title: Evidence of global-scale aeolian dispersal and endemism in isolated geothermal microbial communities of Antarctica

authors: Herbold, Craig W.

subjects: Science & Technology

abstract: New evidence in aerobiology challenges the assumption that geographical isolation is an effective barrier to microbial transport. However, given the uncertainty with which aerobiological organisms are recruited into existing communities, the ultimate impact of microbial dispersal is difficult to assess. To evaluate the ecological significance of global-scale microbial dispersal, molecular genetic approaches were used to examine microbial communities inhabiting fumarolic soils on Mt. Erebus, the southernmost geothermal site on Earth. There, hot, fumarolic soils provide an effective environmental filter to test the viability of organisms that have been distributed via aeolian transport over geological time. We find that cosmopolitan thermophiles dominate the surface, whereas endemic Archaea and members of poorly understood Bacterial candidate divisions dominate the immediate subsurface. These results imply that aeolian processes readily disperse viable organisms globally, where they are incorporated into pre-existing complex communities of endemic and cosmopolitan taxa.

text: Evidence of global-scale aeolian dispersal and endemism in isolated geothermal microbial communities of Antarctica New evidence in aerobiology challenges the assumption that geographical isolation is an effective barrier to microbial transport. However, given the uncertainty with which aerobiological organisms are recruited into existing communities, the ultimate impact of microbial dispersal is difficult to assess. To evaluate the ecological significance of global-scale microbial dispersal, molecular genetic approaches were used to examine microbial communities inhabiting fumarolic soils on Mt. Erebus, the southernmost geothermal site on Earth. There, hot, fumarolic soils provide an effective environmental filter to test the viability of organisms that have been distributed via aeolian transport over geological time. We find that cosmopolitan thermophiles dominate the surface, whereas endemic Archaea and members of poorly understood Bacterial candidate divisions dominate the immediate subsurface. These results imply that aeolian processes readily disperse viable organisms globally, where they are incorporated into pre-existing complex communities of endemic and cosmopolitan taxa.

year: 2014-05-01

title: Vacuum Steam Desuperheating and Condensation: An Experimental Investigation

authors: Lokhande, Akash

abstract: Steam condensation plays an essential role in supplying and removing heat in many industrial applications, including the energy sector. It therefore is a phenomena of significance that requires deep understanding. This thesis presents effective vacuum steam condensation on the shell-side of vertical shell and tube condenser (VSTC) accompanying steam desuperheating. It describes a fundamental study of heat transfer in VSTC with considerations of several factors; explicitly degree of superheat related with each vacuum steam pressure, temperature waviness in desuperheating section, and steam condensation in absence of non-condensable gas (NCG). Experiments performed on the VSTC are: 
Steam desuperheating and condensation in the shell-side VSTC at a variety of vacuum steam pressures and respective steam flowrates, vacuum steam desuperheating and condensation in the shell-side of VSTC at reduced steam flowrates, and vacuum steam desuperheating and condensation at tube wall temperatures up to steam saturation temperature (T₂ ≥ Tsat) to analyse dry heat transfer in the desuperheating section. To examine the stated aim, test facility was built in the laboratory of the University of Waikato.
By generating desuperheating and condensation models for each test pressure, this investigation proves that vacuum steam condensation best occurs without involvement of superheat. About 60% of the VSTC occupied with desuperheating, and the heat transfer involved in desuperheating is minor approximately 1 kW, whereas, the condensation section of VSTC has heat transfer about 10 kW. By reducing the steam flowrate, 10% reduction in the desuperheating section and 20% to 50% reduction in the Reynolds number was observed. After raising the tube wall temperature up to the steam saturation temperature, a smooth temperature profile across the desuperheating the section was seen with significant sensible heat transfer. Obstruction linked with superheated steam condensation in the dairy industrial leads to poor heat transfer area utilization by the desuperheating section and therefore, reduction of the evaporator rating or oversizing of the heat exchangers to attain appropriate duty.

text: Vacuum Steam Desuperheating and Condensation: An Experimental Investigation Steam condensation plays an essential role in supplying and removing heat in many industrial applications, including the energy sector. It therefore is a phenomena of significance that requires deep understanding. This thesis presents effective vacuum steam condensation on the shell-side of vertical shell and tube condenser (VSTC) accompanying steam desuperheating. It describes a fundamental study of heat transfer in VSTC with considerations of several factors; explicitly degree of superheat related with each vacuum steam pressure, temperature waviness in desuperheating section, and steam condensation in absence of non-condensable gas (NCG). Experiments performed on the VSTC are: 
Steam desuperheating and condensation in the shell-side VSTC at a variety of vacuum steam pressures and respective steam flowrates, vacuum steam desuperheating and condensation in the shell-side of VSTC at reduced steam flowrates, and vacuum steam desuperheating and condensation at tube wall temperatures up to steam saturation temperature (T₂ ≥ Tsat) to analyse dry heat transfer in the desuperheating section. To examine the stated aim, test facility was built in the laboratory of the University of Waikato.
By generating desuperheating and condensation models for each test pressure, this investigation proves that vacuum steam condensation best occurs without involvement of superheat. About 60% of the VSTC occupied with desuperheating, and the heat transfer involved in desuperheating is minor approximately 1 kW, whereas, the condensation section of VSTC has heat transfer about 10 kW. By reducing the steam flowrate, 10% reduction in the desuperheating section and 20% to 50% reduction in the Reynolds number was observed. After raising the tube wall temperature up to the steam saturation temperature, a smooth temperature profile across the desuperheating the section was seen with significant sensible heat transfer. Obstruction linked with superheated steam condensation in the dairy industrial leads to poor heat transfer area utilization by the desuperheating section and therefore, reduction of the evaporator rating or oversizing of the heat exchangers to attain appropriate duty.

year: 2015

title: Kei hea te tangi a te Tūī? An exploration of Kaitiakitanga in urban spaces

authors: Walker, Erana

subjects: Kaitiakitanga

abstract: Indigenous people’s connection to the natural world differs from place to place. In Aotearoa, New Zealand, Māori connection to nature is often articulated through the concept of kaitiakitanga whilst intertwining concepts of whakapapa, wairua, mana, mauri and place. Kaitiakitanga captures the relationships, narratives and practices that Māori utilise to protect kin of the natural environment as well as Māori communities in general. Over recent decades increase use of kaitiakitanga with respect to resource management has been linked to ideas of guardianship and stewardship, departing from important aspects such as place, whakapapa, intergenerational knowledge, spirituality and resource use. Calls to recognise the diverse ways kaitiakitanga has and can be expressed by Māori have echoed through academic literature, encouraging wider perspectives and application of the concept to develop. This has reinvigorated not only the need for natures protection but also the recognition of cultural knowledges and concepts in practicing kaitiakitanga. 
 
As with most indigenous people, Māori have experienced urbanisation that has spanned across generations of whānau and hapū. Urbanisation has the ability to challenge health outcomes, cultural practices and cultural knowledge, and more importantly, relationships to nature. Growing urbanisation and environmental degradation continue to challenge people and our relationships to nature. There is now a need to understand how urban spaces may also challenge the concepts that encourage connections to nature like kaitiakitanga. Moreover, there is a need to understand if such cultural concepts can become challenged when transient Māori reside in another tribal group’s boundaries. This research provides a deeper analysis of kaitiakitanga by understanding its application within the urban space of Kirikiriroa/Hamilton. From data gathered through a survey, focus groups and interviews, this research project illustrates the experiences of Māori in the urban space who know and practice kaitiakitanga in Kirikiriroa/Hamilton. More importantly, this study posits the integral role of place connection and mana in supporting and shaping kaitiakitanga practices in urban spaces.

The data from participants shows a clear narrative of kaitiakitanga from both local and transient Māori exist and indicates that kaitiakitanga is practiced in accordance with their location and whakapapa to their area of residence. The study has found that kaitiakitanga practices have adapted to suit urban spaces allowing for both transient and local knowledges to exist within the urban space. The key findings of this research show many influences that impact kaitiakitanga practices like the recognition of childhood spaces and experiences, ideas of kinship, cultural knowledges, spirituality, mobility, nature as well as modernisation. Through exploring participants use and knowledge of kaitiakitanga, this research provides a new lens in which to view this concept and bring to the fore, the various experiences and ways that participants connect to place, people, culture and most importantly, nature.

text: Kei hea te tangi a te Tūī? An exploration of Kaitiakitanga in urban spaces Indigenous people’s connection to the natural world differs from place to place. In Aotearoa, New Zealand, Māori connection to nature is often articulated through the concept of kaitiakitanga whilst intertwining concepts of whakapapa, wairua, mana, mauri and place. Kaitiakitanga captures the relationships, narratives and practices that Māori utilise to protect kin of the natural environment as well as Māori communities in general. Over recent decades increase use of kaitiakitanga with respect to resource management has been linked to ideas of guardianship and stewardship, departing from important aspects such as place, whakapapa, intergenerational knowledge, spirituality and resource use. Calls to recognise the diverse ways kaitiakitanga has and can be expressed by Māori have echoed through academic literature, encouraging wider perspectives and application of the concept to develop. This has reinvigorated not only the need for natures protection but also the recognition of cultural knowledges and concepts in practicing kaitiakitanga. 
 
As with most indigenous people, Māori have experienced urbanisation that has spanned across generations of whānau and hapū. Urbanisation has the ability to challenge health outcomes, cultural practices and cultural knowledge, and more importantly, relationships to nature. Growing urbanisation and environmental degradation continue to challenge people and our relationships to nature. There is now a need to understand how urban spaces may also challenge the concepts that encourage connections to nature like kaitiakitanga. Moreover, there is a need to understand if such cultural concepts can become challenged when transient Māori reside in another tribal group’s boundaries. This research provides a deeper analysis of kaitiakitanga by understanding its application within the urban space of Kirikiriroa/Hamilton. From data gathered through a survey, focus groups and interviews, this research project illustrates the experiences of Māori in the urban space who know and practice kaitiakitanga in Kirikiriroa/Hamilton. More importantly, this study posits the integral role of place connection and mana in supporting and shaping kaitiakitanga practices in urban spaces.

The data from participants shows a clear narrative of kaitiakitanga from both local and transient Māori exist and indicates that kaitiakitanga is practiced in accordance with their location and whakapapa to their area of residence. The study has found that kaitiakitanga practices have adapted to suit urban spaces allowing for both transient and local knowledges to exist within the urban space. The key findings of this research show many influences that impact kaitiakitanga practices like the recognition of childhood spaces and experiences, ideas of kinship, cultural knowledges, spirituality, mobility, nature as well as modernisation. Through exploring participants use and knowledge of kaitiakitanga, this research provides a new lens in which to view this concept and bring to the fore, the various experiences and ways that participants connect to place, people, culture and most importantly, nature.

year: 2021