title: From frozen continent to tourism hotspot? Five decades of Antarctic tourism development and management, and a glimpse into the future

authors: Liggett, Daniela

subjects: Antarctic tourism

abstract: Representing the main commercial activity on the Antarctic continent, Antarctic tourism is increasingly thrust into the limelight as both benefactor and detractor to the environmental and political integrity of Antarctica. In view of its unprecedented growth, questions arise about the limitations of future tourism development in Antarctica. This paper assesses Antarctic tourism development over the last five decades and evaluates its current and future status from the viewpoints of Antarctic tourism stakeholders. This assessment is informed by interviews with Antarctic tourism stakeholders and a Delphi study undertaken in 2007. The authors found that Antarctic tourism stakeholders are concerned about the increasing scale and diversification of Antarctic tourism and generally subscribe to a conservation imperative when expressing their hopes for the future use of Antarctica and the development of Antarctic tourism. In conclusion, the rapid development of Antarctic tourism requires structural, institutional and legislative changes if Antarctic tourism regulation is to remain successful.

text: From frozen continent to tourism hotspot? Five decades of Antarctic tourism development and management, and a glimpse into the future Representing the main commercial activity on the Antarctic continent, Antarctic tourism is increasingly thrust into the limelight as both benefactor and detractor to the environmental and political integrity of Antarctica. In view of its unprecedented growth, questions arise about the limitations of future tourism development in Antarctica. This paper assesses Antarctic tourism development over the last five decades and evaluates its current and future status from the viewpoints of Antarctic tourism stakeholders. This assessment is informed by interviews with Antarctic tourism stakeholders and a Delphi study undertaken in 2007. The authors found that Antarctic tourism stakeholders are concerned about the increasing scale and diversification of Antarctic tourism and generally subscribe to a conservation imperative when expressing their hopes for the future use of Antarctica and the development of Antarctic tourism. In conclusion, the rapid development of Antarctic tourism requires structural, institutional and legislative changes if Antarctic tourism regulation is to remain successful.

year: 2011-04

title: The Effect of Powder Characteristics and Processing Conditions on the Microstructure and Mechanical Properties of Titanium Alloys Made by Powder Forging

authors: Jia, Mingtu

subjects: Titanium

abstract: Powder compact forging was used to produce Ti and Ti-6Al-4V rocker arms using pre-alloyed and blended elemental powders. Green powder compacts with high relative density were manufactured by warm compaction. Due to the characteristics of raw powders, interlocking and cold welding are the main mechanisms for HDH powder compaction, while warm welding is the main mechanism for GA powder compaction. During induction heating of the powder compact, it was found that necks formed extensively in as-sintered HDH Ti powder compact, leading to an average elongation to fracture of 7.5%, whereas necks did not form so extensively in as-sintered HDH Ti-6Al-4V and GA Ti-6Al-4V powder compacts, which make them brittle due to their low relative density.

As a rapid consolidation process, the densification rate was enhanced by powder compact forging due to pore collapsing caused by material flow driven by a large amount of localized plastic deformation. The degree of powder consolidation of powder compact forging using HDH Ti, HDH and GA Ti-6Al-4V powders were studied by characterising their porosity distributions, microstructure, mechanical properties and fracture behaviour. Due to the positive effect of shear deformation on the powder consolidation of powder compact forging, the powder compact in the centre of forged parts were consolidated completely with full density and had better mechanical properties than those from ingot metallurgy.

The effects of heat treatments on microstructure and mechanical properties of as-forged HDH Ti part, HDH and GA Ti-6Al-4V parts were investigated, and the ductility of forged HDH Ti part was improved significantly by annealing treatment. Recrystallization annealing was regarded as one of the best heat treatments to achieve the high ductility of as-forged HDH and GA Ti-6Al-4V parts, which can open the applications of forged HDH Ti-6Al-4V part with high oxygen content (~0.5%). The mechanical properties of forged HDH and GA Ti-6Al-4V parts after solution and aging treatment and recrystallization annealing were much better than those from both the ones from reported pre-alloyed approaches and wrought parts, which were caused by the enhancement of powder consolidation during recrystallization process.

Blended elemental approach and mechanical alloying method were applied to produce Ti-6Al-4V rocker arm by powder compact forging at 1350 oC. The effect of holding time at forging temperature on the samples produced by forging the compact of HDH Ti/Al-V master alloy powder mixture was studied, and it was found that a holding time of 5-10 minutes at forging temperature is required to get the as-forged part with good mechanical properties and homogeneous microstructure of free undissolved master alloy powders. Also, in order to reduce the holding time for achieving composition homogeneity, the powder mixture of Ti and Al-V master alloy powders was milled to produce Ti/Al-40wt%V composite powder. With such composite powder, the master alloy layers/particles were dissolved rapidly into Ti matrix, but the oxygen pick up during milling and powder passivation make the mechanical properties of the forged samples inferior to those of the parts made by powder compact forging of the powder mixture or pre-alloyed powder.

text: The Effect of Powder Characteristics and Processing Conditions on the Microstructure and Mechanical Properties of Titanium Alloys Made by Powder Forging Powder compact forging was used to produce Ti and Ti-6Al-4V rocker arms using pre-alloyed and blended elemental powders. Green powder compacts with high relative density were manufactured by warm compaction. Due to the characteristics of raw powders, interlocking and cold welding are the main mechanisms for HDH powder compaction, while warm welding is the main mechanism for GA powder compaction. During induction heating of the powder compact, it was found that necks formed extensively in as-sintered HDH Ti powder compact, leading to an average elongation to fracture of 7.5%, whereas necks did not form so extensively in as-sintered HDH Ti-6Al-4V and GA Ti-6Al-4V powder compacts, which make them brittle due to their low relative density.

As a rapid consolidation process, the densification rate was enhanced by powder compact forging due to pore collapsing caused by material flow driven by a large amount of localized plastic deformation. The degree of powder consolidation of powder compact forging using HDH Ti, HDH and GA Ti-6Al-4V powders were studied by characterising their porosity distributions, microstructure, mechanical properties and fracture behaviour. Due to the positive effect of shear deformation on the powder consolidation of powder compact forging, the powder compact in the centre of forged parts were consolidated completely with full density and had better mechanical properties than those from ingot metallurgy.

The effects of heat treatments on microstructure and mechanical properties of as-forged HDH Ti part, HDH and GA Ti-6Al-4V parts were investigated, and the ductility of forged HDH Ti part was improved significantly by annealing treatment. Recrystallization annealing was regarded as one of the best heat treatments to achieve the high ductility of as-forged HDH and GA Ti-6Al-4V parts, which can open the applications of forged HDH Ti-6Al-4V part with high oxygen content (~0.5%). The mechanical properties of forged HDH and GA Ti-6Al-4V parts after solution and aging treatment and recrystallization annealing were much better than those from both the ones from reported pre-alloyed approaches and wrought parts, which were caused by the enhancement of powder consolidation during recrystallization process.

Blended elemental approach and mechanical alloying method were applied to produce Ti-6Al-4V rocker arm by powder compact forging at 1350 oC. The effect of holding time at forging temperature on the samples produced by forging the compact of HDH Ti/Al-V master alloy powder mixture was studied, and it was found that a holding time of 5-10 minutes at forging temperature is required to get the as-forged part with good mechanical properties and homogeneous microstructure of free undissolved master alloy powders. Also, in order to reduce the holding time for achieving composition homogeneity, the powder mixture of Ti and Al-V master alloy powders was milled to produce Ti/Al-40wt%V composite powder. With such composite powder, the master alloy layers/particles were dissolved rapidly into Ti matrix, but the oxygen pick up during milling and powder passivation make the mechanical properties of the forged samples inferior to those of the parts made by powder compact forging of the powder mixture or pre-alloyed powder.

year: 2013

title: He tangi mai i te puehu: He whakatewhatewha i te mahi whakamāori me te reo ā-tuhi a ngā tūpuna

authors: Apiata, Hāwea

subjects: Māori spirituality

abstract: Kei te pūtahi o tēnei tuhinga whakapae ko te whakatewhatewha i te whakapapa o te whakaaro Māori (Māori intellectual history) mā ēnei pātai e rua: He aha ā te Māori i tuhituhi ai i te tōmuatanga o te rautau rua tekau? Ā, he pēhea tāna wetewete i ngā huatau whakawairua nō waho i te ao Māori? 

Ina koa, ko tā te tuhinga whakapae nei he whakaaranga, he whakaatu hoki i ētahi huarahi e toru hei rangahau i ngā whakapapa o te whakaaro taketake: ko te ketuketu rua mahara (archival research); ko te tātari ariā (conceptual analysis); me te reo e whakamahia ana kia wetewete i te kaupapa. Mā te mahi ketuketu rua mahara e āhei ai ki te wānanga i ngā whakaputanga a Wiremu Takana, he kaituhi, he kaiwhakamāori nō Ngāti Kahungunu. Ka whakaputaina tāna tuhinga tuatahi i te tau 1915. Ā, e rua anō i whakaputaina e ia i te tau whai muri mai i 1916. Ko ēnei tuhinga āna e whakatewhatewha ana i te whakamāoritanga o te rongopai me te āheinga o ngā pūrākau Māori kia whakamārama i ngā whakaakoranga Moromona. Kāore anō kia āta tātaritia, kia āta rangahaua āna pukapuka e tētahi atu o mua. Ko te huarahi rangahau tuarua ko te tātari i te whakamāoritanga o ētahi ariā whakawairua e kitea ana i roto i ngā karaipiture o te Hāhi o Ihu Karaiti o te Hunga Tapu o ngā Rā o Muri nei. E toru ngā ariā kua tīpakongia hei tirotiro, arā, ko heaven, hell me baptism. Ā, hei whakawhānui atu i te titiro ki tēnei kaupapa, ka huritaongia ngā hua o te tuhinga reo Māori, arā, ka matapakina ngā take kia tuhituhi i te mahi rangahau i roto i te reo Māori.

I te mutunga iho, mā te āta wānanga i ngā whakaputanga reo Māori a te Hāhi o Ihu Karaiti (LDS) e whakawhānuitia ai tō tātou māramatanga ki te hītori o te mahi whakaputa pukapuka i roto i te Hāhi, te mahi punenga a te Māori, te whakareretanga o ngā tuhituhinga reo Māori, me te hītori o te Hāhi o Ihu Karaiti i Aotearoa nei.

text: He tangi mai i te puehu: He whakatewhatewha i te mahi whakamāori me te reo ā-tuhi a ngā tūpuna Kei te pūtahi o tēnei tuhinga whakapae ko te whakatewhatewha i te whakapapa o te whakaaro Māori (Māori intellectual history) mā ēnei pātai e rua: He aha ā te Māori i tuhituhi ai i te tōmuatanga o te rautau rua tekau? Ā, he pēhea tāna wetewete i ngā huatau whakawairua nō waho i te ao Māori? 

Ina koa, ko tā te tuhinga whakapae nei he whakaaranga, he whakaatu hoki i ētahi huarahi e toru hei rangahau i ngā whakapapa o te whakaaro taketake: ko te ketuketu rua mahara (archival research); ko te tātari ariā (conceptual analysis); me te reo e whakamahia ana kia wetewete i te kaupapa. Mā te mahi ketuketu rua mahara e āhei ai ki te wānanga i ngā whakaputanga a Wiremu Takana, he kaituhi, he kaiwhakamāori nō Ngāti Kahungunu. Ka whakaputaina tāna tuhinga tuatahi i te tau 1915. Ā, e rua anō i whakaputaina e ia i te tau whai muri mai i 1916. Ko ēnei tuhinga āna e whakatewhatewha ana i te whakamāoritanga o te rongopai me te āheinga o ngā pūrākau Māori kia whakamārama i ngā whakaakoranga Moromona. Kāore anō kia āta tātaritia, kia āta rangahaua āna pukapuka e tētahi atu o mua. Ko te huarahi rangahau tuarua ko te tātari i te whakamāoritanga o ētahi ariā whakawairua e kitea ana i roto i ngā karaipiture o te Hāhi o Ihu Karaiti o te Hunga Tapu o ngā Rā o Muri nei. E toru ngā ariā kua tīpakongia hei tirotiro, arā, ko heaven, hell me baptism. Ā, hei whakawhānui atu i te titiro ki tēnei kaupapa, ka huritaongia ngā hua o te tuhinga reo Māori, arā, ka matapakina ngā take kia tuhituhi i te mahi rangahau i roto i te reo Māori.

I te mutunga iho, mā te āta wānanga i ngā whakaputanga reo Māori a te Hāhi o Ihu Karaiti (LDS) e whakawhānuitia ai tō tātou māramatanga ki te hītori o te mahi whakaputa pukapuka i roto i te Hāhi, te mahi punenga a te Māori, te whakareretanga o ngā tuhituhinga reo Māori, me te hītori o te Hāhi o Ihu Karaiti i Aotearoa nei.

year: 2021