2,895 research outputs found
Estudio del impacto del oleaje sobre diques de bloques en puertos utilizando el método de elementos finitos y partÃculas (PFEM)
Esta tesina trata de analizar algunos de los problemas más habituales que se
presentan a la hora de construir de un puerto de grandes dimensiones. Se estudiará el
proceso de la construcción de un puerto y se desarrollarán aplicaciones que permitan
evaluar, para cada una de sus fases, los riesgos o problemas asociados y las posibles
soluciones a los mismos. Para ello, se mejorará y desarrollará el paquete de software
PFLOW, una excelente y potente herramienta computacional para estudio del
comportamiento del agua y la interacción entre fluido y estructura.
En esta tesina se presenta la aplicación práctica de las últimas mejoras realizadas al
programa PFLOW para la creación de distintas aplicaciones informáticas para la resolución
de diversos problemas dentro del campo de la ingenierÃa marÃtima. El trabajo incluye los
desarrollos llevados a cabo, la validación a la que fue sometido el programa y las diversas
aplicaciones del método de los elementos finitos y partÃculas para el caso de la interacción
entre fluido y estructura
Estudio del impacto del oleaje sobre diques de bloques en puertos utilizando el método de elementos finitos y partÃculas (PFEM)
Esta tesina trata de analizar algunos de los problemas más habituales que se
presentan a la hora de construir de un puerto de grandes dimensiones. Se estudiará el
proceso de la construcción de un puerto y se desarrollarán aplicaciones que permitan
evaluar, para cada una de sus fases, los riesgos o problemas asociados y las posibles
soluciones a los mismos. Para ello, se mejorará y desarrollará el paquete de software
PFLOW, una excelente y potente herramienta computacional para estudio del
comportamiento del agua y la interacción entre fluido y estructura.
En esta tesina se presenta la aplicación práctica de las últimas mejoras realizadas al
programa PFLOW para la creación de distintas aplicaciones informáticas para la resolución
de diversos problemas dentro del campo de la ingenierÃa marÃtima. El trabajo incluye los
desarrollos llevados a cabo, la validación a la que fue sometido el programa y las diversas
aplicaciones del método de los elementos finitos y partÃculas para el caso de la interacción
entre fluido y estructura
Use of nanofiltration membrane technology for ceramic industry wastewater treatment
A study has been undertaken of an advanced wastewater treatment approach using polymer nanofiltration membranes, in
an attempt to obtain water of sufficient quality to allow it to be reused in the same production process or, alternatively, to be
discharged without any problems. The study has initially focused on the removal of organic matter (reduction of COD) and
the most representative ions present in the wastewater, such as Na+
, Mg2+, Cl-
, and SO4
2-
.
In a first part of the study, with a view to optimising the experimental phase, a simulation has been performed of the
nanofiltration process using the NanoFlux software. Among other things, the simulation allows the most suitable membranes
to be selected as a function of the permeate flow rate and desired level of retention in the substances to be removed. The
subsequent experimentation was carried out in a laboratory tangential filtration system that works with flat membranes.
It was found that retention values of about 90% were obtained for the studied substances, with a good permeate flow rate,
using low operating pressures. These results demonstrate the feasibility of the studied technology and its potential as a
treatment for improving ceramic industry wastewater qualit
Strategies towards sustainability environmental from the local areas and the university
El propósito del presente trabajo es explorar un posible arreglo socioambiental pensado desde lo local que propicie el desarrollo sustentable, por medio del privilegio de la articulación de lo social (ciudadanÃa y educación) con el medio ambiente (capacidad de renovación).
El planteamiento central es que ante un modelo social dominante que es insustentable, en el sentido que refuerza la desigualdad socioeconómica y el deterioro ambiental; se demanda pensar y actuar en formas novedosas e integradoras de lo social con la natural y del presente con el futuro para hacer posible sentar bases para un desarrollo sustentable de largo plazo. Para tal fin, se formula un arreglo que articule lo social (ciudadanÃa y educación) con el medio ambiente (capacidad de renovación) desde ámbitos locales, por medio de estrategias de acción gestionadas socialmente.The aim of this paper is to explore and present a suitable socio-environmental proposal conducive to sustainable development considering the local aspects emphasizing on the joint between the social (citizenship and education) with the environmental (renewability). The rationale of the study is that having a dominant unsustainable social model that reinforces socioeconomic inequality and environmental degradation, a need of developing more integrative and innovative ways to cope with the social and the natural as well as the present and the future is required in order to lay the foundations for a more long-term sustainable development.
To that end, a suitable arrangement is presented in order to articulate the social aspects (citizenship and education) to the environmental ones (renewability) from a local perspective, managed through social action strategies.Fil: González López, Sergio.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad.Fil: Salvador BenÃtez, J. Loreto.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad.Fil: Arand a Sánchez, José MarÃa.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad
Cerámica y Vidrio Use of nanofiltration membrane technology for ceramic industry wastewater treatment
A study has been undertaken of an advanced wastewater treatment approach using polymer nanofiltration membranes, in an attempt to obtain water of sufficient quality to allow it to be reused in the same production process or, alternatively, to be discharged without any problems. The study has initially focused on the removal of organic matter (reduction of COD) and the most representative ions present in the wastewater, such as Na , Cl -, and SO 4 2-. In a first part of the study, with a view to optimising the experimental phase, a simulation has been performed of the nanofiltration process using the NanoFlux software. Among other things, the simulation allows the most suitable membranes to be selected as a function of the permeate flow rate and desired level of retention in the substances to be removed. The subsequent experimentation was carried out in a laboratory tangential filtration system that works with flat membranes. It was found that retention values of about 90% were obtained for the studied substances, with a good permeate flow rate, using low operating pressures. These results demonstrate the feasibility of the studied technology and its potential as a treatment for improving ceramic industry wastewater quality. Key words: Nanofiltration, Membrane, Wastewater, Ceramic Tiles Industry, Red/White Ceramics Uso de la tecnologÃa de nanofiltración a través de membranas para el tratamiento de aguas residuales de la industria cerámica Este estudio ha sido emprendido con el fin de acercar la nanofiltración a través de membranas poliméricas al tratamiento de las aguas residuales industriales de la industria cerámica, esperando obtener un agua con la suficiente calidad como para ser reutilizada en el propio proceso productivo o, alternativamente, poder verterla. El estudio se ha centrado en la eliminación de materia orgánica (reducción de D.Q.O) y algunos iones presentes en las aguas residuales, tales como Na . En primer lugar, se ha realizado una simulación del proceso de nanofiltración usando el software NanoFlux. Entre otras cosas, la simulación permite seleccionar las membranas más apropiadas en función del caudal de permeado obtenido y en función del nivel de retención de la sustancia que se desea eliminar. En una segunda parte, se realizaron los ensayos experimentales en un sistema de laboratorio de filtración tangencial que trabaja con membranas planas. La retención obtenida para las sustancias estudiadas es de aproximadamente el 90%. Todo ello, con un buen caudal de permeado y usando bajas presiones de trabajo. Estos resultados demuestran la viabilidad de la tecnologÃa y su potencial como tratamiento para mejorar la calidad de las aguas residuales de esta industria
A New Under-Sampling Method to Face Class Overlap and Imbalance
Class overlap and class imbalance are two data complexities that challenge the design of effective classifiers in Pattern Recognition and Data Mining as they may cause a significant loss in performance. Several solutions have been proposed to face both data difficulties, but most of these approaches tackle each problem separately. In this paper, we propose a two-stage under-sampling technique that combines the DBSCAN clustering algorithm to remove noisy samples and clean the decision boundary with a minimum spanning tree algorithm to face the class imbalance, thus handling class overlap and imbalance simultaneously with the aim of improving the performance of classifiers. An extensive experimental study shows a significantly better behavior of the new algorithm as compared to 12 state-of-the-art under-sampling methods using three standard classification models (nearest neighbor rule, J48 decision tree, and support vector machine with a linear kernel) on both real-life and synthetic databases
Deposition of Al2O3-TiO2 Nanostructured Powders by Atmospheric Plasma Spraying
Al2O3-13%TiO2 coatings were deposited on stainless steel substrates from conventional and nanostructured
powders using atmospheric plasma spraying (APS). A complete characterization of the
feedstock confirmed its nanostructured nature. Coating microstructures and phase compositions were
characterized using SEM, TEM, and XRD techniques. The microstructure comprised two clearly differentiated
regions. One region, completely fused, consisted mainly of nanometer-sized grains of c-Al2O3
with dissolved Ti+4. The other region, partly fused, retained the microstructure of the starting powder
and was principally made up of submicrometer-sized grains of a-Al2O3, as confirmed by TEM. Coating
microhardness as well as tribological behavior were determined. Vickers microhardness values of conventional
coatings were in average slightly lower than the values for nanostructured coating. The wear
resistance of conventional coatings was shown to be lower than that of nanostructured coatings as a
consequence of Ti segregation. A correlation between the final properties, the coating microstructure,
and the feedstock characteristics is give
Tuning the separation properties of zeolitic imidazolate framework core-shell structures via post-synthetic modification
The conversion of ZIF-8 into ZIF-7 via post-synthetic modification with benzimidazole has been monitored by quantifying the liberated 2-methylimidazole by chromatography. The reaction kinetics have been adjusted to the shrinking core model, providing the diffusion coefficient of bIm inside the pores and the reaction kinetic constant (2.86 × 10-7 cm2 s-1 and 1.36 × 10-4 cm s-1, respectively). A wide variety of ZIF-7/8 hybrid core-shell frameworks have been obtained during this reaction. The most promising have been characterized by SEM/TEM, TGA, N2 and CO2 adsorption, FTIR and 13C NMR, showing features of the coexistence of both phases inside the frameworks. Their structures have also been simulated, providing comparable XRD and adsorption results. The hybrid material has been used as a filler for PBI mixed matrix membranes (MMMs) applied to H2/CO2 separation, enhancing the performances of the bare PBI polymer and MMMs containing ZIF-8 or ZIF-7 as a filler, with a maximum H2 permeability value of 1921 Barrer and a H2/CO2 selectivity of 11.8
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