Browsing by Author "10092390 - Beukes, Johan Paul"
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The AeroCom evaluation and intercomparison of organic aerosol in global models
Tsigaridis, K.; Beukes, J.P.; Tiitta, P.; Van Zyl, P.G.; Daskalakis, N. (EGU, 2014)This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry ... -
Aerosol characterisation including oxidative potential as a proxy of health impact: a case of a residential site in a highly industrialised area
Josipovic, Miroslav; Segakweng, C. Keitumetse; Beukes, J. Paul; Van Zyl, Pieter G.; Leal-Liousse, Catherine (NACA, 2019)This study aimed to characterise aerosols sampled in the vicinity of a major industrialised area, i.e. the Vaal Triangle. It included the determination of oxidative potential as a predictive indicator of particle toxicity. ... -
An air quality assessment in the industrialised western Bushveld Igneous Complex, South Africa
Venter, Andrew D.; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Pienaar, Jacobus J.; Tiitta, Petri; Laakso, Lauri (ASSAf, 2012)South Africa has the largest industrialised economy in Africa, with significant mining and metallurgical activities. A large fraction of the South African mineral assets is concentrated in the Bushveld Igneous Complex ... -
Ambient aromatic hydrocarbon measurements at Welgegund, South Africa
Jaars, K.; Beukes, J.P.; Van Zyl, P.G.; Venter, A.D.; Josipovic, M.; Pienaar, J.J.; Tiitta, P.; Laakso, L. (EGU, 2014)Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ... -
The anthropogenic contribution to atmospheric black carbon concentrations in southern Africa: a WRF-Chem modeling study
Kuik, F.; Beukes, J.P.; Van Zyl, P.G.; Josipovic, M.; Laakso, L.; Lauer, A.; Vakkari, V. (EGU, 2015)South Africa has one of the largest industrialized economies in Africa. Emissions of air pollutants are particularly high in the Johannesburg-Pretoria metropolitan area, the Mpumalanga Highveld and the Vaal Triangle, ... -
Aqueous solubility of Cr(VI) compounds in ferrochrome bag filter dust and the implications thereof
Du Preez, S.P.; Beukes, J.P.; Van Dalen, W.P.J.; Van Zyl, P.G.; Loock-Hattingh, M.M. (WRC, 2017)The production of ferrochrome (FeCr) is a reducing process. However, it is impossible to completely exclude oxygen from all of the high-temperature production process steps, which may lead to unintentional formation of ... -
Assessment of atmospheric trace metals in the western Bushveld Igneous Complex, South Africa
Van Zyl, Pieter G.; Beukes, Johan P.; Du Toit, Grizelda; Hendriks, Johan; Pienaar, Jacobus J.; Laakso, Lauri (ASSAf, 2014)Trace metal species emitted into the atmosphere from natural and anthropogenic sources can cause various health-related and environmental problems. Limited data exist for atmospheric trace metal concentrations in South ... -
Assessment of polar organic aerosols at a regional background site in southern Africa
Booyens, Wanda; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Laakso, Lauri (Springer, 2019)A recent paper reported GCxGC-TOFMS analysis used for the first time in southern Africa to tentatively characterise and semi-quantify ~1000 organic compounds in aerosols at Welgegund – a regional background atmospheric ... -
Atmospheric boundary layer top height in South Africa: measurements with lidar and radiosonde compared to three atmospheric models
Korhonen, K.; Laakso, L.; Beukes, J.P.; Van Zyl, P.G.; Josipovic, M.; Tiitta, P. (EGU, 2014)Atmospheric lidar measurements were carried out at Elandsfontein measurement station, on the eastern Highveld approximately 150 km east of Johannesburg in South Africa throughout 2010. The height of the planetary ... -
Atmospheric trace metals measured at a regional background site (Welgegund) in South Africa
Venter, Andrew D.; Van Zyl, Pieter G.; Beukes, Johan P.; Josipovic, Micky; Hendriks, Johan; Laakso, Lauri (EGU, 2017)Atmospheric trace metals can cause a variety of health-related and environmental problems. Only a few studies on atmospheric trace metal concentrations have been conducted in South Africa. Therefore the aim of this study ... -
Automated continuous air monitoring
Beukes, Johan Paul; Venter, Andrew Derick; Josipovic, Miroslav; Van Zyl, Pieter Gideon; Jaars, Kerneels; Dunn, Marcell; Laakso, Lauri (Elsevier, 2015)Anthropogenic and anthropogenically induced emissions (such as emissions due to land use change) of various gaseous and particulate atmospheric species have substantially increased since the onset of the industrial ... -
Carbon balance of a grazed savanna grassland ecosystem in South Africa
Räsänen, Matti; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Venter, Andrew D.; Jaars, Kerneels; Siebert, Stefan J.; Laakso, Lauri (EGU, 2017)Tropical savannas and grasslands are estimated to contribute significantly to the total primary production of all terrestrial vegetation. Large parts of African savannas and grasslands are used for agriculture and cattle ... -
Characterisation and liberation of chromium from fine ferrochrome waste materials
Van Staden, Y.; Beukes, J.P.; Van Zyl, P.G.; Dawson, N.F.; Du Toit, J.S. (Elsevier, 2014)Three types of generic chromium (Cr)-containing wastes are generated during ferrochrome (FeCr) production, i.e. slag, bag filter dust (BFD) and venturi sludge. Slag is by volume the largest waste; however, fine FeCr waste ... -
Characterisation of sub-micron particle number concentrations and formation events in the western Bushveld Igneous Complex, South Africa
Hirsikko, A.; Tiitta, P.; Beukes, J.P.; Laakso, L.; Vakkari, V. (EGU, 2012)South Africa holds significant mineral resources, with a substantial fraction of these reserves occurring and being processed in a large geological structure termed the Bushveld Igneous Complex (BIC). The area is also ... -
Characterising particulate organic nitrogen at a savannah-grassland region in South Africa
Booyens, Wanda; Van Zyl, Pieter G.; Beukes, Johan P.; Vakkari, Ville; Josipovic, Miroslav; Laakso, Lauri (MDPI, 2019)Although atmospheric organic N compounds are considered to be important, especially in new particle formation and their contribution to brown carbon, these species are not that well understood. This can be partially ... -
Characterization of satellite-based proxies for estimating nucleation mode particles over South Africa
Sundström, A.-M.; Laakso, L.; Beukes, J.P.; Van Zyl, P.G.; Josipovic, M.; Venter, A.D.; Jaars, K.; Pienaar, J.J.; Piketh, S.; Chiloane, E.K. (EGU, 2015)Proxies for estimating nucleation mode number concentrations and further simplification for their use with satellite data have been presented in Kulmala et al. (2011). In this paper we discuss the underlying assumptions ... -
The chemical composition and fluxes of atmospheric wet deposition at four sites in South Africa
Conradie, E.H.; Van Zyl, P.G.; Pienaar, J.J.; Beukes, J.P.; Venter, A.D. (Elsevier, 2016)South Africa is the economic hub of southern Africa and is regarded as an important source region of atmospheric pollutants. A nitrogen dioxide (NO2) hotspot is clearly visible from space over the South African Mpumalanga ... -
Chemical composition, main sources and temporal variability of PM1 aerosols in southern African grassland
Tiitta, P.; Beukes, J.P.; Van Zyl, P.G.; Josipovic, M.; Venter, A.D.; Jaars, K.; Pienaar, J.J.; Laakso, L. (EGU, 2014)Southern Africa is a significant source region of atmospheric pollution, yet long-term data on pollutant concentrations and properties from this region are rather limited. A recently established atmospheric measurement ... -
Coal-based reducing agents in ferroalloys and silicon production
Tangstad, Merete; Beukes, Johan Paul; Steenkamp, Joalet; Ringdalen, Eli (Elsevier, 2019)Manganese, chromium, and silicon ferroalloys are typical examples of alloys that are produced using carbon materials to remove oxygen from the raw materials. A majority of such alloys are currently produced in electric ... -
Comparison of physical properties of oxidative sintered pellets produced with UG2 or metallurgicalgrade South African chromite: a case study
Glastonbury, R.I.; Beukes, J.P.; Van Zyl, P.G.; Jordaan, A.; Campbell, Q.P. (SAIMM, 2015)The physical properties of oxidative sintered pellets produced from typical South African UG2 ore are compared with the physical properties of pellets produced with conventional South African metallurgical-grade chromite ore ...