Evaluating the Catalytic Performance of La1-xCexNi1-yZnyO3 Nanostructure Perovskites in the Carbon Dioxide Reforming of Methane

AbstractIn this research nanostructure perovskites La1-xCexNi1-yZnyO3 were prepared by sol-gel auto-combustion method and their application were evaluated for methane reforming with carbon dioxide and syngas production. Catalysts were designed by Response Surface Method (RSM) based on central composite design (CCD) with three factors of catalyst characteristics, x, y and Tc. The prepared catalysts were examined in methane reforming process at 750 ˚C temperature and atmospheric pressure. Analysis of variance (ANOVA) showed that parameters don’t have any linear effect on catalytic activity and their effect is proportional to square form. Among this investigated parameters, Ni content effect is considerable and calcination temperature (Tc) has a partial effect. In this research R2 value was 94.88%. The optimum catalyst which determined by RSM was La0.60Ce0.40Ni0.81Zn0.19O3 in 747 ˚C calcination temperature that corresponds to empirical result. The XRD characterization of optimum catalyst showed that perovskite catalyst was formed in rhombohedra phase with nanostructure crystals and the SEM of optimum catalyst confirmed the nano scale of prepared particles

The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

Haumea—one of the four known trans-Neptunian dwarf planets—is a very elongated and rapidly rotating body1, 2, 3. In contrast to other dwarf planets4, 5, 6, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system7, and the Centaur Chiron was later found to possess something similar to Chariklo’s rings8, 9. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea’s equator and the orbit of its satellite Hi’iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea’s spin period—that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea’s largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates1, 10, 11. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.J.L.O. acknowledges funding from Spanish and Andalusian grants MINECO AYA-2014-56637-C2-1-P and J. A. 2012-FQM1776 as well as FEDER funds. Part of the research leading to these results received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378. B.S. acknowledges support from the French grants ‘Beyond Neptune’ ANR-08-BLAN-0177 and ‘Beyond Neptune II’ ANR-11-IS56-0002. Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ERC grant agreement no. 669416 ‘Lucky Star’). A.P. and R.S. have been supported by the grant LP2012-31 of the Hungarian Academy of Sciences. All of the Hungarian contributors acknowledge the partial support from K-125015 grant of the National Research, Development and Innovation Office (NKFIH). G.B.-R., F.B.-R., F.L.R., R.V.-M., J.I.B.C., M.A., A.R.G.-J. and B.E.M. acknowledge support from CAPES, CNPq and FAPERJ. J.C.G. acknowledges funding from AYA2015-63939-C2-2-P and from the Generalitat Valenciana PROMETEOII/2014/057. K.H. and P.P. were supported by the project RVO:67985815. The Astronomical Observatory of the Autonomous Region of the Aosta Valley acknowledges a Shoemaker NEO Grant 2013 from The Planetary Society. We acknowledge funds from a 2016 ‘Research and Education’ grant from Fondazione CRT. We also acknowledge the Slovakian project ITMS no. 26220120029

Catalytic Oxidation of Toluene over LaBO 3 (B=Fe, Mn and Co) and LaCo 0.7 B′ 0.3 O 3 (B′=Fe and Mn) Perovskite-type

In this paper, LaB

Retracted: Association of capillaroscopy findings in nailfold with color doppler changes in wrist and fingers of patients with collagen vascular disease

This article was withdrawn and retracted by the Journal of Fundamental and Applied Sciences and has been removed from AJOL at the request of the journal Editor in Chief and the organisers of the conference at which the articles were presented (www.iccmit.net). Please address any queries to [email protected]

Design optimization of an LPG thermal cracker for multiple objectives

International Journal of Chemical Reactor Engineering9