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Experimental and numerical study of plain-woven aramid fabric

EMMANUEL ALEJANDRO FLORES JOHNSON Jose Gonzalo Carrillo Baeza RICARDO ALBERTO GAMBOA CASTELLANOS (2014)

In this paper, the tensile properties of plain-woven aramid fabric style 724 (Kevlar® 129 fibre, 1000 denier, 24×24 yarns per inch) and the tensile properties of individual aramid yarn extracted from the fabric are presented. It was found that this fabric is balanced with less than 5% difference in strength between the warp and weft directions. The mechanical properties of the individual yarns were found to be lower than those reported for Kevlar® 129 fibre, which is explained by the fact that the yarns were damaged during the extraction process or weaving process.

Article

ARAMID FIBRE PLAIN-WOVEN FABRIC YARN MATERIAL PROPERTIES FINITE-ELEMENT MODELLING INGENIERÍA Y TECNOLOGÍA

Análisis de factibilidad técnica del uso de poliuretano para simular apariencia de piel en una cubierta de automóvil

Guillermo Maguey Nava (2018)

El concepto principal de la presente tesina se enfoca en una aplicación con una tecnología existente, plateando investigar el uso de un material basado en poliuretano sobre un panel de ventana trasera de un automóvil tipo “sedan” y “coupe”, es decir sobre una nueva aplicación basado en un proceso de manufactura existente. Este componente forma parte del interior del vehículo y se localiza debajo del vidrio trasero (coloquialmente llamado medallón) y detrás de la segunda fila de asientos de este tipo de automóviles. Este material fue desarrollado por la división de poliuretanos de BASF con el nombre de “Elastoskin®” y tiene uso en otros componentes del automóvil como paneles de puerta y panel de instrumento conocido comúnmente como tablero de un automóvil. La idea surge durante una visita del fabricante de plásticos BASF al centro de ingeniería de General Motors de México, visita en la cual muestran la existencia de este material. De igual forma surge con la intención de resolver una serie de problemas que se han presentado repetidamente en las pruebas de validación de este componente durante el desarrollo de su diseño; tales como la delaminación y presencia de aberturas con componentes con las que hace interface. Con este planteamiento se pretende resolver una serie de limitantes de diseño que se han tenido que enfrentar debido a las propiedades de los materiales que se utilizan actualmente para el moldeo de este panel. El material “Elastoskin®” es usado por fabricantes de automóviles en componentes como panel de instrumentos y panel de puerta. El objetivo de la presente tesina es analizar la factibilidad técnica del uso de este material en un panel de ventana trasera, considerando los requerimientos a cumplir en este panel por parte de General Motors. No se hace un análisis de la potencial reducción de costo, debido a la limitante de obtener este tipo de datos, ya que no existe un planteamiento comercial para su uso, por parte de General Motors y BASF.

The main idea for this study is focused in the usage of a current technology with a proposal to find out the option of using a polyurethane material in a rear window trim panel, which is used in sedan and coupe automotive vehicle, it means a new application based on existing material and manufacture process. This rear window trim is a piece located in the interior of the vehicle under the rear glass and behind of passenger’s second seat row of this kind of vehicles commented before (sedan and coupe). This material was developed by BASF polyurethane division and its commercial name is “Elastoskin®” and currently it is used in other interior parts of the vehicle such as door panels and instrument panels also known as IP in the automotive industry. The idea raised up during an exposition of the company BASF to General Motors Mexico Engineering Center, exposition where BASF presented this material and some applications. At the same time the idea raised up to have the material as an option to solve some issues that General Motors has experimented so often during validation test of this rear window trim design development; such as delamination and some gap condition with another pieces that rear window trim interfaces. This proposal also has the objective of solving some design constrains that this trim panel has faced, due to the properties of material used currently to manufacture it. As commented before, “Elastoskin®” material is used in components as instrument panel and door panels, but by some others automotive companies. The objective of this study is to analyze the technical feasibility of using this material in a rear window trim, meeting the requirements that General Motors specifies for this trim panels. There is not accurate information regarding material cost, due to there is not a commercial proposal between General Motors and BASF, this is why an accurate potential cost reduction is not consolidated in this study.

Other

Academic Sepecialization

Desarrollo tecnológico Propiedades físicas de materiales Poliuretano Proceso de manufactura Technological development Material physic properties Polyurethane INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PLÁSTICOS PLÁSTICOS

Influence of structural defects on the electrical properties of carbon nanotubes and their polymer composites

GUSTAVO DOMINGUEZ RODRIGUEZ JORGE ALEJANDRO TAPIA GONZALEZ G.D. SEIDEL FRANCIS AVILES CETINA (2016)

The influence of carbon nanotube (CNT) structural damage (CNTSD) on the axial and transverse electrical conductivities of CNT/polymer composites is explored through a hierarchical multiscale modeling strategy. The composite cylinder and Mori–Tanaka's methods are used to model effective representative volume elements of CNT/polymer composites containing different fractions of defects. The axial and transverse CNT conductivities are adversely influenced by CNTSD, with the decrease being more pronounced for small radius CNTs. The predictions indicate that an 8% fraction of CNTSD decreases the axial and transverse conductivities of composites containing randomly oriented CNTs by 25–30%. Similar reductions in conductivity are found for both random and clustered damage.

Article

CARBON DEFECTS NANOTUBES YARN INGENIERÍA Y TECNOLOGÍA INGENIERÍA Y TECNOLOGÍA

Influence of structural defects on the electrical properties of carbon nanotubes and their polymer composites

GUSTAVO DOMINGUEZ RODRIGUEZ JORGE ALEJANDRO TAPIA GONZALEZ G.D. SEIDEL FRANCIS AVILES CETINA (2016)

The influence of carbon nanotube (CNT) structural damage (CNTSD) on the axial and transverse electrical conductivities of CNT/polymer composites is explored through a hierarchical multiscale modeling strategy. The composite cylinder and Mori–Tanaka's methods are used to model effective representative volume elements of CNT/polymer composites containing different fractions of defects. The axial and transverse CNT conductivities are adversely influenced by CNTSD, with the decrease being more pronounced for small radius CNTs. The predictions indicate that an 8% fraction of CNTSD decreases the axial and transverse conductivities of composites containing randomly oriented CNTs by 25–30%. Similar reductions in conductivity are found for both random and clustered damage.

Article

CARBON DEFECTS NANOTUBES YARN INGENIERÍA Y TECNOLOGÍA

A comparative study of a self strain-monitoring carbon nanotube film and carbon fibers under flexural loading by electrical resistance changes

J.B. Pinto S. Kern José de Jesús Ku Herrera J. Yasui Valeria La Saponara K. J. Loh1 (2015)

With the increased use of composites for load-carrying structures, the ability to obtain strain and damage information is critical to maintain reliable structures in the field. A promising class of multifunctional composites with the ability to self-sense strain and/or damage is possible through the use of carbon fibers and carbon nanotubes. This paper presents a comparative study of two sensors for fiber-reinforced polymer composites: the sensors are the carbon fibers themselves, and a non-structural carbon nanotube (CNT) film applied through spray deposition. The changes in resistance of the sensors are compared under monotonic and cyclic flexural loading. Within the limits of this study and the current CNT sensor configuration, the carbon fibers are shown to have a higher sensitivity for strain and damage sensing. However, the CNT film appears to track the performance of GFRPs reasonably well for tensile strains.

Article

CARBON FIBERS DAMAGE DETECTION FIBER REINFORCED PLASTICS FIBERS NANOCOMPOSITE FILMS REINFORCED PLASTICS STRAIN YARN INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Tests for Waterproofing Materials, Made of Opuntia ficus-indica

ARTURO SANTAMARIA ORTEGA MIGUEL ANGEL RUBIO TOLEDO Gerardo Hernández Neria RICARDO VICTORIA URIBE Sandra Alicia Utrilla Cobos MARCO ANTONIO GARCIA ALBARRAN (2018)

Cacti are thoroughly found all across the Mexican Territory. In the mountain ranges, and sierras. The cactus known as Opuntia ficus-indica grows naturally in the State of Mexico. Cacti have been used for millennia for multiple purposes. From culinary, to art involving other materials such as calcium oxide and salt. There are about 300 different species of cacti around the globe. About 100 are found in Mexico. Extensive research has been made and often, new and innovative uses are discovered. This paper features another use for Opuntia ficus-indica: Waterproofing on building surfaces exposed to the elements (i.e. Sunlight and humidity). This paper shows the process involving six stages using Opuntia ficus-indica combined with different natural materials were experimented with, and tested by evaluating their unique performance.

Mexican cacti have captivated the scientific community due their extraordinary characteristics and benefits.This research established a new way to use this ancestral plant as a substitute for other construction materials that given their industrial and technological processes have -in several cases- skyrocketed their costs, besides of being a constant hazard for the environment. Thus, by looking back how ancestors used to solve their construction needs, it would ultimately allow us to find better ways to protect the environment. Production process is analyzed; experimented with it; and its prominent characteristics analyzed derived from Opuntia ficus-indica extract combined with other natural materials to be then used it as a waterproofing material.

Article

Nopal Diseño Mexico Material Natural Materials Cactus Opuntia Ficus Indica Design Waterproofing Preakly pear Construction BIOLOGÍA Y QUÍMICA

Sistemas de abastecimiento y distribución hidráulica en los conventos franciscanos y agustinos en el Michoacán virreinal. Los casos de Tzitzuntzán y Cuitzeo

Mirna Lorena Ruiz Solórzano (2012)

Facultad de Arquitectura. Investigación y restauración de sitios y monumentos

The research work presented in this master's thesis with the title: "Systems of supply and hydraulic distribution in Franciscan and Augustinian convents in Michoacan Viceregal. The cases of Tzintzuntzan and Cuitzeo ", takes as a line of research the historical Technology of Virreinal architecture in terms of hydraulic systems in convents of mendicant orders, specifically in Michoacán. Considering that with the technology and constructive techniques of the Spaniards upon their arrival in the New World, new constructive solutions were created between constructive friars and native Indians who materialized in the architecture of the water proper to these convents under study Of Tzintzuntzan and Cuitzeo. The hydraulic technology carried out by the friars is diverse and complete, such as water pipes for supply, rainwater harvesting, mills of various types, irrigation systems and territorial improvements, among others. Hydraulic projects, as mentioned by Tarsicio Pastrana, are found in two fields; Those that cover the basic needs and those that improve the productive characteristics of a region, such as works that focus on hydraulic engineering for industry and for the improvement of areas, where dams, drains, mills, etc. are located. Which, even without those mentioned, a region could subsist basically, but are necessary for the consolidation of the region. This is why the present work will focus on those of first necessity; To those who generally have to do with all the work of conducting, capturing, storing and evicting water, which the friars and the Indians designed in the convents under study.

EL trabajo de investigación que se presenta en esta tesis de maestría con el Título: “Sistemas de Abastecimiento y distribución hidráulica en conventos Franciscanos y Agustinos en e l Michoacán Virreinal. Los casos de Tzintzuntzan y Cuitzeo”, toma como línea de investigación la Tecnología histórica de la arquitectura Virreinal en cuanto a los sistemas hidráulicos en los conventos de órdenes mendicantes, específicamente en Michoacán. Considerándose que con la tecnología y técnicas constructivas de los españoles a su llegada al Nuevo Mundo, se dio paso a la creación de nuevas soluciones constructivas conjuntas entre frailes constructores e indios nativos que se materializaron en la arquitectura del agua propia para estos conventos objeto de estudio de Tzitzuntzan y Cuitzeo. La Tecnología hidráulica realizada por los frailes es diversa y completa, se encuentran por ejemplo canalizaciones de agua para suministro, obras de captación de agua de lluvia, molinos de diversos tipos, sistemas de riego y mejoras territoriales, entre otros. Los proyectos hidráulicos como lo menciona Tarsicio Pastrana, se encuentran en dos campos; los que cubren las necesidades básicas y los que mejoran las características productivas de una región, como las obras que se enfocan a la ingeniería hidráulica para la industria y para el mejoramiento de las zonas, en donde se ubican las presas, desagües, ingenios, etc., las cuales aún sin las mencionadas una región podría subsistir básicamente, pero son necesarias para la consolidación de la región. Es por esto que el presente trabajo se enfocará, a los de primera necesidad; a los de que tienen que ver en general con toda obra de conducción, captación, almacenaje y desalojo de aguas, que diseñaron los frailes e indígenas en los conventos objeto de estudio.

Master thesis

HUMANIDADES Y CIENCIAS DE LA CONDUCTA FA-M-2012-0007 Panorama Tratados Material Identificación

SUSTRATOS EN LA HORTICULTURA

ELIA CRUZ CRESPO ALVARO CAN CHULIM MANUEL SANDOVAL VILLA RUBEN BUGARIN MONTOYA AGUSTIN ROBLES BERMUDEZ (2013)

This article shows a general outline of horticultural substrates usage, advantages of its use and, factors to be considered in their choice; as well as the physical, chemical and biological properties that need to be assessed. This is because today, substrates are an important component in modern agriculture, specifically in the semi-hydroponic vegetable species systems. It could be concluded that there is great diversity of materials that can be used as agricultural substrates, however, there are criteria to be considered for its election such as: plant requirements that better adjust the ideal characteristics of a substrate and environmental effect.

El presente artículo presenta un bosquejo general de los sustratos de uso hortícola, las ventajas, los factores a considerar en su elección y las propiedades físicas, químicas y biológicas que se deben evaluar. Esto porque en la actualidad, los sustratos representan un componente importante en la agricultura moderna, específicamente en los sistemas semi-hidropónicos de especies hortícolas. Se concluye, que existe una gran diversidad de materiales que pueden utilizarse como sustratos agrícolas, pero existen criterios que deben considerarse para su elección como: requerimientos de las plantas, que se ajusten en lo posible a las características ideales de un sustrato, así como efecto en el medio ambiente.

Article

Vermicompost jal tezontle propiedades properties. HORTICULTURA CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Effect of HVOF processing parameters on the properties of nicocraly coatings by design of experiments

HAIDEÉ RUIZ LUNA David LOZANO Juan Manuel Alvarado-Orozco Andrés Valarezo CARLOS AGUSTIN POBLANO SALAS LUIS GERARDO TRAPAGA MARTINEZ FRANCISCO JAVIER ESPINOZA BELTRAN Juan Muñoz Saldaña (2014)

The effect of three principal, independent, high-velocity oxygen fuel (HVOF)-processing parameters on the properties of NiCoCrAlY coatings deposited using commercial powders is reported here. The design of experiments (DoE) technique at a two-level factorial and a central composite rotatable design was used to analyze and optimize the HVOF spraying process. The deposition parameters investigated were (1) fuel flow, (2) oxygen flow, and (3) stand-off distance. The effect of these processing variables was evaluated using selected responses, including porosity and oxide content, residual stresses, and deposition efficiency. Coatings with low porosity as well as with low residual stress were obtained using high fuel-rich conditions at a stand-off distance between 250 and 300 mm. At shorter and longer stand-off distances, respectively, either excessive flattening of splats or un-molten condition occurred, resulting in high levels of porosity and residual stress. The response surface, the empirical relationships among the variables, and the response parameters allowed the selection of optimum deposition parameters and the improvement of coating properties.

Article

Design of experiments HVOF NiCoCrAlY Process parameters Properties Residual stress INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS INGENIERÍA Y TECNOLOGÍA QUÍMICAS PROCESOS QUÍMICOS

Propuesta de una situación didáctica con el uso de material didáctico para la comprensión de la noción de semejanza en estudiantes de segundo de secundaria

Proposal of a didactic situation with the use of teaching material for the understanding of the notion of similarity in secondary school students

EDUARDO CARLOS BRICEÑO SOLIS (2017)

See the result of the application of a didactic situation with secondary students to analyze how to understand the notion of similarity with the use of didactic material. The situation is based on the Theory of Didactic Situations with activities of construction of geometric figures with the use of tangram as material of didactic. The goal is that students generate a geometric representation of similarity and conjecture the idea of reason. The results of the strategies with the use of the material to generate explanations on the notion of similarity .

Se reporta el resultado de la aplicación de una situación didáctica con estudiantes de secundaria para analizar cómo comprenden la noción de semejanza con el uso de material didáctico. La situación se fundamentó en la teoría de situaciones didácticas con actividades de construcción de figuras geométricas con el uso del tangram como material de uso didáctico. El objetivo es que los estudiantes generen una representación geométrica de semejanza y conjeturen la idea de razón. Los resultados muestran estrategias con el uso del material para generar explicaciones sobre la noción de semejanza.

Producción Científica de la Universidad Autónoma de Zacatecas UAZ

Article

HUMANIDADES Y CIENCIAS DE LA CONDUCTA Situación didáctica Material didáctico Semejanza