A programmable logic controller based laboratory analysis of conventional and intelligent control schemes for non-liner systems

Published ArticleIntelligent Neural Network (NN) based control schemes have surmounted many of the limitations found in the conventional control approaches such as Proportional Integral Derivative (PID) control. Nevertheless, these modern control techniques have only recently been introduced for use on industrial computational platforms such as the Programmable Logic Controller (PLC). Intelligent control on PLCs thus remains an area that is open to further research and development. In this paper, a strongly non-linear mechatronic type system, namely the Ball-on-Wheel balancing system, is developed using a PLC as its control platform. The research details the implementation of an intelligent controller on a standard, medium specification PLC. The results from the intelligent controller are then compared to those produced by a variety of conventional controllers as physical parameters are varied. Finally, the system is presented as a stimulating educational tool that addresses the knowledge gap that exists in industry pertaining to the implementation of these intelligent control algorithms on PLCs

Synchronisation of oestrus in sheep early in the breeding season: the vaginal environment and fertility

No Abstrac

Rontgendiagnostiek voor 'n nuwe uitdaging - die toegepaste fisiologie.

Since the discovery of X-rays in 1895 by Conrad Rontgen, progress in the technical field has more or less kept pace with advancement in clinical radiology. One aspect of radiology, however, lagged behind the enormous progress in technology, namely the applied physiology. Diagnostic radiology has to a large extent concentrated on static documentation of physiological and pathological processes, while facilities for documentation of flow patterns are being made available to an increasing extent. A vast scope for research, teaching, and detecting incipient pathological processes is afforded by using techniques where the actual processes are recorded and stored by means of e.g. video tapes and cine radiology. By correlating live radiology with clinical data, the changes indicative of early or incipient pathology can be observed and stored for reference in a library to supplement the standard film "museums" of teaching hospitals.p. 6-8 : Publikasies van die Universiteit van Pretoria (Nuwe Reeks)http://explore.up.ac.za/record=b179616

The effect of Telfast® 180 on driver behaviour, decision-making and reaction time.

The principal objective of the study was to examine the effect of Telfast® 180, an antihistamine, on driver behaviour, decision-making, and reaction time. A sample of 255 volunteers participated in the study. The sample was randomly divided into two groups, viz. a placebo and a Telfast group. One of the groups received Telfast and the other a placebo. Initially all the participants were given a standardised driving test, as well as a psychomotor test. Immediately thereafter the placebo group received their placebo tablets and the Telfast group their Telfast tablets. Exactly 2,6 hours later every participant was tested again, using the same tests as before. No statistically significant differences were found between the Placebo group and the Telfast group. No sedative effects due to Telfast® 180 were thus evident

The synchronisation of oestrus in sheep. 1. Dosage and time of prostaglandin administration following progestagen pretreatment

No Abstrac

Hormone levels in peripheral plasma of the Afrikaner cow I. Progesterone and luteinizing hormone levels during the oestrous cycle

No Abstrac

Effect van het aanbieden van strooisel in de vroege opfokperiode op het ontwikkelen van verenpikken bij leghennen = Effect of substrate during early rearing of laying hens on the development of feather pecking behaviour

In this report the possible preventive effect of substrate during early rearing of laying hens on the development of feather pecking at a later age is described

Waterrantsoenering bij leghennen op batterijen

Reeds enige tijd wordt in de praktijk geëxperimenteerd met het rantsoeneren van water bij leghennen, teneinde luxe consumptie en vermorsing van water tegen te gaan. Dit wordt gedaan door het beperken van de tijd dat water ter beschikking is

DNA phylogeny, morphology and pathogenicity of Botryosphaeria species on grapevines

Several species of Botr yosphaeria are known to occur on grapevines, causing a wide range of disorders including bud mortality, dieback, brown wood streaking and bunch rot. In this study the 11 Botryosphaeria spp. associated with grapevines growing in various parts of the world, but primarily in South Africa, are distinguished based on morphology, DNA sequences (ITS-1, 5.8S, ITS-2 and EF1-) and pathological data. Botryosphaeria australis, B. lutea, B. obtusa, B. parva, B. rhodina and a Diplodia sp. are confirmed from grapevines in South Africa, while Diplodia porosum, Fusicoccum viticlavatum and F. vitifusiforme are described as new. Although isolates of B. dothidea and B. stevensii are confirmed from grapevines in Portugal, neither of these species occurred in South Africa, nor were any isolates of B. ribis confirmed from grapevines. All grapevine isolates from Portugal, formerly presumed to be B. ribis, are identified as B. parva based on their EF1- equence data. From artificial inoculations on grapevine shoots, we conclude that B. australis, B. parva, B. ribis and B. stevensii are more virulent than the other species studied. The Diplodia sp. collected from grapevine canes is morphologically similar but phylogenetically distinct from D. sarmentorum. Diplodia sarmentorum is confirmed as anamorph of Otthia spiraeae, the type species of the genus Otthia (Botryosphaeriaceae). A culture identified as O. spiraeae clustered within Botryosphaeria and thus is regarded as probable synonym. These findings confirm earlier suggestions that the generic concept of Botryosphaeria should be expanded to include genera with septate ascospores and Diplodia anamorphs