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Faculty of Engineering and Built Environment

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End date: 1999Has files: Yes

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    An analysis of the factors influencing the relationship between soil properties and optimum moisture content and the formulation of an abbreviated test method of determinig maximum dry density
    (1997) Allinsin, Anthony James; Coetzee, J.
    The strength and durability of any soil structure is dependent on the quality of the compaction of the soil. This quality is measured by employing a standard compaction test, which provides a standard with which density may be compared, called the maximum dry density, and the moisture content of the soil at which this is achieved, called the optimum moisture content. As a matter of routine during quality control, the particle size distribution, plasticity index and liquid limit of the soil are determined at the same time as its maximum dry density and optimum moisture content.
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    Cost effective electrical reticulation of the rural areas in Transkei at the district of Lady Frere (Nkolonga)
    (1995) Booi, Bongani Mpumelelo; Khumalo, J.
    The purpose of this study is to investigate the most cost effective way of electrifying rural areas in the Transkei concentrating in the district of Lady Frere. One Administrative Area (A.A) was used for research. Questionnaires were send to people of this area where a like rat format was followed. For the purpose of this study, 20 families were randomly selected for investigation.
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    An investigation into the development of a portable, ultrasonic, density measuring instrument
    (1987) Hulse, Nigel Douglas; Stewart, A. B.
    In the gold mining industry, one of the significant physical properties of the mineral slurry is its density and it is important to be able to measure this parameter in most processes. There are many techniques for determining the density of fluids, but because of the hostile, abrasive nature of mineral slurry, very few of these are suitable, This dissertation describes the deveiopment, construction and testing of a portable, ultrasonic, density measuring instrument. The instrument uses an ultrasonic transducer as the primary measuring element, and system operation is based on the fact that the driving impedance of the transducer varies with changes in the physical properties, and hence the characteristic impedance, of the surrounding medium into which the ultrasonic energy is being transferred. The technique may a-Lao be used to measure the relative concentrations of two liquids in a mixture or emulsion, provided that the characteristic impedances of the liquids are sufficiently dissimilar. The electronic circuitry is fairly straightforward, consisting essentially of an oscillator, driving circuit for the transducer and a voltage monitor to provide a d.c. voltage proportional to the impedance of the transducer, and hence to the density of the surrounding medium. Most of the research has been concentrated on the probe design, as the type of transducer, the type and thickness of facing material and the method of construction all contribute to the sensitivity of the instrument. A design of probe assembly has been developed that may be used for both slurry density measurement and the measurement of the ratio of aqueous to organic liquids in emulsion.
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    An investigation into the quality of supply voltage dip-proofing
    (1998) Lange, Lyle George; Crow, A.
    With the ever increasing electrical demand on an electrical system, the quality of the supply will be tested more and more. And it is with this deteriorating quality that the topic of voltage dips and depressions has become a contentious issue amounts the industrial sector and supply authorities, hence the means to combat this issue in recent years.
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    The development of techniques for the analysis of reactive dyes in textile dyeing wastewater
    (1999) Hansa, Ayesha; Buckley, Chris
    An environmental problem facing the textile industry is the coloured effluent from the dyeing of cellulosic fibres with reactive dyes. Reactive dye loss during dyeing operations is about 10 to 40 %, indicating the need to learn more about the fate of these dyes. Increasing environmental regulations are driving technical innovation to manage this problem. Good analytical techniques for the separation and detection of reactive dyes and their derivatives are necessary for monitoring dye-house effluent, as well as in the optimisation of dye synthesis, purification, formulation and application.
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    Development of an interface monitor to operate over a data transmission line
    (1994) Crankshaw, Brett Robert; Bajic, Vladimir B.; Galbraith, Bruce G.
    One of the telecommunication facilities provided by Telkom S.A. is connection to the National and International X.25 data network. This network follows the international data protocol standard based upon the CCITT Recommendation X.25. The network allows data calls to be made from the X.25 user in very much the same fashion as a caller on the Public Switched Telephone Network (PSTN), in that the caller must specify the number of the called user on the network in order to be connected. It is in this environment, specifically in the testing and maintaining of these data circuits, that this study is based.
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    Controlling the feedrate of material from a vibratory pipe conveyor using an electro-magnetic vibrator and load cell system
    (1994) Janse van Vuuren, Gary Peter; Eitelberg, E.
    This work presents a novel way of controlling the feed rate of raw material from a vibratory pipe feeder system. The system consists of a hopper, feeder pipe, electromechanical vibrator and a loadcell which measures the mass of the complete system. Raw material is gravity fed onto the vibrating pipe whose amplitude of vibration controls the amount of material fed.
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    Design of a non-linear analog PID controller
    (1997) Govender, Poobalan; Bajic, Vladimir B.
    In this study we propose an analogue nonlinear PID controller with antiwindup and dead-time compensation to optimise the control of loops experiencing degradation in the control performance as a result of dead-time and saturation nonlinearity. Loops containing a significant dead-time are notoriously difficult to control. The proposed controller optimises the control of loops experiencing the negative effects of saturation and dead-time.
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    The design of digital signal processing electronics for a steel wire ropetesting instrument
    (1989) Nair, Dhavan; Scott, R. W.
    This thesis describes the design work undertaken at the Anglo American Electronics Laboratory to implement an electronic instrumentation system to evaluate the condition of steel wire ropes.