Investigation to define the propagation characteristics of a finite amplitude acoustic pressure wave Final report

Aerodynamic noise generation by finite amplitude pressure wave propagation through entropy producing region

Investigation to define the propagation characteristics of a finite amplitude acoustic pressure wave

A theoretical analysis of the propagation characteristics of a finite amplitude pressure wave is presented. The analysis attempts to study the contribution of entropy-producing regions to the mechanism of aerodynamic noise generation. It results in a nonlinear convective wave equation in terms of entropy and a thermodynamic 'J' function. A direct analogy between the derived governing equation and those used in classical literature is obtained. An idealization of the processes considered permits the uncoupling of the equations of motion with a consequent construction of an acoustic analogy treating shock wave emission of finite amplitude acoustic waves. An engineering approach is reflected in the concept of an extended plug nozzle whose function is to facilitate aerodynamic noise attenuation by modifying the entropy-producing regions

電腦與香港法律研究

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Working times in atypical forms of employment: the special case of part-time work

Chapitre 5, à la suite de la conférence ACSEG 2001 à RennesIn the present article, we attempt to devise a typology of forms of part-time employment by applying a widely used neuronal methodology called Kohonen maps. Starting out with data that we describe using category-specific variables, we show how it is possible to represent observations and the modalities of the variables that define them simultaneously, on a single map. This allows us to ascertain, and to try to describe, the main categories of part-time employment

The role of solvents in the lives of Kenyan street children: an ethnographic perspective

This paper explores the use of solvents among a group of street children in Ruiru, a satellite town of Nairobi. Solvent use is functional- dulling the senses against the hardship of the streetyet it also provides a link to the support structure of the ‘street family’ as a potent symbol of shared experience. Organisations working to rehabilitate street children are criticised for failing to appreciate the social context of solvent dependence amongst street children. Dependence on glue is preceded by dependence on ‘street families’, therefore organisations working to rehabilitate street children need to ensure they work through, rather than in conflict with, the ‘street family’. Key Words: Solvents, street children, Kenya, ethnograph

A Case Study: The Effect of Repeated Read-Alouds of Complex Texts on the Comprehension of a Preschool Student

Abstract The purpose of my research is to explore how the comprehension of a preschool student is impacted through being engaged in a total of twelve read alouds and discussions using complex texts in the form of a chapter book. During the conducting of this research, a preschooler participates in read alouds conducted by the researcher and engages in a post-reading discussion about the reading. Each read aloud is then repeated a second time followed by second post-reading discussion. My research seeks to answer to what extent can a preschool student retell and discuss content from a complex text? How does the use of repeated readings of complex texts impact the comprehension and vocabulary knowledge of a preschool student? The data is collected through the use of observations and comprehension rubrics

THE lMMUNE RESPONSE OF PLAICE WITH PARTICULAR EMPHASIS ON ANTIGENIC SIMULATION BY TISSUE PARASITES

Antibody responses to soluble and cellular antigens have been demonstrated in juvenile and adult plaice, Pleuronectes platessa L. A relatively strong precipitating antibody was produced to calf serum, but not to bovine serum albumin. The onset, and magnitude of antibody production was temperature dependant and physico-chemical characterisation of plaice precipitins indicated they were of the IgM class. Plaice also produced haemagglutinins, following injection of rabbit erythrocytes, with a suggestion of a heightened response upon secondary stimulation with the antigen. An evaluation was made of the humoral immune.response of the fish to three tissue parasites; Rhipidocotyle johnstonei and Cryptocotyle lingua, the metacercariae of which develop in the musculature and. connective tissue of plaice; and Trypanosoma platessae, a haemoflagellate. Elevated levels of β-globulin were detected in the sera of T. platessae infected plaice, and it is suggested that this may be associated with antibody secretion to the parasite. Further studies were made on the biology of T. platessae, including efforts to maintain the parasite, by passage, in the laboratory. Natural and experimental infections with the metacercariae of C. lingua and R. johnstonei induced a temperature dependant, precipitin response in plaice. Application of the indirect fluorescent antibody technique suggested that the functional antigens of both parasites included somatic elements, however the antigens of R. johnstonei were also clearly associated with secretory tissues. A 'natural' antibody, present in the sera of the majority of test plaice, was found to precipitate in agar gel with an antigenic extract of the nematode, Proleptus obtusus. This was considered of particular interest, as P. obtusus is a parasite specific to the dogfish and is unknown in plaice. The precipitin, first suspected of being non-specific C-reactive protein, was later characterised as 19S IgM. The nature of serological and immunological changes in fish subjected to immunisation and. parasitic infection was reviewed and discussed in relation to the findings of the present project