UTN- FRC -Producción Académica de Investigación y Desarrollo - Artículos
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Item Vanadium and titanium oxide supported on mesoporous CMK-3 as new catalysts for oxidative desulfurization.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Juárez , Juliana María; Falcón , Horacio; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Juárez , Juliana MaríaVanadium supported-CMK-3 catalysts with vanadium loading of 1–7 wt.% were studied in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. The activity was compared with titanium supported-CMK-3. Structural and textural characterization of the catalysts was performed by means of N2 adsorption, XRD, UV–vis–DRS, Raman spectroscopy, XPS, TEM and TPR. The dispersion and the nature of the vanadium species depend on the V loading, so does the catalyst activity. Vanadium supported-CMK-3 with 7 wt.% of vanadium loading was the most active catalyst for ODS of DBT using hydrogen peroxide (H2O2) as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at short time in mild conditions. Carbon ordered mesoporous CMK-3 with high surface area and high pore volume promotes a very good anchorage of metallic oxides in the carbons framework reaching high active sites distribution and more stable nanoclusters. The reusability of the catalyst indicates that V-CMK-3 is a potential catalyst for the ODS of dibenzothiopheneItem Sulfur elimination by oxidative desulfurization with titanium-modified SBA-16.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Ponte , María Virginia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María Laura; Ponte , María Virginia; Ledesma , Brenda Cecilia; Vallés , Verónica AlejandraTiO2-modified mesoporous SBA-16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. Pure TiO2 was used as reference. The titania-based catalysts were characterized by chemical analysis, XRD, EDX and TEM. The titanium state as tetrahedral (in Ti-SBA-16 sample) or octahedral (in TiO2/SBA-16 sample) coordination surrounding in the silicate matrix was determined by XPS, UV–vis DRS, FTIR, Raman and XANES. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction temperature, nature of the substrate and reuse of catalysts). In addition, we carried out a kinetic study and the activation energy was determined. We achieved 90% of S removal from a 0.2 wt.% dibenzothiophene solution at 60 ◦C in less than 1 h of reaction. The best catalytic results are obtained with high exposed surface of nanometric TiO2 species of TiO2/SBA-16 sample. The activated catalyst is very active in ODS reaction and can be reused four times with no loss in activity.Item Optimization of the synthesis of SBA-3 mesoporous materials by experimental desing.(Univesidsad Tecnológica Nacional., 2015) Ponte , María Virginia; Rivoira , Lorena Paola; Cussa , jorgelina; Martínez , María Laura; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Anunziata; Cussa , jorgelina; Rivoira , Lorena PaolaSBA-3 mesoporous materials are characterized by hexagonal regular arrangements of channels with diameters >2 nm, high specific surface areas and high specific pore volumes. In the work reported herein, experimental design-response surface methodology (RSM) is used to model and optimize the synthesis conditions for SBA-3 mesoporous materials. In this study, we evaluate the influences of surfactant/silica source molar ratios, aging times, temperature and pH on the synthesis of SBA-3 mesoporous materials by analyzing the XRD intensities pertaining to the [100] signal. Response surfaces were obtained using the BoxeBehnken design, and the combination of reaction parameters was optimized. By applying statistical methodology, higher levels of the objective function (XRD intensities pertaining to the [100] signal) were obtained using cetyltrimethylammonium bromide (CTAB)/tetraethyl orthosilicate (TEOS) molar ratios of 0.07 and 0.16, HCl/TEOS molar ratios of 8 and 11, reaction temperatures of 35 and 45 ◦C and aging times of 12e24 h. The mesoporous SBA-3 samples obtained were characterized using small-angle X-ray powder diffraction (XRD), BET, FTIR and 29Si NMR-MAS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).Item Synthesis and characterization of 2D-hexagonal, 3D-hexagonal and cubic mesoporous materials using CTAB and silica gel.(Univesidsad Tecnológica Nacional., 2016) Martínez , María Laura; Falcón, Horacio; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar AlfredoHighly ordered mesoporous materials SBA family (Santa Barbara Amorphous), with symmetry of two-dimen sional (2D)-hexagonal SBA-3, three-dimensional (3D)-hexagonal P63/mmc (SBA-7) and cubic Pm3n (SBA-1) were synthesized by a simple and easy procedure, designed using silica gel as a silicon source, CTAB (cetyltrimethylammonium bromide) as a structure-directing agent, in highly acidic conditions. The effect of the variation of temperature and reaction time allowed us to obtain the optimum condition to prepare SBA-1, SBA-3 and SBA-7 materials. The sodium silicate generated “in situ” by dissolution of the silica gel, at different con centrations of NaOH and the variation of the synthesis temperature and reaction time are the three factors which allow obtaining different SBA phases. Thus, the best SBA-3, SBA-1 and SBA-7 materials with well-ordered meso- porous system can be obtained in the range of 0.8, 0.9 and 1.0 NaOH concentration and 30 and 25 °C and 45, 2880, 1440 min (for SBA-3, SBA-1 and SBA-7 respectively)Item Vanadium oxide supported on mesoporous SBA-15 modified with AI and Ga as a highly active catalyst in the ODS of DBT.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María LauraVanadium oxides supported on mesoporous SBA-15 catalysts with different vanadium loadings were studied in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. The catalytic activity was improved when SBA-15 framework was modified by adding Al and Ga. Structural and textural characterization of the catalysts were performed by means of XRD, N2 adsorption, UVeVis eDRS, XPS, NMR, TEM, Raman, TPR and Py-FTIR. UVeViseDRS and Raman demonstrated that highly dispersed vanadium VO—3 species are responsible for the high activity in the sulfur removal. The Ga modified support with an intermediate V/Si ratio of 1/30 was the most active catalyst for ODS of DBT, using hydrogen peroxide as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at a short time in mild conditions. Gallium and aluminum incorporation into the support modified suc cessfully the nature of the SBA-15 surface by generating Bronsted and Lewis acidity. The interaction between the acid sites with the active vanadium sites improved the activity of the catalysts. The high dispersion depended on the vanadium loading and on the nature of the support. The more acidic support allowed better dispersion of the vanadium species due to stronger interaction metal-support. The reusability of the catalysts indicates that vanadium oxide supported on mesoporous SBA-15 modified with Ga and Al are potential catalysts for the ODS of dibenzothiopheneItem Estudio experimental y modelado del flujo hidráulico en suelos limo-bentoníticos compactados para su uso en barreras naturales(Revista de Geología Aplicada a la Ingeniería y al Ambiente, 2015) Alercia Biga, Carolina; Eberhardt, Marcelo G.; Arrúa , Pedro A.; Aiassa Martínez, Gonzalo MartínLos suelos loéssicos de Córdoba, presentan una estructura macroporosa y un marcado comportamiento inestable en presencia del agua. Esta característica estructural, los vuelve vulnerables en los procesos de conducción y transporte de agentes externos bajo fenómenos de infiltración. Su mejoramiento mediante el empleo y adición de materiales naturales como la motmorillonita sódica, hace posible su uso como barreras naturales de baja permeabilidad acorde a lo reglamentado por los organismos internacionales. De esta forma, se logra la disminución de su valor de conductividad hidráulica lo cual permite su empleo en la construcción de depósitos de rellenos sanitarios. En este trabajo, se presentan resultados de infiltración en muestras remoldeadas de suelo local con adición de bentonita sódica en diferentes porcentajes, moldeadas con diferentes valores de densidad de compactación. Se analizó el comportamiento hidráulico mediante el uso de un equipo de permeabilidad a pared flexible y se ha establecido el ascenso capilar. Los resultados indican que es posible la disminución de la infiltración de un fluido permeante a través del medio poroso, mediante el incremento de la densidad natural del suelo optimizada mediante procesos mecánicos en conjunto con la incorporación de bentonita. Se observó una respuesta experimental no lineal en las curvas de infiltración obtenidas en diferentes mezclas mejoradas con adición de bentonita. Este comportamiento de características variables, en función del tiempo y de la presencia de adición incorporada, permitió establecer los parámetros necesarios para calibrar el modelo de infiltración propuesto.Item Target tracking system using multiple cameras and bayesian estimation(IEEE LATIN AMERICA TRANSACTIONS, 2016) González Dondo, Diego; Redolfi, Javier; Griffa, M.; Steiner, Guillermo; Canali, Luis RafaelIn recent years, the increase in amount of camera networks available has led to the rise up of new techniques and applications of signal processing. In this work, an implementation of image sensor network, cameras, for mobile target tracking is shown. More specifically, it is performed an application of particle filter in a distributed way, based on leader agents for state estimation. Finally, simulations are presented, as well as a real experiment made with a camera network to track a mobile platform.Item Calibration of multi-camera systems(Journal of Intelligent & Robotic Systems, 2014) González Dondo, Diego; Trasobares, Fernando; Yoaquino, Leandro; Padilla, Julián; Redolfi, Javier—The use of multi-camera systems in target tracking applications demands to know positions and orientations of each one of the cameras in a global coordinate system. In this work is described the development and implementation of an extrinsic calibration method for multi camera systems. A theoretical analysis of each stage of the process is shown, pointing out methods and tools. Furthermore, a new calibration pattern is proposed. The validation is performed with simple experiments and in a real deployment of IP cameras.Item Novel preparation of CMK-3 nanostructured material modified with titania applied in hydrogen uptake and storage.(Univesidsad Tecnológica Nacional., 2016) Juárez , Juliana María; Ledesma , Brenda Cecilia; Gómez Costa, Marcos Bruno; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Ledesma , Brenda CeciliaThis work deals with the development of a novel procedure to synthesize titania-modified nano structured carbon employing Ti-SBA-15 as hard template. The new mesoporous carbon displays high specific surface area of 1044 m2/g and large pore volume of 0.7 cm3/g. XRD pattern of Ti-CMK-3 indicates that the ordered structure of this material is similar to the CMK-3. XRD, XPS and UVeVis-DRS analysis indicated that Ti is highly dispersed as anatase phase in Ti-CMK-3. The synthesized Ti-CMK-3 exhibited significantly enhanced H2 storage properties (2.6 wt%, equivalent to 13 mmol/g) compared with CMK-3 without Ti (2.2 wt%, 11 mmol/g) at 77 K and 10 bar.Item Novel and simple one-pot method for the synthesis of Ti02 modified-CMK-3 applied in oxidative desulfurization of refractory organosulfur compounds.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Ledesma , Brenda Cecilia; Juárez , Juliana María; Beltramone , Andrea Raquel; Juárez , Juliana María; Ledesma , Brenda CeciliaTi-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The precursors of silicon, carbon and titanium are incorporated together with the other components during the only step of the synthesis. The method developed here, allows reducing time and energy consumption by 60% and thus, the cost of the overall process of synthesis. Structural and textural characterization of the titanium modified-mesoporous carbon was performed by N2 adsorption, XRD, UV–Vis DRS, XPS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was synthesized by dif- ferent methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur com- pounds. The catalyst prepared by the one-pot method is capable to oxidize high amount of sulfur (2000 ppm) in only 30 min of reaction time at 60–80 °C. The good performance and stability of the catalyst prepared using a novel synthesis method was attributed to well dispersed anatase nanospecies over the high area mesoporous carbon. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for ODS reactions.