title: The chronology of occupation at Teouma, Vanuatu: Use of a modified chronometric hygiene protocol and Bayesian modeling to evaluate midden remains

authors: Petchey, Fiona

subjects: Teouma

abstract: A number of radiocarbon dates, both published and unpublished have been obtained from archaeological deposits across the Teouma site on the island of Efate in Vanuatu. These are on a range of materials from the midden and associated cemetery including charcoal (13) and shell (7) as well as a number of less commonly dated 14C sample types including bone from 2 terrestrial giant tortoises (?Meiolania damelipi), 8 pigs (Sus scrofa) and 2 chickens (Gallus gallus). Thirty-six human bone collagen dates and 5 Conus sp. shell ring artifacts from the cemetery context have been discussed in detail elsewhere (Petchey et al., 2014). In this paper, we evaluate the radiocarbon data according to observed contextual associations and established understandings of 14C offsets, and collate all available information in a Bayesian framework to establish the age and duration of the settlement at Teouma. This analysis provides a maximum age range for the Lapita deposits of between 3000 and 2560 cal BP and a most likely start date of 2920–2870 cal BP and end date of 2870–2750 cal BP (68.2% prob.). This is slightly younger age for the deposits than previously reported, but is in keeping with evaluation of the burials themselves, the majority of which are dated to between 2940 and 2720 cal BP. This age range indicates that the site was in use at the same time as colonization events in Tonga (2850–2830 cal BP) and Fiji (3020–2860 cal BP), and supports the hypothesis that Vanuatu was at the center of a region-wide interaction sphere for several generations after initial settlement.

text: The chronology of occupation at Teouma, Vanuatu: Use of a modified chronometric hygiene protocol and Bayesian modeling to evaluate midden remains A number of radiocarbon dates, both published and unpublished have been obtained from archaeological deposits across the Teouma site on the island of Efate in Vanuatu. These are on a range of materials from the midden and associated cemetery including charcoal (13) and shell (7) as well as a number of less commonly dated 14C sample types including bone from 2 terrestrial giant tortoises (?Meiolania damelipi), 8 pigs (Sus scrofa) and 2 chickens (Gallus gallus). Thirty-six human bone collagen dates and 5 Conus sp. shell ring artifacts from the cemetery context have been discussed in detail elsewhere (Petchey et al., 2014). In this paper, we evaluate the radiocarbon data according to observed contextual associations and established understandings of 14C offsets, and collate all available information in a Bayesian framework to establish the age and duration of the settlement at Teouma. This analysis provides a maximum age range for the Lapita deposits of between 3000 and 2560 cal BP and a most likely start date of 2920–2870 cal BP and end date of 2870–2750 cal BP (68.2% prob.). This is slightly younger age for the deposits than previously reported, but is in keeping with evaluation of the burials themselves, the majority of which are dated to between 2940 and 2720 cal BP. This age range indicates that the site was in use at the same time as colonization events in Tonga (2850–2830 cal BP) and Fiji (3020–2860 cal BP), and supports the hypothesis that Vanuatu was at the center of a region-wide interaction sphere for several generations after initial settlement.

year: 2015-12

title: Construction and demolition waste as low-cost materials for the removal of heavy metal ions from wastewater

authors: Ranaweera, Kavitha H.

abstract: Water pollution due to heavy metal ion contaminations and management of construction and demolition waste (CDW) are two major environmental issues faced by the world today. Exposure to heavy metal ions can cause serious health problems, and therefore, treatment of heavy metal contaminated water/wastewater to protect the environment and people is essential. The management of CDW has become a serious problem due to the large amounts generated each year. Only a small percentage of this waste is recycled, while the majority is disposed of in landfills with space running out to accommodate these materials. Repurposing CDW as low-cost materials for heavy metal ion treatment is thus a promising strategy as this not only contributes to CDW management but also to heavy metal ion remediation.
The research described in this thesis investigated the applicability of five CDW materials (particle board wood dust (PBW), medium density fiberboard (MDF) fines, biochar derived from particle board offcuts (PBB), Gibraltar board fines (GBF), and demolished concrete (DC)) for the treatment of Cd(II), Cu(II), Pb(II), and Zn(II) ions. The selected CDW materials were characterized by performing FTIR, SEM-EDX, TGA, XRD, and surface area analysis to identify the composition and nature of these materials. The effect of different parameters (metal ion type, contact time, initial metal ion concentration, pH, and material dosage) on the heavy metal ion removal process was investigated in single metal ion solution systems utilizing a batch method. All studied materials exhibited high removal efficiency for Pb(II) ions compared to the other metal ions except DC, which showed high removal efficiency towards Cu(II) ions. Therefore, Pb(II) was selected to evaluate the effect of other parameters for PBW, MDF fines, PBB, and GBF, whilst Cu(II) was used for DC. The results indicated that the main heavy metal ion removal mechanism of PBW, MDF fines, and PBB was adsorption, while DC and GBF utilized precipitation. The effect of competitive metal ions on the heavy metal ion removal
process was investigated using a Cd(II)-Cu(II) multi-metal ion system for DC and a Cd(II)-Pb(II) multi-metal ion system for other materials using a batch method. The results indicated that the presence of Cd(II) ions reduced Pb(II) ion removal efficiency for PBW, MDF fines, and PBB and Cu(II) ion removal efficiency of DC. However, Pb(II) ion removal by GBF was not affected. Experiments were carried out to investigate whether the selected CDW materials leached out any toxic substances. The results indicated that PBW and MDF fines increased TOC concentrations, while GBF increased calcium and sulfate concentrations in treated water.
Adsorption isothermal, kinetic, and adsorbent regeneration studies were carried out for CDW materials which utilized adsorption for the heavy metal ion removal. Adsorption isothermal studies were performed for single metal ion systems, and the Freundlich isotherm model fitted better with the experimental data of all studied materials. Adsorption kinetics of both single and multi-metal ion systems were evaluated, and the experimental data fitted better with either pseudo-second-order or Elovich kinetic models for all studied systems. The adsorbent regeneration studies were performed using 0.1 M HCl as a regeneration agent for three adsorption-desorption cycles for both metal ion systems. High % desorption values were obtained during the first cycle, however, the adsorption capacity was reduced in the subsequent cycles for all studied adsorption systems.
Column analyses were conducted for GBF and PBB for both single (Pb(II)) and multi-metal ion systems (Cd(II)-Pb(II)). High % removal values were obtained for Pb(II) ions in both metal ion systems for both materials. The experimental data of the PBB was fitted to column adsorption models as PBB utilized adsorption for heavy metal ion removal, and the Yan model fitted well with the experimental data of both metal ion systems. The results indicate that CDW materials have potential for heavy metal ion treatment. Further research is required to investigate the applicability of these materials in real-world applications.

text: Construction and demolition waste as low-cost materials for the removal of heavy metal ions from wastewater Water pollution due to heavy metal ion contaminations and management of construction and demolition waste (CDW) are two major environmental issues faced by the world today. Exposure to heavy metal ions can cause serious health problems, and therefore, treatment of heavy metal contaminated water/wastewater to protect the environment and people is essential. The management of CDW has become a serious problem due to the large amounts generated each year. Only a small percentage of this waste is recycled, while the majority is disposed of in landfills with space running out to accommodate these materials. Repurposing CDW as low-cost materials for heavy metal ion treatment is thus a promising strategy as this not only contributes to CDW management but also to heavy metal ion remediation.
The research described in this thesis investigated the applicability of five CDW materials (particle board wood dust (PBW), medium density fiberboard (MDF) fines, biochar derived from particle board offcuts (PBB), Gibraltar board fines (GBF), and demolished concrete (DC)) for the treatment of Cd(II), Cu(II), Pb(II), and Zn(II) ions. The selected CDW materials were characterized by performing FTIR, SEM-EDX, TGA, XRD, and surface area analysis to identify the composition and nature of these materials. The effect of different parameters (metal ion type, contact time, initial metal ion concentration, pH, and material dosage) on the heavy metal ion removal process was investigated in single metal ion solution systems utilizing a batch method. All studied materials exhibited high removal efficiency for Pb(II) ions compared to the other metal ions except DC, which showed high removal efficiency towards Cu(II) ions. Therefore, Pb(II) was selected to evaluate the effect of other parameters for PBW, MDF fines, PBB, and GBF, whilst Cu(II) was used for DC. The results indicated that the main heavy metal ion removal mechanism of PBW, MDF fines, and PBB was adsorption, while DC and GBF utilized precipitation. The effect of competitive metal ions on the heavy metal ion removal
process was investigated using a Cd(II)-Cu(II) multi-metal ion system for DC and a Cd(II)-Pb(II) multi-metal ion system for other materials using a batch method. The results indicated that the presence of Cd(II) ions reduced Pb(II) ion removal efficiency for PBW, MDF fines, and PBB and Cu(II) ion removal efficiency of DC. However, Pb(II) ion removal by GBF was not affected. Experiments were carried out to investigate whether the selected CDW materials leached out any toxic substances. The results indicated that PBW and MDF fines increased TOC concentrations, while GBF increased calcium and sulfate concentrations in treated water.
Adsorption isothermal, kinetic, and adsorbent regeneration studies were carried out for CDW materials which utilized adsorption for the heavy metal ion removal. Adsorption isothermal studies were performed for single metal ion systems, and the Freundlich isotherm model fitted better with the experimental data of all studied materials. Adsorption kinetics of both single and multi-metal ion systems were evaluated, and the experimental data fitted better with either pseudo-second-order or Elovich kinetic models for all studied systems. The adsorbent regeneration studies were performed using 0.1 M HCl as a regeneration agent for three adsorption-desorption cycles for both metal ion systems. High % desorption values were obtained during the first cycle, however, the adsorption capacity was reduced in the subsequent cycles for all studied adsorption systems.
Column analyses were conducted for GBF and PBB for both single (Pb(II)) and multi-metal ion systems (Cd(II)-Pb(II)). High % removal values were obtained for Pb(II) ions in both metal ion systems for both materials. The experimental data of the PBB was fitted to column adsorption models as PBB utilized adsorption for heavy metal ion removal, and the Yan model fitted well with the experimental data of both metal ion systems. The results indicate that CDW materials have potential for heavy metal ion treatment. Further research is required to investigate the applicability of these materials in real-world applications.

year: 2024

title: Brown bodies, white coats: Postcolonialism, Māori women, and science

authors: McKinley, Elizabeth

abstract: This project investigates the historical construction of 'Māori woman' and the constitution of the subjectivities of Maori women scientists today. The central question that is raised by the thesis is 'Do discourses of 'race' and gender found in Enlightenment science at the time of Aotearoa New Zealand's colonization continue to affect the contemporary subjectivity of Māori women scientists, and if so, how?' I have used literary historical techniques and feminist narrative interviews to collect the research data. Deconstruction, and its technique of 'double reading', has been applied through out the thesis to both the literary historical texts (imperial archives) and the transcripts of the interviews. I have argued that a poststructuralist view of the 'splitting the subject' to enable multiple positions must be read alongside the postcolonial view of a contemporary 'colonized subject' of an already 'split' subjectivity. 
This thesis is divided into two sections. Section A investigates Māori women as the objects of science. I argue that in Aotearoa New Zealand journeys of discovery and colonization were also scientific journeys that brought 'Māori woman' under the intellectual control of the emerging 'scientific' academy. At the same time, drawing on the 'imperial archives', I show that stereotypical signifiers are incorporated within scientific discourses and shape the fictions that these texts represent. In Section B I draw on open-ended interviews with 16 Māori women scientists who were asked to discuss their identity in relation to their schooling and workplaces. I explore the conditions by which the subject 'Māori women scientist' emerges and how the Maori women experience these conditions in relation to how they see themselves. I conclude by arguing that the identity of 'Māori woman scientist' appears to be 'impossible fiction' due to the fragmented nature of the sign - 'Māori, 'woman' and 'scientist' - that can be 'traced' to the historical construction of the signs.

text: Brown bodies, white coats: Postcolonialism, Māori women, and science This project investigates the historical construction of 'Māori woman' and the constitution of the subjectivities of Maori women scientists today. The central question that is raised by the thesis is 'Do discourses of 'race' and gender found in Enlightenment science at the time of Aotearoa New Zealand's colonization continue to affect the contemporary subjectivity of Māori women scientists, and if so, how?' I have used literary historical techniques and feminist narrative interviews to collect the research data. Deconstruction, and its technique of 'double reading', has been applied through out the thesis to both the literary historical texts (imperial archives) and the transcripts of the interviews. I have argued that a poststructuralist view of the 'splitting the subject' to enable multiple positions must be read alongside the postcolonial view of a contemporary 'colonized subject' of an already 'split' subjectivity. 
This thesis is divided into two sections. Section A investigates Māori women as the objects of science. I argue that in Aotearoa New Zealand journeys of discovery and colonization were also scientific journeys that brought 'Māori woman' under the intellectual control of the emerging 'scientific' academy. At the same time, drawing on the 'imperial archives', I show that stereotypical signifiers are incorporated within scientific discourses and shape the fictions that these texts represent. In Section B I draw on open-ended interviews with 16 Māori women scientists who were asked to discuss their identity in relation to their schooling and workplaces. I explore the conditions by which the subject 'Māori women scientist' emerges and how the Maori women experience these conditions in relation to how they see themselves. I conclude by arguing that the identity of 'Māori woman scientist' appears to be 'impossible fiction' due to the fragmented nature of the sign - 'Māori, 'woman' and 'scientist' - that can be 'traced' to the historical construction of the signs.

year: 2003