Causalidade entre o crescimento económico, a emissão de CO2 e o consumo de energias renováveis em Portugal

Mestrado em Métodos Quantitativos para a Decisão Económica e Empresarial

Flower abscission and fruit set on table grapes (Vitis vinifera L.): unraveling physiological and molecular mechanisms

Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia - UL

Avaliação da eficácia in vivo da L-arginina na elasticidade da pele

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2012.

Evaluation of a root extract gel from Urtica dioica (Urticaceae) as analgesic and anti-inflammatory therapy in rheumatoid arthritis in mice

Purpose: To develop and characterize an herbal gel prepared from methanol root extract of Urtica dioica (Urticaceae) (Stinging nettle) for the treatment of arthritis in mice. Methods: A methanol root extract from Urtica dioica was prepared, and a gel was then prepared using Carbopol 934. The prepared gel was subjected to various physical tests (color, appearance, pH, texture, viscosity) and in vivo evaluation, including primary skin irritation, analgesic, and anti-inflammatory tests, in arthritic mice and compared with 2 % indomethacin gel, which was used as standard. Results: The prepared herbal gel was of light gray color with a smooth texture. It showed a pH of 7.1 and a viscosity of 21.2 cps. The gel exhibited pseudoplastic rheology, as evidenced by shear thinning with increased shear rate. It was non-irritating to the skin in primary skin irritation test in mice and showed 55.05 % inhibition of paw edema in a carrageenan-induced hind rat paw edema model, comparable to that of the standard gel (53.93 %), after 24 h. The gel showed 58.21 % analgesia, versus 61.19 % analgesia for the indomethacin gel standard in writhing test. Conclusion: The topical gel from methanol root extract of U. dioica may be an efficacious and safe alternative to non-steroidal anti-inflammatory drugs in the treatment of rheumatoid arthritis but this requires further investigations to ascertain its safety and clinical efficacy.

Étude paléopathologique préliminaire à travers l'analyse macroscopique et scanographique : exemple du cimetière St. Matthew, ville de Québec (1771-1860)

Sachant que plusieurs maladies entrainent des lésions qui ne sont pas toujours observables à l’oeil, cette étude préliminaire en paléopathologie humaine utilise une approche complémentaire issue de l’imagerie médicale, le ct-scan, afin de fournir des diagnostics plus précis. L’objectif est donc de tester ici l’efficacité et les limites de l’analyse scanographique durant l’analyse de spécimens archéologiques. Un échantillon de 55 individus a été sélectionné à partir de la collection ostéologique provenant du cimetière protestant St. Matthew (ville de Québec, 1771 – 1860). Une analyse macroscopique et scanographique complète a alors été effectuée sur chaque squelette. Les observations macroscopiques ont consisté à enregistrer une dizaine de critères standardisés par la littérature de référence en lien avec des manifestations anormales à la surface du squelette. Les ct-scans ont été réalisés à l’Institut National de la Recherche Scientifique de la Ville de Québec avec un tomodensitomètre Somatom de Siemens (définition AS+ 128). Les données scanographiques ont permis d’enregistrer une série de critères complémentaires sur la structure interne de l’os (amincissement/épaississement de la corticale, variation de densité, etc.) Selon la méthode du diagnostic différentiel, des hypothèses ou diagnostics ont été proposés. Ils sont principalement basés sur les critères diagnostiques mentionnés dans les manuels de référence en paléopathologie, mais aussi à l’aide de la littérature clinique et l’expertise de médecins. Les résultats présentés ici supportent que: 1) Dans 43% des cas, les données scanographiques ont apporté des informations essentielles dans la diagnose pathologique. Cette tendance se confirme en fonction de certaines maladies, mais pas d’autres, car certains diagnostics ne peuvent se faire sans la présence de tissus mous. 2) La distribution spatiale de la plupart des lésions varie selon les régions anatomiques, aussi bien en macroscopie qu’en scanographie. 3) Certains types de maladie semblent associés à l’âge et au sexe, ce qui est conforté par la littérature. 4) Cette recherche démontre aussi que le processus de diagnose nécessite, dans 38% des cas, une analyse complémentaire (ex. histologie, scintigraphie, radiographie) pour préciser le diagnostic final.

SIMULATIONS OF NEWTONIAN AND NON-NEWTONIAN FLOWS IN DEFORMABLE TUBES

Computational models for the investigation of flows in deformable tubes are developed and implemented in the open source computing environment OpenFOAM. Various simulations for Newtonian and non-Newtonian fluids under various flow conditions are carried out and analyzed. First, simulations are performed to investigate the flow of a shear-thinning, non-Newtonian fluid in a collapsed elastic tube and comparisons are made with experimental data. The fluid is modeled by means of the Bird-Carreau viscosity law. The computational domain of the deformed tube is constructed from data obtained via computer tomography imaging. Comparison of the computed velocity fields with the ultrasound Doppler velocity profile measurements show good agreement, as does the adjusted pressure drop along the tube's axis. Analysis of the shear rates show that the shear-thinning effect of the fluid becomes relevant in the cross-sections with the biggest deformation. The peristaltic motion is simulated by means of upper and lower rollers squeezing the fluid along a tube. Two frames of reference are considered. In the moving frame the computational domain is fixed and the coordinate system is moving with the roller speed, and in the fixed frame the roller is represented by a deforming mesh. Several two-dimensional simulations are carried out for Newtonian and non-Newtonian fluids. The effect of the shear-thinning behavior of the fluid on the transport efficiency is examined. In addition, the influence of the roller speed and the gap width between the rollers on the xxvii transport efficiency is discussed. Comparison with experimental data is also presented and different types of moving waves are implemented. In addition, the influence of the roller speed and the gap width between the rollers on the transport efficiency is discussed. Comparison with experimental data is also presented and different types of moving waves are implemented.

Étude paléopathologique préliminaire à travers l'analyse macroscopique et scanographique : exemple du cimetière St. Matthew, ville de Québec (1771-1860)

Sachant que plusieurs maladies entrainent des lésions qui ne sont pas toujours observables à l’oeil, cette étude préliminaire en paléopathologie humaine utilise une approche complémentaire issue de l’imagerie médicale, le ct-scan, afin de fournir des diagnostics plus précis. L’objectif est donc de tester ici l’efficacité et les limites de l’analyse scanographique durant l’analyse de spécimens archéologiques. Un échantillon de 55 individus a été sélectionné à partir de la collection ostéologique provenant du cimetière protestant St. Matthew (ville de Québec, 1771 – 1860). Une analyse macroscopique et scanographique complète a alors été effectuée sur chaque squelette. Les observations macroscopiques ont consisté à enregistrer une dizaine de critères standardisés par la littérature de référence en lien avec des manifestations anormales à la surface du squelette. Les ct-scans ont été réalisés à l’Institut National de la Recherche Scientifique de la Ville de Québec avec un tomodensitomètre Somatom de Siemens (définition AS+ 128). Les données scanographiques ont permis d’enregistrer une série de critères complémentaires sur la structure interne de l’os (amincissement/épaississement de la corticale, variation de densité, etc.) Selon la méthode du diagnostic différentiel, des hypothèses ou diagnostics ont été proposés. Ils sont principalement basés sur les critères diagnostiques mentionnés dans les manuels de référence en paléopathologie, mais aussi à l’aide de la littérature clinique et l’expertise de médecins. Les résultats présentés ici supportent que: 1) Dans 43% des cas, les données scanographiques ont apporté des informations essentielles dans la diagnose pathologique. Cette tendance se confirme en fonction de certaines maladies, mais pas d’autres, car certains diagnostics ne peuvent se faire sans la présence de tissus mous. 2) La distribution spatiale de la plupart des lésions varie selon les régions anatomiques, aussi bien en macroscopie qu’en scanographie. 3) Certains types de maladie semblent associés à l’âge et au sexe, ce qui est conforté par la littérature. 4) Cette recherche démontre aussi que le processus de diagnose nécessite, dans 38% des cas, une analyse complémentaire (ex. histologie, scintigraphie, radiographie) pour préciser le diagnostic final.

Molecular Origins of Higher Harmonics in Large-Amplitude Oscillatory Shear Flow: Shear Stress Response

Recent work has focused on deepening our understanding of the molecular origins of the higher harmonics that arise in the shear stress response of polymeric liquids in large-amplitude oscillatory shear flow. For instance, these higher harmonics have been explained by just considering the orientation distribution of rigid dumbbells suspended in a Newtonian solvent. These dumbbells, when in dilute suspension, form the simplest relevant molecular model of polymer viscoelasticity, and this model specifically neglects interactions between the polymer molecules [R.B. Bird et al., J Chem Phys, 140, 074904 (2014)]. In this paper, we explore these interactions by examining the Curtiss-Bird model, a kinetic molecular theory designed specifically to account for the restricted motions that arise when polymer chains are concentrated, thus interacting and specifically, entangled. We begin our comparison using a heretofore ignored explicit analytical solution [Fan and Bird, JNNFM, 15, 341 (1984)]. For concentrated systems, the chain motion transverse to the chain axis is more restricted than along the axis. This anisotropy is described by the link tension coefficient, ε, for which several special cases arise: ε = 0 corresponds to reptation, ε > 1/8 to rod-climbing, 1/2 ≥ ε ≥ 3/4 to reasonable predictions for shear-thinning in steady simple shear flow, and ε = 1 to the dilute solution without hydrodynamic interaction. In this paper, we examine the shapes of the shear stress versus shear rate loops for the special cases ε = (0,1/8, 3/8,1) , and we compare these with those of rigid dumbbell and reptation model predictions.

Ultra high-pressure homogenized emulsions stabilized by sodium caseinate: effects of protein concentration and pressure on emulsions structure and stability

Microstructure, physical properties and oxidative stability of emulsions treated by colloid mill (CM), conventional homogenization (CH, 15 MPa) and ultra-high-pressure homogenization (UHPH, 100–300 MPa) by using different concentrations of 1, 3 and 5 g/100 g of sodium caseinate (SC), were evaluated. The application of UHPH treatment at 200 and 300 MPa resulted in emulsions that were highly stable to creaming and oxidation, especially when the protein content increased from 1 to 3 and 5 g/100 g. Further, increasing the protein content to 3 and 5 g/100 g in UHPH emulsions tended to change the rheological behavior from Newtonian to shear thinning. CH emulsions containing 1 g/100 g of protein exhibited Newtonian flow behavior with lower tendencies to creaming compared to those formulated with 3 or 5 g/100 g. This study has proved that UHPH processing at pressures (200–300 MPa) and in the presence of sufficient amount of sodium caseinate (5 g/100 g), produces emulsions with oil droplets in nano-/submicron scale with a narrow size distribution and high physical and oxidative stabilities, compared to CM and CH treatments.

Engineering interfacial silicon dioxide for improved metal-insulator-semiconductor silicon photoanode water splitting performance

Silicon photoanodes protected by atomic layer deposited (ALD) TiO2 show promise as components of water splitting devices that may enable the large-scale production of solar fuels and chemicals. Minimizing the resistance of the oxide corrosion protection layer is essential for fabricating efficient devices with good fill factor. Recent literature reports have shown that the interfacial SiO2 layer, interposed between the protective ALD-TiO2 and the Si anode, acts as a tunnel oxide that limits hole conduction from the photoabsorbing substrate to the surface oxygen evolution catalyst. Herein, we report a significant reduction of bilayer resistance, achieved by forming stable, ultrathin (<1.3 nm) SiO2 layers, allowing fabrication of water splitting photoanodes with hole conductances near the maximum achievable with the given catalyst and Si substrate. Three methods for controlling the SiO2 interlayer thickness on the Si(100) surface for ALD-TiO2 protected anodes were employed: (1) TiO2 deposition directly on an HF-etched Si(100) surface, (2) TiO2 deposition after SiO2 atomic layer deposition on an HF-etched Si(100) surface, and (3) oxygen scavenging, post-TiO2 deposition to decompose the SiO2 layer using a Ti overlayer. Each of these methods provides a progressively superior means of reliably thinning the interfacial SiO2 layer, enabling the fabrication of efficient and stable water oxidation silicon anodes.

Relación entre atrofia cortical difusa y desempeño cognitivo : estudio en población mayor de 60 años en un hospital universitario en la ciudad de Bogotá

El presente trabajo tuvo como objetivo evaluar la existencia de la relación entre la atrofia cortical difusa objetivada por neuroimagenes cerebrales y desempeños cognitivos determinados mediante la aplicación de pruebas neuropsicológicas que evalúan memoria de trabajo, razonamiento simbólico verbal y memoria anterógrada declarativa. Participaron 114 sujetos reclutados en el Hospital Universitario Mayor Méderi de la ciudad de Bogotá mediante muestreo de conveniencia. Los resultados arrojaron diferencias significativas entre los dos grupos (pacientes con diagnóstico de atrofia cortical difusa y pacientes con neuroimagenes interpretadas como dentro de los límites normales) en todas las pruebas neuropsicológicas aplicadas. Respecto a las variables demográficas se pudo observar que el grado de escolaridad contribuye como factor neuroprotector de un posible deterioro cognitivo. Tales hallazgos son importantes para determinar protocoles tempranos de detección de posible instalación de enfermedades neurodegenerativas primarias.

Specific shear-dependent viscoelastic third-grade fluid model

A specific modified constitutive equation for a third-grade fluid is proposed so that the model be suitable for applications where shear-thinning or shear-thickening may occur. For that, we use the Cosserat theory approach reducing the exact three-dimensional equations to a system depending only on time and on a single spatial variable. This one-dimensional system is obtained by integrating the linear momentum equation over the cross-section of the tube, taking a velocity field approximation provided by the Cosserat theory. From this reduced system, we obtain the unsteady equations for the wall shear stress and mean pressure gradient depending on the volume flow rate, Womersley number, viscoelastic coefficient and flow index over a finite section of the tube geometry with constant circular cross-section.

Extensional orogenic collapse captured by strike-slip tectonics:

The late Paleozoic collision between Gondwana and Laurussia resulted in the polyphase deformation and magmatism that characterizes the Iberian Massif of the Variscan orogen. In the Central Iberian Zone, initial con- tinental thickening (D1; folding and thrusting) was followed by extensional orogenic collapse (D2) responsible for the exhumation of high-grade rocks coeval to the emplacement of granitoids. This study presents a tectonometamorphic analysis of the Trancoso-Pinhel region (Central Iberian Zone) to ex- plain the processes in place during the transition froman extension-dominated state (D2) to a compression-dom- inated one (D3).Wereveal the existence of low-dipping D2 extensional structures later affected by several pulses of subhorizontal shortening, each of them typified by upright folds and strike-slip shearing (D3, D4 and D5, as identified by superimposition of structures). The D2 Pinhel extensional shear zone separates a low-grade domain from an underlying high-grade domain, and it contributed to the thermal reequilibration of the orogen by facil- itating heat advection from lower parts of the crust, crustal thinning, decompression melting, and magma intru- sion. Progressive lessening of the gravitational disequilibrium carried out by this D2 shear zone led to a switch from subhorizontal extension to compression and the eventual cessation and capture of the Pinhel shear zone by strike-slip tectonics during renewed crustal shortening. High-grade domains of the Pinhel shear zone were folded together with low-grade domains to define the current upright folded structure of the Trancoso-Pinhel re- gion, the D3 Tamames-Marofa-Sátão synform. Newdating of syn-orogenic granitoids (SHRIMP U\\Pb zircon dat- ing) intruding the Pinhel shear zone, together with the already published ages of early extensional fabrics constrain the functioning of this shear zone to ca. 331–311 Ma, with maximum tectonomagmatic activity at ca. 321–317 Ma. The capture and apparent cessation of movement of the Pinhel shear zone occurred at ca. 317– 311 Ma.

Cork oak transplant: A new reality? A Physiological Approach to maximize sucess rate.

Cork oak tree (Quercus suber L.), in Portugal, is considered the national tree and have special demands and legal protection when dealing with silviculture management (pruning, debarking, thinning). Being a species of slow growth, cork oak transplanting procedures can be a valuable asset either from the economic or ecological rationales to relocate trees, re-populate areas affected by high tree mortality, increase tree density to control erosion on montado ecosystems or landscape design. This study focuses the impacts and physiological responses of ten juvenile rain fed cork oak trees (with diameter at breast height between 6 and 16cm), when subjected to transplant operations. The work was conducted in a cork oak woodland experimental plot at the campus of the University of Évora (SW Portugal), during the year of 2015. Tree’s transplants were performed with a truck-mounted hydraulic spade transplanter coupled with a proposed methodology to maximize tree survival rates, addressing techniques to limit canopy transpiration and to improve root systems prior to transplant. Tree ecophysiological indicators (sap flow, leaf water potentials and stomatal conductance) were monitored comprising the periods before and after transplant operations, and water stress avoidance practices were established to promote post-transplant tree status recovery, including irrigation to match average daily accumulated sap flow. Transplant operations were considered successful when the tree's water uptake inferred from sap flow exhibited a high correlation with solar radiation and returned to its undisturbed or pre-transplant water potential gradients in the following 2 to 3 weeks. The post-transplant tree nourishment follow up included permanent sap flow measurements and identified the time elapsed after transplantation from which the tree recovers its normal transpiration thresholds and response. Our results suggest that by following the proposed methodology the sampled cork oak trees exhibited a transplant success rate of 90%.

Reducing competition in agroforestry by pruning native trees.

The degree to which pruning helps reestablish balance in agroforestry was assessed in a system established in São Carlos, São Paulo, Brazil, in 2008. Seven native tree species were planted at a density of 600 trees/ha in five strips of three rows each, and annual crops were cultivated in the 17-m crop strips between the tree strips. Competition was established after 35 months, decreasing the aboveground biomass production of corn planted close to the trees. An assessment of black oats in the dry season following tree pruning showed that the proximity of trees caused reductions in plant and panicle density, aboveground biomass production, number of grains per panicle and grain weight. Because pruning was not sufficient to maintain crop yields, tree thinning is recommended in order to minimize competition and restore conditions for adequate crop production.