Total metallic dispersion of sulfided Pt-Re/Al2O3 naphtha reforming catalysts

Catalysts with Pt, Re and Pt-Re supported on γ alumina were prepared by impregnation or catalytic reduction methods. The activation was performed by calcination–reduction or only direct reduction treatment. These catalysts and a commercial one were sulfided with H2S at 500°C and characterized by chemical analysis, TPR, test reactions (cyclohexane dehydrogenation and cyclopentane hydrogenolysis), chemisorption of H2 and O2 and TEM. The test reactions were affected by S according to the interaction Pt-Re and metallic dispersion of the catalysts, which are functions of the preparation technique. The presence of S inhibits H2 chemisorption, which cannot be used as a measure of the metallic dispersion. Nevertheless, sulfidation or Pt-Re alloying does not affect the O2 chemisorption and this chemisorption can be used to calculate the total (Pt+Re) metallic dispersion with a stoichiometry ratio Pt or Re/O equal to 1.Fil: Pieck, Carlos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Gonzalez, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Hydroisomerization–cracking of n-octane on Pt/WO42−–ZrO2 and Pt/SO42−–ZrO2: Effect of Pt load on catalyst performance

The hydroconversion (isomerization–cracking) of n-octane was studied at 300°C, 1.5 MPa, WHSV=4 and H2/nC8=6 using oxoanion promoted zirconia with different Pt concentrations (0.1, 0.5 and 1%) as catalysts. Tungstate was added to zirconia by impregnation with ammonium meta-tungstate or tungstic acid solutions and calcined at 800°C. Sulfate was added by impregnation with 2N H2SO4 and calcined at 620°C. Isooctanes are intermediate products that are cracked to C3–C5 alkanes with predominance of isoalkanes. Sulfate zirconia is the most active and selective catalyst to cracking products. The addition of 0.1% of Pt produces an increase in activity and stability, respect of the support without metal. However, the increase in Pt content (0.5 and 1.0%) produces a decrease in nC8 conversion and in cracking products. The metallic properties of Pt are decreased by its strong interaction with the support, mainly with sulfate zirconia; at the same time, Pt decreases the acid cracking activity of the support.Fil: Grau, Javier Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Preventing self-poisoning in [Pt/Al2O3 + SO42−-ZrO2] mixed catalysts for isomerization-cracking of heavy alkanes by prereduction of the acid function

The activity and stability of composite catalysts obtained by mixing Pt/Al2O3 with SO42−-ZrO2, were studied in the reaction of hydroisomerization-cracking of n-octane (300 °C, 1.5 MPa, WHSV=4 h−1, H2/n-C8=6) obtaining light isoalkanes (isobutane, isopentane, isohexane), very important components of the pool of reformulated gasoline. Both components of the composites were pretreated in H2 before mixing. Prereduction eliminated the fraction of SO42− reducible at low temperature, thought to produce SO2 during reaction, a poison for the metal function. A reduction in the poisoning of the metal, produced by adsorption of S compounds, was tried in order to get a higher metal activity for the production of atomic H, needed for the hydrogenation of coke precursors and the prevention of deactivation. The pretreatment temperature was adjusted between 300 and 500 °C in order to keep a suitable amount of sulfate, needed for a sustainable isomerizing-cracking activity and for the stabilization of the tetragonal crystal phase of ZrO2, the most catalytically active crystal phase. When compared to non-reduced catalysts, composites reduced at 300–350 °C displayed improved activity and stability for benzene hydrogenation, a metal-catalyzed reaction, and the results were addressed to a decrease in S poisoning. In the pretreated composites the SO42−-ZrO2 active tetragonal phase was maintained in spite of the loss of S. For isomerization-cracking of n-octane, the pretreated catalysts showed a higher selectivity to isobutane and a fairly longer stability than non-pretreated catalysts, like Pt/SO42−-ZrO2 and SO42−-ZrO2 mixed with Pt/Al. TPO tests showed that the catalysts were essentially free of coke. This fact was addressed to a lower coking rate on prereduced sites and to a higher metal activity for hydrogenation of coke precursors.Fil: Grau, Javier Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Tetragonal structure, anionic vacancies and catalytic activity of SO42−-ZrO2 catalysts for n-butane isomerization

Abstract An assessment of the influence of the crystal structure, surface hydroxylation state and previous oxidation/reduction pretreatments on the activity of sulfate-zirconia catalysts for isomerization of n-butane was performed using crystalline and amorphous zirconia supports. Different sulfation methods were used for the preparation of bulk and supported SO42−-ZrO2 with monoclinic, tetragonal and tetragonal+monoclinic structures. Activity was important only for the samples that contained tetragonal crystals. The catalysts prepared from pure monoclinic zirconia showed negligible activity. SO42−-ZrO2 catalysts prepared by sulfation of crystalline zirconia displayed sites with lower acidity and cracking activity than those sulfated in the amorphous state. Prereduction of the zirconia samples with H2 was found to greatly increase the catalytic activity, and a maximum rate was found at a reduction temperature of 550–600 °C, coinciding with a TPR peak supposedly associated with the removal of lattice oxygen and the creation of lattice defects. A weaker dependence of catalytic activity on the density or type of surface OH groups on zirconia (before sulfation) was found in this work. A model of active site generation was constructed in order to stress the dependence on the crystal structure and crystal defects. Current and previous results suggest that tetragonal structure in active SO42−-ZrO2 is a consequence of the stabilization of anionic vacancies in zirconia. Anionic vacancies are in turn supposed to be related to the catalytic activity for n-butane isomerization through the stabilization of electrons from ionized intermediates.Fil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Pieck, Carlos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Shimizu, Kiyoyuki. National Institute for Resources and Environment (NIRE) (AIST, MITI); JapónFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Pt/SO42−-ZrO2 catalysts prepared from Pt organometallic compounds

New Pt/SO42−-ZrO2 catalysts were prepared using precalcined SO42−-ZrO2 and organometallic Pt precursors. The objective was to obtain a bifunctional catalyst with improved metal properties, which are mostly suppressed in Pt/SO42−-ZrO2 prepared in a standard fashion. The synthesis route used low temperatures to form the Pt particles in order to avoid sulfate decomposition and Pt poisoning. The use of precalcined zirconia decreased ionic diffusion, related to crystallization of the gel and encapsulation of Pt particles. As detected by TPR and cyclohexane dehydrogenation tests, after reducing at 270 °C, Pt on the new catalyst had metallic properties. Its dehydrogenation activity was higher than that of a standard Pt/SO42−-ZrO2 catalyst (prepared from H2PtCl6). After activating in air at 300 °C, its activity for n-butane isomerization (300 °C, 1 atm., H2:n-C4=6, WHSV=1 h−1) was low, very likely because of incomplete elimination of adsorbed water. After activation in air at 600 °C, the isomerization activity was almost similar to that of standard Pt/SO42−-ZrO2 but the dehydrogenation activity decreased to negligible values. The deleterious interaction between Pt and SO42−-ZrO2 that occurred during calcination was possibly related to oxidation of the metal. On the other side, high reduction temperatures did not enhance the metal activity beyond the level obtained after reducing at 270 °C. On the contrary, the higher the reduction temperature, the lower the activity for cyclohexane dehydrogenation that was obtained. This effect was seemingly related to poisoning by sulfur compounds. The new materials could be potentially useful for reacting systems needing a bifunctional catalyst and an acid function like SO42−-ZrO2 but their operation is limited if high temperatures in air or H2 are necessary for activation.Fil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Pieck, Carlos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Shimizu, Kiyoyuki. National Institute for Advanced Industrial Science and Technology (AIST); JapónFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Audiovisual Tool for understanding Audio concepts for being used in bachelor’s degree programmes

[EN] In the Audio Signal Processing field, there exists difficulties in order to explain different concepts such as, compression, masking, quantization, sampling, among others. Further, most of these concepts require the use of audio laboratories and multiple practical session that must carry out students. Another issue is that there are students that are not able to internalize these concepts straightforwardly and require more practical sessions. In order to address these problems, we have developed an audiovisual tool, designed with Matlab, that can be used for professors and students. This tool allows to analyze, test and apply the audio concepts to real audio signals. The developed tool has been successfully experienced by professors of the audio signal processing field that recommend its use in upcoming academic courses.This research has been partly funded by TIN2014-53495-R, BES-2013-063783, BES-2013- 065034, TEC2013-47141-C4-4-R and FPU AP-2012/71274.Antoñanzas Manuel, C.; Gutiérrez Parera, P.; Simarro Haro, MDLA.; Belloch, JA. (2016). Audiovisual Tool for understanding Audio concepts for being used in bachelor’s degree programmes. En 2nd. International conference on higher education advances (HEAD'16). Editorial Universitat Politècnica de València. 495-502. https://doi.org/10.4995/HEAD16.2016.2923OCS49550

Effects of different inertial load settings on power output using a flywheel leg curl exercise and its inter-session reliability

This study aimed to analyze the influence of the inertial load on both concentric and eccentric power output production during the flywheel leg curl exercise, and to assess the reliability of power output variables. Sixteen participants (8 males, 8 females) attended 4 testing sessions. During testing, participants performed one set of eight repetitions using a specific inertial load (0.083, 0.132, 0.182, 0.266 and 0.350 kg·m2) with a flywheel leg curl exercise. Concentric (CON) power, eccentric (ECC) power and the ECC/CON ratio were analyzed. The reliability analysis between sessions was performed. A significant interaction of inertia load x gender was found in CON power (p < 0.001) and in ECC power (p = 0.004), but not in the ECC/CON ratio (p = 0.731). A significant with-in (inertia loads) effect was found in CON power (p < 0.001) and in ECC power (p < 0.001), but not in the ECC/CON ratio (p = 0.096). CON power showed very high reliability scores, ECC power showed high to very high reliability scores, while the ECC/CON ratio ranged from poor to moderate. A significant between gender effect was found in CON power (p < 0.001) and in ECC power (p < 0.001), but not in the ECC/CON ratio (p = 0.752). This study is the first to report that power output in the flywheel leg curl exercise is altered by the inertia load used, as well as power output is different according to gender. CON and ECC power output presents high to very high reliability scores, and the ECC/CON ratio should not be used instead. These results can have important practical implications for testing and training prescription in sports

Validity and Reliability of the V-Cut Dribbling Test in Young Basketball Players

Purpose: Change of direction while dribbling appears to be of interest for on-court performance in basketball. The study aim was to assess the validity and reliability of the V-cut dribbling test (VcutBk) in young basketball players. Methods: Ninety-two young basketball players from 8 to 21 years old (74% male) were classified in relation to peak height velocity (PHV) offset. To examine validity and test–retest reliability, VcutBk was performed in 2 identical sessions separated by 1 week. Participants also performed the V-cut test and linear sprint test with and without dribbling to analyze correlations between tests in different somatic maturity stages. Results: The relationships of the VcutBk with the other tests and skill-time-related deficits were interpreted from large (r > .51) to very large (r > .71). The comparisons between pre-PHV and post-PHV groups of basketball players showed significant and large effect in the VcutBk (d = 2.04; mean difference = 2.59; 95% CI, 1.86 to 3.32). Also, significant main effects when comparing PHV groups were reported in all skill-time-related deficits (P < .001, η 2 p = . 13 − .28 , moderate to large effect size). Test–retest reliability and signal-to-noise ratio analysis did not show substantial between-trials differences in VcutBk. Reliability scores showed high intraclass correlation coefficient (.95) and low coefficient of variation (0.23%). Conclusions: The VcutBk seems to be a valid and reliable test to assess change of direction while dribbling. VcutBk performance and skill-time-related deficits seem to be sensitive to somatic maturity. Basketball coaches should consider the VcutBk to assess young basketball players

Functionalization of 3D scaffolds with protein-releasing biomaterials for intracellular delivery

[EN] Appropriate combinations of mechanical and biological stimuli are required to promote proper colonization of substrate materials in regenerative medicine. In this context, 3D scaffolds formed by compatible and biodegradable materials are under continuous development in an attempt to mimic the extracellular environment of mammalian cells. We have here explored how novel 3D porous scaffolds constructed by polylactic acid, polycaprolactone or chitosan can be decorated with bacterial inclusion bodies, submicron protein particles formed by releasable functional proteins. A simple dipping-based decoration method tested here specifically favors the penetration of the functional particles deeper than 300 &#956;m from the materials' surface. The functionalized surfaces support the intracellular delivery of biologically active proteins to up to more than 80% of the colonizing cells, a process that is slightly influenced by the chemical nature of the scaffold. The combination of 3D soft scaffolds and protein-based sustained release systems (Bioscaffolds) offers promise in the fabrication of bio-inspired hybrid matrices for multifactorial control of cell proliferation in tissue engineering under complex architectonic setting-ups.We are indebted to MINECO (BFU2010-17450), AGAUR (2009SGR-0108 and SGR2009-516), DGI (CTQ2010-19501) and CIBER de Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN, Spain) for funding our research on Inclusion bodies. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, and Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. EGF is supported by the Programa Personal de Tecnico de Apoyo (Modalidad Infraestructuras cientifico-tecnologicas, MICINN). We also thank technical assistance from the Servei de Cultius Celulars, Produccio d'Anticossos i Citometria (SCAC) Laboratori de Luminescencia i Espectroscopia de Biomolecules (LLEB) and Servei de Microscopia, all at the Universitat Autonoma de Barcelona (UAB). We are also indebted to the Protein Production Platform (CIBER-BBN) for helpful technical assistance and for protein production and purification services (http://bbn.ciber-bbn.es/programas/plataformas/equipamiento). AV received an ICREA ACADEMIA award.Seras-Franzoso, J.; Steurer, C.; Roldan, M.; Vendrell, M.; Vidaurre-Agut, C.; Tarruella, A.; Saldana, L.... (2013). Functionalization of 3D scaffolds with protein-releasing biomaterials for intracellular delivery. Journal of Controlled Release. 171(1):63-72. https://doi.org/10.1016/j.jconrel.2013.06.034S6372171

Relationship between Sprint, Change of Direction, Jump, and Hexagon Test Performance in Young Tennis Players

[EN] The hexagon agility test is widely used in tennis players’ fitness evaluation, although its validity has not been fully stablished. This study aimed to assess the relationships between sprinting, jumping, and change of direction (COD) ability and hexagon test performance. Thirty-five under-16 tennis players completed a testing battery including the hexagon test, 20-m linear sprint, bilateral and unilateral countermovement jumps (CMJ), triple leg-hop for distance, T-Test, 5-0-5 and Pro-Agility test on two different sessions, separated by one week. The intraclass correlation coefficient (ICC) and the standard error of measurement (SEM) were used to assess the reliability of the test. Pearson’s product correlations (r) were used to analyze the relationships between the hexagon test and the other fitness tests. Statistical significance was set at p < 0.05. The hexagon test showed high relative reliability (ICC = 0.88) and low SEM values (0.17 s). Significant small to large correlations were found between the hexagon test time and linear sprint time (r = 0.40 to 0.60), COD tests (r = 0.53 to 0.79), and jumping performance (r = -0.40 to -0.68). The hexagon test is a simple, quick, easy-toimplement and reliable test, which allow it to be included in tennis players’ testing batteries. The test is related to measures of speed, power and agility, although the magnitude of these relationships does not allow for the replacement of the more traditional assessments (e.g., CMJ, 20-m sprint, T-Test) within tennis players’ testing batteries.S