Engineering and Information Technology Collected Works - Theses

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    Ignition of brown coal particles
    Thomas, Geoffrey Raymond. (University of Melbourne, 1970)
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    A study of separation in turbulent boundary layers
    Fairlie, B. D. (University of Melbourne, 1973)
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    A distributed logic computer
    Dunn, Paul Alexander. (University of Melbourne, 1978)
    This thesis describes the development of a distributed logic computer. The computer employs a large number of processing cells instead of the usual single central processor connected to a large number of memory "cells". Each processing cell can contain either data or a stored instruction. In addition each processing cell is able to execute an instruction communicated to it. Instructions are transmitted from the cell in which they are stored to the data cell on which they are to act. At the completion of execution of an instruction/ the data cell concerned itself transmits an instruction to the next stored instruction to be transmitted for execution. The address of the following instruction cell is contained in the instruction previously executed, that is each transmitted instruction also contains the address of its successor, unless execution of the instruction stream is to cease. Communication between processing cells is accomplished by means of a communication network. This network consists of a tree-like arrangement of interconnected communication cells which conveys messages (instructions) from a source processing cell to a destination processing cell. The network employs packet switching using a relative processing cell address. Since no central processor is employed, there is no centralised control of address selection or execution. An arbitrary number of execution streams may proceed concurrently. Instructions have been provided which allow program divergence, to achieve parallelism, and which provide synchronisation at the completion of concurrent processes. A scheduling queue is included at the root of the communication network to provide mutual exclusion for critical resources. The problem of deadlock and the solutions used are discussed in some detail. The development and design features of the computer are described and the performance of both the communication network itself, and the processor as a whole, is discussed. The processor has been simulated in detail to allow a quantitative evaluation of various aspects of performance. The unique programming techniques associated with the processor are illustrated in detail. A symbolic cross-assembler has been used in conjunction with the simulator to assist in program preparation for execution, and assembly listings are included in illustrating programming techniques. One technique in particular which has received attention is referred to as "software pipelining" and measurements of performance of representative programs are discussed. Data flow principles are also examined in relation to the principles of operation of this computer.
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    A geostatistical study of an iron orebody
    Dunlop, John Stuart Ferguson (University of Melbourne, 1978)
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    The measurement of the concentration of benz(a)pyrene in the air of Melbourne
    McGuirk, Gerard Michael. (University of Melbourne, 1976)
    The work described in this report is a continuation of the investigations of Hannah1 and Cowdell2, into the concentration of benz(a)pyrene (BaP) in the air of Melbourne. These workers were unable to achieve accurate results due to limitations in the methods they employed. The method chosen for determining airborne BaP concentrations in this study consisted of high volume sampling of airborne particulates, Soxhlet extraction of the particulate samples, separation of the organic extract by two-dimensional thin layer chromatography, and spectrophotofluorimetric determination of the separated BaP. The steps in this method were investigated in order to determine the major causes of inaccuracies in the analysis. Significant losses of BaP were found to occur during particulate sample extraction and the evaporation of the solvent used to elute chromatographic adsorbent samples. These losses constituted the major limitation on the accuracy of the method. A means of avoiding or minimizing the loss due to the latter cause is suggested. A modified form of the two dimensional thin layer chromatographic separation technique was developed which made possible the simultaneous and complete separation of BaP from up to eight organic extract samples on a single 20 x 20 cm. TLC plate. This new technique is well suited to routine analyses for BaP. The concentration of airborne BaP was determined at an urban location in Melbourne during two one week sampling periods. The concentration of BaP at this location varied from 0. 1 to 1.0 ?g/1001 m3. These levels are similar to those reported for Toronto, a comparable city, but significantly lower than those reported for highly industrialized areas.
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    A study of the tensile rheology of linear and branched polyethylenes and the manner in which molecular characteristics determine the behaviour of polyethylene melts in processes which involve tensile deformations
    Wiese, A. D. (University of Melbourne, 1975)
    A constant stress melt tensile rheometer and a device to test blow moulding parisons were constructed and used to evaluate the tensile melt flow behaviour of six high density polyethylenes (HDPE's) and two low density polyethylenes(LDPE's). The gel permeation technique was used to determine values of number and weight average molecular weight for the HDPE's. A cone and plate viscometer was utilized to evaluate the shear flow behaviour of the same polymers. The melt tensile viscosities of the HDPE's decreased as tensile stress was increased from 1 x 103 to 5 x 104 N/m2. In the same range of shear stress, the HDPE's displayed shear viscosities which also decreased with increasing stress. However, the Trouton�an relationship was not obeyed. For a temperature increase of from 150� to 190� C the melt tensile viscosities of the HDPE's decreased by as much as fifty percent, but the tensile elastic modulus remained basically constant. At 150�C, the melt tensile viscosities of the two LDPE's remained independent of, or increased with stress in the range 1 x 103 to 5 x 104 N/m2. The parison testing study showed that HDPE resins having narrow molecular weight distributions appear to give optimum parison dimensional uniformity and stability during blow moulding.
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    Study of airborne particulates in Melbourne metropolitan region
    Dixit, S. C. N. (University of Melbourne, 1974)
    Using High volume sampler, the air in Melbourne Metropolitan region was sampled and analysed for total suspended particulates, particulate lead, sulphate and nitrate. The results were compared with important cities of the world. The thesis also consists of an exhaustive Literature Survey regarding airborne particulate pollution, its effects and the methodology of sampling and analysis.
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    A survey of air pollutant emissions in Australia : 1962 to 1985
    Cromie, Roderick Gilles. (University of Melbourne, 1974)
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    Reservoir outlets, spillways and basin shape characteristics : designs & studies
    Michels, Vladimir S. (University of Melbourne, 1971)
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    The mechanical properties of polymeric films cast from solution
    Tenen, J. (University of Melbourne, 1971)
    The mechanical properties of polymeric films were investigated. The polymers were simple in nature and consisted mainly of poly-n-butyl methacrylate and polymethyl methacrylate, cast as films from solution. A series of poly-n-butyl methacrylates of different molecular weights was prepared and analysed and the effect of molecular weight on glass transistion temperature was determined and compared with theoretical correlations. The methods of mechanical testing included micro-indentation hardness, gravelometer and falling weight impact tests. The last two were carried out with a combination of films as well as with single film systems, and such tests are commonly used in the automotive lacquer industry. The three methods of test were assessed and suggestions for improvements have been made where necessary.