Showing items 38201 - 38220 of 63376

Organizational Studies: IOS 222E

  • Authors: Ngcebetsha, Tembeka , Akpan, Wilson
  • Date: 2008-11
  • Language: English
  • Type: Examination paper
  • Identifier: vital:17970 , http://hdl.handle.net/10353/d1010542
  • Description: Organizational Studies: IOS 222E, examination November 2008.
  • Full Text: false
  • Date Issued: 2008-11

Organophosphate flame retardant’s signatures in the Buffalo River Estuary and their removal using modified cyclodextrins

  • Authors: Bika, Sinozuko Hope
  • Date: 2022-03
  • Subjects: Water purification chemicals industry , Organic water pollutants , Rivers
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/27500 , vital:67363
  • Description: The increasing scarcity of fresh and clean water in many places around the world is a major concern. Water is a basic need that must be availed to humans, plants and animals at any given time. It is a requirement that each human on earth should get between 20-50 L of fresh, clean and pure water a day. It is very difficult to keep up with this need due to drastic increase in global pollution by emerging contaminants. The increase is due to human activities, modern way of life, industrialization and improper disposal of materials that contain these OPFRs. Organophosphate flame retardants OPFRs are the organic pollutants considered in this study. OPFRs are semi volatile compounds SVOCs that are used in many industries as flame retardants and additives. They were developed because of environmental and health concerns of previously used brominated and chlorinated flame retardants FRs. They show acute toxicity and exhibit adverse effects such as neurotoxicity, they are also carcinogenic to humans and animals. In recent years, some researchers have started investigating the occurrence and distribution of OPFRs in South African rivers. The aim of this study was to identify signatures of OPFRs in the aquatic environment of Buffalo River Estuary, and soil from a nearby dumpsite: and to develop a method for their removal using modified cyclodextrins. In this study, the concentration of OPFRs were investigated in sediments and soil samples collected from Buffalo River Estuary. This estuary is located close to a major port in East London city in the Eastern Cape Province, South Africa. Collection of samples was done across two seasons i.e. winter and spring. OPFRs in sediment and soil samples in this study were extracted using ultrasonic extraction method. Solid-phase extraction SPE was employed for the cleanup of the extracts, in order to reduce potential matrix interference and also for sample purification. The congeners of interest in this study were Tris 2-Choroethyl phosphate TCEP and Tris 1,3-Dicloro-2-propyl phosphate (TDCP). Samples were air dried immediately on arrival at the laboratory after being stored in an ice chest at 4 ℃ and further processed for further analysis.The concentrations of OPFRs were determined using GC-μECD (gas chromatograph coupled with micro electron capture detector) from soil and sediments in that area and they were found high in winter compared to spring owing to high level of discharge of industrial and domestic waste into the aquatic system and also the nearby dumpsite. The total concentrationof OPFRs Ʃ 2OPFRs for sediments and soil for both seasons was 39935±7619 μg/g and 10376±601 μg/g, respectively. The dominant congener in the Buffalo River Estuary was TCEP. The ecological risk assessment was estimated for the study area, and TCEP moderate risk while TDCP presented low risk. From this study, it could be inferred that the Buffalo River Estuary and the nearby dumpsite in East London are polluted by emerging pollutants i.e. OPFRs. Hence, strict control measures should be put in place to monitor all activities contributing to such magnitude of pollution in the estuary, which is of great economic value to the country. Furthermore in this study, an insoluble and hydrophilic polymer EDTA-Cysteine-β-Cyclodextrin was prepared and synthesized for the remediation of OPFRs in soil and sediments. This newly developed method was tested for the removal of TDCP an OPFR congener and it was successful with an average removal rate of 77.49 percent. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
  • Full Text:
  • Date Issued: 2022-03

Organosilicon compounds as fluorescent chemosensors for fluoride anion recognition

  • Authors: Gai, Lizhi , Mack, John , Lu, Hua , Nyokong, Tebello , Li, Zhifang , Kobayashi, Nagao , Shen, Zhen
  • Date: 2015
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/241424 , vital:50938 , xlink:href="https://doi.org/10.1016/j.ccr.2014.10.009"
  • Description: Recent developments in organosilicon-based chemosensors for F− recognition are reviewed. The design strategies for improving the photophysical properties of organosilicon-based chemosensors are elaborated, with an emphasis placed on their utility for biological applications. The photophysical properties and electronic structures are analyzed in depth with reference made to the results of molecular modeling calculation and possible future research directions are assessed.
  • Full Text:
  • Date Issued: 2015

Organosilicon compounds as fluorescent chemosensors for fluoride anion recognition

  • Authors: Gai, Lizhi , Mack, John , Lu, Hua , Nyokong, Tebello , Li, Zhifang , Kobayashi, Nagao , Shen, Zhen
  • Language: English
  • Type: Article
  • Identifier: vital:7241 , http://hdl.handle.net/10962/d1020245
  • Description: Recent developments in organosilicon-based chemosensors for F− recognition are reviewed. The design strategies for improving the photophysical properties of organosilicon-based chemosensors are elaborated, with an emphasis placed on their utility for biological applications. The photophysical properties and electronic structures are analyzed in depth with reference made to the results of molecular modeling calculation and possible future research directions are assessed. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2014.10.009
  • Full Text: false

Oriel Hall House Committee 1969, Gail Martin in front row

  • Date: 1969
  • Subjects: Rhodes University -- History -- Photographs Rhodes University -- Students -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/17260 , vital:22231 , PIC/M 6810
  • Description: This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1969

Oriel Hall leaver's dinner high table, 1969

  • Date: 1969
  • Subjects: Rhodes University -- History -- Photographs Rhodes University -- Students -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/17307 , vital:22234 , PIC/M 6811
  • Description: This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1969

Oriel Hall leaver's dinner high table, 1969

  • Date: 1969
  • Subjects: Rhodes University -- History -- Photographs Rhodes University -- Students -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/17285 , vital:22233 , PIC/M 6812
  • Description: This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1969

Oriel House

  • Subjects: Rhodes University College -- Buildings -- Photographs
  • Type: Image
  • Identifier: vital:14185 , http://hdl.handle.net/10962/d1018109 , MS 10 542 , CD 55
  • Description: Oriel House was the first women's residence and was completed in 1915. It was built to Baker and Kendall's plans.
  • Full Text: false

Oriel House float during Rag week, possibly Gail Martin and other young women on the float, 1966

Oriel House float during Rag week, with Anne Boland sitting on top, 1966

Oriel House photograph with Gail Martin in the front row, 1968

  • Date: 1968
  • Subjects: Rhodes University -- History -- Photographs Rhodes University -- Students -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/17358 , vital:22240 , PIC/M 6815
  • Description: This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1968

Oriel House photograph with Gail Martin in the front row, 1969

  • Date: 1969
  • Subjects: Rhodes University -- History -- Photographs Rhodes University -- Students -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/17367 , vital:22241 , PIC/M 6816
  • Description: This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
  • Full Text: false
  • Date Issued: 1969

Oriel House setting out for Rag procession, 1969

Orient School - Message

  • Authors: Badat, Saleem
  • Date: 2008-11-03
  • Language: English
  • Type: Text
  • Identifier: vital:7697 , http://hdl.handle.net/10962/d1015842
  • Full Text:
  • Date Issued: 2008-11-03

Orientation Course for New Lecturers Programme at Rhodes University, 1982

  • Authors: Henderson, Derek Scott
  • Date: 1982
  • Language: English
  • Type: text
  • Identifier: vital:7568 , http://hdl.handle.net/10962/d1018445
  • Full Text:
  • Date Issued: 1982

Orientation Week : welcome message from the vice-chancellor Dr Saleem Badat, 2007

  • Authors: Badat, Saleem
  • Date: 2007
  • Subjects: Rhodes University
  • Language: English
  • Type: text
  • Identifier: vital:7650 , http://hdl.handle.net/10962/d1015778
  • Full Text:
  • Date Issued: 2007

Origin and metallogenic significance of alkali metasomatism in the Paleoproterozoic Mapedi Formation, Kalahari Manganese Field, South Africa

  • Authors: Ikwen, Emmanuella Biye
  • Date: 2023-10-13
  • Subjects: Uncatalogued
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424632 , vital:72170
  • Description: The occurrence of alkali-rich metasomatic assemblages has been widely reported in various regions of the Kalahari Manganese Field (KMF). This alkali metasomatism has been characterized by the secondary introduction of elements such as K, Na, Li, Ba, P, V, Zn, As, amongst others. This study further explores the possibility of widespread alkali metasomatism in the KMF by reporting on and examining the occurrence of sugilite and other alkali-rich minerals at the contact between the Transvaal and Olifantshoek Supergroups in the Hotazel Mine area of the north-eastern KMF. The lithologies observed at the contact show macroscopic (such as cross cutting veins) and microscopic evidence of hydrothermal alteration. Using analytical methods such as X-ray diffraction, X-ray fluorescence, and scanning electron microscopy, results showed that in the north-eastern region of the KMF, the metasomatism observed at the Transvaal-Olifantshoek contact is mainly characterized by enrichment in sodium, and the occurrence of sodium minerals, predominantly in the form of aegirine. The aegirine forms exclusively in the quartzites of the Mapedi Formation along with minerals such as sugilite, baryte, banalsite, amongst others. Albite also occurs within the quartzites, but also within the Mapedi red shales. The secondary nature of these minerals is established by geochemical comparisons with pristine, as well as alkali-metasomatized samples of the same formation which were obtained from other parts of the KMF and Postmasburg. These comparisons showed that the Mapedi quartzites in the north-eastern KMF have undergone extensive oxidation compared to samples of the same formation which were obtained from Postmasburg. The north-eastern quartzites have an average hematite abundance of 17 wt.% compared to Postmasburg quartzite which have an average of 7 wt.% hematite. Furthermore, some quartzite samples contained up to 40 wt.% in hematite content. The comparisons also showed that Mapedi quartzites from the north-eastern KMF are substantially more sodium enriched compared to Mapedi quartzites from the Postmasburg region, which on average have sodium oxide content below detection limits. Geochemical comparisons were made between pristine Hotazel Formation samples from north-western KMF (Gloria Mine) and samples obtained from the north-eastern KMF (Hotazel Mine). Results showed that the samples obtained from the top of the Hotazel Formation (in the Hotazel mine area) are likely altered hematite lutite and not Banded Iron Formation, evident by their substantially high manganese oxide content (over 30 wt.% in some cases). When compared to pristine samples, the lutite also showed evidence of hydrothermal alteration, predominantly in the form of phosphate and barium enrichment, evident by the occurrence of baryte and apatite. The alkali metasomatism occurring at the contact between the Transvaal and Olifantshoek Supergroups was shown to be predominantly characterized by enrichment in Na, K, Li, Al, Ba, Sr, and P. The metasomatism characterized in this study was also proposed to possibly post-date an earlier metasomatic event which was characterized by leaching of silica and extensive oxidation of the rocks observed at the Transvaal-Olifantshoek contact in the north-eastern KMF. The occurrence of the alkali-rich minerals outlined above geochemically parallels other alkali-rich metasomatic assemblages reported in other parts of the KMF, as well as in the Postmasburg Manganese Field. Thus, based on the consistent occurrence of secondary, alkali-rich mineral assemblages across the KMF, characterized by the common occurrence of aegirine along with minerals such as sugilite and albite, there is evidence of a large-scale alkali metasomatism in the KMF. This study also explores the possible role that the Transvaal-Olifantshoek unconformity might have played in acting as a major conduit for fluid propagation because the observed mineral assemblages occur right at the contact between the Hotazel and Mapedi Formations. The occurrence of the alkali-rich minerals predominantly around the unconformity, as well as the relative depletion of phosphates in stratigraphically deeper parts of the Hotazel suggest that the fluid metasomatism was aided by the Olifantshoek-Transvaal unconformity surface. This study concludes that there is evidence for a strong link between the metasomatism occurring at the contact between the Hotazel and Mapedi formations (in the north-eastern KMF) and what is observed in the broader KMF region. , Thesis (MSc) -- Faculty of Science, Geology, 2023
  • Full Text:
  • Date Issued: 2023-10-13

Original jazz music

  • Authors: Unknown
  • Subjects: McGregor, Chris--1936-1990 , Dollar Brand , Jazz at the Playhouse
  • Language: English
  • Type: Article
  • Identifier: vital:13737 , http://hdl.handle.net/10962/d1012751
  • Description: Photocopied article from the South African newspaper The Star about Chris McGregor rehearsing for the concert Jazz at the Playhouse. There is a picture with this article of Chris McGregor (left) talking to 4 other persons.
  • Full Text:

Orire eira

Orire eira

  • Disclaimer
  • Privacy
  • Copyright
  • Contact