Assessing the impact of Eskom power plant emissions on ambient air quality over KwaZamokuhle

Coal-fired power plants are considered a major source of criteria air pollutants. The existence of such activities close to densely populated areas has an impact on human health and more generally on the environment. The impact of a pollutant typically depends on its residence time and the existence of background concentration levels. This study evaluates the dispersion of PM2.5, SO2 and NOX emissions from Eskom power plants (Arnot, Hendrina, and Komati) located close to KwaZamokuhle Township. AERMOD was used to assess the contribution of each plant to the air quality of the township. This steady-state dispersion model was used to simulate surface concentrations (1-hour, 24-hour and annual average concentrations) on a 50km domain for 2015-2017. The modelled results together with data obtained from Eskom’s KwaZamokuhle monitoring site were used to estimate the extent to which these power plants contribute to the ambient air quality of KwaZamokuhle Township. The results confirm that the power plants do contribute to concentrations of PM2.5, SO2, and NOx in the ambient air of the township. However, based on a comparison between the modelled and monitored data, it was inferred that power plants are not the only significant source of these criteria pollutants. Evidence from temporal variations in the monitored data shows that domestic burning is likely the major contributor since the variability is more closely associated with burning habits. It is therefore likely that existing regulatory strategies that focus mostly on the industrial sector may not be successful in improving ambient air quality in low-income settlements like KwaZamokuhle

Variability of ambient particulate matter loading at Henties Bay, Namibia

An earlier version of this paper was presented at the National Association of Clean Air (NACA) Conference in October 2022 and was published in its Proceedings.The Namibian coast is one of the areas of international interest for aerosol studies. This is due to the region’s importance for the global radiation budget because of the presence of a semi-permanent stratocumulus cloud along the coast. Aerosol particles may scatter/ absorb radiation and directly influence how long clouds last by modifying their properties. This is all dependent on the particles’ chemical and physical properties influenced by the sources they were emitted from. In this study, we identified and investigated episodes of high (HAE) and low (LAE) PM concentrations and the meteorology that may favour their occurrence. Here, we investigated PM2.5 (particles with an aerodynamic diameter of 2.5 μm or less) and PM10 (particles with an aerodynamic diameter of 10 μm or less) at Henties Bay, Namibia. Daily aerosol measurements were taken with E-samplers between 15 and 29 July 2019. The Hybrid Single- Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to investigate the long-range atmospheric transport of air masses that reached Henties Bay. The study found that during HAEs, the average PM2.5 concentration was 28.40 ± 18.10 μg/m3 and the average PM10 concentration was 68.20 ± 44.3 μg/m3. In contrast, during LAEs, the average PM2.5 concentration was 13.3 ± 9.52 μg/m3 and the average PM10 concentration was 30.00 ± 23.00 μg/m3. In both fractions, there was an observed dominant contribution from marine sources.The National Research Foundation of South Africa.http://www.cleanairjournal.org.zaam2024Geography, Geoinformatics and MeteorologyNon

Divalent and Multivalent Activation in Phosphate Triesters: A Versatile Method for the Synthesis of Advanced Polyol Synthons

This is the peer reviewed version of the following article: Thomas, C. D., McParland, J. P. and Hanson, P. R. (2009), Divalent and Multivalent Activation in Phosphate Triesters: A Versatile Method for the Synthesis of Advanced Polyol Synthons. Eur. J. Org. Chem., 2009: 5487–5500. doi:10.1002/ejoc.200900560, which has been published in final form at http://doi.org/10.1002/ejoc.200900560. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The construction of mono- and bicyclic phosphate trimesters possessing divalent and multivalent activation and their subsequent use in the production of advanced polyol synthons is presented. The method highlights efforts to employ phosphate tethers as removable, functionally active tethers capable of multipositional activation and their subsequent role as leaving groups in selective cleavage reactions. The development of phosphate tethers represents an integrated platform for a new and versatile tether for natural product synthesis and sheds light on new approaches to the facile construction of small molecules

The relationship of SOC to well-being and its effect on the perception of a selected number of work characteristics

Thesis (MA)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: Many Black nurses who originally come from previously disadvantaged communities find themselves at present in relatively senior positions. The reality is, however, that many of these employees are still residing in residential areas where transformation and changes are still very limited and progress hardly noticeable. Such employees experience the stressful world of nursing on the one hand while on the other hand they also have to battle with the realities of the legacy of Apartheid. These may include aspects such as financial burdens, long distances from work, poor public transport, high crime rates in their communities and schools that are yet to improve standards. There are still Black South Africans, amongst them Black nursing sisters, who have to battle with these problems daily, in addition to having to cope with occupational stressors. One would assume then that they may be experiencing a large degree of strain and burnout. This research was therefore concerned with those nurses who remain productive and efficient in their work by overcoming constant occupational and non-occupational demands and stressors. Not all nurses, however, experience ill health due to stressors. There are nurses who do cope well. Two research questions were investigated with reference to the above: (a) Why some Black nursing sisters appear to cope better than others; and (b) What the role of Sense of Coherence (SOC) is as a coping resource. The study therefore investigated the statistical relationship between (a) SOC and well-being and (b) the effect that SOC has on the perception of a selected number of work characteristics. Significant Pearson Correlations were found between SOC and psychosomatic strain symptoms and burnout frequency. No significant relationship was found between SOC and burnout intensity. A significant relationship was found between SOC and work demands, as well as SOC and career rewards. Findings further indicate that no significant relationship was found between organisational climate, leadership relations, influence at work, time pressures and adverse factors in the work environment. Two-way ANOVAs indicate that no significant main effect exists in respect of SOC on psychosomatic strain symptoms. The study also indicates that a significant main effect exists for SOC on burnout frequency, whereas no significant main effect exists for SOC on burnout intensity. No significant interaction effect exists between SOC and age on psychosomatic strain symptoms, burnout frequency and burnout intensity. A significant interaction effect exists between SOC and education level on burnout intensity, while there is no significant interaction effect between SOC and educational level on psychosomatic strain symptoms and burnout frequency. A significant main effect exists for SOC on the perception of leadership relations, influence at work and career rewards. Findings further indicate that no significant main effect exists for SOC on the perception of: orgnisational climate, time pressures, work demands and adverse factors in the work environment. No significant interaction effect exists between SOC and age on the perception of organisational climate, influence at work, work demands, time pressures, career rewards, leadership relations and adverse factors in the work environment. Results indicate that no significant interaction effect exists between SOC and educational level on the perception of organisational climate, influence at work, work demands, time pressures, career rewards, leadership relations and adverse factors in the work environment. The results thus indicate that a positive correlation exists between SOC and wellbeing.AFRIKAANSE OPSOMMING: Talle verpleegters uit voorheen benadeelde gebiede, bevind hulself huidiglik in relatiewe senior posisies. Die werklikheid is egter dat hierdie werknemers nog steeds onder andere in woongebiede bly waar transformasie en verandering gering is en algemene vordering nie waarneembaar is nie. Hierdie werknemers ondervind die stresvolle omstandighede van verpleging eendersyds en andersyds voer hulle 'n stryd teen die nalatenskap van apartheid. Dit kan aspekte soos finansiele probleme, lang afstande van hul werkplek, publieke vervoer, hoë misdaadsyfers in hul gemeenskappe asook skole waar die opvoedkundige standaarde nog aangespreek moet word, insluit. Daar is nog talle Swart Suid-Afrikaners, Swart verpleegsusters onder andere wat daagliks met hierdie probleme die stryd voer met 'n langsame veranderingsproses, terwyl hulle ook met talle stressors in hul beroepe te make het. Dit kan dus aanvaar word dat hierdie persone 'n groot mate van stres en uitbranding ondervind. Hierdie navorsing het te make met daardie groep verpleegsters wat produktief en bekwaam in hul werk bly funksioneer het, weens die feit dat hulle hierdie voordurende beroeps-en nie-beroeps vereistes en stressors suksesvol die hoof kan bied. Nie al die verpleegsters se geestegesondheid word dus deur genoemde stresfaktore benadeel nie en kan deurgaans effektief funksioneer. Twee navorsings-vraagstukke is met betrekking tot bogenoemde Suid-Afrikaanse realiteit ondersoek: (a) Waarom sommige Swart verpleegsusters die stressors in hul beroeps-en lewensomstandighede beter as ander hanteer en (b) Watter rol speel koherensiebelewing ("SOC") as enstreshantering meganisme. Die studie het (a) die verhouding tussen koherensiebelewing en werknemer welsyn en (b) die rol van koherensiebelewing ("SOC") as enmeganisme vir die hantering van stres, nagevors. Beduidende Pearson Korrelasies tussen koherensiebelewing, psigosomatiese stressimptome en die frekwensie van uitbranding is gevind. Geen beduidende verband is tussen koherensiebelewing, werkseise en loopbaanbelonings gevind nie. Die resultate dui verder aan dat daar geen beduidende verband tussen organisatoriese klimaat, leierskap verhoudings, invloed by die werk, tydsdruk, en nadelige faktore in die werksomgewing bestaan nie. Twee-rigting variansie ontledings dui egter aan dat daar geen beduidende hoof effek tussen koherensiebelewing en psigosomatiese stressimptome bestaan nie. Die studie dui ook op 'n beduidende hoof effek tussen koherensiebelewing en die frekwensie van uitbranding. Geen beduidende hoof effek is tussen koherensiebelewing en uitbranding intensiteit gevind. Geen beduidende interaksie effek bestaan tussen koherensiebelewing en ouderdom op psigomatiese stressimptome, frekwensie van uitbrandiqg en uitbrandings intensiteit nie. 'n Beduidende interaksie effek bestaan tussen koherensiebelewing en opvoedkundige kwalifikasie op uitbranding intensiteit, terwyl daar geen interaksie effek bestaan tussen psigomatiese stressimptome en frekwensie van uitbranding nie. 'n Beduidende hoof effek ten opsigte van koherensiebelewing op die persepsie van leierskap-verhoudings, invloede by die werk, en loopbaanbelonings is gevind. Die navorsing dui verder daarop dat geen betekenisvolle hoof effek bestaan ten opsigte van koherensiebelewing op die persepsie van organisatoriese klimaat, tydsdruk, werksvereistes en nadelige faktore in die werksomgewing nie. 'n Statisties beduidende hoof effek ten opsigte van koherensiebelewing op die persepsie van leierskap-verhoudings, invloede by die werk, en loopbaanbelonings, bestaan. Geen beduidende interaksie effek bestaan tussen koherensiebelewing en ouderdom op die persepsie van organisatoriese klimaat, invloed by die werk, werkseise, tydsdruk, loopbaanbelonings, leierskap-verhoudings en nadelige faktore in die werksomgewing nie. Resultate toon geen statisties beduidende interaksie effek tussen koherensiebelewing en opvoedkundige kwalifikasie op die persepsie van organisatoriese klimaat, invloede by die werk, werkseise, tydsdruk, loopbaanbelonings, leierskap-verhoudings en nadelige faktore by die werk nie. Die resultate dui derhalwe op 'n positiewe verband tussen koheresensiebelewing en werknemerwelstand

South African Highveld concentrations of outdoor Total Gaseous Mercury

It is well-known that the Highveld is one of the country's poorest air quality regions. This is due to the abundance of anthropogenic activities such as coal-fired power plants, mining, and cement production among others. The formerly mentioned source is regarded globally and has been extensively studied as the leading source of ambient mercury. Mercury is recurrently oxidized and reduced between its environmental forms. Methyl-mercury poses adverse effects on humans if inhaled/consumed in excessive amounts. In this research, the authors conducted a first-ever characterization of total gaseous mercury (TGM) concentrations over the Highveld regio