A 1-D Vaneless Diffuser Model Accounting for the Effects of Spanwise Flow Stratification

The radial vaneless diffuser, though comparatively simple in terms of geometry, poses a significant challenge in obtaining an accurate 1-D based performance prediction due to the swirling, unsteady and distorted nature of the flow field. Turbocharger compressors specifically, with the ever increasing focus on achieving a wide operating range, have been recognised to operate with significant regions of spanwise separated flow, particularly at off design conditions.
Using a combination of single passage Computational Fluid Dynamics (CFD) simulations and extensive gas stand test data for three geometries, the current study aims to evaluate the onset and impact of spanwise flow stratification in radial vaneless diffusers, and how the extent of the aerodynamic blockage presented to the flow throughout the diffuser varies with both geometry and operating condition. Having analysed the governing performance parameters and flow phenomena, a novel 1-D modelling method is presented and compared to an existing baseline method as well as test data to quantify the improvement in prediction accuracy achieved.

A 1-D radial vaneless diffuser model accounting for the effects of aerodynamic blockage

The radial vaneless diffuser, though comparatively simple in terms of geometry, poses a significant challenge in obtaining an accurate 1-D based performance prediction due to the swirling, unsteady and distorted nature of the flow field. Turbocharger compressors specifically, with the ever increasing focus on achieving a wide operating range, have been recognised to operate with significant regions of spanwise separated flow, particularly at off-design conditions.

Using a combination of single passage Computational Fluid Dynamics (CFD) simulations and extensive gas stand test data for three geometries, the current study aims to evaluate the onset and impact of spanwise aerodynamic blockage in radial vaneless diffusers, and how the extent of the blocked region throughout the diffuser varies with both geometry and operating condition. Having analysed the governing performance parameters and flow phenomena, a novel 1-D modelling method is presented and compared to an existing baseline method as well as test data to quantify the improvement in prediction accuracy achieved.

An Evaluation of Vaneless Diffuser Modelling Methods as a Means of Improving the Off-Design Performance Prediction of Centrifugal Compressors

An evaluation of existing 1-D vaneless diffuser design tools in the context of improving the off-design performance prediction of automotive turbocharger centrifugal compressors is described. A combination of extensive gas stand test data and single passage CFD simulations have been employed in order to permit evaluation of the different methods, allowing conclusions about the relative benefits and deficiencies of each of the different approaches to be determined. The vaneless diffuser itself has been isolated from the incumbent limitations in the accuracy of 1-D impeller modelling tools through development of a method to fully specify impeller exit conditions (in terms of mean quantities) using only standard test stand data with additional interstage static pressure measurements at the entrance to the diffuser. This method allowed a direct comparison between the test data and 1-D methods through sharing common inputs, thus achieving the aim of diffuser isolation.

Crucial to the accuracy of determining the performance of each of the vaneless diffuser configurations was the ability to quantify the presence and extent of the spanwise aerodynamic blockage present at the diffuser inlet section. A method to evaluate this critical parameter using CFD data is described herein, along with a correlation for blockage related to a new diffuser inlet flow parameter ⚡, equal to the quotient of the local flow coefficient and impeller tip speed Mach number. The resulting correlation permitted the variation of blockage with operating condition to be captured.

Multifocal remitting-relapsing cerebral demyelination twenty years following allogeneic bone marrow transplantation

We report a case study of a female who received an allogeneic bone marrow transplantation (BMT) from a sex-mismatched related donor and who, after a twenty-year interval, developed an acute fulminant biopsy-proven demyelinating disorder of cerebral white matter which followed a remitting-relapsing chronic course. In situ hybridization studies using Y-chromosome-specific markers revealed Y-chromosome-positive mononuclear cells in biopsy samples of white matter. Magnetic resonance imaging (MRI) studies of the asymptomatic healthy male donor showed multiple white matter lesions. These observations suggest that donor lymphocytes were sensitized to central nervous system (CNS) antigens prior to or at the time of transplantation but remained dormant for 20 years before becoming activated to cause widespread demyelination.

Design, analysis and performance of a polymer-carbon nanotubes based economic solar collector

A low cost flat plate solar collector was developed by using polymeric components as opposed to metal and glass components of traditional flat plate solar collectors. In order to improve the thermal and optical properties of the polymer absorber of the solar collector, Carbon Nanotubes (CNT) were added as a filler. The solar collector was designed as a multi-layer construction with an emphasis on low manufacturing costs. Through the mathematical heat transfer analysis, the thermal performance of the collector and the characteristics of the design parameters were analyzed. Furthermore, the prototypes of the proposed collector were built and tested at a state-of-the-art solar simulator facility to evaluate its actual performance. The inclusion of CNT improved significantly the properties of the polymer absorber. The key design parameters and their effects on the thermal performance were identified via the heat transfer analysis. Based on the experimental and analytical results, the cost-effective polymer-CNT solar collector, which achieved a high thermal efficiency similar to that of a conventional glazed flat plate solar panel, was successfully developed.

Turbulent heat transfer and coherent vortical structures in gas turbine film cooling

Unsteady coherent structures and turbulent heat transfer in a film cooling flow is studied by using detached eddy simulation (DES). Detailed computations for an inclined jet in crossflow by a single row of 35 degree round holes on a flat plate were performed at blowing ratios of 0.5 and 1.0, and a density ratio of 2.0. The correlation between the coherent vortical structures and the unsteady heat transfer is carefully examined. The instantaneous flow fields and heat transfer distributions are found to be characterized by the formation of large coherent vortical structures. These structures enhance the thermal mixing process and turbulent heat transfer to the wall. From the inspection of both unsteady adiabatic film cooling effectiveness and heat transfer coefficient, these two are found to have substantial local fluctuations due to the large unsteadiness of coherent structures. The fluctuation of the adiabatic effectiveness and heat transfer coefficient, for example, can be as high as 15 and 50 percent of the time-mean value, respectively. It could result in the detrimental effect on film cooling performance.

Folgazões do mogi-abaixo : música, caipiridade e paisagens cantadas

Esta investigação tem por objetivo perceber os protagonismos associados à música raiz na região do Sul de Minas, estado brasileiro de Minas Gerais. Desenvolvido no âmbito da etnomusicologia, trata-se de um estudo etnográfico realizado entre os anos de 2009 e 2012 no município de Jacutinga, localizado no Vale do Sapucaí. Como música raiz entende-se nesse contexto um universo musical que engloba vários “ritmos”, “formas” ou “estilos”, como a moda-de-viola, o pagode-de-viola, a querumana, a guarânia, dentre outros, performado por uma dupla cantando em dueto com acompanhamento da viola caipira. O termo engloba os segmentos música caipira e música sertaneja no sentido em que, para os protagonistas, as classificações convergem. O conceito de paisagem cantada é adotado como principal ferramenta de análise uma vez que no romance – gênero cantado e central da música raiz - a poética-narrativa atua como testemunha da história de um universo associado ao modo de vida rural do centro-sudeste brasileiro. A memória é portanto entextualizada na moda – unidade mínima musical de análise – que ao ser performada evoca um catálogo de elementos identificadores de uma cartografia humana, territorial e sonora, associadas a um universo designado por caipira. O sentido de pertencimento e de identificação com este paradigma promove uma recontextualização destes elementos fazendo emergir novas paisagens e novas práticas onde eles são ressignificados, adquirindo, em alguns casos, o valor de marcos sonoros (ex: o carro-de-boi, o berrante e o monjolo). Paralelamente, o processo de materialização da música que conduziu à sua fixação em disco e ao aparente desaparecimento da situação de performance participativa, transformou a própria música raiz num marco sonoro através do qual a caipiridade é representada.

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

Caractéristiques familiales associées à l'initiation précoce à la consommation de psychotropes

Cette recherche porte sur les caractéristiques familiales associées à l'initiation précoce à la consommation de psychotropes chez les enfants âgés de 10, 11 et 12 ans. Cette étude s'appuie sur le constat suivant : bien que la plupart des individus s'initient à la consommation de psychotropes au cours de l'adolescence ou au début de l'âge adulte, un certain nombre d'entre eux en consommeront dès l'enfance (Oxford, Harachi, Catalano et Abbott, 2000). Aussi, on note que depuis le début des années 1990, les jeunes manifesteraient de moins en moins leur désapprobation à l'égard de la consommation de psychotropes, augmentant ainsi le niveau d'inquiétude face à cette situation (Johnston, O'Malley et Bachman, 1999). Il est reconnu que les enfants qui s'initient à la consommation de psychotropes, tels que le tabac, l'alcool et la marijuana, avant l'âge de 12 ans augmentent singulièrement leurs risques de développer des problèmes de consommation (abus, dépendance) à l'adolescence et à l'âge adulte (Kuperman, Chan, Kramer, Bierut, Bucholz, Fox, Hesselbrock et al. , 2005; Lambert, 2005), et de présenter différents problèmes d'adaptation sur les plans personnel, familial et social (Kuperman et al. , 2005). II semble donc important de s'intéresser à cette problématique, d'autant plus que la période de développement prépubertaire est reconnue fondamentale, notamment sur le plan du développement social, émotionnel, physique, comportemental, cognitif et affectif (Thomassin, 2004). Afin d'intervenir en amont de ces difficultés et d'offrir des programmes de prévention adaptés aux enfants s'étant initiés précocement aux psychotropes, il s'avère essentiel de mieux connaître les caractéristiques familiales associées à ce phénomène (Gouvernement du Québec, 2001). Cela se justifie par le fait qu'il appartient au système familial d'exercer une influence positive afin que l'enfant adopte des comportements adaptés (Clark, Cornelius, Kirisci, et Tarter, 2005; Sung, Erkanli, Angold, et Costello, 2003; Thomassin, 2004). On retrouve effectivement différentes caractéristiques familiales qui seraient associées à l'initiation précoce des enfants à la consommation de psychotropes, notamment, la structure familiale (Saint-Jacques, Turcotte, Drapeau, Cloutier et Doré, 2004), les caractéristiques personnelles des parents dont la présence d'un problème avec la justice, de santé mentale ou de consommation de psychotropes, les pratiques éducatives lacunaires des parents à l'égard des enfants, ainsi qu'un faible engagement parental (Vitaro, Carbonneau, Gosselin, Tremblay et Zoccolillo, 2000). Les objectifs de l'étude sont donc : (1) d'identifier les caractéristiques familiales associées à l'initiation précoce à la consommation de psychotropes chez ces enfants et (2) d'identifier, parmi ces caractéristiques familiales, celles qui sont les plus fortement associées à une initiation précoce aux psychotropes."--Résumé abrégé par UMI.

The Consul March 2 & 5, 1966

Concert program for The Consul March 2 & 5, 1966

The University Sinfonietta, February 15, 1966

Concert Program for The University Sinfonietta, February 15, 1966

Concerto Competition Winners Showcase February 1, 2001

Concert Program for Concerto Competition Winners Showcase February 1, 2001

The Tales of Hoffmann November 10, 11, 12, 13, 1988

Concert Program for The Tales of Hoffmann November 10, 11, 12, 13 1988