Structural transformation of tungsten oxide nanourchins into IF–WS2 nanoparticles: an aberration corrected STEM study

IF–WS2 nanoparticles synthesized starting from tungsten oxide nanourchins have been investigated by using aberration corrected scanning transmission electron microscopy (Cs-STEM). The synthesis process produced IF–WS2 nanoparticles of two different and well differentiated ranges of size. High resolution HAADF–STEM images and their comparison with simulated STEM micrographs reveal the predominance of stacking of the type 1T close to the border of the structure; the observation of this kind of stacking, observed previously in IF–MoS2 but never reported before in the case of the IF–WS2 nanostructures, adds a new dimension to the existing understanding of structure and stacking in the case of the nanostructures of transition metal chalcogenide

Insights into the structure of MoS2/WS2 nanomaterial catalysts as revealed by aberration corrected STEM

Molybdenum disulfide/Tungsten disulphide (MoS2/WS2) is a compound very useful for its properties; it is used as lubricant, catalyst in hydrodesulfuration, in hydrogen fuel storage, etc. As part of the 2nd Joint Congress of the Portuguese and Spanish Microscopy Societies the present work reports about the different types of MoS2/WS2 nanomaterials which have been investigated by using aberration corrected STEM namely: (1) MoS2 nanotubes (2) MoS2 hexagonal nanoplates, (3) rippled or helical MoS2 nanowires, (4) Co-doped MoS2/WS2 nanowires and (5) fullerene-like WS2 nanoparticle

SEM, AFM and CLSM microscopic techniques as tools for characterization of cellulose, polyaluminum and aluminum recovered from Tetra Pak packaging

In this chapter, the characterization of the morphological features of sub-products of Tetra Pak packaging using SEM, AFM and CLSM microscopic techniques is presented. In a first step, the separation of the components of the Tetra Pak was done using hydropulping mechanical process; the principal obtained products include cellulose, aluminium and polyethylene+aluminum. The last one called Polyaluminum. After this, the morphological analysis was obtained. The results show that such microscopy techniques are adequate for describe the high degree of purity of the components after recycling

Experimental evidence of icosahedral and decahedral packing in one-dimensional nanostructures

Abstract: The packing of spheres is a subject that has drawn the attention of mathematicians and philosophers for centuries and that currently attracts the interest of the scientific community in several fields. At the nanoscale, the packing of atoms affects the chemical and structural properties of the material and, hence, its potential applications. This report describes the experimental formation of 5-fold nanostructures by the packing of interpenetrated icosahedral and decahedral units. These nanowires, formed by the reaction of a mixture of metal salts (Au and Ag) in the presence of oleylamine, are obtained when the chemical composition is specifically Ag/Au = 3:1. The experimental images of the icosahedral nanowires have a high likelihood with simulated electron micrographs of structures formed by two or three Boerdijk Coxeter Bernal helices roped on a single structure, whereas for the decahedral wires, simulations using a model of adjacent decahedra match the experimental structures. To our knowledge, this is the first report of the synthesis of nanowires formed by the packing of structures with 5-fold symmetry. These icosahedral nanowire structures are similar to those of quasicrystals, which can only be formed if at least two atomic species are present and in which icosahedral and decahedral packing has been found for bulk crystals

Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review

The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic

La ganadería ante escenarios complejos.

La calidad de las contribuciones, producto de la pluma de especialistas en los temas tratados, el presente es un libro que esperamos, basándonos en la importancia de los temas tratados, sea de utilidad y abone a la reflexión de los estudiosos de la ganadería mexicana y, por supuesto, en beneficio de las familias ganaderas y de los consumidores de sus productos.este libro refleja en muchos sentidos la situación de la ganadería mexicana, a la que se le están demandando mayor producción y productividad, que los procesos productivos tengan la menor huella ecológicposible, que los alimentos sean inocuos, que se abatan costos de producción y, cada vez aumentan las presiones de diversos grupos para, que se incluyan los protocolos de bienestar animal, solamente por citar algunos de los retos que tiene. Algunas de estas demandas son complementarias, otras se contraponen, lo que hace valiosos a los estudios que desde las ciencias sociales se realizan y, desde diversas ópticas, se hagan propuestas de política pública balanceadas que consideren lo mejor de cada enfoque, pero sin desechar por completo los antagónicos.Universidad Autónoma Chaping

Estudio de la calidad bacteriológica del aire en tecnoacademia -Cúcuta.

La microflora del aire generalmente proviene del suelo, el agua y las actividades de los organismos vivos. Son de gran importancia, ya que su presencia pueden suponer un riesgo para la salud de las personas. Objetivo. Esta investigación abordó la presencia de bacterias y hongos del aire en las instalaciones de Tecnoacadémica regional Norte de Santander. Método. Se tomaron muestras de aire por la técnica de exposición de placa, se caracterizaron las colonias formadas por sus características macroscópicas y microscópicas. Resultados. Se identificaron bacterias grampositivas y gramnegativas. Géneros de hongos filamentosos: Curvularia sp, Aspergillus sp, Penicillium sp, Fusarium sp. Conclusión. Se encontró que las bacterias grampositivas y los hongos filamentos predominaron con mayor frecuencia. Si bien, estos microorganismos presentes en el ambientes son potencialmente patogénicos para la salud humana, son agentes aerobiológicos frecuentes  en el entorno

A Novel Inverse Kinematic Solution of a Six-DOF Robot Using Neural Networks Based on the Taguchi Optimization Technique

The choice of structural parameters in the design of artificial neural networks is generally based on trial-and-error procedures. They are regularly estimated based on the previous experience of the researcher, investing large amounts of time and processing resources during network training, which are usually limited and do not guarantee the optimal selection of parameters. This paper presents a procedure for the optimization of the training dataset and the optimization of the structural parameters of a neural network through the application of a robust neural network design methodology based on the design philosophy proposed by Genichi Taguchi, applied to the solution of inverse kinematics in an open source, six-degrees-of-freedom robotic manipulator. The results obtained during the optimization process of the structural parameters of the network show an improvement in the accuracy of the results, reaching a high prediction percentage and maintaining a margin of error of less than 5%

A Novel Inverse Kinematic Solution of a Six-DOF Robot Using Neural Networks Based on the Taguchi Optimization Technique

The choice of structural parameters in the design of artificial neural networks is generally based on trial-and-error procedures. They are regularly estimated based on the previous experience of the researcher, investing large amounts of time and processing resources during network training, which are usually limited and do not guarantee the optimal selection of parameters. This paper presents a procedure for the optimization of the training dataset and the optimization of the structural parameters of a neural network through the application of a robust neural network design methodology based on the design philosophy proposed by Genichi Taguchi, applied to the solution of inverse kinematics in an open source, six-degrees-of-freedom robotic manipulator. The results obtained during the optimization process of the structural parameters of the network show an improvement in the accuracy of the results, reaching a high prediction percentage and maintaining a margin of error of less than 5%