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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.
111

The environmental impact of hospital waste incinerators

Jafari Mosavi, S. A. A. January 1993 (has links)
This thesis makes a study of the environmental impact of waste incineration and particularly of hospital waste incineration. Literature relevant to the topic is discussed. The environmental impact of the incineration process itself and the different methods used in the disposal of wastes was assessed. The nature of waste is reviewed in relation to quantities, composition and classification. Legislation concerning hospital waste disposal is summarised. The study also focuses on methods of waste disposal including the characteristics and nature of incineration, the activities involved in the combustion process of hospital waste and the nature of incinerator stack emissions and the biological material released to the environment. Other methods of disposal are explained. The perceived and inherent risks associated with hospital waste incineration are discussed. The results of the data collected during this research are presented, analyzed and discussed. The thesis also anal yses the link between hospital waste incineration and EIA. 1n addition the importance of the effects of hospital waste incineration on human health are discussed. Environmental Impact Assessment (EIA) is discussed including its methodology. The advantages, disadvantages and its use in the UK and Iran are reviewed. A critique of the Environmental Impact Assessment submitted by Environmental Technology Consultants Ltd. (ETC). for the proposed incinerator at Kirkby is given. The thesis concludes with a consideration of the application of EIA techniques to planning applications for hospital waste incinerator and makes a number of recommendations as to their use and applicability.
112

Two-dimensional turbulent jet on a combined wall having step changes in wall curvature

Noguchi, Y. January 1985 (has links)
A study of a two-dimensional turbulent jet with a combination of two wall curvature parameters has been made. The wall consists of a plane, a logarithmic spiral and a plane surface. A large amount of attention has been paid to establish good two-dimensionality and to obtain best possible accuracy in the measurements with the hotwire anemometer system. The development of the mean velocity components, the three normal stresses and the shear stress are presented. The effects of the sudden changes in curvature on the structure of the flow are observed. The corrections of the hot-wire's directional sensitivity are also evaluated and applied using third order correlations. The correlations on the plane and the curved surface show details of the large scale motions at the outer part of the jet. The dissipation measurements have also been made. These measurements enable the evaluation of the terms of the turbulent kinetic energy equation. In addition, an attempt has been made to calculate the development of the plane wall jet using the measured turbulent kinetic energy balance to evaluate the empirical functions in the governing equations. -The measured values have been also used for the computation as the starting data.
113

Acoustic diffusion and scattering coefficients for room surfaces

Hargreaves, T. J. January 2000 (has links)
This project concerns quantifying the diffuseness of sound reflections from surfaces by means of a diffusion coefficient. Afthough it is now acknowledged that diffuse reflections are important in determining sound fields within rooms, no standardised diffusion coefficient currently exists. Definition of a universal coefficient would permit comparison of different surfaces and aid the understanding of diffusion. It would also benefit diffuser designers and room acoustic computer modellers. Previously proposed diffusion parameters for room surfaces are investigated and new ones developed. One approach is to parameterise the uniformity of the scattered energy measured as a polar response; a number of such parameters have been previously published. These are appraised using measured and predicted 2D and 3D polar responses for a diverse range of sample surfaces. The situations in which the parameters succeed and fail are discussed and it is demonstrated that none is ideal. A new polar response coefficient, superior to those previously published, is presented. This satisfies many criteria of the ideal diffusion measure and is likely to be standardised by the Audio Engineering Society. It is shown that the application of all polar response diffusion parameters is, however, limited. Two recently proposed alternative approaches to evaluating a scattering coefficient, which involve measuring the invariance of the energy reflected from a surface to its orientation, are discussed. One of these is a free field technique and the other requires reverberant conditions. Practical analysis shows that the reverberation chamber method is superior. It is likely to be standardised by ISO. An empirical reverberation chamber technique is also investigated, as is the possibility of quantifying the diffusion efficacy of surfaces from their effect on sound field diffuseness. Both of these approaches require further research. It is concluded that to provide maAmum benefit, the choice of diffusion coefficient is application dependent.
114

The active control of low frequency room modes

Avis, M. R. January 2000 (has links)
The normal modes of an enclosed sound field introduce spatial, time and frequency domain artefacts to signals reproduced in such an environment, such that undesirable colouration of these signals may be perceived. Modal density with respect to frequency is minimal at low frequencies, and in small rooms this means that widely spaced discrete modes dominate sound reproduction up to frequencies of the order of one hundred Hertz. The removal of unwanted colouration is not straightforward; conventional passive absorptive treatments offer poor performance at low frequencies, and where their use is attempted costs (in terms of space consumption) may be prohibitive. This Thesis presents a series of investigations into the active control of low frequency acoustic resonance, using both adaptive digital filters in feedforward and feedback configurations, and fixed feedforward controllers. The adaptive filters are based around the active control of acoustic impedance, using hardware available to the project as the product of previous work at Salford University. The application of the technique to the control of modes in a three dimensional environment is however novel. The fixed feedforward controllers use a novel application of an analytical modal decomposition of an enclosed soundfield as the basis for a digital IIR acoustic model. This model is utilised in order to manipulate the locations of z-plane poles and change the behaviour of the sound field. These two techniques are applied to a number of control tasks in one- and threedimensional test environments, using numerical models and practical hardware implementations. The tasks include pressure cancellation, and more usefully the control of frequency domain Q-factor and corresponding modal decay times. It is shown that active impedance methods are superior in the duct; the fixed feedforward controllers suffer from the combined effect of the finite source impedance of practical control loudspeakers with changing and strongly modal radiation loads. In the room, both techniques are shown to be capable of useful reductions in modal Q-factor and decay time. Fixed methods offer control over a defined spatial volume, and adaptive techniques may be further developed by the refinement of the control hardware.
115

A study of the microstructure and wear of high speed steels

El-Rakayby, A. M. January 1986 (has links)
The present work describes the successful extraction of the secondary hardening carbides of high speed steels, which allowed the identification of these carbides by crystalloqraphic, and microanalysis techniques. The secondary hardening carbide of high speed steels was found to be the-cubic M2C carbide and not the MC carbide as previously claimed. The secondary kic carbide was found to precipitate in the over-tempered state well beyond peak hardness. The sequence of secondary carbide precipitation has been determined. The relation between wear resistance and hardness of high speed steels has been found to be non-linear due to microstructural changes at and beyond peak hardness. However, primary carbides of the MC and M6C types of carbides were found to be stable during tempering, of these steels. It has been shown that the primary carbides did not contribute to the wear resistance of steels tempered to peak hardness. -However, the primary carbides were found to contribute to the wear rate of over-tempered steels due to their abrasive role.
116

Some floristic and chemotaxonomic studies of the flowering plants of Makkah

Meelad, M. M. H. S. January 1987 (has links)
This thesis consists of four chapters, which together contains the results of the author's floristic studies on the flowering plants of Makkah and his chemotoxonic studies of Cassia senna and Cassia holosericea. The first chapter includes a phyto-geographic account of and a floristic history of Saudi Arabia and ends with a listing of the research objectives of the present study. Chapter two delineates the area of study and contains full details of both the botanical and chemical experimental methods employed in the floristic and soil analysis studies. In the main chapter three, the first flora of Makkah is presented, together with the first English-Arabic glossary of botanical terms. This chapter also includes a detailed Discussion and Commentary on the flora of Makkah together with the results of the first soil analysis of this region of Saudi Arabia. The final chapter four contains the experimental methods used in a chemotaxonomic study of two morphologically identical Cassia plants, namely of C. senna and C. holosericea. For the chemical studies, the technique of paper chromatography and electrophoresis were employed, whilst for the taxonamic studies, light and scanning electron microscopic investigations were performed. These studies showed that at the chemical level and at the microscopic level the two plants could be distinguished and it is thus concluded that either they should retain their separate species classification or that they should be considered as subspecies.
117

Analytical studies on honey

Mistry, R. P. January 1987 (has links)
The floral and the geographical origins of honey can be determined by microscopic examination of the pollen present, however this technique cannot be applied to highly strained or pollen free honeys. Thus, there is a need for a chemical technique that can be applied to such samples. This present work was undertaken with the help of the British Beekeepers Association and their members, who provided honey samples of known origin within the United Kingdom for chemical evaluation and comparison. There were 192 samples of English honey from the U. K. survey and an additional 69 samples including those of foreign origin obtained from various sources. A selection of 11 foreign and 5 English honeys were examined for proteins present by the technique of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. This approach was abandoned since preliminary studies indicated that a correlation between the proteins and the geographical origin was not possible. For 256 samples out of the 261, the free amino acids and the pollens present were examined. The free ninhydrin positive substances were separated by ionexchange chromatography and then concentrated. Forty ninhydrin positive substances were detected by a combination of paper electrophoresis and chromatography and 28 of these compounds were identified. quantitative measurements of the concentration of 13 detectable amino acids were made on an automatic amino acid analyser. The average concentration of the 13 amino acids of the 191 samples of the U. K. survey and those of the 5 predominant pollens of the U. K. have been given in Table A. The major floral sources of-each honey were confirmed by quantitative pollen analysis of the original sample. It was found that by performing discriminant analysis using the computer package Statistical Package for Social Sciences (SPSS) that the amino acid concentration measurements could be correlated to the floral source of the samples examined, provided the sub-group samples were sufficiently large. The overall pattern of floral sources coupled with the detection of ninhydrin positive substances can be used successfully to categorise unspecified samples. This is then followed by correlation, in some cases, with amino acid concentration measurements using the SPSS to predict a definite geographical region. The potential role of using the SPSS predictive classifications to evaluate the following aspects of honey production were indicated to be successful. These aspects were: honeydew and nectar honeyst feeding sugar to honeybees, the effects of heating honey, adulteration especially with foreign honeys and/or commercial sugar products, commercial processing methods and floral source with reference to plant family.
118

Tissue culture and frost tolerance studies in Solanum

Anjum, M. A. January 1994 (has links)
In vitro shoot cultures of two commercial cultivars of Solanum tuberosum, Desiree and Mans Piper, and of two wild species S. commersonil and S. acaule, were established from single nodal explants and seedling tissues respectively. Callus cultures were initiated from potato stem, leaf and tuber explants. Cell suspension cultures were obtained from tuber and stem-derived calluses of S. tuberosum. Protoplasts were isolated from leaves of greenhouse-grown plants and from suspension-cultured cells of S. tuberosum, and in vitro shoot cultures of S. tube rosum and S. commersonii. Plantlets were regenerated from tuber discs, internodal explants, growing calluses, suspension-cultured cells and protoplast-derived calluses. Microtubers were induced from nodal explants of these Solanum species. Attempts were made to select frost-tolerant cell lines through resistance to hydroxyproline, by direct transfer of axillary buds, callus cultures and suspensioncultured cells to media containing different concentrations of hydroxyproline. Selection was also made after exposure of suspension-cultured cells to a freezing temperature (-6° C), and to gamma-irradiation (20 Gy). Several hyp-resistant cell lines were established from callus cultures and suspension-cultured cells but not from axillary buds. Most of these selected cell lines were found to show increased tolerance to frost. Plants were regenerated from one of the hyp-tolerant, frosttolerant cell lines. The cellular damage to S. tuberosum cv. Desiree callus cells due to freezing temperatures was examined, and the cellular structure of the callus of three Solanum species and one frost-tolerant cell line was compared by electron microscopy.
119

Lateral-torsional buckling of haunched members in portal frames : an assessment of BS 5950 (part 1)

Junid, S. M. B. S. January 1992 (has links)
The research described in this thesis, relates mainly to the current method of design of steel portal frame structures. The study is divided into two major parts, first being the full-scale test on a 24 metre span frame and the second deals with the problems of lateral-torsional buckling in the haunch region of the frame. Detailed accounts of the full-scale testing on the 24 metre span frame and the experimental results are given. Supplementary tests on beams cut out from the tested frame in order to establish the strain-hardening factor are also presented. A literature survey on the published material pertinent to the lateral torsional-buckling of a tapered member was undertaken. Different methods of treatment for the elastic stability of tapered members and any evidence from previous research in this area were reviewed. Details of an appropriate finite element and the corresponding computer programme are given. This section describes the assumptions and the Finite Element formulations adopted in the computer programme. The earlier work on this analysis dealt only with prismatic members and this was extended to solve tapered sections. Therefore, a full calibration of the finite element formulation for a tapered member was carried out. The stability clauses in BS 5950 are introduced systematically. Theoretical work which leads to the formulation of the clauses in Appendix G is also described. These stability clauses were assessed by the analysis of selected prismatic and tapered members using the finite element formulation. From this assessment some modifications to the clauses are proposed. The results of the modified clauses are compared with those given by the finite element analysis and the original clauses. Lastly, the modified clauses are checked with the results of the portal frame tested, to confirm its validity. This study leads to the proposal for some amendments in the clauses in Appendix G and Clause 5.5.3.5. of BS 5950.
120

Disability, discrimination and equal opportunities : a comparative study of legal models addressing the employment rights of disabled persons, with particular reference to Britain and the United States

Doyle, B. J. January 1993 (has links)
Against the background of growing demands in Britain for anti-discrimination legislation covering disabled persons, the study examines the case for reform, and the shape which such legislation might take, in the employment field. Using the socio-legal tradition, the meaning of disability is explored and the demography, nature and experience of disability is described. The evidence of employment discrimination against disabled persons is evaluated and their position in the labour market is plotted. Existing law on disabled employment rights in Britain is set out and its strengths and weaknesses weighed. The employment rights of disabled workers in the European Community, the United States, Canada and Australia are narrated. Then, using comparative legal methodology, a number of problems and issues in the regulation of disability-related employment discrimination (and the promotion of equal opportunities) are recounted and critically analysed. These problems and issues include the definition of disability discrimination, identification of the protected class, fitness for work and employment qualification, use of reasonable accommodation and positive action, preferential treatment and the role of quotas, and enforcement strategies and remedial action. The experience of the United States is recruited as the primary basis of comparison and lessons for suggested legal reforms in Britain are pointed out. Some general conclusions on the efficacy of disability discrimination laws are drawn. The study surveys a wide variety of primary and secondary legal materials, including legislation and case law, and reviews the pertinent literature drawn from legal scholarship and other relevant disciplines. It does so in the context of a theoretical perspective that borrows from the body of legal theory and concepts developed in race and gender discrimination law.

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