Propuesta didáctica para adecuar la asignatura de ciencia de los materiales de la carrera de Ingeniero Industrial Administrador de la Facultad de Ciencias Químicas de la UANL, para implementarla en la modalidad a distancia utilizando material didáctico im

Tesis (Maestría en Enseñanza Superior) U.A.N.L.

Una experiencia de evaluaci??n alternativa en la asignatura de Fundamentos de Ciencia en los Materiales en la E.P.S de Ingiener??a de Gij??n

Resumen tomado de la publicaci??n

Ciencia de los materiales : reforma de las enseñanzas medias : segundo ciclo.

Programa para el desarrollo de la asignatura de ciencias de los materiales de segundo ciclo del bachillerato técnico industrial. Se exponen la justificación, los objetivos, las actividades y la programación. Dicho programa se estructura en trece partes con distintos temas cada uno. La bibliografía se refiere a cada una de las partes.

Safmat: casos prácticos de materiales en la sala de aprendizaje flexible

El grupo de innovación docente GIDC E-PPM del Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica ha desarrollado una nueva herramienta para favorecer el autoaprendizaje y complementar el trabajo tutelado. El proyecto SAFMAT (Sala de Aprendizaje Flexible en Materiales) utiliza la plataforma Moodle y consiste en una serie de casos prácticos, clasificados por temática y grado de dificultad SAFMAT permite tanto el trabajo tutorizado como individual del alumno. La posibilidad de trabajar sin límite de tiempo y de forma remota permite al alumno profundizar y complementar los conocimientos adquiridos durante las clases teóricas y laboratorios de varias asignaturas de su currículum

Estudio de materiales de construcción neolíticos mediante diferentes técnicas instrumentales

Se han aplicado técnicas de análisis instrumental (FRX, DRX, ATR-IR, TG-ATD, SEM-EDX, MO) al estudio de fragmentos constructivos de época neolítica obtenidos de diferentes yacimientos de la Provincia de Alicante (España). La secuencia y el orden de aplicación de las técnicas se fija en función de las características y la cantidad disponible de cada muestra, estableciéndose con ello un protocolo de trabajo que se aplica siempre al resto de muestras, lo que nos permite comparar los resultados entre sí. El uso de dichas técnicas nos ha permitido la caracterización de los fragmentos constructivos, lo que nos ha llevado a conocer el grado de tecnología alcanzado por estas sociedades, sugiriéndonos que podíamos estar ante los inicios de la aplicación de la tecnología de la cal en esta zona de la Península Ibérica. En este trabajo se presenta una visión global de los resultados obtenidos hasta el momento.

Nueva aplicación potencial de dos técnicas instrumentales para la caracterización de materiales de construcción prehistóricos

En este trabajo se ponen de manifiesto las ventajas de la utilización de la Termogravimetría acoplada a Espectrometría de masas (TG-EM) y de la Espectrometría Infrarroja mediante Reflectancia Total atenuada (ATR-FTIR) frente a las técnicas usadas tradicionalmente de Termogravimetría (TG) y de Espectroscopia Infrarroja por Transformada de Fourier en modo transmisión (FTIR) en el estudio de materiales de construcción prehistóricos de diversos yacimientos de la Provincia de Alicante (España).

Hydrogen storage in CO2-activated amorphous nanofibers and their monoliths

Amorphous carbon nanofibers (CNFs), produced by the polymer blend technique, are activated by CO2 (ACNFs). Monoliths are synthesized from the precursor and from some ACNFs. Morphology and textural properties of these materials are studied. When compared with other activating agents (steam and alkaline hydroxides), CO2 activation renders suitable yields and, contrarily to most other precursors, turns out to be advantageous for developing and controlling their narrow microporosity (< 0.7 nm), VDR(CO2). The obtained ACNFs have a high compressibility and, consequently, a high packing density under mechanical pressure which can also be maintained upon monolith synthesis. H2 adsorption is measured at two different conditions (77 K / 0.11 MPa, and 298 K / 20 MPa) and compared with other activated carbons. Under both conditions, H2 uptake depends on the narrow microporosity of the prepared ACNFs. Interestingly, at room temperature these ACNFs perform better than other activated carbons, despite their lower porosity developments. At 298 K they reach a H2 adsorption capacity as high as 1.3 wt.%, and a remarkable value of 1 wt.% in its mechanically resistant monolith form.

Presencia de carbonato cálcico (CaCO3) recarbonatado en un probable fragmento constructivo de la ocupación neolítica cardial de Benàmer

Análisis mediante diferentes técnicas instrumentales (ATR-IR, TG, MO, SEM, DRX, FRX, etc..) de un fragmento constructivo procedente de un yacimiento Neolítico-Mesolítico de Cantera Benàmer (Muro d'Alcoi, Alicante).

Análisis instrumental del recubrimiento de las paredes internas de dos estructuras negativas de tipo silo de la ocupación neolítica postcardial de Benàmer

Análisis instrumental mediante diferentes técnicas (ATR-IR, DRX, TG, SEM, MO, FRX, etc..) del recubrimiento de la pared interna de dos estructuras negativas (silos)del yacimiento Neolítico-Mesolítico de Cantera Benàmer (Muro d'Alcoi, Alicante).

Stabilisation of low softening point petroleum pitch fibres by HNO3

This paper deals with the stabilisation of low softening point pitch fibres obtained from petroleum pitches using HNO3 as oxidising agent. This method presents some advantages compared with conventional methods: pitches with low softening point (SP) can be used to prepare carbon fibres (CF), the stabilisation time has been reduced, the CF yields are similar to those obtained after general methods of stabilisation, and the initial treatments to increase SP when low SP pitches are used to prepare CF, are avoided. The parent pitches were characterised by different techniques such as diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), elemental analysis and solvent extraction with toluene and quinoline. The interaction between HNO3 and the pitch fibres, as well as the changes occurring during the heat treatment, have been followed by DRIFTS.

Isotropic petroleum pitch as a carbon precursor for the preparation of activated carbons by KOH activation

Results show that it is possible to activate a low softening point isotropic petroleum pitch, without intermediate pre-treatments, by chemical activation with KOH. The chemical activation is carried out by direct heat treatment of a mixture of the isotropic pitch and KOH. It produces activated carbons (ACs) with micropore volumes as high as 1.12 cm3/g, and BET surface areas around 3000 m2/g. The activating agent/precursor ratios studied (from 1/1 to 4/1; wt./wt.) show, as expected, that increasing the ratio enhances the adsorption characteristics of the resulting AC.

Effect of carbon fibres on the mechanical properties and corrosion levels of reinforced portland cement mortars

The changes in mechanical properties of portland cement mortars due to the addition of carbon fibres (CF) to the mix have been studied. Compression and flexural strengths have been determined in relation to the amount of fibres added to the mix, water/binder ratio, curing time and porosity. Additionally, the corrosion level of reinforcing steel bars embedded in portland cement mortars containing CF and silica fume (SF) have also been investigated and reinforcing steel corrosion rates have been determined. As a consequence of the large concentration of oxygen groups in CF surface, a good interaction between the CF and the water of the mortar paste is to be expected. A CF content of 0.5% of cement weight implies an optimum increase in flexural strength and an increase in embedded steel corrosion.

Activated carbon fibre monoliths

Activated carbon fibre monoliths were prepared by physical activation of carbon fibre monoliths derived from two kinds of pitch-based carbon fibre (CF) (carbon fibres from a coal tar pitch and carbon fibres derived from a petroleum pitch). The monoliths were conformed using a coal tar pitch binder. The carbon fibre monoliths and the activated carbon fibre monoliths were studied by scanning electron microscopy (SEM) and gas adsorption (i.e. N2 at 77 K and CO2 at 273 K). The results obtained reveal that monoliths perform a good activation process that produce a quite high development of microporosity (BET surface areas around 2600 m2/g and N2 micropore volume of 1.23 cm3/g). On the other hand, it is remarkable that the activation process used allow to easily control the degree of activation and hence to select the adsorption capacities of the activated carbon fibre monoliths.

Stabilisation of low softening point petroleum pitch fibres by iodine treatment

A method using iodine has been developed for the stabilisation of low softening point (SP) pitch fibres that avoids air stabilisation in the production of carbon fibres (CF). The interaction between iodine and petroleum pitches has been studied by following the changes in the hydrogen content, aromatic or aliphatic, during the heat treatment of iodine-treated pitch fibres. Two low SP petroleum pitches were used and the iodine-treated pitch fibres were analysed by TGA, DSC, DRIFT, XPS and SEM. The results confirm that using this novel method pitches with low SP can be used to prepare CF with two advantages, compared with conventional methods. The stabilisation time is considerably reduced and treatments to increase the SP, usually required when low SP pitches are used to prepare CF, can be avoided.

Activation of polymer blend carbon nanofibres by alkaline hydroxides and their hydrogen storage performances

In the present work we study the hydroxide activation (NaOH and KOH) of phenol-formaldehyde resin derived CNFs prepared by a polymer blend technique to prepare highly porous activated carbon nanofibres (ACNFs). Morphology and textural characteristics of these ACNFs were studied and their hydrogen storage capacities at 77 K (at 0.1 MPa and at high pressures up to 4 MPa) were assessed, and compared, with reported capacities of other porous carbon materials. Phenol-formaldehyde resin derived carbon fibres were successfully activated with these two alkaline hydroxides rendering highly microporous ACNFs with reasonable good activation process yields up to 47 wt.% compared to 7 wt.% yields from steam activation for similar surface areas of 1500 m2/g or higher. These nano-sized activated carbons present interesting H2 storage capacities at 77 K which are comparable, or even higher, to other high quality microporous carbon materials. This observation is due, in part, to their nano-sized diameters allowing to enhance their packing densities to 0.71 g/cm3 and hence their resulting hydrogen storage capacities.