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Sol–gel La2O3–ZrO2 mixed oxide catalysts for biodiesel production

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Journal of Energy Chemistry 2018年第2期27卷 565-572页

作者： Daniela Salinas Catherine Sepúlveda Néstor Escalona J.L.GFierro Gina Pecchi departamento de Fisicoquimica. Facultad de Ciencias quimicas Universidad de Concepcion Post Office 160-C Concepcion Chile departamento de quimica Facultad de Ciencias Universidad del Biobio Post Office 5-C Concepcion Chile departamento Ingenieria quimica y Bioprocesos Escuela de lngenieria Pontificia Universidad Catolica de Chile Avda. Vicuria Mackenna 4870 Maeul Santiago 7820436 Chile Centro de Investigacion en Nanotecnolagia y Materiales Avanzados (CIEN-UC) Pontificia Universidad Catolica de Chile Post Office 306 Santiago Chile departamento de quimica Fisica Facultad de Quimica Pontificia Universidad Catolica de Chile Post Offce 306 Santiago Chile Instituto de Catalisis y Petroleoquimica CSIC 28049 Madrid. Espana

Different La2O3 contents（0, 1, 2, 3, and 5 wt%） were used to prepared La2O3-ZrO2 mixed oxides calcined at 600 ℃ by the sol-gel method. The catalytic activity was measured as biodiesel production from canola oil through a transesterification reaction. The characterization results indicate that the La2O3 monolayer formation and extent of basicity of m-ZrO2 have a large influence on biodiesel *** biodiesel conversion（56% at 4 h） was obtained with the 3% La2O3-ZrO2 catalyst in the presence of basic sites and the formation of a monolayer of La2O3. The decrease in the catalytic activity for 5% La2O3-ZrO2 resulted from the loss of active sites on the catalyst because of agglomeration, which was suggested by XPS and the isoelectric point. The kinetic data fit to a pseudo-first order constant, and the largest kinetic constant corresponds to 3% La2O3-ZrO2, currently the largest heterogeneous non-alkaline metal catalyst reported for a transesterification reaction.

关键词： La2O3 -ZrO2 Sol-gel Biodiesel Canola oil Transesterification

Natural and anthropogenic sources of lead, zinc, and nickel in sediments of Lake Izabal, Guatemala

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Journal of Environmental Sciences 2020年第10期32卷 117-126页

作者： Elisandra Hernandez Jonathan Obrist-Farner Mark Brenner William F.Kenney Jason H.Curtis Edward Duarte Geosciences and Geological and Petroleum Engineering department Missouri Uniuersity of Science and Technology.RollaMO 65409USA. department of Geological Sciences University of FloridaGainesvilleFL 32611USA Land Use and Enuironmental Change Institute Uniuersity of FloridaGainesvilleFL 32611USA escuela de quimica Universidad de San Carlos de Guatemala01012Guatermala

Sediments in Lake Izabal,Guatemala,contain substantial lead (Pb),zinc (Zn),and nickel (Ni).The lack of historical data for heavy metal concentrations in the sediments makes it difficult to determine the sources or evaluate whether inputs of metals to the lake have changed through *** measured the relative abundances and concentrations of Pb,Zn,and Ni by X-Ray Fluorescence core scanning and by Inductively Coupled Plasma Optical Emission Spectrometry in three sediment cores to explore stratigraphic distributions of metals in the lake *** amounts of Pb and Zn in the core taken near the Polochic delta suggest that galena and sphalerite mining increased Pb and Zn delivery to Lake Izabal between ~1945 and 1965 *** up-core Ni increase in the core taken near a different mine on the north shore of Lake Izabal suggests that recent nickel mining operations led to an increase in Ni concentrations in the local sediments,but amounts in the other cores indicate that Ni is not widely distributed throughout the *** cores from Lake Izabal are reliable recorders of heavy metal input to the lake,and were measured to establish background metal levels,which would otherwise be *** of Pb,Zn,and Ni in older,pre-20th-century Lake Izabal sediments reflect input from natural erosion of *** results provide previously unavailable estimates of background metal concentrations in Lake Izabal before the onset of *** results are necessary for future monitoring related to mining contamination of the lake ecosystem.

关键词： Lake Izabal Heavy metals Lead contamination Anthropogenic impacts Mining Guatemala

Preparation of Rod-like Aluminum Doped Zinc Oxide Powders by Sol-gel Technique Using Metal Chlorides and Acetylacetone Precursors

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Journal of Wuhan University of Technology(Materials Science) 2018年第6期33卷 1293-1297页

作者： KESHTKAR Javad VARGAS GARCIA Jorge Roberto GALAVIZ PEREZ Jorge MARTINEZ TRINIDAD José escuela Superior de Ingenieria Mecánica y Eléctrica Instituto Politécnico NacionalMéxico07738CDMXMéxico escuela Superior de Ingenieria quimica e Industrias Extractivas Instituto Politécnico NacionalMéxico07738CDMXMéxico Universidad Juárez Autònoma de Tabasco DivisiònAcadémica Multidisciplinaria de Jalpa de MéndezRibera AltaJalpa de MéndezTabasco86205México

Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SEM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.

关键词： aluminum doped ZnO rod-like metal chloride sol gel acetylacetone

Purification and Biochemical Characterization of a Protease Inhibitor Ⅱ Family from Jalapeno Pepper(Capsicum annuum L.)

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Advances in Bioscience and Biotechnology 2014年第7期5卷 661-668页

作者： Juan Pablo Carrillo-Montes Roberto Arreguin-Espinosa Jose Luis Munoz-Sanchez Manuel Soriano-Garcia departamento de quimica de Biomacromoleculas Instituto de QuimicaUniversidad Nacional Autonoma de MexicoMexico DFMexico departamento de Bioquimica Escuela Nacional de Ciencias Biologicas del Instituto Politécnico NacionalMéxico DFMéxico

Capsicum annuum L. was initially domesticated in Mexico and northern Central America, and represented an ancient Neotropical plant food complex. The purpose of this paper is to report the isolation and purification of a novo-member of a protease inhibitor from jalapeño pepper (Capsicum annuum L.) (PIJP). The molecular weight of PIJP inhibitor is 5.95 kDa with 56 amino acids and 6 Cys residues with high inhibitory activity to trypsin with a Ki value of 95 nM. This inhibitor according to the alignment with homologous from NCBI and Pfam databases is a member of proteinase inhibitors II. It is worthwhile to mention a major compositional difference between the proteinase inhibitor II families which have 8 Cys residues. PIJP is the first purified proteinase inhibitor, member of this family with only 6 Cys residues.

关键词： Protease Inhibitory Activity Protease Inhibitor Protein Purification Jalapeno Pepper Capsicum annuum L.

Compliance Experimental determination in Nonstandard SEN Samples in API 5L Steel Pipe in the Short Radial Direction

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材料科学与工程（中英文版） 2010年第5期4卷 27-32页

作者： Daniel Angeles Herrera Gonzailez Velaizquez Jorge Luis Morales Ramirez Angel de Jesus departamento de lngenieria y Materiales Instituto Polit~cnico Nacional Escuela Superior de Ingenieria Quimica e IndustriasExo-activas Mexico D.F 07738 Mexico

Sequential Injection Analysis of Ampicillin in Pharmaceuticals by Using Potentiometric detectors Based on PVC and Sol-Gel Membranes

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American Journal of Analytical Chemistry 2011年第4期2卷 491-499页

作者： Nestor Zarate Alberto N.Araujo M.Conceicao B.S.M.Montenegro Ricardo Perez-Olmos Dpto.quimica Analítica Escuela Universitaria de Ingenieria Tecnica IndustrialUniversidad del Pais VascoPlaza de la Casilla 348012Bilbao REQUIMTE Dpto.de Quimica FisicaFaculdade de FarmaciaUniversidade do PortoRua Anibal Cunha 1644050 PortoPortugal

This work describes the construction and the evaluation of the general performance of new ampicilli-nate-selective electrodes based on manganese (III) tetraphenylporphyrin [Mn(III) TPP-Cl] as ionophore, incorporated in both PVC and sol-gel membranes and directly applied onto a conductive graphite/epoxy resin support. The units were constructed without inner reference solution adopting conventional configuration and in the case of PVC membrane the tubular configuration was also adopted. The good working characteristics of these electrodes, made possible its application to the determination of ampicillin in pharmaceuticals formulations, both in conventional batch analysis and in flow conditions, when the electrodes were coupled to a SIA system. In the last case the potentiometric sensors presented linear response towards ampicillin concentration between 5.0 × 10–4 and 5.0 × 10–2 mol?l–1 with slopes of –57.4 and –63.5 mV?dec–1 for the PVC and sol-gel membranes, respectively. The developed procedures enable mean relative standard deviations better than 3% for all the samples analysed. The obtained results do not statistically differ from those furnished by applying the HPLC reference method.

关键词： Ampicillin SIA Potentiometric detection Pharmaceutical Formulations

Flotation of Brazilian and Colombian Coals Using a Negative Bias

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Journal of Chemistry and Chemical Engineering 2013年第2期7卷 170-174页

作者： Irineu Brum H. Villegas W. Banguero J. Guerrero C. Sampaio J. Barraza Laboratorio de Processamento Mineral Centro de Tecnologia Universidad Federal Rio Grande do Sul Porto Alegre Brasil escuela de Ingenierla quimica Universidad del Valle Cali 25360 Colombia

Brazil and Colombia have large reserves of coal. Those reserves in Brazil are located predominantly in the south and the main reserves in Colombia are located in the north. despite the relative ease of exploitation, these resources have been underestimated as a source of energy. Currently, these countries are developing projects and partnerships aiming to qualify this mineral resource, adding quality to the final product of the processing plants. In this scenario, the processing of Brazilian and Colombian coal in flotation columns appears as a promising alternative, having been successful in mineral systems containing fine particles. The paper aims to study the overall process of column flotation for a specific Brazilian coal and a specific Colombian coal. The material used in this study consists of fine coal from Brazil （Copelmi） and Colombia （Cerrejon）. The objective is to recover carbonaceous matter and reduce the ash and contaminants grade. The two coals were floated using a negative bias in a 5 cm diameter conventional flotation column of 5 m high. Flotation parameter investigated included air velocity in the range 0.6 to 1.5 cm/s. For all runs, a constant negative bias of-0.25 cm/s and a pulp concentration of 8% w/w were used. For Cerrej6n coal, 300 g/ton of frother and 907 g/ton of collector was used, whereas for Copelmi coal, 600 g/ton of frother and 1,815 g/ton of collector was employed. The frother was a commercial Aerofroth 65 （AF65）, whereas the collector was Kerosene. For the Colombian coal, in general, yield, organic recovery, ash recovery and water recovery decreased with the increasing air rate. However, for Brazilian coal the air rate had no significant effect. For Colombian coal, the highest yield （60% w/w） and organic recovery （69% w/w） were obtained at the lowest air rate （0.6 cm/s）.

关键词： Negative bias column flotation coal.

Territorial Planning for Coastal Zones in Chile:The Need for Geographical-Environmental and Natural Risk Indicators for Spatial decision Support Systems

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International Journal of Geosciences 2013年第6期4卷 17-29页

作者： Fernando Pena-Cortes Daniel Rozas-Vasquez Gonzalo Rebolledo Jimmy Pincheira-Ulbrich Miguel Escalona Enrique Hauenstein Luis Vargas-Chacoff Carlos Bertran Jaime Tapia Marco Cisternas Laboratorio de Planificacion Territorial Nucleo de Investigacion en Estudios AmbientalesUniversidad Catolica de TemucoTemucoChile Programa de Doctorado en Sistematica y Biodiversidad Universidad de ConcepcionConcepcionChile escuela de Ciencias Ambientales Facultad de Recursos NaturalesUniversidad Catolica de TemucoTemucoChile Instituto de Ciencias Marinas y Limnologicas Universidad Austral de ChileValdiviaChile Instituto de quimica de Recursos Naturales Universidad de TalcaTalcaChile escuela de Ciencias del Mar Pontificia Universidad Catolica de ValparaisoValparaisoChile

Coastal zones are very dynamic and fragile environments, constituting a landscape ever more heterogeneous, fragmented and with increasing levels of complexity due to the changing relationship between man and nature. Integrated coastal zone management therefore requires detailed knowledge of the system and its components, based—to a large extent—on technical and scientific information. However, the information generated must be in line with the political requirements necessary for decision-making and planning. Thus the use of indicators to give a simplified view of the many components of the territory, and at the same time to provide important information about patterns or trends, becomes a tool of the utmost importance. These indicators can be understood as measurable characteristics of the environment, which facilitate comprehension of the processes occurring at different scales and serve as a reference to inform the population and support decision-making. The aim of the present note is to demonstrate briefly the need to develop geographical-environmental and natural risk indicators to facilitate comprehension of the dynamic of spatial and temporal landscape patterns, particularly in coastal environments. This approach offers an historical summary of the natural, socio-economic and political processes which currently make up the territory, and which without doubt will continue to influence it in the future. At the same time, it is proposed that information should be integrated on the basis of this framework with a view to generating spatial decision support systems in a context of planning and integrated management of the coastal zones of Chile.

关键词： Coastal Zone Territorial Planning Indicators Spatial decision Support System Chile

Performance Quality Testing under Combined Loading of Polyethylene Pipes Reinforced with Aramid Fiber

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Journal of Mechanics Engineering and Automation 2014年第8期4卷 639-647页

作者： Hilario Hemamdez-Moreno Erik Vargas-Rojas Victor Manuel Sauce-Rangel Ivan Mortera-Bravo Jorge LuisGonzhlez-Velazquez Maarten P. Kruijer Margarita Navarrete-Montesinos ESIME (escuela Superior de Ingenieria Mecanica y Electrica) Unidad Ticoman lnstituto Politecnico Nacional Distrito Federal07340 Mexico ESIQIE (escuela Superior de Ingenieria quimica e lndustrias Extractivas) Instituto Politecnico Nacional Distrito Federal 07300Mexico department of Research & development Pipelife Netherlands B. K Enkhuizen P.O. Box 380 1600 A J The Netherlands Instituto de lngenieria Universidad Nacional Autonoma de Mexico Distrito Federal 04510 Mexico

This paper presents the results of the performance quality testing of polyethylene pipes reinforced with aramid fibers, intended for applications such as discharging and gathering oil pipelines, and describes the test rig specifically designed for this purpose. The pipe specimens are submitted to impact with a device that simulates the collision of a pickaxe, and of a backhoe loader. After the impact, the pipes are tested under combined loading comprising internal pressure, and transverse loading; some pipe specimens without previous impact are tested as well. The results show that the reinforced thermoplastic pipes can fully withstand maximal operating pressure levels in the presence of damage and additional transverse loading.

关键词： Combined pressure-bending testing oil industry reinforced thermoplastic pipe composite materials.