Characterization tests for insulation boards made from corn cob and natural glues

In recent years there has been a growing interest in developing news solutions for more ecologic and efficient construction, including natural, renewable and local materials, thus contributing in the search for more efficient, economic and environmentally friendly construction. Several authors have assessed the possibility of using various agricultural sub products or wastes, as part of the effort of the scientific community to find alternative and more ecologic construction materials. Corn cob is an agricultural waste from a very important worldwide crop. Natural glues are made from natural materials, non-mineral, that can be used as such or after some modifications to achieve the behaviour and performance required. Two examples of these natural glues are casein and wheat flour-based glues that were used in the present study. Boards with different compositions were manufactured, having as variables the type of glue, the dimension of the corn cob particles and the features of the pressing process. The tests boards were characterized with physical and mechanical tests, such as thermal conductivity (λ) with a ISOMET 2104 and 60 mm diameter contact probe, density (ρ) based on EN 1602:2013, surface hardness (SH) with a PCE Shore A durometer, surface resistance (SR) with a PROCEQ PT pendular sclerometer, bending behaviour (σ) based on EN 12089:2013, compression behaviour (σ10) based on EN 826:2013 and resilience (R) based on EN 1094-1:2008, with a Zwick Rowell bending equipment with 2 kN and 50 kN load cells (Fig. 1), dynamic modulus of elasticity (Ed) with a Zeus Resonance Meter equipment (Fig. 5) based on NP EN 14146:2006 and water vapour permeability (δ) based on EN 12086:2013. The various boards produced were characterized according to the tests and the ones with the best results were C8_c8 (casein glue, grain size 2,38-4,76 mm, cold pressing for 8 hours), C8_c4 (casein glue, grain size 2,38-4,76 mm, cold pressing for 4 hours), F8_h0.5 (wheat flour glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours), FEV8_h0.5 (wheat flour, egg white and vinegar glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours) and FEVH68_c4 (wheat flour, egg white, vinegar and 6 g of sodium hydroxide glue, grain size 2,38-4,76 mm, cold pressing for 4 hours). Taking into account the various boards produced and respective test results the type of glue and the pressure and pressing time are very important factors which strongly influence the final product. The results obtained confirmed the initial hypotheses that these boards have potential as a thermal and, eventually, acoustic insulation material, to use as coating or intermediate layer on walls, floors or false ceilings. This type of board has a high mechanical resistance when compared with traditional insulating materials.The integrity of these boards seems to be maintained even in higher humidity environments. However, due to biological susceptibility and sensitivity to water, they would be more adequate for application in dry interior conditions.

A shared-disk parallel cluster file system

Dissertação apresentada para obtenção do Grau de Doutor em Informática Pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Whole life health insurance

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de mestre em Matemática e Aplicações

Hepatic parasympathetic nerve dysfunction involved in the deregulation of postprandial whole-body insulin sensitivity:a road to diabetes and associated pathologies

FCM: UC Fisiologia - Teses de Doutoramento

Mathematical modelling of shallow flows: closure models drawn from grain-scale mechanics of sediment transport and flow hydrodynamics

Canadian Journal of Civil Engineering 36(10) 1605–16

DU GRAIN À LA MUSIQUE : MANIPULATIONS EN TEMPS RÉEL

Dans cet article, nous présenterons une étude comparative de quelques techniques de manipulation du signal comme la Transformée de Fourier à Court Terme, la Synthèse Granulaire Asynchrone et PSOLA, notamment dans le cadre de leur utilisation en temps réel. Nous présenterons succinctement le fonctionnement de ces trois méthodes dans l’environnement Max / MSP avec l’utilisation de la librairie GABOR. La manipulation des paramètres propres à chaque méthode a des conséquences sur les variables musicales, et l’utilisation de ces méthodes implique des corrélations entre les paramètres techniques du traitement du signal et des attributs musicaux spécifiques. Ainsi, nous essayerons d’explorer les espaces des paramètres et de la perception musicales entre le temps, la période et le spectre (les rythmes, les fréquences et les timbres) en comparant les différentes méthodes en vue de leur croisement dans un système de traitement commun.

Influence of grain size of aggregate in freeze/thaw cycles of lime mortars

XII DBMC – 12th International Conference on Durability of Building Materials and Components, Vol.2, Porto, 2011, p.737-744

Coordinating development: uncovering the mechanisms that coordinate organ growth and patterning with the development of the whole body

Organisms produce correctly patterned structures across a wide range of organ and body sizes. Despite considerable work revealing the mechanisms that regulate the growth and patterning of organs, those responsible for coordinating organ development with whole-body development are still largely unknown.(...)

Sol-gel entrapped biosystems: enzyme(s) and whole cells

In this work two different procedures to utilize the sol-gel technology were applied to immobilize/encapsulate enzymes and living cells. CO2 has reached levels in the atmosphere that make it a pollutant. New methods to utilize this gas to obtain products of added value can be very important, both from an environmentally point of view and from an economic standpoint. The first goal of this work was to study the first reaction of a sequential, three-step, enzymatic process that carries out the conversion of CO2 to methanol. Of the three oxidoreductases involved, our focus was on formate dehydrogenase (FateDH) that converts CO2 to formate. This reaction requires the presence of the cofactor β-nicotinamide adenine dinucleotide in reduced form (NADH). The cofactor is expensive and unstable. Our experiments were directed towards generating NADH from its oxidized form (NAD+), using glutamate dehydrogenase (GDH). The formation of NADH from NAD+ in aqueous medium was studied with both free and sol-gel entrapped GDH. This reaction was then followed by the conversion of CO2 to formate, catalysed by free or sol-gel entrapped FateDH. The quantification of NADH/NAD+ was made using UV/Vis spectroscopy. Our results showed that it was possible to couple the GDH-catalyzed generation of the cofactor NADH with the FateDH-catalyzed conversion of CO2, as confirmed by the detection of formate in the medium, using High Performance Liquid Chromatography (HPLC). The immobilization of living cells can be advantageous from the standpoint of ease of recovery, reutilization and physical separation from the medium. Also dead cells may not always exhibit enzymatic activities found with living cells. In this work cell encapsulation was performed using Escherichia coli bacteria. To reduce toxicity for living organisms, the sol-gel method was different than for enzymes, and involved the use of aqueous-based precursors. Initial encapsulation experiments and viability tests were carried out with E. coli K12. Our results showed that sol-gel entrapment of the cells was achieved, and that cell viability could be increased with additives, namely betaine that led to greater viability improvement and was selected for further studies. For an approach to “in-cell” Nuclear Magnetic Resonance (NMR) experiments, the expression of the protein ctCBM11 was performed in E. coli BL21. It was possible to obtain an NMR signal from the entrapped cells, a considerable proportion of which remained alive after the NMR experiments. However, it was not possible to obtain a distinctive NMR signal from the target protein to distinguish it from the other proteins in the cell.