Otro título: Sinfonía para quinteto

Número 311 en el catálogo de Vicente Galbis e Hilari García

Otro título: Himne a València

Número 259 en el catálogo de Vicente Galbis e Hilari García, bajo el título "Himne a València"

Bolero : para orquesta, banda y coro [Manuscrito]

Número 254 en el catálogo de Vicente Galbis e Hilari García

CuH-ZSM-5 as Hydrocarbon Trap under Cold Start Conditions

Cold start tests are carried out to evaluate the performance of copper-exchanged zeolites as hydrocarbon traps under simulated gasoline car exhaust gases, paying special attention to the role of copper in the performance of these zeolites. It is concluded that the partial substitution of the protons in the parent H-ZSM-5 zeolite is highly beneficial for hydrocarbon trapping due to the formation of selective adsorption sites with specific affinity for the different exhaust components. However, it is also observed that uncontrolled exchanging process conditions could lead to the presence of CuO nanoparticles in the zeolite surface, which seem to block the pore structure of the zeolite, decreasing the hydrocarbon trap efficiency. Among all the zeolites studied, the results point out that a CuH-ZSM-5 with a partial substitution of extra-framework protons by copper cations and without any detectable surface CuO nanoparticles is the zeolite that showed the best performance under simulated cold start conditions due to both the high stability and the hydrocarbon retaining capacity of this sample during the consecutive cycles.

NOx storage and reduction over copper-based catalysts. Part 2: Ce0.8M0.2Oδ supports (M = Zr, La, Ce, Pr or Nd)

5% copper catalysts with Ce0.8M0.2Oδ supports (M = Zr, La, Ce, Pr or Nd) have been studied by rapid-scan operando DRIFTS for NOx Storage and Reduction (NSR) with high frequency (30 s) CO, H2 and 50%CO + 50%H2 micropulses. In the absence of reductant pulses, below 200–250 °C NOx was stored on the catalysts as nitrite and nitro groups, and above this temperature nitrates were the main species identified. The thermal stability of the NOx species stored on the catalysts depended on the acid/basic character of the dopant (M more acidic = NOx stored less stable ⇒ Zr4+ < none < Nd3+ < Pr3+ < La3+ ⇐ M more basic = NOx stored more stable). Catalysts regeneration was more efficient with H2 than with CO, and the CO + H2 mixture presented an intermediate behavior, but with smaller differences among the series of catalyst than observed using CO alone. N2 is the main NOx reduction product upon H2 regeneration. The highest NOx removal in NSR experiments performed at 400 °C with CO + H2 pulses was achieved with the catalyst with the most basic dopant (CuO/Ce0.8La0.2Oδ) while the poorest performing catalyst was that with the most acidic dopant (CuO/Ce0.8Zr0.2Oδ). The poor performance of CuO/Ce0.8Zr0.2Oδ in NSR experiments with CO pulses was attributed to its lower oxidation capacity compared to the other catalysts.

Chemical composition of minerals in peridotides from the 15°20'N transform fault, Atlantic Ocean

Information about the first finding of awaruite in oceanic peridotites is given. Petrography of rocks, mineralogy, and minerals associated with awaruite are characterized.

Geochemistry of nodules from a young seamount

Manganese nodules made of radiating rods of well crystallized birnessite were sampled at 8 degree 481.2'N, 103 degree 53.8W, 1875 m below sea level by a dredge that also collected hyaloclastite and basaltic talus. The nodule field is on the floor of a caldera within a young tholeiitic seamount and was discovered and photographed during a deep-two survey. It is interpreted as a brecciated hydrothermal deposit, crystallized from an amorphous manganese oxide precipitate that formed when seawater-based hydrothermal fluids mixed with oxidized seawater. The nodules and surrounding igneous rocks have subsequently been encrusted with hydrogenous ferromanganese oxides.

Chemistry and fluid inclusions of the sheeted dike comples of ODP Holes 137-504B and 140-504B

Fluid inclusions in variably altered diabase recovered from Ocean Drilling Program Legs 137 and 140 at Hole 504B, Costa Rica Rift, exhibit fluid salinities up to 3.7 times that of seawater values (11.7 wt% NaCl equivalent) and exhibit uncorrected homogenization temperatures of 125°C to 202°C. The liquid-dominated inclusions commonly are entrapped in zones of secondary plagioclase and may be primary in origin. Fluid salinities are similar to compositions of fluids venting on the seafloor (0.4-7.0 wt% NaCl) and overlap with those measured in metabasalt samples recovered from near the Kane Fracture Zone on the Mid-Atlantic Ridge and from the Troodos ophiolite, Cyprus. The salinity variations may reflect hydration reactions involving formation of secondary mineral assemblages under rock-dominated conditions, which modify the ionic strength of hydrothermal fluids by consuming or liberating water and chloride ion. Rare CO2-CH4-bearing inclusions, subjacent to zones where talc after olivine becomes an important secondary mineral phase (1700 mbsf), may have formed due to local interaction of seawater and olivine at low water to rock ratios. Corrected average fluid inclusion homogenization temperatures exhibit a gradient from 159°C at a depth of 1370 mbsf to 183°C at a depth of 1992 mbsf and are in apparent equilibrium with the present conductive downhole temperatures. These data indicate that fluid inclusions may be used to estimate downhole temperatures if logging data are unavailable. The compositional and thermal evolution of the diabase-hosted fluids may reflect late-stage, off-axis circulation and conductive heating of compositionally modified seawater in the sheeted dike complex at Hole 504B.

Investigation of manganese nodules from the Malvinas (Falkland) Plateau

Manganese nodules occurring within marine sediments of presumably Upper Miocene-Lower Pliocene age from cores obtained by the Argentine oceanographic vessel ARA Islas Orcadas in 1977 on the Malvinas (Falkland) Plateau and neighbouring Scotia Sea were studied with the aim of comparing them with other fossil nodules found on the mainland of Argentina that were also ascribed to the marine environment. After optical mineralogical, chemical, X-ray and trace element analysis, the studied "nodules" proved to be actually wacke clasts cemented by manganese oxides with a high Fe/Mn ratio corresponding to a continental environment. The studied "nodules" thus differ from the Argentine mainland nodules and are supposed to have been transported from continental environments and then deposited in the marine realms. The wacke clasts became then nuclei for the deposition of the marine manganese oxides of the coatings. The proportion of trace elements, which is high, suggests the growth of the nodules in the marine environment.

Structural and mechanical properties of nanostructured granular alumina catalysts

Granular gamma-Al2O3 support and 8 wt % CuO/gamma-Al2O3 catalyst were synthesized by a sol-gel granulation method. The pore structure, crush strength, hardness, and elasticity of these sol-gel-derived catalysts were studied and compared with similar commercial catalysts prepared by non-sol-gel methods. Alumina and CuO-coated alumina granular particles prepared by different methods have different macro- and microstructure. The sol-gel-derived granular gamma-alumina and CuO-coated gamma-alumina granular particles have a structure defined by compact packing of uniform, nanosized gamma-alumina crystallites. They are characterized by a more uniform pore size distribution and larger surface area as compared to similar commercial samples with a structure defined by packing of aggregates consisting of nonuniform gamma-alumina crystallites. Because of the differences in the macro- and microstructure, the sol-gel-derived granular samples offer higher crush strength and greater hardness than the commercial samples.

Preparation and characterization of copper catalysts supported on mesoporous Al2O3 nanofibers for N2O reduction to N2

A series of mesoporous Al2O3 samples with different porous structures and phases were prepared and used as supports for Cu/Al2O3 catalysts. These catalysts were characterized by N-2 adsorption, NMR, TGA, XRD, and UV - vis spectroscopic techniques and tested for the catalytic reaction of N2O decomposition. The activity increased with the increasing calcination temperatures of supports from 450 to 900 degreesC; however, a further increase in calcination temperature up to 1200 degreesC resulted in a significant reduction in activity. Characterization revealed that the calcination temperatures of supports influenced the porous structures and phases of the supports, which in turn affected the dispersions, phases, and activities of the impregnated copper catalyst. The different roles of surface spinel, bulk CuAl2O4, and bulk CuO is clarified for N2O catalytic decomposition. Two mechanism schemes were thus proposed to account for the varying activities of different catalysts.

Liquidus temperatures in calcium ferrite slags in equilibrium with molten copper

Experimental laboratory methods have been developed that enable phase-equilibria studies to be carried out on slags in the system Ca-Cu-Fe-O in equilibrium with metallic copper. These techniques involve equilibration at temperature, rapid quenching, and chemical analysis of the phases using electron-probe X-ray microanalysis (EPNIA). Equilibration experiments have been carried out in the temperature range of 1150 degreesC to 1250 degreesC (1423 to 1523 K) and in the composition range of 4 to 80 wt pct "Cu2O," 0 to 25 wt pct CaO, and 20 to 75 wt pct "Fe2O3" in equilibrium with metallic copper. Liquidus and solidus data are reported for the primary-phase fields of spinel (magnetite) and dicalcium ferrite. The resulting data have been used to construct liquidus isotherms of the CaO-"Cu2O"-"Fe2O3" system at metallic copper saturation.

Cu and Fe oxides dispersed on SBA-15:a Fenton type bimetallic catalyst for N,N-diethyl-p-phenyl diamine degradation

A bimetallic oxidation catalyst has been synthesized via wet impregnation of copper and iron over a mesoporous SBA-15 silica support. Physicochemical properties of the resulting material were characterized by XRD, N2 physisorption, DRUVS, FTIR, Raman, SEM and HRTEM, revealing the structural integrity of the parent SBA-15, and presence of highly dispersed Cu and Fe species present as CuO and Fe2O3. The CuFe/SBA-15 bimetallic catalyst was subsequently utilized for the oxidative degradation of N,N-diethyl-p-phenyl diamine (DPD) employing a H2O2 oxidant in aqueous solution.

In-situ XPS study on the reducibility of Pd-promoted Cu/CeO2 catalysts for the oxygen-assisted water-gas-shift reaction

Cu/CeO2, Pd/CeO2, and CuPd/CeO2 catalysts were prepared and their reduction followed by in-situ XPS in order to explore promoter and support interactions in a bimetallic CuPd/CeO2 catalyst effective for the oxygen-assisted water-gas-shift (OWGS) reaction. Mutual interactions between Cu, Pd, and CeO2 components all affect the reduction process. Addition of only 1 wt% Pd to 30 wt% Cu/CeO2 greatly enhances the reducibility of both dispersed CuO and ceria support. In-vacuo reduction (inside XPS chamber) up to 400 °C results in a continuous growth of metallic copper and Ce3+ surface species, although higher temperatures results in support reoxidation. Supported copper in turn destabilizes metallic palladium metal with respect to PdO, this mutual perturbation indicating a strong intimate interaction between the Cu–Pd components. Despite its lower intrinsic reactivity towards OWGS, palladium addition at only 1 wt% loading significantly improved CO conversion in OWGS reaction over a monometallic 30 wt% Cu/CeO2 catalysts, possibly by helping to maintain Cu in a reduced state during reaction.

Hydrogen production by steam reforming of DME in a large scale CFB reactor. Part I:computational model and predictions

This study presents a computational fluid dynamic (CFD) study of Dimethyl Ether steam reforming (DME-SR) in a large scale Circulating Fluidized Bed (CFB) reactor. The CFD model is based on Eulerian-Eulerian dispersed flow and solved using commercial software (ANSYS FLUENT). The DME-SR reactions scheme and kinetics in the presence of a bifunctional catalyst of CuO/ZnO/Al2O3+ZSM-5 were incorporated in the model using in-house developed user-defined function. The model was validated by comparing the predictions with experimental data from the literature. The results revealed for the first time detailed CFB reactor hydrodynamics, gas residence time, temperature distribution and product gas composition at a selected operating condition of 300 °C and steam to DME mass ratio of 3 (molar ratio of 7.62). The spatial variation in the gas species concentrations suggests the existence of three distinct reaction zones but limited temperature variations. The DME conversion and hydrogen yield were found to be 87% and 59% respectively, resulting in a product gas consisting of 72 mol% hydrogen. In part II of this study, the model presented here will be used to optimize the reactor design and study the effect of operating conditions on the reactor performance and products.