149 research outputs found
Die ontwikkeling en evaluering van 'n opleidingskursus vir privaat praktisyns in die sielkunde
No full textEnglish: The employment options available to South African psychologists are clearly spelled
out in the guidelines given by the Professional Board for Psychology (HPCSA,
2006). According to these guidelines, psychologists may work for a variety of
organisations or may opt for self-employment in private practice. PsySSA (2006)
indicates that the Health Professions Council of South Africa has near to 6000
psychologists on its psychology register and that 4300 psychologists (excluding
industrial psychologists, research psychologists and psychologists in community
service) were employed in private practice during 2005. The psychology industry in
South Africa is estimated at a value of R2,5 milliard per annum, approximately 65%
(1,6 milliard) of which is generated in private practice.
The training of psychologists at most South African universities is largely focused on
equipping the psychologist in private practice with the skills to be a therapist,
counsellor, consultant or researcher, and little or no attention is given to preparing
the psychologist for managing a psychology practice; which comprises elements of
self-employment and entrepreneurship. Moreover, training in the principles of
practice management at South African universities is focused on the ethics of
practice as opposed to practice management itself. The conclusion to be drawn from
these statements is that the business component of psychology training in South
Africa is currently neglected.
The purpose of this research is to develop and evaluate a training programme for
registered psychologists making an entry into private practice. This programme was
developed and evaluated by employing a qualitative research methodology in three
phases and was supplemented with the use of quantitative methods. During the
first phase of the research, a background study and needs assessment were performed by means of conducting a comprehensive literature study on the nature
and content of training models for psychology practice management in the South
African context as well as internationally, and by means of qualitative interviews with
10 successful psychologists in private practice in the Free State. In addition to this,
an analysis of training practices at South African universities was conducted. The
literature study and qualitative interviews with practitioners and training institutions
confirmed the research problem, i.e. that formal training in the management of a
psychology practice is inadequate and that a pressing need for such training exists
in South Africa. The final step in the first research phase comprised the compilation
of a structured questionnaire, drawing upon the training agenda formulated from the
literature study as well as the supplementary qualitative interviews. This
questionnaire was designed with the aim of determining the current state, nature and
content of the potential training needs for existing and prospective psychologists in
South African private practice.
Deriving from the inputs of the first phase, phase two of the research saw the
development, presentation and evaluation of an experimental training programme for
private practitioners by making use of an experiential model (Kolb, 1984). Phase
three of the research process comprised the documentation and evaluation of the
final training programme by four specialists.
The contribution of this study is such that it attempts to meaningfully integrate the
study terrains of psychology and the management sciences, not only to assist
prospective psychologists to meet the challenges of private practice but also in the
interests of the natural evolution of the profession and its optimal positioning in the
South African health services sector. The competencies attained by successful
private practitioners through experience and which enables them to establish their
practices successfully, currently exists as an informal knowledge system between
practitioners. This knowledge base should be theoretically grounded and presented
to practitioners during the training preceding the establishment of a private practice.
It is hoped that the alignment between the theoretical models and the wisdom of practitioners, acquired through the valuable lessons they have learned, has been
captured in this study, and that it may in future be used as a suitable basis for
training.Afrikaans: Riglyne van die Beroepsraad vir Sielkunde spel die indiensnemingsopsies wat vir
Suid-Afrikaanse sielkundiges beskikbaar is, duidelik uit (HPCSA, 2006). Hiervolgens
kan sielkundiges in 'n verskeidenheid van organisasies werk, of het die keuse van
self-indiensneming in privaat praktyk. PsySSA (2006) dui aan dat daar nagenoeg
6000 sielkundiges op die Sielkunde-register van die Raad op
Gesondheidsdiensberoepe van Suid-Afrika verskyn en dat sowat 4300 sielkundiges
(uitgesonder bedryfsielkundiges, navorsingsielkundiges en sielkundiges in
gemeenskapsdiens), gedurende 2005 in privaat praktyk was. Skattings suggereer
dat die Sielkunde-industrie in Suid-Afrika na raming minstens R2,5 miljard per jaar
beloop, waarvan sowat 65% (R1,6 miljard) in privaat praktykomset gerealiseer word.
Opleiding van sielkundiges aan die meeste Suid-Afrikaanse universiteite fokus
grotendeels op die sielkundige in privaat praktyk se vaardighede as terapeut,
voorligter, konsultant of navorser, maar skenk dikwels min of geen aandag aan die
sielkundige se vaardighede as praktykbestuurder en ondernemer wat elemente soos
self-indiensname en entrepreneurskap behels, nie. Die opleiding aan Suid-
Afrikaanse universiteite in privaat praktykbestuursbeginsels is ook eerder gefokus op
praktyketiek as op praktykbestuur. Dit volg uit voorgenoemde dat die
besigheidskomponent van Sielkunde-opleiding in Suid-Afrika verwaarloos word.
Die doel van hierdie navorsing is om ‘n opleidingskursus vir geregistreerde
sielkundiges wat die terrein van privaat praktyk wil betree, te ontwikkel en te
evalueer. Die ontwikkeling en evaluering van die opleidingskursus is deur ’n
kwalitatiewe navorsingsmetodologie wat in drie fases geskied het en met
kwantitatiewe metodes verryk is, onderneem. In Fase Een is 'n agtergrondstudie en
'n behoeftepeiling gedoen deur ’n omvattende literatuurstudie uit te voer oor die aard en inhoud van opleidingsmodelle vir Sielkunde- privaat praktykbestuur in die Suid-
Afrikaanse, sowel as die wêreldwye konteks en deur met 10 suksesvolle
sielkundiges in privaat praktyk in die Vrystaat, kwalitatiewe onderhoude te voer.
Addisioneel tot hierdie opname is opleidingspraktyke aan Suid-Afrikaanse
universiteite ge-analiseer. Die literatuurstudie en kwalitatiewe onderhoude met
praktisyns en die opleidinginstansies het die navorsingsprobleem, naamlik dat
formele opleiding in die bestuur van ’n Sielkunde-praktyk ontoereikend is en dat daar
‘n dringende behoefte aan opleiding in hierdie verband is, bevestig. As ‘n finale stap
in die eerste navorsingsfase is die opleidingsagenda wat uit die literatuurstudie
geformuleer is, asook die kwalitatiewe onderhoude aanvullend daartoe, benut om ‘n
gestruktureerde vraelys op te stel waarmee die huidige stand, sowel as die aard en
inhoud van moontlike opleidingsbehoeftes vir huidige en voornemende Sielkundeprivaat
praktisyns in Suid-Afrika, bepaal is.
In Fase twee van die navorsing is 'n eksperimentele opleidingsprogram vir privaat
praktisyns uit insette van die eerste navorsingsfase ontwikkel, aangebied en geevalueer
deur van ‘n eksperiënsiële model (Kolb, 1984) gebruik te maak. Fase Drie
van die navorsingsproses het die dokumentering en evaluering van die finale
opleidingsprogram (deur vier kundiges) behels.
Die bydrae van die studie is daarin geleë dat dit 'n poging is om die studieterreine
van die Sielkunde en die Bestuurswetenskappe sinvol te probeer integreer, nie bloot
met die doel om die uitdagings van die voornemende sielkundige in privaat praktyk
te help hanteer nie, maar ook in belang van die natuurlike ontwikkeling van die
professie en die optimale posisionering daarvan in die gesondheidsdiensmark in
Suid-Afrika. Die kundigheid wat suksesvolle privaat praktisyns deur ervaring opdoen
en wat hulle in staat stel om hul praktyke suksesvol op te rig, te bestuur en te
beeïndig, bestaan as informele kennissisteem tussen praktisyns. Hierdie
kennisbasis behoort bloot teoreties gefundeerd, tydens opleiding wat
praktykoprigting voorafgaan as voorbereiding vir praktisyns, aangebied te word. Die
passing tussen die teoretiese modelle van besigheidsoprigting en die wysheid van praktisyns wat lesse deur ervaring geleer het, word hopelik in hierdie studie vervat
en kan in die toekoms as opleidingsbasis benut word
Die ontwikkeling en evaluering van 'n opleidingskursus vir privaat praktisyns in die sielkunde
No full textEnglish: The employment options available to South African psychologists are clearly spelled out in the guidelines given by the Professional Board for Psychology (HPCSA,
2006). According to these guidelines, psychologists may work for a variety of
organisations or may opt for self-employment in private practice. PsySSA (2006)
indicates that the Health Professions Council of South Africa has near to 6000
psychologists on its psychology register and that 4300 psychologists (excluding
industrial psychologists, research psychologists and psychologists in community
service) were employed in private practice during 2005. The psychology industry in
South Africa is estimated at a value of R2,5 milliard per annum, approximately 65%
(1,6 milliard) of which is generated in private practice.
The training of psychologists at most South African universities is largely focused on
equipping the psychologist in private practice with the skills to be a therapist,
counsellor, consultant or researcher, and little or no attention is given to preparing
the psychologist for managing a psychology practice; which comprises elements of
self-employment and entrepreneurship. Moreover, training in the principles of
practice management at South African universities is focused on the ethics of
practice as opposed to practice management itself. The conclusion to be drawn from
these statements is that the business component of psychology training in South
Africa is currently neglected.
The purpose of this research is to develop and evaluate a training programme for
registered psychologists making an entry into private practice. This programme was
developed and evaluated by employing a qualitative research methodology in three
phases and was supplemented with the use of quantitative methods. During the first phase of the research, a background study and needs assessment were performed by means of conducting a comprehensive literature study on the nature
and content of training models for psychology practice management in the South
African context as well as internationally, and by means of qualitative interviews with
10 successful psychologists in private practice in the Free State. In addition to this,
an analysis of training practices at South African universities was conducted. The
literature study and qualitative interviews with practitioners and training institutions
confirmed the research problem, i.e. that formal training in the management of a
psychology practice is inadequate and that a pressing need for such training exists
in South Africa. The final step in the first research phase comprised the compilation
of a structured questionnaire, drawing upon the training agenda formulated from the
literature study as well as the supplementary qualitative interviews. This questionnaire was designed with the aim of determining the current state, nature and content of the potential training needs for existing and prospective psychologists in South African private practice.
Deriving from the inputs of the first phase, phase two of the research saw the
development, presentation and evaluation of an experimental training programme for
private practitioners by making use of an experiential model (Kolb, 1984). Phase three of the research process comprised the documentation and evaluation of the final training programme by four specialists.
The contribution of this study is such that it attempts to meaningfully integrate the study terrains of psychology and the management sciences, not only to assist prospective psychologists to meet the challenges of private practice but also in the interests of the natural evolution of the profession and its optimal positioning in the South African health services sector. The competencies attained by successful private practitioners through experience and which enables them to establish their practices successfully, currently exists as an informal knowledge system between practitioners. This knowledge base should be theoretically grounded and presented to practitioners during the training preceding the establishment of a private practice. It is hoped that the alignment between the theoretical models and the wisdom of practitioners, acquired through the valuable lessons they have learned, has been captured in this study, and that it may in future be used as a suitable basis for training.Afrikaans: Riglyne van die Beroepsraad vir Sielkunde spel die indiensnemingsopsies wat vir Suid-Afrikaanse sielkundiges beskikbaar is, duidelik uit (HPCSA, 2006). Hiervolgens
kan sielkundiges in 'n verskeidenheid van organisasies werk, of het die keuse van
self-indiensneming in privaat praktyk. PsySSA (2006) dui aan dat daar nagenoeg 6000 sielkundiges op die Sielkunde-register van die Raad op Gesondheidsdiensberoepe van Suid-Afrika verskyn en dat sowat 4300 sielkundiges (uitgesonder bedryfsielkundiges, navorsingsielkundiges en sielkundiges in gemeenskapsdiens), gedurende 2005 in privaat praktyk was. Skattings suggereer dat die Sielkunde-industrie in Suid-Afrika na raming minstens R2,5 miljard per jaar beloop, waarvan sowat 65% (R1,6 miljard) in privaat praktykomset gerealiseer word.
Opleiding van sielkundiges aan die meeste Suid-Afrikaanse universiteite fokus grotendeels op die sielkundige in privaat praktyk se vaardighede as terapeut, voorligter, konsultant of navorser, maar skenk dikwels min of geen aandag aan die sielkundige se vaardighede as praktykbestuurder en ondernemer wat elemente soos self-indiensname en entrepreneurskap behels, nie. Die opleiding aan Suid-Afrikaanse universiteite in privaat praktykbestuursbeginsels is ook eerder gefokus op praktyketiek as op praktykbestuur. Dit volg uit voorgenoemde dat die besigheidskomponent van Sielkunde-opleiding in Suid-Afrika verwaarloos word.
Die doel van hierdie navorsing is om ‘n opleidingskursus vir geregistreerde sielkundiges wat die terrein van privaat praktyk wil betree, te ontwikkel en te evalueer. Die ontwikkeling en evaluering van die opleidingskursus is deur ’n kwalitatiewe navorsingsmetodologie wat in drie fases geskied het en met kwantitatiewe metodes verryk is, onderneem. In Fase Een is 'n agtergrondstudie en 'n behoeftepeiling gedoen deur ’n omvattende literatuurstudie uit te voer oor die aard en inhoud van opleidingsmodelle vir Sielkunde- privaat praktykbestuur in die Suid-Afrikaanse, sowel as die wêreldwye konteks en deur met 10 suksesvolle
sielkundiges in privaat praktyk in die Vrystaat, kwalitatiewe onderhoude te voer.
Addisioneel tot hierdie opname is opleidingspraktyke aan Suid-Afrikaanse universiteite ge-analiseer. Die literatuurstudie en kwalitatiewe onderhoude met praktisyns en die opleidinginstansies het die navorsingsprobleem, naamlik dat formele opleiding in die bestuur van ’n Sielkunde-praktyk ontoereikend is en dat daar ‘n dringende behoefte aan opleiding in hierdie verband is, bevestig. As ‘n finale stap in die eerste navorsingsfase is die opleidingsagenda wat uit die literatuurstudie geformuleer is, asook die kwalitatiewe onderhoude aanvullend daartoe, benut om ‘n gestruktureerde vraelys op te stel waarmee die huidige stand, sowel as die aard en inhoud van moontlike opleidingsbehoeftes vir huidige en voornemende Sielkundeprivaat praktisyns in Suid-Afrika, bepaal is.
In Fase twee van die navorsing is 'n eksperimentele opleidingsprogram vir privaat
praktisyns uit insette van die eerste navorsingsfase ontwikkel, aangebied en geevalueer
deur van ‘n eksperiënsiële model (Kolb, 1984) gebruik te maak. Fase Drie van die navorsingsproses het die dokumentering en evaluering van die finale opleidingsprogram (deur vier kundiges) behels.
Die bydrae van die studie is daarin geleë dat dit 'n poging is om die studieterreine van die Sielkunde en die Bestuurswetenskappe sinvol te probeer integreer, nie bloot met die doel om die uitdagings van die voornemende sielkundige in privaat praktyk te help hanteer nie, maar ook in belang van die natuurlike ontwikkeling van die professie en die optimale posisionering daarvan in die gesondheidsdiensmark in Suid-Afrika. Die kundigheid wat suksesvolle privaat praktisyns deur ervaring opdoen en wat hulle in staat stel om hul praktyke suksesvol op te rig, te bestuur en te beeïndig, bestaan as informele kennissisteem tussen praktisyns. Hierdie kennisbasis behoort bloot teoreties gefundeerd, tydens opleiding wat praktykoprigting voorafgaan as voorbereiding vir praktisyns, aangebied te word. Die passing tussen die teoretiese modelle van besigheidsoprigting en die wysheid van praktisyns wat lesse deur ervaring geleer het, word hopelik in hierdie studie vervat en kan in die toekoms as opleidingsbasis benut word.University of the Free Stat
Co-ownership shares in condominium – A comparison across jurisdictions and standards
No full textCondominium is one of the prevalent forms of three- dimensional (3D) property rights (Paulsson, 2007, p. 32). The condominium concept common to a number of jurisdictions consists of three elements: (a) individual ownership of an apartment, (b) co-ownership (joint ownership) of the land and the common parts of the building, and (c) membership of an incorporated or unincorporated owners' association (van der Merwe, 2015, p. 5). The ownership shares of condominium unit owners in the common property are here referred to as co-ownership shares; yet, alternative terms include ownership fraction, condominium share, participation quota, share value, and unit entitlement. The co-ownership share determines the proportional contribution to the common expenses and the share of common profits, as well as the voting power of each condominium unit owner in the administration of the condominium. The most common approaches to the determination of the co-ownership shares are based on equality, relative size or relative value of each condominium unit, or a combination of such (van der Merwe, 1994, p. 57-58). The literature presents detailed descriptions and comparative analysis related to condominium systems in different jurisdictions (e.g. van der Merwe, 2016; 2015; Paulsson, 2007; EUI, 2005; UNECE, 2005); however, the technical and procedural aspects related to the allotment of co-ownership shares still need to be further investigated. This paper aims to compare methods and procedures applied for the allotment of co-ownership shares of condominium systems in the following seven jurisdictions; Denmark, Germany, South Africa, Sweden, Switzerland, the Netherlands, and Turkey. Also, international geographic information standards are analyzed to assess the extent to which they facilitate allocation of co-ownership shares. The main purpose is to clarify the legal provisions and methodologies related to the determination of co-ownership shares in national condominium systems and bring new insights to countries, which are trying to revise their national provisions for fairer implementations
A retrospective analysis of nickel exposure data at a South African base metal refinery
No full textThis study aimed to analyze historical soluble nickel exposure data from a South African base metal refinery and to identify trends in the soluble nickel exposure from 1981 until 2014 in the electrowinning department.
Exposure data were presented in an exposure matrix, which described exposure profiles for both area and personal exposures inside two tankhouses. Exposure data were standardized by converting total nickel aerosol concentrations to inhalable nickel concentrations (correction factor 3.0). One-way analyses of variances (ANOVA) were conducted to identify significant differences in log-transformed area and personal exposures from 1982 until 2014, and the trends were assessed with linear regression. Differences were evaluated in area exposure between sections inside the tankhouses, i.e., East, West, and Center bays and in personal exposure between occupations, i.e., cell workers, crane drivers, and supervisors.
Area exposure in Tankhouse 1 declined significantly (p ≤ 0.0001) between 1982 and 1986 with a factor of 29. However, after 1986 no significant downward trend in area exposure was evident in Tankhouse 1. Personal exposures in Tankhouse 1 significantly (p ≤ 0.0001) decreased with a factor of three between 1991 and 2014. No significant trends were evident in area and personal exposure in Tankhouse 2. Downward exposure trends were evident in Tankhouse 1 and may be ascribed to the implementation of various control measures and process changes, e.g., increasing polypropylene bead load. Limited data were available for Tankhouse 2, therefore, no trend in exposure could be established. Retrospective analyses may be used to identify trends and anomalies in exposure which might not have been identified during daily exposure monitorin
The role of functional excipients in solid oral dosage forms to overcome poor drug dissolution and bioavailability
No full textMany active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution
rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral
bioavailability of these compounds is usually very low as a result of their poor solubility properties.
In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have
been applied as a means to improve their aqueous solubility and dissolution rates. With respect to
formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution
process of the drug, or specialized dosage forms can be formulated that improve dissolution rate
through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing
agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well
as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques
such as inclusion complexes and solid dispersions. These formulation approaches are discussed
with available examples with specific reference to positive outcomes in terms of drug solubility and
bioavailability enhancemen
Phosphorus supplementation to grazing beef cows in the Molopo region (Saratoga) of the North-West Province
No full textEnglish: An investigation was launched to determine the influence of the P status of grazing beef
cattle on their production and reproduction on the veld of Saratoga in the Northwest
Province. The study at this site dealt with the following aspects:
topographical, climatic and nutritional factors which might have had an
influence on the study;
the lick intake and the effects of P supplementation on the productive
performance of beef cows;
the effect of P supplementation on the reproductive performance of beef
cows and calf performance; and
rib bone and blood as indicators of the P status of the reproducing beef
cows.
The main treatments (+P and -P) basically comprised 60 beef cattle type cows. These
cows were divided in two separate groups of 30 each. The +P cows were supplemented
with P and salt in a lick, while the -P cows received only a salt lick.
An extremely poor rainfall during a very dry 1992, had the effect that the quantity and
quality of vegetation ranged from average to poor at the site. The lick intake was
extremely high with the start of the trial at Saratoga. The intake of the +P treatment group
later decreased to the acceptable level of 80 g NaC1 - and 6 g P/cow/day but the -P
treatment group was still maintaining a high salt lick intake.
The production of the cows, in the +P treatment over the trial period at Saratoga was
significantly (P < 0.05) better compared to the -P treatment cows. The +P cows
achievement in terms of the growth of their calves was in general better compared to the
calves of the -P cows. However, there was no difference in terms of reproduction
between the treatments during the whole period of the trial. When considering all
measured variables, the -P cows realised the poorest performance in the trial at Saratoga.
The results suggested that the -P cows could not produce without receiving a certain
amount of supplementary P in their diet, especially when drought conditions prevailed.
At Saratoga there was a rapid loss of weight of the cows in both treatments shortly after
the trial commenced. The -P cows very rapidly developed clinical symptoms, notably
stiffness, anorexia and discoordination, followed with deaths a few months after the trial
started. At this stage (weaning) the -P cows averaged only 112.1 mg P/cm3, which is a
significantly (P < 0.05) lower P content of fresh bone compared with the +P cows (124.4
mg P/cm3). This is thus an indication of a P deficiency, as we assured at this stage
(weaning). However, the average of the P content of fresh bone over the trial period
showed no indication of a P deficiency between the two treatments.
The purpose of this study was to determine if a P deficiency exists at Saratoga in the
Molopo. Although, the results of the trial led to the hypothesis that an excessive intake of
NaCI may induce a P deficiency in ruminants, as could have been the case in the -P
treatment group at Saratoga, no clear answers were provided by the trial during the first
phase of investigation. According to the results further and more detailed research is
needed, concerning not only P but NaCI as well. However, in the interim it must be
accepted that the cows suffered from a P deficiency when not supplemented with P on the
veld and it will be wise to provide some P especially when extreme drought conditions
prevail.Afrikaans: 'n Ondersoek is ingestelom die invloed van die P-status van weidende vleisbeeste op hul
produksie en reproduksie op die veld van Saratoga in die Noordwes Provinsie te bepaal.
Die studie by die lokaliteit het die volgende aspekte aangespreek:
topografie, klimatologiese en voedingsaspekte wat die studie kon
beïnvloed;
die lekinname en die effek van P-aanvulling op die produksievermoë van
vleisbeeskoeie;
die effek van P-aanvulling op die reproduksie van die vleisbeeskoeie en
prestasie van kalwers; en
ribbebeen en bloed as indikators van die P-status van die reproduserende
vleisbeeskoeie.
Die hoofbehandelings (+P en -P) het basies uit 60 vleisbeestipe koeie bestaan. Hierdie
koeie is in twee afsonderlike groepe van 30 elk verdeel. Die +P koeie het P en sout in 'n
lek ontvang en die -P koeie slegs 'n soutlek.
'n Uiterse swak verspreiding van die reënval gedurende 'n baie droë 1992, het die gevolg
gehad dat die kwantiteit en kwaliteit van die veld gewissel het van gemiddeld tot swak.
Die lekinname was uiters hoog met die aanvang van die proef op Saratoga. Die inname
van die +P groep het egter later gedaal tot die aanvaarbare vlak van 80 g NaCI- en 6 g P
per koei per dag inteenstelling met die -P groep wat nog steeds 'n hoë inname
gehandhaaf het.
Die koeie in die +P behandeling op Saratoga se prestasie oor die proefperiode, in terme
van produksie was betekenisvol (P < 0.05) beter vergeleke met dié van die -P
behandeling koeie. Die +P koeie se prestasie in terme van die prestasie van hul kalwers
was ook oor die algemeen beter in vergelyking met dié van die -P behandeling. Alhoewel
daar oor die volle periode van die proef geen verskil was, in terme van reproduksie tussen
die behandelings nie. As alle gemete veranderlikes in ag geneem word, het die -P koeie
die swakste gevaar in die proef op Saratoga. Uit al die resultate het dit egter geblyk dat
die -P koeie nie kon presteer, sonder die aanvulling van 'n sekere hoeveelheid P in hul
dieët nie, veral wanneer droogte toestande geheers het.
Op Saratoga het daar 'n skielike massaverlies van die koeie in beide die +P en -P
behandeling, kort na die aanvang van die proef, voorgekom. Die -P koeie het skielik
kliniese simptome naamlik, styfheid, anoreksia en inkoërdinasie ontwikkel, gevolg deur
vrektes 'n paar maande na aanvang van die studie. Op die stadium (speen) het die -P
koeie 'n gemiddeld van slegs 112.1 mg P/em3 gehad, wat 'n betekenisvolle (P < 0.05)
laer been inhoud het in vergelyking met die +P koeie (124.4 mg Pzcrrr'). Dit is dus 'n
indikasie van 'n P-tekort, net vir die stadium (speen). Alhoewel die totale gemiddeld van
die P-inhoud van been geen indikasie van 'n P-tekort, tussen die behandelings getoon het
me.
Die doel van die studie was om te bepaal of daar 'n P-gebrek op Saratoga in die Molopo
bestaan. Alhoewel die resultate van die proef aanleiding gegee het tot die hipotese dat 'n
P-tekort by herkouers geïnduseer kan word deur 'n oorinname van NaCI, soos wat die
geval was met die -P koeie op Saratoga is geen duidelike antwoord deur die proef
gedurende die eerste fase van die ondersoek verskaf nie. Na aanleiding van die resultate
het 'n behoefte vir verdere en meer gedetaileerde ondersoeke ten opsigte van die
aanvulling van P en NaCI, ontstaan. In die tussentyd moet egter aanvaar word dat die
koeie 'n P-tekort getoon het in die afwesigheid van P-aanvulling op die veld en dat dit
wys sou wees om P in ekstreme droogtetoestande te verskaf.May and Stanley Smith Charitable Trus
Thermal characterisation of the furnace tap floor environment of a platinum group metals smelter
No full textMaster of Health Sciences in Occupational Hygiene, North-West University, Potchefstroom CampusBackground: South Africa is the leading global producer of platinum group metals (PGMs), a vital industry that relies on high-temperature smelting processes. The smelting of PGM ore occurs in furnaces operating at extreme temperatures of 1350–1600°C, which generate significant radiant heat. Molten materials, released from the furnace during furnace tapping, pose an additional source of radiant heat. This intense thermal environment creates substantial risks of heat stress for workers performing tasks on the furnace tap floors. Despite the critical role these areas play in smelting operations, the thermal environment of furnace tap floors at PGM smelters remains poorly characterised. Understanding these conditions is essential for improving worker safety and informing the design of effective protective equipment. Objectives: To quantify various environmental variables (heat flux, dry-bulb temperature [DBT], wet-bulb temperature [WBT], globe temperature [GT], relative humidity [RH], wet-bulb globe temperature [WBGT] and air velocity) on the matte and slag tap floors, to assess and compare the spatial variation of the thermal variables within and across the tap floors, and to compare the heat flux and WBGT values to reference values. Method: Environmental variables were measured across a grid on the matte and slag tap floors at a PGM smelter during normal tapping conditions. Environmental monitoring instruments, including heat stress monitors and a thermal comfort measurement system, were used to quantify heat flux, DBT, WBT, GT, RH and indoor wet-bulb globe temperature (WBGTi) on the tap floors. Contour maps of the thermal variables were generated using Surfer® software to assess spatial variations. Observations were made regarding the tappers’ duration of presence in various locations, activity levels and clothing. This information was used to estimate the time-weighted average effective WBGT (TWA-WBGTeff) values according to the ISO 7243 standard for various exposure scenarios. Heat flux exposure at various locations was estimated and compared to the recommended maximum durations for aluminised clothing. Results: The following mean levels of thermal variables were measured on the slag tap floor: 35.6 ± 3.6°C (DBT), 22.1 ± 1.9°C (WBT), 50 ± 10.4°C (GT), 16.2 ± 5.5% (RH), 29 ± 3.7°C (indoor wet-bulb globe temperature [WBGTi]) and 974 ± 537 W/m² (heat flux). The matte tap floor exhibited the following levels of these variables: 35.8 ± 3.1°C (DBT), 20.8 ± 1.8°C (WBT), 48.5 ± 9.2°C (GT), 11.1 ± 2.3% (RH), 27.8 ± 3.2°C (WBGTi) and 554 ± 458 W/m2 (heat flux). Hotspots on the matte tap floor were observed surrounding the active tap-hole and launder, whereas the slag tap floor exhibited a hotspot at the centre front and cooler regions at the sides. A moderate to strong and statistically significant correlation was observed between WBGT and heat flux on both the matte (rs(15) = 0.68, p = 0.006) and slag tap floors (rs(19) = 0.67, p = 0.002). The TWA-WBGTeff exceeded their respective limits in all scenarios except when only 20 minutes per hour was spent on the tap floors. The heat flux levels at various locations (< 4600 W/m2) did not exceed the exposure durations since no maximum exposure duration is recommended at this heat flux level. Conclusion: The matte and slag tap floors present distinct and non-uniform thermal environments with spatially varying conditions. On the matte tap floor, heat is concentrated around the active launder while the slag tap floor presents a more balanced thermal environment, reflecting the difference in tapping practices between the floors. The correlation between heat flux and WBGT suggests future research regarding its potential as a proxy for conventional heat stress metrics. Elevated thermal conditions are present on the tap floors that pose a risk of heat stress to furnace tappers depending on location and exposure duration. More than 20 minutes per hour on the tap floor when wearing an aluminised suit poses a risk of heat stress to furnace tappers. These findings could inform future workplace interventions by identifying high-risk areas and understanding the factors contributing to heat stress, enabling more targeted and effective strategies to protect furnace tappers.Master
Developing zero-waste baselines to identify compressed air system inefficiencies in deep-level mines.
No full textThesis (MEng)--Stellenbosch University, 2023.ENGLISH ABSTRACT: As one of the main exporting industries of South Africa, the gold mining industry has seen a decrease in gold exports in past years. A weakening economy and rolling blackouts prompt Eskom to increase it’s tariff to battle the lack of supply and ever-increasing demand. As the price of electricity increases, the operating costs of mines increase, due to the high reliance on electricity by the mines. The largest electricity consumer on deep-level mines are the compressors and compressed air system. Not only is compressed air the largest consumer of electricity, it was determined to be a very ineffective and inefficient system due to numerous losses and improper use of the resources. Between 30 and 40 % of savings can be realized if the compressed air system inefficiencies are repaired. This highlights the need to identify, localise and quantify the inefficiencies in the compressed air system, with the goal to reduce the overall operating costs of the compressed air system. The compressed air system consists of the supply side, which are the compressors, the distribution network, which is the network of pipes, valves and meters, and lastly, the demand side, which is all the equipment which consumes the compressed air to function. Some unavoidable losses found in the compressed air network are friction losses, however, these losses only reduce pressure and not mass flow. The phenomenon auto compression can also increase pressures in lower levels, due to the weight of the air. Optimal operation of a system can be described as the best achievable performance of the system in question. Optimal performance can be compared to a system performing with zero waste. Zerowaste on the other hand, is a concept and paradigm which challenges operation design to limit and minimise wastages in any given system, either by recycling or optimizing the system. With these concepts in mind, the zero-waste baseline concept was derived as a comparative performance indicator of any given system. Using the zero-waste baseline, a method was developed to identify, localise and quantify compressed air system inefficiencies, by comparing the actual performance of the system with the developed zero-waste baselines. These baselines are developed based on the demand side equipment and the time of use of the specified equipment. With the principle of mass conservation, the difference between actual performance and the zerowaste baseline can be calculated and is then defined as the wastages and inefficiencies in the compressed air system. The zero-waste baseline method was tested on a deep-level gold mine. The major consuming equipment were determined to be refuge bays, pneumatic drills, pneumatic cylinders and pneumatic loaders. It was found that this mine wasted 229 MWh every day, which is equal to R300 622 per day. After physical audits of the major underground levels, the error of the waste calculation was calculated to be 4 %. Therefore, this method can be implemented to determine where the largest wastages are and assist in fixing these wastagesAFRIKAANSE OPSOMMING: Goud is een van die grootste produkte wat in Suid Africa uitgevoer word, maar die bedryf is besig om laer gehalte en verlaagde hoeveelhede goud uit te voer. ’n Verswakende ekonomie, krag onderbrekings en ’n verhoogde elektrisiteit tarief is verdere nagevolge van Eskom wat nie genoeg elektrisiteit kan opwek om by die aanoudende groeiende vraag na elektrisiteit te bevredig. Soos wat die elektrisieit tarief toeneem, neem die bedryfskostes van die goud-myn-bedryf toe, as gevolg van die afhanklikheid wat die myn-bedryf of elektrisiteit het. Daar was bevind dat die saamgepersde lug-sisteem baie oneffektief en ondoeltreffend is, as gevolg van verskeie ondoeltreffendhede en misbruik van die lug in die sisteem. Tussen 30 % en 40 % van die elektrisiteits kostes kan gespaar word as al die ondoeltreffendhede verwyder word. Hierdie verhoogde eletrisiteitskostes beklemtoon die belangrikheid om die ondoeltreffendhede to identifiseer, lokaliseer en te kwantifiseer. Die saamgepersde lug-sisteem bestaan uit beide ’n verskaffings-kant, wat die kompressors is, ’n verspreidings-netwerk, wat die pype, kleppe en sensors is, en ’n vraag-kant, wat al die toerusting insluit wat die saamgepersde lug gebruik. Van die onvermydelike ondoeltreffendhede in die saamgepersde lug-sisteem is as gevolg van wrywing in die pyp netwerk. Let wel, dat wrywing slegs die druk in die sisteem verminder en nie die massa vloei in die sisteem nie. Verder is daar autokompressie in die sisteem wat bydra tot die verhoogde druk in die sisteem, as gevolg van die saamgepersde lug se eie gewig. Optimale operasie van ’n sisteem kan beskryf word as die beste behaalbare toestand van die sisteem. Optimale operasie kan vergelyk word met ’n sisteem wat geen vermorsings produseer. Nul-vermorsing is ’n paradigma en konsep wat die traditionele ontwerp van operasies uitdaag om eerder te streef na produksie van geen vermorsings, deur die vermorsings te herwin of om die sisteem te optimaliseer. Met hierdie definisies in gedagte, was die nul-vermorsing basislyn konsep afgelei as ’n vergelykende toestand indikator van enige toepasbare sisteem. Deur van die nul-vermosring basislyn gebruik te maak, was daar ’n metode ontwerp wat die ondoeltreffendhede in die sisteem identifiseer, lokaliseer en kwantifiseer. Hierdie basislyne word ontwikkel deur die toerusting wat die saamgepersde lug gebruik te identifiseer en die hoeveelheid lug wat die toerusting deur die dag gebruik, saam te tel. Die verskil tussen die nul-vermorsing basislyn en die werklike toestand van die sisteem kan gedefinieer word as die vermorsings en ondoeltreffendhede in die sisteem. Die nul-vermorsing basislyn metode was getoets op ’n diep-vlak myn. Die grootste lug-verbruikende toerusting was geidentifiseer as veiligheids kamers, pneumatiese bore, pneumatiese silinders en pneumatiese laaiers. Daar was bevind dat die myn 229 MWh elke dag vermors, wat gelykstaande is aan R300 622 per dag. Nadat fisiese ondergrondse audits gedoen is, was daar bevind dat die metode afwyk met 4 % van die werkilike toestand. Daarom kan die metode gebruik word om die ondoeltreffendhede to lokaliseer.Master
What lies
No full textMagister Artium - MAHis brown hands, tanned darker than they already were from hours of supervising men
shoveling sand and mixing concrete on building sites, gripped the steering wheel. Hendrick
Vermeulen drove down Voortrekker Road after a long day’s work. He had dropped off the
last of the guys with his bakkie and was looking forward to resting. He was enjoying the cool
night air blowing up his arm. And there it was, that mountain. There was nothing more to
think about it. It meant nothing to him; a big rock, a marker to remind where he was. The rich
people were there by the mountain; he was not. He drove on
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