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Optimization of tensile strength in injection molded polyamide-6 pieces using neuronal network techniques and non-linear programming
No full textThe main objective of this research is the optimization of tensile stress of injection molded parts of polyamide-6 to establish process conditions that maximize tensile strength of parts in a real industrial process. The methodology consisted in development of assays based on I-optimal experimental design to get a data base. Four parameters were considered as inputs: injection holding pressure, injection packing time, % wt virgin material and % wt recycled material. Measurement of maximum tensile stress in parts was made according to ISO 527-1 standard. Three models were developed by the techniques Response Surface Methodology, Back Propagation Neural Network and Generalized Regression Neural Network to predict parts maximum tensile stress. Finally, the best model (with lowest forecasting error) was optimized by Trust Region Method Based on Interior Point Techniques for Nonlinear Programming to maximize tensile strength. This proposed methodology is capable for modeling the process with low error and for stablish process conditions to obtain the maximum tensile stress on molded parts. Keywords: Plastic Injection Molding; Tensile stress; Polyamid-6; Response Surface; Backpropagation Neural Network; Generalized Regression Neural Network; Nonlinear programming
Characterization of structural and optical properties of the mesoporous Ce-MCM-41 hybrid materials
Get PDFCe-modified mesostructured MCM-41-type hybrid materials with different Si/Ce molar ratios (Si/Ce = 10, 30 and 50) were synthesized by the surfactant-assisted hydrothermal method and their structural and optical properties were characterized by small angle X-ray scattering (SAXS), field emission scanning electron microscopy (FE-SEM) equipped with embedded EDS system, ultraviolet and visible diffuse reflectance (UV–vis DR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Ce-MCM-41 samples show highly ordered 2D porous hexagonal mesostructures and oval and spherical morphologies with particle size between 300 and 600 nm, depending on the incorporated Ce amount. Incorporation of Ce4+ into ordered mesoporous silica generates oxygen defects in ceria-silica composites with the formation of Ce3+ species as confirmed by the XPS analyses. Cerium incorporation modified their structural regularity and resulted in an effective red shifting of the band gap (2.82 eV at 2.64 eV) due to the creation of intermediate energy states. Both asymmetry and broadening of Raman active F2g mode confirmed the presence of the structural defects. These ordered mesoporous Ce-MCM-41 hybrid materials are potentially attractive for their use as novel photocatalysts in the degradation of organic pollutants present in wastewater employing UV and visible light
Energy, exergy and techno‑economic analysis for biobutanol production: a multi‑objective optimization approach based on economic and environmental criteria
Get PDFCurrently, butanol obtained by fermentation is considered as potential biofuel. In this work, it has been simulated and optimized a process to produce acetone, butanol and ethanol by means of lignocellulosic material. To accomplish this task, initially, it was planned the raw material selection, followed by the simulation in MATLAB of simultaneous saccharification, fermentation and separation reactor (SFS) and finally, the stream coming from fermentation was purified. The separation stage was selected from three different options to purify that effluent. The entire process was evaluated under a robust optimization process considering environmental, economic and energetic objective functions by means of a hybrid stochastic method, differential evolution with tabu list. The obtained results showed that the best scheme to produce and purify butanol was the SFS-3C, which considers thermally coupled columns to purify acetone, butanol and ethanol. In general terms, it was obtained as result 0.138 $/kgbutanol, 0.132 points/kgbutanol and 66.8 regarding to the total annual cost, environmental impact and exergy efficiency, respectively
Reactive Distillation Column Design for Tetraethoxysilane (TEOS) Production: Economic and Environmental Aspects
Get PDFIn this work, the reactive distillation (RD) is suggested to produce TEOS as an intensified technology. In general, the concept of process intensification may overcome the traditional process, since it allows design technology with reduction on equipment size, improvement in energy and mass transfer, and reduction in capital cost. Therefore, this work will approach TEOS production by means of two systems, the conventional reaction including the product separation (reaction/separation) and a reactive distillation. In order to evaluate both ways to produce TEOS, the two systems were evaluated considering the total annual cost (TAC) and return of investment (ROI) as economic indexes and the Eco-indicator 99 as an environmental index. As a result, the reactive distillation shows better performance as concern to TAC values; however, when purities above 99.5% wt are obtained, the reaction/separation system overcomes the RD as concern to ROI values. Moreover, when the environmental impact is measured, the RD showed a bigger impact near 30% in comparison with the reaction/separation system
Desarrollo de un acabado plata de alto desempeño para cuero de marroquinería
Get PDFEste proyecto es sobre una empresa que se dedica a la manufactura de bolsos que su material es de piel en color metálico plata. Siendo el más utilizados por las tendencias de moda actuales.
Sin embargo, ha tenido problemas en su proceso final de control de calidad ya que sufre una pérdida de la estructura superficial de la piel por el roce que tiene con el uso diario del cliente y existe desgaste en las áreas que tienen contacto directo con manos (sudoración).
Se pretende buscar por qué o en que parte del proceso de acabado son deficientes los materiales que se agregan al cuero. Posiblemente porque algunos de estos provocan el deterioro prematuro del producto o son de deficiente calidad.
Se trabajará con la fórmula original y se procesaran otras pruebas con diferentes tipos de materiales similares sin modificar la formula inicial
Efecto de los productos empleados en el Pickle para curtido sustentable de alta Calidad.
Get PDFHoy en día vivimos con la necesidad de realizar productos y procesos más sustentables y ecológicos, la industria del cuero se obligada a reducir su impacto ambiental buscando alternativas de curtición de cromo.
Una de las opciones potenciales para sustituir el cromo es la curtición con tara tamizada modificada física y químicamente buscando potencializar su efecto tanino. A partir de los diseños experimentales realizados hasta el día de hoy con tara modificada se busca reducir la astringencia y mejorar la penetración de las moléculas de los taninos a través de la estructura del cuero.
Además del proceso físico y químico en la tara se busca mejorar los procesos de curtición ya que hasta ahora se han utilizado procesos similares de curtición vegetal tradicional y se busca analizar diferentes variables en los procesos para potencializar el efecto de la curtición con tara para mejorar tanto la apariencia como el desempeño del cuero.
El enfoque de este proyecto es analizar en la fase de pickle que es la fase donde se prepara el cuero para la curtición con tara, las variables de sal y ácido fórmico, y en base a los resultados obtenidos concretar si tenemos mejores resultados en las pruebas de temperatura de contracción y cómo podríamos proceder a realizar mejoras en este proceso para tener mejor desempeño en el cuero orgánico sustentable
Analysis of Insulating Material of XLPE Cables considering Innovative Patterns of Partial Discharges
Get PDFEste trabajo tiene como objetivo analizar la calidad del aislamiento en cables subterráneos de alta tensión XLPE mediante un prototipo que clasifica los siguientes tipos habituales de patrones de descarga parcial (DP): (1) DP interno, (2) DP superficial, (3) descarga de corona en el aire, y (4) descarga de corona en aceite, además de considerar dos nuevos patrones de DP: (1) falso contacto y (2) suelo flotante. En el laboratorio de ensayos se realizaron pruebas y mediciones para obtener los patrones y estudiar casos de descargas parciales.
Equipos y Materiales (LEPEM) de la Comisión Federal de Electricidad de México (CFE) utilizando un equipo de medición LDIC y norma IEC60270. Para clasificar los seis patrones de descargas parciales mencionados anteriormente, una Red Neural Probabilística Bayesiana, se utilizará el método modificado (PNNBM) que tiene la característica de utilizar una gran cantidad de datos y no está saturado. Adicionalmente, PNN converge, encontrando siempre una solución en un corto período de tiempo con un bajo costo computacional. El aislamiento de dos de alto voltaje. Se analizaron cables con diferentes características. Los resultados de la prueba nos permiten concluir qué cable tiene mejor aislamiento
Calzado terapéutico de descanso auxiliar al tratamiento de la ascitis plantar
Get PDFEl calzado desarrollado envuelve el requerimiento de uso como auxiliar al tratamiento de la FP, y cubre principalmente dos aspectos: la disminución de la talagia plantar mediante la crioterapia; y la mejora del padecimiento mediante un sistema integral de amortiguación de impacto lograda mediante la potencialización de los mecanismos 10 naturales amortiguación de impacto, grasa plantar y el arco plantar, propiciando la distribución de las cargas y el estiramiento del sistema aquíleo calcáneo plantar, que pretende relajar los sistemas involucrados obteniendo una potencial mejora en los usuarios, permitiendo una marcha y una bipedestación lo más natural posible
Anticancer potential of Thevetia peruviana fruit methanolic extract
Get PDFThevetia peruviana (Pers.) K. Schum or Cascabela peruviana (L.) Lippold (commonly known as ayoyote, codo de fraile, lucky nut, or yellow oleander), native to Mexico and Central America, is a medicinal plant used traditionally to cure diseases like ulcers, scabies, hemorrhoids and dissolve tumors. The purpose of this study was to evaluate the cytotoxic, antiproliferative and apoptotic activity of methanolic extract of T. peruviana fruits on human cancer cell lines.
The cytotoxic activity of T. peruviana methanolic extract was carried out on human breast, colorectal, prostate and lung cancer cell lines and non-tumorigenic control cells (fibroblast and Vero), using the MTT assay. For proliferation and motility, clonogenic and wound-healing assays were performed. Morphological alterations were monitored by trypan blue exclusion, as well as DNA fragmentation and AO/EB double staining was performed to evaluate apoptosis. The extract was separated using flash chromatography, and the resulting fractions were evaluated on colorectal cáncer cells for their cytotoxic activity. The active fractions were further analyzed through mass spectrometry.
The T. peruviana methanolic extract exhibited cytotoxic activity on four human cancer cell lines: prostate, breast, colorectal and lung, with values of IC50 1.91 ± 0.76, 5.78 ± 2.12, 6.30 ± 4.45 and 12.04 ± 3.43 μg/mL, respectively. The extract caused a significant reduction of cell motility and colony formation on all evaluated cancer cell lines. In addition, morphological examination displayed cell size reduction, membrane blebbing and detachment of cells, compared to non-treated cancer cell lines. The T. peruviana extract induced apoptotic cell death, which was confirmed by DNA fragmentation and AO/EB double staining. Fractions 4 and 5 showed the most effective cytotoxic activity and their MS analysis revealed the presence of the secondary metabolites: thevetiaflavone and cardiac glycosides
