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Methane Dry Reforming over Alumina Supported Co Catalysts

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Chemical Research in Chinese Universities 2004年第4期20卷 457-461页

作者： Sergio l. González cortés Malcolm l. H. Green Inorganic Chemistry laboratory University of OxfordInorganic Chemistry Laboratory University of Oxford South Parks Road OX1 3QR UKSouth Parks Road OX1 3QR UK

A series of Co/γ-Al_2O_3 catalysts were prepared with the impregnation method and characterized by means of the BET specific surface area, X-ray diffraction(XRD), thermogravimetric analysis(TGA) and laser Raman spectroscopy. The Co/γ-Al_2O_3 catalysts were activated by using H_2, 20%CH_4/H_2 or CH_4, respectively. There was no obvious difference between the activities of the Co/γ-Al_2O_3 catalyst activated by using the different activation methods for methane dry reforming. The catalytic properties of the Co/γ-Al_2O_3 catalysts with different Co loadings were also investigated. The optimized Co loading for the Co/γ-Al_2O_3 catalyst pretreated with 20% CH_4/H_2 is around 12%(mass fraction).

关键词： Methane dry reforming Alumina supported cobalt catalysts Catalytic deactivation

Changes in rainfall partitioning caused by the replacement of native dry forests of lithraea molleoides by exotic plantations of Pinus elliottii in the dry Chaco mountain forests, central Argentina

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Journal of Arid land 2020年第5期12卷 717-729页

作者： Samia S cortÉS Juan I WHITWORTH-HUlSE Eduardo l PIOVANO Diego E GURVICH Patricio N MAGlIANO land Science Research Center(CICTERRA-CONICET)and National University of Córdoba Av.Vélez Sarsfield 1611X5016GCA CórdobaArgentina Multidisciplinary Institute of Plant Biology National University of Córdoba and CONICETCC 495X5000JJC CórdobaArgentina Environmental Study Group Institute of Applied Maths of San LuisNational University of San Luis and CONICETEjército de los Andes 950D5700HHW San LuisArgentina Department of Biology Faculty of ChemistryBiochemistry and PharmacyNational University of San LuisEjército de los Andes 950D5700HHW San LuisArgentina

The replacement of native dry forests by commercial(exotic)tree plantations could generate changes in rainfall partitioning,which further affects the water *** this study,we determined(i)the rainfall partitioning into interception,throughfall and stemflow,(ii)the role of rainfall event size on rainfall partitioning,(iii)the pH of water channelized as throughfall and stemflow,and(iv)the runoff in lithraea molleoides(a native species)and Pinus elliottii(an exotic species)stands in the dry Chaco mountain forests,central *** average,interception,throughfall and stemflow accounted for 19.3%,79.5%and 1.2%of the gross rainfall in *** stand,and 32.6%,66.7%and 0.7%of the gross rainfall in *** stand,*** of interception,throughfall and stemflow presented positive linear relationships with the increment of rainfall event size for both tree species(Pll cases).Percentages of interception,throughfall and stemflow were all related to the increment of rainfall event size,showing different *** increasing rainfall event size,interception exponentially decreased,throughfall asymptotically increased and stemflow linearly *** *** and *** stands presented significant differences in the pH values of water channelized as throughfall(6.3 vs.6.7,respectively;Plow(4.5 vs.5.8,respectively;Ply 0.3%of the gross rainfall in *** stand and was zero in *** *** results showed that the native species *** presented 13.6%more water reaching the topsoil(i.e.,net rainfall;net rainfall=gross rainfall-interception-runoff)than the exotic species *** study improves our understanding of the effects of native vegetation replacement on the local water balance in the dry forest ecosystems.

关键词： drylands ecohydrology land use changes spatial heterogeneity water-limited environments

Computational algorithms to simulate the steel continuous casting

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 596-607页

作者： A. Ramírez-lópez G. Soto-cortés M. Palomar-Pardavé M.A. Romero-Romo R. Aguilar-lópez Institute Polytechnic National(Mexico) Department of Materials Metropolitan Autonomous University

Computational simulation is a very powerful tool to analyze industrial processes to reduce operating risks and improve profits from equipment. The present work describes the development of some computational algorithms based on the numerical method to create a simulator for the continuous casting process, which is the most popular method to produce steel products for metallurgical industries. The kinematics of industrial processing was computationally reproduced using subroutines logically programmed. The cast steel by each strand was calculated using an iterative method nested in the main loop. The process was repeated at each time step （？t） to calculate the casting time, simultaneously, the steel billets produced were counted and stored. The subroutines were used for creating a computational representation of a continuous casting plant （CCP） and displaying the simulation of the steel displacement through the CCP. These algorithms have been developed to create a simulator using the programming language C＋＋. Algorithms for computer animation of the continuous casting process were created using a graphical user interface （GUI）. Finally, the simulator functionality was shown and validated by comparing with the industrial information of the steel production of three casters.

关键词： continuous casting simulation numerical method computational algorithm

Removing contaminants from tannery wastewater by chemical precipitation using CaO and Ca(OH)2

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1107-1111页

作者： Adriana Reyes-Serrano Joel Elópez-Alejo Manuel AHernández-cortázar Ignacio Elizalde Instituto Politécnico Nacional Centro Mexicano para la Producción más LimpiaCiudad de México 07340Mexico

The removal of Cr,sulfates and Chemical Oxygen Demand(COD)from industrial tannery wastewater by chemical precipitation was carried out using Calcium oxide(CaO)and Calcium hydroxide(Ca(OH)2).Different doses of alkalis,ranging from deficiency to excess hydroxyl species over the stoichiometric necessary,were used to remove theoretically the 100%of Cr[0.3-3.2 g alkali·(g Cr^3+)^-1].The precipitation was carried out at room temperature,10 min of vigorous stirring,200 r·min^-1 and a settling time of 24 h,followed by separation and characterization of liquid *** result of addition of alkalis,pH underwent increase as did the alkali *** removal of Cr,and sulfates also increased as alkali concentration did,although for first species the changes at higher alkali contents were less *** removal on the other hand,did not follow a unique trend,instead exhibited a *** on our results,selection of a specific dose of alkali was carried out taking as reference the efficiency on total chromium removal,keeping the pH in the range 7 to 9 to ensure Cr precipitation as chromium *** those conditions,jar test was used to produce enough liquid product in order to determine the removal percent of several other *** removal percent of the species was as follows:Cr,SO4^2-,ZnSO4,FeSO4,CN^-1,NiSO4,Fe2[Fe(CN)6]at 99.8%,66.9%,99.6%,21.4%,70.9%,52.8%and 76.4%with CaO,and 99.8%,61.6%,99.9%,7.1%,84.0%,54.4%and 90.5%with Ca(OH)2,respectively.

关键词： Tannery wastewater Alkali Removal Chromium Sulfates Synergistic effect

Kinetics and mechanisms of the catalytic thermal cracking of asphaltenes adsorbed on supported nanoparticles

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Petroleum Science 2016年第3期13卷 561-571页

作者： Tatiana Montoya Blanca l.Argel Nashaat N.Nassar Camilo A.Franco Farid B.cortés Department of Chemical and Petroleum Engineering University of Calgary 2500 University Drive NW CalgaryAB Canada Grupo de Investigacion Fenomenos de Superficie-Michael Polanyi Facultad de Minas Universidad Nacional de Colombia Sede Medellin Medellin Colombia Grupo de Investigacion en Yacimientos de Hidrocarburos Facultad de Minas Universidad Nacional de Colombia Sede Medellfn Kra 80 No. 65-223 Medellfn Colombia

The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene *** upgrading and recovery processes of these unconventional oils are typically water and energy intensive,which makes such processes costly and environmentally *** catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ *** this study,the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-C_7 asphaltenes was investigated using a thermogravimetric analyzer coupled with *** performance of catalytic thermal cracking of n-C_7asphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support *** a fixed amount of adsorbed n-C_7asphaltenes（0.2 mg/m～2）,bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles,confirming their synergistic *** corrected OzawaFlynn-Wall equation（OFW） was used to estimate the effective activation energies of the catalytic *** mechanism function,kinetic parameters,and transition state thermodynamic functions for the thermal cracking process of n-C_7 asphaltenes in the presence and absence of nanoparticles are investigated.

关键词： Catalytic thermal cracking Adsorption Nanoparticles SHS n-C7 asphaltene

AASlD practice guidance on drug,herbal,and dietary supplement-induced liver injury:also useful for hepatobiliary surgeons

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Hepatobiliary Surgery and Nutrition 2023年第5期12卷 746-751页

作者： Jose María Pinazo-Bandera Miren García-cortés Raúl J.Andrade Service of Gastroenterology and Hepatology University Hospital Virgen de la VictoriaInstituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BionandUniversidad de MálagaMálagaSpain Centro de Investigación Biomédico en Red Enfermedades Hepáticas y Digestivas(CIBERehd) MadridSpain

Drug-induced liver injury(DIlI)is a term used to describe an unexpected liver reaction to drugs,but also to herbal products and dietary supplements(HDS).In the current therapeutic armamentarium,only a small number of available drugs are still capable of causing liver damage in *** include,in addition to paracetamol-the prototypical example of this group-niacin(now rarely used to treat hypercholesterolaemia),intravenous methotrexate and probably ketamine(an intravenous hypnotic used in critically ill patients for rapid sequence induction)(1).

关键词： Drug-induced liver injury(DIlI) hepatotoxicity causality assessment Revised Electronic Causality Assessment Method(RECAM)

Computational algorithms for simulating the grain structure formed on steel billets using cellular automaton and chaos theories

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 24-34页

作者： A.Ramírez-lópez G.Soto-cortés J.González-Trejo D.Muoz-Negrón Department of Materials Metropolitan Autonomous University Institute Polytechnic National Institute Technologic Autonomous of Mexico

The development of some computational algorithms based on cellular automaton was described to simulate the structures formed during the solidification of steel *** algorithms described take results from the steel thermal behavior and heat removal previously calculated using a simulator developed by present authors in a previous *** time is used for displaying the steel transition from liquid to mushy and *** it is also used to command computational subroutines that reproduce nucleation and grain *** routines are logically programmed using the programming language C＋＋ and are based on a simultaneous solution of numerical methods （stochastic and deterministic） to create a graphical representation of different grain structures *** grain structure obtained is displayed on the computer screen using a graphical user interface （GUI）.The chaos theory and random generation numbers are included in the algorithms to simulate the heterogeneity of grain sizes and morphologies.

关键词： continuous casting solidification grain growth algorithms computer simulation

A cellular automata model for simulating grain structures with straight and hyperbolic interfaces

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 699-710页

作者： A.Ramírez-lópez M.Palomar-Pardavé D.Muñoz-Negrón C.Duran-Valencia S.lópez-Ramirez G.Soto-cortés Materials and Energy Department Metropolitan Autonomous UniversityMexico Department of Industrial Engineering Technological Autonomous Institute of MexicoMexico Department of Molecular Engineering Mexican Institute of PetroleumMexico

A description of a mathematical algorithm for simulating grain structures with straight and hyperbolic interfaces is shown. The presence of straight and hyperbolic interfaces in many grain structures of metallic materials is due to different solidification conditions, in- eluding different solidification speeds, growth directions, and delaying on the nucleation times of each nucleated node. Grain growth is a complex problem to be simulated; therefore, computational methods based on the chaos theory have been developed for this purpose. Straight and hyperbolic interfaces are between columnar and equiaxed grain structures or in transition zones. The algorithm developed in this work involves random distributions of temperature to assign preferential probabilities to each node of the simulated sample for nucleation according to previously defined boundary conditions. Moreover, more than one single nucleation process can be established in order to gen- erate hyperbolic interfaces between the grains. The appearance of new nucleated nodes is declared in sequences with a particular number of nucleated nodes and a number of steps for execution. This input information influences directly on the final grain structure （grain size and dislribution）. Preferential growth directions are also established to obtain equiaxed and columnar grains. The simulation is done using rou- tines for nucleation and growth nested inside the main function. Here, random numbers are generated to place the coordinates of each new nucleated node at each nucleation sequence according to a solidification probability. Nucleation and growth routines are executed as a func- tion of nodal availability in order to know if a node will be part of a grain. Finally, this information is saved in a two-dimensional computa- tional array and displayed on the computer screen placing color pixels on the corresponding position forming an image as is done in cellular automaton.

关键词： grain growth interfaces grain size and shape computational methods algorithms cellular automata computer simulation

Arylhydrazones Derivatives Containing a Benzothiazole Moiety, Efficient ligands in the Palladium-Catalyzed Mizoroki-Heck and Suzuki-Miyaura Cross-coupling Reactions under IR Irradiation

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Chinese Journal of Chemistry 2017年第12期35卷 1881-1888页

作者： Fernando Ortega-Jiménez José Guillermo Penieres-Carrillo José Guadalupe lópez-cortés M. Carmen Ortega-Alfaro Selene lagunas-Rivera Departamento de Cieneias Qulmicas Facultad de Estudios Superiores Cuautitlān-UNAM Campo i Avenida lro. de Mayo s/n Cuautitlán Izcalli C.P. 54740 Estado de México México Instituto de Qulmiea UNAM Circuito Exterior Ciudad Universitaria Coyoacán C.P. 04360 Cuidad de México México Instituto de Ciencias Nucleares UNAM Circuito Exterior Ciudad Universitaria Coyoacán C.P. 04360 Ciudad de México México Catedrático CONA CyT-TecNM-Instituto Tecnológico de Tuxtla Gutiérrez Carretera Panamericana Km 1080 Col Juan Crispin Tuxtla Gutiérrez C.P. 29050 Chiapas México

A simple arylhydrazone containing the benzothiazole moiety which may be used as an efficient ligand in the palladium-catalyzed Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions, under infrared irradiation as an alternative source of energy, is presented. The reactions proceeded with extremely high efficiency under mild conditions and produced very good yields.

关键词： arylhydrazones palladium-catalyzed cross-coupling reaction IR-irradiation