5 research outputs found

    Synthesis of the Ti-Silicate Form of BEC Polymorph of B-Zeolite Assisted by Molecular Modeling

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/jp805400u Published Work, see http://pubs.acs.org/page/policy/articlesonrequest/index.html[EN] The K(+) free pure silica form of polymorph C (BEC) of beta-zeolite has been synthesized with a cationic organic structure directing agent (SDA) that was predicted best, out of a series of nine potentials, by means of modeling techniques. On the bases of this synthesis method, the Ti-BEC zeolite has been obtained which owing to the pore topology and dimensions shows a higher epoxidation activity than the Ti-beta-polymorph either with H(2)O(2) or organic peroxides as oxidants.The authors thank the CICYT for financial support (Project MAT 2006-14274-CO2-01). G.S. thanks "Centro de Calculo de la Universidad Politecnica de Valencia" for the use of their computational facilities. M.M. and P.S. thank ITQ for a scholarship. We also thank intramural project CRENATUM.Moliner Marin, M.; Serna Merino, PM.; Cantin Sanz, A.; Sastre Navarro, GI.; Díaz Cabañas, MJ.; Corma Canós, A. (2008). Synthesis of the Ti-Silicate Form of BEC Polymorph of B-Zeolite Assisted by Molecular Modeling. The Journal of Physical Chemistry C. 112(49):19547-19554. https://doi.org/10.1021/jp805400uS19547195541124

    Synthesis and Structure of a 22 12 12 Extra-Large Pore Zeolite ITQ-56 Determined by 3D Electron Diffraction

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    [Image: see text] A multidimensional extra-large pore germanosilicate, denoted ITQ-56, has been synthesized by using modified memantine as an organic structure-directing agent. ITQ-56 crystallizes as plate-like nanocrystals. Its structure was determined by 3D electron diffraction/MicroED. The structure of ITQ-56 contains extra-large 22-ring channels intersecting with straight 12-ring channels. ITQ-56 is the first zeolite with 22-ring pores, which is a result of ordered vacancies of double 4-ring (d4r) units in a fully connected zeolite framework. The framework density is as low as 12.4 T atoms/1000 Å(3). The discovery of the ITQ-56 structure not only fills the missing member of extra-large pore zeolite with 22-ring channels but also creates a new approach of making extra-large pore zeolites by introducing ordered vacancies in zeolite frameworks

    Objectively measured and self-reported leisure-time sedentary behavior and academic performance in youth: The UP&DOWN Study

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    The objective of this study was to examine the associations of objectively measured and self-reported sedentary behavior during leisure time with academic performance and patterns of sedentary behavior with academic performance. This study was conducted with 1146 youth aged 12.5 ± 2.5 years in Spain during 2011–2012. Leisure-time sedentary behavior during out-of-school hours was assessed by accelerometry and self-report. Academic performance was assessed through school grades.Evaluación de la interacción entre genética y actividad física en el estado físico y la salud en escolares y adolescentes con Síndrome de Down: estudio de seguimiento a tres años Plan Nacional de I+D+i. Ministerio de Ciencia e Innovación (Ref. DEP2010-21662-C04-02).2.893 JCR (2015) Q1, 24/151 Medicine, general & internal, 34/172 Public, environmental & occupational healthUE

    Perceived environment in relation to objective and self-reported physical activity in Spanish youth. The UP&DOWN study

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    The aims of the present study were to assess the association of environmental perception with objective and self-reported physical activity (PA) and the relation between environmental perception and meeting PA recommendations on children and adolescents. A sample of 1520 youth (770 boys) aged 8-18 years (12.1 ± 2.5 years) from the UP&DOWN study were included in the data analyses. Environmental perception was assessed with the short adapted version of the ALPHA environmental questionnaire. PA was objectively (accelerometers) and self-reported measured (PA Questionnaire for Children, Patient-centered Assessment and Counseling for Exercise Questionnaire and Finnish PA Index). Linear regression models were used to assess the association of environmental perception with PA. Bivariate logistic regression models were used to assess differences between environmental perception and meeting PA recommendations. Environmental perception was positively associated with both objective and self-reported PA. Some differences were found in the association of environmental perception and PA between sex-and age-specific groups. Youth who perceived a more favourable environment were more likely to meet PA recommendations (at least 60 min · day− 1 of moderate to vigorous PA (MVPA)). Results suggest that environmental perceptions of children and adolescents may play an important role in achieving higher levels of PA.Plan Nacional de I+D+I MICINN (DEP 2010-21662-C04- 00)2.539 JCR (2016) Q2, 17/81 Sport Sciences1.280 SJR (2016) Q1, 31/280 Orthopedics and Sports Medicine, 18/195 Physical Therapy, Sports Therapy and Rehabilitation, 29/127 Sports ScienceNo data IDR 2016UE
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