1021/cs5006376Concepción, P., Corma, A., López Nieto, J. M., & Pérez-Pariente, J. (1996). Selective oxidation of hydrocarbons on V- and/or Co-containing aluminophosphate (MeAPO-5) using molecular oxygen. Applied Catalysis A: General, 143(1), 17-28. doi:10.1016/0926-860x(96)00068-3KAMIYA, Y., NISHIYAMA, H., YASHIRO, M., SATSUMA, A., & HATTORI, T. (2003). The Role of Bronsted and Lewis Acid Sites of Vanadyl Pyrophosphate Measured by Dimethylpyridine-temperature Programmed Desorption in the Selective Oxidation of Butane. Journal of the Japan Petroleum Institute, 46(1), 62-68. doi:10.1627/jpi.46.62Yoda, E., & Ootawa, A. (2009). Dehydration of glycerol on H-MFI zeolite investigated by FT-IR. Applied Catalysis A: General, 360(1), 66-70. doi:10.1016/j.apcata.2009.03.009Tichý, J. (1997). Oxidation of acrolein to acrylic acid over vanadium-molybdenum oxide catalysts. Applied Catalysis A: General, 157(1-2), 363-385. doi:10.1016/s0926-860x(97)00025-2Andrushkevich, T. V., & Popova, G. Y. (1991). Mechanism of heterogeneous oxidation of acrolein to acrylic acid. Russian Chemical Reviews, 60(9), 1023-1034. doi:10.1070/rc1991v060n09abeh001126López Nieto, J. M., Concepción, P., Dejoz, A., Knözinger, H., Melo, F., & Vázquez, M. I. (2000). Selective Oxidation of n-Butane and Butenes over Vanadium-Containing Catalysts. Journal of Catalysis, 189(1), 147-157. doi:10.1006/jcat.1999.2689Davydov, A. (2003). Molecular Spectroscopy of Oxide Catalyst Surfaces. doi:10.1002/0470867981Shee, D., & Deo, G. (2009). Adsorption and ODH reaction of alkane on sol–gel synthesized TiO2–WO3 supported vanadium oxide catalysts: In situ DRIFT and structure–reactivity study. Journal of Molecular Catalysis A: Chemical, 308(1-2), 46-55. doi:10.1016/j.molcata.2009.03.032Bhattacharyya, K., Varma, S., Tripathi, A. K., Bharadwaj, S. R., & Tyagi, A. K. (2009). Mechanistic Insight byin SituFTIR for the Gas Phase Photo-oxidation of Ethylene by V-Doped Titania and Nano Titania. The Journal of Physical Chemistry B, 113(17), 5917-5928. doi:10.1021/jp8103529Centi, G., Cavani, F., & Trifirò, F. (2001). Selective Oxidation by Heterogeneous Catalysis. Fundamental and Applied Catalysis. doi:10.1007/978-1-4615-4175-2Tichý, J., & Davydov, A. A. (1976). Interaction of acrolein with vanadium-molybdenum oxide catalyst surface. Collection of Czechoslovak Chemical Communications, 41(3), 834-838. doi:10.1135/cccc19760834Blasco, T., & Nieto, J. M. L. (1997). Oxidative dyhydrogenation of short chain alkanes on supported vanadium oxide catalysts. Applied Catalysis A: General, 157(1-2), 117-142. doi:10.1016/s0926-860x(97)00029-xPavarelli, G., Velasquez Ochoa, J., Caldarelli, A., Puzzo, F., Cavani, F., & Dubois, J.-L. (2015). A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol. ChemSusChem, 8(13), 2250-2259. doi:10.1002/cssc.201500095Centi, G., Cavani, F., & Trifirò, F. (2001). Control of the Surface Reactivity of Solid Catalysts. Fundamental and Applied Catalysis, 203-283. doi:10.1007/978-1-4615-4175-2_5Griffith, C. S., & Luca, V. (2004). Ion-Exchange Properties of Microporous Tungstates. Chemistry of Materials, 16(24), 4992-4999. doi:10.1021/cm049335

Il valore dell’incertezza : gli effetti della pandemia tra crisi e cambiamento

L’emergenza pandemica attuale svela il tema della vulnerabilità umana, l’incertezza che accompagna le esistenze, nonché l’impossibilità di esercitare un controllo sull’intreccio di variabili che interagiscono in un sistema complesso. Si presenta come sintomo di una crisi più profonda di quella esclusivamente sanitaria: è la crisi dei paradigmi epistemologici e socio-economici della società modernamente intesa, rispetto ai quali si impone l’esigenza di un cambiamento radicale. Perché non guardare a tale crisi anche come a un’occasione? Il contributo si interroga sulla possibilità che il cambiamento possa generare una (ri)nascita, grazie a soggetti protagonisti di narrazioni inedite. In tale contesto si inserisce l’indagine qualitativa L’educazione ai tempi del Coronavirus (e dopo), svolta dal CREIF (Università di Bologna) con l’obiettivo di indagare quali siano state, da parte dei professionisti dell’educazione, le emozioni vissute e le risposte elaborate durante la prima fase dell’emergenza. La ricerca ha esplorato le aree relative al senso e alla motivazione attribuiti alla propria azione educativa, ai timori emersi, alle idee sollecitate dal cambiamento, interrogandosi sulle possibili condizioni strutturali in grado di favorire «uscite creative». La valorizzazione del lavoro in équipe — in grado di alimentare processi riflessivi — e la centralità dei processi di accompagnamento e formazione continua emergono quali elementi cruciali

Efeito da maturação epididimária no conteúdo de micro-RNAs em espermatozoides bovinos

Pesquisa sem auxílio de agências de fomentoTrabalho de Conclusão de Curso (Graduação)Os micro-RNAs (miRNAs) são uma classe de pequenas moléculas RNAs não codificantes de proteínas que atuam no processo regulatório de diversos eventos biológicos, como a espermatogênese. Com isso, acredita-se que essas moléculas possuem relação com o desenvolvimento embrionário, sendo importantes para estudos de fertilidade em touros. No presente estudo, objetivou-se avaliar a influência da maturação epididimária sobre os miRNA espermáticos bovinos, identificando quais tiveram sua quantidade aumentada ou diminuída após passar pelo canal do epidídimo. Foram utilizadas amostras de sêmen de cinco touros para a extração e isolamento dos miRNAs, utilizando o kit mirVana™ miRNAisolation (Invitrogen), para posterior construção de biblioteca, utilizando o kit RealSeq®-AC (Small RNA SomaGenics®) e para sequenciamento, utilizando a IlluminaNextSeqTM 500 V2 high-output 75 ciclos. Para a análise da quantidade de miRNAs foram utilizados na seleção e normalização dos dados os softwares DESeq2 e edgeR. Foi possível identificar 28 miRNAs que tiveram sua quantidade diminuída após passar pelo canal do epidídimo e 40 miRNAs que tiveram sua quantidade aumentada. Portanto, a partir desse trabalho, foi possível evidenciar que a maturação epididimária promove alteração no conteúdo de miRNAs dos espermatozoides bovinos, sendo de extrema importância para aprimorar a predição e o diagnóstico de problemas de fertilidade em touros, posteriormente, expandindo esses estudos em humanos

Detection of pulsations and a spectral feature in the X-ray emission of the isolated neutron star 1RXS J214303.7+065419/RBS 1774

We report on the results of a deep XMM-Newton observation of RBS 1774, the most recent dim isolated neutron star candidate found in the ROSAT archive data. Spectral and timing analysis of the high-quality PN and MOS data confirm the association of this source with an isolated neutron star. The spectrum is thermal and blackbody-like, and there is evidence at a significance level > 4sigma that the source is an X-ray pulsar, with spin period of 9.437 s. Spectral fitting reveils the presence of an absorption feature at ~0.7 keV, but at this level data do not have enough resolution to allow us to discriminate between an absorption line or an edge. We compare the newly measured properties of RBS 1774 with those of other known dim isolated neutron stars, and discuss possible interpretations for the absorption feature.Comment: 21 pages, 5 figures, ApJ accepte