Optimization of the coal reserve utilization at Grootegeluk Mine, Waterberg coalfield, with regards to the phosphorus content in coal

Submitted to: School of Mining Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa September 2015Most coal seams in the Waterberg Coalfield contain medium to high levels of phosphorus in coal. Thermal coal, which has a lower value than metallurgical coal, is produced from these coal seams. Metallurgical coal used as feed for char production has especially stringent phosphorous content specifications. Phosphorous levels vary both laterally and vertically through the coal succession of the Vryheid Formation. If the coal horizons with elevated phosphorus could be identified and selectively removed, significant amounts coal could be saved and utilized as metallurgical coal through the life of the mine. Different mining horizons with regards to their phosphorus content have to be determined to increase the amount of char plant feed coal. Bench definitions and their techno-economic applications are therefore the main purpose of the current investigation. Bench 11 is currently the only source utilized for char plant feed coal. The char plant is therefore entirely dependent on coal supply from Bench 11. This poses a risk on the continual production of char at Grootegeluk Mine. It was determined that this bench is not suitable for char plant feed coal in certain areas of the resource. A high phosphorus coal horizon was identified in the upper portion of the bench. If this coal is removed separately, the phosphorus content of the coal in the remaining portion of the bench would be suitable for char plant feed coal. This alternative step is dependent on the phosphorus distribution in the resource and may therefore not always be effective. No changes to the other bench definitions could be established that would increase the amount of potential char plant feed coal. Three further aspects were investigated: The potential to reduce phosphorus in coal by means of coal beneficiation was determined. Results showed that phosphorus levels in coal cannot be lowered sufficiently by means of coal beneficiation. Secondly, the suitability of using different coal analyses to improve the estimation of phosphorus in coal was investigated. Results showed that phosphorus prediction and analyses cannot be enhanced nor replaced by other coal analyses. Lastly, the importance of Zone 1 as a source of low phosphorous coal was investigated. Zone 1 is currently not part of the mine plan, but if mined, it could be used as a source for blending; thereby increasing the amount of char plant feed coal from the reserves. In certain portions of the resource, utilizing Zone 1 may be the only feasible way of securing the continual supply of low phosphorus content coal. Analytical exploration borehole data of phosphorus in coal is limited in certain areas of the resource. Due to the variability of phosphorus in the coal horizons, more borehole data is required to increase the estimation accuracy of phosphorus in the coal. Based on such data, mining horizons might be changed in future to secure more char plant feed coal

Continuous succinic acid fermentation by Actinobacillus succinogenes

Please read the abstract in the section front of this document.Dissertation (MEng)--University of Pretoria, 2012.Chemical Engineeringunrestricte

Continuous and batch cultures of Escherichia coli KJ134 for succinic acid fermentation : metabolic flux distributions and production characteristics

BACKGROUND: Succinic acid (SA) has become a prominent biobased platform chemical with global production quantities increasing annually. Numerous genetically modified E. coli strains have been developed with the main aim of increasing the SA yield of the organic carbon source. In this study, a promising SA-producing strain, E. coli KJ134 [Biotechnol. Bioeng. 101:881–893, 2008], from the Department of Microbiology and Cell Science of the University of Florida was evaluated under continuous and batch conditions using D-glucose and CO2 in a mineral salt medium. Production characteristics entailing growth and maintenance rates, growth termination points and metabolic flux distributions under growth and non-growth conditions were determined. RESULTS: The culture remained stable for weeks under continuous conditions. Under growth conditions the redox requirements of the reductive tricarboxylic acid (TCA) cycle was solely balanced by acetic acid (AcA) production via the pyruvate dehydrogenase route resulting in a molar ratio of SA:AcA of two. A maximum growth rate of 0.22 h-1 was obtained, while complete growth inhibition occurred at a SA concentration of 18 g L-1. Batch culture revealed that high-yield succinate production (via oxidative TCA or glyoxylate redox balancing) occurred under non-growth conditions where a SA:AcA molar ratio of up to five was attained, with a final SA yield of 0.94 g g-1. Growth termination of the batch culture was in agreement with that of the continuous culture. The maximum maintenance production rate of SA under batch conditions was found to be 0.6 g g-1 h-1. This is twice the maintenance rate observed in the continuous runs. CONCLUSIONS : The study revealed that the metabolic flux of E. coli KJ134 differs significantly for growth and non-growth conditions, with non-growth conditions resulting in higher SA:AcA ratios and SA yields. Bioreaction characteristics entailing growth and maintenance rates, as well as growth termination markers will guide future fermentor designs and improvements.http://www.microbialcellfactories.com/content/12/1/80am2013ai201

Continuous succinic acid fermentation by Actinobacillus succinogenes

Fermentations were performed in an external recycle bioreactor using CO2 and D-glucose at feed concentrations of 20 and 40 g L . Severe biofilm formation prevented kinetic analysis of suspended cell (‘chemostat’) fermentation, while perlite packing enhanced the volumetric productivity by increasing the amount of immobilised cells. The highest productivity of 6.35 g L h was achieved at a dilution rate of 0.56 h . A constant succinic acid yield of 0.69±0.02 g/(g of glucose consumed) was obtained and found to be independent of the dilution rate, transient state and extent of biofilm buildup — approximately 53% of the carbon that formed phosphoenolpyruvate ended up as succinate. Byproduct analysis indicated that pyruvate oxidation proceeded solely via the formate-lyase pathway. Cell growth and corresponding biofilm formation were rapid at dilution rates higher than 0.35 h when the product concentrations were low (succinic acid<10 g L ), while minimal growth was observed at succinic acid concentrations above this threshold.http://http://www.elsevier.com/locate/bejhb201

Transcriptomic changes associated with husk scald incidence on pomegranate fruit peel during cold storage

CITATION: Belay, Z. A. et al. 2020. Transcriptomic changes associated with husk scald incidence on pomegranate fruit peel during cold storage. Food Research International, 135. doi:10.1016/j.foodres.2020.109285The original publication is available at https://www.sciencedirect.com/journal/food-research-internationalPomegranate fruit is valued for its social, economic, aesthetic and health benefits. The fruit rapidly loses quality after harvest due to continued metabolic responses and physiological disorders under sub-optimal conditions. The incidence of physiological disorder such as husk scald manifests during storage and commercial shipping, which affects the appearance and limits marketability. Despite the importance of pomegranate husk scald, little information is available about the origin and molecular mechanisms. Therefore, the aim of this study was to investigate the scald incidence of pomegranate fruit at molecular level using RNA-Seq (Ion Proton™ Next Generation Sequencing) by analyzing peel transcriptomic changes. The RNA-seq analysis generated 98,441,278 raw reads. 652 Differentially Expressed Genes (DEGs) with a fold change of > |2|, a p value ≤ 0.05 and a false discovery rate (FDR) of <0.05 were identified between healthy and scald fruit peels. An analysis of the gene ontologies of these DEGs revealed the 432 genes were assigned with molecular functions, 272 as cellular components and 205 as part of biological processes. In this analysis, genes (Pgr023188 and Pgr025081) that encode uncharacterized protein and gene (Pgr007593) that encodes glycosyltransferase showed significantly highest fold changes. Genes (Pgr003448, Pgr006024 and Pgr023696) involved in various iron binding and oxidoreductase activities were significantly suppressed. This is the first transcriptome analysis of pomegranate fruit peel related to husk scald development. Results obtained from this study will add valuable information on husk scald related changes on pomegranate fruit at genomic level and provide insight on other related physiological disorders.https://www.sciencedirect.com/science/article/pii/S0963996920303100?via%3DihubPublishers versio

Distinct host-immune response toward species related intracellular mycobacterial killing : a transcriptomic study

CITATION: Madhvi Abhilasha et al. 2020. Distinct host-immune response toward species related intracellular mycobacterial killing : a transcriptomic study. Virulence, 11(1):170-182, doi:10.1080/21505594.2020.1726561.The original publication is availablle at: https://www.ncbi.nlm.nih.govThe comparison of the host immune response when challenged with pathogenic and nonpatho- genic species of mycobacteria can provide answers to the unresolved question of how pathogens subvert or inhibit an effective response. We infected human monocyte derived macrophages (hMDMs) with different species of mycobacteria, in increasing order of pathogenicity, i.e. M. smegmatis, M. bovis BCG, and M. tuberculosis R179 that had been cultured in the absence of detergents. RNA was isolated post-infection and transcriptomic analysis using amplicons (Ampliseq) revealed 274 differentially expressed genes (DEGs) across three species, out of which we selected 19 DEGs for further validation. We used qRT-PCR to confirm the differential expression of 19 DEGs. We studied biological network through Ingenuity Pathway Analysis® (IPA) which revealed up-regulated pathways of the interferon and interleukin family related to the killing of M. smegmatis. Apart from interferon and interleukin family, we found one up-regulated (EIF2AK2) and two down-regulated (MT1A and TRIB3) genes as unique potential targets found by Ampliseq and qRT-PCR which may be involved in the intracellular mycobacterial killing. The roles of these genes have not previously been described in tuberculosis. Multiplex ELISA of culture supernatants showed increased host immune response toward M. smegmatis as compared to M. bovis BCG and M.tb R179. These results enhance our understanding of host immune response against M.tb infection.Publisher's versio

Ukushenxisa imiboniso yedijithali ngentsebenziswano : imbonakalo yedijithali kwimeko yokuxubeka nzulu nokuhlaziywa

Text in English, with abstracts and keywords in English, Zulu and XhosaLink to the dataset (catalogue): https://doi.org/10.25399/UnisaData.14101913.v1Digital image editing is rooted in the analog practices of photographic retouching from the late nineteenth century. This study interrogated how novel contributions of new media practice can inform understanding of the relationship between digital and analog media. The study also sought to explore new conceptual avenues in the creation of digital art that incorporates key aspects of both new and traditional media. This study employed a literature review of selected discourses related to new media studies. Specifically, the work of scholars Lev Manovich, Jay David Bolter, Richard Grusin, and Filipe Pais on the interplay between traditional and new media formed the cornerstone of the analysis. These discourses contextualise an analysis of several contemporary case studies of digital artists, with a particular focus on John Craig Freeman and the Oddviz collective. These works were selected for the way in which they destabilise conventional notions of digital photography in new media and the way digital content can be ‘displaced’ into a physical space. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography, and intermediality. The dissertation concludes with an overview of my work that incorporates the concepts derived from my analysis of the case studies. It discusses how my exhibition Digital Tourist, a mixed media installation, makes use of photogrammetry and AR to displace the private connections of an individual life into the public space of the gallery.Ukuhlelwa kwezithombe zezindaba zedijithali kususelwe emikhubeni ye-analokhu yokuthwebula kabusha izithombe kusukela ngasekupheleni kwekhulu leshumi nesishiyagalolunye leminyaka.. Lolu cwaningo luphenye ukuthi iminikelo yenoveli emisha yokwenziwa kwezezindaba ezintsha zingakwazisa kanjani ukuqonda kobudlelwano phakathi kwezindaba zedijithali ne-analokhu. Ucwaningo luphinde lwafuna ukubheka izindlela ezintsha zomqondo ekwakhiweni kobuciko bedijithali obufaka izinndaba ezibalulekile kokubili kwezokuxhumana nezendabuko ezintsha. Izinkulumo ezikhethiwe ezihlobene nezifundo zezindaba ezintsha zibuyekeziwe. Ngokuqondile, umsebenzi wezazi uLev Manovich, Jay David Bolter, Richard Grusin noFilipe Pais ekusebenzisaneni phakathi kwabezindaba bendabuko nabasha kwakha okuzobhekwa ngqo uma kuhlaziywa. Lezi zinkulumo zigxila ekuhlaziyweni kwezifundo zamanje zamaciko edijithali, kugxilwe kakhulu kuJohn Craig Freeman kanye neqoqo le-Oddviz. Le misebenzi yakhethwa ngendlela yokuthi ingazinzisi imiqondo ejwayelekile yokuthwebula izithombe zedijithali emithonjeni emisha kanye nokuthi okuqukethwe kwedijithali "kungahanjiswa kanjani" endaweni ebonakalayo. Ukusuka kulokhu kuhlaziywa kuvela imiqondo eminingana esebenza njengezimpawu ezihlukanisayo zokufuduswa kwabezindaba. Lezi zingqikithi zifaka phakathi ukwakheka, inkumbulo, ukwakheka kobunikazi, ukuziphendulela kanye nokuzibandakanya. Idezetheyishini iphetha ngokubuka konke ngomsebenzi wami ohlanganisa imiqondo esuselwe ekuhlaziyweni kwami kwezifundo zocwaningo. Ingxoxo ihlanganisa ukuthi umbukiso wami we-Zivakashi zeDijithali, ukufakwa kwabezindaba okuxubile, isebenzisa uhlelo lokuthwebula olusebenzisa ulimi noma ifothogrametri ne-AR ukukhipha ukuxhumana kwangasese kwempilo yomuntu ngamunye endaweni yomphakathi yegalari.Ukuhlela imifanekiso yedijithali yinkqubo eyendeleyo, nowaqalwa kwiminyaka yokugqibela yenkulungwane yeshumi elinethoba, kwimisebenzi yezifaniso/yeanalogu ekuhlaziyweni kweefoto. Esi sifundo siphonononga ukuba igalelo elikhethekileyo leendlela ezintsha zonxibelelwano lwemiboniso/imidiya lingenza njani ukuqinisa ukuqonda unxulumano phakathi kwemiboniso yedijithali neyeanalogu. Kwakhona, esi sifundo sizama ukuphanda iindlela ezintsha ezisetyenziswa kubugcisa bedijithali neziquka imiba ephambili yemiboniso yale mihla neyakudala. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography and intermediality. Kuphononongwe iingxoxo ezithile ezimalunga nezifundo zemiboniso yale mihla. Kuqwalaselwe ngakumbi imisebenzi yeengcali ooLev Manovich, Jay David Bolter, Richard Grusin kunye noFilipe Pais malunga nonxulumano phakathi kwemiboniso yakudala neyale mihla njengesiseko solu hlalutyo. Ezi ngxoxo zifaka emxholweni uhlalutyo lwezifundo zokuzekelisa zale mihla malunga nabazobi bale mihla, kugxininiswa kwindibanisela ka John Craig Freeman nekaOddviz. Le misebenzi ikhethwe ngenxa yokuba iyazichitha iingcinga eziqhelekileyo malunga nokufota ngedijithali kwimiboniso yale mihla nangendlela iziqulatho zedijithali “zinokushenxiswa” zisiwe kwindawo ebambekayo. Olu hlalutyo luveze iingcinga eziliqela nezisebenza njengeempawu zoshenxiso lwemiboniso. Imixholo iquka imifuziselo, ukukhumbula, ukwenziwa kwesazisi, ukuzazisa ngezinto onazo, unxulumano phakathi kwemiboniso eyahlukeneyo Le ngxelo yophando igqibela ngokushwankathela umsebenzi wam ohlanganisa iingcinga ezivele ekuhlalutyeni kwam izifundo ezingumzekelo. Ingxoxo ibonisa ukuba umboniso wengqokelela yemisebenzi yam owaziwa ngokuba yiDigital Tourist, ubusebenzise njani ubuchwepheshe ekuthiwa yifotogrametri (obokufumana ulwazi ngokuhlalutya imifanekiso) ekushenxiseni unxulumano lwabucala lobomi bomntu ibubeke kwindawo ebonwa nguwonkewonke apho kubukwa imifanekiso neefoto (igalari).https://doi.org/10.25399/UnisaData.14101913.v1Arts and MusicM.A. (Visual Arts

Die oorwinningsperspektief in die afskeidsredes van Jesus volgens Johannes 13:31 - 16:33

D.Litt. et Phil. (Biblical Studies)Please refer to full text to view abstrac