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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effects of operating conditions on the hydrodynamic lubricant film thickness at the piston-ring/cylinder liner interface of a firing diesel engine

Sochting, Sven January 2009 (has links)
Conventional investigations into the performance of piston-rings in internal combustion engines are performed at relatively low speeds and consider only steady state operation conditions. Loss of power in internal combustion (IC) engines is becoming an increasing issue when they are operated at high engine speeds. This project is directed at developing technology to establish whether this phenomenon is influenced by a lubricant related effect. In a normal operating environment automotive engines typically operate under transient operating conditions. These rapid changes in operation conditions may influence the thickness of the hydrodynamic film which lubricates the interfaces between the piston-ring and liner. During this project two capacitance methods were employed in a fired compression ignition engine, an amplitude modulated (AM) system originally developed by Grice and a new "high speed" capacitance technique based on a frequency modulated principle. The first part of this thesis is concerned with the development and implementation of a new apparatus suitable for measuring the thickness and extent of the hydrodynamic oil film which lubricates the piston-rings and liner. The nature of the working principle of the high speed capacitance measurement system required the design, manufacture, assembly and commissioning of a novel dynamic calibration apparatus. The new system can also be used for static calibration (AM system) of capacitance based distance measuring systems. It uses a manufacturer calibrated closed loop controlled piezo-actuator to present a target relative to the sensor face. Some previous investigations concluded a stable oil film thickness. However, this work shows that there are cyclic variations of the oil film thickness OFT on a stroke to stroke and cycle to cycle basis. A series of measurements was conducted under various fixed speed load points. The effects of using lubricants of different viscosity on the minimum (OFT) between liner and piston ring have been little studied and this work shows that it was possible to speciate measurements of different lubricants. This thesis also describes a measurement of the oil film thickness during abrupt changes in engine operating conditions.
2

Stand structure, canopy architecture and thinning response in mature Queensland maple (Flindersia brayleyana F. Muell) plantations

Brown, P. Unknown Date (has links)
No description available.
3

A Troubled Paradise: Stakeholder perceptions of tourism in the Daintree region of Far North Queensland, Australia

Hardy, A. Unknown Date (has links)
No description available.
4

Deerkmekaar, a play Re-membering: A writers journey through lack, retrieval and transformation

Gillot, V. R. Unknown Date (has links)
No description available.
5

A cross-national comparative study of the roles of men in contemporary France and Britain

Ferguson, M. E. January 1988 (has links)
The purpose of this thesis is to increase understanding and contribute to knowledge about the attitudes and behaviour of men in contemporary France and Britain. The thesis has three main aims: firstly, to provide the first cross-national comparison of French and British writing and research on the place of men in contemporary society; secondly, to identify similarities and differences in the roles of men in France and Britain; and thirdly, to determine to what extent and in what way such similarities and differences are linked to the social structures and cultural background of each country. The thesis focusses on two main facets of the male experience: the relationship between men and women and the interaction between fathers and their children. Men's attitudes and behaviour are examined in relation to issues such as the division of household tasks and child care within the family, parental roles, female employment, role reversal, gender stereotyping and changes towards a new image of masculinity in society. Particular consideration is given to differences in governmental attitudes in France and Britain towards the introduction of family policy measures for men as fathers. The thesis ends with a discussion of legislative, social and educational measures which could be introduced in France and Britain in order to promote greater flexibility in men's roles and consequently improve gender equality in each country. The data analysed in the thesis are derived from a questionnaire-based empirical study involving 101 men in Britain and seventy-five men in France. The respondents' experience of and attitudes towards their roles in society are analysed and interpreted in the light of profile data relating to their family circumstances and with reference to knowledge about the broader socio-cultural context.
6

Family and leisure: a comparative sociological study of middle-class families and their leisure patterns in France and Great Britain

Greenfield, Sheila M. January 1985 (has links)
No description available.
7

Ocular biotribology and contact lens lubrication mechanisms

Ross, G. M. January 2009 (has links)
The work described in this thesis is concerned with mechanisms of contact lens lubrication. There are three major driving forces in contact lens design and development; cost, convenience, and comfort. Lubrication, as reflected in the coefficient of friction, is becoming recognised as one of the major factors affecting the comfort of the current generation of contact lenses, which have benefited from several decades of design and production improvements. This work started with the study of the in-eye release of soluble macromolecules from a contact lens matrix. The vehicle for the study was the family of CIBA Vision Focus® DAILIES® daily disposable contact lenses which is based on polyvinyl alcohol (PVA). The effective release of linear soluble PVA from DAILIES on the surface of the lens was shown to be beneficial in terms of patient comfort. There was a need to develop a novel characterisation technique in order to study these effects at surfaces; this led to the study of a novel tribological technique, which allowed the friction coefficients of different types of contact lenses to be measured reproducibly at genuinely low values. The tribometer needed the ability to accommodate the following features: (a) an approximation to eye lid load, (b) both new and ex-vivo lenses, (c) variations in substrate, (d) different ocular lubricants (including tears). The tribometer and measuring technique developed in this way was used to examine the surface friction and lubrication mechanisms of two different types of contact lenses: daily disposables and silicone hydrogels. The results from the tribometer in terms of both mean friction coefficient and the friction profiles obtained allowed various mechanisms used for surface enhancement now seen in the daily disposable contact lens sector to be evaluated. The three major methods used are: release of soluble macromolecules (such as PVA) from the lens matrix, irreversible surface binding of a macromolecule (such as polyvinyl pyrrolidone) by charge transfer and the simple polymer adsorption (e.g. Pluoronic) at the lens surface. The tribological technique was also used to examine the trends in the development of silicone hydrogel contact lenses. The focus of the principles in the design of silicone hydrogels has now shifted from oxygen permeability, to the improvement of surface properties. Presently, tribological studies reflect the most effective in vitro method of surface evaluation in relation to the in-eye comfort.
8

Alternative emanzipationsvorstellungen in der DDR unter Honecker (1971-1990) : ein Diskussionsbeitrag zur Rolls der Frau

Matheja-Theaker, Mechthild Maria January 1991 (has links)
Over the last twenty years the situation of women in the German Democratic Republic has been the subject of a considerable number of studies. The approach has generally been of a sociological or socio-political nature. In this thesis I propose to go one step further by examining the information that may be gained from literary sources. In a state where the media are subject to censorship, and thus controlled, one can refer to literature as an acknowledged source of inside information. Literary works often provide a forum for the formulation and discussion of ideas, which could not be aired elsewhere. Chapter 1 shows why literature, which had always been allocated a special role by the GDR's leading party, the SED, may be regarded as a reliable indicator of everyday life in that country. In this thesis I compare the findings of an analysis of women's literature with sociological data on the one hand and the portrayal of the "ideal" women in GDR media and official writings on the other. The thesis takes an interdisciplinary approach and draws on sources in political, legal, sociological, and cultural fields alike. This constellation of sources allows me to show that the views that female writers expressed in their works frequently coincide with sociological findings. Both of these sources were frequently found to be at odds with statements made in official writings and the media. Such insights could not have been provided by a study conducted from within one discipline.
9

PHOTOVOLTAIC SYSTEM PROPOSAL TO REDUCE KOKOMO TRANSMISSION PLANT’S ELECTRICAL DEPENDENCY

Troy Turner (6646640) 10 June 2019 (has links)
<div>Automotive manufacturers are striving to go green, while exceeding the expectations of their stakeholders. The Engineering Technology Capstone Project focused on implementing a photovoltaic (PV) system at the Kokomo Transmission Plant (KTP). The installation of a PV system will reduce KTP’s dependency on fossil fuels, while reducing their carbon footprint. The capstone project is to improve KTP’s environmental impact while reducing their electrical consumption cost in kilowatt per hour (kWh). The capstone project investigated the type of roof mounted PV system, maintenance, cost, benefits and environmental impact.</div>
10

Development of nanosponges from erythrocyte ghosts for removal of streptolysin-O and α haemolysin from mammalian blood

Chhabria, Vikesh Nandkishore January 2017 (has links)
Bacteria can cause many different types of infections. Virulence factors e.g. adherence proteins, biofilm formation, endotoxins and exotoxins allow invasion by bacteria and cause infections such as respiratory, urinary, and intestinal and blood stream infections. If left untreated they can lead to a condition known as sepsis. Sepsis is a whole body inflammatory response that can be fatal. The aim of this study is to develop biomimetic nanosponges from mammalian erythrocyte ghosts, as a potential treatment for toxin related sepsis.

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