title: A Seabased wave energy device: An experimental investigation

authors: Zhu, Haofeng

subjects: wave energy converters

abstract: Ocean waves are a largely untapped treasure-house of renewable energy resource, and the potential renewable energy harvested from ocean waves is considerable around the world. Abundant research and development on this field have been conducted to accomplish the aims in different stages, and the technology has been undergoing all the time. However, despite tremendous energy potential, technologies of ocean wave, the wave energy converter (WEC), are still relatively immature compared to other renewable technologies.
This thesis presents basic motion character of a WEC device that the performance of one of WECs in relationship between power take off (PTO) part and buoy. The device is a simple 1:50 scaled model which referred to a point absorber buoy device like the device of the Seabased project that the buoy connected with PTO by a wire reacts the water surface to respond excited waves, and drives the PTO with a spring.
The tests were conducted in a small water tank. In order to investigate the relationship between buoy performance and PTO part, two different springs were used respectively in PTO, which one spring is stiff and the other one is softer, and model device experienced irregular and regular wave conditions. The softer spring case indicated that the buoy was sensitive to the passing waves but it was hard to provide a restoring force, so the period of one heave motion of buoy was relatively long, which was totally opposed to that of the stiffer spring case. Moreover, the natural frequency of model device was also calculated by mathematical model, and this theoretical value was less than that of experimental value from test.
This model device could be improved and perfected and subjected to small scaled water tank tests for offshore device to investigate the basic characters for motion with methods of mathematical model or simulation and experimental results.

text: A Seabased wave energy device: An experimental investigation Ocean waves are a largely untapped treasure-house of renewable energy resource, and the potential renewable energy harvested from ocean waves is considerable around the world. Abundant research and development on this field have been conducted to accomplish the aims in different stages, and the technology has been undergoing all the time. However, despite tremendous energy potential, technologies of ocean wave, the wave energy converter (WEC), are still relatively immature compared to other renewable technologies.
This thesis presents basic motion character of a WEC device that the performance of one of WECs in relationship between power take off (PTO) part and buoy. The device is a simple 1:50 scaled model which referred to a point absorber buoy device like the device of the Seabased project that the buoy connected with PTO by a wire reacts the water surface to respond excited waves, and drives the PTO with a spring.
The tests were conducted in a small water tank. In order to investigate the relationship between buoy performance and PTO part, two different springs were used respectively in PTO, which one spring is stiff and the other one is softer, and model device experienced irregular and regular wave conditions. The softer spring case indicated that the buoy was sensitive to the passing waves but it was hard to provide a restoring force, so the period of one heave motion of buoy was relatively long, which was totally opposed to that of the stiffer spring case. Moreover, the natural frequency of model device was also calculated by mathematical model, and this theoretical value was less than that of experimental value from test.
This model device could be improved and perfected and subjected to small scaled water tank tests for offshore device to investigate the basic characters for motion with methods of mathematical model or simulation and experimental results.

year: 2020

title: The microclimatology of Antarctic soils

authors: MacCulloch, Roger James Lee

subjects: Antarctica

abstract: An understanding of the microclimatology of the ice free areas in Antarctica is needed to better quantify the impacts of human activities on this fragile environment and to help monitor global climate change processes. This research was undertaken to characterise the surface and sub surface factors influencing Antarctic soil microclimates and quantify the sub surface thermal processes resulting from these conditions.
A measurement programme was developed and implemented at three contrasting sites within the Dry Valleys of the McMurdo Sound Region, Antarctica during the 1994-95 summer season, and samples were collected for further analysis in New Zealand. Climatic variables measured included the surface radiation and energy balance, soil and air temperature, and windspeed and direction. Important soil physical and thermal properties such as moisture content, bulk density, particle density, grainsize distribution, salinity, specific heat and thermal conductivity were also measured.
The sites investigated were located at Scott Base on Ross Island in the coastal climate zone, at the foot of Mount Brooke in the Coombs Hills which has a high mountainous climate, and in the Northwind Valley (Greenville Valley) in the Convoy Range which is climatically midway between the two. Apart from being climatically different, the soils examined at each site were also different. Basalt derived soil was examined at Scott Base, dolerite derived soil was studied at the Coombs Hills, and a sandy soil derived from sandstone was examined in the Northwind Valley. 
Similar amounts of shortwave radiation were recorded at each site under comparable conditions, although surface albedo varied significantly which determined the amount of radiation reflected. Consequently, the Scott Base site, which had the darkest surface and lowest albedo, had the greatest net radiation inputs, and the Northwind Valley site had the lowest due to its pale colour and high albedo.
Despite this, the Northwind Valley soil had the largest soil heat flux. The reason for this is not fully understood, but involves the soil temperature gradient which is the main determinant of the soil heat flux. The warmer climate at Scott Base resulted in generally warmer soil temperatures which produced an active layer greater than two times that seen at either of the other sites. Due to its relatively high moisture content, ice-cement was found at about 0.25 m which delineates the summer O°C isotherm, and indicates the permafrost is at a similar depth.
At the other two sites which were a lot colder, there was no permanent ice cement found due to their dry nature. The active layer was approximately 0.10 m deep at the Coombs Hills site, and was only 0.08 m at the Northwind Valley site. The permafrost at these sites would also be at about these depths. Soil temperatures, which were strongly negative, fluctuated by up to 5°C at a depth of about 0.20 m at these two sites.
Under snow cover, the soil heat flux at both the Scott Base and Coombs Hills sites became negative which means energy was being lost from the profile, and the penetration depth of diurnal temperature variations was reduced.
The main factors influencing the soil thermal regime are incoming solar radiation, air temperature, windspeed, and surface albedo. Soil properties including moisture content, thermal conductivity and heat capacity are less important in determining the variations observed.

text: The microclimatology of Antarctic soils An understanding of the microclimatology of the ice free areas in Antarctica is needed to better quantify the impacts of human activities on this fragile environment and to help monitor global climate change processes. This research was undertaken to characterise the surface and sub surface factors influencing Antarctic soil microclimates and quantify the sub surface thermal processes resulting from these conditions.
A measurement programme was developed and implemented at three contrasting sites within the Dry Valleys of the McMurdo Sound Region, Antarctica during the 1994-95 summer season, and samples were collected for further analysis in New Zealand. Climatic variables measured included the surface radiation and energy balance, soil and air temperature, and windspeed and direction. Important soil physical and thermal properties such as moisture content, bulk density, particle density, grainsize distribution, salinity, specific heat and thermal conductivity were also measured.
The sites investigated were located at Scott Base on Ross Island in the coastal climate zone, at the foot of Mount Brooke in the Coombs Hills which has a high mountainous climate, and in the Northwind Valley (Greenville Valley) in the Convoy Range which is climatically midway between the two. Apart from being climatically different, the soils examined at each site were also different. Basalt derived soil was examined at Scott Base, dolerite derived soil was studied at the Coombs Hills, and a sandy soil derived from sandstone was examined in the Northwind Valley. 
Similar amounts of shortwave radiation were recorded at each site under comparable conditions, although surface albedo varied significantly which determined the amount of radiation reflected. Consequently, the Scott Base site, which had the darkest surface and lowest albedo, had the greatest net radiation inputs, and the Northwind Valley site had the lowest due to its pale colour and high albedo.
Despite this, the Northwind Valley soil had the largest soil heat flux. The reason for this is not fully understood, but involves the soil temperature gradient which is the main determinant of the soil heat flux. The warmer climate at Scott Base resulted in generally warmer soil temperatures which produced an active layer greater than two times that seen at either of the other sites. Due to its relatively high moisture content, ice-cement was found at about 0.25 m which delineates the summer O°C isotherm, and indicates the permafrost is at a similar depth.
At the other two sites which were a lot colder, there was no permanent ice cement found due to their dry nature. The active layer was approximately 0.10 m deep at the Coombs Hills site, and was only 0.08 m at the Northwind Valley site. The permafrost at these sites would also be at about these depths. Soil temperatures, which were strongly negative, fluctuated by up to 5°C at a depth of about 0.20 m at these two sites.
Under snow cover, the soil heat flux at both the Scott Base and Coombs Hills sites became negative which means energy was being lost from the profile, and the penetration depth of diurnal temperature variations was reduced.
The main factors influencing the soil thermal regime are incoming solar radiation, air temperature, windspeed, and surface albedo. Soil properties including moisture content, thermal conductivity and heat capacity are less important in determining the variations observed.

year: 1996

title: E kore e ngaro, he takere waka nui: Te mātauranga whakatere waka me ōna take nunui

authors: Tuaupiki, Jackie Whetumarama

abstract: E kapi ana te hautoru o te ao i te Moana nui a Kiwa. I ngā tau manomano ka huri, ka puea ake i Āhia ki te tonga mā rāwhiti, he iwi māia, he iwi mātau ki te hanga me te whakatere i ō rātou waka. Ka tupu ngātahi hoki i a rātou tētehi mātauranga whakatere i tarawhitia e rātou ngā tōpito katoa o te Moana nui a Kiwa. Koinei ngā tāngata tuatahi, nāna i kau ngā ara terenga waka onamata. Nō ngā tau maha i muri iho, ka whanake tēnei mātauranga me tō rātou hangarau waka, ā, ka tīmata ngā terenga whakawhiti roa e tau haeretia ana ngā moutere o Poronīhia, tatū mai ki Aotearoa. Engari ia, i roto i te wā, i tino waikauere ngā mahi whakatere waka, ā, i ētehi moutere o Poronīhia, i wairuhi kau, he mahara noa i mau i te kōrero tuku iho. Ko tātou tērā, te iwi Māori.

Otirā, i roto i ngā tau e whā tekau ka pahemo atu rā, kua whakawhāiti mai tētehi ohu ki te whakahaumanu i ngā mahi whakatere waka me tōna mātauranga. He waka hourua kua hangaia i Poronīhia, i te ātārangi tawhito hei amo i ngā whakamanawatanga o ngā iwi me ngā kaupapa whakarauora i ēnei mahi tūpuna. Ka tika te oha ki te hunga hāpai kura i takere nui ai, i haumi tūporo ai ki te whakahaumanu i te mātauranga whakatere waka. Nō reira, o ngā mahi rangatira kua tutuki i te rāngai waka i Aotearoa i ngā tau tata nei, ko tā tēnei rangahau, he kohura i ētehi o ngā take nunui me ngā kaupapa whakahirahira e puta mai ana i mua i te aroaro o te mātauranga whakatere waka me ōna kaumoana i ēnei rangi, ki tā te Māori titiro. Waihoki, ko te pānga o aua take nunui ki te ahurea Māori. Koinei te matū o tēnei tuhinga kairangi. He pūtoi whakaaro, he whakaemieminga kōrero ki te whakatakoto i ngā huatau o ngā puhi kai moana Māori e tākawe ana i tēnei wānanga.

Mātua rā, e kore e tukua kia riro anō ngā mahi whakatere waka i te nenewhatanga o te rā, tau ki te rua. Kua whakatupuria e te wā he kura kaumoana Māori, māna ngā take matua o tēnei tuhinga roa e whakatutuki ki tua i te pae kai ao.

“E kore e ngaro, he takere waka nui”

text: E kore e ngaro, he takere waka nui: Te mātauranga whakatere waka me ōna take nunui E kapi ana te hautoru o te ao i te Moana nui a Kiwa. I ngā tau manomano ka huri, ka puea ake i Āhia ki te tonga mā rāwhiti, he iwi māia, he iwi mātau ki te hanga me te whakatere i ō rātou waka. Ka tupu ngātahi hoki i a rātou tētehi mātauranga whakatere i tarawhitia e rātou ngā tōpito katoa o te Moana nui a Kiwa. Koinei ngā tāngata tuatahi, nāna i kau ngā ara terenga waka onamata. Nō ngā tau maha i muri iho, ka whanake tēnei mātauranga me tō rātou hangarau waka, ā, ka tīmata ngā terenga whakawhiti roa e tau haeretia ana ngā moutere o Poronīhia, tatū mai ki Aotearoa. Engari ia, i roto i te wā, i tino waikauere ngā mahi whakatere waka, ā, i ētehi moutere o Poronīhia, i wairuhi kau, he mahara noa i mau i te kōrero tuku iho. Ko tātou tērā, te iwi Māori.

Otirā, i roto i ngā tau e whā tekau ka pahemo atu rā, kua whakawhāiti mai tētehi ohu ki te whakahaumanu i ngā mahi whakatere waka me tōna mātauranga. He waka hourua kua hangaia i Poronīhia, i te ātārangi tawhito hei amo i ngā whakamanawatanga o ngā iwi me ngā kaupapa whakarauora i ēnei mahi tūpuna. Ka tika te oha ki te hunga hāpai kura i takere nui ai, i haumi tūporo ai ki te whakahaumanu i te mātauranga whakatere waka. Nō reira, o ngā mahi rangatira kua tutuki i te rāngai waka i Aotearoa i ngā tau tata nei, ko tā tēnei rangahau, he kohura i ētehi o ngā take nunui me ngā kaupapa whakahirahira e puta mai ana i mua i te aroaro o te mātauranga whakatere waka me ōna kaumoana i ēnei rangi, ki tā te Māori titiro. Waihoki, ko te pānga o aua take nunui ki te ahurea Māori. Koinei te matū o tēnei tuhinga kairangi. He pūtoi whakaaro, he whakaemieminga kōrero ki te whakatakoto i ngā huatau o ngā puhi kai moana Māori e tākawe ana i tēnei wānanga.

Mātua rā, e kore e tukua kia riro anō ngā mahi whakatere waka i te nenewhatanga o te rā, tau ki te rua. Kua whakatupuria e te wā he kura kaumoana Māori, māna ngā take matua o tēnei tuhinga roa e whakatutuki ki tua i te pae kai ao.

“E kore e ngaro, he takere waka nui”

year: 2017