A three dimensional finite volume approach to the thermo-mechanical modelling of the shape casting of metals

This paper presents a three dimensional, thermos-mechanical modelling approach to the cooling and solidification phases associated with the shape casting of metals ei. Die, sand and investment casting. Novel vortex-based Finite Volume (FV) methods are described and employed with regard to the small strain, non-linear Computational Solid Mechanics (CSM) capabilities required to model shape casting. The CSM capabilities include the non-linear material phenomena of creep and thermo-elasto-visco-plasticity at high temperatures and thermo-elasto-visco-plasticity at low temperatures and also multi body deformable contact with which can occur between the metal casting of the mould. The vortex-based FV methods, which can be readily applied to unstructured meshes, are included within a comprehensive FV modelling framework, PHYSICA. The additional heat transfer, by conduction and convection, filling, porosity and solidification algorithms existing within PHYSICA for the complete modelling of all shape casting process employ cell-centred FV methods. The termo-mechanical coupling is performed in a staggered incremental fashion, which addresses the possible gap formation between the component and the mould, and is ultimately validated against a variety of shape casting benchmarks.

Modelling interacting phenomena during the solidification of metals in the casting process

A variety of interacting complex phenomena takes place during the casting of metallic components. Here molten metal is poured into a mould cavity where it flows, cools, solidifies and then deforms in its solid state. As the metal cools, thermal gradients will promote thermal convection which will redistribute the heat around the component (usually from feeders or risers) towards the solidification front and mushy zone. Also, as the evolving solid regions of the cast component deform they will form gap at the cast-mould interface. This gap may change the rate of solidification in certain parts the casting, hence affecting the manner in which the cast component solidifies. Interaction between a cast component and its surrounding mould will also govern stress magnitudes in both the cast and mould -these may lead to defects such as cracks. This paper presents a multiphysics modelling approach to this complex process. Emphasis will be placed on the interacting phenomena taking place during the process and the modelling strategy used. Comparisons with plant data are also be given.

Protected cropping of strawberry plants in subtropical Queensland

The effect of protected cropping on the performance of two strawberry cultivars ('Festival' and 'Rubygem') and two breeding lines (Breeding Lines 1 and 2) was studied in subtropical Queensland, Australia over two years. Production in this area is affected by rain, with direct damage to the fruit and the development of fruit diseases before harvest. The main objective of the study was to determine whether plants grown under high plastic tunnels had less rain damage, less disease incidence, and higher yields than plants grown outdoors. Our studies show that marketable yields were up to 40% higher in the plants under the tunnels compared with yields of the plants outdoors. This was mainly because fruit from the plants grown under the tunnels had lower incidences of rain damage and/or grey mould. There were no consistent differences in the relative numbers of small and/or misshaped fruit in the two growing environments. This research highlights the potential of protected cropping for strawberry producers in subtropical areas that receive significant rainfall during the growing season.

Rheology of fresh mortar

Resumen: Los materiales basados en cementos presentan una enorme importancia tecnológica. Para una correcta utilización es necesario que sea posible su transporte y conformado en un estado “fresco”, por lo que es fundamental controlar su comportamiento reológico. En esta conferencia se describe el comportamiento reológico de morteros y productos relacionados, en situaciones prácticas, donde se tratarán casos concretos, y se discutirán las principales características de cada comportamiento. Además, se presentarán los nexos de unión entre la reología y la tecnología de los materiales de la construcción. Abstract: Cement-based materials are of enormous technological importance and their satisfactory performance depends on being able to transport and mould them in the freshly mixed state. This conference describes the rheology of mortars and related products in the context of practical situations, and deals with testing and measurement, together with the main features of their behaviour. It explores the links between rheology and technology.

Le polar de la Caraïbe francophone : enjeux de l’appropriation du genre

Pour minoré et ignoré qu’il fût, le roman policier est désormais légitimé par l’institution littéraire. À parcourir les livres publiés dans la Caraïbe francophone, le genre demeure dans la marge de cette production [issue de la Caraïbe francophone (Haïti, Guadeloupe, Guyane française, Martinique)]. Quoiqu’il en soit, on notera que les années 1990 ont inauguré une véritable éclosion de publications de polars. Tout cela augure d’une acclimatation de ce genre qui ne s’accompagne pas moins de questionnements sur les spécificités éventuelles du polar caribéen francophone. Se situe-t-il dans la convention? Tente-il au contraire d’établir une distanciation avec la norme? C’est pour répondre à ces interrogations que cette thèse se propose d’explorer les enjeux de l’appropriation du polar provenant de cette aire géographique. À l’aune de la poétique des genres, de la sociocritique et de l’intermédialité, un corpus composé de quatorze romans fait l’objet d’une étude approfondie. Dans le premier chapitre, un bref récapitulatif permet de situer les œuvres à l’étude dans l’histoire littéraire du genre tout en soulignant l’adaptation du polar dans la Caraïbe de langue française. Il en ressort qu’un nombre significatif d’écrivains, attentifs à la latence du magico-religieux dans leur société, mettent en scène le surnaturel alors que le roman policier conventionnel plébiscite la méthode logico-déductive. C’est la raison pour laquelle le second chapitre s’intéresse à l’usage de l’inexplicable et son rapport avec le cartésianisme. Quant au troisième chapitre, il se penche sur un topos du genre : la violence telle qu’elle surgit dans ses dimensions commémoratives et répétitives de l’histoire tumultueuse de la Caraïbe. Notre corpus tend à relier la notion du crime, fut-il d’emprise originelle, à l’histoire post-coloniale. Dans la mesure où les personnages constituent un élément clé du genre, ils sont sondés, dans un quatrième chapitre, en regard de la critique sociale qu’ils incarnent et véhiculent. Le dernier chapitre cherche à circonscrire l’intermédialité qui structure et qualifie l’œuvre au sein du roman policier depuis sa genèse. Somme toute, ces divers axes contribuent à mieux comprendre le phénomène de transposition du polar dans cette région du monde.

Estudo da imobilização das proteases aspárticas da flor de Cynara cardunculus L. Reologia da coalhada

Mestrado em Biotecnologia, Faculdade de Engenharia de Recursos Naturais, Univ. do Algarve, 2005

Ontologia do espaço : critica da critica da entificação social do ser enquanto pressuposto a uma teoria espacial interpenetrada a “ontologia do ser social”, de Gyorgy Lukacs

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, Programa de Pós Graduação em Geografia, 2015.

Mucormycosis in Australia: contemporary epidemiology and outcomes

Mucormycosis is the second most common cause of invasive mould infection and causes disease in diverse hosts, including those who are immuno-competent. We conducted a multicentre retrospective study of proven and probable cases of mucormycosis diagnosed between 2004-2012 to determine the epidemiology and outcome determinants in Australia. Seventy-four cases were identified (63 proven, 11 probable). The majority (54.1%) were caused by Rhizopus spp. Patients who sustained trauma were more likely to have non-Rhizopus infections relative to patients without trauma (OR 9.0, p 0.001, 95% CI 2.1-42.8). Haematological malignancy (48.6%), chemotherapy (42.9%), corticosteroids (52.7%), diabetes mellitus (27%) and trauma (22.9%) were the most common co-morbidities or risk factors. Rheumatological/autoimmune disorders occurred in nine (12.1%) instances. Eight (10.8%) cases had no underlying co-morbidity and were more likely to have associated trauma (7/8; 87.5% versus 10/66; 15.2%; p <0.001). Disseminated infection was common (39.2%). Apophysomyces spp. and Saksenaea spp. caused infection in immuno-competent hosts, most frequently associated with trauma and affected sites other than lung and sinuses. The 180-day mortality was 56.7%. The strongest predictors of mortality were rheumatological/autoimmune disorder (OR = 24.0, p 0.038 95% CI 1.2-481.4), haematological malignancy (OR = 7.7, p 0.001, 95% CI 2.3-25.2) and admission to intensive care unit (OR = 4.2, p 0.02, 95% CI 1.3-13.8). Most deaths occurred within one month. Thereafter we observed divergence in survival between the haematological and non-haematological populations (p 0.006). The mortality of mucormycosis remains particularly high in the immuno-compromised host. Underlying rheumatological/autoimmune disorders are a previously under-appreciated risk for infection and poor outcome.