Collision integrals for nonelastic processes in plasma kinetic theory

Collision integrals for nonelastic processes in plasma kinetic theor

On the validation of a code and a turbulence model appropriate to circulation control airfoils

A computer code for calculating flow about a circulation control airfoil within a wind tunnel test section has been developed. This code is being validated for eventual use as an aid to design such airfoils. The concept of code validation being used is explained. The initial stages of the process have been accomplished. The present code has been applied to a low-subsonic, 2-D flow about a circulation control airfoil for which extensive data exist. Two basic turbulence models and variants thereof have been successfully introduced into the algorithm, the Baldwin-Lomax algebraic and the Jones-Launder two-equation models of turbulence. The variants include adding a history of the jet development for the algebraic model and adding streamwise curvature effects for both models. Numerical difficulties and difficulties in the validation process are discussed. Turbulence model and code improvements to proceed with the validation process are also discussed

Los pronombres demostrativos de la lengua chaná (Entre Ríos, Argentina)

La categoría de los pronombres demostrativos es universal en las lenguas naturales, pero las características funcionales, formales, sintácticas y pragmáticas de estos elementos varían considerablemente de una a otra lengua. El propósito de este trabajo es describir las características funcionales, formales, sintácticas y pragmáticas de los demostrativos en la lengua indígena obsolescente chaná, perteneciente a la familia charrúa, que cuenta actualmente con un último semi hablante terminal residente en la ciudad de Paraná (provincia de Entre Ríos). Se trata de un idioma que se ha transmitido durante más de un siglo y medio de manera anormal, como lengua secreta femenina. En su estado actual, esta lengua presenta un sistema bastante simple de pronombres demostrativos, que distingue dos distancias y dos géneros. En la presente ponencia se describen y analizan los aspectos morfológicos, rasgos semánticos, funciones sintácticas y usos pragmáticos documentados de estos deícticos. Se comparan los datos actuales con los documentados para la misma lengua en 1815 por Dámaso A. Larrañaga, en Soriano (República Oriental del Uruguay), cuando era todavía un idioma vivo (aunque moribundo), de transmisión norma

Tumor cerebral: incidência, diagnóstico e tratamento

Relatório de estágio de licenciatura, Bioquímica, Faculdade de Ciências e Tecnologia da Universidade do Algarve, 2010O tumor cerebral é um tumor raro. A sua relevância incide no facto de pertencer aos tipos de tumores para os quais não existe cura, que provocam défices profundos nos doentes e cujos sintomas são muitas vezes negligenciados. Este estudo engloba doentes com diagnóstico de tumor cerebral maligno, internados no período de 1 de Junho de 2008 a 30 de Julho de 2010, no Hospital de Faro E.P.E.. Foram contabilizados 84 processos clínicos, porém apenas 52 destes puderam ser analisados. Destes 52 processos, 56% pertenciam ao sexo masculino sendo que a maior frequência foi encontrada na faixa etária dos 71 aos 75 anos. Apenas metade dos doentes realizou biopsia e o tipo de tumor cerebral maligno mais frequente foi o glioblastoma, contando com 32 diagnósticos, sendo que 81% da totalidade dos casos são tumores gliais. Somente 29% dos doentes ainda se encontram vivos até à data e o tempo de sobrevivência foi de apenas 1 mês para 24% dos doentes falecidos após diagnóstico de tumor cerebral maligno. Do total de diagnósticos analisados somente realizaram cirurgia 30 doentes, 18 fizeram radioterapia e 13 foram propostos a quimioterapia. Cefaleias, hemiparesia, convulsões, confusão, astenia, febre, afasia, paralisia facial, prostração, desorientação e vómitos, foram os sintomas constatados mais frequentemente.The brain tumor is a rare tumor. Its importance relies in the fact that it belongs to the tumor types for which there’s no cure and that causes profound deficits in patients, which symptoms are often, overlooked. This study includes patients whose malignant brain tumor diagnosis, was carried out from June 1st 2008 to July 30th 2010, in Hospital de Faro E.P.E.. 84 clinical cases were reported, but only 52 of these could be analysed. From these 52 cases, 56% were male and the highest frequency was found in the age range of 71 to 75 years. Only half of the patients performed biopsy and the malignant brain tumor glioblastoma was the most frequent, with 32 diagnoses, where 81% of all cases are glial tumors. Only 29% of patients are still alive so far and the survival time was only 1 month to 24% of deceased patients after diagnosis. In the total of diagnoses examined only 30 patients underwent surgery, 18 had radiotherapy and 13 were proposed to chemotherapy. Headache, hemiparesis, seizures, confusion, weakness, fever, aphasia, facial paralysis, prostration, disorientation and vomiting were the most observed symptoms

An assessment and application of turbulence models for hypersonic flows

The current approach to the Accurate Computation of Complex high-speed flows is to solve the Reynolds averaged Navier-Stokes equations using finite difference methods. An integral part of this approach consists of development and applications of mathematical turbulence models which are necessary in predicting the aerothermodynamic loads on the vehicle and the performance of the propulsion plant. Computations of several high speed turbulent flows using various turbulence models are described and the models are evaluated by comparing computations with the results of experimental measurements. The cases investigated include flows over insulated and cooled flat plates with Mach numbers ranging from 2 to 8 and wall temperature ratios ranging from 0.2 to 1.0. The turbulence models investigated include zero-equation, two-equation, and Reynolds-stress transport models

Stabilising selection in populations of drosophila

1. The work presented in this thesis is concerned with the study of stabilising selection for body size in D.melanogaster. 2. The method followed in this study was to create differences in body size through selection and observe the changes in fitness associated with these differences. Also, once the differences were created, we observed the effects of natural selection on the selected lines when selection was relaxed. 3. The consideration of this problem involves the choice of a suitable estimate of fitness as well as the definition of a suitable ecological system in which fitness should be measured. We decided that the best indicator of fitness available is the biomass produced per unit of time in competition with a standard competitor, in a live -yeast system. 4. The physiological changes responsible for the changes in body size may or may not affect fitness, tinder the conditions described. Given hypothetical differences in physiological parameters like feeding rate, efficiency of food conversion and critical size we were able to simulate in a computer the outcome of competition between strains differing in one or more of these parameters. This allowed us to make predictions of the changes in competitive ability and the productivity of the cultures. Therefore we were able to analyse our results in terms of a system rather than in terms of individual characters. 5. It was found that the physiological changes responsible for the changes in body size of the selected lines were probably changes in feeding rate associated with changes in the critical size. However, the "nature" of growth is affected in this case since we can detect differences in body size in flies exhibiting the same development time. This change in the "nature" of growth can be explained if we postulate an unbalance of growth in the selected lines. 6. Although the changes iñ body size obtained by selection are quite sùbstantial, it was difficult to detect a consistent change in compeitive ability measured against a standard competitor. It is suggested that this difficulty might be due to changes in the variance of the growth parameters correlated with changes in their mean. Within the range of deviations of body size from the unselected value these changes in variance would counteract the possible changes in fitness which are a consequence of selection. 7. Relaxation of selection for lines selected for large and small body size had little effect in bringing the mean fialue of the character back to the unselected level. One possible exception was verified when selection was relaxed in a population cage. Back selection had an immediate response, similar to that of forward selection. The experiments which tested the competitive ability of the back selected lines were not conclusive. Selection for short development time in the selected lines did not affect body size;,the changes in competitive ability were not well defined. Selection for fast and slow development had some response when development time was measured under pure culture conditions. Under competitive conditions the apparent advantage of the fast line disappeared but the disadvantage of the slow line persisted. The response to selection for fast and slow development was accompanied by a reduction in body size below the unselected level in the fast line and an increase in the slow line above the same level. 8. Selection for large and small body size under competitive conditions showed some response in both directions though less well marked than when selection was carried out under optimal conditions. 9. Inbreeding caused a proportionally equal decrease in body size in all the lines. This decrease was more accentuated when body size was measured under competitive conditions. Competitive ability was affected differentially in the 1st generation of inbreeding, but this difference disappeared subsequently. Viability was reduced below the non -inbred level. 10. The experiments on egg production of the selected and unselected flies grown under different conditions in the larval stage fed different amounts of food in the adult stage revealed a superiority of the unselected over the selected lines. 11. The crosses between the Pacific and the Kaduna populations showed no breakdown or improvement in competitive ability in the Fl or the F2, suggesting that the genes controlling the growth ability which is correlated with competitive ability are the same in the two populations

Test code for the assessment and improvement of Reynolds stress models

An existing two-dimensional, compressible flow, Navier-Stokes computer code, containing a full Reynolds stress turbulence model, was adapted for use as a test bed for assessing and improving turbulence models based on turbulence simulation experiments. To date, the results of using the code in comparison with simulated channel flow and over an oscillating flat plate have shown that the turbulence model used in the code needs improvement for these flows. It is also shown that direct simulation of turbulent flows over a range of Reynolds numbers are needed to guide subsequent improvement of turbulence models

Chemical Abundances of the Damped Lya Systems at z>1.5

We present chemical abundance measurements for 19 damped lya systems observed with HIRES on the 10m W.M. Keck Telescope. Our principal goal is to investigate the abundance patterns of the damped systems and thereby determine the underlying physical processes which dominate their chemical evolution. We place particular emphasis on gauging the relative importance of two complementary effects often invoked to explain the damped lya abundances: (1) nucleosynthetic enrichment from Type II supernovae and (2) an ISM-like dust depletion pattern. Similar to the principal results of Lu et al. (1996), our observations lend support both for dust depletion and Type II SN enrichment. Specifically, the observed overabundance of Zn/Fe and underabundance of Ni/Fe relative to solar abundances suggest significant dust depletion within the damped lya systems. Meanwhile, the relative abundances of Al, Si, and Cr vs. Fe are consistent with both dust depletion and Type II supernova enrichment. Our measurements of Ti/Fe and the Mn/Fe measurements from Lu et al. (1996), however, cannot be explained by dust depletion and indicate an underlying Type II SN pattern. Finally, the observed values of [S/Fe] are inconsistent with the combined effects of dust depletion and the nucleosynthetic yields expected for Type II supernovae. This last result emphasizes the need for another physical process to explain the damped lya abundance patterns. We also examine the metallicity of the damped lya systems both with respect to Zn/H and Fe/H. Our results confirm previous surveys by Pettini and collaborators, i.e., [] = -1.15 +/- 0.15 dex. [abridged]Comment: 18 pages, 4 embedded figures, 20 additional figures. Accepted to the Astrophysical Journal 10/20/98. Uses Latex2e, emualteapj.sty, and onecolfloat.st