Vice Chancellor New staff welcome address, 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Type: text
- Identifier: vital:7646 , http://hdl.handle.net/10962/d1015774
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Type: text
- Identifier: vital:7646 , http://hdl.handle.net/10962/d1015774
- Full Text:
- Date Issued: 2007
Rhodes University 2007 Graduation Ceremonies Address
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7628 , http://hdl.handle.net/10962/d1012595
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7628 , http://hdl.handle.net/10962/d1012595
- Full Text:
- Date Issued: 2007
Rhodes University : into 2007 and beyond
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7655 , http://hdl.handle.net/10962/d1015783
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7655 , http://hdl.handle.net/10962/d1015783
- Full Text:
- Date Issued: 2007
Preface to Rhodes University Research Report, 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7654 , http://hdl.handle.net/10962/d1015782
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7654 , http://hdl.handle.net/10962/d1015782
- Full Text:
- Date Issued: 2007
A preliminary perspective on the Office of the Vice-Chancellor and appeals related to exclusions and admissions
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7644 , http://hdl.handle.net/10962/d1015772
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7644 , http://hdl.handle.net/10962/d1015772
- Full Text:
- Date Issued: 2007
Rhodes University Orientation Week : Welcome address of the vice-chancellor of Rhodes University, Dr Saleem Badat, 5 February 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7651 , http://hdl.handle.net/10962/d1015779
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7651 , http://hdl.handle.net/10962/d1015779
- Full Text:
- Date Issued: 2007
Address at the opening of the OutRhodes Pride Week, 21 August 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7652 , http://hdl.handle.net/10962/d1015780
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7652 , http://hdl.handle.net/10962/d1015780
- Full Text:
- Date Issued: 2007
Vice Chancellor's message to the Toronto Old Rhodian Reunion
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7648 , http://hdl.handle.net/10962/d1015776
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7648 , http://hdl.handle.net/10962/d1015776
- Full Text:
- Date Issued: 2007
Message to the New Zealand Old Rhodian Reunion
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7647 , http://hdl.handle.net/10962/d1015775
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7647 , http://hdl.handle.net/10962/d1015775
- Full Text:
- Date Issued: 2007
Vice Chancellor's Oppidan Newspaper message, 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7649 , http://hdl.handle.net/10962/d1015777
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7649 , http://hdl.handle.net/10962/d1015777
- Full Text:
- Date Issued: 2007
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
- 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
SAIAB extension opening : lunch for the Deputy-Minister of Science and Technology
- Authors: Badat, Saleem
- Date: 2007
- Subjects: South African Institute of Aquatic Biodiversity (SAIAB)
- Language: English
- Type: text
- Identifier: vital:7657 , http://hdl.handle.net/10962/d1015785
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: South African Institute of Aquatic Biodiversity (SAIAB)
- Language: English
- Type: text
- Identifier: vital:7657 , http://hdl.handle.net/10962/d1015785
- Full Text:
- Date Issued: 2007
The use of thermal modelling in improving rural subsistence aquaculture
- Authors: Bailey, Dylan Francis
- Date: 2007
- Subjects: Sustainable aquaculture -- South Africa , Aquaculture industry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10715 , http://hdl.handle.net/10948/473 , Sustainable aquaculture -- South Africa , Aquaculture industry -- South Africa
- Description: There has been a long history of attempts to promote subsistence rural aquaculture within South Africa. Many of these attempts have failed due to inadequate support from government and support agencies. There has been a recent revived interest in promoting rural aquaculture development. Presented in this project are six scenarios demonstrating the potential application of thermal modelling techniques to improving subsistence rural aquaculture. These scenarios were based on a model validated against a real life system, and run with environmental data for the year 2005. Bovine manure, grass thatch, cereal straw and Typha spp. water reeds were tested for thermal performance. These results were then applied to the scenarios. The open and kraal enclosed pond scenarios yielded the widest deviation in temperatures throughout the year, with an average temperature of 3.8oC and 6.0oC above ambient and a temperature range of 10.6oC and 12.4oC for the year respectively. Eliminating solar radiation and reducing wind speed resulted in an average difference of 1.5oC below ambient and a temperature range of 7.5oC for the year. When completely enclosed in a well-sealed traditional Xhosa style hut, the pond had an average difference of 5.6oC below outside ambient temperature, with a range of 7.8oC for the year. A passive solar heating scenario added to the sealed hut scenario, which when run continuously maintained an average difference of 34.7oC above outside ambient temperatures, with a range of 56oC for the year. When a hypothetical 25oC temperature control was included in the model, the system maintained an average of 7.1oC above ambient outside temperatures, with a temperature range of 0.8oC throughout the year. The wider range of temperatures made available through the use of thermal modelling approaches provides a more diverse range of species available for subsistence rural aquaculture at any site, significantly improving its potential.
- Full Text:
- Date Issued: 2007
- Authors: Bailey, Dylan Francis
- Date: 2007
- Subjects: Sustainable aquaculture -- South Africa , Aquaculture industry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10715 , http://hdl.handle.net/10948/473 , Sustainable aquaculture -- South Africa , Aquaculture industry -- South Africa
- Description: There has been a long history of attempts to promote subsistence rural aquaculture within South Africa. Many of these attempts have failed due to inadequate support from government and support agencies. There has been a recent revived interest in promoting rural aquaculture development. Presented in this project are six scenarios demonstrating the potential application of thermal modelling techniques to improving subsistence rural aquaculture. These scenarios were based on a model validated against a real life system, and run with environmental data for the year 2005. Bovine manure, grass thatch, cereal straw and Typha spp. water reeds were tested for thermal performance. These results were then applied to the scenarios. The open and kraal enclosed pond scenarios yielded the widest deviation in temperatures throughout the year, with an average temperature of 3.8oC and 6.0oC above ambient and a temperature range of 10.6oC and 12.4oC for the year respectively. Eliminating solar radiation and reducing wind speed resulted in an average difference of 1.5oC below ambient and a temperature range of 7.5oC for the year. When completely enclosed in a well-sealed traditional Xhosa style hut, the pond had an average difference of 5.6oC below outside ambient temperature, with a range of 7.8oC for the year. A passive solar heating scenario added to the sealed hut scenario, which when run continuously maintained an average difference of 34.7oC above outside ambient temperatures, with a range of 56oC for the year. When a hypothetical 25oC temperature control was included in the model, the system maintained an average of 7.1oC above ambient outside temperatures, with a temperature range of 0.8oC throughout the year. The wider range of temperatures made available through the use of thermal modelling approaches provides a more diverse range of species available for subsistence rural aquaculture at any site, significantly improving its potential.
- Full Text:
- Date Issued: 2007
The battle for Cassinga : conflicting narratives and contested meanings
- Authors: Baines, Gary F
- Date: 2007
- Language: English
- Type: Conference paper
- Identifier: vital:6156 , http://hdl.handle.net/10962/d1007073
- Description: Nearly thirty years ago the name Cassinga (or Kassinga) came to the attention of the world. At the time the name evoked a range of responses, from outrage to grief to the celebration of military bravado. It still does so. And Cassinga will continue to elicit such responses as long as participants and witnesses are alive and the events remain part of living memory. Obviously perpetrators and survivors remember the events of 4 May 1978 differently. Memory is, after all, selective. The recollections of participants and witnesses are framed by personal and political agendas. This much is abundantly clear from the conflicting accounts of Cassinga that appear in the media and literature, especially the exchanges that take place between parties with a stake in how the events are remembered. Thus a report headlined “Battle of Cassinga still rages” published on the 29th anniversary suggested that the events are still shrouded in controversy and that there is no agreement about what transpired in the southern Angolan town. The title of this paper reflects my concern with the battle for rather than of Cassinga. The choice of preposition is intended to signify the ongoing contestation over the meaning of Cassinga.
- Full Text:
- Date Issued: 2007
- Authors: Baines, Gary F
- Date: 2007
- Language: English
- Type: Conference paper
- Identifier: vital:6156 , http://hdl.handle.net/10962/d1007073
- Description: Nearly thirty years ago the name Cassinga (or Kassinga) came to the attention of the world. At the time the name evoked a range of responses, from outrage to grief to the celebration of military bravado. It still does so. And Cassinga will continue to elicit such responses as long as participants and witnesses are alive and the events remain part of living memory. Obviously perpetrators and survivors remember the events of 4 May 1978 differently. Memory is, after all, selective. The recollections of participants and witnesses are framed by personal and political agendas. This much is abundantly clear from the conflicting accounts of Cassinga that appear in the media and literature, especially the exchanges that take place between parties with a stake in how the events are remembered. Thus a report headlined “Battle of Cassinga still rages” published on the 29th anniversary suggested that the events are still shrouded in controversy and that there is no agreement about what transpired in the southern Angolan town. The title of this paper reflects my concern with the battle for rather than of Cassinga. The choice of preposition is intended to signify the ongoing contestation over the meaning of Cassinga.
- Full Text:
- Date Issued: 2007
Characterisation of InAs-based epilayers by FTIR spectroscopy
- Authors: Baisitse, Tshepiso Revonia
- Date: 2007
- Subjects: Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10534 , http://hdl.handle.net/10948/474 , Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Description: This study focuses on the characterization of InAs and InAs1-xSbx epitaxial layers by infrared reflectance and transmittance spectroscopy and Hall measurements. Reflectance measurements were performed in order to obtain the dielectric parameters and to extract from these information about the electrical properties (mobility and carrier concentration) of this important III-V material system. The transmittance measurements were used to determine the bandgap of InAsSb. Infrared reflectivity and transmittance measurements were performed in the wavelength range 200 – 2000 cm-1 on InAs and InAsSb layers grown on three types of substrates. A classical two oscillator model that takes into account both the free carriers and the lattice, was used to analyse the reflectance data using the BMDP® computer curve fitting software. The dielectric parameters and the electrical properties (carrier concentration and mobility) were extracted from the simulations. Due to the low free carrier concentration in the epitaxial structures, the plasma resonance frequency (ωp) values obtained from the simulations of reflectance spectra measured above 200 cm-1, were in the order of 20-30 cm-1. These low values were confirmed by direct measurements of ωp in reflectance spectra obtained in the range 15-200 cm-1. The simulated carrier concentration and mobility values determined optically were compared to the values determined by Hall measurements at room temperature and previously reported values by other researchers. The simulated values obtained were in reasonable agreement with the Hall values. The simulated and measured carrier concentrations obtained for InAs layers were significantly higher than the intrinsic carrier concentration for InAs at room temperature, indicating notable concentrations of donors resulting from the growth process.
- Full Text:
- Date Issued: 2007
- Authors: Baisitse, Tshepiso Revonia
- Date: 2007
- Subjects: Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10534 , http://hdl.handle.net/10948/474 , Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Description: This study focuses on the characterization of InAs and InAs1-xSbx epitaxial layers by infrared reflectance and transmittance spectroscopy and Hall measurements. Reflectance measurements were performed in order to obtain the dielectric parameters and to extract from these information about the electrical properties (mobility and carrier concentration) of this important III-V material system. The transmittance measurements were used to determine the bandgap of InAsSb. Infrared reflectivity and transmittance measurements were performed in the wavelength range 200 – 2000 cm-1 on InAs and InAsSb layers grown on three types of substrates. A classical two oscillator model that takes into account both the free carriers and the lattice, was used to analyse the reflectance data using the BMDP® computer curve fitting software. The dielectric parameters and the electrical properties (carrier concentration and mobility) were extracted from the simulations. Due to the low free carrier concentration in the epitaxial structures, the plasma resonance frequency (ωp) values obtained from the simulations of reflectance spectra measured above 200 cm-1, were in the order of 20-30 cm-1. These low values were confirmed by direct measurements of ωp in reflectance spectra obtained in the range 15-200 cm-1. The simulated carrier concentration and mobility values determined optically were compared to the values determined by Hall measurements at room temperature and previously reported values by other researchers. The simulated values obtained were in reasonable agreement with the Hall values. The simulated and measured carrier concentrations obtained for InAs layers were significantly higher than the intrinsic carrier concentration for InAs at room temperature, indicating notable concentrations of donors resulting from the growth process.
- Full Text:
- Date Issued: 2007
Purchasing determinants of food insercurity conditions amongst shoppers in Klipplaat
- Ballantine, Nicole Marguerite
- Authors: Ballantine, Nicole Marguerite
- Date: 2007
- Subjects: Food -- Safety measures , Food supply -- South Africa -- Klipplaat , Households -- South Africa -- Klipplaat , Quality of life -- South Africa -- Klipplaat
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9404 , http://hdl.handle.net/10948/835 , Food -- Safety measures , Food supply -- South Africa -- Klipplaat , Households -- South Africa -- Klipplaat , Quality of life -- South Africa -- Klipplaat
- Description: This study sought to investigate the purchasing determinants of food insecurity conditions in Klipplaat, in the Eastern Cape. The study comprised a pilot study and main study (n=459) making use of an adapted version of the Household Food Insecurity Access Scale. It was found that food insecurity conditions in Klipplaat were high, with most households experiencing food insecurity conditions between three and ten times per month. Income level was found to have a significant effect on food insecurity conditions in Klipplaat. The availability of efficient transport and refrigeration was also found to significantly influence the experience of food insecurity conditions.
- Full Text:
- Date Issued: 2007
- Authors: Ballantine, Nicole Marguerite
- Date: 2007
- Subjects: Food -- Safety measures , Food supply -- South Africa -- Klipplaat , Households -- South Africa -- Klipplaat , Quality of life -- South Africa -- Klipplaat
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9404 , http://hdl.handle.net/10948/835 , Food -- Safety measures , Food supply -- South Africa -- Klipplaat , Households -- South Africa -- Klipplaat , Quality of life -- South Africa -- Klipplaat
- Description: This study sought to investigate the purchasing determinants of food insecurity conditions in Klipplaat, in the Eastern Cape. The study comprised a pilot study and main study (n=459) making use of an adapted version of the Household Food Insecurity Access Scale. It was found that food insecurity conditions in Klipplaat were high, with most households experiencing food insecurity conditions between three and ten times per month. Income level was found to have a significant effect on food insecurity conditions in Klipplaat. The availability of efficient transport and refrigeration was also found to significantly influence the experience of food insecurity conditions.
- Full Text:
- Date Issued: 2007
Freshwater invertebrate fauna of the Tristan da Cunha islands (South Atlantic Ocean), with new records for Inaccessible and Nightingale Islands
- Authors: Barber-James, Helen M
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7001 , http://hdl.handle.net/10962/d1008360
- Description: As part of a multidisciplinary floristic-faunistic study, a three week survey of the invertebrate fauna of Inaccessible Island (South Atlantic Ocean) was carried out in October / November 1989. In addition, one day of collecting was done on Nightingale Island. This paper deals only with the fauna associated with freshwater ecosystems from these islands, some of which are usually associated with marine or brackish conditions. On Inaccessible Island, five distinct types of freshwater body were identified - pH neutral streams, acidic streams (pH 5), an open pool of standing water (pH 6), areas of acidic bog, and seepages down rock faces. The survey, the most comprehensive for Inaccessible Island to date, has resulted in the discovery of 19 aquatic invertebrate species previously unrecorded on Inaccessible Island, two new to Nightingale Island, and 14 of which are new to the Tristan da Cunha archipelago. Many of the species are known from other parts of the world, indicating a low degree of endemicity within the freshwater invertebrate community. Recolonisation from the source populations, preventing an isolated gene pool, may account for the low endemicity. Several of the species have a degree of salinity tolerance, enabling them to withstand transportation across tracts of ocean, and others have marine origins.
- Full Text:
- Date Issued: 2007
- Authors: Barber-James, Helen M
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7001 , http://hdl.handle.net/10962/d1008360
- Description: As part of a multidisciplinary floristic-faunistic study, a three week survey of the invertebrate fauna of Inaccessible Island (South Atlantic Ocean) was carried out in October / November 1989. In addition, one day of collecting was done on Nightingale Island. This paper deals only with the fauna associated with freshwater ecosystems from these islands, some of which are usually associated with marine or brackish conditions. On Inaccessible Island, five distinct types of freshwater body were identified - pH neutral streams, acidic streams (pH 5), an open pool of standing water (pH 6), areas of acidic bog, and seepages down rock faces. The survey, the most comprehensive for Inaccessible Island to date, has resulted in the discovery of 19 aquatic invertebrate species previously unrecorded on Inaccessible Island, two new to Nightingale Island, and 14 of which are new to the Tristan da Cunha archipelago. Many of the species are known from other parts of the world, indicating a low degree of endemicity within the freshwater invertebrate community. Recolonisation from the source populations, preventing an isolated gene pool, may account for the low endemicity. Several of the species have a degree of salinity tolerance, enabling them to withstand transportation across tracts of ocean, and others have marine origins.
- Full Text:
- Date Issued: 2007
Global diversity of mayflies (Ephemeroptera, Insecta) in freshwater
- Barber-James, Helen M, Gattolliat, Jean-Luc, Sartori, Michel, Hubbard, Michael D
- Authors: Barber-James, Helen M , Gattolliat, Jean-Luc , Sartori, Michel , Hubbard, Michael D
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7002 , http://hdl.handle.net/10962/d1008361
- Description: The extant global Ephemeroptera fauna is represented by over 3,000 described species in 42 families and more than 400 genera. The highest generic diversity occurs in the Neotropics, with a correspondingly high species diversity, while the Palaearctic has the lowest generic diversity, but a high species diversity. Such distribution patterns may relate to how long evolutionary processes have been carrying on in isolation in a bioregion. Over an extended period, there may be extinction of species, but evolution of more genera. Dramatic extinction events such as the K-T mass extinction have affected current mayfly diversity and distribution. Climatic history plays an important role in the rate of speciation in an area, with regions which have been climatically stable over long periods having fewer species per genus, when compared to regions subjected to climatic stresses, such as glaciation. A total of 13 families are endemic to specific bioregions, with eight among them being monospecific. Most of these have restricted distributions which may be the result of them being the relict of a previously more diverse, but presently almost completely extinct family, or may be the consequence of vicariance events, resulting from evolution due to long-term isolation.
- Full Text:
- Date Issued: 2007
- Authors: Barber-James, Helen M , Gattolliat, Jean-Luc , Sartori, Michel , Hubbard, Michael D
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7002 , http://hdl.handle.net/10962/d1008361
- Description: The extant global Ephemeroptera fauna is represented by over 3,000 described species in 42 families and more than 400 genera. The highest generic diversity occurs in the Neotropics, with a correspondingly high species diversity, while the Palaearctic has the lowest generic diversity, but a high species diversity. Such distribution patterns may relate to how long evolutionary processes have been carrying on in isolation in a bioregion. Over an extended period, there may be extinction of species, but evolution of more genera. Dramatic extinction events such as the K-T mass extinction have affected current mayfly diversity and distribution. Climatic history plays an important role in the rate of speciation in an area, with regions which have been climatically stable over long periods having fewer species per genus, when compared to regions subjected to climatic stresses, such as glaciation. A total of 13 families are endemic to specific bioregions, with eight among them being monospecific. Most of these have restricted distributions which may be the result of them being the relict of a previously more diverse, but presently almost completely extinct family, or may be the consequence of vicariance events, resulting from evolution due to long-term isolation.
- Full Text:
- Date Issued: 2007
Freshwater invertebrate fauna of the Tristan da Cunha islands (South Atlantic Ocean), with new records for Inaccessible and Nightingale Islands
- Barber-James, Helen Margaret
- Authors: Barber-James, Helen Margaret
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6940 , http://hdl.handle.net/10962/d1011964
- Description: As part of a multidisciplinary floristic-faunistic study, a three week survey of the invertebrate fauna of Inaccessible Island (South Atlantic Ocean) was carried out in October / November 1989. In addition, one day of collecting was done on Nightingale Island. This paper deals only with the fauna associated with freshwater ecosystems from these islands, some of which are usually associated with marine or brackish conditions. On Inaccessible Island, five distinct types of freshwater body were identified - pH neutral streams, acidic streams (pH 5), an open pool of standing water (pH 6), areas of acidic bog, and seepages down rock faces. The survey, the most comprehensive for Inaccessible Island to date, has resulted in the discovery of 19 aquatic invertebrate species previously unrecorded on Inaccessible Island, two new to Nightingale Island, and 14 of which are new to the Tristan da Cunha archipelago. Many of the species are known from other parts of the world, indicating a low degree of endemicity within the freshwater invertebrate community. Recolonisation from the source populations, preventing an isolated gene pool, may account for the low endemicity. Several of the species have a degree of salinity tolerance, enabling them to withstand transportation across tracts of ocean, and others have marine origins.
- Full Text:
- Date Issued: 2007
- Authors: Barber-James, Helen Margaret
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6940 , http://hdl.handle.net/10962/d1011964
- Description: As part of a multidisciplinary floristic-faunistic study, a three week survey of the invertebrate fauna of Inaccessible Island (South Atlantic Ocean) was carried out in October / November 1989. In addition, one day of collecting was done on Nightingale Island. This paper deals only with the fauna associated with freshwater ecosystems from these islands, some of which are usually associated with marine or brackish conditions. On Inaccessible Island, five distinct types of freshwater body were identified - pH neutral streams, acidic streams (pH 5), an open pool of standing water (pH 6), areas of acidic bog, and seepages down rock faces. The survey, the most comprehensive for Inaccessible Island to date, has resulted in the discovery of 19 aquatic invertebrate species previously unrecorded on Inaccessible Island, two new to Nightingale Island, and 14 of which are new to the Tristan da Cunha archipelago. Many of the species are known from other parts of the world, indicating a low degree of endemicity within the freshwater invertebrate community. Recolonisation from the source populations, preventing an isolated gene pool, may account for the low endemicity. Several of the species have a degree of salinity tolerance, enabling them to withstand transportation across tracts of ocean, and others have marine origins.
- Full Text:
- Date Issued: 2007
Bioremediation of trace organic compounds found in precious metals refineries wastewaters: A review of potential options
- Barbosa, V L, Tandlich, Roman, Burgess, Jo E
- Authors: Barbosa, V L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6469 , http://hdl.handle.net/10962/d1005798 , http://dx.doi.org/10.1016/j.chemosphere.2007.01.018 , http://www.sciencedirect.com/science/article/pii/S0045653507001026
- Description: Platinum group metal (PGM) refining processes produce large quantities of wastewater, which is contaminated with the compounds that make up the solvents/extractants mixtures used in the process. These compounds often include solvesso, β-hydroxyxime, amines, amides and methyl isobutyl ketone. A process to clean up PGM refinery wastewaters so that they could be re-used in the refining process would greatly contribute to continual water storage problems and to cost reduction for the industry. Based on the concept that organic compounds that are produced biologically can be destroyed biologically, the use of biological processes for the treatment of organic compounds in other types of waste stream has been favoured in recent years, owing to their low cost and environmental acceptability. This review examines the available biotechnologies and their effectiveness for treating compounds likely to be contained in precious metal extraction process wastewaters. The processes examined include: biofilters, fluidized bed reactors, trickle-bed bioreactors, bioscrubbers, two-phase partitioning bioreactors, membrane bioreactors and activated sludge. Although all processes examined showed adequate to excellent removal of organic compounds from various gaseous and fewer liquid waste streams, there was a variation in their effectiveness. Variations in performance of laboratory-scale biological processes are probably due to the inherent change in the microbial population composition due to selection pressure, environmental conditions and the time allowed for adaptation to the organic compounds. However, if these factors are disregarded, it can be established that activated sludge and membrane bioreactors are the most promising processes for use in the treatment of PGM refinery wastewaters.
- Full Text:
- Date Issued: 2007
- Authors: Barbosa, V L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6469 , http://hdl.handle.net/10962/d1005798 , http://dx.doi.org/10.1016/j.chemosphere.2007.01.018 , http://www.sciencedirect.com/science/article/pii/S0045653507001026
- Description: Platinum group metal (PGM) refining processes produce large quantities of wastewater, which is contaminated with the compounds that make up the solvents/extractants mixtures used in the process. These compounds often include solvesso, β-hydroxyxime, amines, amides and methyl isobutyl ketone. A process to clean up PGM refinery wastewaters so that they could be re-used in the refining process would greatly contribute to continual water storage problems and to cost reduction for the industry. Based on the concept that organic compounds that are produced biologically can be destroyed biologically, the use of biological processes for the treatment of organic compounds in other types of waste stream has been favoured in recent years, owing to their low cost and environmental acceptability. This review examines the available biotechnologies and their effectiveness for treating compounds likely to be contained in precious metal extraction process wastewaters. The processes examined include: biofilters, fluidized bed reactors, trickle-bed bioreactors, bioscrubbers, two-phase partitioning bioreactors, membrane bioreactors and activated sludge. Although all processes examined showed adequate to excellent removal of organic compounds from various gaseous and fewer liquid waste streams, there was a variation in their effectiveness. Variations in performance of laboratory-scale biological processes are probably due to the inherent change in the microbial population composition due to selection pressure, environmental conditions and the time allowed for adaptation to the organic compounds. However, if these factors are disregarded, it can be established that activated sludge and membrane bioreactors are the most promising processes for use in the treatment of PGM refinery wastewaters.
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- Date Issued: 2007